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US-72118885-A | Curb inlet with removable gutter form
ABSTRACT
A curb inlet having a removable non-concrete gutter form, which is an arcuate, generally rectangular strip having a concave front face and a convex rear face with a plurality of handles secured to the rear face and, also secured to that rear face, a plurality of aligning horizontal sleeves each having a tube portion and a latch portion and each having a locking bolt slidably mounted in the sleeves. The form can be locked in place in a pre-cast curb inlet member by the bolts entering openings in that pre-cast member. The form retains concrete when the concrete is poured against the pre-cast member. After the concrete sets, the bolts are withdrawn from the openings and the form can be removed through an access opening therein. The form strip may be a fiberglass-plastic resin structure.
This invention relates to an improved curb inlet with a removable gutter form.
BACKGROUND OF THE INVENTION
Precast concrete curb inlets have been made for a long time. One shown in U.S. Pat. No. 4,192,625, included an integral form portion, which was described as preferably being made from fiberglass. A similar curb inlet, made entirely from reinforced concrete without a fiberglass form portion, had been on the market long before that patent issued.
In both of these curb inlets, a portion extending across the front and spaced down from the top-panel providing the inlet opening was permanently in place before installation and remaining there after installation, it was used as a form when the gutter was poured, and it could not be used again. Therefore, each time a curb inlet of that type was set in place and the gutter was poured the gutter form member remained with the curb inlet.
OBJECTS OF THE INVENTION
An object of the present invention is to provide an improved curb inlet in which the gutter form is removable after the concrete gutter has been poured and set. As a result, it can be used again repeatedly with other curb inlets.
Another object of the invention is to simplify the overall installation of drainage facilities and reduce the overall costs.
Other objects and advantages of the invention will appear from the following description of some preferred forms of the invention.
SUMMARY OF THE INVENTION
The invention provides an improved curb inlet with an integral casting which provides a rear wall, two side walls, and a top wall. This top wall may be provided with an opening to receive an access cover. The front is left open between its bottom and top. For the pouring operation, the opening is covered by a removable gutter form member bridging between the side walls. This removable form may be of a fiberglass-plastic or other reinforced plastic structure or may be of steel or other metal or any other suitable material. This form member defines the limit and shape of the gutter when that is poured.
This removable form is preferably provided with a pair of handles that help during placement, removal, and movement from one location to another. At each end of the form are locking bolts which fit into openings provided in the side walls of the curb inlet near the front face; the bolts are slidable in a sleeve, like a sliding latch for a door or gate. Thus, the form may be locked to the curb inlet by sliding the bolts into the bolt openings, and removed from the curb inlet by sliding the bolts out of the bolt openings, once the pouring has been done and the concrete has set. This removable form is preferably an arcuate or curved member that is generally rectangular in outline but with a curved wall.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in perspective of a curb inlet embodying the principles of the invention, with the removable gutter form being shown in front before its installation.
FIG. 2 is a similar view with the gutter form member in place for pouring.
FIG. 3 is a fragmentary rear perspective view of a portion of the curb inlet with the removable gutter form in place, the top wall being broken away to show the form.
FIG. 4 is a view in perspective similar to FIGS. 1 and 2 with the gutter form removed after pouring and with the concrete access cover shown removed to provide the access to the interior of the curb inlet needed for removal of the gutter form.
FIG. 5 is a similar view in perspective showing the finished gutter-curb combination with the curb inlet in place.
FIG. 6 is an enlarged view in rear elevation of the removable gutter form. On the left the locking bolts are shown in their closed position, as when they enter the opening in the curb inlet, and on the right the locking bolts are shown in their open position.
FIG. 7 is a view in end elevation of the removable gutter form of FIG. 6.
FIG. 8 is a view in elevation of one of the handles for the removable gutter form.
FIG. 9 is a further enlarged view in elevation of one of the locking bolts in its closed position.
FIG. 10 is a similar enlarged view, with the locking bolt in its open position.
DESCRIPTION OF A PREFERRED EMBODIMENT
As shown in FIG. 1, a curb inlet 15 of the present invention has two vertical side walls 16 and 17, a rear wall 18 (See FIGS. 3 and 4), and a top wall 20. It may also have a short stiffening portion 21 extending across the bottom between the curved front faces 22 and 23 of the two side walls 16 and 17. The bottom is open, and in the top wall 20 is a central opening 24. The curb inlet 15, as so far described, is an integral casting of reinforced concrete. A separately cast concrete access cover 25 is designed to fit snugly in the opening 24, resting on a ledge 26, flush with the top surface of the top wall 20. The cover 25 may, if desired, be provided with a pick-receiving hole 27.
Cast into the interior surface of each side wall 16 and 17 of the curb inlet 15, near where the wall approaches its curved front face 22 or 23, are openings 28 to receive the locking bolts, described below. There may be two such openings 28 in each side wall 16, 17. The opening 28 may be made by drilling, if desired, instead of by casting, through casting is the normal procedure. Their location and alignment is important.
A removable gutter form 30 is an important part of this invention. It comprises an arcuate strip 31 which is generally rectangular, as seen in front or rear elevation (FIG. 6), though arcuate as seen in side elevation (FIG. 7). The front surface 32 is concave and the rear surface 33 convex. On the rear surface 33 of this member is affixed, as by an adhesive cement or (if metal such as steel) by welding, a pair of handles 34 and 35. In the drawing, they are shown as done by a process in which they are sunk into a structure incorporating a plastic, such as a fiberglass-resin structure and are curved over by more fiberglass-resin or other plastic-base reinforced structure strips. Each handle 34 or 35 has a central portion 36 which can be grasped by a hand, two support portions 37 and 38 that are perpendicular to the portion 36, and two base portions 39 and 40 which abut the rear surface 33 of the strip 31 and are cemented or welded or otherwise secured to it. When the strip 31 is made from a fiberglass-plastic structure, the embedment in and covering over by fiberglass-resin strips is preferred but cementing is possible; when it is metal, welding may be used.
The removable gutter form 30 also has at each end a pair of sleeve members 41 and 42 which cooperate with a locking bolt 43 or 44. The sleeves may be adhered to the strip 31 by embedment in and covering over by the fiberglass-resin (or other suitable) material, or may be by a suitable cement or, when the form is metal, by welding or other suitable means. Each sleeve 41, 42 comprises a tube 45, and an open portion 46 having a latch slot 47 and a slide portion 48. Each locking bolt 43 or 44 may simply be an L-shaped member 50 with a cylindrical main portion 51 and a shorter portion 52 that is generally vertical. The main portion 51 has a locking end 53. The shorter portion 52 is preferably provided with threads 54 on which a nut 55 may be threaded or, if desired, the portion 52 may be left plain and a washer of suitable size and strength welded to it. When the locking bolt 43 or 44 is in its open position, as shown in FIG. 10 and at the right hand side of FIG. 6, the bolt 43 or 44 is slid so that the locking end 53 is well within the sleeve 41 or 42, whereas the shorter portion 52 lies entirely beyond the open portion 46 of the sleeve 41 or 42. The bolt 43 or 44 may be moved into closed position by rotating the bolt about 90° to raise the shorter portion 52, and then the bolt 43 or 44 may be slid into the tube 41 or 42 until the end portion 53 enters one of the openings in the curb inlet 15. Then the bolt 43 or 44 is rotated back so that the shorter portion 52 engages the locking slot 47; then the bolt 43 or 44 cannot be forced in either direction. This position is shown in FIG 9. For unlocking, the bolt 43 and 44 is again raised about 90° and then moved out, to the position of FIG. 10 as shown before.
Preferably, each locking bolt 43 or 44 is provided with a chain 60 which is anchored to the shorter portion 52 slightly above the nut 55 and is held there. The other end of the chain 60 is secured to a support portion 37 or 38 of the handle 34 or 35 before the handle is secured to the strip 31. It is better for the removable gutter form 30 to be in place, locked to the curb inlet 15 at the time when the member is installed.
Preferably, the upper bolt tube 45 is substantially in line with the handles 34 and 35, though that may not be necessary.
In installation, as shown in FIG. 3, a bottom edge 61 of the curb inlet 15 is placed on top of a standard drainage inlet box 62, with the gutter form 30 in place, its locking bolts 43 and 44 engaged in the cast holes 28 in the curb inlet 15. Then concrete may be poured up to the gutter flow line F, which is shown in broken lines in FIG. 2.
When the concrete has been poured and has set, the result is like that shown in FIG. 4. At that time the concrete access cover 25 can be removed with a pick ax or a lid lifter, and then a man either drops down inside the curb inlet 15 or may reach down with his arm and unlock the bolts 43 and 44. Usually it is done by getting inside, because of the size of the device, but it can be done by reaching down especially for a smaller size curb inlet 15. Once the locking bolts 43 and 44 are withdrawn from the openings 28, the form 30 is easily detached from the poured concrete and is extracted through the opening 24 of the curb inlet 15. When the form 30 is removed, the finished result looks somewhat as shown in FIG. 5 with the curb inlet 15 flush with the top of a curb 65 and with the gutter 66 properly located, so that it and the curb inlet 15 provides an opening 67 known as a drop inlet.
To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.
What is claimed is:
1. A curb inlet including in combination:a concrete member having a rear wall, side walls, each said side wall having at least one bolt-receiving opening near its forward face, and a top wall with an access opening therethrough, a concrete access cover removably fitting in said access opening, and a removable non-concrete gutter form comprising an arcuate, generally rectangular strip having a concave front face and a convex rear face with a plurality of handles secured to said rear face and, also secured to that rear face, a plurality of aligning horizontal sleeves each having a tube portion and a latch portion and each having a locking bolt slidably mounted in said sleeves, said locking bolt being extendable beyond the edge of said form and retractable to within the area of said form, said bolts being spaced to conform to the spacing of the bolt-receiving openings in said side walls and used to secure the form in its pouring position, so that the form can be locked in place by the bolts entering said bolt-receiving openings, said form then retaining concrete when the concrete is poured, and after the concrete sets, by withdrawing the bolts from the bolt-receiving openings, the form can be removed from said concrete member taken out through said access opening for reuse in installation of another curb inlet.
2. The curb inlet of claim 1 wherein the form strip is a fiberglass-plastic resin structure.
3. The curb inlet of claim 2 wherein said handles and sleeves are secured by embodiment in the strip and covering over by more fiberglass-resin material.
4. The curb inlet of claim 2 wherein said handles and sleeves are secured to said rear face by a suitable cement.
5. The curb inlet of claim 1 wherein said form strip is a metal member.
6. The curb inlet of claim 5 wherein said handles and sleeves are welded to said rear face.
7. The curve inlet of claim 1 wherein there are two said bolt-receiving openings in each side wall and two sleeves at each end of said form strip.
8. A curb inlet including in combination:a box-like reinforced concrete member having rear wall, side walls, each said side wall having a pair of cast recessed holes near its forward face, a top wall with an access opening therethrough, and a strengthening bottom-front member bridging said side walls at their front, the bottom otherwise being open, a concrete access cover removably fitting in said access opening, and a removable non-concrete, sheet-like gutter form comprising an arcuate, generally rectangular strip having a concave front face and a convex rear face with a pair of spaced-apart handles secured to said rear face and, also secured to that rear face, two pairs of aligning horizontal sleeves, one such pair at each end, each sleeve having a tube portion and a latch portion, and a locking bolt slidably mounted in each said sleeve, said locking bolts each being extendable beyond the edge of said form to engage in said cast recessed holes and retractable to within the area of the form, where they are withdrawn from said holes, said bolts being spaced to conform to the spacing of the cast holes to secure the form in its pouring position, so that the form can be locked in place with the bolts in said cast holes, said form then retaining concrete during pouring, and later, when the concrete has set, each bolt can be unlocked and the whole form removed from said concrete member, and taken out through said access opening for reuse in another curb inlet.
9. The curb inlet of claim 8 wherein said form strip is made of a fiberglass-resin structure and said handles and sleeves are secured thereto by embodiment in said structure and covering over by the same type of structure.
10. The curb inlet of claim 7 wherein said form strip is made of metal and the handle and sleeves welded to it.
11. A method of installing a curb inlet,a precast concrete member having a rear wall, side walls, each said side wall having a pair of recessed openings near its forward face, and a top wall with an access opening therethrough capable of receiving a removable concrete access cover, the steps of securing to said precast member a thin removable gutter form comprising an arcuate, generally rectangular strip with a concave front face and a convex rear face and with a pair of handles secured to said rear face and, also secured to that rear face, a pair of aligning horizontal sleeves with a tube portion and a latch portion and with locking bolts slidably mounted in said sleeves, said securing being done by extending said locking bolts beyond the edge of said form into said recessed openings, installing said precast member into position for pouring concrete around it, with the gutter form retained by said locking bolts extending into said retained openings, pouring concrete to provide curb and a gutter, said form helping to shape a portion of said gutter, after the poured concrete has set, retracting the bolts and sliding them to a position within the edge of the form, and then removing the form through said access opening for reuse in another curb inlet.
| 1985-04-09 | en | 1986-09-09 |
US-24159094-A | Filter element having a flat and non-flat configuration
ABSTRACT
A filter element of the present invention provides low pressure loss, superior filter performance and bonding of filtering material, and compactness. An inlet path of a nearly semicircular configuration which is formed in the width direction of a filter element is open at its upper side and closed at its lower side. An outlet path is closed at its upper side and open at its lower side. Corrugated filtering material has continuous mountain portions and valley portions. The mountain portions have a large radius of curvature R1, and the valley portions have a small radius of curvature R2. The valley portions are bonded to a flat filtering material. The open surface area of the inlet path is larger than the closed surface area of the outlet path 16. Preferably, R1/R2 is set so as to be within the range of 1.5 to 3.0.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a filter element utilized in an oil filter, air cleaner device, fuel filter, or the like.
2. Description of the Related Art
An automobile, for example, is equipped with a fuel filter which includes a filter element for the purpose of removing contaminants from fuel which is supplied to an engine.
As shown in FIG. 10, the filter element may uses flat filtering material 181 and corrugated filtering material 182. In fabricating this filter element, adhesive 2a is applied in narrow stripes along the longer direction (corrugating direction) to the corrugated filtering material 182 on the upper side (upstream or fuel inlet side) 71 and to the flat filtering material 181 on the lower side (downstream or fuel outlet side) 79, respectively. Following this, the flat filtering material 181 is overlaid with the corrugated filtering material 182, and these materials are then rolled into a spiral shape.
In the above-mentioned filter element, it is not necessary to align with care the flat filtering material 181 and the corrugated filtering material 182 when performing rolling. In addition, the corrugated filtering material 182 is in the configuration most easily formed when forming with a corrugated roller. Because of this, efficiency is good and productivity is good as well.
However, the ratio of the open area of the fuel inlet path 14 on the upper side 71 to the sealed area of the fuel outlet path 16 is 1:1, and the cross-sectional configuration of both is symmetrical. The inlet path 6 is desired to be large enough because the fuel 6 may include contaminants therein. However, because of the above configuration, the amount of fuel 6 entering into the inlet path 14 is restricted, and filter performance is inadequate.
The fuel filter of Japanese Patent Application Laid-open No. 126907/1990 (U.S. Pat. No. 5,002,666) has been proposed in this regard.
As shown in FIGS. 11 and 12, the above-mentioned fuel filter is provided midway in a fuel line 90, which supplies fuel 6. The fuel filter 9 comprises a filter case 91, a cover 92 installed atop the filter case 91, and a filter element 1 contained within the filter case 91.
Fuel 6 enters the fuel filter 9 via an inlet 920 formed in the center of the cover 92, is filtered by the filter element 1, and is supplied to the engine not illustrated via an outlet 930 formed in the center of the bottom of the filter case 91.
As shown in FIG. 13 further, the filter element 1 may be porous filter paper 10 which has been fabricated in a corrugated shape with alternate mountains and valleys and which is then rolled into a spiral shape to form a tubular configuration.
The corrugated filter paper 10 is bonded such that the respective valleys 131 and 151 and the respective mountains 139 and 159 of corrugated filtering materials 13 and 15 are facing each other. Alternating tubular inlet paths 14 and outlet paths 16 are formed between the mountains 139 and 159. As shown in FIG. 12, the lower side 79 of the inlet paths 14 is bonded with adhesive 2b.
In addition, as shown in FIG. 12 and FIGS. 14A and 14B, the upper side 71 of the outlet paths 16 is bonded with adhesive 2a.
The inlet paths 14 are open on the upper side 71 and closed on the lower side 79. Meanwhile, the outlet paths 16 which are adjacent to the inlet paths 14 are closed on the upper side 71, and the lower side 79 is open.
In this filter element 1, as shown in FIG. 12, fuel 6 flows into the inlet paths 14 from the upper side 71, and the fuel 6 passes through porous filter paper 10, passing from the inlet paths 14 to the outlet paths 16. At this time, contaminants mixed in with the fuel 6 are trapped on the filter paper 10 on the side of the inlet paths 14.
The above-mentioned fuel element 1 may also be utilized as any of various types of filters for air cleaners and the like in addition to use as a fuel filter for automobiles.
Next, in manufacturing the foregoing filter element, lengthy filtering material is first formed into a corrugated configuration to fabricate corrugated filtering materials 13 and 15, as shown in FIG. 13. Following this, adhesive 2a and 2b is applied in narrow stripes along the longer direction to the corrugated filtering material 13 on the upper side 71 and to the corrugated filtering material 15 on the lower side 79, respectively. Next, the corrugated filtering materials 13 and 15 are laid one atop the other such that the respective valleys 131 and 151 and mountains 139 and 159 of the corrugated filtering materials 13 and 15 face each other as shown in FIG. 14B, and filter paper 10 is obtained. Following this, the filter paper 10 is rolled along the direction of length into a spiral shape.
However, when rolling the foregoing roll filter paper 10, the adhesive 2a and 2b may protrude as shown in FIG. 14A, or the bonding of the adhesive may be imperfect. Because of this, the chance exists that the lower side 79 of the inlet paths 14 and the upper side 71 of the outlet paths 16 may not be perfectly closed.
In addition, when superposing the corrugated filtering material 13 and the corrugated filtering material 15, it is necessary to perform alignment with care so that the respective valleys 131 and 151 and the respective mountains 139 and 159 face each other, which poses problems in productivity for volume production.
In addition, if the tubes of the inlet paths 14 and outlet paths 16 are not bonded inter alia, an imperfect seal is obtained, and dust-filtration performance is diminished.
SUMMARY OF THE INVENTION
The present invention is to solve the problems set forth above, and has as an object to provide an improved filter element.
Another object of the present invention is to provide a filter element which has a large open surface area on an upper side of the fluid to be filtered, and which has a structure which may be manufactured with comparative ease.
Still another object of the present invention is to provide a filter element which has high resistance to pressure.
A further object of the present invention is to provide a filter element which curtails the amount of closing material on the upper side which closes the fluid passages at the position close to the upper side.
According to the improved structure of the present invention, a second filtering material of corrugated shape is provided between a first filtering material of flat shape and a third filtering material of flat shape such that the ridges of the mountain portions of the second material touch the first material and the ridges of the valley portions of the second material touch the third material. The areas between the ridges of the mountain portions and the ridges of the valley portions of this second material are formed as arc-shaped walls which are convexities that primarily face the first material. The area between the second material and the third material is taken to be the inlet side opening, and the opening surface area of the inlet side is made larger than the closed surface area of the closed material on the upper side.
It is preferable for the mountain portions to be made virtually semicircular with a radius of curvature R1, and it is preferable for the valley portions to be made with a radius of curvature R2 which is sufficiently smaller than the radius of curvature R1. It is further preferable for the ratio of the radius of curvature R1 and the radius of curvature R2 to be made not less than 1.5 and not more than 3.0
Additionally, the first material and the third material may share or is made of a common piece of material in which the flat material and corrugated material are rolled such that the flat material which touches the inner and outer peripheries of the corrugated material serves as the first material and the third material.
According to the present invention, manufacturing is simple because the filter element is structured with a flat material and a corrugated material, and along with this, because the open surface area of the inlet for the fluid to be filtered can be made large, the problems of the filter element of the prior art are solved because it is possible to simultaneously achieve simplification of manufacturing and a larger size of the open surface area of the inlet.
Further, because the areas between the ridges of the mountain portions and the ridges of the valley portions are structured as arc-shaped walls which are convexities that primarily face the first material or, more preferably, the two arc-shaped walls are made to be continuous and virtually semicircular, the present invention demonstrates superior pressure resistance with regard to the pressure of the fluid to be filtered acting from the inlet-side opening. Because of this, deformation of the second material due to progressive clogging of the second material can be suppressed, and stabilized superior filter performance can be maintained for long periods.
Moreover, because the areas between the ridges of the mountain portions and the ridges of the valley portions are structured as arc-shaped walls which are convexities that primarily face the first material, and the open surface area of the inlet side is made to be larger than the closed surface area of the closed material on the upper side, the closure material on the upper side can be curtailed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a perspective view of a filter element according to a first embodiment of the present invention;
FIG. 2 is an explanatory view showing the configuration and dimensions of a corrugated filtering material of the first embodiment;
FIG. 3 is a top plan view of the upper side of the filter element of the first embodiment;
FIG. 4 is an explanatory view showing the state of crimped closure of the lower side in the inlet paths of the filter element of the first embodiment;
FIG. 5 is an explanatory-view showing the state of manufacture by superposition of a flat filtering material and a corrugated filtering material of the first embodiment;
FIG. 6 is an explanatory view showing the method of rolling of the filter paper of the first embodiment;
FIG. 7 is an explanatory view showing the operation of the filter element of the first embodiment;
FIG. 8 is a graph showing the relationships of the compactness and the pressure loss of the filter element to the ratio (R1/R2) of radii of curvature of the mountain portions and valley portions of the corrugated filtering material in the first embodiment;
FIGS. 9A to 9C are explanatory views showing the configuration and dimensions of corrugated filtering material having a linear portion in a filter element according to a second embodiment of the present invention;
FIG. 10 is an explanatory view showing problems of a filter element of the prior art;
FIG. 11 is a partially cutaway sectional view of a fuel filter in which another filter element of the prior art is incorporated;
FIG. 12 is an explanatory view showing the operation of another filter element of the prior art;
FIG. 13 is an explanatory view showing the method of manufacture of another filter element of the prior art; and
FIGS. 14A and 14B are explanatory views showing the problems of another filter element of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, embodiments of a filter element according to the present invention will be described with reference to the attached drawings.
A filter element 3 for filtering fluid 6 according to a first embodiment, as shown in FIG. 1, is made of a lengthy flat filtering material 31 as a first filtering material 31b and a third filtering material 31a as well as a lengthy corrugated filtering material 32 as a second filtering material arranged one atop the other, with these rolled in their directions of length. The filter element 3 may be used in the well known manner, for instance, as shown in FIG. 12.
The filter element 3 has inlet paths 14 which are formed along its axial length and which have a cross-sectional shape of a substantially or nearly semicircular configuration, as well as outlet paths 16 which are formed side by side with the inlet paths 14 and extends axially.
The inlet paths 14 are open on their upper side 71, and their lower side 79 is closed with adhesive 4b (best shown in FIG. 4).
The outlet paths 6, conversely, are closed with adhesive 4a on their upper side (best shown in FIG. 3), and they are open on their lower side.
The corrugated filtering material 32 has mountain portions 329 and valley portions 321 arranged in alternation.
The inlet paths 14 are formed between the mountain portions 329 and one end of the flat filtering material 31a positioned at the inner surface of the mountain portions 329 as the third material. Conversely, the outlet paths 16 are formed between the valley portions 321 and the other end of the flat filtering material 31b positioned at the outer surface of the valley portions 321 as the first or third filtering material.
The flat filtering material 31a and the ridges of the valley portions 321 of the corrugated filtering material 32 are bonded by means of adhesive 4c so that these are mutually independent and form the adjacent inlet paths 14 extending axially.
As shown in FIGS. 2 and 3, the cross-section of the inlet paths 14 is made semicircular.
In addition, as understood from FIGS. 1 to 3, the open surface area of the inlet paths 14 at the upper side 71 becomes larger than the closed surface area of the outlet paths 16 due to the above configuration.
In the actual practice, the radius of curvature R1 of the mountain portions 329 is made large (0.8 mm), whereas the radius of curvature R2 of the valley portions 321 is made small (0.4 mm). In this case, the ratio (R1/R2) of the radius of curvature R1 of the mountain portions 329 to the radius of curvature R2 of the valley portions 321 is 2.0. The pitch P of adjacent valley portions 321 is made to 2.5 mm. The distance H between the inner-surface ridge of the mountain portions 329 and the bottom surface of the flat filtering material 31 is made to 1.4 mm. The thickness of the flat filtering material 31 and the corrugated filtering material 32 is 0.2 mm each.
Additionally, as shown in FIGS. 1 and 4, the lower side 79 of the inlet paths 14 is closed in a nearly flat configuration by means of adhesive 4b. That is, the mountain portions 329 of the corrugated filtering material 32 are pressed with respect to the flat filtering material 31, thereby forming a pressed area 39 to provide a large opening area of the outlet paths 16.
In manufacturing the above-described filter element, a sheet of filtering material is formed with mountains 329 and valleys 321 to provide the corrugated filtering material 32. As shown in FIG. 5, this corrugated material 32 in a plate form is laid on the flat filtering material 31 in a plate form with the adhesive 4b at the lower side 79 for bonding, and the lower side of the material 32 is pressed by a weight 5 to form the pressed area 39. Thereafter, as shown in FIG. 6, the bonded materials 31 and 32 are rolled into a spiral shape with the adhesive 4a on the material 32 only at the upper side thereof.
With respect to the above embodiment of this invention, as shown in FIG. 8, measurements were made regarding the relationships between the ratio (R1/R2) of the radii of curvature R1 and R2 of the corrugated filtering material 32, the compactness of the filter element, and the pressure loss of the filtering material. The above-mentioned measurements were conducted by varying the radii of curvature of the corrugated filtering material.
The compactness of the filter element refers to the overall volume of the filter element which is required in order to demonstrate identical filtering capacity.
Additionally, pressure loss refers to the differential pressure generated when the fluid passes from the inlet path to the outlet path.
It can be seen from FIG. 8 that the larger the ratio (R1/R2) of the radii of curvature of the mountain portions and valley portions of the corrugated filtering material 32 is, the greater or better is the compactness or size reduction of the filter element and the lower is the pressure loss. Also, when the foregoing ratio is within the range of 1.5 to 3.0, there is no particular pressure loss, and compactness is good.
In the above-described embodiment, the outer surface of the ridges of the mountain portions 329 are kept in contact with the flat filtering material 31 (31b). Additionally, the outer surface of the ridges of the valley portions 321 are kept in contact with the flat filtering material 31 (31a). Of the corrugated filtering material 32 between the ridges of the mountain portions 329 and the ridges of the valley portions 321, virtually all of the range toward the outer surface of the ridges of its mountain portions 329 forms an arc-shaped wall which is a convexity that primarily faces the flat filtering material 31b, and the small range close to the valley portions 321 is formed in a semicircular configuration that is a convexity facing the flat filtering material 31a. In this embodiment, the arc-shaped walls which are convexities facing the flat filtering material 31b are continuous with other arc-shaped walls which are ridges of the mountain portions 329, and form mountain portions which are semicircular overall.
Additionally, the radius of curvature R1 of the mountain portions 329 is made larger than the radius of curvature R2 of the valley portions 321, and the area in cross section of the inlet ports 14 is made larger than the area in cross section of the outlet paths 16. This permits greater resistance to clogging, improved filter performance, and reduced pressure loss, and can achieve much greater compactness of the filter element 3.
Next, as shown in FIGS. 2 and 3, at the upper side 71 of the filter element 3 where fuel flows in, the open surface area of the inlet paths 14 is larger than the closed surface area of the outlet paths 16. At the lower side 79 where fuel 6 flows out, conversely, the open surface area of the outlet paths 16 is larger than the closed surface area of the inlet paths 14. Because of this, pressure loss during passage of fuel 6 through the filter element 3 is small.
In addition, because the corrugated filtering material 32 has a uniform curvature in semi-circular shape, as shown in FIG. 7, the pressure 60 on the filter surface by the fuel acts in the direction of tension. Because of this, there is no deformation of the corrugated filtering material 32, and sufficient filter performance can be demonstrated.
Next, the flat filtering material 31 and the valley portions 321 of the corrugated filtering material 32 are bonded by adhesive 4c. Because of this, the differential pressure of the inlet paths 14 and outlet paths 16 does not cause deformation such that the substantially semicircular shape of the flat filtering material 31 and corrugated filtering material 32 is widened. Further, there is no deformation or adhesion that constricts the outlet paths. The pressure loss from the inlet paths 14 to the outlet paths 16 can therefore be reduced.
Additionally, because the valley portions 321 with the small radius of curvature R2 are bonded to the flat filtering material 31, the width of the bond areas can be made small, there is little loss of filter surface area due to bonding, and only a small amount of adhesive need be applied.
In addition, because there is no adhesion of the flat filtering material 31 and corrugated filtering material 32, filtering is performed over the entire surfaces of both filtering materials. Because of this, superior filter performance can be demonstrated.
Furthermore, the openings of the inlet paths 14 are susceptible to clogging by contaminants in the fluid, but clogging of the inlet paths can be reduced by enlarged cross-sectional area.
Because the inlet paths 14 are the passages for contaminated fuel, the flow of the fuel is likely to become poor, and wide passages are required. However, because the outlet paths 16 are the passages for filtered fluid, the flow of the fluid is good, and the passages may be narrower than the inlet paths 14.
For this reason, enlarging the cross-sectional area of the inlet paths 14 and reducing the cross-sectional area of the outlet paths 16 causes the filter element with well-balanced fluid flow to be formed.
Also, in this embodiment, one sheet of continuous flat filtering material 31 is rolled so that its superposed inner and outer peripheries serve respectively as the first material and the third material, but separate and independent flat filtering materials may be laminated so that either the upper or lower layer serves as the first material, with the other serving as the third material.
For this reason, the inlet paths 14 and outlet paths 16 are not misaligned, and moreover the cross-sectional configuration of the inlet paths 14 and outlet paths 16 which are formed between the flat filtering material 31 and corrugated filtering material 32 of the filter paper 30 is uniform. In addition, as shown in FIGS. 5 and 6, because the configuration of one of the filtering is flat materials, there is no need to align with care the two filtering materials.
Therefore, it is simple to maintain the amount of adhesive 4a and 4b which is applied at a constantly correct amount, and there is no protrusion of adhesive. Additionally, imperfect sealing does not occur, and bonding is also good.
In addition, it is possible to simplify and reduce the times for application operations, thereby also obtaining suitability for mass production.
Additionally, at the lower side of the inlet paths 14, the corrugated filtering material 32 is pressed with respect to the flat filtering material 31. Because of this, bond strength and seal reliability are enhanced. Also because of this, the surface area of the outlet paths can be enlarged, and the throughput resistance of the outlet side can be reduced.
In addition, when binding filter paper onto a bending roller for applying a corrugated shape to the filter paper, the bindability of the filter paper can be improved. Because of this, the filter paper can be formed reliably.
The foregoing description has described the case where rolling is performed with the flat filtering material lying on the outer side even when rolling is performed with the flat filtering material and the corrugated filtering material lying one atop the other, but it is also possible to perform rolling with the corrugated filtering material lying on the outer side, and similar effects are obtained in this case as well.
In a second embodiment of the present invention, as shown in FIGS. 9A to 9C, a part of the mountain portion or valley portion of the corrugated filtering material has a linear portion. In other respects, this embodiment is identical to the first embodiment.
That is, in the filter element of this embodiment, as shown in FIG. 9A, the corrugated filtering material 32 is provided with a linear portion S1 between the mountain portion 329 and the valley portion 321. In this embodiment the distance H between the topmost ridge of the mountain portion 329 and the bottom surface of the flat filtering material 31 is made to 2.0 mm, and the length of the foregoing linear portion S1 is made to 0.8 mm.
Next, in the above-mentioned corrugated filtering material 32, when the boundary of the radii of curvature R1 and R2 is a curved surface as in the first embodiment, pulsations are generated in the filtering material by the flow of the fluid, and the durability of the filtering material may be degraded. However, by providing a linear portion S1 between the mountain portion 329 and the valley portion 321, as in the case shown in FIG. 9A, the boundary of the radii of curvature R1 and R2 becomes a straight line. Because of this, there is no pulsation and the durability of the filtering material can be improved.
In addition, as shown in FIG. 9B, a linear portion S2 can also be provided on the mountain portion 329 of the corrugated filtering material 32. The linear portion S2 is desirably of a length not more than 0.8 mm. The pitch P of the adjoining valley portion 321 is desirably not less than 3.0 mm.
Next, in the foregoing corrugated filtering material 32, as has been described above, the ridge of narrow width at the cross section of the inlet paths 14 is enlarged, and the height of the inlet path cross section is reduced. Because of this, the number of windings of the filter paper can be made greater, and the total inlet path cross section can thereby be enlarged.
Additionally, as shown in FIG. 9C, a linear portion S3 can also be provided on the valley portion 321 of the corrugated filtering material 32. By means of this, the bond area of the corrugated filtering material 32 and-the flat filtering material 31 can be made larger, thereby enhancing the bond reliability.
In addition, in order to allow adjustment of the ratio (R1/R2) of the radii of curvature R1 and R2 of the corrugated filtering material 32, R1 or R2 may be combined with a linear portion.
The filter element of this embodiment provides linear portions S1 and S2 between the mountain portion 329 and valley portion 321 of the corrugated filtering material 32, or on the mountain portion 329. Because of this, the fluid flow area of the inlet paths 14 is made larger than that of the outlet paths 16, and filtering performance is superior.
We claim:
1. A filter element comprising:a first filtering material of substantially flat configuration; a second filtering material of substantially non-flat configuration which allows fluid to be filtered to pass in the direction of thickness and has a plurality of mountain portions and valley portions which are formed in parallel alternation so as to extend to a lower side from an upper side of fluid flow, ridges of said mountain portions being in contact with said first material, more than one-half of said second material forming said mountain portions and said mountain portions being in convex relation only toward said first material; a third filtering material of substantially flat configuration provided in contact with ridges of said valley portions of said second material; an upper side closing material which closes spaces between said first material and said second material at a position close to the upper side of the fluid flow; a lower side closing material which closes spaces between said second material and said third material at a position close to the lower side of the fluid flow; spaces defining fluid inlet paths between the ridges of said valley portions and the ridges of said mountain portions being formed by axially extending arc-shaped walls which are convexities; and a closed surface area of said upper side closing material being smaller than an upper side open surface area of said inlet path.
2. A filter element according to claim 1, wherein said second material and one of said first and third materials are bonded to form a single unit, and plurality of such units are stacked so that said first material functions as said third material.
3. A filter element according to claim 2, wherein said closing materials are formed by adhesives for bonding.
4. A filter element according to claim 3, wherein said single unit is formed as a lengthy material which is rolled in a spiral configuration.
5. A filter element according to claim 4, wherein said mountain portions of said second material are convexities which face the inner rolled periphery of said one of said first and third materials.
6. A filter element according to claim 1, wherein two said arc-shaped walls which are positioned both sides of each of said ridges of said mountain portions of said second material are formed as a substantially continuous arc of radius of curvature R1.
7. A filter element according to claim 6, wherein each of said ridges of said valley portions is formed as an arc of radius of curvature R2, and said radius of curvature R2 is smaller than said radius of curvature R1.
8. A filter element according to claim 7, wherein the ratio R1/R2 of radii R1 and R2 is not less than 1.5 and not more than 3.0.
9. A filter element according to claim 1, wherein two said arc-shaped walls which are positioned both sides of each of said ridges of said mountain portions are formed as a substantially continuous arc of radius of curvature R1, each of said ridges of said valley portions is formed as an arc of radius of curvature R2, and the radius of curvature R2 is smaller than the radius of curvature R1.
10. A filter element according to claim 1, wherein said second material and said third material are such that said mountain portions are pressed toward said third material at a position close to said lower side of fluid flow, and said lower side closing material is provided at said pressed portion.
11. A filter element according to claim 1, wherein said mountains and valleys of said second material are pressed toward said third material and deformed into a straight shape only at the lower side of the fluid flow to close said fluid inlet path.
12. A filter element according to claim 1, wherein said valleys have flat portions which contact with said at least one of first and third materials.
13. A filter element according to claim 1 wherein a flat portion of prescribed width is located on each of said ridges of said mountain portion of said second material.
14. A filter elementa first filtering material of substantially flat configuration; a second filtering material of substantially non-flat configuration which allows fluid to be filtered to pass in the direction of thickness and has a plurality of mountain portions and valley portions which are formed in parallel alternation so as to extend to a lower side from an upper side of fluid flow, ridges of said mountain portions being in contact with said first material; a third filtering material of substantially flat configuration provided in contact with ridges of said valley portions of said second material; an upper side closing material Which closes spaces between said first material and said second material at a position close to the Upper side of the fluid flow; a lower Side closing material which closes spaces between said second material and said third material at a position close to the lower side of the fluid flow; spaces defining fluid inlet paths between the ridges of said valley portions and the ridges of said mountain portions being formed by axially extending arc-shaped walls which are convexities; and a closed surface area of said upper side closing material being smaller than an upper side open surface area of said inlet path; two said arc-shaped walls which are positioned on both sides of each of said ridges of said mountain portions being formed as a substantially continuous arc of radius of curvature R1, each of said ridges of said valley portions being formed as an arc of radius of curvature, and the radius of curvature R2 is smaller than the radius of curvature R1, a ratio R1/R2 of radii R1 and R2 being not less than 1.5 and not more than 3.0.
15. A filter element according to claim 14, wherein ratio R1/R2 is around 2.0.
16. A filter element comprising:a first filtering material having a substantially uniform thickness and rolled into a spiral shape; a second filtering material having a substantially uniform thickness, being formed into a corrugated configuration having mountain portions and valley portions, and rolled into a spiral shape in a manner sandwiched between said first material; said mountain portions being formed so as to be mutually parallel together and extending from an upper side of fluid flow to a lower side with its height becoming lower at said lower side; each of said mountain portions of said second material having an arc-shaped cross section which is less than a semicircle and larger than each of said valley portions and which is a continuous convexity facing the inner periphery of the roll of said first material; said valley portions of said second material being formed between said mountain portions so as to have external surfaces each of which has a radius of curvature R2 smaller than a radius of curvature R1 of said arc-shaped cross section of said mountain portions; a lower side closing material disposed between a surface of an inner periphery of said arc-shaped cross section of said second material and a surface of inner periphery of said first material, positioned at said lower side of fluid flow, and bonding said first material and said second material together so that an inlet path formed therebetween is closed thereby; and an upper side closing material disposed between a surface of an outer periphery of said arc-shaped cross section of said second material and a surface of outer periphery of said first material, positioned at said upper side of fluid flow, and bonding said first material and said second material together so that an outlet path formed therebetween is closed thereby, the closed surface area thereof being smaller than an upper side open surface area of said inlet path.
17. A filter element comprising:a first filtering material having a substantially uniform thickness and rolled into a spiral shape; a second filtering material having a substantially uniform thickness, being formed into a corrugated configuration having mountain portions and valley portions, and rolled into a spiral shape in a manner sandwiched between said first material said mountain portions being formed so as to be mutually parallel together and extending from an upper side of fluid flow to a lower side with its height becoming lower at said lower side; each of said mountain portions of said second material having an arc-shaped cross section which is less than semicircular and which is a convexity facing the inner periphery of the roll of said first material; said valley portions of said second material being formed between said mountain portions so as to have external surfaces each of which has a radius of curvature R2 smaller than a radius of curvature R1 of said arc-shaped cross section of said mountain portions; a lower side closing material disposed between a surface of an inner periphery of said arc-shaped cross section of said second material and a surface of inner periphery of said first material, positioned at said lower side of fluid flow, and bonding said first material and said second material together so that an inlet path formed therebetween is closed thereby; and an upper side closing material disposed between a surface of an outer periphery of said arc-shaped cross section of said second material and a surface of outer periphery of said first material, positioned at said upper side of fluid flow, and bonding said first material and said second material together so that an outlet paths formed therebetween is closed thereby, the closed surface area thereof being smaller than an upper side open surface area of said inlet path, the ratio R1/R2 of radii R1 and R2 being not less than 1.5 and not more than 3.0.
18. A method of manufacturing a filter element comprising:a formation step wherein a corrugated filtering material of a substantially uniform thickness having alternating mountain portions and valley portions, each of said mountain portions having an arc-shaped cross-section which is nearly semicircular and formed such that a radius of curvature R1 of said arc-shaped cross section of each of said mountain portions is larger than a radius of curvature R2 of each of said valley portions; an assembly step following said formation step wherein said corrugated filtering material is disposed between flat first and second filtering materials so that an inlet path of fluid flow is formed between the corrugated material and the first filtering material, and an outlet path of fluid flow is formed between said corrugated filtering material and said second filtering material at an opposite side of said inlet path; a first closing step closing a lower side of said inlet path by means of adhesive material; and a second closing step closing an upper side of said outlet path by means of adhesive material such that a closed surface area is smaller than an upper side open surface area of said inlet path.
19. A method according to claim 18, wherein an assembly of said corrugated material and said first flat material are rolled in a spiral configuration such that said first flat material defines said second flat material and an arc-shaped cross section of said mountain portions of said corrugated material become convexities facing a center of roll, and wherein said first flat material is positioned on both inner and outer sides of said corrugated material.
20. A method of manufacturing a filter element comprising:a formation step wherein a corrugated filtering material of a substantially uniform thickness having alternating mountain portions and valley portions, each said mountain portion having an arc-shaped cross-section which is nearly semicircular and formed such that a radius of curvature R1 of said arc-shaped cross section of each of said mountain portions is larger than a radius of curvature R2 of each of said valley portions; an assembly step following said formation step wherein said corrugated filtering material is disposed between two flat filtering material layers so that an inlet path of fluid flow is formed between the corrugated material and one of the two filtering material layers, and an outlet path of fluid flow is formed between the corrugated material and the other of the two filtering material layers at an opposite side of said inlet path; a first closing step closing a lower side of said inlet path by means of adhesive material; and a second closing step closing an upper side of said outlet path by means of adhesive material such that a closed surface area is smaller than an upper side open surface area of said inlet path, said first closing step including a pressing step in which a lower side of said corrugated filtering material is pressed to said one flat filtering material layer so that a cross-sectional closed surface area of said inlet path is reduced.
21. The filter element comprising:a first filtering material shaped in substantially flat configuration; a second filtering material shaped in a corrugated configuration in cross section which is an alternation of a first ridge portion, a second ridge portion and a connection portion between said first ridge portion and said second ridge portion, said second filtering material being in contact with said first filtering material at said first ridge portion to form a fluid outlet path with said first filtering material, and said connection portion being continuously curved to convex substantially only towards said first filtering material; a third filtering material shaped in substantially flat configuration and in contact with said second ridge portion to form a fluid inlet path with said second filtering material; an upstream closure provided at an upstream side of said fluid outlet path relative to direction of fluid flow; and a downstream closure provided at a downstream side of said fluid inlet path relative to the direction of fluid flow, wherein said first ridge portion and said second ridge portion are shaped substantially in an arc form having a first radius R1 of curvature and a second radius R2 of curvature smaller than said first radius R1 of curvature, respectively.
22. The filter element according to claim 21, wherein a ratio R1/R2 of said radii of curvature is between 1.5 and 3.0.
23. The filter element comprising:a first filtering material shaped in substantially flat configuration; a second filtering material shaped in a corrugated configuration in cross section which is an alternation of a first ridge portion, a second ridge portion and a connection portion between said first ridge portion and said second ridge portion, said second filtering material being in contact with said first filtering material at said first ridge portion to form a fluid outlet path with said first filtering material, and said connection portion being continuously curved to convex substantially only towards said first filtering material; a third filtering material shaped in substantially flat configuration and in contact with said second ridge portion to form a fluid inlet path with said second filtering material; an upstream closure provided at an upstream side of said fluid outlet path relative to direction of fluid flow; and a downstream closure provided at a downstream side of said fluid inlet path relative to the direction of fluid flow, wherein said second filtering material is deformed to be in substantially flat form only at the downstream side so that said first ridge portion and said connection portion become parallel to said third filtering material.
24. A filter element comprising:a first filtering material shaped in substantially flat configuration; a second filtering material shaped in a corrugated configuration in cross section which is an alternation of a first circular portion having a radius R1 of curvature, a second circular portion having a radius R2 of curvature smaller than said radius R1 of curvature and a connection portion between said first circular portion and said second circular portion, said second filtering material being in contact with said first filtering material at said first circular portion to form a fluid outlet path with said first filtering material, and a ratio R1/R2 of said radii of curvatures being between 1.5 and 3.0; a third filtering material shaped in substantially flat configuration and in contact with said second circular portion to form a fluid inlet path with said second filtering material; an upstream closure provided at an upstream side of said fluid outlet path relative to a direction of fluid flow; and a downstream closure provided at a downstream side of said fluid inlet path relative to the direction of fluid flow.
25. The filter element to claim 24, wherein said connection portion is shaped in a curved form which convexes only toward said first filtering material.
26. The filter element according to claim 24, wherein said connection portion includes a straight portion.
| 1994-05-12 | en | 1996-10-08 |
US-28083288-A | Method for generating an operating system by a static link-editor
ABSTRACT
In an operating system generation method of a computer, a symbolic name is converted into an identification code, which is further converted into an address. This enables an inter-reference operation to be achieved between a kernel and input/output device drivers, thereby independently generating the input/output device drivers and the kernel. As a result, depending on the hardware configuration of the user system, input/output device drivers can be incorporated into the operating system.
BACKGROUND OF THE INVENTION
The present invention relates to an operating system of a computer, and in particular, to an operating system generation method in which input/output device control programs can be incrementally added to an operating system.
An operating system (to be abbreviated as an OS herebelow) includes a basic portion of the operating system (to be abbreviated as a kernel herebelow) serving basic functions of the operating system such as process management, memory management and input/ output device control programs (to be referred to as input/output device drivers herebelow) for controlling input/output devices connected as peripheral devices. An operating system includes only one kernel, whereas a plurality of drivers are provided in association with the respective input/output devices.
In general, as the number of input/output devices connected to the computer increases, there appears an increased number of different types of drivers. In addition, since different types of input/output devices are connected to the various computer systems for the respective users, the combination of the drivers included in the operating system varies between user systems. Consequently, a procedure is required to incorporate the driver into the operating system depending on the hardware constitution of the user system.
When a driver is incorporated into an operating system, there arises a necessity of mutual reference between the driver and the kernel of the operating system for control of the input/output devices. The mutual reference is effected through three types of operations as follows:
(1) Routine call from the kernel to the driver;
(2) Routine call from the driver to the kernel; and
(3) Reference to data from the driver to the kernel.
When a user program issues an input/output request, the kernel calls a driver routine associated with the request, which corresponds to (1) above.
On the other hand, at an execution of an input/output operation, the driver routine calls the kernel routine to effect processing which can be controlled only by the kernel, which corresponds to (2) above. In addition, the driver routine references data managed by the kernel such as an address of data and a data length of data associated with the input/ output operation, which corresponds to (3) above.
When incrementally adding a driver to the operating system, the mutual reference between the kernel and the driver is required to be enabled. In general, a source program of the kernel or the driver is described by use of a symbolic name and also in a case of the mutual reference. On the other hand, in an object program or a program in an object form at an execution, all symbolic names are required to be translated into absolute addresses. When incorporating a driver into the operating system, there arises a problem of a method to translate the symbolic names to be subjected to the mutual reference between the kernel and the driver, which is referred to as a problem of an address solution herebelow.
Heretofore, there have been employed two methods of incorporating a driver in an operating system, namely, a static link method and a dynamic link method.
FIG. 2 shows the static link method in which a driver 5 calls a routine "KSUBm" in a kernel 3. When the driver 5 is linked with an object module 1 of the kernel 3 by use of the static linkage editor 7 (which is an ordinary linkage editor, namely, "static" is added thereto only for discrimination from another prior art technology of FIG. 3), a load module 18 is generated. The contents of the load module 18 thus produced include a load module 4 of the kernel 3 and a load module 6 of the driver 5, which are however combined into an integrated load module 18 of the operating system. In the load module 18, an address (XXX) of a "KSUBm" routine 17 is inserted into a location where this routine 17 is to be called (in an operand of a CALL instruction in the driver (a) 6). As described above, according to the static link method, the address solution between the kernel and the driver is accomplished when the link edit operation is conducted. This is because that since all object modules (that is, the kernel 3 and the driver 5 are simply object modules in FIG. 2, and this notification does not imply that the kernel and the driver exist in the same module and applies to all other drawings) of the drivers requiring the kernel are linked by use of the linkage editor 7, the absolute address (XXX in the example above, which is not necessarily a physical address) of the symbolic name (KSUBm in this example) to be subjected to the mutual reference can be completely recognized by the linkage editor 7.
The dynamic link method has been described in pages 173 to 176 of the "Operating Systems" written by S. E. Madnick, J. J. Donovan and published from McGraw-Hill in 1974. Referring now to FIG. 3, the address solution of the dynamic link method will be described.
In the dynamic link method, the kernel 3 and the driver 5 are not linked into a load module by use of a dynamic linkage editor 19, namely, there are produced segments 4 and 6 which are mutually independent of each other. In FIG. 3, a portion where the driver 5 calls a routine "KSUBm" in the kernel 3 retains the symbolic name "KSUBm" is retained (in the driver 6 of FIG. 3), this is true also after the processing of the linkage editor 19 for the dynamic link is accomplished. When the symbolic name "KSUBm" is referenced during an execution of the driver 6, a linkage interruption occurs in the kernel 4. A linkage interruption processing routine 21 of the kernel 4 possesses a relation table between routines and these addresses 22 including correspondences between the routine names related to the symbolic names and addresses thereof. When the linkage interruption occurs, an address (XXX) corresponding to the routine name "KSUBm" is passed to the driver 5, which in turn calls the "KSUBm" routine 17 by use of the address (XXX).
In this fashion, according to the dynamic link method, the symbolic name is retained up to the execution so as to effect the address solution at the execution.
The method to incorporate a driver in an operating system according to the prior art technology is attended with the following problems.
In general, the kinds of input/output devices connected to a computer are desired to be changed depending on the utilization situation of the computer. For this purpose, there is required means which enables the user to incrementally add a driver to the operating system in accordance with the utilization condition of the computer.
However, in the static link method described with reference to FIG. 2, it is impossible to add a new driver to the operating system which is a load module for the following reason. That is, in this method, the linkage editor 7 translates, in the link edit operation, symbolic names subjected to the mutual reference between the kernel 3 and the driver 5 into addresses so as to generate an operating system 18 as an executable load module. In other words, it is impossible for the conventional linkage editor 7 to add a new driver to the operating system 18 in the load module format for which the address solution has already been completed so as to achieve the address solution for a symbolic name to be subjected to the mutual reference thereafter. In consequence, in order to accomplish the user's request for the addition of a driver, it is necessary to achieve the link edit operation again for the object module 1 of the kernel 3 and other drivers, or to prepare various kinds of operating systems 18 for respective combinations of the drivers. However, in general, the user cannot obtain the object module 1 of the kernel 3 and other drivers 5. Moreover, when the utilization situation of the computer in the future cannot be forecasted, the combinations of the drivers cannot be easily determined in advance.
On the other hand, according to the dynamic link method described with reference to FIG. 3, the address solution is accomplished on the symbolic names for which the mutual reference is effected between the kernel 3 and the driver 5 during the execution of the operating system 18; in consequence, it is possible to add a driver to the operating system 18. However, in order to implement this method, the following two items are essential as described above:
(1) Special compiler and linkage editor capable of generating a plurality of segments and of retaining symbolic names also after the processing.
(2) Hardware causing a linkage interruption when a symbolic name is referenced.
However, an ordinary computer is not provided with such special software and hardware, therefore the dynamic link method cannot be adopted.
As described above, in the driver incorporation method of the prior art technology, there exists a problem that a driver cannot be added to the operating system depending on the change in the kind of the input/ output device connected to the computer.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an operating system generation method which is capable of incrementally adding a driver to an operating system by use of the same ordinary software as that used in the static link method and not employing special hardware and software necessitated in the dynamic link method.
The object above is achieved as follows, namely, a symbolic name in the kernel referenced by a driver is assigned with an identification code such as a number so that the symbolic name is translated into the identification code when the driver is compiled such that the driver specifies the identification code when the computer is initiated or at an execution so as to obtain an address corresponding to the symbolic name in the kernel.
On the other hand, the object is also achieved as follows, namely, another identification code is assigned to the driver such that the kernel specifies the identification code at an initiation of the computer so as to attain an address corresponding to the symbolic name in the driver referenced by the kernel.
With the provisions above, the linkage between the kernel and the driver is established and hence a driver can be incrementally added to the operating system.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic diagram showing an embodiment of the address solution method between a driver and a kernel according to the present invention;
FIG. 2 is an explanatory diagram useful to explain the static link method;
FIG. 3 is an explanatory diagram useful to explain the dynamic link method;
FIG. 4 is a flowchart showing an operation of the linkage library in a case of a routine call;
FIG. 5 is a flowchart showing an operation of the program interrupt processing;
FIG. 6 is an address table of a routine and/or area in a kernel;
FIG. 7 is a flowchart showing an operation of the linkage library in a case of an area access;
FIG. 8 is a schematic diagram for explaining a calling method of a call from a kernel to a driver;
FIG. 9 is a flowchart showing an operation of the driver table initialization from a kernel; and
FIG. 10 is a configuration diagram showing a computer system to which the present invention is applied.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, description will be given of an embodiment according to the present invention.
FIG. 1 shows a configuration diagram of an embodiment of the address solution according to the present invention.
Object modules 1 consisting of programs and tables necessary for constituting the kernel 3, the driver 5, and other operating system components are subjected to a linkage by use of the static linkage editor 7 so as to generate two load modules 2, a load module 4 primarily including a kernel, and a load module 26 mainly comprising a new driver to be added.
In order to explain the present invention, the kernel 3 includes a routine "KSUBm" 8 to be called from the driver 5, a program interrupt processing routine 9 operative in response to a program interruption issued at an execution of the driver 5, a driver table 11 for storing therein addresses of the load module 6 of the driver 5, and a driver table initializing routine 10 for storing addresses in the driver table 11. The other routines and tables are omitted for simplification of the diagram, which also applies to the configurations in the other drawings.
In the kernel 3, a representative routine not shown is a driver included as the basic routine of the operating system, for example, a driver for a keyboard.
As described above, the object module of the kernel 3 is linked by the linkage editor 7 so as to generate a load module 4 of the kernel.
The static linkage editor 7 is a linkage editor quite commonly used in general and is identical to the static linkage editor 7 of FIG. 2. This is ordinarily simply called a linkage editor, and hence a term "linkage editor" is used in the following description.
The load module 4 of the kernel includes, like the object module of the kernel 3 thereof, "KSUBm" 17, the program interrupt processing 23, routines of the driver table initializing routine 24, and the driver table 25. Naturally, these routines and tables are translated into a load module, namely, an execution format so as to operate in an integral fashion with other portions of the load module 4 of the kernel.
The object module the driver 5 is linked with the linkage library 12 and the driver definition table 14 by the linkage editor 7, thereby generating the load module 26. In FIG. 1, there is shown a state where a plurality of drivers 6 including drivers (a), (b), etc. are to be added to the operating system.
In FIG. 1, two linkage editors 7 are shown, which does not necessarily mean that two editors 7 exist but that the load module 4 of the kernel and the load module 26 mainly including the driver 6 are separately generated by use of the linkage editor 7.
When the load module 26 is generated, the linkage library 12 extracts only a portion 13 required by the driver 6 such that the pertinent portion is incorporated in the driver 6 according to the execution format (16 of FIG. 1).
As described above, according to the present invention, since the kernel and the driver are separately linked by use of the linkage editor so as to generate the separate load modules, the kernel need not be linked again when a new driver is added, which facilitates the operation to add the new driver. In general, it is difficult for the user to obtain the object module of the kernel. Under this situation, according to the present invention, the user can easily attain an operating system of a computer system including desired input/output devices.
The load module 4 mainly including the kernel, and the load module 26 primarily including the driver 6 thus generated are required to, when used as the operating system in the main memory, operate in an integrated fashion by mutually using routines and data respectively contained therein. Details about the operations above will be next described with reference to three cases thereof.
(1) When a routine in the kernel is called from the driver
Description will be given of a case where in the driver 5 of FIG. 1, the "KSUBm" routine 8 in the kernel 3 is called by use of a procedure of CALL KSUBm (also in an object module, 0 is inserted in general in place of "KSUBm" as an undefined address; however, by use of an external reference table associated with the object module, it is known that the called routine is "KSUBm"). It is assumed that in the load module 4 of the kernel, the "KSUBm" routine 17 is allocated with the first address thereof set as "XXX". In general, load modules are generated in a memory device such as a magnetic disk, however, the address "XXX" does not indicate an address in such a memory device, namely, it indicates an address in the memory (main memory) in which the operating system is loaded at an execution.
On the other hand, in the load module 26 mainly including the driver 6, there is contained only a portion of the linkage library 12 necessary to call the "KSUBm" routine, which is the linkage procedure 16 of FIG. 1. The procedure to call the "KSUBm" routine of the driver 6, includes setting an address (YYY) to the operand thereof. The address "YYY" is the first address of the linkage procedure 16, that is, when CALL YYY in the driver 6 is executed, the linkage procedure 16 starts the operation thereof.
The operation of the linkage procedure 16 will be described with reference to FIG. 4. In step 40, it is judged to determine whether or not the first address of the routine ("KSUBm" in this case) corresponding to Id=m has already been known in the linkage procedure 16. This judgment is conducted according to whether or not the address of "KSUBm" has already been set to a work area WKm in the linkage procedure 16. If the address has been known, control is passed to step 46; otherwise, a program interrupting instruction (pigment) is issued. In this case, m is used as a parameter for the identification code (Id). In association with the issuance of the program interrupting instruction, control is transferred to the program interrupt processing in the kernel of the load module 4, which will be described later. As a result of the operation thus effected, namely, as return information, the first address (XXX) of the "KSUBm" routine 17 is passed to the linkage procedure 16. The address (XXX) is then set to the work area WKm (step 44). In the step 46, a jump to subroutine instruction is employed to cause the "KSUBm" routine 17 at the address (XXX) to start an operation. After the operation of the "KSUBm" routine 17 is finished, the linkage procedure 16 executes a return instruction so as to execute an instruction subsequent to the CALL YYY of the driver 6.
As described above, by use of the load module 26 containing the driver 6 thus separately generated, the routine in the load module 4 of the kernel 3 can be called.
Next, description will be given of another feature of the operation described above. Of the operations effected by the linkage procedure 16, the operation to attain the address (XXX) of the "KSUBm" routine 17 in the kernel of the load module 4 can be effected through one execution of the processing of the step 40 of FIG. 4 as described above. (In general, since there exists a large overhead in association with an issuance of the program interrupting instruction, the fact that the operation above can be effected through one execution of the step 40 means that the overhead is minimized and hence the processing speed is improved.) However, in a computer system in which the overhead can be neglected, the steps 40 and 44 may be omitted so as to issue the program interrupting instruction for each operation.
Next, referring to FIGS. 5 and 6, the operation of the program interrupt processing routine 23 will be described. FIG. 6 shows an address table 60 to which addresses corresponding to the identification codes (Id's) in the program interrupt processing routine 23 are set in the order thereof.
In step 50, the program recognizes the identification code (Id) passed as a parameter from the linkage procedure 16. Thereafter, based on the address table 60, an address corresponding to the identification code (Id) is obtained (step 52). For example, in a case of Id=m, the address (XXX) of the "KSUBm" routine 17 is attained. In step 54, by use of the obtained address as information, control is returned to the linkage procedure 16 which has issued the program interrupting instruction.
Through the operation above, the routine in the kernel 3 can be called from the driver 6.
Another feature of the operation will now be described. In the program interrupt processing routine 23, a call is issued to operate the "KSUBm" routine 17. In association therewith, the linkage procedure 16 need only issue a program interrupting instruction in any case. This method improves the processing speed as compared with the method in which the address of the required routine is attained for each operation and then the routine is called by use of the linkage procedure 16; however, as described in conjunction with FIG. 4, the overhead is increased when compared with the method in which only one operation is effected to obtain the address. This method nevertheless leads to an effect that a sequence of processing associated with the linkage procedure 16 and the program interrupt processing routine 23 is simplified.
(2) When data is written from the driver into an area of the kernel or when data is read from an area of the kernel
Data read/write operation effected from the driver 5 on an area in the kernel 3 is basically the same as that effected when a routine in the kernel 3 is called from the driver 5. In consequence, description will be given mainly of several operations different therebetween.
Although not shown in the drawings, in order to access an area of the kernel 3 from the driver 5, there are prepared the procedures GETDATA and PUTDATA. GETDATA is a procedure employed by the driver 5 to read data from an area of the kernel 3, whereas PUTDATA is used to write data in the area.
From an object program 5 of a driver in which such procedures are described, the linkage editor 7 produces a load module 26. In the load module 26 of the driver 6, there are incorporated as a linkage procedure 16 portions of the linkage library 12 corresponding to GETDATA and PUTDATA. On the other hand, CALL GETDATA written in the driver 5 is translated in to call ZZZ (ZZZ indicates a first address of a linkage procedure associated with GETDATA) in the load module 6 of the driver.
The operations above are the same as those accomplished when a routine is called.
Referring now to FIG. 7, description will be given of the operations of the linkage procedure corresponding to GETDATA and PUTDATA.
Since processing of steps 70 to 74 are similar to the processing of the steps 40 to 44 of FIG. 4, description thereof will be omitted. In step 76, by using as an address the content of a work area WKi to which an access address has been set in the step 74, data is read in a case of GETDATA and data is written in a case of PUTDATA.
The operation of the program interrupt processing routine 23 corresponding to the operation above is identical to the content of the description already given in conjunction with FIGS. 5 and 6, and hence description thereof will be omitted.
Through the operations above, an access from the driver 6 to an area in the kernel of the load module 4 is possible, namely, data is written in the area and data is read therefrom.
(3) When a call is issued from the kernel 4 to the driver 6
Description will be given of the operation of this case with reference to FIG. 8, which shows in detail portions of FIG. 1 necessary for explaining the operation above.
In a case where a call is issued from the kernel of the load module 4 to the driver 6, the operation should be subdivided into two parts. In the first part, an address solution for the call to the driver 6 is executed when the computer system is set up (Immediately after the operating system is loaded in the main memory). In the second part, the driver 6 is actually called from the kernel.
(a) Address solution
First, description will be given of the reason why the address solution is required to be achieved when the setup or initiation is achieved on the computer system. In the setup operation of the computer system, the operating system is loaded in the main memory so as to set the system to a state capable of coping with interruptions from input/output devices. Consequently, in a case where the address solution has not been effected at the setup of the computer system, since the routine to operate in association with interruptions from the input/output devices is in kernel of the load module 4, when the routine calls the driver 6, a wrong address is accessed as a result, which may lead to a program runaway in some cases. In order to avoid this disadvantage, the address solution is conducted at the setup of the computer system. In the setup operation of the computer system, the reset state is first established and then the loading of the operating system and the initialization of the respective tables in the operating system are effected in an interrupt disabled state; in consequence, as a portion of the processing above, there is operated the driver table initializing routine 24, which will be described in the following paragraphs.
In FIG. 8, a driver definition table 25 is disposed to store therein the first addresses of routines corresponding to the various functions such as open, close, get, and put functions of the driver 6 in an order of the identification (Id) codes.
In the description above, there has not been explained that the driver 6 includes a plurality of functions because such a description is not required and may complicate the description.
As shown in FIG. 8, the driver definition table 25 includes information pairs each comprising a driver name (the name need not be necessarily assigned, namely, information such as an identification code may be specified) and a first address of a coupling routine, which will be described later. The address of this table 15 is recognized by the kernel of the load module 4 in a predetermined fashion.
The constitution of the driver 6 includes a table containing the coupling routine, the routines associated with the respective functions of the open, close, get, and put functions, and the first addresses of these routines.
The addresses stored in the driver definition table 15 and the first addresses of the routines associated with the respective functions in the driver 6 are subjected to the address solution, when a linkage operation is achieved by the linkage editor 7, so as to be stored in the respective locations.
In FIG. 8, a solid line with an arrow mark and a broken line with an arrow mark represent a subroutine call and a data flow, respectively. These operations of the processing are effected by the driver table initializing routine 24.
Referring next to FIG. 9, the operation of the driver table initializing routine 24 will be described.
Step 80 judges to determine the termination of the driver table initializing routine 24. That is, for all drivers 6 thus added thereto, it is checked to determine whether or not the driver table 25 is completely generated. Naturally, if the table generation is finished, the operation of this routine 24 is terminated. In step 82, an address of a driver (k) is obtained from the driver definition table 15, where (k) indicates that the object of the processing is the driver (k). In addition, the address of the driver (k) is, as described above, the first address of the coupling routine of the driver (k). The processing of step 82 is designated by use of a broken line with an arrow mark (p) in FIG. 8.
In step 84, a call is issued to the coupling routine of the driver (k). This processing is represented by a solid line with an arrow mark (q) in FIG. 8. In FIG. 8, it is assumed that k is identical to a.
The coupling routine thus called sets, as shown in FIG. 8, a first address (AAA for k=a) of the table in which the first address of each functional routine of the driver (k) is stored and thereafter only executes a return instruction. This processing is represented by broken lines each having an arrow mark (r) and (s) in FIG. 8.
In step 86, from the table storing the first address of each functional routine of the driver (k), the content thereof is transferred to an area corresponding to the driver (k) in the driver table 25. The processing portion associated with the storage is indicated by a broken line with an arrow mark (t) in FIG. 8.
By conducting the operations from the step 80 to the step 86 for all drivers, the address solution is accomplished for all drivers added thereto in association with the case where the driver 6 is called from the kernel of the load module 4.
(b) Call issued from the kernel to the driver
Since the first address of each routine of the driver 6 is already stored in the driver table 25, it is only necessary to issue a call by use of the address stored in the driver table 25. In the most favorable case, the call can be effected with an instruction by use of an indirect addressing method.
Through the operations above, the address solution is effected in a case where a call is issued from the kernel of the load module 4 to the driver 6; furthermore, the execution thereof does not cause any wrong operation.
In the description of the sequence of operations above, there have not been described the data write and read operations to be achieved from the kernel onto an area in the driver for the following reasons. That is, in general, the driver is called from the kernel and applications and can be called in a duplicated fashion, the program structure of the driver is required to be a reentrant structure. However, in a case where the driver possessed data, if duplicated calls are issued thereto, the data may be possibly rewritten or destroyed by mistake. In order to prevent such an adverse operation, data is not located in the driver in an ordinary case. If data is to be possessed in the driver, an access from the kernel to the data can be effected in a similar fashion to that of the operation employed to call the driver, which will not require any particular explanation.
FIG. 10 shows an example of a configuration of a computer system to which the present invention is applied. In this configuration, a processor 90, a memory 91, a magnetic disk device 92, a floppy disk device 93, display equipment 94, and a keyboard 95 are interconnected via a bus 96 to each other.
In the computer system like that shown in FIG. 10, an operating system thereof is generally generated as follows.
Object modules of the respective programs constituting the kernel, the driver, an other operating system components are beforehand created on a floppy disk 93. Next, an execution of a linkage editor is effected by use of the processor 90 so as to link the object modules above such that the result of the linkage operation is stored on a magnetic hard disk 92. The states of these operations are indicated by means of the display 94, so that information to be externally supplied to the linkage editor is inputted from the keyboard 95.
Although description has been given of a computer environment for generating an operating system in quite a general case, this is also similar to the environment associated with the present invention. Moreover, it is assumed that the object modules are beforehand stored on a floppy disk 93, the magnetic disk 92 may also be employed for the storage. The storage and management of the object modules and load modules are effected by use of a floppy disk and a magnetic disk in the unit of files corresponding to the respective modules and hence do not depend on the storage location, namely, the storage device or the storage medium of each file.
The load module of the generated operating system is loaded, when the computer system is initiated, in the memory 91 so as to be executed by the processor 90.
According to the present invention, without necessitating the special compiler, linkage editor, and hardware necessary for the dynamic link method, namely, by use of the same software as that employed in the conventional static link method, there can be provided a driver incorporation method in which a driver can be incrementally added to an operating system, which leads to an effect that a combination of the drivers, in the operating system can be changed depending on the individual user's need.
We claim:
1. In a computer system, a method of generating an operating system by the computer system including generating a load module of the operating system from object modules of a kernel program and a plurality of driver programs by a static link-editor, the method comprising the steps of:linking object modules of a kernel program to prepare a first load module, said kernel program including a plurality of kernel subroutine programs, an interrupt-processing program, a driver table initializing program and a driver table; linking object modules of a plurality of driver programs, a linkage library and a driver definition table to prepare a second load module, the object modules of each of said driver programs including a read/write sequence having a read/write instruction for reading or writing data in a working area of said kernel program, and the object module of said linkage library including a read/write linkage procedure for executing said read/write instruction; linking each of said driver programs and said read/write linkage procedure according to the read/write sequence in each of said driver programs; rewriting a portion of said read/write instruction including said read/write sequence into a starting address of said read/write linkage procedure linked to said step of linking each of said driver programs and said read/write linkage procedure, wherein read/write linkage procedure interrupts to said kernel subroutine program controlling said working area are started from a predetermined starting address of the load module corresponding to execution of said read/write sequence; storing addresses corresponding to each of said driver programs to said driver table of said first load module by referring to said driver definition table when said driver table initializing program is executed; and storing addresses corresponding to one of said kernel subroutine programs to said driver program by executing said interrupt processing program upon a call sequence for calling one of said kernel subroutine programs when said driver program is executed.
2. In a computer system, a method of generating an operating system by the computer system including generating a load module of the operating system from object modules of a kernel program and a plurality of driver programs by a static link-editor, each of said driver programs including a plurality of driver-function subroutine programs and coupling-routine programs for executing one of driver-function subroutine programs corresponding to a call from said kernel program, said kernel program including a driver call sequence for calling one of a plurality of driver-function subroutines and a driver function subroutine table for storing a starting address of each of said driver function subroutine programs, said driver call sequence including a name of the driver program and a name of the driver-function subroutine program in said driver program, and said object modules including a driver-definition information table for indicating a relationship between each name of said driver program and each of said starting addresses of said coupling routine programs in each of said driver programs, the method comprising the steps of:linking object modules of a kernel program to prepare a first load module, said kernel program including a plurality of kernel subroutine programs, an interrupt-processing program, a driver table initializing program and a driver table; linking object modules of a plurality of driver programs, a linkage library and a driver definition table to prepare a second load module; storing addresses corresponding to each of said driver programs to said driver table of said first load module by referring to said driver definition table when said driver table initializing program is executed; and storing addresses corresponding to one of said kernel subroutine programs to said driver program by executing said interrupt processing program upon a call sequence for calling one of said kernel subroutine programs when said driver program is executed; and linking said driver-definition information table with other driver definition tables of said object modules, wherein said kernel program calls said coupling-routine program by referring to said driver-definition information table corresponding to execution of said driver function subroutine call sequence, and said coupling-routine program executes the driver-function subroutine program according to a calling of said kernel program, said coupling-routine program returns said starting address of said executed driver-function subroutine program to said kernel program after execution of said driver-function subroutine program, and said kernel program stores said returned starting address in said driver function subroutine table and executes said driver function subroutine program directly corresponding to execution of said driver call sequence for calling said driver function subroutine program again.
| 1988-12-07 | en | 1992-08-04 |
US-96721792-A | Biomagnetometer having flexible sensor
ABSTRACT
A biomagnetometer includes a magnetic field sensor unit having a magnetic field pickup coil. A vessel contains the sensor unit. The vessel includes a flexible contact face with the magnetic field sensor unit mounted in the interior of the vessel adjacent to the flexible contact face. Insulation at the flexible contact face of the vessel prevents excessive heat flow through the flexible contact face. Pickup units using this structure can be connected together into flexible or rigid arrays. In operation, the pickup coil is cooled to a temperature of less than its superconducting transition temperature. A detector measures the magnitude of magnetic fields sensed by the sensor unit.
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of application Ser. No. 07/551,841, filed Jul. 17, 1990, now U.S. Pat. No. 5,158,932, for which priority is claimed, which is a continuation-in-part of application Ser. No. 07/386,948, filed Jul. 31, 1989, now U.S. Pat. No. 5,061,680, for which priority is claimed. This application is also a continuation-in-part of pending application Ser. No. 07/831,905, filed Feb. 6, 1992, for which priority is claimed.
This invention relates to apparatus for the measurement of biomagnetic signals produced by the body, and, more particularly, to such apparatus in which the magnetic pickup coils are provided in a flexible container.
The human body produces various kinds of energy that may be used to monitor the status and health of the body. Perhaps the best known of these types of energy is heat. Most healthy persons have a body temperature of about 98.6 F. A measured body temperature that is significantly higher usually indicates the presence of an infection or other deviation from normal good health. A simple medical instrument, the clinical thermometer, has long been available to measure body temperature.
Over 100 years ago, medical researchers learned that the body also produces electrical signals. Doctors today can recognize certain patterns of electrical signals that are indicative of good health, and other patterns that indicate disease or abnormality. The best known types of electrical signals are those from the heart and from the brain, and instruments have been developed that measure such signals. The electrocardiograph measures electrical signals associated with the heart, and the electroencephalograph measures the electrical signals associated with the brain. Such instruments have now become relatively common, and most hospitals have facilities wherein the electrical signals from the bodies of patients can be measured to determine certain types of possible disease or abnormality.
More recently, medical researchers have discovered that it is possible to measure the magnetic fields which are produced by the electrical currents that flow in the body. The research on correlating magnetic fields with various states of health, disease and abnormality is underway, but sufficient information is available to demonstrate that certain emitted magnetic fields are associated with abnormal conditions. Medical studies are investigating the nature of the normal and abnormal magnetic fields of the brain and heart, and seeking to correlate those fields with body functions and patient health.
For example, if it were known that a particular abnormality, such as epilepsy, stroke, or cardiac arrhythmia, were associated with an abnormal magnetic field produced at a particular location in the body, it might be possible to detect the abnormality at an early stage, while it was treatable, and then apply other medical knowledge to chemically treat or surgically remove that precise portion of the body with minimal side effects on the patient. Magnetic studies of the brain and heart therefore offer the potential for understanding and treating some of tile most crippling diseases and conditions known.
The biomagnetometer is an instrument that measures magnetic fields produced by the body, particularly the brain and heart. The biomagnetometer is a larger, more complex instrument than the medical instruments mentioned earlier, primarily because the magnetic fields produced by the body are very small and difficult to measure. Typically, the strength of the magnetic field produced by the brain is about 0.000000001 Gauss, at a distance of 1-2 centimeters from the head. The strength of the magnetic field produced by the heart is about 100 times larger. By comparison, the strength of the earth's magnetic field is about 0.5 Gauss, or about five hundred million times larger than the strength of the magnetic field produced by the brain, as measured externally to the head. Most electrical equipment also produces magnetic fields, in many cases much larger than that of the earth's field. It is apparent that, unless special care is taken, it is not possible to make magnetic measurements of the human body because the external influences such as the earth's magnetism and nearby apparatus can completely overwhelm and mask the magnetic fields from the body.
The biomagnetometer includes a magnetic field pickup coil connected to a very sensitive detector of the electrical signals produced by the magnetic signals sensed by the pickup coil. The currently most widely used detector is a Superconducting QUantum Interference Device or SQUID, which, in combination with a superconducting pickup coil, is sufficiently sensitive to detect magnetic signals produced by the brain. (See, for example, U.S. Pat. Nos. 4,386,361, 4,403,189, and 5,194,117, whose disclosures are incorporated by reference, for descriptions of various types of SQUIDs.) The detector, pickup coil, and their associated equipment require special operating conditions such as a cryogenic dewar, and cannot be placed into the body or attached directly to the surface of the body. In the current instrument, the dewar is operated at liquid helium temperature (about 4.2K), to maintain the SQUID detector, the pickup coil, and the electrical connection between them in the superconducting state. Only when the pickup coil, SQUID detector, and interconnections are superconducting can the biomagnetometer detect the magnetic fields produced by the small electrical currents of the body.
The conventional biomagnetometer therefore includes a dewar structure in which the pickup coil, the SQUID detector, and the electrical interconnects are cooled by liquid helium. The dewar normally is constructed with a small-diameter "tail" section, which permits placement of the pickup coil in close proximity to the patient, typically less than about 2 centimeters away. (See U.S. Pat. No. 4,773,952, whose disclosure is incorporated by reference, for a description of the construction of the dewar.) Special electronics is provided to attenuate external effects such as the earth's magnetic field and the magnetic fields of nearby electrical instruments. (For a description of such a device, see U.S. Pat. Nos. 3,980,076 and 4,079,790, whose disclosures are herein incorporated by reference.) The patient and detector can also be placed into a magnetically quiet enclosure that shields the patient and the detector from the external magnetic fields. (For a description of such an enclosure, see U.S. Pat. No. 3,557,777, whose disclosure is herein incorporated by reference.) With these special precautions, medical researchers and doctors can now make accurate, reliable measurements of the magnetic fields produced by the brain and by the heart, and are studying the relationship of these fields with diseases and abnormalities.
The existing approach of enclosing the pickup coil and the SQUID detector in a liquid-helium dewar is acceptable in many circumstances. Nevertheless, it would be desirable to have another approach wherein the physical size of the equipment could be reduced, to permit more flexibility in the use of the biomagnetometer. It would also be desirable to permit larger arrays of pickup coils to be placed closer to larger regions of the individual subjects' heads or chests than is now possible. The heads of subjects vary greatly in size and shape, and the existing approach can only be used for relatively small areas of the head at one time. The present invention fulfills these needs, and further provides related advantages.
SUMMARY OF THE INVENTION
The present invention provides a construction for a biomagnetometer having an array of magnetic field pickup coils that is much more easily manipulated into place adjacent a subject than was previously possible, because it is held in a flexible container. In the new approach, the pickup coils may be placed closer to the subject, and thence closer to the source of the magnetic field, than possible with the prior approach. Larger numbers of pickup coils may be placed close to a greater variety of patients whose head sizes and shapes vary substantially from one patient to another, and who may be wearing bandages or other medical appliances.
In accordance with the invention, a biomagnetometer includes a magnetic field sensor unit. The sensor unit has a magnetic field pickup coil made of a material having a superconducting transition temperature. There is a vessel means for containing the magnetic field sensor unit, the vessel means including a flexible contact face with the magnetic field sensor unit mounted in the interior of the vessel mean s adjacent to the flexible contact face. Insulation means at the flexible contact face of the vessel means prevents excessive heat flow through the flexible contact face. A number of such vessels and their contained sensor units may be mechanically connected together either flexibly or rigidly to form an array. There is additionally a means for cooling the pickup coil to a temperature of less than its superconducting transition temperature, and a detector means for measuring the magnitude of magnetic fields sensed by the sensor unit.
The pickup coils are preferably made of "high Tc" material, material that becomes superconducting at critical temperature (Tc) of at least 77K, and preferably at even higher temperature. The pickup coils need only be cooled to a few degrees Kelvin below their Tc value to be operable. It is far easier to cool such pickup coils and maintain them at 77K or higher, or at intermediate temperatures between 10K and 77K, than to cool and maintain them at lower temperatures such as 10K or below as required for conventional biomagnetometers. Significantly, less insulation is required to maintain such pickup coils at their superconducting temperatures. Many materials of construction become brittle at low temperatures, and operating at temperatures above 77K decreases the likelihood of a failure of these materials. The pickup coils may therefore be placed close to the interior wall of a flexible container that can be reshaped to fit to the contour of the body of the subject. Thus, the pickup coils are closer to the source of the magnetic fields than previously possible both because the container wall can be made thin (because less insulation is required) and because the entire container can be reshaped to conform to the surface of the body immediately above the source of the magnetic fields. The flexible container is insulated to maintain the pickup coils below their Tc, to prevent chilling of the subject, and for cryogenic efficiency.
Each pickup coil and its detector may be provided on the same support or in different parts of the same container to operate them at essentially the same temperature. Alternatively, they may be placed into different containers and maintained at different superconducting temperatures. The structure having provision for two superconducting temperatures allows the pickup coil to be positioned remotely from the detector, which results in major advantages from the standpoint of the practical utilization of the biomagnetometer in those cases where the detector must be operated at temperatures below the operating temperature of the pickup coil, and typically at temperatures near absolute zero.
With the discovery of superconductors having superconducting transition temperatures above 77K, the biomagnetometer of the invention can be constructed with the pickup coil and the electrical connector of a material having a superconducting transition temperature above 77K, the boiling point of liquid nitrogen. The pickup coil may be remotely placed and maintained below its superconducting transition temperature, and the electrical connector may also be readily maintained below its superconducting transition temperature.
The detector may still be maintained at an acceptable operating temperature, which may be near absolute zero or at some higher temperature. SQUIDs fabricated from materials which become superconducting at higher temperatures while maintaining high sensitivity would permit the detector to be operated at a higher temperature than 10K, and possibly even higher than 77K. Both the magnetic pickup coils and the detector may be operated at relatively high temperature, and even at the same high temperature, but physically separated in the manner disclosed herein.
In one preferred approach the detector remains essentially stationary, and the pickup coil is readily moved about while remaining tethered to the detector. The detector always stays at its operating temperature, while an electrical connector and thermal connector in the tether may be disconnected to replace the pickup coil with another design of pickup coil without serious thermal interruption to the apparatus. In another preferred approach, the detector coils and SQUIDs are both made of high-Tc materials and are packaged together inside the same flexible container.
Other features and advantages of the invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view of a biomagnetometer apparatus;
FIGS. 2A-C are elevational views of several configurations of pickup coil and container operable with the present invention;
FIG. 3 is a perspective view of the operational arrangement of the apparatus of FIG. 1;
FIG. 4 is a side sectional view of a preferred flexible tube;
FIG. 5 is a cross sectional view of the tube of FIG. 4, taken along line 5--5;
FIG. 6 is a side sectional view of a pickup unit made in accordance with the invention;
FIG. 7 is a side sectional view of another embodiment of the pickup unit;
FIG. 8 is a perspective view of a pickup coil formed on a substrate;
FIG. 9 is a perspective view of a gradiometer formed on two substrates;
FIG. 10 is a perspective view of a pickup coil and a SQUID formed on a substrate;
FIG. 11 is a perspective view of a gradiometer made of a pickup coil and SQUID on each of two substrates;
FIG. 12 is a side sectional view of an insulated vessel;
FIG. 13 is a side sectional view of another embodiment of the insulated vessel;
FIG. 14 is an elevational view of three integrated pickup units Joined together in an array;
FIG. 15 is a sectional view of an alternative approach in accordance with the invention; and
FIG. 16 is a sectional view of a flexible sensor utilizing multiple spring-mounted detector capsules.
DETAILED DESCRIPTION OF THE INVENTION
A biomagnetometer 10 is illustrated in FIG. 1. In this biomagnetometer 10, the magnetic field pickup coils are maintained and operated at a different temperature than the detectors. The biomagnetometer 10 includes a number of pickup coils 12 in a first container 14. The pickup coil 12 is formed of a material having a superconducting transition temperature of greater than 77K. The presently preferred material of construction of the pickup coil 12 is YBa2 Cu3 O7-x, where x is typically about 0.1-0.2, depending upon the fabrication approach of the oxide. This material has been demonstrated to have a superconducting transition temperature of greater than 77K. Other materials having superconducting transition temperatures greater than 77K are also acceptable. Some examples include Bi2 Ca2 Sr2 Cu3 O10 and Tl2 Ba2 Ca2 Cu3 O10. As used herein, the "superconducting transition temperature" (Tc) is the highest temperature at which the material becomes superconducting, in the absence of an applied magnetic field.
When small, low frequency magnetic fields are to be received by a pickup coil, the coil must be maintained in the superconducting state to permit the current generated by the small magnetic field variations to flow freely and not be dissipated as ohmic heating, and to eliminate noise due to the dissipation process. It is not required that the pickup coil be maintained at a temperature near absolute zero, and therefore the construction of the pickup coil from "high temperature superconductors" having superconducting transit ion temperatures at or above 77K is acceptable. Construction of the pickup coil from high temperature superconductors is not required, and more conventional low-temperature superconductors such as niobium (having a Tc below 77K) may instead be used in a less preferred embodiment.
The container 14 is formed as an insulated vessel 16 having an interior volume 18 for containing liquid nitrogen or other liquefied gas, or a refrigerated gas, as a coolant. The walls of the vessel 16 can be made of rigid materials such as fiberglass or insulating foam, a construction well known in the industry for making liquid nitrogen dewars. The walls of the vessel 16 can also be made of flexible materials such as corrugated stainless steel in the form of an elongated, double walled tube, or supported membranes such as plastics. Such flexible metal construction is well known in the industry for transfer tubes used to move cryogenic liquids. A thin membrane construction is known in the industry to protect against intense cold, as in aerospace applications. The walls of the vessel 16 can also be made of a composite construction, wherein part is rigid and part is flexible. With this approach, some portions of the walls of the vessel 16 can be made of a thin rigid material such as fiberglass, and other portions could be made of a flexible material so that the container 14 could be reshaped to conform to the body of the subject. The insulated walls of the vessel 16 prevent discomfort from the cold for the human subject contacted with the surface of the container 14. Details of the design of the pickup coils 12, their supports, and the vessel 16 will be presented subsequently.
The use of materials for the pickup coils 12 having superconducting transition temperatures greater than 77K dictates the design of the system to a large degree. If the materials had lower superconducting transition temperatures, then a larger amount of insulation and a more powerful coolant than liquid nitrogen would be required. Experience has shown that achieving such lower temperatures in the container 14 is difficult, particularly if the walls 16 are flexible to permit reshaping of the container. The use of higher temperature superconductors allows liquid nitrogen cooling or even cooling with other liquefied gases or by mechanical means, without excessive insulation mass in the walls 16 of the container 14. Liquid nitrogen cooling is preferred, because liquid nitrogen is cheap, plentiful, and widely available in most hospitals and research facilities. It also has a relatively high heat of vaporization and therefore relatively high cooling efficiency. If cooling below the boiling point of liquid nitrogen, 77K at 1 atmosphere pressure, is required, the cooling is more difficult. The design of flexible insulated components is also much more difficult.
A detector 30 for each of the pickup coils 12 is placed within a second container 32. The detectors 30 are highly sensitive detectors of small electrical currents, and are preferably superconducting quantum interference devices (SQUIDs). The detectors 30 are formed of a material that is superconducting at temperatures below its superconducting transition temperature.
For some applications, the detectors 30 are preferably cooled to a temperature of near to absolute zero, such as below about 10K, and most preferably to liquid helium temperature, 4.2K. The detectors 30 must be operated in the superconducting state to provide maximum sensitivity. For some applications, it is preferably operated at a temperature close to absolute zero to minimize, as much as possible, thermally induced noise that degrades sensitivity in the detection circuit. In particular for many biomagnetic applications, the detectors 30 are operated near to absolute zero in order to reduce this noise in the circuit. It may not be sufficient for these applications to cool the detector just to a superconducting temperature, where that temperature is above about 30K, because thermally induced noise or noise arising from other sources at these higher temperatures may overwhelm the detected signal.
In other applications, however, it is not necessary to maintain the detector near to absolute zero, but only below its superconducting transition temperature. SQUIDs have been fabricated from high temperature superconductors of the type discussed previously, an example being a SQUID made from YBa2 Cu3 O7-x material. Some high temperature SQUID detectors have noise levels, when operated at temperatures approaching or above 77K, substantially higher than those of SQUIDs operated at near absolute zero. These high temperature SQUIDs might be used where the magnetic signals to be measured are relatively large, as in magnetocardiographic measurements of the heart, for example. Low temperature SQUIDs, such as those made of niobium and operated near to absolute zero, might be used where the magnetic signals to be measured are relatively much smaller (and therefore more likely to be undetectable in the instrument noise of a high temperature SQUID), as in magnetoencephalographic measurements of the brain.
Thus, while in some preferred embodiments the SQUIDs are low temperature SQUIDs operating near absolute zero in liquid helium, the invention is not so restricted. The SQUIDs may be high temperature SQUIDs operated near, or above, 77K, where the instrument noise requirements permit. In either case, however, the SQUIDs are operated below their superconducting transition temperatures.
Returning to the discussion of the biomagnetometer shown in FIG. 1, to maintain the detectors 30 at temperatures near absolute zero, the second container 32 has an interior insulated wall 34 that permits it to be filled with liquid helium or other appropriate liquefied gas having a boiling point near absolute zero. Around the insulated walls 32 are heat shields 36 and an exterior insulated wall 38. The walls 34 and 38 are made of fiberglass, are good thermal insulators, and are vacuum impermeable. A vacuum line 40 is provided to communicate with the space between the walls 34 and 38, so that a vacuum may be drawn in this volume. Alternatively, a self-pumping getter can be used to maintain a vacuum. The detectors 30 are mounted on a support 42, which in turn is suspended through an opening in the top of the container 32. Heat shields 44 and the use of thermally insulating fiberglass in the support 42 insulate the detector 30 against heat loss through the opening. Wires 46 that act as electrical contacts from the detectors 30 to external instrumentation extend along the length of the support 42. The combination of the walls 34 and 38, the heat shields 98 and 44, and the vacuum between the walls 34 and 38 permits the detectors 30 to be maintained at a temperature near absolute zero without undue expenditure of coolant. The construction of such dewar vessels is described in greater detail in U.S. Pat. No. 4,773,952, whose disclosure is incorporated by reference. Alternatively, the detector may be cooled by a mechanical cooler, such as the type disclosed in U.S. Pat. No. 4,872,321, which disclosure is incorporated by reference.
The pickup coils 12 and the detectors 30 are electrically connected by a lead system 50. The leads of the system 50 extend from each pickup coil 12 to its respective detector 30, to convey signals from the pickup coil 12 to the detector 30. A lead 52 connects directly to the pickup coil 12 and is external to the second container 32, but connects to the interior of the second container 32 at a connector 56. From the connector 56, another lead 58 extends to a junction block 60, and another lead 62 extends from the junction block 60 to the detector 30. These various leads pass through several temperature environments, which will be described subsequently.
The leads 52, 58, and 62, as well as any elements of the connector 56 and junction block 60 that might carry current, are made of a material that is super conducting at the operating temperature of the system. Signals from each pickup coil 12 are conveyed to its detector 30 with no resistive loss in current, when these components are maintained in the superconducting state. The same YBa2 Cu3 O7-x material used for the coil 12 is preferred for use in these element and other high Tc superconductors are also operable.
A third container 70 encloses the lead system 50 and maintains it in the superconducting state. The lead 52 that extends from the pickup coil 12 to the connector 56 passes through the interior of the first container 14 for a short distance, and then through the interior of an elongated tube 72.
The walls of the tube 72 are preferably, but not necessarily, flexible. FIGS. 4 and 5 illustrate the preferred construction of the container 70 in more detail. An outer wall 100 and an inner wall 102 are made of a corrugated nonmagnetic metal such as brass, beryllium, or copper. Such a corrugated construction permits limited flexibility of the walls and bending of the container 70 along its long axis. It permits a greater degree of elastic bending than possible with the metal itself. Such flexible construction is known for fabricating flexible bellows used in transferring cryogenic fluids. In one approach, the space between the outer wall 100 and the inner wall 102 is vacuum pumped to reduce conduction and convection heat loss and is wrapped with superinsulation 104. The space within the inner wall 102, holding the lead system 50, is filled with a liquefied gas, such as liquid nitrogen, to maintain the lead system 50 below its superconducting transition temperature during operation. The lead system may be formed from straight wires, if sufficiently flexible, or from the superconducting materials deposited upon a flexible substrate, such as a corrugated substrate, to achieve at least the same degree of flexibility as the outer and inner walls.
In the preferred approach, the interior of the tube 72 is continuous with, and communicates with, the interior of the first container 14. The tube 72 has a cryogenic liquid fill tube 75 near its uppermost region, so that a cryogenic liquid, most preferably liquid nitrogen, can be poured into the interior of the tube 72 and thence into the interior of the first container 14. In operation, the lead 52 is thereby maintained at a temperature below its superconducting transition temperature.
The lead 58, the junction block 60, and a lower portion of the lead 52 are contained within an insulated container 75 that is also part of the third container 70. The container 75 is attached to the underside of the second container 32, and has evacuated walls 78 to provide insulation sufficient for efficient thermal operation. A fill tube 80 permits liquid nitrogen to be poured into the interior of the container 76, so that the lead 58, the junction block 60, and the portion of the lead 62 within the container 76 are maintained at about 77K, below their superconducting transition temperatures. The upper portion of the lead 82 passes through a seal 82 into the interior of the second container 32, and is thence connected to the appropriate leads of the detector 30. The upper portion of the lead 62 is maintained at a temperature at which it is superconducting.
The connector 56 is provided between the leads 52 and so that they may be readily disconnected from each other. While it would be acceptable to have the lead system 50 be a continuous length of superconducting material, it is desirable to provide the connector 56 so that the portion of the lead system 50 exterior to the containers 32 and 75 may be readily disconnected. By this approach, the entire pickup coil array may be removed and replaced with another array, without requiring that the detector SO be warmed. The connector 56 may be a plug connector that seals against loss of liquid gas, an inductively coupled connector, or other acceptable type known in the field of cryogenics.
FIGS. 1, 2A, 2B, and 2C show some alternative configurations for an array of pickup coils 12 and the corresponding first container 14. In FIG. 1, the container 14 is configured to generally fit over the skull of a subject, somewhat like a cap, so that the array of coils 12 may be placed at many different locations relative to the brain of the subject. In FIG. 2A, the coils 12 and container 14 are in a gently curved form that could be placed against the body, as for example over the chest to sense magnetic fields produced by the heart. In FIG. 2B the coils 12 and container 14 are depicted in a flat form. FIG. 2C illustrates a form having two arrays of pickup coils 12 and 12', located respectively in two containers 14 and 14'. This configuration is suited for simultaneous measurements of different parts of the body, as, for example, two separate portions of the brain, or the peripheral nervous system and the brain. In each case, there is provided a tube 72, fill tube 80, and one side of the connector 56. Any or all of these containers may be made partly or entirely flexible, as will be described subsequently.
It will be appreciated that these various configurations are presented as illustrative, and that custom configurations can be designed and built using the techniques described herein. The important point is that, using the approach of the invention, the detector, which may require an operational temperature near absolute zero, is physically separated from the pickup coils, which need only be operated in the superconducting state and not necessarily near absolute zero, and connected with a lead system that also need only be operated in the superconducting state and not necessarily near absolute zero. Using high temperature superconductors having superconducting transition temperatures above 77K, the structure used to maintain the pickup coil and the lead system at or below the superconducting temperature is much simpler and less bulky than the structure used to maintain the detector near absolute zero.
FIG. 3 illustrates the use of the biomagnetometer 10, constructed according to the prior description and as shown in FIG. 1. A subject 90 sits in a chair 94 with the first container 14 on the subject's head, and with an array of pickup coils therein positioned around the head. The second container $2 and container 75 are mounted above and some distance from the subject 90. The flexible tube 72 extends from the first container 14 to the containers 32 and 76.
This approach has important advantages over the prior approach, which is generally illustrated in FIG. 1, of U.S. Pat. No. 4,793,355, whose disclosure is incorporated by reference. In this prior approach, the pickup coils were necessarily located within the rigid, bulky dewar, and as a result could not be easily moved. The ability to arbitrarily position the pickup coils was also significantly limited. In the present approach, the pickup coils are located close to the body of the subject, resulting in greater signal strength and hence higher resolution and improved signal-to-noise ratio. A large array of pickup coils 12 can be placed in proximity to the subject, and on all sides. This capability is expected to be of great significance in advanced techniques now under development for correlating signals obtained simultaneously from arrays of pickup coils. The flexible tube 72 permits the subject to move around slightly, thereby avoiding undue constraints that might cause unwanted responses in the brain. The use of a connector 56 between the tube 72 and the lead 58 allows the entire tube 72, array of pickup coils 12, and first container 14 to be disconnected and replaced with another unit without bringing the detector 30 to ambient temperature, which was impossible with the apparatus illustrated in the '355 patent.
The '355 patent discloses an approach for automatically tracking the position of the pickup coil and the subject. This approach is readily applied in conjunction with the present invention. Each of the first containers 12 shown in FIGS. 1-3 includes a position monitoring sensor 92 that is used in conjunction with the apparatus disclosed in the '355 patent to monitor the position of the coil array.
As the technology of superconductors advances, it is possible that materials which are superconducting at even higher temperatures, up to ambient temperature, will be discovered. The present invention is operable with such materials used in the pickup coils and the conducting portions of the lead system 50. In this instance, insulation for the containers that contain the lead system 50 is greatly reduced and may not be required, except where the leads are brought to lower temperatures for connection with the detector 30.
FIGS. 6 and 7 illustrate two designs for the vessel 16 wherein all or part of the vessel wall is flexible. In FIG. 6, each pickup coil 12 within the vessel 16 has a detector 30, preferably a superconducting quantum interference device, integral with the pickup coil 12. The output signals of the detectors 30 are transmitted to conventional ambient temperature electronics (not shown) through a cable 200. The interior of the vessel 16, including the integral pickup coil/detector unit, is cooled to less than the superconducting transition temperatures of the super conductor materials in the pickup coil 12 and the detector 30 by a stream of coolant 202 supplied from a reservoir 204. The coolant can be either a liquid, such as liquid nitrogen, or a refrigerated gas, such as gaseous nitrogen produced from liquid nitrogen and which has a temperature below that required. The higher the required temperature, the less difficult is the maintenance of that temperature using a refrigerated gas coolant.
In FIG. 7, all of the detectors 30 are placed at a central location within the vessel 16, with superconducting wires 210 leading to the pickup coils 12. The interior of the vessel 18 is cooled by conduction from a cryostat 212, such as that disclosed in U.S. Pat. No. 4,872,321. An insulated conducting wire such as a copper wire bundle 214 extends from the cold region of the cryostat 212 to the vessel 16. The detectors 30 are preferably mounted directly in contact with the end of the copper wire bundle 214, and are cooled by conduction of heat from the detectors 30 to the cryostat 212. The pickup coils 12 are cooled by individual copper wire bundles 216 extending from the bundle 214 to the individual pickup coils 12.
The cooling and pickup coil/detector arrangements of FIGS. 6 and 7 may be used in an appropriate intermixed manner, with, for example, the cooling approach of FIG. 8 used with the detector placement of FIG. 7. The selection of particular configurations is usually made with the cooling requirements in mind. The higher the Tc values of the materials used in constructing the pickup coils and detectors, the less cooling power is typically required.
In all of the embodiments discussed herein, the pickup coils 12 are preferably formed as thin film depositions on a substrate. FIG. 8 illustrates such a pickup coil 12 deposited as a thin film loop 220 on a substrate 222. The material of the thin film loop 220 is a high-Tc superconductor, preferably YBa2 Cu3 O7-x, where x is 0.1-0.2 or less, and the substrate 222 is compatible with the superconductor, preferably (100) LaAlO3. The thin film loop 220 is prepared by patterning the substrate 222 in a conventional fashion and then depositing the superconductor, typically by sputtering. The procedures for the deposition of high temperature superconductors onto substrates are well known in the art, see the publications listed in the following paragraph. A gradiometer or more complex form of pickup coil 12 can be prepared by superimposing two of the substrates 222 with interconnected loops 220 deposited thereon, either in direct contact or separated by standoffs 224, see FIG. 9.
The embodiment discussed in reference to FIG. 6 has the pickup coil 12 and the detector 30 on a single supporting substrate, and an implementation of this approach is depicted in FIG. 10. A SQUID detector 30 is deposited on the same substrate 222 as the thin film loop 220 that operates as the pickup coil 12. Connecting conductors 226 of the same high-Tc superconducting material connect the thin film loop 220 to the detector 30. A shielding layer 228 of the same high-Tc superconducting material may be deposited underlying the SQUID detector 30 to shield it from the magnetic field. Techniques for depositing thin film SQUID detectors 30 and thin film loops 220 on substrates 222 are known in the art, see for example, U.S. Pat. No. 5,134,117; J. Gao et al., "Controlled preparation of all high-Tc SNS-type edge junctions and DC SQUIDs", Physica, C171, pages 126-130 (1990); R. Gross et al., "Low Noise YBa2 Cu3 O7 grain boundary junction dc SQUIDs", Appl. Phys. Lett., vol. 57(7), pages 727-729 (Aug. 13, 1990); K. P. Daly et al., "Substrate step-edge YBa2 Cu3 O7 rf SQUIDs", Appl. Phys. Lett., Vol. 58(8), pages 548-545 (Feb. 4, 1991); and M. S. DiIorio et al., "Practical high Tc Josephson junctions and dc SQUIDs operating above 85K", Appl. Phys. Lett., Vol. 58(22), pages 2552-2554 (June 1991).
Although in FIG. 10 only a single thin film loop 220 and its associated detector 30 are shown, thin film deposition technology permits large numbers of pickup coils 12 and, where desired, associated detectors SO to be deposited on a single substrate 222. This technology also permits the production of numbers of pickup coils 12 that are placed at different locations within the vessel 16.
Another embodiment, shown in FIG. 11, utilizes two substrates 222 vertically displaced from each other, with a pickup coil 220 and its associated SQUID 30 on each of the substrates 222. The output of one of the SQUIDs 30 is subtracted from the other in a subtraction circuit 223. The difference between the two SQUID signals is a measure of the magnetic field gradient.
It is important that the vessel 16 be properly insulated so that an unacceptably large heat flow into the vessel 16 from the surroundings will not occur. That heat flow would not only drive the superconductors into the normal state, but would also result in discomfort for the subject if a portion of the heat flows from the subject's body. Several configurations have been identified as permitting the pickup coils to be placed closely to the subject while also providing adequate insulation.
FIG. 12 depicts one preferred configuration of the vessel 15, termed the pickup unit 256. The pickup unit 256 has a wall 240 made of a flexible material that maintains its physical integrity at the cryogenic temperature maintained within the vessel 16. A preferred material of construction for the wall 240 is a layered structure formed of sheets of a thin polymeric material such as mylar, and layers of cloth. The pickup coils 12 are affixed to the interior of the wall 240, along a region termed the contact region 242. The pickup coils 12 are placed onto at least one, preferably at least two, and most preferably a plurality of, individual substrates that are affixed to the wall 240 in the contact region 242. The individual substrates and pickup coils are spaced apart a sufficient amount that the wall 240 retains its flexibility.
Packets of insulation 244 such as pieces of polystyrene foam are affixed to the interior of the wall 240. The packets of insulation are fixed to the wall 240 to form a continuous, but flexible, layer in regions apart from the contact region 242, and are interspersed between the pickup coils 12 in the contact region 242. The pickup coils 12 are not insulated from the interior of the vessel 16 by overlying packets of insulation, because the pickup coils 12 must be cooled to their operating temperatures by conduction to the interior of the vessel 16. Individual small packets or pieces of foam are used, rather than a large or continuous piece, so that the vessel retains its flexibility. A portion of the wall 240, away from the contact region 242, could be made of a rigid insulator material, as long as the rigid portion does not prevent the flexible contact region 242 from being operable.
The reduction of heat conduction through the contact region 242 is important, because such heat input has the most direct effect in driving the superconductors of the pickup coils 12 normal, and because that heat comes directly from the body of the subject against which the contact region 242 is pressed, possibly making the subject uncomfortable. To reduce the heat loss through the contact region 242 even further, a number of layers 246 of flexible plastic such as mylar or Kevlar(R) are sealed over the exterior surface of the contact region 242. The edges of the layers 246 are sealed against the wall 240 in a dry environment, to permit insulating air to remain between the layers 246 but to exclude moisture that could freeze to form ice during use of the vessel 16.
An alternative approach, shown in FIG. 13, places each pickup coil 12 in its own insulated housing 250. The insulated housing 250 is constructed from foam insulation such as polystyrene, hollowed out to receive the pickup coil 12. Packets of insulation 244 are affixed to the other interior surfaces of the wall 240. A preferred cooling approach is to direct liquid or gaseous coolant into the interior of the housing 250 through coolant lines 252 and vent the interior of the housing 250 with vent lines 254.
The pickup units 256 can be joined together in arrays. The pickup coils 12 and the detectors 30 are both made from superconductors having a superconducting transition temperature of 77K or above. In the embodiment of FIG. 14, several of the pickup units 256 (in this case with both the pickup coil and the detector therein) are connected together with pieces of tape or sewn strips 257 to form a conformable array that can be assembled in the field, by doctors or scientists to form an "ad hoc" array useful for a particular investigation.
FIG. 15 illustrates another embodiment of the device utilizing a flexible wall for the vessel containing the coolant. The vessel 15 of FIG. 15 includes a rigid wall portion 300 that defines the general configuration of the vessel, here in the form of a helmet to be placed over the head of the subject. A flexible wall portion 302 of the vessel 16 is adapted for contact with the body of the subject, and closes the vessel 15. The flexible wall portion 302 is constructed in the same manner as the flexible walls discussed previously.
The pickup coils 12, preferably made of high temperature superconductors, are attached to pickup coil supports 904. The pickup coil supports 304 are slidably mounted in support tubes 306 fixed to the rigid wall portion 300, with the axis of each tube 306 directed generally inwardly. An inwardly-directed biasing force, provided by a spring 308 in each of the support tubes 306, against the coil supports 904 forces the supports 304 and thence the pickup coils 12 inwardly against the inner wall of the flexible wall 302. The biasing force causes the pickup coil 12 to conform to the shape of the flexible wall 302. When the apparatus is placed into contact with the body of the subject, the flexible wall 302 conforms to the shape of the body. The pickup coils 12 in turn conform to the shape of the flexible wall 302. With this arrangement, the pickup coils 12 may be conformed to fit closely to the shape of the body of the subject.
Coolant is provided to the interior of the vessel 16 through a coolant tube 310, like that discussed previously. Signals from the pickup coils 12 can be processed by integrally mounted SQUID detectors, as in this illustrated approach, and the output signals transmitted on leads 312. Alternatively, the signals from the pickup coils 12 can be transmitted to remotely positioned SQUID detectors maintained at colder temperatures. Packets of insulation 244, like those discussed previously, are affixed to the interior of the flexible wall 302, and optionally the rigid wall 300.
FIG. 16 depicts another embodiment that incorporates several of the previously discussed concepts. The vessel 16 includes a rigid support structure 400 that supports at least one, and preferably several, capsules 402. The walls of the structure 400 are formed of a thermally insulating, nonmagnetic material such as fiberglass, and optionally include internal or external insulating foam packets 404. The interior of the structure 400 is cooled by a flow of coolant, such as a liquefied gas or a cooled gas, from an input line 405, and exhausted by an output line 408. The structure 400 may be provided in any shape, and is here illustrated in the form of a helmet that can fit over the head of a subject.
The capsules 402 each contains at least one pickup coil 12 and, preferably, a detector 30 such as a SQUID for each of the pickup coils 12. Signals from the pickup coil are detected by the detector 30, and the output signals of the detector 30 are transmitted to external electronics through pairs of leads 410. Each capsule 402 may be cooled internally by a flow of coolant, such as a liquefied gas or a cooled gas, from an input line 412 and exhausted by an output line 414. Thus, the capsules may be cooled by conduction from the coolant in the structure 400, directly by coolant supplied by the input line 412, or a combination of the two. The capsules 402 are made from a thermally insulating material such as fiberglass. However, if cooling by conduction from the coolant in the structure 400 is relied upon, the portion of the wall of the capsule 402 contacting the interior of the structure 400 may be made of a thermally conducting material, or have conducting inserts through the wall.
Each capsule 402 is slidably mounted in the wall of the structure 400, with seals 418 preventing leakage of the coolant within the structure 400, if any. Each capsule 402 is resiliently biased inwardly by a spring 418 reacting between the structure 400, preferably its exterior wall, and the capsule 402. This approach permits the vessel 16 having the single-sized structure 400 to be operable for subjects of different sized and shaped heads, and for persons having bandages and the like. Stated alternatively, the inner surfaces of the capsules together constitute a flexible contact face whose position locally adjusts to the underlying body shape responsive to the spring force. The structure 400 is placed over the head and the capsules 402 allowed to relax inwardly in response to the spring force, with the inner end of each capsule 402 contacting the body of the subject. Measurements are then taken in the normal fashion.
The present approach produces completely new results unavailable with conventional dewar-based biomagnetometer systems. The fabrication of both the pickup coils 12 and the detectors 30 from high temperature superconductors (having Tc of 77K or more) permits sufficient insulation to be provided using conventional foam, non-vacuum insulation material such as polystyrene. The coolant can be a readily available, inexpensive coolant such as liquid or refrigerated gaseous nitrogen. In some forms, the entire integrated pickup unit 256 becomes a package weighing less than one pound that can be held in the palm of the hand, as compared with conventional biomagnetometers typically weighing over 70 pounds and being over 4 feet long. The performance of the integrated pickup unit 256 may be limited in some applications by the inability to cool the detector to near-absolute zero to suppress noise, but the convenience of the unit more than makes up for this limitation by providing increased convenience for many other uses.
Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention, Accordingly, the invention is not to be limited except as by the appended claims.
What is claimed is:
1. A biomagnetometer, comprising:a magnetic field sensor unit, the sensor unit including a magnetic field pickup coil made of a material having a superconducting transition temperature; vessel means for containing the magnetic field sensor unit, the vessel means includinga flexible contact face adapted for contacting to a subject whose biomagnetism is to be measured, with the magnetic field sensor unit mounted in the interior of the vessel means adjacent to the flexible contact face, and rigid support structure means for defining the general configuration of the vessel means, the flexible contact face being attached to the support structure means; insulation means at the flexible contact face of the vessel means for preventing excessive heat flow through the flexible contact face; means for cooling the pickup coil to a temperature of less than its superconducting transition temperature; and detector means for receiving an output signal of the pickup coil and for measuring the magnitude of magnetic fields sensed by the sensor unit.
2. The biomagnetometer of claim 1, wherein the vessel means includes a flexible bag.
3. The biomagnetometer of claim 1, wherein the flexible contact face includes a layered structure of a thin polymeric material and cloth.
4. The biomagnetometer of claim 1, wherein the insulation means includes packets of insulation affixed to an interior wall of the vessel means.
5. The biomagnetometer of claim 1, wherein the detector means includes a superconducting quantum Interference device mounted within the vessel means.
6. The biomagnetometer of claim 1, wherein the detector means includes a superconducting quantum interference device mounted outside the vessel means.
7. The biomagnetometer of claim 1, wherein the pickup coil is formed of a material having a superconducting transition temperature of at least about 77K.
8. The biomagnetometer of claim 1, wherein the sensor unit further includesa magnetic field pickup coil support upon which the magnetic field pickup coil is mounted.
9. The biomagnetometer of claim 1, wherein the support structure means comprises a first portion of a wall of a vessel and the flexible contact face comprises a second portion of the wall of the vessel, the support structure means and the flexible contact face together comprising the wall of the vessel containing the magnetic field sensor unit therein.
10. The biomagnetometer of claim 1, further includingbiasing means for forcing the pickup coil against an interior side of the flexible wall portion.
11. The biomagnetometer of claim 1, wherein the vessel means comprisesa support structure, and at least two capsules, each capsule containing at least one pickup coil, with each capsule resiliently mounted to the support structure.
12. A biomagnetometer, comprising:a plurality of pickup units, each pickup unit comprisinga magnetic field sensor unit, the sensor unit including a magnetic field pickup coil made of a material having a superconducting transition temperature, vessel means for containing the magnetic field sensor unit, the vessel means including a contact face adapted for contacting to a subject whose biomagnetism is to be measured, with the magnetic field sensor unit mounted in the interior of the vessel means adjacent to the contact face, and insulation means at the contact face of the vessel means for preventing excessive heat flow through the contact face, means for mechanically interconnecting the plurality of pickup units to form a flexible array that is conformable to the shape of a body of a subject, the means for mechanically interconnecting permitting the plurality of pickup units to flex relative to each other; and detector means for receiving an output signal of the pickup coil and for measuring the magnitude of magnetic fields sensed by the sensor units.
13. The biomagnetometer of claim 12, wherein the vessel means of at least some of the pickup units includes a flexible bag.
14. The biomagnetometer of claim 12, wherein the detector means includes a superconducting quantum interference device for each of the pickup coils, the superconducting quantum interference device being located within each of the respective vessel means.
15. The biomagnetometer of claim 12, wherein each sensor unit further includesa magnetic field pickup coil support upon which the magnetic field pickup coil is mounted.
16. The biomagnetometer of claim 12, further including means for cooling the pickup coils to a temperature of less than their superconducting transition temperatures.
17. The biomagnetometer of claim 12, wherein the pickup coils are formed of materials having a superconducting transition temperature of at least about 77K.
18. The biomagnetometer of claim 12, wherein the contact face is formed of a layered structure of a thin polymeric material and cloth.
19. The biomagnetometer of claim 12, wherein the insulation means includes packets of insulation affixed to an interior wall of the vessel means.
20. The biomagnetometer of claim 12, wherein the means for mechanical interconnecting is a flexible connector.
| 1992-10-27 | en | 1995-08-15 |
US-18264680-A | Stereo signal demodulator having an improved separation characteristic
ABSTRACT
A stereo signal demodulator includes a switching circuit for separating the stereo composite signal into left and right signal components. A composite stereo signal is attenuated in a preset quantity and superimposed upon the left and right signal components after they are separated by the switching circuit. The superimposed signals cancel the crosstalk components, not by switching the composite signal, but only by attenuating the stereo composite signal in the preset quantity. Consequently, the attenuator for reducing the stereo composite signal can be provided separately from the switching circuit for the stereo demodulation. The switching circuit can then be driven by the entire power supply voltage without any DC potential loss caused by the attenuator. Moreover, there is no DC potential loss by the attenuator, and transistors of the stereo switching circuit can operate with a power voltage margin. The distortion-free dynamic range of the output can be widened and the separation factor can be enhanced. The bias voltage of the active elements is also raised, so that the distortion factor characteristics can be improved. The composite signal attenuated in the preset quantity is superimposed upon the demodulated left and right signal components. Thus, it is possible to eliminate the distortion in the attenuated composite signal, and especially to eliminate the distortion in the demodulated output signals.
BACKGROUND OF THE INVENTION
The present invention relates to demodulators and, more particularly, to stereo signal demodulators for demodulating FM (Frequency Modulated) composite stereo signals of pilot tone systems.
An FM composite stereo signal of a pilot tone system, is generally described as a composite signal consisting of a main channel signal, a sub-channel signal, a pilot signal and a SCA (Subsidiary Communication Authorization) signal. The main channel signal is a summation signal (L+R) of left and right audio signals, and the sub-channel signal contains a component of a difference signal (L-R). The sub-channel signal is an AM (Amplitude Modulated) signal of a subcarrier signal (38 KHz) modulated by the difference signal. The pilot signal is a 19 KHz signal and is a reference signal used for the separation of the left and right audio signals. The SCA signal is used for auxiliary communication. However, this SCA signal is a signal component which is not necessary for the stereo demodulation. It is generally removed from the stereo composite signal before the composite signal is supplied to the stereo demodulator. Therefore, the term, "the stereo composite signal" means, hereinafter, the composite of main and sub-channel signals and the pilot signal.
The circuit for separately extracting the right and left signals from this composite signal are mainly two systems, one being a switching-type circuit and the other being a matrix-type circuit.
In the matrix-type circuit, after a filter separates the stereo composite signal into the main channel signal and the sub-channel signal, the sub-channel signal is demodulated by the subcarrier signal of 38 KHz to produce the difference signal (L-R). Those signals (L+R) and (L-R) are summed and subtracted to recover the signals L and R. However, the matrix-type circuit is not used so commonly because the circuit construction is complicated and the operation stability of this type is poor.
According to the switching system, on the other hand, the composite signal is switched so that it is separated into two signals L and R. Since the circuit construction of the switching system is simple and since the operations are relatively stable, the switching system has recently been used almost exclusively.
Although various types of circuits are proposed and used as a demodulator of the switching type, a demodulator using a differential amplifier, as disclosed in U.S. Pat. No. 3,617,641, is generally used because it is easily made in the form of a semiconductor integrated circuit. That is, the composite signal is fed to the common emitter junction of two transistors constituting the differential amplifier. They are separated by supplying a subcarrier frequency signal of 38 KHz to the base of one transistor. The other subcarrier frequency signal has a phase which is opposite to the above subcarrier signal and is supplied to the base of the other transistor.
In this instance, the separated left and right signals have the opposite signal components superposed thereon, more or less, as crosstalk components. A circuit for cancelling those crosstalk signal components is generally added. Thus crosstalk cancelling circuit is designed to attenuate the composite signals so that they have substantially the same signal level as the crosstalk components. The attenuated composite signals are separated into the attenuated left and right signals. The attenuated left and right signals of the separated left and right signals are added to cancel the crosstalk signal components. An example of such a crosstalk cancelling circuit is also described in the above U.S. patent as a circuit of resistors 100, 101 and 102 and transistors 60, 71 and 72.
The attenuation of the composite signal is usually performed by means of a T-type resistor circuit. However, in a stereo demodulator of the switching type, having such crosstalk cancelling circuit, both the attenuation of the composite signals and the separation of the attenuated composite signal are performed by a cascade connected circuit of the T-type resistor circuit; two differential amplifier type switches, and a load resistor. Especially, the T-type resistor circuit is inserted between the emitters of two transistors of the lower positioning different differential amplifier. As a result, the emitters of those transistors have a preset DC potential which is determined by the T-type resistor circuit. Consequently, bias potentials applied to the differential amplifiers, connected in series, have to be set to consider the DC potential, and the active elements, (such as the respective transistors) operate in a linear range. Even if the points described above are considered to set the bias potentials, together with the electric characteristics (such as the distortion factor), a the demodulator having the conventional crosstalk cancelling circuit cannot operate with good characteristics if power supply voltage drops significantly.
A description is now given of the case in which the power supply voltage is reduced or drops significantly. Since a DC voltage loss caused by the T-type resistor circuit is inevitable, the bias voltages applied to the active elements (such as transistors) are accordingly lowered. Thus, the active elements then begin operate in their non-linear regions. In the worst case, the transistors are driven into their saturated regions, and in the signal injecting operation for cancelling the crosstalk components is not accomplished. Then, the separation factor of the demodulation signals deteriorates remarkably. Even if the active elements are operated at a higher supply voltage which is free from a reduction of the separation factor, the margin of the voltage supplied to the active elements is lowered by the DC potential loss of the T-type resistor circuit so that the distorsion factor characteristics of the separated stereo signals deteriorate.
SUMMARY OF THE INVENTION
It is, therefore, a major object of the present invention to provide a stereo signal demodulator which has a demodulated output with improved separation and distortion, even when the power supply voltage is lowered.
Another object of the present invention is to provide a stereo signal demodulator which is suitable for construction on a semiconductor integrated circuit, with a minimum increase in the number of elements.
According to the present invention, a stereo signal demodulator includes: a switching circuit for separating the stero composite signal into left and right signal components. The separated signals are fed to an input terminal, and a circuit respectively superposes a stereo composite signal attenuated by a present amount upon the left and right signal components which are separated by the switching circuit.
According to the stereo signal demodulator of the present invention, the signals superposed on the separated left and right signal components to cancel the crosstalk components are not attained by switching the composite signal. The superposed signals are produced only by a preset attenuation of the stereo composite signal. Consequently, attenuator for reducing the stereo composite signal can be provided separately from the switching circuit for the stereo demodulation. The switching circuit can thus be driven by the entire power of the supply voltage without any DC potential loss caused by the attenuator. Moreover, since no DC potential loss is caused by the attenuator, the respective transistors of the stereo switching circuit can be operated with a power voltage margin, so that the distortion-free dynamic range of the output can be widened and that the separation factor can be enhanced. Still moreover, when the operations of the present invention are accomplished at the same power supply voltage as that of the prior art, the bias voltage to the active elements is also raised, so that the distortion factor characteristics can be improved. Also, since the composite signal attenuated in the preset quantity is superposed upon the demodulated left and right signal components, it is possible to eliminate the distortion in the attenuated composite signal which is caused in the prior art by the switching of the attenuated composite signal, and especially, to eliminate the distortion in the demodulated output signals due to the crosstalk cancelling operation.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings, in which:
FIG. 1 is a circuit diagram showing a stereo signal demodulator of switching type using a differential amplifier according to the prior art;
FIG. 2 is a circuit diagram showing a stereo signal demodulator according to a preferred embodiment of the present invention; and
FIG. 3 is a graphical diagram showing the characteristic curves indicating the power supply voltage to separation factor of the stereo signal demodulator according to the prior art and according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the stereo signal demodulator according to the prior art, shown in FIG. 1, the composite signals are fed to an input terminal 18, which is connected to the base of a transistor 16. The emitter of transistor 16 is connected to a signal attenuator 29 consisting of a T-type resistor circuit network composed of resistors 21 and 22 and a variable resistor 23. The collector of the transistor 16 is connected to the common junction point of the emitters of switching transistors 11 and 12, for separating left and right channel signals from the composite signal. The bases of the switching transistors 12 and 11 are respectively supplied with the sub-carrier signal of 38 KHz, as a switching signal. The sub-carrier is received through switching signal input terminals 24 and 25, to separate the left and right signals from the composite signal. The phases of the switching signals applied to the switching signal input terminals 24 and 25 are opposite to each other. The collectors of the transistors 12 and 11 are respectively connected to right and left signal output circuits 50 and 40 which are current mirror circuits composing of transistors 7, 8 and 27 and transistors 5, 6 and 26, respectively. The outputs of the right and left signal output circuits 50 and 40 are respectively fed to right and left signal output terminals 3 and 2. To the left and right signal output circuits 40 and 50 are supplied a power supply voltage from a power supply terminal 1.
In order to cancel the left and right crosstalk components which are contained in the respective signals appearing at the right and left signal output terminals 3 and 2, there is provided a crosstalk cancellation switching circuit 28 composing of transistors 9, 10 and 13. These transistors 9 and 10 have their respective emitters connected in common. Their collectors are connected to the respective collectors of the transistors 11 and 12. Their bases are connected to the respective bases of the transistors 12 and 11. To the common junction point of the emitters of the transistors 9 and 10 is connected the collector of the transistor 13, which has its emitter connected with the signal attenuator 29. Its base is connected to a ground terminal 4 through a reference voltage source 14.
The operations of the demodulator according to the prior art will be described next. The composite signal is fed to the input terminal 18 and amplified by the transistor 16. The amplified signal is fed from the collector of the transistor 16 to the common junction between the emitters of the transistors 11 and 12. At this time, in response to the switching signal of 38 KHz fed to the switching signal input terminals 24 and 25, the transistors 11 and 12 are repeatedly switched between conductive and inconductive states, in an alternate manner.
Thus, the composite signal amplified by the transistor 16 are subjected to time division by the transistors 11 and 12. As a result, the right channel signal is fed to the right signal output circuit 50 in response to the conduction of the transistor 12, to derive a current output at the right signal output terminal 3, while the left channel signal is fed to the left signal output circuit 40 in response to the conduction of the transistor 11 to derive a current output at the left signal output terminal 2. The transistors 5 and 6 and the transistors 7 and 8, which constitute the current mirror circuits of the signal output circuits 40 and 50, are of PNP type. Therefore, their current gains are low and they might have characteristic deviations caused by their manufacturing condition. However, since the base current of those transistors are increased by the transistors 26 and 27, symmetry is maintained between the generated left and right output signals. Thus, the composite signals are demodulated into a stereophonic signal.
However, the right channel signal contains the crosstalk components of the left channel signal and vice versa, if they remain as they are. The crosstalk causes a deterioration in the separation between the right and left channel signals. In order to cancel those crosstalk components, therefore, there are additionally provided the crosstalk cancellation switching circuit 28 and the signal attenuator 29.
More specifically, the composite signal is applied to emitter of the transistor 16, through the input terminal 18 and is attenuated by a constant amount in the T-type resistor circuit network, which is the signal attenuator 29, composed of the resistors 21, 22 and 23. The attenuated signal is fed through the transistor 13 to the transistors 9 and 10. The crosstalk cancelling signals are superposed upon the right and left signal output circuits 50 and 40 after they are separated by the transistors 9 and 10, as they become conductive and nonconductive. Accordingly, by setting the resistances of the resistors 21, 22 and 23 for suitably attenuating the composite signal, the crosstalk component of the left channel which is contained in the right channel signal and the crosstalk component of the right channel which is contained in the left channel signal can be cancelled. Thus, the separation between the right and left channel signals is enhanced.
With the circuit construction thus far described, however, if the level of the composite signal and the stereo demodulation gain are raised, the separation between the right and left channel signals abruptly deteriorates when the power supply voltage fed to the power supply terminal 1 becomes too low.
Specifically, if the composite signal input voltage level and the demodulation gain are set at 1 vrms and -1 dB, respectively, a current of about 1 mA flows through the collectors of the transistors 6 and 7 and the same current flows through the loads or filter circuits which may be coupled to the signal output terminals 2 and 3. In this case, some potential loss occurs in the T-type resistor circuit network composed of the resistors 21, 22 and 23, so that the DC potential is raised at the junction point of the resistors 21 and 22. Since this DC potential is determined by the attenuation factor of the signal attenuator 29, this potential level is preset at about 0.4 V by selecting the resistances of the resistors 21, 22 and 23, for obtaining the attenuation factor by which the maximum separation is achieved.
Consequently, if an input voltage level of the composite signal is assumed at 1 vrms as described in the above, the composite signal has the maximum amplitude of 1.4 V. The base bias of the transistor 16 has to be higher than 2.6 V if some margin (0.1 V) is taken. Then, the composite signal having the maximum amplitude of 1.4 V swings the 2.6 V base bias of the transistor 16, as the center. Therefore, the base potentials of the transistors 9, 10, 11 and 12 have to be 4.8 V at the minimum if consideration is taken of the collector-emitter voltage of the transistor 16 under its saturated condition of the distortion characteristics of the demodulator. As a result, when the power supply voltage becomes lower than 6 V, the collector-emitter voltages of the transistors 9, 10, 11 and 12 are reduced, so that they are brought into their saturated conditions. Then, the transistors 9 and 10 of the crosstalk cancellation switching circuit 28 become inoperative. The crosstalk cancelling effect is decreased and the separation factor between the right and left channels abruptly deteriorates.
This particular condition is illustrated in FIG. 3. In this Figure, a curve 100 indicates the characteristics of the power supply voltage VCC to the separation factor of the stereo signal demodulator, according to the prior art. As will be understood from the characteristic curve 100, the separation factor is 55 dB if the power supply voltage VCC is higher than 6 V, but separation abruptly deteriorates if the power supply voltage VCC is lower than 6 V. This is because the cancelling effect is decreased due to the reduction of the power supply voltage. Moreover, although the separation factor between the right and left channel does not deteriorate near the power supply voltage of 6 V, the collector-emitter voltages of the transistors 9, 10, 11 and 12 are low because they are about 0.5 V, so that the distortion factor deteriorates responsive to those transistors.
Thus, in the stereo signal demodulator of FIG. 1, according to the prior art, when the input level of the composite signal and the demodulation gain are designed at high levels, the separation abruptly deteriorates with the reduction in the power supply voltage. According to the conventional demodulator, it is impossible to raise the composite signal input level and the demodulation gain while improving the voltage reduction characteristics. In addition, the distortion factor, in the case of the operation at a low power supply voltage, deteriorates. In other words, in the conventional demodulator, it is extremely difficult to set the base bias potentials of the transistors 9, 10, 11, 12 and 16 to satisfy the aforementioned conditions while improving the voltage reduction characteristics.
Next, a demodulator shown in FIG. 2, according to a preferred embodiment of the present invention, will be described. In this stereo signal demodulator, a crosstalk cancellation circuit 35 is connected in parallel with transistor 16 to the input terminal 18 to which the composite signal or the main and sub-channel signals of the composite signal are supplied. Therefore, the attenuator 29 (FIG. 1) which was connected to the transistors 16 and 13 in the prior art circuit can be eliminated. Instead, the emitters of the transistors 16 and 13 can be grounded through resistors 17 and 15, respectively.
The outputs of the crosstalk cancellation circuit 35 are taken from the collectors of transistors 19, 20 and are connected directly to the left channel signal output terminal 2 and to the right channel signal output terminal 3. By this configuration, the composite signal fed into the input terminal 18 is applied to both the base of the transistor 16 and the bases of transistors 19 and 20, which constitute the crosstalk cancellation circuit 35. Between the emitters of the transistors 19 and 20 is connected a T-type resistor circuit network consisting of resistors 30 and 31 and a variable resistor 32. The collectors of these transistors are connected to the left and right channel signal output terminals 2 and 3, respectively. According to this circuit construction, therefore, the transistors 9, 10 and 13, the resistor 15 and the constant voltage source 14 form a DC output current compensation circuit and are not parts of a crosstalk cancellation circuit, which is different from the conventional demodulator shown in FIG. 1.
The operations of the stereo signal demodulator, according to the preferred embodiment of the present invention, will be described next. The demodulated composite signal of the pilot tone system is applied to the input terminal 18, i.e., the composite signal is amplified by the common emitter amplifier of the transistor 16 and the resistor 17. The amplified signal is fed to the common junction point between the emitters of the transistors 11 and 12. These transistors 11 and 12 are repeatedly switched between conductivity and nonconductivity in response to the switching signals of 38 KHz produced from the pilot tone of 19 KHz and supplied to the switching signal input terminals 24 and 25. The amplified composite signal is subjected to time division as transistors 11 and 12 switch on and off. Thus, the composite signal is separated into the right and left channel signals.
More specifically, when the transistor 12 switches on, the right channel signal appears at the right channel signal output terminal 3 responsive to the output current through the output circuit 50, which is composed of the transistors 7, 8 and 27. On the other hand, when the transistor 11 switches on, the left channel signal appears at the left channel signal output terminal 2 responsive to the output current through the output circuit 40, which is composed of the transistors 5, 6 and 26. These left and right channel signals appear at the two channel signal output terminals 2 and 3, respectively, and contain the corsstalk components of the opposite channels, as described hereinbefore.
However, the two channel signal output terminals 2 and 3 also receive the composite signal from the crosstalk cancellation circuit 35, with such a quantity that it can cancel the aforementioned crosstalk components. More specifically, the composite signal fed to the input terminal 18 is applied to the respective bases of the transistors 19 and 20. The composite signal fed to the transistor 16 is attenuated to perform a normal stereo switching action. The signal applied to the transistors 19 and 20 is attenuated by the resistors 30, 31 and 32 connected between the emitters of those transistors in order to generate the signals for the crosstalk cancellation. This attenuated composite signal for the crosstalk cancellation is fed to the left channel signal output terminal 2 and the right channel signal output terminal 3, through the respective collectors of the transistors 19 and 20. Therefore, by suitably setting the resistance values of the resistors 30, 31, 32 and 17, the crosstalk components of the opposite channels contained in the left and right channel signals can be cancelled.
In this demodulator, the resistance values of the resistors 17, 30 and 31 are preferably 1.2 kohms, and 5.1 kohms, respectively. Therefore, it is sufficient that the resistance value of the variable resistor 32 is adjusted to maximize the separation factor. The attenuation quantity for maximizing the separation factor, (i.e., the optimum ratio of the base to collector signal level of the transistor 19 or 20) is k1 =0.1817, if that optimum ratio is assumed to k1. The resistance value of the resistor 32 for obtaining this value of k1 is at about 752 ohms, and then the maximum separation factor can be obtained. Moreover, the range of k which is necessary for attaining the separation factor higher than 50 dB is from 0.1768 to 0.1868. If, in this case, the resistance values of the resistors 17, 30 and 31 are left as they are, it is sufficient for the resistance value of the resistor 32 to be adjusted over the range from 653 ohms to 876 ohms. Thus, the separation factor of the right and left channels is increased.
Incidentally, other combinations of the resistors 17, 30 and 31, can be used. It is sufficient that the resistance value of the resistor 32 is adjusted in accordance with the selected combination. Needless to say, when the separation factor is higher than 40 dB, k=0.1654 to 0.1986 holds, so that the range of the resistance value of the resistor 32 can be widened.
It is not necessary to connect the T-type resistor circuit network composed of the resistors 30, 31 and 32 between the emitters of the transistors 19 and 20. The respective emitters may be alternatively grounded through a single resistor having the resistance value adjusted to cancel the crosstalk components. In this modification, two terminals are required for the respective emitter resistors, so that the embodiment mentioned hereinbefore is more advantageous.
When the composite signal input voltage level and the demodulation gain are respectively assumed at 1 vrms and -1 dB as described in the above, and since the emitter of the transistor 16 is connected to the ground terminal 4 through the resistor 17, the base bias of the transistor 16 may be 2.2 V with a slight margin (0.1 V). Therefore, the voltage level of the reference voltage source 14 may be designed at 2.2 V. Then, the composite signal having the maximum amplitude of 1.4 V swings the base voltage of the transistor 16 from the base bias voltage of 2.2 V. Moreover, if consideration is taken of the collector-emitter voltage of the transistor 16, under its saturated condition and the distortion characteristics of the demodulator, the base potential of the transistors 9, 10, 11 and 12 may be set at 4.4 V.
On the other hand, the crosstalk components appearing at the left and right channel signal output terminals 2 and 3 are cancelled because the output of the crosstalk cancel circuit 35 is respectively fed directly to those terminals 2 and 3. Accordingly, when the power supply voltage fed to the power supply terminal 1 becomes lower than 6 V, the crosstalk of the switching circuit composed of the transistors 11 and 12 is increased. However, the transistors 19 and 20 of the crosstalk cancellation circuit 35 are saturated at a low power supply voltage, as compared to the voltage at which the transistor 11 and 12 are saturated. The crosstalk cancelling operation is maintained even with the reduction in the power supply voltage, at which the transistors 19 and 20 of the crosstalk cancellation circuit 35 are saturated. Consequently, even if the main voltage becomes as low as about 4 V, the separation factor between right and left channels does not abruptly deteriorate. This is because the switching circuit is not connected in series with the crosstalk cancellation circuit 35.
This condition is illustrated in FIG. 3 by a curve 200. Specifically, the separation factor of 55 dB is obtained if the power supply voltage is higher than 6 V. The separation factor of 50 dB can be obtained even when the power supply voltage becomes as low as 4 V.
Moreover, as described hereinbefore, since the base bias potentials of the transistors 16, 11 and 12 can be designed at low levels, their collector-emitter voltages can be increased to the same power supply voltage that is used in the prior art. For instance, for the power supply voltage of 6V, the collector-emitter voltages of the transistors 11 and 12 have a value of 0.9 V, and of the transistor 16 has a value of 2.2 V, so that the distortion factor can be further decreased.
According to this preferred embodiment, the crosstalk cancellation circuit 35 is connected to the input terminal 18 in parallel with the transistor 16. The transistor 16 operates as a common emitter amplifier. The signal attenuator 29 (FIG. 1) is not connected to the emitter of the trasistor 16 (FIG. 2) as in the prior art. By these constructions, the base potentials of the transistor 16 and the transistor 11 and 12 can be easily designed, so that the degree of freedom for the circuit is increased very much. On the contrary, in the conventional demodulator, the base bias of the transistor 16 has to be determined in accordance with both the composite signal input voltage level and the attenuation constant of the signal attenuator 29, so that the degree of freedom for the circuit design is considerably decreased. In addition, since a transistor 16 is used as the common emitter amplifier according to this embodiment, there is such advantage that the input dynamic range can be increased.
According to the stereo signal demodulator of this embodiment, even when the composite signal input level is assumed at 1 vrms and the demodulation gain is as high as -1 dB, the separation factor between the right and left channels is sufficiently high at the power supply voltage of about 4 V. A much lower distortion is achieved for the same power supply voltage. Moreover, the base potentials of the transistor 16 and the switching transistors 11 and 12 can be easily designed. The input dynamic range can also be widened.
As described hereinbefore, according to the present invention, even when the composite signal input level is high and the stereo demodulation gain is also high, it is possible to provide a stereo signal modulator which can have a high separation factor, excellent voltage reducing characteristics, and a reduced distortion factor.
It should be noted here that the present invention should not be limited to the aforementioned embodiment. It can be modified in various forms without departing from the scope and spirit of the present invention. For example, although the resistor 32 is a variable type, in the present embodiment, it may be fixed in accordance with the composite signal attenuation because the attenuation for cancelling the crosstalk components can be easily determined. In addition, the two output circuits 40 and 50 are constructed by current mirror circuits in order to generate the current outputs, but they may have other circuit constructions, such as resistor loads.
Moreover, the present invention can naturally be formed into an integrated circuit, constructed on a single semiconductor substrate. It is suitable for such integration construction because it contains no capacitor element. Moreover the composite signal demodulating means may be not only the differential amplifiers but also diode switching circuits. Furthermore, the transistors 9, 10 and 13, the resistor 15 and the reference voltage source 14 constitute a DC current applying circuit which compensates for the change in the output DC current due to the switching of the transistors 11 and 12. Consequently, if the left and right channel output terminals 2 and 3 are coupled through coupling capacitors to filter circuits or the like of the next stage, the DC current supplying circuit of the transistors 9, 10 and 13, etc. can be eliminated. This is because, even if the aforementioned bias circuit is eliminated, the output signal are transfered to the next stage despite any change in output.
What is claimed is:
1. A stereo signal demodulator comprising an input terminal supplied with a stereo composite signal, a first transistor having a base coupled to said input terminal and an emitter coupled to a reference potential by way of a resistor, switching citrcuit means coupled to receive a collector output of said first transistor and alternately coupled to generate an output signal at its first and second output ends in response to first and second switching signals, said first switching signal having a phase opposite to the phase of said second switching signal, left and right channel output terminals coupled to said first and second output ends of said switching circuit means, respectively, the output signal generated at said first output end of said switching circuit means comprising essentially a left channel signal and a right channel crosstalk signal, the output signal generated at said second output end of said switching circuit means comprising essentially a right channel signal and a left channel crosstalk signal, crosstalk cancellation circuit means having second and third transistors each having a base coupled to said input terminal and a resistor circuit means coupled between emitters of said second and third transistors, an attenuated stereo composite signal being generated at collectors of said second and third transistors, respectively, and means for supplying said attenuated stereo composite signal to said left and right channel output terminals in order to obtain a high channel separation factor between left and right channels.
2. The stereo signal demodulator claimed in claim 1, wherein said resistor circuit means has three resistors forming a T-type resistor circuit network, said T-type resistor circuit network having first and second ends connected respectively to the emitters of said second and third transistors and a third end connected to said reference potential.
3. The stereo demodulator claimed in claim 2, wherein said switching circuit means has fourth and fifth transistors, said fourth transistor having a base supplied with said first switching signal, an emitter coupled to the collector of said first transistor and a collector coupled to said first output end, said fifth transistor having a base supplied with said second switching signal, an emitter coupled to the collector of said first transistor and a collector coupled to said second output end.
4. A stereo signal demodulator comprising an input terminal supplied with a stereo composite signal, a first transistor having a base coupled to said input terminal and an emitter coupled to a reference potential through a first resistor, constant voltage source means for generating a constant voltage at its output end, a second transistor having a base coupled to said output end of said constant voltage source means and an emitter coupled to said reference potential through a second resistor, switching circuit means for receiving a collector output of said first transistor and for generating a first signal comprising a left channel signal and a right channel crosstalk component at a first output end of said switching circuit means and a second output signal comprising a right channel signal and a left channel crosstalk component at a second output end of said switching circuit means, said left and right channel signals being generated in response to a sub-carrier wave signal, a D.C. output current compensation circuit means for receiving a D.C. current flowing through a collector of said second transistor and for alternately generating a D.C. current at said first and second output ends in response to said sub-carrier wave signal, the first output end of said switching circuit means and the second output end of said D.C. output voltage compensation circuit means being coupled to each other, the second output ends of said switching circuit means and the first output end of said D.C. output voltage compensation circuit means being coupled to each other, the D.C. current at the first output end of said D.C. output voltage compensation circuit means being generated when said first signal is generated at the first output end of said switching circuit means, the D.C. current at the second output end of said D.C. output voltage compensation circuit means being generated when said second signal is generated at the second output end of said switching circuit means, crosstalk cancellation circuit means having third and fourth transistors each having a base connected to said input terminal and a resistor attenuation circuit connected between emitters of said third and fourth transistors, for generating an attenuated composite stereo signal at collectors of said third and fourth transistors, left and right channel output terminals coupled respectively to the first and second output ends of said switching circuit, and means for connecting collectors of said third and fourth transistors to said left and right channel output terminals, respectively, in order to supply the attenuated composite signals to said left and right channel output terminals.
5. The stereo signal demodulator claimed in claim 4, wherein said resistor attenuation circuit comprises third, fourth and fifth resistors, said third and fourth resistors being connected in series between the emitters of said third and fourth transistors, said fifth resistor being connected between a connection point of said third and fourth resistors and said reference potential.
6. The stereo signal demodulator claimed in claim 5, wherein said switching circuit comprises fifth and sixth transistors, and said D.C. output current compensation circuit means comprises seventh and eighth transistors, said fifth transistor having an emitter connected to the collector of said first transistor and a collector connected to the first output end of said switching circuit means, said sixth transistor having an emitter connected to the collector of said first transistor and a collector connected to the second output end of said switching circuit means, said seventh transistor having a base connected to a base of said sixth transistor, an emitter connected to the collector of said second transistor and a collector connected to the second output end of said D.C. output voltage compensation circuit, said eighth transistor having a base connected to a base of said fifth transistor, an emitter connected to the collector of said second transistor and a collector connected to the first output end of said D.C. output voltage compensation circuit means, said fifth and sixth transistors being in a conductive state and a nonconductive state alternately in response to said sub-carrier wave signal, said seventh and eighth transistors operating alternately in a conductive state and a nonconductive state in response to said sub-carrier wave signal.
7. The stereo signal demodulator claimed in claim 6, further comprising first and second output circuit means of a current mirror type, said first output circuit means supplying a signal corresponding to said first signal to said left channel output terminal, said second output circuit supplying a signal corresponding to said second signal to said right channel output terminal.
8. A stereo signal demodulator comprising an input terminal supplied with a stereo composite signal, a power supply terminal, a ground terminal, a first transistor having a base coupled to said input terminal and an emitter coupled to said ground terminal by way of a first resistor, reference voltage source means for generating a reference voltage at its output, second transistor means having a base coupled to the output of said reference voltage source and an emitter coupled to said ground terminal by way of a second resistor, first and second switching signal input terminals supplied with a sub-carrier wave signal, the sub-carrier wave signal supplied to said first switching signal input terminal having a phase which is opposite to the phase of the sub-carrier wave signal supplied to said second switching signal input terminal, switching circuit means having third and fourth transistors forming a first differential amplifier, said third transistor having a base coupled to said first switching signal input terminal and an emitter coupled to a collector of said first transistor, said fourth transistor having a base coupled to said second switching signal input terminal and an emitter coupled to the collector of said first transistor, D.C. output current compensation circuit means having fifth and sixth transistors forming a second differential amplifier, said fifth transistor having a base coupled to said first switching signal input terminal and an emitter coupled to a collector of said second transistor, said sixth transistors having a base coupled to said second switching signal input terminal and an emitter coupled to the collector of said second transistor, collectors of said third and sixth transistors being coupled to each other, collectors of said fourth and fifth transistors being coupled to each other, first current mirror output circuit means coupled between the collector of said third transistor and said power supply terminal, second current mirror output circuit means coupled between the collector of said fourth transistor and said power supply terminal, a left channel output terminal coupled to said first current mirror output circuit means, a right channel output terminal coupled to said second current mirror output circuit means, crosstalk cancellation circuit means having seventh and eighth transistors and a resistors circuit, said seventh and eighth transistors each having a base coupled to said input terminal, said resistor circuit having a first end coupled to an emitter of said seventh transistor, a second end coupled to an emitter of said eighth transistor and a third end coupled to said ground terminal, and means for coupling collectors of said seventh and eighth transistors of said left and right channel output terminals, respectively, said switching circuit means receiving the stereo composite signal through the collector of said first transistor and generating a first signal comprising a left channel signal and a right channel crosstalk signal at the collector of said third transistor and a second signal comprising a right channel signal and a left channel crosstalk signal at the collector of said fourth transistor, said switching circuit means operating in response to said sub-carrier wave signal, said D.C. output current compensation circuit means receiving a D.C. current through the collector of said second transistor and generating a first D.C. current at the collector of said fifth transistor and a second D.C. current at the collector of said sixth transistor in response to said sub-carrier wave signal, said crosstalk cancellation circuit means attenuating said stereo composite signal and generating an attenuated stereo composite signal at collectors of said seventh and eighth transistors, whereby a wide input dynamic range, low distortion in left and right channel output signals and a high degree of channel separation are obtained at a low power supply voltage, and further D.C. voltages are maintained constant at left and right channel output terminals.
9. The stereo signal demodulation circuit claimed in claim 8, wherein said resistor circuit comprises third, fourth and fifth resistors, said third and fourth resistors being coupled in series between the first and second ends of said resistor circuit, said fifth resistors being coupled between a common point on said third and fourth resistors and the third end of said resistor circuit.
10. The stereo signal demodulation circuit claimed n claim 9, wherein said first current mirror output circuit means comprises ninth and tenth transistors, and said second current mirror output circuit means comprises eleventh and twelfth transistors, said ninth transistor having an emitter coupled to said power supply terminal and a collector coupled to the collector of said third transistor, said tenth transistor having a base coupled to a base of said ninth transistor, an emitter coupled to said power supply terminal and a collector coupled to said left channel output terminal, said eleventh transistor having an emitter coupled to said power supply terminal and a collector coupled to the collector of said fourth transistor, said twelfth transistor having a base coupled to a base of said eleventh transistor, an emitter coupled to said power supply terminal and a collector coupled to said right channel output terminal, the base and the collector of said ninth transistor being coupled together, the base and the collector of said eleventh transistor being coupled together.
11. The stereo signal demodulation circuit claimed in claim 10, wherein said first current mirror output circuit means further comprises a thirteenth transistor, and said second current mirror output circuit means further comprises a fourteenth transistor, said thirteenth transistor having a collector coupled to said ground terminal and a base and an emitter coupled respectively to the collector and the base of said ninth transistor, said fourteenth transistor having a collector coupled to said ground terminal and a base and an emitter coupled respectively to the collector and the base of said eleventh transistor.
| 1980-08-29 | en | 1983-06-28 |
US-57286890-A | Composite closure with seal proportioning lip
ABSTRACT
A composite closure with a side seal proportioning lip is disclosed, with the closure including an outer plastic closure cap, and a plastic sealing liner positioned adjacent a top wall portion of the cap. The sealing liner includes a central disc-shaped portion, and an integral relatively thick, annular sealing bead portion. The closure is thus configured to effect a "top/side seal" with an associated container. The construction includes an annular liner-retaining lip having a relatively flexible annular inner edge portion which coacts with the sealing bead portion of the liner to self-adjust and proportion the degree of sealing engagement between the sealing bead portion of the liner and the associated container.
TECHNICAL FIELD
The present invention relates generally to closures which can be sealingly fitted to bottles and like containers, and more particularly to a composite closure including an outer plastic closure cap, and an inner plastic sealing liner, with the cap including a deflectable lip which can deform the sealing liner to obtain the desired sealing engagement with an associated container.
BACKGROUND OF THE INVENTION
Packaging arrangements including a bottle or a like container, and an associated closure fitted thereto, are suitable for a wide variety of goods, in particular liquids such as beverages. In this regard, economical and effective closure constructions for containers including carbonated beverages, wherein the contents are pressurized, have proven challenging to perfect.
U.S. Pat. No. 4,378,893, to Wilde, et al., discloses a composite closure construction which has proven to be very commercially successful due to its high degree of suitability for use on containers having pressurized contents. This construction includes an internally threaded, outer plastic closure cap, with a sealing liner fitted in the closure cap adjacent to a top wall portion thereof. U.S. Pat. Nos. 4,343,754 and 4,497,765 disclose methods and apparatus for effecting efficient manufacture of this type of closure.
One particularly advantageous feature of this type of closure is the nature of its sealing arrangement. Specifically, the generally disc-shaped sealing liner of the closure includes an annular sealing bead portion which defines a generally inwardly facing sealing surface. By this arrangement, a so-called "top/side" seal is formed with the associated container, that is, sealing engagement is effected at both the upwardly facing top surface, and outwardly facing side surface of the container.
Experience has shown that the internal gas pressure of a container having a carbonated beverage or the like can act against the inside of the top wall of this type of closure, thereby acting to deform or bow the top wall upwardly. While this cold-flow phenomenon (sometimes referred to as "creep" of the plastic material) can lessen the sealing engagement of the closure with the top surface of the container, the combination top/side seal assures that the side seal is maintained, thus maintaining the sealing integrity of the construction.
Despite the desirable functional characteristics of this construction, certain conditions can detract from its effectiveness. One potential problem concerns the inevitable manufacturing tolerances encountered in container manufacture, wherein a closure may be fitted to either a relatively small or relatively large container. Similar containers made from different materials may also exhibit dimensional differences in their finishes.
The side seal of the closure is generated by compression of the liner material at the inside diameter of the annular sealing bead portion when the closure is applied to a bottle finish. The amount of liner compression is determined by the outside diameter of the bottle finish relative to the inside diameter of the sealing bead portion.
To form an effective seal, the relatively low compression of the liner material at the side seal by a smaller diameter bottle requires that the length (i.e., height) of the side seal be relatively long. In contrast, high compression of the liner material by a relatively large diameter bottle only requires a short side seal length to assure the desired sealing.
Accordingly, it is desirable to provide an arrangement which is configured to change the side seal length depending upon the finish diameter of the container to which the closure is fitted.
In addition to providing the desired degree of sealing engagement between the closure and the associated container, a closure should preferably be configured to facilitate high-speed, automatic application. As noted, a container having a relatively large outside diameter results in relatively high compression of the liner material attendant to closure application, and providing an arrangement which facilitates such application is desirable.
One undesirable result of the compression of the closure liner material can be an extrusion-like deformation of the material so that it tends to move past the annular retaining lip down the side wall of the bottle finish. This can have the undesirable effect of increasing the so-called vent release angle of the closure. Specifically, for threaded closures used on carbonated beverages, it is ordinarily desirable to facilitate the venting of gas pressure from within the container prior to release and disengagement of the closure threads. Under those conditions where the liner material has extruded past the retaining lip, the angle through which the closure must be rotated to release the seal, and thus initiate venting, can be undesirably increased, thereby decreasing the amount of rotation between initiation of venting and disengagement of the threads. Accordingly, it is desirable to minimize such extrusion of the liner material past the retaining lip.
Finally, it is generally desirable to enhance the efficiency of closure manufacture. As disclosed in the above-noted patents, closures of the subject type are formed by in situ compression molding of the liner material by depositing a pellet of molten plastic in the closure cap, and thereafter compressing and molding the molten material so that it flows against the annular liner retaining lip and forms the sealing liner.
To assure that the lining material is confined generally within the region defined by the annular lip, the use of an annular sleeve, which fits about the liner-shaping molding plunger, is preferred. This annular sleeve engages the annular lining retaining lip as the liner material is molded, thereby acting to confine the material as desired.
Problems can arise when attempting to line relatively hot and pliable closure caps. Experience has shown that under these conditions, the liner material can be forced past the relatively pliable retaining lip of the closure cap, resulting in plastic "flash" around the lip. This is undesirable because it can undesirably increase the vent release angle of the closure, and detracts from the aesthetic aspects of the construction.
With consideration of the above design problems, the present closure has been particularly configured to provide the desired degree of sealing for closures exhibiting varying diameters within normal tolerances, while at the same time providing consistent venting characteristics. High-speed manufacture and application are desirably accommodated.
SUMMARY OF THE INVENTION
In accordance with the present invention, a composite closure is disclosed which includes an outer plastic closure cap having an annular liner-retaining lip, and a plastic sealing liner positioned adjacent a top wall portion of the closure. Notably, the annular lip of the closure cap is configured to deform the sealing liner to thereby provide a self-adjusting or self-proportioning cooperation with the liner attendant to application to a container, whereby the degree of sealing engagement with the associated container is automatically varied. At the same time, the configuration of the lip promotes high-speed application by acting to guide the closure onto the container, with the arrangement further facilitating consistent high-speed manufacture and lining of the closure.
The composite closure of the present invention includes a plastic outer closure cap having a top wall portion, an annular skirt portion depending from the top wall portion, and an annular liner-retaining lip which projects inwardly from the annular skirt portion in closely spaced relation to the top wall portion. In the illustrated embodiment, the skirt portion includes an internal thread formation, and a plurality of axially extending vent grooves to facilitate the release of gas pressure when the closure is fitted to a container having carbonated contents.
The closure further includes a plastic sealing liner positioned adjacent the top wall portion which is retained in the closure cap by the annular lip. The sealing liner is preferably compression molded in situ to a disc-shaped configuration, and includes an annular sealing bead portion positioned adjacent the annular lip. The annular sealing bead portion defines a generally inwardly facing sealing surface, with the liner thus configured to provide a so-called top/side seal with an associated container. The side sealing action is provided by the engagement of the inwardly facing sealing surface of the bead portion with the associated container.
In accordance with the present invention, the annular lip of the closure cap is configured to coact and cooperate with the annular bead portion of the liner to provide a self-adjusting or self-proportioning action. Specifically, the annular lip is deflectable so as to deform the annular sealing bead portion of the liner, and thereby proportion the degree of sealing engagement of the inwardly facing sealing surface of the bead portion with the associated container. This effect is achieved by configuring the annular lip to include a relatively flexible and deflectable inner edge portion which can move and flex under the influence of a container having a sufficiently large diameter so as to engage this portion of the annular lip.
In the illustrated embodiment, the annular lip further includes a relatively inflexible base portion positioned adjacent the skirt portion of the closure cap, with the deflectable inner edge portion extending inwardly of the base portion. By deflection of the inner edge portion relative to the skirt portion of the closure, the bead portion of the sealing liner is deformed. In this manner, a relatively large container (which subjects the liner to high compression) acts to deform the liner and shorten the length of the side seal, while a relatively smaller container (which subjects the liner to relatively low compression) subjects the lip to little or no deflection, whereby a relatively long side seal is formed.
In the preferred form, the annular lip of the closure cap facilitates high-speed closure application. To this end, the lip defines an annular guide surface facing generally away from the top wall portion of the closure, with this surface acting to guide the closure onto the container for sealing engagement of the inwardly facing sealing surface with the container. In the illustrated embodiment, this guide surface is provided on the deflectable, inner edge portion of the annular lip, and is of a frusto-conical configuration so that the surface converges inwardly toward the top wall portion of the closure.
To further facilitate application, the sealing liner of the closure preferably defines a frusto-conical annular surface which extends between the free edge of the deflectable inner edge portion of the annular lip, and the inwardly facing sealing surface of the bead portion of the liner. In the preferred form, this annular surface of the liner converges inwardly toward the top wall portion at the same angle as the guide surface of the annular lip, and is preferably adjacent and abutting to the lip guide surface so that the annular surface of the liner is a continuation thereof. In the most preferred form, the two frusto-conical annular surfaces collectively define a generally continuous frusto-conical surface, which acts in a ramp-like fashion to guide the closure onto the container and establish the desired sealing engagement between the inwardly facing sealing surface of the liner and the container.
Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view in partial cross-section of a composite closure embodyinq the principles of the present invention;
FIG. 2 is a fragmentary, relatively enlarged view illustrating the side seal proportioning lip of the present composite closure;
FIGS. 3 and 4 are views similar to FIG. 2 illustrating the manner in which the seal proportioning lip of the present construction cooperates with containers having varying dimensions;
FIG. 5 is a view similar to FIG. 2 illustrating the manner in which the seal proportioning lip of the present construction facilitates high-speed closure application, particularly to a relatively large container;
FIG. 6 is a view similar to FIG. 5 further illustrating application of the present closure to a relatively large container; and
FIG. 7 is a fragmentary view illustrating formation of the present composite closure.
DETAILED DESCRIPTION
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
With reference now to FIG. 1, therein is illustrated a composite closure 10 embodying the principles of the present invention. As will be further described, the closure 10 is particularly configured for use in connection with an associated container C, such as a bottle or the like, and is particularly effective for use with carbonated beverages or like pressurized contents.
A composite closure embodying the present invention may be formed in accordance with the teachings of U.S. Pat. Nos. 4,343,754 and 4,497,765, which are incorporated herein by reference. In accordance with the teachings of these patents, composite closure 10 can be efficiently formed by compression molding, including compression molding of the outer plastic closure cap, and in situ compression molding of the sealing liner of the construction.
In the illustrated embodiment, closure 10 includes a generally cup-like plastic closure cap or shell 12 having a circular top wall portion 14, and a cylindrical, annular skirt portion 16 depending from the top wall portion. Skirt portion 16 is preferably provided with an internal thread formation 18, which is configured to mate with a like thread formation on an associated container C.
In the illustrated embodiment, the closure 10 includes a tamper-evident feature, comprising an annular pilfer band 22 depending from skirt portion 16. The pilfer band includes a plurality of inwardly extending flexible projections 24 which are configured to coact with the finish of the container C during removal of the closure from the container. The pilfer band 22 is distinguished from the skirt portion 16 of the closure by a circumferentially extending score line 26 which extends through the side wall portion of the closure cap. The pilfer band 22 is at least partially detachably connected to the skirt portion 16 by a plurality of circumferentially spaced frangible bridges 28 which extend between the inside surfaces of the skirt portion and the pilfer band. A tamper-evident feature such as illustrated can be formed in accordance with the teachings of U.S. Pat. No. 4,418,828. Alternately, a pilfer band may be configured in accordance with the teachings of U.S. Pat. No. 4,938,370.
Composite closure 10 is composite in nature in that it includes the outer closure cap 12, and a sealing liner 30 which is preferably compression-molded in position in the closure cap 12. The sealing liner is configured to create a so-called "top/side seal" in association with the container C. Such a seal effects sealing engagement with both the generally upwardly facing surface of the container C, as well as with the generally outwardly facing surface thereof. This type of seal has proven particularly effective with containers having carbonated contents, since even though internal gas pressure (acting against the inside top surface of the closure) can affect the sealing engagement of the liner at the top of the container, the sealing integrity of the arrangement at the side of the container is maintained.
To provide this type of sealing arrangement, the sealing liner 30 includes a generally disc-shaped central portion 32, and an integral, relatively thick annular sealing bead portion 34. The sealing bead portion 34 defines a generally vertical, generally inwardly facing sealing surface 36 which effects the side seal of the closure, with the central portion 32 providing the desired top seal.
In accordance with the present invention, the closure cap 12 includes an annular liner-retaining lip 38 which projects inwardly from the annular skirt portion 16 of the closure in closely spaced relation to the top wall portion 14. A plurality of circumferentially spaced gussets 40 can be provided extending between the skirt portion 16 and the annular lip to enhance the rigidity of the base portion of the annular lip 38. As will be further described, annular lip 38 has been particularly configured in accordance with the principles of the present invention to provide a self-adjusting or proportioning action by deforming the sealing liner 30 (as generally illustrated in phantom line in FIG. 2), whereby the degree of sealing effected by the inwardly facing side seal surface 36 is automatically varied when fitted to containers having varying dimensions.
As noted, the present type of closure has proven effective on containers having carbonated contents, in part because the construction can accommodate the normal manufacturing tolerances which result in varying dimensions for containers to which the closures are fitted. Ordinarily, such varying dimensions are accommodated by subjecting the sealing liner of the closure to either a lesser or greater degree of compression during application. Application is facilitated by the formation of a frusto-conical surface on the sealing liner which extends between its inwardly facing sealing surface and the associated annular lip.
The closure of the present invention is configured to further enhance the performance of this type of closure when fitted to containers exhibiting normal manufacturing dimensional tolerances. To this end, the annular lip 38 has been specifically configured in a generally compound configuration, including a relatively rigid and inflexible base portion 42 adjacent the skirt portion of the closure, and a relatively flexible inner edge portion 44 extending inwardly of the base portion 42.
The inner edge portion 44 is relatively thinner in cross-section than the base portion 42, and has a generally inwardly tapering or converging shape. By virtue of the rigidification of the base portion 42 by the gussets 40, the inner portion 44 tends to flex and deform, relative to the base portion, generally at the inner junctions of the gussets with the lip 38. Thus, in the illustrated construction including gussets 40, the flexible inner portion 44 of the lip 38 is generally defined as that portion of the lip extending inwardly of the gussets.
In the preferred form, the inner edge portion 44 defines a frusto-conical guide surface 46 (FIGS. 2, 3) which faces generally away from the top wall portion 14 of the closure cap, and converges inwardly toward the top wall portion. Most preferably, the sealing liner 30 includes a frusto-conical annular guide surface 48 (FIG. 2) which also converges inwardly toward the top wall portion and is preferably configured generally as a continuation of the annular guide surface 46, whereby the guide surface 46 and the guide surface 48 collectively define a frusto-conical surface.
The self-adjusting and proportioning action of the present sealing construction is illustrated in FIGS. 3 and 4. In FIG. 3, the present closure is illustrated being fitted to a container C having a relatively small outside diameter, with the original configuration of the sealing liner 30 being illustrated in phantom line.
As will be observed, the relatively low degree of interference between the relatively small container and the sealing liner 30 results in relatively light compression of the liner at both its top and side sealing regions. In view of this, it is preferred that a relatively long (referring to the axial extent) side seal be formed. This is achieved since the annular lip 38 is dimensioned so that compression and deformation of the sealing liner 30 takes place with little or no engagement of the container with the annular lip 38, and thus little or no deformation of the liner by deflection of edge portion 44.
FIG. 4 illustrates the manner in which the present closure acts to proportion the degree of sealing engagement of the inwardly facing sealing surface 36 of the liner 30 with a container having a relatively large outside diameter. Again, the original disposition of the sealing liner (and annular lip) are illustrated in phantom line.
In view of the relatively high degree of interference which is created between this large container and the sealing liner, it is preferred that a relatively short seal length be created between the inwardly facing surface 36 and the outwardly facing surface of the container. This is achieved by the coaction of the container with the relatively flexible outer edge portion 44 of the annular lip 38, which in turn acts to shape and deform the annular sealing bead portion 34 of the liner 30.
Specifically, and as illustrated in FIGS. 5 and 6, application of the closure to this relatively large container results in engagement of the container with the relatively flexible outer portion 44 of the annular lip, which in turn initiates compression and deformation of the liner prior to engagement of the liner with the container. By this action, the side sealing surface at 36 is effectively shortened, with compression of the liner by both the annular lip and the container acting to force the lining material toward the center of the closure. The eventual result is illustrated in FIG. 4. It will be noted by comparison to FIG. 3, that the engagement of the inwardly facing surface 36 is significantly less with the relatively large container of FIG. 4 than with the relatively small container of FIG. 3.
Several other advantages provided by the present sealing construction should be noted in FIGS. 4-6. The preferred provision of annular guide surfaces 46 and 48 assist in guiding the closure into position for the desired sealing engagement with the container C. The guide surface 46 of the relatively flexible inner edge portion 44 of the annular lip desirably acts to compress and shape the liner as the closure is applied, with the preferred frusto-conical configuration providing the desired action.
In view of this action, a sufficiently large entrance angle for accommodating the relatively large container is automatically created at the sealing surface 36, thereby obviating the need to form the annular surface 48 of the liner with a steeply sloped configuration. Resort to relatively steeply angled lead-in surfaces on the liner can be counterproductive. A steep angle results in a relatively short, low compression side seal on a small container, and a relatively long, high compression seal on a large container, contrary to the desired effect, which is achieved with the present invention. The illustrated arrangement thus acts to assure the desired application and engagement, even though the physical interference and friction between the container and the closure may be relatively high.
As noted, the present construction functions such that during application to a relatively large container, the resultant high compression of the liner material acts to displace the liner material generally toward the center of the closure. The engagement between the relatively flexible inner edge portion of the annular lip 38 and the container desirably acts to provide a relatively tight hoop seal to confine the liner material in the region at which the side and top seals are intended to be formed. This arrangement desirably acts to abate and prevent any extrusion of the liner material downwardly between the annular lip and the container finish, which extrusion can sometimes occur in known constructions. Such extrusion can act to increase the degree of rotation which is required for releasing the seal of the closure (sometimes referred to as the vent release angle) thereby decreasing the degree of rotation between initiation of gas venting, and disengagement of thread formation 18 from the container threads. Since gas venting is preferably completed prior to disengagement of the threads, the present construction desirably acts to assure that venting is initiated when intended, thereby acting to assure completion of venting prior to thread disengagement.
A further advantage of the present construction concerns in situ liner formation. Liner formation is effected by depositing a molten pellet of liner-forming material in the closure cap, preferably with the top wall portion 14 positioned downwardly, with the liner material thereafter compressed to mold it to the configuration of the liner. During this process, a central liner-forming plunger is employed, with a concentric sleeve disposed thereabout for engagement with the annular lip of the closure.
Experience has shown that in current forms of the present type of composite closure, the outer closure cap is preferably cooled for a relatively extended period prior to in situ liner formation. Ordinarily, attempts at lining closure shells while they are still relatively hot from the molding operation can result in plastic flashing around the annular lip of the closure shell, which is believed to result from the lip being pliable and not sufficiently cool as to exhibit sufficient rigidity to resist the liner-forming pressures without undesired deformation.
As illustrated in FIG. 7, the configuration of the present closure cap 12, including the compound annular lip 38, desirably addresses this problem by providing relatively greater surface area for the molding tooling T to seal against, with the lip acting to redirect the flow of molten liner material inwardly. It is believed that this causes some of the liner material to prematurely "freeze off" or solidify before the end of the liner-shaping process. The molten liner material following the solidified material meets with more resistance as it compresses toward the annular lip 38, and the associated liner forming tooling sealing surfaces. Thus, manufacturing efficiency is enhanced, since the need for an extended cooling period for the outer cap prior to lining is avoided.
From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. No limitation with respect to the specific embodiment illustrated herein is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.
What is claimed is:
1. A composite closure for a container, comprising:an outer closure cap having a top wall portion, an annular skirt portion depending from said top wall portion, and annular liner-retaining lip means projecting inwardly from said annular skirt portion in closely spaced relation to said top wall portion; and a sealing liner positioned adjacent said top wall portion and retained by said annular lip means, said sealing liner including an annular sealing bead portion positioned adjacent said annular lip means and having a generally inwardly facing sealing surface, said lip means defining an annular guide surface means facing generally away from said top wall portion for guiding said closure onto the associated container for sealing engagement of said inwardly facing sealing surface with the associated container, said sealing bead portion of said liner defining an annular surface extending between said annular guide surface means and the inwardly facing sealing surface of said bead portion, said guide surface means converging inwardly and upwardly toward said top wall portion, said annular surface of said sealing liner converging inwardly and upwardly toward said top wall portion and comprising a continuation of the inwardly converging annular guide surface means of said annular lip means to define a frusto-conical surface therewith.
2. A composite closure for a container, comprising:an outer closure cap having a top wall portion, an annular skirt portion depending from said top wall portion, and annular liner-retaining lip means projecting inwardly from said annular skirt portion in closely spaced relation to said top wall portion; and a sealing liner positioned adjacent said top wall portion and retained by said annular lip means, said sealing liner including an annular sealing bead portion positioned adjacent said annular lip means and having a generally inwardly facing sealing surface, said lip means being deflectable to deform said annular sealing portion of said liner to thereby proportion the degree of sealing engagement of said inwardly facing sealing surface of said liner with the associated container, said annular lip means comprising a base portion positioned adjacent said skirt portion, and a relatively flexible and deflectable inner edge portion extending inwardly of said base portion, said inner edge portion being deflectable relative to said skirt portion upon engagement with the associated container for deforming said sealing bead portion of said liner, said annular lip means defining an annular guide surface facing generally away from said top wall portion, said guide surface converging inwardly and upwardly toward said top wall portion, and being engageable with the associated container.
3. A composite closure in accordance with claim 2, whereinsaid sealing bead portion of said liner defines an annular surface extending between said annular guide surface of said lip means and the inwardly facing sealing surface of said bead portion.
4. A composite closure in accordance with claim 2, whereinsaid inner edge portion of said lip means is relatively thinner than said base portion and has a generally inwardly tapering shape.
5. A composite closure in accordance with claim 2, includinga plurality of circumferentially spaced gussets extending between said skirt portion and said annular lip means, said relatively flexible inner edge portion comprising that portion of said lip means extending inwardly of said gussets.
6. A composite closure for a container, comprising:an outer closure cap having a top wall portion, an annular skirt portion depending from said top wall portion, and annular liner-retaining lip means projecting inwardly from said annular skirt portion in closely spaced relation to said top wall portion; and a sealing liner positioned adjacent said top wall portion and retained by said annular lip means, said sealing liner including an annular sealing bead portion positioned adjacent said annular lip means and having a generally inwardly facing sealing surface, said lip means being deflectable to deform said annular sealing portion of said liner to thereby proportion the degree of sealing engagement of said inwardly facing sealing surface of said liner with the associated container, said annular lip means comprising a base portion positioned adjacent said skirt portion, and a relatively flexible and deflectable inner edge portion extending inwardly of said base portion, said deflectable inner edge portion having an upwardly and inwardly converging annular surface facing generally toward said top wall portion and engaging said annular sealing bead portion of said liner, said inner edge portion being deflectable relative to said skirt portion upon engagement with the associated container for deforming said sealing bead portion of said liner.
7. A composite closure in accordance with claim 6, whereinsaid annular lip means defines an annular guide surface facing generally away from said top wall portion, said guide surface converging inwardly and upwardly toward said top wall portion, and being engageable with the associated container.
8. A composite closure in accordance with claim 7, whereinsaid sealing bead portion of said liner defines an annular surface extending between said annular guide surface of said lip means and the inwardly facing sealing surface of said bead portion.
9. A composite closure in accordance with claim 6, whereinsaid inner edge portion of said lip means is relatively thinner than said base portion and has a generally inwardly tapering shape.
10. A composite closure in accordance with claim 6, includinga plurality of circumferentially spaced gussets extending between said skirt portion and said annular lip means, said relatively flexible inner edge portion comprising that portion of said lip means extending inwardly of said gussets.
| 1990-08-27 | en | 1991-11-12 |
US-11497593-A | Palatable balanced amino acid-modified diet
ABSTRACT
In the present invention, L-amino acids comprise the medical food which provides a source of protein-equivalent of free purified L-amino acids in a palatable powdered form which can be incorporated into a liquid beverage or into proprietary low-protein solid food products without adversely affecting the organoleptic qualities of these foods. The mixture can act to deliver a protein-equivalent in heretofore unavailable and, thereby, novel ways. Some important considerations contributing to the value of the composition of the L-amino acids and the process by which the amino acid-modified diet is administered are: a protein-equivalent as low in total L-amino acid elements as is nutritionally safe, in quantities to balance the amino acid contributions from the natural foods with up to 100% of certain unpalatable L-amino acids: L-glutamic acid, L-asparatic acid, L-arginine, and L-methionine, replaced by their more palatable counterparts: L-glutamine, L-asparagine, L-citrulline, and L-cystine, respectively; and a dietary prescription which assigns the medical food intake on the basis of both energy and protein needs remaining after the low protein natural foods and proprietary products are accounted for.
RELATED APPLICATION
This is a Continuation of application Ser. No. 07/742,855 filed Aug. 8, 1991, now abandoned, which is a Continuation-in-Part of U.S. Ser. No. 07/433,714, filed Nov. 9, 1989, abandoned.
BACKGROUND OF THE INVENTION
This invention relates to amino acid-modified diets, specifically to the composition and administration of an amino acid-modified medical food for patients with certain rare inborn errors of amino acid metabolism in which treatment using medical foods is efficacious; those disorders characterized by enzymatic defects in the degradative pathways of one or more essential amino acids.
BACKGROUND OF THE INVENTION
A rare disorder is defined by the Orphan Drug Act as one that "affects fewer than 200,000 persons in the United States or that affects more than 200,000 persons in the United States and for which there is no reasonable expectation that the costs of developing and making available in the United States a treatment for such disease will be recovered from sales in the United States" (The Orphan Drug Act, Publ Law 97-414, Jan. 4, 1983). The group of disorders known as the inborn errors of amino acid metabolism meet the first criterion of a rare disorder. An estimated 5,000 persons with inborn errors of amino acid metabolism have been identified in the U.S. and followed by treatment programs (Schuett, 1990). Each of these disorders, when untreated, will produce irreversible mental retardation which is largely preventable when affected individuals are administered amino acid modified diets.
The principle of an amino acid-modified diet as a treatment modality for this group of disorders is to ameliorate the biochemical imbalances which result from the amino acid(s) primarily involved. By the process of substrate reduction, one or more offending amino acid substrate(s) are substantially lowered to meet essential nutritional requirements, thereby constituting a severe reduction which comprises 70-95% of total protein requirements.
Strict adherence to the protein-restricted diet eliminates nearly all foodstuffs of animal origin (meat, poultry, fish, milk, eggs, and their products); places severe limits on grains, cereals, and starchy foodstuffs (wheat, corn, rice, potatoes, and their products which include flours, breads, and baked goods), and, thereby, reduces natural foodstuffs to a liberal consumption of relatively few foods, those naturally low in protein (fruits, some vegetables, pure fats and sugars). Without nutritional supplementation, a diet limited to the allowed natural foods would severely compromise protein nutriture and would provide inadequate energy, vitamins, and minerals to support normal growth and development. Therefore, in order to apply the process of substrate reduction to a safe treatment for persons with these disorders, alternative means of nutrition support have been developed, using "medical foods."
The term medical food is defined as "a food which is formulated to be consumed or administered internally under the supervision of a physician and which is intended for specific dietary management of a disease for which distinctive nutritional requirements, based on recognized scientific principles, are established by medical evaluation" (Sec 5, Orphan Drug Act 21 U.S.C. 360 ec). Amino acid-modified mixtures developed to meet the challenges of nutrition support for patients with inborn errors of amino acid metabolism are recognized as examples of medical foods (American Academy of Pediatrics--Committee On Nutrition, 1987). These medical foods have been created primarily to supply protein to patients with these disorders, in a form known as a "protein equivalent," which is purposefully and markedly deficient in one or more essential amino acids. Each protein-equivalent comprises all of the remaining essential amino acids and supplies additional nitrogen from nonessential amino acids. The medical foods incorporate energy from carbohydrate and/or lipid and supply those vitamins and minerals recognized to be essential for humans.
Heretofore, a variety of medical-foods have been developed and implemented for treating inborn errors of amino acid metabolism. When administered to patients as the major source of protein and energy, in combination with natural foods which are carefully prescribed in amounts to supply the essential amount of the offensive amino acid(s), biochemical control of the disorder may be achieved. The amino acid,modified diet has, therefore, revolutionized the treatment and clinical outcomes of certain of these rare disorders.
Phenylketonuria (PKU), a disorder of the essential amino acid, phenylalanine, is the more prevalent and intensively studied of this group of rare disorders. PKU afflicts one in 10,000 U.S. born infants and the U.S. treatment program population with PKU was estimated to comprise 4,100 patients in 1988 (Schuett, 1990). Medical foods with a low phenylalanine content were developed for infants with PKU in the late 1950s and have served as prototypes for the development of medical foods for PKU and other amino acid disorders, largely due to their successes when administered to infants and young children. However, unanticipated problems in the continued acceptance of these products in later childhood and adolescence, with subsequent losses of biochemical control and reductions in intellectual progress, have arisen as the amino acid-modified diet has been applied to persons with PKU for longer periods. A 1988 survey of U.S. PKU treatment programs suggests that more than 40% of persons with PKU by eight years of age are no longer adhering to the dietary treatment, in spite of a consensus among the majority of programs to continue the treatment indefinitely (Schuett, 1990).
The strong and unpleasant organoleptic qualities of low-phenylalanine medical foods are well known to those skilled in the art of administering these foods and are assumed to be an obligatory characteristic of a protein-equivalent (Sarrett and Knauff, 1985). As used in this patent application, the term "organoleptic" refers to the sensory qualifies of foods: tastes, odors, and textures. Low-phenylalanine medical foods have not generally been thought of as foods or beverages in the commercial sense and, heretofore, improving their organoleptic qualities has received little interest by academia or industry. However, medical foods constitute the main food experience for persons who consume them, they do have organoleptic qualities, and, moreover, these qualities affect their acceptance or rejection. With prolonged use, refusal of medical foods as a result of their strong tastes and unwanted odors (Kitagawa et al., 1987) and/or their gritty textures (Francis, 1987( Schuett, 1991 ) has resulted in a need to develop new products and novel ways to deliver a protein-equivalent, energy, and other essential nutrients with acceptable organoleptic qualities for patients as they grow older.
Heretofore, two methods have been applied in the U.S. to create a low-phenylalanine protein-equivalent: 1) Enzymatic or chemical hydrolysis of an existing protein, with subsequent removal of phenylalanine; and 2) Formulation of a combination of purified L-amino acid elements, without the addition of phenylalanine. Both processes yield relatively unpalatable medical foods which are prepared as powders and administered as pastes or as liquid beverages. A third method, developed in Japan, is reported to yield a better tasting protein-equivalent in the form of a low-phenylalanine peptide (LPP) (Kitagawa et al., 1987). Thirty-two healthy subjects found the LPP to be significantly more palatable than conventional low-phenylalanine medical foods. However, only one subject reported "liking" the taste of the LPP. Moreover, 15 of 19 children with PKU, 11/2 to 10 years of age, reported the taste of the LPP as "bad", none of the children liked LPP better than the conventional medical foods, and four of the children refused to take the LPP (Kitagawa et al., 1987). These data, along with a reported cost of the LPP which is three to four times higher than that of conventional low-phenylalanine medical foods, have reduced the feasibility of this method and, hence, no medical food comprising a protein-equivalent in this form has been made available on a commercial scale in the U.S.
There are separate nutritional problems besetting prior amino acid-modified diet compositions and the processes used in their administration which have exacerbated the high costs and undesirable organoleptic qualities associated with these diets. These problems become more troublesome at the age when medical foods, like infant formulas, no longer serve as the sole source of nutrition, a process which begins at approximately six months of age when solid natural foods are added to the diet.
Low-phenylalanine medical food compositions have been formulated to supply at least 100% of the requirements for essential nutrients, except phenylalanine and energy, and the recommended method for the administration theoretically ensures the practitioner that they achieve this (Acosta, 1989; Matalon and Matalon, 1989; Francis, 1987). Two erroneous and, heretofore, unrecognized assumptions are associated with this use of a low-phenylalanine diet, thereby reducing its operability beyond early infancy. First, natural foods are assumed to provide little or no contribution to essential amino acid requirements, with the exception of phenylalanine, thereby placing an inappropriately high emphasis on the amino acid contribution of medical foods. Second, the protein-energy density in natural foods is assumed to enable a simultaneous adherence to the severely low natural food protein restriction and the relatively high energy prescription, thereby placing an inappropriately low emphasis on the energy contribution of medical foods. A third related and erroneous, albeit recognized (Francis, 1987), assumption is that a low-phenylalanine protein-equivalent, by its synthetic nature and theoretically low nutritional value, needs to be administered in an amount which yields a total protein intake in excess of standard requirements for nearly all healthy persons; in the U.S., the Recommended Dietary Allowances (RDA) (Acosta, 1989; Matalon and Matalon, 1989). Kindt et al. (1983) showed this assumption to be erroneous in a group of one to two year olds who maintained adequate growth, nutritional status, and biochemical control of PKU over a two year period during which they received the RDA level of protein, primarily as a low-phenylalanine protein-equivalent.
A critical parameter for evaluating the nutritional value of dietary proteins is the essential amino acid composition. By a procedure well-known to those skilled in the art of administering amino acid-modified diets, amino acid scoring, the content of each essential amino acid in a dietary protein (or mixture of proteins) is expressed as a percentage of the same amino acid in the same quantity of protein (generally the milligrams of amino acid per gram of protein) selected as the reference standard. The essential amino acid showing the lowest percentage is referred to as the nutritionally limiting amino acid. The evaluation is thereby dependent upon the reference protein standard chosen. The current recommended standard for the evaluation of the nutritional value of food proteins for persons of all ages is the 1985 Food and Agriculture Organization-World Health Organization-United Nations University essential amino acid requirement pattern for preschool-aged children (FAO, 1990). This pattern suggests that a protein of high nutritional value comprises 22% of the total amino acids as essential amino acids, a substantially lower percentage than the infant pattern of 43% of the total amino acids as essential amino acids (FAO-WHO-UNU, 1985).
All of the prior art products comprise a full complement of the essential amino acids, except phenylalanine. For protein-equivalents derived from hydrolysis of a protein, much of the amino acid pattern of the native protein may be retained. However, the hydrolysis of cow's milk protein (casein), which is the process used in the manufacture of the first developed and most widely administered U.S. product for infants, Lofenalac® (Mead Johnson, Evansville, Ind.), results in partial conversion of the amide forms of the nonessential amino acids glutamine and asparagine, to their unpalatable dicarboxylic acid forms, glutamic acid and aspartic acid, respectively (Buist, Prince et al. 1991, in press). Free L-amino acid mixtures, which can be formulated to any desired amino acid pattern and is the process used in the manufacture of the most widely administered U.S. product for children and adolescents, Phenyl-Free® (Mead Johnson, Evansville, Ind.), have incorporated the unpalatable glutamic acid and aspartic acid forms preferentially over glutamine, asparagine, or other more palatable amino acids, thereby creating unduly unpalatable mixtures.
Nayman et al. (1979) has recommended that human milk serve as the reference standard protein for medical foods used to treat inborn errors of metabolism. While human milk is a reference standard for human infant nutrition which has not been improved upon, its amino acid composition has not been shown to be optimal beyond infancy. The prior work of Kitagawa et al. (1987) is the first to offer a rationale for the composition of a low-phenylalanine protein-equivalent, which they specify was based on the amino acid pattern of cow's milk formulas available for infant feeding. Because the protein-equivalent was administered to children of all ages, this composition contradicts the most recent FAO/WHO recommendations that a protein of high nutritional value comprise the reference standard essential amino acid pattern for preschoolaged children (FAO, 1990). Moreover, the manufacture of the majority of formulations appears to be a matter of practical convenience or economic advantage. This is particularly apparent for the nonessential amino acids, for which there is no reference protein standard, and which show a much wider range among the various low-phenylalanine protein-equivalents than the essential amino acids. For example, Phenyl-Free® comprises a protein-equivalent devoid of L-alanine ($60/kg wt), L-proline ($85/kg wt), and L-serine ($145/kg wt), with relatively large quantities of L-glycine ($11/kg wt) (1990 L-amino acid price list, Ajinomoto USA, Torrance, Calif.), in spite of the work by Harper et al. (1970) which suggests that amino acid imbalances and adverse effects on growth can occur using synthetic proteins over prolonged periods, compromising disproportional intakes of amino acids regardless of their essentiality. Moreover, there is some evidence to suggest that the levels of individual nonessential amino acids influence both the total protein and essential amino acid requirements of humans (Kies, 1974).
The current approach to the administration of the low-phenylalanine diet is to prescribe the natural foods in the amounts estimated to meet the essential phenylalanine requirement; medical foods are prescribed to provide a protein-equivalent in excess of the estimated protein requirement (100-130% above the protein RDA); and additional "free-foods" which are limited to table sugar, jams, jellies, shortening, and candies, are prescribed to meet the remaining estimated energy requirement. The provisions are made for adequate phenylalanine and protein intakes, with an erroneous assumption that adequate energy intakes will follow. Matalon and In Matalon (1989), the daily use of low-phenylalanine proprietary products to help satiate children is recommended, thereby reducing the likelihood of the over consumption of higher-phenylalanine natural foods to meet energy requirements. This process, however, has not been taught by these authors nor by other prior art references which constitute the protocols currently used to administer amino acid-modified diets in the U.S. (Acosta, 1989; Matalon and Matalon, 1989) and in Europe (Francis, 1987).
Link (1990) focused on vitamin and mineral intakes. This approach was not applied to protein and energy. The author computed adequate total protein and energy in a group of adolescents with PKU. However, the sources of energy are not described and the computed mean natural protein intake (19-23 g/day) would have exceeded estimated amounts (5-15 g/day) to maintain biochemical control of PKU (Acosta, 1989; Matalon and Matalon, 1989). The data suggest that energy needs were met, but presumably from natural foods, thereby exceeding phenylalanine requirements. The implication of this report, as well as the experimental work leading to this invention, is that as children with PKU grow older and absolute energy requirements increase, additional energy will need to come from the medical foods and/or low-protein proprietary products which are nearly devoid of phenylalanine.
SUMMARY OF THE INVENTION
The prior art addresses the three components comprising the amino acid-modified diet for persons with PKU; however, the method of administration of these components does not in concept nor in practice balance the overall protein and energy intake. It is heretofore unrecognized that each component has an inherent protein to energy density: 1) low-phenylalanine medical foods which are relatively high in protein and low in energy; 2) low-phenylalanine natural foods which are relatively low in protein and low in energy; and 3) very low or no-phenylalanine proprietary products which are very low in protein and relatively high in energy (Francis, 1987).
Heretofore, prior art has also not recognized medical foods as "foods" which can be used to meet energy needs and to provide satiety to the otherwise highly-restricted, relatively low in energy and satiety and, thereby, unappealing natural foods. On the contrary, medical foods that are concentrated in their protein-equivalent content and supply little or no energy from carbohydrate or fat are used for persons with PKU beyond infancy. Their recommended administration, beginning at age one year is in a small volume, as a "medicine" (Francis, 1987). The theory behind this approach is twofold. First, since the medical foods are unpalatable, the smaller the volume, theoretically the easier these products are to consume. Second, because the medical foods are relatively low in energy, a wider range of natural foods or low-protein proprietary products can be allowed (Francis, 1987). The applicability of this theory is reduced as persons with PKU grow older, absolute energy needs increase, and it becomes increasingly challenging to meet energy requirements from natural foods without exceeding phenylalanine requirements.
In the present invention, L-amino acids comprise the medical food which provides a source of protein-equivalent of free purified L-amino acids in a palatable powdered form which can be incorporated into a liquid beverage or into proprietary low-protein solid food products without adversely affecting the organoleptic qualities of these foods. The mixture can act to deliver a protein-equivalent in heretofore unavailable and, thereby, novel ways. Some important considerations contributing to the value of the composition of the L-amino acids and the process by which the amino acid-modified diet is administered are: a protein-equivalent as low in total L-amino acid elements as is nutritionally safe, in quantities to balance the amino acid contributions from the natural foods with up to 100% of certain unpalatable L-amino acids: L-glutamic acid, L-asparatic acid, L-arginine, and L-methionine, replaced by their more palatable counterparts: L-glutamine, L-asparagine, L-citrulline, and L-cystine, respectively; and a dietary prescription which assigns the medical food intake on the basis of both energy and protein needs remaining after the low protein natural foods and proprietary products are accounted for.
A major objective of the present invention was to create a cost-effective low-phenylalanine protein-equivalent possessing acceptable organoleptic qualities compared with previous medical foods and which could, thereby, be made available on a commercial scale and be used for prolonged periods. In experimental work leading to the present invention, taste-tests of solutions comprising the 20 L-amino acids found in protein-equivalents led to the identification of three particular L-amino acids with the strongest unacceptable tastes in isolation and which were incompatible with other L-amino acids when combined as mixtures (Buist, Prince et at. 1991, in press). The relative unpalatability of these particular L-amino acids, L-aspartic acid, L-glutamic acid, and L-methionine, is not new and was disclosed by Winitz in U.S. Pat. No. 3,701,666 issued Oct. 31, 1972 which claims a process for improving their palatabilities in a complete diet composition administered as an aqueous solution. To be useful beyond infancy, a low-phenylalanine medical food does not require a complete diet composition nor a liquid diet form because the persons for whom such a medical food is intended are able to eat solid natural foods which contribute some nourishment.
The present invention obviates the taste problems associated with L-amino acids by a novel design. All L-amino acids are supplied in the lowest amounts compatible with nutritional balance, accounting for their contributions from allowed natural foods. For those amino acids with more organoleptically acceptable (better in taste, odor, texture) nutritionally equivalent forms, these forms are used preferentially to replace their less palatable counterparts in up to 100% of the mounts determined to be nutritionally necessary in a medical food. The overall composition which incorporates these principles was introduced to 12 persons with PKU, 2-12 years old. Described as "good" in taste, it was accepted by all subjects and is currently being tested for its long-term nutritional and biochemical safety and efficacy in these subjects during a two year clinical research trial (National Institutes of Health Research Award, Gnt. No. 1 R01 H0 26360-01, MRDD).
A second objective of the present invention was to create a low-phenylalanine protein-equivalent composition which yields a high nutritional value and, moreover, a process of administration of the protein-equivalent which results in the lowest estimated safe intake of L-amino acids.
To create a protein-equivalent of high nutritional value, experimental studies leading to the present invention evaluated the essential and nonessential amino acid intakes of six healthy school-aged children who were experiencing adequate growth and of eight school-age children with PKU who were adhering strictly to the dietary treatment. The mean individual essential and nonessential amino acid intakes were computed as milligrams of amino acid per gram of protein (Prince, Buist, Leklem, 1991 b). The essential amino acids in the natural foods consumed by the children with PKU were evaluated relative to the 1990 FAO reference standard and the nonessential amino acids in the diets of the PKU children were compared to intakesof the healthy subjects. The differences comprise the amino acid pattern of the present invention, with the exception of phenylalanine which is devoid in the invention. This composition has not been previously disclosed and offers two distinct advantages over prior art compositions of amino acid-modified protein-equivalents: 1) It accounts for both natural foods and nonessential amino acids and, thereby, is based on the total diet as consumed rather than on the essential amino acids in the medical food as a single protein; and 2) It provides a strategy, with experimental support, for reducing the levels of L-amino acids in a protein-equivalent of high nutritional value. Twelve patients are currently receiving the protein-equivalent as a part of total protein intakes which are planned to provide 100% of the protein RDA. Adequate dietary and plasma amino acid levels, growth, and blood chemistries suggest acceptable protein nutriture.
Using this same concept, a third advantage to the present invention is in its method of use to balance protein, amino acid, and energy intakes. To gain insight into the energy and protein necessary in a low-phenylalanine medical food designed for patients beyond infancy, experimental work assessed the separate contributions of medical foods and natural foods to the total protein and energy intakes of a sample of 15 children and adolescents with PKU (Prince, Buist, Leklem, submitted for publication 1991a). In support of the prior art by Link (1990), the individuals with PKU achieved adequate overall energy and protein intakes, but with excess energy and protein contributed by natural foods, resulting in unacceptable biochemical control for 11 of the 15 patients. Although unrecognized by the prior art of Link and others and, therefore, not obvious to those skilled in the art, these data which led to the present invention suggest that the assumption that the current method for administration of the overall diet can meet energy needs without excess protein and phenylalanine is not valid for school-aged individuals. Therefore, what is needed from a medical food is not only a protein-equivalent, essential vitamins and minerals, but also energy. Experimental work leading to the present invention suggests that a palatable L-amino acid mixture can be compatible with the very low or no-protein proprietary products which offer a substantial source of low-phenylalanine energy. Blinded taste-tests of baked goods made from these products (Wel-Plan Baking Mix®, Dietary Specialities, New York) fortified with the L-amino acid mixture composition of the present invention have been well-received by healthy controls and patients, thereby offering novel ways to deliver a low-phenylalanine protein-equivalent and energy.
The L-amino acid mixture which comprises the present invention represents the first medical food for school-aged children and adolescents with PKU which can be used to yield a palatable and balanced modified diet with respect to total amino acid, protein, and energy intakes.
More specifically this invention is directed to a balanced palatable modified diet for patients with inborn errors of essential amino acid metabolism. The invention comprises (a) natural foods which are unbalanced or limited for the patients due to deficiencies in essential amino acids, energy and protein; and (b) a protein-equivalent of a plurality of L-amino acids and a medical food or a low protein proprietary product capable of supplying energy formulated to at least an amount required to fortify the limiting deficiencies of essential amino acids, energy and protein in the unbalanced natural foods. Typically, the protein-equivalent of a plurality of L-amino acids are palatable in nature.
The protein-equivalent of L-amino acids can include from about 0 to 99% by weight of L-glutamic acid and from about 1 to 100% of L-glutamine based on the total combined weight of L-glutamic acid and L-glutamine. In that case, the L-glutamine replaces the L-glutamic acid in the protein equivalent of L-amino acids. The protein-equivalent of L-amino acids can also include from about 0 to 99% by weight of L-aspartic acid and from about 1 to 100% of L-asparagine based on the total combined weight of L-aspartic acid and L-asparagine. In that case, the L-asparagine replaces the L-aspartic acid in said protein equivalent of L-amino acids. In another instance, the protein-equivalent of L-amino acids includes from about 0 to 99% by weight of L-arginine and from about 1 to 100% of L-citrulline based on the total combined weight of L-arginine and L-citrulline, wherein the L-citrulline replaces the L-arginine in the protein equivalent of L-amino acids. A further alternative for the protein-equivalent of L-amino acids includes from about 0 to 99% by weight of L-methionine and from about 1 to 100% of L-cystine based on the total combined weight of L-methionine and L-cystine, so that the L-cystine replaces the L-methionine in the protein equivalent of L-amino acids. Moreover, the protein-equivalent of L-amino acids can comprise an amount of L-glutamine which will replace from about 1 to 100% weight of L-glutamic acid in the protein-equivalent of L-amino acids, and/or an amount of L-asparagine which will replace from about 1 to 100% weight of L-aspartic acid in the protein-equivalent of L-amino acids, and/or an amount of L-citrulline which will replace from about 1 to 100% weight of L-arginine in the protein-equivalent of L-amino adds, and/or an amount of L-cystine which will replace from about 1 to 100% weight of L-methionine in the protein-equivalent of L-amino acids.
The protein-equivalent of L-amino acids can be formed by the acetylation or the esterification of the plurality of L-amino acids. This acetylated or esterified product provides modifications in the taste and texture qualities of the L-amino acid constituents.
The subject invention also contemplates a method for producing a balanced palatable modified diet for patients with inborn errors of essential amino acid metabolism. This method comprises (a) providing natural foods which are unbalanced or limited for said patients due to deficiencies in essential amino acids, sources of energy and protein; and (b) combining with said natural foods a palatable protein-equivalent of a plurality of L-amino acids and a medical food capable of supplying sources of energy formulated to at least an amount required to fortify the limiting deficiencies of essential amino acids, energy and protein in said natural foods. In a preferred method, prior to providing the natural foods to the patient, the amount of natural foods which a patient can tolerate is determined by analyzing the blood amino acid level of the patient. It is then compared to the amount of the amino acid in the natural foods. Based on the amount of natural foods which the patient can tolerate, the amount of protein equivalent and medical food to provide to the patient is determined.
Further objects and advantages of the invention will become apparent from a consideration of the following examples and description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The L-amino acid mixture comprises a protein-equivalent, the composition and administration which will fortify low protein natural foods and proprietary products consumed by persons with inborn errors of amino acid metabolism for which nutritional treatment using an amino acid-modified protein-equivalent and medical foods is efficacious. It is intended that the L-amino acid mixture be incorporated into a variety of liquid or solid food forms as medical foods, thereby balancing the intake of individual amino acids, protein, and energy from low protein natural foods and proprietary products.
The method of use of protein-equivalents, medical foods, natural foods, and proprietary products for persons with the PKU disorder, is described by the prior art (Acosta, 1989; Matalon and Matalon, 1989; Francis, 1987). It is to be understood that the methods and steps used in the composition and administration of the present invention do not incorporate a similar philosophy and that the balanced palatable modified diet will require the new protein-equivalent amino acid composition disclosed in this application. Accordingly, administration of this invention would be by practitioners appropriately trained in its use.
The protein-equivalent is comprised of purified L-amino acids. It should be understood that those skilled in the pertinent art appreciate that individual L-amino acids differ in their organoleptic and nutritional qualities and that practitioners also understand that there are hypothetical "reference proteins" of high quality containing specified patterns of amino acids against which single proteins or a combination of proteins may be evaluated (FAO, 1990). The amino acid proportionality pattern of a protein is considered to be the most important determinant of protein quality (FAO, 1990) and is expressed as a score, derived from the amino acid scoring procedure as amino acid ratios (mg of amino acid in 1 g test protein/mg of the same amino acid in 1 g reference protein) of nine essential amino acids plus tyrosine and cystine. The reference pattern recommended by the 1989 FAO/WHO Expert Consultation on Protein Quality Evaluation for all persons aged one year and older contains (mg amino acid/g protein): histidine, 19; isoleucine, 28; leucine, 66; lysine, 58; methionine plus cystine, 25; phenylalanine plus tyrosine, 63; threonine, 34; tryptophan, 11; valine, 35. The lowest single amino acid ratio is termed the "amino acid score" for the protein and the corresponding amino acid is the "apparent limiting amino acid" in the protein.
In Example 1 of Appendix A, the amino acid scoring procedure is used to compare the essential amino acid pattern of the test U.S. diet (FAO, 1990) and the test amino acid-modified diet (Prince, Buist, Leklem, 1991b) against the recommended reference pattern. The U.S. Food and Nutrition Board subcommittee on the 10th edition of the RDA (FNB, 1989) recommended use of the reference pattern presented in Example 1 for the formulation of special purpose diets in clinical practice. Example 1 shows that there are differences between the essential amino acid pattern of the test U.S. diet and the test amino acid-modified diet, relative to the reference pattern, heretofore unrecognized.
The amino acid-modified diet for persons with inborn errors of amino acid metabolism represents a special purpose diet in its formulation. When the protein-equivalent portion of the diet is comprised of free L-amino acids, the amino acid composition is maximally flexible. Prior art has not disclosed the food group proportions comprising the natural foods which contribute some essential and nonessential amino acids and, thereby, protein to the amino acid-modified diet. Strict adherence to the natural protein restriction would eliminate nearly all of the food groups which supply significant amounts of protein to the average U.S. diet (meat, fish, poultry, 48%; dairy, 17%; eggs, 4%) (USDA, 1983, 1986, 1987), thereby altering the levels and sources of amino acids. Without actual data to describe the reported consumption pattern for the special subpopulation of individuals who consume low-protein natural foods, formulation of a protein-equivalent which would be nutritionally compatible with the levels and sources of amino acids in those foods was heretofore impossible. These data are disclosed in this patent application, illustrated in Example 1, as the essential amino acid pattern of the natural low-protein food intakes reported by eight school children with PKU who were strictly adhering to the prescribed amino acid-modified diet (Prince, Buist, Leklem, 1991b). The ultimate choice of the L-amino acids employed in this invention is a result of these data which were derived from the experimental work done in its development. This approach is in accordance with the current state of protein quality evaluation (FNB, 1989; FAO, 1990) even though its value has not been recognized heretofore by those skilled in the art of designing and administering protein-equivalents for inborn errors of amino acid metabolism. As shown in Example 1, the total essential amino acid proportion of the reference protein is approximately 34 percent of the total amino acid nitrogen (339 mg of each 1 g protein). The remaining amino acid nitrogen can be comprised of nonspecific nitrogen from nonessential amino acids or from essential amino acids fed in excess of need. The reported composition of both the U.S. diet and the natural foods in the amino acid-modified diet supply some of this as essential amino acids, which comprise 42 percent and 39 percent of the total amino acid nitrogen, respectively (See Example 1 ). The remainder is supplied mostly as nonessential amino acids for which no U.S. diet reference pattern has been heretofore disclosed.
To ignore the level and sources of the nonessential amino acids in a chemically-defined protein-equivalent is not in concept with the state of knowledge of the nutritional value of dietary proteins. Nitrogen balance, the classical approach to estimating requirement levels of dietary protein and adequacy of various protein sources, has been shown to be subject to rather drastic changes by source-level variations in dietary supplements of nonessential amino acids (Kies, 1974).
In a novel approach to providing a balanced intake of nonessential amino acids relative to essential amino acids and usual dietary consumption patterns, the choice of the nonessential amino acids employed in this invention was based on the pattern of intake of health, children.
Example 2 in Appendix B, the amino acid scoring procedure is used to compare the nonessential amino acid pattern of the test amino acid-modified diet (Prince, Buist, Leklem, 1991b) against the reference healthy diet pattern (Prince, Buist, Leklem, 1991b). Example 2 shows that there are differences between the nonessential amino acid pattern of the reference diet which constitutes the reported food intakes of six healthy school children (Prince, Buist, Leklem, 1991b) and the test amino acid-modified diet, heretofore unrecognized. The total (essential and nonessential) amino acid intakes are similar between the healthy diet and the amino acid-modified diet, approximately 93 and 94 percent, respectively, when the data from Example I (essential amino acid intake patterns) and Example 2 (nonessential amino acid intake patterns) are combined. There is 6 to 7 percent of the total protein unaccounted for, presumably as other forms of nonspecific nitrogen.
As discussed hereinabove, the composition of the protein component of the palatable balanced modified diet is one of the key aspects of the invention. The specific amino acid composition for this protein-equivalent is important for its operability with respect to achieving the objectives of this invention, relative to palatability and protein quality. The procedure used in the design of the protein-equivalent is illustrated in Example 3 in Appendix C. This composition will work because it accounts for the essential and nonessential amino acids which comprise natural food intakes, it adjusts for the heretofore disclosed organoleptic qualities of particular L-amino acids, and thereby provides a palatable balanced amino acid-modified diet. However, other possible modifications in keeping with the invention disclosure and in the patent claims may be used. In particular, the Example 3 illustrates the composition of a low-phenylalanine protein-equivalent; a similar procedure used to define the amino acid composition could be applied to any disorder of amino acid metabolism, whereby one or more offensive amino acids could be reduced in a protein-equivalent. Likewise other forms of L-amino acids, through the techniques of acetylation and esterification, could be employed to improve palatability or solubility of compounds. For instance, as an example of acetylation, the substitution of L-tyrosine with N-acetyl-L-tyrosine can be conducted. Adjustments in the amino acid pattern of the protein-equivalent may also be necessary to maintain consistency with improvements in the so-called reference protein.
The advantages to the subject composition are illustrated in Example 4 in Appendix D which compares the L-amino acid profiles of conventional low-phenylalanine protein equivalents and of this invention to the reference protein. The amino acid score of the palatable balanced protein-equivalent is improved to 1.00 when combined with natural foods and both sources of amino acids are administered according to the procedure.
Protein synthesis, breakdown, and thus requirements by the body are energy-dependent and thereby sensitive to dietary energy deprivations (FNB, 1989). Administration of a protein-equivalent without concern for adequate energy intake and balance between natural and medical foods overlooks this critical relationship. Prior art has not provided an approach to the administration of the low-phenylalanine diet which ensures the practitioner nor the consumer of the diet that the combination of the diet components: natural foods, proprietary products, and medical foods will achieve the necessary biochemical control of the disorder through the severe natural protein restriction and simultaneously achieve adequate energy intake to promote utilization of the dietary protein. For healthy persons, with adequate energy intake, the safe level of protein intake is reduced below the level necessary if energy intake is inadequate. There are no data to suggest these relationships do not apply to persons who must consume a portion of their protein and energy as medical foods.
As discussed hereinabove, the source-level of the energy component of the palatable balanced amino acid-modified diet is one of the key aspects of the invention. It is desirable to reduce the protein-equivalent to its lowest safe level of intake, thereby providing the lowest levels of unpalatable elements in the diet at the lowest cost (the average cost of L-amino acids is $70/kg, 1990 L-amino acid price list, Ajinomoto USA, Torrance, Calif.). The low-phenylalanine energy sources which are available are more palatable and less expensive than low-phenylalanine protein-equivalents. The specific composition of low-phenylalanine energy is not as critical as its source and level, but all of these factors are important for the operability of this protein-equivalent with respect to achieving the objectives of this invention, relative to its method of use and the provision of a total diet balanced in its amino acid, protein, and energy components. Food consumption data for the United States indicate that approximately 16% of the total food energy of healthy persons is derived from protein (USDA, 1983). This is termed the protein-energy ratio (P:E) and when expressed as a percentage is: PE ratio %=protein (g/100 g)×[(4×100)/food energy (kcal/100 g)]. Despite wide variations in food energy intake, this ratio remains similar for both sexes in all age groups (Pellett, 1990). The ratio in the U.S. diet at approximately 16% is well above the reference ratios of 7-11% which are considered to constitute a dietary intake sufficient in protein relative to energy (Pellett, 1990).
The energy component of the amino acid-modified diet is comprised of natural foods, proprietary products, and conventional medical foods. It should be understood that those skilled in the pertinent art appreciate that the individual diet components differ in their P:E ratios and that practitioners also understand that the ratio of protein to energy in a diet is a useful indicator of protein sufficiency (Beaton and Swiss, 1974). However, the prior art has not discussed the P:E ratio comprising the natural foods and proprietary products which contribute both protein and energy to the amino acid-modified diet. Strict adherence to the natural protein restriction would reduce the sources of energy in the diet, a concept not previously discussed by practitioners. Without actual data to describe the P:E ratios of the natural foods and proprietary products consumed by persons with PKU or other such disorders, formulation of a medical food which would be nutritionally compatible with the P:E ratio of the natural diet was heretofore impossible. These data are disclosed in this patent application and are a result of our novel approach in examining the natural diet contributions of protein and energy, quite separate from the medical food contributions.
A primary objective of the low-protein natural foods and proprietary products in an amino acid-modified diet is to supply natural protein at a level to meet the essential requirement for the offensive amino acid. Secondary objectives include providing energy and variety to the diet. The primary objective of the protein-equivalent and the medical foods by which it is delivered is to supply protein at a level to meet at least 100% of the requirement for all the remaining essential amino acids, and at least 100% of the requirements for protein, vitamins, and minerals (Acosta, 1989). The amount of energy to be supplied by medical foods, as described herein, has not been previously disclosed.
The administration of this invention uses a novel approach in that the primary objective of the protein-equivalent and the medical foods is to supply energy at a level to meet 100% of the total energy requirement once the energy intake from prescribed natural foods is accounted for. In order to administer the medical foods using this procedure, the practitioner must examine the P:E ratio of the natural diet. As discussed hereinabove, the administration of the palatable balanced amino acid-modified diet is one of the key aspects of the invention. It is an object of the present invention to provide a method of use of amino acid-modified protein-equivalents and medical foods which will assure a palatable balanced total diet. Example 5 in Appendix E demonstrates the procedure by which the P:E ratio of one medical food has been formulated for a hypothetic 8-year-old male with PKU, using the protein-equivalent disclosed in this invention. The short-term safety and efficacy of the invention has been demonstrated both clinically and biochemically in 12 persons with PKU who will continue to consume the medical food on a long-term basis (1990 Annual Progress Report, National Institutes of Health Research Award, Gnt. No. R01 H0 26360-01, MRDD).
The list of components and their amounts given in Example 6 in Appendix F comprise the elements of the medical food and natural foods for a daily diet of a hypothetic 8-year-old male with PKU, to result in a total balanced amino acid-modified diet. Other variations are possible. For example, adding the L-amino acid mixture to the low-protein starches used to make breads and pastas.
Having illustrated and described the principles of our invention in a preferred embodiment thereof, it should be readily apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles.
REFERENCES CITED
U.S. Patent Documents
U.S. Pat. No. 3,701,666 October, 1972 Winitz 99/1
Other Publications
Acosta P. B. Protocol 2: nutrition support of children, adolescents, and adults with phenylketonuria (PKU) using Maxamaid-XP® medical food for phenylketonuria or Maxamum-XP® medical food for phenylketonuria. In: Acosta P. B. (ed), The Ross Metabolic Formula System Nutrition Support Protocols 1989 (pp 9-17); Columbus, Ohio: Ross Laboratories.
American Academy of Pediatrics, Committee On Nutrition (1987). Evaluation of new products used in the dietary treatment of infants, children, and pregnant women with metabolic disorders. Evanston, Ill.: American Academy of Pediatrics.
Beaton G. H., Swiss L. D. Evaluation of the nutritional quality of food supplies: prediction of "desirable" or "safe" protein.; calorie ratios. Am J Clin Nutr 1974; 27: 485-504.
Buist N. R. M., Prince A. P., Huntington K. L., Tuerck J. M., Powell B. R., Waggoner D. D. Approaches to the dietary management of hyperphenylalaninemia. In: Desnick R. J. (ed) Treatment of Genetic Diseases 1991; New York: Churchill Livingstone.
Codex Alimentarius Commission Document Alinorm (89/30) 1989. Rome, IT: Food and Agriculture Organization.
Food and Agriculture Organization of the United Nations (FAO). Report of the Joint FAO/WHO Expert Consultation on Protein Quality Evaluation 1990: 1-66.
Food and Agriculture Organization, World Health Organization, United Nations University 1985. Energy and protein requirements: report of a joint FAO/WHO/UNU expert consultation (Tech Rpt Ser No. 724). Geneva, SZ: World Health Organization.
Food and Nutrition Board (FNB). Recommended dietary allowances, 10th ed. 1989. Washington, D.C.: National Academy Press.
Francis, D. E. M. Phenylketonuria. In: Francis D. E. M. (ed). Diets for Sick Children, 4th ed 1987 (pp 224-261 ); Boston, Mass.: Blackwell Scientific Publications.
Kies K. Comparative value of various sources of nonspecific nitrogen for the human. J Agr Food Chem 1974; 22: 190-193.
Kindt E., Motzfeldt K., Halvorsen S., Lie S. O. Protein requirements in infants and children: a longitudinal study of children treated for phenylketonuria. Am J Clin Nutr 1983; 37: 778-785.
Kitagawa T., Owada M., Aoki K., Arai S., Oura T., Matsuda I. et al. Treatment of phenylketonuria with a formula consisting of low-phenylalanine peptide: a collaborative study. Enzyme 1987; 38: 321-327.
Link R. Phenylketonuria diet in adolescents--energy and nutrient intake--is it adequate? Postgraduate Med J 1989; 65 (suppl 2): 521-524.
Matalon K., Matalon R. Nutrition support of infants, children, and adolescents with phenylketonuria. Metab Curr 1989; 2: 9-14.
National Institutes of Health Research Award, Gnt. No. 1 R01 H0 26360-01, MRDD.
Nayman R., Thomsen M. E., Scriver C. R., Clow C. L. Observations on the composition of mill-substitute products for the treatment of inborn errors of amino acid metabolism. Comparisons with human milk. Am J Clin Nutr 1979; 32: 1279-1289.
Nutrition and Diet Services:(NDS) 1988. Computerized nutrient analysis database for 1800 foods in the U.S. diet; Milwaukie, Oreg.
Pellett P. L. Protein requirements in humans. Am J Clin Nutr 1990; 5a: 723-727.
Prince A. P., Buist N. R. M., Leklem J. E. Contribution of natural foods and medical foods to protein and energy intakes in phenylketonuria, (submitted for publication) 1991a.
Prince A. P., Buist N. R. M., Leklem J. E. An alternative approach to the nutritional treatment of school-aged patients with phenylketonuria based on tastes, intakes, and plasma levels of amino, acids, (submitted for publication) 1991b.
Sarrett H. P., Knauff K. H. Development of special formulas for the dietary management of inborn errors of metabolism. In: Wapnir R. A. (ed). Congenital Metabolic Diseases 1985 (pp 169-185); New York: Marcel Dekker.
Schuett V. E. National survey of treatment programs for PKU and selected other inherited metabolic diseases (DHHS Publ. No. HRS-MCH-89-5). Rockville, Md.: U.S. Govt Printing Office.
Schuett V. E. National PKU News 1991; 3: 8, 10, 11.
United States Department of Agriculture (USDA) 1976-1987. The composition of foods: raw, processed, and prepared (Revised agriculture handbook no. 8-1 to 8-16). Washington, D.C.: U.S. Government Printing Office.
United States Department of Agriculture (USDA) 1983. Nationwide Food Consumption Survey 1977-78. Food Intakes: Individuals in 48 States, Year 1977-78. Report No. I-1. Consumer Nutrition Division, Human Nutrition Information Service. U.S. Department of Agriculture (pp 1-617); Hyattsville, Md.
United States Department of Agriculture (USDA) 1984. Nationwide Food Consumption Survey. Nutrient Intakes: Individuals in 48 States, Year 1977-78. Report No. 1-2. Consumer Nutrition Division, Human Nutrition Information Service. U.S. Department of Agriculture (pp 1-439); Hyattsville, Md.
United States Department of Agriculture (USDA) 1986. Nationwide Food Consumption Survey. Continuing Survey of Food Intakes by Individuals. Men 19-50 Years, 1 Day, 1985. Report No. 85-3. Nutrition Monitoring Division, Human Nutrition Information Service. U.S. Department of Agriculture (pp 1-94); Hyattsville, Md.
United States Department of Agriculture (USDA) 1987. Nationwide Food Consumption Survey. Continuing Survey of Food Intakes by Individuals. Women 19-50 Years and Their Children, 1-5 Years, 4 Days, 1985. Report No. 85-4. Nutrition Monitoring Division, Human Nutrition Information Service (pp 1-182); Hyattsville, Md.
______________________________________
Example 1. Essential Amino Acid Reference Pattern of the
U.S. Diet Compared with
the Test Pattern of the Amino Acid-Modified Diet
Amino Acid Scoring Procedure
Test
Ratio Amino Ratio
Amino Acid
Refer- Test Amino Refer-
Acid- Amino
(mg/g ence U.S. Acid ence Modified
Acid
protein) Pattern Diet Score Pattern
Diet Score
______________________________________
Histidine
.sup. 19.sup.1
--.sup.2
--.sup.3
.sup. 19.sup.1
.sup. 22.sup.4
1.16.sup.5
Isoleucine
28 52 1.86 28 43 1.54
Leucine 66 77 1.17 66 74 1.12
Lysine 58 68 1.17 58 42 0.72
Methionine +
25 35 1.40 25 35 1.40
cystine
Phenylalanine +
63 78 1.24 63 75 1.19
tyrosine
Threonine
34 39 1.15 34 36 1.06
Tryptophan
11 12 1.09 11 12 1.09
Valine 35 54 1.54 35 49 1.40
Total essential
339 415 -- 339 388 --
amino acids
______________________________________
.sup. 1 Reference amino acid pattern (FAO, 1990).
.sup.2 Test amino acid pattern based on the essential amino acid
composition of reported dietary intakes for healthy persons of all ages
(USDA, 1984). No data for histidine available.
.sup.3 Amino acid score of reported test protein is 1.09 with tryptophan
as the first limiting amino acid, followed by threonine (1.15) and lysine
leucine (1.17).
.sup.4 Test amino acid pattern based on the essential amino acid
composition of the dietary intakes reported by eight school children with
PKU strictly adhering to an amino acidmodified diet, as estimated from
USDA Food Composition data (USDA, 1976-1987), the primary data source and
secondary sources which comprise the Nutrition & Diet Services database
(NDS, 1988).
.sup.5 Amino acid score of reported test protein is 0.72 with lysine as
the first limiting amino acid, followed by threonine (1.06), tryptophan
(1.09), and leucine (1.12).
______________________________________
Example 2. Nonessential Amino Acid Reference Pattern of
Healthy Children Compared with the Test Pattern of the
Amino Acid-Modified Diet
Amino Acid Scoring Pattern
Test
Amino Ratio
Reference Acid- Amino
Amino Acid Healthy Modified Acid
(mg/g protein) Diet Diet Score
______________________________________
Arginine - citrulline
.sup. 52.sup.1
.sup. 50.sup.2
0.96.sup.3
Aspartate - asparagine
83 93 1.12
Alanine 45 42 0.93
Glutamate - glutamine
221 208 0.94
Glycine 41 37 0.90
Proline 90 70 0.78
Serine 55 47 0.85
Total nonessential amino acids
587 547 --
Total amino acids
925 935 --
______________________________________
.sup.1 Reference amino acid pattern based on the nonessential amino acid
composition of the dietary intakes reported by six healthy children, as
estimated from USDA Food Composition data (USDA, 1976-1987), the primary
data source and secondary sources which comprise the Nutrition & Diet
Services database (NDS, 1988).
.sup.2 Test amino acid pattern based on the nonessential amino acid
composition of the dietary intakes reported by eight school children with
PKU strictly adhering to an amino acidmodified diet, as estimated and
computerized from the above sources.
.sup.3 Amino acid score of test protein is 0.78 with proline as the first
limiting amino acid, followed by serine (0.85) and glycine (0.90).
__________________________________________________________________________
Example 3. Derivation of the L-Amino Acid Composition of the
Protein-Equivalent Used in the Palatable, Balanced
Amino Acid-Modified Diet
Column
Column
Column
Column
6 4 + 8 Column
Column
Column
Column
Column
2 - 4 = 5
Final 5 = 7
Medical
9
1 2 3 4 Medical
Recipe
Total
Food Total
Reference Pattern
Natural Foods
Food 20 g Diet mg L-AA/g
Diet
mg/l g
× 28 g
mg/l g
× 8 g
20 g Protein
28 g Protein
mg AA/g
Protein
Protein
Protein
Protein
Protein
Equivalent
Protein
Equivalent
Protein
__________________________________________________________________________
Essential Amino Acids
Histidine 19.sup.1
532.sup.2
22.sup.3
176.sup.4
356.sup.5
425.sup.6
532.sup.7
18.sup.8
19.sup.9
Isoleucine 28 784 43 344 440 530 784 22 28
Leucine 66 1848 74 592 1256 1500 1848 63 66
Lysine 58 1624 42 336 1288 1545 1624 64 58
Methionine --.sup.10
-- 18 144 210 250 354 10 12.5
Cystine --.sup.11
-- 17 136 210 250 354 10 12.5
Total S-containing
25.sup.12
700 35 280 420 500 708 20 25
Phenylalanine
--.sup.13
-- 44 335 0 0 335 0 12
Tyrosine --.sup.14
-- 31 265 1164 1395 1429 58 51
Total aromatic
63.sup.15
1764 75 600 1164 1395 1764 58 63
Threonine 34 952 36 288 664 795 952 33 34
Tryptophan 11 308 12 96 212 255 308 11 11
Valine 35 980 49 392 588 705 980 29 35
Total essential
339(37%) 388(41%) 318(34%)
Nonessential Amino Acids
Arginine-citrulline
52.sup.16
1456 50 400 1056 1265 1456 53 52
Aspartate-asparagine
83.sup.17
2324 93 744 1580 1895 2324 79 83
Alanine 45 1260 42 336 924 1110 1260 46 45
Glutamate-glutamine
221.sup.18
6188 208 1664 4524 5430 6188 226 221
Glycine 41 1148 37 296 852 1022 1148 43 41
Proline 90 2520 70 560 1960 2350 2520 98 90
Serine 55 1540 47 376 1165 1400 1540 58 55
Total nonessential
587(63%) 547(58%) 603(65%)
Total amino acids
926 935 921
__________________________________________________________________________
(--) indicates no data available
Footnotes to Example 3
.sup.1 1985 FAO/WHO/UNU suggested pattern of amino acid requirements for
preschool children (2-5 years) (FAOWHO-UNU, 1985). Essential amino acid
requirement values, expressed am mg amino acid/kg body weight, were
divided by the recommended safe level of protein intake (g protein/kg bod
weight) to calculate the corresponding amino acid scoring pattern (mg/g
protein). The Codex Committee on Vegetable Proteins (CCVP) endorsed the
use of this suggested pattern as the reference for calculating amino aci
scores for all ages except the infant (Codex Alimentarius Commission
Document, FAO, 1989).
.sup.2 RDA protein 7-10 yrs = 28 g (1.0 g/kg), based on median weight
(50th percentile) for a reference child of 7-10 yrs (20 kg).
.sup.3 Amino acid values are based on estimated intakes of 8 children wit
PKU, 8-11 yrs consuming a strictdiet (Prince, Buist, Leklem, 1991b).
.sup.4 Allowed natural protein = 8 g based on an estimated median
phenylalanine requirement of 12 mg/kg wt (Matalon and Matalon, 1989
suggest a range of 9-15 mg/kg wt). For each 44 mg phenylalanine in the
diet of 8 children with PKU, 1 g protein was provided (Prince, Buist,
1991a). Therefore, a 28 kg child × 12 mg/kg = 336 mg phenylalanine
divided by 44 mg/g protein = 8 g protein.
.sup.5 The remaining quantities of amino acids from a proteinequivalent
were computed as the difference between columns 2 and 4.
.sup.6 The total dietary proteinequivalent from amino acids, computed as
the sum of columns 4 and 6. The values were increased by an additional 20
to account for the water of hydration (MW = 18) lost when an intact
protein is hydrolyzed (Kindt et al., 1983).
.sup.7 The total dietary protein intake from natural foods and medical
foods, computed as the sum of columns 4 and 5.
.sup.8 Amino acids, mg/l g protein, in the medical food invention derived
from column 5, mg amino acids/20 g proteinequivalent divided by 20. For
example, histidine = 356 mg/2 g proteinequivalent final recipe divided by
20 = 18 mg/l g proteinequivalent.
.sup.9 Amino acids, mg/l g protein, in the palatable balanced amino
acidmodified diet = column 7 divided by 28 g protein.
.sup.10,11 See footnote 12.
.sup.12 Total sulfur amino acids. The total of methionine and cystine use
for scoring purposes. Cystine is not an essential amino acid but can be
synthesized from methionine. Cystine in a diet can thus "spare"
methionine, and the total of the two has been found more satisfactory for
scoring purposes than methionine alone (FAO, 1990).
.sup.13,14 See footnote 15.
.sup.15 Total aromatic amino acids includes the contribution of both
phenylalanine and tyrosine. Tyrosine is not an essential amino acid but
can be synthesized from phenylalanine. Tyrosine in a diet can thus "spare
phenylalanine, and the total of the two comprises the essential
requirement (Food & Nutrition Board, 1989).
.sup.16 Citrulline is a nonprotein amino acid, for which data concerning
the amount in foodstuffs are unavailable. Arginine composition of foods i
available and arginine can be synthesized from citrulline. Because
Lcitrulline may offer organoleptic advantages and, theoretically, should
"spare" arginine, the two are considered interchangeable (Buist, Prince e
al., 1991, in press).
.sup.17 Asparagine is the amide form of the dicarboxylic amino acid,
aspartate, for which data concerning the amount in foodstuffs are not
available from USDA. Aspartate composition of foods is available (USDA,
1976-1987). Because Lasparagine offers organoleptic advantages, the two
forms are considered interchangeable (Buist, Prince at al., 1991, in
press).
.sup.18 Glutamine is the amide form of the dicarboxylic amino acid,
glutamine, for which data concerning the amount in foodstuffs are not
available from USDA. Glutamate composition of foods is available (USDA,
1976-1987). Because Lglutamine offers organoleptic advantages, the two
forms are considered interchangeable (Buist, Prince et al., 1991, in
press).
__________________________________________________________________________
Example 4. L-Amino Acid Composition of Conventional Low-Phenylalanine
Protein-Equivalent and the
Palatable Balanced Protein-Equivalent Compared to the Reference
Pattern.sup.1
Palatable
Balanced
Reference
Phenyl- Maxamaid-
Maxamum-
Protein-
Protein
Free(*)
PKU-2(*)
PKU-3(*)
XP(*)
XP(*) Equivalent
__________________________________________________________________________
Essential Amino Acids
Histidine 19.sup.2
19(1.00).sup.3
22(1.18).sup.4
22(1.18).sup.4
45(2.37).sup.5
45(2.37).sup.5
18(0.95).sup.6
Isoleucine 28 45(1.61)
56(2.00)
55(1.96)
60(2.14)
60(2.14)
22(0.78)
Leucine 66 71(1.07)
94(1.43)
93(1.41)
102(1.54)
102(1.54)
63(0.95)
Lysine 58 78(1.34)
68(1.16)
66(1.14)
78(1.35)
78(1.35)
64(1.10)
Methionine -- 26 22 22 17 17 10
Cystine -- 14 22 22 25 25 10
Total S-containing
25 40(1.60)
44(1.76)
44(1.76)
42(1.68)
42(1.68)
20(0.80)
Phenylalanine
-- 0 0 0 0 0 0
Tyrosine -- 38 56 56 90 91 58
Total aromatic
63 38(0.61)
56(0.88)
56(0.88)
90(1.43)
91(1.44)
58(0.92)
Threonine 34 38(1.13)
45(1.32)
44(1.30)
50(1.47)
50(1.47)
33(0.97)
Tryptophan 11 12(1.06)
18(1.59)
18(1.59)
20(1.82)
20(1.82)
11(1.00)
Valine 35 52(1.48)
68(1.93)
66(1.88)
65(1.86)
66(1.88)
29(0.83)
Total essential
339 393 471 464 552 554 318
Nonessential Amino Acids
Arginine 52 28 33 33 80 67 26
Citrulline -- 0 0 0 0 0 26
Total arginine-citrulline
52 28(0.54)
33(0.63)
33(0.63)
80(1.54)
67(1.29)
52(1.00)
Aspartate 83 218 94 93 65(0.78)
55(0.66)
0
Asparagine -- 0 0 0 0 0 79
Total aspartate-asparagine
83 218(2.63)
94(1.13)
93(1.12)
65(0.78)
55(0.66)
79(0.95)
Alanine 45 0(0.00)
38(0.85)
38(0.85)
36(0.80)
36(0.80)
46(1.02)
Glutmate 221 78 199 196 84 102 0
Glutamine -- 197 0 0 0 8 226
Total glutamate-glutanine
221 275(1.24)
199(0.90)
196(0.89)
84(0.38)
110(0.50)
226(1.02)
Glycine 41 136(3.32)
22(0.55)
22(0.55)
62(1.50)
63(1.54)
43(1.05)
Proline 90 0(0.00)
88(0.98)
87(0.96)
72(0.80)
72(0.80)
98(1.09)
Serine 55 0(0.00)
50(0.91)
49(0.89)
44(0.80)
45(0.82)
58(1.05)
Total nonessential
587 657 524 518 443 448 602
Total amino acids
926 1050 995 982 995 1002 920
__________________________________________________________________________
(*) = Registered Trademark
Footnotes to Example 4
.sup.1 Amino acid ratios, scores using the amino acid scoring procedure,
are shown in parentheses where appropriate.
.sup.2 Reference amino acid pattern for essential amino acids based on
recommended pattern for all ages (FAO, 1990), reference pattern for
nonessential amino acids based on reported intakes of six healthy school
children (Prince, Buist, Leklem, 1991b).
.sup.3 Phenyl-Free ® is a free amino acid mixture manufactured and
distributed in the U.S. by BristolMeyers Co., Evansville IN. The amino
acid score is 0.61 with total aromatic amino acids as the first apparent
limiting amino acids followed by histidine (1.00).
.sup.4 PKU-2 ®, PKU3 ® are free amino acid mixtures manufactured
by Milupa Corp, Friedrichsburg, Germany, and distributed in the U.S. by
BristolMeyers. The amino acid score for each is 0.88 with the total
aromatic amino acids as the first apparent limiting amino acids followed
by histidine (1.18).
.sup.5 Maxamaid-XP ®, MaxamumXP ® are free amino acid mixtures
manufactured by Scientific Hospital Supplies, Inc., Liverpool UK, and
distributed in the U.S. by Ross Laboratories, Columbus OH. The amino acid
score for each is 1.35 with lysine as the first apparent limiting amino
acid followed by the total aromatic amino acids (1.44).
.sup.6 The palatable balanced proteinequivalent has an amino acid score o
0.78 with isoleucine as the first apparent limiting amino acid followed b
the total sulfurcontaining amino acids (0.80).
__________________________________________________________________________
Example 5. Sample Diet Prescription Used to Administer the Medical Food
and
Natural Foods to a Hypothetic 8-Year-Old Male with Phenylketonuria
__________________________________________________________________________
1. Establish prescription
Reference
Intake.sup.1
Phenylalanine (mg)
335
Protein (g)
28
Energy (kcal)
2800
2. Fill phenylalanine prescription from natural foods
Natural Food Composition.sup.2
/100 kcal
/l g protein
/335 mgphe
Phenylalanine (mg)
39 44 335
Protein (g)
0.9 -- 8
Energy (kcal)
-- 114 900
3. Determine energy, protein needed from medical food
Theoretical
Reference Intake From Remaining from
Intake
(minus) Natural Foods
(equals)
Medical Foods.sup.3
Phenylalanine (mg)
335 - 335 = 0
Protein (g)
28 - 8 = 20
Energy (kcal)
1960 - 900 = 1060
__________________________________________________________________________
.sup.1 Reference phenylalanine intake = 12 mg/kg wt (Matalon and Matalon,
1989); protein = 1.0 g/kg wt (FNB, 1989); energy = 70 kcals/kg wt (FNB,
1989). Median wt = 28 kg (FNB, 1989).
.sup.2 Natural food composition = 39 mg phenylalanine and 0.9 g
protein/100 kcal; 44 mg phenylalanine and 114 kcals/1 g protein (Prince,
Buist, Leklem, 1991a).
.sup.3 Optimal medical food P:E ratio = 7.5% based on 20 g protein .times
4 calories/g/1060 calories. Current medical foods available for hypotheti
child with PKU have 20-98% P:E ratios.
______________________________________
Example 6. Composition of Balanced Palatable Medical Food
Used to Supply Protein-Equivalent and Energy to a
Hypothetic 8-Year-Old Male with Phenylketonuria
Total Percent
Medical
Natural Diet Reference
Food Foods Per 1 Day Standard
______________________________________
Protein (g)
.sup. 20.sup.1
.sup. 8.sup.2
.sup. 28.sup.3
.sup. 100.sup.3
Energy (kcal)
.sup. 1060.sup.4
.sup. 900.sup.5
.sup. 1960.sup.6
.sup. 100.sup.6
Amino acids (mg):
Histidine .sup. 356.sup.7
.sup. 176.sup.7
532 100
Isoleucine 440 344 784 100
Leucine 1256 592 1848 100
Lysine 1288 336 1624 100
Methionine 210 144 354 100
Cystine 210 136 354 100
Total sulfur
420 280 708 100
Phenylalanine
0 335 335 100
Tyrosine 1164 265 1429 100
Total aromatic
1164 600 1764 100
Threonine 664 288 952 100
Tryptophan 212 96 308 100
Valine 588 392 980 100
Arginine- 1056 400 1456 100
citrulline
Aspartate- 1580 744 2324 100
asparagine
Alanine 924 336 1260 100
Glutamate- 4524 1664 6188 100
glutamine
Glycine 852 296 1148 100
Proline 1960 560 2520 100
Serine 1165 376 1540 100
Gum arabic .sup. (.5%).sup.8
-- -- --
Gum Tragacanth
(.5%) -- -- --
______________________________________
(--) indicates no data available
Footnotes to Example 6
.sup.1 Protein-equivalent for medical food would be approximately 20%
higher than values here (refer to Example 3).
.sup.2 Allowed natural protein = 8 g based on an estimated median
phenylalanine requirement of 12 mg/kg wt (Matalon and Matalon, 1989). For
each 44 mg phenylalanine in natural diets of 8 children with PKU, 1 g
protein was provided (Prince, Buist, 1991a). Therefore, a 28 kg child
× 12 mg/kg = 336 mg phenylalanine divided by 44 g/g protein = 8 g
natural protein.
.sup.3 Reference standard is Recommended Dietary Allowance (RDA) for 7-10
year old male, 1.0 g protein/kg wt, based on median wt of 28 kg.
.sup.4 Energy in medical food based on the use of a proteinfree medical
food, Periflex ® (Scientific Hospital Supplies, Ltd.) which has been
demonstrated to be safe and efficacious when combined with the
proteinequivalent of this invention. Amount determined from natural
intake, relative to energy requirement (see footnote 5).
.sup.5 Natural food energy = 900 kcals based on experimental work (Prince
Buist, 1991a). For each 1 g protein in natural diets of 8 children with
PKU, 114 calories were provided. Therefore, 8 g natural protein ×
114 kcals/g = 912 calories.
.sup.6 Reference standard is Recommended Dietary Allowance (RDA) for 7-10
year old male, 70 kcals/kg wt, based on median wt of 28 kg.
.sup.7 Refer to Example 3.
.sup.8 Gum arabic and tragacanth added to medical food at .5% by weight o
final food if prepared as a powder diluted to a liquid beverage. These
amounts have demonstrated an ability to improve textural qualities.
What is claimed is:
1. In a balanced palatable medical diet for treatment of patients with inborn errors of essential amino acid metabolism including natural foods which are unbalanced or limited for said patients due to deficiencies in essential amino acids and sources of energy and protein, the improvement comprising a palatable protein-equivalent of L-amino acids which comprises an amount of L-glutamine comprising from about 90 to 100% by weight of the total combined weight of L-glutamic acid and L-glutamine in said protein-equivalent of L-amino acids, an amount of L-asparagine which comprises about 90 to 100% by weight of the total combined weight of L-aspartic acid and L-asparagine in said protein-equivalent of L-amino acids, an amount of L-citrulline which comprises up to about 50% by weight of the total combined weight of L-citrulline and L-arginine in said protein-equivalent of L-amino acids, and an amount of L-cystine which comprises from about 20 to 80% by weight of the total combined weight of L-cystine and L-methionine in said protein-equivalent of L-amino acids, the balanced palatable formulation and natural foods together comprising a protein source for about 100% of the protein intake of said patients with inborn errors of metabolism and being nutritionally equivalent to protein from natural food, being compatible with the maintenance of good nutrition and being incorporatable into Medical Foods without compromising the organoleptic properties thereof.
2. The balanced palatable medical diet of claim 1, wherein said deficiencies in essential amino acids and sources of energy and protein comprise phenylketonuria.
3. The balanced palatable medical diet of claim 1 wherein said palatable protein-equivalent of L-amino acids is formed by the acetylation of L-amino acids for producing modifications in the taste and texture qualities of the L-amino acid constituents.
4. The balanced palatable medical diet of claim 1 wherein said palatable protein-equivalent of L-amino acids is formed by the esterification of L-amino acids for producing modifications in the taste and texture qualities of the L-amino acid constituents.
5. The balanced palatable medical diet of claim 1 wherein said palatable protein-equivalent of L-amino acids is prepared as a separate product which is ingestable as is, or is combined with a solid food material, a beverage mix, or a powdered additive which are used to fortify foods with the palatable protein equivalent.
6. In a method for producing a balanced palatable medical diet for treatment of patients with inborn errors of essential amino acid metabolism including natural foods which are unbalanced or limited for said patients due to deficiencies in essential amino acids and sources of energy and protein, the improvement comprising providing a non-palatable protein-equivalent of L-amino acids with a palatable protein-equivalent of L-amino acids which includes the steps of providing an amount of L-glutamine comprising from about 90 to 100% by weight of the total combined weight of L-glutamic acid and L-Glutamine in said protein-equivalent of L-amino acids; providing an amount of L-asparagine which comprises about 90 to 100% by weight of the total combined weight of L-aspartic acid and L-asparagine in said protein-equivalent of L-amino acids; providing an amount of L-citrulline which comprises up to about 50% by weight of the total combined weight of L-citrulline and L-arginine in said protein-equivalent of L-amino acids; and providing an amount of L-cystine which comprises from about 20 to 80% by weight of the total combined weight of L-cystine and L-methionine in said protein-equivalent of L-amino acids, the balanced palatable formulation and natural foods together comprising a protein source for about 100% of the protein intake of said patients with inborn errors of metabolism and being nutritionally equivalent to protein from natural food, being compatible with the maintenance of good nutrition and being incorporatable into Medical Foods without compromising the organoleptic properties thereof.
7. The method of claim 6, wherein said deficiencies in essential amino acids and sources of energy and protein comprise phenylketonuria.
8. The method of claim 6, which further includes the step of forming said palatable protein-equivalent of L-amino acids by the acetylation of said L-amino acids thereby producing modifications in the taste and texture qualities of the L-amino acid constituents.
9. The method of claim 6, which further includes the step of forming said palatable protein-equivalent of L-amino acids by the esterification of said L-amino acids thereby producing modifications in the taste and texture qualities of the L-amino acid constituents.
10. The method of claim 6, which further includes the step of preparing said palatable protein-equivalent of L-amino acids in formulations which can be ingested or prepared by combinination with a solid food material, a beverage, or used as a powdered additive to other foods.
| 1993-08-31 | en | 1995-05-02 |
US-11634380-A | Detection of moving objects
ABSTRACT
A system for detecting and classifying vehicles, moving in the vicinity of a seismic detector, includes a time threshold circuit and, complementary to this circuit, two parallel amplitude detector circuits. One detector circuit utilizes amplitude thresholding to distinguish the seismic vibrations characteristic of moving vehicles, from other seismic vibrations. The other detector circuit utilizes amplitude thresholding to distinguish the seismic vibrations characteristic of a particular kind of moving vehicle (e.g. a tracked vehicle), from other seismic vibrations. The results of these two amplitude detector circuits and of the time threshold circuit are utilized by an indicator circuit and an indication of detected vehicle kind (e.g. tracked or wheeled) provided. Indication may be relayed, to a remote observer, by radio transmission.
The present invention relates generally to the detection of moving objects and particularly to the recognition of and the differentiation between different kinds of vehicles.
There are several ways in which moving objects can be detected and recognized in the case of an object moving across the ground one way of detecting the object is to obtain information from the seismic vibrations which it produces. Seismic vibrations propagate in the ground in several modes of elastic wave motion. Some of these are confined to the neighbourhood of the surface of the ground and are thus known as surface waves. Information about the moving object can extracted from a seismic detector placed on the ground so as to detect surface waves.
According to the present invention a system for the detection of vehicles includes a seismic detector providing an electrical output and circuitry responsive to the output including a first detector capable of determining whether the peak amplitude of the output signal from the seismic detector is above or below a first amplitude threshold which distinguishes between signals due to vehicles and signals not due to vehicles, a second detector arranged in parallel with the first detector and capable of determining whether the peak amplitude of the said signal is above or below a second amplitude threshold higher than the first amplitude threshold which distinguishes between signals due to particular kinds of vehicles, a third detector arranged in parallel with the first and second detectors and capable of determining whether the duration of the said signal is above or below a time threshold which distinguishes between signals due to vehicles, and signals not due to vehicles and indicator means for indicating to a local or remote observer the states of the three detectors contemporaneously.
The first amplitude threshold and the time threshold are used to differentiate between moving objects which are vehicles and moving objects which are not vehicles, and the second amplitude threshold and the time threshold can, for example, be one used to differentiate between tracked vehicles and wheeled vehicles.
The first and third detectors can for example each be a combination of at least one amplifier, a signal peak extractor and a comparator for determining whether the peak of the output of the amplifier is above or below the level of a reference signal representative of the appropriate threshold.
The third detector preferably incorporates a C-R network arranged so that the capacitor is charged by the signal after amplification, and a device for determining whether the capacitor is still charging after a given time interval.
The indicator means can, for example, include an optical display element such as a lamp for indication to a local observer or a radio transmitter for transmitting indicator signals for remote observation.
Embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:
FIG. 1: is a graph of voltage against time illustrating possible envelope outputs from a seismic detector arranged to detect seismic vibrations;
FIG. 2: is a block schematic diagram of a vehicle classifier embodying the present invention;
FIG. 3: is a block schematic diagram illustrating part of the classifier of FIG. 2 in more detail;
FIGS. 4(a) to 4(d): are waveforms illustrating the operation of the part of the classifier illustrated in FIG. 3.
It is an object of the present invention in one aspect to differentiate with a reasonable degree of success between moving objects which are vehicles and those which are not and to classify those vehicles detected into tracked vehicles, e.g. military tanks, and wheeled vehicles, e.g. cars and trucks. FIG. 1 is a graph of voltage against time illustrating possible voltage envelope profiles from a seismic detector arranged to detect seismic vibrations. It illustrates three unrelated typical waveforms (a), (b) and (c) which would be obtained as the output profiles, i.e. envelopes, in the case of respectively a wheeled vehicle, a tracked vehicle and an explosion from a gun. The waveform (a) consists orginally of noise before the vehicle is within range of detection. As the vehicle comes into range the peak amplitude of the seismic vibrations it produces gradually rises above the noise level until the vehicle passes the nearest point to the geophone and thereafter falls again as the vehicle goes out of range of detection again. A first threshold V(w) can be used to differentiate the signal from noise. The waveform (b) is similar to the waveform (a) except that the waveform (b) reaches a higher peak when the vehicle is at the nearest point to the geophone. A second threshold V(t) can be used to distinguish the waveform (b) from the waveform (a).
In connection with the present invention it has been discovered that in general tracked vehicles always produce a peak amplitude seismic signal higher than that produced by a wheeled vehicle (even when the tracked vehicle is travelling slowly on soft ground and the wheeled vehicle is travelling quickly on hard ground). Therefore the waveform (b) can be recognized as that produced by a tracked vehicle because it rises above the threshold V(t). The waveform (c) also rises above both thresholds V(w), V(t) because it is produced by an explosion. However the waveforms (a) and (b) can be distinguished from the waveform (c) because they exist for a much longer time.
FIG. 2 is a block schematic diagram of a vehicle classifier embodying the present invention. A geophone 1 is placed close to a route (not shown) to be monitored. The geophone 1 receives seismic vibrations and produces an output signal representative of their magnitude. The output signal is amplified by an amplifier 3. The output of the amplifier 3 is fed to each of an amplifier 5, an amplifier 7 and a duration channel 9 arranged in parallel. The respective gains, of the amplifier 5, A5, and the amplifier 7, A7, are such that: ##EQU1## where V(t) and V(w) are the thresholds illustrated in FIG. 1. The peak amplitudes of the signal produced by the amplifier 5 are extracted by a signal peak extractor 11. The output of the peak extractor 11 is compared in a comparator 13 with a fixed voltage produced by a voltage source 15. Likewise the peak amplitudes of the signal produced by the amplifier 7 are extracted by a signal peak extractor 17 whose output is a compared in a comparator 19 with the fixed reference voltage produced by the voltage source 15.
The comparator 13 produces a "1" output whenever the output of the peak extractor 11 is greater than the reference voltage and a "0" output whenever the output of the peak extractor 11 is less than the reference voltage. Likewise, the comparator 19 produces a "1" output whenever the output of the peak extractor 17 is greater than the reference voltage and a "0" output whenever the output of the peak extractor 17 is less than the reference voltage. The output of the comparator 13 and the output of the comparator 19 are fed to logic 21. The logic 21 has two outputs, one to an AND gate 23 and one to an AND gate 25. The logic 21 computes from the outputs from the comparator 13 and the comparator 19 whether a vehicle is detected and, if so, whether it is a tracked vehicle or a wheeled vehicle. If a tracked vehicle is detected the logic 21 feeds an output signal to the AND gate 23. If a wheeled vehicle is detected the logic 21 feeds an output signal to the AND gate 25.
The duration of the seismic signal produced by any moving object is detected in the duration channel 9. This produces an output signal representing detection of a vehicle only if the duration of the seismic signal is greater than a predetermined time threshold. If the duration channel 9 produces an output, the output is fed in parallel to the AND gate 23 and the AND gate 25. Whenever the AND gate 23 detects contemporaneously an output from the logic 21 and an output from the duration channel 9 it causes an indicator 27 to operate indicating detection of a tracked vehicle. Whenever the AND gate 25 detects an output from the logic 21 contemporaneously with an output from the duration channel 9 it causes an indicator 29 to operate indicating detection of a wheeled vehicle.
The output of the duration channel 9 may also be fed directly to an indicator 31 to indicate any detected seismic signal having a duration greater than the predetermined time threshold. The indicator 31 can be used to alert an observer that vehicles may be approaching the vehicle classifier.
Since the amplifiers 5, 7 have gains in the ratio of the thresholds V(w), V(t) the signals compared with the reference voltage in the comparators 13, 19 are in that ratio. Therefore the comparator 19 detects whether the seismic signal is greater than V(w), and the comparator 13 detects whether the seismic signal is greater than V(t). If a tracked vehicle is detected there is a "1" output from both the comparator 13 and the comparator 19. If a wheeled vehicle is detected a "0" output is produced by the comparator 13 and a "1" output is produced by the comparator 19. If no vehicle is detected a "0" output is produced by both of the comparators 13, 19. In the course of comparing the outputs from the comparator 13 and the comparator 19 the logic 21 delays producing an output if a "1" output is indicated by the comparator 19 only until the maximum value of the seismic signal (the maximum output from the peak extractor 17) has been detected. This ensures that the indicator 29 is not operated erroneously in the case of a tracked vehicle which has only begun to come into range of detection.
The indicators 27, 29 and 31 can for example be optical indicators such as lamps which can be supplemented with audio indicators such as buzzers. Alternatively they can include radio transmitters which are used to transmit radio signals to a remote receiver if the vehicle classifier is left unattended.
In another embodiment of the invention the amplifiers 5, 7 can have the same gain; in that case a further voltage source will be used providing a further reference voltage V(t)/V(w) times greater than that produced by the voltage source 15. The reference voltage produced by the voltage source 15 will be applied only to the comparator 19, while that produced by the further reference source will be applied only to the comparator 13.
FIG. 3 is a block schematic diagram of the duration channel 9 shown in FIG. 2. The input from the amplifier 3 is compared in a comparator 33 with a signal generated by a feed-back loop consisting in turn of the comparator 33, a monostable circuit 35, an integrator 37 and an amplifier 39. The output from the amplifier 39 to the comparator 33 is also compared in a comparator 41 with a fixed reference voltage produced by a voltage source 43. The comparator 41 has a "1" output whenever its input from the amplifier 39 is greater than the reference voltage. Otherwise it has a "0" output. The output of the comparator 41 is fed directly to the AND gate 23, the AND gate 25 and the indicator 31.
Operation of the duration channel 9 will now be described with reference to FIGS. 4a to 4d which are typical waveforms of signal amplitude as a function of time. The input from the amplifier 3 is illustrated in FIG. 4a. An actual waveform might contain many cycles more than those shown in FIG. 4a. The comparator 33 produces an output pulse whenever the input from the amplifier 3 is greater than a voltage V1 determined by the characteristics of the feed-back loop. These pulses are shown in FIG. 4b. The monostable circuit 35 produces a series of pulses each of equal length for each input pulse received from the comparator 33. This series is shown in FIG. 4c. The integrator 37 consists basically of a C-R network. Each pulse in the series from the monostable circuit 35 will charge the capacitor of the integrator 37. If the pulses from the monostable circuit 35 are spaced closely enough together the capacitor of the integrator 37 will not fully discharge between pulses and the voltage across it will therefore rise as shown in FIG. 4d. The fixed reference voltage produced by the voltage source 43 is denoted in FIG. 4d by the level V2. When the voltage across the capacitor of the integrator 37 is sufficiently high, after amplification by the amplifier 39, to be greater than the reference voltage V2 the comparator 41 produces an output.
The time constant of the C-R network of the integrator 37 is selected so that the duration channel 9 can be used to distinguish between signals from vehicles, which in general are of high frequency, and signals from people or animals which are in general of low frequency. In other words the time constant is selected so that the capacitor of the integrator 37 is continually charged by the signals due to a vehicle but not charged by the signals due to a person or an animal. Also, if a short signal occurs it will begin to charge the capacitor of the integrator 37 but as soon as the signal dies away the capacitor will discharge. Therefore the reference voltage V2 can be set so that any signal of short duration, for example from an explosion of a gun, will not charge the capacitor of the integrator 37 sufficiently to reach the voltage level V2 required for the comparator 41 to give an output.
The voltage V1 is in general variable although it is shown in FIG. 4a as being a steady level because over the first few cycles of an input signal it does not vary, as a result of the delay corresponding to the time constant of the integrator 37.
It has been found that operating over an approximate range of 0 to 5 meters and using a commercial geophone GSC 20D (manufactured by Geospace Corporation) the thresholds V(t) and V(w) (FIG. 1) are respectively 3.3 mV (rms) and 0.3 mV (rms) respectively.
I claim:
1. In a system for detecting moving ground vehicles of the type including a seismic detector capable of detecting seismic vibrations generated by moving vehicles and of providing in response a corresponding electrical signal; first detector means connected to the seismic detector, responsive to the electrical signal, for providing a first information signal, to distinguish electrical signals having peak amplitudes above and below a first amplitude threshold, namely a threshold of such set value as to distinguish electrical signals corresponding to seismic vibrations of peak amplitude characteristic of moving ground vehicles, from electrical signals corresponding to other seismic vibrations; and indicator means connected to the first detector means, responsive to the information signal therefrom, for indicating the presence of a detected moving vehicle; the improvement comprising a second detector means connected to the seismic detector, parallel to the first detector means, responsive to the electrical signal, for providing a further information signal, to distinguish electrical signals having peak amplitudes above and below a second amplitude threshold, namely a threshold of such set value as to distinguish electrical signals corresponding to seismic vibrations of peak amplitude characteristic of moving ground vehicles of a particular kind from electrical signals corresponding to seismic vibrations of peak amplitude characteristic of other sources including moving vehicles not of this particular kind; said indicator means also being responsive to said further information signal, and being capable of providing in response an indication of the kind of moving vehicle detected, said system further including a duration channel connected to the seismic detector for discriminating against electrical signals of less than and longer than a given time interval, the duration channel including, connected in series in the following order: a first signal comparator, a monostable, an integrator, and an amplifier; the amplifier being connected to the first signal comparator to provide a first reference signal, the duration channel also including a second signal comparator connected to the amplifier, and a voltage source connected to the second signal comparator to provide a second reference signal for defining the time interval.
2. A system according to claim 1 wherein the second amplitude threshold is such as to distinguish an electrical signal corresponding to seismic vibrations that are of peak amplitude characteristic of a moving tracked vehicle from an electrical signal corresponding to seismic vibrations that are of peak amplitude characteristic of other sources including moving wheeled vehicles.
3. A system according to claim 1 wherein the indicator means includes a logic circuit capable of responding to changes of said information signals, the logic circuit being capable of providing a delayed indication whenever the first information signal changes corresponding to an electrical signal of peak amplitude rising above the first amplitude threshold, the indication distinguishing between two outcomes, namely: a first outcome where the further information signal changes corresponding to an electrical signal of peak amplitude that rises above the second amplitude threshold; and a second outcome where the electrical signal peak amplitude rises to a maximum amplitude between the first and second amplitude thresholds.
4. A system according to claim 3 wherein the logic circuit is capable of comparing changes of said information signals, and detecting, and providing indication of, the second outcome by checking between changes of the first information signal corresponding to an electrical signal of peak amplitude that rises above and falls below the first amplitude threshold, that there is no change in the further information signal.
5. A system according to claim 1 wherein each detector means includes: an amplifier of specified gain a peak extractor connected to the amplifier for determining the peak amplitude of electrical signals amplified thereby, and a comparator connected to the peak extractor; and a common voltage source connected to the comparators; the amplifiers each being of different gain and in combination with the voltage source defining respectively the first and second amplitude thresholds for distinguishing the electrical signals.
| 1980-01-07 | en | 1992-04-21 |
US-68913746-A | Isolation of xylene isomers
Patented Nov. 21, 1950 ISOLATION OF XYLENE ISOMERS David M. Mason, Linden, N. J assignor to Standard Oil Development Company, a corporation of Delaware Application August 8, 1946, Serial No. 689,137
11 Claims.
This invention relates to a method for isolation of para-xylene and meta-xylene from crude xylenes and from mixtures of hydrocarbons containing xylenes. More particularly, the invention is concerned with separation of para-xylene by selective fractional crystallization of a liquid mixture of the isomers in the presence of a third component which inhibits spontaneous crystallization of meta-xylene and permits the formation of a ternary system having a much lower eutectic than the binary eutectic of metaand para-xylene. I
The xylenes m-, and p-) are principally present in certain petroleum and coal tar products. o-Xylene under atmospheric pressure boils at 144.4 C. m-Xylene and p-xylene normally boil at 139.2 C. and 138.5" C., respectively. It is possible, therefore, to separate o-xylene from mand p-xylenes in substantially pure form by fractional distillation. Separation of m-xylene from p-xylene is not practically feasible by fractional distillation. Chemical methods have been useful for obtaining separated concentrates of pand m-xylenes but the purity and yields of the chemically separated products require improvement.
It is known that to some extent p-xylene may be recovered from a mixture of mand p-xylene by fractional crystallization at temperatures below 11 C. However, these isomers form a solid eutectic mixture at a temperature of about -53 C., and this mixture contains 87 parts by weight of metato 13 parts by weight of para-xylene. For example, from a concentrate containing 71% meta, 21 para, and 8% of other aromatic hydrocarbons, cooled to just above the eutectic point, only about half the para-xylene is crystallized out, and the other half remains as an impurity with the meta-xylene concentrate. Consequently, efforts were made to cool to temperatures below the binary eutectic point by use of certain third components, such as several alcohols and hydrocarbons, which in effect give rise to a potential ternary system with its own ternary eutectic temperature which is lower than the binary eutectic temperature of metaand para-xylene. Still, in actual practice it was found difiicult to use these third components because they did not permit extensive controlled cooling, which is important for obtaining a maximum degree of separation when the mixed solid and liquid phases are cooled to a temperature below the true binary eutectic point.
A principal object of this invention is to provide a practical process for separating first paraxylene as crystals from supercooled mixed para and meta isomers at temperature below the binary eutectic point of the mixture in the presence of an inhibitor of crystallization of the meta-xylene, then separating meta-xylene crystals from the resulting supercooled liquid mixture nearly freed of para-xylene.
It has now been found that, after the removal of substantially all the ortho-xylene from a mixture of xylene isomers by fractional distillation, by conducting the crystallization of para-xylene in the presence of certain inhibitors of crystallization for meta-xylene in suitable proportion, the mixture blended with the -inhibitor can be cooled to very low temperatures, of the order of 15 to 30 centigrade degrees below the eutectic points of the blends so as to cause a greater proportion of the para-xylene. to crystallize and separate out. After separation of the para-xylene from the thus-cooled meta-xylene, crystallization of the meta-xylene may be induced by seeding and a substantial portion of the meta-xylene may be crystallized and separated.
In using previously proposed third components, such as the alcohols and the low boiling hydrocarbons, the spontaneous crystallization points of the diluted mixtures are lowered erratically a few degrees, e. g., to about C. or thereabouts, by 20 mole per cent of the third components. On the other hand, the dependable meta-xylene crystallization inhibitors suitable for cooling, such as ethyl benzene, isoheptene, and meta-ethyl toluene, in proportions of 20 mole per cent inhibit spontaneous crystallization of meta-xylene in the isomer mixtures at temperatures as low as C. and lower, and permit dependable cooling.
In general, according to the present invention, an aromatic fraction boiling between 136 C. and 144 C. and of high xylene content is fractionated to separate a cut boiling between 136 C. and 141 C, and which contains predominantly metaand para-xylenes. Any of the distillations necessary in carrying out the process of the present invention can be accomplished by use of available distillation equipment. The xylene fraction boiling between 138 C. and 141 C. is placed in a vessel designed for carrying outcooling and crystallization. This is equipped with a stirrer and the proper connections for introducing the cooling medium into the jacketed part of the kettle. From to 1 volume of the meta-xylene crystallization inhibitor is added per volume of the xylene distillate placed in the kettle or crystallization vessel. A cooling medium, such as liquefied ethylene or other refrigerant, capable of lowering the contents of the kettle down to temperatures of the order of 70 C. and lower, is introduced into the jacketed part of the apparatus, and the mixture in the apparatus is cooled to a temperature below 70 C. but not to the point where the meta-xylene spontaneously crystallizes. During the cooling process, crystals of para-xylene continue to form until nearly all of the paraxylene is crystallized.
After separation of the para-xylene crystals from the cooled mother liquor containing metaxylene, the mother liquor is warmed to slightly below the meta-xylene saturation temperature. Crystallization of meta-xylene is induced by seeding with crystalsor otherwise, and cooling is again applied, whereupon the meta-xylene crystallizes out until the temperature approaches the equilibrium eutectic point of meta-xylene, paraxylene and the inhibitor. After separation of the meta-xylene crystals from the mother liquor, the resultant liquid equilibrium mixture contains paraxylene and meta-xylene in the ratio of approximately 11:89. The remaining liquid may be admixed with a fresh supply of xylene distillate to be subjected to a similar fractional crystallization, or may be employed for motor fuel or solvent use. The inhibitor may be recovered for reuse, if desirable.
The para-xylene crystals may b removed from the liquid mixture undergoing cooling by filtration. The meta-xylene crystals may be removed likewise from the seeded mother liquor. The filtrations may be accomplished either by basket type centrifugin or by means of a suction filter. Any other convenient means of separating the crystals from the liquid phases may be used.
Alternatively, some or all of the ethyl benzene present in the original xylene mixture may be retained therein to serve as a crystallization inhibitor. Additional ethyl benzene or one of the other inhibitors, preferably meta-ethyl toluene, may be added; then the process may be carried out as described above.
In the accompanying drawing is shown a graph indicating the eutectic temperatures and the temperatures to which the xylene mixtures may be cooled without spontaneous crystallization when inhibited with varying proportions of ethyl benzene. Isoheptene and meta-ethyl toluene in varying proportions have similar effects, the latter even expanding the safe cooling zone.
Details of the invention will be understood from the following examples given for the purpose of illustration.
Example 1 45% meta-xylene. After warming to 77 C., crystallization of meta-xylene was induced by seeding the mother liquor, which was again cooled to a final temperature of 86 C. while metaxylene crystals were formed. Approximately 50% of the original meta-xylene was recovered in the meta-xylene crystals thus formed and separated from the residual mother liquor.
Example 2 A crude xylene fraction to be processed contained:
Per cent Para-xylene 26 Meta-xylene 68 Other Cs aromatics 6 The crude xylene was blended with meta-ethyl toluene concentrate until the blend contained 20 mole per cent metaethyl toluene concentrate. This blend was cooled to temperatures lower than 94 C. without crystallization. In safely cooling this blend, approximately of the para-xylene crystallized, leaving a liquor containing meta-xylene in a ratio of 95 to 5 of para-xylene.
The ethyl toluene was removed from the liquor by distillation, then 65% of the meta-xylene crystallized and was separated on cooling the liquor to 60 C.
Example 3 reached its eutectic point, at which the meta to para ratio is 87.5 to 12.5.
It will be noted that by using the potent inhibitors of meta-xylene crystallization, first nearly all the para-xylene is isolated, then a large proportion of the meta-xylene can be isolated from the mother liquor which yielded the paraxylene crystals. The potent inhibitors give safely assured cooling to increase the concentration of the meta-xylene in the remaining liquid phase or mother liquor as para-xylene is crystallized and separated.
There has been no basis for" prediction of substances which act as potent crystallization inhibitors preferentially toward one of the isomers, but it may be noted from results obtained in accordance with the present invention that the potent inhibitors have in common at least 7' carbon atoms per molecule, doubly bonded carbons, and an alkyl side chain. The structural orientation of these substances may be such as to block crystallization of the meta-xylene.
I claim:
1. The method of recovering substantially pure para-xylene from mixtures thereof with metaxylene which comprises forming a liquid solution of metaand para-xylene with a third component selected from the class consisting of ethyl benzene, meta-ethyl toluene, and a mixture of methyl hexenes and dimethyl pentenes, cooling the solution to a temperature below 53" C. but
above the eutectic temperature of the system: meta-xylene para-xylene third component, whereby para-xylene crystals are formed and meta-xylene is inhibited from crystalllzing spontaneously by the action of the third component, and removing substantially pure para-xylene crystals from the cooled solution.
2. The method of recovering substantially pure para-xylene and substantially pure meta-xylene from mixtures thereof which comprises forming a liquid solution of metaand para-xylene with a third component selected from the class consisting of ethyl benzene, meta-ethyl toluene, and a mixture of methyl hexenes and dimethyl pentenes,'cooling the solution to a temperature below 53 C. but above the eutectic temperature of the system: meta-xylenepara-xylene-third component, whereby para-xylene crystals are formed and meta-xylene is inhibited from crystallizlng spontaneously by the action of the third component, removing substantially pure paraxylene crystals from the cooled solution, inducing crystallization of meta-xylene in the cooled solution, and separating substantially pure metaxyiene crystals from the cooled solution.
3. The method according to claim 2 wherein the crystallization of meta xylene is induced by removing the meta xylene crystallization inhibitor and thereafter cooling the xylene solution freed oi the inhibitor to a temperature below the melting point of meta xylene.
4. The method according to claim 2 wherein the crystallization of meta xylene is induced by seeding the cooled solution with meta xylene crystals.
5. A process according to claim 2 in which the third component is ethyl benzene.
6. A process according to claim 2 in which the third componentis meta-ethyl toluene.
7. A process according to claim 2 in which the third component is a mixture of methyl hexenes and dimethyl pentenes.
8. A process according to claim 2 in which the solution contains at least 20 moi. per cent of the third component as the solution is cooled to a temperature between 50 C. and --94 C.
9. The method of recovering substantially pure para-xylene and substantially pure meta-xylene irom mixtures thereof which comprises forming a liquid solution of metaand para-xylene with ethyl benzene, cooling the solution to a temperature below --53 C. but above the eutectic temperature of the system: meta-xylene-para-xylene-ethyl benzene, whereby para-xylene crystals are formed and meta-xylene is inhibited from crystallizing spontaneously by the action of the ethyl benzene, removing the substantially pure para-xylene crystals from the cooled solution, removing ethyl benzene from the solution, again cooling the solution to a temperature below the melting point of meta-xylene and separating substantially pure meta-xylene crystals from the solution.
10. The method as described in claim 9, in which the solution contains at least about 20 mole per cent of the diluent as the solution is cooled below 60 C.
11. The method of recovering substantially pure para-xylene and substantially pure metaxylene from mixtures thereof which comprises forming a liquid solution of metaand paraxylene with ethyl benzene, cooling the solution to a temperature below --53 C. but above the eutectic temperature of the system: meta-xylene para-xylene ethyl benzene, whereby para-xylene crystals are formed and meta-xylene is inhibited from crystallizing spontaneously by the action of the third component, removing substantially pure para-xylene crystals from the cooled solution, seeding the cooled solution with meta-xylene crystals whereby meta-xylene in the cooled solution crystallizes out and recovering substantially pure meta-xylene crystals from the cooled solution.
DAVIDMMASON.
REFERENCES CITED The following references are of record in the file of this patent:
. OTHER REFERENCES Ganot: Elementary Treatise on Physics: 15th Edition, 1901, Published by Wm. Wood 8: O0. in New York, N. Y.
1. THE METHOD OF RECOVERING SUBSTANTIALLY PURE PARA-XYLENE FROM MIXTURES THEREOF WITH METAXYLENE WHICH COMPRISES FORMING A LIQUID SOLUTION OF META- AND PARA-XYLENE WITH A THIRD COMPONENT SELECTED FROM THE CLASS CONSISTING OF ETHYL BENZENE, META-ETHYL TOLUENE, AND A MIXTURE OF METHYL HEXENES AND DIMETHYL PENTENES, COOLING THE SOLUTION TO A TEMPERATURE BELOW -53*C. BUT ABOVE THE EUTECTIC TEMPERATURE OF THE SYSTEM: META-SYLENE-PARA-XYLENE-THIRD COMPONENT, WHEREBY PARA-XYLENE CRYSTALS ARE FORMED AND META-XYLENE IS INHIBITED FROM CRYSTALIZING SPONTANEOUSLY BY THE ACTION OF THE THIRD COMPONENT, AND REMOVING SUBSTANTIALLY PURE PARA-SYLENE CRYSTALS FROMT HE COOLED SOLUTION.
| 1946-08-08 | en | 1950-11-21 |
US-16848988-A | Variable compliance device
ABSTRACT
A variable compliance device having a tool plate attached between a tool and a robot arm to allow limited movement of the tool plate relative to the robot arm. A concave bill seat connected to the tool plate and a pin having a concave surface house a bearing ball. An inflatable diaphragm exerts a force on a piston toward the pins to force the pins against the bearing balls. Movement of the tool plate relative to the robot arm causes the pins to move relative to the robot arm. The force of the diaphragm on the pins resists movement of the tool plate relative to the robot arm, and restores the tool plate to its original position after the outside force is removed. If the pins are moved beyond a selected point, a sensor senses the movement and sends a signal to shut down the robot.
TECHNICAL FIELD
This invention relates in general to robotic tooling systems. More particularly, the invention relates to variable compliance devices for coupling robot tooling to robot arms.
BACKGROUND AND SUMMARY OF THE INVENTION
A variable compliance device is coupled between a robot arm and a robot tool to provide sufficient compensation to allow for slight misalignment between the robot tool and its environment. When the robot tool encounters a misaligned part or other obstruction, an outside force is applied to the tool. The variable compliance device alows the tool to rotate or to move laterally or longitudinally relative to the robot arm, without damaging the robot arm. When the outside force is removed, the compliance device restores the tool to its original position relative to the robot arm.
If excessive force is applied to a tool, the tool may be moved beyond the limits of the compliance device's ability. U.S. Pat. No. 4,717,003, issued Jan. 5, 1988, to McCormick et al., discloses and describes a variable compliance device that includes a means for sensing movement of a tool attached to the device and for shutting down the robot when an overload condition is encountered. The device can be adjusted by air pressure during operation of the device.
A variable compliance device may also include a quick change adapter, so the robot tool can be easily changed to a different type. A quick change adapter is disclosed and described in U.S. Pat. No. 4,676,142, ssued June 30, 1987, to McCormick et al.
The variable compliance device of the invention includes a tool plate for attachment to a tool and means for coupling the tool plate to a robot arm. The compliance device allows limited longitudinal, lateral, and angular movement of the tool plate relative to the robot arm.
A plurality of bearing balls are located in concave ball seats associated with the tool plate. A pin having a concave surface engages each bearing ball, so that longitudinal, lateral, or angular movement of the tool plate relative to the robot arm caused by an outside force causes at least one of the pins to move relative to the robot arm.
A bias means exerts a force against the pins toward the bearing balls. The force of the pins against the bearing balls resists movement of the tool plate relative to the robot arm. This force also restores the tool plate to its original position relative to the robot arm after the outside force is removed during compliance.
The bias means includes an inflatable diaphragm that can be inflated or deflated to a selected pressure. Inflating the diaphragm to a higher pressure increases the rigidity of the coupling, increasing the force required to move the tool plate relative to the robot arm. The higher pressure also increases the force that restores the tool plate to its original position.
The variable compliance device of the invention also includes a sensor that senses when any of the pins is moved beyond a selected point. The sensor then signals the robot to shut down in order to avoid damage to the robot, the tool, or the workpiece due to an excessive force.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a cross-sectional view of a variable compliance device incorporating the invention;
FIG. 2 is a side view, partially in section, of the variable compliance device shown in FIG. 1;
FIG. 3 is a top view of the variable compliance device shown in FIG. 1;
FIG. 4 is a cross-sectional view of the first alternate embodiment of the invention;
FIG. 5 is a cross-sectional view of a second alternate embodiment of the variable compliance device of the invention;
FIG. 6 is a cross-sectional view of a third alternate embodiment of the variable compliance device of the invention; and
FIG. 7 is a cross-sectional view of a fourth alternate embodiment of the variable compliance device of the invention.
DETAILED DESCRIPTION
FIGS. 1-3 show one embodiment of the invention. The variable compliance device 10 of the invention is attached to a robot arm 14. A housing 16 and a rear cover 18 are connected together by a plurality of cap screws 20 and lock washers 22. The housing 16 and the rear cover 18 are connected to the robot arm 14 by a plurality of cap screws 24 and lock washers 26.
A resilient diaphragm 28 is mounted between the housing 16 and the rear cover 18. The diaphragm 28 encloses a chamber 30 between the diaphragm 28 and the rear cover 18. Air pressure is provided to inflate the diaphragm 28 through a passageway 32 through the rear cover 18. A fluid input fitting 34 is connected to the end of the passageway 32. Tubing 36 extends from the fitting 34 through the interior of the robot arm 14 to a variable air regulator (not shown). Air or other fluid can be provided through the tubing 36, the fitting 34, and the passageway 32 to inflate or deflate the diaphragm 28 by increasing or decreasing the fluid pressure within the chamber 30.
An annular piston 38 is mounted against the diaphragm 28. As the fluid pressure within the chamber 30 is increased, the inflating diaphragm 28 exerts an increasing force on the annular piston 38 in a direction away from the rear cover 18, to the left in FIG. 1 and upward in FIG. 2. The piston 38 has three conical depressions 40 in the surface opposite the diaphragm 28. The depressions 40 are evenly spaced around the piston 38, and could vary in number, if desired.
Three substantially cylindrical pins 42 are mounted within openings 44 in the housing 16 and are evenly spaced to correspond to the concave depressions 40 in the piston 38. Each pin 42 has a hemispherical head 46 that engages one of the depressions 40 in the piston 38. Self-lubricating bearings 48 between the pins 42 in the housing 16 allow the pins 42 to slide longitudinally relative to the housing 16. Each pin 42 has a shallow groove 50 around the circumference of the pin 42.
The end 52 of each pin 42 opposite the hemispherical head 46 is a conical concave surface 52. The concave surface 52 may have a constant slope angle or the slope angle may change over the diameter of the pin 42.
A front cover 54 is connected to the housing 16 and the rear cover 18 by a plurality of cap screws 56 and lock washers 58. The front cover 54 secures a tool plate 60. The tool plate 60 can move laterally, axially, or longitudinally relative to the front cover 54 and the housing 16. The tool plate 60 can also rotate about the longitudinal axis 62 of the variable compliance device 12. A ball cage 64 and a plurality of bearing balls 66 are mounted between the tool plate 60 and the front cover 54 to facilitate the angular rotation and lateral movement of the tool plate 60 relative to the front cover 54.
The tool plate 60 has a plurality of openings 68 to provide easy access to the cap screws 20 and 24. The tool plate 60 also has four threaded openings 70, shown in FIG. 3, for the attachment of a tool (not shown) to the tool plate 60. A groove 72 and a small threaded opening 74 provide for proper registering of the tool on the tool plate 60.
Three concave ball seats 76 are connected to the tool plate 60 corresponding to the pins 42. The concave ball seats 76 may have a constant slope angle or the slope angle may change over the diameter of the ball seat. The concave ball seats 76 and the concave ends 52 of the pins 42 oppose one another to form ball chambers 78. A bearing ball 80 is mounted within each ball chamber 78 for engagement with the ball seat 76 on the tool plate 60 and with the concave end 52 of each pin 42.
As an alternative, the bearing balls 80 could be integrally formed on the ends 52 of the pins 42. The pins 42 operatively engage the ball seats 76, either directly or through the bearing balls 80.
FIG. 2 illustrates a subminiature basic switch 82, mounted in the housing 16 next to each pin 42. A bearing ball 84 is held against the switch 82 by the side of the pin 42. The switch 82 is connected to an electrically conductive wire 86, shown in FIG. 1. The electric wire 86 leads through the interior of the robot arm 14 to the robot (not shown).
In operation, a robot tool (not shown) is attached to the tool plate 60. Air or other fluid is injected through the air fitting 34 in the air passageway 32 to the chamber 30. The diaphragm 28 is inflated until the fluid pressure within the chamber 30 reaches a selected level. The diaphragm 28 exerts a force on the piston 38 toward the pins 42. The piston 38 forces the pins 42 into the bearing balls 80. A high fluid pressure within the chamber 30 causes the diaphragm 28 to exert a high force against the piston 38 and the pins 42. The high force on the pins 42 resists movement of the tool plate 60 relative to the robot arm 14 and the housing 16.
When the robot tool encounters an obstacle during the operation of the robot, the outside force will cause the tool plate 60 to be moved relative to the housing 16, if the force of the pins 42 on the bearing balls 80 is overcome. The tool plate 60 may be moved longitudinally, laterally, or angularly.
Movement of the tool plate 60 relative to the housing 16 causes the bearing balls 80 to exert a force on the pins 42. This force causes the pins 42 to move longitudinally relative to the housing 16. The slope angles on the concave ball seats 76 and on the concave surfaces 52 of the pins 42 define a spring constant for the pins 42. A constant slope angle will result in a constant force response during lateral compliance of the tool plate 60 relative to the housing 16. A changing slope angle could be used to result in a true spring constant, or even more exotic spring constants that change proportionately to lateral motion.
When the obstacle and the resulting outside force are removed, the force of the pins 42 on the bearing balls 80 causes the tool plate 60 to return to its original position relative to the housing 16. The bearing balls 80 tend to move toward the centers of the concave ball seats 76 and the concave surfaces 52 of the pins 42. During lateral movement, each ball 80 will move equidistant up the concave surface 52 and the ball seat 76, as long as these surfaces remain parallel.
If the pins 42 move beyond a selected point, the bearing balls 84 fall into the grooves 50 on the pins 42, away from the switches 82. The switches 82 are then activated and send a signal through the electric wire 86 to the robot (not shown). The electrical signal may be used in a variety of manners. For example, the signal may shut the robot off or give a warning to the robot operator.
FIG. 4 illustrates an alternate embodiment of the invention. In this embodiment, the variable compliance device 88 has a quick change adapter 92 mounted between a modified tool plate 90 and the front cover 54. The front cover 54, the housing 16, the rear cover 18, and the robot arm 14 are identical to the first embodiment.
A diaphragm 28 is mounted between the housing 16 and the rear cover 18, and encloses a chamber 30. The chamber 30 is pressurized by a fluid such as air from a passageway 32, a fitting 34, and tubing 36. The diaphragm 28 exerts a force on a piston 38 and a plurality of pins 42. The pistons 42 exert a force on the bearing balls 80 which are mounted within ball chambers 78 between the pins 42 and ball seats 76.
The ball seats 76 are mounted within a quick change body 94. The quick change body 94 is secured to the housing 16 by the front cover 54. A ball cage 64 and a plurality of bearing balls 66 allow the quick change body 94 to move relative to the front cover 54.
The tool plate 90 is connected to the quick change body 94. A pair of spherical pins 96, mounted on the tool plate 90, engage a pair of conical seats 98 on the quick change body 94 to properly orient the tool plate 90.
The tool plate 90 is secured to the quick change body 94 by a locking pin 100. The locking pin 100 is secured to the tool plate 90 by a bowed retaining ring 102. The locking pin 100 is secured to the quick change body 94 by a plurality of bearing balls 104. The bearing balls 104 engage an annular groove around the circumference of the locking pin 100.
The bearing balls 104 are held within the groove of the locking pin 100 by a ball retainer 106 and a piston 108. The ball retainer 106 is connected to the quick change body 94, and a gasket 110 seals between the ball retainer 106 and the quick change body 94. A body O-ring 112 and a piston O-ring 114 form seals between the piston 108 and the quick change body 94. A ball retainer O-ring 116 seals between the piston 108 and the ball retainer 106. The piston 108 is biased downward toward the bearing balls 104 by a curved spring washer 118. The biasing action of the curved spring washer 118 may be assisted by fluid pressure provided by a fluid such as air from a fitting 120 and tubing 122. Fluid pressure can be supplied to the opposite side of the piston 108 through a passageway 124, a fitting 126, and tubing 128 to force the piston 108 towards the curved spring washer 118 to disconnect the locking pin 100 and release the tool plate 90.
Air pressure can also be applied through another air fitting (not shown) behind the air fitting 126. This air pressure passes through a passageway 129 to allow the tool to perform auxiliary functions, such as closing a gripper.
The modified tool plate 90 has one or more electrical connectors 130 that are connected to one or more fixed electrical contacts 132. These are used to pass electrical signals from the tool to the robot control. The fixed contact 132 engages an electrical spring contact 134 mounted in the quick change body 94. An electrical wire 136 extends from the spring contact 134 through the interior of the robot arm 14 to the robot controller (not shown).
In operation, the embodiment illustrated in FIG. 4 operates similarly to the first embodiment. If the tool encounters an obstacle, the tool plate 90 and the quick change adapter 92 are moved relative to the housing 16. Movement of the quick change adapter 92 relative to the housing 16 causes the pins 42 to move longitudinally relative to the housing 16. When the outside force has been removed, the pins 42 return the quick change adapter 92 to its original position. If the pins 42 are moved beyond a selected point, movement of the pins 42 activates a switch 82 that sends a signal to the robot. The robot can thus be deactivated or a warning signal can be given.
The quick change adapter 92 allows the tool to be changed easily. Air can be injected through the air fitting 126 and the air passageway 124 to cause the piston 108 to move upward away from the tool plate 90. This releases the bearing balls 104 so that the balls 104 move outward away from the locking pin 100. The locking pin 100 and the tool plate 90 can then be pulled away from the quick change adapter 92. A different tool, mounted on a different tool plate 90, can then be inserted into the quick change adapter 92. Air pressure is injected through the air fitting 120 to cause the piston 108 to move downward toward the tool plate 90. The piston 108 forces the bearing balls 104 inward toward the groove in the locking pin 100.
FIG. 5 illustrates a second alternate embodiment of the invention. The operation of the variable compliance device 138 shown in FIG. 5 is identical to the operation of the variable compliance device 88 shown in FIG. 4. However, in FIG. 5, the air fittings 140, 142, and 144 and the electrical wire 146 are outside of, rather than within, the interior of the robot arm 14.
The air fitting 140 provides air through an air passageway 148 in the modified rear cover 150 to the air chamber 30 enclosed by the diaphragm 28. The air fitting 142 provides air through an air passageway 152 to force the piston 108 downward toward the tool plate 90. The air fitting 144 provides air through a passageway 154 to force the piston 108 upward away from the tool plate 90. Additional air fittings (not shown) provide air pressure to allow the tool to perform various functions, such as closing a gripper.
The electrical wire 146 is attached to an electrical connector 156 that is connected to the exterior surface of the modified quick change body 158. The electrical connector 156 is connected to an electrical spring contact 160 that engages the fixed contact 132 and the electrical connector 130 on the tool plate 90.
In operation, the embodiment of the invention shown in FIG. 5 works identically to the embodiment shown in FIG. 4. Any movement of the tool plate 90 and the quick change body 158 relative to the housing 16 will cause the pins 42 to move longitudinally relative to the housing 16. The pins 42 return the tool plate 90 and the quick change body 158 to their original positions when the outside force is removed. Movement of the pins 42 beyond a selected point is sensed by a sensing means and a signal is sent to the robot.
FIG. 6 shows another embodiment of the invention. In this embodiment, the variable compliance device 162 has a robot adapter plate 164 that may be attached to a robot arm with fasteners inserted through holes 166 in the robot adapter plate 164. The variable compliance device 162 also has a housing 168 and a front cover 170, attached to the robot adapter plate 164 by a plurality of cap screws 172.
Three or more ball seats 174 are mounted around the inner circumference of the front cover 170. A bearing ball 176 is located on each ball seat 174. Each bearing ball 176 is contained within a ball chamber 178 formed by a ball seat 174 and the conical end 180 of a generally cylindrical pin 182.
The pins 182 are mounted around the outer circumference of a tool plate 184. The tool plate 184 is secured by the front cover 170 for limited movement relative to the housing 168. Movement of the tool plate 184 relative to the housing 168 is sensed by an inductive proximity switch 186 mounted on the housing 168.
An inflatable diaphragm 188 encloses a chamber 190 within the tool plate 184. Air can be injected into or expelled out of the chamber 190 through an air hook-up 192 and passageway 194. When air is injected into the chamber 190, the diaphragm 188 exerts a radially outward force on a piston 196. The piston 196 exerts a radially outward force on each of the pins 182. A high fluid pressure within the chamber 190 exerts a high force against the pins 182 and makes it difficult for the tool plate 184 to move relative to the housing 168. A reduced fluid pressure within the chamber 190 makes it easier for the tool plate 184 to move relative to the housing 168.
Another alternate embodiment of the invention, shown in FIG. 7, has a robot adapter plate 164, a modified housing 198, and a modified front cover 200, held together by cap screws 202. The front cover 200 secures a tool plate 204. A tool plate cover 206 is secured to the tool plate 204 by cap screws 208.
A single center pin 210 is mounted in the center of the tool plate cover 206, opposite a ball seat 212 mounted in the center of the housing 198. The center pin 210 and the ball seat 212 form a ball chamber 214 that houses a bearing ball 216.
Three or more additional cylindrical pins 218 are mounted around the tool plate 204. These pins 218 oppose a like plurality of ball seats 220 mounted on the front cover 200. The pins 218 and the ball seats 220 oppose one another to form ball chambers 222 that house bearing balls 224.
The tool plate 204 and the tool plate cover 206 house a pair of sensor plates 226 that bear against the ends of the pins 210 and 218. A Hall effect sensor 227 mounted on one of the sensor plates 226 looks across to a magnet 229 mounted on the other sensor plate 226 and detects any relative movement between the sensor plates 226.
A diaphragm 228 houses a chamber 230 between the two sensor plates 226. An air fitting 232 and a passageway 234 povide means for supplying air to the air chamber 230.
Increasing the fluid pressure within the chamber 230 causes the sensor plates 226 to exert a force against the pins 210 and 218. The increased force makes it more difficult for the tool plate 204 to move relative to the housing 198. Movement of the tool plate 204 relative to the tool plate cover 206 is senced by the sensor plates 226.
Only the preferred embodiments of the invention have been illustrated in the accompaying drawings and described in the detailed description. The invention is not limited to the embodiments disclosed, but is intended to embrace any alternatives, modifications, rearrangements, or substitutions of parts or elements as fall within the spirit and scope of the invention.
We claim:
1. A variable compliance device comprising:a tool plate for attachment to a tool; housing means for coupling the tool plate to a robot arm to allow limited longitudinal, lateral, and rotational movement of the tool plate relative to the robot arm; the tool plate and the housing means defining a central, axially extending passageway; bearings between said housing means and said tool plate to facilitate lateral and rotational movement of the tool plate relative to the housing means; a plurality of concave ball seats mounted on the tool plate and positioned at circumferentially spaced points around the central, axially extending passageway; a plurality of balls each recessed in one of the ball seats of the tool plate; a plurality of pins each slidably mounted on the housing means and each having a concave surface for operative engagement one of the balls in the concave ball seats so that longitudinal, lateral, or rotational movement of the tool plate relative to the robot arm caused by an outside force causes the pins to move relative to the housing means; and pnuematic bias means associated with the pins for exerting a force against the pins towards the concave ball seat to resist movement of the tool plate relative to the housing means and to restore the tool plate to its original position relative to the housing means after the outside force is removed.
2. A variable compliance device comprising:a tool plate for attachment to a tool; housing means for coupling the tool plate to a robot arm to allow limited longitudinal, lateral, and rotational movement of the tool plate relative to the robot arm; the tool plate and the housing means defining a central, axially extending passageway; a plurality of concave ball seats associated with the tool plate and located at circumferentially spaced points around the central, axially extending passageway; a bearing ball located in each ball seat for movement on the concave surface; a plurality of pins, each pin slidably mounted on the housing means and having a concave surface on a first end for engagement with a corresponding one of the bearing balls so that longitudinal, lateral, or rotational movement of the tool plate relative to the housing means caused by an outside force applied to the tool plate causes at least one of the pins to move relative to the housing means; and pneumatic adjustable bias means associated with all of the pins for exerting a force against all of the pins toward the bearing balls to resist movement of the tool plate relative to the housing means and to restore the tool plate to its original position relative to the housing means after the outside force is removed.
3. A variable compliance device as recited in claim 2, wherein the bias means is adjustable to exert a selected force against the pin.
4. A variable compliance device as recited in claim 2, wherein the bias means further comprises:an inflatable diaphragm operatively engaging the second end of the pin; and means for inflating the diaphragm to a selected pressure to resist slidable movement of the pin.
5. A variable compliance device as recited in claim 4, wherein the inflating means extends through the interior of the robot arm.
6. A variable compliance device as recited in claim 2, further comprising sensing means operatively associated with each pin for sensing movement of the associated pin relative to the robot arm beyond a selected point.
7. A variable compliance device as recited in claim 6, wherein the sensing means comprises:a subminiature basic switch; and a bearing ball initially held against the switch by the pin and released to activate the switch when the pin moves beyond a selected point relative to the robot arm.
8. A variable compliance device as recited in claim 2, wherein the pin is substantially cylindrical and the concave surface is on one end of the cylinder.
9. A variable compliance device as recited in claim 2, further comprising a piston between the pin and the bias means for transfering force from the bias means to the pin.
10. A variable compliance device as recited in claim 2, further comprising a quick change adapter mounted between the tool plate and the robot arm to allow tools to be quickly connected to and disconnected from the tool plate.
11. A variable compliance device as recited in claim 4, further comprising a quick change adapter mounted between the tool plate and the robot mounting arm to allow tools to be quickly connected to and disconnected from the tool plate.
12. A variable compliance device as recited in claim 11, further comprising means for providing fluid pressure to the quick change adapter to connect a tool to the tool plate or to disconnect a tool from the tool plate.
13. A variable compliance device as recited in claim 12, wherein the inflating means and the means for providing fluid pressure to the quick change adapter extend through the interior of the robot arm.
14. A variable compliance device as recited in claim 12, wherein the inflating means and the means for providing fluid pressure to the quick change adapter are outside of the robot arm.
15. A variable compliance device as recited in claim 2, wherein the concave ball seat and the concave surface on each pin have constant slope angles.
16. A variable compliance device as recited in claim 2, wherein the concave ball seat and the concave surface on each pin have changing slope angles to represent a selected spring constant.
| 1988-03-15 | en | 1989-12-05 |
US-44636889-A | Selective call receiver theft protection device
ABSTRACT
A selective call receiver allows reprogramming of the options stored within a code plug only after entry of a correct password. After a predetermined number of unsuccessful attempts to enter a correct password, the selective call receiver is user disabled such that the user may not reenable the selective call receiver without returning the receiver to the manufacturer or without replacing expensive components thereof.
FIELD OF THE INVENTION
This invention relates in general to electronic devices with reprogrammable memories, and in particular to selective call receivers with reprogrammable code plugs.
BACKGROUND OF THE INVENTION
The theft of electronic devices is on the rise because of the convenient size of the devices and the high monetary return a thief can receive for stolen devices. One such electronic device is a selective call receiver. Many electronic devices have a variety of options, some or all of which can be activated upon purchase. For individualization of a device, it is desirable that a user be able to alter some or all of the device's optional features. These options are typically stored in an electrical erasable, programmable read only memory (EEPROM), but can be stored in other programmable nonvolatile memory devices. Allowing the user the ability of reprogramming some or all of the options, however, also allows a thief to reprogram these options unless the electronic device is protected against unauthorized reprogramming.
Each selective call receiver has a unique selective call address that allows for the receiver to receive selective call messages so addressed. The selective call address is typically stored in an EEPROM called a code plug. Other selective call receiver options are customarily established by other information stored in the code plug. Regrettably, allowing code plug reprogrammability to the user also allows for possible reprogramming of the EEPROM unauthorized by the user.
Generally, stolen selective call receivers are useless unless the selective call address can be changed. If the selective call address remains unchanged, the new user of the selective call receiver could only receive messages intended for the previous owner. In various selective call receivers manufactured today, the frequency that the receiver operates on can be altered by reprogramming the code plug. Altering the frequency would allow the selective call receiver to operate within another selective call system making the purchase of the stolen selective call receiver more desirable. Also, the purchase of a stolen electronic device would be less desirable if the user could not take advantage of all of the options for which the device was designed.
Thus, what is needed is a method and apparatus for protected reprogrammability of an electronic device.
SUMMARY OF THE INVENTION
In carrying out the above and other objects of the invention in one form, there is provided an apparatus to allow authorized reprogramming of at least a portion of the options stored in an electronic device, such as a selective call receiver, and to user disable the electronic device if a predetermined password is not correctly entered within a predetermined number of attempts.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a selective call receiver according to the present invention.
FIG. 2 is a top front left perspective of a selective call receiver according to the present invention.
FIG. 3 is a bottom front right perspective of a selective call receiver according to the present invention.
FIG. 4 is a depiction of the preferred embodiment of the present invention.
FIG. 5 is a flowchart of the protected reprogramming operation of the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a selective call receiver comprises an antenna 10 for receiving signals coupled to a selective call receiver circuit 12 that demodulates the signals received. A microprocessor controller 14 is coupled to the receiver circuit 12 for processing the received signals. A memory 16 is coupled to the microprocessor controller 14 for storing those messages containing the address of the selective call receiver as determined by the microprocessor controller 14. A code plug 18 is preferably an electrical erasable, programmable read only memory (EEPROM) coupled to the microprocessor 14 for providing option information, such as the address and frequency of the selective call receiver, to the microprocessor 14. Also stored in the code plug 18 are configurations of various optional features which enhance the operation and/or performance of the selective call receiver, such as the length and types of various alerts and alarms, the type of code used by the selective call receiver (e.g., alphanumeric, numeric or voice) and various reminder chirps such as an unread message reminder chirp every half hour.
A serial communications interface 19 comprises a serial input/output data port that allows digital communication between a device outside the selective call receiver and the microprocessor 14. A display device 20 visually presents information and is controlled by the microprocessor controller 14. Alerts 22 provide alarms, such as audible and visual alerts, to inform the selective call receiver user of various events and is also controlled by the microprocessor controller 14. User controls 24 allow the user to command the microprocessor controller 14 to perform the selective call receiver operations such as selecting and reading messages and other selective call operations well known to those skilled in the art. The user controls 24 typically include control switches such as an ON/OFF control button, directional controls, and a message read control. A battery 26 is coupled to the receiver circuit 12, the microprocessor 14, the display 20 and the alerts 22 to provide power for the operation of the selective call receiver. For a more detailed description of the structure and operation of a selective call radio paging receiver of the type shown in FIG. 1, reference is made to U.S. Pat. No. 4,518,961, U.S. Pat. No. 4,649,538, and U.S. Pat. No. 4,755,816, all commonly assigned to the same assignee as the present invention, and the teachings of which are hereby incorporated by reference.
Referring next to FIG. 2, the selective call receiver comprises a housing 30 including openings 32a and 32b in a front plate 34 with user selectable control buttons 24a and 24b, and 24c, respectively, accessible therethrough. A visual alert 22a is also viewable through opening 32a. An audible alert 22b is mounted behind slotted opening 32c. The display device 22 is a liquid crystal display (LCD) viewable through another opening 36 in a top plate 38. The display 20 of the preferred embodiment is capable of displaying alphanumeric information. Each activation of the user selectable control buttons 24a and 24b select one of the messages stored in memory 16 (FIG. 1). By activating the user selectable control button 24c, the user can display the selected stored message on the display device 20. A clip 40 is mounted on a back plate 41 of housing 30 to allow the user to mount the selective call receiver on the user's clothing, such as a belt or a pocket.
Referring to FIG. 3, a right plate 42 of the selective call receiver has an ON/OFF power switch 44 mounted thereon. Other user selectable controls could be added to the selective call receiver but are not essential to the operation of the present invention. A bottom plate 46 of the selective call receiver has an opening 48 for inserting the battery 26 (FIG. 1). A battery cover 50 restrains the battery 26 within the selective call receiver. The serial communications interface 19 has three receptacles 52a, 52b, and 52c for receiving three conductive plugs thereby forming a digital data input/output port.
Referring next to FIG. 4, an interface unit 60 contains the three conductive plugs to allow the selective call receiver 10 to be physically and electrically coupled thereto. In the preferred embodiment, the interface unit 60 allows reprogramming of the code plug 18 (FIG. 1) via a program in the microprocessor 14 of the selective call receiver. Reprogramming of the code plug 18 is handled by a computer 62 via a computer data port 64, such as an RS232 data port. The computer 62 could be a personal computer and the interface unit 60 could additionally serve as a battery charger for charging the battery 26 (FIG. 1).
Referring to FIG. 5, the processing of the reprogramming routine of the computer 62 (FIG. 4) starts at step 70, where the selective call receiver is accessed by the computer 62 via the interface unit 60 and the serial communications interface 19 (FIG. 3). The computer 62 places the selective call receiver in a upload mode 72, whereby the computer 62 uploads the information stored in the code plug 18. A password is requested from the user 74. The password is received 76 from a keyboard of the computer 62. If the password data received is equivalent to the password information stored in the code plug 78, a lockout counter LOCKOUTCNT is initialized to zero 80. The code plug can then be read or reprogrammed 84. The password information in the code plug can be encrypted to prevent anyone tampering with the serial communications interface 19 from reading the password information.
If the received password data is not equivalent to the password information stored in the code plug 78, LOCKOUTCNT is incremented by one 90. If LOCKOUTCNT does not equal seven 92, the reprogramming routine requests another password from the user 74. If LOCKOUTCNT equals seven 92, the selective call receiver is user disabled 94 and no further attempts to enter a correct password by the user will be allowed. The selective call receiver can be user disabled in a variety of ways. In the preferred embodiment, the display 20 (FIG. 2) displays an alphanumeric message stored in nonvolatile memory every time that the display 20 is activated. The alphanumeric message is "PAGER DISABLED". In addition, when the receiver is user disabled an audible alert 22b and/or a visual alert 22a could be activated either continuously or intermittently which has the added advantages of being annoying to the user who attempted unauthorized reprogramming and quickly discharging the battery 26 causing the receiver to have no operating power.
An alternate embodiment would allow for the receiver to be functionally disabled upon the entry of a first incorrect password but would allow subsequent entries of passwords up to the predetermined number of attempts. After a predetermined number of failed attempts to enter the correct password, no further attempts to enter a correct password would be allowed. A subsequently entered correct password would functionally reenable the selective call receiver.
Once user disabled, the receiver can only be reenabled by returning the selective call receiver to a manufacturer designated repair facility or by replacing the parts so disabled. In the preferred embodiment, purchase of the user disabled parts for replacement amounts to a price substantially equivalent to the purchase of a new selective call receiver, thereby making theft of the protected selective call receivers economically disadvantageous.
We claim:
1. An electronic device comprising:programmable memory means for storing password information and a predetermined encryption algorithm; interface means for transmitting information to and receiving data from an external programming device; data conversion means for translating said data received according to said predetermined encryption algorithm to obtain password data and reprogramming data; reprogramming means for reprogramming said programmable memory means with said reprogramming data if said password data is substantially equivalent to said password information; and disabling means for user disabling said electronic device if said password data is not substantially equivalent to said password information on each of a predetermined number of inputs.
2. The electronic device of claim 1 further comprising counter means for initializing a lockout counter if said password data is substantially equivalent to said password information and for counting each input of said password data where said password data is not substantially equivalent to said password information, wherein said disabling means user disables said electronic device in response to said lockout counter counting to said predetermined number.
3. The electronic device of claim 1 wherein said electronic device comprises at least one output device and wherein said disabling means user disables said at least one output device if said password data is not substantially equivalent to said password information on each of said predetermined number of inputs.
4. The electronic device of claim 1 further comprising lockout means for user disabling said input means if said password data is not substantially equivalent to said password information on each of said predetermined number of inputs.
5. A selective call receiver comprising:a reprogrammable memory; an input/output interface for allowing communication between said reprogrammable memory and an external programming device; and device disabling means for user disabling said selective call receiver in response to a predetermined number of unauthorized attempts by said external programming device to reprogram at least a portion of said reprogrammable memory.
6. The selective call receiver of claim 5 further comprising output means for presenting information to a user, and wherein said device disabling means comprises:a lockout counter for counting each of said unauthorized attempts to reprogram said reprogrammable memory; and output disabling means for user disabling said output means in response to said lockout counter counting to said predetermined number.
7. The selective call receiver of claim 5 wherein said device disabling means further comprises:lockout means for preventing any further attempts to reprogram said reprogrammable memory in response to said predetermined number of unauthorized attempts to reprogram at least said portion of said reprogrammable memory.
8. The selective call receiver of claim 6 further comprising:authorization means for generating a first signal if password data received from said external programming device via said input/output interface is substantially equivalent to password information stored within said reprogrammable memory and for generating a second signal if said password data is not substantially equivalent to said password information; reprogramming means for reprogramming in response to said first signal at least a portion of said reprogrammable memory with reprogramming data received from said external programming device via said input/output interface; and counter adjusting means for initializing said lockout counter for each occurrence of said first signal and for incrementing said lockout counter for each occurrence of said second signal.
9. The selective call receiver of claim 6 wherein said output means comprises a display device.
10. The selective call receiver of claim 6 wherein said output means comprises an audio alert device.
11. The selective call receiver of claim 6 further comprising interface disabling means for user disabling said input/output interface in response to said lockout counter counting to said predetermined number.
12. The selective call receiver of claim 9 wherein said display device comprises an alphanumeric display device.
13. The selective call receiver of claim 9 wherein said output means further comprises an audio alert device.
14. The selective call receiver of claim 10 wherein said output disabling means comprises alert means for activating said audio alert device in a predetermined manner.
15. The selective call receiver of claim 12 wherein said output disabling means comprises stored message display means for providing stored message information to said display device for presentation thereon.
16. The selective call receiver of claim 13 wherein said output disabling means comprises continuous alert means for continuously activating said audio alert device in response to said lockout counter counting to said predetermined number.
17. The selective call receiver of claim 13 wherein said output disabling means comprises intermittent alert means for intermittently activating said audio alert device in response to said lockout counter counting to said predetermined number.
18. The selective call receiver of claim 14 wherein said alert means intermittently activates said audio alert device.
19. The selective call receiver of claim 14 wherein said alert means continuously activates said audio alert device.
20. The selective call receiver of claim 15 wherein said stored message display means provides said stored message information to said display device for continuously presenting thereon.
21. The selective call receiver of claim 15 wherein said stored message display means provides said stored message information to said display device for intermittently presenting thereon.
22. The selective call receiver of claim 15 wherein said stored message display means provides said stored message information to said display device for presentation thereon upon each activation of said display device.
23. The selective call receiver of claim 8 further comprising data conversion means for de-encrypting a password received from said external programming device according to a predetermined algorithm stored within said reprogrammable memory to obtain said password data for providing to said authorization means.
24. The selective call receiver of claim 23 wherein said data conversion means de-encrypts data received from said external programming device according to said predetermined algorithm to obtain said reprogramming data for providing to said reprogramming means.
25. In an electronic device having a reprogrammable memory, an input/output port for communication with an external device, and at least one output device, said at least one output device capable of being user disabled such that a user of the electronic device may not reenable the at least one output device, a method for reprogramming the reprogrammable memory comprising the steps of:(a) establishing communications via the input/output port with an external programming device; (b) receiving a password from the external programming device; (c) determining whether said password received from the external programming device is equivalent to a predetermined password stored in said reprogrammable memory; (d) repeating steps (b) and (c) if said password received is not equivalent to the predetermined password and if a predetermined number of said passwords have not been received, said predetermined number greater than one; (e) user disabling said at least one output device after said predetermined number of said passwords so received are determined to be not equivalent to the predetermined password; (f) receiving reprogramming information from said external programming device if said password is equivalent to the predetermined password; and (g) reprogramming said reprogrammable memory in response to said reprogramming information.
26. The method according to claim 25 wherein said at least one output device comprises a display and a control means for activating said display, and said step (e) of user disabling said at least one output device of said electronic device includes the step of displaying a predetermined message in response to all subsequent activations of said display by said control means.
27. The method according to claim 25 wherein said at least one output device comprises an audible alert, and said step (e) of user disabling said at least one output device includes the step of activating said audible alert in a predetermined manner in response to said predetermined number of said passwords so received not equivalent to said predetermined password.
28. The method according to claim 25 further comprising the step of(h) preventing further reception of said reprogramming information after said predetermined number of said passwords are received without receiving said predetermined password.
29. The method according to claim 25 wherein said step (b) of receiving said password comprises the steps of:(i) receiving an encrypted password from said external programming device; and (j) converting said encrypted password to said password according to a predetermined de-encrypting algorithm stored in said reprogrammable memory.
| 1989-12-05 | en | 1991-12-17 |
US-14186598-A | Chemical cabinet employing air flow baffles
ABSTRACT
This invention concerns a cabinet for chemical canister storage and dispensing. More particularly, this invention concerns a cabinet structure comprising: walls connected to a base and a top to provide an enclosed structure; wherein at least one wall has at least one vent opening on the lower portion thereof; wherein an upper portion of the cabinet has a exhaust outlet hole; wherein one or more baffles are positioned within the cabinet structure to direct a flow of air over fittings of a canister, a cabinet manifold, or both as the air moves from the at least one vent opening to the exhaust outlet hole.
BACKGROUND OF INVENTION
This invention generally pertains to a cabinet for housing canisters of chemicals.
Cabinets for housing canisters of chemicals are well known. Many of these cabinets include valves and weldments which handle the chemicals during dispensing of the chemicals. Likewise, the canisters often have weldments and/or valves attached thereto. Previous cabinets had holes at the base for in-flow of air and an exhaust port out the top. There are continued efforts to improve these cabinets.
SUMMARY OF INVENTION
The present inventor has found that prior cabinets could be rendered safer by channeling the in-flow of air over weldments and valves, which are the most likely places where leaks in the system might occur. If the air flow were directed over these points, any leaks would be more quickly evaporated and pulled into the exhaust, rather than for example dripping and collecting at the base of the cabinet. This invention provides a solution to these and other disadvantages and problems of the prior chemical cabinets.
In one broad respect, this invention is a cabinet structure comprising: walls connected to a base and a top to provide an enclosed structure; wherein at least one wall has at least one vent opening on the lower portion thereof; wherein an upper portion of the cabinet has a exhaust outlet hole; wherein one or more baffles are positioned within the cabinet structure to direct a flow of air over fittings of a canister, a cabinet manifold, or both as the air moves from the at least one vent opening to the exhaust outlet hole.
In another broad respect, this invention is a cabinet useful for holding a canister, comprising: an enclosure adapted to house a canister that has fittings attached thereto, one or more baffles attached to the inside of the enclosure, wherein the enclosure includes at least one vent opening on the lower portion of the enclosure and at least one exhaust hole on the upper portion of the enclosure; wherein the one or more baffles are adapted to direct a flow of air that enters the enclosure through at least one vent opening over the fittings of the canister when the canister is positioned for normal use within the enclosure, or over a valve manifold in the enclosure, or both.
In another broad respect, this invention is a method of increasing the flow of gas through at least a portion of a chemical supply cabinet, comprising: providing a cabinet structure comprising: rectangular walls connected to a base and a top to provide an enclosed structure; wherein at least one wall has at least one vent opening on the lower portion thereof; wherein either the top or a wall includes an exhaust outlet hole; providing one or more baffles that are positioned within the cabinet structure to direct a flow of air over fittings of a canister, a cabinet manifold, or both as the air moves from the at least one vent opening to the exhaust outlet hole.
Advantageously, the present invention provides a cabinet structure in which air flow is channel past the fittings of a canister to thereby increase flow velocity over the fittings. This provides enhanced safety since any liquid in the area of the fittings is more rapidly evacuated from the cabinet than has been previously accomplished. Furthermore, use of baffles provides a simple and inexpensive mechanism by which increase flow is accomplished. It is envisioned that baffles can be added during initial construction of a cabinet. Alternatively, the baffles may be added as a retrofit to an existing cabinet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a front view of a cabinet of this invention.
FIG. 2 depicts the top of the cabinet of this invention.
FIG. 3 depicts a front view of the cabinet with doors closed and the interior not being shown.
FIGS. 4a, 4b, 4c, and 4d depict exploded, front, front, and top views, respectively of the baffles employed in this invention.
FIGS. 5a and 5b depict illustrate a cabinet of this invention that may be constructed to render it suitable for use in hazardous, explosive environments by isolating all electronic components in areas that are blanketed with an inert gas.
FIG. 6 depicts a representative bulk chemical delivery system that may be used in the practice of this invention.
FIGS. 7A, 7B, and 7C illustrate a representative valve manifold box which may be used in this invention.
FIGS. 8A-8F illustrate another representative cabinet of this invention.
DETAILED DESCRIPTION OF THE INVENTION
A general, non-limiting description of metallic canisters, chemical refill system, operating procedures, components, starting manifold system, and so forth, which may be used in the cabinet of this invention is set forth in U.S. Pat. Nos. 5,465,766; 5,562,132; 5,590,695; 5,607,002; and 5,711,354, all of which are incorporated herein by reference. It is envisioned that other manifolds, canisters, refill systems and so forth can be employed in the practice of this invention. The particular type and structure of the manifolds, canisters, refill systems, and the like is not critical in the practice of this invention.
A representative cabinet of this invention is shown in FIG. 1. The cabinet in FIG. 1 includes a rectangular walls connected to a base and a top to provide an enclosed structure. At least one wall of the cabinet has at least one vent opening on the lower portion thereof (i.e., lower half). The top typically includes an exhaust outlet hole, but the exhaust may also be expelled through one or more holes in any wall, preferably in the upper half of the cabinet. One or more baffles may be positioned within the cabinet structure to direct a flow of air over fittings of a canister, a cabinet manifold, or both as the air moves from the at least one vent opening to the exhaust outlet hole. More particularly, cabinet 10 is adapted to house one or more canisters 100 that include weldments and fittings 110. As shown in FIG. 1, the cabinet 10 includes base 11 and top 12 which includes a exhaust hole (not shown). The cabinet has a grating 13, and inclined surfaces 14 leading to a trough 15. Darkened lines 16 depict the baffles which direct air from vent opening (not shown) to exhaust (not shown). Included in cabinet 10 are valve manifolds 17 by which air is directed by the baffles. The manifolds include valves 18 and tubing 19. The cabinet 10 may be made up of four walls. In FIG. 1, one wall immediately faces the viewer, one wall is positioned behind the canisters 100, one wall lies in the plane of edge 21 and perpendicular to the plane of the drawing, and one wall lies in the plane of edge 22 and perpendicular to the plane of the drawing. Tubing 23 leads out of the cabinet 10 through holes 24 in the top as shown in FIG. 2. FIG. 2 also depicts exhaust hole 25. FIG. 3 shows doors 26 and 27, cut-out for touch screen display 28, door handle areas 29.
As shown in FIGS. 4a, 4b, 4c, and 4d the baffles include fitting holes 30 which fit over the fittings of the canisters. The decrease in area through which air may flow serves to increase the flow rate of air over the canister fittings.
In FIG. 4a there is shown one embodiment of a baffling system 400 which may be used in the cabinet of this invention such as is depicted in FIG. 1. The system 400 includes a primary baffle plate 401. The plate 400 may include one or more holes 401. A hole 401 may be cut or bored from the material used to make the plate 400. However, it should be appreciated that the plate need not be monolithic, and instead may be assembled from two or more segments. A hole 401 preferably is positioned on the plate 400, and is of such dimensions, such tat fittings of a given canister (such as depicted in FIG. 1) may pass through hole 401. In this way, the plate 400 may be fitted over a canister so that gas, which is moving through the hole from the canister-side of the plate 400, is directed over the fittings. Thus, the holes are adapted to direct flow of gas over the fittings. It should be appreciated that while the plate 400 in FIG. 4a shows two holes 401, a single hole 401 can be alternatively employed if only one canister is housed in the cabinet, or three or more holes 401 may be included if there are multiple canisters.
The plate 40 has dimensions adapted to provide a seal against the walls of the cabinet, with or without the assistance of framing (e.g., frame 410) that serves to support or anchor the plate 400. The plate 400 may alternatively be configured with flaps so that the plate may be fastened directly to the walls rather than to the frame. The plate may be fastened using any fastener, such as bolts, rivets, tape, appropriate adhesive, and the like, or may be positioned in appropriately configured grooves or the like in the walls.
The system 400 may also include one or more vertical panels 420 positioned to channel gas flow from the holes 401 over the length of the fittings of the canister. In this manner a higher flow rate of gas may be maintained over the entire length of the fittings.
The plate 401 and panels 420 may be made of the same or different material. The materials used to fabricate these components of a system 400 may be metal such as stainless steel, polymeric composition such as plexiglass, glass, and the like. The materials may be the same type as the cabinet, or may be different. Typically, the material is a polymer. In general it is desirable for the material to be resistant to corrosion from the chemicals stored in the canister.
One embodiment of the system that may be included in the cabinet 101 of FIG. 1 is illustrated in FIGS. 36 and 37 of U.S. Pat. No. 5,711,354, incorporated herein by reference.
A cabinet used in the practice of this invention may be constructed to render it suitable for use in hazardous, explosive environments. In general, this is accomplished by isolating all electronic components in areas that are blanketed with an inert gas. In this way, a spark emanating from an electronic component will be in an environment having essentially no oxygen, which significantly reduces the likelihood of an explosion due to vapors that may be present in the cabinet. One non-limiting, representative embodiment of this cabinet is depicted in FIGS. 5A and 5B.
In FIGS. 5A and 5B, the numbers shown correspond to the components described above with respect to FIG. 3, with the proviso that in FIGS. 5A and 5B the numbers are followed with the letter "A". It is seen that in FIGS. 5A and 5B, the control box 370A and touch screen 393A have been isolated in the cabinet 700. The control box 370A may include electronic instrumentation (not shown) such as the process control instrumentation. During use the housings for the control box 370A and 393A are blanketed in an inert gas, which may be supplied by one or more purge lines 771. The one or more purge lines 771 may be connected to the housing for touch screen 393A. Additional conduits may be employed to allow inert gas to flow to the control box, directly, that is not connected to the purge line 771. In this way, a single line may be employed to provide a inert gas blanket over both the touch screen and the control box. One or more pressure relief valves 772 may be used to provide initial purge and to vent excess inert gas from the housings used for the control box and the touch screen. A purge control unit 773 may be included which serves to time the initial high pressure purge, and to monitor and meter inert gas to the isolated components. Conventional purge controllers may be employed such as is available from Expo Safety Systems. A door 390A may include a door lock 395A and vents 396A.
As shown in FIG. 5B, the touch screen 393A may be encased in a housing depicted by phantom lines 394A. To fully isolate the touch screen, additional components may be employed such as use of a plastic window (e.g., an electro-conductive polycarbonate sheet) 394D that is held in place by gasket material 384B, plastic (e.g., acrylic) spacer 384C having holes for purge gas feed, touch screen window gasket material 394E, and purge enclosure frame 394F. When the touch screen is further isolated in this representative fashion, the touch screen may be accessed by use, for example, of a steel ball 394G which is manipulated through use of magnetic wand and lanyard 394H.
The baffled cabinets of this invention may also be used in the chemical delivery system 100 as shown in FIG. 6. The system includes at least one bulk canister cabinet 101 which houses a bulk canister, not shown, that supplies chemical to the secondary (intermediate) cabinets either directly or indirectly through manifold boxes 110, and ultimately to the process tool which uses the chemical. The system may optionally include a second bulk cabinet 102 that holds, as shown by cutaway view, a second bulk canister 103 which typically has a capacity of about 200 liters or more. The second bulk canister can supply chemical to the valve manifold boxes when the first bulk canister 101 is being replaced, refilled, repaired, or for any other reason. Alternatively, second bulk cabinet 102 may be employed to refill first cabinet 101 during normal operation.
The cabinet 101 or 102 may include a manifold 104 which may be the same or different in each cabinet. Line 105 from the second canister may be connected to the manifold of the first canister in cabinet 101. If second cabinet 102 is used, a switch over capability, such as a switch over manifold, may be employed which allows the system to provide chemical from second cabinet 102 while first cabinet 101 is being replaced or refilled. Switch over to second bulk canister 102 may be automated such as by use of process control instrumentation well known to one of skill in the art, such as is available from various commercial sources, such as Omron, Inc. Alternatively, overall system management may be controlled using a programmable computer control system that manages canister replacement and purge functions and controls and monitors system parameters, such as a MARS™ Control System as described for example in U.S. Pat. Nos. 5,465,766 and 5,711,354. The controller may also administrate a purge sequence and normal run mode. A purge sequence serves to purge the manifold and canister connection lines prior to removal of an expired bulk chemical supply canister or after a new canister is installed. During a run mode, the system will provide chemical to the process tool, which may be initiated after installation of a bulk chemical supply canister. In one respect, the overall system may be controlled by a single controller in the bulk canister cabinet, with or without a controller on the secondary cabinet and the valve manifold box to supply data back to the primary controller. Alternatively, each bulk and secondary cabinet, and each valve manifold box, may be equipped with a separate controller to control the functions thereof.
Lines 106 lead from the manifold in cabinet 101 to one or more valve manifold boxes such as valve manifold boxes 110. Any number of valve manifold boxes 110 may be employed. In one embodiment, up to four boxes are used. Each box 110 may contain a manifold 111 such as depicted in FIGS. 7A, 7B, and 7C, discussed herein. The valve manifold boxes 110 serve to split a stream of chemical by a distribution manifold into multiple lines 112 that lead to either a process tool which uses the chemical or to secondary cabinets 120 and 125 which house one or more smaller canisters 121. Each cabinet may contain any desired number of canisters, and one or more canisters may contain a different chemical that may be supplied to a process tool through a separate distribution manifold. In FIG. 6, secondary cabinet 120 houses two smaller canisters 121 while secondary cabinet 125 houses one smaller canister 121. The precise configuration of the manifold in the valve manifold box is not critical in the practice of this invention so long as the function of providing a stream of chemical to the balance of the system and process tool is achieved. The configuration of the valves in the valve manifold box may be varied to allow for serviceability of the components downstream of the valve manifold box and to allow for independent purging and maintenance of individual lines. Optionally, the line from a manifold box 110 to a secondary cabinet 120 may be disconnected and the system designed and programmed to switch over so that a refill canister 121 delivers make up chemical to another canister 121 with the other canister supplying chemical to the process tool. To facilitate change out of the canister 121 designated to primarily deliver chemical to the process tool, the manifold may be designed, and the controller programmed to enable the refill canister 121 to deliver chemical to the process tool. Typically, however, if either the refill or supply canister is being changed out or the like, the system is designed so that chemical from the manifold box 110 switches over to directly feed the process tool. Process tools may alternatively be fed directly from the valve manifold box in the absence of a secondary cabinet. Similarly, in addition to providing chemical to at least one manifold box, the bulk cabinet may also provide chemical directly to one or more process tools. The valve manifold box may include any number of output lines, and typically includes up to four output lines. In FIG. 6, four output lines are employed. The system of FIG. 6 may be used with only one large cabinet or three or more bulk cabinets.
A valve manifold box 200 which may be used in the practice of this invention is depicted in FIGS. 7A, 7B, and 7C. In FIG. 7A, inlet valve 210 receives chemical as from an exit line from the supply manifold of FIG. 6. Inlet valve 210 may be a manual or pneumatic valve or a dual activator valve that would allow full purging of the manifold if there is a need to service the manifold valves. It is contemplated that a valve manifold 110 may optionally receive chemical from multiple sources, such as from two or more bulk canisters. The use of welded connections to the inlet valve and pneumatic activators may enhance the safety considerations relating to spill detection. A line 211 from the inlet valve 210 leads to a group of two or more exit ports, with four exit ports being depicted in FIG. 7A. Line 211 is pressurized by gas, such as helium, from pressure line 220. Pressure line 220 is supplied gas via a source of gas (not shown) which delivers pressurized gas to gas inlet valve 221, thereafter flowing through line 222 and regulator valve 223 which controls the flow into line 220. Pressure line 220 is optional, although typically employed for practicality. The chemical is split in the splitter section 230 of the valve manifold box 200 via two or more pairs of properly ported purge valves 231 and liquid control valves 232. With liquid control valves 232 closed, the valve porting still allows purge gas from purge valve 231 to flow across the top of the seat of liquid control valves 232 and into the exit ports 234 that may couple to an output line that feeds an intermediate cabinet or process tool which may optionally employ an on-board refillable container. This purging allows the purge or draining of liquid in one branch while the others remain on-line. Output valves 233 regulate the output of chemical through each of the output lines. The valve manifold may be contained within housing 240 which may be in the form of a rectangular box made up of six walls. The housing 240 may be made of any suitable material such as sheet metal which is assembled using conventional methods such as by welding or use of suitable fasteners. The front wall may optionally be made of a clear material such as Plexiglas. The housing 240 may include appropriately sized and positioned holes for inlet and outlet lines. In addition, the manifold box may include a liquid sensor and drain outlet from which liquid chemical may be removed that has collected on the bottom of the manifold box. The bottom of the box may be sloped so that a spill may collect in a particular location. The sensor may provide a signal to the controller whereby an operator is alerted, the line to the manifold box is shut down, and so forth.
FIG. 7B is a first side view of the valve manifold box 200. In FIG. 7B, a side view of the inlet side of the valve manifold box, there are removable plates on each end to allow for more flexibility and easier changes to piping and/or connections to the valve manifold box. The removable plate may be a split plate.
FIG. 7C is a second side view of the valve manifold box 200. In FIG. 7C, the outlet side is shown which also uses removal plates and in this case it is a split plate to allow ease of removal to add additional lines while one or more are already in place.
FIGS. 8A-8F illustrate various views of another representative cabinet of this invention. The baffles include holes 30 that serve to direct flow over the manifold. This cabinet also includes splash guards 50 that serve to protect an operator from chemical upon opening the doors to the cabinet.
As used herein, "process tool" refers to a process tool which ultimately uses the chemical provided by the system of this invention. The system of this invention may thus provide chemicals to any process tool which requires a chemical during its use. Such process tools may include apparatuses for chemical vapor deposition, photolithography, and etch applications. These process tools are frequently used in the fabrication of electronic devices such as integrated circuits, memory circuits, flat panel display, possibly fiber optic manufacturing, multichip modules (e.g., "MCMs"), and so forth. In addition, it should be appreciated that while this invention may be used to supply a chemical such as TEOS to a process tool such as a CVD reactor used in the fabrication of integrated circuits, memory devices, and the like, the system may be used in other processes.
The types of chemicals which may be transferred using the bulk delivery system of this invention may vary widely depending on the type of process tool and desired outcome. Nonlimiting examples of representative chemicals include tetraethylorthosilicate ("TEOS"), triethylphosphate, trimethyl phosphite, trimethyl borate, titanium tetrachloride, tantalum compounds, and the like; solvents such as chlorinated hydrocarbons, ketones such as acetone and methylethylketone, esters such as ethyl acetate, hydrocarbons, glycols, ethers, hexamethyldisilazane ("HMDS"), and the like; solid compounds dispersed in a liquid such as barium/strontium/titanate cocktails (mixtures). If the chemical being delivered is solid suspended in an organic liquid, the manifold may be designed so as to allow for liquid flush of all the lines to prevent solids accumulating in the lines upon evaporation of the organic liquid. If dispersions are employed, it is preferable to flush the lines out with liquid solvents such as triglyme or tetrahydrofuran (THF) so that compounds are not precipitated in the lines when the lines are depressurized. These examples of chemicals are not intended to be limiting in any way. The chemicals may be of a variety of purities, and mixtures of chemicals can be used. In one embodiment, a single type of chemical is employed. A given chemical may advantageously have a purity of 99.999% or more with respect to trace metals.
Further modifications and alternative embodiments of this invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. Equivalent elements may be substituted for those illustrated and described herein, and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention.
What is claimed is:
1. A cabinet structure comprising:rectangular walls connected to a base and a top to provide an enclosed structure; a valve manifold within the cabinet structure that is attached to a wall; a baffle structure that encloses the valve manifold;wherein at least one wall has at least one vent opening on the lower portion thereof; wherein either the top or a wall includes an exhaust outlet hole; wherein the baffle structure directs a flow of air over the valve manifold as the air moves from the at least one vent opening to the exhaust outlet hole.
2. The cabinet structure according to claim 1 wherein the structure includes four walls.
3. The cabinet structure according to claim 1 wherein the top includes at least one hole for lines from the canister, cabinet manifold or both.
4. The cabinet structure according to claim 1 wherein one wall is composed of two doors.
5. The cabinet structure according to claim 1 wherein the baffle structure is made of a plastic.
6. The cabinet structure according to claim 1 further comprising a canister connected to the valve manifold in the cabinet via fittings on the canister, and wherein the canister contains a volatile chemical.
7. A cabinet useful for holding a canister, comprising:an enclosure adapted to house a canister that has fittings attached thereto, a valve manifold that is within and attached to the cabinet structure; one or more baffles attached to the inside of the enclosure that encloses the valve manifold,wherein the enclosure includes at least one vent opening on the lower portion of the enclosure and at least one exhaust hole on the upper portion of the enclosure; wherein the one or more baffles are adapted to direct a flow of air that enters the enclosure through at least one vent opening over the valve manifold in the enclosure.
8. A method of increasing the flow of gas through at least a portion of a chemical supply cabinet, comprising:providing a cabinet structure comprising:rectangular walls connected to a base and a top to provide an enclosed structure;wherein at least one wall has at least one vent opening on the lower portion thereof; wherein either the top or a wall includes an exhaust outlet hole; providing a baffle structure that together with three walls and the top encloses the valve manifold, wherein the baffle structure has at least one hole that directs the air that moves from the at least one vent opening to the exhaust outlet hole so that the air flows over the valve manifold.
9. Thc method according to claim 8 wherein the structure includes four walls.
10. The method according to claim 8 wherein the top includes at least one hole for lines from the canister, valve manifold or both.
11. The method according to claim 8 wherein one wall is composed of two doors.
12. The method according to claim 8 wherein the baffle structure is made of a plastic.
13. The method according to claim 8 further comprising a canister connected to the valve manifold in the cabinet via fittings on the canister, and wherein the canister contains a volatile chemical.
| 1998-08-28 | en | 2000-08-22 |
US-78658291-A | Method of making improved polyester filaments, yarns and tows
ABSTRACT
Air-jet texturing with drawing, especially cold-drawing, or hot-drawing or other heat-treatments of spin-oriented crystalline polyester filaments, and particularly polyester feed yarns, that have been prepared by spinning at speeds of, e.g., 4 km/min, and have low shrinkage and no natural draw ratio in the conventional sense, provides useful technique for obtaining uniform drawn filaments of desired denier and thereby provides improved flexibility to obtain air-jet textured filaments and yarns of various denier. The resulting yarns have useful properties that are improved in certain respects.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 07/338,251, filed by Knox and Noe Apr. 14, 1989, which is now allowed and to issue as U.S. Pat. No. 5,066,447, and which is sometimes referred to herein as the parent application, but is also itself a continuation-in-part application of application Ser. No. 07/053,309, filed May 22, 1987, as a continuation-in-part of application Ser. No. 824,363, filed Jan. 30, 1986.
TECHNICAL FIELD
This invention concerns improvements in and relating to polyester (continuous) filaments, especially in the form of textured yarns, and more especially to a capability to provide from the same feed stock such polyester continuous filament yarns of various differing deniers, as desired, and of other useful properties, including improved processes; new polyester yarns, resulting from such processes, and downstream products from such filaments and yarns.
BACKGROUND OF PARENT APPLICATION
Textile designers are very creative. This is necessary because of seasonal factors and because the public taste continually changes, so the industry continually demands new products. Many designers in this industry would like the ability to custom-make their own yarns, so their products would be more unique, and so as to provide more flexibility in designing textiles.
Polyester (continuous) filament yarns have for many years had several desirable properties and have been available in large quantities at reasonable cost, but, hitherto, there has been an important limiting factor in the usefulness of most polyester flat yarns to textile designers, because only a limited range of yarns has been available from fiber producers, and the ability of any designer to custom-make his own particular polyester flat yarns has been severely limited in practice. The fiber producer has generally supplied only a rather limited range of polyester yarns because it would be more costly to make a more varied range, e.g. of deniers per filament (dpf), and to stock an inventory of such different yarns.
Also, conventional polyester filaments have combinations of properties that, for certain end-uses, could desirably be improved, as will be indicated hereinafter. It is important to recognize that what is important for any particular end-use is the combination of all the properties of the specific yarn (or fiber), sometimes in the yarn itself during processing, but also in the eventual fabric or garment of which it is a component. It is easy, for instance, to reduce shrinkage by a processing treatment, but this modification is generally accompanied by other changes, so it is the combination or balance of properties of any filament (or staple fiber) that is important. Generally, hereinafter, we refer to flat (i.e., untextured) filament yarns. It will be recognized that, where appropriate, the technology may apply also to polyester filaments in other forms, such as tows, which may then be converted into staple fiber, and used as such in accordance with the balance of properties that is desirable and may be achieved as taught hereinafter, but the advantage and need that the invention satisfies is more particularly in relation to flat filament yarns (i.e. untextured continuous filament yarns), as will be evident.
For textile purposes, a yarn must have certain properties, such as sufficiently high modulus and yield point, and sufficiently low shrinkage, which distinguish these yarns from feeder yarns that require further processing before they have the minimum properties for processing into textiles and subsequent use. These feeder yarns are sometimes referred to as feed yarns, which is how we refer to them herein, for the most part. Conventionally, flat polyester filament yarns used to be prepared by melt-spinning at low speeds (to make undrawn yarn that is sometimes referred to as LOY) and then drawing and heating to reduce shrinkage and to increase modulus and yield point.
It has long been known that such undrawn (LOY) polyester filaments draw by a necking operation, as disclosed by Marshall and Thompson in J. Applied Chem., 4, (April 1954), pp. 145-153. This means that the undrawn polyester filaments have a natural draw ratio. Drawing such polyester filaments has not been generally desirable (or practiced commercially) at draw ratios less than this natural draw ratio because the result has been partial-drawing (i.e., drawing that leaves a residual elongation of more than about 30% in the drawn yarns) that has produced irregular "thick-thin" filaments which have been considered inferior for most practical commercial purposes (unless a specialty yarn has been required, to give a novelty effect, or special effect). For filament yarns, the need for uniformity is particularly important, more so than for staple fiber. Fabrics from flat (i.e. untextured) yarns show even minor differences in uniformity from partial drawing of conventional undrawn polyester yarns as defects, especially when dyeing these fabrics Thus, uniformity in flat filament yarns is extremely important. The effect of changing the draw ratio within the partial-draw-range of draw ratios (below the natural draw ratio) has previously had the effect of changing the proportions of lengths of drawn and undrawn filament in previous products. Thus, hitherto it has not been possible to obtain from the same LOY feed yarn two satisfactory different uniform yarns whose deniers per filament (dpfs) have varied from each other's by as much as 10%, because one of such yarns would have been non-uniform (or filaments would have broken to an unacceptable extent).
Undrawn polyester filaments have been unique in this respect because nylon filaments and polypropylene filaments have not had this defect. Thus, it has been possible to take several samples of a nylon undrawn yarn, all of which have the same denier per filament, and draw them, using different draw ratios, to obtain correspondingly different deniers in the drawn yarns, as desired, without some being irregular thick-thin yarns, like partially drawn polyester filaments. This is pertinent to a relatively new process referred to variously as "warp-drawing", "draw-warping" or "draw-beaming", as will be evident herein.
For many textile processes, such as weaving and warp knitting, it has been customary to provide textile yarns in the form of warp yarns carefully wound on a large cylinder referred to as a beam. A beaming operation has always involved careful registration and winding onto the beam of warp yarns provided from a large creel. Formerly, the warp yarns on the creel used to be drawn yarns, already suitable for use in textile processes, such as weaving and knitting.
Recently, there has been interest in using flat undrawn filament yarns, which have generally been cheaper than drawn yarns, and incorporating a drawing step in the beaming operation, as disclosed, e.g., by Seaborn, U.S. Pat. No. 4,407,767. This process is referred to herein as "draw-warping", but is sometimes called draw-beaming or warp-drawing. At least three commercial draw-warping machines have been offered commercially. Barmag/Liba have cooperated and built a unit, which is described and illustrated in Chemiefasern/Textilindustrie, February 1985, page 108 and pp. E14-15. There are also articles in Textile Month, March 1985, page 17, and in Textile World, May 1985, page 53. Karl Mayer/Dienes sell commercial draw-beaming systems, as advertised, e.g., on page 113 of the same February 1985 issue of Chemiefasern/Textilindustrie. The concept was discussed by Frank Hunter in Fiber World, September 1984, pages 61-68, in an article entitled "New Systems for Draw-Beaming POY Yarns", with reference to the Liba/Barmag and Karl Mayer systems using polyester POY and nylon. The Karl Mayer system was also described by F. Maag in Textile Month, May 1984, pages 48-50. Karl Mayer also have patents, e.g., DE 3,018,373 and 3,328,449. Cora/Val Lesina have also been selling draw-warping systems for some time, and have patents pending. These commercial machines are offered for use with polyester, polyamide or polypropylene yarns, the drawing systems varying slightly according to the individual yarns. As indicated, the object is to provide beams of drawn warp yarns, that are essentially similar to prior art beams of warp yarns, but from undrawn feed yarns. The advantages claimed for draw-warping are set out, e.g., in the article by Barmag/Liba, and have so far been summarized as better economics and better product quality.
As indicated, draw-warping had been suggested and used for polyester yarns. The article by Barmag/Liba indicates that POY, MOY or LOY yarn packages can be used to cut the raw material costs. POY stands for partially oriented yarn, meaning spin-oriented yarn spun at speeds of, e.g., 3-4 km/min for use as feeder yarns for draw-texturing. Huge quantities of such feeder yarns have been used for this purpose over the past decade, as suggested in Petrille, U.S. Pat. No. 3,771,307 and Piazza & Reese, U.S. Pat. No. 3,772,872. These draw-texturing feeder yarns (DTFY) had not been used, e.g., as textile yarns, because of their high shrinkage and low yield point, which is often measurable as a low T7 (tenacity at 7% elongation) or a low modulus (M). In other words, POY used as DTFY is not "hard yarn" that can be used as such in textile processes, but are feeder yarns that are drawn and heated to increase their yield point and reduce their shrinkage. MOY means medium oriented yarns, and are prepared by spinning at somewhat lower speeds than POY, e.g., 2-2.5 km/min, and are even less "hard", i.e., they are even less suitable for use as textile yarns without drawing. LOY means low oriented yarns, and are prepared at much lower spinning speeds of the order of 1 km/min or much less.
As has already been explained above and by Marshall and Thompson, conventional undrawn LOY polyester has a natural draw ratio. Attempts at "partial drawing" at lower draw ratios (such as leave a residual elongation of more than about 30% in the drawn yarns) will generally produce highly irregular "thick-thin" filaments, which are quite unsuitable for most practical commercial purposes. Among other important disadvantages, this severely limits the utility of LOY polyester as a practical draw-warping feed yarn. When undrawn polyester draw-texturing feed yarns of high shrinkage are prepared at higher spinning speeds, there is still generally a natural draw ratio at which these yarns prefer to be drawn, i.e., below which the resulting yarns are irregular; although the resulting irregularity becomes less noticeable, e.g., to the naked eye or by photography, as the spinning speed of the precursor feed yarns is increased, the along-end denier variations of the partial drawn yarns are nevertheless greater than are commercially desirable, especially as the resulting fabrics or yarns are generally dyed. Yarn uniformity is often referred to in terms of % Uster, or can be expressed as Denier Spread, as will be discussed hereinafter. It is not merely a question of denier uniformity, although this may be a convenient check on whether a yarn is uniform, as partially-drawn denier variations often mean the filaments have not been uniformly oriented along-end, and variations in orientation affect dye-uniformity. Dyeing uniformity is very sensitive to variations resulting from partial drawing. So, even for polyester POY prepared at relatively high spinning speeds, as will be seen hereinafter in the Example, partial drawing of such POY has produced yarn that is unacceptable, e.g., from a dyeing uniformity standpoint. Thus, hitherto, even with POY, such as has been used as feed yarn for draw-texturing (often referred to as DTFY herein), it has not been practical to draw-warp the same such POY (DTFY) to two different dpfs that vary from each other by as much as 10% and obtain two satisfactory uniform drawn yarns without significant broken filaments, because one would have been partially drawn.
Thus, it will be understood that a serious commercial practical defect of prior suggestions for draw-warping most prior undrawn polyester (POY, MOY or LOY) had been the lack of flexibility in that it had not been possible to obtain satisfactory uniform products using draw ratios below the natural draw ratio for the polyester feed yarn. This was different from the situation with nylon POY or polypropylene.
So far as is known, it had not previously been suggested that a draw-warping process be applied to a polyester textile yarn, i.e., one that was itself already a direct-use yarn, such as had shrinkage properties that made it suitable for direct use in textile processes such as weaving and knitting without first drawing. Indeed, to many skilled practitioners, it might have seemed a contradiction in terms to subject such a yarn to draw-warping because such a yarn was already a textile yarn, not a feed yarn that needed a drawing operation to impart properties useful in textile processes such as weaving or knitting.
According to the parent application (Ser. No. 07/338,251 referred to hereinabove, the disclosure of which is hereby incorporated herein by reference), processes were provided for improving the properties of feed yarns of undrawn polyester filaments. Such processes involved drawing with or without heat during the drawing and with or without post heat-treatment, and are most conveniently adapted for operation using a draw-warping machine, some such being sometimes referred to as draw-beaming or warp-drawing operations.
Preferred undrawn polyester feed yarns comprise spin-oriented polyester filaments of low shrinkage, such as have been disclosed in Knox U.S. Pat. No. 4,156,071. Alternatively, spin-oriented feed yarns of low shrinkage may be prepared at speeds higher than are used in the Knox patent, including speeds and conditions such as are disclosed by Frankfort & Knox in U.S. Pat. Nos. 4,134,882 and 4,195,051.
The parent application was primarily concerned with the preparation of and improvement of flat yarns and filaments, as indicated. The present invention is concerned primarily with the air-jet texturing of such yarns to provide novel textured yarns.
SUMMARY OF INVENTION
According to the present invention, there are provided the following new processes:
A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is partially drawn to a uniform yarn by hot-drawing or by cold-drawing, with or without heat-setting, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is drawn to a uniform yarn by cold-drawing, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is drawn to a uniform yarn by hot-drawing without any post heat treatment, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is drawn to a uniform yarn by hot-drawing, with post heat treatment to reduce shrinkage, at such draw ratio to provide said uniform yarn of elongation-to-break at least about 30%, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is heat treated, without drawing, and then said heat treated yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
A process for providing a mixed-shrinkage air-jet textured polyester yarn from feed yarns of spin-oriented flat polyester filaments, characterized in that a feed yarn (A) is drawn to a uniform drawn yarn of high shrinkage by cold-drawing without any post heat treatment, and in that a feed yarn (B) is drawn to a uniform drawn yarn of lower shrinkage by hot or by cold-drawing with a post heat treatment to reduce shrinkage, and said uniform drawn yarns are co-mingled and air-jet textured, said feed yarns (A) and (B) being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms
A process for providing a mixed-shrinkage air-jet textured polyester yarn from feed yarns of spin-oriented flat polyester filaments, characterized in that a feed yarn (A) is drawn to a uniform drawn yarn of high shrinkage by cold-drawing without any post heat treatment, and in that a feed yarn (B) is drawn to a uniform drawn yarn of lower shrinkage by cold-drawing without any post heat treatment, wherein said draw ratios for drawing feed yarns (A) and (B) are selected to provide an elongation for the uniform drawn yarn of lower shrinkage from feed yarn (B) at least about 10% greater than the elongation of the uniform drawn yarn of higher shrinkage from feed yarn (A), and said uniform drawn yarns are co-mingled and air-jet textured, said feed yarns (A) and (B) being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (SI) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
Preferably, at least some difference in shrinkage of said mixed-shrinkage air-jet textured yarns is developed while said yarns are in the form of a weftless warp sheet prior to knitting or weaving, by heat relaxing said warp sheet under tension not exceeding the shrinkage tension of the high shrinkage filaments.
The process of the invention is particularly useful in giving a capability of providing yarns desirably textured and with filaments of low denier, less than about 1, which are in great demand commercially at this time.
Polyester polymers, used herein, may, if desired, be modified by incorporating ionic dye sites, such as ethylene-5-M-sulfo-isophthalate residues, where M is an alkali metal cation, for example in the range of about 1 to about 3 mole percent ethylene-5-sodium-sulfo-isophthalate residues, to provide dyeability with cationic dyes, as disclosed by Griffing and Remington in U.S. Pat. No. 3,018,272. A suitable polymer of relative viscosity (LRV) about 13 to about 18 is particularly useful. Representative copolyesters used herein to enhance dyeability with disperse dyes are described in part by Most U.S. Pat. No. 4,444,710, Pacofsky U.S. Pat. No. 3,748,844, Hancock U.S. Pat. No. 4,639,347, and Frankfort and Knox U.S. Pat. Nos. 4,134,882 and 4,195,051, and representative chainbranching agents used herein to reduce shrinkage, especially of polyesters modified with ionic dye sites and/or copolyesters, are described in part in Knox U.S. Pat. No. 4,156,071, MacLean U.S. Pat. No. 4,092,229, and Reese U.S. Pat. Nos. 4,883,032, 4,996,740, and 5,034,174. To obtain spin-oriented feed yarns of low shrinkage from modified polyesters, it is generally advantageous to increase polymer viscosity by about +0.5 to about +1.0 LRV units and/or add minor amounts of chainbranching agents (e.g., about 0.1 mole percent).
As will be understood, according to the present invention, the various embodiments and variations disclosed in the parent application may be modified by including an air-jet texturing operation. Air-jet texturing is itself a known process, and commercial machines are available for practicing air-jet texturing.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows schematically a typical commercial draw-warping machine that may be used to practice an aspect of the process of the invention.
FIGS. 2-6 are graphs.
FIGS. 7-9 compare along-end denier Uster traces.
FIGS. 10-12 are curves showing load plotted v. elongation (-to-break).
FIGS. 13-15 are more along-end denier Uster traces.
FIGS. 16 and 17 are photographs of dyed fabrics.
FIGS. 18-20 are more curves showing load plotted v. elongation.
DETAILED DESCRIPTION
Many of the parameters and measurements mentioned herein are fully discussed and described in the aforesaid Knox patent in the and Frankfort & Knox patents, all of which are hereby specifically incorporated herein by reference, so further detailed discussion herein would, therefore, be redundant. Such parameters include the tensile, shrinkage, orientation (birefringence), crystallinity (density and crystal size), viscosity and dye-related measurements, except in so far as mentioned and/or modified hereinafter.
Most of the drawing disclosure from our parent application is included hereinafter, for convenience, because the variations may be applicable also to various texturing processes according to the parent invention. Air-jet texturing (AJT) may be carried out conventionally, using commercial equipment, such for example, as is available from Barmag, an example being referred to hereinafter, in relation to AJT Examples and Tables XVI and XVII. Indeed, the drawing and AJT stages may all conveniently be carried out on a commercial AJT machine, if desired. When post heat-set yarns are desired, the heat setting may precede or follow the AJT stage of the process.
Preferred polyester feed yarn filaments are undrawn in the sense disclosed by Knox, Frankfort & Knox, Petrille and Piazza & Reese. Sometimes such filaments are referred to as spin-oriented, because the orientation (and crystallization eventually derived therefrom) is caused by high-speed spinning, as opposed to the older process of first spinning at low speeds, of the order 0.5 (or as much as 1) km/min, to make LOY, followed by drawing and annealing which older process produces a completely different crystal fine structure in such conventional drawn yarns, in contrast to the combination of lower orientation and larger crystals derived from high-speed spinning (spin-orientation). This combination provides many advantages, such as improved dyeability and shrinkage properties, as disclosed by Knox and by Frankfort & Knox.
A low shrinkage is an essential requirement for textile yarns, as discussed by Knox; in fact, the shrinkage behavior of conventional drawn polyester yarns has not been as good as for other yarns, e.g., cellulose acetate, and this has caused textile manufacturers to use correspondingly different techniques for polyester fabric construction and finishing. At relatively high spinning speeds, e.g., as described by Frankfort & Knox, of the order of 5 km/min and higher, it is difficult to obtain uniform filaments without the desired low shrinkage under preferred spinning conditions. However, at speeds of the order of 4 km/min, as disclosed by Knox, special spinning conditions are necessary to prepare the preferred feed yarns of low shrinkage and having the other requirements of uniformity and tensile properties. In contrast, POY has lower crystallinity and significantly higher shrinkage such as is desired for use as feeder yarns for draw-texturing, this having been a very much larger end-use than direct-use untextured polyester filament yarn. It becomes increasingly difficult to obtain extremely low shrinkage values in undrawn polyester yarns directly by high speed spinning, and so the preferred feed yarns will, in practice, rarely have S1 below about 2%, although this may be desirable.
The shrinkage and shrinkage tension measurements were as measured in U.S. Pat. No. 4,156,071, except that the loads were 5 mg/denier for 30 minutes when measuring S1 (boil-off shrinkage), and for 3 minutes at 350° F. (177° C.) for S2 and DHS, to simulate trade heat-set conditions. The thermal stability (S2) is a measure of the additional change in length on exposure to dry heat (350° F.) after initial boil-off shrinkage (S1). The feed yarns of this invention have S2 values of less than about +1%, i.e., the yarns do not shrink significantly during the test. Under the test conditions, some yarns may elongate, in which case the S2 value is given in a parenthesis. The feed yarns generally do not elongate more than about 3%. The resulting drawn yarns have S2 values of less than about +2% (i.e, shrink less than about 2%) and generally do not elongate greater than about 3%. The net shrinkage is the sum of S1 and S2 and, accordingly, is designated S12 ; although this has not often been referred to in the literature, it is a very important value, in some respects, for the fabric manufacturer, since a high and/or non-uniform net shrinkage (S12) means an important loss in effective fabric dimensions, as sold to the eventual consumer. Uniformity of shrinkage is also not often referred to, but is often very important in practice in fabric formation. The drawn filaments of the present invention show an important advantage over conventional polyester in this respect.
The combination of low shrinkage values (S1, S2 and S12) of the feed yarns used in the process of the invention (hereinafter the feed yarns) distinguishes such feed yarns from conventional POY, which as DTFY, i.e. as a feeder yarn for draw-texturing, preferably has low crystallinity and so higher shrinkage, and from conventional drawn yarns. Preferably the feed yarns have both S1 and S12 values less than about 6%.
It is very surprising that the feed yarns can be fully or partially cold-drawn uniformly, in other words to provide drawn yarns/filaments of uniform denier (along-end), in contrast to the less satisfactory results of cold-drawing conventional undrawn polyester filaments. The ability to fully or partially draw by cold-drawing polyester filaments according to the present invention to provide uniformly drawn filaments is an important advantage, since this makes it possible to improve tensiles without a drastic reduction in dyeability or increase in shrinkage, and thus provide yarns and filaments with an improved combination of tensiles, dyeability and shrinkage. This cold-drawing does increase the low shrinkage values of the feed yarns, and there is some reduction in the easy dyeability, these being such notable advantages of the feed yarns (in contrast to conventional polyester), and this is a good example of the need to consider the total combination (or balance) of properties of any polyester filaments or yarns, rather than a single property in isolation. However, even this combination of increased shrinkage and reduced dyeability of the resulting drawn yarns is still generally significantly improved over conventional drawn polyester, because of the different crystal fine structure that results from spin-orientation, and consequent crystallization. The low shrinkage values, especially S12, distinguish the drawn products, i.e., filaments and yarns of the invention from conventional drawn polyester. Preferably, these drawn products have both S1 and S12 values less than about 6%.
In some end-uses, a low shrinkage tension is very important because less tension is generated during yarn processing, and later, in fabrics, less puckering occurs, in contrast to drawn yarns. A preferred value for both feed yarns and drawn products is less than 0.15 grams/denier.
Of the tensile measurements, only the post yield modulus (PYM) requires explanation and definition, as follows, and as illustrated with reference to FIGS. 2 and 3, which are both graphs plotting stress (σ) against elongation (E) for a preferred feed yarn, FIG. 2, and a resulting drawn yarn, FIG. 3. The stress (σ) at any elongation (E) which is measured as a percentage of the original length) is given in grams/denier by:
Stress (σ)=0.01 (100+E)×(Load/initial denier).
Thus the stress is calculated in terms of the denier at the time of measurement (which denier changes during elongation) whereas the tenacity is usually recorded in terms of the initial denier only. If a yarn has a yield zone, as shown in FIG. 2, this will be clear on a plot of stress v. E. The yield zone (E"-E') is the range of elongation for which the stress first decreases and then increases below σy, i.e., when the yarn yields because the stress decreases below peak value σy as E increases beyond E' (when σ passes through peak value σ'y) until the stress again regains peak value σ"y at E" (the post-yield point). As indicated hereinbefore, preferred feed yarns were described by Knox, and have advantages in some end-uses (somewhat like cellulose acetate) partly because of their relatively low modulus. This advantage in aesthetics is however accompanied by a relatively low yield point (shown by a relatively large yield zone) which can be a disadvantage if it is desirable to use such yarns as filling, because the sudden increases in stress imposed by many weaving techniques may stretch such yarns irreversibly and only intermittently, with a resulting defect that can be revealed when the woven fabric is later dyed.
It is surprising that the feed yarns which, according to the invention, show a distinct yield zone, E"-E'>0, in the plot of Stress v. E, so that there is a natural draw ratio in this sense looking at the plot, but such feed yarns do not perform as if there is a natural draw ratio when drawn at lower draw ratios, since such preferred feed yarns draw uniformly at such low draw ratios, in contrast to conventional POY spun at similar speeds but of higher shrinkage.
The post yield modulus is defined herein as the slope of the plot of stress v. elongation between E7 and E20, i.e., elongations of 7 and 20%, and is given by the relationship: ##EQU1##
However, since generally one records load/initial denier, rather than stress, PYM is always calculated herein according to the following equivalent relationship: ##EQU2##
The √PYM after boil-off (ABO) should be in the approximate range 2.5 to 5, preferably 3 to 5, corresponding to absence of any yield zone.
Reverting to the feed yarns, the minimum value of T7 (0.7 g/d) and the range of EB (40-120%) coupled with large crystals, are important characteristics of spin-oriented yarns that provide the ability to be drawn uniformly as indicated above, in contrast with conventional POY and other undrawn yarns of higher shrinkage which are not capable of consistent drawing at low draw ratios to provide filaments of equivalent uniformity. Such combination of parameters approximates to a yield zone of less than 15%. Preferably the T7 is at least 0.8 g/d, and the EB is less than 90%, corresponding to a yield zone of less than 10%. In practice, T7 is not usually greater than 1.7 g/d for feed yarns, and more usually less than about 1.2 g/d. Drawing increases the T7, the preferred minimum of T7 is about 1 g/d, with EB about 20-90%, and preferably about 20-60%, which provides sufficient initial tensiles for textile processability, even for weaving. Thus, by drawing, especially by cold-drawing, it is possible to improve the tensiles (and textile processability) of preferred feed yarns so that they can sustain sudden stresses such as are encountered for filling yarns in weaving processes, without impairing the uniformity, or losing all the advantages of improved dyeability and better shrinkage properties than conventional drawn polyester yarn. Preferred tenacity (T), and modulus (M), values in g/d, respectively, are at least 2.5, and in the range 40-100 for the drawn yarns, which provide useful textile properties with a wider range of fabric textile aesthetics than available with conventional drawn polyester. These drawn yarns are "hard yarns" with essentially no yield zone, unlike preferred precursor feed yarns, as shown by the range of √PYM (ABO) mentioned above.
Although the process of the invention is not limited to cold-drawing, the importance of the ability for the first time to carry out cold-drawing (fully and partially drawing) of undrawn polyester yarns should be emphasized, because of the improvement in uniformity that results. External heaters are an inevitable source of variability, and therefore non-uniformity, end-to-end, as well as along-end. The latter improvement also improves tensile properties and uniformity of shrinkage. Use of heaters also leads to "stop-marks" in the resulting fabrics, which can be avoided by cold-drawing. Uniformity is also affected by any lack of uniformity in the feed yarns, e.g., non-uniform interlace.
The tensiles are measured in the Example and shown in Tables I-III first on yarns AW, then ABO and also ADH, meaning, respectively, "As Warped", "After Boil-Off" and "After Dry Heat", to distinguish the state of the yarns at different stages of textile processing, it being understood that some of the values were measured on yarn taken from tubes, e.g., for comparison yarns, while others were taken from beams.
The importance of large crystals has already been mentioned hereinabove, and by Knox and Frankfort & Knox, and their presence is shown by the density and crystal size, which should be as already mentioned. These parameters distinguish the feed yarns and the resulting drawn products from all conventional drawn yarns, from conventional POY and from spin-oriented yarns spun at low speeds, as described in those patents. Preferably, the drawn products are of density about 1.37 to about 1.415 g/cm3.
The relationship between crystal size (CS) and density (ρ) is illustrated in FIG. 4, for both feed yarns and drawn yarns, whereas in FIG. 5, the relationship between RDDR and √PYM is illustrated.
The Relative Disperse Dye Rate, as defined and described by Knox, is significantly better than for conventional drawn polyester, and is preferably at least 0.09, for the drawn products, despite the fact that they have been drawn. The combination of this good dyeability (reduced from the corresponding feed yarns to an extent that depends on the drawing conditions and any heat setting) with tensile properties that are improved, especially the absence of any yield zone, as shown by the range of post yield modulus indicated above, distinguishes the novel drawn products from the prior art.
The K/S Dye Uptake values herein in Tables I, II and III were measured (as described by Frankfort & Knox, except that a McBeth spectrophotometer was used) on fabrics dyed with 4% on weight of fabric (OWF) of Teranil Yellow 2GW in a bath buffered to a pH of 5.5, boiled for 25 minutes, whereas the fabrics for Table IV were dyed with 4% OWF of Blue GLF at 95° C. for 60 minutes
The Jersey Warp Knit fabrics were dyed in a minijet, with 1.5% OWF Eastman Polyester Blue GLF at a pH buffered to 5.0-5.5 for 40 minutes under pressure at 260° F. so as to favor the fabrics that do not have easy dye-at-boil characteristics (Tables II/III) If the fabrics had been dyed at the boil, those in Table I would have been well and uniformly dyed, whereas those in Table II/III would not have dyed very well and would have been even less uniform than shown in Table II/III. Δ Wt/Area % is a measure of area fabric shrinkage during this dyeing and subsequent heat-setting (dry at 300°-350° F. for 1 minute exposure with 5% overfeed).
The fabrics in Tables I, II and III were judged for dye uniformity and appearance as follows:
Fabric swatches (full width, i.e., approximately 20 inches wide and about 20-25 inches long) were laid on a large table covered with dull black plastic; the room lighting was diffuse fluorescent light. Four different attributes were judged:
(a) long streaks, i.e., those that persist throughout length of fabric sample and that are parallel to the selvedge;
(b) short, hashy streaks, i.e., those that do not persist throughout the length of the fabric sample;
(c) dye mottle, i.e., spotty pattern of light and dark regions, the spots being one or a few millimeters in diameter;
(d) deep dye streaks, i.e., intensely colored parts of the fabric, the color intensity being higher than the average of the fabric sample;
The rating scale is:
5=no defect visible, absolutely uniform;
4=minor unevenness observed, acceptable for almost all end uses;
3=unevenness noticeable, not usable for high quality goods, may be used for utility apparel, second grade clothes;
2=unevenness highly noticeable, too uneven for any apparel;
1=extremely uneven, disastrously defective.
Each fabric sample was paired against each of the others and thus rated, such that the resulting ratings scaled the fabrics in this series. The fabrics and their ratings were given to laboratory colleagues for critique and found to be consistent and acceptable.
The Mullen Burst Test is a strength criterion for fabrics and was measured (lbs/in) according to ASTM 231-46. The Burst Strength is obtained by dividing the Mullen Burst by the Area Weight (oz/sq yd). Fabrics from drawn filament yarns according to the invention preferably have Burst Strengths (ABO) in the approximate range 15-35 (lbs/in)/(oz/sq yd) and also greater than about the value defined by the following relationship:
Burst Strength (ABO)>31[1-EB (ABO)/100], where EB (ABO)≃100[(EB +S1)/(100-S1)], and where S1 and EB are the boil-off shrinkage and elongation-to-break, respectively, as already mentioned. Burst strength (ABO) is preferably expressed in terms of S1 and EB using the above expression for EB (ABO) to give the following relationship:
Burst strength (ABO)>31[1-(E.sub.B +S.sub.1)/(100-S.sub.1)].
FIG. 6 illustrates the Burst Strength plotted against EB (ABO) for drawn yarns (AW) of EB about 20-90% and S1 <10%, with preferred drawn yarns (AW) of EB about 20-60% and S1 <6%.
The intrinsic viscosity [η] is generally in the approximate range 0.56-0.68 for textile yarns.
Preferred birefringence values for the feed yarns are in the approximate range 0.05-0.12, especially 0.05-0.09, and are correspondingly higher for the drawn products, namely 0.07-0.16. Birefringence values are very difficult to measure unless the yarns are of round cross section, and there is an increasing tendency for customers to prefer various non-round cross sections, because of their aesthetics.
Draw-warping may be carried out according to the directions of the manufacturers of the various commercial machines The draw ratio (DR) will generally be given by: ##EQU3## where EB is the elongation of the feed yarns and RDR is the residual draw ratio of the resulting warp-drawn yarns, and, using E'B, the elongation of such warp-drawn yarns, instead of the feed yarns, may be given by: ##EQU4## This RDR will generally be more than about 1.1×, and especially more than about 1.2×, i.e. to give corresponding E'B of more than 10%, and especially 20% or more, but this is largely a matter of customer preference.
Relative denier spread and Uster data as reported in Tables VII-XII are the ratios of the % coefficient of variations of results measured on warp-drawn yarns and corresponding feed yarns. The denier spread and Uster data are measured on a Model C-II Uster evenness tester, manufactured by Zwellweger-Uster Corporation. The denier spread data, which relate to long-term variations in yarn uniformity, are based on samples measured under the following conditions:
Yarn speed--200 meters/minute
Machine sensitivity--12.5 (inert setting)
Evaluation time--2.5 minutes
Chart speed--10 cm./minute
Uster data, which relate to short-term variations in yarn uniformity, are measured at:
Yarn speed--25 meters/minute
Machine setting--normal
Evaluation time--1 minute
Chart speed--100 cm./minute
Draw tension variation along the length of a continuous filament yarn is a measure of the along-end orientation uniformity and relates to dye uniformity. Yarns having a high draw tension variation give nonuniform, streaky dyed fabrics. Draw tension is measured with a Extensotron® Model 4000 transducer equipped with a 1,000 gram head which is calibrated at 200 grams, and the yarns are drawn at the RDR's specified while passing at an output speed of 25 meters/minute through a 100 cm. long tube heated to the temperature that is specified. The average draw tension is determined from 500 measurements, and the percent coefficient of variation is calculated and reported.
The parent invention lends itself to many variations, some of which are now described briefly:
1. (A) -Co-draw nylon POY (which can be cold drawn and partially drawn too) and the preferred feed yarns described herein, to provide a nylon/polyester mixed yarn warp.
(B) -Use heat-setting to reduce level of shrinkage and differential shrinkage of yarns if desired for any end-use.
2. Co-draw preferred feed yarns of different cross sections/deniers for a patterned warp, all at same shrinkage level. Use heat-setting to reduce level of shrinkage and differential shrinkage of yarns if desired for any end-use.
3. Co-draw split warp sheets, some cold and others with heat, to give a mixed shrinkage pattern warp.
4. Variable along-end heating would give varying shrinkage, and so give a patterned warp.
5. Use preferred feed yarns of different heat setting capability.
6. Use draw-warping to reduce denier and obtain unusually low denier warps.
7. Co-draw more than one beam, some of which have been alkali treated and then break the alkali-treated ends to give spun-like effect.
8. Hot draw in a bath containing dyestuffs, UV-screeners, or other additives to take advantage of high dye rate of the preferred feed yarns.
9. Cold draw with or without post-heat setting single ends of preferred feed yarns, for use as filling yarns. This could be performed on the loom itself.
10. Edge-crimp while cold-drawing preferred feed yarns. The resulting 8-10% shrinkage plus subsequent 1-2% elongation would give crimped yarns in fabric.
11. Use additives to increase light fastness of the preferred feed yarns.
From the foregoing, it will be clear that there are many ways to take advantage of the benefits of the preferred feed yarns in various drawing processes as described herein. The main advantages of these feed yarns over conventional POY can be summarized as:
1. Reduced sensitivity to heat means the eventual fabrics will be more uniform, and there is less potential for stop-marks.
2. By using the ability for cold-drawing, significantly improved uniformity can be obtained, with a useful combination/balance of tensile and shrinkage properties. This can be used to improve the tensiles (yield zone) with only slight loss of the improved dyeability of the feed yarn, so that it can be used, e.g., as a filling yarn for weaving, or for drawing and airjet texturing or for drawing and crimping for staple.
3. The process can involve less trimer production and fuming of the finish, which can lead to other advantages, for instance the feed yarn manufacturer can apply a finish that will persist and remain satisfactory beyond the draw-warping operation, i.e., reduce or avoid the need to apply further finish for weaving or knitting.
4. The resulting drawn products have generally higher rate of alkali weight reduction than conventionally drawn POY and fully drawn yarns.
5. The flexibility for the draw-warper to custom-tailor his desired combination of tensiles, shrinkage, dyeability and denier over a large range cf draw-ratios while maintaining uniformity may be most prized advantage of many fabric designers.
6. The resulting drawn products have lower modulus than conventional drawn polyester, and so have generally better aesthetics.
7. Any type of draw-warping machine can be used, or even a tenter frame or slasher unit, for example, modified to incorporate warp beaming.
Indeed, further modifications will be apparent, especially as these and other technologies advance. For instance, any type of draw-winding machine may be used. Also, as regards variation 9, for example, the yarns may have any end uses that have been or could be supplied by fully oriented yarns, including weft knitting yarns, and supply yarns for twisting or draw winding.
EXAMPLES
In the following Examples, as in the parent application, Tables I-XV and the accompanying disclosure are only of drawing of feed yarns, without any air-jet texturing (AJT) according to the invention. Then these Tables and disclosure are followed by Tables XVI and XVII with accompanying disclosure of AJT according to the present invention, using feed yarns as disclosed earlier in the Example, as indicated. It will be understood that, in like manner, other disclosures according to the parent application may be modified by incorporating AJT according to the present invention. Accordingly, Table 1 shows, for 6 separate draw-warping operations carried out according to the invention of the parent application (designated I-1 through I-6), yarn characteristics, warping conditions and fabric characteristics, and includes appropriate corresponding details for yarns that were not processed according to the invention (designated IA, IB and IC) so that their characteristics may be compared with yarns (I-1 through I-6) warp-drawn according to that invention.
Following Table I, details are given in Comparison Tables II and III for warp-drawing other control yarns, i.e. these warp-drawing processes were also for purposes of comparison only.
Following Tables II and III, another series of 8 draw-warping operations were carried out according to the invention of the parent application, with details given in Table IV, and designated as IV-2 through IV-9. IV-1 is merely the feed yarn used for these draw-warping operations.
Following Table IV, several important characteristics of the feed yarns used for draw-warping are compared side-by-side for convenience in Tables V and VI. V-3 was a feed yarn used to carry out the draw warping processes according to the invention of the parent application, as shown in Tables I and IV, whereas V-1 is the feed yarn used in Comparison Table II and V-2 is the feed yarn used in Comparison Table III. Similarly VI-3 was used according to that invention, whereas VI-1 and VI-2 were used for comparison experiments. The results are shown in the later Tables.
As disclosed in the Examples and hereinbefore, the drawing can be carried out under various conditions. Cold-drawing is the term used when no external heat is applied; but, as is well known, exothermic heat of drawing and the friction of the running threadline will generally and inevitably heat any snubbing pin unless specific means are used to avoid or prevent this. Cold-drawing will generally somewhat raise the shrinkage of the resulting drawn yarn; this may be tolerable, depending on the balance of properties desired, and may be desirable for certain end-uses. Hot-drawing, where the feed yarn is heated, or when a cold-drawn yarn is annealed after drawing, will enable the operator to produce drawn yarns of low shrinkage, similar to that of the feed yarn; this will also reduce the dyeability somewhat, but the resulting dyeability will still be significantly higher than that of conventional drawn polyester.
The parameters of the test feed yarns in the Examples were within the preferred ranges specified hereinabove. The draw-warping processes were carried out on an apparatus provided by Karl Mayer Textilmaschinenfabrik GmbH, D-6053 Obertshausen, Germany, illustrated schematically in FIG. 1, with reference to the Karl Mayer machine, (other commercial machines have also been used successfully and have arrangements that are somewhat similar or analogous). A sheet of warps is drawn by feed rolls 1A and 1B from a creel (not shown) on the left and is eventually wound on a beam 8 on the right of FIG. 1. Feed rolls 1A are heatable, if desired, whereas feed rolls 1B are non-heatable. The warp sheet then passes up in contact with an inclined plate 2, that may, if desired, be heated so as to preheat the warps, before passing over a heatable pin 3, sometimes referred to as a snubbing pin, and then down in contact with another inclined plate 4, which may, if desired, be heated so as to set the drawn warps before passing to the set of draw rolls 5A and 5B, that are driven at a greater speed than the feed rolls, so as to provide the desired warp draw ratio, and wherein draw rolls 5A may be heated if desired, whereas draw rolls 5B are non-heatable. The warps may, after leaving the draw rolls 5A and 5B, bypass directly to the beam winder 8, as shown in one option in FIG. 1, or may, if desired, undergo relaxing by passing down in contact with another inclined plate 6, which may be heated to relax the warps as they pass to a set of relax rolls 7A and 7B, that are driven at a speed appropriately less than that of the draw rolls, so as to provide the desired overfeed, and wherein relax rolls 5A may be heated, if desired, whereas relax rolls 5B are non-heatable, before passing to beam winder 8.
PARENT EXAMPLE
This first compares the results of six draw-warping processes according to the invention of the parent application, (tests I-1 to I-6), using feed yarns of 108 denier, 50 filament (trilobal), that are spin-oriented with large crystals as described above, on the one hand, in contrast with two conventional drawn polyester yarns IA and IB and with a spun-oriented direct-use polyester yarn IC so to contrast the properties of these drawn yarns (tests I-1 through 6 and IA,B) and of the direct-use yarn IC and of fabrics made therefrom. Item IC is not a drawn yarn but a spun-oriented direct-use yarn that was also the feed yarn used to prepare yarns I-1 through I-6 (to show the effects of the draw-warping processes) and fabrics therefrom.
Tests 1 and 6 were essentially fully drawn to residual elongations of 25.4% and 30.7%, respectively, which correspond to residual draw ratios (RDR) of 1.254× and 1.307×, respectively. Yarns in Tests 2 through 5 were drawn at lesser draw ratios to residual elongations greater than 30%, corresponding to a residual draw ratio (RDR) greater than 1.3×. Yarns in Tests 4-6 were drawn cold (without externally-applied heat) wherein the heat of draw and friction increased the temperatures to about 70° C. All test yarns gave acceptable tensiles as indicated by an initial modulus (M) greater than 40 g/d, a tenacity at 7% elongation (T7) of 1 g/d or greater and an elongation to break (EB) less than 90% and especially less than 60%. The test yarns also maintained acceptable tensiles after boil-off shrinkage (ABO) and after dry heat shrinkage (ADH). The retention of tensiles after exposure to heat is attributed to a combination of densities (ρ) greater than about 1.355 g/cm3 (and especially greater than about 1.37 g/cm3) and very large crystals characterized by a wide-angle X-ray (WAXS) crystal size (CS) of at least 60 Angstroms and greater than about (250ρ-282.5) Angstroms. The thermal stability (S2) is characterized by the additional change in yarn length on heating to 350° F. (177° C.) of less than about 2% (the (1.6) figure indicating an increase in length of 1.6% for I-4) after initial boil-off shrinkage (S1) of less than about 10% and preferably less than about 6%, giving a net shrinkage (S12 =S1 +S2) of less than about 8% and preferably less than about 6%.
In contrast, commercially available fully drawn hard yarns (IA and IB) have much inferior thermal stability (S2) values of about 5% and net shrinkages (S12) of about 12%, because they have smaller crystals of crystal size (CS) of 56 Angstroms and 44 Angstroms, respectively. The fully drawn hard yarns (IA and IB) also show about a 50% reduction in their initial tensiles (e.g., modulus, M, and tenacity at 7% elongation, T7) after shrinkage (ABO) and (ADH).
The test yarns (I-1, 2, 3, 5 and 6) have similar thermal stability to the commercially available direct-use yarn (IC), but sustained tensiles, as characterized by a tenacity at 7% elongation (T7) of greater than about 1 g/d and a post yield modulus (PYM) before and after boil-off of at least 5 g/d.
The test yarns (I-1 through 6) are further characterized by an improved dyeability as indicated by a Relative Disperse Dye Rate (RDDR) of at least 0.075 and preferably of at least 0.09 and greater than (0.165-0.025 √PYM, ABO). The test yarns have RDDR values 1.5× to 3× fully drawn hard yarns and depending on warp-draw process conditions, RDDR values nearly comparable to the commercially available direct-use yarn IC. Drawing the test yarns without added heat (i.e., cold, except for internal heat of draw) enhances dyeability, whereas external heat in general lowers dyeability.
The test yarns (I-1 through 6) were knit into Jersey warp knit fabrics and dyed under commercial conditions --i.e., similar to those used for fabrics made with fully drawn hard yarns--but with a critical disperse dye (Blue GLF) to enhance non-uniformity. All test yarns give very uniform fabrics, comparable to commercially available fully drawn hard yarns (IA) and direct-use yarns (IC). This was unexpected since test yarns (I-2 through 5) were drawn to residual elongations greater than 30% and test yarns (I-4 through 6) were drawn cold.
The retention of uniformity is attributable to this unique and surprising capability of these test yarns to be partially drawn (hot or cold) to such residual elongations as are greater than 30%, and even greater than 40%, while maintaining uniform along-end denier and shrinkage properties. This unique capability of uniform drawing is believed to be due to a combination of an initial yield stress (σ'y) of at least about 0.8 g/d and preferably 0.9 g/d which approximately corresponds to a tenacity at 7% (T7) of at least about 0.7 g/d and preferably 0.8 g/d and a yield zone (E"-E') less than about 15% and preferably less than about 10% and a crystal structure characterized by large crystals of crystal size (CS) of at least 55 Angstroms and greater than about (250 ρ-282.5) Angstroms for density (ρ) values 1.35-1.39 g/cm3. The unique crystal structure is believed to permit the yarns to draw in a uniform manner, similar to nylon, without neck-drawing which would give rise to along-end denier and shrinkage non-uniformity.
The test yarn fabrics (I-1 through 6) also show improved thermal stability as characterized by ΔWt/area (%) values less than the commercially available fully drawn hard yarn (IA). The test yarn fabrics (I-1 through 6) also had acceptable Burst Strengths (ABO) of at least 15[(lbs.yd2)/(oz.in)] and greater than about 31[1-(EB +S1)/(100-S1)] where EB and S1 are measured on the yarns (AW).
An important advantage when cold draw-warping was performed, was the absence of stop-marks on the resulting fabrics.
Although the draw-warping machine used in this Example was manufactured by Karl Mayer, the process has also been demonstrated with other machines, including draw-warping machines manufactured by Liba-Barmag and by Val Lesina, and slashers manufactured by Tsudakoma Corp.
The following abbreviations have been used in the Tables.
PY=Post Yield
RT=Room Temperature;
RND=Round;
TRI=Trilobal
ABO=After Boil-Off;
ADH=After Dry Heat;
AW=As Warped
OFF=Not heated; measured at approx. 70° C. due to heat of friction and draw
EWDR=WDR×[(100-% over feed)/100]
ΔWt./Area (%)=[1-Area Wt. (finished)/Area Wt.(greige)]100
Burst Strength=Mullen Burst/Area Wt.
* (Corrected for TiO2 pigment)
In Comparison Tables II and III, commercially available partially oriented yarns (POY) such as are used as feed yarns for draw-texturing were selected as control yarns for feeding to same draw-warping machine. Control yarn II is a nominal 115-34 trilobal POY with 0.035% TiO2 and 0.658 intrinsic viscosity and is characterized in detail hereinafter as V-1 in Table V. Control feed yarn III is a nominal 107-34 round POY with 0.30% TiO2 and of 0.656 intrinsic viscosity and is characterized in detail hereinafter as V-2 in Table V. Control feed yarn V-1 was draw-warped to a residual elongation of about 24% using temperatures similar to test I-1 and 2, except the set plate was at 160° C. The draw-warped yarn II-1 had poorer thermal stability than test yarns I-1 through 6, as characterized by an S2 value >2% and a net shrinkage (S12) greater than 8%. The dyeability of II-1 was significantly lower than the test yarns I-1 through 6 with an RDDR value of 0.062, or less than 0.075. The poorer dyeability is consistent with crystal size (CS) less than 60 Angstroms. Although the dyed Jersey warp knit fabrics had acceptable thermal stability and Burst Strength as indicated by Δwt/area of 29.4% and a Burst Strength of 26.6 (lbs.yd2)/(oz.in), the dyed fabrics had poorer uniformity v. fabrics from test yarns (I-2 through 5), drawn to higher residual draw ratios.
The control feed yarn V-2 was draw-warped under identical conditions as the test yarn (V-3) except the draw ratio was increased because of the higher initial elongation-to-break (EB) versus the test yarn. The control draw-warped yarns III-1 and 6 were fully drawn; III-2 to 5 were partially drawn; and III-4 through 6 were drawn without heat added. Control yarn III-5 was nearly fully drawn to a residual elongation of about 30% and then relaxed 10% to a final residual elongation-to-break of about 43%.
The dyeability of all the draw-warped POY (control yarns II and III) were poorer than that of the test yarns (I), except for III-4 which was drawn cold and had an excessive net shrinkage of 18.6%. The poorer dyeability of the control yarns II and III is consistent with smaller crystals of crystal size (CS) less than about (250ρ-282.5) Angstroms.
The dyed warp knit Jersey fabrics (III-1 through 6) had poorer uniformity than the corresponding test yarn fabrics (I-1 through 6) supporting the observation that conventional POY cannot be partially drawn as uniformly as the test feed yarn used here wherein selected combinations of initial yield properties and unique crystal structure provides a feed yarn that can be drawn to any residual draw ratio (hot or cold) and give a uniform yarn with acceptable tensiles and better thermal stability and dyeability than conventional drawn polyester. This can be illustrated by comparing the along-end denier uster traces of the actual drawn yarns. This has been done for three sets of yarns in FIGS. 7, 8 and 9. Thus FIG. 7 compares such Uster traces for control yarn III-1 vs. test yarn I-1, while FIG. 8 compares control yarn III-2 vs test yarn I-2, and FIG. 9 compares control yarn III-4 vs. test yarn I-4. The better uniformity of each test yarn is very evident from each Figure.
Referring to Table IV, Yarn IV-1 is a round nominal 75-40 filament yarn which was treated under different drawing and overfeed conditions on a single-end basis (IV-2 through IV-9). Drawing and/or heat treatments increase the orientation (birefringence, Δn) and density, ρ, of the test yarn IV-1. The initial tensiles as characterized by the initial modulus, M, and tenacity at 7% elongation (T7) were enhanced, except for the modulus values of yarns IV-2, IV-4 and IV-6 which were obtained under these conditions: draw temperatures of about 100° C., presence of water, and drawing conditions ranging from slight relaxation to slight draw. The yarns are characterized by low shrinkage of less than 6% and low shrinkage tension (ST) less than 0.15 g/d, except for yarns IV-8 and 9 drawn 1.10×. All yarns had good dyeability similar to the feed yarn, except for yarns IV-7 and 9 drawn 1.05× and 1.10×, respectively, at 180° C., which have somewhat lower dyeability.
The improvements to the yarn mechanical properties by various heat treatments are further illustrated by comparison of the Load-Elongation curves of the yarns in Table IV. In FIG. 18, curves a, b and C. represent yarns IV-3, IV-2 and IV-1, respectively, and are compared. In FIG. 19, curves a-d represent yarns IV-9, IV-7, IV-5, and IV-1 respectively, and are compared. In FIG. 20, curves a-d represent yarns IV-8, IV-6, IV-4, and IV-1, respectively, and are compared. In all cases, heat treatment, especially under tension or slight drawing, enhanced the mechanical properties of the test yarn IV-1 as a warp yarn for knitting and weaving.
The feed yarns are compared in Table V where V-1 and V-2 are commercially available POY used in the Example as the sources of control yarns II-1 and III-1 through 6, respectively, and V-3 is the test feed yarn used in the Example as the source of test yarns I-1 through 6, and is the direct-use yarn IC shown in Table I. The control feed yarns V-1 and V-2 differ significantly from the test feed yarn V-3 in that the yarns have lower yield points (σ'y), longer yield zones (E"-E'), and poorer thermal stability with boil-off shrinkages greater than 10%. The control feed yarns had densities less than 1.35 g/cm3 and very small crystals giving diffuse scattering by wide-angle X-ray (WAXS).
Additional feed yarns are compared in Table VI where yarns VI-1 and VI-2 are commercially available POY, similar to yarns V-1 and V-2 used in the Examples II and III, and are used as the sources of control yarns VII-1 through VII-6 and VIII-1 through VIII-6, X-1 through X-6 and XI-1 through XI-6, XIII-1 through XIII-8 and XIV-1 through XIV-8, respectively; and yarn VI-3 is the test feed yarn used as the source for test yarns IX-1 through IX-6, XII-1 through XII-6, and XV-1 through XV-5, and is similar to the direct-use yarn IC shown in Table I. The control feed yarns VI-1 and VI-2 differ significantly (from the test feed yarn VI-3) in that they have lower yield points ('y), longer yield zones (E"-E'), and poor thermal stability with boil-off shrinkages greater than 10%. The control feed yarns had densities less than 1.35 g/cm3 and very small crystals giving diffuse scattering by wide-angle X-ray (WAXS). The load-Elongation curves are compared in FIGS. 10-12, and were obtained by drawing at 19° C./65% RH and 25 meters per minute using an along-end stress-stain analyzer manufactured entered by Micro Sensors Incorporated. The nonuniform neck yield region is very pronounced for the control yarns VI-1 and VI-2 in FIGS. 10 and 11, respectively, by the almost horizontal portions of the curves. The test yarn VI-3 does not exhibit neckdown, but uniform plastic flow behavior, as shown by its much more uniform along-end yield behavior in FIG. 12.
The commercially available POY VI-1 and VI-2 and the test yarn VI-3 were hot drawn at 100° C. (Tables VII-IX, respectively) and cold drawn (Tables X-XII, respectively) over a wide range of draw ratios on an experimental single-end warp draw unit giving yarns of varying residual draw ratio (RDR). The control yarns VI-I and VI-2, when partially drawn to RDR greater than about 1.3, had poor along end denier uniformity as shown by high values of relative Denier Spread, and relative Uster, and by short dark dye streaks (called mottle) in dyed knit tubing. The test yarn VI-3, however, could be partially drawn hot (Table IX) and cold (Table XII) to residual draw ratios (RDR) greater than about 1.3, and gave partially drawn yarns with acceptable along end denier uniformity and dyed knit tubing essentially free of dye defects. The control yarns could only be drawn uniformly when drawn hot (Tables VI-IX) or cold (Tables X-XII) to residual draw ratios (RDR) of less than about 1.3. The test yarns, however, still are preferred for drawing hot or cold to residual draw ratios less than about 1.3 as they gave improved along end uniformity (over the fully drawn control yarns) as indicated by lower values of relative along-end denier and Uster, and less visual dye defects (mottle) in the dyed knit tubing.
In FIGS. 13-15, along-end Uster traces are compared for the control yarns VII-2 and VIII-3 and test yarn IX-2, respectively, partially drawn hot to approximate residual draw ratios (RDR) of about 1.5×: that is to elongations in each of their respective "yield" regions. Only the test yarn had acceptable along-end Uster when partially drawn to within its yield region. The high relative Uster values of the control yarns (VII-2, for example) gave rise to pronounced dye mottle (DM) in dyed knit tubing while the test yarn IX-2 gave commercially acceptable uniformity with only a few faint dye streaks, as shown in FIGS. 16 and 17, respectively.
Another technique frequently used to define along end uniformity of the drawing process is the measurement of the coefficient variation (% CV) of the drawing tension (DT). In Tables XIII-XV, the control yarns VI-1 and VI-2 and the test yarn VI-3, respectively, were drawn over a wide temperature range from cold (the temperature in this case was defined here as 19° C.) i.e. at room temperature, with no external heat added, to 224° C., and over a wide range of draw-ratios (1.1 to 1.9×) giving a corresponding wide range of residual draw ratios (RDR) of about 1.15 to 2×, depending on the particularly feed yarn's starting elongation. The control yarns VI-1 and VI-2 could not be partially drawn hot or cold to residual draw ratios (RDR) greater than about 1.3-1.4 as indicated by their high along end draw tension % CV values greater than 2%. The test yarn VI-3 could be uniformly partially drawn hot and cold drawn over the entire draw ratio range tested as indicated by along end draw tension % CV values of less than 2%.
Warp beaming which includes a heat treatment to enhance yarn properties is incorporated, herein, as a form of "warp drawing" where the beaming can include relaxation, i.e., draw ratios of less than 1.0×, or restrained conditions, i.e., draw ratio of about 1.0×. Tenter Frames or Slasher units, for example, modified to incorporate warp beaming, are alternate forms of warp treatment of which warp drawing is currently the most common. However, the test yarn of this invention makes the alternate warp treatments commercially viable routes to obtain enhanced warp yarn properties.
The feed yarns for use in this invention are highly crystalline with excellent thermal stability and dyeability which characteristics may be essentially maintained after hot (or cold) drawing. These feed yarns are also capable of being drawn hot or cold uniformly to residual elongations greater than about 30%, which provides the flexibility of tailoring draw-warped yarns of given tensiles, shrinkage, and dyeability for specific end-use requirements. Conventional POY cannot provide this flexibility in a single feed yarn.
AIR-JET TEXTURING EXAMPLES
As indicated earlier, Tables XVI and XVII show some results of drawing and air-jet texturing according to the present invention. The term AJT is used herein variously to indicate air-jet texturing and air-jet textured, according to context.
Table XVI shows the properties resulting from AJT according to the invention of undrawn feed yarns that were similar to feed yarns IC, IV-1, V-3 and VI-3, but of 91 denier and 100 filaments. All four yarns were processed similarly by cold drawing, then (sequentially) AJT on a Barmag FK6T-80 machine, using a conventional air-jet at 125 psi (8.8 kg/cm2), and heat set at 105° C. at speeds of 300 mpm, but the cold draw ratios were varied, as indicated, to provide bulky (looped) textile yarns with filament deniers between about 0.7 and 0.9 before boil-off shrinkage (BBO) and filament deniers between about 0.77 and 0.94 after boil-off shrinkage (ABO). The deniers shown in Table XVI are for drawn yarns. (Denier)DAJT is the denier of the yarn measured after AJT. (Denier)D is an estimated value for the drawn yarn before AJT, calculated from the draw ratio (DR) used and the denier of the undrawn feed yarn, which is referred to hereinafter as (Denier)Flat
(Denier).sub.D =(Denier).sub.Flat /DR
The denier of AJT yarn XVI-1 (wherein no draw was taken) showed an increase in yarn denier of about 10% due to the formation of filament loops (i.e., the ratio (Denier)DAJT /(Denier)Flat was greater than about 1.1); however, as expected, the denier of the actual filaments remained the same.
The "Bulk" of an AJT yarn is herein defined by the ratio of yarn deniers; that is, the Bulk is calculated by subtracting the calculated value of the denier of the drawn yarn before AJT (Denier)D from the denier of the yarn measured after AJT (Denier)DAJT and given as a percentage of the denier of the drawn yarn before AJT (Denier)D ; that is, ##EQU5## Preferred AJT yarns have Bulk values at least about 10%.
As expected, AJT yarn strengths (Tenacity, T and Tenacity-at-break, TB, herein defined as the product of Tenacity×RDR), were lower than those of the drawn flat yarns, owing to the filament loop structure; but our AJT yarn strengths were adequate for bulky fabric end uses.
AJT yarns XVI-2 and XVI-3 were uniformly partially cold drawn to provide residual elongations greater that 40%, and were capable of being uniformly dyed without along-end dye variations (such as would result from nonuniform thick-thin drawing, characteristic of partially drawn conventional POY). Even at a residual elongation of 27%, AJT yarn XVI-4 had boil-off and dry-heat shrinkages (BOS and DHS) of 12.7 and 11.0%, respectively, with a differential shrinkage (DHS-BOS) less than +2%. With mild heat setting, these BOS and DHS shrinkages can be reduced to less than about 3%.
Co-mingling (plying) 2 or more cold drawn AJT textile yarns, wherein at least one AJT yarn has been heat set to shrinkages less than about 3%, and a second AJT yarn has not been heat set, so has significantly higher shrinkage, provides a simplified route to a mixed shrinkage AJT yarn. Similar mixed shrinkage AJT yarns may be provided with the lower shrinkage component provided by alternative techniques, for instance by hot drawing, with or without heat setting. Alternatively, mixed shrinkage AJT yarns may be provided by co-mingling 2 or more drawn filament bundles wherein both bundles are drawn by cold drawing without post heat treatment, but the bundles are cold drawn to different elongations, preferably differing by about 10% or more (compare EX. XVI-2 to XVI-4, for example). The resulting mixed shrinkage drawn yarn may then be AJT to provide a mixed shrinkage textured yarn.
The higher-shrinkage components of our mixed shrinkage yarns of the invention differ from yarns made by drawing a conventional POY, in that our higher shrinkage yarns have a differential shrinkage (DHS-BOS) typically less than about 2%, this low differential shrinkage for a higher shrinkage component provides a very stable level of mixed shrinkage over a large end-use processing temperature range. The level of the "feed" yarn interlace is optimized for desired mixed shrinkage and AJT yarn aesthetics.
Preferred AJT filament yarns are prepared from undrawn feed yarns that have been treated with caustic in the spin finish (as taught by Grindstaff and Reese, in allowed copending application Ser. No. 07/420,459, filed Oct. 12, 1989) to enhance their hydrophilicity and provide improved moisture-wicking properties, and comfort. Incorporating filaments of different deniers and/or cross-sections may also be used to reduce filament-to-filament packing and thereby improve tactile aesthetics and comfort. Unique dyeability effects may be obtained by co-mingling drawn filaments of differing polymer modifications, such as homopolymer dyeable with disperse dyes and ionic copolymers dyeable with cationic dyes.
A mixed shrinkage flat yarn can be formed in a similar manner, wherein the yarns by-pass the air-jet.
In a similar manner a 73 denier 68 filament undrawn textile flat yarn was uniformly cold AJT to various draw ratios with AJT yarn properties summarized in Table XVII.
To provide drawn polyester filament yarns that are capable of being dyed with cationic dyestuffs, and are easier to nap and brush or cut into staple and flock, polyester co polymer of relative viscosity (LRV) about 13 to about 18 and containing about 1 to about 3 mole percent of ethylene-5-sodium-sulfo isophthalate is preferred. Accordingly, undrawn feed yarns that were capable of being partially and cold drawn to provide uniform drawn filament yarns were prepared by spinning 15.3 LRV copolymer at about 285° C., and quenching, using laminar cross-flow quench apparatus with a 5.6 cm delay, essentially as described in U.S. Pat. No. 4,529,638, and converging the filament bundle at about 109 cm with metered finish tip guides, and withdrawing at spin speeds of 2,468 and 2,743 mpm, respectively, to provide 100 filament undrawn yarns of nominal 0.75 denier per filament and elongations about 113% and 102%, respectively. The undrawn yarns can be drawn up to 1.77× and 1.68×, respectively, to provide drawn filament yarns (of at least about 20% elongation) that may be air-jet textured to provide bulky, soft cationic-dyeable textured yarns. The undrawn yarns may also be drawn with or without heat treatment and combined with homopolymer drawn filament yarns to provide mixed dyeability yarns.
TABLE I
__________________________________________________________________________
YARN NO. I-1 I-2 I-3 I-4 I-5 I-6 IA IB IC
__________________________________________________________________________
Undrawn Denier 108.0 108.0
108.0 108.0
108.0
108.0
70.6 69.3 108.0
Drawn Denier 81.8 91.5 92.2 93.9 93.2 83.6 -- -- --
Filaments - Shape
50 TRI
50 TRI
50 TRI
50 TRI
50 TRI
50 TRI
34 TRI
34 RND
50 TRI
TiO.sub.2, % 0.035 0.035
0.035 0.035
0.035
0.035
0.10 0.10 0.035
Viscosity, [η]
0.65 0.65 0.65 0.65 0.65 0.65 0.656
0.61 0.65
WARPING CONDITIONS
Draw Ratio, Speeds
Warp Draw Ratio (WDR)
1.34 1.18 1.18 1.18 1.30 1.47 -- -- --
Take-Up Speed (m/min)
500 500 500 500 500 500 -- -- --
Relax/Overfeed (%)
0 0 0 0 10 10 -- -- --
Effective WDR (EWDR)
1.34 1.18 1.18 1.18 1.17 1.32 -- -- --
Temperatures (°C.)
Feed Rolls 60 60 60 60 60 60 -- -- --
Preheat Plate 86 86 86 RT RT RT -- -- --
Draw Pin 95 95 95 OFF OFF OFF -- -- --
Set Plate 170 170 195 RT RT RT -- -- --
Relax Plate RT RT RT RT 195 195 -- -- --
YARNS
Shrinkages - AW, 5 mg/d
Boil-Off, S.sub.1 (%)
5.9 4.4 2.3 8.9 2.8 1.7 6.7 7.0 3.4
Thermal Stability, S.sub.2 (%)
1.2 0.7 1.2 (1.6)
0.2 1.1 5.1 5.3 (0.3)
Net, S.sub.12 (%)
7.1 5.1 3.5 7.3 3.0 2.8 11.8 12.3 3.1
Tension, ST (g/d)
0.42 0.24 0.22 0.17 0.03 0.04 0.22 0.22 0.07
Tensiles - AW
Modulus, M (g/d)
84.4 70.9 76.0 58.7 61.0 70.4 117.6
99.9 49.5
Ten. at 7%, T.sub.7, (g/d)
2.2 1.7 1.8 1.4 1.3 1.8 3.7 3.1 0.9
Ten. at 20%, T.sub.20 (g/d)
3.6 2.5 2.8 2.1 2.4 3.4 4.8 4.1 1.4
PY Modulus, PYM (g/d)
15.1 9.1 11.0 7.9 11.5 16.6 13.8 12.3 5.5
Elongation, E.sub.B (%)
25.4 42.8 40.0 48.4 45.2 30.7 24.9 25.2 74.9
Tenacity, T (g/d)
3.7 3.2 3.4 3.0 3.2 3.7 5.1 4.3 2.7
Tensiles - ABO
Modulus, M (g/d)
55.7 50.5 63.9 45.1 47.8 54.6 54.6 52.1 54.8
Ten. at 7%, T.sub.7 (g/d)
1.7 1.3 1.6 1.0 1.2 1.5 1.3 1.4 1.0
Ten. at 20%, T.sub.20 (g/d)
3.1 2.1 2.5 1.7 2.3 3.3 3.3 3.6 1.4
PY Modulus, PYM (g/d)
14.6 8.7 9.9 7.5 11.4 18.1 19.7 21.7 4.7
Elongation, E.sub.B (%)
31.2 48.0 43.2 56.4 44.2 28.1 32.5 33.7 84.4
Tenacity, T (g/d)
3.4 3.0 3.2 2.8 3.0 3.4 3.6 3.8 2.6
Tensiles - ADH
Modulus, M (g/d)
70.6 63.8 66.6 53.4 62.9 62.0 51.7 53.6 43.9
Ten. at 7%, T.sub.7 (g/d)
1.5 1.3 1.4 1.1 1.4 1.5 1.1 1.2 1.1
Ten. at 20%, T.sub.20 (g/d)
3.2 2.3 2.4 1.9 2.4 3.4 2.2 2.1 1.3
PY Modulus, PYM (g/d)
17.2 10.5 10.6 8.5 10.6 19.0 11.2 9.5 2.9
Elongation, E.sub.B (%)
34.2 50.1 47.3 56.0 43.8 27.3 41.3 43.4 87.3
Tenacity, T (g/d)
3.6 3.1 3.3 3.0 3.2 3.5 3.6 4.1 2.8
Crystallinity - AW
Density, ρ (g/cm.sup.3)*
1.3810
1.3869
1.3998
1.3815
1.3864
1.3880
1.3758
1.3764
1.3624
Crystal Size, CS (Å)
75 73 71 64 71 72 56 44 66
Dyeability - AW
Yarn 0.093 0.123
0.121 0.154
0.129
0.098
0.062
0.045
0.164
Rel. Disp. Dye Rate (RDDR)
Fabric 9.0 12.6 13.1 13.3 13.0 9.9 6.5 8.7 16.2
Dye Uptake (K/S)
FABRICS
Fabric Type Jersey Warp Knit
Course × Wale, greige
62 × 35
58 × 34
57 × 34
59 × 33
55 × 36
55 × 36
60 × 34
-- 60 × 34
Course × Wale, finished
58 × 52
59 × 47
58 × 44
56 × 50
54 × 46
53 × 48
58 × 34
-- 60 × 34
Area Wt. (oz/yd.sup.2), greige
3.88 4.12 4.18 4.09 4.27 3.87 3.44 -- 4.58
Area Wt. (oz/yd.sup.2), finished
5.26 5.37 5.21 5.76 5.12 4.82 4.98 -- 5.46
ΔWt./Area (%)
35.6 30.3 24.6 40.8 19.9 24.5 44.8 -- 19.2
Mullen Burst (lbs/in)
135 111 103 101 101 118 124 -- 84
Burst Strength 25.7 20.7 19.8 17.5 19.7 24.5 24.9 -- 15.4
(lb · yd.sup.2 /oz · in)
Dyed Fabric Rating
(1 = worst; 5 = no defect)
Long Streaks (LS)
5 4 4 5 4 2 5 -- 5
Short Streaks (SS)
3 3.5 4 4.5 4 4 4 -- 3
Dye Mottle (DM)
5 5 5 5 4 4 5 -- 5
Deep Dye Streaks (DDS)
5 5 5 5 5 5 5 -- 5
Average Rating (AR)
4.5 4.4 4.5 4.9 4.25 3.75 4.75 -- 4.5
__________________________________________________________________________
TABLES II and III
__________________________________________________________________________
YARN NO. II-1 III-1
III-2
III-3
III-4
III-5
III-6
__________________________________________________________________________
Undrawn Denier
114.6
106.7
106.7
106.7
106.7
106 106.7
Warped Denier 74.4 70.6 80.2 79.7 81.4 82.4 71.1
Filaments - Shape
34 TRI
34 RND
34 RND
34 RND
34 RND
34 RND
34 RND
TiO.sub.2, % 0.035
0.30 0.30 0.30 0.30 0.30 0.30
Viscosity, [η]
0.658
0.656
0.656
0.656
0.656
0.656
0.656
WARPING CONDITIONS
Draw Ratio, Speeds
Warp Draw Ratio (WDR)
1.62 1.54 1.34 1.34 1.34 1.44 1.65
Take-Up Speed (m/min)
500 500 500 500 500 500 500
Relax/Overfeed (%)
0 0 0 0 0 10 10
Effective WDR (EWDR)
1.62 1.54 1.34 1.34 1.34 1.30 1.49
Temperatures (°C.)
Feed Rolls 60 60 60 60 60 RT RT
Preheater Plate
86 86 86 86 RT RT RT
Draw Pin 95 95 95 95 OFF OFF OFF
Set Plate 160 170 170 195 RT RT RT
Relax Plate RT RT RT RT RT 195 195
YARNS
Shrinkages - AW, 5 mg/d
Boil-Off, S.sub.1 (%)
5.5 6.8 4.8 4.3 25.8 1.6 2.1
Thermal Stability, S.sub.2 (%)
2.6 3.2 2.0 2.0 (7.2)
1.0 2.2
Net, S.sub.12 (%)
8.1 10.0 6.8 6.3 18.6 2.6 4.3
Tension, ST, (g/d)
0.22 0.41 0.22 0.22 0.18 0.05 0.26
Tensiles - AW
Modulus, M (g/d)
79.5 98.8 79.0 79.9 60.0 70.5 81.4
Ten. at 7%, T.sub.7 (g/d)
2.7 3.4 2.0 2.1 1.4 1.7 2.6
Ten. at 20%, T.sub.20 (g/d)
4.0 4.8 3.2 2.4 2.2 3.2 4.8
PY Modulus, PYM (g/d)
14.7 16.3 13.1 14.1 8.8 15.5 22.9
Elongation, E.sub.B (%)
24.4 24.2 42.3 38.2 48.1 43.0 26.3
Tenacity, T (g/d)
4.0 4.6 4.0 4.1 3.5 4.1 4.8
Tensiles - ABO
Modulus, M (g/d)
48.3 44.5 41.2 53.9 37.7 60.8 50.2
Ten. at 7%, T.sub.7 (g/d)
1.5 1.7 1.3 1.5 0.8 1.5 1.9
Ten. at 20%, T.sub.20 (g/d)
3.4 3.9 2.6 2.9 1.1 3.0 4.5
PY Modulus, PYM (g/d)
19.0 22.0 13.3 14.4 2.8 15.3 25.9
Elongation, E.sub. B (%)
30.7 28.8 44.3 40.0 90.6 40.2 23.2
Tenacity, T (g/d)
3.7 4.1 3.5 3.7 2.6 3.7 4.3
Tensiles - ADH
Modulus, M (g/d)
54.5 70.1 60.9 64.9 12.5 66.7 63.5
Ten. at 7%, T.sub.7 (g/d)
1.4 1.6 1.3 1.4 0.8 1.3 1.5
Ten. at 20%, T.sub.20 (g/d)
3.4 3.9 2.7 2.8 1.0 2.8 4.3
PY Modulus, PYM (g/d)
19.9 22.8 14.2 14.3 1.8 15.1 27.3
Elongation, E.sub.B (%)
31.6 32.2 47.1 43.0 112.8
47.5 28.7
Tenacity, T (g/d)
3.7 4.1 3.5 3.7 2.6 3.7 4.3
Crystallinity - AW
Density, ρ (g/cm.sup.3)*
1.3807
1.3824
1.3783
1.3838
1.3590
1.3940
1.3842
Crystal Size, CS (Å)
52 58 53 61 Small
55 60
Dyeability - AW
Yarn 0.062
0.049
0.071
0.061
0.124
0.074
0.052
Rel. Disp. Dye Rate
(RDDR)
Fabric 5.7 5.1 8.4 7.0 9.3 8.0 5.6
Dye Uptake (K/S)
FABRICS
Fabric Type Jersey Warp Knit
Course × Wale, greige
55 × 35
56 × 38
60 × 38
60 × 36
62 × 33
62 × 35
58 × 36
Course × Wale, finished
56 × 47
56 × 50
56 × 50
56 × 50
67 × 58
56 × 50
56 × 44
Area Wt. (oz/yd.sup.2), greige
3.40 3.41 3.85 3.84 3.80 3.78 3.54
Area Wt. (oz/yd.sup.2), finished
4.4 4.55 4.96 5.11 6.57 5.03 4.05
ΔWt./Area (%)
29.4 33.4 28.8 33.1 72.9 33.1 14.4
Mullen Burst (lbs./in.)
117 123 113 110 91 99 117
Burst Strength
26.6 27.0 22.8 21.5 13.9 19.7 28.9
(lbs. · yd.sup.2 /oz · in)
Dyed Fabric Rating
(1 = worst; 5 = no defect)
Long Streaks (LS)
4 4 3 2 1 4 3
Short Streaks (SS)
3 3 2 3 5 4 3
Dye Mottle (DM)
2 3 3 2 5 2 3
Deep Dye Streaks (DDS)
5 5 5 5 1 5 5
Average Rating (AR)
3.5 3.75 3.25 3 3 3.75 3.5
__________________________________________________________________________
TABLE IV
__________________________________________________________________________
YARN NO. IV-1 IV-2 IV-3 IV-4 IV-5 IV-6 IV-7 IV-8 IV-9
__________________________________________________________________________
Draw Ratio -- RELAX RELAX
TAUT TAUT 1.05 1.05 1.10 1.10
Draw Temperature (°C.)
-- 100 180 100 180 95 180 95 180
Wet/Dry -- WET DRY WET DRY WET DRY WET DRY
Density ρ (g/cm.sup.3)*
1.3719
1.3877
1.3936
1.3862
1.3908
1.3756
1.3976
1.3801
1.397
Birefringence (Δ.sub.n)
0.071
0.102 0.122
0.101
0.109
0.081 0.121
0.099 0.127
Crystal Size, CS (Å)
72 75 72 66 72 68 75 -- --
Modulus, M (g/d)
48.5 40.7 51.0 46.0 52.8 48.4 58.3 54.6 66.6
Tenacity at 7%, T.sub.7 (g/d)
0.9 1.0 1.2 1.1 1.2 1.1 1.3 1.3 1.3
Elongation, E.sub.B (%)
89.1 86.9 76.5 85.2 81.2 66.7 60.2 56.1 47.8
Tenacity, T (g/d)
3.0 2.9 2.9 2.9 3.0 2.9 3.0 3.0 3.0
Shrinkage Tension, ST (g/d)
0.07 0.02 0.02 0.02 0.03 0.14 0.09 0.20 0.17
Dye Uptake (K/S)
17.7 -- -- 15.6 16.3 16.7 12.2 16.8 10.7
__________________________________________________________________________
TABLE V
______________________________________
YARN NO. V-1 V-2 V-3
______________________________________
Undrawn Denier 114.6 106.7 108.0
Filaments - Shape 34 TRI 34 RND 50 TRI
TiO.sub.2, % 0.035 0.30 0.035
Viscosity, [η] 0.658 0.656 0.65
Boil-Off Shrinkage, S.sub.1 (%)
33.4 17.6 3.4
Modulus, M (g/d) 27.9 34.3 49.5
Tenacity at 7% Elong., T.sub.7 (g/d)
0.58 0.62 0.87
Stress at 7% Elongation, σ.sub.7 (g/d)
0.62 0.66 0.93
Yield Stress, σ.sub.y (g/d)
0.68 0.75 0.96
Yield Zone, E"-E' (%)
21.5 18.0 6.0
Elongation to Break, E.sub.B (%)
118.4 95.8 74.9
Uniform Partial Draw
No No Yes
______________________________________
σ.sub.7 = T.sub.7 × 1.07
Stress, σ = (Load (g)/initial denier) × (1 + Elongation
(%)/100)
E' = Elongation to yield point (σ'.sub.y)
E" = Elongation to post yield point (σ".sub.y), where
(σ'.sub.y = σ".sub.y)
TABLE VI
______________________________________
Yarn No. VI-1 VI-2 VI-3
______________________________________
Undrawn Denier 127.2 107.0 101.4
Filaments - Shape
34 RND 34 RND 50 TRI
TiO2, % 0.30 0.30 0.035
Boil-Off Shrinkage, S1 (%)
54.8 11.1 3.2
Modulus, M (g/d) 22.0 25.1 36.6
Ten. at 7% Elong., T7 (g/d)
0.56 0.69 0.99
Stress at 7% Elong., σ.sub.7 (g/d)
0.60 0.74 1.06
Yield Stress, σ.sub.y (g/d)
0.65 0.85 1.09
Yield Zone, E"-E' (%)
46 26 8
Elong. at Break, EB (%)
136.2 120.7 73.3
Uniform Partial Draw
NO NO YES
______________________________________
Yarns VI1 thru VI3 had a nominal Viscosity [7] of 0.65.
σ.sub.7 = T7 × 1.07
Stress, σ = [Load (g)/initial denier) × (1 + Elong.
E' = Elongation to yield point (σ'.sub.y)
E" = Elongation to post yield point (σ".sub.y), where
(σ'.sub.y = σ".sub.y)
TABLES VII-IX
__________________________________________________________________________
Yarn No. VI-1
VII-1
VII-2
VII-3
VII-4
VII-5
VII-6
__________________________________________________________________________
Warp Draw Ratio, WDR
1.00
1.39
1.48
1.57
1.69
1.82
1.97
Residual Draw Ratio, RDR
2.36
1.59
1.51
1.41
1.35
1.21
1.12
Elongation-to-Break, Eb (%
136.2
58.9
51.1
40.8
34.5
21.2
12.3
Rel. Denier Spread, WD/Feed
1.00
3.03
2.05
1.27
1.19
1.29
1.42
Rel. Uster, WD/Feed
1.00
7.58
5.12
2.33
1.58
2.69
1.79
Dyed Fabric Ratings, (DM)
-- 1 1 3 3 4 5
__________________________________________________________________________
Yarn No. VI-2
VIII-1
VIII-2
VIII-3
VIII-4
VIII-5
VIII-6
__________________________________________________________________________
Warp Draw Ratio, WDR
1.00
1.22
1.30
1.39
1.49
1.60
1.73
Residual Draw Ratio, RDR
2.21
1.72
1.63
1.51
1.41
1.30
1.21
Elongation-to-Break, Eb (%)
120.7
71.7
62.6
51.4
40.8
29.9
21.4
Rel. Denier Spread, WD/Feed
1.00
2.52
1.89
0.98
0.81
1.00
0.88
Rel. Uster, WD/Feed
1.00
5.67
4.03
1.73
0.85
1.08
1.37
Dyed Fabric Ratings, (DM)
-- 1 1 2 3 4 5
__________________________________________________________________________
Yarn No. VI-3
IX-1
IX-2
IX-3
IX-4
IX-5
IX-6
__________________________________________________________________________
Warp Draw Ratio, WDR
1.00
1.05
1.12
1.19
1.28
1.38
1.49
Residual Draw Ratio, RDR
1.73
1.63
1.53
1.44
1.35
1.24
1.13
Elongation-to-Break, Eb (%)
73.3
63.5
52.9
43.9
35.1
24.4
12.5
Rel. Denier Spread, WD/Feed
1.0 0.79
0.67
0.47
0.72
0.61
0.94
Rel. Uster, WD/Feed
1.0 0.92
0.96
0.60
0.51
0.45
0.41
Dyed Fabric Ratings, (DM)
-- 4 4 4 5 5 5
__________________________________________________________________________
WARP DRAW SPEED, METERS/MINUTE
600
PRE-HEATER PLATE TEMP., C. 90
DRAW PIN TEMP., C. 100
SET PLATE TEMP., C. 140
POST SET PLATE ROLL TEMP., C.
55
RELAXATION, % 0
__________________________________________________________________________
TABLES X-XII
__________________________________________________________________________
Yarn No. VI-1
X-1 X-2 X-3 X-4 X-5 X-6
__________________________________________________________________________
Warp Draw Ratio, WDR
1.00
1.39
1.48
1.57
1.69
1.82
1.97
Residual Draw Ratio, RDR
2.36
1.56
1.52
1.44
1.31
1.22
1.14
Elongation-to-Break, Eb (%)
136.2
55.5
51.6
43.9
30.8
21.7
14.0
Rel. Denier Spread, WD/Feed
1.00
8.89
8.13
1.12
0.86
0.92
1.29
Rel. Uster, WD/Feed
1.00
8.57
5.40
1.26
1.05
1.12
1.64
Dyed Fabric Ratings, (DM)
-- 1 1 1 3 4 4
__________________________________________________________________________
Yarn No. VI-2
XI-1
XI-2
XI-3
XI-4
XI-5
XI-6
__________________________________________________________________________
Warp Draw Ratio, WDR
1.00
1.22
1.30
1.39
1.49
1.60
1.73
Residual Draw Ratio, RDR
2.21
1.69
1.60
1.48
1.37
1.28
1.17
Elongation-to-Break, Eb (%)
120.1
69.2
60.1
47.6
36.8
27.9
17.5
Rel. Denier Spread, WD/Feed
1.00
6.28
4.94
0.91
0.84
0.69
0.83
Rel. Uster, WD/Feed
1.00
4.30
3.00
0.82
0.75
0.67
0.75
Dyed Fabric Ratings, (DM)
-- 1 1 1 2 3 4
__________________________________________________________________________
Yarn No. VI-3
XII-1
XII-2
XII-3
XII-4
XII-5
XII-6
__________________________________________________________________________
Warp Draw Ratio, WDR
1.00
1.05
1.12
1.19
1.28
1.38
1.49
Residual Draw Ratio, RDR
1.73
1.65
1.52
1.45
1.33
1.23
1.13
Elongation-to-Break, Eb (%)
73.3
65.1
52.1
45.2
32.9
23.2
13.0
Rel. Denier Spread, WD/Feed
1.0 0.96
1.14
0.83
1.27
0.86
0.93
Rel. Uster, WD/Feed
1.0 0.54
0.64
0.52
0.60
0.53
0.50
Dyed Fabric Ratings, (DM)
-- 4 4 4 5 5 5
__________________________________________________________________________
WARP DRAW SPEED, METERS/MINUTE
600
PRE-HEATER PLATE TEMP., C. RT
DRAW PIN TEMP., C. RT
SET PLATE TEMP., C. 180
POST SET PLATE ROLL TEMP., C.
RT
RELAXATION, % 0%
__________________________________________________________________________
TABLES XIII-XV
__________________________________________________________________________
DRAW RATIO, WDR
1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
__________________________________________________________________________
Feed Yarn No. VI-1
Drawn Yarn No. XIII-1
XIII-2
XIII-3
XIII-4
XIII-5
XIII-6
XIII-7
XIII-8
Residual Draw Ratio, RDR
-- 1.89
1.75
1.62
1.51
1.42
1.34
1.26
1.19
Draw Tension, % CV
(Draw Temp., C.)
19 C. -- 2.8 2.1 3.1 4.2 6.7 2.9 3.8 4.2
79 C. -- 4.8 4.3 3.2 4.2 4.6 3.4 2.1 4.5
100 C. -- 5.1 4.2 4.0 4.4 4.7 3.7 2.0 2.2
122 C. -- 4.3 4.8 5.2 4.9 4.0 2.6 1.7 2.3
174 C. -- 4.1 3.2 5.3 4.6 4.4 3.7 2.6 2.1
224 C. -- 5.1 4.8 3.8 4.9 4.3 3.9 3.2 2.3
Feed Yarn No. VI-2
Drawn Yarn No.
XIV-1
XIV-2
XIV-3
XIV-4
XIV-5
XIV-6
XIV-7
XIV-8
Residual Draw Ratio, RDR
2.01
1.85
1.70
1.58
1.47
1.38
1.30
1.23
Draw Tension, % CV
(Draw Temp. C.)
19 C. 2.5 1.9 2.5 3.4 3.0 2.9 3.1 3.6
79 C. 3.2 3.6 3.2 2.7 2.0 1.5 1.4 1.8
100 C. 2.7 3.4 3.8 2.1 2.1 1.4 1.0 1.5
122 C. 3.1 3.0 3.5 2.5 2.1 1.8 1.2 --
174 C. 4.5 5.9 3.1 3.1 2.7 2.2 2.0 --
224 C. 4.0 4.5 4.1 3.1 2.5 2.0 3.4 --
Feed Yarn No. VI-3
Drawn Yarn No.
XV-1
XV-2
XV-3
XV-4
XV-5
Residual Draw Ratio, RDR
1.57
1.44
1.33
1.24
1.15
Draw Tension, % CV
(Draw Temp., C.)
19 C. 1.9 1.2 1.5 1.7 1.7
79 C. 3.2 1.8 0.9 0.8 0.9
100 C. 2.3 1.6 1.2 1.0 0.9
122 C. 2.0 1.8 1.3 1.1 0.9
174 C. 2.6 2.1 1.4 1.1 0.9
224 C. 3.7 2.4 1.6 1.4 1.0
__________________________________________________________________________
MODEL 4000 EXTENSOTRON (TM) - MICRO SENSORS, INC.
(New Englander Industrial Park, Holliston, Mass. 01746)
DRAW SPEED 25 METERS/MINUTE
DRAW ZONE 1 METER NONCONTACT HOT TUBE
SAMPLE LENGTH 50 METERS
TENSIONOMETER 1000 GRAM HEAD CALIBRATED TO 200 GRAMS
% CV DRAW TENSION 500 DATA POINTS
RESIDUAL DRAW RATIO, RDR = [1 + ELONGATION(%)/100%]feed/MACHINE
DRAW RATIO
__________________________________________________________________________
TABLE XVI
______________________________________
Example XVI- 1 2 3 4
______________________________________
Process 1.0 1.1 1.2 1.32
Draw Ratio (DR)
Drawn Yarn Properties
(Denier) DAJT 101.4 95.0 85.8 77.3
(Denier) D 91 85 77 69
Bulk, % 11.4 11.8 11.4 12.0
E.sub.B, % 61.1 57.1 41.3 27.2
RDR 1.61 1.57 1.41 1.27
T, gpd 1.96 2.22 2.42 2.64
T.sub.B, gpd 3.16 3.49 3.42 3.34
BOS, % 3.5 4.3 8.2 12.7
DHS, % 2.8 4.1 7.6 11.0
(DHS-BOS), % -0.7 -0.2 -0.6 -1.7
______________________________________
TABLE XVII
______________________________________
Example XVI- 1 2 3 4
______________________________________
Process 1.0 1.1 1.2 1.32
Draw Ratio (DR)
Drawn Yarn Properties
(Denier) DAJT 81.8 75.1 70.4 64.7
(Denier) D 73.0 66.4 60.8 55.3
Bulk, % 12.1 13.1 15.7 17.0
E.sub.B, % 64.4 60.9 43.3 29.6
RDR 1.64 1.61 1.43 1.30
T, gpd 2.12 2.46 2.58 2.78
T.sub.B, gpd 3.48 3.96 3.69 3.61
BOS, % 3.4 4.9 8.2 11.8
DHS, % 3.2 4.4 7.1 10.4
(DHS-BOS), % -0.2 -0.5 -1.1 -1.4
______________________________________
We claim:
1. A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is partially drawn to a uniform yarn by hot-drawing or by cold-drawing, with or without heat-setting, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
2. A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is drawn to a uniform yarn by cold-drawing, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about 1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms
3. A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is drawn to a uniform yarn by hot-drawing without any post heat treatment, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
4. A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is drawn to a uniform yarn by hot-drawing, with post heat treatment to reduce shrinkage, at such draw ratio to provide said uniform yarn of elongation-to-break at least about 30%, and then said uniform yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
5. A process for preparing a textured polyester yarn, wherein a feed yarn of spin-oriented polyester filaments is heat treated, without drawing, and then said heat treated yarn is air jet textured, said feed yarn being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
6. A process for providing a mixed-shrinkage air-jet textured polyester yarn from feed yarns of spin-oriented flat polyester filaments, characterized in that a feed yarn (A) is drawn to a uniform drawn yarn of high shrinkage by cold-drawing without any post heat treatment, and in that a feed yarn (B) is drawn to a uniform drawn yarn of lower shrinkage by hot or by cold-drawing with a post heat treatment to reduce shrinkage, and said uniform drawn yarns are co-mingled and air-jet textured, said feed yarns (A) and (B) being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1 39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
7. A process for providing a mixed-shrinkage air-jet textured polyester yarn from feed yarns of spin-oriented flat polyester filaments, characterized in that a feed yarn (A) is drawn to a uniform drawn yarn of high shrinkage by cold-drawing without any post heat treatment, and in that a feed yarn (B) is drawn to a uniform drawn yarn of lower shrinkage by cold-drawing without any post heat treatment, wherein said draw ratios for drawing feed yarns (A) and (B) are selected to provide an elongation for the uniform drawn yarn of lower shrinkage (B) at least about 10% greater than the elongation of the uniform drawn yarn of higher shrinkage from feed yarn (A), and said uniform drawn yarns are co-mingled and air-jet textured, said feed yarns (A) and (B) being of elongation-to-break (EB) about 40 to about 120%, tenacity at 7% elongation (T7) at least about 0.7 grams/denier, boil-off shrinkage (S1) less than about 10%, thermal stability as shown by an S2 value less than about +1%, net shrinkage (S12) less than about 8%, maximum shrinkage tension (ST) less than about 0.3 grams/denier, density (ρ) about 1.35 to about 1.39 grams/cubic centimeter, and crystal size (CS) about 55 to about 90 Angstroms and also at least about (250 ρ-282.5) Angstroms.
8. A process according to claim 6 or 7, wherein difference in shrinkage of said mixed-shrinkage air-jet textured yarns is developed while said yarns are in the form of a weftless warp sheet prior to knitting or weaving, by heat relaxing said warp sheet under tension not exceeding the shrinkage tension of the high shrinkage filaments.
9. A process according to any one of claims 1 to 7, wherein the filaments of the drawn yarns are of denier less than 1.0.
10. A process according to any one of claims 1 to 7, wherein the polyester polymer contains about 1 to about 3 mole percent of ethylene-5-sodium-sulfo isophthalate.
| 1991-11-01 | en | 1993-09-14 |
US-52411274-A | Glass fibers coated with a silanized butadiene polymer
ABSTRACT
A composition for use in the treatment of glass fibers to promote a strong bonding relationship between glass fibers and plastics and elastomeric materials comprising a silanized butadiene polymer which has been reacted with a halosilane and the product reacted with an epoxide to replace the halogen groups of the silane with beta-haloalkoxy groups.
This is a continuation of application Ser. No. 347,298, filed Apr. 2, 1973 and now abandoned.
This invention relates to a composition for use in the treatment of glass fibers, and more particularly to a composition for use in the treatment of glass fibers to improve the processing and performance characteristics of glass fibers for reinforcement of elastomeric materials and resins in the manufacture of glass fiber reinforced elastomeric products and in the manufacture of glass fiber reinforced plastics.
The term "glass fibers", as used herein, is intended to refer to and include (1) continuous fibers formed by rapid attenuation of hundreds of streams of molten glass and to strands formed when such continuous glass fiber filaments are gathered together as they are being formed; and to yarns and cords formed by plying and/or twisting a number of strands together, and to woven and non-woven fabrics which are formed of such glass fiber strands, yarns or cords, and (2) discontinuous fibers formed by high pressure steam, air or other suitable attenuating force directed onto multiple streams of molten glass issuing from a glass melting bushing or from an orifice containing spinner, and to yarns that are formed when such discontinuous fibers are gathered together to form a sliver which is drafted into a yarn; and to woven and non-woven fabrics formed of such yarns of discontinuous fibers, and (3) combinations of such continuous and discontinuous fibers in strands, yarns, cords and fabrics formed thereof.
It is now common practice to combine glass fibers with elastomeric materials in the manufacture of glass fiber-reinforced elastomeric and resinous products. As is known to those skilled in the art, the glass fibers prior to combination with elastomeric materials or resinous materials are first coated with a size composition to improve the processing characteristics of the glass fibers and impart the desired degree of lubricity to the glass fibers and thus prevent destruction of the fibers through mutual abrasion, without destroying the fibrous characteristics of the glass fibers. Subsequent to application of the size coating or film to the individual glass fiber filaments, the glass fibers for use as reinforcement for elastomeric materials are frequently formed into strands, cords, yarns or fabrics, hereinafter referred to as bundles, for impregnation with an elastomer compatible adhesive, generally in the form of a blend of a resorcinol-aldehyde resin and an elastomer.
One of the distinguishing features of glass fibers as compared to other synthetic fibers stems from the fact that the glass fiber surfaces are highly hydrophilic in nature, with the result that a thin but tenacious film of moisture is formed on the glass fiber surfaces almost immediately as the glass fibers are formed. This film of moisture has a detrimental effect on establishing a secure bonding relationship between the glass fiber surfaces and elastomeric materials with which the glass fibers are combined in the manufacture of glass fiber reinforced elastomeric products.
It is now known to the art that the effect of the film of moisture referred to above on the bonding relationship between glass fibers and elastomeric or resinous materials can be minimized by formulating the treating or size composition to include an organo silicon compound, usually in the form of a hydrolyzable silane. While the use of such organo silicon compounds represents a distinct improvement in the art, such compounds are nevertheless subject to certain disadvantages. One disadvantage in the use of such silanes is their high cost which imposes economic limitations on the amount of the silanes which can be formulated into a size composition. In addition, it has been found that such silanes are frequently not chemically bonded to the film-forming component of the size composition and, consequently, the bond established between the film forming component and the individual glass fiber surfaces frequently does not have maximum strength.
It has also been proposed to introduce a silicon atom to the polymeric matrix in an attempt to increase the bonding strength of the film forming material to the glass fiber surfaces. For example, in U.S. Pat. No. 3,650,810 there is disclosed a component for a size composition in which an organo silane containing ethylenic unsaturation is copolymerized with butadiene and styrene, or with an alpha-olefin.
It has also been proposed to add a trihalosilane directly to polymeric butadiene whereby the trihalosilane simply adds across the ethylene double bond in accordance with the following: ##EQU1##
The primary difficulty with film forming polymeric materials prepared in this manner is that they are not stable, particularly in aqueous media, and consequently decompose to evolve HX (e.g., HCl) which has a detrimental effect on the treated fibers.
It is accordingly an object of the present invention to produce and to provide a method for producing a film forming material containing silicon atoms chemically bonded thereto which is stable against the release of hydrogen halides and which can be used to promote a secure bonding relationship between glass fibers and elastomeric or resinous materials in the manufacture of glass fiber reinforced elastomeric or resinous products.
It is a related object of the invention to provide glass fibers which have been treated with a polymeric material having silicon atoms chemically bonded therein to establish a secure bonding relationship between the glass fibers and elastomeric or resinous materials with which the treated glass fibers have been combined in the manufacture of glass fiber reinforced elastomeric or resinous products.
The concepts of the present invention reside in a film-forming polymeric material for use in the treatment of glass fibers in which a halosilane is added across the ethylenic double bond of an elastomeric polymeric and the remaining halogen atoms attached to the silicon atom are replaced, preferably by way of a beta-haloalkoxy group.
In the preferred practice of the present invention, an elastomeric polymer based on butadiene is first reacted with a halosilane containing at least one hydrogen atom bonded directly to the silicon atom to add the halosilane across the double bond. The product of this reaction is then further reacted with an epoxide. Without limiting the present invention as to theory, it is believed that the reaction product of the halosilane with the polymeric material results in a polymer including units ##EQU2## and the epoxide ##EQU3## reacts with the remaining halogen atoms to form beta-haloalkoxy groups as follows ##EQU4## in the polymer matrix. The use of an epoxide is particularly advantageous in that the beta-haloalkoxy group which is formed not only prevents the evolution of HCl, but also serves to stabilize the resulting product from hydrolysis of the beta-chloroalkoxy group attached to the silicon atom. As will be appreciated by those skilled in the art, hydrolysis of the halogen atoms of the groups represented by (II) can lead to gelling of the polymer through crosslinking, particularly in aqueous media. It has been found, on the other hand, that the beta-haloalkoxy groups serve to stabilize the product of the reaction and render it significantly more resistant to hydrolysis.
The concepts of the present invention are applicable to elastomeric polymers and preferably polymers based upon butadiene, containing ethylenic unsaturation. Suitable polymers include homopolybutadiene, copolymers of butadiene and furfural, copolymers of butadiene and styrene, copolymers of butadiene and acrylonitrile, terpolymers of butadiene, styrene and acrylonitrile, terpolymers of butadiene, styrene and vinyl pyridine, copolymers of butadiene and maleic anhydride, copolymers of butadiene and alkyl acrylates and methacrylates in which the alkyl groups contain 1 to 4 carbon atoms. Such copolymers generally contain at least 55% butadiene, and preferably 60% butadiene. The chemical composition of the rubbery polymer is not critical so long as the polymer has at least 1.5 carbon-to-carbon double bonds per 1000 carbon atoms.
The average molecular weight of the polymer containing the ethylenic unsaturation is not a critical variable in the process of the invention. It has been found, however, that liquid polymers are simpler to react since no solvent is required. It is accordingly preferred to employ liquid polymers, that is polymers having a molecular weight less than 6000. Best results are usually achieved when use is made of polymers having an average molecular weight within the range of 300 to 5000, and preferably 500 to 3000. As will be appreciated by those skilled in the art, use can be made of higher molecular weight polymers by simply dissolving the polymer in a suitable inert organic solvent.
As the halosilane, use can be made of a variety of halosilanes containing at least one hydrogen atom bonded to the silicon atom and at least one halogen atom (and preferably chlorine or bromine) bonded to the silicon atom. Preferred silanes are those having the formula ##EQU5## wherein X is halogen, and preferably chlorine or bromine, and R is halogen as described above, hydrogen or an organic group. Preferred organic groups include C1 to C6 alkyl (e.g., methyl, ethyl, propyl, isopropyl, etc.); C2 to C6 alkenyl (e.g., vinyl, allyl, butenyl, etc.); an aryl group containing 6 to 10 carbon atoms (e.g., phenyl, tolyl, benzyl, naphthyl, etc.), cycloalkyl containing 4 to 8 carbon atoms (e.g., cyclopentyl, cyclohexyl, etc.) as well as halogen, hydroxy, etc. substituted derivatives thereof.
Representative of such silanes are trichlorosilane, tribromosilane, dichlorosilane, vinyldichlorosilane, allyldichlorosilane, methyldibromosilane, phenyldichlorosilane, cyclohexyldichlorosilane, chlorophenyldichlorosilane, etc.
Trihalosilanes are generally preferred for use in the practice of this invention. The organodihalosilanes are interesting reactants, and particularly the unsaturated dihalosilanes. It is believed that the reaction product between the polymer containing ethylenic unsaturation and such dihalosilanes include units ##EQU6## where R is vinyl, and this unsaturated group provides a reactive site for crosslinking of the polymer on curing.
The reaction between the silane and the polymer is carried out in the presence of a catalyst of the type conventionally employed in the reaction of unsaturated compounds with trichlorosilanes. The preferred catalyst is chloroplatinic acid, but use can also be made of other platinum catalysts including platinum on a charcoal support, PtCl4, PtCl2 and complexes formed between PtCl4 and olefins such as ethylene or cyclohexene. In addition, use can also be made of organic amines.
The reaction is preferably carried out using the liquid polymer as the reaction medium although use can be made of an inert organic solvent if desired. Suitable solvents, when a solvent is employed, include saturated aliphatic hydrocarbons such as pentane, hexane, heptane; aromatic hydrocarbons such as benzene, toluene, xylene, etc., as well as numerous others. The reaction temperature is not critical and can be varied within wide limits. In general, higher reaction temperatures favor shorter reaction times. It has been found that good results are achieved with a reaction temperature within the range of 20° to 200°C although higher or lower temperatures can be employed depending upon the reaction time and on whether a solvent is used. If the polymer is a solid polymer, the use of a solvent for the polymer is essential.
A catalytic amount of the catalyst is usually sufficient to catalyze the reaction. For example, use can be made of 0.00005 to 0.001 mole of catalyst per mole of the silane, and preferably 0.0001 to 0.0005 mole of catalyst per mole of silane.
Reactant proportions are similarly not critical to the practice of the invention. It is generally sufficient that the halosilane be employed in amounts within the range of 0.1 to 50 parts by weight per 10 parts by weight of the polymer. As will be appreciated, use can be made of up to 1 mole of halosilane per mole of carbon-to-carbon double bonds in the polymer, if desired, to introduce the maximum number of silicon atoms into the polymeric matrix.
After reaction with the halosilane, the polymer is then reacted with an epoxide. In general, it is desirable to employ the epoxide in an amount sufficient to react with all of the halogen atoms bonded to the silicon atom, that is, one mole of epoxide per mole of halogen atoms bonded to silicon. Greater amounts of epoxide can be used although there is frequently no advantage in using such excesses. The reaction proceeds spontaneously although the reaction can be accelerated by the addition of heat. For best results, the reaction with the epoxide is carried out at a temperature within the range of 20° to 200°C.
As the epoxide, use can be made of a variety of mono- and diepoxides. preferred are alkylene oxides ##EQU7## wherein R2 is halogen or an alkyl group containing 1 to 20 carbon atoms, and preferably 1 to 6 carbon atoms. Representative alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, pentylene oxide, hexylene oxide, etc.
Also suitable for use in the practice of the invention are epoxides having the formula ##EQU8## wherein R3 is an aryl group and preferably phenyl or phenyl substituted with an amino group, a halogen group, an alkyl group; alkyl containing 1 to 20 carbon atoms and substituted derivatives thereof; an alkenyl group containing 2 to 8 carbon atoms (e.g., vinyl, allyl, etc.); a group having the formula ##EQU9## wherein R' is hydrogen or methyl. Illustrative of such epoxides are phenyl glycidyl ether, cresyl glycidyl ether, allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, a mixture of n-octyl and n-decyl glycidyl ethers (Epoxide No. 7 from Procter and Gamble) and a mixture of n-dodecyl and n-tetradecyl glycidyl ethers (Epoxide No. 8 from Procter and Gamble).
Use can also be made of diepoxides, such as the following epoxides of the formula ##EQU10## wherein R3 is a divalent organic radical such as oxyalkyleneoxy containing 1 to 10 carbon atoms; oxyalkyleneoxyalkyleneoxy containing 2 to 20 carbon atoms; divalent aromatic groups such as a group of the formula ##SPC1##
A number of such epoxides are commercially available from Dow and Ciba and include the following: ##EQU11## ##SPC2##
Also suitable are cycloalkane epoxides, including the following: ##SPC3##
In using epoxides containing more than one epoxide groups per mole, such as diepoxides, it is frequently desirable to employ the diepoxides in combination with a monoepoxide of the type described above to minimize gelling of the resulting product through cross-linking. It is preferred to employ the diepoxides combined in mole ratios less than 1:1 based upon the total number of halogen atoms contained in the silane, with the balance of the monoepoxide being sufficient to react with the halogen atoms of the halosilane. For best results, the ratio of the monoepoxide to diepoxide is 2:1 to 5:1.
Again, without limiting the present invention as to theory, it is believed that the epoxide or epoxides react with the halogen atoms attached to the silicon atom in accordance with the following: ##EQU12## The resulting beta-haloalkoxy groups are believed to stabilize the product and provide improved adhesion between the product and hydrophilic surfaces such as those of glass fibers.
The resulting silicon modified polymer is particularly well suited for use as a fiber forming component in a glass fiber treating composition, such as a size composition. For this purpose, use can be made of an aqueous dispersion of the modified polymer alone or in combination with conventional additives in such compositions, such as glass fiber anchoring agents in the form of organo silicon compounds, emulsifying agents, glass fiber lubricants and the like. The silane modified polymer has been found to be quite effective in the establishment of a secure bonding relationship between glass fibers and resinous plastics and elastomeric materials in the manufacture of glass fiber reinforced plastics and elastomeric products.
A wide variety of conventional emulsifying agents can be used in the practice of the invention. Preferred are the nonionic emulsifying agents, such as the polyoxyethylene derivatives of fatty acid partial esters of sorbitol anhydrides or the polyoxyethylene derivatives of fatty alcohols containing 8 to 22 carbon atoms or of akyl substituted phenols wherein the alkyl groups contain 6 to 18 carbon atoms. Such emulsifiers are commercially available and include "Tween 80" from Atlas Chemical Industries, Inc. which is a polyoxyethylene derivative of the trioleate ester of sorbitan, "Tween 60" which is a polyoxyethylene derivative of the sterarate ester of sorbitan and available from Atlas, and the "Triton" series of emulsifiers from Rohm and Haas which are polyoxyethylene derivatives of alkyl-substituted phenols.
As will be appreciated by those skilled in the art, anionic and cationic emulsifying agents can also be used in the practice of the invention. Representative of such emulsifying agents are the alkali metal fatty acid sulfates (e.g. sodium lauryl sulfate), alkali metal salts of alkyl aryl sulfonates (e.g. sodium alkyl benzene sulfonates), as well as numerous others.
The size composition of the invention can be, if desired, formulated to include at least one glass fiber anchoring agent in the form of an organo silicon compound.
As the organo silicon coupling agent, use can be made of a very wide variety of silicon containing coupling agents known to those skilled in the art to be useful for this purpose. In general, suitable organo silicon compounds include organo silanes containing 1 to 3 readily hydrolyzable groups, such as halogen (bromine, chlorine, fluorine or iodine), or alkoxy having 1 to 6 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, etc., and containing at least one organic group attached directly to the silicon atom, with any remaining valences on the silicon atom being taken up by hydrogen. In aqueous solution, such silanes tend to hydrolyze to form the corresponding silanols and/or siloxanes and hence the anchoring agent is present in the aqueous size composition of the invention as the silane, silanol and/or siloxane.
The organic group or groups attached to the silicon atom can be any of a variety of groups including alkyl having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, hexyl, etc.; alkenyl containing 2 to 8 carbon atoms, such as vinyl, allyl, etc.; cycloalkyl having 4 to 8 carbon atoms, such as cyclopentyl, cyclohexyl, etc.; aryl containing 6 to 15 carbon atoms, such as phenyl, naphthyl, benzyl, etc., and the halogen, amino, hydroxy, mercapto, glycidoxy or epoxy substituted derivatives thereof. It will be understood that wherein the organo silane contains more than one group, the various organic groups attached to the silicon atom can be the same or different from each other.
Representative of the compounds falling within the above group are ethyldichlorosilane, propyltrichlorosilane, n-butyltrimethoxysilane, gamma-aminopropyltrimethoxy silane, delta-aminobutyltriethoxysilane, bis-(gamma-aminopropyl)dimethoxy silane, delta-aminobutylethyldimethoxysilane, beta-hydroxyethyltriethoxysilane, glycidoxypropyltrimethoxysilane, gamma-chloropropyltrichlorosilane, vinyldichlorosilane, gamma-aminoallyltrimethoxy silane, beta-aminovinyltriethoxysilane, 3,4-epoxycyclohexyltrimethoxysilane, 3-aminocyclohexylethyltriethoxysilane, para-aminophenyltriethoxysilane, methacryloxypropyltrimethoxysilane, N-(beta-aminoethyl)gamma-aminopropyltrimethoxy silane, gamma-mercaptopropyltriethoxysilane, gamma-hydroxypropyltrimethoxysilane, as well as a variety of others. In general, those silanes preferred are those in which at least one organic group is substituted by at least one amino group.
One particularly preferred amino-substituted organo silane which has been found to provide excellent results in the practice of the present invention is a polyfunctional amino-substituted compound having the formula: ##EQU13## wherein R is lower alkyl (e.g., methyl, ethyl, propyl), x is an integer between 0 and 2, and y and z are integers. Compounds of the foregoing type are available from Dow Corning Corporation under the trademark Z-6050.
While the organo silicon compounds suitable for use as a coupling agent in accordance with the present invention have been described above with reference to the organo silane, it will be understood by those skilled in the art that the above may also be used in the form of the corresponding silanols and polysiloxane polymers.
It has been found that certain combinations of the foregoing organo silicon compounds in the composition of this invention provide unexpected superior results in the manufacture of glass fiber-reinforced elastomeric products. It is particularly advantageous to employ a combination of the polyfunctional amino-substituted compound designated Z-6050 with an amino-substituted alkyl silane of the formula
H.sub.2 N -- (CH.sub.2).sub.w -- SiZ.sub.3 (X)
where w is an integer from 2 to 5 and Z is a readily hydrolyzable group as described above. Preferred is gamma-aminopropyltriethoxysilane.
Another combination of anchoring agents which have been found to provide good results in this invention is a substantially equimolar mixture of
H.sub.2 N -- CH.sub.2 -- CH.sub.2 NH -- CH.sub.2 -- CH.sub.2 -- CH.sub.2 -- SiZ.sub.3
and an alkyl silane, such as methyltriethoxy silane.
The relative proportions of the butadiene-based polymer, emulsifying agent and anchoring agent in the composition of this invention are not critical and can be varied within wide limits. It is generally preferred that the polybutadiene component range from 5 to 30 parts by weight of the composition on a dry basis, and preferably 7 to 25 parts by weight. The amount of emulsifying agent should be an amount sufficient to emulsify the polybutadiene and provide a stable system. It has been found that an amount within the range of 5 to 30 parts by weight on a dry or water-free basis is generally sufficient.
The total amount of anchoring agent can similarly be varied within wide ranges. Usually, an amount within the range of 1.0 to 15, and preferably 2 to 8, parts by weight on a dry or water-free basis is sufficient. When use is made of two or more anchoring agents, each is employed in a weight ratio of within the range of 1/3 to 3 based on the weight of each of the other anchoring agents.
Having described the basic concepts of the invention, reference is now made to the following examples which are provided by way of illustration, and not by way of limitation, of the practice of the invention.
EXAMPLE 1
This example illustrates the preparation of a silicon-modified polybutadiene in accordance with the concepts of the invention.
A quantity of 500 g of a liquid polybutadiene having an average molecular weight of 2700 (Lithene QH from Lithium Corporation of America) is placed in a 1 liter round bottom flask equipped with a mechanical stirrer, an addition funnel, thermometer and reflux condenser. There was added to the reaction vessel 37.44 cc (0.37 moles) of trichlorosilane and 5 ml of a solution of 10 g of chloroplatinic acid in 150 ml of isopropanol. The reaction mixture is heated to 80°C and an additional 0.25 mole of catalyst is added. The reaction is allowed to proceed until the reaction temperature reaches 175°C, several hours later.
Thereafter, 80 cc (1.145 moles) of propylene oxide are added to the reaction vessel, and the resulting mixture is heated to 60°C. for 1 hour.
The resulting product is a viscous liquid polybutadiene.
EXAMPLE 2
This example illustrates the use of the modified polybutadiene prepared in Example 1 as a film forming component in a glass fiber size.
A sample of 20 g of the polybutadiene prepared in Example 1 is emulsified with Tween 85 in water to provide the following size composition:
Parts by weight
Modified polybutadiene
20
Tween 85 (emulsifier)
20
Water to solids content of 5%
The amount of water employed in size compositions of the invention is generally an amount to provide a dry solids content within the range of 0.5 to 20% by weight. The size composition is applied to glass fibers in an amount sufficient to deposit from 0.1 to 10% by weight dry solids on the individual glass fiber filaments.
EXAMPLE 3
This example illustrates another size composition embodying the features of this invention.
A sample of 20 g of the modified polybutadiene prepared in Example 1 is formulated into the following composition:
Parts by weight
Tween 85 (emulsifier)
20.0
Modified polybutadiene
20.0
Gel agent (SA 1300) 6.0
Gamma-aminopropyltriethoxysilane
8.2
Polyaminosilane (Z-6050)
4.2
Water constitutes the balance of the composition, and the amount of water is adjusted to provide the desired solids content as described above. The resulting composition can be applied to glass fibers to form a thin coating on the surfaces thereof to impart to the glass fibers the desired degree of lubricity and bonding with elastomeric materials and resins in the manufacture of glass fiber reinforced elastomeric or resinous products.
The size composition of the present invention is quite stable and can be stored over long periods of time if desired. The stability of the composition can be further improved by adding thereto a gel agent to adjust the viscosity to a desired level, preferably a viscosity of 100 to 300 cps, as shown in the above Example 3. The gel agent renders the composition thixotropic and thus provides the additional advantage of maintaining the composition on the glass fiber surfaces as the glass fibers are randomly whipped during the forming process.
As the gel agent, use can be made of a wide variety of materials having thixotropic properties. For this purpose, use is preferably made of gel agents formed of celulose or cellulose derivatives, including carboxymethyl cellulose as well as lower alkyl and lower alkylene glycol ethers of cellulose or methyl cellulose. For example, use can be made of the dimethyl ether of cellulose, the diethyl ether of cellulose, etc., wherein the alkyl in the ether contains 1 to 4 carbon atoms, including methyl, ethyl, propyl, etc. As indicated above, use can also be made of lower alkylene glycol ethers of cellulose and methyl cellulose wherein the glycol forming the ether contains 2 to 4 carbon atoms, including ethylene glycol, propylene glycol and butylene glycol. Representative of suitable cellulose and cellulose derivatives include dimethyl ether of cellulose, ethylene glycol ethers of cellulose, such as hydroxyethyl cellulose marketed by Dow Chemical Company under the trademark XD 1300, propylene glycol ethers of methyl cellulose, which are marketed by Dow Chemical Company under the trade name Methocel HG, methyl cellulose which is marketed by Dow under the trade name Methocel MC, and butylene glycol ethers of methyl cellulose which are marketed by Dow under the trade name Methocel HB. In addition to the cellulose-type gel agents described above, use can also be made of various other gel agents such as the cross-linked polyacrylamides marketed by Dow Chemical Company under the designation "SA 1300".
The amount of gel agent is not critical and is an amount sufficient to adjust the viscosity to within the desired range. An amount of gel within the range of 0.5 to 10 parts is generally sufficient.
EXAMPLE 4
This example illustrates a size composition embodying a glass fiber lubricant.
A modified polybutadiene emulsion is prepared using the procedure described in Example 1. The resulting polybutadiene is then formulated with a glass fiber lubricant to form the following:
Parts by weight
Modified polybutadiene from Example 1
10.0
Emulsifying agent (Tween 85)
5.0
Emulsifying agent (Tween 60)
5.0
Gamma-aminopropyltrimethoxysilane
3.7
Polyaminosilane (Z-6050)
2.0
Lubricant (Sulfonated mineral oil,
Twitchell 7440 from Emery Chemicals)
3.0
The balance of the composition is water which is present in an amount to adjust the solids content to within the range of 0.5 to 20% by weight. The composition of Example 4 can be applied to form a thin film coating in accordance with the procedure described in Example 2 in an amount sufficient to provide a dry coating constituting from 0.1 to 10% by weight of the fibers.
As desired, a wide variety of glass fiber lubricants can be used in accordance with the concepts of the present invention as illustrated in Example 4. Glass fiber lubricants are well known to those skilled in the art and include fatty acid amines containing 8 to 36 carbon atoms, such as lauryl amine, stearyl amine, palmityl amine, etc., solubilizable mineral oils, such as sulfonated mineral oils marketed by Emery (e.g. Twitchell 7440) and amides prepared by the reaction of a fatty acid containing 8 to 36 carbon atoms, such as lauric acid, palmitic acid, oleic acid, linoleic acid with poly(polyoxyethylene) amines. Another lubricant which can be used in the present invention is an amide formed by the reaction of one of the fatty acids mentioned above with a polyamine having the formula: ##EQU14## wherein x is an integer. Suitable amines of this type are marketed by Jefferson Chemical and have average molecular weights ranging up to about 2000. The reaction between the fatty acid and the polyamine can be conveniently carried out by admixing the amine with the acid in a molar ratio of at least 2 moles of acid per mole of amine, and heating the mixture to a temperature between 50°-100°C. However, it will be understood by those skilled in the art that a wide variety of other glass fiber lubricants in addition to those specifically described above can be used in accordance with the concepts of the present invention. Similarly, it is possible, and sometimes desirable, to use mixtures of the foregoing lubricants where use is made of a lubricant.
Additional silicon-containing polybutadienes and treating compositions embodying the same are illustrated by way of the following examples.
EXAMPLE 5
Using the procedure described in Example 1, a liquid copolymer of butadiene and styrene containing 75% butadiene and 25% styrene and having an average molecular weight of 2600 is reacted with trichlorosilane in a ratio of 1 part by weight of trichlorosilane per 10 parts by weight of the copolymer in the presence of chloroplatinic acid.
After the reaction is completed, a stoichiometric excess of butylene oxide is added to the reaction vessel. The product of the reaction is a highly viscous liquid silicon-modified butadiene-styrene copolymer.
EXAMPLE 6
Using the procedure described in Example 1, a liquid copolymer of butadiene and acrylonitrile containing 70% butadiene and 30% acrylonitrile and having an average molecular weight of 1700 is reacted with trichlorosilane in a ratio of 1 part by weight of the halosilane per 12 parts by weight of the copolymer in the presence of a platinum catalyst.
After the reaction is completed in about 6 hours, a stoichiometric excess of Epoxide No. 7 from Procter and Gamble is added to the reaction vessel. The resulting product is a silicon-modified butadiene-acrylonitrile copolymer.
EXAMPLE 7
A quantity of 500 g of a liquid terpolymer containing 70% butadiene, 20% styrene and 10% vinyl pyridine having an average molecular weight of 2300 is reacted with trichlorosilane in a ratio of 1 part by weight of halosilane per 15 parts by weight of the terpolymer in the presence of the catalyst described in Example 1.
The resulting product is then reacted with a stoichiometric amount of allyl glycidyl ether. The product is a viscous terpolymer.
EXAMPLE 8
Using the procedure described in Example 1, a liquid copolymer of 80% butadiene and 20% maleic anhydride having an average molecular weight of 2470 is reacted with trichlorosilane in a ratio of 1 part by weight of halosilane per 13 parts by weight of the copolymer in the presence of a chloroplatinic acid catalyst.
The product of the reaction is then reacted with a slight stoichiometric excess of propylene oxide to form a viscous silicon-modified copolymer.
EXAMPLE 9
A homopolymer of butadiene having an average molecular weight of 750 (Lithene QL) is reacted with trichlorosilane in a ratio of 1 part by weight of silane per 8 parts by weight of the polymer. The resulting product is then reacted with a stoichiometric amount of a mixture of propylene oxide and the diepoxide DER 332 described above, with the mixture containing 0.2 mols of the diepoxide per mole of propylene oxide.
The product is a viscous liquid polybutadiene.
EXAMPLE 10
A polybutadiene having an average molecular weight of 2300 (Lithene AH) is reacted with allyldichlorosilane in a weight ratio of 1 part of silane per 10 parts by weight of the polymer using the procedure described in Example 1.
The resulting product is then reacted with propylene oxide in a mole ratio of 2.1 moles of propylene oxide per mole of halosilane used.
The product is a syrupy liquid.
EXAMPLE 11
The terpolymer of butadiene, styrene and vinyl pyridine described in Example 7 is reacted with phenyldichlorosilane in a ratio of 1 part of silane per 10 parts of polymer using the procedure of Example 1. The product is then reacted with p-aminophenyl glycidyl ether in a mole ratio of 2 moles of ether per mole of silane employed.
The product is a highly viscous liquid.
Size compositions embodying the modified polybutadienes of Examples 5 to 11 are illustrated by the following:
EXAMPLE 12
Parts by weight
Modified butadiene polymer of one
of Examples 5 to 11 10
Emulsifying agent 10
Water to solids content of 0.1 to 20%
EXAMPLE 13
Parts by weight
Modified butadiene polymer of one
of Examples 5 to 11 10
Emulsifying agent 10
Organo silicon compound anchoring agent
3
Water to solids content of 0.1 to 20%
EXAMPLE 14
Parts by weight
Modified butadiene polymer of one
of Examples 5 to 11 10
Emulsifying agent 10
Organo silicon compound anchoring agent
5
Lubricant and/or gel agent
5
Each of the compositions of Examples 12 to 14 containing any one of the modified butadiene polymers of Examples 5 to 11 can be applied to glass fibers as a size, preferably as the glass fibers are formed. Alternatively, the treating compositions of this invention can also be employed as impregnating compositions for application to a bundle of glass fibers whereby the solids of the impregnant serve to penetrate the bundle and coat the fibers while separating the fibers each from the other. In the formulation of such impregnating compositions it is generally desirable to employ a high solids content, preferably a solids content of 10 to 50% by weight, to maximize the solids loaded onto the bundle.
The glass fibers treated with the compositions of Examples 1 to 14 can be used in the formation of textiles, such as woven and non-woven fabrics, in accordance with conventional processing techniques. Alternatively, the fibers treated with one of the compositions of Examples 1 to 14 can be directly combined with plastic resins in the manufacture of glass fiber reinforced plastics, laminates, coated fabrics and the like. The thin film coating of the invention on the surfaces of the individual glass fiber filaments operates to securely anchor the glass fibers to the plastic resin. Resins used in the manufacture of such products are well known to those skilled in the art, and are generally thermoplastic and thermosetting resins, including polyesters, polyepoxides, etc.
In the preferred use, glass fibers which have been treated in accordance with the present invention are employed as reinforcement for elastomeric materials in the manufacture of glass fiber-reinforced elastomeric products such as tires, drive belts, V-belts, etc. Glass fibers having a size coating thereon embodying the concepts of this invention can be combined directly with elastomeric materials without further processing whereby the coating formed of the modified butadiene polymer serves to securely bond the glass fiber surfaces to the elastomeric material.
The polybutadiene component of the coating is capable of undergoing curing and/or vulcanization with the elastomeric material constituting the continuous phase. However, it is frequently preferred to form the fibers treated with the size composition of this invention into cords formed of two or more strands of sized fibers which have been plied and twisted together, yarns, threads or fabrics, referred to as bundles, and subject the bundles of sized fibers to impregnation with an elastomer compatible material.
As the elastomer compatible material, use is preferably made of a blend of a resorcinol-aldehyde resin and an elastomer; such impregnating compositions are now well-known to those skilled in the art and are described in U.S. Pat. Nos. 3,391,052; 3,402,064; 3,424,608; 3,506,476; 3,533,830; 3,567,671 and 3,591,357 as well as numerous others. While the relative proportions of the components are not critical to the practice of this invention, it is generally preferred that such blends contain 2 to 10 parts by weight of the resorcinol-aldehyde resin per 15 to 100 parts by weight of the elastomer.
The use of such impregnating compositions is illustrated by way of the following examples.
EXAMPLE 15
Glass fibers which have been sized with the composition of Example 2 are formed into bundles formed of strands of glass fibers which have been plied and twisted together, and the resulting bundles are subjected to impregnation in a conventional manner as described in U.S. Pat. No. 3,424,608 with the following impregnating composition formulated in accordance with U.S. Pat. No. 3,567,671:
Impregnating Composition
______________________________________
Total parts by wt.
Resorcinol-formaldehyde resin latex
(Penacolite R 2170 - 75% solids)
48
Vinyl pyridine-butadiene-styrene terpolymer
latex (Gentac FS - 42% solids)
900
Vinyl chloride-vinylidene chloride copolymer
latex (Dow Latex 874 - % solids)
350
Microcrystalline paraffin wax
(Vultex Wax Emulsion No. 5 - 56% solids)
100
Water 832
______________________________________
Impregnation with the above composition is carried out to deposit in the glass fiber bundle dry solids constituting 10 to 30% by weight of the glass fiber system.
It has been found that even superior results are obtained where the vinyl chloride-vinylidene chloride copolymer in the above impregnant is replaced by a dicarboxylated butadiene-styrene copolymer. Such copolymers are commercially available from Goodyear under the trademark "Pliolite", such as Pliolite 4121. The use of such a composition is illustrated by the following.
EXAMPLE 16
Bundles of glass fibers in which the individual glass fibers have been sized with the composition of Example 3 are impregnated with the following:
Impregnating Composition
______________________________________
Total parts by wt.
Resorcinol-formaldehyde resin latex
48
(Penacolite R 2170 - 75% solids)
Vinyl pyridine-butadiene-styrene terpolymer
latex (Gentac FS - 42% solids)
900
Dicarboxylated butadiene-styrene copolymer
latex (Pliolite 4121 - 50% solids)
350
Microcrystalline paraffin wax
(Vultex Wax Emulsion No. 5 - 56% solids)
100
Water 832
______________________________________
Bundles of glass fibers which have been sized with any of the compositions of Examples 11 to 14 can be subjected to impregnants of the following general examples.
EXAMPLE 17
Parts by wt. solids
Resorcinol-formaldehyde resin
2 - 10
Vinyl pyridine-butadiene-styrene terpolymer
20 - 60
Vinyl chloride-vinylidene chloride copolymer
or dicarboxylated butadiene-styrene
copolymer 15 - 40
Microcrystalline paraffin wax
2 - 30
EXAMPLE 18
Parts by wt. solids
Resorcinol-formaldehyde resin
2 - 10
Vinyl pyridine-butadiene-styrene terpolymer
20 - 60
EXAMPLE 19
Parts by wt. solids
Resorcinol-formaldehyde resin
2 - 10
Natural rubber 20 - 60
The balance of the foregoing compositions is water and the amount of water is adjusted to provide a solids content within the range of 20 to 55% by weight. Application of the impregnating composition is usually made in an amount sufficient to deposit in the sized fiber bundle dry solids constituting from 10 to 25% by weight of the fiber system.
In facilitating the combination of glass fibers treated in accordance with the present invention with elastomeric materials, the individual glass fibers containing a coating on the surfaces thereof from Examples 1 to 14 or bundles of glass fibers sized with one of the compositions of Examples 1 to 14, and impregnated as described above, are mixed with elastomeric material or otherwise laid down in the desired arrangement for combination with the elastomeric material, as in the manufacture of glass fiber-reinforced belts or in the manufacture of rubber tires reinforced with cords of glass fibers. The combination of glass fibers and elastomeric material is processed in a conventional manner by mold or cure under heat and compression or vulcanized for advancement of the elastomeric material to a cured or vulcanized stage while in combination with the treated glass fibers or bundles of glass fibers whereby the glass fibers or bundles of glass fibers becomes strongly integrated with the elastomeric materials in the glass fiber-elastomeric product.
In the final system, the elastomeric material with which the glass fibers or bundles of glass fibers are combined, constitutes a continuous phase. Such continuous phase elastomeric materials may comprise elastomers or rubbers of the type incorporated into the treating compositions or the elastomeric material can differ therefrom. It is believed that the tie-in between the individually coated glass fibers or the impregnated bundles of glass fibers and the elastomeric materials forming the continuous phase occurs primarily during cure or vulcanization of the elastomeric material in combination with the treated glass fibers.
It will be apparent that various changes and modifications can be made in the details of procedure, formulation and use without departing from the spirit of the invention, especially as defined in the following claims.
We claim:
1. Glass fibers having a coating thereon, said coating comprising a polybutadiene prepared by first reacting a butadiene homopolymer or copolymer having an average molecular weight less than 6000 and containing at least 1.5 carbon-to-carbon double bonds per 1000 carbon atoms with a halosilane having the formula ##EQU15## wherein X is halogen and R is selected from the group consisting of halogen, hydrogen and an organic group, in the presence of a catalyst capable of causing addition of an H-Si group across an ethylenic double bond, the amount of the halosilane being sufficient to constitute one mole of halosilane per mole of carbon-carbon double bond in the homopolymer or copolymer, said amount being within the range of 0.1 to 50 parts by weight of halosilane per 10 parts by weight of the homopolymer or copolymer, and reacting the product with an epoxide selected from the group consisting of an alkylene oxide, an epoxide having the formula ##EQU16## wherein R3 is an organic group, a diepoxide having the formula ##EQU17## a cyclohexane epoxide and mixtures thereof, with the amount of the epoxide being sufficient to react with all of the halogen atoms bonded to the silicon atoms.
2. Glass fibers as defined in claim 1 wherein the coating also includes a glass fiber anchoring agent selected from the group consisting of organo silanes, their hydrolysis products and combinations thereof.
3. Glass fibers as defined in claim 1 wherein the coating contains a glass fiber lubricant.
4. Glass fibers as defined in claim 1 wherein the coating is a coating on the individual glass fiber surfaces.
5. Glass fibers as defined in claim 1 wherein the epoxide is an alkylene oxide.
6. Glass fibers as defined in claim 1 wherein the glass fibers are in the form of a bundle of glass fibers and said coating constitutes an impregnant in the bundle.
7. Glass fibers as defined in claim 6 wherein the individual glass fibers forming the bundle have a thin size coating on the surfaces thereof.
8. Glass fibers as defined in claim 6 wherein the glass fibers forming the bundle are in the form of strands which have been plied and twisted together to form a cord.
9. A glass fiber bundle comprising a plurality of glass fibers, a thin coating on the individual glass fiber filaments comprising a polybutadiene prepared by first reacting a butadiene homopolymer or copolymer having an average molecular weight less than 6000 and at least 1.5 carbon-to-carbon double bonds per 1000 carbon atoms with a halosilane having the formula ##EQU18## wherein X is halogen and R is selected from the group consisting of halogen, hydrogen and an organic group, in the presence of a catalyst capable of causing addition of a H-Si group across an ethylenic double bond, the amount of the halosilane being sufficient to constitute one mole of halosilane per mole of carbon-carbon double bond in the homopolymer or copolymer, said amount being within the range of 0.1 to 50 parts by weight of halosilane per 10 parts by weight of the homopolymer or copolymer, and reacting the product with an epoxide selected from the group consisting of an alkylene oxide, an epoxide having the formula ##EQU19## wherein R3 is an organic group, a diepoxide having the formula ##EQU20## a cyclohexane epoxide and mixtures thereof, and an impregnant in the bundle, said impregnant comprising an elastomer compatible material, with the amount of the epoxide being sufficient to react with all of the halogen atoms bonded to the silicon atoms.
10. A bundle as defined in claim 9 wherein the elastomer compatible material comprises a blend of a resorcinol-aldehyde resin and an elastomer.
11. A bundle as defined in claim 9 wherein the elastomer compatible material comprises a blend of a resorcinol-aldehyde resin, a butadiene-styrene vinyl pyridine terpolymer, a polymeric material selected from the group consisting of a vinyl chloride-vinylidene chloride copolymer and a carboxylated butadiene-styrene copolymer, and an incompatible wax.
12. A bundle as defined in claim 11 wherein the polymeric material is a carboxylated butadiene-styrene copolymer.
13. A bundle as defined in claim 12 wherein the carboxylated copolymer is a dicarboxylated butadiene-styrene copolymer.
14. A bundle as defined in claim 11 wherein the polymeric material is a vinyl chloride-vinylidene chloride copolymer.
15. A bundle as defined in claim 9 wherein the halosilane is a trihalosilane.
16. A bundle as defined in claim 9 wherein the epoxide is an alkylene oxide.
17. A bundle as defined in claim 9 wherein the coating also includes a glass fiber anchoring agent selected from the group consisting of organo silanes, their hydrolysis products and combinations thereof.
18. A bundle as defined in claim 9 wherein the glass fibers forming the bundle are in the form of strands which have been plied and twisted together to form a cord.
| 1974-11-15 | en | 1976-05-11 |
US-27262994-A | Laminate
ABSTRACT
An anisotropy-free laminate having much higher strength and stiffness as compared with conventional articles is here disclosed which can be prepared by laminating an orientated ultra-high-molecular-weight polyethylene onto an adhesive layer obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its derivative at a temperature lower than the melting point of the orientated ultra-high-molecular-weight polyethylene. The anisotropy-free material having high strength and high stiffness of the present invention can be substituted for various materials such as metals, lumber and FRP, and is also lightweight and excellent in water resistance.
This is a continuation of application Ser. No. 07/973,571, filed Nov. 9, 1992, abandoned, which is a continuation of application Ser. No. 07/516,926, filed Apr. 30, 1990, now abandoned.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates a laminate, and more specifically, it relates to an anisotropy-free laminate having high strength and high stiffness which comprises a specific orientated polyethylene layer and a specific adhesive layer.
(b) Description of the Prior Art
The so-called ultra-high-molecular-weight polyethylenes having noticeably high molecular weights are excellent in impact resistance and wear resistance and have self-lublicating properties, and therefore they are used as characteristic engineering plastics in many fields.
This ultra-high-molecular-weight polyethylene has a much higher molecular weight than a usual polyethylene, and thus it is known that a fiber or sheet having higher strength and higher stiffness than before can be obtained by highly orientating the ultra-high-molecular-weight polyethylene.
However, in the case of the sheet, physical values such as strength in a direction perpendicular to an orientating direction and modulus of elasticity are extremely low owing to its high anisotropy, and thus applications of the sheet are limited. Here, it can be expected that the directional property-free sheet having high strength and high stiffness can be obtained by superposing and sticking, for example, the two sheets on each other, these sheets being mutually diverted from each other as much as an angle of 90°, but when the conventional adhesion technique is employed, adhesive force is weak and physical properties such as strength and stiffness deteriorate inconveniently. For this reason, such a technique is not practical.
For example, in a suggested laminate in which the ultra-high-molecular-weight polyethylene is used, a press molded rod-like or plate-like ultra-high-molecular-weight polyethylene material is skived to form a sheet, and the latter is then stuck on another substrate via an adhesive polymer (Japanese Patent Laid-open Publication No. 143137/1986).
However, this kind of laminate is proved with a feature of the ultra-high-molecular-weight polyethylene such as wear resistance, but it has some drawbacks of the other kind of material simultaneously. In addition, functional effects such as high strength and high stiffness cannot be obtained because of non-orientation. Therefore, the suggested laminate is not always satisfactory from the viewpoint of performance.
On the other hand, in order to form the laminate, it is necessary to heat the resins of both the layers up to a higher temperature than their melting points so as to thermally fuse them, but When the orientated materials are heated in excess of their melting points, the effect of orientation is lost and tensile performance deteriorates noticeably.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an anisotropy-free laminate having high strength and high stiffness by combining a specific orientated polyethylene layer with a specific adhesive layer.
That is, the present invention intends to provide a laminate comprising
(A) an orientated polyethylene layer obtained by orientating an ultra-high-molecular-weight polyethylene sheet at a temperature lower than the melting point of this polyethylene, the aforesaid polyethylene sheet having an intrinsic viscosity of 5 to 50 dl/g in decalin at 135° C., and
(B) an adhesive layer containing a resin obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its derivative.
According to the present invention, an anisotropy-free material having high strength and high stiffness can be prepared which can be substituted for various materials such as metals, lumber and FRP and which is lightweight and excellent in water resistance.
DETAILED DESCRIPTION OF THE INVENTION
Now, the present invention will be described in detail.
Surprisingly, an orientated ultra-high-molecular-weight polyethylene can be stuck on an adhesive layer obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its derivative even at a temperature lower than the melting point of the orientated ultra-high-molecular-weight polyethylene, and the above-mentioned lamination of these layers permits providing an anisotropy-free laminate having much higher strength and stiffness as compared with conventional articles.
Next, the respective layers used in the present invention will be described in more detail.
(1) Orientated polyethylene layer (A)
The orientated polyethylene layer (A) of the present invention can be obtained in the form of a sheet or film by orientating an ultra-high-molecular-weight polyethylene having a specific molecular weight at a temperature less than the melting point of the polyethylene.
The ultra-high-molecular-weight polyethylene has an intrinsic viscosity of 5 to 50 dl/g, preferably 8 to 40 dl/g, more preferably 10 to 30 dl/g in decalin at 135° C. which correspond to a viscosity average molecular weight of 500,000 to 12,000,000, 900,000 to 9,000,000, and 1,200,000 to 6,000,000, respectively. When the intrinsic viscosity is less than 5 dl/g, the orientated sheet or film has poor mechanical properties. Inversely, when it is more than 50 dl/g, workability such as tensile orientation deteriorates inconveniently.
The ultra-high-molecular-weight polyethylene having the above-mentioned specific properties which is used in the present invention can be obtained by the homopolymerization of ethylene or the copolymerization of ethylene and α-olefin in the presence of a catalyst comprising a catalytic component containing at least one of compounds in which transition metal elements in the groups IV to VI of the periodic table are present and, if necessary, an organic metal compound.
The usable α-olefin has 3 to 12 carbon atoms, preferably 3 to 6 carbon atoms. Typical examples of the α-olefin include propylene, butene-1, 4-methylpentene-1, hexene-1, octene-1, decene-1 and dodecene-1. Of these examples, propylene, butene-1, 4-methylpentene-1, hexene-1 are preferable. Furthermore, examples of a comonomer include dienes such as butadiene, 1,4-hexadiene, vinylnor bornene and ethylidene-norbornene, and they may be used in combination. The content of α-olefin in the ethylene-α-olefin copolymer is from 0.001 to 10 mole%, preferably 0.01 to 5 mole%, more preferably 0.1 to 1 mole%.
Typical and suitable examples of the compounds containing transition metal elements in the groups IV to VI of the periodic table which comprise the catalytic component include titanium compounds, vanadium compounds, chromium compounds, zirconium compounds and hafnium compounds. These compounds may be used in combination of plural kinds.
Examples of the titanium compounds include halides, alkoxy halides, alkoxides and halogenated oxides of titanium, and compounds of tetravalent titanium and trivalent titanium are preferable. Typical examples of the tetravalent titanium compounds include those represented by the general formula
Ti(OR).sub.n X.sub.4-n
wherein R is an alkyl group having 1 to 20 carbon atoms, ah aryl group or an aralkyl group, X is a halogen atom, and n is 0≦n≦4, and in particular, titanium tetrachloride is preferable.
An example of the trivalent titanium compound includes titanium trihalide such as titanium trichloride, and other examples of the trivalent titanium compounds include those which can be obtained by reducing tetravalent alkoxytitanium halides represented by the general formula
Ti(OR).sub.m X.sub.4-m
wherein R is an alkyl group having 1 to 20 carbon atoms, an aryl group or an aralkyl group, X is a halogen atom, and m is 0≦m≦4, with an organic metal compound of a metal in the groups I to III of the periodic table.
Of these titanium compounds, particularly preferable ones are the compounds of tetravalent titanium.
Examples of the vanadium compound include halides, alkoxy halides, alkoxides and halogenated oxides of vanadium. Typical examples of the vanadium compound include vanadium tetrahalide such as vanadium tetrachloride, a compound of tetravalent vanadium such as tetraethoxyvanadium, compounds of pentavalent vanadium such as vanadium oxytrichloride, ethoxydichlorovanadium, triethoxyvanadium and tributoxyvanadium, and compounds of trivalent vanadium such as vanadium trichloride and vanadium triethoxide.
The above-mentioned titanium compound or vanadium compound may be treated with one or more of electron-donating compounds. Examples of the electron-donating compounds include ethers, thioethers, thiolphosphines, stibines, arsines, amines, amides, ketones and esters.
The titanium compound or the vanadium compound may be used together with a magnesium compound. Examples of the jointly usable magnesium compound include metallic magnesium, magnesium hydroxide, magnesium carbonate, magnesium oxide, magnesium fluoride, magnesium chloride, magnesium bromide, magnesium iodide; double salts, double oxides, carbonates, chlorides and hydroxides containing a magnesium atom and a metal selected from silicon, aluminum and calcium; those which can be obtained by treating or reacting these inorganic solid compounds with an oxygen-containing compound, a sulfur-containing compound, an aromatic hydrocarbon or a halogen-containing material; and oxides containing silicon or aluminum and the above-mentioned magnesium compounds.
In the case that the titanium compound or the vanadium compound is used together with the magnesium compound, any particular restriction is not put on a contact manner of both the compounds and therefore a known manner can be employed.
Examples of the oxygen-containing compound include water, organic oxygen-containing compounds such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters, polysiloxanes and acid amides, and inorganic oxygen-containing compounds such as metal alkoxides and oxychlorides of metals. Examples of the sulfur-containing compound include organic sulfur-containing compound such as thiols and thioethers, and inorganic sulfur-containing compounds such as sulfur dioxide, sulfur trioxide and sulfuric acid. Examples of the aromatic hydrocarbon include various monocyclic and polycyclic aromatic hydrocarbons such as benzene, toluene, xylene, anthracene and phenanthrene. Moreover, examples of the halogen-containing material include chlorine and compounds such as hydrogen chloride, metal chlorides and organic halides.
Another example of the catalyst system is a catalyst obtained by combining an organic aluminum compound with a reaction product of the titanium compound and an organic magnesium compound such as the so-called Grignard compound.
A further other example of the catalyst system is a catalyst obtained by combining an organic aluminum compound with a solid material which can be prepared by bringing an inorganic oxide such as SiO2 or Al2 O3 into contact with the above-mentioned solid catalyst component containing magnesium and titanium.
In these catalyst systems, the titanium compound can be used as an adduct with an organic carboxylic acid ester, and the above-mentioned inorganic solid compound containing magnesium can be used after subjected to a contact treatment with an organic carboxylic acid ester. Furthermore, the organic aluminum compound can be used as an adduct with an organic carboxylic acid ester without any problem. In every case, the catalyst prepared in the presence of an organic carboxylic acid ester can be utilized without any problem.
A typical example of the chromium compound catalyst is what is called the Phillips catalyst in which chromium trioxide or a compound capable of partially forming chromium oxide by calcination is supported on an inorganic oxide carrier. Examples of the inorganic oxide carrier include silica, alumina, silica-alumina, titania, zirconia and thoria and mixtures thereof, and above all, silica and silica-alumina are preferable.
Examples of the chromium compound which can be supported on the carrier include oxides of chromium and compounds of at least partially forming chromium oxide by calcination, for example, halides, oxyhalides, nitrates, acetates, sulfates and alcoholates of chromium. Typical examples of the chromium compound include chromium trioxide, chromium chloride, potassium dichromate, ammonium chromate, chromium nitrate, chromium acetate, chromacetylacetonato and ditertiary butyl chromate.
The chromium compound can be supported on the carrier in a known manner such as impregnation, distillation removal of a solvent or sublimation, and so a suitable supporting manner can be selected in compliance with the kind of chromium compound to be used. The amount of chromium to be supported is from 0.1 to 10% by weight, preferably from 0.3 to 5% by weight, more preferably from 0.5 to 3% by weight with respect to the weight of the carrier in terms of a chromium atom.
The carrier on which the chromium compound has been supported in the above-mentioned manner is then calcined so as to activate the same. The activation by the calcination is usually carried out in a substantially water-free non-reducing atmosphere, for example, in the presence of oxygen, but it may be effected in the presence of an inert gas or under reduced pressure. Preferably, dried air is used. The calcination is carried out at a temperature of 450° C. or higher, preferably 500° to 900° C. for an interval of from several minutes to several hours, preferably from 0.5 to 10 hours. The activation is preferably carried out using plenty of dried air, e.g., under a fluidized state.
At the time of the supporting treatment or the calcination, the activation can be adjusted in a known manner, for example, by adding a titanate or a salt containing fluorine.
Furthermore, the catalyst supporting the chromium compound may be reduced with carbon monoxide, ethylene or organic aluminum prior to its using.
Examples of the zirconium compound and the hafnium compound include zirconium compounds and hafnium compounds in which a group having a conjugated π electron is present as a ligand, and typical examples thereof are compounds represented by the general formula
R.sup.1.sub.a R.sup.2.sub.b MR.sup.3.sub.c R.sup.4.sub.d
wherein M is a zirconium atom or a hafnium atom; each of R1, R2, R3 and R4 is a hydrocarbon residue having 1 to 20 carbon atoms, a halogen atom or a hydrogen atom, and at least one of R1, R2, R3 and R4 is the hydrocarbon residue; and a, b, c and d are values which meet the condition formula of a+b+c+d=4. Preferable examples of the hydrocarbon residue in the formula include an alkyl group, an aryl group, a cycloalkyl group, an aralkyl group, an alkoxy group, a cycloalkadienyl group, a sulfur-containing hydrocarbon residue, a nitrogen-containing hydrocarbon residue and a phosphorus-containing hydrocarbon residue.
Examples of the above-mentioned alkyl group include methyl, ethyl, propyl, isopropyl, butyl, hexyl, octyl, 2-ethylhexyl, decyl and oleyl groups; and examples of the aryl group include phenyl and tolyl groups; examples of the cycloalkyl group include cyclopentyl, cyclohexyl, cyclooctyl, norbornyl and bicyclononyl groups; and examples of the aralkyl group include benzyl and neophyl groups.
Examples of the cycloalkadienyl group include cyclopentadienyl, methylcyclopentadienyl, ethylcyclopentadienyl, dimethylcyclopentadienyl, indenyl and tetrahydroindenyl groups; and examples of the alkoxy group include methoxy, ethoxy, propoxy and butoxy groups. Examples of the sulfur-containing hydrocarbon residue include thioethyl and thiophenyl groups; and examples of the nitrogen-containing hydrocarbon residue include dimethylamide, diethylamide and dipropylamide groups.
Other examples of the above-mentioned hydrocarbon residue include unsaturated fatty residues such as vinyl, allyl, propenyl, isopropenyl and 1-butenyl groups, and an unsaturated alicyclic group such as a cyclohexenyl group. Examples of the halogen atom include fluorine, chlorine and bromine.
Needless to say, the above-mentioned zirconium compound or hafnium compound can be used by supporting the compound itself on the aforesaid inorganic oxide carrier.
One example of the organic metallic compound used in the method for the preparation of the ultra-high-molecu-lar-weight polyethylene powder of the present invention is an organic metallic compound containing a metal in the groups I to IV of the periodic table which is known as one component of the Ziegler type catalyst. Preferable examples of this organic metallic compound include organic aluminum compounds represented by the general formula Rn Al3-n (wherein R is an alkyl group having 1 to 20 carbon atoms, an aryl group or an alkoxy group; X is a halogen atom; and n is O<n≦3, and in the case of N≧2, the respective R's may be identical or different), organic zinc compounds represented by the general formula R2 Zn (wherein R is an alkyl group having 1 to 20 carbon atoms, and both of R's may be identical or different), and mixtures thereof.
Examples of the organic aluminum compound include triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diethylaluminum chloride, monoethoxydialkylaluminum and diethoxymonoalkylaluminum, and compounds represented by the following general formula which can be obtained by reacting trialkylaluminum with water can be also used: ##STR1## wherein R is a hydrocarbon group having 1 to 18 carbon atoms, and n is a value of 2≦n≦100, preferably 2≦n≦50.
Any particular restriction is not put on the amount of the organic metal compound to be used, but usually it is used 0.1 to 1,000 mole times as much as that of the transition metal compound.
The polymerization reaction is carried out in a substantially oxygen-free and water-free condition in a gaseous phase or in the presence of a solvent which is inert to the catalyst or by using the monomer itself as the solvent, and examples of the solvent which is inert to the catalyst include aliphatic hydrocarbons such as butane, isobutane, pentane, hexane, octane, decane and dodecane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene and toluene; and petroleum fractions. Polymerization temperature is lower than the melting point of the ultra-high-molecular-weight polyethylene which will be produced, and it is usually from -20° to 110° C., preferably from 0° to 90° C.
When the polymerization temperature is higher than the melting point of the ultra-high-molecular-weight polyethylene, a 20-fold or more orientation magnification cannot be achieved in a subsequent orientation step unpreferably.
Polymerization pressure is usually from 0 to 70 kg/cm2 G, preferably from 0 to 60 kg/cm2 G.
The molecular weight of the polymerization product can be adjusted by changing the polymerization temperature, the polymerization pressure, the kind of catalyst, the molar ratio of the catalytic component, the addition of hydrogen to the polymerization system and the like, and any particular restriction is not put on a molecular weight adjustment manner.
Needless to say, a two-stage or multi-stage polymerization in which polymerization conditions such as hydrogen concentration and polymerization temperature are different can also be carried out without any problem.
Thus, the powdery ultra-high-molecular-weight polyethylene can be obtained.
The orientated polyethylene layer (A) of the present invention can be prepared by orientating the thus obtained ultra-high-molecular-weight polyethylene having specific properties at a temperature lower than the melting point of the ultra-high-molecular-weight polyethylene, usually by compression-molding at lower than the melting point of the ultra-high-molecular-weight polyethylene powder, and then orientating the same, or alternatively by carrying out the above-mentioned compression molding, then rolling and orientating the same.
The pressure in the compression molding step can be selected from a wide range, and it is usually from 0.1 MPa to 2 GPa, preferably 1 to 500 MPa.
Furthermore, the temperature in the compression molding step is lower than the melting point of the ultra-high-molecular-weight polyethylene, usually at a temperature of 90° to 140° C., preferably 110° to 135° C.
As techniques of the tensile orientation which follows the compression molding step, there are nip orientation, roll orientation, hot air orientation, cylinder orientation, hot plate orientation and the like, and in these orientation manners except the nip orientation manner, the orientation is effected between a pair of nip rolls or crowbar rolls having different speeds.
The temperature in the tensile orientation step is lower than the melting point of the ultra-high-molecular-weight polyethylene, usually at a temperature of 20° to 160° C., preferably 60 to 150° C., more preferably 90° to 145° C., especially more preferably 90° to 140° C. and most preferably 90° to 130° C.
A tensile orientation velocity can be suitably selected, depending upon techniques of the tensile orientation, the molecular weight and composition ratio of the polymer. Usually, in a batch orientation, it is in a range of from 1.0 to 100 mm/minute, preferably 5 to 50 mm/minute, but the higher velocity is economical, and so it is preferably in a continuous orientation, in a range of from 0.1 to 500 m/minute, preferably 1.0 to 100 m/minute, more preferably 10 to 200 m/minute.
Needless to say, the operation of the tensile orientation can be carried out once or more in a multi-stage system. In this case, it is preferred that the temperature in the first stage is higher than in the second stage.
The rolling can be carried out by a known manner, but the molded sheet may be rolled by a pair of pressure rolls having different rotational directions, while the polyethylene used in the present invention is maintained in a solid phase without melting the same, so that a rolled sheet or film is obtained. At this time, a deformation ratio of the material by the rolling operation can be selected in a wide range, and in general, this ratio is from 1.2 to 20, preferably from 1.5 to 10 in terms of a rolling magnification (length of the material after the rolling/that of the material before the rolling). In the rolling operation, the temperature of the material is 20° C. or higher and lower than its melting point, preferably 90° C. or higher and lower than its melting point. Needless to say, multi-stage rolling is also possible in which the rolling operation is repeated once or more.
It is desirable to increase the orientation magnification of the tensile orientation or the total orientation magnification of the rolling and the tensile orientation as much as possible, but as for the ultra-high-molecular-weight polyethylene of the present invention, the above-mentioned magnification is usually from 20 times or more, preferably 60 times or more, more preferably from 80 to 200 times.
As described above, it is essential that the respective steps of from the compression step to the rolling step are carried out at a temperature lower than the melting point [Tm0 (°C.)] of the ultra-high-molecular-weight polyethylene powder to be used, and when this temperature is in excess of Tm0, it is difficult to achieve an orientation magnification of 20 times or more. In the present invention, the melting point of the polyethylene in a step in front of the orientation step, i.e., the melting point [Tm1 (°C.)] of the polyethylene after the compression molding step or the rolling step must meet the following relation formula:
T.sub.m1 ≧T.sub.m0 -5
If the polyethylene is melted prior to reaching the orientation step, the above formula cannot be met, so that the cut of the material occurs in the orientation step, or even if the orientation is accomplished, physical values of the product cannot be expected.
According to the above-mentioned method, the fiber-like, sheet-like or film-like orientated polyethylene layer (A) having a tensile modulus of elasticity of 50 GPa or more can be obtained.
No particular restriction is put on the thickness of the sheet-like or film-like orientated polyethylene layer (A), so long as the objects of the present invention can be achieved by the layer. However, the thickness of the layer is usually from 10 to 500 μm, preferably from 50 to 500 μm, more preferably from 100 to 300 μm.
(2) Adhesive layer (B)
The laminate of the present invention is composed of the aforesaid orientated polyethylene layer (A) and an adhesive layer (B). The latter (B) used in the present invention is an adhesive resin layer obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its derivative, or an olefin polymer layer containing the adhesive resin.
Examples of the olefin polymer include ethylene polymers and ethylene-α-olefin copolymers prepared in the presence of a Ziegler catalyst, ethylene polymers prepared by high-pressure radical polymerization, and mixtures thereof. Above all, ethylene-α-olefin copolymers are particularly preferred. As α-olefin which will copolymerize with ethylene, various kinds thereof can be used, but the preferable α-olefin has 3 to 12 carbon atoms, preferably 3 to 8 carbon atoms. Typical examples of the α-olefin include propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, decene-1, dodecene-1 and mixtures thereof. The content of the α-olefin in the ethylene-α-olefin copolymer is 20 moles or less, preferably 15 moles or less.
Furthermore, the above-mentioned polyethylenes prepared by the high-pressure method which can be used as the adhesive layer (B) include an ethylene-vinyl ester copolymer or an ethylene-acrylic ester copolymer having a comonomer concentration of 20% by weight or less, preferably 10% by weight or less.
These olefin polymers used in the present invention have a density of 0.935 g/cm3 or less, preferably from 0.930 to 0.900 g/cm3, more preferably from 0.930 to 0.910 g/cm3 When the above-mentioned density is more than the above-mentioned upper limit, i.e., 0.935 g/cm3, a clearance between the melting points of the orientated polyethylene layer (A) and the adhesive layer (B) is small, so that temperature conditions are limited in the heating lamination step and sufficient adhesive strength cannot be obtained unpreferably. Moreover, the intrinsic viscosity [η] of the olefin polymer is usually from 0.5 to 3 dl/g, preferably from 1 to 2 dl/g.
These olefin polymers having the above specific properties may be blended with compounds other than the above-mentioned olefin polymers in so far as these compounds do not disturb the achievement of the objects of the present invention. Examples of such other compounds include mutual copolymers such as ethylene, propylene, butene-1, 4-methylpentene-1, hexene-1 and octene-1, copolymers such as ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, copolymers of ethylene and vinyl ester, unsaturated carboxylic acid, unsaturated carboxylic ester or the like, polyisobutylene and mixtures thereof.
The unsaturated carboxylic acid for modifying the above-mentioned olefin polymer is a monobasic acid or a dibasic acid, and typical examples of these acids include acrylic acid, propiolic acid, methacrylic acid, crotonic acid, isocrotonic acid, oleic acid, elaidic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid and mixtures thereof.
Examples of the derivatives of the unsaturated carboxylic acid include metallic salts, amides, esters and anhydride of the above-mentioned unsaturated carboxylic acids, and above all, maleic anhydride is most preferable.
The modification of the olefin polymer with the unsaturated carboxylic aid and/or its derivative proceeds as follow:
The unsaturated carboxylic acid or its derivative (hereinafter referred to simply as "unsaturated carboxylic acid") is added to the ethylene-α-olefin copolymer or the olefin polymer composition containing the above-mentioned copolymer as the main component. In this case, the amount of the unsaturated carboxylic acid is from 0.05 to 10% by weight, preferably from 0.1 to 7% by weight with respect to the weight of the olefin. Afterward, they are heated in the presence of an organic peroxide, so that reaction occurs.
This reaction can be carried out by melting and mixing the materials in a kneader such as an extruder or a Banbury mixer in the absence of a solvent, or alternatively the above reaction may be done by heating and mixing them in a solvent such as an aromatic hydrocarbon such as benzene, xylene or toluene, or an aliphatic hydrocarbon such as hexane, heptane or octane. The former procedure is more preferable, because of simple operation, being economical, and continuous connection to a subsequent step.
Next, the thus modified olefin polymer is suitably molded into a sheet or film in a known manner in order to obtain the desired adhesive layer.
When the amount of the unsaturated carboxylic acid is in excess of 10% by weight, decomposition and crosslinking reaction tend to take place together besides the addition reaction. Inversely, when it is less than 0.05% by weight, the object of the present invention of improving the adhesive properties cannot be achieved.
Suitable examples of the organic peroxide include benzoyl peroxide, lauryl peroxide, azobisisobutyronitrile, dicumyl peroxide, t-butyl hydroperoxide, α,α'-bis(t-butylperoxydiisopropyl)benzene, di-t-butyl peroxide and 2,5-di(t-butylperoxy)hexyne. The organic peroxide is used in an amount of from 0.005 to 2.0 parts by weight, preferably from 0.01 to 1.0 part by weight based on 100 parts by weight of the total amount of the reaction product of the above-mentioned rubber and unsaturated carboxylic acid and the olefin polymer. When the amount of the organic peroxide is less than 0.005 part by weight, the effect of the modification cannot be exerted substantially, and when it is more that 2.0 parts by weight, any additional effect is scarcely obtained and moreover excessive decomposition and crosslinking reaction tend to occur.
(3) Preparation of laminate
The laminate of the present invention is basically composed of the above-mentioned orientated polyethylene (A) and the adhesive layer (B), and these layers (A) and (B) may be laminated repeatedly to form a multi-layer laminate, or they may be interposed between other substrates to form a multi-layer structure. That is, examples of the multi-layer laminates include two-layer, three-layer, four-layer and five-layer laminates of A/B, B/A/B, A/B/A, A/B/C (C means another kind of material layer), A/B/C/B, B/A/B/A, C/B/A/B, C/B/A/B/C and the like.
The orientated polyethylene layer (A) used in the present invention has a high anisotropy, and physical values in the orientation direction of the layer (A) are noticeably different from those in the direction perpendicular to the orientation direction. Therefore, when the plural layers are used, they should be laminated so that the orientation directions of these layers may deviate from each other, for example, as much as an angle of from more than 0° to 90° or less, preferably an angle of 10° to 90°, whereby the laminate can be obtained in which the anisotropy is extremely decreased and physical properties such as strength and modulus of elasticity are balanced.
The materials, usable in the laminate, other than the layers (A) and (B) include synthetic resins such as polyamide resin, polyvinylidene chloride resin, saponified material of ethylene-vinyl acetate copolymer, polyester resin, polyvinyl chloride resin, polystyrene resin, ABS resin, polycarbonate resin, polyvinyl alcohol resin, fluorine-contained resin, polyphenylene oxide resin, polyphenylene sulfide resin, polyether-ether ketone resin, polyamide-imide resin, polyimide resin, polyacetal resin, polysulfone resin, polyarylate resin, polyether imide resin and polyparabanic acid resin, synthetic and natural rubbers such as ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, polybutadiene rubber, butadiene-styrene copolymer rubber, butadiene-acrylonitrile rubber, polychloroprene rubber, acrylic rubber and silicone rubber, metals such as aluminum, iron, zinc and copper, woods such as veneer boards and pylwood board, glass, ceramics, concrete, gypsum, asbestos, FRP, and woven and unwoven fabrics and papers of natural fibers, synthetic fibers and mineral fibers such as carbon fiber, aramide fiber and metallic fiber.
The laminate of the present invention can be formed by press molding, air-pressure forming (vacuum forming) or rolling, and these molding techniques can be optionally employed. For example, the orientated polyethylene sheet (A) which has been previously molded, the sheet-like adhesive layer (B) and, if necessary, the sheet (C) of another kind of material are laminated onto each other, and they are then molded by means of a press molding machine, the temperature of which is adjusted to a level higher than the melting point of the adhesive layer (B) and lower than the melting point of the orientated polyethylene sheet (A), in order to obtain the integrally molded laminate. At this time, pressure is from 0.1 to 40 MPa, preferably from 1 to 20 MPa.
The laminate of the present invention is formed preferably at a temperature lower than the melting point of the orientated polyethylene (A), more preferably at a temperature lower than the melting point of the orientated polyethylene (A) or higher than the melting point of the adhesive layer (B), most preferably in a temperature range of from 120° to 135° C. In the laminate obtained at a temperature more than the melting point of the polyethylene (A), tensile strength and modulus of tensile elasticity are unpreferably low.
Any particular restriction is not put on the morphology of the laminate of the present invention, and therefore the laminate can take any shape of a film, a sheet, a tube, a plate, a pipe, a bottle, a container and the like.
Now, the present invention will be described in detail in reference to examples, but the scope of the present case should not be limited to these examples.
EXAMPLE 1
An ultra-high-molecular-weight polyethylene powder (melting point 143° C.) having an intrinsic viscosity of 18 dl/g in decalin at 135° C. was compression-molded at a temperature of 130° C. under a pressure of about 100 kg/cm2 by the use of a press molding machine in order to obtain a 100-mm-wide, 100-mm-long, 1.2-mm-thick sheet. It was confirmed by measurement that the melting point of the thus obtained sheet was 143° C. which was the same as in its powdery state.
Next, this sheet was fed to between a pair of rolls having a roll clearance of 70 μm and an adjusted roll surface temperature of 135° C. in,order to roll the sheet 6 times in terms of its length. The rolled sheet was then cut to remove its opposite side end portions therefrom so that its width might be 75 mm, and the sheet was then subjected to tensile orientation at a temperature of 135° C. at a tensile velocity of 50 mm/minute by the use of a tensile test machine with a thermostat bath so that the original sheet might be drawn 5 times in terms of its length (the total magnification of the rolling and the tensile orientation 30 times), whereby the orientated sheet having a width of 40 mm and a thickness of 150 μm was obtained. This sheet was then cut into pieces having a length of 40 mm, and each sheet piece would be used as a sheet (A).
On the other hand, 0.2 part by weight of maleic anhydride and an organic peroxide (2,5-dimethyl-2,5-di(t-butylperoxyhexane-3) were added to 100 parts by weight of straight-chain polyethylene having an MI of 1.0 and a density of 0.920, and they were then kneaded at 200° C. for 15 minutes by means of a Banbury mixer. Afterward, a inflation film having a thickness of 30 μm was formed therefrom. This film was then cut into 40-mm-wide, 40-mm long pieces which would be used as films (B).
The two sheets (A) were superposed upon each other so that orientating directions of the sheets might deviate from each other as much as 90° , and the film (B) was then interposed between these sheets (A). They were then pressed at a temperature of 135° C. under a pressure of 100 kg/cm2 for one minute by the use of a pressing machine again, thereby obtaining a laminate.
The thus obtained laminate had a tensile strength of 0.8 GPa and a modulus of elasticity of 75 GPa. Furthermore, the adhesive strength of the two sheets (A) was 3.8 kg/4 cm which was such that the sheets were sufficiently practical.
Comparative Example 1
In Example 1, the molding of a sheet was carried out at 145° C., and in this case, the resulting sheet had a melting point of 136° C. Rolling and then tensile orientation were done in the same manner as in Example 1, but the total orientation magnification was as low as 10 times. The resulting laminate had a tensile strength of 0.35 GPa and a modulus of elasticity of 22 GPa.
Comparative Example 2
In Example 1, lamination was carried out at 150° C., and in this case, the resulting laminate had a tensile strength of 0.54 GPa and a modulus of elasticity of 31 GPa.
Comparative Example 3
In Example 1, straight-chain polyethylene which was not modified with maleic anhydride was used as an adhesive layer, and in this case, adhesive strength was 1.5 kg/4 cm. After all, any satisfactory laminate was not obtained.
Comparative Example 4
In Example 1, rolling was effected at a roll temperature of 145° C., and in this case, extension was scarcely achieved substantially, and when tensile orientation was done, it was difficult to obtain 5-fold or more orientation magnification.
Comparative Example 5
In Example 1, an unorientated ultra-high-molecular-weight polyethylene sheet having a thickness of 150 μm was used as the sheet (A) in order to form a laminate. The resulting laminate had a tensile strength of 35 MPa and a modulus of elasticity of 1.1 GPa.
In this connection, melting points and some physical properties were measured as follows:
[Measurement of melting point]
On a DSC device, 5 mg of a sample was set, and measurement was then made at a temperature rise rate of 10° C./minute. A temperature at which the top of an endothermic peak was present was regarded as a melting point.
[Tensile strength, modulus of elasticity and adhesive strength]
Modulus of elasticity and tensile strength were measured at a temperature of 23° C. at a tensile velocity of 100 mm/minute by the use of a strograph R. The modulus of elasticity was calculated from a value of stress at a strain of 0.1%. The sectional area of the sample which was necessary for the calculation was obtained by measuring the weight and length of the sample on condition that the density of polyethylene was regarded as 1 g/cm3.
Furthermore, tensile strength was obtained by measuring a layer peeling strength when peeling was made at 180° at a tensile velocity of 150 mm/minute by the use of the same test device.
What is claimed is:
1. A laminate comprising(A) an orientated polyethylene layer obtained by orientating an ultra-high-molecular-weight polyethylene sheet having an intrinsic viscosity of 5 to 50 dl/g in decalin at 135° C., at a temperature lower than the melting point of said polyethylene, and wherein said ultra-high-molecular-weight polyethylene sheet is prepared by a process consisting essentially of compression molding said ultra-high-molecular weight polyethylene at a temperature below the melting point of said ultra-high-molecular weight polyethylene, and (B) an adhesive layer containing a resin obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its derivative, and at least one additional layer of said ultra-high-molecular-weight polyethylene sheet (A).
2. A laminate according to claim 1 wherein said ultra-high-molecular-weight polyethylene for said orientated polyethylene layer (A) is what is obtained by the homopolymerization of ethylene or the copolymerization of ethylene and an α-olefin,
3. A laminate according to claim 2 wherein said α-olefin has 3 to 12 carbon atoms.
4. A laminate according to claim 2 wherein the content of said α-olefin in said ethylene-α-olefin copolymer is from 0.001 to 10 mole %.
5. A laminate according to claim 1 wherein a temperature at which ethylene for said orientated polyethylene layer (A) is polymerized is in a range of from -20° to 110° C.
6. A laminate according to claim 1 wherein a temperature at which said ultra-high-molecular-weight polyethylene for said orientated polyethylene layer (A) is orientated is in a range of from 20° to 160° C.
7. A laminate according to claim 1 wherein a rolling magnification (length of the sheet after the rolling/that of the sheet before the rolling) which is a deformation ratio of said ultra-high-molecular-weight polyethylene for said orientated polyethylene layer (A) by the rolling operation is in a range of from 1.2 to 20.
8. A laminate according to claim 1 wherein the melting point of said ultra-high-molecular-weight polyethylene for said orientated polyethylene layer (A) after the compression molding or the rolling is in a range of the formula T.sub.m1 ≧T.sub.m0 -5 wherein Tm0 denotes the melting point of an ultra-high-molecular-weight polyethylene powder.
9. A laminate according to claim 1 wherein said orientated polyethylene layer (A) has a thickness of 50 to 500 μm.
10. A laminate according to claim 1 wherein said olefin polymer for said adhesive layer (B) is ethylene polymer or ethylene-α-olefin copolymer prepared in the presence of a Ziegler catalyst, ethylene polymer or copolymer prepared by high-pressure radical polymerization, or a mixture thereof.
11. A laminate according to claim 10 wherein said α-olefin in said olefin polymer for said adhesive layer (B) has 3 to 12 carbon atoms.
12. A laminate according to claim 10 wherein an α-olefin content in said ethylene-α-olefin copolymer for said adhesive layer (B) is 20 mole % or less.
13. A laminate according to claim 10 wherein said ethylene copolymer for said adhesive layer (B) prepared by said high-pressure radical polymerization is ethylene-vinyl ester copolymer or ethylene-acrylic ester copolymer.
14. A laminate according to claim 13 wherein the concentration of comonomers in said ethylene-vinyl ester copolymer or ethylene-acrylic ester copolymer is 20% by weight or less.
15. A laminate according to claim 1 wherein the density of said olefin polymer for said adhesive layer (B) is 0.935 g/cm3 or less.
16. A laminate according to claim 15 wherein the density of said olefin polymer for said adhesive layer (B) is in a range of from 0.930 to 0.900 g/cm3.
17. A laminate according to claim 1 wherein the intrinsic viscosity of said olefin polymer for said adhesive layer (B) is in a range of from 0.5 to 3 dl/g.
18. A laminate according to claim 1 wherein said olefin polymer for said adhesive layer (B) is a mutual copolymer such as propylene, butene-1, 4-methylpentene-1, hexene-1 or octene-1, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, a copolymer of ethylene and vinyl ester, unsaturated carboxylic acid or unsaturated carboxylic ester, polyisobutylene, or a mixture thereof.
19. A laminate according to claim 1 wherein said unsaturated carboxylic acid for modifying said olefin polymer for said adhesive layer (B) is acrylic acid, propiolic acid, methacrylic acid, crotonic acid, isocrotonic acid, oleic acid, elaidic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid or a mixture thereof.
20. A laminate according to claim 1 wherein said derivative of said unsaturated carboxylic acid for modifying said olefin polymer for said adhesive layer (B) is a metallic salt, an amide, an ester or an anhydride of said unsaturated carboxylic acid.
21. A laminate according to claim 20 wherein said derivative of said unsaturated carboxylic acid for modifying said olefin polymer for said adhesive layer (B) is maleic anhydride.
22. A laminate according to claim 1 wherein said unsaturated carboxylic acid or its derivative for modifying said olefin polymer for said adhesive layer (B) is used in an amount of 0.05 to 10% by weight with respect to an ethylene-α-olefin copolymer or an olefin polymer composition containing this copolymer as the main component in the presence of an organic peroxide.
23. A laminate according to claim 22 wherein the amount of said organic peroxide which is added to said unsaturated carboxylic acid or its derivative for modifying said olefin polymer for said adhesive layer (B) is in a range of from 0.005 to 2.0% by weight.
24. A laminate according to claim 1 which is a multi-layer laminate basically comprising a repeated structure of said orientated polyethylene layer (A) and said adhesive layer (B), or a single-layer or a multi-layer laminate comprising said layers (A) and (B) and another material interposed between said layers (A) and (B).
25. A laminate according to claim 1 which is a laminate comprising said orientated polyethylene layer (A) and said adhesive layer (B) which is prepared at a temperature lower than the melting point of said orientated polyethylene layer (A).
26. A laminate according to claim 1 which is a laminate comprising said orientated polyethylene layer (A) and said adhesive layer (B) which is prepared at a temperature lower than the melting point of said orientated polyethylene layer (A) or at a temperature higher than the melting point of said adhesive layer (B).
27. A laminate according to claim 1 which is a laminate comprising said orientated polyethylene layer (A) and said adhesive layer (B) which is prepared at a temperature in a range of from 120° to 135° C.
28. A laminate according to claim 1 wherein said ultra-high-molecular-weight polyethylene for said oriented polyethylene layer (A) has been oriented by a tensile orientation or a roller and tensile orientation.
29. A laminate according to claim 1 wherein said ultra-high-molecular-weight polyethylene for said oriented polyethylene layer (A) has been oriented with an orientation magnification of from 20 to 200 times.
30. A laminate according to claim 1 wherein said ultra-high-molecular-weight polyethylene for said oriented polyethylene layer and adhesive layer containing a resin obtained by modifying an olefin polymer with an unsaturated carboxylic acid and/or its derivative in the presence of an organic peroxide so that reaction occurs;wherein said oriented polyethylene layer (A) and said adhesive layer (B) are laminated together at a temperature lower than the melting point of said polyethylene.
31. The laminate of claim 1, wherein said oriented polyethylene layer (A) is processed without a melting step before said orienting.
32. The laminate of claim 1, wherein said polyethylene is produced by polymerizing ethylene or copolymerizing ethylene and an α-olefin at a temperature lower than the melting point of said ultra-high-molecular-weight polyethylene.
33. The laminate of claim 32, wherein said oriented polyethylene layer is produced by a process consisting essentially of said polymerizing or copolymerizing step and said orienting step.
34. The laminate of claim 1, further comprising, a second oriented polyethylene layer (A') layered on said adhesive layer, obtained by orienting an ultra-high-molecular-weight polyethylene sheet at a temperature lower than the melting point of said polyethylene, said ultra-high-molecular-weight polyethylene having an intrinsic viscosity of 5-50 dl/g in decalin at 135° C. and said polyethylene having an orientation magnification of 20 times or more,wherein said layer (A) and said layer (A') have orientation directions which deviate from each other at an angle of from 10° to 90°.
35. The laminate of claim 1, wherein said orientation magnification is 60 times or more.
36. The laminate of claim 35, wherein said orientation magnification is from 80 to 200 times.
| 1994-07-11 | en | 1995-08-29 |
US-22610194-A | Robot assembly
ABSTRACT
A robot assembly, including a central hub, has two arms arranged for independent rotation about the hub. Two carriers, oriented 180° apart from each other, are coupled to an end of each of the arms. A drive is provided for rotating the arms in opposite directions to extend one or the other of said carriers radially from said central hub, and for rotating the arms in the same direction to effect rotation of the carriers.
This is a continuation of application Ser. No. 07/873,422, filed 23 Apr. 1992, now abandoned, which is a continuation-in-part of application Ser. No. 07/644,852, filed 22 Jan. 1991, now U.S. Pat. No. 5,227,708, which is a continuation of application Ser. No. 07/424,771, filed Oct. 20, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. TECHNICAL FIELD
The present invention relates to robotics. More particularly, the present invention relates to a robot assembly for the simultaneous manipulation of multiple objects, for example semiconductor wafers.
2. Description of the Prior Art
The use of robot arms is a well established manufacturing expedient in applications where human handling is inefficient and/or undesired. For example, in the semiconductor arts robot arms are used to handle wafers during various process steps. Such process steps include those which occur in a reaction chamber, e.g. etching, deposition, passivation, etc., where a sealed environment must be maintained to limit the likelihood of contamination and to ensure that various specific processing conditions are provided.
Current practice includes the use of robot arms to load semiconductor wafers from a loading port into various processing ports within a multiple chamber reaction system. The robot arm is then employed to retrieve the wafer from a particular port after processing within an associated process chamber. The wafer is then shuttled by the robot arm to a next port for additional processing. When all processing within the reaction system is complete, the robot arm returns the semiconductor wafer to the loading port and a next wafer is placed into the system by the robot arm for processing. Typically, a stack of several semiconductor wafers is handled in this manner during each process run.
In multiple chamber reaction systems it is desirable to have more than one semiconductor wafer in process at a time. In this way, the reaction system is used to obtain maximum throughput. In the art, a robot arm used in a reaction system must store one wafer, fetch and place another wafer, and then fetch and place the stored wafer. Although this improves use of the reaction system and provides improved throughput, the robot arm itself must go through significant repetitive motion.
One way to overcome the inefficiency attendant with such wasted motion is to provide a robot arm having the ability to handle two wafers at the same time. Thus, some equipment manufacturers have provided a robot arm in which the two carriers are rotated about a pivot by a motor with a belt drive at the end of the arm. In this way, one wafer may be stored on one carrier while the other carrier is used to fetch and place a second wafer. The carriers are then rotated and the stored wafer may be placed as desired. Such mechanism is rather complex and requires a massive arm assembly to support the weight of a carrier drive located at the end of an extendible robot arm. For example, three drives are usually required for a system incorporating such a robot arm: one drive to rotate the arm, one drive to extend the arm, and one drive to rotate the carriers. Thus, any improvement in throughput as is provided by such a multiple carrier robot arm comes at a price of increased cost of manufacture, increased weight and power consumption, and increased complexity and, thus, reduced reliability and serviceability.
Another approach to providing a multiple carrier robot arm is to place two robot arms coaxially about a common pivot point. Each such robot arm operates independently of the other and improved throughput can be obtained through the increased handling capacity of the system, i.e. two arms are better than one. However, it is not simple to provide two robot arms for independent operation about a common axis. Thus, multiple drives and rigid shafts must be provided, again increasing the cost of manufacture and complexity while reducing reliability.
SUMMARY OF THE INVENTION
The present invention is a robot assembly, including a central hub having two arms. Each arm is arranged for rotation relative to the hub. Two carriers, spaced apart from each other, are provided for handling various objects, such as semiconductor wafers. Each carrier is coupled to an end of each of the arms. A drive is provided for rotating the arms in opposite directions from each other to extend one or the other of the carriers radially from the central hub, and for rotating both arms in the same direction to effect rotation of the carriers about the hub. In the preferred embodiment, one drive is used for rotation of one arm and a second drive is used for rotation of the other arm. By synchronizing drive operation the arms can be rotated in the same or opposite directions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a robot assembly according to the present invention;
FIG. 2 is a detailed plan view of a robot assembly according to the present invention;
FIG. 3 is a detailed plan view of a portion of a robot assembly according to an alternative embodiment of the invention; and
FIGS. 4a, 4b, and 4c are schematic representations depicting operation of a robot assembly according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is best understood by referring to the Drawings in connection with review of this Description. The present invention is a robot assembly adapted to handle multiple objects. In the preferred embodiment, the invention finds application in a reaction system, as is used in the manufacture of semiconductors. For example, the present invention is useful for inserting and withdrawing wafers through a reaction chamber port.
The present invention allows two objects, such as semiconductor wafers, to be handled simultaneously for either insertion, withdrawal, or rotation, such that one wafer may be stored on the robot assembly while the other is placed. This unique feature allows increased throughput during wafer processing when contrasted with prior art robot assemblies which must go through an entire manipulation cycle to effect wafer storage. In this way, the reaction chamber is continuously used to process a wafer, i.e. there is no `dead-time` while a processed wafer is replaced in the stack and a `fresh` wafer is fetched, as with prior art systems. The present invention provides similar advantages when used in a daisy-chain type processing arrangement, i.e. multiple reaction chambers used sequentially for a series of processing steps.
In FIG. 1, a robot assembly 2 is shown in plan view in the context of a reaction system 3. The robot assembly 2 is arranged centrally within the reaction system 3 for movement of a semiconductor wafer 13 to and from the reaction chambers 7, 9, and 11. It should be noted that although the exemplary embodiment of the invention discloses a robot assembly centrally located within a reaction system, with the reaction system including three reaction chambers, the present invention is intended for many different applications. Thus, the exemplary embodiment should not be considered limiting the scope of the invention. That is, the present invention is readily adapted for use with any wafer handling application, including reaction systems having any number of reaction chambers and any sort of orientation for the robot assembly.
The robot assembly 2 includes a first arm 6 and a second arm 8 arranged such that one end of each arm is coupled to a central hub 4. Each arm may be rotated independently of the other arm in either a clockwise or a counter-clockwise fashion about hub 4. Thus, the arms may be rotated in both a similar and in an opposite direction. "Rotation may be accomplished by any motive source 40, such as an electrically operated motor or motors."
The motive source should be configured to rotate arm 6 and arm 8 reversibly in either opposing directions or in the same direction. In the preferred embodiment of the invention, the arms are rotatable independently and coaxially about the hub and the motive source is a magnetically coupled motor of the type described in pending U.S. patent application Ser. No. 644,852, filed 22 Jan. 1991, now U.S. Pat. No. 5,227,708, which is a continuation of U.S. patent application Ser. No. 424,771, filed 20 Oct. 1989, now abandoned. Both applications are assigned to Applied Materials, Inc., assignee of the present application.
The arms 6/8 each include a pivot (28 and 29, respectively) provided at an end of the arm opposite the end coupled to hub 4. The arms are pivotally coupled to struts 24/25. The struts, in turn, are coupled by pivots 18/19, to a first wafer carrier 10. Each strut may include a meshing gear 14/15 at an end within the carrier 10 to maintain the carrier 10 in rigid radial alignment with the hub 4 as the struts are pivoted during operation of the robot assembly. In some embodiments of the invention a figure-eight belt may be substituted for the meshing gear 14/15, if desired.
The arms and linkage shown in FIG. 1 form a compound articulated mechanism which is sometimes referred to in the mechanical arts as a frog-leg mechanism. In FIG. 1, the carrier 10 is shown in a partially extended position, for example delivering or retrieving a wafer from a reaction chamber.
A second wafer carrier 12 is also shown in FIG. 1, in which arms 6/8 are joined to struts 36/37 at pivots 34/35 located at one end of the struts. The struts 36/37 are also joined at pivots 20/21, located at the other end of the struts, to the carrier 12. As discussed more fully below, the carrier 12 is linked to the arms 6/8 in an identical manner to that for the carrier 10, such that the two carriers are maintained 180° apart from each other about the axis of the hub 4.
FIG. 2 is a detailed top plan view of robot assembly 2 showing one carrier 10 in a partially extended position and another carrier 12 in a partially retracted position. Arrows in the Fig. show relative motion of arms 6 and 8 about the hub 4. The carrier 10 is coupled to the arms 6/8 by the struts 24/25. The struts 24/25 are configured for rotation in concert with the arms 6/8 by operation of pivots 18/19 at the carrier 10 and pivots 28/29 at the arms 6/8.
The carrier 12 is pivotably coupled to struts 36/37 at pivots 20/21. Struts 36/37 are in turn pivotably coupled to the arms 6/8 at pivots 34/35.
It should be noted that, although the arms 6/8 are each shown having two pivots, one for each carrier/strut, the arms could readily be configured such that the carriers/struts share a single pivot point on each arm. Such arrangement is shown in FIG. 3, in which arms 6/8 are arranged to pivot about the hub 4 at one end of the arms. The other end of each arm includes a single pivot point 40/42, respectively. The arms are coupled at the pivots points 40/42 to two struts each, one strut for each carrier. Thus, the arm 6 is coupled to one strut 24 (for carrier 10) and to another strut 36 (for carrier 12) at pivot 40. While the arm 8 is coupled to one strut 22 (for carrier 10) and to another strut 37 at pivot 42.
Operation of the present invention is shown in FIGS. 4a, 4b, and 4c. In FIG. 4a, the robot assembly 2 is shown undergoing rotational motion of both carriers 10/12 simultaneously about the hub 4, as is indicated by the arrow in the Figure. In preparation for this rotational motion, the arms 6/8 are independently rotated clockwise or counterclockwise about the hub 4 until they are 180° apart, at which point the carriers 10/12 are equidistant from the hub 4. Rotation of the carriers is then effected by rotating both arms 6/8 in the same direction, e.g. clockwise. This rotational force is coupled to the carriers 10/12 through associated struts 24/25 and 36/37.
FIG. 4b shows operation of the robot assembly in which the first carrier 10 is retracted and the second carrier 12 is extended. As is indicated by the arrows, respective counter-clockwise/clockwise motion of the arms 6/8 about the hub 4 exerts a pulling force on the struts 24/25, drawing one carrier 10 toward the hub 4. At the same time, the arms 6/8 exert a pushing force on the struts 36/37 forcing the other carrier 12 away from the hub 4.
FIG. 4c shows operation of the robot assembly in which second carrier 12 is retracted and the first carrier 10 is extended. As is indicated by the arrows, respective clockwise/counter-clockwise motion of the arms 6/8 about the hub 4 exerts a pulling force on the struts 36/37, drawing one carrier 12 toward the hub 4. At the same time, the arms 6/8 exert a pushing force on the struts 24/25 forcing the other carrier 10 away from the hub 4.
The present invention is useful for manipulating multiple objects. As described above, a preferred embodiment of the invention finds application in a reaction system for processing semiconductor wafers. In FIG. 1, a carrier 10 is shown in an extended position, while the other carrier 12 is shown in a retracted position. Thus, one carrier 12 may be used to store a semiconductor wafer, while a carrier 10 is, for example, withdrawing a semiconductor wafer 13 from a reaction chamber 11.
In operation, the robot arm fetches a wafer from a stack of wafers and places the wafer in a reaction chamber. The robot arm then fetches a second wafer while the first wafer remains in the reaction chamber. After sufficient processing time has elapsed, the first wafer is withdrawn from the reaction chamber and the robot arm now carries two wafers, one processed and one fresh. The carriers, when positioned as shown in FIG. 3a, are then rotated, such that a fresh wafer on one carrier is placed into the reaction chamber, while a processed wafer on the other carrier is returned to the stack of wafers. The robot arm then loads another fresh wafer from the stack of wafers and returns to the reaction chamber. The process just described is repeated as required. Additionally, the robot arm of the present invention is readily adapted for use in daisy-chain processes where wafers are moved sequentially through a series of reaction chambers as part of a process flow.
In contrast, prior art robot assemblies require that, for the operation described above, a first wafer is removed from the reaction chamber by the robot assembly and returned to a stack of wafers for storage. The robot assembly is then used to fetch a second wafer and place it in a reaction chamber. During the interval between storage of the first wafer and placing a the second wafer into the reaction chamber, the reaction chamber is idle. This deadtime seriously degrades throughput in the reaction system. The present invention therefore reduces handling and the number of steps involved in moving a wafer within a reaction system and replacing the wafer with a fresh wafer, thus increasing throughput (by eliminating unnecessary and wasted robot assembly motion).
Although the invention is described herein with reference to the preferred embodiment of the robot assembly, one skilled in the art will readily appreciate that applications, other than those involving the handling of semiconductor wafers in a reaction system, and other manipulation schedules, and geometries, etc. may be substituted for those set forth herein without departing from the spirit and scope of the present invention. For example, it is not necessary to have independent coaxial motion of the arms about the hub. Rather, various motions may be provided without departing from the spirit and scope of the invention. Accordingly, the invention should only be limited by the Claims included below.
We claim:
1. A robot assembly, comprising:a central hub comprising an axis; two arms, each arm pivoted at said axis for independent rotation about the axis of said hub; two carriers, arranged to maintain an orientation 180° apart from each other; an articulated linkage for coupling an end of each said arm to each said carrier; said linkage comprising a meshing mechanism for maintaining said carriers in radial alignment with said hub; and a drive coupled to each arm for independently rotating each arm about the axis of said hub, such that rotating the arms in opposite directions extends one of said carriers radially from said central hub while at the same time retracting the other of said carriers radially toward said hub, and such that rotating the arms in the same direction about the axis of said hub effects rotation of the carriers in the same direction about the axis of said hub.
2. The robot assembly of claim 1, wherein each said drive comprises a magnetically coupled motor.
3. The robot assembly of claim 1, wherein said carriers are adapted for manipulating semiconductor wafers.
4. In a reaction system for processing semiconductor wafers, a robot assembly, comprising:a central hub comprising an axis; a first arm coupled coaxially to said hub at an end of said first arm and pivoted at said axis for independent rotation about said hub; a second arm coupled to said hub at an end of said second arm and pivoted at said axis for independent rotation about said hub coaxial with that of said first arm; two carriers arranged to maintain an orientation 180° apart from each other; other; a first articulated linkage for coupling one carrier to an end of each of said arms; a second articulated linkage for coupling the other carrier to an end of each of said arms; said first and second articulated linkage each including a meshing mechanism, whereby said carriers are maintained in radial alignment with said hub; and a drive coupled to each arm for independently rotating each arm about the axis of the hub, such that rotating the arms in opposite direction extends one of said carriers radially from said central hub while at the same time retracting the other of said carriers radially toward said hub, and such that rotating the arms in the same direction about the axis of said hub effects rotation of the carriers in the same direction about the axis of said hub.
5. The robot assembly of claim 4, wherein said drives comprises magnetically coupled motors.
| 1994-04-11 | en | 1995-09-05 |
US-97270297-A | Non-reusable syringe
ABSTRACT
Non-reusable syringe having a syringe body, a hypodermic needle and a slidable piston for drawing and discharging fluid through the needle. In one embodiment, the non-reusable syringe includes a movable engagement member. A first position of the movable engagement member permits initial withdrawal of the piston, allowing fluid to be drawn into the syringe. Initial withdrawal of the piston moves the movable engagement member into a second position. After the fluid has been substantially discharged, the second position of the movable engagement member captures the piston and prevents the piston from being withdrawn again. In another embodiment, the movable engagement member is mounted on, and movable with respect to, the piston. The non-reusable syringe can also include a releasable connection between the piston and the piston driver. Once the piston has been captured, a second attempt to use the syringe will separate the piston from the piston driver, further preventing reuse of the syringe. The non-reusable syringe can also include a stop mechanism to prevent complete withdrawal of the piston, thereby precluding the possibility of tampering with or removing the movable engagement member and/or the piston.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 08/587,514 filed Jan. 17, 1996 (now abandoned), entitled Non-Reusable Syringe, which claims the benefit of United States provisional application No. 60/000,079, filed Jun. 8, 1995.
This claims the benefit of United States provisional application No. 60/000,079, filed Jun. 8, 1995.
BACKGROUND OF THE INVENTION
This invention relates to hypodermic syringes capable of being used only once.
It is well-known that Acquired Immunodeficiency Syndrome (AIDS) is a destructive and deadly disease for which a cure has not been found, and that Human Immunodeficiency Virus (HIV)--the virus that causes AIDS--is transmitted by the exchange of body fluids such as blood. Despite these established medical facts, many injecting drug users continue to share and thus reuse hypodermic syringes contaminated with HIV-infected blood. This practice is now a leading cause of HIV infection and, ultimately, AIDS.
To address this epidemic, various attempts have been made to design hypodermic syringes that are capable of being used only once, in order to eliminate the possibility of sharing a hypodermic syringe contaminated with HIV-infected blood. Illustrative is Somers et al. U.S. Pat. No. 5,328,484.
As the AIDS epidemic has grown, so has the need for a non-reusable syringe that can be readily and inexpensively manufactured, that is reliable in operation, that permits the operator to remove air bubbles from the syringe using the same techniques employed with conventional syringes, and that does not require the operator to perform any special or additional steps not required by conventional syringes.
Accordingly, it is an object of the invention to provide a non-reusable syringe employing a small number of parts, and which can be mass-produced using conventional materials used in hypodermic syringes.
It is a further object of the invention to provide a non-reusable syringe capable of reliably drawing and dispensing fluids from and into the body.
It is a further object of the invention to provide a non-reusable syringe that operates in the same manner as a conventional syringe, including the removal of air bubbles from the syringe before fluid is dispensed into the body.
It is a further object of the invention to provide a non-reusable syringe that does not require the use of special or additional steps not employed during the operation of a conventional syringe.
SUMMARY OF THE INVENTION
These and other objects of the invention are accomplished, in accordance with the principles of the invention, by providing a hypodermic syringe with a movable engagement member. In one embodiment of the invention, before the syringe is used, the movable engagement member is in a first position that permits withdrawal of the syringe piston in the conventional manner, thus allowing fluid to be drawn into the syringe. During initial withdrawal of the piston, the movable engagement member is moved to a second position. After the syringe is filled to capacity with the fluid to be dispensed, conventional techniques can be used to remove any air bubbles from the syringe (e.g., by holding the syringe vertically with the needle pointing up and then moving the piston back and forth and/or gently striking the side of the syringe). The syringe is then "fired" by moving the piston toward the needle, thus discharging the fluid in the conventional manner. When the fluid is substantially discharged, the movable engagement member engages and captures the piston, thereby preventing reuse of the syringe.
In another embodiment of the invention, the movable engagement member is mounted on, and movable with respect to, the piston. In its first position, the movable engagement member permits initial withdrawal of the piston, and is movable by the initial withdrawal to a second position which engages the syringe body following substantial discharge of the fluid, thereby preventing further use of the syringe.
The non-reusable syringe constructed according to the invention can include a releasable connection between the piston and the piston driver. Once the piston has been captured, a second attempt to use the syringe will separate the piston from the piston driver, further preventing reuse of the syringe. The non-reusable syringe can also include a stop mechanism to prevent complete withdrawal of the piston, thereby precluding the possibility of tampering with or removing the movable engagement member and/or the piston.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial sectional view of one embodiment of the non-reusable syringe constructed according to the present invention, with the piston driver shown partially withdrawn for clarity.
FIG. 2 is an enlarged partial sectional view of the non-reusable syringe shown in FIG. 1, showing the movable engagement member before the syringe is used.
FIG. 3 is a sectional view of the non-reusable syringe shown in FIG. 2, taken along the line 3--3.
FIG. 4 is an enlarged partial sectional view of the non-reusable syringe shown in FIG. 1, during initial withdrawal of the piston as fluid is drawn into the syringe body.
FIG. 5 is an enlarged partial sectional view of the non-reusable syringe shown in FIG. 1, after the fluid has been discharged and the piston captured, thus preventing reuse of the syringe.
FIG. 6 is an enlarged partial sectional view of another embodiment of the non-reusable syringe constructed according to the present invention, during initial withdrawal of the piston as fluid is drawn into the syringe body. The piston driver and the releasable connection between the piston driver and the piston are removed for clarity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 depicts, in partial section, an overall view of one embodiment of the non-reusable syringe 10 constructed according to the present invention. The non-reusable syringe 10 contains a syringe body 20, preferably of circular cross section. Syringe body 20 is typically made of plastic material and can be fabricated by methods well known to those skilled in the syringe manufacturing art, such as injection molding. Syringe body 20 has an integrally molded flange 21 at one end, which is held in the conventional manner between the index and middle fingers when the syringe is to be discharged. Flange 21 may also be fabricated separately from syringe body 20 and attached thereto with an adhesive or other suitable fastening means. Attached to or integrally molded with the other end of syringe body 20 is a fitting 22 adapted to receive and retain a hypodermic needle 30 having a sharpened tip 31 for puncturing the skin. Needle 30 may be enclosed with a conventional protective sheath (not shown), which is removed before the syringe is used and may be replaced after use as an additional safety precaution.
Slidably received in syringe body 20 is a piston driver 40, which can also be made by conventional plastic injection molding. Attached to or preferably integrally molded onto one end of piston driver 40 is a flange 41, which is held in the conventional manner to fill and discharge syringe 10. Piston driver 40 includes longitudinal ribs 42 and 43, preferably integrally molded thereon and annularly displaced from one another by 90°, which support piston driver 40 in syringe body 20. Piston driver 40 includes, at the end opposite flange 41, a connector 44 which is preferably integrally molded with piston driver 40. Connector 44 seats in an insert 45 recessed into the top portion of a piston 50. Insert 45 is made of rubber or a synthetic elastomer, thus forming a releasable connection between connector 44 and insert 45. The releasable connection is made sufficiently strong to maintain the connection between connector 44 and insert 45 when piston 50 is initially withdrawn, as hereinafter described. Connector 44, and the associated seat in insert 45, may be of any other suitable shape in addition to that shown in FIGS. 1, 2, 4 and 5, such as a sphere which thus forms a releasable ball and socket joint.
As an additional safety precaution, a conventional cap or sheath (not shown) can be placed over flanges 21 and 41 to prevent inadvertent withdrawal of piston driver 40 before syringe 10 is to be used, such as during transit or handling.
Piston 50, described in detail with reference to FIGS. 2-5, is preferably made of a substantially rigid material and can also be injection molded plastic. An O-ring 51 made of rubber or a synthetic elastomer is fitted in the outside surface of piston 50, thus forming a fluid seal with the inside of syringe body 20.
A movable engagement member 60 is integrally molded with syringe body 20 at its end adjacent needle 30. Alternatively, movable engagement member 60 may be a separate mechanism, and attached to the inside of syringe body 20 at the end adjacent to needle 30 with an adhesive or other suitable fastening means. The construction and operation of movable engagement member 60 are described in detail with reference to FIGS. 2-5.
A retaining member 70 controls the position of movable engagement member 60, also as hereinafter described with reference to FIGS. 2-5.
Referring to FIGS. 2-3, piston 50 is preferably made of a substantially rigid material such as injection molded plastic. O-ring 51 forms a liquid seal between piston 50 and syringe body 20. Piston 50 has a cavity defined by the annular walls 52 and 53, the top surface 54 and the ledge surface 55. Annular wall 53 further defines an opening to the cavity, which is dimensioned to permit piston 50 to be initially withdrawn when movable engagement member 60 is held by retaining member 70. Retaining member 70 is dimensioned so that it engages ledge surface 55 when piston 50 is initially withdrawn.
Piston 50 may be made in two parts, for example along the dotted line 56 shown in FIG. 2, to facilitate placement of retaining member 70 during the manufacturing process. After retaining member 70 is in place, the top portion of piston 50 may be joined to the bottom portion by an adhesive, thermal fusing, etc.
Movable engagement member 60 is preferably spring-like and formed from a material capable of deformation yet able to return to its original shape. Various materials are suitable for this purpose, for example a plastic such as polypropylene, or a metal compatible with medical applications such as stainless steel. Movable engagement member 60 is supported by a post 61 and a cross bar 62. Preferably, movable engagement member 60, post 61 and cross bar 62 are plastic and are all integrally molded with syringe body 20, as shown in FIGS. 1-2. Movable engagement member 60 includes two legs 63, which are normally outwardly extending as shown generally in FIG. 1. The length of legs 63 are dimensioned so that following use of syringe 10, when legs 63 are in their normal outwardly extending position, the ends 64 of legs 63 will interfere with ledge 55, thus preventing reuse of syringe 10.
Other variations of movable engagement member 60 are possible, such as a spring-loaded mechanism capable of moving from a first position that permits initial withdrawal of piston 50, to a second position that captures piston 50 following substantial discharge of the fluid from syringe 10.
Retaining member 70 is preferably of circular shape, but may be any other suitable configuration. Retaining member 70 may be made of plastic, a metal such as stainless steel, or any other substantially rigid material suitable for medical applications. As shown in FIGS. 2-3, legs 63 are deformed and held in that position by retaining member 70 until syringe 10 is to be used. Because retaining member 70 is dimensioned to engage ledge surface 55, initial withdrawal of piston 50 will remove retaining member 70 from movable engagement member 60, thus freeing legs 63 to return to their normal outwardly extending position.
Retaining member 70 is made sufficiently thick so that it seats on ledge 55 while still retaining legs 63 in their deformed position. This will prevent retaining member 70 from slipping off ends 64 before syringe 10 is to be used, such as might occur during transit or handling. Alternatively, to insure that retaining member 70 does not slip off ends 64, optional protrusions 65 (shown with dotted lines in FIG. 4) may be provided adjacent ends 64.
Other methods to hold legs 63 in their deformed position can be employed, such as the use of frangible connections between legs 63 and post 61, spring-loaded members, snap rings and the like.
The operation of syringe 10 is shown in FIGS. 4-5. Grasped in the conventional manner, piston driver 40 is withdrawn, thereby withdrawing piston 50. This causes ledge surface 55 to engage retaining member 70, which slides off legs 63. At the same time, wall 53 engages legs 63 to insure that they are held in their deformed position until movable engagement member 60 passes through the piston cavity opening. When piston 50 is withdrawn clear of movable engagement member 60, legs 63 return to their normal outwardly extending position (as shown in FIG. 4).
Further withdrawal of piston 50 permits syringe 10 to be filled to capacity in the conventional manner. Any air bubbles may then be removed using conventional methods, such as holding syringe 10 vertically with needle 30 pointing up and then moving piston driver 40 back and forth and/or gently striking the side of syringe body 20 while it is held in that position.
Syringe 10 is then "fired" by moving piston driver 40 toward needle 30, thus discharging the fluid in the conventional manner. As piston 50 approaches the bottom of syringe body 20, wall 53 engages legs 63, deforming them sufficiently to permit movable engagement member 60 to pass back through the cavity opening of piston 50. Because retaining member 70 is free to "float" within the cavity of piston 50, retaining member 70 will not reengage and deform legs 63 of movable engagement member 60. Legs 63 are then freed to return to their normal outwardly extending position (as shown in FIG. 5). Any further attempt to withdraw piston 50 will cause ends 64 of legs 63 to interfere with ledge surface 55, preventing reuse of syringe 10. Additionally, because piston 50 is now trapped at the bottom of syringe body 20, any such further effort to withdraw piston 50 will separate connector 44 from insert 45, thus disengaging piston driver 40 from piston 50.
To prevent syringe users from tampering with piston 50 and/or movable engagement member 60, or replacing piston 50 with a conventional syringe piston, a stop mechanism may be incorporated into syringe 10 to preclude complete withdrawal of piston 50, thus preventing access to both piston 50 and movable engagement member 60. The stop mechanism may take many forms, such as interfering protrusions on syringe body 20 and piston driver 40. As another example, flange 21 may be fabricated separately from syringe body 20, with an internal diameter of portion 21a less than the diameter of piston 50 and with appropriate clearance slots for longitudinal ribs 42 and 43. When attached to syringe body 20, flange 21 will prevent piston 50 from being completely withdrawn from syringe body 20.
FIG. 6 shows an enlarged partial sectional view of a second embodiment of the non-reusable syringe constructed according to the present invention. As will be apparent, the construction of, and the materials used in, this second embodiment are similar to the first embodiment shown in FIGS. 1-5. Accordingly, only the differences between the two embodiments will be specifically described.
Referring to FIG. 6, non-reusable syringe 100 contains syringe body 120, piston 150, needle 130, O-ring 151 and the other components of hypodermic syringes as described in detail with reference to FIG. 1. The piston driver and the releasable connection between the piston driver and piston 150 have been omitted from FIG. 6 for clarity.
Movable engagement member 160 is attached to or integrally molded with piston 150. As described with reference to FIGS. 1-5, movable engagement member 160 is deformable and includes two legs 163 with ends 164. In this second embodiment, legs 163 point away from needle 130.
A retaining member 170, preferably of circular shape, controls the position of movable engagement member 160 as in the first embodiment.
Annular ring 155 is preferably integrally molded with syringe body 120. Before initial withdrawal of piston 150, retaining member 170 holds movable engagement member 160 in the deformed position below annular ring 155. The opening of annular ring 155, defined by annular wall 156, is dimensioned to permit deformed movable engagement member 160 to be initially withdrawn. Retaining member 170 is dimensioned to have a larger diameter than the opening of annular ring 155, to prevent retaining member 170 from passing through the opening of annular ring 155.
Syringe body 120 may be made in two parts, such as along dotted line 121 shown in FIG. 6, to facilitate placement of retaining member 170 during manufacture. For example, the bottom portion 122 of syringe body 120 may be assembled first with needle 130. Retaining member 170 may be placed in position to deform movable engagement member 160, after which the top portion of syringe body 120 may be joined to bottom portion 122 by an adhesive, thermal fusing, etc.
As shown in FIG. 6, during initial withdrawal of piston 150, annular ring 155 engages retaining member 170, which slides off legs 163. When movable engagement member 160 has passed through the opening of annular ring 155, legs 163 return to their normal outwardly extending position. Further withdrawal of piston 150 and air bubble removal are now possible, as described with reference to FIGS. 2-5.
When syringe 100 is "fired" in the conventional manner, piston 150 approaches annular ring 155. Annular wall 156 sufficiently deforms legs 163 to permit movable engagement member 160 to pass through the opening of annular ring 155. Retaining member 170 "floats" between the bottom of syringe body 120 and annular ring 155, and thus will not reengage and deform legs 163 of movable engagement member 160. Legs 163 thus return to their normal outwardly extending position once they are completely through the opening of annular ring 155. Any further attempt to withdraw piston 150 will cause ends 164 of legs 163 to interfere with the surface 157 of annular ring 155, preventing reuse of syringe 100. Similarly, such an attempt to withdraw piston 150 will separate the piston driver (not shown) from piston 150, as described with reference to FIGS. 1-5.
A stop mechanism, such as described with reference to the first embodiment, may be incorporated into this second embodiment shown in FIG. 6, to prevent tampering with movable engagement member 160 or replacing the movable engagement member 160/piston 150 assembly with a conventional syringe piston.
It will be understood that the foregoing is only illustrative of the principles of this invention, and that various other modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. For example, the piston may be constructed with a cavity, and the movable engagement member may be mounted on the piston within that cavity. This will reduce the combined space occupied by the piston and the movable engagement member, thus minimizing the overall size of the non-reusable syringe while maximizing the amount of fluid that may be discharged from it.
The invention claimed is:
1. A non-reusable syringe comprising:a syringe body having a closed end through which a hypodermic needle is mounted; a piston slidably received in and forming a seal with said syringe body for drawing and discharging fluid through said needle; and movable engagement means attached to said syringe body and having a first position not engaging said piston such that said piston can be initially withdrawn and movable by said initial withdrawal to a second position which engages said piston following substantial discharge of the fluid, thereby preventing further use of said syringe.
2. The non-reusable syringe defined in claim 1 further comprising:a retaining member, wherein said movable engagement means is held in said first position by said retaining member, said retaining member being disengaged from said movable engagement means by said initial withdrawal of said piston.
3. The non-reusable syringe defined in claim 1 wherein said movable engagement means is integrally molded with said syringe body.
4. The non-reusable syringe defined in claim 1 wherein said piston includes a cavity open to and facing said closed end of said syringe body and said movable engagement means in said second position engages at least one surface defining said cavity following substantial discharge of said fluid.
5. The non-reusable syringe defined in claim 1 further comprising:stop means on said syringe body to prevent complete withdrawal of said piston from said syringe body.
6. The non-reusable syringe defined in claim 1 further comprising:a piston driver releasably connected to said piston, whereby following said engagement of said piston a further attempt to use said syringe will separate said piston driver from said piston.
7. A non-reusable syringe comprising:a syringe body having a closed end through which a hypodermic needle is mounted; a piston slidably received in and forming a seal with said syringe body for drawing and discharging fluid through said needle; and movable engagement means attached to said piston and having a first position with respect to said piston not engaging said syringe body such that said piston can be initially withdrawn and movable by said initial withdrawal to a second position with respect to said piston which engages said syringe body following substantial discharge of the fluid, thereby preventing further use of said syringe.
8. The non-reusable syringe defined in claim 7 further comprising:a retaining member, wherein said movable engagement means is held in said first position by said retaining member, said retaining member being disengaged from said movable engagement means by said initial withdrawal of said piston.
9. The non-reusable syringe defined in claim 7 wherein said movable engagement means is integrally molded with said piston.
10. The non-reusable syringe defined in claim 7 further comprising:stop means on said syringe body to prevent complete withdrawal of said piston from said syringe body.
11. The non-reusable syringe defined in claim 7 further comprising:a piston driver releasably connected to said piston, whereby following said engagement of said syringe body a further attempt to use said syringe will separate said piston driver from said piston.
12. The non-reusable syringe defined in claim 7 wherein said piston includes a cavity and at least a portion of said movable engagement means in said first position is contained in said cavity.
| 1997-11-18 | en | 1998-11-10 |
US-37806195-A | Method for attaching microspheres to a substrate
ABSTRACT
A composition of matter includes a solid substrate having covalent bonds, provided by a connecting ligand, to at least one of (a) and (b), namely: (a) a single layer of at least one species of microspheres containing residual reactive functions; (b) a multiplicity of layers of at least one species of microspheres, wherein adjoining layers of multiplicity of layers are covalently linked together, the innermost layer of the multiplicity of layers having the covalent bonds to the solid substrate connected thereto, while at least the outermost layer of the multiplicity of layers contains residual reactive functions; the species of microspheres being selected from microspheres of silica, polyacrylic acid, polyglutaraldehyde, polyacrolein, poly(chloromethylated styrene) and albumin. At least some of the residual reactive functions may be used to immobilize drugs, prodrugs, proteins, biological cells and other controllably releasable substances.
This is a continuation of U.S. application Ser. No. 07/979,900, filed Nov. 23, 1992, now abandoned.
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a composition of matter in which microspheres are covalently bonded to a support of solid substrate, the thus-bonded microspheres containing residual reactive functions.
Due to their spherical shape and high surface area, microspheres have numerous applications such as specific cell labelling, cell separation, phagocytosis, diagnostics, cell growth, affinity chromatography and hemoperfusion (see e.g., Margel, S., Applied Biochemistry and Biotechnology, 1983, 8, 523; Lazar, A., Silverstein, L., Margel, S. and Mizrahi, M., Dev. in Biol. Stand., 1985, 60, 456; Pines, M. and Margel, S., J. of Immunoassay, 1986, 7, 97; Palzer, R., Walton, J. and Rembaum, A., In Vitro, 1978, 14, 336; Rembaum, A. Yen, S. P. S. and Volkson, W., Chem. Tech., 1978, 8, 182). Recently, in order to improve the quality and usefulness of polymeric microspheres, significant progress has been made in the synthesis of microspheres with narrow size distribution. Highly uniform polymeric microspheres are currently effective for applications such as adsorbents for HPLC, calibration standards and spacers for liquid crystals [Ugelstad, J., Soderberg, L., Berge, A. and Bergstom, J., Nature (London), 1983, 303, 5].
From a practical point of view, the efficiency and use of polymeric microspheres in solution, particularly microspheres smaller in their diameter than approximately 0.4μ, are still limited, because of some major disadvantages, e.g., difficulties in separation of free ligand from ligand bonded to the microspheres and instability of the microspheres in solution towards agglutination. The latter disadvantage is the major reason for the difficulties obtaining while carrying out reactions with polymeric microspheres.
Polymeric microspheres covalently bonded with appropriate antibodies or lectins have been studied for mapping of cell receptors. For example, polyaldehyde microspheres in sizes ranging from 0.1μ to 0.7μ bonded with anti-thy 1,2 antibodies were used for specific labelling of T lymphocytes. Similar microspheres covalently bonded with the drug disodium chromoglycate were used for specific labelling of rat basophilic leukemia cells (Pacht, I., Mazurek, N. and Margel, S., Drug Conjugates of Polymeric Microspheres as Tools in Cell Biology, Plenum Publishing Corporation, 1982, pp. 109-123).
Polystyrene beads crosslinked with divinylbenzene of approximately 30μ diameter containing on the surface sulfate groups (negative charge) electrostatically attached to polystyrene particles of 0.1-0.5μ diameter containing quaternary ammonium groups (and which are available from Dionex Corporation), are used in ion chromatography for ion separation (Small, H., Stevens, T. S. and Bauman, W. W., Anal. Chem., 1975, 47, 1801; Gjesde, D. T. and Fritz, J. S., in "Ion Chromatography", 2nd edn., Huhig, Heidelberg, 1987). These hybrid type ion exchange resins (pellicular resins) have a low capacity; moreover, the attached colloid particles are limited in their size (up to approximately 0.5μ) and can be removed from the bead core by competition reaction.
A few patents describe the adhesion of various microsphere types, e.g. glass microspheres, to an appropriate support, by impregnating the latter with the microspheres in the presence of a thickener and an adhesive agent for binding the microspheres to the support. This binding agent usually contains epoxide compounds or other adhesive materials (Seuzaret, L., FR 2,609,835; Thomson, E. et al EP 209337; Hicks, I. A. et al, U.S. Pat. No. 4,548,863).
The patents literature also describes a procedure for grafting of polyacrolein microspheres having diameters of to 0.2μ onto the surface of organic polymers such as polystyrene, by high energy radiation (Co irradiation) process (Margel, S., IL 67619; Rembaum, A. et al, U.S. Pat. No. 4,534,996). According to this process, a deaerated acrolein in aqueous solution is polymerized in the presence of an appropriate surfactant and the organic support, by the high energy source. However, this method suffers from a number of major disadvantages: (a), the need for a high energy source; (b) the mechanism for the high energy process is not clear and the process is not properly controllable; (c) the structure of the obtained composite materials is not homogeneous and distinctive, and furthermore, part of the surface of the grafted support is barely coated with microspheres, while the other part of the surface is coated heterogeneously with one or several layers of microspheres; (d) the high energy process for covalent binding of polyacrolein microspheres onto the surface of polymers is not applicable to inorganic substrates, e.g. glass, semiconductive materials such as silicon, and some organic polymers such as polytetrafluoroethylene; (e) the high energy process is not applicable for binding onto the surface of solid substrates, microspheres which were previously prepared.
The present invention relates to compositions of matter which incorporate microspheres, while avoiding the disadvantages of the prior art products.
SUMMARY OF THE INVENTION
The present invention accordingly provides a composition of matter which comprises a solid substrate having covalent bonds to at least one member selected from sub-groups (a) and (b), namely: (a) substantially a single layer of at least one species of microspheres containing residual reactive functions; (b) a multiplicity of layers of at least one species of microspheres, wherein adjoining layers of the multiplicity of layers are covalently linked together, the innermost layer of the multiplicity of layers having the above-mentioned covalent bonds to the solid substrate connected thereto, while at least the outermost layer of the multiplicity of layers contains residual reactive functions. The covalent bonds referred to above may be provided by a ligand denoted "(A)", and the adjoining layers of the multiplicity of layers may be covalently linked together by a connecting ligand denoted "(B)", the ligands (A) and (B) being the same as or different from each other.
The microspheres included in the present compositions are preferably organic polymeric microspheres, but alternatively inorganic microspheres whether polymeric or not, such as glass and silica, are also deemed to be within the scope of the present invention. The microspheres have a preferred diameter within the range of 300 Angstrom units to 8μ.
It will be apparent that the at least one species of microspheres may consist of substantially a single species, or alternatively may consist of more than one species. Moreover, when there is present in the inventive compositions a multiplicity of microsphere layers, this may consist of substantially the same species of microspheres or may include different species of microspheres. More particularly, each layer of the multiplicity of layers may contain substantially only a particular species of microspheres, or alternatively, at least one layer of the multiplicity of layers may include more than one species of microspheres.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an SEM photomicrograph depicting an embodiment of the invention in which polyacrolein microspheres are covalently bound to glass discs.
FIG. 2 shows SEM photomicrographs depicting embodiments of the invention in which polyacrolein microspheres are covalently bound to polyethylene (PE) film, namely, (a) an unmodified PE surface, (b) a PE[CO2 H] surface, (c) PE[CH2 OSi<(CH2)4 NH2 ] surface, (d) a PE[CH2 OSi<(CH2)4 NH2 ] surface already bonded to polyacrolein microspheres.
DETAILED DESCRIPTION OF THE INVENTION
The present compositions, which incorporate supported microspheres, have many potential applications, for example those already outlined above where the use of microspheres is already known per se. Also, e.g. the present inventive compositions can be used to immobilize drugs, prodrugs, enzymes, proteins, antibodies, biological cells and other controllably releasable substances, merely by way of illustration. It is to be understood that immobilization of any of these materials may be effected by creation of chemical bonds, e.g. covalent, ionic and/or coordinate bonds between reactive functions therein and the residual reactive functions of the supported microspheres. Alternatively or additionally, however, these materials may have merely a physical connection with the supported microsphere compositions, e.g. they may be adsorbed thereon and/or entrapped therein, thus the term "immobilization" is to be understood broadly as denoting chemical bonding and/or physical connection.
The microspheres themselves may be made of, e.g., polyacrolein, polyglutaraldehyde, poly(chloromethylated styrene, albumin or silica, and may have a wide or narrow size distribution, as desired. The compositions or the microspheres which they incorporate may be designed with a variety of physical properties as regards, for example, biodegradability, rigidity or porosity. The solid substrates to which the microspheres are covalently bonded may in turn be made from a variety of materials, such as, for example, organic polymers (e.g. polyalkenes such as polyethylene), inorganic polymers such as glasses, or semiconductive materials such as silicon. Where the bonding between the microspheres and the solid substrates and/or the linkage between adjacent layers of microspheres in a multilayer system, is/are provided by ligands, these may have, e.g., omega-functional groups such as amino, cyano, trialkoxysilyl, trihalosilyl, formyl, haloalkyl, hydroxyalkyl, isocyanato, carboxyl or derivatives of carboxyl such as alkoxycarbonyl, halocarbonyl or hydrazidocarbonyl.
It will be apparent to persons skilled in the art that the compositions of the invention may be prepared in any convenient way. For example, a ligand can be covalently bonded to a solid substrate at one end of the ligand, and the other end of the ligand may be covalently attached to microspheres. More than one layer of microspheres may be assembled in a similar manner. It may be necessary to pretreat the substrate material to impart chemical activity to the surface thereof, for subsequent chemical reaction with a suitable ligand and/or reactive microspheres. It will also be appreciated that the reactions described are carried out in such manner as to leave a monolayer of microspheres, or at least the outer layer of a microsphere multilayer, with residual reactive functions. It will further be appreciated by skilled persons that residual reactive functions (such as those illustrated above) can be converted by methods known per se to other reactive functions. There now follows a description of exemplary but non-limiting starting materials.
Microsphere Starting Materials
Monodispersed silica microspheres of various sizes were obtained from Merck, Darmstadt, Germany. Monodispersed polyacrylic acid microspheres were purchased from Polysciences, Warrington, Pa., U.S.A. Polyglutaraldehyde microspheres and polyacrolein microspheres of various types (non-fluorescent, fluorescent and magnetic) and diameters were prepared according to a published method (Margel, S., Meth. in Enzymol., 1985, 112, 164). Poly (chloromethylated styrene) microspheres were prepared according to a published procedure (Margel, S., Nev, E. and Fisher, I., J. Poly. Sci. Chem. Ed., 1991, 29, 347). Albumin microspheres were prepared according to a published method (Longo, W. E., Iwata, H., Lindheimer, T. A. and Goldberg, E. P., J. Pharm. Sci. 1982, 71(12), 1323; Kanzta, J., Scholz, W., Anderson, M. J.. and Ruchholz, W. M., J. Immun. Meth. 1984, 75, 31.
Surface Treatment of Substrate Materials
Glass substrates were washed with either aqueous NaOH solution (10%) or with aqueous HF solution at pH 3, followed by extensive washing with water and appropriate organic solvents (e.g. chloroform and/or ethanol). In most cases, the glass substrates were plasma treated before the surface modification. Silicon wafers were washed with appropriate organic solvents (e.g. chloroform and/or ethanol) and were then plasma treated before the surface modification. Polyethylene substrates, as well as cellulose substrates, were each washed with appropriate organic solvents (e.g. chloroform and/or ethanol) and were subsequently stored under anhydrous conditions.
Reactive Ligands
The following were purchased from ABCR, Karlsruhe, West Germany: Cl3 Si(CH2)17 CH3, (MeO)3 Si(CH2)17 CH3, Cl3 Si(CH2)3 CN, (MeO)3 Si(CH2)3 CN, (MeO)3 Si(CH2)3 NH2, Cl3 Si(CH2)3 CO2 Me and (MeO)3 Si(CH2)3 CO2 Me and p-Cl3 SiC6 H4 CH2 Cl.
Cl3 Si(CH2)16 CN was synthesized by a procedure similar to that described by Balachander, N. and Sukenik, C. N., Tet. Let., 1988, 29, 55, as follows: ##STR1## Synthesis of Cl3 Si(CH2)16 CO2 Me was accomplished similarly, using I(CH2)5 CO2 Me instead of I(CH2)5 CN.
Surface Modification of the Substrates
Ligands of the type p-Cl3 SiC6 H4 CH2 Cl, Cl3 Si(CH2)n X and/or (RO)3 Si(CH2)n X, where RO is alkoxy, n=3 or 16 and X═CN, NH2 or CO2 Me, were covalently bonded to the surface of the cleaned substrates (e.g. glass, silicon, cellulose and polyethylene containing OH functionality on its surface), by shaking these substrates with an organic solvent containing the appropriate ligand(s). The substrates were then removed from the solvent and washed a few times with ethanol and/or chloroform. In some cases, the washing also included Soxhlet treatment for a few hours. The ligand concentration in the organic solvents was usually above 0.01% w/v and in most cases above 0.1% w/v. Exemplary organic solvents are bicyclohexyl, chloroform, methylene chloride and toluene, but other solvents may of course be used. The reaction is carried out in most cases at room temperature. However, similar results can also be obtained at both lower and higher temperatures, e.g. up to the boiling point of the solvent. Ligands of the type (RO)3 Si(CH2)n X, where RO is alkoxy, n=3 could also be bonded to the above substrates, by shaking the appropriate substrate with the ligand in aq. medium, e.g. for several hours at 90° C., using 0.1M sodium acetate, pH 5.5; the bonded substrate is then washed with water, ethanol and chloroform successively (Wikstrom P., Mandenius C. F. and Larsson P. O., J. of Chromatography, 1988, 455, 105).
Scheme 1 describes some of the surface modifications effected at substrate surfaces containing hydroxyl functionality, e.g., glass, cellulose, Si and modified polyethylene (PE). Cleaned surfaces containing hydroxyl functionality may be reacted with ligands such as Cl3 Si(CH2)n X or (RO)3 Si(CH2)n X where X is, e.g., CO2 Me or CN, according to procedures described above, in order to obtain surfaces having omega- ester or cyano functionality. The ester groups can be converted to free carboxyl by soaking the substrates containing the omega- ester groups in 0.1N aqueous HCl solution, for 1 hour at room temperature; after removal from the aqueous solution, the substrate was washed extensively with water, acetone and chloroform, successively. The ester groups can be converted to hydrazide groups by soaking the substrates containing the omega- ester groups in concentrated hydrazine hydrate solution for 2 hours at 50° C.; after removal from the aqueous solution, the substrate was washed extensively with water, acetone and chloroform, successively. The ester groups can be converted to CH2 OH groups by dipping the substrates containing the omega- ester groups in LiAlH4 or BH3 in tetrahydrofuran (THF) for a few hours at room temperature or at higher temperatures, e.g. up to 50° C.; after removal from the THF solution, the substrate was washed extensively with water, acetone and chloroform, successively. ##STR2##
The cyano groups can be converted to CH2 NH2 groups by reducing the substrates containing the omega- cyano groups with LiAlH4 or BH3, as just described. The amino groups can be converted to isocyanate groups by soaking the thus-obtained substrates containing the omega- amino groups in a 20% toluene solution of phosgene, for a few hours at room temperature; after removal from the toluene solution, the substrate was washed extensively with water, acetone and chloroform, successively.
Surfaces provided with chloromethyl groups were prepared by reacting surface hydroxyl groups with ligands such as Cl3 SiC6 H4 CH2 Cl according to previously described procedures. The formed surface chloromethyl groups were converted to aldehyde using a published method (Syper, L. aud Meochowski, J., Synthesis, 1984, 747).
As shown in Scheme 2, polyethylene and polypropylene surfaces are oxidized according to a published method (Whitesides, G. M. and Ferguson, G. S., Chemtracts-Organic Chemistry, 1988, 1, 171). Briefly, these substrates are oxidized by dipping them in H2 SO4 /H2 O/CrO3 (29:42:29 weight ratio) solution at 70° C. for 2 minutes, followed by washing with water and acetone. Alternatively, plasma treatment of polyethylene or polypropylene results in the formation of surface hydroxyl functionality. ##STR3##
Polyethylene and polypropylene containing surface halocarbonyl groups (e.g. PE[COCl]) are obtained by dipping the oxidized polymer e.g. PE[CO2 H], in 10 ml. dry ether containing 1 g. PCl5 for 1 hour at room temperature. The PE[COCl] (e.g.) is then removed from the ether solution and is used immediately, without further washing, for the next modification of the substrate surface.
Polyethylene and polypropylene containing surface hydrazide groups (e.g. PE[CONHNH2 ]) are obtained by soaking the PE[COCl] (e.g.) in dry dimethylformamide solution containing 10% w/v hydrazine hydrate at room temperature for one hour. The substrate is then removed from the DMF solution and washed extensively with water, acetone and chloroform, successively.
Solid substrates such as polyethylene, polypropylene, glass and Si, containing surface isocyanate functionality (e.g. PE[NCO]) are obtained by soaking such substrates containing surface primary amine or hydrazide functionality, in dry toluene solution containing 20% phosgene at room temperature for 1 hour. The substrates are then quickly removed and used immediately for the covalent binding of appropriate polymeric microspheres.
Sensitive surface analytical methods e.g. ESCA. FTIR-ATR, ellipsometry and contact angle measurements [Balachander, N. and Sukenik, C. N., Tet. Let., 1988, 29, 55; Bain, C. D. and Whitesides, G. M., Angew. Chem. Int. Ed. Engl., 1989, 28(4), 506] prove the binding of the ligands to the substrates and the presence of the desired omega-functional groups, e.g. adsorption peak in the IR at 1750 cm.-1 for ester groups. Scanning electron microscopy pictures are usually used to demonstrate the binding of the microspheres onto the modified substrates.
The invention will now be further illustrated by the following non-limiting Examples.
EXAMPLE 1
Glass discs containing surface covalent-bound amine functionality, prepared by reaction of Cl3 Si(CH2)3 CN and/or (MeO)3 Si(CH2)3 CN with surface OH groups, followed by reduction of CN to CH2 NH2, were soaked at room temperature for 12 hours in an aqueous solution containing 1% w/v monodispersed polyacrolein microspheres of 0.7μ average diameter. The glass discs were then removed from the aqueous solution and washed extensively with water. Scanning electron microscopy (SEN) demonstrated the coverage of the glass discs with a monolayer of polyacrolein microspheres (FIG. 1). This monolayer is stable and is not removed by repeated washing with cold water and/or boiling chloroform, or by prolonged treatment with chloroform in a Soxhlet apparatus.
When a similar experiment was carried out using polyacrolein microspheres which had been pretreated with NaBH4 to reduce CHO groups to CH2 OH, less than 3% of the surface of the glass discs was covered with microspheres.
EXAMPLE 2
Example 1 was repeated, substituting for the 1% microspheres solution, 10-3 %, 10-1 % and 10% w/v solutions. The percentage coverage obtained was <5%, >25% and >30%, respectively.
EXAMPLE 3
Example 1 was repeated. The washed glass discs were subsequently soaked for 12 hours in an aqueous solution containing 0.1% w/v of fluorescent polyacrolein microspheres (FITC-labelled) of 0.1μ average diameter, removed from this solution and washed extensively with water. The glass discs were highly fluorescent in a fluorescent microscope, and SEM photomicrographs showed that the 0.1μ fluorescent microspheres were bonded to the glass surfaces in between the spaces of the 0.7μ microspheres previously bonded to the glass.
EXAMPLE 4
When Example 1 was repeated using Cl3 Si(CH2)16 CN instead of Cl3 Si(CH2)3 CN, the percentage coverage decreased by approximately 10%.
EXAMPLE 5
When Example 1 was repeated, using microspheres of average diameter 0.03, 0.05, 0.4, 2.0 and 7.5μ, instead of 0.7μ, similar results were obtained for the first three sizes, but the percentage coverage for the 7.5μ diameter microspheres was below 20%, that is to say significantly less than in the other cases.
EXAMPLE 6
When Example 1 was repeated, using instead of the 0.7μ polyacrolein microspheres, fluorescent microspheres (rhodamine-labelled) and/or magnetic microspheres of 0.2μ average diameter, similar results were obtained.
EXAMPLE 7
When Examples 1-6 were repeated, using Si wafers instead of glass discs, similar results were obtained.
EXAMPLE 8
Example 1 was repeated, using polyethylene film instead of the glass discs and polyacrolein microspheres of 0.4μ (instead of 0.7μ) average diameter. FIG. 2 shows SEM photomicrographs demonstrating the gradual changes on the polyethylene film surface, during the progression of the microsphere coating process.
EXAMPLE 9
When Examples 1-6 were repeated, using polyethylene and/or polypropylene film instead of glass discs, similar results were obtained, except that in most cases, the percentage coverage of the substrate surfaces by the microspheres was approximately 10% to 30% lower.
EXAMPLE 10
When Examples 1 and 5 were repeated, using instead of the glass discs, glass tubes of 1 ml. capacity, glass flasks of 5 ml. capacity, or glass fibers of approximately 1 mm. diameter, similar results were obtained.
EXAMPLE 11
When Example 9 was repeated, using as substrate in place of the film, polyethylene fibers of approximately 1 mm. diameter, similar results were obtained.
EXAMPLE 12
When Example 1 was repeated, using polyglutaraldehyde microspheres instead of polyacrolein microspheres, similar results were obtained.
EXAMPLE 13
When Example 1 was repeated, using an ethanol solution containing microspheres in place of the corresponding aqueous solution, similar results were obtained.
EXAMPLE 14
When Example 1 was repeated, using polyacrylic acid microspheres instead of polyacrolein microspheres, similar results were obtained.
EXAMPLE 15
When Example 8 was repeated under basic conditions at pH 11.5 (in presence of diisobutylethylamine) using poly (chloromethylated styrene) microspheres instead of polyacrolein microspheres, similar results were obtained.
EXAMPLE 16
When Examples 1, 5 and 15 were repeated, using substrates containing surface hydrazide (instead of amine) functionality, similar results were obtained.
EXAMPLE 17
When Example 15 was repeated, using instead of the aqueous microsphere solution a CCl4 microsphere solution, similar results were obtained, except that the bonded microspheres tended to be clustered rather than separated.
EXAMPLE 18
When Example 1 was repeated, using glass discs containing isocyanate functionality instead of amine functionality, and additionally replacing the polyacrolein microspheres in water by silica microspheres of 0.25μ average diameter in dry toluene, similar results were obtained.
EXAMPLE 19
When Example 18 was repeated at 50° C., using polyethylene film containing surface halocarbonyl groups in place of the glass discs containing isocyanate groups, similar results were obtained.
EXAMPLE 20
Example 1 was repeated, using glass discs containing aldehyde functionality instead of amine functionality, and additionally replacing the polyacrolein microspheres by albumin microspheres of approximately 0.1μ average diameter. Scanning electron microscopy photomicrographs demonstrated the binding of the microspheres to the glass. When a similar experiment was carried out, using glass discs that were coated with amine functionality and/or were not coated at all, the microspheres did not bond significantly to the glass discs.
EXAMPLE 21
When Examples 1 and 5 were repeated using (MeO)3 Si(CH2)3 NH2 which has been coated onto glass discs in aqueous solution instead of Cl3 Si(CH2)3 CN, similar results were obtained.
EXAMPLE 22
Example 21 was repeated using microspheres of approximately 0.05 and 0.4μ and Eliza Titer plates (immuno plates of NUNC, Denmark), instead of glass discs. Scanning electron microscopy photomicrographs, as well as fluorescent markers (made by reacting aminoacridine with the supported microspheres) demonstrated the binding of the microspheres to the titer plates.
When a similar experiment was carried out, using titer plates that were not coated with (MeO)3 Si(CH2)3 NH2, the microspheres did not bond significantly to the titer plates.
EXAMPLE 23
Multiple layers of microspheres can be bonded onto a solid substrate by (e.g.) binding a second layer of bivalent or polyvalent reactant onto reactive sites on the surface of the first layer of microspheres, followed by a second layer of microspheres, and so on. Thus, a second layer of polyacrolein microspheres was established by first reacting Cl3 Si(CH2)16 CN with the initial monolayer of polyacrolein microspheres bonded to glass discs, obtained as described in Example 1, then reducing the free CN groups derived from the reactant to CH2 NH2 groups, and finally bonding a second layer of polyacrolein microspheres of 2μ average diameter, as described in Example 1.
EXAMPLE 24
Cationic ion exchange resins were produced by oxidizing the aldehyde groups of the bonded polyacrolein microspheres, to carboxyl groups. The oxidation was effected by passing oxygen for 6 hours through a 0.1M NaOH aqueous solution containing the substrate-bonded polyacrolein microspheres.
EXAMPLE 25
Cationic ion exchange resins were also obtained by the covalent binding of 1-aminopropanesulfonic acid (1-APSA) to the substrate-bonded polyacrolein and/or poly (chloromethylated styrene) microspheres. This was accomplished by soaking the substrate-bonded microspheres for 12 hours at room temperature in aqueous solution at pH 11, containing 100 mg. of 1-APSA. The thus-modified substrate-bonded microspheres were then removed and washed extensively with water followed by acetone. Anionic exchange resins were obtained in similar manner, by using N,N-diethylaminoethylamine (DEAE) in place of the 1-APSA.
EXAMPLE 26
In this example, a radiolabelled protein is immobilized at the surface of glass disc substrate-bonded polyacrolein or polyglutaradehyde microspheres, average diameter about prepared as described in Examples 1, 12 and 16, respectively, by shaking the thus-supported microspheres for 24 hours at room temperature with a saline solution (0.5 ml.) containing 125 I-Bungarotoxin (64 μg.), followed by repeated washing (decantation) with saline solution to remove unbound 125 I-Bungarotoxin. A Γ counter showed that approximately 1,300 picomoles/cm.2 protein was bonded to each of the supported microsphere systems.
When a control experiment was carried out, in which the supported microsphere system was first pretreated with NaBH4 (to reduce the aldehyde groups), it was found that only about 5 picomoles/cm2 125 I-Bungarotoxin was bonded to each of the supported microsphere systems.
EXAMPLE 27
When Example 26 was repeated, but using Protein A instead of Bungarotoxin, similar results were obtained. The product could then be used for removing trace amounts of immunoglobulins.
EXAMPLE 28
Poly (chloromethylated styrene) microspheres bonded to polyethylene film, prepared according to Example 15, were shaken for 24 hours at 50° C. with an aqueous solution of 0.1% (w/v) deferoxamine at pH 11.5, unbonded deferoxamine was removed by repeated water washing (decantation). The immobilized deferoxamine product could be used for the removal of traces of FeCl3 from aqueous solutions.
EXAMPLE 29
Substrate-bonded microspheres prepared according to Examples 1 and 15 were soaked for a few hours at room temperature in an aqueous solution containing 0.1% phenol red. The colored product was washed several times with benzene and then air dried. On introducing into water, the phenol red slowly diffused therefrom, so that the intensity of the red color in water increased gradually. This illustrates the possibility of using such products for controlled release purposes.
EXAMPLE 30
Substrate-bonded microspheres prepared according to Example 1 were treated with gelatin at pH 7.0, in a similar manner to the procedure of Example 26. The product was shaken for 1 hour with a physiological solution (PBS) containing 1% fixed human red blood cells, then washed several times with PBS. The attached red blood cells showed up clearly under the microscope. This demonstrates the potential use of the supported microspheres of the present invention for cell immobilization, and thus also for cell growth.
EXAMPLE 31
The wells of Eliza titer plates coated with polyacrolein microspheres of 800 Angstrom units average diameter were incubated at room temperature for approximately 15 minutes with 0.1 ml PBS solution containing 0.1 μg sheep immunoglobulins (SIgG). The Eliza plates were then washed thoroughly with PBS. Residue aldehydes and amines were blocked by incubating the plate/microsphere supported SIgG with 1% bovine serum albumin and 1% ethanolamine in aqueous solution. Biotinylated antibodies against the SIgG were determined by using a common Eliza procedure of interacting the supported SIgG with serial dilutions of the biotinylated antibodies against SIgG; this was followed by reaction of the SIgG-bound antibodies with Extravidin peroxidase. The detection limit of this system was approximately 1 ng.
When similar experiments were performed using non-coated Eliza titer plates and/or Eliza titer plates coated with amines instead of plates coated with microspheres, the detection limit was decreased significantly.
While the present invention has been particularly described with reference to preferred embodiments thereof, it will be appreciated by persons skilled in the art that many variations and modifications may be made. Accordingly, the invention is not to be construed as limited to such preferred embodiments, rather the scope and spirit of the invention are to be understood from the claims which follow.
I claim:
1. A method of manufacturing an article having a monolayer of microspheres comprising:reacting a surface of a solid substrate with a connecting ligand to covalently bond the ligand to the surface of the substrate to form a ligand-bonded substrate; and contacting the ligand-bonded substrate with a dispersion of microspheres that contain intrinsic reactive functions, in a liquid carrier, for a time sufficient to covalently bond the microspheres to the ligand; and wherein after formation of microsphere/ligand covalent bonds, residual unreacted intrinsic reactive functions remain in the microspheres; said article being further characterized by the fact that the microspheres are bound to said substrate by means consisting of said connecting ligand.
2. A method in accordance with claim 1, further including the step of pretreating the surface of the solid substrate, prior to reacting the surface of the substrate with the ligand, to render the substrate surface reactive with said ligand.
3. A method in accordance with claim 1, wherein the substrate has a surface hydroxyl functionality and the ligand is selected from the group consisting of p-Cl3 SiC6 H4 CH2 Cl, Cl3 Si(CH2)n X; (RO)3 Si(CH2)n X; and mixtures, and wherein RO is an alkoxy, n=3 or 16, and X═CN, H2 N or CO2 CH3, to provide a functionality selected from the group consisting of an omega-CH2 Cl, --CN, --NH2, and --CO2 CH3, respectively.
4. A method of manufacturing an article having a plurality of layers of microspheres, including the steps of:reacting a surface of the solid substrate with a first ligand to covalently bond the first ligand to the surface of the substrate to form a ligand-bonded substrate; and contacting the ligand-bonded substrate with a dispersion of first microspheres, that contain intrinsic reactive functions, in a liquid carrier, for a time sufficient to covalently bond the first microspheres to the ligand; reacting the first microspheres with another ligand disposed farthest from the substrate, said another ligand being the same as or different from the first ligand, to covalently bond the first microspheres to said another ligand; and contacting said another ligand with another dispersion of microspheres, that contain intrinsic reactive functions, said another microspheres disposed farthest from the substrate, for a time sufficient to covalently bond said another microspheres to the second ligand, said another microspheres being the same or different from said first microspheres; and wherein after formation of microsphere/ligand covalent bonds, residual unreacted intrinsic reactive functions remain in the microspheres; said article being further characterized by the fact that said microspheres are bound to said substrate by means consisting of said first ligand.
5. A method in accordance with claim 4 further including the step of covalently bonding said first microspheres to one or more intermediate layers of ligand, and covalently bonding each one or more said intermediate layers respectively to one or more intermediate layers of microspheres, that contain intrinsic reactive functions, prior to contacting the another ligand with the another microspheres; andwherein after formation of microsphere/ligand covalent bonds, residual unreacted intrinsic reactive functions remain in the microspheres.
| 1995-01-25 | en | 1997-07-29 |
US-80990077-A | Selector switch relay
ABSTRACT
A rotary device acts as a switch and relay for manual or remote operation with the use of a rotary solenoid and a unique ratchet and automatic electrical contact opening and closing mechanism. The ratchet coacts with a spring loaded drive bar mounted perpendicular to a central axis of a rotary switch shaft. The drive bar is biased toward a ratchet face which carries a plurality of angularly arranged inclined surfaces. A detent wheel is fixed to the shaft with a pair of springs maintaining the detent wheel in a first position. A rotary solenoid is attached to the ratchet wheel and acts to drive the ratchet wheel to in turn cause rotation of the detent wheel and changing of switch positions.
An automatic electrical contact opening and closing mechanism used with the rotary selector switch relay device has a first spring urging a contact arm and contact into a first position with the contact in electrical engagement with a fixed contact. A second spring is mounted to assert a second spring force on the contact arm opposed to the urging of the first spring at a preselected time. The second spring force builds in magnitude upon pivoting of the cam track carried by a track arm to overcome the first spring force at a preselected time and cause snap disengagement of the contact and fixed contact.
BACKGROUND OF THE INVENTION
There are numerous applications in the electric power industry where medium power switching devices are needed. Various electromechanical relays, contactors and manually operated selector and control switches are often used. Often such devices are limited in their applications to new demands of electric power systems.
For example, conventional manually operated rotary switches easily provide a large number of electrical poles and positions sometimes required for power switching but are not designed to operate at high speed and often not by means of remote control. Known electromechanical relay and contactors can be operated remotely at high speeds but provide only few contacts when used in medium power switching as from 5 to 30 amps. Often complicated and multiplied switching devices are used in complicated schemes which can add to cost and reduce reliability of power control systems.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a single device that has operating characteristics of both a switch and a relay.
It is another object of this invention to provide a rotary selector switch relay device capable of operating as a switch or relay and capable of remote or manual actuation.
It is still another object of this invention to provide a device in accordance with the preceding objects which can operate a large number of contacts at high speed to provide momentary maintained or stepping functions.
It is still another object of this invention to provide a device in accordance with the preceding objects which has good reliability and is capable of operating in a variety of power control systems.
Still another object of this invention is to provide an improved ratchet means and rotary solenoid combination in an electrical switching device which means maximizes the output of the rotary solenoid.
Still another object of this invention is to provide a highly efficient automatic electrical contact opening and closing mechanism for use with a shaft which is mounted for predetermined arcuate movement about an elongated shaft axis to enable rapid and automatic stepping of a switch shaft.
A rotary selector switch relay device can be operated manually or remotely at high switching speed with high switch shaft torque and using a minimum sized rotary solenoid. The selector switch relay has an axially extending switch shaft carrying a plurality of substantially radially extending contacts with the shaft being mounted for rotation about its axis. A detent wheel is coaxial with the switch shaft and fixed to the shaft. Spring means acts to maintain the detent wheel and shaft in a first portion. A spring loaded drive bar is mounted substantially perpendicular to a central axis of the shaft and resiliently biased in one direction along the axis and reciprocally movable along the axis. The drive bar is preferably mounted in a slot so that radial rotation of the bar about the shaft axis causes corresponding simultaneous rotation of the shaft and detent wheel. A drive ratchet is coaxially mounted with respect to the shaft and engages the drive bar and carries a plurality of angularly arranged inclined or cam surfaces whereby reciprocal arcuate movement of the ratchet causes arcuate movement of the shaft and detent wheel in a single direction at predetermined arcuate increments. A rotary solenoid is attached to the ratchet wheel. The spring means acts to multiply arcuate movement in the shaft over corresponding arcuate movement of the ratchet so that a solenoid with a relatively small degree of arcuate movement and high power can be used to cause a high degree of arcuate movement in the switch shaft.
An automatic electrical contact opening and closing mechanism for use with a shaft which is mounted for predetermined arcuate movement about an elongated shaft axis, has a track arm carrying a cam track with the arm fixed to the shaft for reciprocal arcuate movement therewith. A contact arm is mounted at a pivot point and carries a cam follower pin engaging the cam track. An electrical contact is fixed to the contact arm and a first spring means urges the contact arm and contact with a first spring force into a first position where the contact is in electrical engagement with a fixed contact. A second spring means is mounted to assert a second spring force on the contact arm to oppose and overcome the urging of the first spring means at a preselected time. The second spring force builds in magnitude upon pivoting of the cam track to overcome the first spring force at said preselected time and cause snap disengagement of the contact and fixed contact, with reciprocal pivoting of the cam track causing said first spring force to overcome the second spring force only when the cam track returns to its original arcuate position.
It is a feature of this invention that small sized rotary solenoids can be used yet high power and fast switching obtained. It is preferred to use electrical contacts which are mechanically held in selected position and thus cannot be opened by shock and vibration. Manual operation can be carried out without interfering with remote operation. For example, no matter what the arcuate position of the shaft abouts its axis, caused by manual operation, the remote drive can reliably pick up and index from that point. It is a still further feature that the manual operation can be unidirectional indexing which provides the same contact operation sequence as remote operation.
It is a still further feature that parts can be easily made as for example the symmetrical detent wheel substantially lowers complexity over non-symmetrical detent wheels.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features, objects and advantages of the present invention will be better understood from a reading of the following specification in conjunction with the drawings in which:
FIG. 1 is a side view of a rotary selector switch relay device in accordance with a preferred embodiment of this invention;
FIG. 2 is a cross sectional plan view on line 2--2 of FIG. 1;
FIG. 3 is a cross sectional view taken through line 3--3 of FIG. 2;
FIG. 4 is a side elevation on sight line 4--4 of FIG. 3;
FIG. 5 is a cross sectional view taken on line 5--5 of FIG. 3;
FIG. 6 is an enlarged view of a track arm showing a dotted line view of the track arm in a second position;
FIG. 7 is a cross sectional side elevation on line 7--7 of FIG. 2;
FIG. 8 is a cross sectional view through line 8--8 of FIG. 7; and
FIG. 9 is a diagrammatic showing of the switch contacts.
DESCRIPTION OF PREFERRED EMBODIMENTS
With reference now to the drawings the rotary selector switch relay device is indicated generally at 10 and has a rotary switch section 11, a rotary solenoid 12 driving a ratchet asembly 13 to activate a detent wheel 14 rigidly connected to the switch shaft 20. An automatic electrical contact opening and closing mechanism 15 activates the solenoid 12 to a stepping mode of operation.
The rotary switch section 11 is of substantially conventional design as known in the art and described for example in U.S. Pat. No. 4,001,740 issued Jan. 4, 1977. A switch shaft 20 is mounted on rotary bearings as is conventional for movement about its elongated axis and carries outwardly extending conventional switch contacts 21, 21' which are preferably positioned radially of the shaft. Contacts 22 are positioned in each conventional plastic disc or section at eight equal arcuate positions therearound. The contacts 21, 21' rotate to contact selected ones of the eight radially arranged rows of contacts 22. In addition to the rows, there are columns of contacts, corresponding to the disc segments, which may for example number twenty with representative examples being shown at 23, 24 and 25. The exact numbers of contacts in the columns and rows can be varied as desired. Preferably the contacts 21 carried for rotation with the shaft make mechanical contact with the contacts in the rows and columns as known in the art. In a preferred embodiment, eight rows are used with switching positions at 45 degree increments.
A handle 26 is fixed to the shaft to allow manual rotation of the shaft about its axis for manual operation of the switch. This handle extends out of one end of the device and the other end is covered by a casing 19.
Adjacent the rotary switch is the ratchet assembly and detent wheel section which comprises a mounting plate 30 carrying bolts 31 at four corners thereof extending to a forward mounting plate 32'. Mounting plate 32 has four bolts 33 for fixing plastic insulating segments of the contact carriers together between plates 32 and 32' as known in the art. Rear mounting plate 80 is supported by bolts 81 with the solenoid 12 supported by bolts 81'. A detent wheel 14 is fixed to the shaft 20 and is preferably symmetrical about the shaft axis comprising a plurality of peaks 40 and valleys 41. The shaft and detent wheel are mounted for rotation in the direction of arrow 42 (FIG. 8).
The detent wheel 14 and shaft are maintained in position by side loading of rollers 43, 43' each of which are identical and mounted for rotation about pins 44, 44'. Levers 45, 45' on either side of the detent wheel are mounted for rotation about pivot pins 46, 46' and maintained in place by spring retaining rings 47, 47' for pivoting. Springs 48, 48' are mounted at corner rods as best shown in FIG. 8 and resiliently urge the rollers against the detent wheel 14 and maintain the detent wheel in position. The spring action of these spring means will be further described.
The ratchet assembly 13 comprises a ratchet wheel member 50 pinned by pin 51 to the output shaft 52 of the rotary solenoid 12. The ratchet wheel member 50 has a stepped cylindrical passageway 54. The axis of switch shaft 20 is preferably coaxially aligned with the axis of the rotary solenoid shaft 52.
The detent wheel 14 has an elongated neck portion of extension 57 the outer diameter of which mates with cylindrical bore 54. A spring 60 having a diameter such as to mate with a cylindrical recess 61 and lie within an internal recess of the extension piece 57 is provided. A flat elongated drive bar 70 is mounted perpendicular to the axis of the shafts 20 and 52 in slot 55 of extension 57, and spring biased against the ratchet portion 50 by spring 60 which permits the bar to move toward the detent wheel when the ratchet is rotated opposite to the direction of arrow 42 (FIG. 8) with the bar sliding up on the inclined surfaces such as surface 71.
The rotary solenoid 12 can be a small angle rotary solenoid because as will be described, its output will be magnified by the mechanical action of the springs 48, 48'. Thus high power can be obtained with a solenoid that would be larger than the one used if all the power were to result from the rotary action of the solenoid. In the preferred embodiment, the rotary solenoid is one which has 25 degrees of arcuate movement yet the switching positions can be 45 degrees apart.
The rotary solenoid has an automatic electrical contact opening and closing mechanism to open and close the contacts energizing the solenoid and thus permit stepping of the switch automatically if desired. This mechanism is mounted on rear mounting plate 80. The plate 80 carries fixed butt contacts 83, 84 of a circuit for the solenoid and are mounted on a suitable insulated mounting block with both 83 and 84 being considered a single fixed contact for purposes of discussion. Similarly movable butt contacts 85 and 86 will be considered as a single contact for purposes of the discussion. The contacts 85 and 86 are mounted on a Y-shaped conductive support 87 spring biased into engagement with a substantially L-shaped contact arm 88 which carries support 87. The actual mounting between 87 and contact arm 88 is a spring biased arrangement having a spring 90 urging support 87 against the arm 88 while having a stabilizing pin 91 as known. The spring 90 acts on contacts 85, 86 to give contact spring pressure in the closed position and assure thorough contact in the closed position of the switch. The contact arm 88 is mounted for movement about pivot pin 89 with its associated retaining ring 92. A cam pin 93 is fixed on the arm 88 and positioned in a generally sector-shaped cam track 94 carried by a track arm 95 which is in turn fixedly mounted on the output shaft 52 of the solenoid. The arm 95 is fixed on the pivotal shaft 52 by pin 96. A first coil spring 100 is mounted on a pin 101 on the arm 88 and to a stationary pin 102 substantially fixed to support 80. A second coil spring 103 is attached at one end to pin 101 and mounted at another end to an extension of the track arm 95 at pin 105.
As the pin 93 follows the dotted outline path in the direction of arrow 107 due to arcuate movement of track arm 95 (FIG. 6), it will be seen that spring pressure of spring 100 will maintain the contacts in the closed position until point is reached where the buildup of pressure in spring 103 caused by extension of the spring will cause snap action to disengage the contacts.
Turning now to the operation of the rotary selector switch relay device, the handle 26 when rotated provides positive mechanical operation of up to twenty columns and perhaps eight rows or more of switch contacts. Rotation of the shaft by manual operation causes rotation of the bar 70 about the axis of the switch shaft with the bar riding up the inclined surfaces 71 and biased into its position against the ratchet by the spring 60. The ratchet does not move during manual operation but the bar rotates about the shaft axis and moves axially of the shaft as required to overcome the ratchet stationary position. Thus the bar moves toward and away from the detent wheel as required by the angular motion. The bar is prevented from movement perpendicular to the shaft axis by the interfit of spring 60 in recess 76 of the bar. Regardless of where the bar 70 is left after manual operation, it is always in position to be activated by ratchet movement of the ratchet member when the solenoid is activated. Manual operation causes unidirectional indexing of the contacts which provide the same contact operation sequence as provided by remote actuation due to actuation of the solenoid.
The rotary solenoid 12 in the preferred embodiment has an output of 25 degrees with the ratchet 50 having a series of eight angular portions or ramps 71 at 45 degrees cut into the face. The purpose of the angular portions 71 is to engage the drive bar and thus engage with the slotted detent wheel when it turns clockwise. The engagement occurs for only 25 degrees of arcuate turning about the shaft at which point the drive bar 70 and the detent wheel with its slotted extension continue to rotate clockwise as shown in FIG. 8, to a 45 degree switch position while the drive ratchet 50 returns to 0 degrees after slipping past the spring loaded drive bar. The instant the slotted detent wheel locks in at the 45 degree incremental position as shown in FIG. 8, the drive ratchet has returned to 0 degrees, that is its starting position, and the drive bar reengages the ratchet for further switching operation.
The mechanical link between the rotary solenoid 12 and the switch shaft 20 is the drive bar 70 which is free to float both axially and radially in the slot 55 although it is under constant force from the spring 60 urging it toward the ratchet 50. The radial float is limited about the axis of the shaft by the outer diameter of the spring 60 engaging the recess 76 as previously described. The tangential float of the drive bar in the slot 55 is minimal.
It should be noted that the contacts radially mounted on the switch shaft must index 45 degrees between positions. The 25 degree rotary solenoid when operated remotely, drives the detent wheel about 22 1/2 degrees or halfway after angular losses. It is the function of the spring assembly connected to the detent wheel to pull the detent wheel the remaining half of the 45 degrees. This is caused by the clockwise rotation of the detent wheel causing the rollers 43, 43' to roll over the appropriate peaks 40 and act on the trailing slopes of the valleys 41. In the rest position the rollers 43, 43', due to the spring action, mechanically lock the detent wheel 14 in position at 45 degree increments by locating in the appropriate valleys. This positions the centers of the rollers 44, 44' exactly on a center line indicated at 120 which corresponds to a switch position. When the detent wheel 14 is rotated by manual or remote operation, the rollers 43, 43' roll up the two appropriate slope surfaces of the valleys while storing energy in the springs 48, 48' as they undergo extension. As the detent wheel 14 rotates clockwise, both roller center lines of pins 44, 44' move counterclockwise along a radii as indicated at R1 in each case. This moves the centerlines of pins 44, 44' from a point exactly on center line 120 to new points defined by center line 130 and vertical lines 131, 131'. This counterclockwise shift causes the rollers 43, 43' to assume driving the detent wheel 3 1/2 degrees before the halfway point of 22 1/2 degrees. That is, the rotary solenoid need only drive and detent wheel 14 about 19 degrees for the detent wheel to start to index to the 45 degree position under the influence of the springs mounting the rollers 43, 43'.
The 25 degree rotary solenoid 12 can easily index a 22 inch pound load of the selector switch relay device 45 degrees in less than 25 milliseconds when operated remotely. This remote operation has been described thus far as a one-position change. That is when the rotary solenoid is energized, it drives the shaft causing it to index 45 degrees. At this point the solenoid must be deenergized to allow the drive ratchet to return to 0 degrees before the device can be indexed to another position. The control of electric power to the rotary solenoid is preferably used to allow the device to operate as a multiposition, remote operated selector switch. The ratchet assembly coacts in this manner with a control which interrupts power when required and acts to open and close the electrical contact to energize and deenergize the solenoid automatically.
In the preferred embodiment the interrupter contact is closed when the rotary solenoid is at 0 degrees, that is deenergized as best shown in FIG. 3. The contacts remain closed as the solenoid shaft rotates through 25 degrees. Upon completing the 25 degree stroke, the interrupter contact opens, deenergizing the solenoid circuit and remains open, allowing the solenoid to return its drive shaft to 0 degrees by the conventional spring biasing of the solenoid. At 0 degrees, the interrupter contact recloses and once again completes the solenoid coil circuit in a conventional circuit arrangement.
The rotary solenoid 12 is energized to cause the shaft to index when the power is applied to a terminal such as 160 through the closed contacts 83, 85 which are butted and held closed by the spring 90. The force of compression spring 90 is overcome so as to develop about 2 ounces of pressure on the butt contacts. This pressure is sufficient to provide good electrical conductivity at 0 degrees of rotation of the shaft 52 and is maintained during 25 degrees of arcuate movement causes by the solenoid stroke. When the solenoid is energized, the track arm 95 rotates clockwise 25 degrees. As the track arm rotates, pin 93 follows the moving track as indicated by arrow 107. When pin 105 has rotated 12 1/2 degrees, it has extended the spring 103 so that the load developed is equal to the load developed by spring 100 now extended between the studs 101 and 102. At this point the contact arm 88 tends to rotate counterclockwise due to the 1/2 extension on spring 103. However, rotation of spring 100 cannot occur because of the cam arrangement and the pin 93. As the track arm 95 continues to rotate spring 103 increases its loading on the pin 101 and the track arm 95 tends to rotate under a constantly increasing force. When the track arm 95 approaches 25 degrees, or the end of its stroke, the pin 93 starts to slip by the center portion 94A of the cam track 94. This motion results in counterclockwise movement of the contact arm 88 allowing the contacts 83, 85 to start opening. This begins just prior to the track arm 95 reaching 25 degrees of arcuate movement. Contacts 83 and 85 do not actually open until the full 25 degree stroke is accomplished. This results from the angle of the support 87 to the extension portion 180 of the member 88 which angle decreases as pressure is released on the compression spring maintaining the contacts closed until 25 degrees is reached.
When the portion 94A is fully at its 25 degree arcuate movement position, pin 93 rapidly moves from the lower righthand corner of the appendage 94A following the path of arrow 107 causing a snap breaking of the contacts 83, 85 since the spring pressure of spring 103 overcomes the spring pressure of spring 101. This deenergizes the rotary solenoid and it starts to return to 0 degrees. At that point, spring 103 begins to develop a load equal to the load developed by spring 100 and the contact arm 88 starts its tendency to rotate clockwise. However, rotation is prevented by the appendage 94A blocking the pin 93. When pin 93 reaches the upper left-hand corner of the cam track, the arm 88 starts to rotate clockwise and recloses the contacts 83, 85 which completes the rotary solenoid power stroke and reset of the solenoid shaft to 0 degrees.
It is known that a rotary solenoid is a highly inductive, direct current load. Switching loads of this nature often present problems due to excessive contact arcing. Often various methods to eliminate arcing or minimize the damage done by it are utilized. One of these is to have the contacts break at high speed and stretch the arc until it breaks. This method is preferred and is carried out by the automatic electrical contact opening and closing mechanism as described.
While a specific example of the present invention has been shown and described, many variations are possible. For example, while two identical spring assemblies and mounting springs 48, 48' have been shown, in some cases only one spring assembly need be used. Care must be taken to redesign portions of the device so as to prevent unbalance in that case. While the drive bar 70 is preferably mounted for reciprocal axial movement along the shaft, in some cases the ratchet can be spring loaded and the bar stationary in an obvious reversal of parts. This again is not preferred due to the problems of mounting and the like.
While a symmetrical detent wheel 14 is preferred, in some cases nonsymmetrical wheels can be used although this increases machining costs and may make it impossible for the wheel to be used in areas which require clockwise or counterclockwise action.
What is claimed is:
1. A rotary selector switch relay device capable of remote operation at high switching speed, having high torque but using a minimum sized rotary solenoid, said selector switch relay comprising,an axially extending switch shaft carrying a plurality of substantially radially extending contacts, with said shaft being mounted for rotation about its axis, a detent wheel coaxial with said switch shaft and fixed thereto, spring means acting to maintain said detent wheel and shaft in a first position, a spring loaded drive bar mounted substantially perpendicular to a central axis of said shaft and resiliently biased in one direction along said axis and reciprocally movable along said axis, said drive bar being mounted in a slot whereby radial rotation of said bar about said shaft axis causes corresponding simultaneous rotation of said shaft and detent wheel, a drive ratchet coaxially mounted with respect to said shaft engaging said drive bar and carrying a plurality of angularly arranged inclined surfaces whereby reciprocal arcuate movement of said ratchet causes arcuate movement of said shaft and detent wheel in a single direction at predetermined arcuate increments, a rotary solenoid for driving said ratchet wheel, said spring means acting to multiply arcuate movement in said shaft over corresponding arcuate movement of said ratchet means whereby a solenoid with a small degree of arcuate movement and high power can be used to cause a high degree of arcuate movement in said switch shaft.
2. A rotary selector switch relay device in accordance with claim 1 wherein a spring abuts said drive bar and acts to prevent substantial radial movement of said bar.
3. A rotary selector switch relay device in accordance with claim 1 wherein said detent wheel carries an extension coaxial with said drive ratchet and mounting a spring for maintaining said drive bar in a predetermined radial position.
4. A rotary selector switch relay device in accordance with claim 3 wherein said extension of said detent wheel defines a notch carrying said drive bar for reciprocal movement therein in a first and second direction along the axis of said switch shaft.
5. A rotary selector switch relay device in accordance with claim 4 wherein said spring means comprising a roller pivotally mounted on a lever arm,said detent wheel comprising a plurality of peaks and valleys with said roller resting in a first valley and said arm being pivotally mounted to enable said roller to pass successively from one valley to another as said detent wheel is rotated, said spring means further comprising a spring urging said roller into a valley, whereby when said detent wheel turns about said shaft axis, spring pressure builds up at a first leg of travel of said roller wheel as it rides up a peak of the detent so that as it passes the peak and rides down the next side, said built up spring pressure provides a driving force to further turn said detent wheel along with said switch shaft.
6. A rotary selector switch relay device in accordance with claim 5 and further providing a second spring means identical to said first-mentioned spring means and carrying a pivotally mounted roller having a pivot axis substantially 180 degrees about said detent wheel from a pivot axis of said roller of said first-mentioned spring means.
7. A rotary selector switch relay device in accordance with claim 1 and further comprising manual handle means connected with said switch shaft to enable manual switching of said shaft into a plurality of preselected arcuate positions.
8. A rotary solector switch relay device in accordance with claim 7 wherein said handle is located at an end of said shaft and said drive ratchet and solenoid are located at another end of said shaft.
9. An automatic electrical contact opening and closing mechanism in accordance with claim 7 wherein said shaft is a shaft of a rotary solenoid having a predetermined degree of arcuate movement about its axis,said electrical contact mounted on said contact arm and said fixed contact when in engagement, activating arcuate movement of said solenoid shaft whereby said mechanism is an interrupter mechanism for automatic stepping of said switch shaft to alternate switch positions about the switch shaft axis.
10. A rotary selector switch relay device in accordance with claim 8 wherein said radial solenoid defines a solenoid shaft substantially coaxial with said switch shaft and mounting said ratchet wheel at one end, a second end of said rotary solenoid shaft comprising an automatic electrical contact opening and closing mechanism with said mechanism comprising,a track arm carrying a cam track with said arm fixed to said shaft for reciprocal arcuate movement therewith. a contact arm mounted at a pivot point and carrying a cam follower pin engaging said cam track, an electrical contact fixed to said contact arm, first spring means urging said contact arm and contact with a first spring force into a first position where said contact is in electrical engagement with a fixed contact, and second spring means mounted to assert a second spring force on said contact arm opposed to the urging of said first spring means, said second spring force building in magnitude upon pivoting of the cam track to overcome said first spring force and cause snap disengagement of said contact and fixed contact with reciprocal pivoting causing said first spring force to overcome said second spring force.
11. A rotary selector switch relay device in accordance with claim 8 wherein said detent wheel and said roller are so arranged and spring biased that said spring powers said detent wheel after arcuate rotation of said rotary solenoid to a point less than the full degree of travel of said rotary solenoid.
12. A rotary selector switch relay device in accordance with claim 1 wherein said switch shaft has eight arcuate switching positions and carries a plurality of contacts at preselected positions along its length.
13. An automatic electrical contact opening and closing mechanism for use with a shaft which is mounted for a predetermined arcuate movement about an elongated shaft axis, said mechanism comprisinga track arm carrying a cam track with said arm fixed to said shaft for reciprocal arcuate movement therewith in a path of less than 360°, a contact arm mounted at a pivot point and carrying a cam follower pin engaging said cam track. an electrical contact fixed to said contact arm, first spring means urging said contact arm and contact with a first spring force into a first position where said contact is in electrical engagement with a fixed contact, and second spring means mounted to assert a second spring force on said contact arm opposed to the urging of said first spring means at a preselected time, said second spring force building in magnitude upon pivoting of said cam track to overcome said first spring force at said preselected time and cause snap disengagement of said contact and fixed contact with reciprocal pivoting of said cam track causing said first spring force to overcome said second spring force only when said cam track returns to its original arcuate position.
14. An automatic electrical contact opening and closing mechanism in accordance with claim 13 and further comprising said first and second spring means being coil springs.
15. An automatic electrical contact opening and closing mechanism in accordance with claim 13 and further comprising said cam track being an enclosed encircling path.
16. An automatic electrical contact opening and closing mechanism in accordance with claim 15 wherein said shaft is interconnected with a rotary solenoid of an electrical rotary selector switch.
17. A rotary selector switch relay device ratchet means comprising,an open faced rotary ratchet having a plurality of inclines arranged about an axis, bar means engaging said rotary ratchet with said bar and ratchet being mounted for rotation about a shaft axis and with said bar being perpendicular to said shaft axis, spring means urging said ratchet and bar into engagement but permitting movement of said bar and ratchet with respect to each other upon actuation of one of said bar or ratchet.
| 1977-06-24 | en | 1979-01-30 |
US-45738254-A | Conversion of hydrocarbons
Jan- 27, 195 B. l. SMITH ET AL 2,871Ql83 CONVERSION OF HYDROCARBONS Filed Sept. 21. 1954 1 PRODUCTS FLUE GASES LOW TEMPERATURE BURNER M U U D S E R 22 FLUIDIZATION TRANSFER LINE REACTOR HIGH TEMPERATURE BURNER LIGHT GASES Brook Smith Inventors: Edward ion XC John W. Herrmonn Attorney United States Pa e '0" CONVERSION OF HYDROCARBONS Brook I. Smith, Elizabeth, and Edward D. Boston, Westfield, N. J., and John W. Herrmann, Woodside, N. Y., assignors to Esso Research and Engineering Company, a corporation of Delaware Application September 21, 1954, Serial No. 457,382
6 Claims. (Cl. 208-54) atoms, and preferably having 2 or 3 carbon atoms, and' for converting normally liquid hydrocarbons such as coal tars, asphalts, cycle stocks, petroleum tars, whole petroleum crudes, distillates and residual fractions therefrom, or mixtures thereof. A paramount feature of the present invention is the convertingof petroleum oils and light gases therfrom in a system utilizing a single inventory of heat transferring particulate contact solids such as spent catalyst, sand, refractory beads, etc. Preferably, coke produced by the process is the contact solid used. References herein to the use of coke as heat carrying particles will be understood, however, to be exemplary and not limiting.
In the conversion of petroleum hydrocarbons by contact with heat-carrying substantially catalytically in-ert solids, two distinct processes are envisioned; namely, coking mainly for production of liquid fuel products or intermediates (fuels coking) and, secondly, conducting the cracking operation at a higher temperature for the production of chemical raw materials or intermediates such as ethylene, butadiene, aromatics, etc. These two types of conversion processes are generally carried out under considerably dilferent conditions.v The charging stock to a fuels coking operation usually is a heavy, high boiling, low value petroleum residuum containing ashforming constituents, high Conradson carbon, and catalyst contaminants that render other methods of upgrading unattractive. temperatures in the range of 850 to 1200" F. As a relatively long time must be allowed for the cracking reaction, the fuels coking operation requires a fairly large hold-up of coke in proportion to the oil feed rate in order to avoid bed bogging and agglomeration of the solid particles. Because of the long reaction time required, a fluidized solids bed coking system is preferred.
In contrast, thermal cracking to produce unsaturates of low molecular Weight is generally carried out in a higher temperature range upwards of from 1200 F. in order to obtain high yields of the desired products. It is custom- The operation is generally conducted at 2,871,183 Patented Jan. 27, 1959 a fuels coking process wherein oils are pyrolytically converted to yield naphthas and higher boiling distillates suitable for motor fuels, furnace fuels or for further treatment such as catalytic cracking, into a combination with a thermal cracking process wherein light hydrocarbon gases are converted to materials such as diolefins and olefins useful as chemicals or chemical intermediates. Preferably, the light gases are obtained from the fuels coking products. By means of this integration, this invention succeeds in obtaining from a petroleum oil, in economically balanced proportions, high yields of desira-' ble chemical compounds and of light and middle distillates while producing as an ultimate degradation product a petroleum coke of superior quality.
Although the process of this invention may be most advantageously carried out in a three-vessel system, i. e.,
a fuels coking zone, a high temperature thermal cracking zone and a contact solids heating zone, other variations or combinations in the number of reaction vessels used will be readily apparent to those skilled in the art. Thus a reduction in the number of vessels can be made by conducting two of the operations in separate zones within one vessel. Further, in certain applications, the present process may be suitably combined with other refining processes such as catalytic cracking to augment its ad vantages.
Another object of this invention is to devise an integrated process utilizing the fluidized solids technique wherein selected fractions of petroleum derivatives are converted at high temperatures by contact with a continuously circulating stream of contact solids maintained at different optimum reaction temperatures in successive reaction zones, whereby optimum product yields and distributions are secured. It is a further object to provide for in the integrated process, specific processing sequences whereby unnecessary and undesirable secondary thermaltached drawing, forming a part of the specification, is
discussed in detail.
The drawingdiagrammatically depicts one preferred embodiment of'the present invention. This embodiment is designed to process in a three-vessel system two different feed stocks, e. g., a heavy petroleum oil such as a vacuum residuum and light hydrocarbon gases such as propane and/or ethane. A'salient feature of the process illustrated is that the effluent from the high temperature transfer line thermal cracking zone is introduced into the base of a somewhat lower temperature fluid bed fuels coking zone. Here it is quenched and is used to supply heat and most or all of the fluidization gas to the fuels coking zone. zone can, however, be separately quenched and separated,
' if desired. Prompt quenching of the cracked gases from The effluent from the high temperature following manner.
degradation and can be accomplished by other means, such as by the injection of water, steam, cool solids, etc. into the cracked gases.
Briefly the objects of this invention are attained in the A single inventory of heat-carrying particulate petroleum coke is circulated through the combination process supplying heat to a plurality of thermal cracking reactors. The coke removes from the reaction zones the carbonaceous residues produced. The heatcarrying coke is first heated in a heating zone, preferably a. combustion zone wherein either a portion of the cokeor extraneous fuel such asnatural gas or fuel oil is burned, heating the coke to a temperature in the range of 900 to 2000 F. At least a portion of the coke is heated to a temperature above the highest reaction zone temperature. This high temperature coke is circulated to a thermal cracking zone, preferably a transfer line reactor. Here it contacts and converts light, hydrocarbon gases. The hot solids maintain the zone at a temperature in the range of 1200 to 1800 F. whereby chemical products such as diolefins and olefins are produced. Diluents, such as steam, may be used, if desired. This coke, along with another portion of coke from the heating zone, if desired, is then circulated from the high temperature zone to a fuels coking zone. The latter is, preferably, a fluidized solids coking zone, although it may also be a transfer line zone. An oil, for example, a heavy petroleum residual oil, is injected into the fuels coking zone and undergoes pyrolysis in contact with the hot fluidized coke particles at a temperature in the range of 850 to 1200 F. This thermal cracking produces relatively lighter butnormally liquid hydrocarbons such as naphthas and gas oils and a small amount of gas. Some coke is produced and is deposited on the coke particles of the fluid bed. The coke or part thereof is then returned to the heating zone to be reheated therein. A portion of the net coke produced is removed from the process.
With particular reference to the attached drawing, a preferred process will be described for the conversion of a heavy, low value residual oil such as a petroleum vacuum residuum. The major items of equipment shown in the drawing are a combustion vessel or burner 1, a transfer line, high temperature thermal cracker 10, and a.
lower temperature fluid bed coking vessel 20 designed to produce light and middle distillates. Light hydrocarbon gases are used as the feed stock to the high temperature zone. These may be obtained from any convenient source within the refinery. Preferably, however, these gases, e. g., predominantly ethane and/or propane, are obtained from the efiluent of the low temperature coker 20. While a fuels coker may produce substantial amounts of ethylene and propylene, there ordinarily is not a sufficient amount produced to warrant recovery of the gases.
By integration of the high temperature cracking step with the fuels coking process, the amount of ethylene, for example, may be substantially increased by cracking the ethane content of the low temperature or fuels coker light gaseous product at a high temperature, e. g., 14-00 to 1600 F. and at relatively short vapor residence times, e. g., 0.01 to 10 seconds.
Referring to the drawing, it can be seen that the system has but a single inventory of circulating heat transferring contact solids, e. g., coke'particles of about -1000 microns in diameter produced by the process. As some of the vessels operate with a fluidized bed of the coke, it is preferred to maintain coke in the process having a size range of about 40 to 1000 microns, although this size rangemay go beyond these limits in some cases.
Heat, for the process is generated by burning a portion of the coke produced by the cracking reactions. In cases where the value of the coke is greater than liquid or gaseous fuels, the latter may be burnt to impart. part or all of the required heat to the solid particles. A. fluid bed of burning coke is maintained in a low temperature burner vessel 1 by air supplied by line 3. This burher operates at a temperature in the range of 950 to 1300 F. Flue gas generated by the combustion passes overhead after having entrained solids removed by a cyclone system and is removed from the vessels by line 5. Heat exchange means can be used to extract the specific heat content ofthe flue gas before venting it. As is later described, this heat exchange can be made by direct contact with a portion of the circulating coke in the system.
in order to supply the necessary high temperature solids to the high temperature cracking zone, an auxiliary or high temperature burner 2 is used. Solids are transferred from the low temperature burner El to the high temperature burner 2 by means of standpipe 6. Air supplied to the high temperature burner by line 4 serves to fluidize and partially burn the solids in the burner. The temperature of solids is raised therein to about 1300 to 2000 F. The flue gases resulting from the high temperature combustion pass upwardly through line 9 to the low temperature burner. Here they are cooled by heat exchange with the fluid bed of solids contained therein.
Other less preferred means of supplying heated solid particles to the process can, of course, be used. Thus in place of fluid beds, gravitating or moving beds may be used within the. vessels 1 and 2. Alternatively, a transfer line burner may also be used. Instead of operating two combustion zones at two different temperatures, one combustion zone operating at a high temperature may be used and the coke circulation rate to the low temperature fuels coker may be correspondingly decreased.
The high temperature cracking zone in this example is :1V transfer line reactor 10 operated at a temperature in the range of l200 to 1800 F., preferably 1400" to 1700 F., and a hydrocarbon partial pressure in the range of 5 to 40 p. s. i. The solids, along with the vaporous conversion products, are transferred through the reactor 10 at velocities above about 10 ft./sec., e. g., 60 ft./sec. High temperature coke is supplied to reactor 10 by line 8 and line 11 introduces the light gases to be converted. The time-temperature conditions during the gas (i. e., ethane, propane) cracking are preferably chosen to limit ethane conversion per pass to about 50 to 65% in order to obtain high (70 to wt. percent) ethylene yield on ethane cracked and to minimize the formation of methane. The ratio of light feed gases to high temperature solids may vary from 0.1 to 5 standard cu. ft./ lb.
It is preferred to conduct the effluent including entrained solids from the transfer line reactor directly to the fuels coker. The cracked light gases will then be quenched by the cooler solids in the fuels coker to a temperature substantially below their cracking temperature and the eflluent from the chemical reactor will serve to supply heat and fluidization gas to the fuels coker, thereby decreasing heat requirements and fluidization steam requirements. However, to avoid commingling of the products from the two reactors, gases issuing from the transfer line reactor may be conveyed through a separate cyclone system to remove entrained solids and thence to a conventional separating and final processing system. It will be appreciated, however, that by conveying the overhead from the transfer line reactor to the fuels coker, the need for, a solid separation system, e. g., a cyclone is eliminated.
The fuels fluid bed coking reactor 20 has maintained in it a fluid bed of particulate coke in a manner well known by the art. The coking temperature in this fuels reactor may vary from about 850 to 1200 F. Lower temperatures in the, range of 850 to 1000 F. are used when. heavier distillates suitable as feed to a catalytic cracking process are desired, andv somewhat higher temperatures in the. range of 1000 to 1200 F. are used when lighter distillates, e. g., naphthas, are desired as the primary product. An inert gas, preferably steam, may besupplicd by line. 16v to the base of the fuels coker to supply fluidization gas thereto or to augment the fluidizetion gas supplied by the chemicals coker. Gas rates are adjusted to maintain fluidization velocities in the range of 0.2 to 5 ft./sec.
The petroleum oil to be upgraded, which may be suitably preheated to reduce the heat load on the system, is injected into the vessel by line 17. Any source of oil may be used as feed to the coker including whole crudes, but, preferably, low value oils such as vacuum residua or cycle stocks are used. Preferably, the oil is injected into the vessel through suitable dispersion nozzles at a plurality of horizontal and vertical points so as to obtain uniform dispersion of the oil on the contact solids. The oil injection rate may vary from 0.1 to 2.0 lbs. of oil/hr./lb. of solids contained in the vessel. Conditions are adjusted so as to obtain from 5 to 25 wt. percent C conversion on a coke-freebasis. C conversion on a cokefree basis is defined as: 100 times wt. percent of product having 3 or less carbon atoms divided by the wt. percent of fresh feed less the wt. percent of coke formed. The cracked vapors, upon emerging from the fluid bed, pass through a cyclone system 19 whereby entrained solids are removed and returned to the bed, and then are taken overhead by line 18. This coker product may be further processed in a conventional manner, e. g., by fractionation, hydrocracking, reforming, desulfurization, etc. to obtain the light gases and heavier liquid products of desired quality. 1
The heavy liquid bottoms from the fuels coker can be recycled to the coker for further treatmentor may be recycled to an auxiliary coking zone where it may be subjected to somewhat more severe conditions of temperature and pressure because of its refractory nature. If a secondary fuels coking zone is used,.the vapors from this zone can be reintroduced into the primary fuels coking zone.
In a preferred embodiment of the invention there is separated from the dry gases from the fuels coker ethane and other light paraffinic hydrocarbons and these are transferred to the high temperature cracking zone to be cracked to unsaturated chemical compounds. Paraflinic gases from catalytic cracking, field ethane and propane, or other light hydrocarbon gases may also be fed to the high temperature cracking zone.
In order to supply heat to the fuels coker, coke is circulated from the low temperature burner via line 7 in the amounts of 2 to 20 lbs./lb. of oil injected into the coker. Coke is removed from the base of the fuels coking reactor by standpipe 22 and circulated to the low temperatureburner to be reheated;- Toremove liquid hydrocarbons that may adhere to this coke removed by the standpipe, the coke. can be stripped with steam or other gases.
There normally will be an excess of coke produced by the cracking reaction and this excess is removed by line 12. This coke will be of superior quality as compared to the coke produced in the conventional fluid coking process. Normally, fluid coke has a relatively high sulfur content, particularly, when a sulfurous oil is charged. In the present invention as the coke is repeatedly contacted with light gases at a high temperature in the transfer line reactor, the coke will be substantially desulfurized and this desulfurization enhances the value of the coke removed as product.
The following Table I presents a specific example of the pertinent operating conditions applicable to this process and presents a specific example of the products obtainable, from the feed stock indicated, when the process is operated in accordance with the conditions presented in the table. The effluent from the chemicals reactor is discharged into the fuels coker. The ethylene and propylene products and the gases introduced into the chemicals reactor are obtained by the separation of the fuels coker efiluent by well known processes such as distillatron, low temperature absorption, sulfuric acid absorption of olefins, etc. i
6 TABLE I Operating conditions:
Contact solid Petroleum coke.
Particle size 40 to 1000 microns. Median particle size 250 microns.
Total coke inventory.. 400 tons.
Low temperature burner Pressure at top of bed Temperature Coke hold-up (45 lbs./
c. f. bed density) tons. Air injection rate 45,000 s. c. fJmin.
High temperature burner Pressure at top of bed 15 p. s. i. g.
1 0 p. s. i. g. 1125 F.
Temperature 1675" F. Coke hold-up (45 lbs./
0. f. bed density).. 20 tons. Air injection rate 10,000 s. c. f./min.
Fuels, fluid bed, coker Pressure at top of bed 7 p. s. i. g. Temperature 950 F.
0;, conversion per pass Coke hold-up (45 lbs./
0. f. bed density)- 200 tons. Oil injection rate 5,000 lbs/min. Volume of gases supplied from chemicals reactor 7,400 s. c. f./ min.
Chemical, transfer line, reactor 7 wt. percent.
Pressure, outlet 21 p. s. i. g. Temperature, outlet 1500 F. Density of coke-gas suspension 1 lb./c. f. Hydrocarbon gas injec:
tion rate 4,200 s. c. f./min. Average vapor residence time 0.4 second.
Coke circulation rates From high temperature burner to transfer line reactor From low temperature burner to high temperature burner From low temperature burner to fuels coker 27.5 tons/min. From fuels coker to low temperature burner 30.6 tons/min.
Feed stockEast Texas vacuum residuum 4.0 API gravity 24 wt. percent Conradson carbon 850 F.+ boiling point 0.1 wt. percent ash 1.51 H/C atomic ratio The light hydrocarbon gases introduced into the transfer line reactor comprise:
2.0 vol. percent CH 56.5 vol. percent C H 7.5 vol. percent C H 30.1 vol. percent C H 3.9 vol. percent C H Products, percent based on feed 2.5 tons/min.
2.5 tons/min.
games All 1015' F.+ material from fuels coker products is recycled to coker to extinction.
The present invention is susceptible to variations, particularly in the manner of circulating the heat-carrying solids, to effect certain heat economies.- Thus, the eifluent from the high temperature chemicals cracking operation, with or without entrained solids, can be separately quenched by solidswithdrawn from the relatively cooler fuels coker. Or solids withdrawn from the lower temperature fuels coker can be used, in addition to the abovedescribed quenching or separately therefrom, to quench and abstract heat from the burner flue gases. This latter variation is most advantageously used when a high temperature transfer line burner is used to supply heat to the process; Reference to co-pending application, Conversion of Heavy Petroleum Hydrocarbons, Serial No. 457,383 by Martin and Herrmann filed contemporaneously herewith, will make these and other variations readily apparent.
Having described the invention, what is sought to be protected by Letters Patent is succinctly set forth in the following claims.
What is claimed is:
1. A process wherein hydrocarbons are converted which comprises injecting a normally liquid, heavy petroleum oil into a fuels coking zone containing particulate coke maintained as a relatively dense fluidized bed at a temperature below 1200 F., whereby said heavy petroleum oil undergoes pyrolysis upon contact with said particulate coke evolving substantial quantities of relatively light hydrocarbon vapors having less than 6 carbon atoms and including ethane, distillate vapors and heavy ends, separating thus formed light hydrocarbon vapors having less than 6 carbon atoms and contacting said vapors with another portion of particulate coke maintained at a temperature above 1200" F. in a transfer line reactor zone to obtain ethane conversions in the range of 50-60% per pass, separating as product the efliuent of said transfer line reactor zone from said portions of particulate coke, circulating particulate coke so separated to a combustion zone to be partially combusted and heated therein to a temperature in the range of 900 to 2000 F., at least a portion of the coke being heated to a temperature above the temperature in said transfer line reactor zone, and passing heated coke to said fuels coking zone and to said transfer line reactor zone.
2. The process of claim 1 wherein said hydrocarbon light gas comprises hydrocarbons having up to 4 carbon atoms, when said other portion of particulate coke is maintained at a temperature in the range of 1400' to 1600 F. in said transfer line reactor at a hydrocarbon partial pressure of 5 to 40 p. s. i., and wherein the efiluent including entrained solids from said transfer line reactor is injected into the relatively dense fluidized bed of said fuels coking zone.
3. The process of claim 2 wherein said combustion zone comprises a relatively large holdup fluidized solids combustion zone operating at a temperature in the range of 950 to 1300 F. and a smaller holdup fluidized solids combustion zone operating at a temperature in the range of l300 to 2000 F. wherein particulate coke is circulated from said relatively large holdup combustion zone through said smaller holdup combustion zone and then circulated through said transfer line reactor to said fuels coking zone, wherein particulate coke is circulated from said relatively large holdup combustion zone to said fuels coking zone, and wherein particulate coke is circulated from the relatively dense fluidized bed of said fuels coking zone to said relatively large holdup combustion zone.
4. A combined process for converting heavy, high boiling petroleum oils containing catalyst contaminants which comprises thermally cracking said oil at relatively low temperatures in a coking zone by contacting it in liquid phase with heat-carrying particulate solids maintained as a relatively dense fluidized bed at a temperature in the range of 850 to 1200 F. to form light gases, distillate vapors, heavy ends and coke, separating said light gases and contacting them in a high temperature, transfer line thermal cracking zone with highly heated particulate solids at a temperature in the range of l400 to 1700" F. to produce unsaturated hydrocarbons, and promptly quenching said unsaturated hydrocarbons to prevent their degradation.
5. The process of claim 4 wherein said unsaturated hydrocarbons are quenched by injection into the lower portion of said fuels coking zone.
6. The process of claim 4 wherein solids are withdrawn from said coking zone and injected into the efliuent from said high temperature thermal cracking zone to quench said efliuent and arrest further hydrocarbon conversion thereof.
References Cited in the file of this patent UNITED STATES PATENTS
1. A PROCESS WHEREIN DYDROCARBONS ARE CONVERTED WHICH COMPRISES INJECTING A NORMALLY LIQUID, HEAVY PETROLEUM OIL INTO A FUELS COKING ZONE CONTAINING PARTICULATE COKE MAINTAINED AS A RELATIVELY DENSE FLUIDIZED BED AT A TEMPERATURE BELOW 1200''F. WHEREBY SAID HEAVY PETEOLEUM OIL UNDERGOES PYROLYSIS UPON CONTACT WITH SAID PARTICULATE COKE EVOLVING SUBSTANTIAL QUANTITIES OF RELATIVELY LIGHT HYDROCARBON VAPORS HAVING LESS THAN 6 CARBON ATOMS AND INCLUDING ETHANE, DISTILLATE VAPORS AND HEAVY ENDS, SEPARATING THUS FORMED LIGHT HYDROCARBON VAPORS HAVING LESS THAN 6 CARBON ATOMS AND CONTACTING SAID VAPORS WITH ANOTHER PORTION OF PARTICULATE COKE MAINTAINED AT A TEMPERATURE ABOVE 1200''F. IN A TRANSFER INE REACTOR ZONE TO OBTAIN ETHANE CONVERSIONS IN THE RANGE OF 50-60% PER PASS, SEPARATING AS PRODUCT THE EFFLUENT OF SAID TRANSFER LINE REACTOR ZONE FROM SAID PORTIONS OF PARTICULATE COKE, CIRCULATING PARTICULATE COKE SO SEPARATED TO A COMBUSTION ZONE TO BE PARTIALLY COMBUSTED AND HEATED THEREIN TO A TEMPERATURE IN THE RANGE OF900'' TO 2000'' F., AT LEAST A PORTION OF THE COKE BEING HEATED TO A TEMPERATURE ABOVE THE TEMPERATURE IN SAID TRANSFER LINE REACTOR ZONE, AND PASSING HEATED COKE TO SAID FUELS COKING ZONE AND TO SAID TRANSFER LINE REACTOR ZONE.
| 1954-09-21 | en | 1959-01-27 |
US-73315096-A | Filter circuit using a junction capacitor of a semiconductor
ABSTRACT
A filter circuit using junction capacitors of semiconductors of the present invention prevents the distortion of signal waveforms and is not affected by parasitic capacitors. The filter circuit includes a resistor whose first terminal is connected to an input terminal and whose second terminal is connected to an output terminal. A first junction capacitor is connected between a control voltage supply terminal and an output terminal and a second junction capacitor is connected between the output terminal and ground. An alternate embodiment of the filter circuit includes a pnp transistor, whose emitter is connected to the direct current power supply via a resistor, whose collector is grounded, and whose base is connected to the output terminal.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a semiconductor integrated circuit, more specifically, relates to a filter circuit using a junction capacitor of a semiconductor.
2. Description of the Prior Art
A junction capacitor which makes use of a depletion layer of a p-n junction and a thin film capacitance which makes use of a thin film as a dielectric are two kinds of capacitances used in a filter circuit comprising a resistor and a capacitance in a semiconductor integrated circuit. The thin film capacitance requires a mask and a manufacturing process which are exclusively applied to the manufacturing of this thin film. On the other hand, the manufacturing of the junction capacitor is relatively cost-effective compared to that of the thin film, because the manufacturing process of an npn transistor which is generally applied to a semiconductor integrated circuit can be applied to the junction capacitor in the same manner. However, the junction capacitor is characterized in that the capacitance value changes depending on the voltage applied. Assuming the voltage applied to the junction capacitor is Vc, the capacitance value C is represented by the following equation (1); ##EQU1## where, K is a proportional constant, which depends on an impurity density level around the junction, n varies within the range of 2<n<3, which depends on the shape of the impurity diffusion constituting the junction. For example, in case of a step junction, n equals 2, while in case of a linear gradient junction, n equals 3. In case of diffusion-shape such as a Gaussian shape or a complementary error function shape, the value of n varies between that of the step junction and that of the linear gradient junction as disclosed in the book, titled "Analog Integrated Circuit", by Alan B Grebene, translated by Shuji Nakazawa et al., published by Kindai Kagaku-sha.
FIG. 22 is a graph diagram which embodies the equation (1), where three examples in the cases of n=2.1, 2.5, and 2.9 are respectively plotted when Vc varies from 0 to 2. FIG. 22 shows the decreasing inclination of a capacitance varies when the value of n varies. As a whole, the value of the capacitance decreases when the voltage applied to the junction capacitor increases.
FIG. 19 is a circuit configuration showing an example of a conventional lowpass filter circuit using a junction capacitor. The configuration of FIG. 19 comprises an input terminal 1, an outputs terminal 2, a resistor 3, and a junction capacitor 7. In FIG. 19, the lowpass filter is realized by a series connection of the resistor 3 and the junction capacitor 7.
FIG. 20 is a circuit configuration showing that a conventional lowpass filter circuit using as a transistor a junction capacitor. In FIG. 21, the collector of an npn transistor 49 is connected to a direct current power supply, the base of the npn transistor 49 is grounded, and the emitter of the npn transistor 49 is connected to the output terminal 2. Since this transistor 49 is constructed so that the emitter electric potential is higher than the base potential, the base has a reverse bias, and no electric current flows in the transistor. In this state, a junction capacitor C is formed between the base and the emitter. In FIG. 20, explanation is omitted, on those elements which have the same reference numbers as those in FIG. 19, since they represent the same elements.
FIG. 21 shows a semiconductor structure where a lowpass filter is realized on an integrated circuit substrate. In FIG. 21, both a resistor 3 and a junction capacitor 7 are defined on a p type substrate. The junction capacitor 7 is defined between a p layer defined on an n layer on a P substrate and an n layer defined on the p layer. In other words, the junction capacitor 7 is defined in a region where a diode mark lies, which is shown by an arrow C in FIG. 21. On the other hand, as shown by an arrow R, the resistor 3 is defined in a region which is isolated from the junction capacitor 7 on the p layer which is defined on the n layer right above the P type substrate.
The input/output gain G of this lowpass filter with such a configuration is represented by an equation (2), where the value of the resistor 3 is R, the capacitance value of the junction capacitor 7 is C, and the frequency of an inputted signal is f; ##EQU2## Since the junction capacitor 7 is, in this case, a junction capacitor, the value of the capacitance C in the equation (2) varies depending on the applied voltage, according to the equation (1). Accordingly, the input/output gain G varies as the value of the capacitance C varies.
Accordingly, when an alternating current signal is inputted into the lowpass filter of FIG. 19, the input/output gain changes depending on the electric potential of the signal. As a result, the waveform of an output signal is distorted, as shown in FIG. 23. The waveform shown with the solid line in FIG. 23 represents a signal which is outputted from the output terminal 2 when a sine wave is applied to the input terminal 1 of the lowpass filter circuit shown in FIG. 19. The waveform shown with the dotted line represents an ideal sine wave output which is outputted from the output terminal 2 when the sine wave is applied to the input terminal 1 of the ideal lowpass filter. The capacitance value of the junction capacitor 7 in the lowpass filter of FIG. 19 varies depending on the value of the applied voltage as mentioned above. For example, the capacitance value increases at the moment when the voltage of the inputted signal decreases, and decreases at the moment when the voltage of the inputted signal increases.
As understood from the equation (2), the input/output gain G decreases as the capacitance value of the junction capacitor 7 increases at the point where the voltage of the inputted signal is low, while the input/output gain G increases as the capacitance value of the junction capacitor 7 decreases at the point where the voltage of the inputted signal is high. Shown in FIG. 23, a gap is left between the sine waveform of the output signal and that of the ideal signal in the bottom side. This phenomenon is prevented either by suppressing the amplitude of the signal inputted to the filter circuit, or by raising the DC level of the inputted signal so that the voltage applied to the junction capacitor 7 becomes high.
However, if the amplitude of the inputted signal is suppressed, this may deteriorate the signal-to-noise (S/N) ratio. The voltage applied to the junction capacitor 7 is not raised limitlessly in relation to the power supply voltage used in the integrated circuit. Moreover, the leakage current at the reverse bias of the p-n junction increases if the voltage applied to the junction capacitor 7 is raised.
Accordingly, although using a junction capacitor as a capacitance of a filter circuit has advantages over the use of a thin film capacitance in terms of cost-effective manufacturing, however it has an inevitable defect that the output signal waveform is distorted.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a filter circuit in which a distortion of the waveform is prevented as much as possible, even if a junction capacitor is used.
According to one aspect of the invention, a lowpass filter circuit comprises resistor whose one terminal is connected to an input terminal and whose other terminal is connected to an output terminal; a first junction capacitor which is connected between a control voltage supply terminal and an output terminal; and a second junction capacitor which is connected between the output terminal and a ground.
According to another aspect of the invention, a highpass filter circuit comprises a first junction capacitor whose one terminal is connected to an input terminal and whose other terminal is connected to an output terminal; a level shift circuit whose input termial is connected to the input terminal; a second junction capacitor whose one terminal is connected to an output terminal of the level shift circuit and whose other terminal is connected to the output terminal; and a serial circuit, consisted of a resistor and a constant voltage supply, which is connected between the output terminal and a ground.
According to other aspect of the invention, the first junction capacitor of the lowpass filter circuit is formed by an npn transistor, a collector of the npn transistor is connected to the direct current power supply, an emitter of the npn transistor is connected to a terminal of the control voltage supply, and a base of the npn transistor is connected to the output terminal; and the second junction capacitor of the lowpass filter circuit is formed by an npn transistor, a collector of the npn transistor is connected to a direct current power supply, a base of the npn transistor is grounded, and an emitter of the npn transistor is connected to the output terminal.
According to further aspect of the invention, the first junction capacitor of the highpass filter circuit is formed of an npn transistor, a collector of the npn transistor is connected to the direct current power supply, an emitter of the npn transistor is connected to the input terminal, and a base of the npn transistor is connected to the output terminal; and the second junction capacitor of the highpass filter circuit is formed of an npn transistor, a collector of the npn transistor is connected to the direct current power supply, a base of the npn transistor is connected to the level shift circuit, and an emitter of the npn transistor is connected to the output terminal.
Preferably, the lowpass filter circuit further comprises a pnp transistor, an emitter of the pnp transistor is connected to the direct current power supply via a resistor; a collector of the pnp transistor is grounded; and a base of the pnp transistor is connected to the output terminal.
Preferably, the highpass filter circuit further comprises a pnp transistor, an emitter of the pnp transistor is connected to the direct current power supply via a resistor; a collector of the pnp transistor is grounded; and a base of the pnp transistor is connected to the output terminal.
According to still further aspect of the invention, the level shift circuit of the highpass filter comprises an input terminal connected to a base of an npn transistor; collector of the transistor is connected to the direct current power supply; an emitter of the transistor is connected to an anode input of a serial connection consisted of one or more diodes; and a cathode output of the serially connected diode is grounded via a constant current supply, as well as connected to an output terminal of the level shift circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit configuration of a lowpass filter according to a first embodiment of the invention.
FIG. 2 is a circuit configuration of a lowpass filter constructed using a transistor according to the first embodiment of the invention.
FIG. 3 shows a semiconductor structure where a lowpass filter is realized on an integrated circuit substrate according to the first embodiment of the invention.
FIG. 4 shows variation of a compound capacitance value according to the first embodiment of the invention.
FIG. 5 shows comparison of the compound capacitance value between the first embodiment of the invention and the prior art.
FIG. 6 is a circuit configuration of a highpass filter according to a second embodiment of the invention.
FIG. 7 is a circuit configuration of a highpass filter constructed using a transistor according to the second embodiment of the invention.
FIG. 8 shows a semiconductor structure where a highpass filter is realized on an integrated circuit substrate according to the second embodiment of the invention.
FIG. 9 is a diagram of the detailed configuration of the level shift circuit in FIG. 6.
FIG. 10 shows voltages on the major points in the circuit of FIG. 6.
FIG. 11 is a diagram in which a parasitic capacitor formed by a junction capacitor is illustrated in addition to the circuit shown in FIG. 1.
FIG. 12 is a circuit configuration of a lowpass filter according to a third embodiment of the invention.
FIG. 13 is a circuit configuration of a lowpass filter constructed using a transistor according to the third embodiment of the invention.
FIG. 14 shows a semiconductor structure where a lowpass filter is realized on an integrated circuit substrate according to the third embodiment of the invention.
FIG. 15 is a diagram in which a parasitic capacitor formed by a junction capacitor is illustrated in addition to the circuit shown in FIG. 6.
FIG. 16 is a circuit configuration of a highpass filter according to a fourth embodiment of the invention.
FIG. 17 is a circuit configuration of a highpass filter constructed using a transistor according to the fourth embodiment of the invention.
FIG. 18 shows a semiconductor structure where a highpass filter is realized on an integrated circuit substrate according to the fourth embodiment of the invention.
FIG. 19 is a circuit configuration of a conventional lowpass filter circuit using a junction capacitor.
FIG. 20 is a circuit configuration of a conventional lowpass filter circuit constructed using a transistor.
FIG. 21 shows a semiconductor structure where a conventional lowpass filter is realized on an integrated circuit substrate.
FIG. 22 shows how the value of junction capacitor changes depending on applied voltage.
FIG. 23 shows how waveform is distorted in a conventional filter circuit using a junction capacitor.
FIG. 24 is a circuit configuration of a conventional highpass filter circuit using a junction capacitor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1.
FIG. 1 is a circuit configuration of a lowpass filter according to a first embodiment of the invention. The configuration of FIG. 1 comprises an input terminal 1, an output terminal 2, a resistor 3, junction capacitors 4, 5 of a semiconductor, and a control voltage supply 6. According to the first embodiment of the invention, two capacitance, each of which has half of the conventional value of the capacitance C, are connected in the output side of the resistor 3. A lowpass filter which is not affected by the variation of the inputted voltage is realized in such connection. Assuming that the area for the respective junction capacitors 4, 5 on the semiconductor substrate is half of that of the junction capacitor 7 of FIG. 19 in order to compare the invention with the prior art. In other words, if the same voltage is applied respectively to the junction capacitors 4, 5 in FIG. 1 and to the junction capacitor 7 in FIG. 19, the respective values of the junction capacitors 4, 5 are half of that of the junction capacitor 7.
FIG. 2 is a circuit configuration of a lowpass filter constructed using a transistor according to the first embodiment of the invention. In FIG. 2, the collector of a second npn transistor 42 is connected to a direct current power supply Vcc, its base is grounded, and its emitter is connected to the output terminal 2. The emitter of a first npn transistor 41 is connected to the control voltage supply 6, its collector is connected to the direct current power supply Vcc, its base is connected to the output terminal 2. Since these transistors 41, 42 are so constructed that the electric potential of the respective emitters is higher than that of the respective bases, no current flows through the transistors because the reverse bias potential is applied to the respective bases. In this state, junction capacitors C1, C2 are formed, respectively, between the respective bases and the emitters of the transistors 41, 42. Explanation is omitted, in FIG. 2, on those elements which have the same reference numbers as those in FIG. 1, since they represent the same elements.
FIG. 3 shows a semiconductor structure where a lowpass filter is realized on an integrated circuit substrate according to the first embodiment of the invention. The junction capacitor 4 is defined between a p layer defined on an n layer right above a P type substrate and an n layer defined on the p layer. In other words, the junction capacitor 4 is defined at a place where a diode mark C2 lies in FIG. 3. The junction capacitor 5 is defined on the other part between the p layer defined on the n layer right above the P type substrate and the n layer defined on the p layer. In other words, the junction capacitor 5 is defined at a place where a diode mark C1 lies in FIG. 3. On the other hand, as shown by an arrow R, the resistor 3 is defined in a region where is isolated from the junction capacitors 4, 5 on the p layer which is defined on the n layer right above the P type substrate.
In addition to the above, a parasitic capacitor Cs2 is formed between the n layer right above the P type substrate and the p layer defined on the n layer around the portion of C2. A parasitic capacitor Cs1 is formed between the n layer right above the P type substrate and the p layer defined on the n layer around the portion of C1. Further explanation on these parasitic capacitors Cs1, Cs2 is omitted in this embodiment, since they are explained in detail in the third embodiment.
The operation of a lowpass filter according to the first embodiment is explained below. The circuit shown in FIG. 1 is a lowpass filter comprising the input terminal 1 and the output terminal 2. The capacitance as a constituent part of the filter is a compound capacitor comprising of the junction capacitors 4 and 5, which are connected in parallel. The value of the compound capacitance in this circuit is the sum of the respective values of these junction capacitors 4 and 5, which is represented by the equation (3), assuming that the voltage value of the control voltage supply 6 is Va and voltage applied to the junction capacitor 4 is Vc; ##EQU3## where, K1 and K2 are, proportional constants respectively, and n varies within the range of 2<n<3.
FIG. 4 is a simulation graph which embodies the equation (3) in case of K1, K2=K. In FIG. 4, three examples in case of n=2.1, 2.5, and 2.9 are respectively plotted when the applied voltage Va equals to 2 V! and Vc varies from 0 V! to 2 V!, for the sake of simplification of the explanation. FIG. 4 shows that the variation of the compound capacitance C is significantly small where the value of the voltage Vc which is applied to the junction capacitor 4 is close to 1 V!. This is because the sum of the value of the capacitor 4 and capacitor 5 cancels the variation of the respective capacitance to each other, since the voltage applied to the junction capacitor 5 decreases when the voltage applied to the junction capacitor 4 increases, and the voltage applied to the junction capacitor 5 increases when the voltage applied to the junction capacitor 4.
FIG. 5 is a diagram in the case of n=2.5, and K1=K2=K in respective FIG. 4 and FIG. 22 are superposed in order to compare the invention with the prior art. FIG. 5 shows that the variation of the capacitance value C in the filter circuit of the present invention is lower than that in the filter circuit of the prior art in the region where the value of the voltage Vc is close to 1. Since the input/output gain G in the filter circuit of FIG. 1 is represented by the same equation (2) as the prior art, the distortion of the waveform is lessened due to the decrease in the variation of the capacitance value C in the filter circuit of the present invention.
On the other hand, the variation of the capacitance value C increases where the value of Vc is close to either 0 or 2, in case of the present invention. However, a normal operation of the circuit cannot be expected when the signal which is inputted to the filter circuit of FIG. 1 exceeds the range between ground 0 V! and the voltage of the control voltage supply 6. The operational margin is usually taken so that the electric potential of a signal does not come close to ground nor to the voltage of the control voltage supply 6. Therefore, the filter circuit is used within the range where the variation of the capacitance is small.
Embodiment 2.
FIG. 6 shows an embodiment in which the present invention is applied to a highpass filter. The circuit construction of FIG. 6 comprises an input terminal 1, an output terminal 2, junction capacitors 8, 9, a resistor 10, a constant voltage supply 11, and a level shift circuit 12. The level shift circuit 12 operates so that the center level of the signal received from the input terminal 1 is shifted lower as much as a constant voltage without changing the amplitude of the inputted signal. The constant level should be shifted more than the level of the amplitude of the signal to be inputted. The value of the constant voltage supply 11 is set to the electric potential which is lowered by half of the level-shift quantity of the level shift circuit 12 from the level of the electric potential center of the signal inputted from the input terminal 1.
FIG. 7 is a circuit configuration of a highpass filter constructed using a transistor according to the second embodiment of the invention. In FIG. 7, the collector of a first npn transistor 43 is connected to a direct current power supply Vcc, its emitter is connected to the input terminal 1, and its base is connected to the output terminal 2. The collector of a second npn transistor 44 is connected to the direct current power supply Vcc, its base is connected to the level shift circuit, and its emitter is connected to the output terminal 2. Since these transistors 43, 44 are so constructed that the electric potential of the respective emitters is higher than that of the respective bases, no current flows through the transistors because the reverse biases are applied to the respective bases. In this state, junction capacitors C1, C2 are formed, respectively, between the respective bases and the emitters of the transistors 43, 44. Explanation is omitted, in FIG. 7, on those which have the same reference numbers as those in FIG. 6, since they represent the same elements.
FIG. 8 shows a semiconductor structure where a highpass filter is realized on an integrated circuit substrate according to the second embodiment of the invention. The junction capacitor 8 is defined between a p layer defined on an n layer right above a P type substrate and an n layer defined on the p layer. In other words, the junction capacitor 8 is defined at a place where a diode mark C1 lies in FIG. 8. The junction capacitor 9 is defined on the other part between the p layer defined on the n layer right above the P type substrate and the n layer defined on the p layer. In other words, the junction capacitor 9 is defined at a place where a diode mark C2 lies in FIG. 8. On the other hand, as shown by an arrow R, the resistor 10 is defined on a region which is isolated from the junction capacitors 8, 9 on the p layer which is defined on the n layer right above the P type substrate. Although the level shift circuit 12 and the constant voltage supply 11 are illustrated in FIG. 8 as they are located in an outside circuit, they are merely illustrated from the convenience of explanation. They can of course be defined on the same P type substrate as the other elements.
In addition to the above, a parasitic capacitor Cs2 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion of C2. A parasitic capacitor Cs1 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion of C1. Further explanation on these parasitic capacitors Cs1, Cs2 is omitted in this embodiment, since they are explained in detail in the fourth embodiment.
FIG. 9 is a conventional circuit configuration of the level shift circuit 12 shown in FIG. 6. The circuit configuration shown in FIG. 9 is one example of the level shift circuit 12, although other circuit structural variations are possible. The configuration of FIG. 9 comprises an npn transistor 24, a plurality of diodes 25, a constant current supply 26, an input terminal 21, an output terminal 22, and a power supply 23. When a signal is inputted into the input terminal 21, the center electric potential of the input signal is shifted as much as the base-emitter voltage of the transistor 24 plus the voltage drop of the plurality of the diodes, and then signal is outputted to the output terminal 22. In this operation, only the center electric potential of the inputted signal is shifted, and the amplitude of the signal is kept to the same value as before when the signal is outputted to the output terminal 22.
FIG. 10 shows the waveform relationship among the inputted signal on the X point, the signal on the Z point after it passed the level shift circuit 12, the electric potential on the Y point in the constant voltage supply 11 and the electric potential on the T point (output point), when a sine wave is inputted from the input terminal 1 of the highpass filter. The minimum magnitude level on the T point corresponds to the Y point. For example, if assuming the respective levels of the X, Y, and Z points are set as shown in FIG. 10, the level of the signal after the input signal has passed through the level shift circuit 12 descends so that its central value shifts from the level of the voltage on the X point to that on the Z point. This central electric potential on the Z point is lower than the electric potential on the Y point, and the electric potential at the maximum amplitude of the signal which flows on the Z point is set lower than the electric potential on the Y point as well as that on the T point. Since the impedance of the level shift circuit 12 is high in terms of direct current, while it is low in terms of alternating current, the X point and the Z point are shorted state in terms of alternating current, although the respective electric potentials on the X point and on the Z point are different in terms of direct current.
Accordingly, both the junction capacitors 8, 9 are supplied with the reverse bias, and the above relationship is maintained such that the voltage applied to the capacitor 9 decreases when the voltage applied to the capacitor 8 increases, while the voltage applied to the capacitor 9 increases when the voltage applied to the capacitor 8 decreases. Accordingly, the sum of the value of the capacitor 8 and that of the capacitor 9 cancels the respective variation of the capacitance value. The capacitance as a constituent part of the filter is a sum of the junction capacitors 8 and 9. The input/output gain G in this circuit is represented by the equation (4), if assuming the sum of the respective junction capacitors 8, 9 is C, the value of the resistor 10 is R, and the frequency of the inputted signal is f; ##EQU4##
According to the present invention, the variation of the input/output gain G can be prevented since the variation of the capacitance value C is suppressed according to the equation (4). As a result, the distortion of the waveform of the signal passed through the filter circuit is suppressed.
Embodiment 3.
FIG. 11 shows parasitic capacitors formed by junction capacitors between a collector and a base in the IC structure, respectively, in addition to the circuit shown in FIG. 1. The configuration of FIG. 11 comprises a collector-base parasitic capacitor (Cs2) 13 in addition to the junction capacitor 4, a collector-base parasitic capacitor (Cs1) 14 in addition to the junction capacitor 5, and power supplies Vcc 15, 16 of, for example, 5 V!.
As briefly mentioned in the first embodiment, the parasitic capacitor Cs2 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion around C2. The parasitic capacitor Cs1 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion around C1. In FIG. 11, the anode of the parasitic capacitor Cs1 is connected to the output terminal 2, and its cathode is connected to the power supply 15. The anode of the parasitic capacitor Cs2 is grounded, and its cathode is connected to the power supply 16. Accordingly, a desired characteristic of the filter circuit is not obtained because of this Cs1 which is actually added as a capacitance, even if the capacitance value C in the filter circuit is set to the sum of the C1 and C2. On the other hand, the (collector-base) parasitic capacitor Cs2 gives no effect on the characteristic of the filter circuit even if the electric potential on the N point changes, because the anode (p type diffusion side which constitutes the base region) of the parasitic capacitor Cs2 is grounded.
FIG. 12 is a circuit configuration of a lowpass filter comprising a parasitic capacitor eliminating circuit according to the third embodiment of the present invention. FIG. 13 is a circuit configuration of a lowpass filter constructed using a transistor according to the third embodiment of the invention. FIG. 14 shows a semiconductor structure where a lowpass filter is realized on an integrated circuit substrate according to the third embodiment of the invention.
The configuration of FIG. 12 comprises a pnp transistor 17, and a resistor 18. The transistor 17 and the resistor 18 comprises an emitter-follower 30. The emitter of the transistor 17 in the emitter-follower 30 is connected to the power supply 15 via the resistor 18, the base of the transistor 17 which is an input of the emitter-follower 30 is connected to the output terminal 2, and the collector of the emitter-follower 17 is grounded
In the configuration as mentioned above, the one terminal of the parasitic capacitor 14 is connected to the input of the emitter-follower, while the other terminal of it is connected to the output of the emitter-follower (the emitter of the transistor 17). On this account, the voltage on the respective terminals of the parasitic capacitor (Cs1) 14 is equal to the base-emitter voltage VBE, which is always kept constant. Accordingly, the frequency characteristic of the lowpass filter circuit is not affected, because neither charge nor discharge occurs in the parasitic capacitor 14.
FIG. 13 is a circuit configuration of a lowpass filter constructed using a transistor according to the third embodiment of the invention. In FIG. 13, the emitter of a first npn transistor 45 is connected to the control voltage supply 6, its collector is connected to the emitter of the transistor 17, and its base is connected to the output terminal 2. On the other hand, the collector of a second npn transistor 46 is connected to the direct current power supply Vcc, its base is grounded, and its emitter is connected to the output terminal 2. Since these transistors 45, 46 are so constructed that the electric potential of the respective emitters is higher than that of the respective bases, no current flows through the transistors because the reverse bias is supplied with the respective bases. In this state, junction capacitors C1, C2 are formed, respectively, between the respective bases and the emitters of the transistors 45, 46. Explanation is omitted, in FIG. 13, on those which have the same reference numbers as those in FIG. 12, since they represent the same elements.
FIG. 14 shows a semiconductor structure where a lowpass filter is realized on an integrated circuit substrate according to the third embodiment. The junction capacitor (C2) 4 is defined between a p layer defined on an n layer right above a P type substrate and an n layer defined on the p layer. In other words, the junction capacitor (C2) 4 is defined at a place where a diode mark C2 lies in FIG. 14. The junction capacitor (C1) 5 is defined on the other part between the p layer defined on the n layer right above the P type substrate and the n layer defined on the p layer. In other words, the junction capacitor 5 is defined at a place where a diode mark C1 lies in FIG. 14. On the other hand, as shown by an arrow R, the resistor 3 is defined in a region which is isolated from the junction capacitors 4, 5 on the p layer which is defined on the n layer right above the P type substrate. On the other hand, the pnp transistor 17 is defined in another region which is isolated from the junction capacitors C1 and C2. In other words, the pnp transistor is defned among an isolation region defined on the P type substrate, an n epitaxial layer and a p layer which is defined on the n epitaxial layer. The collector of the pnp transistor is grounded, its emitter is connected to the power supply Vcc via a resistor which is defined in the other region, and its base is connected to the output terminal 2.
As mentioned above, the parasitic capacitor Cs2 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion of C2. The parasitic capacitor Cs1 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion of C1. The one terminal of the parasitic capacitor (Cs1) 14 is connected to the output terminal 2, while the other terminal of it is connected to the emitter of the transistor 17. On the other hand, the one terminal of the parasitic capacitor (Cs2) 13 is grounded and the other terminal of it is connected to the power supply 16.
Embodiment 4.
FIG. 15 shows parasitic capacitors formed by junction capacitors between a collector and a base in the IC structure, respectively, in addition to the circuit shown in FIG. 6. The configuration of FIG. 15 comprises a collector-base parasitic capacitor (Cs1) 19 in addition to a junction capacitor (C1) 8, a collector-base parasitic capacitor (Cs2) 20 in addition to a junction capacitor (C2) 9, and power supplies Vcc 15, 16, for example, 5 V!.
As briefly mentioned in the second embodiment, the parasitic capacitor Cs2 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion of C2 (between the collector and the base). The parasitic capacitor Cs1 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion of C1 (between the collector and the base). In FIG. 15, the one terminal of the parasitic capacitor Cs1 is connected to the output terminal 2 (T point), and the other terminal is connected to the power supply 15. The one terminal of the parasitic capacitor Cs2 is connected to an output terminal of the level shift circuit 12 (Z point), and the other terminal is connected to the power supply 16. Accordingly, in terms of alternating current, the one terminal of this parasitic capacitor Cs1 is connected to the T terminal, and the other terminal of it is grounded.
Accordingly, a desired characteristic of the filter circuit is not obtained because of this Cs1 which is actually added as a capacitance, even if the capacitance value C in the filter circuit is set to the sum of the C1 and C2. On the other hand, the parasitic capacitor Cs2 gives less effect on the characteristic of the filter circuit even if the electric potential changes, because the impedance is usually significantly small at the Z point of the output of the level shift circuit 12 to which the anode of the parasitic capacitor Cs2 is connected.
FIG. 16 is a circuit configuration of a highpass filter comprising a parasitic capacitor eliminating circuit according to the fourth embodiment of the present invention. FIG. 17 is a circuit configuration of a highpass filter constructed using a transistor according to the fourth embodiment of the invention. FIG. 18 shows a semiconductor structure where a highpass filter is realized on an integrated circuit substrate according to the fourth embodiment of the invention.
The configuration of FIG. 16 comprises a pnp transistor 17, and a resistor 18. The transistor 17 and the resistor 18 consists of an emitter-follower 30. The emitter of the transistor 17 in the emitter-follower 30 is connected to the power supply 15 via the resistor 18, the base of the transistor 17 which is an input of the emitter-follower 30 is connected to the terminal 2, and the collector of the emitter-follower 17 is grounded.
In the configuration as mentioned above, the one terminal of the parasitic capacitor 19 is connected to the output of the emitter-follower, while the other terminal of it is connected to the input of the emitter-follower (the base of the transistor 17). On this account, the voltage on the respective terminals of the parasitic capacitor (Cs1) 19 is equal to the base-emitter voltage VBE, which is always kept constant. Accordingly, the frequency characteristic of the lowpass filter circuit is not affected by the voltage variation, because neither charge nor discharge occurs in the parasitic capacitor 19.
FIG. 17 a circuit configuration of a highpass filter constructed using a transistor according to the fourth embodiment of the invention. In FIG. 17, the collector of a first npn transistor 47 is connected to the emitter of the pnp transistor 17, its emitter is connected to the input terminal 1, and its base is connected to the output terminal 2. On the other hand, the collector of a second npn transistor 48 is connected to the direct current power supply Vcc, its base is connected to the output of the level shift circuit (Z point), and its emitter is connected to the output terminal 2. Since these transistors 47, 48 are so constructed that the electric potential of the respective emitters is higher than that of the respective bases, no current flows through the transistors because the reverse bias is applied to the respective bases. In this state, junction capacitors C1, C2 are formed respectively between the respective bases and the emitters of the transistors 47, 48. Explanation is omitted, in FIG. 17, on those which have the same reference numbers as those in FIG. 16, since they represent the same elements.
FIG. 18 shows a semiconductor structure where a highpass filter is realized on an integrated circuit substrate according to the fourth embodiment. The junction capacitor 8 is defined between a p layer defined on an n layer right above a P type substrate and an n layer defined on the p layer. In other words, the junction capacitor 8 is defined at a place where a diode mark C1 lies in FIG. 18. The junction capacitor 9 is defined on the other part between the p layer defined on the n layer right above the P type substrate and the n layer defined on the p layer. In other words, the junction capacitor 9 is defined at a place where a diode mark C2 lies in FIG. 18. On the other hand, as shown by an arrow R, the resistor 10 is defined in a region which is isolated from the junction capacitors 8, 9 on the p layer which is defined on the n layer right above the P type substrate. The level shift circuit 12 and the constant voltage supply 11 are illustrated in FIG. 18 as they are located in an outside circuit, they are merely illustrated from the convenience of explanation. The level shift circuit 12 and the constant voltage supply 11 can of course be defined on the same P type substrate as the other elements.
On the other hand, the pnp transistor 17 is defined in another region which is isolated from the junction capacitors C1 and C2. In other words, the pnp transistor is defined among an isolation region defined on the P type substrate, an n epitaxial layer, and a p layer which is defined on the n epitaxial layer. The collector of the pnp transistor is grounded, its emitter is connected to the power supply Vcc via a resistor which is defined in the other region, and its base is connected to the output terminal 2.
In addition to the above, the parasitic capacitor Cs2 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion around C2. The parasitic capacitor Cs1 is formed between the n layer right above the P type substrate and the p layer defined on the n layer in the portion around C1. The one terminal of the parasitic capacitor (Cs1) 19 is connected to the output terminal 2, while the other terminal of it is connected to the emitter of the transistor 17. On the other hand, the one terminal of the parasitic capacitor (Cs2) 20 is connected to the output of the level shift circuit and the other terminal of it is connected to the power supply 16.
What is claimed is:
1. A low pass filter circuit comprising:a signal input terminal, a signal output terminal, and a control voltage supply terminal; a first resistor having a first terminal connected to the signal input terminal and a second terminal connected to the signal output terminal; a first junction capacitor having a first variable capacitance, the first junction capacitor being connected between the control voltage supply terminal and the signal output terminal and comprising a first npn transistor having a collector, an emitter, and a base, the collector of the first npn transistor being connected to a direct current power supply, the emitter of the first npn transistor being connected to the control voltage supply terminal, and the base of the first non transistor being connected to the signal output terminal; a second junction capacitor having a second variable capacitance, the second junction capacitor being connected between the signal output terminal and ground and comprising a second an npn transistor having a collector, an emitter, and a base, the collector of the second npn transistor being connected to the direct current power supply, the base of the second npn transistor being grounded, and the emitter of the second npn transistor being connected to the signal output terminal; a second resistor; and a pnp transistor having a collector, a base, and an emitter, the emitter of the pnp transistor being connected to the direct current power supply via the second resistor, the collector of the pnp transistor being grounded, and the base of the pnp transistor being connected to the signal output terminal.
2. A high pass filter circuit comprising:a signal input terminal and a signal output terminal; a first junction capacitor having first and second terminals, the first terminal of the first junction capacitor being connected to the signal input terminal the second terminal of the first junction capacitor being connected to the signal output terminal; a level shift circuit having an input terminal and an output terminal, the input terminal being connected to the signal input terminal; a second junction capacitor having first and second terminals, the first terminal of the second junction capacitor being connected to the output terminal of the level shift circuit the second terminal of the second junction capacitor being connected to the signal output terminal; and a serial circuit connected between the signal output terminal and ground, the serial circuit including a first resistor and a constant voltage supply.
3. The high pass filter circuit according to claim 2 further comprising:a direct current power supply, and wherein: the first junction capacitor comprises a first npn transistor having a collector, a base, and an emitter, the collector of the first npn transistor being connected to the direct current power supply, the emitter of the first npn transistor being connected to the signal input terminal, and the base of the first npn transistor being connected to the signal output terminal; and the second junction capacitor comprises a second npn transistor having a collector, a base, and an emitter, the collector of the second npn transistor being connected to the direct current power supply, the base of the second npn transistor being connected to the level shift circuit, the emitter of the second npn transistor being connected to the signal output terminal.
4. The high pass filter circuit according to claim 3 further comprising:a second resistor; and a pnp transistor having a collector, a base, and an emitter, the emitter of the pnp transistor being connected to the direct current power supply via the second resistor, the collector of the pnp transistor being grounded, and the base of the pnp transistor being connected to the signal output terminal.
5. The high-pass filter circuit according to claim 3 wherein the level shift circuit comprises:a third npn transistor having a collector, a base, and an emitter, the base of the third npn transistor being connected to the input terminal of the level shift circuit, and the collector of the third npn transistor being connected to the direct current power supply; at least one diode being connected in series with the third npn transistor, the diode having an anode and a cathode, the anode being connected to the emitter of the third npn transistor; and a constant current supply having first and second terminals, the first terminal of the constant current supply being connected to the output terminal of the level shift circuit and to the cathode of the diode, the second terminal being connected to ground.
6. The high-pass filter circuit according to claim 4 wherein the level shift circuit comprises:a third npn transistor having a collector, a base, and an emitter, the base of the third npn transistor being connected to the input terminal of the level shift circuit, and the collector of the third npn transistor being connected to the direct current power supply; at least one diode being connected in series with the third npn transistor, the diode having an anode and a cathode, the anode being connected to the emitter of the third npn transistor; and a constant current supply having first and second terminals, the first terminal of the constant current supply being connected to the cathode of the diode and to the output terminal of the level shift circuit, the second terminal of the constant current supply being connected to ground.
| 1996-10-16 | en | 1998-06-02 |
US-78729385-A | Method for reducing emissions utilizing pre-atomized fuels
ABSTRACT
Methods and composition are provided to facilitate the utilization of highly viscous hydrocarbons as clean burning fuels.
RELATED APPLICATIONS
The present application is a continuation-in-part of application Ser. No. 653,808 filed Sept. 24, 1984, which in turn is a continuation-in-part of application Ser. No. 547,892, filed Nov. 2, 1983.
TABLE OF CONTENTS
1. Introduction
2. Background of the Invention
2.1. Viscous Hydrocarbons
2.2. Transportation of Viscous Hydrocarbons
2.3. Combustion of Oil-in-Water Emulsions
2.4. Microbial Surface Active Compounds
3. Summary of the Invention
4. Nomenclature
5. Brief Description of the Figures
6. Detailed Description of the Invention
6.1. Surfactant Packages
6.2. Viscous Crude Oils and Residual Oils
6.3. Emulsion Formation
6.3.1. Formation of Pre-Atomized Fuels at High Temperatures
6.3.2. Formation of Pre-Atomized Fuels Using A Thermally Cracked Hydrocarbon Discharge
6.3.3. Mixing of A Slurry with A Pre-Atomized Fuel
6.3.4. Emulsification of HIghly Viscous Hydrocarbons to Obtain Clean-Burning Pre-Atomized Fuels
6.4. Properties of α-Emulsan-Stabilized Hydrocarbosols
6.5. Blending of Hydrocarbons
6.6. Transportation and Utilization of Hydrocarbosols
7. Examples
7.1 Preparation of Bioemulsifiers
7.1.1. Preparation of Technical Grade α-Emulsan
7.1.2. Additional Preparations of Acinetobacter calcoaceticus Bioemulsifiers
7.2. Viscous Hydrocarbon Characteristics
7.2.1. Boscan Crude Oil
7.2.2. Texas Fireflood Crude Oil
7.2.3. Number 6 Residual Test Fuel Oil
7.2.4. Union Cutback Tar
7.2.5. California Vacuum Resid
7.2.6. Oklahoma Vacuum Resid
7.2.7. Catalytic Hydrogenated Resid (H-Oil)
7.2.8. ROSE Resid
7.2.9. German Visbreaker Resid
7.2.10. Texas Visbreaker Resid
7.2.11. Pyrolysis Pitch
7.2.12. Methods for Determining Hydrocarbon Characteristics
7.2.13. Methods for Determining Hydrocarbon Characteristics, Including Asphaltene Content
7.3. Viscosity Reduction Experiments
7.3.1. Surfactant Packages and Emulsification of Hydrocarbons
7.3.2. Effect of Methanol in Aqueous Phase on Pre-Atomized Fuel Viscosity
7.3.3. Effect of Water Content on Pre-Atomized Fuel Viscosity
7.3.4. Temperature Effects on Hydrocarbosols
7.3.5. Comparative Static Testing
7.3.6. Stabilizer Comparisons
7.3.7. Mixing of A Slurry with A Pre-Atomized Fuel
7.3.8. Formation of Pre-Atomized Fuels at High Temperature under Pressure
7.3.9. Formation of Pre-Atomized Fuels Using A Thermally Cracked Hydrocarbon Discharge
7.4. Pipelining Pilot Test
7.5. Direct Combustion Test on Pre-Atomized Fuels
7.5.1. Furnace Assembly and Instrumentation
7.5.2. Preparation of Pre-Atomized Fuel for Combustion Test
7.5.3. Combustion Test Procedure
7.5.4. Results of Preliminary Combustion Test
7.5.5. Results of Combustion Emissions Test
7.6. Direct Combustion of Pitch-In-Water Pre-Atomized Fuel and Particulate Emissions Reduction
1. INTRODUCTION
This invention relates to the utilization of highly viscous hydrocarbons, including heavy crude oils and residual oils. More particularly, this invention relates to the utilization of viscous hydrocarbons through the formation of low-viscosity hydrocarbon-in-water emulsions, including
(a) chemically non-stabilized hydrocarbon-in-water emulsions;
(b) chemically stabilized hydrocarbon-in-water emulsions; and
(c) bioemulsifier-stabilized hydrocarbon-in-water emulsions, the latter being called hydrocarbosols, in which the hydrocarbon droplets dispersed in the continuous aqueous phase are substantially stabilized from coalescence by the presence of bioemulsifiers and in particular, microbial bioemulsifiers, surrounding the droplets at the hydrocarbon/water interface. Furthermore, this invention relates to the combustion of pre-atomized fuels which include both hydrocarbosols and other hydrocarbon-in-water emulsions made with viscous hydrocarbons.
Transportation of highly viscous hydrocarbons via conventional pipelines or other methods, including tankers and barges, cannot presently be accomplished practically without reduction of the viscosity of the hydrocarbons to put them into a pumpable form. Even when transportation over long distances is not a factor, viscosity reduction is nonetheless required to make efficient use of highly viscous hydrocarbons as burnable fuels. This invention presents alternative means to viscosity reduction of extremely recalcitrant heavy crudes and residuals, potentially more successful and economical than methods requiring heating or dilution with lighter petroleum stocks. Formation of hydrocarbon-in-water emulsions effectively reduces the viscosity of heavy hydrocarbon materials, thereby facilitating shipping and pumping with conventional equipment, as well as in situ handling. Furthermore, the pre-atomized fuels formed by the methods of this invention can be burned directly by conventional means, without dewatering or demulsification, resulting in significant emissions reductions. Indeed, highly viscous hydrocarbons, which if burned in an unemulsified form would not meet environmental standards, can now be made to behave comparably to environmentally acceptable cleaner burning fuels by using such highly viscous hydrocarbons in the form of pre-atomized fuels.
Under circumstances where transportation distances from production location to utilization sites are considerable, giving rise to long transit times and/or the potential for shutdowns en route, or where long storage periods are required, the use of hydrocarbosols is especially advantageous. Because the microbial bioemulsifiers predominantly reside at the hydrocarbon/water interface, essentially covering the surface of the hydrocarbon droplets, the hydrocarbon droplets are effectively protected from coalescence and the reduced viscosity of the hydrocarbosols is effectively maintained over time. The substantial stability and improved pumpability of the hydrocarbosols allows them to be transported practically over long distances or remain stationary for long periods of time prior to utilization.
2. BACKGROUND OF THE INVENTION
2.1. VISCOUS HYDROCARBONS
While large quantities of high-quality, relatively inexpensive, light crude oils presently are recoverable from world-wide geographical locations, ever-increasing consumption of petroleum fuels and other petroleum products and the energy crisis precipitated by such high demands have brought interest to bear on the enormous reserves of low-gravity, viscous hydrocarbons which also exist throughout the world. Viscous hydrocarbons present in natural deposits have been generally classified as viscous crude oils, bitumen or tar and have been variously called heavy crudes, native bitumen, natural bitumen, oil sands, tar sands, bituminous sands or deposits and natural asphalts, all of which materials are chemically gradational and nearly indistinguishable without standardized analyses. [For a discussion of the general characteristics of viscous hydrocarbons and the problem of precisely defining or classifying them, see Meyer, "Introduction" in: The Future of Heavy Crude and Tar Sands, p. 1, Mining Informational Services, McGraw Hill, Inc., New York (1981). See also Section 6.2 infra.]
The geograhphical distribution of heavy crude reserves is given in Table I [abstracted from Meyer and Dietzman (1981), "World Geography of Heavy Crude Oils," in: The Future of Heavy Crude and Tar Sands, pp. 16-28, Mining Informational Services, McGraw Hill, Inc., New York (1981)]. The total estimated figure for oil in place is 6200×109 barrels. Venezuela heads the list with roughly half of this total, 3000×109 barrels. Canada follows closey with 2950×109 barrels (this total includes hydrocarbon in bitumen), while the United States has an estimated 77×109 barrels. To put these figures in perspective, the total world reserves of oil lighter than 20° API is estimated to be about 660×109 barrels. Yet undiscovered reserves are estimated at 900×109 barrels. Thus, heavy crude is more plentiful than conventional oil by about a factor of four. Further considering the amount of heavy residual oils that result from the processing of conventional crudes, the amount of heavy oils that exists worldwide is very great indeed.
TABLE I
______________________________________
WORLD HEAVY OIL DEPOSITS
(Billions of Barrels)
Resource
Estimated
Country In-Place Recoverable
______________________________________
Venezuela 3000 500
Canada 2950 213
United States 77 30
Italy 12 1
Madagascar 25 1
Iran 29 3
Iraq 10 1
______________________________________
It is clear that reserves of conventional light crudes are being depleted much faster than heavy crudes and that development of world reserves of viscous hydrocarbons will eventually become necessary to support world petroleum demands. Significant production of heavy crudes has begun, primarily by steam-assisted enhanced recovery methods. For example, recent estimates place production of heavy crude oil in California at 250,000 barrels per day. Future estimates [Barnea, "The Future of Heavy Crude and Tar Sands," in: The Future of Heavy Crude and Tar Sands, pp. 13-15, Mining Informational Services, McGraw Hill, Inc., New York (1981)] project that by the year 2000, production of heavy oil plus the bitumen from tar sands will increase to one-third of the world's total oil production. Such rapid development of heavy oil resources will extend the petroleum era and should: (1) allow products from heavy crudes to benefit from the existing energy infrastructure; (2) assure fuel supplies to the transportation sector and feed-stock to petrochemical plants; (3) be a stabilizing factor for world petroleum prices, increasing the number of oil producing countries; ( 4) reduce the strategic and political aspects of oil production; and (5) postpone the need for massive investments in coal conversion and other facilities for synthetic oil production.
With regard to residual fuel oil, the recent trend in the United States has been a reduced demand for such materials. Consequently, refiners who can afford to have made sizable capital investments in cokers and other heavy end cracking processes to increase the production of light fractions from each barrel to crude. The result has been a decrease in residual oil production capacity and a decline in fuel quality.
Five years ago 1% sulfur residual fuel oils with API gravities of 17° were common. The typical 1% sulfur residual oil today has an API gravity of 10°, and there has been increased availability of even lower gravity oils, including those with "negative gravity", i.e., API less than zero. Part of the reason for this change in quality has been the mix of crude oil slates being used by the refiners. With the wider application of tertiary recovery techniques, increased amounts of crudes from deeper wells, and the development of heretofore less desirable, i.e., heavier, reserves, the quality of crude oils can be expected to continue to decline. Eventually "sweet" high quality crude oils will probably be much more costly than heavier crudes and may cease to be available in large quantities.
Coupled with lower crude oil quality have been changes in refinery operations, wherein capacity has been added to increase the yield of the more profitable lighter fractions. To this end there has been increasing application of cokers, heavy oil crackers, visbreakers, and other processes. The end result is that there are fewer refiners with the capability of producing large quantities of high-quality residual fuel oil. Supporting this trend is the relative rarity of "straight run" residual fuel oils. With the quality of residual fuel oils on the decline, concerns have been raised regarding the ability to burn these and future residual oils in an environmentally acceptable manner. There is a clear need for developments which will make it possible to burn lower quality materials as cleanly as higher quality materials.
2.2. TRANSPORTATION OF VISCOUS HYDROCARBONS
The problem of transporting viscous hydrocarbons, be it out of a producing well, off a tanker or, especially, through a pipeline, is one of pumpability. Consequently, methods for transporting viscous hydrocarbons such as heavy crude oils have focused on modifying the oil into a pumpable form. Two general approaches have been considered. For waxy crudes, it is desirable to transport the oil above its pour point, i.e., above the temperature at which wax crystals in the oil inhibit its ability to flow. One method directed to this end is the use of pour-point depressants to reduce the pour point and maintain fluidity. Generally, this method is of value only with those oils of sufficiently low viscosities to permit transportation at ambient temperatures.
For highly viscous crudes, the approach taken has been to reduce the viscosity. When the curde is to be transported by pipeline, the viscosity must be sufficiently reduced to flow through conventional lines using conventional pumping equipment. Several methods have been used to reduce the viscosities of heavy crude oils for pipelining purposes. These methods include preparation of oil/solid slurries, mixing water with oil to form reduced viscosity emulsions, heating the oil to lower its viscosity and diluting the oil with low viscosity hydrocarbons such as condensate, gasoline, or naphtha [Sloan et al., "Pipeline Transportation of Heavy Oils," in: The Future of Heavy Crude and Tar Sands, pp. 719-726, Mining Informational services, McGraw-Hill, Inc. New York (1981)].
Reported methods for reducing the viscosities of viscous hydrocarbons by formong oil-in-water emulsions for the purposes of transporting them through pipelines or pumping them from wells have involved the use of chemical additives. Among the chemicals which have been proposed or used are bases such as sodium hydroxide or ammonia [U.S. Pat. Nos. 3,380,531; 3,487,844; and 3,006,354], nonionic surfactants [U.S. Pat. Nos. 3,425,429 and 3,467,195] and combinations of nonionic and anionic surfactants [U.S. Pat. Nos. 4,239,052 and 4,249,554]. Instability of oil-in-water emulsions can present a problem; for instance, oil-in-water emulsions are known to break or invert into unpumpable forms. Increasing the amount of chemicals used to maintain stability can result in prohibitive costs.
It is notable that in a recent review of methods for pipelining heavy crude oils (see Sloan et al.; supra) it was pointed out that there have been limited, if any, commercial applications of the emulsion approach to pipelining. It is also noteworthy that Sloan et al. concluded that the heating and dilution methods for reducing viscosity, despite the fact that they are energy-intensive and relatively costly, remain the major candidates for pipelining transport of heavy crude oils.
2.3. COMBUSTION OF OIL-IN-WATER EMULSIONS
The vast majority of combustible emulsions known in the art are water-in-oil emulsions, primarily consisting of relatively small amounts of water (1-10% by volume) in oil to enhance combustion. Some combustible oil-in-water emulsions have been described [see e.g., U.S. Pat. Nos. 3,958,915; 4,273,611, 4,382,802 and 4,392,865]. Notably, however, the oil phases used have primarily been light, low viscosity fuels and other low viscosity oils, e.g., kerosene, gasoline, gas oil, fuel oils and other oils which are liquid at room temperature. Combustible thixotropic jet fuels and other safety fuels have been described in U.S. Pat. Nos. 3,352,109; 3,490,237 and 4,084,940. Under resting (stationary) conditions, these oil-in-water emulsions are in the form of gels with apparent rest viscosities of 1000 cps and preferably 50,000-100,000 cps. These thixotropic oil-in-water emulsions exhibit low viscosities under high pumping (high shear) rates.
2.4. MICROBIAL SURFACE ACTIVE COMPOUNDS
Many microbes can utilize hydrocarbon as their sole source of carbon for growth and energy production. The hydrocarbon substrates may be linear, branched, cyclic or aromatic. In order to rapidly assimilate such water-insoluble substrates, the microbes require a large contact area between themselves and the oil. This is achieved by emulsifying the oil in the surrounding aqueous medium. Hydrocarbon degrading microbes frequently synthesize and excrete surface active agents which promote such emulsification.
For example, th growth of Mycobacterium rhodochrous NCIB 9905 on n-decane yields a surface active agent which was reported by R. S. Holdom et al. [J. Appl. Bacteriol. 32, 448 (1969)] to be a nonionic detergent. J. Iguichi et al. [Agric. Biol. Chem., 33, 1657(1969)] found that Candida petrophilium produced a surface active agent composed of peptides and fatty acid moieties, while T. Suzuki et al. [Agric. Biol. Chem., 33, 1919 (1969)] found trehalose lipid in the oil phase of culture broths of various strains of Arthrobacter, Brevibacterium, Corynebacterium and Nocardia. Wagner has reported the production of trehalose lipids by Nocardia rhodochrous and Mycobacterium phlei and their use in oil recovery [U.S. Pat. Nos. 4,392,892 and 4,286,660].
Torulopsis gropengiesseri was found to produce a sophorose lipid, while rhamnolipids are reported by K. Hisatsuka et al. [Agric. Biol. Chem., 35, 686 (1971)] to have been produced by Pseudomonas aeruginosa strain S7B1 and by S. Itoh et al. [Agric. Biol. Chem., 36, 2233 (1971)] to have been produced by another P. aeruginosa strain, KY4025. The growth of Corynebacterium hydrocarboclastus on kerosene was reported by J. E. Zajic and his associates [Dev. Ind. Microbiol., 12, 87 (1971); Biotechnol. Bioeng., 14, 331 (1972); Chemosphere 1, 51 (1972); Crit. Rev. Microbiol., 5, 39; U.S. Pat. No. 3,997,398] to produce an extracellular heteropolysaccharide which, among other properties, emulsified kerosene, Bunker C fuel oil and other fuel oils.
Gutnick et al. discovered that Acinetobacter calcoaceticus ATCC 31012 (previously designated Acinetobacter sp. ATCC 31012 and also called RAG-1) produces interfacially active extracellular protein-associated lipopolysaccharide biopolymers called emulsans. These biopolymers are produced and build up as a capsule or outer layer around the bacterial cell during growth and are eventually released or sloughed off into the medium, from which they can be harvested as extracellular products. Acinetobacter calcoaceticus ATCC 31012 produces α-emulsans when grown on ethanol or fatty acid salts [U.S. Pat. Nos. 4,230,801; 4,234,689 and 4,395,354] and β-emulsans when grown on crude oil or hexadecane [U.S. Pat. No. 3,941,692]. The α-emulsans and β-emulsans can be derivatized to an O-deacylated form called psi-emulsans [U.S. Pat. No. 4,380,504]. The α-emulsans, β-emulsans and psi-emulsans can be deproteinized to yield apo-α-emulsans, apo-β-emulsans and apo-psi-emulsans, respectively [U.S. Pat. Nos. 4,311,830; 4,311,829 and 4,311,831, respectively].
Cooper and Zajic [Adv. Appl. Microbiol. 26:229-253 (1980)] have reviewed the production of surface active compounds by microorganisms. Some of the surface active agents described are listed in Table II.
TABLE II
______________________________________
MICROBIAL SURFACE ACTIVE COMPOUNDS
PRODUCING
STRUCTURAL TYPE MICROORGANISM(S)
______________________________________
Carbohydrates-Lipids
Trehalose-Lipids
Norcardia, Mycobacterium,
Corynebacterium, Arthrobacter
Rhamnose-Lipids Pseudomonas aeruginosa
Sophorose-Lipids
Torulopsis spp.
Polysaccharide-Lipid
Candida tropicalis,
Acinetobacter calcoaceticus
Amino Acid-Lipids
Lipopeptides Bacillus, Streptomyces,
Corynebacterium, Mycobacterium
Ornithine-Lipids
Pseudomonas, Thiobacillus,
Agrobacterium, Gluconobacter
Phospholipids Thiobacillus, Corynebacterium,
Candida, Micrococcus
Fatty Acids/Neutral Lipids
Pseudomonas, Mycococcus,
Penicillium, Aspergillus,
Acinetobacter, Micrococcus,
Candida
______________________________________
3. SUMMARY OF THE INVENTION
This invention provides novel compositions and methods for manipulating viscous hydrocarbons, including highly viscous crude and residual oils, generally characterized by API gravities of about 20°API or less, viscosities of about 100 centipoise or greater at 150° F., paraffin contents of about 50% by weight or less, and aromatic contents of about 15% or greater by weight, into an emulsified form which (a) can be stored in facilities or transported by methods presently used to handle less viscous materials and (b) can be burned directly as quality combustible fuels.
In an embodiment preferred for transportation purposes, the emulsified form of the viscous hydrocarbon is a hydrocarbosol defined as a bioemulsifier-stabilized hydrocarbon-in-water emulsion wherein the individual hydrocarbon droplets are essentially covered by water-soluble bioemulsifier molecules predominantly residing at the hydrocarbon/water interface, which bioemulsifier molecules form an effective barrier against droplet coalescence and hence promote the maintenance of discrete hydrocarbon droplets dispersed in a continuous, low-viscosity aqueous phase. The hydrocarbosols of this invention have viscosities reduced by at least a factor of about 10 and preferably at least 102 compared to that of the viscous hydrocarbon starting material, said hydrocarbosol viscosities remaining so reduced under static conditions for periods of at least about 1 day, and preferably at least about 30 days.
Surfactant packages for forming hydrocarbosols are provided which comprises a water-soluble chemical surfactant, or a combination of water-soluble chemical and/or biological co-surfactants, preferably nonionic and anionic surfactants, together with a bioemulsifier which, because of any number of characteristics including, but not limited to, high molecular weight, highly specific three-dimensional structure, hydrophobic and hydrophilic nature, polymeric nature and/or sparing solubility in hydrocarbons, binds tightly to the hydrocarbon/water interface and essentially covers the surface of individual hydrocarbon droplets in hydrocarbon-in-water emulsions, effectively maintaining discrete droplets and preventing coalescence and imparting substantial stability to hydrocarbon-in-water emulsions.
Surfactant packages for forming hydrocarbon-in-water emulsions from extremely recalcitrant heavy crudes and heavy residuals are provided. Certain surfactant packages have been discovered which make it possible to emulsify and utilize as fuels the following residual materials, which have heretofore been very difficult if not impossible to handle in the form of hydrocarbon-in-water emulsions: pitches, including pyrolysis pitches, visbreaker residuals, vacuum residuals, including standard vacuum bottoms, catalytic-cracker residuals, catalytic hydrogenated residuals, coker residuals, heavy oil (HO) cracker residuals, residual oil supercritical extraction (ROSE) residuals, tars, cutback tars and bitumens. Such surfactant packages comprise water-soluble nonionic chemical surfactants with or without the addition of (a) chemical stabilizers, including interfacially active polymeric stabiliziers, and/or (b) rheology control agents, including microbiological polysaccharides.
Methods are provided for transporting viscous hydrocarbons wherein a surfactant package is used in a proportion from about 1:100 to about 1:20,000 based on oil to form a hydrocarbosol containing up to about 90% by volume of hydrocarbon in an aqueous phase variously comprising deionized water, municipal water, brines or alcohol/water mixtures, which hydrocarbosol can be shipped by conventional means or pumped through conventional, non-heated pipelines.
Methods are also provided for utilizing viscous hydrocarbons by forming pre-atomized fuels, i.e., hydrocarbosol fuels or hydrocarbon-in-water emulsion fuels and burning them in conventional combustion facilities. Burning such viscous hydrocarbons in emulsified form results in reduced fuel emissions.
Remarkably, it has been discovered that viscous hydrocarbons with very high asphaltene content, including pyrolysis pitches with asphaltene content greater than 50%, can be emulsified into hydrocarbon-in-water emulsions and burned, resulting in significant reductions in particulate emissions. Indeed, emulsified high asphaltene content materials have been observed to burn approximately six times cleaner than the same materials, unemulsified. Even more remarkably, emulsified high asphaltene content materials can be burned at particulate emission rates that are reduced by as much as 50%-70% compared to particulate emission rates for unemulsified heavy oils with approximately one-tenth to one-twelfth the asphaltene content.
4. NOMENCLATURE
The term "hydrocarbosol" is defined as any bioemulsifier-stabilized hydrocarbon-in-water emulsion wherein the individual hydrocarbon droplets are essentially surrounded or covered by water-soluble bioemulsifier molecules predominantly residing at the hydrocarbon/water interface, which bioemulsifier molecules form an ffective barrier against droplet coalescence and hence promote the maintenance of discrete hydrocarbon droplets suspended or dispersed in the continuous, low-viscosity aqueous phase.
The term "water-soluble" is defined to include water-dispersible substances.
The term "viscous hydrocarbon" is defined as any naturally occurring crude oil or any residual oil remaining after refining operations which is generally characterized by a viscosity of about 102 -106 centipoise or greater and otherwise generally, but not necessarily, characterized by an API gravity of about 20° API or less, high metal content, high sulfur content, high asphaltene content and/or high pour point. The term "viscous hydrocarbon," it is to be understood, also encompasses the following nomenclature: vacuum residuals, visbreaker residuals, catalytic-cracker residuals, catalytic hydrogenated residuals, coker residuals, heavy oil (HO) cracker residuals, ROSE (residual oil supercritical extraction) residuals, tars and cut-back tars, bitumen, pitch, pyrolysis pitches and any other terms describing residuals of hydrocarbon processing.
The term "pre-atomized fuel" is defined as any hydrocarbosol and any hydrocarbon-in-water emulsion made from a viscous hydrocarbon and formed by methods described herein for use as a combustible fuel.
The term "bioemulsifier" is defined as any biologically derived substance which, by virtue of any combination of characteristics including, but not limited to high molecular weight, polymeric nature, highly specific three-dimensional structure, hydrophobic and hydrophilic moieties and sparing solubility in hydrocarbons, binds tightly to the hydrocarbon/water interface and essentially covers the surface of individual hydrocarbon droplets in hydrocarbon-in-water emulsions, effectively maintaining discrete droplets and preventing coalescence, and thereby imparting substantial stability to hydrocarbon-in-water emulsions. An example of a bioemulsifier is α-emulsan.
The term "biosurfactant" is defined as any biologically derived substance which reduces the interfacial tension between water and a hydrocarbon and, as a result, reduces the energy requirement (mixing energy) for creation of additional interfacial area. An example of a biosurfactant is a glycolipid.
The term "surfactant package" is defined as any composition useful for forming hydrocarbon-in-water emulsions of viscous hydrocarbons generally characterized by a paraffin content of about 50% by weight or less and an aromatic content of about 15% by weight or greater with viscosities of about 100 centipoise or greater at 150° F., which composition may comprise a chemical surfactant or a combination of chemical co-surfactants or a combination of co-surfactant(s) and biosurfactant(s) or a combination of chemical surfactant(s) and bioemulsifier(s) or a combination of chemical surfactant(s), biosurfactant(s) and bioemulsifier(s), and which may also include chemical emulsion stabilizers, and which may be in aqueous form to which chemical and/or biological rheology control agents may be added.
The term "emulsans," which reflects the polysaccharide structure of these compounds and the exceptional bioemulsifier activity of these materials, generically identifies those capsular/extracellular microbial protein-associated lipoheteropolysaccharides produced by Acinetobacter calcoaceticus ATCC 31012 and its derivatives or mutants, which may be subdivided into the α-emulsans and the β-emulsans. The name "apoemulsan" generically identifies those deproteinized lipopolysaccharides obtained from the emulsans.
The term "α-emulsans" defines those extracellular microbial protein-associated lipopolysaccharides produced by Acinetobacter calcoaceticus ATCC 31012 and its derivatives or mutants in which the lipopolysaccharide components (i.e., without the associated protein) are completely N-acylated and partially O-acylated heteropolysaccharides made up of major amounts of D-galactosamine and an aminouronic acid, the lipopolysaccharide components containing at least 5 percent by weight of fatty acid esters in which (1) the fatty acids contain from about 10 to about 18 carbon atoms; and (2) about 50 percent by weight or more of such fatty acids are composed of 2-hydroxydodecanoic acid and 3-hydroxydodecanoic acid. It follows, therefore, that the deproteinized α-emulsans are called "apo-α-emulsans."
The term "β-emulsans" defines those extracellular microbial protein-associated lipopolysaccharides produced by Acinetobacter calcoaceticus ATCC 31012 and its mutants in which the lipopolysaccharide components (i.e., without the associated protein) are completely N-acylated and partially O-acylated heteropolysaccharides made up of major amounts of D-galactosamine and an aminouronic acid, the lipopolysaccharide components containing less than 5 percent by weight of fatty acid esters in which (1) the fatty acids contain from about 10 to about 18 carbon atoms; and (2) less than 50 percent by weight of such fatty acids are composed of 2-hydroxydodecanoic acid. The deproteinized β-emulsans are called "apo-β-emulsans."
The term "psi-emulsans" defines the O-deacylated extracellular protein-associated microbial polysaccharides obtained from the emulsans, the protein-free components of such psi-emulsans being completely N-acylated heteropolysaccharides made up of major amounts of D-galactosamine and an aminouronic acid and containing from 0 to 1 percent of fatty acid esters in which, when present, the fatty acids contain from about 10 to about 18 carbon atoms. These protein-free components are called "apo-psi-emulsans," regardless of how they are prepared.
The term "polyanionic heteropolysaccharide biopolymers" defines those biopolymers in which (a) substantially all of the sugar moieties are N-acylated aminosugars, a portion of which is N-acylated-D-galactosamine and another portion of which is N-acylated aminouronic acid, a part of the N-acyl groups of such heteropolysaccharide being N-3-hydroxydodecanoyl groups; and (b) at least 0.2 micromoles per milligram of such heteropolysaccharide consist of fatty acid esters in which (1) the fatty acids contain about 10 to about 18 carbon atoms and (2) about 50 percent by weight or higher of such fatty acids are composed of 2-hydroxydodecanoic acid and 3-hydroxydodecanoic acid.
5. BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a graphical representation of the viscosity versus water content profile of emulsan-stabilized hydrocarbosols formulated with Boscan crude oil, wherein the dashed line (at 30% water) indicates near-optimum operating conditions;
FIG. 2 is a graphical representation of the viscosity versus temperature profiles for a heavy crude oil (Boscan) and two emulsan-stabilized hydrocarbosols formulated with Boscan crude oil;
FIG. 3 is a graphical representation of the viscosity versus time profiles for two emulsions formulated with a Texas fireflood crude oil and a surfactant package comprising a nonionic surfactant and an anionic surfactant, showing the effect on viscosity of the addition of emulsan to the surfactant package;
FIG. 4 is a graphical representation of the viscosity versus time profiles for two emulsions formulated with a Texas fireflood crude oil and a surfactant package comprising a nonionic surfactant, showing the effect on viscosity of the addition of emulsan to the surfactant package;
FIG. 5 is a graphical representation of the viscosity versus time profiles for two emulsions formulated with a Kansas crude oil and tap water using a surfactant package comprising a nonionic surfactant and an anionic surfactant, showing the effect on viscosity of the addition of emulsan to the surfactant package;
FIG. 6 is a graphical representation of the viscosity versus time profiles for two emulsions formulated with a Kansas crude oil and Texas brine using a surfactant package comprising a nonionic surfactant and an anionic surfactant, showing the effect on viscosity of the addition of emulsan to the surfactant package;
FIG. 7 is a graphical representation of the viscosity versus time profiles for four emulsions formulated with a Texas fireflood crude oil and a surfactant package comprising a nonionic surfactant and an anionic surfactant, comparing the effect on viscosity of the addition of an emulsion stabilizer (emulsan, or the commonly used emulsion stabilizers, lignin sulfonate and naphthalene sulfonate) to the surfactant package;
FIG. 8 is a schematic representation of a pilot system used for forming and pumping a hydrocarbosol through a three-inch pipeline;
FIG. 9 is a graphical representation of the changes in solids concentration along the flame axis during combustion of a Number 6 fuel oil and a pre-atomized fuel made from Number 6 fuel oil as a function of distance from the front wall of the furnace;
FIG. 10 is a graphical representation of the variation of axial flame temperatures during combustion of a Number 6 fuel oil and a pre-atomized fuel made from Number 6 fuel oil as a function of distance from the front wall of the furnace;
FIG. 11 is a graphical representation of the flue gas carbon monoxide concentration as a function of excess oxygen level determined during the combustion of emulsified pitch, i.e., pitch-in-water, fired at two fuel preheat temperatures; and
FIG. 12 is a graphical representation of measured opacity as a function of excess oxygen level determined during the combustion of emulsified pitch i.e., pitch-in-water, fired at two fuel preheat temperatures.
6. DETAILED DESCRIPTION OF THE INVENTION
6.1. SURFACTANT PACKAGES
The surfactant packages of this invention can be formulated with a wide variety of chemical and microbial surface active agents and are preferably formulated with water-soluble surface active agents to provide for the formation of oil-in-water, as opposed to water-in-oil, emulsions. The surfactant packages can be formulated with numerous chemical surfactants, used alone or in conjunction with chemical co-surfactants of the same type (e.g., a combination of water-soluble nonionic surfactants) or of different types (e.g., a combination of water-soluble nonionic, anionic, cationic and/or amphoteric surfactants), and can be further formulated in combination with (a) a water-soluble biosurfactant or combination of biosurfactants as co-surfactant(s) and/or (b) a water-soluble bioemulsifier or combination of bioemulsifiers as emulsion stabilizer(s). In certain instances, chemical emulsion stabilizers may also be used in place of bioemulsifiers. It may also be desirable in some instances to add a rheology control agent to the surfactant package-containing aqueous phase. It is also possible to formulate surfactant packages comprising only microbial surface active agents, i.e., combinations of biosurfactants and bioemulsifiers. The surfactant packages of this invention vary with the type of viscous oil to be emulsified. The following general compositions are offered by way of illustration. For viscous crudes, surfactant packages can be formulated to comprise at least one chemical surfactant and at least one bioemulsifier. They can also be formulated to comprise at least one water-soluble nonionic surfactant, at least one water-soluble anionic surfactant, and at least one bioemulsifier. For viscous residuals, surfactant packages can be formulated to comprise at least one water-soluble non-ionic surfactant or at least one anionic surfactant or combinations of non-ionic surfactants and anionic surfactants and which can further comprise biosurfactants, bioemulsifiers and/or chemical emulsion stabilizers.
The types of water-soluble nonionic chemical surfactants suitable for use in the surfactant packages are listed in Table III.
TABLE III
CLASSES AND SUBCLASSES OF NONIONIC CHEMICAL SURFACTANTS
Alcohols, ethoxylated
Alkylphenols, ethoxylated
Carboxylic Esters, ethoxylated
Glycerol Esters
Polyethylene Glycol Esters
Anhydrosorbitol Esters
Ethoxylated Anhydrosorbitol and Sorbitol Esters
Natural Fats and Oils, ethoxylated
Ethylene and Diethylene Glycol Esters
Propanediol Esters
Other Carboxylic Acid Esters
Carboxylic Amides, ethoxylated
Amines, polyoxyalkylated
Polyalkylene Oxide Block Copolymers
Poly(oxyethylene-co-oxypropylene) Block Copolymers Reverse Block Copolymers Polyalkylene Oxide Copolymers
In surfactant packages for viscous crudes, the preferred water-soluble nonionic chemical surfactants are ethoxylated alkyl phenols and ethoxylated alcohols. In surfactant packages for viscous residuals, the preferred water-soluble nonionic surfactants are, again, ethoxylated alkyl phenols and also polyoxyalkylated amines and polyalkylene oxide block copolymers. The ethoxylated alkyl phenols are of the general formula:
R.sub.x C.sub.6 H.sub.4 (OC.sub.2 H.sub.4).sub.n OH
wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms (i.e., about C8 to about C12), x represents the number of alkyl groups and is either 1 or 2, and wherein n represents the number of ethoxy groups (moles ethylene oxide) which can range from about 1 to about 150. [For a list of commercially available ethoxylated alkylphenols, see "Surfactants and Detersive Systems" in: Encyclopedia of Chemical Technology, Kirk-Othmer (Third Edition), Volume 22, pp. 366-367, John Wiley & Sons, New York (1983).] In surfactant packages for viscous crudes, preferred ethoxylated alkyl phenols are those having R groups of 8 or 9 carbon atoms and having from about 7 to about 150 ethoxy groups. An example of a particularly preferred ethoxylated alkyl phenol is monononylphenol with about 40 ethoxy groups. In surfactant packages for viscous residuals preferred ethoxylated alkyl phenols are those having alkyl groups of 8 or 9 carbon atoms and having from about 9 to about 150 ethoxy groups. Examples of particularly preferred ethoxylated alkyl phenols for use with viscous residuals are: monooctylphenol with about 16 ethoxy groups, monononylphenol with about 40 ethoxy groups and dinonylphenol with about 150 ethoxy groups.
The ethoxylated alcohols are of the general formula:
R(OC.sub.2 H.sub.4).sub.n OH
wherein R represents an aliphatic group (linear or branched) containing from about 6 to about 18 carbon atoms and wherein n represents the number of ethoxy groups which can range from about 2 to about 100. [For a list of commercially available ethoxylated alcohols, see "Surfactants and Detersive Systems in: Encyclopedia of Chemical Technology, supra, pp. 364-365.] Examples of ethoxylated alcohols include ethoxylated trimethylnonanols with about 3 to about 9 ethoxy groups and ethoxylated secondary alcohols having R groups of about 11 to about 15 carbon atoms with about 3 to about 30 ethoxy groups, but preferably greater than about 7 ethoxy groups.
The polyoxyalkylated amines are of the general formula:
R.sub.x N.sub.y (CH.sub.2).sub.2
wherein R represents an oxyalkyl group containing either 2 or 3 carbon atoms. These R groups can range in number from about 4 to about 500, and that number is represented by x. The number of amine groups is represented by y and the alkyl group is preferably ethyl (C2 H4). Preferred polyoxyalkylated amines are those having R groups of 2 or 3 carbon atoms and having from about 50 to about 450 oxyalkyl groups. An example of a particularly preferred polyoxyalkylated amine is a polyoxyalkylated diamine with about 50 ethoxy groups and about 60 propoxy groups.
The poly(oxyethylene-co-oxypropylene) block copolymers are of the general formula: ##STR1## where a represents the number of oxyethylene groups and b represents the number of oxypropylene groups. Preferred block copolymers are EOPOEO block copolymers wherein the molecular weight of the starting block is 800-1,000 daltons and ethylene oxide is added on such that the final block copolymer is 80% ethylene oxide and has a final molecular weight around 4,500 daltons.
The types of water-soluble anionic chemical surfactants suitable for use in the surfactant packages of this invention are listed in Table IV.
TABLE IV
Classes And Subclasses Of Anionic Chemical Surfactants
Carboxylic Acids and Salts
Sulfonic Acids and Salts
Lignosulfonates
Alkylbenzenesulfonates
Alkylbenzenesulfonates, polymerized
Alkylarylsulfonates, short chain
Alkylarylsulfonates, polymerized
Naphthalenesulfonates
Alkylnaphthalenesulfonates, polymerized
Naphthalene/formaldehyde condensate polymers
Petroleum Sulfonates
Sulfonates with ester, ether, or amide linkages (dialkyl sulfosuccinates)
Other Sulfonates
Sulfuric Acid Esters and Salts
Alcohols, sulfated
Alcohols, ethoxylated and sulfated
Alkylphenols, ethoxylated and/or sulfated
Acids, Amides, and Esters, sulfated
Natural Fats and Oils, sulfated
Phosphoric and Polyphosphoric Acid Esters (and Salts)
Alcohols and Phenols, alkoxylated and phosphated (and their salts)
Other Phosphoric and Polyphosphoric Acid Esters (and their salts)
Carboxylic Acid Esters
In surfactant packages for both viscous crudes and viscous residuals, the preferred water-soluble anionic chemical surfactants are sulfonated or sulfated forms of nonionic surfactants. In surfactant packages for viscous crudes, ethoxylated alcohol sulfates are preferred. In surfactant packages for viscous residuals, sulfonated or sulfated ethoxylated alkylphenols and ethoxylated alcohol sulfates are preferred. In surfactant packages for both viscous crudes and viscous residuals, alkylaryl sulfonates are also preferred anionic chemical surfactants. The ethoxylated and sulfated alcohols are of the general formula:
R(OC.sub.2 H.sub.4).sub.n OSO.sub.3 M
wherein R represents an aliphatic group containing from about 6 to about 16 carbon atoms, preferably from about 12 to about 14, n represents the number of ethoxy groups which can range from about 1 to about 4, l preferably from about 2 to about 3, and M includes, but is not limited to, ammonium (NH4), sodium (Na), potassium (K), calcium (Ca) or triethanolamine, preferably ammonium. [For a list of commercially available ethoxylated alcohol sulfates, see "Surfactants and Detersive Systems" in: Encyclopedia of Chemical Technology, supra, p. 357.] The alcohol moiety of the ethoxylated alcohol sulfate can be an even or odd number or mixture thereof. In surfactant packages for viscous crudes, an example of a particularly preferred ethoxylated alcohol sulfate is poly(3)ethoxy C12 -C14 linear primary alcohol sulfate, ammonium salt. It is also possible to use nonethoxylated alcohol sulfates, i.e., alcohol sulfates of the formula R(OC2 H4)n OSO3 M as described supra but wherein n=0. In surfactant packages for viscous residuals, an example of a particularly preferred nonethoxylated alcohol sulfate is the sodium salt of a sulfated lauryl alcohol.
The sulfated ethoxylated alkylphenols are of the general formula:
RC.sub.6 H.sub.4 (OC.sub.2 H.sub.4).sub.n OSO.sub.3 M
wherein R represents an aliphatic group containing at least about 8 or 9 carbon atoms, n represents the number of ethoxy groups which can range from about 1 to about 100, preferably from about 4 to about 9 and M includes, but is not limited to, ammonium (NH4 +), sodium (Na+), potassium (K+) and calcium (Ca++) or triethanoloamine (TEA), preferably ammonium.
An example of a particularly preferred sulfated ethoxylated alkylphenol is the ammonium salt of a sulfated nonylphenol ethoxylate containing, but not limited to, about 4 ethoxy groups.
The alkylaryl sulfonates are of the general formula:
R.sub.n Ar.sub.m (SO.sub.3).sub.x M
wherein Ar is an aromatic group which is benzyl, naphthyl, phenyl, tolyl, xylyl or ethylphenyl, R is a linear or branched chain alkyl group containing from about 2 to about 16 carbon atoms, n is 1 or 2, m is 1 or greater, x is at least about 1, and M includes, but is not limited to, ammonium, sodium, potassium, calcium or triethanolamine. [For a list of commercially available alkylaryl sulfonates see "Surfactants and Detersive Systems" in: Encyclopedia of Chemical Technology, supra, p. 358.] An example of an alkylaryl sulfonate is a modified amine dodecylbenzene sulfonate. In surfactant packages for viscous residuals, an example of a particularly preferred alkylaryl sulfonate is the sodium salt of polymerized alkylnaphthalene sulfonate.
The preferred water-soluble microbial surface active agents for use in the surfactant packages of this invention are any microbial or other biologically-derived substances which function as bioemulsifiers, i.e., substances which, by virtue of such characteristics as large molecular weight, polymeric nature, highly specific three-dimensional structure, hydrophobic and hydrophilic nature, and sparing solubility in oil, effectively cover the oil/water interface maintaining discrete, individual oil droplets in oil-in-water emulsions thereby substantially stabilizing emulsions from coalescence. Among the preferred bioemulsifiers are heteropolysaccharide biopolymers produced by bacteria of the genus Acinetobacter and the genus Arthrobacter, and in particular, those produced by strains of Acinetobacter calcoaceticus. Such Acinetobacter heteropolysaccharide biopolymers include, but are not limited to, polyanionic heteropolysaccharide biopolymers, α-emulsans, β-emulsans, psi-emulsans, apo-α-emulsans, apo-β-emulsans and apo-psi-emulsans produced by Acinetobacter calcoaceticus ATCC 31012 (deposited at the American Type Culture Collection in Rockville, MD) defined in Section 4 and described in U.S. Pat. Nos. 4,395,353; 4,395,354; 3,941,692; 4,380,504; 4,311,830; 4,311,829; and 4,311,831, respectively (hereby incorporated by reference). Other Acinetobacter calcoaceticus materials that can be used are the products of strains NS-1 (NRRL B-15847), NS-4 (NRRL 8-15848), NS-5 (NRRL B-15849), NS-6 (NRRL B-15860) and NS-7 (NRRL B-15850 ). The foregoing "NS" strains have been deposited at the Northern Regional Research Center in Peoria, IL and have been assigned the foregoing NRRL accession numbers. The "NS" strains of Acinetobacter calcoaceticus are described by Sar and Rosenberg, Current Microbiol. 9(6):309-314 (1983), hereby incorporated by reference. Other Acinetobacter heteropolysaccharide biopolymers are those produced by Acinetobacter calcoaceticus BD4 [Taylor and Juni, J. Bacteriol. 81: 688-693 (1961), hereby incorporated by reference]. Particularly preferred Acinetobacter heteropolysaccharide biopolymers are the α-emulsans, the production of which is further described in U.S. Pat. Nos. 4,230,801 and 4,234,689 (hereby incorporated by reference). The α-emulsans are characterized by a Specific Emulsification Activity of about 200 units per milligram or higher, where one unit per milligram of Specific Emulsification Activity is defined as that amount of emulsifying activity per milligram of bioemulsifier which yields 100 Klett absorption units using a standard hydrocarbon mixture consisting of 0.1 ml of 1:1 (v/v) hexadecane/2-methylnaphthalene and 7.5 ml of Tris-Magnesium buffer.
The foregoing Acinetobacter bioemulsifiers can be used in the surfactant packages of this invention in a variety of forms including, but not limited to, post-fermentation whole broth; cell-free (Millipore-filtered, e.g.) or partially cell-free supernatants of post-fermentation culture broth; the cells themselves; protease-treated, liquid or dried materials; and protease-treated, ultrafiltered, liquid or dried materials.
Numerous other microbial organisms may possibly serve as a source of biological surface active agents, including biosurfactants and bioemulsifiers, for use in the surfactant packages of this invention. Some of these microorganisms and the types of compounds they produce are listed in Table V, though the list is not exhaustive. The surfactant packages of this invention may also be formulated with water-soluble cationic chemical surfactants, including, but not limited to, oxygen-free amines, oxygen-containing amines, amide-linked amines and quaternary ammonium salts. Use of cationic chemical surfactants in conjunction with microbial surface active agents would require that the charge characteristic of the biological compounds be considered. For example, cationic chemical surfactants would probably best be used in conjunction with neutral microbial surface active agents and would probably best not be used in conjunction with the preferred polyanionic heteropolysaccharide bioemulsifiers.
TABLE V
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MICROBIAL SURFACE ACTIVE AGENTS
Microbial Compound
Microbial Source
______________________________________
Carbohydrate-containing
surface active agents
Trehalose lipids
Arthrobacter spp.
Arthrobacter paraffineus KY4303
Mycobacterium spp.
Mycobacterium smegmatis
Mycobacterium kansasii
Mycobacterium tuberculosis
Mycobacterium phlei
Mycobacterium rhodochrous
Mycobacterium fortuitum
Nocardia spp.
Nocardia asteroides
Nocardia rhodochrous
Corynebacterium spp.
Corynebacterium diphtheriae
Brevibacterium
Rhamnolipids Arthrobacter paraffineus
Pseudomonas aeruginosa
Sophorose lipids
Torulopsis spp.
Torulopsis magnoliae
Torulopsis gropengiesseri
Diglycosyl Lactobacillus fermenti
diglycerides
Polysaccharide-
Arthrobacter spp.
lipid complexes
Candida tropicalis
Amino acid-containing
surface active agents
Lipopeptides Bacillus subtilis
Bacillus mesentericus
Candida petrophilum
Streptomyces canus
Corynebacterium lepus
Nocardia asteroides
Mycobacterium paratuberculosis
Mycobacterium fortuitum
Ornithine lipids
Pseudomonas rubescens
Thiobacillus thioxidans
Agrobacterium tumefaciens
Gluconobacter cerinus
Protein Pseudomonas aeruginosa
Phospholipids Thiobacillus thiooxidans
Corynebacterium lepus
Corynebacterium alkanolyticum
Candida tropicalis
Micrococcus cerificans
Fatty acids and
Neutral lipids
Carboxylic acids
Corynbacterium lepus
Pseudomonas spp.
Mycococcus spp.
Penicillium spp.
Aspergillus spp.
Acinetobacter spp.
Micrococcus cerificans
Candida cloacae
Neutral lipids and
mixtures of fatty acids
Mycobacterium rhodochrous
Arthrobacter paraffineus
Arthrobacter paraffineus
ATCC 19558
Mycobacterium lacticolum
Acinetobacter spp.
Thiobacillus thiooxidans
Polysaccharides
Heteropolysaccharides
Xanthomonas campestris
Xanthomonas campestris NRRL
B1459
Arthrobacter viscosus
Arthrobacter viscosus NRRL
B1973
Methylomonas spp.
Homopolysaccharides
Lactobacillus spp.
Methylomonas mucosa NRRL B5696
Lipopolysaccharides
Acinetobacter calcoaceticus
Acinetobacter calcoaceticus
ATCC 31012
Pseudomonas fluorescens
Yersinia pseudotuberculosis
Yersinia pestis
S. calcoaceticus
Other Surface
Active Agents
unknown or poorly
Pseudomonas spp.
characterized Pseudomonas aeruginosa
Pseudomonas oleororans
Pseudomonas putida
Pseudomonas desmolyticam
Pseudomonas methanica
Corynebacterium spp.
Corynebacterium spp. ATCC 21235
Corynebacterium hydrocarbo-
clastus UW0409
Bacillus subtilis
Bacillus hexacarbororum
Candida spp.
Candida utilis
Candida utilis ATCC 9226
Candida guilliermondii
Candida rugosa
Candida lypolytica
Aspergillus niger
Aspergillus versicolor
Desulfovibrio hydrocarbono-
clasticus
Desulfovibrio desulfuricans
Endomycopsis lipolytica
Saccharomycopsis lipolytica
Aerobacter aerogenes
Aerobacter aceti
Aerobacter peroxydans
Alcaligines entrophus
Achromobacter spp.
Achromobacter sp. ATCC 21910
Achromobacter agile
Achromobacter tropunctatum
Actinomyces oligocarbophilus
Aureobasidium pullulans
Arthrobacter sp. ATCC 21908
Micrococcus spp.
Micrococcus spp. ATCC 21909
Micrococcus cerificans ATCC
14987
Micrococcus paraffinae
Microbacterium thodochrous
Mycobacterium phlei
Nocardia opacus
Nocardia corrallina
Pencillium spp.
Pichia spartinae
______________________________________
As an alternative to microbial bioemulsifiers, chemical emulsion stabilizers can be used in surfactant packages. For example surface active polymeric stabilizers such as modified lignins, e.g., Kraft process lignins or sulfonated phenolformaldehyde polymers may be included to confer emulsion stability.
Where the density of the hydrocarbon to be emulsified is such that droplets of the hydrocarbon are prone to settling out of emulsions, it may be desirable to add a rheology control agent to the surfactant package-containing aqueous phase to prevent or hinder such settling. Rheology control agents include, but are not limited to, microbial polysaccharides, such as xanthans.
Surfactant packages can be formulated from nonionic chemical surfactants or combinations of nonionic and anionic chemical surfactants (preferably in about a 1:1 ratio by weight) without bioemulsifiers but, for emulsion stabilization, with bioemulsifiers or chemical emulsion stabilizers in the range of about 1% to about 50% by weight. Surfactant packages comprising bioemulsifiers or chemical emulsion stabilizers in the range of about 10% to about 20% by weight and particularly around 10%-15% by weight are preferred. Examples of surfactant packages comprising bioemulsifiers are: (a) about 10% to about 15% α-emulsan by weight in combination with ethoxylated secondary alcohols having carbon chains of about 11 to about 15 carbon atoms in length [e.g., Tergitol 15-S-X (Union Carbide Corp.), where X represents the number of moles of ethylene oxide and is preferably greater than 7]; (b) about 10% to about 15% α-emulsan by weight in combination with about 20% to about 25% by weight of an ethoxylated trimethylnonanol [e.g., Tergitol TMN-6 (Union Carbide Corp.)] and about 60% to about 70% by weight of an ethoxylated alkyl phenol [e.g., Triton X-114 (Rohm & Haas Co.)]; and (c) about 15% α-emulsan by weight in combination with an ethoxylated alkyl phenol having an R group of about 8 or 9 carbon atoms [e.g., Tergitol NP-40 (Union Carbide Corp.)]. A particularly preferred surfactant package for hydrocarbosol formation comprises about 10% to about 20% α-emulsan by weight in combination with a nonionic ethoxylated alkyl phenol [e.g., Tergitol NP-40] and an anionic ethoxylated alcohol sulfate [e.g., Alfonic 1412-A (Conoco, Inc.)], using the nonionic and anionic surfactants in a proportion of about 1:1. The particularly preferred surfactant packages for hydrocarbosol formation are exemplified by the surfactant package comprising about 15% by weight α-emulsan, about 42.5% by weight Tergitol NP-40 and about 42.5% by weight Alfonic 1412-A. Surfactant packages may be formulated full strength or in diluted aqueous solution.
An example of a surfactant package for use with viscous residuals is a combination of anionic surfactants, 85% by weight of an ethoxylated sulfated nonylphenol, and 15% by weight of the sodium salt of a polymerized alkylnaphthalene sulfonic acid with a molecular weight of at least about 500 daltons and preferably at least about 2000 daltons.
An example of a surfactant package preferred for forming hydrocarbon-in-water emulsions out of pitch, and which works very well for emulsifying other viscous residual oils, is one which comprises about 50% by weight of poly(oxyethylene-co-oxypropylene) block copolymer [e.g., Pluronic F38 (BASF Wyandotte Corp.)], about 20% by weight of ethoxylated dialkylphenol [e.g., DNP 150 (Chemac Corp.), a dinonylphenol with 150 ethoxy groups], about 20% by weight of ethoxylated monoalkylphenol [e.g., Tergitol NP-40 (Union Carbide Corp.)] and about 10% by weight of an interfacially active chemical polymeric stabilizer [e.g., preferably a Kraft process-modified lignin, e.g., Indulin AT (Westvaco Corp.) or alternatively, a sulfonated phenolformaldehyde polymer, e.g., Daxad 17 (W. R. Grace & Co.)]. For pyrolysis pitch it is desirable to include a rheology control agent such as xanthan [e.g., Flodrill-S (Pfizer.)]. The rheology control agent is typically added to the aqueous phase, to which a surfactant package has already been added, in an amount less than 1% by weight of aqueous phase, preferably about 0.15%.
6.2. VISCOUS CRUDE OILS AND RESIDUAL OILS
The surfactant package compositions of this invention can be used to emulsify or emulsify and substantially stabilize numerous viscous hydrocarbons in oil-in-water emulsions which may be subsequently transported and/or directly burned. As there is no universally accepted, precise definition of the viscous hydrocarbons suitable for use in this invention, they are best described in terms of their general characteristics. Viscous hydrocarbons encompass naturally-occurring viscous crude oils (also called heavy crude oils) as well as residual bottom-of-the-barrel products from refineries, such as pyrolysis pitch, vacuum resid, other residual fuel oils and asphalt. [See Section 4, Nomencalature, supra.] While low gravity does not necessarily coincide with high density, these characteristics are generally correlated in viscous hydrocarbons.
Generally, the following characteristics are considered typical of the types of crude oils and residual oils, the handling and utilization of which can be facilitated by the compositions and methods of this invention:
1. Low API gravity, generally at or below about 20° API. This is the most frequently used criterion, both because it is easily measured and because 20° API crude roughly corresponds to the lower limit recoverable with conventional production techniques.
2. Viscosities in the range of about 102 to 106 centipoise (cp) or even higher in some cases.
3. High metal contents. For example, heavy crudes often have nickel and vanadium contents as high as 500 ppm.
4. High sulfur content, e.g., 3 weight percent or more.
5. High asphaltene content.
6. High pour point.
It is to be noted, of course, that lighter crudes may also be emulsified and/or stabilized with the surfactant packages of this invention. However, since the transportation and combustion of light oils do not present the same problems as highly viscous crudes and residuals, the compositions and methods of this invention are more particularly directed to the use of heavy materials. Nevertheless, it may be useful to form pre-atomized fuels out of these light oils for emissions reductions purposes. Those viscous hydrocarbons which can be emulsified with the surfactant packages of this invention and which are most useful to emulsify for transportation and/or burning purposes can be generally defined as having a paraffin content of about 50% by weight or less and an aromatic content of about 15% by weight or greater with viscosities of about 100 centipoise or greater at 150° F. The viscous residuals generally are characterized by a paraffin content in the range from about 4% to about 40% by weight, an aromatic content in the range from about 15% to about 70% by weight and an asphaltene content from about 5% to about 80% by weight.
More specifically, the types of crude oils that can be successfully emulsified and stabilized with the surfactant packages of this invention include Boscan (Venezuela) crude, an east Texas crude, Jibaro and Bartra (Peru) crudes, El Jobo (Venezuela) crude, and a Kansas crude. The specific viscous residuals that can be successfully emulsified and stabilized with surfactant packages of this invention include California vacuum resid, Oklahoma vacuum resid, German visbreaker resid, Texas visbreaker resid, catalytic hydrogenated resid, ROSE resid, cutback tar, and pyrolysis pitch.
Furthermore, residual fuel oils such as those classified as ASTM Grade Number 6 Oils can also be emulsified. Number 6 oils, sometimes referred to as "Bunker C" oils, are high-viscosity oils used mostly in commercial and industrial heating. Their utilization normally requires preheating in the storage tank to permit pumping, and additional preheating at the burner to permit atomizing. The extra equipment and maintenance required to handle Number 6 fuels in nonemulsified form usually precludes its use in small installations. The ASTM standard specifications for Number 6 fuel oils are summarized in Table VI ["Standard Specification for Fuel Oils," ASTM Designation D396-80, in: 1981 Book of ASTM Standards, Part 23].
TABLE VI
______________________________________
DETAILED REQUIREMENTS FOR
NUMBER 6 FUEL OILS
Grade of Fuel Oil
(No. 6, Preheating
Required for Burning
and Handling)
Minimum
Maximum
______________________________________
Flash Point, 60
°C. (°F.)
(140)
Water and Sediment,
2.00.sup.2
Vol %
Saybolt Viscosity, s.sup.1
Universal at (>900) (9000)
38° C. (100° F.)
Furol at 50° C.
(>45) (300)
(122° F.)
Kinematic Viscosity, cSt.sup.1
>92 638
At 50° C. (122° F.)
______________________________________
.sup.1 Viscosity values in parentheses are for information only and not
necessarily limiting.
.sup.2 The amount of water by distillation plus the sediment by extractio
shall not exceed 2.00%. The amount of sediment by extraction shall not
exceed 0.50%. A deduction in quantity shall be made for all water and
sediment in excess of 1.0%.
6.3. EMULSION FORMATION
The surfactant packages of Section 6.1 can be used to form oil-in-water emulsions containing as much as about 90% by volume of the viscous hydrocarbons described in Section 6.2. The aqueous phase into which the hydrocarbon is emulsified can be deionized water, water from a municipal source, or any water, even water with relatively large amounts of dissolved solids such as connate waters or brines, normally located in proximity to oil production, transportation or utilization sites. The aqueous phase can also be an alcohol/water mixture such as methanol/water, ethanol/water or other lower alkanol/water mixtures, and may further contain additives such as anti-corrosion agents, anti-pollution agents or combustion improvers. Oil-in-water emulsions preferably contain oil/water ratios of about 60/40 to about 80/20, and more preferably from about 65/35 to about 75/25.
In forming oil-in-water emulsions, it is economically desirable to use as little of the surfactant package as possible while maintaining acceptable emulsion characteristics to suit the particular transportation or utilization requirements. The surfactant packages of Section 6.1 can be used in proportions of surfactant package:hydrocarbon from about 1:35 to about 1:20,000 by weight. The proportion used can depend on the type of hydrocarbon to be emulsified and/or the purpose for emulsifying it.
Oil-in-water emulsion formation can be brought about by any number of suitable procedures. For example, the aqueous phase containing an effective amount of surfactant package can be contacted with the hydrocarbon phase by metered injection just prior to a suitable mixing device. Metering is preferably maintained such that the desired hydrocarbon/water ratio remains relatively constant. Mixing devices such as pump assemblies, in-line static mixers or colloid mills can be used to provide sufficient agitation to cause emulsification. As a more specific example, for the transportation or utilization of residual oils, it may be possible to emulsify the hot residual oil in about 30% aqueous phase (v/v) with one of the surfactant packages of Section 6.1 as it exits the vacuum still of a refinery.
6.3.1. FORMATION OF PRE-ATOMIZED FUELS AT HIGH TEMPERATURES
Some low gravity residual hydrocarbons are extremely viscous and require very high temperatures to make them fluid enough to handle. Such hydrocarbons can be characterized by a viscosity greater than about 1000 cp at 212° F. Maintaining such high temperatures is not economically feasible for the long term storage and transportation of these hydrocarbons. Also, it is not economically feasible to blend these viscous hydrocarbons with much lighter oils (cutter stock) due to either the quantity of lighter oil required to achieve a viscosity which can be handled or the unfavorable characteristics of the viscous hydrocarbon which do not allow for homogeneous blending of lighter oils.
This invention offers a novel approach to handling extremely viscous hydrocarbons by the stable dispersion of such viscous hydrocarbons into water to form pre-atomized fuels. Pre-atomized fuel formation is achieved by heating the viscous hydrocarbon to a high temperature in order to make it fluid. The hot hydrocarbon phase is brought in contact with the aqueous phase containing appropriate surfactants and/or stabilizers as described in Section 6.1. A key to achieving successful pre-atomized fuel formation is the maintenance of pressure throughout the entire process such that the aqueous phase is not allowed to vaporize. By maintaining the appropriate pressure, i.e., the pressure required to prevent the water in the aqueous phase from boiling, the aqueous phase remains in a liquid state, thus allowing the stable dispersion of the hydrocarbon phase into a continuous water phase. The resulting hot pre-atomized fuel may be rapidly cooled using an appropriate heat exchange device so that the outlet temperature of the pre-atomized fuel is below the vaporization temperature of the aqueous phase at ambient pressure. Alternatively, the pressure may be reduced and the mixture cooled by flashing a portion of the water contained in the pre-atomized fuel.
6.3.2. FORMATION OF PRE-ATOMIZED FUELS USING A THERMALLY CRACKED HYDROCARBON DISCHARGE
As is generally known in the refining industry, residual hydrocarbons obtained from the discharge of thermal cracking units have presented unusual problems. The extreme conditions required in processing to obtain greater quantities of high gravity hydrocarbons have resulted in resids which are very susceptible to separation into distinct, non-mixable fractions. The reasons for the occurrence of this phenomenon are not fully known; however, it is believed that the destabilization of high molecular weight components such as asphaltenes is a contributing factor. When such hydrocarbons are used to form pre-atomized fuels as described in Section 6.3, the resulting oil-in-water emulsion may separate into three phases after a short period of static storage. These phases consist of a low API gravity hydrocarbon bottom phase, a water/surfactant middle phase, and a high API gravity hydrocarbon upper phase. Without wishing to be bound or restricted by any particular theory, applicants theorize that the separation may be due to the slow cooling of the pre-atomized fuel which allows sufficient time for the occurrence of complex interactions that may be attributed to both "sticky state" and Ostwald ripening phenomena. The tendency toward separation can be decreased by the use of an appropriate heat exchange device or method to rapidly quench the freshly formed pre-atomized fuel to a temperature at least about 100° F. below the softening point of the hydrocarbon. By rapidly quenching the oil-in-water emulsion as it exits the mixing unit, a stable pre-atomized fuel is achieved that does not separate with time. It is further theorized that the rapid cooling of the hot pre-atomized fuel does not allow sufficient time for the complex interactions stated above to occur.
6.3.3. MIXING OF A SLURRY WITH A PRE-ATOMIZED FUEL
An economical way to increase the btu content of a liquid fuel is achieved by incorporating a high softening point hydrocarbonaceous material (such as coal, coke, ROSE residual, etc.) into a lower softening point fuel. This is usually accomplished by grinding a high softening point hydrocarbon to form very small particles (usually approximately 100 μm in size) and then, dispersing the solid particles in the liquid fuel. The dispersion of a solid in a liquid, however, usually results in the production of a fuel with unfavorable characteristics such as increased viscosity.
A novel method of economically utilizing a high softening point hydrocarbonaceous material (such as coal, coke, ROSE residual, etc.) is achieved by incorporating it into a pre-atomized fuel. This is accomplished by first grinding a material of high softening point to form very small particles (generally less than about 30 μm) and then forming a slurry by dispersing the particles in a continuous aqueous phase containing a pre-atomized fuel-compatible surfactant package.
The slurry of dispersed particles is mixed at an appropriate ratio with a pre-atomized fuel formulated from a hydrocarbon other than that used to form the slurry. The mixing of a slurry with a pre-atomized fuel results in a liquid fuel which has a viscosity lower than either the slurry or the pre-atomized fuel prior to mixing. The reasons for the reduced viscosity observed in a slurry/pre-atomized fuel mixture are not fully known; however, without wishing to be bound or restricted by any particular theory, applicants believe that the reduction of particle-to-particle interaction is a contributing factor.
6.3.4. EMULSIFICATION OF HIGHLY VISCOUS HYDROCARBONS TO OBTAIN CLEAN-BURNING PRE-ATOMIZED FUELS
Without wishing to be bound or restricted by any particular theory, applicants theorize that the reduction in particulate emissions achieved by burning the pre-atomized fuels described herein is related to particle or droplet size of the hydrocarbon phase in the hydrocarbon-in-water emulsion: generally speaking, the smaller the particle size, the cleaner the burn. The following parameters have been identified as having the greatest impact on particle size reduction: hydrocarbon viscosity (temperature), surfactant characteristics (interfacial tension, solubility, etc.), surfactant treatment rate (surface area protection), energy input (shear) and water temperature (surfactant mobility). Reducing particle size to at least 50 μm and preferably at least 20 μm or smaller is desirable.
By way of illustration, particle size characteristics of hydrocarbon-in-water emulsions made with pyrolysis pitch (Shell Oil Co.), a by-product produced during the production of ethylene from gas oil by thermal cracking, were studied. Emulsions were formed at a 70:30, hydrocarbon:water ratio. The surfactant package used comprised 47.24% by weight EOPOEO block copolymer [Pluronic F38 (BASF Wyandotte Corp.)], 21.38% by weight dinonylphenol with 150 ethoxy groups [DNP 150 (Chemac Corp.)], 21.38% by weight monononylphenol with 40 ethoxy groups [Tergitol NP-40 (Union Carbide Corp.)] and 10% by weight modified lignin [Indulin AT (Westvaco Corp.)]. The emulsions were formed by feeding hydrocarbon and aqueous phases into a G-10 Charlotte Colloid Mill.
The effect of hydrocarbon viscosity on particle size was studied by varying the inlet temperature of the hydrocarbon phase prior to emulsion formation. The surfactant package was used at a treatment rate of 1/250 (w/w), surfactant to hydrocarbon. Inlet temperature of the water phase was 83°-85° F. The production rate was 2 gpm and the gap setting on the mill was 0.035 inches. Acceptable particle sizes (approximately 50 μm or less) were achieved over a hydrocarbon temperature range of 200° F. (2,310 cp) to 290° F. (100 cp). The smallest particle sizes (approximately 20 μm or less) for the greatest volume fractions occurred within a hydrocarbon temperature range of 230° F. (610 cp) to 250° F. (310 cp).
The effect of surfactant concentration on particle size was studied by varying surfactant package treatment rates. Inlet temperatures of the hydrocarbon and aqueous phases to the colloid mill were 250° F. and 80° F., respectively. The production rate was 2 gpm and the gap setting on the mill was 0.035 inches. Treatment rates as low as 1/450, (w/w) surfactant to hydrocarbon, may be used but the smallest particle sizes (approximately 20 μm or less) for the greatest volume fractions were achieved at treatment rates of 1/125 or higher. Treatment rate has been identified as one of the most critical parameters thus far examined in controlling particle size.
Tests performed to determine the effect of inlet water temperature on particle size indicated that under the particular test conditions, no definite or significant correlations existed. The conditions were as follows: inlet water temperatures of 80° F., 103° F. and 118° F., inlet hydrocarbon temperature of 250° F.; treatment rate of 1/125 (w/w), surfactant to hydrocarbon; production rate of 2 gpm and gap setting of 0.035 inches.
The effect of a rheological additive on particle size was studied by adding a viscosity modifier (xanthan, e.g., Flodrill-S by Pfizer.) at 0.15% to the aqueous phase over a range of surfactant treatment rates varying from 1/125 to 1/265 (w/w), surfactant to hydrocarbon. The inlet hydrocarbon and water temperatures were 250° F. and 80° F., respectively. The production rate was 2 gpm and the gap setting was 0.035 inches. The addition of the viscosity modifier resulted in an overall drop of approximately 30% in particle size at a given concentration of surfactant. It is postulated that by introducing additional viscosity via the aqueous phase, the hydrocarbon/water mixture experiences a greater energy input (i.e., more shear), thus producing a smaller particle size.
6.4. PROPERTIES OF EMULSAN-STABILIZED HYDROCARBOSOLS
The hydrocarbon droplets of hydrocarbon-in-water emulsions generally rise to the surface and "float" on the aqueous phase in a process known as creaming, provided the density of the hydrocarbon phase is less than that of the aqueous phase and the droplets in the dispersed phase are too big to be stabilized by Brownian motion. If the "cream" remains undisturbed for a given period of time, the droplets coalesce, giving rise to two separate phases. The emulsans, particularly α-emulsan, are extremely effective in retarding coalescence and the emulsan-stabilized droplets in the "cream" are easily redispersible in the aqueous phase.
The principle factors controlling emulsion stability are electrostatic (charge) effects and steric effects. The properties of emulsans lend themselves to optimal exploitation of these mechanisms. Their large molecular weight and highly specific three-dimensional structure result in an efficient coverage of the hydrocarbon/water interface. This effectively prevents oil-to-oil contact when collisions occur between adjacent droplets. Simultaneously, the polyanionic nature of emulsans causes the surfaces of emulsion droplets to be negatively charged which creates repulsive forces and significantly decreases the collision frequency between hydrocarbon droplets. In addition, the absence of multimolecular emulsan micelles in the water phase and the lack of emulsan solubility in the hydrocarbon phase provides an efficient migration and attachment of the emulsan molecules to the oil/water interface. The overall chemical requirements for emulsion stabilization thus become very small and directly related to the oil droplet size, i.e., interfacial area desired.
The advantages that emulsans offer over classical emulsion stabilizers may be summarized as follows. In a hydrocarbosol, emulsan predominantly resides at the oil/water interface only; essentially no measurable emulsan is found in the water phase nor in the oil phase. Very small amounts of emulsan are required, even in the presence of excess water. The emulsan-stabilized hydrocarbosol effectively resists inversion to water-in-oil emulsions, even at water:oil ratios of less than about 1:4. This is partly due to emulsans' insolubility in oil and may also be due in part to the specific three-dimensional structure of the emulsan molecule. 6.5. BLENDING OF HYDROCARBONS
In some cases hydrocarbons may be too viscous for conventional processing or have characteristics (i.e., low gravity; excessive paraffinic, aromatic, and/or asphaltic contents; etc.) which make them unfavorable to incorporate into stable pre-atomized fuels. One method to reduce viscosity for processing or alleviate unfavorable characteristics is blending the unfavorable hydrocarbon with one which is favorable resulting in a hydrocarbon having characteristics suitable for pre-atomized fuel formation. In this way an otherwise unusable hydrocarbon can be "adjusted" to a usable form.
6.6. TRANSPORTATION AND UTILIZATION OF HYDROCARBOSOLS
Hydrocarbosols, because they contain bioemulsifiers, have properties which allow them to be transported in tankers, barges and more importantly through conventional pipelines, including standard, non-heated pipeline networks. Among the properties exhibited by hydrocarbosols that are particularly important for pipelining are reduced viscosity, stabilization against coalescence even under considerable rates of shear, compatible formation with high-salinity aqueous phases, and non-corrosive nature. Hydrocarbosols with viscosities below about 500 cp at about 60° F. allow the economical use of centrifugal pumps for transportation of oil at acceptable flow rates and reasonable pressure drops. For pipelining purposes, it is desirable to use the surfactant packages of Section 6.1 at their minimum effective concentrations which frequently are in a proportion within the range of about 1:100 to about 1:5,000. Hydrocarbosols may be stored in non-heated storage tanks where agitation may be optionally supplied to maintain homogeneity.
Once transported to their destination, hydrocarbosols can be demulsified if desired. More importantly, hydrocarbosols like other pre-atomized fuels can be utilized directly, without dewatering, as burnable fuels. They can be used in combustion facilities which presently use Number 6 fuel oils, or so-called Bunker C oils, to fire, inter alia, steam generators, heating systems or blast furnaces. Hydrocarbosols, as is the case with other pre-atomized fuels, may potentially allow for less expensive plant operation by reducing fuel costs, storage costs and material handling costs. Hydrocarbosols and other pre-atomized fuels may have applications as substitutes for Number 2 or higher grade fuels depending on the situation.
Where long storage periods or transportation over long distances prior to utilization is not required, the stability exhibited by hydrocarbosols becomes less critical. If short-distance transportation or on-site utilization is contemplated, it may not be necessary to form bioemulsifier-stabilized emulsions. Further, it is not necessary to form stabilized emulsions in order to facilitate combustion; i.e., emulsion stability is not generally required for good combustion characteristics. Therefore, pre-atomized fuels suitable for burning can be made by emulsifying viscous hydrocarbons with the surfactant packages of Section 6.1 which are formulated with a chemical surfactant alone or a combination of chemical surfactants. For instance, a 70/30, Number 6 fuel oil/water emulsion can be made with a surfactant package comprising a nonionic chemical surfactant and an anionic chemical surfactant in equal proportion by weight and the resulting oil-in-water emulsion (which can also be referred to as a pre-atomized fuel) can be burned directly.
7. EXAMPLES
7.1. PREPARATION OF BIOEMULSIFIERS
7.1.1. PREPARATION OF TECHNICAL GRADEα-EMULSAN
The α-emulsans produced by Acinetobacter calcoaceticus ATCC 31012 during fermentation on ethanol are known bioemulsifiers as described in U.S. Pat. No. 4,395,354, incorporated by reference supra. The α-emulsans used in the experiments described infra were technical grade materials (unless otherwise indicated) which were prepared in either of two ways. Both methods of preparation involved enzyme treatment and drying but differed in the order in which these steps were performed. By one method, centrifuged (approximately 90% cell-free) fermentation broth containing α-emulsans resulting from a fermentation of Acinetobacter calcoaceticus ATCC 31012 in ethanol medium was drum-dried and the resulting material was treated in the following manner prior to use. A 10% by weight suspension of the material, so-called technical grade α-emulsan, was prepared in deionized water and heated to 50°-60° C. while continuously stirring. The pH of the suspension was adjusted to pH 8.5 by adding 50% by weight sodium hydroxide (diluted, if necessary). Protease enzyme (NOVO Industries, 1.5M Alcalase) was added at a level of 1 part protease:500 parts solid α-emulsan. The mixture was allowed to remain at 50°-60° C. while being stirred for about three hours. Reactions were run to completion as judged by the absence of visible precipitable emulsan following centrifugation of the reaction mixture. After completion of the enzyme treatment, the reaction mixtures were raised to approximately 70° C. to denature the protease and stop its activity. The solutions were cooled to room temperature and Cosan PMA-30 (Cosan Corporation), a preservative, was added at a level of 1 part Cosan:500 parts α-emulsan solution.
By another method, enzyme treatment of the α-emulsan was performed prior to drum drying according to the following protocol. Fermentation broth containing α-emulsan resulting from a fermentation of Acinetobacter calcoaceticus ATCC 31012 in ethanol medium was centrifuged to remove approximately 90% of the bacterial cells. To the centrifuged broth, protease enzyme (as previously described) was added in a ratio of 1 gram protease:500 units per milligram of Specific Emulsification Activity (where one unit per milligram of Specific Emulsification Activity is defined as that amount of emulsifying activity per milligram of bioemulsifier which yields 100 Klett absorption units using a standard hydrocarbon mixture consisting of 0.1 ml of 1:1 (v/v) hexadecane/2-methylnaphthalene and 7.5 ml of Tris-Magnesium buffer). The protease reaction was run to completion as described supra. The protease-treated centrifuged broth was then evaporated to a 10% (w/v) slurry of α-emulsan. The slurry was sprayed dried and the resulting material is also referred to as technical grade α-emulsan.
7.1.2. ADDITIONAL PREPARATIONS OF ACINETOBACTER CALCOACETICUS BIOEMULSIFIERS
Fermentations of Acinetobacter calcoaceticus ATCC 31012 were run on ethanol as described in U.S. Pat. No. 4,395,354. The following fractions of the resulting broth were used to formulate surfactant packages: whole broth, supernatants, cells, enzyme-treated whole broth, enzyme-treated supernatants, enzyme-treated cells (where the enzyme treatment was as described for the second method in Section 7.1.1. supra), homogenized cells, boiled cells, and so-called "Millipore emulsan." Millipore emulsan is prepared by Millipore filtering whole broth to remove cells, followed by enzyme treatment (described supra) and ultrafiltration. The foregoing preparations were used in liquid or wet form. The Millipore emulsan samples can be further dialyzed against ammonium bicarbonate and freeze-dried prior to use in surfactant packages.
Whole broth and enzyme-treated whole broth from fermentations of Acinetobacter calcoaceticus ATCC 31012 on soap stock (run under conditions similar to those described in U.S. Pat. No. 4,230,801, incorporated by reference, supra) were also used.
Acinetobacter calcoaceticus NS-1 (NRRL B-15847) was grown in a fermenter on ethanol medium under conditions similar to those described in U.S. Pat. No. 4,395,354. Both whole broth and enzyme-treated whole broth were used to formulate surfactant packages.
Acinetobacter calcoaceticus strains NS-4 (NRRL B-15848), NS-5 (NRRL B-15849), NS-6 (NRRL B-15860) and NS-7 (NRRL B-15850) were grown for 3 days in shake flask cultures in 2% ethanol medium as described in U.S. Pat. No. 4,395,354. Enzyme-treated whole broth samples were prepared from the NS-4, NS-5 and NS-7 cultures. Enzyme-treated supernatant samples were prepared from NS-4, NS-5, NS-6 and NS-7 cultures. These preparations were also used to formulate surfactant packages.
7.2 VISCOUS HYDROCARBON CHARACTERISTICS
7.2.1 BOSCAN CRUDE OIL
The Boscan crude oil used in the experiments described infra was a heavy crude produced from the oil fields of western Venezuela. The characteristics of the crude, its specific gravity, API gravity (°API), paraffin content (% by weight), aromatic content (% by weight), asphaltene content (% by weight) and viscosity (in centipoise) versus temperature (degrees Fahrenheit) profile, were determined experimentally and are summarized in Table VII. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE VII
______________________________________
BOSCAN CRUDE OIL CHARACTERISTICS
______________________________________
Specific Gravity = 0.983
API Gravity (calculated)
= 12.5° API
Paraffin content = 18.0% (w/w)
Aromatic content = 60.0% (w/w)
Asphaltene content
= 22.0% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
4,500 140
24,000 100
192,000 60
______________________________________
7.2.2. TEXAS FIREFLOOD CRUDE OIL
The Texas crude oil used in the experiments described infra was produced from an oil field in east Texas (Quitman, TX) by the fireflood method. The characteristics of the crude, its specific gravity at 26° C. [ASTM D1217-81], API gravity, paraffin content, aromatic content and viscosity versus temperature profile, were determined experimentally as described in Section 7.2.12, infra, and are summarized in Table VIII.
TABLE VIII
______________________________________
TEXAS FIREFLOOD CRUDE OIL CHARACTERISTICS
______________________________________
Specific Gravity = 0.981
API Gravity (calculated)
= 12.7° API
Paraffin content = 26.1% (w/w)
Aromatic content = 51.1% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
1,748 160
4,085 140
8,752 120
27,615 100
82,000 80
______________________________________
7.2.3 NUMBER 6 RESIDUAL TEST FUEL OIL
The Number 6 residual fuel oil used in the experiment described in Section 7.5 was obtained from the MIT Energy Laboratory (Cambridge, Mass.) The characteristics of this residual fuel oil, its specific gravity, API gravity, paraffin content, aromatic content, asphaltene content and viscosity versus temperature profile were determined experimentally and are summarized in Table IX. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE IX
______________________________________
RESIDUAL NO. 6 TEST FUEL OIL CHARACTERISTICS
______________________________________
Specific Gravity = 0.977
API Gravity (calculated)
= 13.3° API
Paraffin content = 23% (w/w)
Aromatic content = 38% (w/w)
Asphaltene content
= 39% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
1,200 100
5,000 70
20,000 40
______________________________________
7.2.4. UNION CUTBACK TAR
The Union cutback tar used in the experiments described infra was a California resid which had been mixed with cutter stock to facilitate handling. The characteristics of this tar, its specific gravity, API gravity, paraffin content, aromatic content, asphaltene content, ash content and viscosity versus temperature profile were determined experimentally and are summarized in Table X. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE X
______________________________________
UNION CUTBACK TAR CHARACTERISTICS
______________________________________
Specific Gravity = 0.98
API Gravity (calculated)
= 12.9° API
Paraffin content = 22% (w/w)
Aromatic content = 54% (w/w)
Asphaltene content
= 24% (w/w)
Ash content = 7% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
1,796 210
4,490 190
12,347 170
123,479 130
______________________________________
7.2.5. CALIFORNIA VACUUM RESID
The California Vacuum Resid used in the experiments described infra was a vacuum bottom obtained from a Kern County crude oil and provided by a California refinery. The characteristics of this residual oil, its specific gravity, API gravity, paraffin content, aromatic content, asphaltene content, and viscosity versus temperature profile were determined experimentally and are summarized in Table XI. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE XI
______________________________________
CALIFORNIA VACUUM RESID CHARACTERISTICS
______________________________________
Specific Gravity = .9934
API Gravity (calculated)
= 10.9° API
Paraffin content = 17% (w/w)
Aromatic content = 72% (w/w)
Asphaltene content
= 11% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
4,490 220
27,838 180
206,540 140
______________________________________
7.2.6. OKLAHOMA VACCUM RESID
The Oklahoma vacuum resid used in the experiments described infra was a vacuum bottom obtained from a mid continent refinery. The characteristics of this residual oil, its specifics gravity, API gravity, paraffin content, aromatic content, asphaltene content, and viscosity versus temperature profile were determined experimentally and are summarized in Table XII. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE XII
______________________________________
OKLAHOMA VACUUM RESID CHARACTERISTICS
______________________________________
Specific Gravity = .9364
API Gravity (calculated)
= 19.6° API
Paraffin content = 20% (w/w)
Aromatic content = 70% (w/w)
Asphaltene content
= 10% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
3,098 220
14,143 180
98,780 140
251,440 120
______________________________________
7.2.7. CATALYTIC HYDROGENATED RESID (H-OIL)
The H-oil used in the experiments described infra was obtained by a process in which residual oil is catalytically hydrogenated. This resid was from a refinery in Louisiana. The characteristics of this residual oil, its specific gravity, API gravity, paraffin content, aromatic content, asphaltene content, and viscosity versus temperature profile were determined experimentally and are summarized in Table XIII. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE XIII
______________________________________
H--OIL CHARACTERISTICS
______________________________________
Specific Gravity = 1.0196
API Gravity (calculated)
= 7.3° API
Paraffin content = 22% (w/w)
Aromatic content = 57% (w/w)
Asphaltene content
= 21% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
2,424 200
19,936 160
244,705 120
______________________________________
7.2.8. ROSE RESID
The ROSE resid used in the experiments described infra was obtained by the ROSE (Residuum Oil Supercritical Extraction) process which extracts remaining light fractions from vacuum bottoms. The characteristics of this residual oil, its specific gravity, API gravity, paraffin content, aromatic content, asphaltene content, and viscosity versus temperature profile were determined experimentally and are summarized in Table XIV. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE XIV
______________________________________
ROSE RESID CHARACTERISTICS
______________________________________
Specific Gravity = 1.17
API Gravity (calculated)
= -10.6° API
Paraffin content = 4% (w/w)
Aromatic content = 18% (w/w)
Asphaltene content = 78% (w/w)
______________________________________
7.2.9. GERMAN VISBREAKER RESID
The German visbreaker used in the experiments described infra was obtained by thermal cracking of vacuum bottoms. The visbreaker resid was from a refinery located in the Federal Republic of Germany. The characteristics of this residual oil, its specific gravity, API gravity, paraffin content, aromatic content, asphaltene content, and viscosity versus temperature profile were determined experimentally and are summarized in Table XV. The paraffin, aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE XV
______________________________________
GERMAN VISBREAKER RESID CHARACTERISTICS
______________________________________
Specific Gravity = .9553
API Gravity (calculated)
= 16.6° API
Paraffin content = 17% (w/w)
Aromatic content = 61% (w/w)
Asphaltene content
= 22% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
2,470 200
16,389 160
174,032 120
______________________________________
7.2.10. TEXAS VISBREAKER RESID
The Texas visbreaker used in the experiments, described infra was obtained by thermal cracking of vacuum bottoms. The visbreaker resid was from a refinery location in Texas. The characteristics of this residual oil, its specific gravity, API gravity, paraffin content, aromatic content, asphaltene content, and viscosity versus temperature profile were determined experimentally and are summarized in Table XVI. The paraffin aromatic and asphaltene content were determined by the methods described in Section 7.2.13, infra.
TABLE XVI
______________________________________
TEXAS VISBREAKER RESID CHARACTERISTICS
______________________________________
Specific Gravity = 0.989
API Gravity (calculated)
= 11.6° API
Paraffin content = 28% (w/w)
Aromatic content = 48% (w/w)
Asphaltene content
= 24% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
449 200
898 160
4,624 120
61,782 80
______________________________________
7.2.11. PYROLYSIS PITCH
The pyrolysis pitch used in the particulate emissions reduction test described in Section 7.6 infra was obtained from an ethylene reformer in which gas oil is thermally cracked to produce ethylene. The pyrolysis pitch was provided by Shell Oil Co. The characteristics of this residual material, its specific gravity, pour point, softening point, paraffin content, aromatic content, asphaltene content, and viscosity versus temperature were determined experimentally and are summarized in Table XVII. A comparison of the properties of the neat and emulsified pitch is presented in Table XVIII.
TABLE XVII
______________________________________
PYROLYSIS PITCH CHARACTERISTICS
______________________________________
Specific Gravity = 1.15
Pour point = 130° F.
Softening point = 115° F.
Paraffin content = 2% (w/w)
Aromatic content = 40% (w/w)
Asphaltene content
= 58% (w/w)
______________________________________
Viscosity (cp) Temperature (°F.)
______________________________________
75 300
510 230
3,100 195
______________________________________
TABLE XVIII
______________________________________
TYPICAL PROPERTIES OF NEAT AND EMULSIFIED
PYROLYSIS PITCH
Neat Emulsified
Ultimate Analysis
Pyrolysis Pitch
Pyrolysis Pitch
______________________________________
Moisture, % -- 31.0
Ash, % 0.02 0.015
Carbon, % 92.2 63.6
Hydrogen, % 6.8 4.7
Nitrogen, % 0.22 0.15
Sulfur, % 0.52 0.36
Oxygen, % 0.29 0.20
Calorific Value
Btu/lb, Material injected
17,900 12,351
Btu/lb, Hydrocarbon
17,900 17,900
______________________________________
7.2.12. METHODS FOR DETERMINING HYDROCARBON CHARACTERISTICS
Viscosity versus temperature profiles were obtained by heating the oils to the given temperature of Tables VII-XIII and XV-XVI and measuring viscosities in a Rheomat 30 rheometer (Contraves AG), at an approximate shear rate of 30 sec.-1.
The paraffin content and aromatic content of some of the oils of the foregoing examples were determined by a method in which the oil is separated into fractions based on hydrocarbon solubilities in n-heptane and methylene chloride. The paraffin fraction is defined as that hydrocarbon fraction which is soluble in n-heptane. The aromatic fraction is defined as that hydrocarbon fraction which is soluble in methylene chloride.
The materials used are as follows: an analytical balance, accurate to 0.1 milligram (mg), a 500 millimeter (mm) burette-type chromatography column, tared collection flasks, reagent grade methylene chloride, n-heptane (99 mole percent) and alumina adsorbent. The alumina was activated by heating it in an oven set at 310° C. for 12-14 hours. The alumina was cooled in a dessicator and stored in a tightly capped bottle prior to use. Chromatograph columns packed 3/4 full were used.
The separation was carried out by quantitatively weighing 500 to 1000 mg (±0.1 mg) of sample oil. Viscous oils were weighed into sample pouches made of tissue paper which were subsequently placed into the column. (Non-viscous oils are usually weighed directly into the columns.) After introduction of the sample oil into the columns, 200 to 250 ml of n-heptane were allowed to flow through the column. It was preferable for the solvent to be added in a manner which did not excessively disturb the alumina packing. The eluent was collected in a tared evaporating flask. After all the n-heptane had flowed through the column, the first evaporating flask was replaced with another tared flask.
Methylene chloride was then introduced into the column and allowed to flow through it.
The collected eluents were removed from each flask by vacuum evaporation following appropriate safety precautions. The dry flasks were reweighed and the percentage of paraffins and aromatics were calculated based on the original weight of the oil sample. All samples were run in duplicate.
Specific gravity was determined by weighing a measured volume of sample oil and calculating the ratio of the mass of the oil to the mass of an equal volume of water. API gravities were then calculated from the specific gravity by the general formula: ##EQU1##
7.2.13. METHODS FOR DETERMINING HYDROCARBON CHARACTERISTICS, INCLUDING ASPHALTENE CONTENT
The methods used to characterize the hydrocarbons of Examples 7.2.1, 7.2.3 through 7.2.10 are essentially the same as those in Section 7.2.12. However, a new procedure was utilized for determining the asphaltic in addition to the paraffinic and aromatic contents of viscous hydrocarbons. It is described below.
The paraffin, asphaltene and aromatic contents of the sample hydrocarbons were obtained by a method in which the hydrocarbons are dispersed in n-heptane, the asphaltenes removed by filtration and the remaining components separated based on their solubilities in n-heptane and methylene chloride. The asphaltene fraction (the precipitate) is filtered from a dispersion of the hydrocarbon in n-heptane. The paraffin fraction is that portion soluble in n-heptane. The aromatic fraction is that portion soluble in methylene chloride.
The materials used are as folows: an analytical balance, accurate to 0.1 milligram (mg), a blender (Osterizer Galaxy 14) and blades fitted to a 500 ml Mason jar, preweighed Whatman #1 paper, filter funnel, rotary evaporation apparatus, a 500 millimeter (mm) burette-type chromatography column, tared collection flasks, reagent grade methylene chloride, n-heptane (99 mole percent) and alumina adsorbent. The alumina was activated by heating it in an oven at 310° C. for 12-14 hours. The alumina was cooled in a dessicator and stored in a tightly capped bottle prior to use. Chromatography columns packed 3/4 full were used.
Hydrocarbon samples of 1-2 g were quantitatively added to Mason jars containing 100 ml of n-heptane. After blending for 1-2 minutes at maximum speed, the jar and its contents were washed with an additional 100 ml of n-heptane. The dispersed sample was filtered through Whatman #1 paper and the filtrate collected into Erlenmeyer flasks. After introduction of the filtrate to the column, the effluent was collected into a tared evaporation flask. When n-heptane was completely eluted, 200 ml of methylene chloride was added to the column and the eluted material collected into another tared evaporation flask until the column ran dry.
The eluting solvents were removed using a rotating vacuum evaporator at temperatures appropriate to the solvents.
The tarred filter paper and flasks were reweighed and the percentage of asphaltenes, paraffins, and aromatics were calculated based on the original weight of the sample. Individual samples were run in duplicate. All percentages appearing in the foregoing tables for paraffinic, aromatic and asphaltene content have been adjusted to 100% recovery for comparative purposes.
7.3. VISCOSITY REDUCTION EXPERIMENTS
7.3.1. SURFACTANT PACKAGES AND EMULSIFICATION OF HYDROCARBONS
The compositions of five surfactant packages which have been used successfully to emulsify Boscan crude oil are presented in Table XIX. The α-emulsan used was a technical grade α-emulsan prepared according to the first method described in Section 7.1.1. The chemical surfactants, Tergitol 15-S-X (where X indicates the number of moles of ethylene oxide), Tergitol TMN-6, Tergitol NP-40 (Union Carbide Corp.), Triton X-114 (Rohm & Haas Co.) and Alfonic 1412-A (Conoco) are commercially available. Emulsions were formed in an Osterizer Galaxy 14 blender at low speed in a manner preventing the beating of air into the emulsion. The ratio of Boscan crude to deionized water was 70:30 by volume (v/v). The surfactant packages were used successfully over a range of 1:250-1:2,000 [surfactant package:oil, by weight (w/w)]. The surfactant package comprising 15% α-emulsan, 42.5% Tergitol NP-40 and 42.5% Alfonic 1412-A was considered a preferred surfactant package for use with Boscan crude oil. Emulsions (70/30, Boscan crude/deionized water) formed with this surfactant package at 1 part per 2,000 parts oil have been observed to be stable and maintain reduced viscosities for a period of at least three weeks. In addition, this surfactant package has been used to form 70/30 Boscan crude/water emulsions at as low a treatment rate as 1 part per 20,000 parts oil.
TABLE XIX
______________________________________
SURFACTANT PACKAGES FOR EMULSIFYING
BOSCAN CRUDE
% of Component (w/w)
Package # in Surfactant Package
Component 1 2 3 4 5
______________________________________
α-Emulsan
10 13 -- 15 15
Tergitol 15-S-X
90 -- -- -- --
Tergitol TMN-6
-- 22 -- -- --
Tergitol NP-40
-- -- 100 85 42.5
Triton X-114 -- 65 -- -- --
Alfonic 1412-A
-- -- -- -- 42.5
______________________________________
Other surfactants which successfully [alone or in combination] emulsified general type viscous oils included Alfonic 1012-60 (Conoco, Inc.), an ethoxylated linear alcohol with chain lengths of 10 to 12 carbon atoms (C10 -C12) and 60% ethoxylation; Protowet 4196 (Proctor Chemical Co.), a sodium salt of a sulfosuccinate of a nonyl phenol ethoxylate; Protowet 4337 (Proctor Chemical Co.), sodium dicyclohexyl sulfosuccinate; Tween 80 (ICI Americas, Inc.), polyoxyethylene (20) sorbitan monooleate; Pluronic F88 (BASF Wyandotte Corp.), a block copolymer of propylene oxide and ethylene oxide; Petronate L (Witco Chemical Corp.) a sodium petroleum sulfonate; and Conoco AXS (Conoco, Inc.), ammonium xylene sulfonate.
The compositions of several surfactant packages which have been successfully used to emulsify Oklahoma vacuum resid are listed in Table XX. The α-emulsan used was prepared from a whole broth of emulsan according to the methods described in Section 7.1.2. The surfactants, Tetronic 707 (BASF Wyandotte Corp.), Alipal EP-110, CO-436 (GAF Corp.), Daxad 17 (W. R. Grace & Co.) Nopcosant (Diamond Shamrock), Triton X series and Tamol 850 (Rohm & Haas Co.), Tergitol NP series (Union Carbide Corp.) and Conco Sulfate 219 (Continental Chemical Co.) are commercially available. Emulsions were formed in an Osterizer Galaxy 14 blender at medium speed in a manner preventing the beating of air into the emulsion. The ratio of the Oklahoma vacuum resid to tap water was 70:30 by weight (w/w). The surfactant packages were used successfully over a range of 1:10 to 1:250 (surfactant package:oil) by weight (w/w). The surfactant package comprising 15% Daxad 17 and 85% Alipal CO-436 was considered a preferred surfactant package for use with Oklahoma vacuum resid. The emulsion produced with this package has been observed to be stable and maintain a reduced viscosity for at least 5 weeks. This formulation has been used to form a 70/30 resid/water emulsion at a treatment as low as 1 part to 750 parts of oil.
TABLE XX
__________________________________________________________________________
SURFACTANT PACKAGES FOR PRE-ATOMIZED FUELS
Component
% of component in package (w/w)
__________________________________________________________________________
Package #
1 2 3 4 5 6 7 8 9 10 11 12
13
__________________________________________________________________________
α-Emulsan:
whole broth
15
15
15
15
15
15
-- -- -- -- -- --
--
technical
--
--
--
--
--
--
-- -- -- -- -- --
--
Tetronic 707
85
--
--
--
--
--
-- -- -- -- -- --
--
Alipal EP-110
--
85
--
--
--
--
100
-- -- -- -- --
--
Alipal CO-436
--
--
85
--
--
--
-- 100
-- -- -- --
--
Tamol 850
--
--
--
--
--
--
-- -- -- -- -- --
--
Daxad 17 --
--
--
--
--
--
-- -- 100
-- -- --
--
Nopcosant
--
--
--
--
--
--
-- -- -- 100
-- --
--
Triton X-114
--
--
--
--
--
--
-- -- -- -- -- --
--
Triton X-165
--
--
--
85
--
51
-- -- -- -- 100
--
--
Triton X-405
--
--
--
--
--
--
-- -- -- -- -- --
--
Triton X-705
--
--
--
--
--
--
-- -- -- -- -- --
--
Tergitol NP-6
--
--
--
--
28
11
-- -- -- -- -- --
--
Tergitol NP-8
--
--
--
--
--
--
-- -- -- -- -- --
--
Tergitol NP-40
--
--
--
--
57
23
-- -- -- -- -- --
100
Tergitol NP-70
--
--
--
--
--
--
-- -- -- -- -- --
--
Orzan A --
--
--
--
--
--
-- -- -- -- -- --
--
Lignosol BD
--
--
--
--
--
--
-- -- -- -- -- --
--
Conco Sulfate 219
--
--
--
--
--
--
-- -- -- -- -- --
--
__________________________________________________________________________
Package #
14
15 16 17 18 19
20
21
22
23
24
25
26
27
__________________________________________________________________________
α-Emulsan
whole broth
17
15 -- -- 16.7
--
--
--
--
--
--
15
15
--
technical
--
-- 14.2
14.2
-- --
--
--
--
--
--
--
--
--
Tetronic 707
--
-- -- -- -- --
--
--
--
--
--
--
--
--
Alipal EP-110
--
-- -- -- -- --
--
85
85
--
--
--
--
--
Alipal CO-436
--
-- -- -- -- 85
85
--
--
--
--
--
--
85
Tamol 850
--
-- -- -- -- --
--
--
--
--
--
--
--
15
Daxad 17 --
-- -- -- -- 15
--
15
--
15
--
--
--
--
Nopcosant
--
-- -- -- -- --
15
--
15
--
15
--
--
--
Triton X-114
50
-- 42.8
-- -- --
--
--
--
--
--
--
--
--
Triton X-165
--
-- -- -- -- --
--
--
--
85
85
--
--
--
Triton X-405
--
42.5
-- 42.8
-- --
--
--
--
--
--
--
--
--
Triton X-705
--
-- -- -- 50.0
--
--
--
--
--
--
--
--
--
Tergitol NP-6
--
-- -- -- -- --
--
--
--
--
--
--
--
--
Tergitol NP-8
33
-- 28.6
-- -- --
--
--
--
--
--
--
--
--
Tergitol NP-40
--
42.5
-- 28.6
-- --
--
--
--
--
--
85
--
--
Tergitol NP-70
--
-- -- -- 33.3
--
--
--
--
--
--
--
--
--
Orzan A --
-- -- -- -- --
--
--
--
--
--
--
--
--
Lignosol BD
--
-- 14.2
14.2
-- --
--
--
--
--
--
--
--
--
Conco Sulfate 219
--
-- -- -- -- --
--
--
--
--
--
--
85
--
__________________________________________________________________________
The residual hydrocarbons described in Sections 7.2.4. through 7.2.10. were successfully emulsified into stable pre-atomized fuels with certain of the surfactant packages listed in Table XX. For the California and Oklahoma vacuum resids, a preferred surfactant package was Package #19. For the Union cutback tar, a preferred surfactant package was Package #25. Package #18 was preferred for use with the German visbreaker resid and Package #17 was preferred for the Texas visbreaker resid, the ROSE resid and the catalytically hydrogenated residual oil.
The pyrolysis pitch described in Section 7.2.11 was successfully emulsified into a pre-atomized fuel with a surfactant package containing 47.24% Pluronic F38 (BASF Wyandotte Corp.), 21.38% dinonylphenol (DNP) 150 (Chemac Corp.), 21.38% Tergitol NP-40 (Union Carbide Corp.) and 10% Indulin AT (Westvaco Corp.). Of all surfactant packages tested to date, this surfactant package is the most versatile in the sense that it can be used to emulsify not only the pyrolysis pitch but all the other residual fuel oils described supra. Daxad 17 (W. R. Grace & co.) can be substituted for Indulin AT.
Table XXI lists the types of oils that have and have not yet been successfully emulsified into stable emulsions (see Section 3) with various surfactant packages. All the oils listed as having been successfully emulsified to form stable emulsions can be emulsified with a surfactant package comprising 15% α-emulsan (technical grade), 42.5% Tergitol NP-40, and 42.5% Alfonic 1412-A (weight percent) used at 1 part per 500 parts oil by weight. The method used for determining paraffin and aromatic content (weight percent) is described in Sections 7.2.12 and 7.2.13.
TABLE XXI
______________________________________
PARAFFIN/AROMATIC CONTENT AND
EMULSION STABILITY
Asphaltene
Paraffin Aromatic
Form Stable
Oil Type (%) (%) (%) Emulsions*
______________________________________
Boscan Crude
22 18 60 yes
Uinta Crude
2 83 15 no
So. California 69 12 no
Fuel Oil
Texas Fireflood 26 51 yes
Crude
Bombay Crude 75 8 no
Number 6 39 23 38 yes
Residual
Fuel Oil
Jibaro Crude 19 64 yes
El Jobo Crude 13 52 yes
Kansas Crude 48 41 yes
______________________________________
*See Section 3 for description of stable emulsions.
EFFECT OF METHANOL IN AQUEOUS PHASE ON PRE-ATOMIZED FUEL VISCOSITY
Pre-atomized fuels were formed in a blender at low speed (in a manner preventing the beating of air into the emulsion) with methanol incorporated into the aqueous phase. The hydrocarbon used was a mixture of Number 6 residual fuel oils, designated Amelia Fuel oil. The specific gravity of Amelia Fuel oil was 0.996 and its API gravity was 10.6° API. The viscosity versus temperature profile is shown in Table Table XXII.
TABLE XXII
______________________________________
VISCOSITY VS. TEMPERATURE FOR
AMELIA FUEL OIL
Viscosity (cp)
Temperature (°F.)
______________________________________
1,046 100
1,405 90
2,190 80
3,578 70
6,209 60
______________________________________
The surfactant package comprised 15% α-emulsan (technical grade), 42.5% Tergitol NP-40 and 42.5% Alfonic 1412-A (w/w).
The surfactant package was added to aqueous phases containing various proportions of methanol and deionized water. The aqueous phases were blended at low speed for approximately 15 seconds to form pre-atomized fuels wherein the ratio of Amelia Fuel to aqueous phase was 70:30 (v/v). Enough of the surfactant package was added to the aqueous phase such that the final proportion of surfactant package to Amelia Fuel in the pre-atomized fuel was 1:250. Table XXIII summarizes the variation of viscosity of the pre-atomized fuels as the composition of the aqueous phase was varied. The results suggest that addition of methanol up to at least about 45% does not significantly affect viscosity reduction by the surfactant package.
TABLE XXIII
______________________________________
EFFECT OF METHANOL IN AQUEOUS
PHASE ON VISCOSITY
%.sup.1 Methanol
%.sup.1 Water
Viscosity (cp).sup.2
______________________________________
0 100.0 58.5
1.0 99.0 29.2
2.5 97.5 32.1
4.9 95.1 61.2
10.0 90.0 34.3
11.5 88.5 37.9
12.9 87.1 35.0
15.0 85.0 39.4
24.7 75.3 76.4
44.3 55.7 82.3
100.0 0 1753.7
______________________________________
.sup.1 Weight percent
.sup.2 At 100° F.
7.3.3. EFFECT OF WATER CONTENT OF PRE-ATOMIZED FUEL VISCOSITY
Experiments were performed with the Boscan crude oil described in Section 7.2.1, the Number 6 residual test fuel oil described in Section 7.2.3 and the Amelia Fuel oil described in Section 7.3.2 to determine the effect of variations in the proportion of the aqueous phase to oil phase on pre-atomized fuel viscosity. The surfactant package used in all three sets of experiments comprised 15% α-emulsan (technical grade), 42.5% Tergitol NP-40 and 42.5% Alfonic 1412-A (w/w). The viscosities reported in Tables XXIV, XXV and XXVI were measured on the Rheomat 30 as described in Section 7.2.12.
Boscan crude oil was emulsified at low speed in a blender (as in Section 7.3.1.) in various proportions of water using a surfactant package ratio of 1:250 based on oil. Viscosities were measured at 100° F. The data are tabulated in Table XXIV and presented graphically in FIG. 1.
TABLE XXIV
______________________________________
EFFECT OF WATER CONTENT ON VISCOSITY
OF BOSCAN CRUDE OIL PRE-ATOMIZED FUELS
Water Content Viscosity (cp)
% (v/v) at 100° F.
______________________________________
24 202
27 140
30 111
33 82
35 51
39 36
______________________________________
Similarly, Number 6 residual test fuel oil was emulsified in various proportions of deionized water using a surfactant package ratio of 1:250 based on oil. Viscosities were measured at 100° F. The data are tabulated in Table XXV.
TABLE XXV
______________________________________
EFFECT OF WATER CONTENT ON VISCOSITY
OF NUMBER 6 FUEL OIL PRE-ATOMIZED FUELS
Water Content Viscosity (cp)
% (v/v) at 100° F.
______________________________________
14 1002.1
16 417.6
23 89.5
27 53.7
33 71.6
______________________________________
Additionally, Amelia Fuel oil was emulsified in various proportions of an aqueous phase consisting of 13.3% (w/w) methanol and 86.7% (w/w) deionized water using a surfactant package ratio of 1:250 based on oil. Viscosities were measured at 100° F. The data are tabulated in Table XXVI.
TABLE XXVI
______________________________________
EFFECT OF AQUEOUS PHASE CONTENT ON VISCOSITY
OF AMELIA FUEL OIL PRE-ATOMIZED FUELS
Aqueous Phase Content
Viscosity (cp)
% (v/v) at 100° F.
______________________________________
18 1074
21 573
24 54
27 38
30 33
______________________________________
In all three cases, as the oil:water ratio was increased, the viscosity similarly increased.
7.3.4. TEMPERATURE EFFECTS ON HYDROCARBOSOLS
Hydrocarbosols were prepared at low speed in a blender (as in Section 7.3.1) with Boscan crude oil at oil:water ratios of 72:28 and 63:37 (v/v) using a surfactant package comprising 15% α-emulsan (technical grade), 42.5% Tergitol-NP40 and 42.5% Alfonic 1412-A, (w/w), at a ratio of 1:250 based on oil. The viscosity versus temperature profiles of emulsan-stabilized Boscan crude oil hydrocarbosols were compared to the viscosity versus temperature profiles of the unemulsified crude oil. The temperature effects on hydrocarbosols were much less pronounced than on the crude oil from which the hydrocarbosols were formulated as depicted in FIG. 2.
7.3.5. COMPARATIVE STATIC TESTING
The purpose of these experiments was to determine the stability under static conditions of oil-in-water emulsions of viscous crude oils made with surfactant packages comprising chemical surfactants, with or without bioemulsifier. Specifically, the determination of the time course over which the oil-in-water emulsions maintained a reduced viscosity without breaking or inverting was desired to assess the ease and success with which such emulsions can be handled for transportation and/or storage purposes. Behavior of viscous crude oil-in-water emulsions was of further interest with regard to the possibility of pump failures and shut-downs during pipelining operations where emulsion stability is desirable to avoid emulsion breakage and circumvent the need to re-emulsify prior to re-start of operations.
Several surfactant packages, the compositions of which are shown in Table XXVII, were used to prepare oil-in-water emulsions [oil:water=70:30 on a volume per volume (v/v) basis] in which the ratio of surfactant package to oil was 1:500 on a weight per weight (w/w) basis. The surfactants used to formulate the surfactant packages of Table XXVII are commercially available: Tergitol NP-40 (Union Carbide Corporation) or Alfonic 1412-A (Conoco, Inc.). The surfactant packages were formulated with or without α-emulsan (technical grade) as indicated in the table directly below.
TABLE XXVII
______________________________________
COMPOSITIONS OF SURFACTANT PACKAGES USED
IN STATIC TESTING OF EMULSION STABILITY
Surfactant
% of Component (w/w) in Surfactant Package
Package α-emulsan
Tergitol NP-40
Alfonic 1412-A
______________________________________
A 0 100 0
B 15 85 0
C 0 50 50
D 15 42.5 42.5
E 50 25 25
______________________________________
The method used to prepare oil-in-water emulsions for these experiments was as follows. Into a suitable container, an amount of crude oil was weighed so as to make up 70% (v/v) of the final emulsion. The crude oils used were the Boscan and Texas Fireflood crudes as described in Sections 7.2.1 and 7.2.2, supra and also a Kansas crude. The oil was then heated to 50°-60° C. Into a separate container, the particular surfactant package chosen (see Table XXVII) was weighed so as to yield a 1:500 ratio (w/w) of surfactant package to oil in the final emulsion. Sufficient make-up water was added to the surfactant package to provide a 30% (v/v) aqueous phase in the final emulsion. Three types of aqueous phases were used: tap water, deionized water, or Texas brine. The Texas brine comprised ions in the following approximate concentrations [in parts per million (ppm)]: sodium, 28,600; calcium, 1,800; magnesium, 290; ferric, 27; barium, 17; chloride, 47,900; bicarbonate, 540; and sulfate, 12. The aqueous phase was added to the oil phase and blended using typical blender blades at low speed, as in Section 7.3.1, i.e., in a manner preventing the beating of air into the emulsion. The individual emulsions were stored in sealed containers for periods of up to 29 days. The viscosity was measured daily with a Brookfield RVT Viscometer (Brookfield Engineering), equipped with an RV3 spindle, at 10 rpm at ambient (70°-80° F.) temperature. Five groups of emulsions were subjected to the test and their compositions are indicated in Table XXVIII.
TABLE XXVIII
______________________________________
EMULSION COMPOSITIONS.sup.1
Surfactant
Group Oil Aqueous Package.sup.2
______________________________________
1 Texas Fireflood
Tap Water C
Crude D
E
2 Boscan Crude Deionized Water
A
B
3 Boscan Crude Texas Brine A
B
4 Texas Fireflood
Deionized Water
A
Crude B
5 Texas Fireflood
Texas Brine A
Crude B
6 Kansas Crude.sup.3
Tap Water C
D
7 Kansas Crude Texas Brine C
D
______________________________________
.sup.1 All emulsions were 70:30, oil:water (v/v).
.sup.2 Surfactant Packages are defined in Table XXVII and were used at
1:500, surfactant package:oil (w/w), except for Groups 6 and 7 where the
proportion was 1:1,000.
.sup.3 Kansas crude oil has a viscosity of 1,127 cp at 76° F. The
specific gravity is 0.941 and the API gravity is 18.9° API.
The results for Groups 1-7 (see Table XXVIII) are tabulated in Tables XXIX-XXXV, respectively.
TABLE XXIX
______________________________________
STATIC TEST DATA - GROUP 1
% α-Emulsan (w/w) in Surfactant Package
Time Viscosity (cp)
(days) 0 15 50
______________________________________
0 155 92 138
1 7850 700 6900
2 8920 720 2802
5 9920 1616 3700
6 10960 1790 6234
7 11385 2425 5130
8 10067 2717 4100
12 9800 2791 3495
13 11820 2107 3900
14 10880 2133 2997
16 10000 2060 2800
19 10200 2060 2570
20 10100 1732 2288
29 11700 1948 2760
______________________________________
TABLE XXX
______________________________________
STATIC TEST DATA - GROUP 2
% α-Emulsan (w/w) in Surfactant Package
Time Viscosity (cp)
(days) 0 15
______________________________________
1 65 76
2 76 84
3 84 122
4 91 122
7 84 129
9 53 122
17 60 122
______________________________________
TABLE XXXI
______________________________________
STATIC TEST DATA - GROUP 3
% α-Emulsan (w/w) in Surfactant Package
Time Viscosity (cp)
(days) 0 15
______________________________________
1 160 152
2 167 152
3 144 163
4 141 129
7 167 144
9 130 129
17 144 122
______________________________________
TABLE XXXII
______________________________________
STATIC TEST DATA - GROUP 4
% α-Emulsan (w/w) in Surfactant Package
Time Viscosity (cp)
(days) 0 15
______________________________________
1 2443 733
2 4492 1775
3 5799 2371
4 5776 2580
7 6616 1847
9 6190 2204
17 5282 2037
______________________________________
TABLE XXXIII
______________________________________
STATIC TEST DATA - GROUP 5
% α-Emulsan (w/w) in Surfactant Package
Time Viscosity (cp)
(days) 0 15
______________________________________
1 114 103
2 137 91
3 106 84
4 110 106
7 110 114
9 99 118
17 84 91
______________________________________
TABLE XXXIV
______________________________________
STATIC TEST DATA - GROUP 6
% α-Emulsan (w/w) in Surfactant Package
Time Viscosity (cp)
(days) 0 15
______________________________________
0 171 114
1 380 342
2 798 633
7 1697 1279
8 1691 1222
11 1526 773
15 1406 602
18 1406 494
______________________________________
TABLE XXXV
______________________________________
STATIC TEST DATA - GROUP 7
% α-Emulsan (w/w) in Surfactant Package
Time Viscosity (cp)
(days) 0 15
______________________________________
0 551 418
1 323 228
2 253 171
7 196 133
8 222 133
11 184 114
15 171 114
18 184 114
______________________________________
The results for Group 1 indicate that for emulsions of the Texas fireflood crude in tap water, the addition of 15% (w/w) α-emulsan (technical grade), to a surfactant package containing co-surfactants Tergitol NP-40 and Alfonic 1412-A was preferable to the addition of 50% (w/w) α-emulsan and was also preferable to excluding α-emulsan from the surfactant package. The results for Group 2 indicate that for emulsions of the Boscan crude in deionized water, the addition of 15% (w/w) α-emulsan to a surfactant package containing Tergitol NP-40 only did not improve viscosity reduction, although the measured viscosities of either emulsion, i.e., with or without α-emulsan, were acceptably reduced. The results of Group 3 indicate that for emulsions of the Boscan crude in Texas brine, the addition of α-emulsan to a surfactant package containing Tergitol NP-40 alone did not yield significantly different results from the surfactant package without α-emulsan. Nevertheless, either surfactant package, i.e., with or without α-emulsan yielded acceptably reduced viscosities. The results further demonstrated that brine can be used as aqueous phase. The results for Group 4 indicate that for emulsions of the Texas fireflood crude in deionized water, the addition of 15% (w/w) α-emulsan to a surfactant package containing Tergitol NP-40 only is preferable to omitting α-emulsan from the surfactant package. The results of Group 5 indicate that for emulsions of the Texas fireflood crude in Texas brine, the addition of α-emulsan to a surfactant package containing Tergitol NP-40 alone did not yield significantly different results from the surfactant package without α-emulsan. Nevertheless, either surfactant package, i.e., with or without α-emulsan yielded acceptably reduced viscosities. Comparison of the Group 4 data with that of Group 5 dramatically illustrates the effect of different aqueous phases on the viscosities of Texas fireflood crude oil-in-water emulsions. The data indicate that the use of Texas brine is preferable to the use of deionized water for forming oil-in-water emulsions with Texas fireflood crude. The results for Groups 6 and 7 indicate that for emulsions of the Kansas crude in tap water or Texas brine, the addition of 15% (w/w) α-emulsan to a surfactant package containing co-surfactants Tergitol NP-40 and Alfonic 1412-A was preferable to the exclusion of α-emulsan from the surfactant package. The data from these groups illustrate how the viscosity versus time profiles of emulsions of the same crude oil can vary dramatically as a function of the aqueous phase and also that the viscosity versus time behavior of one type of crude oil/water emulsion can be signficantly different than that of other crude oil/water emulsions.
That the presence of α-emulsan in surfactant packages used to emulsify Texas fireflood crude oil or Kansas crude oil has a significant effect on emulsion stability and maintenance of reduced viscosities can be seen in FIGS. 3, 4, 5 and 6 where the data from Groups 1, 4, 6 and 7 (Tables XXIX, XXXII, XXXIV and XXXV for 0% and 15% α-emulsan) are presented graphically. The lower curves in each figure represent the viscosity versus time profiles for α-emulsan-stabilized hydrocarbosols. The viscosities of the α-emulsan-stabilized hydrocarbosols remain significantly more reduced than that of the emulsions formed with surfactant packages that did not include α-emulsan.
7.3.6. STABILIZER COMPARISONS
An experiment was performed to compare the emulsion-stabilizing effect of α-emulsan with that of known chemical emulsion-stabilizers, naphthalene sulfonate and lignin sulfonate. Specifically, the viscosity versus time profiles at 75° F. were followed for four emulsions containing either α-emulsan, naphthalene sulfonate or lignin sulfonate or no stabilizer at all. All emulsions were formulated with the Texas fireflood crude described in Section 7.2.2. at an oil:water ratio of 70:30 (v/v). Surfactant packages were used at a ratio of 1:500 (w/w) based on oil. The results are shown in FIG. 7. The α-emulsan-stabilized hydrocarbosol was formulated with a surfactant package comprising 15% α-emulsan (technical grade), 42.5% Tergitol NP-40, and 42.5% Alfonic 1412-A (w/w); its viscosity versus time profile is the curve depicted by closed circles. The naphthalene sulfonate-stabilized emulsion was formulated with a surfactant package comprising 15% naphthalene sulfonate, 42.5% Tergitol NP-40 and 42.5% Alfonic 1412-A (w/w); its viscosity versus time profile is the curve depicted by closed triangles. The lignin sulfonate-stabilized emulsion was formulated with a surfactant package comprising 15% lignin sulfonate; 42.5% Tergitol NP-40 and 42.5% Alfonic 1412-A (w/w); its viscosity versus time profile is the curve depicted by closed inverted closed triangles. A fourth emulsion (the control) was formulated with a surfactant package comprising 50% Tergitol NP-40 and 42.5% Alfonic 1412-A (w/w) with no additional emulsion stabilizer; its viscosity versus time profile is the curve depicted by open squares.
Immediately after emulsion formation a zero time point measurement was taken. Thereafter the emulsions were allowed to remain stationary for 28 days during which time period viscosities of the four emulsions were measured daily to determine the increase, if any, in viscosity. The points in FIG. 7 represented by stars indicate that by day 8 for the naphthalene sulfonate stabilized emulsion and by day 12 for the lignin sulfonate-stabilized emulsion, these two emulsions had failed, i.e., inverted into water-in-oil emulsions. It can be seen from FIG. 7 that under the conditions of the experiment, α-emulsan was a significantly more effective stabilizer of Texas fireflood crude oil:water emulsions than were either of the two chemical stabilizers (lignin sulfonate and naphthalene sulfonate) or the co-surfactants (Tergitol NP-40 and Alfonic 1412-A) alone.
α-Emulsan preparations in the form of purified grade, technical grade, whole broth, supernatant, and Acinetobacter calcoaceticus ATCC 31012 bacterial cells (see Section 7.1.) were compared in terms of their ability to form and stabilize emulsions of Oklahoma vacuum resid. All of the emulsions were produced at an oil-to-water ratio of 70:30 (w/w). The aqueous phase contained 1 part surfactant package to 200 parts oil (w/w). The surfactants present at 85% (w/w) were either Triton-165, Alipal EP-110 or Alipal CO-436. Performance was characterized according to emulsion viscosity, phase separation and degree of hydrocarbon incorporation. Most differences were apparent at 2 or more days following emulsion formation. In all cases the α-emulsan preparation comprised 15% (w/w) of the total surfactant package present. Technical grade α-emulsan produced less viscous emulsions than the purified product, regardless of the co-surfactants present. The α-emulsan in whole broth, supernatant and cells respond differently depending upon the co-surfactant used. The most advantageous results are seen with the whole broth. Whole broth repeatedly produced more fluid emulsions than the technical and purified products. All α-emulsan preparations were not equally effective in maintaining stable, low viscosity emulsions for extended periods of time. The α-emulsan present in cells has shown variable results in maintaining emulsions exhibiting reduced viscosities, but this material consistently prevented creaming. Additionally, enzyme treatment offers little benefit in the performance of the emulsans for preparing emulsions with this hydrocarbon. Thus, due to the consistent results obtained with whole broth, it is the α-emulsan source of choice for the emulsification of Oklahoma vacuum resid. α-Emulsans produced by Acinetobacter calcoaceticus ATCC 31012 cultures which utilized soap stock as the carbon source displayed results similar to those obtained from cultures grown on ethanol.
Preparations of materials produced by NS strains of Acinetobacter calcoaceticus as described in Section 7.1.2 were used to form and stabilize emulsions of Oklahoma vacuum resid. All of the emulsions were produced at an oil-to-water ratio of 70:30 (w/w). The aqueous phase contained 1 part surfactant package to 200 parts oil (w/w). The surfactant present at 85% (w/w) was Alipal CO-436. In all cases the NS materials comprised 15% (w/w) of the total surfactant package.
In addition to the bioemulsifiers, there are conventional synthetic surfactants which are also known emulsion stabilizers: lignin sulfonates and naphthalene sulfonates are examples of such materials. Replacement of α-emulsan with these surfactants also allows production of oil-in-water emulsions. However, the lignin sulfonates did not produce emulsions of reduced viscosity for the hydrocarbon used, whereas the naphthalene sulfonates are generally satisfactory replacements for α-emulsan for use with viscous residuals. These naphthalene sulfonates not only produce very fluid emulsions, they also minimize, if not entirely prevent, creaming of the oil. These particular anionic surfactants perform well with all of the co-surfactants mentioned earlier, and will successfully produce emulsions.
7.3.7. MIXING OF A SLURRY WITH A PRE-ATOMIZED FUEL
The composition of a surfactant package that was successfully used both to form a stable pre-atomized fuel from a California vacuum resid and to form a stable slurry from a ROSE resid is listed in Table XX, Package 17. The α-emulsan used was prepared from a technical grade of emulsan as described in Section 7.1.1. The surfactants Lignosol BD (Reed Ltd. Chemical Div.), Triton X series (Rohm & Haas Co.), and Tergitol NP series (Union Carbide Corp.) are commercially available. Both the pre-atomized fuels and slurries were formed in an Osterizer Galaxy 14 blender at high speed in a manner which prevents the incorporation of air into the resulting dispersion. The ratio of California resid and ROSE resid to their respective aqueous phases was 70:30 by weight (w/w). The surfactant package was used at a ratio of 1:100 (surfactant/hydrocarbon) by weight (w/w) for both the pre-atomized fuel and the slurry. The surfactant package comprising 42.8% Triton X-405, 28.6% Tergitol NP-40, 14.2% Lignosol BD, and 14.2% technical grade α-emulsan was the preferred surfactant package for use with both California vacuum resid and ROSE resid. Results of mixing the slurry with the pre-atomized fuel are listed in Table XXXVI.
TABLE XXXVI
______________________________________
VISCOSITY OF PRE-ATOMIZED
FUEL/SLURRY MIXTURE
Viscosity (cp)
______________________________________
1. Pre-Atomized Fuel
220
2. Slurry 515
3. 50/50 Pre-Atomized Fuel/
175
Slurry by weight (w/w)
______________________________________
7.3.8. FORMATION OF PRE-ATOMIZED FUELS AT HIGH TEMPERATURES UNDER PRESSURE
The composition of a surfactant package that was successfully used to form a stable pre-atomized fuel at a high temperature and under pressure was as follows: 88.5% (w/w) Nacconal 90-F (Stepan Chemical Co.), a linear dodecyl benzene sulfonate and 11.5% α-emulsan whole broth. The α-emulsan used was prepared from a post-fermentation whole broth as described in Section 7.1.2. The ratio of the hydrocarbon phase to the aqueous phase was 70:30 (California vacuum resid/tap water) by weight. The surfactant was used at a ratio of 1:200 (surfactant/hydrocarbon) by weight. The pre-atomized fuel was formed as described in Section 6.3 with the following modification: the pre-atomized fuel was formed at 300° F. and approximately 70 psi pressure was maintained in order to prevent the vaporization of the aqueous phase. The pre-atomized fuel was then cooled to a temperature lower than 212° F. using an appropriate heat exchange device and pressure was released. The foregoing experiment was performed with a surfactant package containing only Nacconal 90-F with similar results.
7.3.9. FORMATION OF PRE-ATOMIZED FUELS USING A THERMALLY CRACKED HYDROCARBON DISCHARGE
The composition of a surfactant package that was successfully used to form a stable pre-atomized fuel from a German Visbreaker resid was as follows: 50% Triton X-705 (w/w) (Rohm & Haas Co.), 33.3% Tergitol NP-70 (Union Carbide Corp.) and 16.7% whole broth α-emulsan. The α-emulsan used was prepared from a post-fermentation whole broth according to the methods described in Section 7.1.2. The pre-atomized fuel was formed in an Osterizer Galaxy 14 blender at the highest speed setting in a manner which prevents the incorporation of air into the resulting dispersion. The ratio of the hydrocarbon phase to the aqueous phase was 69.2:30.8 by weight (w/w). The surfactant package was used at a ratio of 1:350 (surfactant/hydrocarbon) by weight (w/w).
The method used to form the pre-atomized fuel is described in Section 6.3 with the following modifications: The water used to form the pre-atomized fuel was divided into two parts: 37.5% by weight of the water was placed in a container and partially frozen to make a slush and 62.5% by weight of the water was combined with the surfactant package and used to form a pre-atomized fuel as described in Section 6.3. The ratio of the hydrocarbon phase to the aqueous phase at this point was 78.3% by weight German visbreaker resid and 21.7% by weight water/surfactant package. The newly formed hot pre-atomized fuel was then combined with the remaining water which had been frozen and the total mixture was immediately placed in an ice bath. This caused an immediate and rapid quenching of the pre-atomized fuel to a temperature at least about 100° F. below the softening point of the hydrocarbon. The pre-atomized fuel produced utilizing this method has been observed to be stable and maintain a reduced viscosity for several weeks.
7.4. PIPELINING PILOT TEST
A pilot scale field test was conducted to determine how a hydrocarbosol would perform under simulated pipelining conditions. Approximately 29 barrels (BBL) of the Boscan crude oil described in Section 7.2.1 were emulsified into approximately 12 barrels of aqueous phase to form an oil-in-water emulsion. The final oil phase to aqueous phase ratio was 70/30 (v/v). The aqueous phase consisted of tap water supplied by the Tulsa, Oklahoma municipal system (total dissolved solids: 221 ppm; total hardness: 151 ppm). Emulsification was accomplished by mixing warm oil with surfactant-containing aqueous phase using a centrifugal pump. The surfactant package used comprised α-emulsan (technical grade) and Tergitol NP-40 at 15% and 85% by weight, respectively. The surfactant package was used at a treatment rate of 1 part surfactant package to 500 parts oil by weight.
The resulting hydrocarbosol was continuously circulated in a pipe loop at an average velocity of 6.7 ft/sec (3.125 inch I.D., 2,560 feet long) for 96 hours using a centrifugal pump. This is shown schematically in FIG. 8.
During the entire test run the observed hydrocarbosol viscosity remained less than 100 cp. [Pressure drop/flow rate data indicated an apparent viscosity of approximately 70 cp at 60° F. for the hydrocarbosol throughout the operation.] This is in dramatic contrast to the viscosity of the Boscan crude before emulsification, approximately 192,000 cp. At the end of the continuous test period, flow through the loop was interrupted for 64 hours to simulate a pump failure. After three days of shutdown, pumping was resumed with no apparent change in hydrocarbosol characteristics. Pressure drops and flow rates were similar after restart as prior to shutdown. There was no need to reemulsify.
During this test, the hydrocarbosol was pumped an actual physical distance of approximately 380 miles. It traversed the pump once every 17 minutes. In this manner, the hydrocarbosol was subjected to stress (shear) roughly equivalent to being pumped a distance of 26,000 miles in a commercial pipeline (considering pipe diameters, pump transits, flow rates, etc.). Such stress is known to cause failure (inversion) of oil-in-water emulsions stabilized by conventional surfactants. Laboratory evaluation of the hydrocarbosol upon completion of the test demonstrated that, should demulsification be desirable, the emulsion could be demulsified readily using standard oil field techniques. Table XXXVII summarizes the pertinent numbers, results, and conditions of the pipelining pilot test.
TABLE XXXVII
______________________________________
SUMMARY OF PIPELINING PILOT TEST DATA
______________________________________
Oil/Water Ratio 70/30
Surfactant Package/Oil Ratio
1/500
Total Running Time 96 hours
Shutdown time prior to successful restart
64 hours
Average flow rate during run
160 gpm
Average flow velocity 6.69 ft/sec
Pipe I.D. 3.125 inches
Distance pumped approx. 380 miles
Number of pump transits approx. 530
Apparent viscosity of emulsion
70 cp
Viscosity of Boscan at 60° F.
190,000 cp
Comparable flow rate in 20" line
210,000 BBL/day
Comparable flow rate in 30" line
475,000 BBL/day
______________________________________
7.5. DIRECT COMBUSTION TEST ON PRE-ATOMIZED FUELS
7.5.1. FURNACE ASSEMBLY AND INSTRUMENTATION
The direct combustion test was run in a large scale (1 Megawatt) furnace assembly, essentially comprising in sequential arrangement: a burner, a brick-lined experimental chamber (also called the refractory-lined combustion tunnel), an after burner, a water-cooled (cold-wall) chamber and an exhaust section, approximately 1.14 meters (m), 4.55 m, 1.24 m, 4.55 m and 1.65 m in length, respectively. The other major components of the facility used include the systems for storage, metering, feeding and control of fuels, for pumping, preheating, and metering of the combustion air, and for cleaning and pumping the combustion products.
The furnace assembly is equipped with water-cooled probes for sampling combustion gases which are drawn off under vacuum and pass through a sample transport line to a set of continuous on-line gas analyzers, specifically a Chemiluminescent NO-NOX Gas Analyzer (Thermo Electron Corporation, Model 10A), an Infrared CO Analyzer (Beckman, Inc., Model 865), an Infrared CO2 Analyzer (Beckman, Inc., Model 865) and a Paramagnetic O2 Analyzer (Beckman, Inc., Model 755). The furnace assembly is also equipped with a water-cooled suction pyrometer for measuring axial flame temperatures at various flame positions within the experimental combustion tunnel. The furnace assembly is further equipped with water-cooled water quench sampling probes through which combustion gases, including particulates, are drawn off under vacuum, are quenched with water and flow through a sampling train, the first component of which is a filter (paper) for collection of solids. This equipment provides for the quantitation of solids in the combustion gases.
7.5.2. PREPARATION OF PRE-ATOMIZED FUEL FOR COMBUSTION TEST
The characteristics of the Number 6 residual test fuel oil used as the oil phase of the pre-atomized fuel are described in Section 7.2.3. Table XXXVIII summarizes the ultimate analysis of the fuel oil. Its heating value was 18,384 Btu/lb.
TABLE XXXVIII
______________________________________
NUMBER 6 RESIDUAL TEST FUEL OIL
ULTIMATE ANALYSIS
Constituent
%
______________________________________
Carbon 85.63
Hydrogen 10.69
Nitrogen 0.47
Sulfur 2.30
Oxygen 0.91
Ash 0.08
Water 0.10
Asphaltenes
10.44
______________________________________
The Number 6 fuel oil was emulsified in water using a surfactant package comprising 15% α-emulsan (technical grade), 42.5% Tergitol NP-40, 42.5% Alfonic 1412-A (in weight percent). The surfactant package was used at a rate of 1 part per 250 parts oil (w/w). The ratio of oil to water in the resulting pre-atomized fuel was approximately 70:30 (v/v). One hundred ten gallons of pre-atomized fuel were prepared in a fuel preparation system which incorporates a Gaulin mechanical homogenizer. The aqueous solution containing the surfactant package was fed via a centrifugal pump into a mixing-T located in the Number 6 fuel oil supply line. This arrangement provided in-line pre-mixing of the oil and water prior to entering a 45 g.p.h. high-pressure mechanical homogenizer (Gaulin). The minimum homogenization pressure of 1000 psi was employed for producing the pre-atomized fuel. The resulting pre-atomized fuel had a viscosity ranging from 70-120 cp at 80° F.
Accurate control of both oil and water flow rates are required to maintain a constant 70/30 oil/water mass ratio during this continuous mixing process. Precise control of the water flow proved to be a problem due to the very low flow rates required, and it is estimated that the oil/water ratio varied between 65/35 and 75/25 during production. Two barrels of pre-atomized fuel were produced with the following composition: Barrel #1--71.25%: 28.75% water by weight; and Barrel #2--69.78% oil: 30.22% water by weight. Both barrels of pre-atomized fuel were produced one week prior to the combustion test and no separation was apparent during this time. Prior to the combustion test both barrels were stirred with a slow speed stirrer.
7.5.3. COMBUSTION TEST PROCEDURE
Standard procedures for firing a Number 6 fuel oil in the type of furnace assembly employed were followed with the exception that the in-line fuel heaters were not used, and the pre-atomized fuel was fired at a temperature of approximately 90° F.
The refractory-lined combustion tunnel was brought up to operating temperature (approximately 1000° C.) using natural gas. The gas run was then removed and replaced by a standard oil gun fitted with a twin fluid atomizer of the Y-jet type. Compressed air at approximately 60 psi was used for the atomizing fluid.
The initial light-off on the oil burner was accomplished using a Number 2 oil as is standard practice. The air and fuel flow rates were then adjusted to give a thermal input of approximately 1 MW or 3.4 MM Btu/hr. A simple on-load fuel transfer from Number 2 fuel oil to the 70/30 pre-atomized fuel was then effected by transferring the suction hose from the barrel of Number 2 fuel to the barrel of pre-atomized fuel.
A significant reduction in fuel flow rate occurred shortly after transfer to the pre-atomized fuel due primarily to the higher viscosity of the pre-atomized fuel and the resultant pressure drop in the fuel lines. Stable flame conditions were maintained during the fuel transfer but good flame conditions could not be achieved as the fuel flow rate fell below the minimum required.
Initially the drop in fuel flow rate was thought to be due to blockage of the atomizer. The Y-jet atomizer was removed, cleaned, and replaced. Light-off was accomplished without any problem using the pre-atomized fuel but low fuel flow rates prevailed. A second atomizer, of the internal-mix type was then employed. Again light-off using the pre-atomized fuel presented no problem but the low fuel flow rate persisted.
Finally it was concluded that the flow problem was due to a partially blocked flow control valve. The nature of this blockage was not determined. A manual by-pass valve around the control valve was opened and the pre-atomized fuel-flow rate was increased to a maximum of approximately 4 lb/min (approximately 0.9 MW input). This resulted in an entirely satisfactory flame having visible characteristics very similar to those of a Number 6 fuel oil flame obtained under similar firing conditions.
A stable flame was maintained throughout the remainder of the test period, during which time minimum excess air levels, solids emissions, and axial flame temperatures were measured.
7.5.4. RESULTS OF PRELIMINARY COMBUSTION TEST
The ignitability and stability of the 70/30 pre-atmoized fuel were found to be comparable with those of a Number 6 fuel oil when fired under similar conditions in the furnace assembly used.
Flame stability was found to be acceptable even when the important combustion parameters of excess air, minimum fuel flow rate, and atomization conditions were not matched. This occurred inadvertently during light-off and when fuel-flow rates fell below the limits for acceptable flame conditions. However, these results indicated that ignition and flame stability were not major problems of the pre-atomized fuel.
Minimum excess air levels of less than 2% were achieved without any visible smoke or carbon monoxide in the flue gas. These figures compare favorably with those ttainable with a Number 6 fuel oil. Table XXXIX summarizes the range of operating conditions examined during this short test in terms of excess air levels and flue gas composition, the major point of interest being the low excess air levels that were obtained.
TABLE XXXIX
______________________________________
EXCESS AIR DATA
% Oxygen in Flue Gas
% Excess Air
Carbon Monoxide (ppm)
______________________________________
0.61 2.83 0
0.54 2.50 0
0.48 2.21 0
0.44 2.03 0
0.20 0.91 100-150
0.16 0.73 150
______________________________________
Pre-Atomized Fuel Input approx. 4 lb/min (0.93 MW Thermal
PreAtomized Fuel Temperature 90° F.
Atomizer air Preheat 500° F.
The visible flame length under these conditions were approximately 6 ft. and the general appearance of the flame was very similar to that of a Number 6 fuel oil flame. The exhaust gas on exit from the high temperature combustion zone appeared to contain a small amount of "white-smoke", very similar in appearance to that observed when firing coal-water slurries under similar conditions. This "white-smoke" was not visible on exit from the stack and its nature was not determined.
A water-cooled probe was used to obtain solids samples from the exhaust gas and along the axis of the flame. FIG. 9 shows the concentration profiles along the flame axis for a Number 6 fuel oil and the 70/30 pre-atomized fuel. The solids concentration at the exit from the combustor was almost identical for those two fuels. The solids concentration within the flame was slightly lower for the 70/30 pre-atomized fuel. These two flames were obtained using two different atomizers; nevertheless the data indicate that the carbon burnout achieved with the pre-atomized fuel fired at 90° F. was comparable to that for the parent Number 6 fuel fired at 240° F. to facilitate atomization.
Axial flame temperatures were also measured using a water cooled suction pyrometer and these are shown in FIG. 10. The 70/30 pre-atomized fuel flame exhibited a slightly lower temperature along the entire length of the combustion chamber. This was entirely compatible with the quenching effect expected from the 30% water content. The measured reduction in flame temperature of 100°-150° C. does not represent a serious problem in most industrial combustion systems.
7.5.5 RESULTS OF COMBUSTION EMISSIONS TEST
Subsequent to the above combustion test, another series of test burns were made using the oils and pre-atomized fuels of these oils, as listed in Table XL.
TABLE XL
______________________________________
TEST FUEL SPECIFICATIONS AND
EMULSION PROPERTIES
______________________________________
Edgington Mohawk
Bunker C Crude Oil*
Bunker C
______________________________________
Specific Gravity
0.99 0.99 0.99
Paraffin 27% 34% 53%
Aromatic 52% 44% 35%
______________________________________
Temp. v. Viscosity
°F. CPS CPS CPS
______________________________________
200 59.65 65.60 47.72
180 83.51 87.50 59.65
160 116.91 168.35 71.58
140 214.74 322.10 107.37
120 429.48 190.88
______________________________________
Pre-Atomized Fuel Viscosities 70-150
PreAtomized Fuel Specific Gravity = 0.99
*California Kern County
Procedures followed to form the pre-atomized fuels are described, supra. The primary purpose of these burns was to demonstrate the potential emissions reductions with pre-atomized fuels. In Table XLI the results of these burn tests are presented. The results indicate that burning such pre-atomized fuels caused significant reductions in NOX and SO2 emissions.
TABLE XLI
______________________________________
RESULTS OF BURN TESTS WITH
PRE-ATOMIZED FUELS
Edgington Mohawk
Bunker C Bunker C Crude Oil*
______________________________________
Baseline NOX (ppm)
550 450 355
Pre-Atomized Fuel
270 325 300
NOX (ppm)
% Reduction 51 28 15
Baseline SO.sub.2 (ppm)
1100 840 300
Pre-Atomized Fuel
650 500 250
SO.sub.2 (ppm)
% Reduction 43 40 17
______________________________________
Pre-Atomized Fuel Viscosities 70-150
PreAtomized Fuel Specific Gravity = 0.99
*California Kern County
All Readings made at 1% O.sub.2
7.6. DIRECTION COMBUSTION OF PITCH-IN-WATER PRE-ATOMIZED FUEL AND PARTICULATE EMISSIONS REDUCTION
Particulate emissions tests were carried out on a pre-atomized fuel made with the pyrolysis pitch described in Section 7.2.11, supra. The surfactant package used to emulsify the pitch contained 47.24% Pluronic F38 (BASF Wyandotte Corp.), 21.38% DNP 150 dinonylphenol (Chemac Corp.), 21.38% Tergitol NP-40 (Union Carbide) and 10% Indulin AT (Westvaco Corp.). The pitch-to-water ratio was 70:30. The surfactant package was used at a treatment rate of 1/250 based on hydrocarbon. Flodrill-S (Pfizer.) was added to 0.15% by weight to the water phase.
The pre-atomized fuel was formed by feeding the hydrocarbon phase (pitch) and aqueous phase (surfactant solution) by Viking gear pumps to a G-10 Charlotte Colloid Mill. The inlet temperature of the hydrocarbon phase was 250° F. The inlet temperature of the aqueous phase was 80° F. On exiting the mill, the emulsion was diverted through a plate-and-frame heat exchanger which has the capacity to cool the emulsion to ambient temperature. The emulsion was found to have low apparent viscosity and exhibited near Newtonian rheological properties. Physically the emulsion contains a broad-size distribution of pitch spheres in a continuous water matrix, wherein 99+% of the pitch spheres have diameters less than about 20 microns.
One set of particulate emissions tests were conducted in a 350 Hp Cleaver Brooks single-burner fuel-tube boiler and were performed in accordance with Environmental Protection Agency (EPA) Methods 1-4 and 17, known in the art. The burner had a rated capacity of 14.7 million Btu/hr, however, due to a limited supply of fuel and steam demand, the tests were conducted at about 37% of capacity, or a firing rate of 5.5 million Btu/hr (mmBtu/hr). All tests were conducted using unheated combustion air and a custom designed low-pressure dual-fluid atomizer, which was originally developed to atomize coal slurry fuels. Compressed air was used as the atomizing working fluid.
Using a mass spectrograph to measure flue gas chemistry and an opacity meter, the combustion characteristics of emulsified pitch were quantified as a function of excess oxygen content. The pertinent data from two test series, conducted using different fuel preheat temperatures, ambient or 20° C. (68° F.) and 60° C. (140° F.), are presented graphically in FIGS. 11 and 12. The carbon monoxide versus percent excess air curves (FIG. 11) show a shift to the left for the preheated fuel. This indicates better combustion and the ability to use lower excess air levels. The improvement was believed to be a result of a finer atomized fuel droplet size distribution associated with a slightly lower fuel viscosity. The opacity versus percent excess air graph (FIG. 12) shows even more dramatically the benefits of fuel preheat. The higher fuel preheat temperature, i.e., 60° C., was achieved using a hot water shell heat exchanger.
In addition to determining changes in flue gas chemistry and opacity as a function of excess oxygen level, two particulate emissions rate tests were conducted using EPA Method 17. Data collected during these latter tests, one each at the two fuel preheat temperatures, are presented in Table XLII along with the resultant calculated carbon conversion efficiencies and particulate carbon concentrations.
TABLE XLII
______________________________________
PARTICULATE EMISSIONS TEST RESULTS
Ambient Run Preheated Run
______________________________________
Fuel Temperature
20-21° C. (68-70° F.)
60° C. (140° F.)
Fuel Flow Rate
428 lbs/hr 452 lbs/hr
Firing Rate 5.28 mmBtu/hr 5.61 mmBtu/hr
Stack Gas
Composition:
% N.sub.2 73.4 73.1
% O.sub.2 4.7 3.1
% CO.sub.2 12.5 13.8
% H.sub.2 O 8.2 8.8
% SO.sub.2
(ppm) 235.0 260.0
(lb/mmBtu) 0.58 0.58
% CO (ppm) 19.5 25.5
(lb/mmBtu) 0.021 0.025
NO.sub.x
(ppm) 45.0 65.0
(lb/mmBtu) 0.08 0.10
Particulates 0.068 lb/mmBtu 0.034 lb/mmBtu
Fuel Ash 0.012 lb/mmBtu 0.012 lb/mmBtu
Particulate Carbon
82% 65%
Carbon Conversion
99.89-99.92% 99.96-99.97%
Efficiency
______________________________________
The particulate emissions rate for the preheated fuel is half that of the ambient fuel; at 0.034 and 0.068 lbs/mmBtu, respectively, they are both well below the 0.10 lbs/mmBtu allowed for particulate emissions by the EPA. The particulate matter collected was composed of very fine dark gray particles. After the 0.012 lb/mmBtu ash content of the fuel is subtracted from the particulate rates for the two tests there is found to be 65% and 82% unburned carbon in the particulate for the preheated and ambient runs, respectively. This amount of carbon corresponds to a carbon conversion of 99.96-99.97 and 99.89-99.92% for the two tests.
The SO2 emissions during the particulate tests were a function of the sulfur content of the fuel. The emissions of 260 and 235 ppm were calculated to correspond to 0.58 lbs/mmBtu of SO2 for the preheated and ambient fuel tests, respectively. Measured and calculated SO2 levels agree very closely.
The carbon monoxide emissions for the tests at 25.5 and 19.5 ppm have been calculated to correspond to 0.025 and 0.021 lbs/mmBtu which are both quite low emissions rates. The NO2 of 65 and 45 ppm are calculated to correspond to 0.10 and 0.08 lbs/mmBtu. These emissions rates are well below the 0.30 lbs/mmBtu the EPA allows. In summary, all the emissions rates were within allowable limits set by the EPA. The test data strongly support the postulate that small spheres of emulsified pitch separate from the atomized fuel droplets during combustion and burn as discrete particles.
Considering the high asphaltene content in the pyrolysis pitch the results of the particulate emissions tests were quite surprising. The fact that particulate emissions rate were exceptionally low, especially for the preheated fuel, provided confirmly evidence that the atomized spray quality of the emulsified pitch was not a dominant factor limiting combustion efficiency. These data clearly suggested that the emulsified pitch particles did not agglomerate to any significant extent, either prior to or during combustion. Consistent with the effects of fuel preheating on flue gas carbon monoxide levels and opacity, particulate emissions rates were reduced by a factor of two, and combustion efficiency increased from about 99.89-99.92% to about 99.96-99.97% when the emulsified fuel was preheated to 60° C.
In a separate independent combustion study conducted at a much lower firing rate, the combustion characteristics of neat pitch, emulsified pitch and heavy oil (No. 6 Oil) were compared. Particulate emissions rates for preheated emulsified pitch were found to be similar to those obtained supra. Under comparable test conditions the particulate emissions rate for preheated emulsified pitch was determined to be as little as one-half and one-sixth of those for heavy oil and heated atomized neat pitch, respectively. The results are presented in Table XLIII.
TABLE XLIII
______________________________________
PARTICULATE EMISSIONS COMPARISONS
Particulates, lb/mmBtu
Oxygen Level 3% O.sub.2
1% O.sub.2
______________________________________
Straight Pitch, 340° F.
0.09 0.29
No. 6 Oil, 180° F.
0.10 --
205° F.
0.07 --
Emulsion A 210° F.
-- 0.05
Emulsion B 195° F.
0.05 --
210° F.
-- 0.07
250° F.
-- 0.07
______________________________________
It is apparent that many modifications and variations of this invention as hereinabove set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.
We claim:
1. A method for reducing particulate emissions during combustion of a hydrocarbon with API gravity of about 20° API or less, viscosity of about 40,000 centipoise at 122° F., paraffin content of about 50% by weight or less, aromatic content of about 15% by weight or greater, and asphaltene content of about 50% by weight or greater which comprises:(a) emulsifying such hydrocarbon to form a hydrocarbon-in-water emulsion having a hydrocarbon water ratio from about 60:40 to about 90:10 by volume and in which emulsion the hydrocarbon has a particle size predominantly of about 50 microns in diameter or less; (b) preheating such hydrocarbon-in-water emulsion prior to combustion; and (c) burning such hydrocarbon-in-water emulsion.
2. The method according to claim 1 in which the hydrocarbon is a residual oil.
3. The method according to claim 1 in which the hydrocarbon is a pitch.
4. A method for reducing particulate emissions during combustion of a hydrocarbon characterized by an asphaltene content of about 50% by weight or greater which comprises:(a) emulsifying such hydrocarbon to form a hydrocarbon-in-water emulsion having a hydrocarbon water ratio from about 60:40 to about 90:10 by volume and in which emulsion the hydrocarbon has a particle size predominantly of about 50 microns in diameter or less; (b) preheating such hydrocarbon-in-water emulsion prior to combustion; and (c) burning such hydrocarbon-in-water emulsion.
5. A method for reducing particulate emissions during combustion of a pyrolysis pitch hydrocarbon which comprises:(a) emulsifying such pyrolysis pitch hydrocarbon to form a hydrocarbon-in-water emulsion having a hydrocarbon water ratio from about 60:40 to about 90:10 by volume and in which emulsion the pyrolysis pitch hydrocarbon has a particle size predominantly of about 50 microns in diameter or less; (b) preheating such hydrocarbon-in-water emulsion prior to combustion; and (c) burning such hydrocarbon-in-water emulsion.
6. The method according to claim 1, 4, or 5 in which the hydrocarbon-in-water emulsion has a hydrocarbon: water ratio of about 70:30.
7. The method according to claim 1, 2, 4 or 5 in which the hydrocarbon in the hydrocarbon-in-water emulsion has a particle size predominantly of about 20 microns in diameter or smaller.
8. The method according to claim 1, 2, 4 or 5 in which the hydrocarbon-in-water emulsion is preheated to at least about 60° C. prior to combustion.
9. The method according to claim 1, 2, 4 or 5 in which the hydrocarbon-in-water emulsion is formed using a surfactant package which comprises about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 40% by weight of an ethoxylated alkyl phenol, or a mixture of ethoxylated alkyl phenols, of the general formula Rx C6 H4 (OC2 H4)n OH where R represents an alkyl group containing from about 8 to about 12 carbon atoms, x represents the number of alkyl groups and is either 1 or 2 and n represents the number of ethoxy groups which can range from about 1 to about 150, and about 10% by weight of an interfacially active polymeric stabilizer.
10. The method according to claim 9 in which the interfacially active polymeric stabilizer in the surfactant package is a modified lignin.
11. The method according to claim 9 in which the interfacially active polymeric stabilizer in the surfactant package is a sulfonated phenolformaldehyde polymer with a molecular weight of about 500 to about 2000 daltons.
12. The method according to claim 1 2, 4 or 7 in which the hydrocarbon-in-water emulsion is formed using a surfactant package which comprises about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 20% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 20% by weight of ethoxylated monononylphenol with about 40 ethoxy groups, and about 10% by weight of a modified lignin.
13. The method according to claim 1, 2, 4 or 5 in which the hydrocarbon-in-water emulsion is formed using a surfactant package which comprises about 47.24% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 21.38% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 21.38% by weight of ethoxylated monononylphenol with about 40 ethoxy groups and about 10% Kraft process-modified lignin.
14. The method according to claim 9 in which the surfactant package is used at a treatment rate of about 1/35 to about 1/450 based on hydrocarbon.
15. The method according to claim 12 in which the surfactant package is used at a treatment rate of about 1/35 to about 1/450 based on hydrocarbon.
16. The method according to claim 13 in which the surfactant package is used at a treatment rate of about 1/35 to about 1/450 based on hydrocarbon.
17. The method according to claim 13 in which the surfactant package is used at a treatment rate of about 1/250 based on hydrocarbon.
18. The method according to claim 1, 2, 4 or 5 in which a rheology control agent is added to the water phase of the hydrocarbon-in-water emulsion.
19. The method according to claim 18 in which the rheology control agent is xanthan.
20. The method according to claim 18 in which the rheology control agent is added to the water phase of the hydrocarbon-in-water emulsion at about 0.15% by weight water phase.
21. The method according to claim 1, 2, 4 or 5 in which the particulate emissions are reduced by a factor of at least about two compared to particulate emissions formed during combustion of the unemulsified hydrocarbon.
22. The method according to claim 7 in which the particulate emissions are reduced by a factor of at least about two compared to particulate emissions formed during combustion of the unemulsified hydrocarbon.
23. The method according to claim 1, 2, 4 or 5 in which the particulate emissions are reduced by a factor of at least about five compared to the particulate emissions formed during combustion of the unemulsified hydrocarbon.
24. The method according to claim 7 in which the particulate emissions are reduced by a factor of at least about five compared to the particulate emissions formed during combustion of the unemulsified hydrocarbon.
25. A method for reducing particulate emissions during combustion of pyrolysis pitch which comprises burning such pyrolysis pitch in the form of a pitch-in-water emulsion, said pitch-in-water emulsion having a pitch-to-water ratio of about 70:30 and being formed with a surfactant package comprising about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 20% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 20% by weight of ethoxylated monononylphenol with about 40 ethoxy groups and about 10% by weight of a modified lignin, such surfactant package being used at a treatment rate of about 1/250 based on pitch.
26. The method according to claim 25 in which the water phase of the pitch-in-water emulsion comprises about 0.15% by weight xanthan.
27. The method according to claim 25 in which the pitch-in-water emulsion is preheated to at least about 60° C. prior to burning.
28. The method according to claim 25 in which the pitch in the pitch-in-water emulsion has a particle size predominantly of about 20 microns in diameter or smaller.
29. The method according to claim 25 in which the particulate emissions are reduced by a factor of at least about two compared to the particulate emissions formed during combustion of the unemulsified pitch.
30. The method according to claim 25 in which the particulate emissions are reduced by a factor of at least about five compared to the particulate emissions formed during combustion of the unemulsified pitch.
31. A surfactant package which comprises about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 40% by weight of an ethoxylated alkyl phenol, or a mixture of ethoxylated alkyl phenols, of the general formula Rx C6 H4 (OC2 H4)n OH where R represents an alkyl group containing from about 8 to about 12 carbon atoms, x represents the number of alkyl groups and is either 1 or 2 and n represents the number of ethoxy groups which can range from about 1 to about 150, and about 10% by weight of an interfacially active polymeric stabilizer.
32. The surfactant package according to claim 31 in which the interfacially active polymeric stabilizer is a modified lignin.
33. The surfactant package according to claim 31 in which the interfacially active polymeric stabilizer is a sulfonated phenolformaldehyde polymer with a molecular weight of about 500 to about 2000 daltons.
34. A surfactant package which comprises about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 20% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 20% by weight of ethoxylated monononylphenol with about 40 ethoxy groups, and 10% by weight of a modified lignin.
35. A surfactant package which comprises about 47.24% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 21.38% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 21.38% by weight of ethoxylated mononylphenol with about 40 ethoxy groups and about 10% Kraft process-modified lignin.
36. A pre-atomized fuel comprising a hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with API gravity of about 20° API or less, viscosity of about 40,000 centipoise or greater at 122° F., paraffin content of about 50% by weight or less, and aromatic content of about 15% by weight or greater into an aqueous phase using a surfactant package which comprises about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 20% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 20% by weight of ethoxylated monononylphenol with about 40 ethoxy groups, and 10% by weight of a modified lignin in a proportion from about 1:35 to about 1:450 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume.
37. A pre-atomized fuel comprising a hydrocarbon-in-water emulsion formed by emulsifying a hydrocarbon with asphaltene content of 50% by weight or greater into an aqueous phase using a surfactant package which comprises about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 20% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 20% by weight of ethoxylated monononylphenol with about 40 ethoxy groups, and 10% by weight of a modified lignin in a proportion from about 1:35 to about 1:450 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume.
38. A pre-atomized fuel comprising a hydrocarbon-in-water emulsion formed by emulsifying pitch into an aqueous phase using a surfactant package which comprises about 50% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 20% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 20% by weight of ethoxylated monononylphenol with about 40 ethoxy groups, and 10% by weight of a modified lignin in a proportion from about 1:35 to about 1:450 by weight based on hydrocarbon, said hydrocarbon-to-water emulsion having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume.
39. A pre-atomized fuel comprising a pitch-in-water emulsion formed by emulsifying pyrolysis pitch into an aqueous phase using a surfactant package which comprises about 47.24% by weight of a poly(oxyethylene-co-oxypropylene) block copolymer, about 21.38% by weight of ethoxylated dinonylphenol with about 150 ethoxy groups, about 21.38% by weight of ethoxylated monononylphenol with about 40 ethoxy groups and about 10% Kraft process-modified lignin in a proportion from about 1:35 to about 1:450 by weight based on hydrocarbon, said hydrocarbon-in-water emulsion having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume.
| 1985-10-15 | en | 1987-05-19 |
US-66726596-A | Poly(ethylene oxalate), product formed of molded therefrom and production process of poly(ethylene oxalate)
ABSTRACT
The invention provides poly(ethylene oxalate) containing recurring units represented by the following formula (1): ##STR1## in a proportion of at least 60 basal mol %, wherein (a) the solution viscosity (η inh ) is at least 0.25 dl/g as measured at 30° C. and a polymer concentration of 0.40 g/dl in a 4:1 (by weight) mixed solvent of m-chlorophenol and 1,2,4-trichloro-benzene,
(b) the melt viscosity (η*) is at least 30 Pa.s as measured at 190° C. and a shear rate of 1,000/sec, and
(c) the density is at least 1.48 g/cm 3 as measured in an amorphous state,
various products formed or molded from the poly(ethylene oxalate) and a production process of the poly(ethylene oxalate). The polymer is high-molecular weight and excellent in melt processability, heat resistance, crystalline properties, mechanical properties and the like, and has good degradability in soil.
FIELD OF THE INVENTION
The present invention relates to poly(ethylene oxalate) which is a biodegradable polymeric material, and more particularly to high-molecular weight poly(ethylene oxalate) excellent in melt processability, heat resistance, crystalline properties, mechanical properties and the like, various products formed or molded from the poly(ethylene oxalate) and a production process of the poly(ethylene oxalate).
Since the poly(ethylene oxalate) according to the present invention has good degradability in soil, it can lighten the burden imposed on the environment. In the poly(ethylene oxalate) according to the present invention, oxalic acid is used as a raw material therefor. Since oxalic acid can be prepared by electrolysis or the like of carbon dioxide in the amosphere, the poly(ethylene oxalate) can be said to be a sort of polymer making good use of carbon dioxide.
The poly(ethylene oxalate) in the present invention is a polymer containing, as a principal component, recurring units having a structure that ethylene oxalate, which is a cyclic ester, is ring-opened, and includes a homopolymer and copolymers.
BACKGROUND OF THE INVENTION
Polymeric materials typified by plastics have hitherto been developed and produced in search of high performance and long-term stability. Therefore, many of the polymeric materials are not decomposed in a natural environment, and so the waste disposal and environmental pollution of plastic products have become a great problem on a world-wide scale. In recent years, there has thus been a strong demand for development of a biodegradable polymeric material which can lighten the burden imposed on the environment. In a biodegradation process of a biodegradable polymeric material, in general, a lytic enzyme externally secreted by microorganisms is first adsorbed on the surface of the material to break chemical linkages such as ester linkages, glycoside linkages or peptide linkages in a polymeric chain by hydrolysis. The polymeric material is degraded by the breaking of the chemical linkages to form low-molecular weight products. The low-molecular weight products are further enzymolyzed to form lower molecular weight products such as monomers and dimers in terms of monomer unit. Whether a polymeric material is biodegradable or not can be determined, for example, by burying a product molded or formed from the polymeric material under the ground and then observing whether the product is degraded or not after a fixed period of time.
As examples of biodegradable polymeric materials developed to date, may be mentioned (A) polymeric materials comprising, as a principal component, a natural substance such as starch or protein; (B) nonaromatic polyesters containing asymmetric carbon atoms; and (C) nonaromatic polyesters containing no asymmetric carbon atom. However, the polymeric materials comprising, as a principal component, the natural substance are poor in melt processability, water resistance, mechanical properties and the like and have been unsatisfactory from the viewpoint of practical use. The nonaromatic polyesters containing the asymmetric carbon atoms are low in productivity because a culture process making use of microorganisms is essential in a production step of a raw monomer or a production step of a polymer. As a result, such polyesters have become extensive and have hence been extremely unsatisfactory from the viewpoint of cost. As examples of the nonaromatic polyesters containing no asymmetric carbon atom, may be mentioned aliphatic polyesters containing no asymmetric carbon atom, such as polysuccinates and polycaprolactone. However, many of these aliphatic polyesters are low in heat resistance as demonstrated by their melting points of about 110° C. or lower and have been difficult to apply to, in particular, fields of food packaging materials and the like, of which high heat resistance is required for sterilization and cooking.
On the other hand, poly(ethylene oxalate) is a nonaromatic polyester containing no asymmetric carbon atom as disclosed in the following documents (i) to (iv) and are known as a polymer having a high melting point. However, the conventional polymers are too low in molecular weight to melt-process, or are poor in mechanical properties, and have hence been worth little from the viewpoint of practical use.
(i) W. H. Carothers et al. reported that ethylene glycol and diethyl oxalate are heated to prepare an ester, and the ester is subjected to fractional crystallization to obtain poly(ethylene oxalate) having a melting point of 153° C. as a high-molecular weight fraction J. Am. Chem. Soc., 52, pp. 3292 (1930)!. When this polymer is heated in a vacuum, depolymerization occurs to form ethylene oxalate of the monomer (1,4-Dioxane-2,3-dione). When this monomer is left at rest at room temperature, polymerization takes place. It was reported that this polymerization reaction is accelerated by heating to form a polymer having a melting point of 172° C. However, the poly(ethylene oxalate) obtained in this process is a low-molecular weight substance near to an oligomer rather than a polymer and cannot be applied to common melt processing techniques. Therefore, the formation of melt-formed products such as films and fibers and physical properties thereof were not reported.
(ii) W. K. Cline et al. proposed a method of preparing poly(ethylene oxalate) having film- and fiber-forming properties by heating cyclic ethylene oxalate at a temperature of about 165° C. to about 210° C. in a nitrogen atmosphere with a catalyst such as antimony trifluoride or stannic chloride (U.S. Pat. No. 3,197,445). The cyclic ethylene oxalate of a monomer is prepared by condensation of diethyl oxalate with ethylene glycol using sodium as a catalyst to synthesize a waxy prepolymer and depolymerizing this prepolymer at 191°-216° C., preferably 175°-190° C. under reduced pressure. The purification of the monomer is performed by sublimation at 190°-210° C. under reduced pressure. Then, the purified monomer was subjected by ring opening polymerization using a catalyst such as antimony trifluoride. However, the poly(ethylene oxalate) obtained by this method is still too low in molecular weight, and it was barely reported to obtain fiber-like product by inserting and withdrawing a glass rod in and from a polymeric melt. Therefore, the physical property values of films and fibers were not reported.
(iii) A. Alksnis et al. reported that anhydrous oxalic acid and ethylene glycol are heated in the presence of p-toluenesulfonic acid in benzene at the reflux temperature of benzene to prepare oligo(ethylene oxalate), and the oligomer is then heated under vacuum in the presence of SnCl2.2H2 O to transesterify the oligomer, thereby obtaining poly(ethylene oxalate) having fiber-forming properties J. Polymer Sci.: Polymer Chemistry Ed., Vol. 15, pp. 1855 (1977)!. However, the poly(ethylene oxalate) obtained by this process is low in molecular weight, and the density of its crystallized product is also as low as at most 1.45 g/cm3. Further, the measurement of its melt viscosity could barely be measured in such a way as the polymer is melted once, and its melt viscosity then measured at a temperature (175° C.) lower than the melting point (178° C.) of the polymer in a supercooling state. Therefore, this polymer is naturally unsuitable for use in melt forming or molding, so that no satisfactory melt-formed or molded product can be provided therefrom, and no report about physical properties of products molded or formed therefrom was made.
(iv) G. E. Zaikov et al. obtained poly(ethylene oxalate) by the polymerization of ethylene oxalate Polymer Degradation and Stability, 9 (1984) pp. 41-50!. Even in crystallized fibers thereof (crystallinity: 73%), however, the density is as extremely low as 1.475 g/cm3. Since the density of normal crystallized poly(ethylene oxalate) is usually 1.50 g/cm3 or higher, the density of the poly(ethylene oxalate) provided by Zaikov et al. is abnormally low, and it is hence considered to be a polymer extremely low in degree of polymerization. Accordingly, this polymer cannot be possibly considered a polymer possible to melt-form or mold.
On the other hand, reports have been scarcely made of copolymers of ethylene oxalate, which each have a sufficiently high molecular weight to permit the application of melt forming or molding. It goes without saying that there is no report about the fact that copolymerization is performed with a view toward improving the melt processability of poly(ethylene oxalate).
Although Zaikov et al. simultaneously reported about a copolymer of ethylene oxalate, the resulting copolymer has a density very low as 1.46 g/cm3 as measured in the form of tablets, and is a copolymer extremely low in the degree of polymerization as demonstrated by the numerical mean of the degree of polymerization of 160. Accordingly, this copolymer cannot be possibly considered a polymer possible to melt-process.
As described in detail above, the prior art poly(ethylene oxalates) have been polymers relatively low in molecular weight and difficult to form or mold into films, fibers and other products having satisfactory physical properties in accordance with the common melt processing techniques. It has also not been proposed to mold or form poly(ethylene oxalate) as a biodegradable polymeric material into various products to use them.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide poly(ethylene oxalate) high in molecular weight and excellent in melt processability, heat resistance, crystalline properties, mechanical properties and the like, various products formed or molded from the poly(ethylene oxalate), and a production process of the poly(ethylene oxalate).
Another object of the present invention is to provide poly(ethylene oxalate) improved in melt processability. More specifically, the object of the present invention is to provide an ethylene oxalate copolymer easy to melt-process, which is improved in heat stability upon melt processing, by a copolymerization process.
A further object of the present invention is to provide poly(ethylene oxalate) which is a biodegradable polymeric material having good degradability in soil, and products formed or molded therefrom.
The present inventors have paid attention to the fact that poly(ethylene oxalate) may become a biodegradable polymeric material having good heat resistance because it has a high melting point and ester linkages in its molecular chain. The inventors have carried out various investigations as to the cause that no high-molecular weight poly(ethylene oxalate) has heretofore been obtained. As a result, it has been found that a high-molecular weight polymer can be obtained by effectively removing impurities present in a monomer. It is also desirable that a ring-opening polymerization reaction be performed at a relatively low temperature.
The poly(ethylene oxalate) according to the present invention is high-molecular weight compared with those obtained by the conventional processes, can be formed or molded into films, fibers, injection-molded products or the like by melt processing techniques, and can lighten the burden imposed on the environment because it exhibits good degradability in soil. The present invention has been led to completion on the basis of these findings.
According to the present invention, there is thus provided poly(ethylene oxalate) containing recurring units represented by the following formula (1): ##STR2## in a proportion of at least 60 basal mol %, wherein (a) the solution viscosity (ηinh) is at least 0.25 dl/g as measured at 30° C. and a polymer concentration of 0.40 g/dl in a 4:1 (by weight) mixed solvent of m-chlorophenol and 1,2,4-trichloro-benzene,
(b) the melt viscosity (η*) is at least 30 Pa.s as measured at 190° C. and a shear rate of 1,000/sec, and
(c) the density is at least 1.48 g/cm3 as measured in an amorphous state.
According to the present invention, there are also provided various products formed or molded from the high-molecular weight poly(ethylene oxalate), such as sheets, films, fibers and injection-molded products.
According to the present invention, there are further provided the following production processes 1 and 2 of poly(ethylene oxalate).
1. A process for the production of poly(ethylene oxalate), which comprises subjecting a cyclic ethylene oxalate monomer obtained by depolymerizing an ethylene oxalate oligomer to ring-opening polymerization by heating the monomer in an inert gas atmosphere, wherein a monomer purified by (i) washing the ethylene oxalate oligomer with an organic solvent to purify, (ii) heating the thus-purified oligomer under reduced pressure to depolymerize, thereby sublimating a monomer formed, and then (iii) recrystallizing the monomer obtained by the sublimation from an organic solvent is used as the cyclic ethylene oxalate monomer.
2. A process for the production of poly(ethylene oxalate), which comprises subjecting a cyclic ethylene oxalate monomer obtained by depolymerizing an ethylene oxalate oligomer to ring-opening polymerization by heating the monomer in an inert gas atmosphere, wherein a monomer obtained by (I) heating a mixture containing the ethylene oxalate oligomer and a high-boiling polar organic solvent under ordinary pressure or reduced pressure to a temperature at which the depolymerization of the oligomer occurs, thereby dissolving the oligomer in the polar organic solvent, (II) further continuing the heating to depolymerize the oligomer in a solution phase, thereby distilling out a monomer formed together with the polar organic solvent, and then (III) recovering the monomer from the distillate is used as the cyclic ethylene oxalate monomer.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will hereinafter be described in detail.
Structure of polymer:
The chemical structure of the poly(ethylene oxalate) according to the present invention is a nonaromatic polyester containing recurring units represented by the formula (1) in a proportion of at least 60 basal mol %, preferably at least 80 basal mol %, more preferably at least 90 basal mol %. Poly(ethylene oxalate) containing the recurring units represented by the formula (1) in a proportion exceeding 99 basal mol % is substantially a homopolymer.
If the proportion of the recurring units (1) is lower than 60 basal mol %, the resulting poly(ethylene oxalate) has a possible problem that its degradability in soil may be impaired, or its heat resistance, crystallinity, mechanical properties and/or the like may be deteriorated.
Exemplary recurring units other than the recurring unit of the formula (1) may include a recurring unit represented by the following formula (2): ##STR3## a recurring unit represented by the following formula (3): ##STR4## wherein n is integer of 1-6, and a recurring unit represented by the following formula (4): ##STR5## wherein m is an integer of 0-6.
The poly(ethylene oxalate) according to the present invention may be roughly divided into polymers of Group (I), which are homopolymers or near homopolymers, and polymers of Group (II), in which the physical properties of the homopolymers are modified by copolymerization, according to the content of copolymerizing components.
The polymers of Group (I) are polymers containing the recurring units of the formula (1) in a proportion exceeding 99 basal mol % and substantially homopolymers. The polymers belonging to Group (I) are characterized by high performance such as high crystallization rate, high melting point, high strength and high modulus of elasticity.
The polymers of Group (II) are polymers containing 60-99 basal mol % of the recurring units of the formula (1) and 1-40 basal mol % of other recurring units selected from those represented by the formulae (2)-(4) and the like. The polymers belonging to Group (II) are characterized by ease of melt processing, such as low crystallization rate, low melting point and high heat stability upon melting.
The recurring units of the formulae (2)-(4) can be introduced into the molecular chain of the poly(ethylene oxalate), for example, by using, as a comonomer, at least one cyclic monomer selected from the group consisting of lactides, glycolides, lactones (having at most 7 carbon atoms) and alkylene oxalates (the alkylene group of which has 3-9 carbon atoms), and subjecting the comonomer to ring-opening copolymerization with the cyclic ethylene oxalate monomer. The copolymerization is carried out in such a manner that these recurring units are contained in a proportion of at least 0.1 basal mol %, whereby the crystallization rate of the resulting poly(ethylene oxalate) can be controlled to improve its melt processability. However, if the proportion of these comonomers containing in the resulting copolymer is too high, the copolymer becomes noncrystalline, so that defects such as impaired heat resistance are liable to develop. Accordingly, the upper limit of the proportion of the recurring units derived from the comonomers is 40 basal mol %, preferably 30 basal mol %. Incidentally, each recurring unit is called one basal mole in the present invention.
Since the lactide and glycolide are cyclic diesters, 2 basal moles of recurring units are generally formed from 1 mole of each of these monomers. The recurring unit derived from the lactide is represented by the formula (2). The recurring unit derived from the glycolide is represented by the formula (3) in which n is 1.
As examples of the lactones, may be mentioned β-propiolactone, β-butyrolactone, pivalolactone, γ-butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone and ε-caprolactone. The recurring unit derived from the lactone is represented by the formula (3) in which n is 2-6.
As examples of the alkylene oxalates, may be mentioned those the alkylene group of which has 3-9 carbon atoms, such as propylene oxalate. The recurring unit derived from the alkylene oxalate is represented by the formula (4).
Physical properties of polymer:
The poly(ethylene oxalate) according to the present invention is a biodegradable polymeric material, which has a high molecular weight, is excellent in heat resistance, crystalline properties, mechanical strength, melt processability and the like and shows good degradability in soil.
<Molecular weight>
The poly(ethylene oxalate) according to the present invention is a high-molecular weight polymer. The molecular weight of the poly(ethylene oxalate) can be evaluated by its solution viscosity (ηinh) and melt viscosity (η*).
The solution viscosity (ηinh) of the poly(ethylene oxalate) according to the present invention is at least 0.25 dl/g, preferably at least 0.30 dl/g, more preferably at least 0.50 dl/g. The solution viscosity (ηinh) is a value obtained by viscosity measurement at 30° C. and a polymer concentration of 0.40 g/dl in a 4:1 (by weight) mixed solvent of m-chlorophenol and 1,2,4-trichlorobenzene. If the solution viscosity of the poly(ethylene oxalate) is lower than 0.25 dl/g, the molecular weight thereof is low, so that a product formed or molded from such a polymer by melt processing may possibly be insufficient in mechanical properties from the viewpoint of practical use. Besides, if the solution viscosity is lower than 0.25 dl/g, the melt viscosity (η*) of the poly(ethylene oxalate) also becomes low, so that such a polymer may possibly be difficult to melt-process.
The melt viscosity (η*) of the poly(ethylene oxalate) according to the present is at least 30 Pa.s, preferably at least 50 Pa.s, more preferably at least 100 Pa.s. The melt viscosity (η*) is a value obtained by viscosity measurement at 190° C. and a shear rate of 1,000/sec. If the melt viscosity (η*) of the poly(ethylene oxalate) is lower than 30 Pa.s, drawdown or melt-down tend to occur upon its extrusion, so that such a polymer may possibly be difficult to melt-form or mold. In the case of, for example, melt spinning of the poly(ethylene oxalate), severe drawdown upon melt extrusion makes spinning difficult or impossible. In addition, if the melt viscosity is too low, products formed or molded from the polymer by melt processing may possibly be insufficient in mechanical properties from the viewpoint of practical use.
<Thermal properties>
Although the poly(ethylene oxalate) according to the present invention is high in melting point, crystallinity and crystallization rate, its thermal properties may be widely varied by changing the composition upon copolymerization. More specifically, (A) a crystalline polymer high in crystallization rate, (B) a crystalline polymer low in crystallization rate and (C) a substantially noncrystalline polymer may be obtained by changing the kinds of copolymerizing components, the proportion of the copolymerizing components upon the copolymerization, and/or the like.
(A) Crystalline poly(ethylene oxalate) high in crystallization rate:
Those belonging to this kind of polymers are homopolymers of ethylene oxalate or copolymers containing copolymerizing components other than ethylene oxalate in an extremely low proportion. Namely, the polymers of Group (I) correspond to the poly(ethylene oxalate) of this kind. However, those containing the copolymerizing components in an extremely low proportion among the polymers of Group (II) may also correspond to this kind of polymers in some cases.
Such poly(ethylene oxalate) typically has the following thermal properties:
(1) the melting point (Tm) being at least 130° C.;
(2) the melt enthalpy (ΔHm) being at least 20 J/g; and
(3) the melt crystallization enthalpy (ΔHmc) being at least 20 J/g.
The melting point (Tm) and melt enthalpy (ΔHm) are a melting point and a melt enthalpy detected when heating an amorphous sheet sample 0.2 mm thick by means of a differential scanning calorimeter (DSC) at a rate of 10° C./min in an inert gas atmosphere. The melt crystallization enthalpy (ΔHmc) is a melt crystallization enthalpy detected when cooling the amorphous sheet sample at a rate of 10° C./min immediately after heating the amorphous sheet sample to 220° C.
The crystalline poly(ethylene oxalate) high in crystallization rate generally has high heat resistance of at least 130° C., preferably at least 150° C., more preferably at least 170° C. in terms of melting point (Tm). Poly(ethylene oxalate) having a melting point (Tm) lower than 130° C. is insufficient in heat resistance, so that when it is used as, for example, a food packaging material, its sterilizing treatment such as retorting becomes difficult. Accordingly, it is difficult to use such a polymer in fields of food packaging materials, wrapping materials for electronic ranges, medical materials, and the like.
As an index to the crystallinity of the crystalline poly(ethylene oxalate) high in crystallization rate, the polymer has a melt enthalpy (ΔHm) of at least 20 J/g, preferably at least 30 J/g, more preferably at least 40 J/g. If the melt enthalpy (ΔHm) is smaller than 20 J/g, it is difficult for the polymer to achieve the heat resistance of at least 130° C., and the resulting molded or formed products may also possibly be insufficient in mechanical properties. As an index to the crystallization rate of the crystalline poly(ethylene oxalate) high in crystallization rate, the polymer has a melt crystallization enthalpy (ΔHmc) of at least 20 J/g, preferably at least 25 J/g, more preferably at least 30 J/g.
The poly(ethylene oxalate) having the above-described thermal properties is particularly suitable for use in molding or forming such as injection molding, multifilament spinning and melt blowing.
(B) Crystalline poly(ethylene oxalate) low in crystallization rate:
Those belonging to this kind of polymers are copolymers containing the recurring units of the formula (1) as a principal component and a small amount of copolymerizing components. Namely, among the polymers of Group (II), copolymers containing the copolymerizing components in a low proportion correspond to the poly(ethylene oxalate) of this kind.
Such poly(ethylene oxalate) typically has the following thermal properties:
(1) the melting point (Tm) being at least 130° C.;
(2) the melt enthalpy (ΔHm) being at least 20 J/g; and
(3) the melt crystallization enthalpy (ΔHmc) being smaller than 20 J/g.
The melting point (Tm), which is used as an index to the heat resistance, and the melt enthalpy (ΔHm), which is used as an index to the crystallinity, are almost the same as those in Group (A). What differs from those in Group (A) is crystallization rate. As an index to the crystallization rate of the crystalline poly(ethylene oxalate) low in crystallization rate, the polymer has a melt crystallization enthalpy (ΔHmc) smaller than 20 J/g, preferably smaller than 15 J/g.
The poly(ethylene oxalate) high in crystallization rate in Group (A) is easy to form coarse crystals upon its extrusion or the like, so that the resulting formed product may possibly become deteriorated. However, when its crystallization rate is made low by copolymerization (Group II) or other means like the polymers in Group (B), the formation of the coarse crystals upon melt processing can be reduced. According to the poly(ethylene oxalate) low in crystallization rate as described above, forming such as monofilament spinning, inflation, blowing and besides extrusion such as T-die extrusion may be improved.
(C) Substantially noncrystalline poly(ethylene oxalate):
Those belonging to this kind of polymers are copolymers containing the recurring units of the formula (1) as a principal component and a relatively great amount of copolymerizing components. Namely, among the polymers of Group (II), copolymers containing the copolymerizing components in a high proportion correspond to the poly(ethylene oxalate) of this kind.
<Heat stability upon melt processing--ease of melt processing>
Since the prior art poly(ethylene oxalate) is unstable to heating, and its thermal decomposition temperature, Td is near to its melting point, Tm, the polymer may possibly undergo thermal decomposition when heating the polymer to a temperature not lower than Tm to melt it upon melt processing, so that difficulty has been encountered on the melt processing. On the other hand, the poly(ethylene oxalate) according to the present invention is considerably improved in heat stability even in a homopolymer because it is produced by ring-opening polymerization of a monomer high in purity. Therefore, its melt processing has come to be feasible with ease.
When Tm of a polymer of Group (II) described above is lowered without greatly lowering its Td by adding a suitable amount of the copolymerizing components, thereby widening a difference between Tm and Td, the heat stability at its melt-processing temperature (usually, Tm+about 10° C.) is widely improved, so that the melt processing becomes feasible with more ease.
The heat stability of a polymer upon melt processing can be quantitatively evaluated, for example, by an average rate of weight loss an average rate of weight loss for 30 minutes from the beginning at a melt-processing temperature (i.e., Tm+10° C.)! on thermal decomposition at the melt-processing temperature in an inert atmosphere in accordance with the TGA process. According to this evaluation, the average rate of weight loss at (Tm+10° C.) of the poly(ethylene oxalate) according to the present invention is generally at most 0.5 wt. %/min, preferably at most 0.3 wt. %/min, more preferably at most 0.2 wt. %/min. On the other hand, the average rate of weight loss of the prior art poly(ethylene oxalate) is high, and so such a polymer is poor in heat stability.
As a method for improving the heat stability of the poly(ethylene oxalate) according to the present invention, there is a method in which a comonomer in an amount of at least 1 basal mol % is suitably copolymerized. This method permits the provision of a polymer improved in the heat stability to such an extent that its average rate of weight loss is reduced to at most 0.1 wt. %/min, or further to at most 0.05 wt. %/min according to conditions.
Such poly(ethylene oxalate) is typically a polymer the melt enthalpy (ΔHm) as an index to the crystallinity of which is smaller than 20 J/g, preferably smaller than 15 J/g. Since the noncrystalline poly(ethylene oxalate) is poor in heat resistance and crystallinity, it may be used in fields of polymer blends, optical materials and the like.
<Density>
The poly(ethylene oxalate) according to the present invention is a high-density polymer whose density is at least 1.48 g/cm3, preferably at least 1.51 g/cm3 as measured in an amorphous state. A polymer whose density is lower than 1.48 g/cm3 as measured in an amorphous state is insufficient in molecular weight and so low in heat stability that foaming occurs upon its melt processing. Therefore, its melt processability and the mechanical properties of products formed or molded from such a polymer by melt processing are extremely unsatisfactory.
<Biodegradability>
The poly(ethylene oxalate) according to the present invention shows good degradability in soil and is hence rated as a biodegradable polymeric material. The degradability in soil can be evaluated by forming an amorphous sheet sample 0.2 mm thick from the poly(ethylene oxalate), burying the sheet sample at the depth of 10 cm under the ground such as a plowland and then observing whether the sheet sample is degraded within a year to lose its original form, or not.
The poly(ethylene oxalate) according to the present invention is degraded in soil within a year. More specifically, the beginning of the degradation is observed in a half month to a month. The reason why the poly(ethylene oxalate) according to the present invention shows good degradability in soil is considered to be attributable to the fact that it is a nonaromatic polyester, and besides it is easy to be digested by microorganisms in soil because it does substantially not contain any asymmetric carbon atom.
Forming or Molding Products:
The poly(ethylene oxalate) according to the present invention can be formed or molded by melt processing into various products such as extruded products of fibers, sheets, films and the like, and injection-molded products. The formed or molded products according to the present invention are characterized by good degradability in soil, high heat resistance, high mechanical properties and the like.
<Unoriented film>
The poly(ethylene oxalate) according to the present invention, which has a melt enthalpy (ΔHm) of at least 20 J/g and is crystalline, can be formed into unoriented amorphous or crystallized sheets (including films). The poly(ethylene oxalate) can be in an industrial scale formed into a sheet (or film) by using an extruder equipped with a T-die and extruding it in the form of a sheet through the T-die at a temperature not lower than its melting point (Tm), for example, in a temperature range of from Tm to (Tm+50° C.). The sheet extruded is generally taken up on a roll. The thickness of the sheet is generally of the order of 1 μm to 3 mm.
The unoriented amorphous sheet formed from the poly(ethylene oxalate) according to the present invention is colorless and extremely high in transparency. When this amorphous sheet is subjected to a heat treatment (heat treatment under fixed length) in a fixed state within a temperature range of from the crystallization temperature (Tc) to the melting point (Tm) for 1 second to 10 hours, an unoriented crystallized sheet can be obtained. The unoriented crystallized sheet according to the present invention is a translucent, tough sheet hard to break even when it is bent.
The unoriented heat-set sheet (unoriented crystallized sheet) formed from the crystalline poly(ethylene oxalate) according to the present invention has the following physical properties:
(1) melting point (Tm): at least 130° C.,
(2) density: at least 1.50 g/cm3,
(3) tensile strength: at least 0.05 GPa,
(4) modulus in tension: at least 1.0 GPa,
(5) elongation: at least 3%, and
(6) heat shrinkage (110° C./10 min): at most 30%.
In particular, the unoriented heat-set sheet formed from the poly(ethylene oxalate), which contains the recurring units represented by the formula (1) in a proportion of at least 90 basal mol % and belongs to Group (I) or a part of Group (II), has the following physical properties:
(1) melting point (Tm): at least 170° C., preferably at least 175° C.,
(2) density: at least 1.53 g/cm3,
(3) tensile strength: at least 0.06 GPa, preferably at least 0.08 GPa,
(4) modulus in tension: at least 1.2 GPa, preferably at least 1.5 GPa,
(5) elongation: at least 3%, and
(6) heat shrinkage (110° C./10 min): at most 20%.
The glass transition temperature (Tg) of the unoriented sheet is generally 20°-50° C. However, it may be lowered to a temperature below that by changing the composition upon copolymerization or adding a plasticizer.
<Uniaxially oriented film>
A uniaxially oriented film (or sheet) can be obtained by uniaxially stretching the amorphous sheet of the poly(ethylene oxalate). More specifically, the amorphous sheet is uniaxially stretched 2-20 times by area by means of rolls or a tenter, generally, within a temperature range of from the glass transition temperature (Tg) to the crystallization temperature (Tc), thereby orienting it. The film obtained by the uniaxial stretching is subjected to a heat treatment (heat treatment under fixed length), generally, in a fixed state within a temperature range of from the crystallization temperature (Tc) to the melting point (Tm) for 1 second to 10 hours, whereby the film can be changed into a tough heat-set film. The thickness of the uniaxially oriented film is generally 1 μm to 3 mm.
The polymer low in crystallization rate belonging to Group (II) is hard to form coarse spherulites upon the formation of the amorphous sheet, and hence tends to provide a uniaxially oriented film having excellent physical properties in particular.
The uniaxially oriented film formed from the crystalline poly(ethylene oxalate) according to the present invention has the following physical properties:
(1) melting point (Tm): at least 130° C.,
(2) density: at least 1.50 g/cm3,
(3) tensile strength (oriented direction): at least 0.07 GPa,
(4) modulus in tension (oriented direction): at least 1.0 GPa,
(5) elongation (oriented direction): at least 3%, and
(6) heat shrinkage (110° C./10 min) (oriented direction): at most 30%.
In particular, the uniaxially oriented film formed from the poly(ethylene oxalate), which contains the recurring units represented by the formula (1) in a proportion of at least 90 basal mol % and belongs to Group (I) or a part of Group (II), has the following physical properties:
(1) melting point (Tm): at least 170° C., preferably at least 175° C.,
(2) density: at least 1.53 g/cm3,
(3) tensile strength (oriented direction): at least 0.10 GPa, preferably at least 0.15 GPa,
(4) modulus in tension (oriented direction): at least 1.2 GPa, preferably at least 1.5 GPa,
(5) elongation (oriented direction): at least 3%, and
(6) heat shrinkage (110° C./10 min) (oriented direction): at most 20%.
The glass transition temperature (Tg) of the uniaxially oriented film is generally 20°-50° C. However, it may be lowered to a temperature below that by changing the composition upon copolymerization or adding a plasticizer.
<Biaxially oriented film>
A biaxially oriented film (or sheet) can be obtained by biaxially stretching the amorphous sheet of the poly(ethylene oxalate). More specifically, the amorphous sheet is biaxially stretched 2-20 times by area by means of rolls and a tenter, generally, within a temperature range of from the glass transition temperature (Tg) to the crystallization temperature (Tc), thereby orienting it. The film obtained by the biaxial stretching is subjected to a heat treatment (heat treatment under fixed length), generally, in a fixed state or in a tensioned state within a temperature range of from the crystallization temperature (Tc) to the melting point (Tm) for 1 second to 10 hours, whereby the film can be changed into a tough heat-set film. The thickness of the biaxially oriented film is generally 1 μm to 3 mm.
Besides, the crystalline poly(ethylene oxalate) according to the present invention can be extruded by means of an extruder equipped with a ring die or the like within a temperature range of from Tm to (Tm+50° C.) and inflated 2-20 times by area in accordance with the inflation process, thereby forming it into a biaxially oriented film. This film can also be changed into a tough heat-set film by subjecting it to a heat treatment within a temperature range of from Tc to Tm.
The polymer low in crystallization rate belonging to Group (II) is hard to form coarse spherulites upon the formation of the amorphous sheet or the inflation, and hence tends to provide a biaxially oriented film having excellent physical properties in particular.
The biaxially oriented film formed from the crystalline poly(ethylene oxalate) according to the present invention has the following physical properties (physical properties in the maximum stretching direction):
(1) melting point (Tm): at least 130° C.,
(2) density: at least 1.50 g/cm3,
(3) tensile strength: at least 0.07 GPa,
(4) modulus in tension: at least 1.0 GPa,
(5) elongation: at least 3%, and
(6) heat shrinkage (110° C./10 min): at most 30%.
In particular, the biaxially oriented film formed from the poly(ethylene oxalate), which contains the recurring units represented by the formula (1) in a proportion of at least 90 basal mol % and belongs to Group (I) or a part of Group (II), has the following physical properties:
(1) melting point (Tm): at least 170° C., preferably at least 175° C.,
(2) density: at least 1.53 g/cm3,
(3) tensile strength: at least 0.10 GPa, preferably at least 0.15 GPa,
(4) modulus in tension: at least 1.2 GPa, preferably at least 1.5 GPa,
(5) elongation: at least 3%, and
(6) heat shrinkage (110° C./10 min): at most 20%, preferably at most 10%.
The glass transition temperature (Tg) of the biaxially oriented film is generally 20°-50° C. However, it may be lowered to a temperature below that by changing the composition upon copolymerization or adding a plasticizer.
<Fibers>
The crystalline poly(ethylene oxalate) according to the present invention can be used for melt-spinning, thereby obtaining fibers. More specifically, the polymer is extruded by means of an extruder equipped with a spinning nozzle having a single orifice or plural orifices in a temperature range of from Tm to (Tm+50° C.) in accordance with the conventional melt spinning process, and the thus-obtained extrudate is taken up at a take-up ratio R1 (take-up speed/extrusion speed) of 2-1,000, further stretched 1-20 times as needed, and subjected to a heat treatment within a temperature range of from Tc to Tm, whereby tough heat-set fibers can be obtained. The poly(ethylene oxalate) according to the present invention can be formed directly into nonwoven fabric by a melt blowing process or the like. The diameter of the fibers is generally of the order of 1 μm to 1 mm.
The polymer low in crystallization rate belonging to Group (II) is hard to form coarse spherulites upon melt spinning of large-diameter yarn such as a monofilament, and hence tends to provide excellent large-diameter yarn in particular.
The fibers formed from the crystalline poly(ethylene oxalate) according to the present invention have the following physical properties:
(1) melting point (Tm): at least 130° C.,
(2) density: at least 1.50 g/cm3,
(3) tensile strength: at least 0.07 GPa,
(4) modulus in tension: at least 3.0 GPa,
(5) elongation: at least 3%, and
(6) heat shrinkage (110° C./10 min): at most 40%.
In particular, the fibers formed from the poly(ethylene oxalate), which contains the recurring units represented by the formula (1) in a proportion of at least 90 basal mol % and belongs to Group (I) or a part of Group (II), have the following physical properties:
(1) melting point (Tm): at least 170° C., preferably at least 175° C.,
(2) density: at least 1.53 g/cm3,
(3) tensile strength: at least 0.15 GPa, preferably at least 0.25 GPa,
(4) modulus in tension: at least 4.0 GPa, preferably at least 6.0 GPa,
(5) elongation: at least 3%, and
(6) heat shrinkage (110° C./10 min): at most 30%.
<Injection-molded product>
The crystalline poly(ethylene oxalate) according to the present invention can be molded into products of various shapes by an injection molding process. The poly(ethylene oxalate) is used for injection molding either as a neat resin by itself or as a composition by blending it with a filler (an inorganic filler and/or a fibrous filler) and other resins. The crystalline poly(ethylene oxalate) according to the present invention can be molded into a tough product by using an injection molding machine equipped with an injection mold and injecting it under conditions of a cylinder temperature within a range of from Tm to (Tm+50° C.), a mold temperature within a range of from 0° to 150° C. and an injection pressure within a range of from 0.01 to 1,000 GPa.
In the injection molding, the poly(ethylene oxalate) high in crystallization rate, which belongs to Group (I) or a part of Group (II), permits injection molding in a high-speed cycle.
The injection-molded product formed from the crystalline poly(ethylene oxalate) according to the present invention has the following physical properties:
(1) melting point (Tm): at least 130° C., preferably at least 170° C.,
(2) flexural strength: at least 0.01 GPa, preferably at least 0.02 GPa, and
(3) modulus in flexure: at least 1.0 GPa, preferably at least 2.0 GPa.
When compositions containing the poly(ethylene oxalate) according to the present invention are used, injection-molded products having various physical properties can be obtained according to the kinds and blending amounts of fillers and blending resins.
Resin composition:
The poly(ethylene oxalate) according to the present invention may be used by itself and, if desired, may be blended with natural or synthetic polymeric materials, fillers and other additives to use it as compositions.
As examples of various materials to be blended, may be mentioned plastic materials such as polycaprolactone, polylactic acid, polyglycolic acid, polysuccinates, poly(3-hydroxybutanoic acid), (3-hydroxybutanoic acid/4-hydroxybutanoic acid) copolymers, starch, cellulose acetate, chitosan, alginic acid, polyvinyl alcohol, polyethylene, polyvinyl acetate, polyvinyl chloride, polystyrene and polyglutamates; rubbers and elastomers such as natural rubber, polyester elastomer, polyamide elastomer, styrene-butadiene-styrene block copolymers (SBS) and hydrogenated SBS; reinforcing fibers such as carbon fibers, silica fibers and glass fibers; inorganic fillers such as carbon black, silica powder, alumina powder, titanium oxide powder, talc, clay and calcium sulfate; and the like. These materials may be blended either singly or in any combination thereof.
The poly(ethylene oxalate) according to the present invention may be blended with plasticizers such as aliphatic monobasic acid esters (butyl oleate etc.), aliphatic dibasic acid esters (hexyl adipate etc.), oxyacid esters (triethyl acetylcitrate etc.) and phthalates (dibutyl phthalate etc.). The compositions obtained by blending these plasticizers can provide flexible formed or molded products having a glass transition temperature not higher than ordinary temperature and may be used in, for example, food packaging materials, wrapping materials and the like.
A low-boiling alcohol, low-boiling ether or the like may be sorbed in the poly(ethylene oxalate) according to the present invention to foam the polymer by heating, thereby providing formed or molded foams. Besides, formed or molded foams may be provided with ease even by a method of partially and pyrolytically decomposing the polymer itself.
The poly(ethylene oxalate) according to the present invention may also be added with various stabilizers such as an light stabilizer, a heat stabilizer and an antioxidant, a waterproofing agent (wax, silicone oil, higher alcohol, lanolin or the like), a pigment, a dye, a lubricant, a flame retardant and/or the like.
Production process of poly(ethylene oxalate):
The high-molecular weight poly(ethylene oxalate) according to the present invention cannot be obtained by the processes disclosed in the above documents (i) to (iv). Even by the processes described in the documents (ii) and (iii) which have reported that a polymer having film- and fiber-forming properties was obtained, any high-molecular weight poly(ethylene oxalate) cannot be obtained. More specifically, the high-molecular weight poly(ethylene oxalate) according to the present invention cannot be obtained even by the process of Cline et al. (abbreviated as "the conventional method 1") in which an ethylene oxalate monomer obtained by decomposing oligo(ethylene oxalate) and sublimating the decomposition product is subjected to ring-opening polymerization as it is, or the process of Alksnis et al. (abbreviated as "the conventional method 2") in which oligo(ethylene oxalate) obtained by the condensation of anhydrous oxalic acid with ethylene glycol is transesterified.
The high-molecular weight poly(ethylene oxalate) according to the present invention can be produced by heating a cyclic ethylene oxalate monomer, which has been obtained by heating oligo(ethylene oxalate) (namely, an ethylene oxalate oligomer) to depolymerize it, in an inert gas atmosphere, thereby subjecting the monomer to ring-opening polymerization. In order to obtain a copolymer by copolymerizing the cyclic ethylene oxalate monomer with a lactide, glycolide, lactone, alkylene oxalate and/or the like, it is only necessary to cause these comonomers to coexist in a predetermined proportion to copolymerize them.
The ethylene oxalate oligomer can be synthesized by a method known per se in the art. For example, an alkyl ester of oxalic acid (for example, diethyl oxalate) and ethylene glycol are subjected to condensation (dealcoholization) to form an ester, whereby the oligomer can be prepared. The condensation reaction can be carried out by, for example, heating the reactants at 150°-200° C., preferably 170°-190° C. for about 1-10 hours, preferably about 2-5 hours. The condensation reaction may be conducted in the presence of a catalyst such as sodium.
In the present invention, a cyclic ethylene oxalate monomer highly purified by a special method is used as the monomer for the poly(ethylene oxalate).
As a first preparation process of the cyclic ethylene oxalate monomer used in the present invention, may be mentioned a process wherein (i) the ethylene oxalate oligomer is washed with an organic solvent to purify, (ii) the thus-purified oligomer is heated under reduced pressure to depolymerize, thereby sublimating a monomer formed, and then (iii) the monomer obtained by the sublimation is recrystallized from an organic solvent, thereby purifying it.
The crude ethylene oxalate oligomer obtained by such a process as described above is previously washed with the organic solvent (for example, an aromatic hydrocarbon such as toluene) prior to the depolymerization-sublimation step to remove impurities which volatilize or bump during sublimation. For that purpose, it is preferable to wash the oligomer with, for example, a heated (e.g., 100°-200° C.) organic solvent.
In order to sublimate the resulting product while depolymerizing the purified oligomer, the purified oligomer and an optional catalyst (for example, tin tetrachloride) are placed in a reaction vessel and heated to 190°-220° C. under reduced pressure (for example, about 5-7 Torr) to depolymerize the oligomer, and the cyclic monomer formed is sublimated to recover in a cooling part of the reaction vessel.
The ethylene oxalate monomer obtained by the sublimation is recrystallized from a solvent (for example, acetonitrile, acetic acid, acetone or the like) to purify, thereby removing impurities mixed into the monomer in the sublimation step. The melting point (Tm) of the purified monomer obtained by such recrystallization is about 144.5° C.
As a second preparation process of the cyclic ethylene oxalate monomer used in the present invention, may be mentioned a process wherein (I) a mixture containing the ethylene oxalate oligomer and a high-boiling polar organic solvent is heated under ordinary pressure or reduced pressure to a temperature at which the depolymerization of the oligomer occurs, thereby dissolving the oligomer in the polar organic solvent, (II) the heating is further continued to depolymerize the oligomer in a solution phase, thereby distilling out a monomer formed together with the polar organic solvent, and then (III) the monomer is recovered from the distillate.
In the second preparation process, the high-boiling polar organic solvent having a boiling point of 225°-450° C., preferably 255°-430° C., more preferably 285°-420° C. is used. Examples of such a polar organic solvent include solvents capable of dissolving the ethylene oxalate oligomer therein, such as dibutyl phthalate (DBP), benzyl.butyl phthalate (BBP) and tricresyl phosphate (TCP).
In the second preparation process, the oligomer and high-boiling polar organic solvent (in a proportion of 0.3-50 times of the weight of the oligomer) are heated under ordinary pressure or reduced pressure, preferably 0.1-90 kPa to a temperature (170°-300° C.) at which the depolymerization of the oligomer occurs, to form a uniform solution. The heating is further continued to depolymerize the oligomer in a solution phase, thereby distilling out a cyclic ethylene oxalate monomer formed together with the polar organic solvent. The azeotropic distillate thus obtained is cooled, and a non-solvent (for example, cyclohexane, toluene, benzene or the like) for the monomer is added as needed, thereby solidifying and precipitating the monomer to separate and recover it from the azeotropic distillate. Thereafter, the monomer is washed with a non-solvent or extracted with a solvent and purified by recrystallization or the like as needed.
In the polymerization process according to the present invention, it is desirable to conduct the ring-opening polymerization of the monomer in a relatively low temperature range of from not lower than 150° C. to lower than 200° C., preferably from 155° C. to 190° C. The ring-opening polymerization of the cyclic ethylene oxalate monomer may preferably be conducted by heating the monomer to a temperature lower than 200° C. in the presence of a catalyst (for example, tin tetrachloride, tin dichloride, tin octanoate, aluminum chloride, zinc chloride, antimony trifluoride, titanium tetrachloride, zinc acetate, lead oxide or the like) in an inert gas atmosphere.
Application fields:
The poly(ethylene oxalate) according to the present invention is suitable for use as food packaging materials capable of subjecting to retorting, wrapping materials for electronic ranges and the like in the form of films and sheets. The foams formed or molded therefrom are suitable for use as containers for instant or precooked foods, containers for perishable fishes and shellfishes, fruit containers, egg containers, cushioning materials, thermal insulating materials and the like, all of which can lighten the burden imposed on the environment. The formed products in the form of a bag, bottles, and the like are used in fields of refuse sacks, food, cosmetics, kitchenware and other daily necessaries as packaging material or containers which can lighten the burden imposed on the environment. The fibers (monofilaments, multifilaments, nonwoven fabrics and the like) are used as packing tapes, fishlines, fishing nets, surgical sutures, sterilizable gauze and bandages, and the like, all of which can lighten the burden imposed on the environment. The poly(ethylene oxalate) according to the present invention is used as heat-sealing materials and barrier materials as well as multi-layer extrusion resins, laminating resins, carding resins, blending resins and the like. It is also used as X-ray resists, UV resists and the like.
ADVANTAGES OF THE INVENTION
According to the present invention, there can be provided high-molecular weight poly(ethylene oxalate) excellent in melt processability, heat resistance, crystalline properties, mechanical properties and the like. The present invention also provides various products formed or molded from the high-molecular weight poly(ethylene oxalate). The present invention further provides a novel production process of the high-molecular weight poly(ethylene oxalate). Since the high-molecular weight poly(ethylene oxalate) according to the present invention has good degradability in soil, it can be used in a wide variety of fields including a food packaging field as sheets, films, fibers, injection-molded products, foams and the like which can lighten the burden imposed on the environment.
EMBODIMENT OF THE INVENTION
The present invention will hereinafter be described more specifically by the following examples and comparative examples. It should however be borne in mind that the present invention is not limited to the following examples only. Incidentally, the following methods were followed for the measurement of the physical properties of polymers and formed or molded products in the following examples.
(1) Solution viscosity (ηinh):
An amorphous sheet of each polymer was used as a sample, and was immersed in a 8:2 (by weight) mixed solvent of m-chlorophenol/1,2,4-trichlorobenzene to dissolve the sample therein by heating at 150° C. for about 10 minutes, thereby preparing a solution in a concentration of about 0.4 g/dl. The viscosity of this solution was measured by means of an Ubbelohde viscometer at 30° C. (unit: dl/g).
(2) Melt viscosity (η*)
A crystallized sheet obtained by heating an amorphous sheet of each polymer at about 130° C. for 10 minutes was used as a sample, and the melt viscosity of the sample was measured at 190° C. and a shear rate of 1,000/sec by means of a "Capirograph" (manufactured by Toyo Seiki Seisaku-Sho, Ltd.) equipped with a nozzle having a diameter (D) of 0.5 mm and a length (L) of 5 mm (unit: Pa.s).
(3) Tg, Tm, ΔHm and ΔHmc:
An amorphous sheet of each polymer was used as a sample and heated by means of a differential scanning calorimeter ("DSC 30 Model", manufactured by METTLER INSTRUMENT AG) at a rate of 10° C./min in a nitrogen gas stream, thereby measuring the glass transition temperature (Tg), melting point (Tm) and melt enthalpy (ΔHm) of the sample. Immediately after the temperature of the sample reached 220° C., the sample was cooled at a rate of 10° C./min, thereby measuring the melt crystallization temperature (Tmc) and melt crystallization enthalpy (ΔHmc) of the sample.
(4) Density:
The density of each polymer was measured in the form of an amorphous sheet, and the density of each formed or molded product was measured on a crystallized product, both, in accordance with JIS R 7222 (a pycnometer method making use of n-butanol).
(5) Degradability in soil:
An amorphous sheet (thickness: 0.2 mm) of each polymer was cut into a strip about 3 cm wide and buried at the depth of 10 cm under the ground of a plowland. The strip was dug up at intervals of a half month to observe its shape to observe the time the amorphous sheet began to degrade so as to deform its shape. The degradability in soil was ranked as "Good" where the shape of the amorphous sheet began to degrade within a year after buried under ground.
(6) Heat shrinkage:
The heat shrinkage was determined by using a strip sample 10 mm wide for films and sheets and using, as a sample, a monofilament as it is for yarn. One end of the sample was held by a clip in such a manner that the length of the sample was 50 mm, and such a sample was hanged in an air-circulating gear oven heated to 110° C. to heat it. After heating for 10 minutes, the sample was taken out of the gear oven to measure the size of the sample, thereby determining its shrinkage.
(7) Tensile properties:
The tensile properties of sheets, films and fibers were measured by using a TENSILON (manufactured by Baldwin Co.) under conditions of a measuring temperature of 23° C., a sample length of 30 mm (in the case of a sheet or film, width: 10 mm) and a pulling rate of 100 mm/min for the measurements of tensile strength and elongation or 10 mm/min for the measurement of modulus in tension.
(8) Heat stability upon melt processing:
The heat stability upon melt processing was determined by regarding a temperature higher than Tm of each polymer sample by 10° C. as a melt-processing temperature and measuring an average rate of weight loss for 30 minutes from the beginning at that temperature by means of a TG 30 type TGA manufactured by METTLER INSTRUMENT AG in a nitrogen gas stream.
EXAMPLE 1!
Preparation Example 1 of monomer:
One-liter autoclave was charged with 585 g (4.0 mol) of diethyl oxalate and 160 g (2.6 mol) of ethylene glycol. The contents were heated for 2 hours at 170° C. and 1 hour at 190° C. to condense them while distilling out ethanol, thereby forming a crude ethylene oxalate oligomer. After completion of the reaction, unreacted compounds were recovered under reduced pressure. Added to the crude oligomer remaining in the autoclave were 400 g of toluene, followed by heating for 2 hours at 130°-140° C. and for 10 minutes at 160°-170° C. with stirring. Thereafter, the contents were cooled and filtered to recover solid matter. This solid matter was dried under reduced pressure at 150° C. to obtain a purified oligomer (powder).
A glass tube oven for sublimation (manufactured by Shibata Scientific Technology Limited) was charged with 10 g of the thus-obtained purified oligomer and 10-20 mg of SnCl4.nH2 O (n=6.5) to heat the contents at 200°-220° C. for about 1 hour under a reduced pressure of about 5-7 Torr, thereby sublimating an ethylene oxalate monomer formed while depolymerizing the oligomer to recover the monomer over a cold finger of the oven. This sublimated monomer was further washed with toluene and then dissolved in 500 g of acetonitrile heated to 40°-50° C. The solution was left at rest at room temperature for 3 days and then filtered. Benzene was added to the mother liquor to precipitate monomer crystals, a liquid phase was decanted, and the monomer crystals were washed twice with benzene at about 50° C. The thus-obtained crystals were dried under reduced pressure at room temperature, thereby preparing a sublimated, recrystallized monomer (MOX-1) (Tm =144.5° C.). Several batches of (MOX-1) were prepared in the same manner as described above.
Synthesis of polymer:
A 4.5 wt. % ether solution of SnCl4.nH2 O (n=6.5) was sprinkled over 50 g of the monomer (MOX-1) so as to add 0.008 g of SnCl4.nH2 O (n=6.5). This monomer was charged into a PFA (tetrafluoroethylene/perfluorovinyl ether copolymer) tube equipped with a gas inlet tube made of a PTFE (polytetrafluoroethylene) tube. After ether and water were blown off by introducing nitrogen gas for 20 minutes, the monomer was heated at 170° C. for 2 hours while introducing nitrogen gas, thereby polymerizing the monomer.
The monomer melted in about 5 minutes from the beginning of the heating, and nitrogen gas bubbled through the molten monomer. The viscosity of the monomer then rapidly increased, and the melt almost completely stopped moving and solidified after about 5-10 minutes to turn to a sponge-like solid. After completion of the heating, the sponge-like solid was allowed to cool at room temperature, thereby crystallizing the solid. After the crystallization, the sponge-like solid was taken out of the PFA tube to obtain a polymer (POX-1). The polymer was quickly placed in a polyethylene bag to store. The physical properties of the thus-obtained polymer are shown in Table 1.
EXAMPLES 2-5!
Copolymers were synthesized in the same manner as in Example 1 except that (R)-(-)-lactide and optional ε-caprolactone were added to the monomer (MOX-1) in their corresponding small amounts shown in Table 1, thereby obtaining copolymers POX-2 (Example 2), POX-3 (Example 3), POX-4 (Example 4) and POX-5 (Example 5). The compositions and physical properties of these copolymers are shown collectively in Table 1.
EXAMPLE 6!
Preparation Example 2 of monomer:
A 300-ml three-necked flask connected to a receiver cooled with ice water was charged with 40 g of a crude ethylene oxalate oligomer prepared in the same manner as in Example 1, to which 200 g of dibutyl phthalate (DBP) were added as a high-boiling polar organic solvent.
While stirring the contents, they were heated at 235°-245° C. under a reduced pressure of 10 kPa in a nitrogen atmosphere, thereby dissolving the oligomer into a uniform solution. The heating was continued at the same temperature to cause the oligomer to depolymerize in the uniform solution phase. Azeotropic distillation of an ethylene oxalate monomer formed with the solvent was performed until the azeotrope was almost distilled out, thereby collecting the whole amount of the azeotropic distillate in the receiver cooled with ice water. To the collected distillate, toluene as a non-solvent was added in an amount twice the collected distillate, and the mixture was allowed to cool, thereby precipitating crystals of the ethylene oxalate monomer. After allowing to cool, the crystal deposited were collected by filtration. The collected crystals were dissolved in acetonitrile at 40°-50° C. to saturation, and the solution was allowed to cool overnight in a refrigerator to recrystallize the monomer. After the recrystallization was conducted repeatedly, the crystals thus obtained were collected by filtration and dried under reduced pressure at about 40° C., thereby obtaining a cyclic ethylene oxalate monomer (MOX-1A) according to the depolymerization process in the uniform solution phase. The same process as described above was conducted repeatedly to obtain several batches of MOX-1A.
Synthesis of polymer:
A polymer (POX-6) was obtained in exactly the same manner as in Example 1 except that the ethylene oxalate monomer (MOX-1A) was used as the monomer. The physical properties of the thus-obtained polymer are shown in Table 1.
EXAMPLES 7-8!
Copolymers (POX-7) and (POX-8) were obtained in exactly the same manner as in Examples 2-5 except that the ethylene oxalate monomer (MOX-1A) and a small amount of glycolide were used as the monomers. The compositions and physical properties of these copolymers are shown collectively in Table 1.
Comparative example 1!
Preparation of monomer:
The purification of the crude ethylene oxalate oligomer with toluene in the preparation process of the monomer in Example 1 was omitted to dry directly the oligomer under reduced pressure at 150° C. The addition of SnCl4.nH2 O was also omitted to depolymerize directly the oligomer using the glass tube oven, thereby sublimating a monomer formed to obtain a sublimated monomer (MOX-2). The purification of the sublimated monomer by recrystallization was omitted to use the monomer in polymerization as it is (in accordance with the conventional method 1).
Synthesis of polymer:
Polymerization was performed in the same manner as in Example 1 except that the monomer (MOX-2) was used as the monomer. The physical properties of the thus-obtained polymer (CPOX-1) are shown in Table 1.
Comparative Example 2!
A 1,000-ml three-necked flask was charged with 40.26 g of anhydrous oxalic acid, 25 ml of ethylene glycol, 500 ml of benzene and 1.52 g of p-toluenesulfonic acid. The contents were heated with stirring for 2.5 hours at the reflux temperature of benzene to obtain a condensate. This condensate was washed with acetone and dried at 80° C. to obtain an oligomer. Added to 10 g of this oligomer was 0.002 g of SnCl2.2H2 O. The mixture was heated at 180° C. for 6 hours while causing argon to flow slowly under a reduced pressure of 0.5-1.0 Torr, thereby carrying out a transesterification reaction to obtain a polymer (CPOX-2) (in accordance with the conventional method 2). The physical properties of the polymer (CPOX-2) are shown in Table 1.
TABLE 1
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Average
rate of
weight
Composition of monomer loss
De-
Mono- Poly- Δ
(*2)
grada-
Den-
Classifi-
mer Comono-
mol
mer η.sub.inh
η*
Tg
Tm ΔHm
Tmc
Hmc
wt. %/
bility
sity
cation (*4)
code mer % code
dl/g
Pa · s
°C.
°C.
J/g
°C.
J/g
min in soil
(*3)
Group
Type
Remarks
__________________________________________________________________________
Ex. 1
MOX-1
-- POX-1
1.25
305
36
180
65 102
53 0.18
Good
1.52
(I) (A)
Ex. 2
MOX-1
Lactide
1.5
POX-1
1.00
135
39
179
78 102
4 0.08
Good
1.52
(II)
(B)
Ex. 3
MOX-1
Lactide
4.3
POX-3
0.89
120
37
175
67 99
2 0.06
Good
1.51
(II)
(B)
Ex. 4
MOX-1
Lactide
4.0
POX-4
0.80
110
40
176
70 105
1 0.06
Good
1.51
(II)
(B)
Capro-
0.1
lactone
Ex. 5
MOX-1
Lactide
16.4
POX-5
0.80
70
42
-- -- -- -- -- Good
1.49
(II)
(C)
Ex. 6
MOX-
-- POX-6
1.31
400
40
183
80 101
47 0.17
Good
1.52
(I) (A)
1A
Ex. 7
MOX-
Glycolide
5.0
POX-7
1.30
400
39
171
53 -- -- 0.05
Good
1.51
(II)
(B)
1A
Ex. 8
MOX-
Glycolide
10.0
POX-8
1.27
380
37
162
10 -- -- 0.05
Good
1.50
(II)
(B)
1A
Comp.
MOX-2
-- CPOX-
0.22
15
33
181
78 107
67 0.36
Good
-- (I) (A)
Conven-
Ex. 1 1 tional
method 1
Comp.
(*1)
-- CPOX-
0.15
<2
32
178
96 102
32 0.55
Good
-- (I) (A)
Conven-
Ex. 2 2 tional
method
__________________________________________________________________________
2
(Note)
(*1) The polymer was synthesized from the oligomer by the
transesterification process
(*2) The average rate of weight loss is an average rate of weight loss fo
30 minutes from the beginning when heated by means of TGA at a
meltprocessing temperature (i.e., Tm + 10° C.) in a nitrogen gas
stream.
(*3) The density was measured in accordance with the density measurement
for the amorphous sheet.
(*4) Classification: the polymers of Groups (I) and (II) are polymers
containing the copolymerizing component in proportions of lower than 1
basal mol % and not lower than 1 basal mol %, respectively. Types (A), (B
and (C) mean a crystalline polymer high in crystallization rate, a
crystalline polymer low in crystallization rate and a noncrystalline
polymer, respectively.
(1) Each amorphous sheet used for measuring the various physical properties was prepared in accordance with the process described in Example 9 which will be described subsequently.
(2) With respect to the degradability in soil, all the amorphous sheets of the respective polymers were observed beginning to degrade in about 0.5-1 month. More specifically, the amorphous sheets of the respective polymers were buried under the ground for 1 month in winter and then taken out of the ground. As a result, all the sheets were observed being decomposed into many pieces principally from their edges. Even if portions of the sheets remained, they whitened and became brittle, so that their mechanical strength was unmeasurable.
EXAMPLE 9!
Amorphous sheet:
The polymer (POX-1) obtained in Example 1 was preheated for about 15 minutes at a temperature of the melting point of the polymer+20° C.!, pressed for 15 seconds under a pressure of 10 MPa by means of a hot press and then quickly transferred to a cold press to quench it, thereby forming an amorphous sheet (S-1) which had a thickness of 0.2 mm and was substantially not oriented. The thus-formed sheet was quickly placed in a polyethylene bag to store. The sheet was colorless and extremely high in transparency. The physical properties of this amorphous sheet are as follows:
(1) thickness: 0.2 mm, density: 1.52 g/cm3 ;
(2) tensile strength: 0.09 GPa;
(3) modulus in tension: 2.2 GPa; and
(4) elongation: 11%.
Besides, the polymers (POX-2) to (POX-8), and (CPOX-1) and (CPOX-2) obtained in Examples 2 to 8, and Comparative Examples 1 and 2, respectively, were used to form unoriented amorphous sheets (S-2) to (S-8), and (CS-1) and (CS-2) in the same manner as described above. However, the preheating temperature of POX-5 was changed to 200° C. The respective amorphous sheet thus obtained were colorless and extremely high in transparency.
EXAMPLE 10!
Unoriented crystallized sheet:
The amorphous sheet (S-1) formed in Example 9 was crystallized by holding it between two PTFE sheets and placing a weight of about 1 kPa thereon to subject the amorphous sheet to a heat treatment at 150° C. for 15 minutes. As a result, a translucent and tough unoriented crystallized sheet, which was hard to break even when it was bent, was obtained. The physical properties of this unoriented crystallized sheet are as follows:
(1) thickness: 0.2 mm;
(2) density: 1.56 g/cm3 or higher;
(3) tensile strength: 0.11 GPa;
(4) modulus in tension: 2.6 GPa;
(5) elongation: 8%; and
(6) heat shrinkage (110° C./10 min):<2%.
The amorphous sheets (S-2) to (S-8), and (CS-1) and (CS-2) formed in Example 9 were also subjected to a heat treatment in the same manner as described above, thereby crystallizing them. Translucent and tough unoriented crystallized sheets, which were hard to break even when they were bent, were obtained from the amorphous sheets (S-2) to (S-4) and (S-6) to (S-8). A transparent unoriented crystallized sheet, which was hard to break even when it was bent, was obtained from the amorphous sheet (S-5). However, brittle unoriented crystallized sheets, which were easy to break even when they were bent, were obtained from the amorphous sheets (CS-1) and (CS-2).
EXAMPLE 11!
Uniaxially oriented film:
The amorphous sheets (S-1), (S-2), (S-5), (S-6), (S-8), (CS-1) and (CS-2) formed in Example 9 were respectively cut into strips 10.0 mm wide. Each of these strips was stretched 4.0 times in an uniaxial direction at 45°-50° C. The stretched film thus obtained was then fixed to a metal frame to heat set the film at 150° C. for 2 minutes while maintaining the length of the film constant, thereby preparing a uniaxially stretched film. Uniaxially oriented films were able to be obtained from the amorphous sheets (S-1), (S-2), (S-5), (S-6) and (S-8). However, the amorphous sheet (CS-1) and (CS-2), which were respectively formed from the polymers low in molecular weight, broke during the stretching. The physical properties of the respective uniaxially oriented films thus obtained are as shown in Table 2.
TABLE 2
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Polymer
code POX-1
POX-2
POX-5
POX-6
POX-8
CPOX-1
CPOX-2
__________________________________________________________________________
Thickness
65 70 60 67 65 (*2) (*2)
(μm)
Density >1.55
>1.55
-- >1.55
>1.55
(g/cm.sup.3)
Tensile 0.21
0.18 0.02
0.23 0.18
strength
(GPa)
Modulus in
5.7 4.8 4.5 5.7 3.9
tension
(GPa)
Elongation
38 40 110 42 50
(%)
Shrinkage
<4 <6 (*1)
<4 <6
(%)
(110° C./10 min)
__________________________________________________________________________
(*1): Unmeasurable due to violent shrinkage.
(*2): The amorphous sheet broke during the uniaxial stretching.
EXAMPLE 12!
Biaxially oriented film:
The amorphous sheets (S-1), (S-2), (S-5), (S-6), (S-8), (CS-1) and (CS-2) formed in Example 9 were respectively cut into pieces 10 cm square. Each of these pieces was biaxially stretched 3.0 times in the machine direction and 3.0 times in the transverse direction at 40°-5° C. by a biaxial stretching machine (manufactured by Toyo Seiki Seisaku-Sho, Ltd.). The stretched film thus obtained was then fixed to a metal frame to heat-treat at 150° C. for 2 minutes while maintaining the length of the film constant, thereby preparing a biaxially oriented film. Biaxially oriented films were able to be obtained from the amorphous sheets (S-1), (S-2), (S-5), (S-6) and (S-8). However, the amorphous sheet (CS-1) and (CS-2), which were respectively formed from the polymers low in molecular weight, broke during the stretching. The physical properties of the respective biaxially oriented films thus obtained are as shown in Table 3.
TABLE 3
__________________________________________________________________________
Polymer
code POX-1
POX-2
POX-5
POX-6
POX-8
CPOX-1
CPOX-2
__________________________________________________________________________
Thickness
11 10 10 10 11 (*2) (*2)
(μm)
Density >1.55
>1.55
-- >1.55
>1.55
(g/cm.sup.3)
Tensile 0.22
0.20 0.03
0.24 0.23
strength
(GPa)
Modulus in
5.3 4.8 2.5 5.2 4.0
tension
(GPa)
Elongation
70 80 >150
75 90
(%)
Shrinkage
<4 <6 (*1)
<4 <6
(%)
(110° C./10 min)
__________________________________________________________________________
(*1): Unmeasurable due to severe shrinkage.
(*2): The amorphous sheet broke during the biaxial stretching.
The biaxially oriented films formed from the amorphous sheets (S-1) and (S-2) were able to be easily heat-sealed by placing each two sheets of the respective amorphous sheets to overlap each other and heating them under pressure by an iron the surface temperature of which was about 200° C.
EXAMPLE 13!
Stretched monofilament:
The amorphous sheets (S-1), (S-2), (S-5), (S-6), (S-8), (CS-1) and (CS-2) formed in Example 9 were respectively cut into strips about 0.5 cm wide. Each of the strips was heated at 130° C. for 10 minutes to crystallize. The crystallized strip was charged into a Capirograph (manufactured by Toyo Seiki Seisaku-Sho, Ltd.) equipped with a nozzle having a diameter (D) of 0.5 mm and a length (L) of 5 mm to melt-extrude it at 190° C. The thus-obtained extrudate was taken up at a take-up ratio R1 (take-up speed/extrusion speed) of 5 to obtain a yarn stock. However, when the amorphous sheet (CS-1) and (CS-2), which were respectively formed from the polymers low in molecular weight, were used, severe drawdown occurred upon the melt extrusion, resulting in a failure to spin. Each of the yarn stocks thus obtained was stretched 4.0 times at 50°-55° C. and then heat-treated at 150° C. for 5 minutes while maintaining its length constant, thereby heat setting it. The physical properties of the respective stretched monofilaments thus obtained are as shown in Table 4.
TABLE 4
__________________________________________________________________________
Polymer
code POX-1
POX-2
POX-5
POX-6
POX-8
CPOX-1
CPOX-2
__________________________________________________________________________
Diameter
114 90 80 120 100 (*2) (*2)
(μm)
Density >1.55
>1.55
-- >1.55
>1.55
(g/cm.sup.3)
Tensile 0.48
0.44 0.03
0.50 0.50
strength
(GPa)
Modulus in
11.0
9.0 3.1 10.0 8.0
tension
(GPa)
Elongation
25 35 >100
30 40
(%)
Shrinkage
<2 <5 (*1)
<2 <6
(%)
(110° C./10 min)
__________________________________________________________________________
(*1): Unmeasurable due to severe shrinkage.
(*2): The amorphous sheet broke during the biaxial stretching.
EXAMPLE 14!
Injection-molded product:
The polymers (POX-1), (POX-2), (POX-5), (POX-6) and (POX-8) were separately heated at 130° C. to crystallize. Each of the crystallized polymers was ground and dried under reduced pressure at 120° C. to obtain crystallized polymer powder. The crystallized polymer powder thus obtained was extruded at about 190° C. in the form of a strand through an extruder. The extrudate was quenched and then chopped into pellets. The pellets are air-dried at 120° C. for 2 hours to crystallize. The crystallized pellets were injected by means of an injection molding machine (cylinder temperature: 200° C., holding pressure: 0.1 GPa, mold temperature: 30° C.) equipped with a mold, thereby producing an injection-molded product in the form of a dumbbell. This molded product was annealed at 120° C. for 5 hours. The physical properties of the respective injection-molded products thus obtained are as shown in Table 5. Both flextural strength and modulus in flexture were measured at 23° C. in accordance with ASTM D 790.
TABLE 5
______________________________________
Polymer
code POX-1 POX-2 POX-5 POX-6 POX-8
______________________________________
Density >1.55 >1.55 -- >1.55 >1.55
(g/cm.sup.3)
Flextural
0.05 0.04 0.03 0.06 0.06
strength
(GPa)
Modulus in
2.6 2.4 2.0 2.5 2.3
flexture
(GPa)
______________________________________
EXAMPLE 15!
Laminated paper:
The polymer (POX-2) obtained in Example 2 was preheated at 200° C. for about 15 minutes, pressed for 15 seconds under a pressure of 10 MPa by means of a hot press and then quickly transferred to a cold press to quench it, thereby forming an amorphous sheet (S-2-1) which had a thickness of 0.1 mm and was substantially not oriented. The thus-formed sheet was colorless and extremely high in transparency. Two amorphous sheets (S-2-1) were used to put base paper of the same kind as that used in milk cartons between them. These sheets were further held between PTFE sheets, followed by heating under pressure at 200° C. by means of a hot press, thereby laminating the sheets of the polymer (POX-2) on both sides of the base paper. This laminate was pressed at about 90° C. by means of a cold press to crystallize the amorphous sheets. A water-resistant glossy base paper web on both sides of which the poly(ethylene oxalate) was laminated was obtained in such a way.
We claim:
1. Poly(ethylene oxalate) containing recurring units represented by the following formula (1): ##STR6## in a proportion or at least 60 basal mol %, wherein (a) the solution viscosity (ηinh) is at least 0.25 dl/g as measured at 30° C. and a polymer concentration of 0.40 g/dl in a 4:1 (by weight) mixed solvent of m-chlorophenol and 1,2,4-trichloro-benzene,(b) the melt viscosity (η*) is at least 30 pa.s as measured at 190° C. and a shear rate of 1,000/sec, and (c) the density is at least 1.48 g/cm3 as measured in an amorphous state.
2. The poly(ethylene oxalate) according to claim 1, which is substantially a homopolymer containing the recurring units represented by the formula (1) in a proportion exceeding 99 basal mol %.
3. The poly(ethylene oxalate) according to claim 1, which is a copolymer containing the recurring units represented by the formula (1) in a proportion of 60-99 basal mol % and recurring units of at least one kind selected from the group consisting of a recurring unit represented by the following formula (2): ##STR7## a recurring unit represented by the following formula (3): ##STR8## wherein n is an integer of 1-6, and a recurring unit represented by the following formula (4): ##STR9## wherein m is an integer of 0-6, in a proportion of 1-40 basal mol %.
4. The poly(ethylene oxalate) according to claim 1, which further has the following physical properties:(d) the melting point (Tm) being at least 130° C.; (e) the melt enthalpy (ΔHm) being at least 20 J/g; and (f) the melt crystallization enthalpy (ΔHmc) being at least 20 J/g,wherein the melting point (Tm) and melt enthalpy (ΔHm) are a melting point and a melt enthalpy detected when heating an amorphous sheet sample 0.2 mm thick by means of a differential scanning calorimeter at a rate of 10° C./min in an inert gas atmosphere, and the melt crystallization enthalpy (ΔHmc) is a melt crystallization enthalpy detected when cooling the amorphous sheet sample at a rate of 10° C./min immediately after heating the amorphous sheet sample to 220° C.
5. The poly(ethylene oxalate) according to claim 1, which further has the following physical properties:(d) the melting point (Tm) being at least 130° C.; (e) the melt enthalpy (ΔHm) being at least 20 J/g; and (g) the melt crystallization enthalpy (ΔHmc) being smaller than 20 J/g.
6. The poly(ethylene oxalate) according to claim 1, which further has the following physical properties:(h) the melt enthalpy (ΔHm) being smaller than 20 J/g.
7. The poly(ethylene oxalate) according to claim 1, which further has the following physical properties:(i) the average rate of weight loss on thermal decomposition being at most 0.5 wt. %/min.
8. The poly(ethylene oxalate) according to claim 1, which further has the following physical properties:(i) the average rate of weight loss on thermal decomposition being at most 0.1 wt. %/min.
9. An unoriented sheet formed from the poly(ethylene oxalate) according to claim 1 and having the following physical properties:(1) melting point (Tm): at least 130° C., (2) density: at least 1.50 g/cm3, (3) tensile strength: at least 0.05 GPa, (4) modulus in tension: at least 1.0 GPa, (5) elongation: at least 3%, and (6) heat shrinkage (110° C./10 min): at most 30%.
10. A uniaxially oriented film formed from the poly(ethylene oxalate) according to claim 1 and having the following physical properties:(1) melting point (Tm): at least 130° C., (2) density: at least 1.50 g/cm3, (3) tensile strength (oriented direction): at least 0.07 GPa, (4) modulus in tension (oriented direction): at least 1.0 GPa, (5) elongation (oriented direction): at least 3%, and (6) heat shrinkage (110° C./10 min) (oriented direction): at most 30%.
11. A biaxially oriented film formed from the poly(ethylene oxalate) according to claim 1 and having the following physical properties:(1) melting point (Tm): at least 130° C., (2) density: at least 1.50 g/cm3, (3) tensile strength: at least 0.07 GPa, (4) modulus in tension: at least 1.0 GPa, (5) elongation: at least 3%, and (6) heat shrinkage (110° C./10 min): at most 30%.
12. Fibers formed from the poly(ethylene oxalate) according to claim 1 and having the following physical properties:(1) melting point (Tm): at least 130° C., (2) density: at least 1.50 g/cm3, (3) tensile strength: at least 0.07 GPa, (4) modulus in tension: at least 3.0 GPa, (5) elongation: at least 3%, and (6) heat shrinkage (110° C./10 min): at most 40%.
13. An injection-molded product formed from the poly(ethylene oxalate) according to claim 1 and having the following physical properties:(1) melting point (Tm): at least 130° C., (2) flexural strength: at least 0.01 GPa, and (3) modulus in flexure: at least 1.0 GPa.
14. A process for the production of poly(ethylene oxalate), which comprises subjecting a cyclic ethylene oxalate monomer obtained by depolymerizing an ethylene oxalate oligomer to ring-opening polymerization by heating the monomer in an inert gas atmosphere, wherein a monomer purified by (i) washing the ethylene oxalate oligomer with an organic solvent to purify, (ii) heating the thus-purified oligomer under reduced pressure to depolymerize, thereby sublimating a monomer formed, and then (iii) recrystallizing the monomer obtained by the sublimation from an organic solvent is used as the cyclic ethylene oxalate monomer.
15. The process according to claim 14, wherein the cyclic ethylene oxalate monomer is subjected to ring-opening polymerization by heating the monomer to a temperature not lower than 150° C. but lower than 200° C. in the presence of a ring-opening polymerization catalyst.
16. The process according to claim 14, wherein a substantial homopolymer containing recurring units represented by the following formula (1): ##STR10## in a proportion exceeding 99 basal mol % is prepared by the ring-opening polymerization of the cyclic ethylene oxalate monomer.
17. The process according to claim 14, wherein the cyclic ethylene oxalate monomer is subjected to ring-opening copolymerization with at least one cyclic monomer selected from the group consisting of lactides, glycolides, lactones (having at most 7 carbon atoms) and alkylene oxalates (the alkylene group of which has 3-9 carbon atoms).
18. The process according to claim 17, wherein a copolymer containing recurring units represented by the following formula (1): ##STR11## in a proportion of 60-99 basal mol % and recurring units of at least one kind selected from the group consisting of a recurring unit represented by the following formula (2): ##STR12## a recurring unit represented by the following formula (3): ##STR13## wherein n is an integer of 1-6, and a recurring unit represented by the following formula (4): ##STR14## wherein m is an integer of 0-6, in a proportion of 1-40 basal mol % is prepared by the ring-opening copolymerization of the cyclic ethylene oxalate monomer.
19. A process for the production of poly(ethylene oxalate), which comprises subjecting a cyclic ethylene oxalate monomer obtained by depolymerizing an ethylene oxalate oligomer to ring-opening polymerization by heating the monomer in an inert gas atmosphere, wherein a monomer obtained by (I) heating a mixture containing the ethylene oxalate oligomer and a high-boiling polar organic solvent under ordinary pressure or reduced pressure to a temperature at which the depolymerization of the oligomer occurs, thereby dissolving the oligomer in the polar organic solvent, (II) further continuing the heating to depolymerize the oligomer in a solution phase, thereby distilling out a monomer formed together with the polar organic solvent, and then (III) recovering the monomer from the distillate is used as the cyclic ethylene oxalate monomer.
20. The process according to claim 19, wherein the cyclic ethylene oxalate monomer is subjected to ring-opening polymerization by heating the monomer to a temperature not lower than 150° C. but lower than 200° C. in the presence of a ring-opening polymerization catalyst.
21. The process according to claim 19, wherein a substantial homopolymer containing recurring units represented by the following formula (1): ##STR15## in a proportion exceeding 99 basal mol % is prepared by the ring-opening polymerization of the cyclic ethylene oxalate monomer.
22. The process according to claim 19, wherein the cyclic ethylene oxalate monomer is subjected to ring-opening copolymerization with at least one cyclic monomer selected from the group consisting of lactides, glycolides, lactones (having at most 7 carbon atoms) and alkylene oxalates (the alkylene group of which has 3-9 carbon atoms).
23. The process according to claim 22, wherein a copolymer containing recurring units represented by the following formula (1): ##STR16## in a proportion of 60-99 basal mol % and recurring units of at least one kind selected from the group consisting of a recurring unit represented by the following formula (2): ##STR17## a recurring unit represented by the following formula (3): ##STR18## wherein n is an integer of 1-6, and a recurring unit represented by the following formula (4): ##STR19## wherein m is an integer of 0-6, in a proportion of 1-40 basal mol % is prepared by the ring-opening copolymerization of the cyclic ethylene oxalate monomer.
| 1996-06-20 | en | 1997-11-18 |
US-12772080-A | Electric discharge lamp
ABSTRACT
A high pressure electric discharge lamp exhibits lowered starting voltages and improved lumen performance by utilizing within the arc discharge tube a starting probe that is electrically isolated at all times.
TECHNICAL FIELD
This invention relates to electric discharge lamps; i.e., lamps in which light (or radiant energy near the visible spectrum) is produced by the passage of an electric current through a vapor or gas. It has particular application to mercury vapor lamps and metal halide vapor arc lamps.
BACKGROUND ART
Lamps of the type described are known in the art. An exemplary lamp is the mercury discharge type. In such lamps light is produced by the passage of an electric current through mercury vapor. These lamps usually employ an outer envelope containing an inert gas or vacuum. An arc discharge tube is mounted within the outer envelope and contains first and second spaced apart main electrodes. The arc tube is hermetically sealed and contains the requisite amount of mercury together with a readily ionizable gas, such as argon, to improve starting.
To further improve starting performance, commercially available high pressure mercury lamps employ a starting probe which is an electrode sealed into the lamp adjacent to one of the main electrodes and electrically connected to the other of the main electrodes through a current limiting resistor.
In a low wattage mercury lamp application a ballast is employed which uses standard line voltage (120 V A.C.) connected through a current limiting inductance directly to the mercury lamp. This ballast provides a high voltage-low energy pulse which is sufficient to break down the gap between the main electrodes and, thus, no starting probe is required. It would be an advance in the art however, if better starting and better lumen maintenance could be provided for electric discharge lamps of the low wattage type.
DISCLOSURE OF INVENTION
It is an object of this invention to improve electric discharge lamps.
It is another object of the invention to enhance the starting capabilities of such lamps.
These objects are accomplished in one aspect of the invention by the provision of an electric discharge lamp which contains an arc tube. The arc tubes has first and second main electrodes and a starting probe adjacent one of them. The starting probe, however, is electrically isolated at all times from the circuitry of the lamp.
Lamps having the above-described construction have been shown to have starting voltages averaging 750 V less than similar lamps constructed without the probe. Furthermore, after an initial burn-in, the lamps of the invention have better lumen maintenance than similar lamps without the probe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of the lamp of the invention; and
FIG. 2 is a graph plotting lumen maintenance of the lamp of the invention against a prior art lamp.
BEST MODE FOR CARRYING OUT THE INVENTION
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above described drawings.
Referring now to the drawings with greater particularity, there is shown in FIG. 1 a low wattage, high pressure electric discharge lamp 10 having an outer envelope 12 containing an inert gas, such as nitrogen, or a vacuum. When nitrogen or a similar gas is employed a pressure of about 350 Torr is preferred.
An hermetically sealed arc discharge tube 14 is mounted within envelope 12 by means of a suitable mount 16. Tube 14 contains first and second main electrodes 18 and 20 and an ionizable medium such as argon at a pressure of 50 Torr together with about 2.3 mg of mercury. Electrode 18 is conventionally connected to one side of a 120 V line source through connector 22, mount 16, connector 24 and lead-in wire 26. Electrode 20 is connected to the other side of a 120 V line source through connector 28 and lead-in wire 30. Lead-in wires 26 and 30 may be sealed in a glass press 32, as is conventional. Lamp 10 in this instance is provided with a screw-in base 34.
The improvement in the above-described lamp is epitomized by the electrically isolated starting probe 36 which is sealed into tube 14 adjacent one of the electrodes, for example, 20. The probe 36 is electrically isolated at all times; i.e., unlike the prior art probes, it is never connected to any of the circuitry of the lamp. The end portion 38 of probe 36 which projects beyond the seal area 40 of tube 14 is a mechanical convenience which allows the probe 36 to be held in position during the sealing operation. The preferred material for the probe 36 is tantalum.
The exact reason for the unexpectedly improved performance consisting of the lowered starting voltage and the improved lumen maintenance which occurs with the electrically isolated probe is unknown. Possible explanations are that the probe, when constructed of tantalum, is serving as a hydrogen getter, or that the probe may be serving to locally enhance the field at the electrode.
The lamp 10 is operated through a low wattage mercury lamp ballast wherein the standard line voltage is connected directly to the lamp through a current limiting inductance. This ballast further provides a high voltage-low energy pulse for starting the lamp.
The following table illustrates the dramatic reduction in starting voltages between aged lamps without a probe and aged lamps with the electrically isolated probe.
TABLE I
______________________________________
With Electrically
Without Probe Isolated Probe
Lamp Starting Lamp Starting
Number Voltage Number Voltage
______________________________________
1 1500 1p 1000
2 1600 2p 400
3 1400 3p 700
4 1500 4p 900
5 1500
Average 1500V Average 750V.
______________________________________
The line voltage was 120 V A.C. and the aging time was 4000 hours.
In referring to the graph of FIG. 2 it will be seen that, although initial lumens are higher in lamps without the probe, within 1000 hours better lumen performance is obtained with the lamp containing the electrically isolated probe.
In another test, with probe 36 electrically connected to electrode 18 through a current limiting resistor, it was visually observed that the energy of the pulse was dissipated across the gap between the probe and the adjacent electrode, thus reducing the ionization between the two main electrodes during the pulse and interferring with starting.
There is thus provided by this invention a new and novel high pressure electric discharge lamp having enhanced starting characteristics and improved lumen performance when compared with similar lamps not utilizing the invention.
While there have been shown and described what are at present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims.
We claim:
1. In a high pressure electric discharge lamp including an outer envelope containing an inert atmosphere, an arc discharge tube mounted within said outer envelope, said arc discharge tube containing first and second spaced apart main electrodes and an ionizable medium, the improvement comprising: means within said lamp for reducing the starting voltage of said lamp by an average of about 50% after said lamp has aged about 4000 hours, said means comprising at least one starting probe positioned in said arc tube, said starting probe being adjacent only one of said main electrodes, and being electrically isolated at all times from any ohmic contact with any other electrode of said lamp and from any ohmic contact or capacitive contact from associated ballast circuitry.
2. The lamp of claim 1 wherein said probe is tantalum.
3. The lamp of claim 1 wherein said ionizable medium comprises substantially argon with an effective amount of mercury.
4. The lamp of claim 3 wherein said inert atmosphere is nitrogen.
| 1980-03-07 | en | 1982-04-06 |
US-3645104D-A | Tower structure
ABSTRACT
A tower structure embodying the geometric properties of a hyperboloid of one sheet. Said tower comprises a lower base, an upper platform, and a plurality of inclined legs extending between said base and said platform. Said inclined legs are so inclined and so spaced, with respect to a central axis, so that upon revolution of any one of said legs about said axis at an essentially constant angle of inclination there is described a surface of revolution which defines said hyperboloid.
Elite ties att Hogan Feb. 29, 1972 [54] TOWER STRUCTURE FOREIGN PATENTS OR APPLICATIONS [72] Inventor: Roy E. Hogan, Berwick, La. Add 6 2i9 10/1955 France ..52/648 Assigneez Phillips Petroleum p y 383,306 1 1/1932 Great Britain ...52/648 [22] Filed: Dec. 29, 1969 Primary Examiner-David J. Williamowsky Assistant Examiner-David H. Corbin [21] Appl. No.: 888,593 Att0meyY0ung and Quigg 52] us. Cl. ..611/46.5 [57] ABSTRACT [51] lint. Cl A tower structure embodying the geometric properties of a [58] Field of Search ..61/46, 46.5; 52/224, 648, 653 hyper oloi of on h Sai w r ompri e a lo r b v an upper platform, and a plurality of inclined legs extending 56] References Cited between said base and said platform. Said inclined legs are so inclined and so spaced, with respect to a central axis, so that UNITED STATES PATENTS upon revolution of any one of said legs about said axis at an essentially constant angle of inclination there is described a sur- 1 2/1967 Sweeney "52/224 x face of revolution which defines said hyperboloid. 3,429,133 2/1969 Hauber.... ....61/46.5 3,488,967 1/1970 Toossi ..61/46.5 19 Claims, 13 Drawing Figures o r a; as ll llllj lllllllllll E u I l nl ION V7 n I4 WATER LINE MMWAMMM i'ALTERNATE WATER LINE I i 12 i I, l r E/////'/ /1, r, I'M, WWW 4 ,1" 1 i ,4 l-i WWW Z7110 [11 Li [C i I J I1; X2) L l ti lii PAIENIEU FEB 29 1972 3.645, 1 0'4 SHEET 1 OF 6 WATER LINE I'ALTERNATE WATER LINE INVENTOR. R. E. HOGAN ,4 TTORNEYS rArtmwrtazelm I 3.645.104-
sum 2 nr 6 INVENTOR. R. E. HOGAN A 7' TORNE VS PATENTEnmzs m2 3,645,104
SHEET 8 BF 6 INVENTOR. R. E. HOGAN BY y TOWER STRUCTURE This invention relates to a tower structure which is adaptable for both onshore and offshore installations.
Towers of various structural designs are widely employed in both onshore and offshore installations to support water tanks, observation platforms, drilling platforms, radar equipment, etc. In many instances, the ultimate use or location requires that the tower structure be specifically designed for specific uses or locations. It would be desirable to have one basic tower structure which can be adapted with minimum modification for a wide variety of uses and/or locations. The present invention provides such a tower structure. The tower structure of the present invention is particularly adapted for offshore locations to support a work platform, such as a drilling platform, for the drilling of oil and/or gas wells.
In recent years the number of wells drilled for oil and/or gas in fields situated below the surface of a body of water, such as the ocean or a lake, has greatly increased. Drilling in such locations requires a tower structure which is adapted to rest upon the bed of the body of water with a portion of the tower extending above the surface of the water. It is also required as a matter of economics that such towers support a platform from which multiple wells can be drilled.
This is a major factor which not only affects the economics, but also affects the design of such towers. The number of wells that can be drilled from such a tower is a function of both well spacing and the depth to the top of the producing formation. The capability to start drilling initially at a high deviation angle is advantageous since it greatly increases the horizontal displacement available at a given depth.
I have discovered that a tower design concept embodying the geometric properties of a hyperboloid of one sheet of revolution provides an excellent solution to the problem of drilling a maximum number of wells at a predetermined angle of inclination from a minimum size platform. Additionally, the hyperboloid concept provides an ideal initial pattern for drilling wells with minimum interference at the surface, and provides maximum platform strength with minimum tonnage and fabrication requirements.
An object of this invention is to provide an improved tower structure which is adapted for supporting a load or work platform in either an onshore or an offshore location. Another object of this invention is to provide a tower structure which is particularly adapted for installation in offshore locations. Another object of this invention is to provide a tower structure which is especially advantageous for the slant hole drilling of wells to relatively shallow producing formations. Another object of this invention is to provide an improved offshore tower structure from which the maximum number of wells can be drilled with or from a minimum size drilling platform configuration. Another object of this invention is to provide an improved tower structure which provides maximum structural strength with minimum structural material requirements. Another object of this invention is to provide an offshore tower structure which is particularly adapted for location in ice areas. Another object of this invention is to provide an offshore tower structure which employs platform space and storage space to maximum efficiency. Other aspects, objects, and advantages of the invention will be apparent to those skilled in the art in view of this disclosure.
Thus, according to the invention, there is provided a tower comprising: a lower base; an upper platform; a plurality of spaced apart, essentially vertically disposed legs, connected to said platform and extending between said base and said platform, and arranged about a central vertical axis; a plurality of upwardly extending, spaced apart, inclined legs connected to and extending between said base and said platform, arranged about said axis at distances greater than the distances of said vertically disposed legs from said axis, and each inclined with respect to said axis so that upon revolution of any one of said inclined legs about said axis at an essentially constant angle of inclination there is described a surface of revolution which defines a hyperboloid of one sheet. Stated another way, the longitudinal axis of each of said legs lies within a surface of revolution which defines a hyperboloid of one sheet.
FIG. 1 is a view in elevation illustrating a tower constructed in accordance with the invention wherein each inclined leg represents a line of form (or ruling, as mathematically defined) of a hyperboloid.
FIG. 2 and FIG. 3 are partial plan views of two representative drilling decks which can be employed in a tower structure of the invention.
FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are diagrammatic views illustrating various storage arrangements which can be employed in the tower structures of the invention.
FIG. 8 is a diagrammatic plan view taken through the gorge of a hyperboloid tower structure, similar to that illustrated in FIG. 1, but wherein two rows of inclined legs are employed.
FIG. 9 and FIG. 10 illustrate two types of clamp arrangements which can be employed in connecting adjacent legs of a tower structure wherein two rows of oppositely inclined legs are employed.
FIG. 11 is a diagrammatic plan view of one type of base structure which can be employed in a tower structure of the invention.
FIG. 12 is a view in cross section illustrating one means for anchoring the inclined legs of a tower structure of the invention to the earth.
FIG. 13 is a partial plan view of another drilling deck which can be employed in a tower structure of the invention, and showing the tops of elliptically arranged inclined legs.
Referring now to said drawings, wherein like reference numerals have been employed to denote like elements, the invention will be more fully explained. FIG. 1 illustrates the hyperboloid concept of the tower of the invention wherein a plurality of inclined legs extend between an upper platform or deck and a lower base. The basic properties of the hyperboloid, e.g., the diameter of the gorge, the angle of inclination of the legs, and the vertical location of the gorge, can be varied to provide the desired leg inclination, gorge size, gorge location, platform size, etc., to adapt the tower structure to a particular location. Thus, the invention provides a basic tower structure which can be adapted for a wide variety of locations and conditions of use.
Referring more specifically to FIG. 1, there are illustrated several embodiments of a tower in accordance with the invention. For convenience, but not by way of limitation, the tower will be further described with particular reference to being used in an offshore location. Said tower is designated generally by the reference numeral 10. Said tower comprises a lower base 12 and an upper platform or well head deck 14. A plurality of spaced apart, essentially vertically disposed, generally straight legs 16 are arranged about a central vertical axis, are connected to said platform 14, and extend between said base 12 and said platform 14. If desired, said vertically disposed legs 16 can also be connected to said base 12, as by grouting, as discussed hereafter. The number of said vertically disposed legs will depend upon tower size, location, use, and other factors, and the invention is not limited to any particular number thereof. However, generally speaking, the number of said vertical legs will usually be in the range of from four to 12. A plurality of spaced apart, inclined, generally straight legs 18 are also arranged about said axis at predetermined distances which are greater than the distances of said vertically disposed legs 16 from said axis. Each of said inclined legs 18 is connected to and extends between said base 12 and said well head deck or platform 14. Each of said inclined legs 18 is inclined in essentially the same direction with respect to the leg adjacent thereto and preferably at essentially the same angle with respect to said axis. Each of said inclined legs 18 is spaced apart symmetrically from said axis, preferably at essentially the same predetermined distance at any given generally horizontal plane located between the extremities of said legs. Said predetermined distance is less at a point intermediate the extremities of said legs than is the distance at said extremities. This lesser distance at said intermediate point defines the gorge of the hyperboloid structure. Said lesser distance can be varied vertically to vary the location of said gorge and thus locate the gorge either at the water line, above the water line,
or below the water line, as may be desired for any particular location. When each of said legs 18 is spaced equidistant from said axis along or on a given generally horizontal plane located between the extremities of said inclined legs, and when said legs are all inclined at essentially the same angle, there is obtained what can be called a circular hyperboloid, i.e., a hyperboloid in which the extremities of said legs 18 define a circle at the base and also define a circle at the well head platform 14. However, it is within the scope of the invention to vary the distance of the legs 18 from said axis on any given generally horizontal plane so that the extremities of said legs 18 at said base 12 and at said platform 14 will define an ellipse, or any other desired geometric design. Said legs 18 can terminate at said base 12 as illustrated in FIG. 12, or can extend below said base a short distance, e.g., l to 4 feet, as indicated by the dotted lines in FIG. 1, depending upon the nature of the sea bed or other location. For example, said legs can extend below base 12 when the sea bed is soft mud. Any suitable number of legs 18 can be employed. The number illustrated in FIG. 1 has been reduced from the number frequently employed so as to simplify the drawing.
When a tower of the invention is employed in an offshore location, as is illustrated in FIG. 1, the tower can, if desired, be employed in ice areas, such as Cook Inlet, Alaska. This can be done very effectively by sheathing the legs 18 with a suitable plate sheathing 20 through the water line area. By so doing and otherwise adjusting the geometric properties of the tower so as to give the legs 18 the desired inclination, the ice sheet will ride up the sheathed section and ultimately break under its own weight and disperse, especially when it changes direction at the gorge. This is an exceptionally effective technique for ice breaking. In many instances, depending upon the amount of ice present, it will be preferred to locate the gorge of the hyperboloid above the water line so as to enhance the movement of ice up the sheathing on the legs 18. This is illustrated in FIG. 1 by the alternate water line location. It will be noted that the tower of the invention is omnidirectional with respect to its exposure to dynamic forces such as waves, wind, etc., and likewise with respect to its structural strength. The employment of the plate sheathing 20 in ice areas completes the omnidirectional properties of the tower in ice areas. Employing the ice sheathing 20 presents only a smooth symmetrical surface to the forces of the ice. This is a distinct advantage over towers which have a plurality of legs extending into the water and each of which can be encountered by the ice. the
Said base 12 can be adapted to rest on the bed of a body of water, as illustrated in FIG. I, or can be adapted to rest on a dry shore location. Said base 12 can be any suitable type of base, as is discussed further hereinafter, for either of said locations. Said well head deck 14 can be any type of platform suitable for the main purpose of the tower. A drilling deck 22 is disposed above said well head deck 141 and supported therefrom by any suitable structural means (not shown). Ladders 24 are provided between said decks 14 and 22. A guard rail 2 of any suitable design, can be provided around the well head deck 14, if desired.
FIG. 2 is a diagrammatic plan view of one embodiment of a drilling deck 22. Shown thereon are the tops of the vertically disposed. legs 16 and the upwardly extending inclined legs 18. The tops of said legs 16 and said legs 13 are open. Piling or conductor tubes of a hollow tubular type are driven downwardly through said vertical legs 16 into the earth below base 12 by conventional pile driving equipment. Said pilings are generally coextensive with said legs 18 and provide very effective support for the tower and prevent both vertical and lateral movement of the tower. If desired, the hollow tubular piling or conductor tubes driven through said legs 16 can also be employed for conducting a drill string down therethrough and into the earth for the drilling of wells. it will be noted that the central space of the drilling deck is relatively vacant. This provides space for the location of auxiliary drilling equipment, such as mud tanks 28, mud pumps, generators, etc., which can remain stationary in the center of the platform. Preferably, the drilling derrick 30 and related equipment will be mounted on wheels adapted to be moved over tracks 32 from one well to another. If desired, a guard rail 34 can be provided around the top of drilling deck 22.
FIG. 3 illustrates an alternate type of drilling deck which can be employed in the practice of the invention, such as when two rows of inclined legs 18 are installed.
FIGS. 4, 5, and 6 illustrate various storage arrangements which can be installed in the towers of the invention. In FIG. 4 a semiconical storage tank, having both an upper component 36 and a lower component 38, has been installed within the space defined by the inner surfaces of the inclined legs 18. In FIG. 5 a semiconical storage tank having only a lower component 38 has been installed in the lower portion of the space defined by the inner surfaces of the inclined legs 18. In FIG. 6 a cylindrical storage tank has been installed within the space defined by said inner surfaces of said inclined legs 18. The storage tank of FIG. 7 has been fabricated by sheathing the inner surfaces of the inclined legs 18 with plate sheathing so as to provide a lower component 38 which makes maximum use of the space within said legs 18. If desired, a storage tank could also be constructed within the upper portion of the hyperboloid in FIG. 7. Placing sheathing on the inner walls of the inclined legs 18 as shown in FIG. 7 also adds to the structural strength of the tower. It will be understood that any suitable type of conventional liquid filling and emptying means (not shown) can be employed in connection with the storage tanks illustrated in FIGS. 4, 5, 6, and 7. In most instances, the storage volume provided within the interior of the hyperboloid will be sufficiently large to permit discharge of the oil, or other liquid stored therein, directly to a tanker or barges through a monomooring buoy. Additionally, if desired, the storage tank(s) may also be employed to serve as buoying or flotation chambers to assist in field erection in offshore locations.
FIG. 8 illustrates one presently preferred embodiment of the invention which can be employed when maximum structural strength is desired. Said FIG. 8 is a diagrammatic plan view taken through the gorge of a tower similar to the tower illustrated in FIG. 1. In FIG. 8 there are shown two rows of inclined legs 18 and 18. The second plurality of spaced apart, inclined, generally straight legs 18 can be inclined in the same direction as said first row of legs 18, if desired. However, for maximum structural strength said second row of legs 18' is preferably inclined in a direction opposite to, and preferably at the same angle, as said first row of legs 18. The legs in said second row of inclined legs 18 are arranged about the central axis at predetermined distances which are greater than the distances of the legs 18 in the first row of inclined legs. Each leg in said second row of legs 18' is preferably connected to and extends between said base 12 and said well head deck 14, similarly as the first row of legs 18. Said second row of legs 18 greatly increases the structural strength and stability of the tower, particularly when said second row of legs 18' is inclined oppositely to the first row of inclined legs 18. Piling or conductor tubes can be installed within said legs 18', and employed for drilling purposes, in a manner similar to said first row of inclined legs 18.
FIG. 9 and FIG. 10 illustrate two types of connecting or clamping means which can be provided between the tangent or adjacent legs of the first plurality of inclined legs 18 and the second plurality of inclined legs 18. In FIG. 9 the clamping means, designated generally by the reference numeral 40, is comprised of two separable members 42 and 44 which are held together by means of bolts (not shown) which can be inserted through the holes illustrated. In use, the two members 42 and 4d are placed about legs in the adjacent rows of inclined legs in the manner illustrated and then bolted together. In FIG. 10 the clamping means comprises a sheet or bar of metal 46 having in each end thereof an arcuate surface 48 adapted to engage the surface of a leg 18 or a leg 18. If desired, the arcuate surface(s) 4% can be welded to the legs 18 and 18'. To provide additional strength a rod 50 extending through the plate 46 can be provided to extend around the tower structure. In both FIG. 9 and FIG. 10, it will be understood that said clamping means can be employed between each pair of adjacent legs 18 and 18', between alternate pairs of adjacent legs 10 and 18', or any other lesser number of clamping means can be employed, such as on every third, fourth, or fifth pair of adjacent legs 1% and 18.
FIG. 11 illustrates diagrammatically one form of base 12 which can'be employed in the towers of the invention. Said base can be of any suitable geometric arrangement depending upon tower size, the requirements of a particular location, etc. As here illustrated, said base comprises a generally circular member 52 of generally circular cross section which is divided into four compartments by means of bulkheads 54. It will be understood to be within the scope of the invention to provide more than four compartments by increasing the number of bulkheads 54. Said compartments can be provided with conventional filling and emptying means, not shown. In one embodiment, legs 18 extend through and terminate at member 52, as shown more clearly in FIG. 12. In another embodiment, said legs 18 can extend through member 52 into the earth as illustrated in FIG. 1. A centrally disposed sheet or plate of steel 56 is disposed in the center of the circular member 52. Said plate of steel 56 is supported and connected to circular member 52 by means of I-beams 53 or other suitable structural members. Vertical legs 16 extend through openings or guides 57 provided in said sheet of metal 56. If desired, said vertical legs can be connected to said sheet 56 as by grouting around openings or guides 57 after legs 16 are in place. Said guides 57 can be any suitable type such as an enlarged tube, or a tube having an upper funnellike or conical opening. If desired, member 56 instead of being a sheet of steel can be a compartmented structure, similar to the outer circular member 52. It will be understood that when an outer row of inclined legs 18 is employed, the circular member sg can be tion of said annulus with grouting. As shown, a portion of the grouting is preferably forced out into the earth beyond the end of leg 18.
Towers constructed in accordance with the invention can be fabricated in any convenient manner. In one presently preferred manner of fabrication, an assembly comprising a base 12, a platform or well head deck 14, and an inner row of inclined legs 18 is prefabricated. If the tower is to be employed in an offshore location, it can then be floated (by the buoyancy provided by base 12) to said location in either an upright or horizontal position employing known techniques. If desired, or necessary, the well head deck end of the structure can be supported by any suitable temporary buoyancy means. Any suitable temporary sealing means can be employed to seal the legs 16 and 18 to exclude water and provide additional buoyancy if desired said base 12 can be partially filled, if desired, so as to partially sink the tower in the water and make it more maneuverable. Upon arrival at the offshore location the tower is upended, if not previously done, and caused to settle onto the sea bed by flooding the compartments in base 12. Hollow, tubular, vertical conductor tubes or piling are then driven downwardly through the vertical legs 16, out the bottom thereof, and into the earth for a suitable distance to serve as piling to anchor and support the tower. Said conductor tubes can be driven through said legs 16 by conventional pile driving techniques. Next, inclined conductor tubes 60 are driven through the inclined legs 18, starting on one side and then driving an alternate conductor on the opposite side, etc. The remainder of the tower and associated equipment can then be installed employing conventional techniques. In drilling operations said conductor tubes in vertical legs 16 and inclined legs 18 serve to conduct a drill string down into the eartlg The following Table I will serve to illustrate various embodimeat otthe I 'XQUFELL...
TABLE I Angle Radius Storage, bbls.
Height, ft., Radius 1 of incli at well No. Well base to well at gorge, nation, head of spacing, cone Cylinder head deck degrees deck, It. wells 1 ft core 3 core 4 15 i 15 3o. 7 37 5. 2 27, 000 21, 000 200 20 30 61. 1 7. 7 14,000 30,000 15 33. 4 50 4. l 37, 000 39, 000 200 25 30 62. 0 62 6.4 100, 000 63,000 15 36. 6 62 3. 7 50, 000 03, 000 200 3D 30 65.1 75 5. 5 128,000 33,000 15 40. 2 75 3. 4 05, 000 )3, 000
1 OI longitudinal centcrlinc of legs 18 (sec FIGURE 1).
2 Based on 30" o.d. pipe size for legs 18; use of 24 o.d. pipe would increase number of wells by about 25%.
3 See FIGURE 6.
enlarged sufficient to accommodate said outer row of legs 10, similarly as for legs 10, or a second circular member 52 can be employed if desired.
Referring now to FIG. 12, each leg 18 can extend through the circular member 52 of base 12 and be connected to said member 52 at its points of intersection therewith, as by welding. Said legs 18 can terminate at member 52, as shown in FIG. 12, or can extend therethrough as shown in FIG. 1. In order to enable a tower to be more positively anchored to the bed beneath the body of water, or to the surface of the earth, each of the inclined legs 18 has disposed therein a generally coextensive, concentric conductor tube which is of a size somewhat smaller than the interior of leg 18. Each conductor tube 60 may be driven downwardly and partially out the lower extremity of leg 10 by means of conventional pile driving technique and equipment. Grouting 62 can be pumped downwardly through the annulus between leg 18 and conductor 60 from the open upper end thereof so as to fill said annulus, or suitable connecting means can be provided adjacent and above circular member $2 for pumping said grouting into the lower portion of said annular space, as desired. Generally speaking, it is usually preferred to fill at least a substantial por- 4 See FIGURE 6.
The above Table 1 illustrates the remarkable flexibility in the towers of the invention which are fabricated in accordance with the hyperboloid concept. For example it will be noted that the number of wells can be increased approximately 25 percent by merely decreasing the outside diameter of the legs 18 from 30 inches to 24 inches. Another advantage of the towers of the invention is that said vertical legs 16 and said inclined legs i515 (and 18 if present) can be the sole support for platforms 14 and 22. No other supporting framework is required. The hyperboloid concept also makes possible the placing of the wells on a larger radius, i.e., adjacent the edges of the well head and the drilling deck, than has been possible in towers of the prior art. This permits greater spacing between wells. If desired, still more space can be obtained on the well head deck by placing well head equipment on alternate wells at higher elevations.
While certain embodiments of the invention have been described for illustrative purposes, the invention is not limited thereto. Various other modifications of the invention will be apparent to those skilled in the art in view of this disclosure. Such modifications are within the spirit and scope of the disclosure.
lclaim:
1. A tower comprising: a lower base; an upper platform; a plurality of spaced apart, essentially vertically disposed legs, connected to said platform and extending between said base and said platform, and arranged about and spaced apart from a central vertical axis; a plurality of upwardly extending, spaced apart, inclined legs connected to and extending between said base and said platform, arranged throughout their length about said axis at distances greater than the distances of said vertically disposed legs from said axis, and each said inclined leg being inclined with respect to said axis at m essentially constant angle of inclination so that the longitudinal axis of each of said inclined legs lies within a surface of revolution which defines a hyperboloid of one sheet; and said vertically disposed legs and said upwardly extending inclined legs being the sole support extending between said platform and said base.
2. A tower comprising: a lower base; an upper platform; a plurality of spaced apart, essentially vertically disposed, generally straight legs arranged about and spaced apart from a central vertical axis, connected to said platform, and extending between said base and said platform; and a plurality of spaced apart, inclined, generally straight legs, arranged throughout their length about said axis at distances greater than the distances of said vertically disposed legs from said axis, each said inclined leg being connected to and extending between said base and said platform, each said inclined leg being inclined in essentially the same direction with respect to the leg adjacent thereto and at essentially the same angle with respect to said axis, and each said inclined leg being spaced from said axis at a symmetrically arranged predetermined distance at any given generally horizontal plane located between the extremities of said inclined legs with said predetermined distance being less at a point intermediate said leg extremities than at said leg extremities; said vertically disposed legs and said upwardly extending inclined legs being the sole support extending between said platform and said base.
3. A tower according to claim 2 wherein: each of said essentially vertical legs extends through said base and into the earth so as to anchor said tower; each of said inclined legs is tubular, has a hollow interior, and has open upper and lower extremities; an inner conductor tube is installed within at least some of said inclined legs; and at least some of said conductor tubes extend out the lower extremity of its associated inclined leg and into the earth so as to further anchor said tower.
a. A tower according to claim 3 wherein: said tower is an offshore tower; said base is adapted to rest upon the bed of a body of water with a portion of said tower extending above the surface of the water; and said conductor tube is adapted to receive a drill string and conduct same downwardly into the earth at an inclination to the vertical.
5. A tower according to claim 4 wherein: said conductor tube is generally coextensive with the inclined leg in which it is installed so as to form an annulus between said conductor tube and said inclined leg; and said annulus is at least partially filled with grouting.
6. A tower according to claim 4 wherein: each of said vertically disposed legs is tubular, has a hollow interior, has open upper and lower extremities, and is adapted to receive a drill string and conduct same downwardly into the earth.
7. A tower according to claim ll wherein liquid storage tank means is disposed below said upper platform and is supported on said base within the region defined by the inner edges of said inclined legs.
8. A tower according to claim 4 wherein: at least a portion of the outer edges of said inclined legs are covered with a continuous sheath of metal plate.
9. A tower according to claim 2 wherein: there is provided a second plurality of spaced apart, inclined, generally straight legs, arranged about said axis at distances greater than the distances of said first plurality of inclined legs from said axis, each connected to said platform and extending between said base and said platform, and each being inclined with respect to each other in the same direction and at essentially the same angle with respect to said axis as the legs of said first plurality of inclined legs.
10. A tower according to claim 9 wherein the inclined legs in said second plurality of inclined legs are each inclined with respect to each other in a direction opposite to the direction of the legs of said first plurality of inclined legs.
11. A tower according to claim 10 wherein connecting means are provided between tangent or adjacent legs of said first plurality of inclined legs and said second plurality of inclined legs.
12. A tower according to claim 9 wherein: each of said essentially vertical legs extends through said base and into the earth so as to anchor said tower; each of said inclined legs is tubular, has a hollow interior, and has open upper and lower extremities; an inner conductor tube is installed within at least some of said inclined legs; and at least some of said conductor tubes extend out the lower extremity of its associated inclined leg and into the earth so as to further anchor said tower.
13. A tower according to claim 12 wherein: said tower is an offshore tower; said base is adapted to rest upon the bed of a body of water with a portion of said tower extending above the surface of the water; and said conductor tube is adapted to receive a drill string and conduct same downwardly into the earth at an inclination to the vertical.
14. A tower according to claim 13 wherein: each of said vertically disposed legs is tubular, has a hollow interior, has open upper and lower extremities, and is adapted to receive a drill string and conduct same downwardly into the earth.
15. A tower according to claim 13 wherein: liquid storage tank means is disposed below said upper platform and is supported on said base within the region defined by the inner edges of said inclined legs.
16. A tower according to claim 11 wherein: at least a portion of the outer edges of said outer row of inclined legs are covered with a continuous sheath of metal plate.
17. A tower according to claim 2 wherein each of said inclined legs is spaced equidistant from said axis at any given generally horizontal plane located between the extremities of said legs and said extremities of said legs are spaced equidistant from said axis to form a generally circular pattern at said extremities of said inclined legs; said vertical legs and said inclined legs providing a support structure which is omnidirectional between said base and said platform with respect to dynamic environmental forces such as wind, ice, and water.
18. A tower according to claim 2 wherein each of said inclined legs is spaced from said axis in a manner to form a generally elliptical pattern at said extremities of said inclined legs.
19. A tower according to claim 1 wherein said vertically disposed legs and said upwardly extending inclined legs provide a support structure which is omnidirectional between said base and said platform with respect to dynamic environmental forces such as wind, ice, and water.
10101.5 Milt
1. A tower comprising: a lower base; an upper platform; a plurality of spaced apart, essentially vertically disposed legs, connected to said platform and extending between said base and said platform, and arranged about and spaced apart from a central vertical axis; a plurality of upwardly extending, spaced apart, inclined legs connected to and extending between said base and said platform, arranged throughout their length about said axis at distances greater than the distances of said vertically disposed legs from said axis, and each said inclined leg being inclined with respect to said axis at an essentially constant angle of inclination so that the longitudinal axis of each of said inclined legs lies within a surface of revolution which defines a hyperboloid of one sheet; and said vertically disposed legs and said upwardly extending inclined legs being the sole support extending between said platform and said base.
2. A tower comprising: a lower base; an upper platform; a plurality of spaced apart, essentially vertically disposed, generally straight legs arranged about and spaced apart from a central vertical axis, connected to said platform, and extending between said base and said platform; and a plurality of spaced apart, inclined, generally straight legs, arranged throughout their length about said axis at distances greater than the distances of said vertically disposed legs from said axis, each said inclined leg being connected to and extending between said base and said platform, each said inclined leg being inclined in essentially the same direction with respect to the leg adjacent thereto and at essentially the same angle with respect to said axis, and each said inclined leg being spaced from said axis at a symmetrically arranged predetermined distance at any given generally horizontal plane located between the extremities of said inclined legs with said predetermined distance being less at a point intermediate said leg extremities than at said leg extremities; said vertically disposed legs and said upwardly extending inclined legs being the sole support extending between said platform and said base.
3. A tower according to claim 2 wherein: each of said essentially vertical legs extends through said base and into the earth so as to anchor said tower; each of said inclined legs is tubular, has a hollow interior, and has open upper and lower extremities; an inner conductor tube is installed within at least some of said inclined legs; and at least some of said conductor tubes extend out the lower extremity of its associated inclined leg and into the earth so as to further anchor said tower.
4. A tower according to claim 3 wherein: said tower is an offshore tower; said base is adapted to rest upon the bed of a body of water with a portion of said tower extending above the surface of the water; and said conductor tube is adapted to receive a drill string and conduct same downwardly into the earth at an inclination to the vertical.
5. A tower according to claim 4 wherein: said conductor tube is generally coextensive with the inclined leg in which it is installed so as to form an annulus between said conductor tube and said inclined leg; and said annulus is at least partially filled with grouting.
6. A tower according to claim 4 wherein: each of said vertically disposed legs is tubular, has a hollow interior, has open upper and lower extremities, and is adapted to receive a drill string and conduct same downwardly into the earth.
7. A tower according to claim 1 wherein liquid storage tank means is disposed below said upper platform and is supported on said base within the region defined by the inner edges of said inclined legs.
8. A tower according to claim 4 wherein: at least a portion of the outer edges of said inclined legs are covered with a continuous sheath of metal plate.
9. A tower according to claim 2 wherein: there is provided a second plurality of spaced apart, inclined, generally straight legs, arranged about said axis at distances greater than the distances of said first plurality of inclined legs from said axis, each connected to said platform and extending between said base and said platform, and each being inclined with respect to each other in the same direction and at essentially the same angle with respect to said axis as the legs of said first plurality of inclined legs.
10. A tower according to claim 9 wherein the inclined legs in said second plurality of inclined legs are each inclined with respect to each other in a direction opposite to the direction of the legs of said first plurality of inclined legs.
11. A tower according to claim 10 wherein connecting means are provided between tangent or adjacent legs of said first plurality of inclined legs and said second plurality of inclined legs.
12. A tower according to claim 9 wherein: each of said essentially vertical legs extends through said base and into the earth so as to anchor said tower; each of said inclined legs is tubular, has a hollow interior, and has open upper and lower extremities; an inner conductor tube is installed within at least some of said inclined legs; and at least some of said conductor tubes extend out the lower extremity of its associated inclined leg and into the earth so as to further anchor said tower.
13. A tower according to claim 12 wherein: said tower is an offshore tower; said base is adapted to rest upon the bed of a body of water with a portion of said tower extending above the surface of the water; and said conductor tube is adapted to receive a drill string and conduct same downwardly into the earth at an inclination to the vertical.
14. A tower according to claim 13 wherein: each of said vertically disposed legs is tubular, has a hollow interior, has open upper and lower extremities, and is adapted to receive a drill string and conduct same downwardly into the earth.
15. A tower according to claim 13 wherein: liquid storage tank means is disposed below said upper platform and is supported on said base within the region defined by the inner edges of said inclined legs.
16. A tower according to claim 11 wherein: at least a portion of the outer edges of said outer row of inclined legs are covered with a continuous sheath of metal plate.
17. A tower according to claim 2 wherein each of said inclined legs is spaced equidistant from said axis at any given generally horizontal plane located between the extremities of said legs and said extremities of said legs are spaced equidistant from said axis to form a generally circular pattern at said extremities of said inclined legs; said vertical legs and saId inclined legs providing a support structure which is omnidirectional between said base and said platform with respect to dynamic environmental forces such as wind, ice, and water.
18. A tower according to claim 2 wherein each of said inclined legs is spaced from said axis in a manner to form a generally elliptical pattern at said extremities of said inclined legs.
19. A tower according to claim 1 wherein said vertically disposed legs and said upwardly extending inclined legs provide a support structure which is omnidirectional between said base and said platform with respect to dynamic environmental forces such as wind, ice, and water.
| 1969-12-29 | en | 1972-02-29 |
US-44387174-A | Lock and interlock mechanism
ABSTRACT
A multiple shelf cabinet has a plurality of slidable shelves and a plurality of pivoted doors closing off said shelves. A combined shelf and door locking mechanism acts to either by means of a key lock prevent all of the doors from being opened and shelves from being slid outwardly or by an interlock device, prevent a second shelf from being slid outwardly when a first shelf is slid out. The locking mechanism includes a vertical locking bar having a plurality of hooking members for holding the doors closed and a plurality of cam members carried by the shelves that engage means on the locking bar to move the same to a locking position as a shelf is slid out.
United States Patent 1 1 Himsl 1 LOCK AND INTERLOCK MECHANISM Ernst G. Himsl, Kitchener. Ontario. C unada [75] Inventor:
[73] Assignee: Sunar Limited, Waterloo. Ontario.
Canada 22 Filed: Feb. 19,1974
21 Appl. No.:443,871
1 1 June 10, 1975 Haunost 312/222 Himsl 312/219 X [57] ABSTRACT A multiple shelf cabinet has a plurality of slidable shelves and a plurality of pivoted doors closing off said shelves. A combined shelf and door locking mechanism acts to either by means of a key lock prevent all of the doors from being opened and shelves from being slid outwardly or by an interlock device, prevent a second shelf from being slid outwardly when a first shelf is slid out. The locking mechanism includes a vertical locking bar having a plurality of hooking members for holding the doors closed and a plurality of cam members carried by the shelves that engage means on the locking bar to move the same to a locking position as a shelf is slid out.
16 Claims, 11 Drawing Figures I LOCK AND INTERLOCK MECHANISM This invention relates to cabinets and more particularly to locking and interlocking mechanism for doors and drawers in such cabinets.
The use of interlocking devices in cabinets that have sliding drawers to prevent more than one drawer to be open at one time is well known. These devices generally include some sort of device that is engaged by means carried on a drawer being opened. and which device is moved to a position wherein other blocking means thereon are positioned to prevent opening of any other drawer. These devices often have a key operated device that acts to hold the device in position to prevent any drawer from being opened.
Where the drawers are of the shelf type with open fronts to permit access to the contents of the drawer or shelf, such a locking arrangement will not prevent access to the contents of the cabinet. In such a case closure doors can be provided that are pivotable about their upper ends and are slidable into the cabinet out of the way in a horizontal position above the shelf. Lock means can be provided to either individually lock the doors or mechanism installed that will simultaneously lock all of the doors.
It is an object of this invention to provide a cabinet having sliding drawers and pivoted doors with a locking mechanism that simultaneously locks both the doors and drawers.
It is a further object to provide an interlock mechanism which can be key operated to lock all drawers and doors.
A still further object is to provide an interlock mechanism which will prevent more than one drawer to be opened at one time but will permit any number of doors to be open.
These and other objects and advantages will be readily apparent from the following disclosure and accompanying drawings in which:
FIG. I is a perspective view of a file cabinet incorporating the invention;
FIG. 2 is a cross-sectional view of the cabinet with one of the drawers in open position;
FIG. 3 is an enlarged perspective view of the locking bar mechanism of FIG. 2;
FIG. 4 is a similar view showing one form of cam and abutment device carried on the side of the sliding shelf;
FIG. 5 is an enlarged cross-sectional view of the cabinet of FIG. 2;
FIG. 6 is a cross-sectional view showing a key lock mechanism;
FIG. 7 is a cross-sectional view taken on the line 77 of FIG. 6;
FIG. 8 is a cross-sectional view taken on the line 8-8 of FIG. 5;
FIG. 9 is a view similar to FIG. 5 showing another form of the invention;
FIG. 10 is a cross-sectional view taken on the line 10-10 of FIG. 9; and
FIG. 11 is an enlarged view taken on the line 11-11 of FIG. 10.
In the embodiment shown in FIGS. 1 to 8, the invention is shown in a multiple drawer cabinet generally indicated I, and which has a plurality of pivoted normally vertical doors 3. The doors 3 each close off access to an open faced drawer or shelf 5 which can be slid outward from within the cabinet on conventional telescoping supports 7. The doors 3 are pivoted on rollers not shown which ride in tracks 9 so that after a door is swung up to a horizontal position it can be slid back into the cabinet as seen in FIG. 2 with the door supported on the track 9.
The locking device includes an elongated bar 11 vertically arranged inside of the cabinet near the front thereof as seen in FIG. 2. The bar 11 is biased by spring 13 upward to an unlocking position. At the upper end of the bar II is a bracket member 23 having a portion 14 that passes through an aperture in a bracket [6 (FIGS. 6 and 7) attached to the front of the cabinet. This serves as a guide for movement of the bar up and down. The lower end of the bar II passes through a similar aperture in the cabinet as seen in FIG. 2.
As seen in FIG. 3 the locking bar carries a plurality of forwardly extending bracket members 15 (only one of which is shown in FIG. 3). The brackets each have a hook portion 17 and a roller I9 extending outward. The hooks 17 are adapted, when in a raised position. to enter into apertures 21 formed in the doors 3 as seen in FIG. 5. When the lock bar 11 is in its lower or locking position the hook I7 prevents the door from being opened.
The bracket 23 on the top part of the bar 11 has a slot 25 through which an eccentric pin 27 protrudes. The pin 27 is carried on a rotatable portion 29 of a key lock device 31. It will be obvious that as the lock is rotated by a key in the position illustrated in FIG. 3, the pin 27 will act on the bracket to force the bracket and bar 11 downward against the spring 13 into locking position. On the other hand, the slot 25 permits free up and down movement of the bracket and bar when the pin 27 is in its upper position.
Mounted on the side of each shelf drawer are elongated guide members 2 having an inclined cam portion 33. A second combined blocking and cam portion 35 is located below the cam portion 33. The rollers 19 carried on the lock bar 11 are positioned to engage the underside of the cam 33 when the bar 11 is in its upper or unlocking position. When the bar 11 is in its lower or locking position the rollers 19 engage the vertical face on the blocking or abutment portion 35.
The operation of the device of FIGS. 1 to 8 will now be described. When all of the doors 3 are closed and the key lock 31 is in its locking condition, the pin 27 holds the bracket 23 and bar 11 in its lower position against spring 13. In this position the hooks l7 prevent any of the doors that are closed from being opened. At the same time the rollers 19 prevent the shelf drawers from being opened because the abutment 35 contacts the rollers. When the key lock is opened the spring 13 raises the bar 11 and the hooks 17 are raised to permit opening of any of the doors 3 to be opened. The rollers 19 are now raised above the level of the abutment 35. As any drawer is opened, the cam portion 33 thereon engages the respective roller 19 and forces the roller and lock bar down into the locking position. The roller rides on the underside of the guide 32. No other drawer or door can then be opened. As the opened drawer is returned the roller again rides on the underside of the guide 32. The inclined portion 36 on the member 35 aids in moving the roller and bar upward into unlocking position.
A modified arrangement is shown in FIGS. 9, I0 and II. In that form the locking bar 41 is similar to that in FIGS. I to 8 except that operating pins or studs 43 are threaded in apertures in the lock bar. The clearance between the hexagonal portion 49 and shoulder 47 which engages the bar 11 permits free up and down movement of the stud in a slot 50 formed in the inner sidewall 52 of the cabinet. A spring clip device 51 is attached to the sidewall 52 that engages the pin 43. A detent portion 54 is urged outward by the pin 43 as it moves between the lower solid line position of FIG. 11 and the upper broken line position. This serves to hold the lock bar and pins in their upper unlocked positions.
The pins 43 function as both the door lock and drawer lock. The doors 55 contain a hook portion 57 that the pin 43 engages when in its lower position. The same pin engages the front vertical face 67 of a molded assembly 61 which includes an upper inclined cam portion 63 and a low cam portion 65. Unlike the embodiment of FIGS. 1 to 8, that of FIGS. 9 to 11 does not have a horizontal track or guide 32 to hold the lock mechanism in its lower locking position since the spring clip 51 serves to hold the bar in either position. The lower cam 65 serves to positively move the pin and lock bar up when the drawer is closed.
The operation of the device of FIGS. 9 to 11 is basically the same as that of FIGS. 1 to 8. The lock bar 41 is positively moved up and down by the key lock but when in unlocked position the bar can be independently moved up and down by the cams 63 and 65 as a drawer is opened and closed. The spring clip 51 serves to hold the bar up or down.
It will be obvious that changes and modifications can be made without departing from the invention. For example, the operation of the lock bar could be reversed with the upper position being the locking position and the lower the unlocked position. This and other changes will be apparent to those skilled in the art and such changes are deemed to be within the scope of the invention which is limited only by the following claims.
I claim:
1. A cabinet having top, bottom, rear and side walls and an open front, a plurality of slidable shelves arranged to slide from an inner position out the open front to an exposed position and a plurality of pivoted doors swingable between vertical closed positions closing access to the shelves and horizontal open positions permitting access to the shelves, each door associated with one shelf, a combined lock means for simultaneously preventing the doors from being moved from their closed positions and preventing sliding of said shelves from their inner positions, said lock means including a vertically movable lock bar movable between a locking and an unlocking position, lock device means on said lock bar and engaging said doors when said lock bar is in locking position and said doors are in closed position said lock device means engaging said shelves to prevent the same from sliding out when the lock bar is in its locking position.
2. The cabinet of claim 1 wherein key lock means are provided on said cabinet arranged to hold said lock bar in its locking position to prevent opening of said doors or sliding of said shelves.
3. The cabinet of claim 1 wherein said shelves carry operator means thereon arranged to move the lock bar to its locking position when any of the shelves are moved from their inner position toward their outer position.
4. The cabinet of claim 3 wherein said operator means comprises cam means arranged to engage said lock device means as the shelves are opened.
5. The cabinet of claim 4 wherein said lock bar is arranged to normally move to its unlocking position and said cam means acts to overcome said normal movement.
6. The cabinet of claim 5 wherein said lock bar is spring biased to its unlocking position.
7. The cabinet of claim 5 wherein said lock bar is moved by gravity to its unlocking position.
8. The cabinet of claim 5 wherein said lock device means includes a plurality of hook members carried by and protruding forwardly from the lock bar and arranged to enter into apertures in said doors and engage said doors to hold them closed when the lock bar is in its locking position.
9. The cabinet of claim 8 wherein said lock device means further includes roller members arranged to be engaged by and moved by said cams as any shelf is slid out, said movement causing movement of said lock bar to its locking position.
10. The cabinet of claim 9 wherein said shelves carry abutment members arranged to engage said rollers when the lock bar is in its locking position to thereby prevent movement of the shelves towards their outer positions.
11. The cabinet of claim 10 wherein key lock means are provided to hold said lock bar in its locking position to prevent any door from being opened.
12. The cabinet of claim 1 wherein said lock device means comprises a plurality of elements extending from the lock bars, hook means on said doors arranged to be engaged by said elements when the doors are in their closed position and said lock bar is moved from its unlocking position to its locking position.
13. The cabinet of claim 12 wherein said shelves each carry a combination lock bar operating member including a cam portion and an abutment portion, said abutment portion located to engage one of said elements when the lock bar is in its locking position and said cam portion engaging said one element when the lock bar is in its unlocking position, said cam portion acting to move said element and the lock bar to its locking position as the shelf carrying the lock bar operating member is moved outward.
14. A multiple shelf cabinet having at least one of the shelves slidable outward, a plurality of doors on said cabinet and independent of said shelves closing said cabinet and each arranged to prevent access to one of said shelves, a combined shelf and door interlock device arranged in one condition to simultaneously lock the doors from being opened and prevent the shelves from being slid outward, and means for holding the interlock device in its one condition.
15. The cabinet of claim 14 wherein the interlock device includes means for holding the same in either a locking condition or an unlocking condition and said shelves carry cam members that act to move the interlock device between its conditions as the shelf is opened and closed whereby when one shelf is opened the other shelves are prevented from being opened until the one shelf is closed.
16. The cabinet of claim 14 wherein the means for holding the interlock device in its one condition comprises a key lock device.
I! II i I
1. A cabinet having top, bottom, rear and side walls and an open front, a plurality of slidable shelves arranged to slide from an inner position out the open front to an exposed position and a plurality of pivoted doors swingable between vertical closed positions closing access to the shelves and horizontal open positions permitting access to the shelves, each door associated with one shelf, a combined lock means for simultaneously preventing the doors from being moved from their closed positions and preventing sliding of said shelves from their inner positions, said lock means including a vertically movable lock bar movable between a locking and an unlocking position, lock device means on said lock bar and engaging said doors when said lock bar is in locking position and said doors are in closed position said lock device means engaging said shelves to prevent the same from sliding out when the lock bar is in its locking position.
2. The cabinet of claim 1 wherein key lock means are provided on said cabinet arranged to hold said lock bar in its locking position to prevent opening of said doors or sliding of said shelves.
3. The cabinet of claim 1 wherein said shelves carry operator means thereon arranged to move the lock bar to its locking position when any of the shelves are moved from their inner position toward their outer position.
4. The cabinet of claim 3 wherein said operator means comprises cam means arranged to engage said lock device means as the shelves are opened.
5. The cabinet of claim 4 wherein said lock bar is arranged to normally move to its unlocking position and said cam means acts to overcome said normal movement.
6. The cabinet of claim 5 wherein said lock bar is spring biased to its unlocking position.
7. The cabinet of claim 5 wherein said lock bar is moved by gravity to its unlocking position.
8. The cabinet of claim 5 wherein said lock device means includes a plurality of hook members carried by and protruding forwardly from the lock bar and arranged to enter into apertures in said doors and engage said doors to hold them closed when the lock bar is in its locking position.
9. The cabinet of claim 8 wherein said lock device means further inCludes roller members arranged to be engaged by and moved by said cams as any shelf is slid out, said movement causing movement of said lock bar to its locking position.
10. The cabinet of claim 9 wherein said shelves carry abutment members arranged to engage said rollers when the lock bar is in its locking position to thereby prevent movement of the shelves towards their outer positions.
11. The cabinet of claim 10 wherein key lock means are provided to hold said lock bar in its locking position to prevent any door from being opened.
12. The cabinet of claim 1 wherein said lock device means comprises a plurality of elements extending from the lock bars, hook means on said doors arranged to be engaged by said elements when the doors are in their closed position and said lock bar is moved from its unlocking position to its locking position.
13. The cabinet of claim 12 wherein said shelves each carry a combination lock bar operating member including a cam portion and an abutment portion, said abutment portion located to engage one of said elements when the lock bar is in its locking position and said cam portion engaging said one element when the lock bar is in its unlocking position, said cam portion acting to move said element and the lock bar to its locking position as the shelf carrying the lock bar operating member is moved outward.
14. A multiple shelf cabinet having at least one of the shelves slidable outward, a plurality of doors on said cabinet and independent of said shelves closing said cabinet and each arranged to prevent access to one of said shelves, a combined shelf and door interlock device arranged in one condition to simultaneously lock the doors from being opened and prevent the shelves from being slid outward, and means for holding the interlock device in its one condition.
15. The cabinet of claim 14 wherein the interlock device includes means for holding the same in either a locking condition or an unlocking condition and said shelves carry cam members that act to move the interlock device between its conditions as the shelf is opened and closed whereby when one shelf is opened the other shelves are prevented from being opened until the one shelf is closed.
16. The cabinet of claim 14 wherein the means for holding the interlock device in its one condition comprises a key lock device.
| 1974-02-19 | en | 1975-06-10 |
US-38846773-A | Vehicle wheel traction mat
ABSTRACT
A traction mat especially suitable for use under a vehicle wheel comprises a series of articulated serpentine traction strips with at least certain of the strips having superior traction edge projections. The mat can be compactly rolled for storage.
United States Patent 1 1 Gantert 1 Jan. 7, 1975 [54] VEHICLE WHEEL TRACTION MAT 1,683,411 9/1928 Remmers 238/14 Inventor: Alfred m 5620 s ke 1,779,414 10/1930 Ames .1 15/239 Shore 5 WQQQQPLQKQUL 60097 I Primary ExaminerM. Henson Wood, Jr. [22] Filed: 1973 Assistant Examiner Richard A. Bertsch [2]] AppL 3 4 7 Attorney, Agent, or Firm-Hill, Gross, Simpson, Van
Santen, Steadman, Chiara & Simpson [52] US. Cl. 238/114, 15/239 [51] Int. Cl E01b 23/00 ABSTRACT [58] Field of Search 15/238 241; 238/14 A traction mat especially suitable for use under a vehicle wheel comprises a series of articulated serpentine [56] References cued traction strips with at least certain of the strips having UNITED STATES PATENTS superior traction edge projections. The mat can be 760,101 5/1904 Burnell 15/239 compactly rolled for storage. 839,059 12/1906 Doebler 15/241 1,465,550 8/1923 Hayden 15/239 20 Claims, 6 Drawing Figures VEHICLE WHEEL TRACTION MAT This invention relates to traction mats especially suitable for use under vehicle wheels to provide emergency traction under conditions such as snow, ice, sand, clay, loose soil, and the like.
Numerous and varied wheel traction assistance structures have been suggested heretofore, but have suffered from anyone or more of a number of shortcom ings among which may be mentioned unduly high cost so as to be unattractive economically, permanent deformability under wheel weight, dangerous cutting edges or sharp points that may injure the users hands or other objects during handling or in storage, bulkiness or unwieldiness for storage purposes, difficult to clean, relative ineffectiveness under unusual circumstances such as deep snow, mud or sand, and the like.
It is accordingly an important object of the present invention to overcome the foregoing and other disadvantages, defects, deficiencies, inefficiencies, shortcomings and problems inherent in prior structures and to attain important improvements and advantages in a new and improved vehicle traction mat as will hereinafter become apparent.
Another object of the invention is to provide a vehicle wheel traction mat of exceptional efficiency, easy handling, rugged construction, indefinite reusability, and low cost.
A further object of the invention is to provide a new and improved vehicle wheel traction mat which can be neatly rolled into a small bundle for storage and handling.
Still another object of the invention is to provide a new and improved vehicle wheel traction mat which can be easily and effectively cleaned after use.
Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawing although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:
FIG. 1 is a fragmental isometric view of a vehicle wheel traction mat embodying features of the invention.
FIG. 2 is a fragmentary enlarged side elevational view of the mat demonstrating its use.
FIG. 3 is an enlarged fragmentary sectional elevational detail view taken substantially along the line III- III of FIG. 1.
FIG. 4 is a schematic side elevational view of the mat in rolled-up condition in a small bundle for storage.
FIG. 5 is a fragmentary plan view of the mat showing a modification.
FIG. 6 is a fragmentary sectional detail view of the mat showing another modification.
As shown in FIG. 1, a traction mat embodying features of the invention involves certain basic structural features found in the well known flexible metallic door mats used in association with entrance doors of buildings and other places to provide a convenient walking surface for catching mud, dirt and snow from the shoes of persons walking thereon. Such mats are necessarily constructed with uniformly plane upper and lower faces. Similar to the door mat construction, the traction mat 10 comprises a series of serpentine traction strips 11 which may be formed from suitable material such as sheet or plate metal, high impact strength plastic and the like. Each of these strips 11 has alternately oppositely projecting undulations 12 defining therebetween corresponding oppositely opening indentations 13. In the illustrated instance, the undulations 12 are of regular generally U-shape with the leg portions of each of the Us slightly divergent so that the crest portions of the undulations can fit interdigitally by projecting into the mouth ends of the indentations 13. In the mat 10, the crest portions of the undulations face generally toward the opposite ends of the mat and the leg portions of the undulations face generally toward the sides of the mat. For flexibility of the mat, the interdigited crest portions of the undulations 12 are articulately coupled by means of suitable hinge pin rods 14 desirably formed from suitable gauge wire and extending through aligned holes 15 in the sides of the crest portions of the undulations. To retain the rods 14 against endwise displacement, they are provided with means at their opposite ends comprising locking terminals 14a bent to extend longitudinally long the outer side of the mat and suitably interlocked as at 17 with the outermost undulation leg of one of the coupled traction strips. Through this arrangement, the traction strips 11 are connected into a flexible mat form which permits the mat to be rolled up into a compact bundle for storage as shown in FIG. 4 and to be readily rolled out for use as required. Further, the articulated construction facilitates cleaning of the mat by shaking it, thrashing it against a surface, and the like.
For ruggedness at each opposite end of the mat 10, reinforcing and stabilizing means such as a closure strip bar 18 may be provided and which may be formed from the same strip material as the traction strips 11 or may be of a slightly heavier gauge if preferred. Each of the end bars 18 is secured to the crests of the endmost un dulations 12 of the mat as by means of rivets 19. Reinforcing means at the opposite ends of the bars 18 may comprise respective turned terminal flanges 2(1 thereon which lap the adjacent outer sides of the side most traction strip undulations and may be secured thereto as by means of rivets 21. In the mat 10 as thus constructed, the upper and lower edges of the traction strips 11 and the bars 18 cooperate to provide upper and lower traction mat faces.
For improved traction reliability in association with vehicle wheels, the mat 10 is provided with means at least at one of its faces to attain superior traction. To this end, improved gripping of the underlying surface (including mud, sand, snow, ice, etc.) is attained by providing at least certain of the transverse articulately connected strips, identified as 11a and which are in general respects the same as the companion serpentine track strips 11, with superior traction edge portions 22 projecting downwardly beyond the face plane of the strips 12. To improve their gripping function, the projections 22 are desirably in the form of generally saw tooth prongs extending seriatim throughout the extent of the lower edges of the strips 11a so that not only the lower edges of the crests but also the lower edges of the side walls of the undulations 12a of the strips 11a have the saw tooth projections 22 providing excellent traction gripping against slipping not only for and aft but also toward either side of the mat. To enhance their effectiveness and durability, the gripping prongs 22 are relatively short compared to root width, and the strips 11a are of extended width downwardly relative to the companion strips 11, thereby providing continuous downwardly projecting traction flanges 23 for the mat 10, with the projections 22 providing superior traction gripping. In a desirable construction, as shown, the flange 23 of each of the strips lla may have an unbro ken solid width at least equal to the length of the prongs 22. Although for extremely severe hard ice conditions, it may be desirable to construct the mat l entirely from the traction strips lla or to have every alternate one of the strips in the mat of the 110 type, for general utility, every third or fourth of the strips in the mat may be one of the strips lla. For snow and loose dirt, mud or sand conditions, ditch or gully caught wheel, and like conditions, the spaced arrangement of the strips 11a along the length of the mat has advantages since the strips 11a can then function as cleats along the lower face of the mat.
Even though good results can be realized by having the upper face of the mat of generally uniform plane, improved traction engagement with a vehicle wheel tire is attained by providing the strips lla with upward traction edge projections 24, preferably in the form of a continuous flange which may have its upper edge in a common plane, but which may be of vertically undulating form to provide a series of blunt upward projections such as one such projection for each undulation crest rather than a plurality of saw tooth projections such as the teeth 22, thereby preventing injury to rubber tire treads.
In use of the mat 11, one end is placed in touch association with the rubber tire of a wheel W (FIG. 2) for which traction aid is desired. As power is applied to the wheel, the tire treads will engage with the end portion of the mat and either climb onto it or pull it further under the wheel until the cleat flanges 23 catch in the underlying material or surface, anchoring the mat and enabling the wheel to roll on over the upper traction surface of the mat, aided by the projecting flanges 24 which press up into the tire tread for increased traction, as exemplified in FIG. 2. Such an arrangement is especially satisfactory where the wheel W must negotiate a relatively steep incline or grade to reach a level surface or at least a surface of a grade which will provide adequate traction for the wheel, considering the particular surface conditions at the time.
For automobile tires, the mat 10 may be from 8 to 9 inches wide and about 3 feet in length. For heavy-duty trucks, a width of about 12 inches by 6 feet may be required. To meet unusual conditions, a plurality of the mats 10 may be laid end to end. Sometimes only one of the driving wheels of a vehicle loses traction and requires traction assistance, and then only one of the mats 10 will suffice, but often both of a pair of traction wheels may require assistance and then two of the mats 10 may be used. By reason of the open mesh or reticulated arrangement effected by the articulatedly connected traction strips of the mat 10, maximum traction area is afforded by the mat with minimum weight. Further, by reason of the articulated connection of the mat strips 11, lla, the mat can be rolled up into a relatively compact bundle as shown in FIG. 4. This permits one or more of the mats to be conveniently stored in a vehicle such as in the storage trunk, leaving maximum storage area free for other uses, avoiding disturbance of other articles in the storage space when it is necessary to remove the traction mat for use. After use, the traction mat can be easily cleaned of any snow or dirt, by
shaking it out, striking it against an unyielding surface, and the like, whereafter the mat can again be rolled up and returned to storage with minimum liability of transferring snow, ice or dirt into the storage space on the mat.
In a typical construction, the width of the strips 11 may be about three-eighth of an inch and the strips lla about three-fourth inch in width, with the undulations 12, 12a about 1 /2 to 2 inches long, the flanges 24 projecting upwardly about one-eighth inch and the flanges 23 with the teeth 22 projecting downwardly about onefourth inch. Spacing of the strips lla inwardly from the ends of the mat 10 may be about 3 to 6 inches and the space between the successive strips lla about 6 to 8 inches, as preferred. In order to facilitate initial placement of the mat under a vehicle tire the traction strips lla nearest the ends of the mat may have only the upwardly projecting superior traction flange 24, with the next succeeding and remaining of the traction strips 11a provided with both the upward and downward superior traction projections.
For heavy duty purposes, such as for trucks, the mat may require additional reinforcement along the sides. For this purpose, the arrangements shown in FIG. 5 may be employed wherein the mat 10 has a reinforcing side closure plates 25 in articulated connection with the outer end portions of the connecting rods 14 and along side the outer most legs of the undulations of the transverse strips 11 and 11a.
Where increased traction is desired at one or both opposite ends of the traction mat, a modification of the end closure plates strip 18 may be provided as represented in FIG. 6. Thus, the mat 10" which may be in other respects similar as already described, is provided with a closure strip 18" secured as by means of rivets 19" to the undulations 12" of the endmost traction strip 11" and either the upper or lower or both edges of the strip 11'' may project beyond the adjacent edges of the strip 11". Thus, the strip 18" may be provided be, an upwardly projecting superior traction flange 27 may be for example, of about 43 inch height above the edge of the strip 11". Alternatively in addition to the upper projection 27, the strip 18" may be provided with a downward superior traction projection 28 which may be in the form of teeth similar to the traction teeth 22 or merely a solid downward projection of the strip 18".
It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.
I claim as my invention:
1. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising:
a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides;
the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations;
means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips;
certain of the strips being of minor width;
others of the strips being substantially wider than said minor width strips;
and a plurality of the narrower strips intervening between adjacent width strips; whereby the wider strips provide superior traction projections from at least one of said faces of the mat.
2. A traction mat according to claim ll, wherein said wider strips project above the upper face of the mat.
3. A traction mat according to claim 1, wherein said wider strips project below the lower face of the traction mat.
4. A traction mat according to claim 3, wherein said wider strips have closely spaced teeth on their lower edges extending entirely along the lower edges including the crest portions and the leg portions of the wider strips.
5. A traction mat according to claim 1, wherein said wider strips project both above the upper face of the mat and from tne lower face of the mat.
6. A traction mat according to claim 5, wherein the upper edges of the wider strips are in a common plane and the lower edges of the wider strips have traction improving teeth thereon.
7. A traction mat according to claim 5, wherein the wider strips extend to a greater width below the lower face of the mat than the wider strips extend above the upper face of the mat.
8. A traction mat according to claim 1, said coupling means comprising rods which extend through holes in the sides of the crest portions and have locking terminals which are bent to extend longitudinally along the outer sides of the mat and have ends which are interlocked with the outermost legs of the strips coupled by the rods.
9. A traction mat according to claim 8, includingreinforcing side closure plates in articulated connection 4 with the connecting rods along the sides of the mat and the terminal portions of the rods connecting said side plates to the sides of the mat.
10. A traction mat according to claim 1, including an end closure strip engaging the crests of the traction strips at least at one end of the mat, said end closure strip having a traction flange portion at least along one edge which projects from the adjacent traction mat face to improve traction at that end of the mat.
111. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising:
a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indendations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides;
the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations;
means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the oppo-, site edges of the strips;
at least certain of the strips having superior traction edge projection flange structure on said crest portions and on said leg portions and extending upwardly above the general upper face plane of the mat; and
said certain strips being spaced from one another longitudinally along the mat, and with a majority of the traction strips intervening between the spaced certain strips and defining said general upper face plane.
12. A traction mat according to claim 11, wherein said projection flange structure comprises a continuous flange on each of said certain strips.
13. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising:
a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides;
the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations;
means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips;
at least certain of the strips having superior traction edge projection flange structure on said crest portions and on said leg portions and extending downwardly from the general lower face plane along the lower face of the mat; and
said certain strips being spaced from one another longitudinally along the mat, with a majority of the traction strips intervening between the spaced certain strips and defining said general lower face plane.
14. A traction mat according to claim 13, wherein said flange structure includes a series of downwardly projecting traction teeth.
15. A traction mat according to claim 14, wherein said teeth are of generally saw tooth form projecting downwardly at uniform intervals along the lower edges of the crest portions and the leg portions of said certain strips and provide effective traction grip against displacement of the mat both longitudinally and laterally.
16. A traction mat according to claim 13, wherein said traction edge projection flange structure comprises a continuous flange on each of said certain strips.
17. A traction mat according to claim 13, wherein said coupling means comprise rods which extend through holes in the sides of the crest portions and having locking terminals which are bent to extend longitudinally along theouter sides of the mat and have ends which are interlocked with the outermost legs of the strips coupled by the rods.
18. A traction mat according to claim 17, including reinforcing side closure plates in articulated connection with the connecting rods along the sides of the mat and the terminal portions of the rods connecting said side plates to the sides of the mat.
19. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising:
a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides;
the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations;
means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips;
certain of the strips being of minor width;
others of the strips being substantially wider than said minor width strips;
and said wider strips being spaced from one another by at least one minor width strip intervening between the wider strips;
said wider strips projecting both above the upper face of the mat and below the lower face of the mat;
said wider strips extending to a greater width below the lower face of the mat than they extend above' the upper face of the mat; whereby the wider strips provide superior traction projections from at least one of said faces of the mat.
20. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising:
a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides; t
the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations;
means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips;
certain of the strips being of minor width;
others of the strips being substantially wider than said minor width strips;
and said wider strips being spaced from one another by at least one minor width strip intervening between the wider strips;
whereby the wider strips provide super traction projections from at least one of said faces of the mat;
and an end closure strip engaging the crests of the traction strips at least at one end of the mat, said end closure strip having a traction flange portion at least along one edge which projects from the adjacent traction mat face to improve traction at that end of the mat.
1. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising: a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides; the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations; means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips; certain of the strips being of minor width; others of the strips being substantially wider than said minor width strips; and a plurality of the narrower strips intervening between adjacent width strips; whereby the wider strips provide superior traction projections from at least one of said faces of the mat.
2. A traction mat according to claim 1, wherein said wider strips project above the upper face of the mat.
3. A traction mat according to claim 1, wherein said wider strips project below the lower face of the traction mat.
4. A traction mat according to claim 3, wherein said wider strips have closely spaced teeth on their lower edges extending entirely along the lower edges including the crest portions and the leg portions of the wider strips.
5. A traction mat according to claim 1, wherein said wider strips project both above the upper face of the mat and from tne lower face of the mat.
6. A traction mat according to claim 5, wherein the upper edges of the wider strips are in a common plane and the lower edges of the wider strips have traction improving teeth thereon.
7. A traction mat according to claim 5, wherein the wider strips extend to a greater width below the lower face of the mat than the wider strips extend above the upper face of the mat.
8. A traction mat according to claim 1, said coupling means comprising rods which extend through holes in the sides of the crest portions and have locking terminals which are bent to extend longitudinally along the outer sides of the mat and have ends which are interlocked with the outermost legs of the strips coupled by the rods.
9. A traction mat according to claim 8, including reinforcing side closure plates in articulated connection with the connecting rods along the sides of the mat and the terminal portions of the rods connecting said side plates to the sides of the mat.
10. A traction mat according to claim 1, including an end closure strip engaging the crests of the traction strips at least at one end of the mat, said end closure strip having a traction flange portion at least along one edge which projects from the adjacent traction mat face to improve traction at that end of the mat.
11. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising: a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indendations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides; the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations; means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips; at least certain of the strips having superior traction edge projection flange structure on said crest portions and on said leg portions and extending upwardly above the general upper face plane of the mat; and said certain strips being spaced from one another longitudinally along the mat, and with a majority of the traction strips intervening between the spaced certain strips and defining said general upper face plane.
12. A traction mat according to claim 11, wherein said projection flange structure comprises a continuous flange on each of said certain strips.
13. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising: a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides; the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations; means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips; at least certain of the strips having superior traction edge projection flange structure on said crest portions and on said leg portions and extending downwardly from the general lower face plane along the lower face of the mat; and said certain strips being spaced from one another longitudinally along the mat, with a majority of the traction strips intervening between the spaced certain strips and defining said general lower face plane.
14. A traction mat according to claim 13, wherein said flange structure includes a series of downwardly projecting traction teeth.
15. A traction mat according to claim 14, wherein said teeth are of generally saw tooth form projecting downwardly at uniform intervals along the lower edges of the crest portions and the lEg portions of said certain strips and provide effective traction grip against displacement of the mat both longitudinally and laterally.
16. A traction mat according to claim 13, wherein said traction edge projection flange structure comprises a continuous flange on each of said certain strips.
17. A traction mat according to claim 13, wherein said coupling means comprise rods which extend through holes in the sides of the crest portions and having locking terminals which are bent to extend longitudinally along the outer sides of the mat and have ends which are interlocked with the outermost legs of the strips coupled by the rods.
18. A traction mat according to claim 17, including reinforcing side closure plates in articulated connection with the connecting rods along the sides of the mat and the terminal portions of the rods connecting said side plates to the sides of the mat.
19. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising: a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides; the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations; means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips; certain of the strips being of minor width; others of the strips being substantially wider than said minor width strips; and said wider strips being spaced from one another by at least one minor width strip intervening between the wider strips; said wider strips projecting both above the upper face of the mat and below the lower face of the mat; said wider strips extending to a greater width below the lower face of the mat than they extend above the upper face of the mat; whereby the wider strips provide superior traction projections from at least one of said faces of the mat.
20. A traction mat having opposite sides and opposite ends and especially suitable for use to provide efficient traction under a vehicle wheel, comprising: a series of substantially rigid serpentine traction strips extending between said sides and having alternately oppositely projecting undulations and intervening oppositely opening indentations defined by crest portions which face generally toward said ends and leg portions which face generally toward said sides; the crest portions of the undulations being interdigitated by projecting into the mouth ends of the indentations; means articulately coupling the interdigitated crest portions of the undulations and thereby connecting the strips into flexible mat form and providing upper and lower traction mat faces along the opposite edges of the strips; certain of the strips being of minor width; others of the strips being substantially wider than said minor width strips; and said wider strips being spaced from one another by at least one minor width strip intervening between the wider strips; whereby the wider strips provide super traction projections from at least one of said faces of the mat; and an end closure strip engaging the crests of the traction strips at least at one end of the mat, said end closure strip having a traction flange portion at least along one edge which projects from the adjacent traction mat face to improve traction at that end of the mat.
| 1973-08-15 | en | 1975-01-07 |
US-3996898-A | Multimode, multispectral imaging system
ABSTRACT
A multispectral imaging system for generating imagery from a broad range of electromagnetic radiation. In a preferred embodiment, the system comprises an image processor unit having a plurality of dedicated inputs formed thereon, each of which connectable to a respective one of a plurality of sensors wherein each sensor is designed to detect wavelengths emanating from a specific spectral region. The image processor unit receives data from a respective sensor, processes such data, and generates an output that is fed to a multimedia controller and computer, the latter being designed to either digitally store, display or provide a printout of the imaging data. In a preferred embodiment, the multimedia controller computer is further designed to transfer such imagery data to a variety of data links to users interfacing with the imaging system. The system may further be modified to accommodate endoscopic sensors for use in procedures related thereto.
FIELD IF THE INVENTION
The present invention relates generally to medical imaging systems, and more particularly, multimode, multifunctional medical imaging systems utilizing an imaging spectrum spanning from UV light, through visible light, to mid and longwave infrared light.
BACKGROUND OF THE INVENTION
Medical imaging devices are well known to those skilled in the art. Such systems typically use the transmission and reflection of radiation to detect the internal structure underlying the skin. Thermographic techniques are also extensively utilized in the interrogation of human tissue, which detect the differences in temperature and the different tissue types in the body portions examined. Such system typically utilizes infrared radiation detectors to detect the different degrees of infrared radiation emitted by heated bodies. Images are also generated by such systems by using visible and infrared radiation. Still further, ultraviolet (UV) radiation is frequently utilized for purposes of defining an area of malignancy/anomaly for surgery, as well as detect the presence of early cancerous and pre-cancerous tissues.
Notwithstanding their utility, most imaging systems in use today are typically specific to limited spectral bands. In this respect, imaging systems are typically dedicated to a select spectral band, for example, visible or infrared, and thus can only be utilized for limited types of procedures. For example, thermographic techniques must typically be performed via infrared radiation imaging systems, whereas techniques requiring the application of UV radiation, as is frequently utilized in certain tumor screening procedures, must necessarily be performed with a dedicated UV imaging system.
While attempts have been made to develop imaging systems that are capable of using a radiation/light source having wavelengths covering a particular spectral band, such as those disclosed in U.S. Pat. No. 4,515,615 to Carroll entitled Apparatus and Method for Detecting Tumors and U.S. Pat. No. 5,088,493 to Giannini et al. entitled Multiple Wavelencth Light Photometer for Non-Invasive Monitoring, such systems nonetheless cover exceptionally narrow spectral bands. For example, the system disclosed in U.S. Pat. No. 4,515,615 is designed to cover wavelengths ranging only from 400 nanometers to 4,000 nanometers. Similarly, the system disclosed in U.S. Pat. No. 5,088,493 is limited to covering wavelengths ranging from approximately 750 nanometers to 900 nanometers.
Accordingly, there is a need in the art for a medical imaging system that is designed to accommodate an imaging spectrum that spans from the ultraviolet through visible mid and longwave infrared wavelengths. In this regard, it would be advantageous to provide an imaging system that, by virtue of its capability to accommodate and provide image processing for several spectral regions, is capable of providing diagnostic medical imaging in a multimode, multifunctional manner that eliminates the need for multiple prior art imaging systems designed to accommodate specific, narrow spectral bands. Specifically, it would be advantageous to provide a single imaging system for use in diagnostics, intraoperative procedure control and monitoring, as well as effective early detection of tumors and the like that currently must be performed by a plurality of imaging systems. There is still further a need for a multifunctional, multispectral imaging system that is capable of being utilized in a wide variety of medical applications that is readily adaptable to existing technology that further lowers the cost and provides the equivalent or greater reliability of most medical imaging systems currently in use.
SUMMARY OF THE INVENTION
The present invention specifically addresses and alleviates the above-deficiencies in the art. In this regard, the present invention is directed to a spectroscopic imaging system designed to accommodate and detect a plurality of spectral regions for producing a composite visible/thermal-infrared image for use in diagnostic and intraoperative procedures. In a preferred embodiment, the system comprises an image processor unit having a plurality of dedicated input ports formed thereon for connecting with a plurality of spectral sensors wherein each respective sensor detects a range of wavelengths falling within a specific spectral band. The image processor unit is designed to take sensor data provided by any of the respective sensors utilized in a given imaging procedure, via traditional image signal processing, and process the data to produce an output, the latter being managed by multimedia controller and computer, to thus subsequently generate either graphic storage, display, and/or hard copy printing, as well as data telecommunication via a variety of data links to users of the system. In a preferred embodiment, an image processor unit is provided with at least four input ports dedicated to interconnect with sensors responsive to ultraviolet, visible and near infrared, midwave infrared, and longwave infrared radiation. In a further refinement of the present invention, the image processor unit may further include dedicated input ports for interconnecting with conventional endoscopic sensors to thus increase the number of applications and techniques for which this system may be utilized.
It is therefore an object of the present invention to provide a multispectral imaging system capable of detecting multiple spectral bands ranging across a wider range of the electromagnetic spectrum than prior art devices.
Another object of the present invention is to provide a multispectral imaging system that is capable of producing substantially greater multispectral imagery than prior art imaging systems.
Another object of the present invention is to provide a single imaging system capable of detecting radiation from a broader image of spectral regions, including ultraviolet, visible and near infrared, midwave infrared, and longwave infrared, than prior art imaging systems.
Another object of the present invention is to provide multispectral imaging system that is further designed and adapted for utilization in endoscopic applications.
A still further object of the present invention is to provide a multispectral imaging system that can be used with conventional imaging equipment, can perform a wider range of imagery than prior art systems, can eliminate the need for a plurality of imaging systems dedicated to particular spectral regions, and can enable medical imaging procedures to be performed at lower cost than prior art imaging systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the components comprising the multispectral imaging system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The detailed description set forth below in connection with the appended drawing is intended merely as a description of the presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the functions and sequence of steps for construction and implementation of the invention in connection with the illustrated embodiment. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.
Referring now to FIG. 1, there is schematically illustrated the components of a multispectral imaging system 10 as constructed according to a preferred embodiment of the present invention. As illustrated, the system 10 comprises an image processor unit 12 having a plurality of inputs 14, 16, 18, 20 and 22 formed thereon for interconnecting with respective ones of a plurality of sensors 24, 26, 28, 30 and 32. As shown, each of the respective sensors, but for endoscopic sensor 32 discussed more fully below, are designed to detect radiation from a specific spectral region. More specifically, a first respective sensor 24 is designed to detect radiation having wavelengths falling within the ultraviolet region of the electromagnetic spectrum, whereas a respective second sensor 26 detects those wavelengths falling within the visible and near infrared spectral region. Third and fourth sensors 28 and 30, respectively, are preferably designed to detect midwave and longwave infrared radiation wavelengths.
According to one preferred embodiment, the multispectral imaging system 10 of the present invention, and more particularly the respective sensors 24-30 utilized therewith, is responsive to and may be utilized for imaging procedures utilizing electromagnetic radiation falling within one of four specific spectral regions of ultraviolet, visible and near infrared, midwave infrared, and longwave infrared radiation. In a preferred embodiment, first sensor 24 will detect ultraviolet radiation having wavelengths ranging from 250-400 nanometers and second sensor 26 will detect visible and near infrared radiation having wavelengths extending from 400 nanometers to 1 micrometer. Third sensor 28, designed to detect midwave infrared radiation, preferably detects such radiation having wavelengths between 3-5 micrometers and fourth sensor 30 will preferably detect longwave infrared radiation having wavelengths between 8 and 12 micrometers.
As will be recognized by those skilled in the art, the aforementioned sensors utilized to detect the various spectral regions identified above may take any of a variety of devices currently available. For example, one preferred ultraviolet radiation sensor comprises a Gen II+(UV) photocathode image intensifier, coupled with a fiber optic minifier and CCD FPA in connection with advanced video electronics to result in a high sensitivity, 12 orders of magnitude dynamic range, multifunction, multispectral UV video camera. Similarly, in the case of the imaging midwave infrared sensor 28, a 128×128 imaging sensor array may be utilized. Still further, visible radiation detector 26 may comprise any conventional imaging detector of visible light, such as a solid state CCD or CDI detector array, or a vidicon tube. Such visible radiation detector 26 may also comprise any conventional imaging detector of visible light whose low light lower response characteristics have been augmented by the addition of an electro-optic image intensifier device.
The signal received from the respective sensors is then processed by the image processor unit 12. The image processor unit 12 provides for sensor fusion, pattern recognition and other traditional image signal processing capabilities well known to those skilled in the art. Advantageously, however, the image processor unit 12 employs an open architecture, and more specifically, interconnect-intensive parallel architecture that enables the same to operate in multimode, multifunctional modular capacity unlike prior art devices. In this regard, it should be understood that such open system architecture referenced herein mimics, and is in fact a conversion of, battlefield tested aerospace multispectral imaging technology which incorporates existing state of the art military sensor hardware but converts and applies the same for use in medical electro-optic applications. Accordingly, the respective outputs of each of the sensors 24-30 connectable to the image processor unit 12 is capable of being received and processed thereby and a corresponding image generated therefrom that cannot be otherwise be done, to date, with current prior art devices that are specific for a particular diagnostic modality.
Such open architecture further enables the image processor unit to be utilized in further electro-optic applications, and in particular endoscopic applications. As illustrated, image processor unit 12 is provided with an input 22 for interconnecting with a conventional endoscopic device 32, such as vascular endoscopes and the like, to thus enable the system 10 to achieve greater flexibility and thus enables the same to be utilized in a greater number of medical procedures.
The system 10 further includes a multimedia controller and computer 40 that is designed to receive the output from the image processor unit 12 and generate graphic imagery data for use in evaluation in any of a plurality of diagnostic or intraoperative procedures. As is well know to those skilled in the art, the multimedia controller and computer 40 may be coupled to either a video display 42, a printer 44 or even a storage or memory 46 such that the resultant imagery data can be evaluated as desired. More specifically, such multimedia controller and computer 40 will specifically be designed so that graphic storage, display, and hard copy printing will be available to the user, as per conventional imaging systems. Furthermore, although not shown, such multimedia controller and computer 40 may further be designed to transmit imagery data via a variety of data links to users interfacing with the system as may be desired. As such, the multispectral imaging system 10 of the present invention not only is capable of being utilized to conduct numerous imaging techniques and procedures utilizing spectral bands extending across a greater portion of the electromagnetic spectrum than prior art devices, but is further capable of generating an imaging output that may be manipulated in any of a number of ways to thus offer the greatest amount of flexibility to the users of such system 10.
To stress such a flexibility of the multispectral imaging system 10 of the present invention, there is provided herebelow a variety of imaging techniques that may be performed via the multispectral imaging system 10 of the present invention that to date cannot otherwise be performed by a single imaging device. With respect to those techniques performed using ultraviolet radiation, and more particularly, radiation having a wavelength from between 250-400 nanometers, the system of the present invention may be utilized to define areas of malignancy or anomaly for surgery, and hence early detection of cancerous and pre-cancerous tissues, as well as the determination of a specific form of lupus erythematosus. Such UV sensor may be further be fused with sensor data from the infrared sensor to enhance such aforementioned imaging techniques. Likewise, such UV spectral band may be fused with data received from the visible sensor for use in forensic and legal applications and counter immune electrophoresis for immunosorbent assay.
With respect to those imaging procedures utilizing visible and near-infrared radiation, such would include non-invasive monitoring of intraoperative cardiac preservation, real-time, immediate evaluation of the procedure success during reperfusion, and comprehensive, real-time measurement of ischemia. Further applications could include documentation for postoperative analysis.
The imaging system of the present invention can further be utilized for non-invasive, low cost thermalgraphy to supplement a mammography. The system may further be utilized during hypothermic neurosurgery for temperature monitoring and procedure control. Additional applications include the diagnosis of malignant melanoma and determination of sarcoma, as well as treatment progress related thereto. The imaging system may further be utilized to monitor patient temperature in hypothermic and hyperthermic procedures, as well as postoperative monitoring of free tissue transfers and reconstructive microsurgery. Further applications include muscular skeletal monitoring and diagnosis related to nerve root diseases, arthritis and inflammation.
It should be understood, however, that the aforementioned applications for use of the imaging system 10 of the present invention is only exemplary and by no means exhaustive. In this regard, it should be understood that numerous other imaging techniques may be performed by the imaging system 10 of the present invention and that future procedures and techniques will undoubtedly be developed in the future for which the system 10 may be utilized.
What is claimed is:
1. A multispectral imaging apparatus for non-invasive monitoring of a body organ in vivo comprising:a) a plurality of radiation sensor devices for detecting radiation from a scene of said body organ wherein each respective sensor detects a range of wavelengths falling within a spectral band selected from the group consisting of ultraviolet, visible, near infrared, midwave infrared, and longwave infrared radiation and generating a signal corresponding thereto; b) an image processor unit having a plurality of dedicated input ports formed thereon for connecting with respective ones of said sensors, said image processor unit being operable to simultaneously receive data from at least two of said sensors from at least two dissimilar spectral bands wherein at least one of the spectral band is ultraviolet, and process said signals generated by said sensors and convert said signals to imagery data related to said scene of said organ; c) a multimedia controller electrically connected to the image processor unit for receiving said imagery data therefrom and displaying an image of said scene.
2. The apparatus from claim 1 wherein said sensor responsive to ultraviolet radiation is responsive to wavelengths ranging from 250 to 400 nanometers.
3. The apparatus from claim 1 wherein said sensor responsive to midwave infrared sensor is responsive to wavelengths ranging from 3 to 5 micrometers.
4. The apparatus from claim 1 wherein said sensor responsive to longwave infrared sensor is responsive to wavelengths ranging from 8 to 12 micrometers.
5. The apparatus from claim 1 wherein said system includes a sensor responsive to visible and near infrared radiation having wavelengths ranging from 400 nanometers to 1 micrometer.
6. The apparatus of claim 1 wherein said multimedia controller is further operable to store and retrieve said imagery data received from said image processor unit.
7. The apparatus of claim 1 further comprising:d) a printer connectable to said multimedia controller for printing imagery data related to said scene of said organ.
8. A method for non-invasively generating images of a scene of a body organ in vivo comprising the steps:a) detecting radiation reflected from said scene of said body organ by at least two of a plurality of sensors wherein one of said sensors is designed to detect ultraviolet radiation and the respective other sensor is designed to detect a wavelength falling within a specific spectral band selected from the group consisting of visible, near infrared, midwave infrared, and longwave infrared radiation; b) generating first and second signals corresponding to said reflected radiation detected by at least two of said plurality of sensors; c) fusing said first and second signals to produce a resultant signal; d) processing and converting said resultant signal to medical image data related to said scene of said organ; and e) generating a visual image of said scene of said organ from medical image data.
9. Method of claim 8 wherein in step a), said sensors are provided to detect radiation falling within ultraviolet, visible and near infrared, midwave infrared, and longwave infrared spectral regions.
10. Method of claim 9 wherein in step a), said ultraviolet spectral region ranges from 250 to 400 nanometers, said visible and near infrared spectral region ranges from 400 nanometers to 1 micrometer, said midwave infrared spectral region ranges from 3 to 5 micrometers and said longwave infrared spectral region ranges from 8 to 12 micrometers.
11. The method of claim 8 wherein in step d), said imagery data received from step c) is stored into a memory.
12. The method of claim 8 wherein in step d), said imagery data is printed out via a printer.
| 1998-03-16 | en | 1999-12-28 |
US-61809696-A | Method for treatment of an aqueous waste material
ABSTRACT
The invention is directed to a method for treating an aqueous waste material in order to reduce the volume of the material for disposal and/or landfill. In the method, an aqueous waste material containing organic compounds is contacted with calcium carbide under conditions which cause water and calcium carbide to react to produce acetylene and a residue. The acetylene is burned in the presence of the residue to further reduce the volume of material for disposal.
FIELD OF THE INVENTION
The present invention relates to a method for the treatment and disposal of wastewater or sludges, particularly hazardous wastewater or sludges in a cost effective manner.
Background
Many treatment schemes have been devised over the years for the treatment of liquid waste material from industrial and military processes. Processes generating waste material for treatment include petroleum and oil refining, agriculture, wood preserving, mineral processing, metal processing, coal tar and manufactured gas plants, paper production, and military operations. The waste material from such processes may include, but is not limited to, wastewater, contaminated soils, groundwater, and waste sludges which may contain acids, bases, solvents, hydrocarbon and polycyclic aromatic compounds, explosives, heavy metals, radioactive materials and other toxic compounds.
Processes for the treatment of waste materials include coagulation, precipitation, flocculation, evaporation, filtration, extraction, incineration, reverse osmosis, scrubbing, carbon adsorption, ion exchange, electrodialysis, ultrafiltration, decantation, settling, biotreatment and the like. Often the treatment schemes are directed to specific waste streams and are not readily adaptable to widely varying waste streams. Furthermore, streams containing very low concentrations of waste material typically require extremely expensive treatment processes in order to remove or otherwise dispose of the hazardous components in the waste streams. Waste streams which are mostly water often require additional processing steps in order to reduce the water content of the stream before or after treatment, particularly if the waste stream is to be landfilled or incinerated. Waste streams having a solids content of about 15 percent by weight or more are referred to herein as sludges.
A method for treating a sludge waste stream is disclosed in U.S. Pat. No. 5,242,601 to Manchak, Jr. et al. In the Manchak, Jr. et al. process a sludge having a moisture content of about 85 to about 90% by weight is combined in a mixing vessel with a treatment agent comprised of calcium oxide and calcium carbide. Steam, ammonia and acetylene are removed from the mixing vessel and the treated sludge is then incinerated.
In the Manchak Jr. et al. process calcium oxide is a required component of the sludge treatment process and, once treated, the sludge is burned at a temperature sufficient to convert essentially all of the calcium hydroxide formed by the reaction of calcium carbide with water into calcium oxide. Acetylene and ammonia are removed from the mixing vessel and the acetylene is scrubbed to remove the ammonia and/or burned off to the atmosphere. At the temperatures required to completely calcine the calcium hydroxide, a significant quantity of fuel is required. After the incineration step, a substantial portion of the calcium oxide is repeatedly recycled to the process. Hence, the Manchak Jr. et al. process relies on the use and recycle of calcium oxide to react with most of the water in the sludge in order to reduce the water content of the sludge.
Accordingly, it is an object of the present invention to provide an improved treatment method for wastewater and/or sludges.
Another object of the invention is to remediate a wastewater and/or sludge stream using a cost effective treatment method.
Still another object of the invention is to significantly reduce the volume of material from a wastewater and/or sludge stream that must be landfilled.
An additional object of the invention is to remediate a wastewater or sludge stream in a manner which produces a substantially non-hazardous solid or semi-solid material that may be recycled to the process, used for effluent treatment or used in the manufacture of building materials.
SUMMARY OF THE INVENTION
With regard to the above and other objects, the present invention provides a method for treating an aqueous waste material. The method comprises mixing the material with calcium carbide to produce acetylene and a residue. The acetylene is burned in the presence of the residue which produces energy to dry the residue to a higher solids concentration for burning.
The method of the invention initially reduces the amount of water in the waste material by reaction between the water and CaC2, and offers the further advantage that acetylene produced by the reaction is used to heat and/or burn the residue, thereby driving additional water from the residue. As a result, the volume of residue to be disposed of may be significantly reduced with materials and energy available directly from the initial reaction step. Also, the solid byproducts of the burning step may be collected and used for pretreatment of the aqueous waste prior to contacting the waste with CaC2 to remove water (CaO+2 H2 O→Ca(OH)2) and to increase waste pH which causes metals to precipitate thereby reducing metal salts toxicity and reducing toxic air emissions from burning the residue.
In another embodiment, the invention provides a process for treating wastewater and sludges. The process comprises contacting calcium carbide with wastewater or sludge containing at least about 80 wt. % water to provide a reaction mass. During or subsequent to the contacting step, the reaction mass is mixed under conditions sufficient to cause substantially all of the calcium carbide to react to form a product containing calcium hydroxide, acetylene and a residue. At least a portion of the acetylene is collected from the product and the collected acetylene is heated and/or burned in the presence of the residue. Without intending to limit the invention, it is preferred to contact the calcium carbide and wastewater or sludge in a separate pre-mix vessel to form a reaction mass and to further mix and burn the reaction mass in a fluidized bed reaction vessel. The residue in the product obtained as a result of contacting calcium carbide with the wastewater or sludge may be heated and/or burned in a separate incineration chamber or in the fluidized bed reaction vessel provided the reaction vessel is designed for incineration conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the invention will now be further described in the following detailed specification in conjunction with the accompanying drawing in which:
FIG. 1 is a flow diagram of a process according to the invention illustrating the main features thereof;
FIG. 2 is a flow diagram of an alternative fluidized bed reactor system according to the invention;
FIG. 3 is a flow diagram of another fluidized bed reactor system according to the invention;
FIG. 4 is a plan view of a fluidized bed reactor system illustrating another arrangement of the system of FIG. 3;
FIG. 5 is a flow diagram of a process according to the invention using a multi-section fluidized bed reactor; and
FIG. 6 is yet another flow diagram of a multi-level fluidized bed reactor system for conducting the process according to the invention.
DETAILED DESCRIPTION
In the method of the present invention, an aqueous waste material is contacted with calcium carbide under conditions which cause the water and calcium carbide to react, forming acetylene and calcium hydroxide. Not only is the amount of water in the waste reduced due to the reaction with the calcium carbide, but the exothermic reaction between the calcium carbide and water drives additional water from the waste by evaporation leaving a residue having a significantly reduced water content and thus a reduced volume. The residue may be heated and/or burned with the acetylene with or without additional fuel to an ash residue. During burning, the organics are oxidized to CO2 and water while metallic salts are reduced by CaC2 to their elemental state thereby reducing the metal toxicity of the residue. As a result of the process of the invention, the volume of residue for disposal or landfill is greatly reduced as compared with conventional processes, and with considerable energy and material savings. The residue in the form of ash is substantially stable and can be safely disposed of on land or used as an additive in, for example, brick manufacture.
In the practice of the present invention, a wide variety of aqueous waste materials may be treated. For example, the process may be used to treat contaminated groundwater and sludges containing waste solvents, radioactive compounds, halogenated compounds, hazardous metals, hazardous metallic compounds and the like. The process is particularly effective on a concentrated wastewater or sludge stream which has previously been treated to reduce the volume of water in the waste stream. Accordingly, the process may be used for treating concentrated streams from primary treatment operations such as ultrafiltration, ion exchange, carbon adsorption, electrodialysis, the solutions obtained from scrubbing hazardous gaseous streams and/or from condensation reactions, sludges emitted from secondary and tertiary treatment operations and spent liquors containing solids from industrial operations including the spent liquors from kraft and sulfite cooking processes from paper mills which must be treated before disposal.
The process of the present invention is especially useful for aqueous waste materials which are difficult to dewater, such as secondary or tertiary sludges from paper mill wastewater treatment systems. The process may be used to increase a secondary or tertiary treatment sludge solids content to facilitate the final disposal to a landfill or incinerator. Until now, it has been difficult or costly to increase the solids content of such a pulp mill secondary or tertiary sludge, which conventionally contains from about 12 to about 18 wt. % solids, to above about 20 wt. % solids. Not only does the method according to the invention provide sludges having a consistency which is suitable for landfilling, but the sludge may be further dewatered and/or burned to ash using acetylene generated from the reaction between the calcium carbide and water.
The invention also lends itself to a wide range of different embodiments in practice, and is therefore versatile and flexible in application. Hence, the method may be adapted to treat liquids, solids and even gaseous waste materials containing moisture. Many types of waste materials may be treated without any significant change in present process equipment or process steps, thereby increasing the savings obtained by use of the method of the invention.
Another advantage of the process of the invention is that calcium carbide acts as a reducing agent for metal compounds which may be in the waste material. For example, copper sulfide may be reduced to metallic copper by the reaction of an aqueous waste containing copper sulfide with calcium carbide. Accordingly, metal compounds in the waste may be converted to non-toxic and substantially stable metallic elements which remain with the ash or residue resulting from the subsequent heating and/or burning of the residue.
A key aspect of the invention is the step of contacting an aqueous waste material with calcium carbide. The contacting step may be conducted either in a fluidized bed, in a vessel containing a mixing device or in a pre-mix vessel prior to introducing the waste material and calcium carbide into a reaction vessel. The contacting is preferably conducted at a controlled rate under gentle agitation or mixing in order to provide essentially complete reaction of the calcium carbide with water. Because the reaction between calcium carbide and water is so rapid and exothermic, the feed rate of waste material and/or calcium carbide to the reactor and/or pre-mix vessel and the agitation conditions in the vessel are controlled so that essentially all of the calcium carbide fed to the vessel is reacted while maintaining suitable temperatures and pressures in the vessel according to the equipment design parameters.
In order to insure substantially complete reaction of the calcium carbide with water in the material to be treated, the contacting, mixing and reaction steps should be conducted for a period of time ranging from at least about 10 seconds to about 1 hour or more depending on the scale of the reaction. An additional amount of water may be added to the residue from the reaction vessel to react with any unreacted calcium carbide provided the residue is not returned to the pre-mix vessel.
A preferred apparatus for reacting the wastewater or sludge stream with calcium carbide is a fluidized bed reaction vessel. Calcium carbide in particulate form may be present in the reaction vessel before feeding in the waste material to be treated or the calcium carbide and waste material may be premixed and added as a premixed stream to the reaction vessel. For direct feed to the reaction vessel, once the calcium carbide is in a fluidized state, the waste material may be directed into the fluidized particle mass at a controlled rate in a manner known to those of ordinary skill. For example, a black liquor gun may be used to feed and distribute the waste material across the cross-sectional area of the reaction vessel. Because of the exothermic reaction between water and calcium carbide, it is preferred to conduct the contacting step between the waste material and calcium carbide in an insulated reaction or mixing vessel. It may also be advantageous to react the calcium carbide and waste material in a batch reaction so that control of the reaction temperature is more easily accomplished with conventional process equipment.
During or prior to the reaction, heat may be added to the mixture or reaction mass by use of an external heating source in order to evaporate additional water from the waste material. Heat may also be recovered during the burning step and used to preheat and evaporate water from the aqueous waste material prior to feeding the waste material to the pre-mix vessel and/or reaction vessel.
The pressure under which the treatment takes place is not believed to be critical to the method of the invention. Accordingly, the pressure in the reaction and/or premix vessel may range from atmospheric, to subatmospheric to superatmospheric.
In a continuous reaction system, calcium carbide and the waste material may be fed substantially continuously to the pre-mix and/or reaction vessel to achieve essentially steady state reaction conditions. Acetylene is preferably collected from the gas leaving the pre-mix vessel and/or reaction vessel as it is formed and is fed to the suction side of a blower which is used to provide fluidizing gas to the fluidized bed reaction vessel. The acetylene returned to the vessel flows through the bed with the fluidizing gas joining any carry through acetylene produced in the contacting step and is burned in the presence of the reactants thereby forming product residue. The residue can be recycled to the mixing vessel and/or safely disposed of and/or used as an additive for the manufacture of bricks.
The amount of calcium carbide mixed with the waste material should be sufficient to react with water in the waste material and to produce an amount of acetylene which is sufficient to heat or burn the residue. Since the reaction between calcium carbide and water is exothermic, water vaporization from the waste may also take place as a result of heat produced from contacting and mixing the waste material and calcium carbide. When the aqueous waste also contains hazardous or toxic metal compounds, additional calcium carbide may be required to react with and reduce the metallic compounds to their elemental state in addition to the amount of calcium carbide required for reacting with water in the waste material. Accordingly, it is preferred to use a slight excess of calcium carbide to react with the water and/or metallic compounds in order to produce sufficient acetylene for use in heating or burning the waste residue.
Thus, the heating or burning step of the process which follows or occurs with the calcium carbide reaction step may be conducted in the same vessel used to contact the aqueous waste, or in a separate vessel. If the fuel value of the residue is too low for sufficient combustion, additional fuel may be added to aid in the heating and combustion of the residue. Alternatively, the addition of calcium carbide may be increased to produce more acetylene, remove more water and produce more heat to aid in heating and burning the waster material being treated.
With reference now to FIG. 1, a treatment system 10 according to the invention may comprise at least one reaction vessel 12, which may use a fluidizing gas blower 14 and distributor 16 or other means for gently mixing the reactants. Other means may include a mechanical mixer, a recirculation pump and the like. The reaction vessel 12 preferably contains a bed of calcium carbide solid particles 18, most preferably a fluidized or agitated bed of calcium carbide solid particles, into which an aqueous waste material is directed by means of feed mechanism 20 having a suitable distributor means for efficient introduction of the material into the reaction vessel 12. The feed mechanism may be a screw conveyor, positive displacement pump, slurry pump or the like and the distributor means may be a black liquor gun or similar device for distributing a slurry in a reaction vessel. It is preferred to pre-mix the calcium carbide 22 and waste material 24 in a pre-mix vessel 26 having an agitator 28 or other suitable mixing device for gently mixing the calcium carbide with the waste. As the reaction between the calcium carbide and water in the waste material proceeds, acetylene and water vapor are formed and exit the pre-mix vessel 26 through exhaust conduit 30. When treating a gaseous aqueous waste stream, the feed of waste material may be directly to a lower portion of the fluidized bed reaction vessel 12 so that the gaseous material flows into and through the fluidized bed of calcium carbide 18 in intimate contact therewith.
Water in the vapor stream exiting the pre-mix vessel 26 may be removed by use of condenser 32 or another suitable dewatering device. The acetylene and water vapor exiting the pre-mix vessel 26 through conduit 30 may be cooled by a cooling fluid or by the fluidizing gas which is preheated in the condenser 32 by flowing the fluidizing gas into the condenser through conduit 34 and out of the condenser through conduit 36 while the vapor stream flows through the condenser through conduit 30 and out through conduit 40. Condensate is removed from the condenser 32 by means of conduit 38, while the cooled acetylene is directed to the suction side of blower 14 by means of conduit 40. Additional air or fuel may be provided to the suction side of blower 14 by means of conduit 42. While FIG. 1 depicts a continuous or semi-continuous operation, it will be recognized that the acetylene produced by reaction between calcium carbide and water may also be collected and stored under pressure for later use in burning the residue resulting from the reaction between calcium carbide and the waste material.
In order to reduce the amount of particulates exiting the reaction vessel 12 through exhaust conduit 44, a cyclone separator or baghouse 46 may be used to separate particulate material from the combustion products. Accordingly, essentially particulate free exhaust gases will exit the separator 46 through exhaust conduit 48, while the particulate solid material may be removed from the separator 46 though conduit 50. Solids or ash 52 from combustion having a reduced water content may be removed from the reaction vessel 12 through conduit 54.
FIG. 2 illustrates an alternative reactor apparatus 60 wherein waste material and/or additional calcium carbide 64 are fed directly to a fluidized bed reaction vessel 62 through feed port 66, inlet valve 68 and inlet conduit 70 and a suitable distribution means as described above. A fluidizing gas 72 which may contain acetylene is fed into the vessel through inlet 74 and distributor 76 in an amount sufficient to fluidize the calcium carbide and waste mixture 78 in the reaction vessel. As the reaction between calcium carbide and water occurs, acetylene 80 is produced and exits the reaction vessel 62 through exit port 82. A purge stream 84 containing waste solids and/or sludge may be removed from the reaction vessel 62 continuously or intermittently through discharge conduit 86 and discharge valve 88.
If burning or heating the sludge does not take place in the fluidized bed reaction vessel, the residue 84 may be fed to the incineration vessel (not shown) for burning or heating the waste to further reduce the water content thereof. In such a case, the acetylene 80 produced during reaction is removed from the fluidized bed reaction vessel by means of a blower or other suitable gas movement device and is burned in the separate incineration vessel with the residue or compressed and stored for later use. Auxiliary equipment such as a condenser, blower and cyclone separator, illustrated and described with reference to FIG. 1 may also be used with the reactor system 60 of FIG. 2.
FIG. 3 is a flow diagram which illustrates the main aspects of another reactor system 90 according to the invention. The reactor system 90 may be operated on a batch, semicontinuous or continuous basis to reduce the water content and to burn an aqueous waste material. As illustrated in FIG. 3, the reactor system 90 contains a pre-mix vessel 92 for premixing a waste stream 94 and calcium carbide particles 96 prior to introducing the mixed stream to a fluidized bed reaction vessel 98. A mixing device 100 may be used to gently mix the reactants in the pre-mix vessel 92 before feeding the reactants to the reaction vessel 98 by means of feed device 102. The feed device 102 may be a screw conveyor, slurry pump, vibrational conveyor or other motive device for transferring the mixed reactants from the premix mix vessel 92 to the reaction vessel 98.
The reaction vessel 98 contains a fluidized reaction mass 104 comprising calcium carbide and waste. The reaction mass 104 is caused to move across the reaction vessel 98 from the inlet side adjacent the feed device 102 to a discharge side 106 which is opposite the inlet side of the reaction vessel 98 by continuous feed of reactants to the reaction vessel 98 and continuous discharge of residue therefrom. Solids or slurry 105 after mixing and reacting exit the reaction vessel 98 though exit valve 107 and exit conduit 106. Fluidizing gas 108 enters the reaction vessel 98 through fluidizing gas inlet 110 and is distributed across the cross-sectional area of the reaction vessel 98 below the reaction mass 104 by distributor 112.
Burning of the waste material and acetylene may take place directly in the reaction vessel 98 or in a separate incineration vessel. When the acetylene is burned in the reaction vessel, it may be combined with acetylene generated in the pre-mix vessel 92 which may be fed directly into the reaction vessel or may flow through conduit 118 and be combined with the fluidizing gas in conduit 108. If desired, the acetylene may also be cooled and the water vapor removed before feeding the acetylene from the pre-mix vessel 92 to the reaction vessel 98. Exhaust gases 114 resulting from the burning of acetylene and the waste material in the reaction vessel 98 exit the reaction vessel through exit port 116. If the exhaust gases 114 contain particulate or hazardous materials, a cyclone separator, baghouse or scrubber may be used to clean the exhaust gases before discharging the gases to the atmosphere.
In FIG. 4, there is illustrated, in plan view, a similar reactor system 120 to the reactor system 90 illustrated in FIG. 3. In the system depicted in FIG. 4, the reaction mass 122 moves in a generally circular path with respect to the vessel walls 124 to provide additional residence time for reaction. A pre-mix vessel 126 provides for premixing an aqueous waste stream 128 with calcium carbide particles which are introduced to the pre-mix vessel through conduit 130. The pre-mix vessel 126 also contains a mixing device 132 for gently mixing the reactants. A feed device 134 such as a screw conveyor, slurry pump, vibrating feeder or the like may be used to introduce the mixed reactants to the reaction vessel 121 so that the reactants enter the reaction vessel at point A. During the reaction, the entire reaction mass 122 is rotated in the direction indicated by arrow 138 so that the reaction mass 122 moves with respect to the vessel walls 124 from the inlet of the reaction vessel at point A to the exit of the reaction vessel at point B. Slurry or solids resulting from the reaction of the aqueous material with calcium carbide are discharged from the reaction vessel 121 through discharge port 136 and discharge conduit 137. A stationary baffle 140 may be used to separate the incoming reactants from the spent reactants as the reaction mass is rotated from the inlet A to the exit B of the reaction vessel.
Fluidizing gas 142 enters the reaction vessel through gas inlet 144 below the reaction mass 122 and is distributed by a distributor across the cross-sectional area of the reactor. Acetylene, fluidizing gas and/or exhaust gases exit the reaction vessel 121 through exhaust port 146.
FIG. 5 illustrates yet another reactor system 150 wherein the reaction mass 152 cascades from one section to another within a multi-section fluidized bed reaction vessel 154. As with the systems illustrated in FIGS. 1, 3 and 4, there is a pre-mix vessel 156 for premixing a waste material stream 158 with particulate calcium carbide 160. The contents of the pre-mix vessel 156 may be gently mixed by agitator 162 or other suitable mixing device. The mixed reactants are fed into the reaction vessel 154 by means of feed device 164 which is used to control the rate of reactant feed to the fluidized bed. Acetylene produced in the pre-mix vessel 156 by reaction between calcium carbide and water in the waste material, may be directed to the fluidizing gas through conduit 166 or directly to the reaction vessel before or after removing water vapor from the acetylene by use of a condenser as illustrated in FIG. 1. The acetylene may also be mixed with the fluidizing gas 168 which enters the lower section of the reaction vessel 154 through inlet 170 and is distributed to the various sections of the reaction vessel by means of distributors 172, 174 and 176.
Ash or slurry residue 178 is discharged from the reaction vessel 154 through outlet 180 for further treatment, recycle, landfill, or use in pretreating the waste material prior to reacting the waste material with calcium carbide. Waste material in the reaction mass 152 may be burned with acetylene produced by the reaction directly in the reaction vessel 154. Exhaust gases 182 resulting from burning of the waste material and acetylene exit the reaction vessel through exhaust gas outlet 184. The exhaust gases may be further treated to remove any particulate or hazardous materials before discharging the gases to the atmosphere.
A multi-level fluidized bed reactor system 190 is illustrated in FIG. 6. The multi-level fluidized bed reaction vessel 192 may be used to treat waste according to the invention. The reaction vessel 192, illustrated in this embodiment, contains an upper fluidized bed 194 containing a reaction mass of calcium carbide and waste material, and a lower fluidized bed 196 which contains waste solids or slurry after essentially completing the reaction of the waste material with calcium carbide. A pre-mixed stream 198 containing calcium carbide solids and waste to be treated enters the reaction vessel 192 through inlet port 200 and is distributed within the upper portion of the reaction vessel by a suitable distribution device. An upper fluidizing gas distributor 202 maintains the reaction mass in the upper fluidized bed 194 in a fluidized state. As the calcium carbide reacts with water in the waste material, acetylene gas 204 is produced and is removed from the reaction vessel 192 through exhaust port 206 by use of a blower or other suitable gas handling device.
The reaction mass in the upper fluidized bed 194 overflows through downcomer conduit 208 which is in flow communication with the lower fluidized bed 196. In the lower fluidized bed, acetylene and the waste material after reaction with calcium carbide are burned to further reduce the water content of the waste material. Fluidizing gas, acetylene and/or additional fuel 2enter the reaction vessel 192 through fluidizing gas inlet port 212. A lower fluidizing gas distributor 214 is used to evenly distribute the fluidizing gas across the cross-sectional area of the reaction vessel so that the reaction mass in the lower fluidized bed 196 is maintained in a fluidized state for more efficient burning.
Ash and or slurry 216 are removed from the lower fluidized bed 196 by means of outlet conduit 218 which is in flow communication with the lower fluidized bed 196. The ash and/or slurry obtained by use of reactor system 190 may be landfilled or further treated as may be required by state and federal environmental regulations.
During any of the reaction and burning steps described above, the temperature of the reaction mass is preferably maintained above about 400° C. so that water is evaporated from the waste material. Accordingly, the reaction vessels and pre-mix vessels may be insulated to retain the heat of reaction and/or combustion and additional heat may be added to the reaction mass by heating the fluidizing gas, either directly or by exchange with the exhaust gases from the reaction vessel. Other means for heating the reaction mass are within the skill of those skilled in the art. The reaction vessel pressure is controlled at about atmospheric pressure by burning or removing vapors from the reaction vessel at a rate sufficient to maintain the pressure.
During the reaction and heating steps, it is preferred to maintain the waste material at an alkaline pH to facilitate burning and to reduce air emissions. This may be achieved by adding a base to the reaction vessel or by recirculating a portion of the concentrate or ash exiting the reaction vessel or incinerator back to the reaction vessel, provided the concentrate or ash contains sufficient calcium oxide and/or calcium hydroxide to achieve the alkaline pH without the addition of base. The dewatered sludge may also be used for pretreatment of the aqueous waste material and/or may be used in other water treatment operations since it often will contain a significant amount of calcium hydroxide formed by the reaction of water with calcium carbide.
The following non-limiting examples illustrate various additional aspects of the invention.
EXAMPLE 1
Calcium carbide (40 grams) was combined with 200 mL of contaminated groundwater in a shallow 500 mL vessel while gently stirring the mixture for 2-3 minutes. The groundwater had the following analytical characteristics:
______________________________________
Color 40,000 mg/L
COD (chemical oxygen demand)
41,200 mg/L
BOD (biological oxygen demand)
990 mg/L
3/4 methylphenol 457 mg/L
pH 8.4
TSS (total suspended solids)
153 mg/L
TDS (total dissolved solids)
62,000 mg/L
Total Kjeldahl Nitrogen
162 mg/L
TOC (total organic carbon)
14,800 mg/L
Humic Acid 12,200 mg/L
Arsenic 5 mg/L
Cadmium 0.12 mg/L
Chromium 35 mg/L
Nickel 2.3 mg/L
Vanadium 8.4 mg/L
Zinc 2.2 mg/L
______________________________________
Upon adding the groundwater to the cylindrical pan, bubbles and foam as well as acetylene gas were formed by reaction between the water and the CaC2. The acetylene gas was ignited with a match and a flame was generated on the top of the mixture indicating combustion of the acetylene gas. When all of the water in the groundwater sample was evaporated or reacted, the organics in the sample began to bum. As the combustion continued, carbon black from the organics in the groundwater was observed in the exhaust fumes and as deposits on the side of the container. Upon completion of the combustion of the organic material, an ash composition remained in the bottom of the container. The combustion process took about 10 minutes. Once the combustion was complete, an amount of water sufficient to consume any remaining CaC2 was added to the container. The remaining ash composition was white in color, and contained dark particles, and had a volume of about 20 milliliters.
As illustrated by the foregoing example, a groundwater sample containing a significant amount of organic and inorganic material may be converted to an ash by reacting the water in the groundwater sample with calcium carbide and burning the reaction product with acetylene gas and with the organic material initially present in the sample. As the acetylene gas and organics burn, additional water is removed from the sample resulting in a solid or semi-solid ash having a greatly reduced volume compared to the initial sample.
EXAMPLE 2
Weak black liquor (50 mL) having a solids content of 15 wt. % from a kraft cooking process of a paper mill was added to a 500 mL shallow cylindrical pan containing 10 grams of calcium carbide while gently stirring the mixture for 2-3 minutes. During the addition of the weak liquor to the cylinder, bubbles and foam as well as acetylene gas formed as a result of the reaction between the calcium carbide and water. The acetylene gas was ignited with a match and a flame formed on the surface of the mixture. As the combustion continued, carbon black was observed in the exhaust gas and accumulated on the side of the container. When all of the water in the black liquor was reacted or evaporated, the organics in the sample began to burn.
When the combustion was complete, the resulting ash was white in color and the liquid supernatant had a yellowish tint. When the ash was dissolved in 10 mL of water, a green liquor was produced with a pH of over about 14 indicating the presence of NaOH. One or two drops of the green liquor were reacted with lead acetate which turned the liquor black, indicating the presence of Na2 S as a result of the reduction of NaSO4 with the calcium carbide.
The foregoing example illustrates the use of calcium carbide to reduce sodium sulfate to sodium sulfide as well as remove water from the sample. Accordingly, the supernatant liquor obtained by dissolving the residue obtained by reacting black liquor with calcium carbide may be recycled and reused in the papermaking process.
EXAMPLE 3
Secondary and tertiary sludges from a paper mill wastewater treatment plant were treated according to the process of the invention. The objective of the treatment was to increase the solids content of the sludge from about 15 wt. % to about 20 wt. %. In the first run, 44.5 grams of sludge containing 15 wt. % solids was mixed with 1.7 grams of calcium carbide in a 500 mL shallow cylindrical pan with gentle stirring for 20 minutes. The final weight of the sludge after reaction was 45.1 grams. The additional solids produced by reacting the sludge with calcium carbide was 2.1 grams. Since the initial solids content of the sludge before treatment was 6.7 grams the final residue has a solids content of 19.5 wt. %.
In the second run, 32.6 grams of sludge containing 15 wt. % solids was added to 2.1 grams of calcium carbide in a 500 mL shallow cylindrical pan with gentle stirring for 20 minutes. The final weight of the sludge after reaction was 33.8 grams. The solids produced by reacting the sludge with calcium carbide was 2.6 grams. The initial solids content of the sludge before treatment was 4.9 grams and the residue had a solids content of 22.2 wt. %.
As illustrated by the foregoing example, about 4 to about 6 wt. % calcium carbide may be used to increase the solids content of a paper mill sludge from about 15 wt. % to about 19 to 25 wt. %. The resulting acetylene gas produced by reacting the water in the sludge with calcium carbide may be burned to further evaporate water from the sludge and/or to reduce the amount of calcium carbide required to increase the sludge solids content. Accordingly, waste streams having a high organic content may be dewatered and/or combusted to reduce the volume of waste material to be landfilled or otherwise disposed of.
Having now described various embodiments and features of the invention, those of ordinary skill will appreciate that these embodiments are capable of numerous modifications, rearrangements and substitutions within the spirit and scope of the appended claims.
What is claimed is:
1. A method for treating an aqueous waste material which consists essentially of mixing the material with calcium carbide to produce acetylene gas and a residue containing water and burning the acetylene gas in the presence of the residue to vaporize water from the residue.
2. The method of claim 1 wherein the aqueous waste material contains one or more organic compounds and the energy produced by burning the acetylene is sufficient to ignite and burn the organic compounds.
3. The method of claim 2 wherein an amount of calcium carbide is used which is sufficient to react with water in the aqueous waste material to provide sufficient acetylene in combination with the one or more organic compounds for heating and burning the residue in order to drive essentially all remaining unreacted water from the residue.
4. The method of claim 3 further comprising collecting a byproduct comprising Ca(OH)2 and/or CaO obtained as a result of heating and burning the residue and contacting the aqueous waste material with the byproduct in order to obtain a waste material having a pH above about 7.0.
5. The method of claim 1 further comprising collecting a byproduct comprising Ca(OH)2 and/or CaO obtained from burning the residue and contacting the aqueous waste material with the byproduct in order to obtain a waste material having a pH above about 7.0.
6. The method of claim 1 further comprising reducing metal salts in the waste material to their elemental state and precipitating the metals.
7. A process for treating wastewater and sludges which consists essentially of:mixing calcium carbide with wastewater or sludge containing at least about 80 wt. % water under conditions sufficient to cause calcium carbide to react with water in the wastewater sludge thereby forming reaction products comprising acetylene gas and a residue containing calcium hydroxide and water; conducting the residue to a reaction vessel; collecting at least a portion of the acetylene gas from the reaction products; and burning the collected acetylene gas in the presence of the residue in the reaction vessel to reduce the water content of the residue.
8. The process of claim 7 wherein an amount of calcium carbide is used which is sufficient to react with water in the aqueous waste material to provide sufficient acetylene for burning the residue in order to drive essentially all remaining unreacted water from the residue.
9. The process of claim 7 wherein the wastewater or sludge stream contains one or more organic compounds and the energy produced by burning the acetylene is sufficient to ignite and burn the organic compounds.
10. The process of claim 7 wherein an amount of calcium carbide is used which is sufficient to react with water in the aqueous waste material to provide sufficient acetylene in combination with the one or more organic compounds for burning the residue in order to drive essentially all remaining unreacted water from the residue.
11. The process of claim 10 further comprising collecting a byproduct comprising Ca(OH)2 and/or CaO obtained as a result of burning the residue and contacting the aqueous waste material with the byproduct in order to obtain a waste material having a pH above about 7.0 prior to mixing the wastewater or sludge stream with the solid calcium carbide particles.
12. The process of claim 7 further comprising collecting a byproduct comprising Ca(OH)2 and/or CaO obtained as a result of burning the residue and contacting the aqueous waste material with the byproduct in order to obtain a waste material having a pH above about 7.0 prior to mixing the wastewater or sludge stream with the solid calcium carbide particles.
13. The process of claim 7 further comprising reducing metal salts in the wastewater or sludge to their elemental state and precipitating the metals.
14. A substantially continuous process for treating an aqueous waste material which consists essentially of:continuously feeding calcium carbide particles and an aqueous waste material through a mixing vessel to cause reaction of calcium carbide with water in the aqueous waste material to produce reaction products comprising acetylene gas and a residue containing calcium hydroxide and water; continuously feeding the residue to a fluidized bed reaction vessel; continuously collecting a least a portion of the acetylene gas from the reaction products; and continuously burning the collected acetylene gas in the presence of the residue in the reaction vessel to reduce the water content of the residue.
15. The process of Claim 14 wherein the aqueous waste material contains one or more organic compounds and the energy produced by burning the acetylene is sufficient to ignite and burn the organic compounds.
16. The process of claim 15 wherein an amount of calcium carbide is used which is sufficient to react with water in the aqueous waste material to provide sufficient acetylene in combination with the one or more organic compounds for burning the residue in order to drive essentially all remaining unreacted water from the residue.
17. The process of claim 16 further comprising collecting a byproduct comprising Ca(OH)2 and/or CaO obtained as a result of burning the residue and contacting the aqueous waste material with the byproduct in order to obtain a waste material having a pH above about 7.0 prior to mixing the aqueous waste material with the calcium carbide.
18. The process of claim 14 further comprising collecting a byproduct comprising Ca(OH)2 and/or CaO obtained as a result of burning the residue and contacting the aqueous waste material with the byproduct in order to obtain a waste material having a pH above about 7.0 prior to mixing the aqueous waste material with the calcium carbide.
19. The process of claim 14 further comprising reducing metal salts in the aqueous waste material to their elemental state and precipitating the metals.
| 1996-03-19 | en | 1998-08-11 |
US-27182594-A | Handle fastening on a utensil, for example a cooking utensil
ABSTRACT
It is difficult in utensils manufactured by die casting or injection molding, for example cooking utensils of an aluminum alloy, to directly fasten a support arm on which in turn a handle piece can be fastened. Therefore, holding bars are needed in most cases, to which the support arm is welded or screwed. The holding bars must be inserted during casting and are during casting always in danger of being washed away. Other solutions, which do away with such holding bars, require an additional operation in order to fasten the support arm on a suitably designed attachment on the utensil. The invention avoids additional structural parts and ties a support arm during the casting operation with a specially designed holding piece into a boss.
FIELD OF THE INVENTION
The invention relates to a handle fastening on a die cast or injection molded utensil, for example a cooking utensil or the like, comprising a support arm which can be fastened to the outer periphery of the utensil, and over which a handle piece can be moved in direction of the utensil and locked to the support arm.
BACKGROUND OF THE INVENTION
Such a handle fastening is known from DE-Patent 22 64 244. When using such an arrangement on cooking utensils or the like, which are cast, for example, out of an aluminum alloy, problems arise with the fastening of the support arm to the utensil. A special holding bar is in most cases integrally formed on the periphery of the utensil. The support arm is later either welded or screwed to the holding bar. It is understood that an exact orientation of the holding bar in relationship to the utensil is difficult during the casting process. Also there is the danger that the holding bar is washed away when the casting material runs in because its fastening in the mold is also difficult to handle. Faulty castings are the unavoidable consequence.
When the support arm is welded to an integrally cast holding bar, deformations of the workpiece can be the result so that required dimensions are no longer maintained. This is particularly bad in mass production, where consecutively oriented operating devices are set for specific dimensions of the workpieces. Thus this operation also harbors the danger that the thereby manufactured semifinished articles cannot be further processed in one production line.
To fasten the support arm by means of a screw connection, regardless whether directly to the utensil or on an integrally cast holding bar, requires much work and furthermore does not guarantee a fixed connection, in particular over a long period of time.
The purpose of the invention is to provide a handle fastening of the above in detail described type in such a manner that neither a holding bar to be cast separately on the utensil is provided, on which bar the support arm would have to be fastened, nor that a special operating step is needed for such a fastening.
The purpose is attained according to the invention in such a manner that a holding piece, which is integral with the support arm, is constructed on the support arm, which holding piece is cast into a boss integrally provided on the utensil.
The invention thus avoids both a holding bar and also the complicated mounting of the support arm on the utensil. However, the holding piece can thereby also not be flushed away during the casting process in contrast to the conventional holding bar because it is a part of the support arm, the remaining area of which stays outside of the mold and can in this manner be easily locked.
It is thereby advantageous when the holding piece is formed of at least one arm part of the support arm which arm part is essentially vertical in the position of use of the utensil; same can thus be contiguous with the sheet-metal arm plates of the support arm, in one piece with these plates, which plates are usually vertically aligned because of the position of use of the utensil. The arm part is designed in a simple manner as a sheet-metal part. In order to prevent in such a design that during the use of the utensil an arm part is torn out of the boss, it is preferably provided that at least one of the flat surfaces of the arm part, which surfaces are approximately parallel to an axis of the handle piece, has at least one recess. The recess is thereby advantageously designed as an opening in the arm part. The holding piece is in this manner form-lockingly securely anchored in the boss because the recess or rather the opening is filled with casting material.
The boss is in a particularly advantageous development of the invention interfaces in direction of the handle piece with a sealing plate which is fastened to the holding piece prior to it being integrally cast. The sealing plate is in this manner a part of the mold and prevents the casting material from penetrating into the remaining area of the support arm which is to be covered at least partially by the handle piece. The sealing plate separates thereby the boss from an area of the support arm which is not covered by the handle piece.
It can in particular also be advantageous when the sealing plate has at least one opening into which the holding piece can be guided, and when moreover the holding piece is designed such that it completely occupies the opening when it is guided into it. The essential congruence of the cross sections of the opening and of the holding piece assures that the casting material essentially stops at the sealing plate and does not penetrate there through to the otherwise needed areas of the support arm.
The holding piece is oriented in relationship to the boss, for example, such that a stop is provided which defines its introduction into the opening and abuts the sealing plate, and/or the holding piece abutting the sealing plate can be locked in this position in a simple manner such that the holding piece on a side of the sealing plate facing the boss, has at least one embossment or the like so that same resting on the sealing plate projects beyond the outer contour of the opening. Thus, a very rigid connection of the holding piece and thus of the support arm to the boss and thus the utensil results, which connection can be highly stressed without thereby having to fear its destruction.
An aesthetically particularly satisfactory design of the handle fastening of the invention results when the sealing plate has an arched designed-arched as a segment of a circular hollow cylinder such that an arch radius, referred to the axis of symmetry of the utensil, is provided and furthermore, if necessary, the edging of the sealing plate is embedded in casting material. Thus an encasing of the boss is not needed.
The arrangement can in a simple manner be such that the handle piece can be locked on the support arm by means of a spring piece, and/or that a sleeve is provided to encase an area of the handle fastening, which area cannot be covered by the handle piece and is connected to the boss. The operations for the assembly of the handle fastening are thus possibly reduced to the mounting of the spring and of the handle piece and the mounting of the sleeve. Such a simple assembly cannot be achieved with the up to now known arrangements.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be discussed in greater detail hereinafter in connection with one exemplary embodiment and the drawings, in which:
FIG. 1 is a central longitudinal cross-sectional view of a handle fastening embodying the invention,
FIG. 2 is a partially cross-sectional top view of FIG. 1, and
FIGS. 3 to 5 are, respectively, a front view, a side view and a top view of a support arm of the invention, all in a schematic illustration.
DETAILED DESCRIPTION
A handle fastening of the invention on a utensil 1 consists according to FIG. 1 essentially of a boss 11 on the utensil 1, a support arm 2, a sealing plate 3, a spring piece 4 and a handle piece 5.
The boss 11 is provided on an outer contour 12 of the utensil i and consists of a casted mass 10 and forms one piece with the utensil also consisting of the casted mass 10.
A holding piece 21 of the support arm 2 is cast into the boss 11 (FIG. 3). The holding piece 21 consists (FIG. 2) of two arm parts 21a and 21b which are constructed as sheet-metal plates and are positioned approximately vertically aligned in the position of use of the utensil 1, with the flat contour of the utensil being adapted approximately to the cross section of the boss 11 without reaching its edge surfaces 11a and 11b.
The arm parts 21a and 21b are one-piece parts of sheet-metal arm plates 22a and 22b of the support arm 2, which together with a connecting bight 22c form its body 22. The body 22 has several stops, openings and guides, with the help of which the here wire-like spring piece 4 can be fastened such that the handle piece 5 can be moved onto the support arm and releasably locked thereto at least partially covering the support arm 2; the details of this are in no direct relationship to the invention and are known to the man skilled in the art so that a discussion thereof is not needed. However, the drawings show that an area 6 of the handle fastening is not covered by the handle piece 5, but is instead covered by a sleeve 7 so that the parts of the support arm 2 and of the spring piece 4, which parts would otherwise be visible there, are also covered during the use of the utensil 1.
The sealing plate 3 closes off the boss 11 in direction of the area 6. It has an arched design with an arch radius R about the axis of symmetry (in most cases the central axis of rotation) of the utensil 1, which axis of symmetry lies outside of the drawing site. FIGS. 1 and 2 show that the edges 3a of the sealing plate 3 are embedded in one edge of the casting material 10 so that a stable orientation of the sealing plate 3 and an aesthetically pleasing design is created.
Two openings 3b, as they can best be recognized in FIG. 4, exist in the sealing plate 3; they are adapted to the cross section of the arm parts 21a and 21b extending through the openings so that there remains no space through which during casting of the holding piece 21 casting material 10 can penetrate into the area 6.
To anchor the arm parts 21a and 21b, openings 21c exist in the arm parts, which openings are filled with casting material 10 during casting.
Stops 22d are shown in particular in FIG. 3 and which are constructed on the sheet-metal arm plates 22a and 22b for assuring that they cannot be moved randomly far into the openings 3a. On the other hand, several embossments 21d can be produced on the arm parts 21a and 21b after the holding piece 21 is placed into the sealing plate 3 so that the sealing plate 3 will be locked and cannot again be removed from the holding piece 21, in particular prior to it being cast into the boss 11 (FIG. 2).
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. In a handle fastening assembly mounting a handle piece on a utensil comprising a longitudinally extending support arm fastenable to the outer periphery of the utensil, and a handle piece having a hollow interior in which said support arm is slidably received so that said handle piece is movable along said support arm, the improvement comprising a shoulder piece disposed on said outer periphery of said utensil, said shoulder piece and said utensil being a single integral piece of a casting material, said support arm being a single integral piece and having at least one arm part which defines a holding piece of said support arm, said holding piece being received within said shoulder piece, said shoulder piece is cast and said holding piece is secured by said casting material therein, said at least one arm part defining vertically oriented surfaces on opposite sides thereof.
2. The handle fastening assembly according to claim 1, wherein said arm part is a sheet-metal part.
3. The handle fastening assembly according to claim 2, wherein said at least one arm part has at least one recess.
4. The handle fastening assembly according to claim 3, wherein said recess is an opening in said arm part.
5. The handle fastening assembly according to claim 1, wherein said handle piece includes locking means for locking said handle piece on said support arm, said locking means being a spring piece resiliently engaged with said support arm.
6. The handle fastening assembly according to claim 1, wherein said support arm includes a covered area covered by said handle piece and an open area disposed between said handle piece and said shoulder piece, a sleeve being provided that encases said open area of said support arm.
7. In a handle fastening assembly mounting a handle piece on a utensil comprising a support arm fastenable to the outer periphery of the utensil, and a handle piece having a hollow interior in which said support arm is slidably received so that said handle piece is movable along said support arm, the improvement comprising a shoulder piece disposed on said outer periphery of said utensil, said shoulder piece and said utensil being a single integral piece of a casting material, said support arm being a single integral piece and having at least one arm part which defines a holding piece of said support arm, said holding piece being received within said shoulder piece, said shoulder piece is cast and said holding piece is secured by said casting material therein, said holding piece further including a sealing plate fastened thereon which interfaces with said shoulder piece so as to define a shape for an interfacing shoulder surface of said shoulder piece.
8. The handle fastening assembly according to claim 7, wherein said sealing plate separates said shoulder piece from an open area of said support arm, said open area being adjacent a covered portion of said support arm which is covered by said handle piece.
9. The handle fastening assembly according to claim 7, wherein said sealing plate has at least one opening into which said holding piece is received.
10. The handle fastening assembly according to claim 9, wherein said holding piece completely occupies said opening of said sealing plate when said holding piece is disposed within said opening.
11. The handle fastening assembly according to claim 9, wherein a stop is provided on said holding piece, which said stop limits an insertion of said holding piece into said opening of said sealing plate and abuts against said sealing plate to define a fixed position for said sealing plate.
12. The handle fastening assembly according to claim 11, wherein said holding piece abutting against said sealing plate is locked in said fixed position.
13. The handle fastening assembly according to claim 12, wherein said holding piece has at least one embossment which is disposed on the side of said sealing plate facing said shoulder piece when said sealing plate is in said fixed position, said at least one embossment projecting beyond an outer contour of said opening and contacting said sealing plate.
14. The handle fastening assembly according to claim 7, wherein said sealing plate has an arched shape having an arch radius defined by an axis of symmetry of said utensil.
15. The handle fastening assembly according to claim 7, wherein a peripheral edge of said sealing plate is embedded in said casting material.
16. The handle fastening assembly according to claim 7, wherein said handle piece includes locking means for locking said handle piece on said support arm, said locking means being a spring piece resiliently engaged with said support arm.
17. The handle fastening assembly according to claim 7, wherein said support arm includes a covered area covered by said handle piece and an open area disposed between said handle piece and said sealing plate, a sleeve being provided that encases said open area of said support arm.
| 1994-07-07 | en | 1996-09-17 |
US-61460096-A | Barbed tubular connectors
ABSTRACT
The present invention relates to a connector for joining flexible tubular members. The connector has a cylindrical body having an outer diameter and at least one circumferential recess. At least one barb member is positioned and retained at least partially in the recess. The barb member has first and second ends with at least one of the ends having a diameter which extends beyond the outer diameter of the tubular body. The first end has a diameter which is greater than that of the second end and a rigid edge for engaging a flexible tubular member. The barb member provided with the connector can resist pull-off of the tubular member from the connector. The present invention also relates to a method for forming such a connector.
FIELD OF THE INVENTION
The present invention relates to a connector for joining flexible tubular members, and particularly a rigid tubular connector having independent barb members for engaging the inner circumference of a flexible tubular member to retain such tubular member on the connector. The present invention also relates to a method for forming such a tubular connector.
BACKGROUND OF THE INVENTION
Tubular connectors can be used in all types of industries for joining flexible tubing, hose, and similar cylindrical members to each other. A typical tubular connector comprises a rigid tubular body adapted to fit in the inner circumference of a free end of the flexible tubing. Such a tubular connector often adopts barb members integrated on its outer circumference. These barb members are force fit into the flexible tubing and have sharp edges to assist in retaining the flexible tubing on the tubular connector. This construction provides enhanced pull-off resistance of the flexible tubing from the connector. U.S. Pat. No. 4,712,809 to Legris, U.S. Pat. No. 4,626,005 to Stifter, U.S. Pat. No. 4,603,890 to Huppee, U.S. Pat. No. 3,966,238 to Washkewicz et al., U.S. Pat. No. 3,948,546 to Welsby et al., U.S. Pat. No. 3,767,233 to Hodge, U.S. Pat. No. 3,711,130 to Betzler, U.S. Pat. No. 2,805,088 to Cline et al., U.S. Pat. No. 1,994,784 to Porzel, and U.S. Pat. No. 1,166,059 to Ledbetter all disclose these or similar tubular connectors.
Conventional tubular connectors are usually formed with integral barb members and tubular bodies. As an example, some tubular connectors can be made by machining down a large size tubular body to form barb members with sharp edges thereon. Other tubular connectors can be molded with barb members integrated on tubular bodies of the connectors. Such barb members are usually made of the same material as that of tubular bodies even though barb members must withstand pull-off forces during use. In addition, the sharp edges of the barb members are difficult, if not impossible, to form in a tubular connector without causing stress raisers which can lead to stress failure. The formed barb members usually remain under stress and often, after a period of time, break in an unacceptable and hazardous manner.
Therefore, it is desirable to provide a novel tubular connector that has less stress in its construction and provides better overall mechanical strength. The present invention provides such a tubular connector to meet the requirements.
SUMMARY OF THE INVENTION
The present invention relates to a connector for joining flexible tubular members. The connector comprises a cylindrical body having an outer diameter and at least one circumferential recess. At least one barb member is positioned and retained at least partially in the recess. The barb member comprises first and second ends with at least one of the ends having a diameter which extends beyond the outer diameter of the tubular body. The first end has a diameter which is greater than that of the second end and a rigid edge for engaging a flexible tubular member. The barb member provided with the connector can resist pull-off of the tubular member from the connector.
According to the connector of the present invention, the outer surface of the barb member uniformly decreases in diameter from the rigid edge to the second end. The cylindrical body is a tubular body and the barb member is made of a material which is more rigid than that of the tubular body.
In a preferred embodiment, the tubular body of the connector includes an end member. A portion of the end member has a greater diameter than that of the tubular body to assist in retaining the tubular member in engagement with the connector. The end member has a first tapered surface extending from an end of the connector to the greater diameter portion and a second tapered surface extending from the greater diameter portion toward the barb member.
The connector of the present invention can have one end of the tubular body integrally formed on an end of a second tubular member, and therefore connects the first tubular member to the second tubular member.
Alternatively, the connector of the present invention comprises a cylindrical body having an outer diameter and at least two circumferential recesses. At least one independent barb member is positioned and retained at least partially in each recess. Each barb member comprises first and second ends with at least one of the ends having a diameter which extends beyond the outer diameter of the tubular body. Each first end has a diameter which is greater than that of the corresponding second end and a rigid edge for engaging a flexible tubular member.
In the alternative embodiment, the cylindrical body is preferably a tubular body. The tubular body is provided with at least one end member. A portion of the end member has a greater diameter than that of the tubular body to assist in retaining the tubular member in engagement with the connector. The connector has a symmetric structure.
The present invention further relates to a method for forming a connector. The method comprises the steps of: providing a cylindrical body having an outer diameter and a free end, and providing onto the reduced diameter end of the cylindrical body at least one barb member adapted to be loosely fit thereon. The barb member comprises first and second ends with at least one of the ends having a diameter which extends beyond the outer diameter of the cylindrical body. The first end has a diameter which is greater than that of the second end and a rigid edge for engaging a flexible tubular member. The method of the present invention also comprises retaining the barb member in position on the cylindrical body, thus forming a connector for engaging a flexible tubular member whereby the barb member resists pull-off of the tubular member from the connector.
Preferably, the cylindrical body of the connector is a tubular body. The retaining step in the method of the present invention comprises reducing the diameter of the cylindrical body at its free end prior to the step of providing the barb member onto the reduced end of the tubular body, and increasing the diameter of the reduced diameter end of the tubular body after the step of providing the barb member onto the reduced end of the tubular body. Alternatively, the retaining step in the method of the present invention comprises swaging down the diameter of the second end of the barb member.
The method of the present invention further comprises the step of forming an end member at the free end of the tubular body. A portion of the end member has a greater diameter than that of the tubular body.
According to the method of the present invention, the barb member is molded or machined to the desired dimensions prior to the step of providing the barb member onto the reduced end of the tubular body.
In another embodiment of the present invention, the method comprises repeating the recited steps on the opposite end of the tubular body for engagement of another flexible tubular member.
The present invention further relates to a connector formed by the method of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become much more apparent from the following description, appended claims, and accompanying drawings, in which:
FIG. 1 is a longitudinal partial section view of a connector according to the present invention;
FIG. 2 is a longitudinal partial section view of the connector shown in FIG. 1 when in use;
FIG. 3 is a longitudinal partial section view of a connector of an alternative embodiment when in use; and
FIGS. 4a to 4d illustrate the formation of the connector shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A barbed tubular connector 1 embodying principles of the present invention is illustrated in FIGS. 1-4. Referring to FIG. 1, the connector 1 comprises a cylindrical body, preferably a tubular body 10. Although the tubular body 10 is typically made of metal, other materials such as various plastics could also be used. The tubular body 10 preferably has an inner circumference 11 with a uniform diameter. At least one circumferential recess 12 is formed on the tubular body 10. The connector 1 further comprises at least one independently formed barb member 14 positioned and retained at least partially in the recess 12. The connector 1 of the present invention has less stress in its construction and better overall mechanical strength.
The independent barb member 14 has first and second ends 16 and 18. At least one of the ends 16 and 18 extends beyond the diameter of the tubular body 10. At the first end 16, a rigid, sharp edge 20 is formed for engaging the inner circumference 22 of a flexible tubular member 24 (FIG. 2), and therefore retains the tubular member 24 on the connector 1. In a preferred embodiment, the barb member 14 is in the shape of a frustum. The first end 16 has a greater diameter than that of the second end 18. The outer surface 15 of the barb member 14 uniformly decreases in diameter from the first end 16 to the second end 18.
The barb member 14 is preferably formed from various metals, such as brass, stainless steel, aluminum and coated steel. Depending upon the material of the tubular member 24, the barb member 14 may be made of nylon or other rigid plastics. The barb member 14 is made of a material which is more rigid than that of the tubular body 10 as well as the flexible tubular member 24 so that it will securely engage and secure the flexible tubular member 14 to the tubular body 10. Such design helps remedy the structural weakness of the sharp edge 20 formed on the barb member 14, and therefore the resultant barb member 14 can provide more pull-off resistance. The barb member 14 is independently formed prior to being fitted onto the tubular body 10. Various conventional methods can be employed to prepare the barb member 14 as discussed hereinafter.
The connector 1 further comprises an end member 30 spaced apart from the barb member 14 and formed at a free end 13 of the connector 1. Such end member 30 is prepared to be free of burrs and sharp edges. The end member 30 has a ridge 32, which has a greater diameter than that of the tubular body 10 of the connector 1. When included, the ridge 32 assists in retaining the tubular member 24 on the connector 1. Taper surfaces 34 and 36 extend oppositely from the ridge 32 toward the free end 13 of the connector 1 and the barb member 14 respectively. The free end 13 of the connector 1 is thus reduced in diameter. In a preferred embodiment, the free end 13 of the connector 1 has a smaller diameter than the inner diameter of the elastic tubular member 24. The smaller diameter of the free end 13 and the taper surface 34 on the connector 1 facilitate the insertion of the connector 1 into the tubular member 24.
Referring to FIG. 2, the connector 1 is force fit within the inner circumference 22 of the flexible tubular member 24. The tubular member 24 can be made of various flexible or elastic materials, such as elastomers and plastics, with fluoropolymers in particular being preferred. Preferably, the tubular member 24 has a smaller inner diameter than the diameter of the tubular body 10. When the connector 1 is being inserted into the inner circumference 22 of the tubular member 24, the tubular member 24 is slightly stretched or expanded to receive the connector 1. After the connector 1 is fully inserted inside the tubular member 24, the stretched tubular member 24 has a tendency to return to its original shape due to its elasticity. Therefore, the elastic tubular member 24 can securely and completely surround the connector 1 to connect with the same.
In the preferred embodiment of the present invention, the tubular body 10 of the connector 1 directly communicates with the inner circumference 22 of the tubular member 24. Therefore, the connection between the connector 1 and the tubular member 24 can be used in fluid conduit. Such connection is a fluid-tight reliable pressure seal of the tubular member 24 to the connector 1 and withstands normal operating pressures without becoming disengaged.
In addition, the portion of the tubular member 24 fitted over the barb member 14 of the connector 1 is further stretched and surrounds the sharp edge 20 more tightly. The sharp edge 20 on the barb member 14 also acts as a barrier for the tubular member 24 to pass over, and therefore prevents the tubular member 24 from being pulled off from the connector 1. In a preferred embodiment when the barb member 14 is made of a material more rigid than that of the tubular body 10, the barb member 14 can withstand even greater pull-off force. Therefore, the connector 1 according to the present invention with the independent barb member 14 can more effectively retain the tubular member 24 on the connector 1.
The connector 1 can be manually inserted in a free end portion of tubular member 24. For an easy insertion, the connector 1 can be screwed onto the tubular member 24 instead of being pushed in. The tubular member 24 can also be removed from the connector 1 manually or with aid of simple tools. The assembly and disassembly of the connector 1 with the tubular member 24 can be completed by conventional methods.
The connection between the connector 1 and tubular member 24 eliminates the need for special tools for assembly, ensures a more rapid connection of the connector 1 with the tubular member 24, makes it possible for easy replacement of the tubular member 24 if a leak develops therein and has a high pull strength because of the sharp edge 20 of the barb member 14.
In addition, the connection of the connector 1 of the present invention and the tubular member 24 is reinforced to resist the tubular member 24 from being pulled-off from the connector 1. According to the present invention, the independent preparation of the barb member 14 can eliminate stress failure occurred in the integral formation of a conventional connector and result in a construction having much less stress remained in the barb member 14. Further, the design choice of using a more rigid material for forming the barb member 14 compensates the structural weakness of a sharp edge in a conventional barb member. Therefore, the connector 1 of the present invention has a better overall mechanical strength to withstand high pull-off forces.
In a preferred embodiment, the connector 1 has its opposite end integrated with one end of a second elongated tubular member 26. In other words, the connector 1 is integrally formed at the end of a second tubular member 26. As a result of such embodiment, the tubular member 24 is effectively connected with the second elongated tubular member 26 through the connector 1.
Referring to FIG. 3, a modified connector 1 of the present invention is shown connecting two tubular members 24. The connector 1 comprises a cylindrical body, preferably a tubular body 10 having at least two circumferential recesses 12 (see FIG. 1) near its ends 13. At least two independent barb members 14 are positioned and retained at least partially in the recesses 12. The connector 1 can also have at least one end member 30 formed at least one of its ends 13. The barb members 14 and the end member 30 have similar structures to the corresponding ones as discussed hereinabove. It is understandable to one of ordinary skill in the art that the barb members 14 are oppositely oriented for retaining one tubular member 24 on each opposite end 13 of the connector 1.
In a preferred embodiment as shown in FIG. 3, the connector 1 has a symmetric structure. Each end 13 of the connector 1 has an end member 30 and same number of barb members 14, such as one barb member 14 in this preferred embodiment, spaced from each other. The barb members 14 and end members 30 have the same dimension, respectively and are oppositely oriented at opposite ends 13 of the connector 1. The connector 1 of this type eliminates identification of one end from the other, and therefore is more convenient in use.
Referring to FIGS. 4a-4d, the formation of a connector 1 of the present invention is illustrated. The method for forming the connector 1 according to the present invention comprises the step of providing a cylindrical body, preferably a tubular body 10 having a free end 13. As noted above, the tubular body 10 can be made of various materials, and is preferably made of a metal such as aluminum. The inner circumference of the tubular body 10 has preferably a uniform diameter, so that no fluid turbulence will occur inside the connector 1 when in use.
In a preferred embodiment as shown in FIG. 4a, the free end 13 of the tubular body 10 is then reduced in diameter by conventional means, such as swaging, rolling, compression forming and the like.
At least one barb member 14 is formed independently from the tubular body 10 by various conventional methods, such as molding and machining. As noted above, the barb member 14 is preferably made of a rigid metal or plastic material. The barb member 14 is formed with a bore adapted to fit onto the reduced free end 13 of the tubular body 10. The barb member 14 is then provided onto the reduced end of the tubular body 10 and is loosely fit thereon. FIG. 4b shows this combination.
After the barb member 14 is drawn onto the reduced end of the tubular body 10, it is then retained in position thereon. To facilitate such retaining, the diameter of the reduced end 13 of the tubular body 10 is enlarged or restored to its initial dimension. Such restoration can be performed by various conventional methods. In the preferred embodiment as shown in FIG. 4c, a spindle 40 is used to increase the diameter of the reduced end 13 on the tubular body 10 by being forced into the inner circumference of the reduced end 13 on the tubular body 10. The diameter of the reduced end 13 on the tubular body 10 is preferably increased to the same dimension of the diameter of the second end 18 of the barb member 14. Therefore, the formed connector 1 can avoid shoulders or snags at the second end 18 of the barb member 14 that prevent the connector 1 from being inserted into the tubular member 24.
In addition, the diameter of the spindle 40 is preferably the same as that of the inner circumference of the tubular body 10 before size reduction. Therefore, the restored tubular body 10 has a uniform inner diameter avoiding any possible fluid turbulence when the formed connector 1 is in use.
In an alternative embodiment of the method for forming the connector 1 of the present invention, a similar independent barb member 14 is pulled onto the free end 13 of the tubular body 10 of the connector 1. The second end 18 of the barb member 14 is then swaged down to retain the barb member 14 in position on the tubular body 10. Preferably, the second end 18 of the barb member 14 is swaged to be flush to the tubular body 10 of the connector 1. Therefore, as noted above, no shoulders or snags will result at the second end 18 of the barb member 14 that prevent the connector 1 from being inserted into the tubular member 24.
In the alternative embodiment, the circumferential recess 12 (see FIG. 1) is formed when the second end 18 of the barb member 14 is swaged down to retain the barb member 14 on the tubular body 10. The retaining is facilitated by swaging down the second end 18 of the barb member 14 after being provided onto the tubular body 10. The diameter of the free end 13 on the tubular body 10 needs not to be changed as in the previous embodiment. Therefore, the method of the alternative embodiment is easier to be carried out.
Although not preferred, an additional retaining member can be placed on the reduced end of the tubular body 10 to retain the barb member 14 in the desired position. Also, the barb member 14 can be bonded to the tubular body 10 by an adhesive, welding or other joining method so that it is retained in the proper position.
In addition, an end member 30 can be formed, through various conventional methods, at the free end 13 of the tubular body 10. The end member 30 can have the same structure and facilitate insertion of the connector 1 into the tubular member 24 as discussed hereinabove. FIG. 4d shows a connector 1 with such end member 30 formed at its free end 13.
The foregoing description is only illustrative of the principle of the present invention. It is to be recognized and understood that the invention is not to be limited to the exact configuration as illustrated and described herein. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention accordingly is to be defined as set forth in the appended claims.
What is claimed is:
1. A connector for joining flexible tubular members comprising:a tubular body having an outer diameter, a free end, an end member, and at least one circumferential recess, wherein a portion of the end member has a greater diameter than that of the tubular body and a first tapered surface extending from the free end of the connector to the greater diameter portion of the end member to assist in engaging a flexible tubular member and for retaining the flexible tubular member in engagement with the connector; and at least one barb member positioned and retained at least partially in the recess, the barb member comprising first and second ends with the second end positioned in the recess and having an outer diameter which is substantially the same as the outer diameter of the tubular body to provide a relatively smooth transition therebetween, and with the first end having an outer diameter which is greater than that of the second end and a rigid edge for engaging the flexible tubular member and for resisting pull-off of the tubular member from the connector.
2. The connector of claim 1, wherein the end member has a second tapered surface extending from the greater diameter portion toward the barb member.
3. The connector of claim 2, wherein one end of the tubular body is integrally formed on an end of a second tubular member.
4. A method for forming a connector comprising the steps of:providing a cylindrical body having an outer diameter and a free end; providing onto the cylindrical body at least one barb member adapted to be loosely fit thereon, said barb member comprising first and second ends with the second end having an outer diameter which is substantially the same as the outer diameter of the cylindrical body to provide a relatively smooth transition therebetween, and with the first end having an outer diameter which is greater than that of the second end and a rigid edge for engaging a flexible tubular member; fixing the barb member in position on the cylindrical body spaced from the first free end thereof with the first end of the barb member facing away from the first free end of the cylindrical body and the second end of the barb member facing the first free end of the cylindrical body; and forming an end member between the first free end of the tubular body and the barb member, wherein a portion of the end member has a greater outer diameter than that of the tubular body, thus forming a connector for engaging the flexible tubular member, whereby the rigid edge of the barb member resists pull-off of the flexible tubular member from the connector.
5. The method of claim 4 wherein said cylindrical body is a tubular body, and said fixing step comprises:reducing the outer diameter of the tubular body at the first free end prior to the step of providing the barb member onto the reduced outer diameter first free end of the tubular body; and increasing the reduced outer diameter first free end of the tubular body after the step of providing the barb member onto the reduced outer diameter first free end of the tubular body.
6. The method of claim 5 further comprising the step of molding the barb member to desired dimensions prior to the step of providing the barb member onto the reduced outer diameter first free end of the tubular body.
7. The method of claim 5 wherein the tubular body has a second free end, and which further comprising repeating the recited steps on the second free end of the tubular body for providing a second barb member for engagement of the connector with another flexible tubular member.
8. The connector formed by the method of claim 7.
9. The method of claim 4 wherein said fixing step comprises swaging down at least the first end of the barb member.
10. The method of claim 4 further comprising the step of machining the barb member to desired dimensions prior to the step of providing the barb member onto the reduced outer diameter first free end of the tubular body.
11. The connector formed by the method of claim 4.
12. A connector for joining flexible tubular members comprising:a body member having a first free end and a first end portion having an outer diameter; a barb member spaced from the first free end of the body member and positioned and retained on the first end portion thereof, the barb member comprising a first end having an outer diameter which is substantially the same as the outer diameter of the body member first end portion, and a second end which has an outer diameter that is greater than that of the first end of the barb member, said second end including a rigid edge for engaging a flexible tubular member; and an end member positioned between the first free end of the body member and the barb member, with a portion of the end member having a greater outer diameter than that of the body member to assist in retaining the flexible tubular member in engagement with the connector, wherein the first end of the barb member faces the first free end of the body member and the second end of the barb member faces away from the first free end of the body member to provide a relatively smooth transition between the first end portion of the body member and the barb member to facilitate sliding insertion of the flexible tubular member onto the connector and over the barb member, with the rigid edge of the barb member to further assist in retaining the flexible tubular member in engagement with the connector.
13. The connector of claim 12 wherein the body member end portion further comprises a recess and the first end of the barb member is positioned and retained in the recess so that the outer diameter of the first end of the barb member is positioned to align with the outer diameter of the body member first end portion.
14. The connector of claim 12, wherein the barb member has an outer surface which uniformly decreases in diameter from the second end to the first end, the body member is a tubular body, and the barb member is made of a material which is more rigid than that of the body member.
15. The connector of claim 12, wherein the end member has tapered surfaces extending to and from the greater outer diameter to facilitate sliding insertion of the flexible tubular member onto the connector and over the end member.
16. The connector of claim 12, wherein said body member has a second free end, and a second end portion having an outer diameter; and further comprising:an additional barb member spaced from the second free end of the body member and positioned and retained on the second end portion, the additional barb member comprising a first end having an outer diameter which is substantially the same as the outer diameter of the body member second end portion, and a second end which has a diameter that is greater than that of the first end of the additional barb member, said second end including a rigid edge for engaging another flexible tubular member; wherein the second end of the additional barb member faces away from the second end of the body member to provide a relatively smooth transition between the second end portion of the body member and the second barb member to facilitate sliding insertion of the flexible tubular member onto the connector and over the additional barb member, with the rigid edge of the additional barb member retaining the flexible tubular member in engagement with the connector.
17. The connector of claim 16, which further comprises a second end member positioned between the second free end of the body member and the additional barb member, with a portion of the second end member having a greater outer diameter than that of the body member to assist in retaining the flexible tubular member in engagement with the connector.
18. The connector of claim 17, wherein the second end member has tapered surfaces extending to and from the greater outer diameter to facilitate sliding insertion of the flexible tubular member onto the connector and over the second end member.
| 1996-03-13 | en | 1998-12-29 |
US-23737199-A | Installing structure for an electrically-driven wheelchair
ABSTRACT
In a wheelchair, a rear wheel part with a pair of rear wheels is assembled to the rear side of a frame in detachable state. The frame is constituted in foldable state. The rear wheel part and the rear side of the frame are provided with a locking member and a receiving member which can be coupled with each other and are arranged corresponding to these. The receiving member is provided with a concave locking surface at the side remote from the locking member. The locking member is provided with an insertion recess in which the receiving member can be inserted, and with a hook which can lock a locking surface of the receiving member inserted in the insertion recess. In the wheelchair, the rear wheel part can be simply assembled to or detached from the frame by the operation of the hook. Also the frame can be folded. Therefore even the wheelchair of heavy weight can be easily housed in a vehicle with a narrow housing space. Also the wheelchair can be simply assembled by the operation of the hook.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to an assembling structure of a wheelchair. More specifically, the present invention relates to assembling structure of a wheelchair where a pair of rear wheels can be simply assembled to an or detached from a frame.
(2) Description of Related Art
In the prior art, for example, an electrically-driven wheelchair is constituted so that rear wheels are driven by an electric motor arranged in the wheelchair itself.
However, the electrically-driven wheelchair has a weight of about 30 kg, because the electrically-driven wheelchair in the prior art contains an electric motor unit comprising an electric motor and a battery operating the electric motor.
Therefore when the electrically-driven wheelchair is raised to be put in a vehicle, this work cannot be performed by one person. Particularly a powerless woman cannot perform any loading work of the electrically-driven wheelchair.
SUMMARY OF THE INVENTION
In this case, if the wheelchair can be dismantled to an easy assembling state, the wheelchair, as disassembled parts of light weight, can be put on a vehicle. That is, if the wheelchair can be dismantled simply, the electrically-driven wheelchair can be put in a vehicle easily by a single individual.
Further, if a frame of the wheel chair can be folded, housing the electrically-driven wheelchair in the vehicle will become easier.
If rear wheels can be simply disassembled and the frame can be folded in such manner, not only an electrically-driven wheelchair but also a general-purpose wheelchair can be easily put in a vehicle with a narrow housing space. As a result, moving of the wheelchair becomes convenient.
The present invention intends to solve the above-mentioned problems. That is, an object of the present invention is to provide assembling a structure of a wheelchair where even a wheelchair of heavy weight can be easily housed in a vehicle with a narrow housing space and can be assembled simply.
The foregoing object can be achieved by assembling structure of a wheelchair having a frame and a rear wheel part in following constitution. The frame has the rear side with the rear wheel part assembled therein in a detachable state, and is constituted in foldable state. The rear wheel part is provided with a pair of rear wheels. The rear wheel part and the rear side of the frame are provided with a locking member and a receiving member which can be coupled with each other and are arranged, respectively. The receiving member is provided with a concave locking surface at the side remote from the locking member. The locking member is provided with an insertion recess in which the receiving member can be inserted, and with a hook in which the locking surface of the receiving member inserted in the insertion recess can be locked.
In assembling the structure of a wheelchair according to the present invention, a frame is stretched from a folded state and a receiving member is inserted in an insertion recess of a locking member. A hook is locked to a locking surface of the receiving member. Then a rear wheel part having a pair of rear wheels can be assembled to the rear side of the frame.
When a wheelchair is to be put in a vehicle, at first, the locking of the hook to the locking surface of the receiving member is released. The receiving member is separated from the insertion recess of the locking member. Then the rear wheel part can be disassembled from the frame. And then the frame is folded. The wheelchair is put in the vehicle in the state that the folded frame and the rear wheel part are disassembled.
Consequently in assembling the structure of the wheelchair according to the present invention, the rear wheel part can be simply assembled to or detached from the frame by an operation of the hook. Also the frame can be folded. Therefore even a wheelchair of heavy weight can be easily housed in a vehicle with a narrow housing space. The wheelchair can be assembled simply by operation of the hook.
The wheelchair may be an electrically-driven wheelchair where an electric motor unit driving the rear wheels is arranged at the rear wheel part.
In this case, since the rear wheel part is provided with the electric motor unit and is heavy in weight, it can be transported in the state separated from the frame. Therefore the electrically-driven wheelchair of heavy weight can be easily put on a vehicle or the like.
The rear wheel part is provided with a pair of main rear wheels arranged at the front side and with a pair of auxiliary rear wheels arranged at the rear side. Further it is preferable that the rear wheel part is assembled to the frame at the coupling portion between the locking member and the receiving member in a rockable state in the vertical direction along the longitudinal direction.
In this case, even at a portion having step difference such as a staircase, the rear wheel part rocks to the frame in the vertical direction along the longitudinal direction. That is, in the wheelchair of this structure, even at a portion having step difference such as a staircase, both the main rear wheel and the auxiliary rear wheel can be grounded. Therefore the wheelchair of this structure can travel the portion having a step difference stably.
Further the wheelchair may be constituted as follows. The hook is constituted by a locking piece arranged at the top end side for locking the locking surface, and a holding lever arranged at the base side for holding while the locking of the locking surface is released. The hook is biased by the biasing means so that it can be restored to the arrangement position to allow locking of the locking surface, and also the hook is pivotally supported between the locking piece and the holding lever in a rotatable state to the bottom part side of the insertion recess and is arranged to the locking member. Further when the locking piece is inserted in the insertion recess of the receiving member, the locking piece is pushed by the receiving member and is rotated to the bottom part side of the insertion recess, and when the receiving member is arranged to the bottom part of the insertion recess, the hook is restored to the arrangement position to allow locking of the locking surface by the biasing force of the biasing means.
In such a wheelchair, at the assembling state of the wheelchair, when the receiving member is inserted in the insertion recess, the locking piece is pushed by the receiving member and is rotated to the bottom part side of the insertion recess. Therefore the receiving member can be inserted in the insertion recess smoothly. When the receiving member is arranged to the bottom part of the insertion recess, the locking piece is restored to the arrangement position to allow locking of the locking surface by the biasing force of the biasing means.
That is, if the receiving member is simply inserted to the bottom part of the insertion recess in the locking member, the receiving member can be automatically locked by the locking member. Therefore in such a wheelchair, the rear wheel part can be assembled to the frame quite simply.
When the rear wheel part is separated from the frame, the holding lever is held and the hook is rotated. The locking piece is separated from the locking surface. Then the locking of the receiving member by the locking member can be released. Therefore in such a wheelchair, the rear wheel part can be disassembled from the frame simply.
In the above-mentioned wheelchair with the biasing means, it is preferable that the insertion recess of the locking member is opened at the upper side and is formed substantially in the vertical direction.
In assembling structure of the wheelchair, when the rear wheel part is assembled to the frame, each receiving member can be simply inserted to the bottom part of the insertion recess in the locking member utilizing the gravity. Further in this case, the looking surface of the receiving member can be automatically locked by the locking piece of the hook in the locking member. Therefore in assembling the structure of the wheelchair, the rear wheel part can be assembled to the frame quite simply. Also in assembling the structure of the wheelchair, the position defining the receiving member in the longitudinal direction is performed not by the hook but by the circumferential surface in the longitudinal direction in the insertion recess. Therefore the coupling strength of the receiving member to the locking member in the moving direction (longitudinal direction) of the wheelchair can be improved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view showing a wheelchair in an embodiment of the invention;
FIG. 2 is a schematic side view of the wheelchair in the embodiment showing the state that a rear wheel part is disassembled from a frame;
FIG. 3 is a schematic rear view of the wheelchair in the embodiment showing the state that a rear wheel part is disassembled from a frame;
FIG. 4 is a schematic rear view of the wheelchair in the embodiment showing a folded state of a frame;
FIG. 5 is an enlarged side view of the wheelchair in the embodiment showing a coupling state of a locking member and a receiving member;
FIG. 6 is an enlarged rear view of the wheelchair in the embodiment showing a coupling state of a locking member and a receiving member;
FIG. 7 is an enlarged perspective view of the wheelchair in the embodiment showing a coupling portion;
FIG. 8 is a diagram of the wheelchair in the embodiment showing the state that a receiving member is coupled to a locking member immediately before the coupling;
FIG. 9 is a diagram of the wheelchair in the embodiment showing the state that a receiving member is coupled to a locking member when the receiving member is to be inserted in an insertion recess; and
FIG. 10 is a diagram of the wheelchair in the embodiment showing operation of a hook when a receiving member is separated from a locking member.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described by way of embodiments shown in the accompanying drawings as follows. The present invention is not limited to the embodiments. All modifications within the requirements of claims or equivalents relating to the requirements shall be included in the scope of the claims.
A wheelchair C in an embodiment is an electrically-driven wheelchair as shown in FIGS. 1-3. In the wheelchair C, a rear wheel part 31 is detachably assembled with a frame 1.
The frame 1 is provided with a leg pipe 2, a front pipe 3 and a back pipe 11 arranged in the order from the front side. The leg pipe 2 is provided with a foot rest 16. The front pipe 3 has the upper side coupled with the upper side of the leg pipe 2 and is arranged in the vertical direction. The back pipe 11 is arranged at the rear side of the frame 1 and substantially in the vertical direction. The front pipe 3 and the back pipe 11 are coupled with each other at the upper side and the lower side by a seat pipe 5 and a base pipe 6 respectively. Also the base pipe 6 is provided with a straight part 6a at the front side and a curved part 6b. The straight part 6a extends in the horizontal direction. The curved part 6b is curved so that a recess retreating upward is provided from the rear end of the straight part 6a.
Further the leg pipe 2 is coupled with the upper side of the front pipe 3 in rotatable state rightward and leftward. A member designated by reference numeral 4 in FIGS. 1 and 2 is a support pipe supporting the leg pipe 2 supplementally. An arm pipe 10 is coupled with the seat pipe 5. The arm pipe 10 is provided with an elbow pad 22 and a skirt guard 24. The skirt guard 24 covers the inside of the wheelchair C. A back rest pipe 12 is coupled with the upper side of the back pipe 11. Further at the rear side of the back pipe 11, a staying pipe 13 and a support pipe 14 are connected. The staying pipe 13 is formed from the intermediate position in the vertical direction of the back pipe 11 and the lower side is extended in rear downward direction. The support pipe 14 extends rearward from the lower side of the back pipe 11 and supports the lower side of the staying pipe 13.
These pipes 2, 3, 4, 5, 6, 10, 11, 12, 13, 14 of the frame 1 are arranged in respective pairs in the left and right sides of the wheelchair C. These pipes 2, 3, 4, 5, 6, 10, 11, 12, 13, 14 constitute left and right side frame parts 1a, 1b respectively in the left and right sides of the wheelchair C. These left and right side frames 1a, 1b, as shown in FIGS. 1 and 4, are arranged so as to narrow the distance in the lateral direction utilizing cross bars 7, 8 and an auxiliary bar 9 described later. That is, these left and right side frames 1a, 1b are arranged so as to fold the frame 1 in the lateral direction.
Also at the lower side of each of the left and right front pipes 3, a front wheel 18 comprising a caster wheel is arranged.
At the lower side of each of the left and right staying pipes 13, an air damper 26 is arranged. Each air damper 26 abuts on each of left and right base stays 40 described later of the rear wheel part 31. Each air damper 26 performs the buffer action of the rear wheel part 31 during the rocking motion.
At the upper side of each of the left and right seat pipes 5, 5, a seat part 20 is arranged as shown in FIGS. 1, 3, 4. The seat part 20 is constituted by a seat member 20a and core pipes 20b, 20b. The seat member 20a has flexibility. Left and right edges of the seat member 20a are connected to the core pipes 20b, 20b respectively.
The cross bars 7, 7 arranged at the front side cross each other in the lateral direction and are pivotally supported mutually at the crossing position. The upper ends of the individual cross bars 7, 7 are fixed to the left and right core pipes 20b, 20b of the seat part 20 respectively. Also the lower ends of the individual cross bars 7, 7 are pivotally supported in rotatable state leftward or rightward to the right and left base pipes 6 being different from the core pipes 20b in the direction of the left side and the right side.
Also the cross bars 8, 8 arranged at the rear side cross each other and are pivotally supported mutually at the crossing position. The upper ends of the individual cross bars 8, 8 are fixed to the left and right core pipes 20b of the seat part 20 respectively. The lower ends of the individual cross bars 8, 8 are pivotally supported in rotatable state leftward or rightward to the individual base pipes 6 being different in the direction of the left side and the right side respectively. Further at the upper side of each of the cross bars 8, 8, the lower end of the auxiliary bar 9 is pivotally supported. The upper ends of the individual auxiliary bars 9, 9 are pivotally supported to the seat pipes 5, 5 in the vicinity of the individual cross bars 8, 8 respectively. These auxiliary bars 9 are stoppers. That is, the distance between the left and right side frame parts 1a, 1b which is widend is limited to constant value by the individual auxiliary bars 9.
The rear wheel part 31 is provided with a pair of main rear wheels 34 and a pair of auxiliary rear wheels 44 as shown in FIGS. 2 and 3. The pair of main rear wheels 34 are arranged at the front side. The pair of auxiliary rear wheels 44 are arranged at the rear side. The individual main rear wheels 34 are supported at rotatable state to the left and right support brackets 32, 32 respectively. The individual main rear wheels 34 are rotated and driven by electric motor units 33 respectively. Each electric motor unit 33 comprises an electric motor 33a with a reduction gear and a battery 33b as a power source of the electric motor 33a. Action of each electric motor unit 33 is controlled by operation of an operator control panel (not shown). The operator control panel (not shown) is assembled in the vicinity of the seat pipe 5.
The left and right support brackets 32 are coupled with each other by three coupling stays 36, 37, 38 arranged in lateral direction. Ends of the left and right support brackets 32 is provided with a base stay 40 extending rearward.
The individual base stays 40 are coupled with each other by a coupling stay 42 arranged in the lateral direction. The auxiliary rear wheels 44 are arranged at the rear side of the individual base stays 40 respectively. Each auxiliary rear wheel 44 is constituted by a caster wheel.
In the case of the embodiment, a receiving member 28 and a locking member 46 are provided so that the rear wheel part 31 is detachably assembled to the frame 1. The receiving member 28 is formed at the lower end of each of the left and right back pipes 11 of the frame 1. The locking member 46 is fixed at the rear side of each of the left and right support brackets 32 of the rear wheel part 31.
Each receiving member 28 is constituted by a bracket 28a, a support shaft 28c and a roller 28g as shown in FIGS. 5 and 6. The bracket 28a is made reverse U-like shape and is fixed to the lower end surface of each back pipe 11. The support shaft 28c is arranged so as to connect both wall parts 28b, 28b of the bracket 28a along the lateral direction. The roller 28g is externally fitted to the support shaft 28c. In the case of the embodiment, the support shaft 28c is constituted by a bolt 28d, a cap nut 28e and a collar 28f. The bolt 28d penetrates the wall parts 28b, 28b. The cap nut 28e is threadedly engaged with the bolt 28d. The collar 28f is externally fitted to the bolt 28d between the wall parts 28b, 28b. Length of the roller 28g is set longer than thickness of the support bracket 32.
The roller 28g is externally fitted in rotatable state to the support shaft 28c. Because it is intended that the rear wheel part 31 can be rocked in the vertical direction along the longitudinal direction to the frame 1. Further the upper side of the roller 28g is made a locking surface 29 to a locking piece 53 as described later provided at the locking member 46.
As shown in FIGS. 5-8, each locking member 46 is provided with an insertion recess 47 and a hook 52. The insertion recess 47 is formed with the upper side opened and is provided substantially in the vertical direction so that each roller 28g can be inserted from the upper side. The hook 52 is arranged at the rear edge side of the insertion recess 47.
Each hook 52 is housed in a housing recess 48. Also each hook 52 is pivotally supported to the support shaft 50 in rotatable state in the vertical direction along the longitudinal direction. The housing recess 48 is arranged between support walls 49, 49 opposed in the lateral direction at the rear side of each support bracket 32. The support shaft 50 is fixed between the support walls 49, 49. Each hook 52 is provided with a locking piece 53 and an operation lever 54. The locking piece 53 is positioned from the axially supported portion of the support shaft 50 to the top end side being the side of the insertion recess 47. The locking piece 53 can lock the roller 28g of the receiving member 28. The holding lever 54 is positioned from the pivotally supported portion of the support shaft 50 to the base side being the rear side of the wheelchair C. The holding lever 54 is held when the hook 52 is operated.
Further each hook 52 is provided with a torsion coil spring 55 as biasing means arranged at the locking piece 53. The coil spring 55 biases the hook 52 to the side of the arrangement position of locking the roller 28g. The spring 55 is externally fitted to the support shaft 50 within the recess 53c. The recess 53c is formed at the upper side of the locking piece 53. The recess 53c is in shape cut away in triangular plate. One end of the coil spring 55 is stopped by a stopper 51 arranged at the upper side of the support walls 49, 49. Other end of the coil spring 55 is brought into abutment on the inner circumferential surface of the recess 53c. The stopper 51 defines the rotational angle of the hook 52. That is, when the holding lever 54 is held and is operated and the locking piece 53 is separated from the locking position of the roller 28g, the stopper 51 abuts on the upper surface of the holding lever 54.
The locking piece 53 of each hook 52 is provided with a defining surface 53a and a guide surface 53b. The defining surface 53a is arranged at the lower surface side of the locking piece 53. The defining surface 53a can lock the locking surface 29 of the roller 28g. The guide surface 53b is arranged at the upper surface side of the locking piece 53. The guide surface 53b is formed in slanting so as to guide the entering of the roller 28g into the insertion recess 47.
Shape and size of the locking piece 53 and further the pivotally supported portion 50 of the hook 52 are set so that next operation of the locking piece 53 can be performed. That is, when the receiving member 28 is inserted into the insertion recess 47, setting is performed so that the locking piece 53 of the hook 52 can be pushed by the roller 28g of the receiving member 28 and can be rotated to the side of the bottom part 47a of the insertion recess 47. When the roller 28g of the receiving member 28 is arranged at the bottom part 47a of the insertion recess 47, setting is performed so that the locking piece 53 of the hook 52 can be restored to the position to allow locking of the locking surface 29 without interfering with the roller 28g by the biasing force of the spring 55. When the hook 52 is restored to the position where the locking surface 29 can be locked by the biasing force of the spring 55, the holding lever 54 abuts on the edge 48a (refer to FIG. 8) at the rear side of the housing recess 48 and is stopped.
In the wheelchair C of the embodiment, when it is used, first, from the folded state of the frame 1 shown by solid line in FIG. 4, the left and right side frame parts 1a, 1b are stretched as shown by dash-and-dot line in FIG. 4.
Next as shown in FIGS. 8 and 9, each roller 28g of each receiving member 28 is inserted into the insertion recess 47 of each locking member 46 from the upper side to the lower side. The hook 52 is locked to the locking surface 29 of the receiving member 28. Then as shown in FIG. 1, the rear wheel part 31 can be assembled to the rear side of the frame 1 and the use as the wheelchair C becomes possible.
In the wheelchair C of the embodiment, at the insertion state into the insertion recess 47 of each receiving member 28, the guide surface 53b of the locking piece 53 of the hook 52 is pushed by the roller 28g of the receiving member 28 and the locking piece 53 is rotated to the side of the bottom part 47a of the insertion recess 47 against the biasing force of the spring 55. Next when the roller 28g of the receiving member 28 is arranged to the bottom part 47a of the insertion recess 47, the locking piece 53 of the hook is automatically restored to the position where the defining surface 53a can lock the locking surface 29, without interfering with the roller 28g by the biasing force of the spring 55. Therefore in the wheelchair C of the embodiment, the rear wheel part 31 can be assembled to the frame 1 quite easily.
When the wheelchair C is to be put on a vehicle, as shown in FIG. 10, at first, the holding lever 54 of the hook 52 is held and restored upward. The locking of the hook 52 to the locking surface 29 of the receiving member 28 is released. Subsequently the side of the back pipe 11 of the frame 1 is raised upward. The roller 28g of the receiving member 28 is separated from the insertion recess 47 of each locking member 46. Then the rear wheel 31 can be detached from the frame 1. In the case of the embodiment, when the holding lever 54 is held, thumb is disposed at the upper surface side of the support pipe 14 of the frame 1 and a forefinger and a middle finger are disposed at the lower surface side of the holding lever 54. If the holding lever 54 is operated so as to clench fingers, the hook 52 can be rotated easily.
And then the frame 1 is folded so that state of dash-and-dot line in FIG. 4 becomes state of solid line. The folded frame 1 and the rear wheel part 31 at the dismantled state are put on a vehicle.
Consequently in the assembling structure of the wheelchair C of the embodiment, the rear wheel part 31 can be easily assembled with or detached from the frame 1 by the operation of the hook 52. Further the frame 1 can be also folded. Therefore even if the wheelchair C is heavy, it can be easily housed in a vehicle with narrow housing space. Also the wheelchair C can be assembled easily by the operation of the hook 52.
Particularly in the embodiment, the wheelchair C is an electrically-driven wheelchair where an electric motor unit 53 driving a main rear wheel 34 is arranged at a rear wheel part 31. However, the rear wheel part 31 can be transported in separated state from the frame 1. Therefore the electrically-driven wheelchair C of heavy weight can be put on a vehicle or the like.
Of course, the assembling structure of the present invention may be applied not only to the wheelchair C with the electric motor unit 33 but also to the wheelchair without the electric motor unit 33.
Further in the embodiment, the rear wheel part 31 is constituted in that a pair of main rear wheels 34 are arranged at the front side and a pair of auxiliary rear wheels 44 are arranged at the rear side. Also in the embodiment, the rear wheel part 31 is assembled to the frame 1 in rockable state in the vertical direction along the longitudinal direction, by the roller 28g at the coupling position between the locking member 46 and the receiving member 28.
Therefore the wheelchair C of the embodiment can travel stably even a portion having step difference, such as a staircase. Because the rear wheel part 31 can rock to the frame 1 in the vertical direction along the longitudinal direction as shown in dash-and-dot line in FIG. 1 (dash-and-dot line showing the base stay 40), and both the main rear wheel 34 and the auxiliary rear wheel 44 can be grounded. Of course, if this point is not considered, the auxiliary rear wheel 44 need not be provided. Further the rear wheel part 31 need not be assembled to the frame 1 in rockable state in the vertical direction along the longitudinal direction.
When the rear wheel part 31 is not assembled to the frame 1 in rockable state in the vertical direction along the longitudinal direction, following constitution may be done. That is, the receiving member 28 is not made the cylindrical roller 28g as in the embodiment, but the receiving member is simply made a convex shape. The surface at the back side in the convex shape being away from the hook may be made the locking surface 29 which can be locked by the locking piece 53.
Further in the wheelchair C of the embodiment, the insertion recess 47 of the locking member 46 is opened at the upper side and is formed substantially in the vertical direction. Therefore when the rear wheel part 31 is assembled to the frame 1, the roller 28g of each receiving member 28 can be simply inserted to the bottom part 47a of the insertion recess 47 in the locking member 46 utilizing the gravity. In this case, the locking surface 29 in the roller 28g of the receiving member 28 can be locked automatically to the defining surface 53a of the hook locking piece 53 in the locking member 46. Therefore the rear wheel part 31 can be assembled to the frame 1 quite simply.
If the insertion recess 47 of the locking member 46 is formed substantially in the vertical direction, following working and effect can be obtained. That is, the position defining in the longitudinal direction of the receiving member 28 is performed not by the hook 52 but by the circumferential surface of the longitudinal direction in the insertion recess 47. Therefore the coupling strength of the receiving member 28 to the locking member 46 in the moving direction (longitudinal direction) of the wheelchair C can be improved.
If such point is not considered, the insertion recess 47 of the locking member 46 may be formed in the horizontal direction or may be bent in L-like shape.
In the embodiment, the two locking members 46 are arranged at the side of the rear wheel part 31 and the two receiving member 28 are arranged at the side of the frame 1. As the modification of the assembling structure, however, at least one set of the locking member 46 and the receiving member 28 may be arranged at the reverse side.
Also in the embodiment, two sets of the locking members 46 and the receiving members 28 corresponding to the locking members 46 are arranged. However, if the rear wheel part 31 can be assembled to the frame 1 stably, one set of the locking member 46 and the receiving member 28 or three sets or more may be assembled to the wheelchair.
What is claimed is:
1. An assembling structure of an electrically-driven wheelchair having a frame and a rear wheel part, wherein the rear wheel part is assembled in a detachable state to the rear side of the frame, said frame being collapsible into a folded state,said rear part including a pair of main rear wheels arranged at the front side, and a pair of auxiliary rear wheels arranged at the rear side, wherein both the main rear wheels and the auxiliary rear wheels are arranged to be grounded, an electric motor unit for driving the main rear wheels, arranged at the main rear wheels, the rear wheel part and the rear side of the frame including a locking member and a receiving member, which can be coupled with each other and are arranged respectively thereon, the receiving member including a concave locking surface at a side remote from the locking member, the locking member including with an insertion recess in which the receiving member can be inserted, and with a hook which can lock the locking surface of the receiving member inserted in the insertion recess, wherein the rear wheel part is assembled to the frame at a coupling portion between the locking member and the receiving member, in a rockable state in the vertical direction along the longitudinal direction as the center of rocking the receiving member.
2. The assembling structure of a wheelchair as set forth in claim 1, wherein the hook is constituted by a locking piece arranged at the top end side for locking the locking surface, and a holding lever arranged at the base side for holding the locking surface while the locking of the locking surface is released,the hook is biased by the biasing means so that it can be restored to the arrangement position to allow locking of the locking surface, and the hook is pivotally supported between the locking piece and the holding lever in rotatable state to the bottom part side of the insertion recess and is arranged to the locking member, and when the receiving member is inserted in the insertion recess of the receiving member, the locking piece is pushed by the receiving member and is rotated to the bottom part side of the insertion recess, and when the receiving member is arranged to the bottom part of the insertion recess, the hook is restored to the arrangement position to allow locking of the locking surface by the biasing force of the biasing means.
3. The assembling structure of a wheelchair as set forth in claim 1, wherein the insertion recess of the locking member is opened at the upper side and is formed substantially in the vertical direction.
4. The assembling structure of a wheelchair as set forth in claim 3, wherein the locking member is arranged at the side of the rear wheel part and the receiving member is arranged at the frame side.
| 1999-01-26 | en | 2000-10-24 |
US-67897784-A | High strength glass-ceramic containing apatite and alkaline earth metal silicate crystals and process for producing the same
ABSTRACT
A high strength glass-ceramic containing apatite and alkaline earth metal silicate (diopside/forsterite/akermanite) crystals having an excellent affinity for a living body and a process for producing the same are disclosed. The glass-ceramic is useful as an implant material such as an artificial dental root and an artificial bone.
FIELD OF THE INVENTION
The present invention relates to a high strength glass-ceramic containing apatite crystals which is useful as an implant material such as an artificial dental root and an artificial bone, and a process for producing the glass-ceramic.
BACKGROUND OF THE INVENTION
In recent years, an artificial material such as an artificial dental root or an artificial bone has been used as a substitute for a dental root or bone. Artificial materials which have heretofore been used for this purpose are anti-corrosive alloys such as a stainless steel and a cobalt/chromium alloy, and polymer such as polymethyl methacrylate and high density polyethylene. These materials, however, have a problem in that when those are used for a long period of time, metallic ions or monomers tend to elute in a living body and, therefore, those are sometimes harmful to a human body. On the other hand, a ceramic material generally exhibits an excellent biocompatibility to a living body and is stable in a living body. It has now received increasing attention as an artificial material.
One of such ceramic materials is single crystalline or polycrystalline alumina. This material is characterized by having a very high strength. The alumina ceramic, however, does not form any chemical bonding with a bone. To fix the alumina ceramic in a living body, therefore, a procedure should be employed in which the alumina ceramic itself is screwed or bored and physically fixed inside a bone. In this case, if the shape of the material is unsuitable, a stress sometimes concentrates in one part of the bone or material, resulting in the absorption of the bone and the formation of collagen fibers in the interface between the bone and the material. This makes loose the fixed part of the material or causes the material to come apart. In order to overcome the above problem, investigations have recently been made to develop ceramics which can form a chemical bonding with a bone and be firmly fixed inside the bone.
Typical examples of such ceramics are a sintered body of hydroxy-apatitie, a Na2 O--CaO--P2 O5 --SiO2 -based bioglass, and a glass-ceramic containing apatite crystals obtained by the precipitation of the apatite crystals from a Na2 O--K2 O--MgO--CaO--P2 O5 --SiO2 -based glass. Hydroxy apatite crystals, however, are converted into tricalcium phosphate when sintered at high temperatures. Consequently, it is difficult to produce a sintered hydroxy-apatite having a dense structure and a high strength. The bioglass and apatite-containing glass-ceramic have a disadvantage in that those can be utilized only in parts where only a small stress is applied, since its mechanical strength is low. In recent years, therefore, glass-ceramic has been developed which can form a chemical bonding with a bone and further has a relatively high strength.
Such a conventional glass-ceramic is produced by the following method: grinding MgO--CaO--P2 O5 --SiO2 -based glass with a MgO content of 7 wt% or less to 200 mesh or less powders, compression molding the glass powders and then heat treating the molding in the sintering temperature range of the glass powders and subsequently in the temperature range where apatite and wollastonite crystals are formed. The thus-obtained glass-ceramic has a bending strength of from 1,200 to 1,400 kg/cm2. Of conventional materials forming a chemical bonding with a bone, the glass-ceramic has the highest strength. In this glass-ceramic, however, since the sintering temperature range of the glass powders is close to the crystal-precipitation temperature range, crystallization proceeds before air bubbles disappear by sintering. For this reason, it is difficult to produce the dense glass-ceramic having a high strength in every time. Thus, the above glass-ceramic has a disadvantage in that the strength varies depending on the production lot. Furthermore, when the glass-ceramic is used as an artificial dental root, it is desired to have a higher mechanical strength.
A glass-ceramic containing apatite crystals and alkaline earth metal silicate crystals such as diopside crystal, forsterite crystal and akermanite crystal is also known. This glass-ceramic is obtained by grinding a MgO--CaO--SiO2 --P2 O5 -based glass with the MgO content of 8 wt% or more to 200 mesh or less powders, molding the glass powders, heat treating the molding in the sintering temperature range of the glass powders (750° to 880° C.) and then heat treating the molding in the temperature range where apatite crystals (Ca10 (PO4)6 O) and alkaline earth metal silicate crystals such as diopside (MgOCaO2SiO2), forsterite (2MgOSiO2) and akermanite (2CaOMgO2SiO2) (830° to 1150° C.) are formed.
In this glass-ceramic, the apatite crystals act to improve the affinity with a living body and the alkaline earth metal silicate crystals act to increase the mechanical strength of the glass-ceramic. Therefore in order to obtain a glass-ceramic having a good affinity with a living body and a high mechanical strength, it is required for the glass-ceramic to contain the apatite crystals and alkaline earth metal silicate crystals as much as possible. However, in the conventional glass-ceramic of this type, if the heat treatment is conducted at high temperatures in order to increase the amount of alkaline earth metal silicate crystals formed, the apatite crystals which have been previously precipitated tend to decrease. Thus, those conventional glass-ceramic have the disadvantage in that if the amount of alkaline earth metal silicate crystals precipitated is increased thereby improving the mechanical strength, the apatite crystals decrease, resulting in lowering the affinity with a living body.
SUMMARY OF THE INVENTION
The present invention is intended to overcome the problems in the conventional glass-ceramic.
One object of the present invention is to provide a glass-ceramic which contains apatite crystals exhibiting an excellent affinity with a living body and has a high strength.
Another object of the present invention is to provide a process for producing the glass-ceramic.
The glass-ceramic of the present invention contains large amounts of apatite (Ca10 (PO4)6 O) and at least one alkaline earth metal silicate crystals selected from the group consisting of diopside (MgO.CaO.2SiO2), forsterite (2MgO.SiO2) and akermanite (2CaO.MgO.2SiO2) which are uniformly dispersed in the glass, and has a composition comprising, in % by weight,
8 to 34% MgO;
12 to 43% CaO;
25 to 40% SiO2 ;
10 to 25% P2 O5 ;
optionally 1 to 10% Al2 O3 and/or ZrO2 ;
with proviso of
MgO+CaO+SiO+P.sub.2 O.sub.5 (+Al.sub.2 O.sub.3 and/or ZrO.sub.2)≧90%,
0 to 10% Li2 O;
0 to 5% Na2 O;
0 to 10% K2 O;
0 to 10% SrO;
0 to 10% B2 O3 ;
0 to 10% TiO2 ;
0 to 10% Nb2 O5 ;
0 to 10% Ta2 O5 ; and
0 to 3% F2,
with proviso of
Li.sub.2 O+Na.sub.2 O+K.sub.2 O+SrO+B.sub.2 O.sub.3 +TiO.sub.2 +Nb.sub.2 O.sub.5 +Ta.sub.2 O.sub.5 +F.sub.2 ≦10%.
A process for producing the glass-ceramic according to the present invention comprises:
molding 200 mesh or less glass powders having the above composition;
heat treating the resulting molding within the sintering temperature range of the glass powders; and
further heat treating the molding within a temperature range where apatite crystals and alkaline earth metal silicate crystals such as diopside, forsterite and akermanite are formed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 4 each shows a relationship between a heat-treatment temperature of an apatite crystal-containing high strength glass-ceramic of the present invention and an X-ray diffraction intensity of the crystal contained in the glass-ceramic.
FIGS. 1 and 3 show the above relationship for apatite crystals; and
FIGS. 2 and 4 show the above relationship for diopside and forsterite crystals.
Glass A: Glass not containing Al2 O3
Glass B: Glass containing Al2 O3
Glass C: Glass not containing ZrO2
Glass D: Glass containing ZrO2
DETAILED DESCRIPTION OF THE INVENTION
The reason why the amount of each component of the glass-ceramic of the present invention is limited to the above-specified range will hereinafter be explained.
If the amount of MgO is less than 8%, the sintering temperature range of the resulting glass composition is close to a crystal-forming temperature range. Therefore, crystallization occurs before disappearance of air bubbles due to sintering and a glass-ceramic of dense structure is difficult to obtain. On the other hand, if the amount of MgO is more than 34%, the amount of apatite crystals formed is undesirably small. Thus, the MgO content is limited to a range of from 8 to 34%.
If the amount of CaO is less than 12%, the amount of apatite crystals formed is undesirably small. On the other hand, if the amount of CaO is more than 43%, devitrification tendency of glass is markable and the desired glass-ceramic is difficult to produce. Thus, the CaO content is limited to a range of from 12 to 43%.
If the amount of SiO2 is less than 25%, devitrification of glass tends to occur and the desired glass-ceramic is difficult to produce. Moreover, since the amounts of calcium and magnesium (alkaline earth metals) silicate crystals formed are small, a glass-ceramic having a high strength is difficult to obtain. On the other hand, if the amount of SiO2 is more than 40%, the resulting glass tends to occur phase separation and a uniform glass cannot be obtained. Thus, the SiO2 content is limited to a range of from 25 to 40%.
If the amount of P2 O5 is less than 10%, the apatite crystals are formed only in small amounts. On the other hand, if the amount of P2 O5 is more than 25%, the phase separation occurs and a uniform glass cannot be obtained. Thus, the P2 O5 content is limited to a range of from 10 to 25%.
A glass composition additionally containing Al2 O3 provides the following effect, although it will be explained in detail later. That is, when the glass composition additionally containing Al2 O3 is heated at a temperature of about 900° to 1,000° C., the apatite crystals are formed in a considerably greater amount than that in a glass composition not containing Al2 O3. If the amount of Al2 O3 added is less than 1%, the effect of accelerating the precipitation of apatite crystals is small. On the other hand, if the amount thereof is more than 10%, the amounts of alkaline earth metal silicate crystals formed are reduced. Thus, the Al2 O3 content is limited to a range of from 1 to 10%.
A glass composition additionally containing ZrO2 provides the following effect, although it will be explained in detail later. That is, if the amount of ZrO2 added is less than 1%, the effect of accelerating the precipitation of apatite crystals is small. On the other hand, if the amount thereof is more than 10%, ZrO2 does not dissolve in the glass. Thus, the amount of ZrO2 added is limited to a range of from 1 to 10%, preferably from 3 to 6%.
The glass-ceramic of the present invention can contain, as well as the above-described components, one or more of compounds selected from the group consisting of Li2 O, Na2 O, K2 O, SrO, B2 O3, TiO2, Nb2 O5, Ta2 O5 and F2, which are harmless to a human body, in a total amount of 10% or less. If the total amount of these additives is 10%, the amounts of apatite crystals and alkaline earth metal silicate crystals formed are reduced. Thus, the total amount of the additives is limited to 10% or less. Accordingly, the total amount of MgO, CaO, SiO2 and P2 O5, or the components plus Al2 O3 and/or ZrO2 is limited to at least 90%, preferably 95 to 98%.
The amount of Li2 O is 0 to 10%, preferably less than 4%.
The amount of Na2 O is 0 to 5%, preferably less than 4%. If the amount of Na2 O added is more than 5%, the amount of apatite crystals formed is markedly decreased.
The amount of K2 O is 0 to 10%, preferably less than 4%.
The amount of SrO is 0 to 10%, preferably less than 5%.
The amount of B2 O3 is 0 to 10%, preferably less than 5%.
The amount of TiO2 is 0 to 10%, preferably less than 5%.
The amount of Nb2 O5 is 0 to 10%, preferably less than 5%.
The amount of Ta2 O5 is 0 to 10%, preferably less than 5%.
The amount of F2 is 0 to 3%, preferably less than 1.5%. If the amount of F2 added is more than 3%, devitrification of glass occurs seriously.
The glass-ceramic having the above composition is produced in the following manner.
A glass having the above composition, either containing or not containing Al2 O3 and/or ZrO2, is ground to a particle size of 200 mesh or less and then molded into a desired form. If, on the other hand, the glass is molded into the desired form directly from a moleten state and then heat treated, although apatite crystals are precipitated in a uniformly dispersed condition, alkaline earth metal silicate crystals such as diopside, akermanite and forsterite, precipitate from the glass surface, forming cracks in the inside of the glass-ceramic. As a result, a glass-ceramic having a high strength cannot be obtained.
In order to obtain a glass-ceramic containing less air bubbles and crystals uniformly dispersed therein, it is a very important condition to employ a finely powdered glass. If the particle size of the glass powders is more than 200 mesh, large air bubbles tend to remain in a glass-ceramic obtained by sintering the glass powders and it is not possible to produce a glass-ceramic having a high mechanical strength. Therefore, the particle size of the powdered glass is limited to 200 mesh or less.
In order to produce the glass-ceramic of the present invention, it is also necessary that a molding of the above glass powders be subjected to a heat treatment within the sintering temperature range of the glass powders and then within a temperature range where apatite crystals and alkaline earth metal silicate crystals such as diopside are formed. A heat treatment of the glass powders within the sintering temperature range thereof is an important factor to obtain a glass-ceramic containing no air bubble and having a high mechanical strength.
The sintering temperature range of the glass powders can be determined by heating a molding of the glass powders at a constant temperature-raising speed and measuring a heat shrinkage of the molding due to the sintering thereof. The sintering temperature range is from a temperature at which the heat shrinkage starts to a temperature at which the heat shrinkage finishes.
A heat treatment within the apatite crystal-forming temperature range is important to precipitate a large amount of apatite crystals necessary for chemically bonding the resulting glass-ceramic to a bone. A heat treatment within the temperature range where alkaline earth metal silicate crystals such as diopside are formed is important to precipitate a large amount of alkaline earth metal silicate crystals, thereby increasing the mechanical strength of the resulting glass-ceramic. Each crystal-forming temperature range can be determined by a differential thermal analysis of the glass powders. A glass powders are heat treated at a temperature at which an exothermic peak appears in a differential thermal analytical curve and then is subjected to an X-ray diffraction analysis. By analyzing the data of the X-ray diffraction analysis, precipitated crystals corresponding to the exothermic peak are identified. The crystal-forming temperature range for each crystal is from a temperature at which heat-evolution starts to a temperature at which heat-evolution finishes.
The effect resulting from the addition of Al2 O3 will hereinafter be explained by reference to FIGS. 1 and 2.
FIGS. 1 and 2 each shows a relationship between an intensity of an X-ray diffraction peak and a retention temperature for heat-treatment for Glass A not containing Al2 O3 and Glass B containing Al2 O3.
The curves indicated by the symbol (i) in FIG. 1 each represents a relationship between an intensity of a main X-ray diffraction peak (d=2.81 Å) of apatite crystals and a retention temperature for heat-treatment. Likewise, in FIG. 2, the symbols (ii) and (iii) represent, respectively, a relationship between an intensity of a main X-ray diffraction peak (d=2.99 Å) of diopside crystals and a retention temperature for heat-treatment, and a relationship between an intensity of a main X-ray diffraction peak (d=3.88 Å) of forsterite crystals and a retention temperature for heat-treatment.
Glass A has a composition comprising, in % by weight, 20.8% MgO, 29.2% CaO, 33.4% SiO2, 16.1% P2 O5 and 0.5% F2. On the other hand, Glass B has the above composition to which 4% Al2 O3 is additionally added. Each glass is ground to 200 mesh or less particles, heated in an electric furnace from room temperature at a temperature-rising rate of 10° C./min., maintaining at a constant temperature between 850° and 1,150° C. for 30 minutes, and then cooled to room temperature. Crystals precipitated from Glasses A and B after the heat-treatment are identified by the powder X-ray diffraction analytical method. In each sample, main crystals precipitated are apatite, diopside and forsterite.
The following can be seen from FIGS. 1 and 2. At retention temperatures below 1,015° C., the intensity of the main X-ray diffraction peak of apatite crystals of Glass B containing Al2 O3 is about 23% greater than that of Glass A not containing Al2 O3, viz., the amount of apatite formed in Glass B is greater than that in Glass A. On the other hand, at retention temperatures below 1,015° C., the amount of diopside crystals formed in Glass B is somewhat smaller than that in Glass A. However, the amount of forsterite crystals formed tends to increase to a certain extent. Thus, the total amount of diopside and forsterite formed in Glass B is nearly equal to that in Glass A. This demonstrates that addition of Al2 O3 results in a considerable increase in the amount of apatite crystals formed. Thus, it can be understood that a crystallized glass as produced by heating a glass containing Al2 O3 like Glass B at temperature of 1,015° C. or less contains a large amount of apatite crystals and, therefore, exhibits an excellent affinity for a living body.
Although the effect of adding Al2 O3 has been explained above by reference to a glass having a certain definite composition, the effect of increasing the amount of apatite crystals precipitated by adding Al2 O3 is not limited to the above composition. Further, the type of alkaline earth metal silicate crystals precipitated by the heat-treatment varies depending on the glass composition. That is, forsterite (2MgO.SiO2) precipitates from a glass having a composition that the MgO content is high; diopside (CaO.MgO.2SiO2), from a glass having a composition that the CaO content is high; and akermanite (2CaO.MgO.2SiO2), from a glass having a composition that the SiO2 content is small, or the P2 O5 content is small. Two or more of the above crystals precipitate when the composition falls within intermediate regions. In the case that additives such as Na2 O, K2 O and Li2 O are added, crystals other than the above-described crystals sometimes precipitate.
The effect resulting from the addition of ZrO2 will hereinafter be explained by reference to FIGS. 3 and 4.
FIGS. 3 and 4 each shows a relationship between an intensity of an X-ray diffraction peak and a retention temperature for heat-treatment for Glass C not containing ZrO2 and Glass D containing ZrO2.
The curves indicated by the symbol (iv) in FIG. 3 each represents a relationship between an intensity of a main X-ray diffraction peak (d=2.81 Å) of apatite crystals and a retention temperature for heat-treatment. Likewise, in FIG. 4, the symbols (v) and (vi) represent, respectively, a relationship between an intensity of a main X-ray diffraction peak (d=2.99 Å) of diopside crystals and a retention temperature for heat-treatment, and a relationship between an intensity of a main X-ray diffraction peak (d=3.88 Å) of forsterite crystals and a retention temperature for heat-treatment.
Class C has a composition comprising, in % by weight, 20.8% MgO, 29.2% CaO, 33.4% SiO2, 16.1% P2 O5 and 0.5% F2. On the other hand, Glass D has the above composition to which 4% ZrO2 is additionally added. Each glass is ground to 200 mesh or less particles, heated in an electric furnace from room temperature at a temperature-rising rate of 10° C./min., maintaining at a constant temperature between 850° and 1,150° C. for 30 minutes, and then cooled to room temperature. Crystals precipitated from Glasses A and B after the heat-treatment are identified by the powder X-ray diffraction analytical method. In each sample, main crystals precipitated are apatite, diopside and forsterite.
As is apparent from curves (iii) in FIG. 3, the apatite crystals start to precipitate at 850° C. and the precipitation amount reaches a constant value at 900° C. However, the amount of apatite crystals gradually decreases at 1,015° C. or more. On the contrary, as is apparent from curves (iv) in FIG. 4, the amount of diopsite crystals precipitated rapidly increases up to 930° C., but the increase thereof is slight at more than 930° C. The amount of forsterite crystals precipitated does not almost change. In comparison between Glass C not containing ZrO2 and Glass D containing ZrO2, the diffraction intensity of the apatite crystals precipitated from Glass D containing 4% ZrO2 is about 13% greater than that of Glass C not containing ZrO2. Similarly, in the diffraction intensity of diopsite crystals, Glass D is about 8% greater than Glass C. In order to increase the mechanical strength of the glass-ceramic, it is necessary to precipitate diopside crystals and forsterite crystals as much as possible by heat treating at higher temperatures. However, the amount of the apatite crystal decreases, resulting in deterioration of the affinity for a living body. Addition of ZrO2 as in Glass D is very effective to increase the amount of diopside crystals without decreasing the amount of apatite crystals. In producing the glass-ceramic, the glass is kept at the maximum temperature (1,020° C.) where the apatite crystals are present stably, for 2 hours. Under the production conditions, the addition effect of ZrO2 is remarkable as the retention time becomes longer. When examining crystals precipitated in the glass-ceramic obtained by molding glass powders of each of Glasses C and D, heating each molding at the temperature-rising rate of 3° C./min. and maintaining the molding at 1,020° C. for 2 hours, the diffraction intensity of apatite crystals of the crystallized glass containing 4% ZrO2 is 20% greater than that of the glass-ceramic not containing ZrO2, and the diffraction intensity of diopside crystals of the glass-ceramic containing 4% ZrO2 is 5% greater than that of the crystallized glass not containing ZrO2. Thus, ZrO2 acts effectively to obtain a glass-ceramic having a good affinity for a living body and a high mechanical strength.
The mother glass of the glass-ceramic of the present invention can be melted at 1,400° to 1,500° C. in a refractory crucible or platinum crucible as in the general glass, using oxides, phosphates, carbonates, fluorides, and the like as starting materials. The molten glass is quenched by flowing over a mold, or passing between cooled rollers, or pouring in water. The thus-obtained glass is then pulverized to 200 mesh or less particles by means of the usual pulverizer such as a pot mill or a jet mill. If necessary, the glass powders are screened to obtain particles having various sizes which are then compounded approximately. The glass powders are molded by procedures generally employed in molding of ceramics, such as press-molding using a metallic mold, slurry cast-molding, extrusion molding, and hydrostatic press-molding. In order to improve rheological properties such as flowability of powder in the molding process, it is effective to add conventional molding aids such as paraffin and stearic acid salts to the glass powders. Another effective method of improving the flowability of glass powders is to granulate the glass powders, i.e., use in a granular form.
Sintering and crystallization of a molding of the glass powders can be achieved by a method in which the glass powders are maintained at temperatures falling within the sintering temperature range of the glass powders, the apatite crystal-forming temperature range, and the alkaline earth metal silicate crystal-forming temperature range as described above, or a method in which the glass powders are gradually heated from the sintering temperature range of the glass powders to the alkaline earth metal silicate crystal-forming temperature range. Moreover, the sintering and crystallization of the glass powders by techniques such as a high temperature press molding method and a hot isostatic press method is effective to obtain a glass-ceramic having a dense structure.
The present invention is described in greater detail by reference to the following examples. Compositions are expressed in % by weight.
EXAMPLES
Glass compositions as shown in the Tables 1 and 2 below were prepared using oxides, carbonates, phosphates, fluorides and the like. Each glass composition was placed in a platinum crucible and melted at 1,400° to 1,500° C. for 1 hour. The thus-obtained glass was quenched by pouring it into water in the molten state and dried. It was then placed in a pot mill and pulverized to a size of 350 mesh or less. A mixture of the glass powders and 5 wt% of paraffin as a binder was placed in a metallic mold and press-molded into a desired form under a pressure of 600 kg/cm2. The molding was placed in an electric furnace, and heated from room temperature to a prescribed temperature between 950° and 1,050° C. at a constant temperature-rising rate of 3° C./min. and maintained at that temperature for 2 hours to achieve sintering and crystallization. Then, the molding was gradually cooled to room temperature in the furnace.
The glass-ceramic was ruptured, and the rupture cross-section was examined by SEM. It was found that the glass-ceramic had a dense structure that almost no air bubble could be found. The glass sample was pulverized, and precipitated crystals were identified by X-ray diffraction analysis. In all cases, it was observed that, together with a large amount of apatite crystals, large amounts of alkaline earth metal silicate crystals such as diopside, forsterite and akermanite precipitated. The type of crystals precipitated is also shown in Tables 1 and 2 below.
Some samples were measured for a bending strength by using a 5×5×25 mm prism the surface of which was polished with No. 1000 aluminum abrasive particles. The results are also shown in Tables 1 and 2 below. As can be seen from Table 1, the glass-ceramic of the present invention has a bending strength as high as from 1,500 to 1,800 kg/cm2.
TABLE 1
__________________________________________________________________________
Example No.
1 2 3 4 5 6
__________________________________________________________________________
MgO 8.0 12.1 20.1 20.8 19.9 20.1
CaO 42.9 36.2 28.1 29.2 28.0 28.1
SiO.sub.2 32.9 32.1 32.2 33.3 32.0 32.2
P.sub.2 O.sub.5
15.7 15.6 15.6 16.2 15.6 15.6
Additives F.sub.2 0.5
SrO 4.0
B.sub.2 O.sub.3 4.0
F.sub.2 0.5
Al.sub.2 O.sub.3 4.0
TiO.sub.2 4.0
F.sub.2 0.5
Temperature-Rising
3 3 3 3 3 3
Rate (°C./min.)
Retention 1030 1030 1000 1020 990 1000
Temperature (°C.)
Retention Time (hr)
2 2 2 2 2 2
Type of Crystals
Apatite
Apatite
Apatite
Apatite
Apatite
Apatite
Precipitated
Diopside
Diopside
Diopside
Diopside
Diopside
Diopside
β-Tricalcium
Forsterite
Forsterite
Forsterite
Forsterite
Phosphate
β-Tricalcium β-Tricalcium
Phosphate Phosphate
Bending 1800 -- -- 1800 1600 1500
Strength (kg/cm.sup.2)
__________________________________________________________________________
Example No.
7 8 9 10 11 12
__________________________________________________________________________
MgO 29.2 12.1 12.1 21.9 18.6 28.7
CaO 16.6 40.2 40.2 30.6 26.1 24.6
SiO.sub.2 37.5 28.1 28.1 35.0 29.8 28.7
P.sub.2 O.sub.5
16.2 15.6 15.6 12.0 23.0 16.0
Additives F.sub.2 0.5
Nb.sub.2 O.sub.5 4.0
Ta.sub.2 O.sub.5 4.0
F.sub.2 0.5
F.sub.2 0.5
K.sub.2 O 2.0
Li.sub.2 O 2.0
Temperature-Rising
3 3 3 3 3 3
Rate (°C./min.)
Retention 950 1000 1000 1000 1000 1000
Temperature (°C.)
Retention Time (hr)
2 2 2 2 2 2
Type of Crystals
Apatite
Apatite
Apatite
Apatite
Apatite
Apatite
Precipitated
Diopside
Akermanite
Akermanite
Akermanite
Akermanite
Forsterite
Forsterite
Diopside
Diopside
Diopside
Diopside
Diopside
β-Tricalcium
β-Tricalcium
β-Tricalcium
β-Tricalcium
β-Tricalcium
Phosphate
Phosphate
Phosphate
Phosphate
Phosphate
Forsterite
Forsterite
Forsterite
Forsterite
Bending 1500 1500 -- 1700 -- --
Strength (kg/cm.sup.2)
__________________________________________________________________________
TABLE 2
__________________________________________________________________________
Example No.
13 14 15 16 17 18 19 20
__________________________________________________________________________
MgO 20.1 19.9 12.0 28.0 12.0 27.8 12.4 12.0
CaO 28.1 28.0 36.0 15.9 40.0 23.9 36.9 35.8
SiO.sub.2 32.2 32.0 32.0 36.0 28.0 27.8 32.8 31.8
P.sub.2 O.sub.5
15.6 15.6 15.5 15.6 15.5 15.5 15.9 15.4
ZrO.sub.2 4.0 4.0 4.0 4.0 4.0 4.0 2.0 5.0
Additives -- F.sub.2 0.5
F.sub.2 0.5
F.sub.2 0.5
F.sub.2 0.5
Na.sub.2 O 1.0
-- --
Temperature-Rising
3 3 3 3 3 3 3 3
Rate (°C./min.)
Retention 1000 1020 1000 1000 1000 1000 1000 1000
Temperature (°C.)
Retention Time (hr)
2 2 2 2 2 2 2 2
Type of Crystals
Apatite
Apatite
Apatite
Apatite
Apatite
Apatite Apatite
Apatite
Precipitated
Diopside
Diopside
Diopside
Forsterite
Diopside
Forsterite
Diopside
Diopside
Forsterite
Forsterite Diopside
Akermanite
Diopside
Forsterite
Forsterite
β-Tricalcium Forsterite
β-Tricalcium
β-Tricalcium
β-Tricalcium
Phosphate Phosphate
Phosphate
Phosphate
Bending 1800 2100 1500 -- -- -- 1600 1800
Strength (kg/cm.sup.2)
__________________________________________________________________________
Example No.
21 22 23 24 25 26 27
__________________________________________________________________________
MgO 11.7 28.1 28.1 28.1 28.1 28.1 28.1
CaO 35.1 24.1 24.1 24.1 24.1 24.1 24.1
SiO.sub.2 31.1 28.1 28.1 28.1 28.1 28.1 28.1
P.sub.2 O.sub.5
15.1 15.7 15.7 15.7 15.7 15.7 15.7
ZrO.sub.2 7.0 2.0 2.0 2.0 2.0 2.0 2.0
Additives -- TiO.sub.2 2.0
SrO 2.0
Ta.sub.2 O.sub.5 2.0
Nb.sub.2 O.sub.5
K.sub.2 O
B.sub.2 O.sub.3
2.0
Temperature-Rising
3 3 3 3 3 3 3
Rate (°C./min.)
Retention 1000 1000 1000 1000 1000 1000 1000
Temperature (°C.)
Retention Time (hr)
2 2 2 2 2 2 2
Type of Crystals
Apatite
Apatite
Apatite
Apatite
Apatite
Apatite
Apatite
Precipitated
Dopside
Diopside
Diopside
Diopside
Diopside
Dopside
Diopside
Forsterite
Forsterite
Forsterite
Forsterite
Forsterite
Forsterite
Forsterite
β-Trical-
β-Trical-
β-Tricalcium
β-Tricalcium
β-Tricalcium
β-Trical-
β-Trical-
cium cium Phosphate
Phosphate
Phosphate
cium cium
Phosphate
Phosphate Phosphate
Phosphate
Bending 1500 -- -- -- 1500 -- --
Strength (kg/cm.sup.2)
__________________________________________________________________________
The glass-ceramic of the present invention contains a large amount of apatite crystals necessary for chemically bonding to a bone and has a very high bending strength of from 1,500 to 1,800 kg/cm2. On the other hand, the conventional products such as a sintered body of a hydroxide apatite, a Na2 O--CaO--P2 O5 --SiO2 -based bioglass, a Na2 O--K2 O--MgO--CaO--P2 O5 --SiO2 -based glass-ceramic containing apatite crystals alone, and a glass-ceramic containing apatite and a wollastonite crystals have a bending strength ranging between 700 and 1,400 kg/cm2. It can be therefore understood that the glass-ceramic of the present invention has a very high bending strength. Furthermore, in the glass-ceramic of the present invention, the bending strength does not almost vary depending on the production lot. Thus, the glass-ceramic of the present invention is very useful as a material for an artificial bone and an artificial dental root.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
What is claimed is:
1. A high strength glass-ceramic having a bending strength from at least 1500 kg/cm2 and containing apatite crystals and at least one alkaline earth metal silicate crystal selected from the group consisting of diopside, forsterite and akermanite and having a composition consisting essentially of, in % by weight,8 to 34% MgO; 12 to 43% CaO; 25 to 40% SiO2 ; 10 to 25% P2 O5 ;with proviso of 90% or more MgO+CaO+SiO+P2 O5, 0 to 10% Li2 O; 0 to 5% Na2 O; 0 to 10% K2 O; 0 to 10% SrO; 0 to 10% B2 O3 ; 0 to 10% TiO2 ; 0 to 10% Nb2 O5 ; 0 to 10% Ta2 O5 ; and 0 to 3% F2,with proviso of 10% or less Li2 O+Na2 O+K2 O+SrO+B2 O3 +TiO2 +Nb2 O5 +Ta2 O5 +F2.
2. A process for producing a high strength glass-ceramic containing apatite crystals and at least one alkaline earth metal silicate crystal, which process comprisesmolding glass powders having a particle size of 200 mesh or less and having a composition consisting essentially of, in % by weight, 8 to 34% MgO; 12 to 43% CaO; 25 to 40% SiO2 ; 10 to 25% P2 O5 ;with proviso of 90% or more MgO+CaO+SiO+P2 O5, 0 to 10% Li2 O; 0 to 5% Na2 O; 0 to 10% K2 O; 0 to 10% SrO; 0 to 10% B2 O3 ; 0 to 10% TiO2 ; 0 to 10% Nb2 O5 ; 0 to 10% Ta2 O5 ; and 0to 3% F2,with proviso of 10% or less Li2 O+Na2 O+K2 O+SrO+B2 O3 +TiO2 +Nb2 O5 +Ta2 O5 +F2, heat treating the resulting molding in a sintering temperature range of the glass powders, and heat treating the molding in the temperature range where alkaline earth metal silicate crystals selected from the group consisting of diopside, forsterite and akermanite are formed.
3. A high strength glass-ceramic having a bending strength from at least 1500 kg/cm2 and containing apatite crystals and at least one alkaline earth metal silicate crystal selected from the group consisting of diopside, forsterite and akermanite and having a composition consisting essentially of, in % by weight,8 to 34% MgO; 12 to 43% CaO; 25 to 40% SiO2 ; 10 to 25% P2 O5 ; 1 to 10% Al2 O3, ZrO2 or bothwith proviso of 90% or more MgO+CaO+SiO+P2 O5 +(Al2 O3 +ZrO2), 0 to 10% Li2 O; 0 to 5% Na2 O; 0 to 10% K2 O; 0 to 10% SrO; 0 to 10% B2 O3 ; 0 to 10% TiO2 ; 0 to 10% Nb2 O5 ; 0 to 10% Ta2 O5 ; and 0 to 3% F2,with proviso of 10% or less Li2 O+Na2 O+K2 O+SrO+B2 O3 +TiO2 +Nb2 O5 +Ta2 O5 +F2.
4. A process for producing a high strength glass-ceramic containing apatite crystals and at least one alkaline earth metal silicate crystal, which process comprises(1) molding glass powders having a particle size of 200 mesh or less and having a composition consisting essentially of, in % by weight, 8 to 34% MgO; 12 to 43% CaO; 25 to 40% SiO2 ; 10 to 25% P2 O5 ; 1 to 10% Al2 O3, ZrO2 or bothwith proviso of 90% or more MgO+CaO+SiO+P2 O5 +(Al2 O3 +ZrO2), 0 to 10% Li2 O; 0 to 5% Na2 O; 0 to 10% K2 O; 0 to 10% SrO; 0 to 10% B2 O3 ; 0 to 10% TiO2 ; 0 to 10% Nb2 O5 ; 0 to 10% Ta2 O5 ; and 0 to 3% F2,with proviso of 10% or less Li2 O+Na2 O+K2 O+SrO+B2 O3 +TiO2 +Nb2 O5 +Ta2 O5 +F2, (2) heat treating the resulting molding in a sintering temperature range of the glass powders, and (3) heat treating the molding in the temperature range where alkaline earth metal silicate crystals selected from the group consisting of diopside, forsterite and akermanite are formed.
| 1984-12-06 | en | 1985-12-24 |
US-43110374-A | Neck exercising device
ABSTRACT
A neck exercising device in the form of a hat with a brim that supports one or more circular tracks in which a ball is free to be rolled around each track. The hat is strapped to the head of the operator and the head is continually moved to cause the ball to roll along the endless track. This head movement will strengthen the neck muscles of the operator. The hat brim may have a plurality of concentric circles, each representing the orbit of a planet in our solar system. The name of the planet as well as its distance from the sun is printed on the hat brim and this can be of an educational value to the person using the device.
0 United States Patent [191 [111 3,866,910
Herring Feb. 18, 1975 NECK EXERCISING DEVICE Primary Ex'aminer--Paul E. Shapiro 76 I t. B dD.H 712L d 1 men or g j g gg??? e Attorney, Agent, or FirmWllllam R. Piper [22] Filed: Jan. 7, 1974 I 57 ABSTRACT [21] Appl. No.: 431,103 A neck exercising device in the form of a hat with a brim that supports one or more circular tracks in H 7 which a hall is free to be rolled around each track. A63) 21/18 A63b 21/222 The hat [8 strapped to the head of the operator and [58,] Field of Search 7272/80, the head is continually moved to cause the ball to roll "I along the endless track. This head movement will 273/109 35/43 46/43 2/209'7 strengthen the neck muscles of the operator. The hat [56] References Cited brim may have a plurality of concentric circles, each representing the orbit of a planet in our solar system. UNITED STATES PATENTS The name of the planet as well as its distance from the 1,991,829 Uriwal sun is printed on the hat and this can be of an edg g fii k i ucational value to the person using the device. c ma e a 3,502,335 3/1970 Sholin 273/109 X 4 Claims, 5 Drawing Figures PATENIEU 3,866,910
Pmmw E 1 191a sum 2 or 2 F'IG'.5
DI! U 3 1 NECK EXERCISING DEVICE BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION An object of my invention is to provide a neckexercising device that is in the shape of a hat that can be strapped to the head of the wearer. The hat has a brim which supports a circular track in which a ball is free to roll. The person can tilt the head and neck to cause the ball to travel around the endless track. The continuous movement of the head and neck must be done in a controlled manner in order to keep the ball rolling around the track while preventing the ball from accidentally jumping out of the track. The controlled movement of the head and neck will exercise and strengthen theneck muscles.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a top plan view of the. hat and illustrates the circular track with a ball, representing the earth, being free to roll along the track.
FIG. 2 is a side perspective view of the device shown strapped to the head of a person using the device. The
dotted lines indicate the variouspositions of the head and hat necessary for causing the ball to travel along the circular track.
FIG. 3 is an enlarged transverse section taken through the hat along the line 3-3 of FIG. 1. The endless circular track is supported by the hat brim and the ball in the track is shown in section.
FIG. 4 is a side elevation of FIG. 3 where the hat has been rotated 90 about its vertical axis in order to illustrate the two strap portions that depend-from the crown of the hat and these can be buckled together under the chin of the wearer for holding the hat in place on the head.
FIG. 5 is a section through a modified form of the device and illustrates a pair of endless tracks arranged in a concentric manner and supported by the hat brim.
DESCRIPTION OF THE PREFERRED EMBODIMENTS In carrying out my invention I provide a neck exercising device in the form of a hat indicated generally at A and having a crown 1 and a brim 2. The brim may be of any desired diameter and it has an upturned flange 3 at its outer edge. If desired, the crown l of the hat A may be provided with a row of ventilation openings 4 that are preferably -arranged nearthe brim 2 and will permit air to circulate near the persons head when the hat is worn. A pair of straps B1 and B2 hang downwardly from the edge of the crown and are provided with the usual buckle for securing the straps under the chin of the wearer for holding the hat in place on the head as shown in FIG. 2.
A novel feature of the invention lies in the provision of a circular track C that extends around the crown l of the hat A and is preferably supported by legs 5 that are secured to the upper surface of the hat brim 2, see especially FIG. 3. The endless track is U-shaped in cross section and it receives a ball D that is free to roll around the track as the hat is tilted into different angular positions. FIG. 2 shows by dotted lines how the wearer of the hat A can sway his head so as to tilt the hat for propelling the ball D along the track. It requires a certain amount of dexterity for the person to move his head for keeping the ball rolling along the track without accidentally causing the ball to jump out of the track. However, if this should happen, the ball D would roll to the edge of the hat brim and be prevented from rolling off from the brim by the circular flange 3, see the dotted position of the ball D on the brim 2 in FIG. 2, where the ball has rolled against the flange 3.
The ball D may represent the planet earth as indicated in FIG. 2, and it is possible to provide data on the upper surface of the hat brim 2 to indicate the names and orbits of the other planets in the solar system, as well as giving the distance in miles these different planets are spaced from the sun, which might be represented by the crown l of the hat A. For-example, in FIG. 1 the orbits of the planets Venus and Mercury are shown lying within the circular track C which represents the orbit for the earth whichis the ball D. Next is the orbit of Mars followed by that of Jupiter. then Saturn, Uranus, Neptune and'Pluto. If a child uses the device to exercise his neck muscles, he can also learn the names of these different planets in the solar system as well as the tremendous distances they are removed from the sun.
As already inferred, the main purpose for the device is to cause the wearer of the hat to exercise his neck muscles by causing the ball D to roll along the track C. A game could be played between two or more children oradults, each one wearing the device and seeing how long he can keep the ball D rolling in the track C without jumpingout. The winner would of course be the one that keeps the ball rolling in the circular track for the longest period of time. The rotary motion of the head and neck in-keeping the ball moving along the track is beneficial to the person having a neck problem or having stiffness of the neck muscles. The device is therefore more than a toy.
A modified form of the invention is illustrated in the sectional view of FIG. 5. In this Figure the hat brim 2 supports not only the circular track C, but also another circular track E that is concentric with the endless track C. Another ball, not shown, and similar to the ball D would travel in the endless track E. In this case the person wearing the hat would'have to keep the two balls in the two'tracks moving along the tracks without jumping out. Any number of concentric tracks could thus be provided.
It is possible to make the brim 2 smaller in diameter and omit the data on top of the brim that indicates the different planets in the solar system and the number of miles they are removed from the sun. The invention can be used as a therapeutic as well as an amusement device by anyone.
I claim:
l. A device of the type described comprising:
a. a crown to fit over the head;
b. a brim extending from the crown;
c. a circular track extending around the crown; d. a ball receivable in the track and being movable therealong when the crown is mounted on a persons head and the person tilts and sways his neck and head in a manner to cause the ball to travel along the track;
e. the track is U-shaped in cross section; and
f. a plurality of legs extend from the brim and support the track in spaced relation from the crown.
2. A device of the type described comprising:
a. a hemispherical crown to fit over the head;
b. a brim extending from the crown with the plane of the brim lying substantially in the plane of the open end of the hemispherical crown, said brim having an upturned circular flange at its outer edge to prevent a ball from falling off from the brim;
c. a circular track extending around the crown and centric to said first mentioned circular track; and
b. a plurality of legs extending upwardly from said brim for supporting said second circular track above said brim.
4. The combination as set forth in claim 2: and in which a. said hemispherical crown has a plurality of ventilation openings arranged in a circular row and adjacent to said brim.
1. A device of the type described comprising: a. a crown to fit over the head; b. a brim extending from the crown; c. a circular track extending around the crown; d. a ball receivable in the track and being movable therealong when the crown is mounted on a person''s head and the person tilts and sways his neck and head in a manner to cause the ball to travel along the track; e. the track is U-shaped in cross section; and f. A plurality of legs extend from the brim and support the track in spaced relation from the crown.
2. A device of the type described comprising: a. a hemispherical crown to fit over the head; b. a brim extending from the crown with the plane of the brim lying substantially in the plane of the open end of the hemispherical crown, said brim having an upturned circular flange at its outer edge to prevent a ball from falling off from the brim; c. a circular track extending around the crown and being spaced therefrom; and d. a plurality of legs extending at right angles from said brim for supporting said track above said brim.
3. The combination as set forth in claim 2: and in which a. a second circular track extends around and is concentric to said first mentioned circular track; and b. a plurality of legs extending upwardly from said brim for supporting said second circular track above said brim.
4. The combination as set forth in claim 2: and in which a. said hemispherical crown has a plurality of ventilation openings arranged in a circular row and adjacent to said brim.
| 1974-01-07 | en | 1975-02-18 |
US-19896662-A | Separable fastener biasing system
Aug. 18, 1964 A. G. CARTER ETAL 3,144,696
SEPARABLE FASTENER BIASING SYSTEM Filed May 31, 1962 ANDREW e. CARTER HERMAN e. ALOFS INVENTORS United States Patent 3,144,696 SEPARABLE FASTENER BEASHQG SYSTEM Andrew G. Carter, Grand Rapids, Mich, and Herman G.
Alofs, 1512 Yorkshire SE, Grand Rapids, Mich; said Carter assignor to Andrew G. Carter and Harriett T.
Carter, a partnership doing business as Carter Engineering Company, Grand Rapids, Mich.
Filed May 31, 1962, Ser. No. 198,966 Claims. (Cl. 24-230) This invention has been developed in conjunction with a safety belt buckle mechanism of the type described in the United States patent of Andrew G. Carter, No. 2,965,- 942. The mechanism described in that patent includes separable buckle sections in normally overlapping relationship, with apertures in one section engaging abutments on the other for the transfer of the forces of belt tension. A cam maintains the locking engagement, and a lever pro- Vides for rotating the cam to release position permitting disengagement of the apertures and abutments. The present invention centers in the portions of such a mechanism associated with biasing the cam and lever to the locking position. The prior patent referred to above utilizes separate springs operating on the cam and lever, respectively, so that a light biasing can be applied to the cam and a heavy biasing to the lever (to resist inertia forces without complicating buckle engagement).
The cam and lever are coaxially mounted on the same shaft, and the biasing action is most effectively provided by torsion springs which are mounted on this same shaft. To establish any substantial torque transfer, a portion of the springs must be rotatively fixed with respect to the shaft, with the opposite end bearing on the cam or lever, as the case may be. The present invention provides for the angular fixing of one end of the spring with respect to the shaft in such a manner that facilitates the application of initial biasing on the assembly of the device. The invention is applicable either to the dual-spring arrangement in which separate springs are used on the cam and lever, or on a single spring in which the cam and lever receive their biasing action from the same spring. An example of the latter arrangement is shown in the earlier United States patent of Andrew G. Carter, No. 2,904,866. A single spring may be used to bias the cam and lever into locking position either with the cams formed integrally with the lever, or as a separate member.
In a device embodying this invention, the shaft not only performs the function of rotatively supporting the cam and lever, but also angularly positions a portion of the spring system through the engagement of a noncircular portion of the shaft with a similarly-shaped portion on the spring. This non-circular discontinuity is preferably merely a flattened chordal portion on the shaft, since this is easily provided by conventional rolling procedures utilized in the forming of metal rod stock. A non-circular hole (preferably of a shape to closely receive the cross-section of the shaft) is formed in preferably one side of the frame, the opposite end of the rod being rotatively received within the frame. The preferred form of the invention also utilizes the engagement of the shaft with the non-circular opening of the frame to fix the axial position of the shaft, as well as securing it rotatively. The several features of the invention will be analyzed in further detail through a discussion of the particular embodiment illustrated in the accompanying drawing. In the drawing:
FIGURE 1 is a side elevation, partially in section, showing a complete buckle mechanism in the engaged and locked condition.
FIGURE 2 illustrates the mechanism shown on FIG- release position shown in FIGURE 3.
FIGURE 3 illustrates the mechanism shown in FIG- URE 2, on a reduced scale, in side elevation, and partially in section.
FIGURE 4 illustrates a fragmentary perspective view of the buckle mechanism with the lever in the release position, and with the opposite buckle section not shown.
FIGURE 5 illustrates on an enlarged scale the perspective view of the end of the shaft.
FIGURE 6 is a fragmentary side elevation of the frame of the buckle, illustrating the D-shaped hole for receiving the shaft.
Referring to the drawing, the illustrated mechanism includes the opposite buckle sections generally indicated at 10 and 11, portions of these being in overlapping relationship, and having the abutments 12 on the section 10 interengaged with the apertures 13 on the section 11. A length of belt indicated at 14 is normally secured tothe section 11, and the belt 15 is adjustably received on the section Iii with an arrangement which forms no part of the present invention. The particular adjustable belt connection shown in the drawing is shown, described, and claimed in our copending application Serial No. 198,965, filed on May 31, 1962.
The buckled section 10 includes a frame 16 having spaced parallel sidewalls 17 and 18 provided with aligned holes receiving the shaft 19. A cam member 20 is rotatively mounted on the shaft 19, and has the portions 21 and 22 disposed to bear against the section 11 to main- .tain the interengagement of the abutments 12 and the apertures 13 when the mechanism is in the locking condition shown in FIGURE 1. A lever 23 is also rotatively mounted on the shaft 19, and has a portion 24 disposed to rotatively engage the portions 21 and 22 to rotate the cam member 20 to the release position, as shown in FIG- URE 3'. The lever 23 has spaced sidewalls 25 and 25a receivable between the sidewalls 1'7 and 18 of the frame 16, and also embracing the shaft 19. The lever 23 is preferably provided with a central bearing member 26 also engaging the shaft 19 to stabilize the position of the abutment 27 with respect to the shaft.
A relatively light spring 28 has one end 29 engaging the bar portion 3%) of the cam member 20 to apply a biasing action urging the cam to locking position. The opposite end of the spring 23 has coils of reduced diameter as shown at 31, and these are formed in a D-shaped configuration closely registering with the same general shape of the shaft 19 to effect a lock which prevents angular movement of that end of the spring with respect to the shaft. The constricted portion 31 of the spring will grip the flat 32 of the shaft very effectively, since the resilience of the spring wire can be utilized to remove the need for close tolerances. It should be noted that the remainder of the spring, from the constricted portion 31 to the end '29, is of sufiiciently large diameter to turn freely on the shaft 19.
The spring 33 is also mounted on the shaft 19, with the constricted end 34 engaging the shaft in the same manner as the constricted end 31. The hook-shaped extension 35 at the opposite end of the spring engages the abutment 27 on the cover 23 to apply the biasing action maintaining the lever in the position shown in FIGURE 1. The forces applied by the spring 33 require that the abutment 27 be held firmly with respect to the shaft 19, and this is the prime function of the central bearing portion 26. With this arrangement, the entire lever 23 may be formed of cast plastic material, Without danger that the lever will flex under the forces of the spring 33 enough to release the hook 35 into a space between the abutment 27 and the shaft 19.
The initial assembly of the mechanism shown in the drawing must be accompanied by a sufficient rotation of the shaft 19 to establish the desired biasing action in the springs 28 and 33. Preferably, the hole in the frame wall 17 is circular in shape, permitting full rotation of the shaft 19 until the shaft engages the wall 18 at the opposite side, where the hole 36 receiving the shaft is formed to closely receive the fiat 32 to establish a nonrotative engagement. A transverse notch 37 interrupts the flat 32, and the notch is of sufficient width to receive the thickness of the wall 18. After the shaft 19 has been rotated 21 sufficient amount to develop the necessary torsion in the springs 28 and 33 (with the end of the shaft adjacent, but not entering the hole 36), it is axially pushed into the hole 36 after being placed in proper angular alignment so that the fiat 32 will be properly received. As the axial movement of the shaft continues, a point is reached where the sidewalls of the notch 37 are disposed to receive the wall 18, and the shaft may be torsionally released at this point. The torque of the springs will induce a rotation of the shaft such that the bottom of the notch 37 will then engage the flat side of the hole 36. The engagement of the notch 36 will have the added effect of preventing axial displacement of the shaft 19.
The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claims. In these claims, it is our intent to claim the entire invention disclosed herein, except as we are limited by the prior art.
We claim:
1. A buckle mechanism comprising:
first and second buckle sections having portions in normally overlapping relationship and having interengaged aperture and abutment means, respectively, on said portions, one of said buckle sections including a frame having opposite side walls provided with aligned holes, one of said holes having a chordal portion, said one buckle section also having:
a shaft normally engaging said holes, said shaft having a chordal portion,
said shaft also having a transverse notch interrupting the chordal portion of said shaft and normally receiving the wall of said frame at said hole to fix the axial and angular position of said shaft with respect to said frame;
cam means rotatably mounted on said shaft and having portions angularly disposed in locking position to bear against the other of said buckle sections to maintain the interengagement of said aperture and abutment means, said cam means being rotatable on said shaft to a release position providing clearance for the disengagement of said aperture and abutment means;
a lever rotatably mounted on said shaft and having abutment means adjacent said shaft and a portion engageable with said cam means to rotate the same to release position,
said lever also having bearing means embracing said shaft adjacent said abutment means;
coil spring means having one end thereof provided with a chordal portion tightly embracing said shaft chordal portion to rotatively fix the said end with respect to said shaft, the opposite end of said spring means biasing said cam means and lever to locking position,
said spring means including separate springs, one of said springs engaging said cam means, and the other engaging said lever abutment means.
2. A buckle mechanism, comprising:
first and second buckle sections having portions in normally overlapping relationship and having interengaged aperture and abutment means, respectively,
on said portions, one of said buckle sections including a frame having opposite side walls provided with aligned holes, one of said holes having a chordal portion, said one buckle section also having:
a shaft normally engaging said holes, said shaft having a chordal portion,
said shaft also having a transverse notch interrupting the chordal portion of said shaft and normally receiving the wall of said frame at said hole to fix the axial and angular position of said shaft with respect to said frame;
cam means rotatably mounted on said shaft and having portions angularly disposed in locking position to bear against the other of said buckle sections to maintain the interengagement of said aperture and abutment means, said cam means being rotatable on said shaft to a release position providing clearance for the disengagement of said aperture and abutment means;
a lever rotatably mounted on said shaft and having a portion engageable with said cam means to rotate the same to release position; and
coil spring means having one end thereof provided with a chordal portion tightly embracing said shaft chordal portion to rotatively fix the said end with respect to said shaft, the opposite end of said spring means biasing said cam means and lever to locking position.
3. A buckle mechanism, comprising: first and second buckle sections having portions in normally overlapping relationship and having interengaged aperture and abutment means, respectively, on said portions, one of said buckle sections including a frame having opposite side walls provided with aligned holes, one of said holes having a discontinuity, said one buckle section also having:
a shaft normally engaging said holes, said shaft having a peripheral axial discontinuity,
said shaft also having a transverse notch forming axially spaced abutments interrupting the discontinuity of said shaft and providing an additional discontinuity thereon, and normally receiving the wall of said frame between axially spaced abutments at said hole to fix the axial and angular position of said shaft with respect to said frame;
cam means rotatably mounted on said shaft and having portions angularly disposed in locking position to bear against the other of said buckle sections to maintain the interengagement of said aperture and abutment means, said cam means being rotatable on said shaft to a release position providing clearance for the disengagement of said aperture and abutment means;
a lever rotatably mounted on said shaft and having a portion engageable with said cam means to rotate the same to release position; and
coil spring means having a plurality of coils at one end thereof provided with a discontinuity tightly embracing said shaft peripheral discontinuity and conforming thereto to rotatively fix the said end with respect to said shaft, the opposite end of said spring means biasing said cam means and lever to locking position.
4. A buckle mechanism, comprising: first and second buckle sections having portions in normally overlapping relationship and having interengaged aperture and abutment means, respectively, on said portions, one of said buckle sections including a frame having opposite side walls provided with aligned holes, at least one of said holes having a discontinuity, said one buckle section also having: a shaft normally engaging said holes, said shaft having a peripheral discontinuity cooperating with the discontinuity of said hole to fix the angular position of said shaft with respect to said frame;
means securing the said shaft axially with respect to said frame;
cam means rotatably mounted on said shaft and having portions angularly disposed in locking position to bear against the other of said buckle sections to maintain the interengagement of said aperture and abutment means, said cam means being rotatable on said shaft to a release position providing clearance for the disengagement of said aperture and abutment means;
a lever rotatably mounted on said shaft and having a portion engageable with said cam means to rotate the same to release position; and
coil spring means having a plurality of coils at one end thereof provided with a discontinuity tightly embracing said peripheral shaft discontinuity and conforming thereto to rotatively fix the said end with respect to said shaft, the
cam means rotatably mounted on said shaft and having portions angularly disposed in locking position to bear against the other of said buckle sections to maintain the interengagement of said aperture and abutment means, said cam means being rotatable on said shaft to a release position providing clearance for the disengagement of said aperture and abutment means;
a lever rotatably mounted on said shaft and having a portion engageable with said cam means to rotate the same to release position; and
coil spring means having a plurality of coils at one end thereof provided with a discontinuity tightly embracing said peripheral shaft discontinuity and conforming thereto to rotatively fix the said end with respect to said shaft, the opposite end of said spring means biasing said cam means and lever to locking position.
References Cited in the file of this patent UNITED STATES PATENTS opposite end of said spring means biasing said cam means and lever to lockin osition 387421 Ken 1888 g P 392,667 Devore Nov. 13, 1888 5. A buckle mechanism, comprising.
1,532,511 Meltz Apr. 7, 1925 first and second buckle sections having portions in cm H W Ila in relationshi nd h Vin t 1,719,422 Breltenbach y 1 n a Y PP g P a a g 9 2,278,650 Drinkwater Apr. 7, 1942 engaged aperture and abutment means, respectively,
2,483,303 Ryslck Sept. 27, 1949 on said portions, one of said buckle sections includ- 2,876,516 Cummings Mar. 10, 1959 mg a frame havlng opposite side Walls provided with 2,904,866 Carter Sept. 22, 1959 allgned holes, at least one of said holes having a 2 965 942 Carter Dec 27 1960 discontinuity, said one buckle section also having:
3,078,538 Brown Feb. 26, 1963 a shaft normally engaglng said holes, said shaft having a peripheral discontinuity; and FOREIGN PATENTS means securing the said shaft axially and angu- 105,689 Great Britain Apr. 26, 1917 larly with respect to said frame; 938,535 Germany Feb. 2, 1956
1. A BUCKLE MECHANISM COMPRISING: FIRST AND SECOND BUCKLE SECTIONS HAVING PORTIONS IN NORMALLY OVERLAPPING RELATIONSHIP AND HAVING INTERENGAGED APERTURE AND ABUTMENT MEANS, RESPECTIVELY, ON SAID PORTIONS, ONE OF SAID BUCKLE SECTIONS INCLUDING A FRAME HAVING OPPOSITE SIDE WALLS PROVIDED WITH ALIGNED HOLES, ONE OF SAID HOLES HAVING A CHORDAL PORTION, SAID ONE BUCKLE SECTION ALSO HAVING: A SHAFT NORMALLY ENGAGING SAID HOLES, SAID SHAFT HAVING A CHORDAL PORTION, SAID SHAFT ALSO HAVING A TRANSVERSE NOTCH INTERRUPTING THE CHORDAL PORTION OF SAID SHAFT AND NORMALLY RECEIVING THE WALL OF SAID FRAME AT SAID HOLE TO FIX THE AXIAL AND ANGULAR POSITION OF SAID SHAFT WITH RESPECT TO SAID FRAME; CAM MEANS ROTATABLY MOUNTED ON SAID SHAFT AND HAVING PORTIONS ANGULARLY DISPOSED IN LOCKING POSITION TO BEAR AGAINST THE OTHER OF SAID BUCKLE SECTIONS TO MAINTAIN THE INTERENGAGEMENT OF SAID APERTURE AND ABUTMENT MEANS, SAID CAM MEANS BEING ROTATABLE ON SAID SHAFT TO A RELEASE POSITION PROVIDING CLEARANCE FOR THE DISENGAGEMENT OF SAID APERTURE AND ABUTMENT MEANS; A LEVER ROTATABLY MOUNTED ON SAID SHAFT AND HAVING ABUTMENT MEANS ADJACENT SAID SHAFT AND A PORTION ENGAGEABLE WITH SAID CAM MEANS TO ROTATE THE SAME TO RELEASE POSITION, SAID LEVER ALSO HAVING BEARING MEANS EMBRACING SAID SHAFT ADJACENT SAID ABUTMENT MEANS; COIL SPRING MEANS HAVING ONE END THEREOF PROVIDED WITH A CHORDAL PORTION TIGHTLY EMBRACING SAID SHAFT CHORDAL PORTION TO ROTATIVELY FIX THE SAID END WITH RESPECT TO SAID SHAFT, THE OPPOSITE END OF SAID SPRING MEANS BIASING SAID CAM MEANS AND LEVER TO LOCKING POSITION, SAID SPRING MEANS INCLUDING SEPARATE SPRINGS, ONE OF SAID SPRINGS ENGAGING SAID CAM MEANS, AND THE OTHER ENGAGING SAID LEVER ABUTMENT MEANS.
| 1962-05-31 | en | 1964-08-18 |
US-7008087-A | Displacer arrangement for external combustion engines
ABSTRACT
An external combustion engine is provided with an engine body containing a cylinder, a working fluid within the cylinder, and a displacer piston reciprocable between two ends of the cylinder. A heat exchanger matrix permeable to said working fluid is provided at one end of the cylinder. The movement of the displacer establishes a flow path through a limited portion of the matrix such that the working fluid exchanges heat with different portions of the matrix at different displacer positions as the fluid is displaced between the two ends of the cylinder.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains generally to the field of external combustion engines such as Stirling cycle engines and is more particularly directed to a regenerative displacer and associated heat exchanger arrangement for subjecting the working fluid in such an engine to a thermodynamic cycle from which is derived a work output.
2. State of the Prior Art
In an external combustion closed cycle engine a sealed working fluid, usually a gas, is alternately displaced between a hot end and a cold end of a displacer cavity by a reciprocating displacer body such that it undergoes successive volumetric expansion and contraction cycles which drive a work piston or otherwise produce a work output.
Many different schemes have been devised for transferring heat to the working fluid during one portion of the displacer stroke and extracting heat from the fluid during another portion of the displacer stroke. Most commonly, the working fluid is passed through a heat exchanger conduit where heat is transferred by conduction between the working fluid and a heat exchanger medium. It is also conventional to provide a regenerator device in the fluid flow path between the hot and cold ends for storing heat as the working fluid passes through the cooling portion of the thermodynamic cycle.
In a conventional heat exchanger all of the working fluid displaced during each stroke of the displacer passes through a single heat exchanger conduit which must be relatively long in order to absorb sufficient heat from all the displaced fluid. As the flow of working fluid through the heat exchanger must necessarily be restricted in order to maintain good heat exchanging contact with the operative surfaces of the heat exchanger, a relatively large drop in working fluid pressure occurs across the heat exchanger. This pressure drop is particularly significant at the cold end of the displacer cavity where gas density is greatest and significantly reduces the overall efficiency of the engine. Various attempts have been made to minimize this pressure drop, such as the design illustrated in "Principles and Applications of Stirling Engines" Colin West, 1986, page 212. In this arrangement, a permeable heater is mounted on the displacer and is heated by conduction through a thin gas layer by a hot head at one end of the displacer bore. As the displacer moves from the cold end to the hot end, the working fluid passes through the porous heater and a regenerator also on the displacer, and is cooled by contact with a liquid cooled working piston. This engine, however, makes use of a very short displacer stroke and relies on large surface areas for heat transfer, in spite of which the work output achieved is minimal in relation to the engine's physical size and weight.
A continuing need exists for improved, more efficient displacer arrangements for Stirling cycle and similar engines.
BRIEF SUMMARY OF THE INVENTION
This invention advances the state of the art by providing a simple but efficient displacer arrangement for an external combustion engine of the type having an engine body, a displacer cavity in the engine body charged with a working fluid and a displacer reciprocable through a stroke between two ends of this cavity.
The improved low pressure drop heat exchanger includes a stationary heat exchanger matrix permeable to the working fluid and associated with one end of the displacer cavity. Working fluid is displaced between the two cavity ends responsive to reciprocating movement of the displacer through a flow path passing through the displacer. This flow path includes an instantaneous flow path through a limited portion of the stationary matrix. The instantaneous flow path is defined by seal elements and port openings on the displacer which place the matrix in fluidic communication with the opposite end of the displacer cavity. The instantaneous flow path follows the reciprocating movement of the displacer and is swept back and forth through the stationary matrix so that the working fluid exchanges heat with different portions of the matrix at different displacer positions along its stroke.
The stationary matrix can be a tube of porous heat conductive material cooled by any suitable means such as a coil carrying a collant fluid through the matrix. The matrix tube is arranged coaxially with and open to the cold space of the displacer cavity so that working fluid may pass between the cavity and the matrix interior substantially along the entire length of the matrix tube. The displacer has one end closed to the matrix side of the displacer cavity and another opposite displacer end open to the hot space of the displacer cavity. One or more ports on the displacer admit fluid flow between the matrix and the open end of the displacer, thus placing the matrix in fluidic communication through the displacer with the hot space of the displacer cavity. A lower dynamic seal is arranged radially between the displacer and the matrix and axially between the displacer ports and the closed displacer end, and an upper dynamic seal is likewise radially arranged but is axially between the ports and the open displacer end. The displacer reciprocates through the matrix such that at least the displacer ports and the lower seal are within the matrix tube at all points of the displacer stroke, while the open end of the displacer is open to the hot space but closed to the matrix. Working fluid displaced by the reciprocating displacer between the hot and cold spaces flows through the matrix. The working fluid tends to follow the path of least resistance through the matrix and therefore will tend to enter or leave the matrix tube in the immediate vicinity of the closed displacer end. The net result is that an instantaneous flow path is created through that axial segment of the matrix which at any given position of the displacer substantially lies between the displacer ports and the closed displacer end. The fluid flow path through the matrix therefore moves continuously together with the displacer, directing working fluid through axially consecutive sections of the matrix in step with the displacer movement. The instantaneous fluid flow path through the matrix remains relatively short and substantially fixed in length as measured between the displacer ports and the cold side of the displacer cavity for all positions of the displacer. As a result, the net length of the flow path through the heat exchanger for each portion of displaced fluid can be made relatively short without diminishing total heat transfer over the entire displacer stroke. As this instantaneous fluid flow path tracks the displacer through the cold matrix, heat from the working fluid is distributed through a relatively large matrix body. The shorter flow path results in a reduced drop in fluid pressure across the heat exchanger matrix and therefore improves the efficiency of the engine.
The novel system is approximately equivalent to several heat exchangers connected in parallel with displaced fluid being directed sequentially through each heat exchanger in turn during different portions of each stroke of the displacer. The total flow path length through each of the parallel heat exchangers is considerably less than would be required of a single heat exchanger of equivalent capacity.
This heat exchanger matrix arrangement is most beneficial at the cold end of the displacer cavity because of the greater gas density and viscosity there. The arrangement disclosed herein may be however reversed and adapted to operation at the hot end of the displacer cavity.
The heat exchanger matrix arrangement of this invention is particularly suited for use with a displacer mounted regenerator element within the fluid flow path between the displacer ports and the open hot end of the displacer. The regenerator is constructed in accordance with known principles to minimize heat losses in an axial direction and insulated about its radial periphery to minimize shuttle losses in the so-called "appendix gap" annulus between the displacer body and the cylinder bore.
Still further, a heat exchanger may be mounted at the hot end of the displacer and supplied with heat primarily by radiation from a radiant heater element at the hot end of the displacer cavity, such that working fluid passes through both the heat exchanger and the regenerator. The displacer mounted regenerator and heat exchanger may be insulated from each other with fluid permeable insulation.
Radiant heat transfer to the displacer mounted heat exchanger may be improved by coating the radiant surface with a thin layer of emissivity enhancing material specified below and characterized by an emissivity coefficient which increases with the temperature of the material. Such coating is particularly advantageous where the radiant heater is made of silicon carbide or similar high temperature ceramic having good thermal conductivity but an emissivity coefficient varying inversely with its temperature. The emissivity enhancing coating may also be applied to the insulation between the regenerator and displacer mounted heat exchanger to re-radiate heat back towards the heat exchanger and minimize thermal losses through the regenerator.
These and other advantages of the present invention will be better understood from the following detailed description taken with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial longitudinal section of a typical Stirling cycle engine illustrating the improved displacer arrangement and showing the displacer in top dead center position within the displacer cavity.
FIG. 2 is a view as in FIG. 1 with arrows indicating the flow path of working fluid displaced during displacer down stroke, the displacer being shown without a guide rod;
FIG. 3 is a view as in FIG. 1 but showing the displacer in bottom dead center position;
FIG. 4 is a view as in FIGS. 1-3 with arrows indicating the flow of working fluid during displacer upstroke and further showing a preferred arrangement of electromagnetic displacer drive coils.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a longitudinal segment of a Stirling cycle engine body 10 which includes a body section 12 and a hot head assembly 14 held in axially assembled relationship by an outer tubular shell 16 acting compressively on the ends (not shown) of the heater head 14 and body section 12. The joint between the heater head and engine body is sealed by a static ring seal 15. The heater head assembly 14 and body section 12 together define a cylindrical displacer cavity or bore 18 which is closed at a hot end 20 and is sealed at an opposite cold end 22 by a reciprocable work piston 24. The displacer cavity 18 is charged with a pressurized working gas such as hydrogen which is subjected to alternate heating and cooling cycles upon being displaced between a hot space 49 and a cold space 48 by a reciprocable displacer 26. The displacer 26 is fixed to the end of a guide rod 28 slidable within an axial bore 30 in the work piston and thus stably supported in centered relationship within the displacer bore 18. The displacer 26 is reciprocated between the hot end 20 and cold end 22 by a suitable displacer drive system (not shown) selected from among various drive systems known in the art.
The heater head assembly 14 includes a radiant heater element 32 having a radiant surface 34 which closes the bore 18 at the hot end. The heater element is heated by any suitable heat source (not shown) such as a gas burner or a flow of hot fluid such as molten sodium circulating through suitable heat exchanger conduits. The heater element 32 is thermally insulated from the engine body 12 and outer shell 16 by insulation rings 33 and 35. Both of these rings are encompassed and held in radial compression by ring 37 and further insulated by outer ring 39.
A tubular matrix 36 coaxially surrounds the cold space 48 of the displacer cavity and extends longitudinally from the cold end 22 to an intermediate point of the displacer bore. The matrix is of heat conductive material and may, for example, consist of copper pellets or particles sintered together to form a porous unitary tubular mass permeable to fluid flow both radially and axially. The matrix 36 is cooled by any appropriate means such as coolant fluid circulating through a coiled conduit 38 embedded in the matrix and having a coolant inlet 38a and coolant outlet 38b.
The matrix 36 has a cylindrical inner surface 40 separated from the displacer bore by a bearing tube 44 perforated by numerous holes 50 along its length such that the matrix is open to the cold space 48 substantially along its entire length. The bearing tube 44 is coaxially interposed between the matrix surface 40 and the displacer 26 and provides a smooth cylinder wall for the displacer.
The displacer 26 includes a cup 52 with a closed bottom 51 filled by a block 54 of inert filler material and fixed to the upper end of guide rod 28. The open upper end of the cup 52 carries a generally cylindrical assembly 56 of fluid permeable materials comprising a regenerator 56b, a heat shield 56c to which is applied a thermal emmissivity enhancing coating 56d and a heat exchanger 56a which has an upper end surface 58 facing the radiant heater surface 34. The lower end 60 of the permeable assembly 56 is spaced from the filler block 54 to define a chamber 53 in the displacer. A circumferential row of radial ports 62 is defined in the cylindrical wall of the displacer cup 52 which open the chamber 53 to fluidic communication with the matrix through whichever bearing sleeve holes 50 happen to be aligned with ports 62 at any given instant during the displacer stroke.
The displacer 26 carries an upper annular seal bearing and back-up ring assembly 43 and cylindrical insulation sleeve 64 which substantially prevent fluid flow into or out of the matrix 36 at points above the radial ports 62 for all positions of the displacer. The sleeve 64 encompasses the lower and intermediate portions of the permeable assembly 56 to confine gas flow through the regenerator 56b and heat shield 56c between the displacer chamber 53 and the heat exchanger 56a. The insulating sleeve 64 also reduces shuttle heat losses through the annular gap between the displacer body and cylinder bore 18. The displacer 26 also carries a lower annular seal beating and back up ring assembly 42 arranged radially between the displacer and the bearing sleeve 44 and longitudinally between the ports 62 and closed cup bottom 51. The dynamic seals 42 and 43 on the displacer cooperate with the bearing tube 44 and divide the displacer bore 18 into an upper hot space 49 and a lower cold space 48.
A fluid flow path is therefore defined between the hot space 49 and cold space 48 of the displacer cavity which beginning from the hot space 49 of the bore 18 passes through the displacer mounted permeable assembly 56 and chamber 53, then through radial ports 62 and aligned apertures 50 in the bearing sleeve 44 into the matrix 36 from which the gas is free to enter the cold space 48 of the displacer bore through all bearing sleeve openings 50 which lie below the lower dynamic seal 42 at any given instant in the stroke of the displacer 26.
Turning now to FIG. 2, the displacer 26 is shown moving downwardly within the bore 18 from the top dead center position of FIG. 1 towards the bottom dead center position shown in FIG. 3. As the displacer moves downwardly from the hot end 20 towards the cold end 22, working gas is displaced from the cold space 48 and forced into the porous cooling matrix 36, from which the only outlet is the path offered by the ports 62 in alignment with a particular set of holes 50 in the bearing tube 44. The gas therefore flows from the matrix 36 into the displacer chamber 53 and then upwardly through the permeable assembly 56 from where it is discharged at the upper end 58 into the hot space 49 of the displacer bore 18.
The fluid displaced from the cold space 48 will tend to follow the path of least resistance indicated by the arrows in FIG. 2 through the matrix 36 and into the displacer chamber 53. This path is obtained by entry into the matrix through the holes 50 below but nearest to the seal 42 and then exiting from the matrix 36 through the holes 50 in current alignment with the displacer ports 62. This flow path minimizes the distance through the matrix traversed by the gas.
As the displacer 26 moves downwardly through the matrix tube 36 the flow path through the matrix illustrated by the arrows sweeps along the matrix keeping pace with the displacer. In other words, the gas influx to the matrix from the cold space 48 will tend to move from one group of holes 50 to the next group of holes 50 as the displacer progresses downwardly because the path of least resistance will always be through the holes 50 nearest to the closed bottom of the displacer. At the same time, flow from the matrix 36 into the displacer will always occur through whichever holes 50 are aligned with the radial ports 62 at any given instant in the displacer stroke. The net result is that the length of the gas flow path from the cold space 48 through the cold matrix 36 and into the permeable assembly 56 remains constant throughout the displacer stroke, but this gas flow path moves through successive sections of the matrix tube following the position of the displacer along the axis of the matrix tube.
Turn now to FIG. 3 where the work piston 24 initially in top dead center position in FIGS. 1 and 2, is shown driven to bottom dead center position by expansion of the working gas at the hot end. The displacer has now reached bottom dead center and from this position the displacer is returned by any suitable displacer drive system towards top dead center. As the displacer 26 moves upwardly in the bore 18 in FIG. 4, working gas is now displaced from the hot space 49 through the permeable assembly 56, chamber 53, ports 52 and aligned holes 50 into the cold matrix 36 where the working gas is cooled, and finally into the cold space 48 of the displacer bore. As before, the gas will tend to follow the path of least resistance through the matrix which is again offered by the holes 50 nearest to the bottom side of the displacer seal 42. The flow path is thus the same as on the up stroke of the displacer described in connection with FIG. 2, except the direction of flow is now reversed. The overall length of the instantaneous flow path through the matrix 32 is also the same and substantially as shown by the arrows in FIG. 4. This instantaneous flow path moves upwardly and sweeps along the matrix tube together with the displacer.
From the foregoing it will be clear that as the displacer 26 moves longitudinally through the matrix tube in either direction the displaced working gas is circulated through sequentially adjacent axial sections of the matrix previously unexposed to hot working gas during each particular stroke of the displacer, and consequently able to quickly absorb substantial amounts of heat from the working gas over a relatively short instantaneous flow path through the matrix.
The permeable displacer assembly 56 preferably comprises a heater 56a, a porous heat shield 56c with a thin re-radiating type of ceramic coating 56d bonded to the upper face of the porous shield, and a regenerator 56b. The heater 56a may be formed of a block of porous graphite which is a good heat conductor and absorber of radiant energy at high temperatures. The porous body 56a functions as a heat exchanger by absorbing radiant heat from the hot head 32 and transferring the heat into the gas by conduction and convection as the gas flows through the displacer in either direction. The heat shield 56c may be of zirconia fiber felt insulation material, a good heat insulator which helps to reduce heat conduction losses between the heater element 56a and the regenerator 56b. The zirconia felt material is commercially available in porosity ranges of 50% to 70% for relatively low restriction to gas passage through the displacer. An emissivity enhancing ceramic coating 56d can be applied on the upper side of the porous heat shield 56c to re-radiate heat energy back into the heater 56a, thereby reducing radiant heat losses from the heater 56a into the regenerator 56b. The ceramic coating 56d is readily available commercially and subsequently will be described in more detail. The regenerator 56b can be fabricated from materials well known in the art, i.e. from fine wire copper and/or stainless steel screens.
In the alternative, the displacer assembly 56 could also be constructed as a single, unitary body of permeable honeycomb material which would combine the functions of heater element 56a and the regenerator 56b into a single operative matrix unit. For example, a preferred honeycomb material has a thin-finned, extruded isosceles triangular matrix surface as described in Transactions of the ASME, Journal of Engineering for Power, October, 1977, page 643. The referenced page is part of an article entitled, "The Effect of Fin Geometry and Manufacturing Process on Ceramic Regenerator Thermodynamic Performance", by C. A. Fucinari, Research Staff, Ford Motor Co., Dearborn, Michigan. The indicated honeycomb triangular matrix structure is available commercially in a lithium aluminum silicate material, Corning No. 5KC552XL, from Corning Glass Works, Ceramic Products Division, Automotive Products Department, Corning, New York 14830. The material is further described in Transactions of the ASME, Journal of Engineering for Power, Paper No. 77-GT-60, March, 1977, entitled "Aluminous Keatite--An Improved Rotary Ceramic Regenerator Core Material", by D. G. Grossman and J. G. Lanning. A flat radiation heat shield, (not shown in the drawings) to reflect heat back towards the hot end of the displacer chamber 53, could be applied to the upper face of the displacer filler block 54.
Heat radiated from the hot head 32 into the upper face of the displacer matrix 56 is efficiently absorbed whether this face is of porous material such as graphite or of a manufactured honeycomb structure because each pore or hoenycomb cell acts as a cavity radiator and absorbs a greater amount of heat than a surface equal to the pore or cell opening, thereby producing a radiation enhancement cavity effect.
When the displacer moves from the cold end to the hot end, the working gas flowing through the honeycomb matrix will absorb heat from the thin (0.005 inch) matrix fins, so that the upper portion of the matrix functions as an effective heat exchanger. As the heated working gas continues to flow downwardly through the honeycomb matrix, heat will be transferred from the hot gas into the progressively cooler thin matrix fins. Also, because of the thin honeycomb fin structure, conductive heat losses through the fin material from the hot to the cold end of the displacer will be relatively low. When the displacer moves from the hot end to the cold end, the opposite process occurs where the working gas flowing through the matrix 56 progressively absorbs heat from the thin fin walls of the honeycomb structure and leaves the upper heated end 58 at a high temperature. Therefore, a single permeable matrix body 56 may function as a combined heat exchanger and regenerator.
The inner radiant surface 34 of the heater head 32 is desirably coated with an emissivity enhancing material. Specifically, a coating 68 as shown in FIGS. 1 through 3, of a proprietary ceramic refractory product commercially available from Ceramic-Refractory Corporation, Rutledge Road, Transfer, Pennsylvania, 16154, is applied as shown in the drawings to the radiating surface of the heater head and extending along the inner wall surface of the displacer bore in the hot space 49. This ceramic refractory coating is available in various formulations characterized by an emissivity coefficient which increases with temperature. According to the manufacturer, these coatings have an emissivity rating of 0.90 at 1600 degrees Fahrenheit, 0.94 at 2000 degrees Fahrenheit, and at 3000 degrees Fahrenheit the emissivity value closely approaches black body radiation characteristics. The heater element 32 may be formed of silicon carbide ceramic which is a very good heat conductor but suffers from an emissivity value which tends to fall off at high temperatures, particularly at the high operating temperatures desired for Stirling engines of this type. At temperatures above 1500 degrees Fahrenheit, metal components are no longer practical and it therefore becomes necessary to resort to alternate materials for construction of the engine heater head assembly. While some ceramics easily withstand temperatures in the three to four thousand degree Fahrenheit range and higher, virtually all ceramics exhibit the characteristic of diminishing emissivity with increasing temperature. This problem is overcome according to this invention by providing the aforementioned emissivity enhancing coating 68 on the radiating surface 34 of the heater element 32. In this manner, the good heat conductivity of the ceramic block 32 is used to advantage for delivering heat to the radiant surface 34 from which it is radiated with the assistance of the coating 68 onto the displacer surface 58. The specified ceramic refractory coating is waterbased and easily applied to the radiant surface 34, and when dry forms a very thin layer 68.
FIG. 4 shows a preferred arrangement for an electromagnetic displacer drive coil assembly 70 arranged coaxially with the displacer bore intermediate the matrix 36 and the bearing sleeve 44. Also shown is an upper bearing seal ring assembly 43 which separates the side of chamber 53 from the hot space 49. In the illustrated example, the drive coil assembly 70 consists of two cylindrical coil winding layers 70a and 70b separated by an intermediate layer 72 of electrically non-conducting open mesh material. The individual turns of each winding layer 70a and 70b are slightly separated in an axial direction so as to allow substantially free flow of the working gas through the winding layers and the intermediate mesh layer 72, maintaining an unobstructed flow path through the drive coil between the matrix 36 and displacer chamber 18.
Particular embodiments of the present invention have been shown and illustrated for purposes of clarity and example only. Many changes, substitutions and modifications to the described embodiments will be readily apparent to those possessed of ordinary skill in the art without thereby departing from the spirit and scope of the present invention which is defined only by the following claims.
What is claimed is:
1. In an external combustion engine of the type having an engine body, a displacer cavity in said body, a working fluid in said cavity and a displacer reciprocable through a stroke between two ends of said cavity, the improvement comprising:a heat exchanger matrix permeable to said fluid and associated with one end of said displacer cavity; and means defining a flow path including an instantaneous flow path through a limited portion of said matrix through which flow path said fluid is displaced between said ends responsive to reciprocating movement of said displacer; said instantaneous flow path being swept through said matrix with movement of said displacer so that said working fluid exchanges heat with different portions of the matrix at different displacer positions along said stroke.
2. The improvement of claim 1 wherein said displacer is closed to one end of said cavity and open to the opposite end of said cavity, said matrix is open to said one cavity end, and said flow path includes port means on said displacer open to fluid flow between a limited portion of said matrix and said opposite cavity end, said port means opening to different portions of the matrix at different positions of the displacer.
3. The improvement of claim 1 wherein said flow path includes regenerator means on said displacer.
4. The improvement of claim 2 wherein said flow path further includes regenerator means on said displacer between said port means and said open displacer end.
5. The improvement of claim 2 wherein said means defining said flow path comprise seal means radially between said displacer and said matrix.
6. The improvement of claim 5 wherein said seal means are axially between said closed displacer end and said port means.
7. The improvement of claim 6 further including second seal means radially between said displacer and said matrix and axially between said port means and said open end of the displacer.
8. The improvement of claim 2 further comprising heat exchanger means on said displacer in said flow path for heating working fluid passing through said displacer and heater means for supplying heat to said heat exchanger means.
9. The improvement of claim 8 wherein said heater means comprises radiant heater means arranged at one end of said cavity opposite said matrix.
10. The improvement of claim 9 further comprising heat insulating means open to fluid flow between said heat exchanger means and said regenerator means on said displacer.
11. In an external combustion engine of the type having an engine body, a displacer cavity in said body, a working fluid in said cavity and a displacer reciprocable through a stroke between two ends of said cavity, the improvement comprising:a heat exchanger matrix permeable to said fluid and associated with one end of said displacer cavity; and means including seal means radially between said displacer and said matrix defining a flow path including an instantaneous flow path through a limited portion of said matrix through which flow path said fluid is displaced between said ends responsive to reciprocating movement of said displacer; said instantaneous flow path being swept through said matrix with movement of said displacer so that said working fluid exchanges heat with different portions of the matrix at different displacer positions along said stroke; heat exchanger means on said displacer in said flow path and radiant heater means arranged at one end of said cavity opposite said matrix for supplying heat to said heat exchanger means for heating working fluid passing through said displacer; and regenerator means on said displacer in said flow path between said heat exchanger matrix and said heat exchanger means.
12. In an external combustion engine of the type having an engine body, a displacer cavity in said body, a working fluid in said cavity and a displacer reciprocable through a stroke between two ends of said cavity, the improvement comprising:a heat exchanger matrix permeable to said fluid and open to one end of said displacer cavity; one end of said displacer being closed to said one end of said cavity and the other end of said displacer being open to the opposite end of said cavity, and port means in said displacer communicating a portion of said matrix with said opposite cavity end for defining a flow path including an instantaneous flow path through a limited portion of said matrix lying between said closed displacer end and said port means through which said fluid is displaced between said ends responsive to reciprocating movement of said displacer; said instantaneous flow path being swept through said matrix with movement of said displacer so that said working fluid exchanges heat with different portions of the matrix at different displacer positions along said stroke.
13. The improvement of claim 12 further comprising regenerator means on said displacer in said flow path between said port means and said open displacer end.
14. In an external combustion engine of the type having an engine body, a displacer cavity in said body, a working fluid in said cavity and a displacer reciprocable through a stroke between two ends of said cavity, the improvement comprising:a heat exchanger matrix permeable to said fluid and open to one end of said displacer cavity; one end of said displacer being closed to said one end of said cavity and the other end of said displacer being open to the opposite end of said cavity; port means in said displacer comunicating a portion of said matrix with said opposite cavity end; seal means between said displacer and said matrix and between said port means and said closed displacer end for diverting fluid flow between said port means and said one end of said cavity through a limited portion of said matrix lying between said closed displacer end and said port means; regenerator means on said displacer between said port means and said open displacer end; said seal means, port means and regenerator means together defining a flow path including an instantaneous flow path through said limited portion of said matrix through which said fluid is displaced between said cavity ends responsive to reciprocating movement of said displacer; said instantaneous flow path being swept through said matrix with movement of said displacer so that said working fluid exchanges heat with different portions of the matrix at different displacer positions along said stroke.
15. The improvement of claim 14 further comprising heat exchanger means on said displacer at said open end thereof in said flow path for heating working fluid flowing through said displacer, and radiant heater means at said hot end for radiantly supplying heat to said displacer mounted heat exchanger means.
16. The improvement of claim 15 further comprising heat insulating fluid permeable means in said flow path between said heat exchanger means and said regenerator means.
17. The improvement of claim 16 further comprising emissivity enhancing means coating said heat insulating means for re-radiating heat towards said heat exchanger means.
18. A regenerative displacer for a closed-cycle external combustion engine of the type having an engine body, a displacer cavity in said body, a working fluid in said cavity and a displacer reciprocable through a stroke between a hot end and a cold end of said cavity, the improvement comprising:regenerator means on said displacer; a cooling matrix open to the cold end of said cavity; and first means associated with said displacer defining a fluid flow path between said hot end and said cold end through said cooling matrix and said regenerator means, said first means directing fluid flow between said regenerator and said cooling matrix through successive portions of said matrix as said displacer moves between said hot and cold ends thereby to maintain a relatively short flow path with a low pressure-drop between said regenerator and said cold end.
19. The improvement of claim 18 wherein said cooling matrix has an inner surface open to the cold end of said cavity, said first means including port means on said displacer of restricted aperture in relation to said open inner surface for diverting fluid flow between the displacer and cooling through a relatively small longitudinal section of said matrix at any given point along the displacer stroke.
20. The improvement of claim 19 wherein an apertured bearing sleeve is interposed between said matrix inner surface and said displacer cavity.
21. A regenerative displacer for a closed-cycle external combustion engine of the type having an engine body, a displacer cavity having a tubular cavity wall in said body, a working fluid in said cavity and a displacer reciprocable through a stroke axis between a hot space and a cold space in said cavity, the improvement comprising:regenerator means on said displacer open to said hot space; a tubular fluid permeable cooling matrix open to said cold space; radial port means on said displacer for admitting fluid flow between said regenerator and said matrix thereby fluidically communicating said hot and cold spaces; and seal means between said displacer and said matrix for diverting flow of displaced fluid through an axially limited section of said matrix tube; said port means reciprocating axially relative to said matrix whereby fluid flow between said regenerator and said cold space is directed through axially successive portions of said cooling matrix during reciprocal movement of said displacer.
22. The improvement of claim 21 wherein an apertured bearing sleeve is interposed between said matrix and said displacer.
23. The improvement of claim 21 further comprising radiant heater means at said hot end for heating a heat exchanger provided on said displacer, said regenerator being intermediate said heat exchanger and said port means in the working fluid path.
24. The improvement of claim 23 wherein said heat exchanger and said regenerator means consist of a single fluid permeable body on said displacer having a radiation absorbing hot end exposed to said radiant heater means and a cooler end open to said port means.
25. The improvement of claim 24 wherein said radiant heater means include a heater head having a heat radiating surface and emissivity enhancing means on said radiating surface for improved radiant heat transfer to said hot sink.
26. The improvement of claim 25 wherein said emissivity enhancing means comprise a thin coating of ceramic material characterized by an emissivity coefficient which increases in proportion to temperature.
| 1987-07-06 | en | 1988-10-04 |
US-84123892-A | Detection assembly for an infrared monitoring system
ABSTRACT
A detection assembly is disclosed for an infrared monitoring system, comprising a strip of elementary infrared detectors for analyzing the background of a scene. The elementary detectors are image formation detectors having sensitive areas smaller than the optical spots produced by the hot objects to be detected. The assembly comprises circuitry adapted for grouping together the image formation detectors virtually into virtual monitoring detectors having sensitive areas adapted to said optical spot, the grouping together circuitry comprising circuitry for summation in elevation of p contiguous intermediate image formation detectors at the pitch of q detectors with overlapping of p-q intermediate detectors from one monitoring detector to the next and circuitry for summation in relative bearing of r image formation samples at the pitch of s samples with an overlap of r-s samples from one monitoring pixel to the next.
This is a continuation of application Ser. No. 07/525,332, filed May 17, 1990, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a detector assembly for a panoramic or sectorial infrared monitoring system.
Such a detector assembly may comprise an optical device, in the focal plane thereof, a detector strip--infrared photodiodes--for analyzing landscapes, or the background of a scene, hybrided to a pre-processing wafer containing charge transfer circuits, namely and essentially, input circuits associated with the photodiodes, for integrating their output currents, preamplification, filtering and multiplexing circuits and an output circuit forming an interface between the preprocessing wafer and a separate subsequent processing wafer.
When the analysis strip comprises photodiodes disposed in a plurality of lines of several photodiodes, the output current of each photodiode may then be processed in an integration circuit delivering a charge signal to a delay line in which it undergoes a given phase-shift, the charge signals delivered by all the delay lines associated with the photodiodes of the same line being added in a summator. The circuit in question is a delay-summation circuit called TDI (time delay integration).
The pre-processing wafer may also comprise base-clipping, evacuation and anti-dazzle circuits, the purpose of the latter function being to derive all the diode current when it is too high and to prevent a saturating current from adversely affecting the operation of the circuits of the processing wafer.
Infrared detector assemblies are used at the present time either in monitoring systems, or in image formation systems or in combined systems.
In image formation systems, for analyzing landscapes in real time, the elementary detectors of the analysis strip must be the smallest possible so as to obtain the best possible angular resolution and thus optimize the recognition and identification range performances.
The strips of the image formation systems may be of several types, for example and at least, the four following ones:
1. Strip comprising a series of elementary detectors aligned in columns and slightly offset with respect to each other. Such an arrangement involves interlacing of the scanning frames, i.e. a shift from one frame to the next, by an opto-mechanical device, which however leads to only a low overlapping rate.
2. Strip comprising two series of elementary detectors aligned respectively in two columns with, in each column, a shift between two adjacent detectors by the dimension of a detector, the shifts of the two columns being alternate. Such a geometrical arrangement also involves interlacing of the scanning frames to obtain an overlap rate close to 2.
3. Strip comprising more than two series, for example four, of detectors aligned respectively in as many columns with, in each column, between two adjacent detectors, the same shift as in the strip of the second type, the respective shifts of the columns being themselves slightly offset with respect to each other. Such geometry already has an overlap rate close to 2 and therefore does not require frame interlacing.
4. Strip comprising two mosaics of detectors disposed in m lines and n (for example four) columns, the respective lines of the two mosaics being alternate. This geometry, similar to that of type 2 provides a redundancy, each image element being analyzed successively by n detector elements.
In monitoring systems the elementary detectors of the strips used up to now were on the contrary sufficiently large to adapt themselves to the optical spots produced by the hot points of the objects (aircraft and other targets) to be detected and whose temperature is very much greater than that of the background of the scene.
As an example of monitoring strip geometry, two columns of detectors have been adopted spaced apart by the dimension of an optical spot produced by a pinpoint target and the detectors of the two columns being respectively slightly offset so as to obtain a certain overlap from one column to the next in order not to produce a signal loss and so to make the target extraction algorithms efficient.
The monitoring strips used up to now, with detectors having a relatively large sensitive area, have however two major drawbacks.
Produced on a small scale, their cost is first of all very high. Then, they do not use redundancy. With a redundancy of order n provided by an IR-CCD detector, saturation of the storage capacities and the processing circuits is rapidly reached because of the size of the elements and so of the amount of photons collected. Technology does not allow the dynamics of the processing circuits to be extended at will. It is necessarily limited, which inevitably leads to a saturation phenomenon which is quite prejudicial in monitoring in which it is desirable to detect objects whose temperature is very much greater than that of the background of the scene. For example, in the saturating temperature range, two hot points of respectively different temperatures can no longer be differentiated. The larger the sensitive areas of the detectors, the higher the fixed spatial noise, the higher should be the dynamics also and, since this is not so, the more the processing circuits risk being saturated.
The purpose of the present invention is then to overcome these drawbacks.
SUMMARY OF THE INVENTION
For this, the present invention provides a detector assembly for an infrared monitoring system for detecting hot objects on the background of a scene, comprising a strip of elementary infrared detectors for analyzing the background of a scene, which detector assembly is characterized by the fact that the elementary detectors are image formation detectors with sensitive areas smaller than the optical spots produced by the hot objects to be detected and it comprises means adapted for grouping together the image formation detectors virtually into virtual monitoring detectors with sensitive areas adapted to said optical spots.
The advantages of the invention are multiple. Advantage is taken of the low cost price of image formation detectors produced on a large scale. The maintenance costs are reduced because of the standardization of the detector module thus obtained. A large part of the associated electronic pre-processing and processing circuits may be used not only in the image formation systems but also in the monitoring systems.
From the saturation point of view, the drawbacks related to detectors with large sensitive areas are eliminated. The grouping together of the elementary detectors makes is possible to obtain virtual monitoring detectors having a sensitive area of any size, so adapted to any optical spot.
In the preferred embodiment of the detector assembly of the invention, geometry correction means are provided for, before grouping together into virtual monitoring detectors, grouping together the elementary image formation detectors into m contiguous intermediate virtual detectors aligned in a column, having the same sensitive area as the image formation detectors.
Still preferably, the grouping together means may be means for bi-directional grouping together, in relative bearing and elevation. These grouping together means may comprise means for summation, in the elevation direction, of p contiguous intermediate detectors at the pitch of q, less than p, detectors with consequently an overlap of (p-q) intermediate detectors from one monitoring detector to the next.
Because of the mechanical scanning, by a mirror pivoting, for example in the azimuth or bearing direction, and because of the electronic scanning for reading the strip of the m intermediate virtual detectors extending in the elevation direction, the intermediate detectors slide over one another, or overlap each other in twos, in the relative bearing direction. Thus, a relative bearing shift is obtained corresponding to intermediate detection "samples", as discussed in "Thermal Imaging Systems", by M. Lloyd, 1975, Chapter 9, pp. 369-387. The reason for such sliding is simple: between 20 the time of reading the intermediate detector no. 1 and the time ε after reading of detector no. m, the strip has moved relatively slightly in the relative bearing direction.
In this case, the grouping together means of the assembly of the invention may advantageously comprise relative bearing summation means similar to the elevation summation means, with overlapping of (r-s) intermediate samples from one monitoring detector, or pixel, to the next.
In this case, the ratio between the number of monitoring pixels and the number of image formation pixels is 1/qs.
Such bi-directional summation provides an appreciable gain:
attenuation is avoided of the signal from pinpoint targets situated at the spatial limit between two scanned lines by two contiguous detectors in the direction perpendicular to that of scanning; thus, the detection probability is increased;
the signal to noise ratio is increased by matching the geometry to the dimension of the optical spots;
the rate of processing the signals is reduced, in the case evoked by qs and thus, taking into account the technologies available, efficient target extraction algorithms may be used.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following description of the generation of monitoring cells in accordance with the invention, with reference to the accompanying drawings, in which:
FIG. 1 shows schematically the strip of detectors of the detection assembly of the invention;
FIG. 2 shows the strip of FIG. 1, after a first grouping together of the detectors (TDI summation);
FIG. 3 shows the strip of FIG. 2 after alignment of the detectors;
FIG. 4 illustrates the sliding in time of the strip of FIG. 3 and the generation of samples;
FIG. 5 shows the equivalent strip of the detector assembly, after generation of the virtual monitoring cells; and
FIG. 6 shows schematically the specific integrated circuit for generation of the monitoring cells.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The different components of the assembly of the invention will now be described, which have already been mentioned in the preamble to this description and are known to a man skilled in the art. The latter may moreover usefully refer to other French patent applications in the name of the applicant, such for example as the applications FR-A-2 591 349, 2 591 350, 2 591 409.
Let us consider a strip of image formation detectors of the 4th type described in the above preamble with, here, two mosaics 1, 2 offset in azimuth, of detectors di disposed, in each mosaic, in m/2 lines parallel to the azimuth direction, of uneven ranks in one 1, and of even ranks in the other 2, and in four columns parallel to the relative elevation direction (FIG. 1). Mosaic 1 thus comprises a first line of four detectors di 11 . . . di 14, a second line of detectors di 31 . . . di 34 . . . and a last line of detectors di m-1,1 . . . di m-1,4 and mosaic 2, a first line of detectors di 21 . . . di 24 . . . and a last line of detectors di m1 . . . di m4, the lines of the two mosaics alternating without overlap.
A first grouping together is achieved by TDI summation so as to group together the four image formation detectors of each line of each mosaic and obtain two columns 3, 4 of intermediate virtual detectors dl 1 . . . dl m-1 and dl 2 . . . dl m, respectively alternating from one column to the other and without overlap, the two columns being offset in time in relative bearing by Ke as depicted in FIG. 2.
A second geometry correction is made for grouping together the detectors of the two columns 3, 4 into a single column 5 of m detectors dl 1 . . . dl m, aligned in elevation, contiguous and having a sensitive area substantially equal to that of the image formation detectors di (FIG. 3).
From the intermediate detectors dl of column 5, or better still from the samples el, such as shown hatched in FIG. 4, the virtual monitoring detectors dv can be formed. It will be noted that a sample el has the same dimension in elevation as an intermediate detector dl and a smaller dimension in relative bearing because of overlapping due to sliding in relative bearing of strip 5 during its reading in elevation. Detectors dv are formed by summation in elevation of p samples el at a pitch of q and by summation in relative bearing of r samples el at the pitch of s. The virtual strip 5, extending in the elevation direction, is displaced--it is naturally a question of a relative displacement--perpendicularly to itself in the relative bearing direction. Thus, speaking of monitoring detectors, reference is actually made, in the relative bearing direction, to the image elements or pixels. In FIG. 5, the monitoring detectors dv i-1,j, dv ij`, dv i+l,j and dv i-1,j+1 have been shown in an exploded view, i representing the rank of the monitoring detector in the elevation direction, j the rank of the monitoring detector in the relative bearing direction, with p=4, q=r=3 and s=2.
The values of parameters p, q, r, s and k are programmable and the monitoring detectors or pixels are obtained by means of an automatic computing device formed here by a specific ASIC circuit integrated on a standard card.
The monitoring cells dv ij thus obtained are adapted in relative bearing to the optical spot and they are elongate in elevation, overlapping of the contiguous cells preventing loss of detection level if one optical spot overlaps two cells.
It will be readily understood that the automatic device must, by programming, have great flexibility so as to be usable in different configurations.
Thus, for example in elevation, each monitoring cell dv ij may also overlap the two cells dv i-1,j and dv i+1,j to which it is contiguous.
In FIG. 6 a portion 21 of the specific integrated circuit has been shown for generating the monitoring cells or pixels from image formation pixels, which comprises a block 22 of even cells and general cell block 23.
The image formation pixels di of even ranks, those at the right of FIG. 1, which are included at 4 in block 22, are grouped together there in relative bearing by a multiplexer 25 followed by an adder 6, whose output is connected to one of the inputs of the multiplexer 25 by a buffer memory 7. The pixels leaving block 2 at 8, those at the right in FIG. 2, enter a time retrieval RAM 9 whose output is connected to the input of block 23 and, more precisely, to the input of multiplexer 10 whose other input receives the image formation pixels di of uneven ranks, those at the left in FIG. 1. The output of multiplexer 10 of block 3 is connected to the input of an adder 11, whose output is connected to a third input of multiplexer 10 by a monitoring cell formation RAM 12.
Blocks 22 and 23 are connected to a sequencer 13 controlled by a ROM 14 containing the parameters p, q, r, s, k.
At the output of memory 9, the image formation pixels of even ranks are offset in relative bearing by k samples after time retrieval of the fourth image formation pixels of uneven ranks: this is the second geometry correction mentioned above with reference to FIG. 3.
All the image formation samples are added in elevation and in relative bearing in block 23, the sum of the samples transiting through a divider block 15, comprising in this case a PROM, connected to the output of block 23 and controlled by sequencer 13 for being divided, in elevation and in relative bearing, and supplying the monitoring cells of FIG. 5.
In actual fact, considering the interlacing of the computations, the specific integrated circuit comprises here three other portions, identical to the above described portion 21, connected in parallel to divider 15.
What is claimed is:
1. In an infrared radiation monitoring system for detecting hot targets in a background that are focused as respective optical spots of a given size in a focal plane of the system, a detector converter arrangement, comprising:a plurality of imaging detectors arranged along an azimuth direction and along an elevation direction in the focal plane for detecting the hot targets and for generating output signals indicative of the hot targets, each imaging detector having a sensor area smaller than the size of a respective optical spot; wherein the imaging detectors are arranged in two matrices or orthogonal rows and columns, each row and column containing multiple imaging detectors, and the matrices are offset relative to each other in a direction extending parallel to the columns; and converter means for processing the output signals and for grouping the imaging detectors along both the azimuth direction and the elevation direction to form an equivalent plurality of virtual monitoring detectors, each having a sensor area greater than the sensor area of a respective imaging detector and substantially equal to the size of the respective optical spot.
2. The detector converter arrangement according to claim 1, wherein the matrices have the same number of rows.
3. The detector converter arrangement according to claim 1, wherein the virtual imaging detectors are arranged in overlapping sub-groups.
| 1992-02-24 | en | 1993-07-20 |
US-35803089-A | Echo canceler-suppressor speakerphone
ABSTRACT
An echo canceler-suppressor speakerphone arrangement effectively addresses the limitations of regeneration and reverberant return echo inherent in the design of speakerphones. The tendency for regeneration is eliminated by employing adaptive echo cancellation in the receive path of the speakerphone arrangement to cancel speakerphone talker echo across a hybrid and thereby reduce the local loop gain to below unity. And the generation of a reverberant return echo to the far-end party is avoided by employing adaptive echo suppression in the transmit path of the speakerphone arrangement. Near-full and full duplex operation are regularly achieved since the receive path remains open at all times and the transmit path has its gain reduced only to the level necessary to suppress excessive reverberant return echo.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to audio systems and, more particularly, to speakerphone circuits which connect to an audio line for providing two-way voice communications.
2. Description of the Prior Art
The use of analog speakerphones have been the primary hands free means of communicating during a telephone conversation for a great number of years. This convenient service has been obtained at the price of some limitations, however.
There are two basic limitations that must be addressed in the design of analog as well as other speakerphones: a tendency for self oscillation or regeneration and the generation of a reverberant return echo to a far-end talker. Both limitations are present because of the high gain needed in both an outgoing or transmit channel and an incoming or receive channel of a speakerphone for acceptable hands free operation. The signal in the transmit channel must be amplified from a microphone associated with the speakerphone to a level high enough to comply with predefined telephone transmit specifications over a telephone's tip-ring connection. And the signal in the receive channel must be amplified from the tip-ring connection to a power level high enough to drive a loudspeaker also associated with the speakerphone. Undesirable coupling between these channels is provided by both a two-wire to four-wire hybrid coupling path and the loudspeaker-to-microphone acoustic coupling path which respectively comprise the electrical and acoustical portions of a local closed loop. This loop will typically have a gain much greater than unity and self oscillation will occur when uncompensated.
Because of the proximity of the loudspeaker to the microphone in most speakerphone arrangements, the speech level at the microphone resulting from speech at the loudspeaker is typically much greater than that produced by the speakerphone user or near-end party. This causes the far-end party's speech emanating from the loudspeaker to be coupled into the microphone and back through the telephone line to the far-end party. The result is a loud and reverberant return echo heard by the far-end party.
Historically, these limitations have been addressed in the design of conventional analog speakerphones. The operation of conventional analog speakerphones is well known and is described in an article by A. Busala, "Fundamental Considerations in the Design of a Voice-Switched Speakerphone," Bell System Technical Journal, Vol. 39, No. 2, March 1960, pp 265-294. Analog speakerphones generally use a switched-loss technique through which the energy of the voice signals in both the transmit and the receive channels are sensed and a switching decision made based upon that information. The voice signal having the highest energy level in either channel will be given a clear talking path and the voice signal in the other channel will be attenuated by having loss switched into its talking path. If voice signals are not present in either the transmit channel or the receive channel, the speakerphone typically goes to an "at rest" mode in which loss is switched into the transmit channel, the receive channel or both channels. The amount of voice switched loss inserted into each talking path by variable loss elements is determined by the margin necessary to guard against local loop self oscillation and is typically set by the position of the speakerphone volume control.
Far-end reverberant return echo is not normally a limitation in the operation of conventional analog speakerphones since more loss is switched into the transmit channel during the reception of receive speech to avoid self oscillation than is necessary to satisfactorily attenuate the return echo. Although these conventional analog speakerphones effectively address the two basic limitations, in so doing they inherently introduce others: noise induced false switching; transmit and/or receive lock-out caused by background conversations or intermittent noise; and initial clipping of syllables. Full duplex or "double talking" is also not possible with these speakerphones since voice switched loss is always inserted into one or the other of the two channels. In recent more sophisticated voice switched speakerphones, which under certain limited ideal electrical and acoustical conditions may operate in a near-full to full duplex mode, this return echo appears as a limitation and has to be addressed in the design of these speakerphones.
Another approach for addressing the basic limitations inherent in speakerphone design is through employing echo cancelers therein. In operation, an echo canceler continuously estimates an impulse response between the speakerphone's loudspeaker and microphone and subtracts an echo estimate from the return path. The theory of operation of echo cancelers and their use in reducing the effects of echoes and acoustic coupling between loudspeakers and microphones in close proximity is described in detail in a number of references. A few of these are: R. Ceruti and F. Pira, "Application of Echo-Canceling Techniques to Audioconference," Proc. of IEEE International Conference on Acoustics, Speech, and Signal Processing, March 1982; O. Horna, "Cancellation of Acoustic Feedback,"COMSAT Technical Review, Vol. 12, Fall 1982. pp. 319-333; Y. Itoh, U. Maruyama, N. Furuya, and T. Araseki, "An Acoustic Echo Canceler for Teleconference," Proc. of IEEE International Communications Conference, June 1985. pp. 46.6.1-46.6.5; and B. Widrow, S. D. Stearns, Adaptive Signal Processing, Prentice-Hall, 1985.
The adaptive filtering techniques of echo cancelers is thus known and has been employed in the transmit and receive channels in an echo canceling speakerphone. Through this approach, local loop loss can be effectively added to both the hybrid and acoustic coupling paths. The time span for the impulse response across the hybrid is typically on the order of 4 milliseconds and this echo may be canceled with a relatively short adaptive filter in an echo canceler which cancels the electrical portion of the loop signal provided through the hybrid coupling path. The impulse response of the acoustic coupling path is typically much longer, however, requiring a very long or cascadable adaptive filter in an echo canceler for canceling the acoustic portion of the loop signal provided through the loudspeaker-to-microphone coupling path. In addition, because acoustic paths are sensitive to any motion, the impulse response can vary in time as the speakerphone user moves, the speakerphone is moved or the acoustic environment changes, all resulting in little or no enhancement. When applied to the acoustic coupling path, therefore, the echo canceling technique can be somewhat unreliable and expensive to implement.
SUMMARY OF THE INVENTION
In accordance with the present invention, an arrangement of an echo canceler-suppressor speakerphone effectively addresses the limitations of regeneration and reverberant return echo inherent in the design of speakerphones. In accordance with one aspect of the invention, the tendency for regeneration is eliminated by employing adaptive echo cancellation in the receive channel to cancel speakerphone talker echo across the hybrid and thereby reduce the local loop gain to below unity. With this arrangement, the receive channel remains open at all times. Receive speech is never interrupted irrespective of whether the speakerphone user is talking or not.
In accordance with another aspect of the invention, the generation of a reverberant return echo to the far-end party is avoided by employing adaptive echo suppression in the transmit channel. A variable gain element in the transmit channel is controlled solely by the receive signal level at a loudspeaker associated with the speakerphone. Thus transmit channel gain is reduced only when a receive signal is present at the loudspeaker and the gain reduction is applied only to the extent necessary to suppress the reverberant return echo to an acceptable level.
In accordance with yet another aspect of the invention, the speakerphone is virtually duplex from the idle mode. There is no initial clipping of transmit or receive speech when either the near-end or far-end party begins speaking, regardless of speech level. Moreover, since the receive channel remains open at all times, "double talking" is also achieved during normal operation of the arrangement.
Thus this arrangement of implementing the speakerphone functions avoids the limitations inherent in speakerphone design without introducing the undesirable effects of conventional voice-switched loss and without the unreliability and associated cost of a very long adaptive filter for use as an acoustic echo canceler.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 depicts a general speakerphone circuit and two types of coupling that most affect its operation;
FIG. 2 is a block representation of the major functional components of an echo canceler-suppressor speakerphone operative in accordance with the principles of the invention;
FIG. 3 is a schematic of an amplifier and control section therefor for limiting the gain of the amplifier, both being employed in this invention; and
FIG. 4 depicts a flow chart illustrating the operation of the speakerphone of FIG. 1.
Throughout the drawings, the same elements when shown in more than one figure are designated by the same reference numerals.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown a general speakerphone circuit 100 to which the invention can be applied. This circuit illustrates the hybrid or electrical and acoustical coupling that most affect the operation of a speakerphone being employed in a telephone connection. A hybrid 110 connects transmit and receive channels of the speakerphone to a telephone line whose impedance may vary depending upon, for example, its length from a central office, as well as other hybrids in the connection. And the hybrid 110 only provides a best case approximation to a perfect impedance match to this line. A part of the signal in the transmit channel to the hybrid 110 thus returns over the receive channel as hybrid coupling or sidetone. With this limitation and the inevitable acoustic coupling between a loudspeaker 111 and a microphone 112, transmit and receive loss controls 113 and 114 are inserted in the appropriate channels to avoid regeneration or self oscillation.
Referring next to FIG. 2, there is shown in accordance with the invention an echo canceler-suppessor speakerphone including circuit components suitable for use in the general speakerphone circuit 100 of FIG. 1. As illustrated, the hybrid 110 is employed for connecting the speakerphone configured in a four-wire circuit configuration with a trip-ring line 201 to a central office. It is to be understood that if the speakerphone was implemented in a digital telephone environment, the hybrid 110 would not be required. Speech from a speakerphone user is picked up by the microphone 112 and coupled through the transmit channel via a microphone preamplifier 212, an echo suppression variolosser 214 and a transmit channel amplifier 213 to the hybrid 110. Transmit channel gain is provided by the microphone preamplifier 212 and the transmit channel amplifier 213. Speech from a far-end party is received by the hybrid 110 and coupled through the receive channel via a receive channel amplifier 222, an analog-to-digital converter 224, an echo canceler 225, a digital-to-analog converter 226, a volume control 300 and a power amplifier 223 to the loudspeaker 111. Receive channel gain is provided by the receive channel amplifier 222 and the power amplifier 223 along with the volume control 300.
After amplification by the receive channel amplifier 222, the speech from the far-end party is coupled to the analog-to-digital converter 224 where it is converted to a digital signal and provided to a first input to the echo canceler 225. This digital signal is also provided to a control unit 231. This control unit 231 provides control functions for the speakerphone, some of which are described in detail later herein. A digital signal processor having part number TMS 32010 is available from Texas Instrument and is suitable for use as control unit 231 with the appropriate coding.
After amplification by the transmit channel amplifier 213, a sample of the speech signal in the transmit channel is similarly coupled to an analog-to-digital converter 232 where it is converted to a digital signal and provided as a reference signal to a second input to the echo canceler 225. This sample of the speech signal in the transmit channel is also provided to the control unit 231. The control unit 231 compares the relative levels of the two signals provided by analog-to-digital converter 224 and analog-to-digital converter 232. If the signal from analog-to-digital converter 224 is higher than the signal from analog-to-digital converter 232, the control unit 231 assumes that speech is being received by the hybrid from a far-end party. If, on the other hand, the speech from analog-to-digital converter 232 is higher than the signal from analog-to-digital converter 224, the control unit 231 assumes that speech is being provided in the transmit channel by the near-end party. Certain other conditions are possible and are considered by the control unit 231 in combination with the relative levels of these two signals. These other possibilities are shown in the flow chart of FIG. 4 and also described later herein.
The sample of the speech signal in the transmit channel is used by the echo canceler 225 to generate a replica of the impulse response of the speech in the hybrid coupling path which is subtracted from the combination of the far-end speech plus the local echo provided by the hybrid 110 to yield only the far-end speech as the output from the echo canceler 225. In this manner, the transmit signal provided across the hybrid coupling path into the receive channel is canceled.
In the operation of the echo canceler 225 in greater detail, a replica of the echo signal is generated by passing as a reference input the sample of the speech signal from the transmit channel through an adaptive digital transversal filter in the canceler. Coefficients in the filter are updated based on minimizing the difference between the echo canceler output and the reference input. An echo canceler error signal continually provided to the control unit 231 by the echo canceler reflects this difference. This same error signal is used by the canceler in updating the coefficients in the filter.
The duration of the impulse response of the echo path determines the number of taps necessary in the filter. At an 8 KHz sampling rate, for example, 64 taps (8 milliseconds) are generally sufficient to cancel the echo. When the transfer function of the filter is adapted to be the same as that of the hybrid coupling path, complete cancellation of the echo is achieved with negligible measurable error. In that the canceler is not provided in advance with a transfer function of the hybrid coupling path, it continuously adapts the coefficients of the filter when adapting is permitted by the control unit 231. There are many echo cancelers presently available and suitable for use in implementing the canceler function required by the canceler 225. One such canceler is an AT&T 257BD cascadable echo canceler.
The limitation associated with the generation of a reverberant return echo to a far-end talker is addressed in the echo canceler-suppressor speakerphone by employing an adaptive variolosser 214 in the transmit channel. This variolosser 214 inserts a variable amount of loss in the transmit channel in response to the level of receive speech present at the loudspeaker 111. A sample of the signal provided to the loudspeaker 111 is rectified and filtered by a rectifier and filter section 233 to achieve a very fast (less than 1 millisecond) attack time and a release time consistent with typical room reverberation time and the burst nature of speech (approximately 150 milliseconds). The rectified and filtered signal is then converted to a logarithmic control signal by a logarithmic amplifier 234.
A threshold detector 235 receives the output of the logarithmic amplifier 234 and prevents low level signals at the loudspeaker 111 from causing a reduction in the transmit channel gain. Once the echo canceler 225 has adapted, such low level signals result in negligible far-end return echo and are therefore not coupled to the echo suppression variolosser 214 by the threshold detector 235. The threshold of threshold detector 235 is preset to a level dependent upon the acoustic coupling between the loudspeaker 111 and the microphone 112 in a particular environment.
In the absence of receive speech or when receive speech at the loudspeaker 111 is at a very low level, speech from the near-end party at the microphone 112 is amplified to a first level by the preamplier 212, passes through the echo suppression variolosser 214 unattenuated, amplified to a second level by the transmit channel amplifier 213 and then coupled to the tip-ring line by the hybrid 110. When the receive speech level at the loudspeaker 111 exceeds the threshold of the threshold detector 235, the transmit channel gain is reduced by the variolosser 214 in proportion to the signal level at the loudspeaker. Since both the transmit and receive channels are fully open in the absence of speech, no thresholds have to be overcome in either direction before full gain is achieved. This speakerphone is therefore at full duplex in the idle mode and clipping of initial syllables does not occur. Moreover, receive speech is never interrupted whether the near-end party is talking or not since during normal operation the receive channel remains fully open. This advantage is especially apparent during teleconferencing when more than one person is using the speakerphone and background conversations are occurring. In addition, in the presence of receive speech, only as much loss is inserted into the transmit channel as is necessary to reduce return echo to the far-end party to an acceptable level. The amount of loss inserted by the variolosser 214 is determined not by the local loop gain, therefore, but rather by the current receive speech level at the loudspeaker 111.
In the operation of the echo canceler-suppressor speakerphone, high volume control settings in conjunction with low level receive speech tend to produce echo canceler filter coefficient divergence. This filter coefficient divergence could possibly result in local loop regeneration. This instability is most likely to occur if these conditions are met before the echo canceler has been allowed to adapt to near-end generated speech in the transmit channel. By way of example, at high volume control settings, gain exists between the echo canceler receive channel input and the transmit channel reference input via the acoustic coupling path. During normal operation of the speakerphone, receive channel signals appearing at a level above the threshold in the threshold detector 235 are coupled to the echo suppression variolosser 214 which inserts sufficient loss to eliminate this gain. Receive channel signals below this threshold, however, are blocked by the threshold detector 235 and do not insert loss into the echo suppression variolosser 214. Hence, these low level signals are coupled from the receive channel into the transmit channel via the acoustic coupling path without a corresponding level of loss being inserted into the variolosser 214. If the gain provided by these low level signals is left uncompensated, the echo canceler 225 attempts to adapt to this receive speech in the transmit channel.
In order to prevent the echo canceler 225 from attempting to adapt to this speech, a reduction in the maximum level of the receive channel gain is provided. The basis for this reduction is determined by the control unit 231 which senses that the speakerphone might become unstable. This reduction is on the order of 10 dB less than the maximum gain that might otherwise be set by the user controlled volume control 300 and is implemented to prevent the possible occurrence of local loop regeneration. This is required if the echo canceler 225 has not yet adapted to the near-end generated speech in the transmit channel or is required to readapt as determined by control circuit 231.
Referring next to FIG. 3, there is shown the schematic of an amplifier and control section suitable for use in volume control 300 for preventing local loop regeneration in the speakerphone. A received signal from the digital-to-analog converter 226 shown in FIG. 2 is provided over line 301 to the non-inverting input of an amplifier 310. This signal is coupled through capacitor 311 and serially arranged resistors comprising variable resistor 312 and resistor 313. Feedback resistance comprising serially arranged resistor 314 and resistor 315 along with reference resistor 316 are also included as circuitry associated with the amplifier 310. The output of amplifier 310 is coupled to the power amplifier 223, shown in FIG. 1 over line 303.
Variable resistors 312 and 314 are ganged together and comprise the user adjustable volume control. Bridged across variable resistor 314 is an analog switch which provides the functionality of a single pole, double throw switch 320, as shown. The position of this switch is determined by the control unit 231 which provides a volume control set and reset flag over line 302. The amplifier thus operates at two variable levels, a first level determined by the speakerphone user and a second level designed to maintain stability in the local loop of the speakerphone while the echo canceler 225 is adapting.
In response to the set flag, the speakerphone operates at the volume level set by the speakerphone user. Responsive to the reset flag, the switch 320 reduces to a reduced variable level the maximum gain from the amplifier 310 by limiting the maximum level of feedback resistance insertable by the speakerphone user across the amplifier 310. Amplification in this type of amplifier is such that the greater the feedback resistance, the greater the amplification from the amplifier.
In order to maintain stability in the operation of the speakerphone, the volume control 300 limits the maximum level to which signals in the receive channel may be amplified before the echo canceler 225 has had a chance to adapt. After stabilization and during normal operation, the speakerphone user may select the normal operating range of volume control levels. Since the upper end of this range is much greater than is permitted during adapting by the echo canceler, operation in this range is prohibited by the control unit 231 until after the echo canceler 225 has adapted.
An explanation as to how this arrangement provides for a variable volume control at both a high level volume range and a reduced volume level range is provided. During normal operation in the high level volume level range (set flag activated), as the tap on variable resistor 312 is moved toward the capacitor 311 and the tap on variable resistor 314 is moved toward the output of the amplifier 310, the gain at the output terminal of amplifier 310 accordingly increases to its maximum possible level. During operation in the reduced volume level range (reset flag activated), moving the tap on variable resistor 312 towards the capacitor 311 still causes an increase in the output voltage of the amplifier 310. As the tap on variable resistor 314 moves toward the output terminal of the amplifier 310, however, the gain at the output of amplifier 310 due to this variable resistor is decreased accordingly since in this operating configuration the feedback resistance decreases as the volume control is increased. The net effect is that the output of the volume control unit 300 increases somewhat, but at a greatly reduced level from that available during operation in the high volume level range.
If during normal operations, the control unit 231 detects that the speakerphone might become unstable, the control unit requires the echo canceler to readapt to the transmit speech. For this condition, and with reference again to FIG. 2, the control unit 231 provides the reset flag to the switch 320 reducing the gain available in the receive channel from the volume control 300. The control unit 231 determines when to have the echo canceler 225 readapt to transmit speech by monitoring the signal level at the output of transmit channel amplifier 213, provided by digital-to-analog converter 232, also the signal level presented to the echo canceler 225 by the analog-to-digital converter 224, and also the echo canceler error signal provided by the echo canceler 225. The conditions that in combination cause the echo canceler 225 to readapt are: when the output of the transmit channel amplifier 213 exceeds a certain threshold; when the relative level of the signal presented to the echo canceler 225 by the analog-to-digital converter 224 is less than the signal at the output of the transmit channel amplifier 213; and when the difference between the level of the output of the transmit channel amplifier and the echo canceler error signal is less than a certain threshold. The control unit 231, detecting the presence of these conditions for a predefined period, assumes that an unstable state exists and thus requires the echo canceler 225 to readapt to a signal in the transmit channel from the near-end location.
For most normal mid-range operating volume levels, no appreciable change in the gain of the amplifier 310 to prevent self oscillation is necessary. And no change is necessary at the low-range operating volume levels. During operation of the speakerphone at these levels, the perceived level of receive speech provided to a near-end user while the echo canceler is adapting and after it has adapted is the same. The volume level change is apparent only when the user has the volume control set at the upper end of of its normal operating range.
Referring now to FIG. 4, there is shown a flow chart illustrating a processing task performed by the circuitry of FIGS. 2 and 3. This processing operation will be more easily understood if the circuitry of FIGS. 2 and 3 are both referenced in combination with this flow chart. The processing task is advantageously determined by a process or program stored in control unit 231. The processing task is one of many performed by the control unit 231 and is therefore entered once each 125 microseconds.
The processing task is entered at decision 401 where it determines if far-end speech is present. If far-end speech is present, the process advances to step 402 where the coefficient freeze flag to the echo canceler 225 is set and then the processing task is exited. In this step 402, the speakerphone is prevented from adapting whenever far-end speech is present. This is achieved by freezing the coefficients in the echo canceler in their existing positions. If at step 401, far-end speech is not present then the process is allowed to advance to step 403. At step 403, the process calculates the power or magnitude of the echo canceler error and then advances to decision 405. At this decision 405, the process determines if the echo canceler has adapted by comparing the error calculated in step 403 with that of the canceler reference input. If the echo canceler has adapted, the process next advances to step 406 where an unadapted counter is set.
The unadapted counter along with an adapted counter are both used in the processing task for providing control functions for the speakerphone. In operation, the unadapted counter is preset to a given count once the process indicates that the speakerphone is adapted as in decision 405. To guard against a few samples causing the echo canceler to prematurely readapt, multiple samples reflective of such need are required before the echo canceler is configured permitting it to adapt. In one illustrated embodiment, the unadapted counter is preset to a count of 1,024. In this embodiment, therefore, 1,024 samples indicating that the speakerphone is unadapted must be provided before the unadapted counter is decremented to zero. Since a sample may be provided each time the processing task is performed (every 125 microseconds), the minimum time required to decrement the unadapted counter to zero is 0.128 seconds.
To similarly guard against a few samples from the echo canceler prematurely indicating that it has adapted, multiple samples reflective of such need are also required before it is considered to have adapted. In the illustrated embodiment, the adapted counter is set at a count of 8,192. Thus 8,192 samples indicating that the speakerphone is adapted must be provided before the adapted counter is decremented to zero. Since a sample may be provided each time the processing task is performed, the minimum time required to decrement the adapted counter to zero is 1,024 seconds.
After the processing step 406, the process next advances to decision 407 where it is determined if the adapted counter is set at zero. If set to zero, the process advances to step 409 where the volume control set flag is activated and the coefficient freeze flag is set. The processing task is then exited. If the adapted counter is not set to zero the process advances to step 408 where the adapted counter is decremented and then the processing task is exited.
Referring once again to decision 405, if the echo canceler is not adapted, the process advances to step 410 where the adapted counter is set. From this step, the process advances to decision 411 where a determination is made as to whether the volume control set flag is activated. If the volume control set flag is not activated, the process advances to step 412 where the coefficient freeze flag is reset and then the processing task is exited. Resetting the coefficient freeze flag unfreezes the coefficients in the echo canceler 225 and permits it to adapt as is possible when near-end generated sounds are present. If the volume control flag is activated at step 411, however, the process then advances to decision 413 where a determination is made as to whether low level receive signals are present. If low level receive signals are present, the process advances to step 409 where the volume control set flag is activated and the coefficient freeze flag is set and the processing task then exited. If low level receive signals are not present at step 413, the process advances to decision 414 where it is determined if the unadapted counter has decremented to zero. If the unadapted counter is not set at zero, the process advances to step 416 where the unadapted counter is decremented. The processing task next advances to step 409 where the volume control set flag is activated and the coefficient freeze flag is set. If in step 414 the unadapted counter is set at zero, however, the processing task advances to step 415 where the volume control reset flag is activated permitting operation at the reduced maximum volume levels set by the control unit 231 and the coefficient freeze flag is reset enabling the coefficients in the canceler 225 to readapt as appropriate to near-end generated sounds in the transmit channel. The processing task is then exited.
Although a specific embodiment of the invention has been shown and described, it will be understood that it is but illustrative and that various modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. An example of such a modification is a speakerphone employing a single digital signal processor which is capable of implementing both the echo cancellation function and the control logic function. It is to be understood, therefore, that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
What is claimed is:
1. An apparatus for processing speech signals for a communication line, the apparatus including a transmit signal path for transmitting speech signals to the communication line and a receive signal path for receiving speech signals from the communication line, the apparatus comprising:loss insertion means in the transmit signal path for attenuating the speech signals for transmission over the communication line; echo canceling means in the receive signal path for canceling transmit speech signals appearing in the receive signal path; receive speech level adjusting means for controlling the level of the speech signals in the receive signal path; means for measuring an estimate of both the level of speech signals received from the communication line and the level of transmit speech signals appearing in the receive signal path; and loss adjusting means operably responsive to the measuring means for proportionally adjusting the level of attenuation inserted by the loss insertion means into the transmit path in response to the estimate of the level of the speech signals received from the communication line, and the receive speech level adjusting means being operably responsive to both the echo canceling means and the measuring means for inserting attenuation into the receive signal path in response to uncanceled transmit speech signals appearing in the receive signal path.
2. The apparatus for processing speech signals as in claim 1 wherein the loss adjusting means includes a predetermined threshold coupling level and comparison means for comparing the speech signal received from the communication line with the threshold coupling level, the loss adjusting means being operable for adjusting the level of attenuation inserted by the loss insertion means into the transmit path when the level of the received speech signal exceeds that of the threshold coupling level.
3. The apparatus for processing speech signals as in claim 1 further including means for measuring the level of the transmit speech signals provided by the apparatus to the communication line for transmission thereover.
4. The apparatus for processing speech signals as in claim 3 wherein the receive speech level adjusting means is operable both in a first condition and in a second condition, operation of the receive speech level adjusting means in the first condition providing a first range of available signal levels and in the second condition providing a second reduced range of available signal levels.
5. The apparatus for processing speech signals as in claim 4 further comprising control means for controlling the receive speech level adjusting means, the control means configuring the receive speech level adjusting means for operation in either the first condition or the second condition.
6. The apparatus for processing speech signals as in claim 5 wherein the echo canceling means requires a period of time to adapt for canceling the transmit speech signals appearing in the receive signal path, the echo canceling means providing an error adapting signal to the control means, responsive to this error adapting signal and to receipt of select relative signal levels from the transmit speech level measuring means and the receive speech level measuring means, the control means determining the level of adaption by the echo canceling means to the transmit speech signals, the control means configuring the receive speech level adjusting means for operation in the first condition when the echo canceling means is adapted to the transmit speech and configuring the receive speech level adjusting means for operation in the second condition during the time period when the echo canceling means is not adapted to the transmit speech.
7. A method of processing speech signals in a voice signal controller, the voice signal controller being connectable to a communication line and including a transmit signal path for transmitting speech signals to the communication line and a receive signal path for receiving speech signals from the communication line, the method comprising the steps of:inserting loss in the transmit signal path for attenuating the speech signals for transmission over the communication line; inserting a time variant signal in the receive signal path for canceling transmit speech signals appearing in the receive signal path; measuring an estimate of both the level of speech signals received from the communication line and the level of transmit speech signals appearing in the receive signal path; and adjusting the level of attenuation inserted by the loss insertion step into the transmit path responsive to the receive speech signals measuring step, and inserting attenuation into the receive signal path in response to uncanceled transmit speech signals appearing in the receive signal path.
8. The method of processing speech signals in a voice signal controller as in claim 7 wherein the level adjusting step includes the steps of measuring a predetermined threshold coupling level and comparing the speech signal received from the communication line with the threshold coupling level, the level adjusting step being operable for adjusting the level of attenuation inserted by the loss inserting step in the transmit path when the level of the received speech signal exceeds that of the threshold coupling level.
9. The method of processing speech signals in a voice signal controller as in claim 7 further including the step of measuring the level of the transmit speech signals provided to the communication line for transmission thereover.
10. The method of processing speech signals in a voice signal controller as in claim 9 wherein the receive speech level adjusting step is operable both in a first condition and in a second condition, operation of the receive speech level adjusting step in the first condition providing a first range of available signal levels and in the second condition providing a second reduced range of available signal levels.
11. The method of processing speech signals in a voice signal controller as in claim 10 further including the step of controlling the receive speech level adjusting step, the controlling step configuring the receive speech level adjusting step for operation in either the first condition or the second condition.
12. The method of processing speech signals in a voice signal controller as in claim 11 wherein the time variant signal inserting step requires a period of time to adapt to the transmit speech signals appearing in the receive signal path for canceling these transmit speech signals, the time variant signal inserting step providing an error adapting signal to the controlling step, responsive to this error adapting signal and to receipt of select relative signal levels provided by the transmit speech level measuring step and the receive speech level measuring step, the controlling step determining the level of adaption by the time variant signal inserting step to the transmit speech signals, the controlling step configuring the receive speech level adjusting step for operation in the first condition when the time variant signal inserting step is adapted to the transmit speech and configuring the receive speech level adjusting step for operation in the second condition during the time period when the time variant signal inserting step is not adapted to the transmit speech.
13. The method of processing speech signals in a voice signal controller as in claim 12 wherein the time variant signal inserting step is provided by an echo canceler.
| 1989-05-30 | en | 1991-05-14 |
US-10036693-A | Programmable controller with fuzzy control function, fuzzy control process and fuzzy control monitoring process
ABSTRACT
A process for monitoring fuzzy control information of a programmable controller having a fuzzy control function and at least one input converting module and/or output converting module by using a fuzzy control monitoring device. This process includes the steps of defining fuzzy membership functions, fuzzy output functions and/or fuzzy result functions using a format comprising a plurality of points, and storing data representing these functions in at least one of the input converting modules and/or output converting modules. Data is generated which includes first fuzzy grade numbers, second fuzzy grade numbers and/or a composite fuzzy set based on the functions. The process further includes the step of monitoring production of the generated data by using the monitoring device. Another control monitoring process of the invention includes the steps of connecting a plurality of programmable controllers comprising at least an input converting module and/or an output converting module, by a network, and storing at least one fuzzy control function in at least one of the input converting modules and/or output converting modules. The process further includes the step of monitoring the fuzzy control information of the plurality of programmable controllers using a single fuzzy control monitoring device coupled to the network.
This is a divisional application of application Ser. No. 07/982,125, filed Nov. 25, 1992, which issued on Nov. 9, 1993 as U.S. Pat. No. 5,261,036 and was a file-wrapper continuation application of application Ser. No. 07/602,535, filed on Oct. 24, 1990, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a programmable controller having a fuzzy control function, which performs fuzzy control on an analog data input, the fuzzy control process thereof and a fuzzy control monitoring process.
2. Description of the Prior Art
Recently, in the control field, control systems to which fuzzy logic principles are applied have been the subject of intense research and development.
FIG. 11 is a diagram (a descriptive representation of a fuzzy-control machine tool) showing the configuration of a prior art fuzzy controller. See "Fuzzy Expert System Configuring Tool Having Real-Time Control Functions", pp. 60-63, Mitsubishi Electric Technical Information Vol. 63, No. 3. In FIG. 11, numeral 10 indicates a fuzzy controller, 20 a system to be controlled by the fuzzy controller, and 30 a setting/monitoring device electrically connected to the controller 10 for setting therein the fuzzy membership functions (hereinafter referred to as "membership functions") and fuzzy control application software, and for monitoring the control operation. The fuzzy controller 10 comprises a general-purpose, high-speed CPU, such as a digital signal processor (DPS), and is composed of an inference engine 11 for making inferences, an A/D converter 12 for converting input analog data into digital data, a D/A converter 13 for converting digital data into analog data and outputting the result, a memory 14 for storing a plurality of membership functions and fuzzy output functions as parameter values and for storing application programs as application software for fuzzy inferences, the setting/monitoring device 30, and a line controller 15 for connecting the fuzzy controller 10.
FIG. 12 shows an example of a fuzzy control application program stored in the memory 14 and executed in the inference engine 11. FIGS. 13a to c show examples of A/D-converted inputs and the conversion thereof into fuzzy grade numbers using a plurality of membership functions, as part of an inferencing process in accordance with the fuzzy control application program example shown in FIG. 12, and a defuzzed inference output, discussed hereafter. FIG. 14 is a flowchart of the fuzzy control process in accordance with the fuzzy control application program shown in FIG. 12.
Operation will now be described using FIG. 14 on the assumption that the fuzzy application program shown in FIG. 12 has been written to the memory 14 in FIG. 11. The inference engine 11 reads the said application program from the memory 14 one line at a time and executes it on a line-by-line basis. The contents of rule R1 on line one are as follows:
if A11 and A12 then B1
The "and" in rule R1 is a minimizing operation for selecting the smaller one of first fuzzy grade numbers A11 and A12. The operation result of the above conditional statement, A1, is also a fuzzy grade number. Hereinafter A11, A12, etc., are referred to as first fuzzy grade numbers and A1, etc., as second fuzzy grade numbers. The inference engine 11 will interpret the above rule R1 and first find the first fuzzy grade number A11.
To find the first fuzzy grade number A11, a fuzzy inference process is started at step 500 in the flowchart shown in FIG. 14. The inference engine 11 reads and interprets, at step 501, the first rule Ri (i=1). At step 502, the inference engine inputs from the controlled object a value x1, via the A/D converter 12, converts the same into a first fuzzy grade number by means of membership function all corresponding to A11 shown in FIG. 13a, and finds A11≡a11(x1)=0.6. Then, to obtain the first fuzzy grade number A12, the inference engine 11 inputs a value x2 via the A/D converter 12, converts the same into a fuzzy grade number by means of membership function a12 corresponding to A12 shown in FIG. 13b, and finds A12≡a12(x2)=0.90. At step 503, the inference engine 11 then performs the following fuzzy operation on the obtained fuzzy grade numbers A11 and A12 and finds the second fuzzy grade number A1, i.e., obtains the second fuzzy grade number A1=0.60 from the following expression: ##EQU1##
Then, at step 504, the inference engine 11 performs the following implication operation:
A1 ○ B1
for the above obtained value A1 (=0.60) using a fuzzy membership output function B1 (hereinafter referred to as a "fuzzy output function") which is different from the previously mentioned membership functions. The " ○ " in the above implication operation A1 ○ B1 contracts the fuzzy output function B1 at the same ratio as the value of the second fuzzy grade number A1. Since A1=0.60 in this case, the fuzzy set which is the result of the implication operation is a reduction of the whole fuzzy output function B1 at a ratio of 1 to 0.6. This operation result is shown by a hatched area in FIG. 13C.
The inference engine 11 then judges, at step 505, whether processing of all rules R1 to Rn is complete. If so, the processing will progress to step 507. Since the processing is not yet complete in this example, the inference engine 11 reads the next rule, i.e., the rule R2 on line two, from the memory 14 and interprets its contents at step 506, and returns to step 502. The contents of line two read:
if A21 and A22 then B2
The inference engine 11 now works membership functions a21 and a22 in accordance with the previously found x1 and x2 and obtains first fuzzy grade numbers 0.75 (from a21(x1)) and 0.50 (from a22(x2)), from which second fuzzy grade number A2 is obtained by the following expression: ##EQU2##
The inference engine 11 then works the above obtained value A2 on fuzzy output function B2 and performs the following operation:
A2 ○ B2
Since A2=0.50, the operation result is a reduction of the whole fuzzy output function B2 at a ratio of 0.50. This operation result is also illustrated in FIG. 13c (the triangle defined by dashed lines). Hereinafter, by repeating step 506 and steps 502 through 505 as mentioned above, the inference engine 11 reads the remaining rules R3 (on line three) to Rn (on line n) in order, performs processing similar to that of rules R1 and R2, and as a result, obtains "n" pieces of inference output comprising A1 ○ B1 to An ○ Bn.
Then, at step 507, the inference engine 11 carries out a fuzzy composition process which composes all of the above implication operation result, i.e., calculates the center of gravity of the overlapped inference outputs, i.e., the figures in FIG. 13c enclosed by a bottom coordinate axis (y axis ) and both vertical axes (grade coordinate axes ). In the present example this is done for values of the above indicated A1 ○ B1 and A2 ○ B2, resulting in a y axis value (in %) as a defuzzy value. At step 508, the above defuzzy value is converted into an analog value by the D/A converter 13 and provided as output y.
By repeating the above steps at predetermined intervals, fuzzy control is carried out on the system 20 to be controlled.
In the above mentioned process, the membership functions a11 to a21, the fuzzy output functions B1 to Bn, and the rules R1 to Rn are all stored in the memory 14 by the setting/monitoring device 30 via the line controller 15. The values of the figures (the results of the implication operations A1 ○ B1 to An ○ Bn) are also monitored, by specifying a whole or part thereof, by the setting/monitoring device 30 via the line controller 15. As is apparent from the flowchart shown in FIG. 14, since the prior art fuzzy controller 10 employs only one inference engine 11 to execute a succession of processes, in series, which are composed of the fuzzy grade number operations (step 502), the minimum value operation (step 503) and the implication operations (step 504), a comparatively long time is needed to perform the processes from input to output. In the first fuzzy grade number conversion by means of the membership function aij, therefore, a table reference system (i.e., a look-up table) is used to reduce the processing time, i.e., tabulated membership functions are stored in the memory 14 beforehand. As an example, if 10 types of 10 membership functions alj are input, each of 256-division accuracy, a memory capacity of:
1 byte×256×10×10=25.6KB
is required and a large area is necessary for the table memory. Similarly, the fuzzy output functions B1 are also tabulated and stored in the memory 14 beforehand, and also require a large area for the table memory.
The fuzzy controller 10 of the prior art configured as described above has problems in that the fuzzy inference operation takes a relatively long time because it is executed in series by one inference engine 11, and in that since a table reference system must be used to reduce the processing time of the fuzzy grade number conversion by way of the membership functions, a comparatively large memory area is required. Moreover, since the fuzzy controller is designed as a dedicated controller, the wiring and connections become complicated in the monitoring of the fuzzy control results when employing a general-purpose controller, such as a programmable controller, resulting in extra cost and loss of time.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to resolve the aforementioned problems in the prior art by providing a programmable controller having a fuzzy control function and using a fuzzy control process and performing a fuzzy control monitoring process, which can process the required fuzzy control functions in a comparatively short time, requires a relatively small memory area for fuzzy control, eliminates extra cost and loss time, and can easily monitor the fuzzy control results.
The fuzzy control process of the invention operates to convert input analog data into digital data, converts the digital data into first fuzzy grade numbers using fuzzy membership functions defined in a definition format composed of a plurality of points, executes fuzzy operation processing instructions as sequence instructions operating on the first fuzzy grade numbers, generates fuzzy sets corresponding to second fuzzy grade numbers which are the execution results of the fuzzy operation processing instructions, using fuzzy output functions defined in a definition format composed of a plurality of points, and defuzzes the fuzzy sets, and converts the defuzzed data into analog data for output. Defuzzing is conducted by finding the moment of each result function, wherein the area of each fuzzy result function is used as the magnitude and the center of the area is used as a coordinate value, and obtaining a defuzzy value by the composite of said moments.
A programmable controller having a fuzzy control function according to the invention comprises an A/D converter for converting input analog data into digital data, a CPU for executing sequence instructions, and a D/A converter for converting digital data into analog data and outputting the analog data, the said A/D converter including fuzzy membership function storing means for storing fuzzy membership functions and fuzzy grade number means for determining first fuzzy grade numbers corresponding to the digital data using the fuzzy membership functions, the CPU having a fuzzy operation processing instruction executing means for receiving the fuzzy grade numbers, for executing fuzzy operation processing instructions as the sequence instructions, and for outputting second fuzzy grade numbers, one of the CPU and the D/A converter having a fuzzy output function storing means for storing fuzzy output functions and fuzzy result function means for determining fuzzy sets using the fuzzy output functions and for outputting the results as fuzzy result functions, the D/A converter including defuzzing means for composing a plurality of the fuzzy result functions and for defuzzing the composite fuzzy set, and at least one of the fuzzy membership functions, fuzzy output functions and fuzzy result functions being defined in a definition format composed of a plurality of points.
The fuzzy control monitoring process for a programmable controller having a fuzzy control function according to the invention monitors, by means of a fuzzy control monitoring device, the fuzzy control information of a programmable controller having a fuzzy control function, including at least one of fuzzy membership functions, fuzzy output functions and fuzzy result functions defined in a definition format composed of a plurality of points, and at least one of first fuzzy grade numbers, and second fuzzy grade numbers and a composite fuzzy set generated using the aforementioned functions.
The fuzzy control monitoring process may use a single fuzzy control monitoring device to monitor the fuzzy control information of a plurality of programmable controllers having a fuzzy control function, via a network.
According to the invention, input analog data is converted into digital data, and then converted into first fuzzy grade numbers using fuzzy membership functions defined in a format composed of a plurality of points. The fuzzy operation processing instructions are executed as sequence instructions using the first fuzzy grade numbers, and fuzzy sets are generated using second fuzzy grade numbers, which are the execution results of the fuzzy operation processing instructions, and fuzzy output functions defined by a plurality of points. The fuzzy sets are defuzzed, converted into analog data, and then output.
In the invention, fuzzy membership function storing means stores fuzzy membership functions, fuzzy grade number generating means produces first fuzzy grade numbers from input data converted into digital data, using the fuzzy membership functions, fuzzy operation processing instruction execution means executes fuzzy operation processing instructions using the first fuzzy grade numbers and outputs second fuzzy grade numbers, fuzzy output function storing means generates fuzzy sets using the second fuzzy grade numbers and fuzzy output functions, and outputs the results as fuzzy result functions. The defuzzing means composes a plurality of fuzzy result functions and defuzzes the composite fuzzy set.
Fuzzy rule setting means sets the fuzzy rules in the application program, and fuzzy rule selecting means causes selectively execution of the fuzzy rules through the use of logical contacts in the said application program.
A first CPU may execute fuzzy operation instructions and a second CPU may execute sequence instructions other than fuzzy operation instructions, according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a programmable controller having a fuzzy control function according to an embodiment of the invention.
FIG. 2 is a block diagram illustrating the details of an A/D converter module shown in FIG. 1.
FIG. 3 is a block diagram illustrating the details of a D/A converter module shown in FIG. 1.
FIG. 4 is a flowchart illustrating operations of the fuzzy control programmable controller shown in FIG. 1.
FIGS. 5a and b are illustrative diagrams of a first fuzzy grade number operation which takes place in the A/D converter module shown in FIG. 2.
FIG. 5c is an illustrative diagram of an implication operation carried out in the D/A converter module shown in FIG. 3.
FIG. 6 is a ladder diagram illustrating an example of an application program for executing fuzzy operation processing instructions.
FIG. 7 to 9 are illustrative diagrams of the calculation method of defuzzy conversion.
FIG. 10 is a diagram illustrating a monitoring process which takes place over a network.
FIG. 11 is a block diagram illustrating a fuzzy controller of the prior art.
FIG. 12 is a diagram illustrating a set of fuzzy rules.
FIG. 13 is an illustrative diagram of a typical fuzzy grade number operation and implication operation in the prior art fuzzy controller.
FIG. 14 is a flowchart illustrating the fuzzy control scheme of the prior art.
In the above figures, reference characters in the different views identify identical or corresponding parts.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, embodiments of the invention will be described according to FIGS. 1 through 10.
FIG. 1 is a block diagram illustrating the configuration of a programmable controller having a fuzzy control function (hereinafter referred to as the "PC"). In FIG. 1, the numeral 40 indicates a controller unit containing a CPU 41 (hereinafter referred to as the "PC-CPU") as its major component. Numeral 42 refers to an application memory used as a storage for application programs comprising any combination of user-prepared sequence instructions and fuzzy inference instructions. An internal memory 43 of the PC-CPU 41 comprises a sequence instruction execution processor 43a identical to that of the prior art and an added fuzzy inference instruction execution processor 43b. The PC-CPU serves as a fuzzy operation processing instruction executing means, and functions to execute the fuzzy inference instructions. A line controller 45 connects a peripheral device 90 (described later) and the PC-CPU 41. An A/D converter module 50, connected to the PC-CPU by an I/O bus 44, converts input analog values into digital values, then converts the results into first fuzzy grade numbers. The A/D converter module 50 has the same hardware configuration as the prior art A/D converter module, and stores fuzzy membership functions (hereinafter referred to simply as "membership functions"). Unit 50 performs the grade number converting function using the membership functions, and is different from the prior art A/D converter module 50A. Input terminals 51 of the A/D converter module 50 receive analog input signals x1 to xm. A D/A converter module 60 operates as a D/A converter and also defuzzes a fuzzy inference result received from the controller unit 40, i.e., derives a defuzzy value and converts it from digital form into an analog value, and outputs the analog value. The D/A converter module 60 has the same hardware configuration as the prior art D/A converter module, but stores fuzzy output functions and has a defuzzy conversion function. It is different from the prior art D/A converter module 60A.
Output terminals 61 provide analog signal y as a fuzzy control output. Digital input module 70 and digital output module 80 resemble those of an ordinary programmable controller, and have digital signal input terminals 71 and digital signal output terminals 81, respectively. Numeral 90 indicates a peripheral device of the PC-PCU 41 used for writing user application programs to the application memory 42, for modification thereof, and for monitoring, etc., of the instruction execution status of the PC-CPU 41 via the line controller 45. The peripheral 90 carries out, via the PC-CPU 41, the writing and modification of fuzzy inference instructions, in addition to the usual sequence instructions of the prior art, the setting of membership functions to the A/D converter module 50, the setting of fuzzy output functions to the D/A converter module 60, and monitoring.
FIG. 2a is a block diagram illustrating the details of the A/D converter module 50. In FIG. 2a, numerals 51 indicate the analog signal input terminals, and 52 a built-in microprocessor (hereinafter referred to as the "μ-P") having an analog port 52a for A/D conversion. Numerals 53 indicate analog switches, and 54 is a sample holder, to which an input analog signal is output when any of the analog switches 53 is selectively switched on by the output signal 58a of a decoder 58 which will be described later. The sample holder 54 holds the input analog signal for a predetermined period of time in accordance with output signal 58b of the decoder 58 and then outputs the same to the analog port 52a of the μ-P 52. The μ-P 52 is a general-purpose processor containing an A/D conversion function, and has a built-in ROM/RAM 55. The built-in ROM/RAM 55 includes a prior art A/D conversion microprogram 55a with a non-linear compensation function and a fuzzy conversion microprogram 55b. The μ-P serves the functions of: (1) an A/D converter, converting analog signals input from the input terminals 51 into digital signals and (2) a fuzzy grade conversion means for converting the digital values into first fuzzy grade numbers using the membership functions. An interface 56 (hereinafter referred to as the "I/F") serves as an output area of the A/D converter module 50 and includes a two-port RAM 57 as a two-port storage. The two-port RAM 57 allows data to be transferred to and from the μ-P 52 and to and from the PC-CPU 41 over the I/O bus 44. In addition to its function as a storage means for the usual A/D converter module, the two-port RAM 57 includes a fuzzy function storing area 57a (see FIG. 2b) for storing coordinate points that define the membership functions (in this embodiment, each membership function is defined by three points on orthogonal coordinate axes), and a fuzzy grade number storing area 57b. Analog input signals are converted into digital signals, and then conversion into first fuzzy grade numbers takes place by means of the membership functions, and the results are stored here. Namely, the two-port RAM 57 serves as a fuzzy grade number storing means for storing first fuzzy grade numbers accessible by/from the PC-CPU 41 of the controller unit 40, and as a storage means for membership functions, as defined by a format composed of a plurality of points (three points in the foregoing example). A decoder 58 (hereinafter referred to as the "DEC") closes any of the open analog switches 53 by decoding a command from the μ-P 52, and directs a command to the sample holder 54 so as to temporarily hold the analog value input via the closed analog switch 53.
FIG. 3a is a block diagram illustrating the details of the D/A converter module 60. In FIG. 3a, numeral 61 indicate analog output terminals, and 62, a built-in microprocessor (hereinafter referred to as the "μ-P") having an analog port 62a, for D/A conversion. Output amplifiers are shown at 63m and at 64 are sample holders. The analog value output from the μ-P 62 is temporarily held by the sample holders 64, converted to low impedance and output by the output amplifiers 63. The μ-P 62 has a built-in ROM/RAM 65 which includes a prior art D/A conversion microprogram 65a and a defuzzy conversion microprogram 65b. An interface 66 (hereinafter referred to as the "I/F") between the I/O bus 44 of the PC-CPU 41 and the D/A converter module 60 has a two-port RAM 67 to allow data to be transferred to/from μ-P 62. In addition to functioning as a storage means as in the case of an ordinary D/A converter module, the two-port RAM 67 has, as shown in FIG. 3a, a fuzzy output function storing area 67a for storing coordinate points that define fuzzy output functions (in this embodiment, one fuzzy output function is defined by three points on orthogonal coordinate axes), and a fuzzy output storing area 67b for storing second fuzzy grade numbers transferred from the PC-CPU 41. A decoder 68 (hereinafter referred to as the "DEC") closes any of the open sample holders 64 by decoding a command from the μ-P 52.
FIG. 4 is a flowchart illustrating the operation of the PC shown in FIG. 1. Flow A indicates the operation of the A/D converter module 50, flow B that of the controller unit 40, and flow C that of the D/A converter module 60. The details of the processing will be hereafter described.
FIG. 5a and b are illustrative diagrams of the operations performed on the first fuzzy grade numbers obtained in correspondence with input data x1, x2 converted into digital values, using the membership functions defined in the three point format, in the A/D converter module 50 shown in FIG. 2. FIG. 5c is an illustrative diagram of the performance of the implication operation on the second fuzzy grade numbers input from the controller unit 40, using the fuzzy output functions defined in the three point format, in the D/A converter module 60.
FIG. 6, as described in more detail hereinafter, shows a portion of an application program example, in ladder form, relating to a fuzzy inference function executed by the PC-CPU 41 shown in FIG. 1.
The operation of the foregoing system will now be described, with reference to FIGS. 1-6. Prior to performing control, a plurality of coordinate points (coordinate data) defining the predetermined membership functions are stored in the two-port RAM 57 (FIG. 2a) inside the A/D converter module 50, via the line controller 45 (FIG. 1) and I/O bus 44 of the controller unit 40, using the peripheral device 90 in FIG. 1. In a similar way, coordinate data defining the predetermined fuzzy output functions are stored in the two-port RAM 67 (FIG. 3a) inside the D/A converter module 60. For both the membership and output functions, each function is defined by three coordinate points in this embodiment.
In FIG. 5a, a11 and a21 are prepared as membership functions for x1 input from the analog input terminal 51 of the A/D converter module 50 (FIG. 1), and are given as a combination of points having coordinate values of the form (P1, P2), in an orthogonal coordinate system. The vertical axis is defined as the grade number, ranging between 0 and 1 {0, 1} and the horizontal axis is defined as the input percentage, ranging from 0 to 100% {0, 100}. In this embodiment, the function a11 is defined by three definition points SPA111, SPA112 and SPA113, and the function a21 is defined by definition points SPA211, SPA212 and SPA213, all of which are stored in the two-port RAM 57. Similarly, in FIG. 5b, a12 and a22 are prepared as membership functions for analog input x2, the function a12 being defined by points SPA121, SPA122 and SPA123, and the function a22 by points SPA221, SPA222 and SPA223 in this embodiment, the functions being stored in the two-port RAM 57.
In FIG. 5c, fuzzy output functions B1 and B2 are used to produce the analog output y which will be output from the analog output terminal 61 of the D/A converter module 60 (FIG. 1). Functions B1 and B2 are given as a combination of orthogonal coordinates, wherein the vertical axis is defined as an output fuzzy value, ranging from 0 to 1 {0, 1} and the horizontal axis is defined as the output percentage, ranging from 0 to 100% {0, 100}. In this embodiment, the function B1 is defined by the three definition points SPB11, SPB12 and SPB13, and the function B2 by the points SPB21, SPB22 and SPB23, with the functions being stored in two-port RAM 67 (FIG. 3).
Operations will now be described according to the flowchart shown in FIG. 4. In flow A, the A/D converter module 50 is started up at step 200, and initialized (J=1) at step 201. The μ-P 52 then inputs the first analog signal xj (j=1) and converts it into a digital value at step 202. At step 203, the μ-P 52 then reads membership functions aij (i=1 to n) (i.e., a11 and a21 in this example) corresponding to the A/D-converted input signal xj (j=1) from the two-port RAM 57, finds the first fuzzy grade numbers Aij (i.e., A11(x1) and A21(x1) in this example) corresponding to each membership function aij (i.e., converts the input xj into a grade number Aij) using the membership functions aij, and at step 204, writes the first fuzzy grade numbers Alj through Anj to a predetermined area of the two-port RAM 57. Then, at step 205, the μ-P 52 judges whether the above operation is complete or not for all input signals xj (j=1 to m; m=2 in this example), and if it is not complete, sets j=j+1 to retrieve the next input signal (here, x2) at step 206 and repeats steps 202 through 204. When this process is complete, flow A terminates at step 207. In actuality, the μ-P 52 executes flow A cyclically at predetermined intervals of time, and at step 204, updates the first fuzzy grade numbers Aij stored in the two-port RAM 57. Details of the operation at major steps in flow A will be described below in accordance with FIGS. 2a, b and FIGS. 5a, b.
At step 202, with regard to the A/D conversion and fuzzy grade number conversion of the analog input signals by means of the membership functions in the A/D converter 50, the μ-P 52 directs a command to the DEC 58, which closes one analog switch 53 by way of an output thereof, whereby the analog signal x1 is input from the input terminal 51 into the sample holder 54. The μ-P 52 causes the sample holder 54 to hold its value, by means of another output from the DEC 58. The μ-P receives the held output value at the A/D input port 52a included therein, converts the same into a digital value, makes the required scale and linearity conversions, and obtains a corresponding digital value. This operation is performed by the A/D conversion microprogram 55a using an established routine stored in the built-in ROM/RAM 55 of the μ-P 52. The process so far is the same or essentially similar to prior art A/D conversion techniques.
Then, at step 203, flow A progresses to the execution of the microprogram 55b, i.e., the fuzzy grade conversion routine, whereby the digital value obtained above (digital value at full scale=100%) is converted into grade numbers by the membership functions a11 and a21. In the present example, as shown in FIG. 5a, in regard to the membership function a11, it is necessary only to find the intersection a11(x1) between value x1 and the straight line connecting points SPA112 and SPA113, which can be calculated from the following formula (1) and which will yield a first fuzzy grade number A11 for the input x1: ##EQU3##
Similarly, for the membership function a21, the intersection of value x1 with the straight line connecting the two points SPA211 and SPA212 is found, which provides the following first fuzzy grade number A21: ##EQU4##
In the above calculations, P1 and P2 are the coordinate values for the respective points, obtainable from the two-port RAM 57, as schematically seen in FIG. 26.
Since the membership functions a11 and a21 are represented by polygonal lines, it is apparent that whether the input x1 intersects either or neither of the polygonal lines is determined nonambiguously.
Then, at step 205, A11 (≡a11(x1)) and A21 (≡a21(x1)) obtained as indicated above are written, as first fuzzy grade numbers of the input x1 according to the membership functions a11 and a21, in a predetermined area 57b of the two-port RAM 57 as also shown in FIG. 2b.
Similarly, thereafter, steps 202 through 206 are repeated and the μ-P 52 causes the DEC 58 to open the analog switch corresponding to the analog input x2, and causes the sample holder 54 to hold the x2 value, and then receives that value at the A/D input port 52a. The x2 value is converted into a digital value, and first fuzzy grade numbers A12 and A22 are found in correspondence with the membership functions a12 and a22 corresponding to the input x2. Fuzzy grade numbers A12 and A22 are obtained for the input x2 in a manner similar to that with respect to x1: ##EQU5##
In a similar way, the other analog inputs (if any) of the A/D converter module are converted into fuzzy grade numbers in correspondence with the corresponding membership functions and the conversion results are written to the predetermined area 57b of the two-port RAM 57. The membership function definition area 57a corresponding to each analog input informs the μ-P 52 of the end of each definition area with a predetermined mark at the termination of each definition.
The above conversion operation is performed cyclically by the A/D converter module 50. Where there are a plurality of A/D converter modules 50, the above conversion operation is carried out asynchronously and in parallel.
The operation in flow B of FIG. 4 will now be explained. The controller unit 40 is started up at step 300. When any of a plurality of pre-prepared fuzzy rule (hereinafter referred to simply as "rule") sets is selected at step 301, the PC-CPU 41 reads, at step 302, the first fuzzy grade numbers Aij (i=1 to n, j=1 to m) from storage in the two-port RAM 57 of the A/D converter module 50 and writes them in internal memory in the PC-CPU 41. At step 303, the PC-CPU 41 then executes the fuzzy operation processing instructions, i.e., performs a fuzzy inference operation which will later be described in detail, using the first fuzzy grade numbers Aij. Namely, instructions 102 to 105 in the sequence ladder diagram segment shown in FIG. 6 are executed in order and the second fuzzy grade numbers Ai (i=1 to n) are output. At step 304, the PC-CPU 41 then transfers the second fuzzy grade numbers Ai to a predetermined area 67b of the two-port RAM 67 in the I/F 66 of the D/A converter module 60 via the I/O bus 44, and terminates flow B at step 305. Flow B, however, is part of the application program, which is run cyclically by the PC-CPU 41, and is therefore executed cyclically. The principal steps of flow B will now be described in detail.
FIG. 6 is a segment of a sequence program illustrated in ladder diagram form which causes the PC-CPU 41 to execute the rules shown in FIG. 12. It is part of the application program(s) stored in the memory 42. Instructions 101 to 106 execute the rules R1 to Rn shown in FIG. 12. Relay M10 110 is a logical contact which acts as a conditional contact controlling the execution/non-execution of the rule sets, and is switched on/off in the application program area (not illustrated). Instructions 107 to 109 correspond to a part of another set of rules (not illustrated in full), like the rules shown in FIG. 12. Relay M11 111 controls the execution/non-execution of this group of rules.
The execution of the rule implementing instructions 101 to 106 will now be described, in comparison with the prior art.
Instruction 101 is the data transfer instruction of the PC-CPU 41 executed at the step 302 in FIG. 4, and operates to transfer data (groups of words in batches) from any specified data area of the two-port RAM 57 in the I/F 56 within the A/D converter module 50 to any specified data area (a data register in this example) within the PC-CPU 41. Namely, the instruction 101 transfers data from the addresses (known to the user) of the two-port RAM 57 which store the first fuzzy grade numbers A11, A21, . . . An1, A12, A22, . . . An2, to data registers in the PC-CPU specified by the user application.
At the instruction 101 in FIG. 6, FROM indicates a batch transfer instruction (an existing sequence application instruction) from any module (device) to the PC-CPU 41.
H10 indicates an address where a transfer destination module is being inserted (i.e., a device address) (H is a symbol representing a hexadecimal constant).
Kmi indicates an address on the two-port RAM; in this example, an address on the two-port RAM 57 in the A/D converter module (K is a symbol representing a decimal constant).
D11 indicates a transfer destination head address.
K2n indicates the number of words to be transferred (K is a decimal constant).
When the PC-CPU 41 executes the above instruction, the A11 value is stored into D11, A21 into D12, An1 into D10+n, . . . A12 into D11+n, A22 into D12+n, . . . and An2 into D10+2n.
Instruction 102 is a fuzzy AND instruction executed at step 303 and is differentiated from the usual AND instruction by the presence of the symbol ˜, i.e., the fuzzy AND instruction is indicated by "˜AND". The processing routine for this instruction is stored in the fuzzy inference instruction execution processor 43b of the internal memory 43 in the PC-CPU 41. The instruction performs the following fuzzy operation between the word resources at the three successive addresses: ##STR1##
Namely, the instruction 102 compares and takes the minimum of the contents of D11 and D11+n; i.e., in this example, a minimum value operation is performed on values A11 and A12, and the smaller value is stored at D11+2n as the second fuzzy grade number A1. Thereafter, similarly, ˜AND instructions 103 through 105 are executed at step 303:
Instruction 103 performs a minimum value operation on the contents of D12 and D12+n, i.e., the values A21 and A22, and the smaller value is stored in D12+2n as A2.
Instruction 104 performs a minimum value operation on the contents of D10+i and D10+2i, i.e., the values Ai1 and Ai2, and the smaller value is stored in D10+3i as Ai.
Instruction 105 performs a minimum value operation on the contents of D10+n and D10+2n, i.e., the values An1 and An2, and the smaller value is stored at D10+3n as An.
Instruction 106 is a data transfer instruction of the PC-CPU 41, executed at step 304 of FIG. 4. It differs from the FROM instruction at instruction 101 in that the transfer direction is opposite, i.e., a batch transfer from any designated data area (a data register in this example) of the PC-CPU 41 to a designated area in any module (here, the two port RAM 67).
Specifically, in instruction 106, TO indicates a batch transfer instruction to transfer data from the PC-CPU 41 to any designated module (device). This is an existing sequence application instruction; its processing routine is stored in the microprogram 43a. H20 indicates an address where a transfer destination module is being inserted (a device address); a D/A converter module address in this example (H indicates a hexadecimal representation).
Km2 indicates an address on a two-port RAM in the destination module; in this example, an address value m2 on the two-port RAM in the D/A converter module 60 (K is a symbol representing a decimal constant). D11+2n indicates the transfer source head address. Note that the head address is that which was the target address of instruction 102.
Kn indicates the number of words to be transferred.
Namely, instruction 106 causes "n" pieces of word data, here A1 to An in memory areas D11+2n to D10+3n storing the fuzzy operation results, to be stored into RAM area 67b (FIG. 3b) at and after address m2 in the two-port RAM 67 of the D/A converter module 60. This completes step 304 in FIG. 4.
Referring again now to FIG. 4, the operation of flow C will now be described. The D/A converter module 60 is started at step 400 and initialized (n=1) at step 401. In a loop comprising steps 402 to 405, the μ-P 62 reads the second fuzzy grade numbers Ai (i=1 to n), which have been stored in memory area 67b after being transferred there by PC-CPU 41 of the controller unit 40 at step 304 of flow B. The pre-stored fuzzy output functions Bi (i=1 to n) are also obtained from the two-port RAM 67 in order. The μ-P 62 then performs implication operations Ai ○ Bi (i=1 to n), and creates fuzzy result functions Ci (i=1 to n) in a definition format defined by three points (like the fuzzy output functions Bi). These fuzzy sets are the fuzzy results of the operation. Then, at step 406, the areas Si of the figures (see FIG. 5c) defined by the fuzzy result functions Ci are found, along with the horizontal axis (y axis) components li of their center of gravity. An area center of the composite fuzzy set obtained by overlapping the figures is determined, and the y axis value of the same (in %) is used as the defuzzy value obtained by defuzzing the composite fuzzy set, as explained in greater detail hereafter.
At step 407, the above defuzzy value is converted into an analog value and output as output y, and the flow C is terminated at step 408.
Like the operation of the A/D converter module 50 shown in flow A and that of the controller unit 40 in flow B, flow C is executed cyclically and independently, and data transfer between the flows is performed by the PC-CPU 41 in the controller unit 40 by accessing the two-port RAM 57 of the A/D converter module 50 and the two-port RAM 67 of the D/A converter module 60. The main steps of the flow C will now be detailed.
In FIG. 3, the D/A converter module 60 performs the defuzzy conversion via the following operation. Each fuzzy output function Bi has been specified by three definition points, which have been written to a predetermined area of the two-port RAM 67 in a given order.
At step 403 of FIG. 4, the μ-P 62 performs the implication operation Ai ○ Bi on each of the second fuzzy grade numbers Ai (i=1 to n). That is, it first reduces the value of each fuzzy output function Bi (i=1 to n) in its vertical axis direction by a ratio set by the second fuzzy grade number Ai. That is, if the second fuzzy grade number Ai is 0.6, for example, the output function Bi will be reduced in the vertical direction to 60% of its original value. Next, μ-P 62 determines the area Si and the area center coordinate li (horizontal axis only) of the triangle defined by the resultant three points or the trapezoid defined by the three points and the vertical axis.
Then, at step 406, by weighting all of the area center coordinates li (i=1 to n) according to the size of the area Si of each figure, the μ-P 62 overlaps and composes them, and finds the horizontal axis coordinate value of the area center of the resultant composite fuzzy set, i.e., the defuzzy value y.
FIG. 7 is an illustrative diagram showing the calculation method where the fuzzy output functions comprise triangles. If the triangle is composed of three points (l1, 0), (l2, h), (l3, 0), the area S and the position x of the area center are obtained as follows:
x=1/3(l1+l2+l3) (5)
S=1/2(l3-l1)h (6)
Where h is the height of the triangle, here determined by the second fuzzy grade number Ai.
FIG. 8 is an illustrative diagram of the calculation method where the fuzzy output function comprises a trapezoid. If the trapezoid is composed of three points (0, h), (l2, h), (l3, 0) and the origin (0, 0), it is divided into a rectangle including the point (l2, h) and the origin (0, 0) and a triangle including the points (l2, h), (l3, 0), and the area S1 and the area center x1 of the rectangle are found by the following expressions:
S1=l2h
x1=l2/2
and the area S2 and the area center x1 of the triangle are found by the following expressions:
S2=1/2(l3-l1)h
x2=1/3(2l2+l3)
and the area S of the said trapezoid is obtained by adding the said areas S1 and S2, and the area center x is obtained by weighting the values x1 and x2 by the sizes of the respective areas S1 and S2, respectively, whereby the area center position x and the area S are obtained by the following expressions: ##EQU6##
Since the fuzzy output function Bi comprises a trapezoid in the example shown in FIG. 5c, the expressions (7) and (8) are used, and
h=A1
l2=P1 (SPB12)
l3=P1 (SPB13)
are used in expressions (7) and (8) to find the area and its center position.
Since the fuzzy output function B2 comprises a triangle as shown in FIG. 4c, expressions (5) and (6) are used, and
h=A2
l1=P1 (SPB21)
l2=P1 (SPB22)
l3=P1 (SPB23)
are used in expressions (5) and (6) to find the area and the center position.
Then, a composite value of the moments, wherein the center positions found above are coordinate values and the area values are their relative magnitudes, is found according to FIG. 9, i.e., if the original areas and center positions are (Si, l1), (S2, l2), respectively, the composite center x and the composite area S are obtained by the following expressions: ##EQU7##
In the present example shown in FIGS. 5, each center position and area of A1 ○ B1 and A2 ○ B2, as previously calculated, are used in the above expressions to obtain the composite center position and area.
In a similar way,
Ai ○ Bi (i=3 to n)
is used to find the composite center position of plural areas greater than 2, if there are more Ai and Bi than A1, A2, B1, B2. Since the composite center position is a % output with respect to the horizontal axis, it is converted into an analog value in an ordinary way and output as the output y. Namely, the μ-P 62 outputs the D/A output value, i.e., the composite center position (the defuzzed value of the composite fuzzy set), to the D/A port 62a, holds the output at that one of the sample holders 64 made active by the output of the DEC 68, converts the same to low impedance by means of the corresponding amplifier 63, and outputs it to the corresponding analog signal output terminal 61 as an analog signal.
As described above, since the input conversion operation (using the fuzzy input membership functions), the fuzzy inference operation (using the main PC-CPU), and the calculation and processing of the area centers of the fuzzy result functions all proceed independently of and in parallel to each other, throughout is increased, speed is not compromised, and the addition of fuzzy inference processing to a sequence control operation allows the same CPU to cyclically carry out fuzzy control as a general PC control function. Moreover, by utilizing spare time made available by the concurrent processing of the fuzzy and defuzzy conversion operations as described above, fuzzy and defuzzy conversions can be performed by way of a numerical operation based on a coordinate based format using three coordinate values or so, instead of a look-up table system. Further, the integration of fuzzy control and sequence control in one PC allows more complex overall control.
The peripheral device 90 in FIG. 1 is capable of creating an application program including fuzzy operation processing instructions in addition to the usual sequence instructions of the prior art, and writes (or modifies) the same to the application memory 42 via the line controller 45 and the PC-CPU 41 in the controller unit 40, and also creates (or modifies) the membership functions and the fuzzy output functions in the three-point definition format and writes the same to the two-port RAMs 57, 67 of the A/D converter module 50 and the D/A converter module 60, respectively. Further, the peripheral device 90, reversely, is capable of reading the data stored in the application memory 42 and the two-port RAMs 56, 67, and the execution results of the PC-CPU 41 and the μ-Ps 52, 62; e.g., the sets of three points defining the membership functions, the fuzzy output functions and the fuzzy result functions, the first and second fuzzy grade numbers, and the defuzzy value of the composite fuzzy set, and indicating the same on the display. At such time, the functions are reproduced as graphic figures. Namely, the peripheral device 90 functions as a fuzzy monitoring device. This function is easily achieved by adding a fuzzy control monitoring program to the peripheral device 90 and executing the same on the CPU (not illustrated) of the peripheral device 90.
FIG. 10 is a block diagram illustrating a circuit wherein one peripheral 90 provided as a fuzzy control monitoring device is equipped with a network connection unit 91 and connected with a plurality of CPUs 40A via a network 92. Referring to FIG. 10, one peripheral device 90 reproduces the fuzzy control status of any of the plurality of PCs on the display.
In the present invention, the fuzzy inference operation, which is executed between fuzzy grade numbers set in various registers using an added fuzzy inference instruction as a sequence instruction executed by the PC-CPU 41, is not limited to the minimum value operation (fuzzy AND) exemplified above. In addition to this, a maximum value operation (fuzzy OR) may be performed, as well as binary operations such as an m×n matrix operation, a maximum value/minimum value operation combination, etc., all of which may be represented and given an execution format in a sequence program.
The implication operation "A ○ B" is performed by the D/A converter 60 in the above embodiment. That is, the three coordinate value sets defining the fuzzy output functions B are stored in the memory (the two-port RAM 67) of the D/A converter 60 and the said implication operation "A ○ B" is executed by the D/A converter's μ-P 62. The implication operation, however, could be performed by the CPU 40 as are others of the fuzzy operations, in which case the fuzzy output functions B would be stored in the memory 42.
Moreover, a compound A/D module, wherein the A/D and D/A converters are operated by one microprocessor, may be used instead of the A/D converter module 50 and the D/A converter module 60 configured independently in the above described embodiment, to produce the same effect as independent converters.
Further, the functions needed to implement the fuzzy operation may be extracted and carried out by an additional second CPU or by separately provided dedicated unit, instead of using the existing PC-CPU 41 as in the present embodiment.
The definition format of the membership functions as described above may be retained while all control functions are concentrated in the single PC-CPU. In this case, the high speed achieved by the pipeline (parallel) system is sacrificed but there is still the advantage that a large of memory, as needed for a table-type look-up system, is not required in fuzzy or defuzzy conversion.
Naturally, more than three points may be employed for the definition of the membership functions, fuzzy output functions, etc.
Switching from one fuzzy inference rule or rule set to another may be achieved easily by controlling logical contacts M10 110 and M11 111, etc., as shown in FIG. 6. The logical contacts can be configured as physical contracts (relay coils, etc.) if desired.
It will be apparent that the invention, as described above, converts A/D-converted digital data into first fuzzy grade numbers using fuzzy membership functions defined by a format composed of a plurality of points, and executes fuzzy operation processing instructions to find second fuzzy grade numbers. The invention defuzzes the fuzzy sets resulting from operations on fuzzy output functions, defined by a plurality of points, using the second fuzzy grade numbers so as to provide a fuzzy control process for a programmable controller which requires a relatively small memory area to store the fuzzy membership functions and fuzzy output functions.
It will also be apparent that the invention can be designed to operate, independently of and in parallel, an A/D converter for computing first fuzzy grade numbers by means of fuzzy membership functions, a CPU for executing fuzzy operation processing instructions for the said first fuzzy grade numbers, and a D/A converter for defuzzing a composite fuzzy set. Further, the invention defines at least one of the fuzzy membership functions, fuzzy output functions and fuzzy result functions in a definition format composed of a plurality of points, so as to minimize the processing burden to the CPU, reconcile and efficiently execute the prior art sequence instructions and fuzzy operation processing instructions, and make the memory area for storing the functions comparatively small.
The invention is designed to monitor, on a fuzzy control monitoring device, the fuzzy control information of a programmable controller having a fuzzy control function comprising at least one of fuzzy membership functions, fuzzy output functions and fuzzy result functions defined in a format composed of a plurality of points, so as to allow the status of fuzzy control to be reproduced and observed. The invention can be designed to monitor the fuzzy control information of a plurality of programmable controllers with fuzzy control functions via a network, so as to allow the status of fuzzy control of the plurality of programmable controllers to be reproduced and observed on one fuzzy control monitoring device.
The invention further includes fuzzy rule setting means for setting fuzzy rules in the application programs and fuzzy rule selecting means for selectively executing the fuzzy rules by means of logical contracts in the said application program, so as to execute the fuzzy operation processing instructions efficiently. If desired, a first CPU can be provided for executing the fuzzy operation instructions, with a second CPU for executing sequence instructions other than fuzzy operation instructions, so as to execute the fuzzy operation processing instructions at high speed.
Finally, the invention includes a defuzzing means for obtaining a composite defuzzy value by the composite operation of moments, wherein the area of a fuzzy result function is used as the magnitude (for weighting) and the center of the area is used as a coordinate value, so as to perform the operation at high speed.
What is claimed is:
1. A fuzzy monitoring process for monitoring fuzzy control information of a programmable controller having a fuzzy control function and at least one of an input converting module and an output converting module, by using a fuzzy control monitoring device, comprising the steps of:defining at least one of fuzzy membership functions, fuzzy output functions and fuzzy result functions using a definition format comprising a plurality of points and storing data representing said at least one function in at least one of said input converting module and said output converting module; generating data including at least one of first fuzzy grade numbers, second fuzzy grade numbers and a composite fuzzy set based on said at least one function; and monitoring the production of said generated data using said monitoring device.
2. A fuzzy control monitoring process for monitoring fuzzy control information of a plurality of programmable controllers connected by a network and each having a fuzzy control function and at least one of an input converting module and an output converting module, by using a single fuzzy control monitoring device, comprising the steps of:defining at least one of fuzzy membership functions, fuzzy output functions and fuzzy result functions using a definition format comprising a plurality of points and storing data representing said at least one function in at least one of said input converting module and said output converting module of each of said plurality of programmable controllers; generating, for each of said programmable controllers, data including at least one of first fuzzy grade numbers, second fuzzy grade numbers and a composite fuzzy set based on a respective said at least one function; and monitoring the production of said generated data of said plurality of programmable controllers using said single fuzzy control monitoring device.
| 1993-08-02 | en | 1995-02-07 |
US-57655475-A | Centerless grinder work support and booty roller therefor
ABSTRACT
A work support for a centerless grinder or the like comprises an elongated floor-supported guide tube adapted to extend along beneath a work piece to be machined in the grinder with a plurality of V-shaped supports arranged on the guide tube in spaced relation therealong and having at their ends a pair of work supporting booty rollers mounted in confronting cooperative work supporting relation on opposite sides of the work to be supported with the axes of the rollers skewed to the axis of the work, each such roller having a booty axle having angularly related roller receiving and axle mounting portions with the latter supported on the V-shaped arms to extend parallel to the axis of the work to be supported, and with means supporting the axle mounting portion on the arms for adjustable rotation about their axes and for locking the axles in adjusted rotated positions, thereby providing for adjustment of the skew angle of the booty rollers relative to the work to be supported.
FIELD OF INVENTION
This invention relates to work supports for centerless grinders, in particular a support which extends away from the grinder on opposite sides thereof for supporting elongated work pieces to be fed into and out of the grinder for machining operations by the grinder. The work piece supports hold the work piece in proper alignment with the support blade and in turn the grinding and regulating wheels of the grinder. The supports include rollers, herein called booty rollers, which are freely rotating and support the work piece for the rotation and translation in opposite directions of movement toward and from the grinder.
BACKGROUND OF THE INVENTION
In my prior U.S. Pat. Nos. 2,775,077, 3,019,571 and 3,091,900 I have disclosed apparatus of the general type to which my instant invention relates. Such apparatus is accessory to centerless grinding machines or the like and comprises a floor-supported guide tube on which are arranged in spaced apart relation therealong a plurality of upwardly extending V-shaped supports with the arms of the V disposed on opposite sides of the work piece to be machined by the grinder. Booty rollers having their axes of rotation skewed to the axis of the work piece are mounted in opposed cooperating work piece supporting relation on the arms. The booty rollers are freely rotating and as the work piece is rotated in the grinder by the regulating wheel, the booty rollers support the work piece for free rotation in proper alignment with the support blade of the grinder.
It is conventional within a centerless grinder to provide a regulating wheel whose axis of rotation is adjustable relative to the axis of the work piece to be machined such that as the regulating wheel rotates in one direction it causes the work piece to rotate and at the same time translates it axially through the grinder causing the work piece to brush in grinding or polishing relation the periphery of the grinding wheel. The angular relation of the axis of the regulating wheel to the axis of the work piece is conventionally referred to as the "helix" angle of the regulating wheel. The skewed relation of the booty rollers to the axis of the work piece is intended to assist translation of the work piece through the centerless grinder.
I have found that difficulty has been encountered in satisfactorily grinding elongated work pieces following the teaching of the prior art. On occasion the work piece, particularly heavy work pieces, seem to have a tendency to stall in the grinder between the regulating wheel and the grinding wheel causing the grinder to grind a flat or dwell mark in the work piece often ruining the same. In addition, I have observed that the speed of translation of work pieces supported by prior art type work supports is not always uniform in passing through the centerless grinder and in consequence causes difficulty in reaching the desired dimension of the work piece during the grinding operation throughout the length of the work piece. In other words, as the amount of material removed from the work piece is dependent upon the exposure of the work piece to the grinding wheel, variations in the translation speed will result in variations in the amount of material removed from the work piece as it passes by the grinding wheel.
I have discovered that the aforementioned stalling as well as the variation in feed or translation rate of the work piece arises from the fact that when the operator varies the helix angle of the regulating wheel, such that the same does not correspond exactly to the skew angle of the booty rollers, the regulating wheel and booty rollers tend to "fight"; the one tending to speed up the translational movement of the work piece while the other tending to slow down the translational movement of the work piece with the result that either the regulating wheel or booty rollers will from time to time predominate in the determination of feed rate. This condition arises, in my opinion, from the fact that as an elongated work piece is being fed into the centerless grinder, a large number of booty rollers will be in supporting relation with the work piece and as the work piece enters the grinder and moves through it, fewer numbers of booty rollers will support the work piece and as a consequence, the skew angle thereof will be less predominant in determining translational rate than the helix angle of the regulating wheel. As the work piece passes through the centerless grinder and is supported by booty rollers on the outfeed side, as more and more of these rollers come in to supporting contact with the work piece the skew angle of the rollers will tend to more and more influence the translational rate of the work piece in relation to the translational rate as determined by the regulating wheel. Accordingly, varying translational rates may arise during movement of a work piece through the centerless grinder.
In severe cases the work piece may actually stall or dwell in the grinder with the concomitant result that a flat or dwell mark appears on the work piece as aforesaid. This may result from the skew angle of the booty rollers sufficiently resisting translation of the work piece so that translational movement is actually arrested in the grinder.
SUMMARY OF THE INVENTION
I have discovered that the aforesaid difficulties can be obviated by providing booty rollers whose skew angle can be adjusted so that it corresponds to the helix angle of the regulating wheel. Accordingly, the operator of the centerless grinder, upon adjusting the feed rate by adjusting the helix angle of the regulating wheel, can then, by adjusting the skew angle of the booty rollers, make the latter correspond, or substantially correspond, to the helix angle of the regulating wheel so that the aforesaid "fighting" therebetween is overcome and as a consequence the feed rate of the work piece is uniform from end to end through the grinder insuring uniform machining throughout its length and avoiding any tendency to stall or dwell within the grinder.
In the conventional centerless grinder the regulating wheel helix angle is variable between one and four degrees relative to the axis of the work piece being ground. Accordingly, according to my invention, the booty rollers are supported on the V-shaped support arms for adjustment of their skew angle between one and four degrees relative to the axis of the work piece to be supported. In carrying out the invention, the booty rollers have an axle with a roller receiving portion and an axle mounting portion which are arranged in end-to-end angled relation with the axes of the respective portions intersecting at a four degree angle. The axle supporting portion is adapted to be mounted on the arms of the V-shaped supports to extend parallel to the axis of the work piece. By adjustably rotating the axle, the helix angle component of the skew angle of the booty roller can be varied up to four degrees in relation to the axis of the work piece and thereby made to correspond to the helix angle of the regulating wheel, it only being necessary for the operator to individually adjust the axles of the booty wheels upon making an adjustment in the helix angle of the regulating wheel.
While the booty rollers may be provided with a steel work piece supporting surface, I have found that in many instances it is desirable to provide a booty roller with an elastomeric work piece supporting surface, such as a polyurethane elastomer. Difficulty has been encountered, however, in that using such elastomeric booty rollers with heavy work pieces has a tendency to cause the elastomeric material to be dislodged from the booty roller assembly because of the substantial axial forces and the compression and expansion of the elastomeric material as the roller revolves in its support of the work piece. I have discovered that this difficulty can be overcome by mechanically interlocking the elastomeric material to the booty roller assembly by casting such material in situ on a knurled exterior surface of an internal bushing within the booty roller. This bushing in turn may be supported on a roller bearing assembly which in turn supports the booty roller on the booty roller receiving portion of the axle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing my work piece supporting fixtures extending from opposite sides of a centerless grinder;
FIG. 2 is a cross sectional view taken substantially on the line 2--2 of FIG. 1;
FIG. 3 is a vertical elevation taken on the line 3--3 of FIG. 1;
FIG. 4 is a cross sectional view taken on the line 4--4 of FIG. 3 but showing a work piece supported by the booty rollers;
FIG. 5 is a plan view of the V-shaped support of FIG. 4;
FIG. 6 is a side elevation of a booty roller assembly; and
FIG. 7 is a side elevation of a booty roller bushing with an elastomeric surface shown in section.
BRIEF DESCRIPTION OF PREFERRED EMBODIMENT
A centerless grinding machine, such as a Cincinnati No. 3 Centerless Grinder manufactured by the Cincinnati Milling Machine Co. is schematically shown in FIGS. 1 and 2 and includes a grinding wheel 10 and a regulating wheel 12 between which is disposed the work piece supporting blade 14 which is carried by a work rest 16. The work rest is bolted in position on a slide 18 forming part of the centerless grinder.
As is conventional in a centerless grinder, the regulating wheel 12 is supported for movement toward and away from the grinding wheel 10 and also for swiveling action in a vertical plane to vary its helix angle with respect to the work piece being ground. This helix angle may be adjusted to lie anywhere between 0° and 7°, with the greater the angle the faster and feed rate of the work through the grinder and vice versa. In addition, the regulating wheel's direction of rotation is reversible as indicated by the arrows in FIG. 1. As a consequence, with the wheel rotating in one direction the work will be fed through the grinder from one side to the other and then by reversing the rotation of the regulating wheel the work can be fed back through the grinder.
When grinding relatively long work pieces it is necessary to support the work on opposite sides of the grinder and such supporting fixtures are shown in FIG. 1 extending from opposite sides of the centerless grinder. In my U.S. Pat. No. 3,091,900I have shown and described in detail the arrangement of such fixtures and reference should be had thereto for a complete description. Suffice it to say that in FIG. 1 an infeed supporting fixture is shown at 20 and an outfeed fixture at 22. Each fixture is supported by a plurality of standards 24 one of which is shown in FIG. 3. At the upper end of each standard there is a cradle 25 for receiving and supporting an elongated guide tube 27. Arranged in spaced relation and supported on the guide tube are a plurality of transversely disposed V-shaped work piece supports provided with opposed, cooperating work supporting booty rollers 26. One of the V-shaped supports is shown in an end view in FIG. 4 and generally indicated at 28. While its construction and operation is more fully described in my aforesaid U.S. Pat. No. 3,091,900, in general the support comprises a pair of upwardly outwardly extending arms 30 and 32 mounted on the guide tube 27. The angular relationship between the arms 30 and 32 is adjustable by the manually operable hand screws 34 and 36 which are threaded through portions of the V-shaped assembly as more particularly described in my 900 patent to effect variation in the included angle A between the arms. Such adjustment provides for accommodating varying diameters of work pieces W and also for making small adjustments in the height of the work piece relative to the centerless grinder thereby providing for accurate alignment of the work piece with the supporting blade 14.
The foregoing is all conventional in the centerless grinder art and serves as background for my invention now to be described. Each of the V-shaped supports is provided with a pair of work supporting booty rollers 26 mounted in confronting cooperative work supporting relation on the arms. Each of the booty rollers is provided as shown in FIG. 6 with an axle 38 which includes a booty roller receiving portion 40 and an axle mounting portion 42 arranged in end-to-end angled relation with the angle therebetween on the order of four degrees. At the intersection of the axle mounting portion and the booty roller receiving portion there is a radially extending shoulder 44 having wrench engaging means thereon, which in the embodiment shown comprises four radially extending spanner wrench receiving sockets 46. The axle mounting portion and the booty roller receiving portion are of cylindrical configuration with the former being threaded at its end 48 in spaced relation from the radially extending shoulder face 50 for reception of a locking nut 52 as shown in FIGS. 4 and 5. Means are provided at the end of the booty roller receiving portion opposite shoulder 44 for retaining the booty roller thereon. Such means comprise an externally threaded length 50 on the booty roller receiving portion with a nut 53 threaded thereon and bearing against a washer 54 which in turn overlies the end of the booty roller, roller bearing assembly 78.
Each of the arms 30 and 32 is provided with an elongate aperture 56 and 58 through which the axle mounting portion 42 of the axle 38 is received with the face 50 of the radial shoulder 44 overlying the arm adjacent the aperture and with the nut 52 bearing against a washer 60 for clamping the shoulder 44 tightly against the arm in any desired rotated position of the axle. As the plane of the V-shaped supports extends perpendicular to the axis of the work piece W and as the face 50 of the shoulder is perpendicular to the axis of the axle mounting portion 42, when the face 50 is tightened against the arms 30 and 32, the axis of the axle mounting portion will extend parallel to the axis of the work piece W. Consequently, by adjustably rotating the axle 38 relative to the supporting arm 30 and 32 prior to tightening the nut 52, the skew angle of the booty roller relative to the axis of the work piece can be adjusted. This skew angle is composed of two components, one lying in a vertical and the other in a horizontal plane relative to the axis of the work as shown by the angles B and C respectively in FIGS. 3 and 5, and in this respect differs from the helix angle of the regulating wheel. The axis of the regulating wheel lies in a vertical plane extending parallel to the axis of the work piece but horizontally displaced from the axis of the work. The resultant angle of angles B and C illustrated in FIGS. 3 and 5 is herein referred to as the skew angle. With a booty roller mounted on a supporting arm with its axle being in the position shown in FIG. 6, namely with the four degree angle between the axes of the axle supporting portion and the booty roller receiving portion lying in a vertical plane, angle C shown in FIG. 5 will be zero while angle B of FIG. 3 will be 4°. As the axle is rotatably adjusted, angle C will increase to a maximum of four degrees while angle B will be reduced from four degrees to zero. At intermediate points, angle B, which represents the helix angle of the booty roller in relation to the work piece, may be made to correspond to the helix angle of the regulating wheel by suitable rotatable adjustment of the booty axle on the support.
In setting up the booty rollers preparatory to grinding or polishing a work piece W in the centerless grinder, the operator will adjust the rotated position of the booty axles so that the angle B closely corresponds with the helix angle of the regulating wheel. Such adjustment is facilitated by the location of the spanner wrench receiving sockets 44. In the preferred arrangement, the sockets are disposed at 90° of rotation the helix angle B of the roller is adjusted by one degree. In other words the sockets provide an indicating means on the shoulder with the angular distance between the sockets corresponding to a predetermined increment of the angle between the portions 40 and 42 of the axle. As a consequence, by reference to the position of the sockets, the operator can adjust the booty roller from zero to four degrees helix angle with respect to the axis of the work piece and thereby have such angle correspond to the helix angle of the regulating wheel between zero degrees and four degrees. Such wrench engaging sockets also facilitate holding the axle in rotatably adjusted positions while tightening the nut 52.
In a preferred embodiment the booty roller is provided with an elastomeric work piece supporting surface to prevent marring or scratching of the work piece. Heretofore I have experimented with booty rollers having such elastomeric work supporting surfaces. However, the difficulty has been that there is a tendency of the elastomeric cover to be displaced axially and dislodged from its position on the booty roller assembly. I believe this has resulted from the squeezing and expansion of the elastomer as well as the heavy weight of the work piece as the roller rotates while at the same time the skew angle of the roller tends to axially displace the elastomer. I have discovered that this can be obviated by the construction herein shown. In FIG. 7 the booty roller is provided with a cylindrical bushing 70 of rigid material such as steel coaxial with the work piece supporting periphery 72 of the roller. The bushing has an inside diameter 74 which is desirably chamfered at 76 at one end. This inside diameter is finished smooth for a press fit over the roller bearing assembly 78 shown in FIG. 6 which is of conventional construction. The chamfered entrance 76 of the ID of the bushing allows the ready press fitting of the bushing over the roller bearing assembly. The roller bearing assembly has an inside bore 79 for reception over the booty roller receiving axle portion 40. The outside surface of the bushing is roughened as by knurling the same as indicated at 80. In manufacturing the booty roller the bushing with the knurled surface 80 is placed in a cylindrical mold concentric with the circular wall of the mold and then a urethane rubber or elastomer such a polyurethane in liquid form is poured into the mold to fill the same and contact the knurled surface 80 of the bushing. The mold is then placed in an oven and the liquid urethane cured to the solid state. Upon curing, the urethane will have entered the interstices of the knurled surface 80 mechanically interlocking the urethane to the bushing 70 and preventing any relative axial displacement of the urethane from the bushing.
In FIG. 7 the elastomer or urethane is shown in section phantom outline at 82. When mounting the booty roller on the booty roller receiving portion 40 of the axle, the shoulder 44 and its beveled face 84 (beveled at an angle corresponding to the four degree inclination between the opposite end portions of the axle) will enter the end of the bushing to bear lightly against the roller bearing assembly 78 as shown in FIG. 7 while the nut 53 will overlie the opposite end and the bearing assembly and bear against the intermediate washer or the like 54 as above mentioned.
During operation of the centerless grinder the regulating wheel 12 will engage the work and rotate the same depending upon the direction of rotation of the regulating wheel and cause a translation or axial movement of the work piece through the grinder. With the helix angle of the regulating wheel closely corresponding to the B angle component of the skew angle of the booty rollers, the booty rollers will assist in the translational movement of the work piece. After the work piece has passed through the grinder, the operator may reverse the direction of regulating wheel rotation and feed the work piece back through the grinder, such opposite rotational movement of the regulating wheel causing translation of the work in the opposite direction. With the work piece rotating in the opposite direction the booty rollers will of course revolve in the opposite direction again assisting the regulating wheel in uniformly feeding the work through the grinder. As a consequence of this arrangement there is no "fighting" between the action of the booty rollers and that of the regulating wheel and no tendency of the work piece to stall in the grinder ruining the same as has occurred with the prior art fixtures.
What is claimed is:
1. In a centerless grinder work support having an elongated floor supported guide tube adapted to extend along beneath a work piece to be machined in the grinder and with a plurality of upwardly extending V-shaped supports arranged on the guide tube in spaced relation therealong with the arms of the V disposed on opposite sides of the work to be supported, a pair of work supporting booty rollers mounted in confronting cooperative work supporting relation on the arms of each V-shaped support with the axes of the rollers skewed to the axis of the work to be supported, an axle for each booty roller, said axle comprising integral opposite end portions, one being a booty roller receiving portion and the other an axle mounting portion, said portions being arranged in end-to-end angled relation, and means supporting said axle mounting portions for adjustable rotation on the arms of the V-shaped supports about axes extending parallel to the axis of the work to be supported and for locking said axle mounting portions in fixed positions on such arms, whereby the skew angle of the booty roller receiving portion may be adjustably fixed relative to the work to be supported.
2. The invention defined by claim 1 characterized in that said means includes an aperture extending through each arm of the V-shaped supports through which the axle mounting portion is extended, said axle mounting portion includes a shoulder adapted to overlie one side of the arm of the V-shaped support adjacent said aperture and nut means threadedly engaged on the axle mounting portion for tightening against the opposite side of the arm adjacent the aperture.
3. The invention defined by claim 2 characterized in that said shoulder has wrench engaging means adapted to permit holding of the axle mounting portion in a fixed rotated position during tightening of said nut means.
| 1975-05-12 | en | 1977-04-19 |
US-66186276-A | Poly(aryloxyphosphazene) copolymers
ABSTRACT
Poly(aryloxyphosphazene) copolymers and foams thereof having a significant portion of C 1 - C 4 alkoxyphenoxy groups are described. The copolymers consist of the units which occur in a nonregular fashion and are represented by the following general formulas: ##STR1## wherein R 1 represents a C 1 - C 4 linear or branched alkyl radical in the ortho-, meta-, or para-position, and R 2 represents hydrogen, a C 1 - C 10 linear or branched alkyl radical, or a C 1 - C 4 linear or branched alkoxy radical substituted on any sterically permissible position on the phenoxy group, with the proviso that when R 2 is alkoxy, OR 1 and R 2 are different. The copolymers of this invention may contain small amounts of randomly distributed units in addition to the repeating units described above, these additional units containing reactive sites enabling the properties of the copolymers to be modified by crosslinking and/or curing. The copolymers are elastomers, have desirable tensile strengths and may be used to form flexible or semirigid foams. The copolymers are extremely fire retardant and produce low smoke loads, or essentially no smoke, when heated in an open flame.
DESCRIPTION OF THE INVENTION
This invention relates to elastomeric poly(aryloxyphosphazene) copolymers, to flexible and semirigid foams produced from said copolymers, and to a process for preparing said copolymers and foams. The copolymers of this invention are soluble in tetrahydrofuran, benzene and dimethylformamide and exhibit excellent flame retardant and film-forming properties. Foams prepared from the copolymers exhibit excellent flame retardant properties and produce low smoke levels, or essentially no smoke, when heated in an open flame. All of the copolymers described may be crosslinked at moderate temperatures in the presence of free radical initiators and the copolymers containing reactive unsaturation additionally may be cured by conventional sulfur curing or vulcanizing additives to modify their properties and expand their field of use.
The preparation of poly(aryloxyphosphazene) copolymers has been disclosed in U.S. Pat. No. 3,856,712 to Reynard et al., U.S. Pat. No. 3,856,713 to Rose et al., and U.S. Pat. No. 3,883,451 to Reynard et al. However, in contrast to the copolymers of the present invention, the copolymers described in the first mentioned Reynard et al. patent contain selected quantities of both alkoxy and aryloxy side chains in the copolymer backbone, whereas the copolymers described in the latter-mentioned Reynard et al. patent are characterized by the presence of halogen-substituted aryl side chains in the copolymer backbone. The copolymers disclosed in the above mentioned Rose et al. patent also differ from the copolymers of the present invention since they are characterized by the presence of only aryloxy and alkyl-substituted aryloxy side chains. Other related art may be found in U.S. Pat. Nos. 3,515,688; 3,700,629; 3,702,833 and 3,856,712, but in each case, the polymers described in these patents differ from the copolymers of this invention in their structure and physical characteristics.
The poly(aryloxyphosphazene) copolymers of this invention are characterized by repeating ##STR2## units which contain substituted aryloxy-substituents (preferably substituted in the para position) on the phosphorous atoms in nonregular fashion and which can be represented by the following formulas: ##STR3## wherein R1 is a C1 - C4 lineaar or branched alkyl radical in the ortho-, meta-, or para-position, and R2 is hydrogen or a C1 - C10 linear or branched alkyl radical or a C1 - C4 linear or branched alkoxy radical, substituted in any sterically permissible position on the phenoxy group with the proviso that when R2 is alkoxy, OR1 and R2 are different. Examples of R1 include ethoxy, methoxy, isopropoxy and n-butoxy. Examples of R2 include methyl, ethyl, n-propyl, isopropyl, sec-butyl, tert-butyl, tert-pentyl, 2-ethylhexyl and n-nonyl.
It is to be understood that while it is presently preferred that all R1 's are the same and all R2 's are the same the R1 can be mixed and the R2 can be mixed. The mixtures may be mixtures of different alkyl radicals or mixtures of different ortho-, meta- and para-isomers. One skilled in the art readily will recognize that steric hindrance will dictate the propriety of using relatively bulky groups in the para-position on the phenoxy ring since as set forth hereinafter the polymers are made by reacting a substituted metal phenoxide with a chlorine atom on a phosphrous atom. Desirably, groups which sterically inhibit this reaction should be avoided. Absent the foregoing proviso, the selection of the various R1 's and R2 's will be apparent to anyone skilled in the art based upon this disclosure.
For the sake of simplicity, the copolymers of the invention which contain the above three repeating units may be represented by the formula [NP(OC.sub. 6 H4 --OR1)a (OC6 H4 --R2)b ]n, wherein n is from about 20 to about 2000 or more, and wherein a and b are greater than zero and a+b=2.
The above described copolymers, as well as those containing reactive sites designated as W below, may be crosslinked and/or cured at moderate temperatures (for example, 200°-350° F.) by the use of free radical initiators, for example, peroxides, using conventional amounts, techniques and processing equipment.
The copolymers of this invention may contain small amounts of randomly distributed repeating units in addition to the repeating units described above. Examples of these additional repeating units are: ##STR4## wherein W represents a group capable of a crosslinking chemical reaction, such as, an olefinically unsaturated, preferably ethylinically unsaturated monovalent radical, containing a group capable of further reaction at relatively moderate temperatures, and the ratio of W:[(--OC6 H4 --OR1)+(--OC6 H4 --R2)] is less than about 1:5. For the sake of simplicity, the copolymers of this invention which are further reactive may be represented by the formula [NP(OC6 H4 --OR1)a (OC6 H4 --R2)b (W)c ]n, wherein W, R1, R2, n, a and b are set forth above, and wherein a+b+c=2. Examples of W are --OCH═CH2 ; --OR3 CH═CH2 ; ##STR5## OR3 CF═CF2 and similar groups which contain unsaturation, where R3 is any aliphatic or aromatic radical, especially --CH2 --. These groups are capable of further reaction at moderate temperatures (for example, 200°-350° F.) in the presence of free radical initiators, conventional sulfur curing or vulcanizing additives known in the rubber art or other reagents, often even in the absence of accelerators, using conventional amounts, techniques and processing equipment.
Examples of free radical initiators include benzoyl peroxide, bis(2,4-dichlorobenzoyl peroxide), di-tert-butyl peroxide, dicumyl peroxide, 2,5-dimethyl(2,5-di-tert-butylperoxy) hexane, t-butyl perbenzoate, 2,5-dimethyl-2,5-di(tert-butyl peroxy) hepyne-3, and 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. Thus, the general peroxide classes which may be used for crosslinking include diacyl peroxides, peroxyesters, and dialkyl peroxides.
Examples of sulfur-type curing systems include vulcanizing agents such as sulfur, sulfur monochloride, selenium, tellurium, thiuram disulfides, p-quinone dioximes, polysulfide polymers, and alkyl phenol sulfides. The above vulcanizing agents may be used in conjunction with accelerators, such as aldehyde amines, thio carbamates, thiuram sulfides, quanidines, and thiazols, and accelerator activators, such as zinc oxide or fatty acids, e.g., stearic acid.
It is also possible to use as W in the above formulas, monovalent radicals represented by the formulas (1) --OSi(OR4)2 R5 and other similar radicals which contain one or more reactive groups attached to silicon; (2) --OR6 NR6 H and other radicals which contain reactive --NH linkages. In these radicals R4, R5 and R6 each represent aliphatic, aromatic and acyl radicals. Like the groups above, these groups are capable of further reaction at moderate temperatures in the presence of compounds which effect crosslinking. The presence of a catalyst to achieve a cure is often desirable. The introduction of groups such as W into polyphosphazene polymers is shown in U.S. Pat. Nos. 3,888,799; 3,702,833 and 3,844,983, which are hereby incorporated by reference.
The ratio of a:b, and of (a+b) :c where units containing W are present in the copolymer, affects the processability, smoke production, glass transition temperature and a number of other properties of the copolymers. These ratios also affect the copolymer's ability to be foamed and the properties, such as the rigidity, or the resulting foams. For example, it has been found that an increase in the mole percent of R1 decreases the amount of smoke generated when the copolymers are subjected to an open flame. It has been found, also, that as the mole percent of R1 approaches 100 percent, the crystallinity of the copolymers increases and their ability to be foamed diminishes. Similarly, it has been found that when the mole percent of W increases, the degree of cross-linking increases and the ability to be foamed diminishes. Accordingly, it is contemplated that the copolymers of this invention contain a mole ratio of a:b of at least about 1:6 and up to about 6:1, and preferably between about 1:4 and 4:1. It is also contemplated that the mole ratio of c:(a+b) will be less than about 1:5, preferably from about 1:50 to about 1:10.
In one embodiment, the copolymers of this invention may be prepared in accordance with the process described in U.S. Pat. No. 3,370,020 to Allcock et al., which description is incorporated herein by reference. Accordingly, the copolymers of this invention may be prepared by a multistep process wherein the first step comprises thermally polymerizing a compound having the formula
(NPCl.sub.2).sub.3
by heating it at a temperature and for a length of time ranging from about 200° C. for 48 hours to 300° C. for 30 minutes, preferably in the absence of oxygen, and most preferably in the presence of a vacuum of at least 10-1 Torr. That is to say, the compounds are heated to a temperature ranging from about 200° C. to about 300° C. for from about 30 minutes to 48 hours, the higher temperatures necessitating shorter contact times and the lower temperatures necessitating longer contact times. The compounds must be heated for such a length of time that only a minor amount of unreacted charge material remains and a major amount of high polymer has been produced. Such a result is generally achieved by following the conditions of temperature and contact time specified above.
It is preferred that the thermal polymerization be carried out in the presence of an inert gas such as nitrogen, neon, argon or a vacuum, e.g., less than about 10-1 Torr inasmuch as the reaction proceeds very slowly in the presence of air. The use of such a gas, however, is not critical.
The polymers resulting from the thermal polymerization portion of the process are in the form of a polymeric mixture of different polymers of different chain lengths. That is to say, the product of the thermal polymerization is a mixture of polymers having the formula
--NPCl.sub.2 --.sub.n
wherein n ranges from about 20 to about 2000. For example, the recovered media may contain minor amounts of a polymer where n is 20 and major amounts of polymer where n is 2000. The media may also contain polymers composed of from 12-1999 recurring units and some unreacted trimer. The complete mixture of polymers and unreacted trimer constitutes the charge to the second step of the process.
The second or esterification step of the process comprises treating the mixture resulting from the thermal polymerization step with a mixture of compounds having the formulas
M(oc6 h4 --or1)x,
M(oc6 h4 --r2)x, and, if desired,
M(w)x,
wherein M is lithium, sodium, potassium, magnesium or calcium, x is equal to the valence of metal M, and R1, R2 and W are as specified above.
The polymer mixture is reacted with the mixture of metal compounds at a temperature and a length of time ranging from about 25° C. for 7 days to about 200° C. for 3 hours.
Again, as in regard to the polymerization step mentioned above, the polymer mixture is reacted with the alkali or alkaline earth metal compounds at a temperature ranging from about 25° C. to about 200° C. for from about 3 hours to 7 days, the lower temperatures necessitating the longer reaction times and the higher temperatures allowing shorter reaction times. These conditions are, of course, utilized in order to obtain the most complete reaction possible, i.e., in order to insure the complete conversion of the chlorine atoms in the polymer mixture to the corresponding ester of the alkali or alkaline earth starting materials.
The above esterification step is carried out in the presence of a solvent. The solvent employed in the esterification step must have a relatively high boiling point (e.g., about 115° C., or higher) and should be a solvent for both the polymer and the alkali or alkaline earth metal compounds. In addition, the solvent must be substantially anhydrous, i.e., there must be no more water in the solvent or metal compounds than will result in more than 1%, by weight, of water in the reaction mixture. The prevention of water in the system is necessary in order to inhibit the reaction of the available chlorine atoms in the polymer therewith. Examples of suitable solvents include diglyme, triglyme, tetraglyme, toluene and xylene. The amount of solvent employed is not critical and any amount sufficient to solubilize the chloride polymer mixture can be employed. Either the polymer mixture or the alkaline earth (or alkali) metal compounds may be used as a solvent solution thereof in an inert, organic solvent. It is preferred, however, that at least one of the charge materials be used as a solution in a compound which is a solvent for the polymeric mixture.
The combined amount of the mixture of alkali metal or alkaline earth metal compounds employed should be at least molecularly equivalent to the number of available chlorine atoms in the polymer mixture. However, it is preferred that an excess of the metal compounds can be employed in order to assure complete reaction of all the available chlorine atoms. Generally, the ratio of the individual alkali metal or alkaline earth metal compounds on the combined mixture governs the ratio of the groups attached to the polymer backbone. However, those skilled in the art readily will appreciate that the nature and, more particularly, the steric configuration of the metal compounds employed may effect their relative reactivity. Accordingly, the ratio of R1 's and R2 's in the esterified product, if necessary, may be controlled by employing a stoichiometric excess of the slower reacting metal compound.
Examples of alkali or alkaline earth metal compounds which are useful in the process of the present invention include
sodium phenoxide
potassium phenoxide
sodium p-methoxyphenoxide
sodium o-methoxypheoxide
sodium m-methoxyphenoxide
lithium p-methoxyphenoxide
lithium o-methoxyphenoxide
lithium m-methoxyphenoxide
potassium p-methoxyphenoxide
potassium o-methoxyphenoxide
potassium m-methoxyphenoxide
magnesium p-methoxyphenoxide
magnesium o-methoxyphenoxide
magnesium m-methoxyphenoxide
calcium p-methoxyphenoxide
calcium o-methoxyphenoxide
calcium m-methoxyphenoxide
sodium p-ethoxyphenoride
sodium o-ethoxyphenoride
sodium m-ethoxyphenoride
potassium p-ethoxyphenoxide
potassium o-ethoxyphenoxide
potassium m-ethoxyphenoxide
sodium p-n-butoxyphenoxide
sodium m-n-butoxyphenoxide
lithium p-n-butoxyphenoxide
lithium m-n-butoxyphenoxide
potassium p-n-butoxyphenoxide
potassium m-n-butoxyphenoxide
magnesium p-n-butoxyphenoxide
magnesium m-n-butoxyphenoxide
calcium p-n-butoxyphenoxide
calcium m-n-butoxyphenoxide
sodium p-n-propoxyphenoxide
sodium o-n-propoxyphenoxide
sodium m-n-propoxyphenoxide
potassium p-n-propoxyphenoxide
potassium o-n-propoxyphenoxide
potassium m-n-propoxyphenoxide
sodium p-methylphenoxide
sodium o-methylphenoxide
sodium m-methylphenoxide
lithium p-methylphenoxide
lithium o-methylphenoxide
lithium m-methylphenoxide
sodium p-ethylphenoxide
sodium o-ethylphenoxide
sodium m-ethylphenoxide
potassium p-n-propylphenoxide
potassium o-n-propylphenoxide
potassium m-n-propylphenoxide
magnesium p-n-propylphenoxide
sodium p-isopropylphenoxide
sodium o-isopropylphenoxide
sodium m-isopropylphenoxide
calcium p-isopropylphenoxide
calcium o-isopropylphenoxide
calcium m-isopropylphenoxide
sodium p-sec butylphenoxide
sodium m-sec butylphenoxide
lithium p-sec butylphenoxide
lithium m-sec butylphenoxide
lithium p-tert. butylphenoxide
lithium m-tert. butylphenoxide
potassium p-tert. butylphenoxide
potassium m-tert. butylphenoxide
sodium p-tert. butylphenoxide
sodium m-tert. butylphenoxide
sodium propeneoxide
sodium p-nonylphenoxide
sodium m-nonylphenoxide
sodium o-nonylphenoxide
sodium 2-methyl-2-propeneoxide
potassium buteneoxide
and the like.
The second step of the process results in the production of a copolymer mixture having the formula
-- NP(OC.sub. 6 H.sub.4 OR.sub.1).sub.a (OC.sub.6 H.sub.4 R.sub.2).sub.b (W).sub.c --.sub.n
wherein n, R1, R2 and W are as specified above, where c, but not a and b can be zero, and where a+b+c=2, and the corresponding metal chloride salt.
The copolymeric reaction mixture resulting from the second or esterification step is then treated to remove the salt which results upon reaction of the chlorine atoms of the copolymer mixture with the metal of the alkali or alkaline earth metal compounds. The salt can be removed by merely precipitating it out and filtering, or it may be removed by any other applicable method, such as by washing the reaction mixture with water after neutralization thereof with, for example, an acid such as hydrochloric acid.
The next step in the process comprises fractionally precipitating the copolymeric material to separate out the high polymer from the low polymer and any unreacted trimer. The fractional precipitation is achieved by the, preferably dropwise, addition of the esterified copolymer mixture to a material which is a non-solvent for the high polymer and a solvent for the low polymer and unreacted trimer. That is to say, any material which is a non-solvent for the polymers wherein n is higher than 350 and a solvent for the remaining low polymers may be used to fractionally precipitate the desired polymers. Examples of materials which can be used for this purpose include hexane, diethyl ether, carbon tetrachloride, chloroform, dioxane methanol, water and the like. The fractional precipitation of the esterified copolymeric mixture generally should be carried out at least twice and preferably at least four times in order to remove as much of the low polymer from the polymer mixture as possible. The precipitation may be conducted at any temperature, however, it is preferred that room temperature be employed. The novel high molecular weight copolymer mixture may then be recovered by filtration, centrifugation, decantation or the like.
The novel copolymeric mixtures of this invention, as mentioned above, are very thermally stable. The mixtures are soluble in specific organic solvents such as tetrahydrofuran, benzene, xylene, toluene, dimethylformamide and the like and can be formed into films from solutions of the copolymers by evaporation of the solvent. The copolymers are water resistant at room temperature and do not undergo hydrolysis at high temperatures. The copolymers may be used to prepare films, fibers, coatings, molding compositions and the like. They may be blended with such additives as antioxidants, ultraviolet light absorbers, lubricants, plasticizers, dyes, pigments, fillers such as litharge, magnesia, calcium carbonate, furnace black, alumina trihydrate and hydrated silicas, other resins, etc., without detracting from the scope of the present invention.
The copolymers may be used to prepare foamed products which exhibit excellent fire retardance and which produce low smoke levels, or essentially no smoke when heated in an open flame. The foamed products may be prepared from filled or unfilled formulations using conventional foam techniques with chemical blowing agents, i.e. chemical compounds stable at original room temperature which decompose or interact at elevated temperatures to provide a cellular foam. Suitable chemical blowing agents include:
______________________________________
Effective Temperature
Blowing Agent Range ° C.
______________________________________
Azobisisobutyronitrile
105-120
Azo dicarbonamide(1,1-azobisform-
amide) 100-200
Benzenesulfonyl hydrazide
95-100
N,N'-dinitroso-N,N'-dimethyl tere-
phthalamide
Dinitrosopentamethylenetetramine
130-150
Ammonium carbonate 58
p,p'-oxybis-(benzenesulfonyl-
hydrazide) 100-200
Diazo aminobenzene 84
Urea-biuret mixture 90-140
2,2'-azo-isobutyronitrile
90-140
Azo hexahydrobenzonitrile
90-140
Diisobutylene 103
4,4'-diphenyl disulfonylazide
110-130.
______________________________________
Typical foamable formulations include: Phosphazene copolymer (e.g., [NP(OC.sub. 6 H5)(OC.sub. 6 H4 --p--OCH3)]n
______________________________________
100 parts
Filler (e.g., alumina trihydrate)
0-100 phr
Stabilizer (e.g., magnesium oxide)
2.5-10 phr
Processing aid (e.g., zinc stearate)
2.5-10 phr
Plasticizer resin (e.g., Cumar P-10,
coumarone indene resin) 0-50 phr
Blowing agent (e.g., 1,1'-azobisformamide)
10-50 phr
Activator (e.g., oil-treated urea)
10-40 phr
Peroxide curing agent (e.g., 2,5-
dimethyl-2,5-di(t-butylperoxy)
hexane) 2.5-10 phr
Peroxide curing agent (e.g., benzoyl
peroxide) 2.5-10 phr
______________________________________
While the above are preferred formulation guidelines, obviously some or all of the adjuvants may be omitted, replaced by other functionally equivalent materials, or the proportions varied, within the skill of the art of the foam formulator.
In one suitable process, the foamable ingredients are blended together to form a homogeneous mass; for example, a homogeneous film or sheet can be formed on a 2-roller mill, preferably with one roll at ambient temperature and the other at moderately elevated temperature, for example 100°-120° F. The homogeneous foamable mass can then be heated, to provide a foamed structure; for example, by using a mixture of a curing agent having a relatively low initiating temperature, such as benzoyl peroxide, and a curing agent having a relatively high intiating temperature, such as 2,5-dimethyl-2,5-di(t-butylperoxy) hexane, and partially pre-curing in a closed mold for about 6-30 minutes at 200°-250° F., followed by free expansion for 30-60 minutes at 300°-350° F. In the alternative, the foaming may be accomplished by heating the foamable mass for 30-60 minutes at 300°-350° F. using a high temperature or low temperature curing agent, either singly or in combination. One benefit of utilizing the "partial pre-cure" foaming technique is that an increase in the molecular weight of the foamable polymer prior to the foaming step enables better control of pore size and pore uniformity in the foaming step. The extent of "pre-cure" desired is dependent upon the ultimate foam characteristics desired. The desired foaming temperature is dependent on the nature of the blowing agent and the crosslinkers present. The time of heating is dependent on the size and shape of the mass being foamed. The resultant foams are generally light tan to yellowish in appearance, and vary from flexible to semirigid, depending upon the glass transition temperature of the copolymer employed in the foam formulation, that is to say, the lower the glass transition of the copolymer the more flexible will be the foam produced therefrom. As indicated, inert, reinforcing or other fillers such as alumina trihydrate, hydrated silicas or calcium carbonate can be added to the copolymer foams and the presence of these and other conventional additives should in no way be construed as falling outside the scope of this invention.
Also, as mentioned above, the copolymers of this invention can be crosslinked at moderate temperatures by conventional free radical and/or sulfur curing techniques when minor amounts of unsaturated groups W are present in the copolymer backbone. The ability of these copolymers to be cured at temperatures below about 350° F. makes them particularly useful as potting and encapsulation compounds, sealants, coatings and the like. These copolymers are also useful for preparing crosslinked foams which exhibit significantly increased tensile strengths over uncured foams. These copolymers are often crosslinked in the presence of inert, reinforcing or other fillers and the presence of these and other conventional additives are deemed to be within the scope of this invention.
The following examples are set forth for purposes of illustration only and are not to be construed as limitations of the present invention except as set forth in the appended claims. All parts and percentages are by weight unless otherwise indicated.
EXAMPLE 1
Preparation of --NPCl2 --n
250 parts of phosphonitrilic chloride trimer, previously recrystallized from n-heptane, were degassed and sealed in a suitable, thick-walled reaction vessel at 10-2 Torr and heated to 250° C. for 6 hours. Polymerization was terminated at this time since a glass ball, 1/2 inch in diameter ceased to flow due to the increased viscosity of the molten mass, when the vessel was inverted. Termination was effected by cooling the vessel to room temperature. The resulting polymeric mixture was then dissolved in toluene to form an anhydrous solution.
EXAMPLE 2
Preparation of [NP(OC6 H4 --p--OCH3)(OC.sub. 6 H5)]n
The anhydrous toluene solution of poly(dichlorophosphazene) formed in Example 1, containing 0.97 equivalents of poly(dichlorophosphazene), was added to an anhydrous diglymebenzene solution of 0.62 equivalents of NaOC6 H4 --4--OCH3 and 0.62 equivalents of NaOC6 H5 at a temperature of 95° C. with constant stirring. After the addition, benzene was distilled from the reaction mixture until a temperature of 115°-116° C. was attained. The reaction was then heated at relfux for 60-65 hours. At the end of this time the copolymer was precipitated by pouring the reaction mixture into an excess of methyl alcohol. The polymer was stirred in the methyl alcohol for 24 hours. Next, it was added to a large excess of water and stirred for an additional 24 hours. The resulting product (40 percent yield) was a semicrystalline solid having a glass transition temperature (Tg) of +0.74° C. The product was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film was flexible, did not burn, and was water-repellant. The copolymer had an Oxygen Index (OI) of 25.0 as determined according to the procedure described in ASTM D-2863-74, "Flammability of Plastics Using the Oxygen Index Method". By this method, material samples, which are 6 × 2 × .01 to 0.03", are held in a U-shaped frame and the burning of the samples under a specific set of conditions is measured. It has been shown that this technique actually measures the lowest oxygen concentration in an atmosphere which will just prevent sustained burning of a top-ignited sample (see Fenimore et al, Combustion and Flame, 10, 135 (1966)). The oxygen index values also have been related to the temperature at which a mixture of fuel and a controlled flow of oxygen will just burn when the fuel is composed of volatile pyrolytic products or fragments (see, Johnson et al, Rubber Age, 107 (No. 5), 29 (1975)). Analysis: Calculated (percent) for 1:1 copolymer of [NP(OC6 H4 --p--OCH3) (OC6 H5)]n : C, 59.77; H, 4.64; N, 5.36; and Cl, 0.00. Found (percent): C, 59.62; H, 4.73; N, 5.38; and Cl, 0.00.
EXAMPLE 3
Preparation of [NP(OC6 H4 --p--OCH3)(OC6 H4 --p--CH3)]n
The procedure of Example 2 was followed, except that to 0.56 equivalents of poly(dichlorophosphazene) were added 0.30 equivalents of NaOC6 H4 --p--OCH3 and 0.30 equivalents of NaOC6 H4 --p--CH3.
The resulting product (58 percent yield) was a crystalline solid having a glass transition temperature (Tg) of +5.90° C. The product had an Oxygen Index of 25.3 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to an opaque, brittle film from a solution in tetrahydrofuran. The film did not burn, and was water-repellant.
EXAMPLE 4
Preparation of [NP(OC6 H4 --p--OCH3)(OC6 H4 --p--C2 H5)]n
The procedure of Example 2 was followed, except that to 0.95 equivalents of poly(dichlorophosphazene) were added 0.50 equivalents of NaOC6 H4 --p--OCH3 and 0.50 equivalents of NaOC6 H4 --p--C2 H5.
The resulting product (43 percent yield) was a crystalline solid having a glass transition temperature (Tg) of -3.76° C. The product had an Oxygen Index of 24.0 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film was flexible, did not burn, and was water-repellant.
EXAMPLE 5
Preparation of [NP(OC6 H4 --p--OCH3)(OC6 H4 --p--isoC3 H7)]n
The procedure of Example 2 was followed, except that to 0.48 equivalents of poly(dichlorophosphazene) were added 0.29 equivalents of NaOC6 H4 --p--OCH3 and 0.29 equivalents of NaOC6 H4 --p--isoC3 H7.
The resulting product (48 percent yield) was a crystalline solid having a glass transition temperature (Tg) of +3.00° C. The product had an Oxygen Index of 26.0 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film was flexible, did not burn, and was water resistant.
EXAMPLE 6
Preparation of [NP(OC6 H4 --p--OCH3)(OC6 H4 --p--tert.C4 H9)]n
The procedure of Example 2 was followed, except that to 1.83 equivalents of poly(dichlorophosphazene) were added 1.09 equivalents of NaOC6 H4 --p--OCH3 and 1.09 equivalents of NaOC6 H4 --p--tert.C4 H9.
The resulting product (51 percent yield) was a crystalline solid having a glass transition temperature (Tg) of +24.1° C. The product had an Oxygen Index of 25.0 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a transparent, tough film from solution in tetrahydrofuran. The film was brittle, did not burn, and was water resistant.
EXAMPLE 7
Preparation of [NP(OC6 H4 --p--OCH3)(OC.sub. 6 H4 --p--secC4 H9)]n
The procedure of Example 2 was followed, except that to 0.56 equivalents of poly(dichlorophosphazene) were added 0.33 equivalents of NaOC6 H4 --p--OCH3 and 0.33 equivalents of NaOC6 H4 --p--secC4 H9.
The resulting product (67 percent yield) was an elastomer having a glass transition temperature (Tg) of -5.03° C. The product had an Oxygen Index of 26.0 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, opaque film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 8
Preparation of [NP(OC6 H4 --p--OCH3)(OC.sub. 6 H4 --p--C9 H19)]n
The procedure of Example 2 was followed, except that to 1.86 equivalents of poly(dichlorophosphazene) were added 1.10 equivalents of NaOC6 H4 --p--OCH3 and 1.10 equivalents of NaOC6 H4 --p--C9 H19.
The resulting product (38 percent yield) was a somewhat tacky elastomeric material having a glass transition temperature (Tg) of -2.23° C. The product had an Oxygen Index of 25.0 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a resilient, opaque film from solution in tetrahydrofuran. The film was resilient, did not burn and was water resistant.
EXAMPLE 9
Preparation of [NP(OC6 H4 --p--OCH3)(OC.sub. 6 H4 --p--O--nC4 H9)]n
The procedure of Example 2 was followed, except that to 1.00 equivalents of poly(dichlorophosphazene) were added 0.59 equivalents of NaOC6 H4 --p--OCH3 and 0.59 equivalents of NaOC6 H4 --p--O--nC4 H9.
The resulting product (46 percent yield) was a crystalline solid having a glass transition temperature (Tg) of -5.03° C. The product had an Oxygen Index of 24.0 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 10
Preparation of [NP(OC6 H4 --p--O--nC4 H9)(OC.sub. 6 H5)]n
The procedure of Example 2 was followed, except that to 0.88 equivalents of poly(dichlorophosphazene) were added 0.49 equivalents of NaOC6 H4 --p--O--nC4 H9 and 0.49 equivalents of NaOC6 H5.
The resulting product (59 percent yield) was an elastomeric material having a glass transition temperature (Tg) of -11.2° C. The product had an Oxygen Index of 23.7 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to an opaque film from solution in tetrahydrofuran. The film was flexible, did not burn, and was water resistant. Analysis: Calculated (percent) for 1:1 copolymer of [NP(OC6 H4 --p--O--nC4 H9)(OC.sub. 6 H5)]n : C, 63.36; H, 5.98; N, 4.62; and Cl, 0.00. Found (percent): C, 63.19; H, 5.78; N, 4.63; and Cl, 0.06.
EXAMPLE 11
Preparation of [NP(OC.sub. 6 H4 --p--O--nC4 H9)(OC.sub. 6 H4 --p--CH3)]n
The procedure of Example 2 was followed, except that to 1.80 equivalents of poly(dichlorophosphazene) were added 1.06 equivalents of NaOC6 H4 --p--O--nC4 H9 and 1.06 equivalents of NaOC6 H4 --p--CH3.
The resulting product (35 percent yield) was a semicrystalline material. The product was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 12
Preparation of [NP(OC.sub. 6 H4 --p--O--nC4 H9)(OC.sub. 6 H4 --p--C2 H5)]n
The procedure of Example 2 was followed, except that to 1.88 equivalents of poly(dichlorophosphazene) were added 1.11 equivalents of NaOC.sub. 6 H4 --p--O--nC4 H9 and 1.11 equivalents of NaOC.sub. 6 H4 --p--C2 H5.
The resulting product (49 percent yield) was an elastomer having a glass trasition temperature (Tg) of -16.9° C. The product had an Oxygen Index of 24.8 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a film from solution in tetrahydrofuran. The film was flexible, did not burn, and was water resistant.
EXAMPLE 13
Preparation of [NP(OC6 H4 --p--O--nC4 H9)(OC.sub. 6 H4 --p--isoC3 H7)]n
The procedure of Example 2 was followed, except that to 1.88 equivalents of poly(dichlorophosphazene) were added 1.11 equivalents of NaOC6 H4 --p--O--nC4 H9 and 1.11 equivalents of NaOC6 H4 --p--isoC3 H7.
The resulting product (52 percent yield) was an elastomer having a glass transition temperature (Tg) of -9.47° C. The product had an Oxygen Index of 23.9 and was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 14
Preparation of [NP(OC6 H4 --p--O--nC4 H9)(OC.sub. 6 H4 --p--tertC4 H9)]n
The procedure of Example 2 was followed, except that to 1.80 equivalents of poly(dichlorophosphazene) were added 1.06 equivalents of NaOC6 H4 --p--O--nC4 H9 and 1.06 equivalents of NaOC6 H4 --p--tertC4 H9.
The resulting product (51 percent yield) was an elastomer. The product was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 15
Preparation of [NP(OC6 H4 --p--O--nC4 H9)(OC.sub. 6 H4 --p--secC4 H9)]n
The procedure of Example 2 was followed, except that to 1.76 equivalents of poly(dichlorophosphazene) were added 1.04 equivalents of NaOC6 H4 --p--O--nC4 H9 and 1.04 equivalents of NaOC6 H4 --p--secC4 H9.
The resulting product (41 percent yield) was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 16
Preparation of [NP(OC6 H4 --p--OCH3)0.5 (OC6 H5)1.5 ]n
The procedure of Example 2 was followed, except that to 1.86 equivalents of poly(dichlorophosphazene) were added 0.56 equivalents of NaOC6 H4 --p--OCH3 and 1.67 equivalents of NaOC6 H5.
The resulting product (58 percent yield) was a crystalline solid having an Oxygen Index of 25.8. The product was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 17
Preparation of [NP(OC6 H4 --p--OCH3)0.4 (OC6 H5)1.6 ]n
The procedure of Example 2 was followed, except that to 1.86 equivalents of poly(dichlorophosphazene) were added 0.45 equivalents of NaOC6 H4 --p--OCH3 and 1.78 equivalents of NaOC6 H5.
The resulting product (60 percent yield) was a crystalline solid having an Oxygen Index of 28.7. The product was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 18
Preparation of [NP(OC6 H4 --p--OCH3)0.5 (OC6 H4 --p--isoC3 H7)1.5 ]n
The procedure of Example 2 was followed, except that to 1.82 equivalents of poly(dichlorophosphazene) were added 0.55 equivalents of NaOC6 H4 --p--OCH3 and 1.64 equivalents of NaOC6 H4 --p--isoC3 H7.
The resulting product was a crystalline solid which was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film for solution in tetrahydrofuran. The film did not burn, and was water resistant.
Example 19
Preparation of [NP(OC6 H4 --p--OCH3)0.4 (OC6 H4 --p--isoC3 H7)1.6 ]n
The procedure of Example 2 was followed, except that to 1.80 equivalents of poly(dichlorophosphazene) were added 0.43 equivalents of NaOC6 H4 --p--OCH3 and 1.73 equivalents of NaOC6 H4 --p--isoC3 H7.
The resulting product (41 percent yield) was a crystalline solid. The product was soluble in benzene, tetrahydrofuran and dimethylformamide. The copolymer mixture was then cast to a tough, transparent film from solution in tetrahydrofuran. The film did not burn, and was water resistant.
EXAMPLE 20
Poly(aryloxyphosphazene) homopolymers and copolymers were prepared by a multistep process beginning with the thermal polymerization of hexachlorocyclotriphosphazene, N3 P3 Cl6, as described in Example 1. The resulting poly(dichlorophosphazene) [NPCl2 ]n was dissolved in a suitable solvent, such as toluene. This polymeric solution was then added to a bis(2-methoxyethyl) ether solution of the desired sodium aryloxide salt at 95° C. (Copolymers were prepared by adding the polymer to a solution containing a 1:1 mole ratio of the two desired sodium aryloxide salts.) The reaction temperature was raised to 115°-116° C. and maintained for 50-65 hours with constant stirring. The thermal polymerization and subsequent reaction are summarized in Equations (1) and (2): ##STR6## After the reaction was completed, the polymers were precipitated by pouring the reaction mixture into an excess of methanol, were washed for 24 hours in methanol, and finally were exhaustively washed with distilled water. The polymers ranged from rigid fiber-like materials to elastomers and, except for a few cases, were colorless. Polymers prepared, and their glass-transition temperatures are listed in Table I. Analytical data were in agreement with the tabulated empirical formulas.
Table 1
______________________________________
Glass Transition Temperatures of
Poly(aryloxyphosphazene) Polymers*
[NP(OR').sub.2 ].sub.n Tg, ° C
______________________________________
R' = C.sub.6 H.sub.5 -7.7
C.sub.6 H.sub.4 -p-CH.sub.3
+2.0
C.sub.6 H.sub.4 -p-C.sub.2 H.sub.5
-19
C.sub.6 H.sub.4 -p-n-C.sub.3 H.sub.7
-34
C.sub.6 H.sub.4 -p-iso-C.sub.3 H.sub.7
-0.10
C.sub.6 H.sub.4 -p-sec-C.sub.4 H.sub.9
-16
C.sub.6 H.sub.4 -p-tert-C.sub.4 H.sub.9
+44
C.sub.6 H.sub.4 -p-OCH.sub.3
+0.60
C.sub.6 H.sub.4 -p-O-n-C.sub.4 H.sub.9
-21
[NP(OR') (OR")].sub.n
R' = C.sub.6 H.sub.5
R" = C.sub.6 H.sub.4 -p-iso-C.sub.3 H.sub.7
-7.8
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p-sec-C.sub.4 H.sub.9
-8.1
______________________________________
*Determined by differential scanning calorimetry. The above values are
based on Indium standard (melt temperature 156.6° C.)
Example 21
Films of unfilled poly(aryloxyphosphazenes) were prepared by compression molding of the raw polymers of Example 20. These films were formed at relatively low temperatures, 100° to 135° C., and at moderate pressures, 1000 to 5000 psi. Nominal thickness ranged from 20 to 30 mils. These films were allowed to remain at ambient conditions for 24 to 48 before die-cutting to the required sample sizes for flame and smoke testing.
A series of filled poly(aryloxyphosphazene) films were prepared by mixing and blending the various polymers with the appropriate fillers on a 2-roll research mill. One roll was heated to approximately 50° C. while the other roll was at ambient temperature. Mixes were blended for 11/2 hour. Three common filler materials were utilized. These were: Hydral-710, alumina trihydrate (64.7% Al2 O3); calcium carbonate (limestone, 325-mesh); and HiSil-233 (precipitated hydrated silica). Three concentration levels of each filter were evaluated and these were prepared on a weight basis: 10, 25 and 50 phr (parts per hundred parts of polyphosphazene).
Flame-retardant properties of the various filled and unfilled poly(aryloxyphosphazene) films were determined using both a Bunsen-burner test and an oxygen index apparatus.
Some samples of unfilled polyphosphazene films when heated in the open flame of a Bunsen-burner dripped profusely. Certain samples developed flaming drips which ignited cotton placed below the sample. Addition of fillers in most cases either prevented dripping or significantly reduced it.
Oxygen Index (OI) of film samples (or foamed samples where appropriate) of filled and unfilled poly(aryloxyphosphazenes) were determined according to the procedure described in ASTM D-2863-74, "Flammability of Plastics Using the Oxygen Index Method". Film samples, 6 × 2 × 0.01 to 0.03", were held in a U-shaped frame during testing. (Where OI of foams was measured, the foams were self-supporting or suspended by a wire through the center of the foam.) The oxygen index test (OI) measures the burning of a material under a specific set of conditions. It has been shown that it actually measures the lowest oxygen concentration in an atmosphere which will just prevent sustained burning of a top-ignitied sample (see Fenimore et al, Combustion and Flame, 10, 135 (1966)). The oxygen index values also have been related to the temperature at which a mixture of fuel and a controlled flow of oxygen will just burn when the fuel is composed of volatile pyrolytic products or fragments (see, Johnson et al, Rubber Age, 107 (No. 5), 29 (1975)).
Smoke-evolution properties of filled and unfilled poly(aryloxyphosphazene) films and foams were evaluated by using an Aminco-NBS Smoke Density Chamber (Model 4-5800, Aminco-NBS Smoke Density Chamber, American Instrument Co.), as described by Gross et al, "A Method of Measuring Smoke Density from Burning Materials", ASTM STP-422 (1967). Samples were tested using the flaming and nonflaming test modes. This small scale test subjects a sample to the two general conditions which prevail in the majority of "real" fires and especially in tunnel tests. In the tests the maximum specific optical density Dm, corrected for soot deposits on the cell windows was measured, and a smoke value per gram, SV/g, or Dm(corr)/g of sample was calculated for each mode. This allows for correction of the smoke density value for its sample weight, since the samples are quite thin. The average value of Dm(corr) using both the flaming and nonflaming modes was also calculated. An average Dm(corr) value of 450 as determined in the NBS Smoke Density Chamber has been adopted as a regulation value by the U.S. Department of Health, Education and Welfare, see HEW Publication No. (HRA) 74-4000 (1974). Generally, NBS smoke values of 450 or less are normally required in those fire or code regulations restricting smoke evolution. Values of 200 or less are uncommon for most organic polymers; those less than 100 are quite rare.
Sample films were prepared by pressing the filled and unfilled materials for 5 to 20 minutes at 100 to 130° C. under 1000 to 5000 psi. The resultant films were die-cut to 3 × 3 × 0.02 to 0.03". Foam samples were die-cut to 3 × 3 × 0.2 to 0.3". These samples were conditioned for 48 hours at 23° C. and 50% relative humidity prior to testing. A modified specimen holder with trough and a modified burner were used in all tests. While some unfilled samples softened and melted somewhat, none filled or overflowed the trough during testing.
Poly(aryloxyphosphazenes) exhibit a high degree of flame resistance and can be considered essentially "self-extinguishing" materials in air. Oxygen index values for some unfilled phosphazene polymers are listed in Table 2. Values of aryloxyphosphazene homo- and copolymers ranged from 23 to 34. In general, as the organic content of the polymer was increased the OI value was lowered. When copolymers were tested, the OI value tended to be nearer that of the corresponding higher organic content homopolymer. For example, [NP(OC6 H5)2 ]n polymer had an OI value of 33.8, whereas the [NP(OC6 H4 --p--iso--C3 H7)2 ]n polymer was rated at 23.4. The corresponding copolymer, [NP(OC6 H5)(OC.sub. 6 H4 --p--iso--C3 H7 ].sub.,, had a value of 25.8. Certain other commercial polymers are listed. These organic polymers, while tested at a thickness of 0.125 inches, indicate the relative flammability for some commercial materials. As will be shown, the addition of fillers may increase or decrease the OI value depending on the polymeric backbone substituents and the type of filler used.
Table 2
______________________________________
Oxygen Index Values for Poly(aryloxyphosphazenes)
and Reference Polymers
Polymer OI
______________________________________
Polyethylene 17.4
Polystyrene 17.8
Poly(vinyl chloride) 43.5
Polycarbonate 27.4
ABS-Rubber 18.3
Silicone Rubber 25.8
[GE-SE 9035]
[NP(OR').sub.2 ].sub.n
R' = C.sub.6 H.sub.5 33.8
C.sub.6 H.sub.4 -p-CH.sub.3
26.4
C.sub.6 H.sub.4 -p-C.sub.2 H.sub.5
25.0
C.sub.6 H.sub.4 -p-nC.sub.3 H.sub.7
25.5
C.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7
23.4
C.sub.6 H.sub.4 -p-sec C.sub.4 H.sub.9
23.9
C.sub.6 H.sub.4-p-tert C.sub.4 H.sub.9
25.2
C.sub.6 H.sub.4 -p-OCH.sub.3
25.5
C.sub.6 H.sub.4 -p-O-nC.sub.4 H.sub.9
23.7
[NP(OR') (OR")].sub.n
R' = C.sub.6 H.sub.5
R" = C.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7
25.8
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p-sec C H
25.9
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p-CH.sub.3
27.0
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p -C.sub.2 H.sub.5
27.0
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7
25.8
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p-sec C.sub.4 H.sub.9
25.9
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p-tert C.sub.4 H.sub.9
26.0
C.sub.6 H.sub.5
C.sub.6 H.sub.4 -p-C.sub.4 H.sub.19
24.7
[NP(OC.sub.6 H.sub.4 -p-OCH.sub.3) (R)].sub.n
R = (OC.sub.6 H.sub.5) 25.0
(OC.sub. 6 H.sub.4 -p-CH.sub.3)
25.3
(OC.sub.6 H.sub.4 -p-C.sub.2 H.sub.5)
24.0
(OC.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7)
26.0
(OC.sub.6 H.sub.4 -p-sec C.sub.4 H.sub.9)
26.0
(OC.sub.6 H.sub.4 -p-tert C.sub.4 H.sub.9)
25.0
Polymer OI
(OC.sub.6 H.sub.4 -p-C.sub.9 H.sub.19)
25.0
(OC.sub.6 H.sub.4 -p-OCH.sub.3)
25.5
(OC.sub.6 H.sub.4 -p-O-nC.sub.4 H.sub.9)
24.0
[NP(OC.sub.6 H.sub.4 -p-OnC.sub.4 H.sub.9) (R)] .sub.n
R = (OC.sub.6 H.sub.5) 23.7
(OC.sub.6 H.sub.4 -p-CH.sub.3)
24.3
(OC.sub.6 H.sub.4 -p-C.sub.2 H.sub.5)
24.8
(OC.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7)
23.9
(OC.sub.6 H.sub.4 -p-sec C.sub.4 H.sub.9)
23.1
(OC.sub.6 H.sub.4 -p-tert C.sub.4 H.sub.9)
24.6
(OC.sub.6 H.sub.4 -p-OCH.sub.3)
24.0
(OC.sub.6 H.sub.4 -p-O-nC.sub.4 H.sub.9)
23.7
[NP(OC.sub.6 H.sub.4 -4-OCH.sub.3).sub.0.5 (OC.sub.6 H.sub.5).sub.1.5
].sub.n 25.8
[NP(OC.sub.6 H.sub.4 -4-OCH.sub.3).sub.0.4 (OC.sub.6 H.sub.5).sub.1.6
].sub.n 28.7
______________________________________
Table 3
__________________________________________________________________________
NBS Smoke Density Test Results
Poly(aryloxyphosphazenes) and Reference Polymers
Dm(Avg.)
Flaming Mode(F)
Nonflaming Mode (N)
F + N
Polymer Dm(corr)
SV/g
Dm(corr)
SV/g
2
__________________________________________________________________________
Polyethylene 150 -- 468 -- 309
Polystyrene 468 -- 460 -- 464
Poly(vinyl chloride)
530 -- 490 -- 510
Polycarbonate >660 -- 44 -- 352+
ABS-Rubber 180 -- 305 -- 243
Silicone Rubber (GE-SE9035)
385 -- 240 -- 313
[NP(OR').sub.2 ].sub.n
R' = C.sub.6 H.sub.5
322 50 204 36 263
C.sub.6 H.sub.4 -p-CH.sub.3
321 68 81 14 201
C.sub.6 H.sub.4 -p-C.sub.2 H.sub.5
305 70 9 2 157
C.sub.6 H.sub.4 -p-nC.sub.3 H.sub.7
286 65 N.D.* N.D.*
N.D.*
C.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7
213 69 63 22 138
C.sub.6 H.sub.4 -p-sec C.sub.4 H.sub.9
230 59 145 24 188
C.sub.6 H.sub.4 -p-tert C.sub.4 H.sub.9
198 84 145 57 172
C.sub.6 H.sub.4 -p-OCH.sub.3
120 27 23 9 72
C.sub.6 H.sub.4 -p-O-nC.sub.4 H.sub.9
60 18 5 1 33
[NP(OR') (OR")].sub.n
R' = C.sub.6 H.sub.5
323 53 19 3 171
R" = C.sub.6 H.sub.5 -4-iso C.sub.3 H.sub.7
R' = C.sub.6 H.sub.5
229 60 48 11 139
R" = C.sub.6 H.sub.4 -p-sec C.sub.4 H.sub.9
R' = C.sub.6 H.sub.5
270 56 101 16 186
R" C.sub.6 H.sub.4 -p-CH.sub.3
R' = C.sub.6 H.sub.5
331 58 54 7 193
R" = C.sub.6 H.sub.4 -p-C.sub.2 H.sub.5
R' = C.sub.6 H.sub.5
281 65 87 19 184
R" = C.sub.6 H.sub.4 -p-tert C.sub.4 H.sub.9
R' = C.sub.6 H.sub.5
166 88 51 13 109
R" = C.sub.6 H.sub.4 -p-C.sub.9 H.sub.19
[NP(OC.sub. 6 H.sub.4 -p-OCH.sub.3) (R)].sub.n
R = (OC.sub.6 H.sub.5)
151 38 72 13 112
(OC.sub.6 H.sub.4 -p-CH.sub.3)
134 35 49 13 92
(OC.sub.6 H.sub.4 -p-C.sub.2 H.sub.5)
139 26 44 10 92
(OC.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7)
148 30 20 3 84
(OC.sub.6 H.sub.4 -p-sec C.sub.4 H.sub.9)
154 28 19 2 87
(OC.sub.6 H.sub.4 -p-tert C.sub.4 H.sub.9)
132 26 0 0 66
(OC.sub.6 H.sub.4 -p-C.sub.9 H.sub.19)
177 32 68 14 123
(OC.sub.6 H.sub.4 -p-OCH.sub.3)
120 27 23 9 72
(OC.sub.6 H.sub.4 -p-O-nC.sub.4 H.sub.9)
108 29 1 0 55
[NP(OC.sub.6 H.sub.4 -p-OCH.sub.3).sub.0.5 (OC.sub.6 H.sub.5).sub.1.5
].sub.n 192 32 48 7 120
[NP(OC.sub.6 H.sub.4 -p-OCH.sub.3).sub.0.4 (OC.sub.6 H.sub.5).sub.1.6
].sub.n 217 46 100 16 159
[NP(OC.sub.6 H.sub.4 -p-O-nC.sub.4 H.sub.9) (R)].sub.n
R = (OC.sub.6 H.sub.5)
104 28 30 7 67
(OC.sub.6 H.sub.4 -p-CH.sub.3)
137 25 28 5 83
(OC.sub.6 H.sub.4 -p-C.sub.2 H.sub.5)
138 26 17 4 78
(OC.sub.6 H.sub.4 -p-iso C.sub.3 H.sub.7)
174 37 22 5 98
(OC.sub.6 H.sub.4 -p-OCH.sub.3)
109 29 1 0 55
(OC.sub.6 H.sub.4 -p-O-nC.sub.4 H.sub.9)
60 18 6 1 33
__________________________________________________________________________
*N.D. = Not Determined.
Filled poly(aryloxyphosphazenes) were also tested, as above. Three common filler materials were employed Alumina trihydrate, Al2 03.3H2 O, has long been used as an effective fire retardant and smoke inhibitor for elastomeric materials, such as polyolefins and polydienes. Calcium carbonate is an inexpensive, inorganic material widely used to increase bulk density in commercial polymeric blends and to prevent dripping in so-called borderline "self-extinguishing" polymer mixtures. It has not been shown to be an effective fire retardant, except as a diluent, and it is not a known smoke suppressant. Hydrated silica is another mineral filler used as a fire-retardant additive and a reinforcing filler in materials, such as polyacrylic polymers.
The physical properties of the poly(arlyoxyphosphazenes) tested cover a range due to the substituent on the phenoxy group. This substituent apparently controls to a large degree the flame retardant and smoke evolution properties of the corresponding phosphazene polymer. The structures investigated were:
[NP(OC.sub.6 H.sub.5).sub.2 ].sub.n, [NP(OC.sub.6 H.sub.4 --p--OCH.sub.3).sub.2 ].sub.n, and [NP(OC.sub.6 H.sub.4 --p--sec--C.sub.4 H.sub.9).sub.2 ].sub.n.
Table 4 lists the flame and smoke density results obtained for filled samples of [NP(OC6 H5)2 ]n. High loadings of alumina and calcium carbonate increased the OI value, whereas addition of various amounts of hydrated silica did not affect this value. Smoke-test results demonstrate a moderate reduction in smoke density as the filler concentrations are increased. Based on these data it would appear that hydrated silica lowers the smoke concentration more than the other two. However, using the SV/g values it can be seen that all appear to be within the same general range and really no concentration or additive is outstanding. Thus, an anomaly occurs where the test numbers show lower smoke values, but when normalized on a weight basis, the values are essentially constant.
Table 4
__________________________________________________________________________
Flame and Smoke Test Results of Filled [NP(OC.sub.6 H.sub.5).sub.2
].sub.n
NBS Smoke Density Test
Dm(Avg)
Flaming Mode(F)
Nonflaming Mode(N)
F + N
Additive (phr).sup.1
Dm(corr)
SV/g
Dm(corr)
SV/g
2 OI
__________________________________________________________________________
0 322 50 204 36 263 33.9
10A 282 68 207 51 245 31.0
10C 268 64 97 27 183 29.4
10S 203 77 141 46 172 29.8
25A 304 76 182 43 243 34.8
25C 283 83 123 34 203 31.5
25S 223 69 116 31 170 29.8
50A 211 49 257 55 234 38.3
50C 300 63 136 29 194 39.6
50S 177 47 143 39 160 29.8
__________________________________________________________________________
.sup.1 Additive used per one hundred parts of polymer.
A = Hydral-710, alumina trihydrate.
C = Limestone-325M, calcium carbonate.
S = HiSil-233, hydrated silica.
Table 5 lists the flame and smoke values determined with filled samples of [NP(OC6 H4 --p--OCH3)2 ]n. Addition of the fillers at all levels increased the OI values. Alumina trihydrate caused the most significant increase; calcium carbonate was least effective. Smoke density values obtained for this polymer were much lower than for the other two polyphosphazenes. Calcium carbonate-filled samples had the lowest smoke density values.
Table 5
__________________________________________________________________________
Flame and Smoke Test Results of Filled [NP(OC.sub.6 H.sub.4 -p-OCH.sub.3).
sub.2 ].sub.n
NBS Smoke Density Test
Dm(Avg)
Flaming Mode(F)
Nonflaming Mode(N)
F + N
Additive (phr).sup.1
Dm(corr)
SV/g
Dm(corr)
SV/g
2 OI
__________________________________________________________________________
0 120 27 23 9 72 25.5
10A 165 38 39 9 102 35.3
10C 79 19 14 3 47 27.3
10S 80 23 25 6 53 28.3
25A 137 30 34 8 86 35.3
25C 83 19 16 4 50 27.3
25S 89 23 32 7 61 27.0
50A 73 18 24 6 49 43.5
50C 40 9 17 3 29 29.8
50S 81 22 45 11 63 30.0
__________________________________________________________________________
.sup.1 Additive used per one hundred parts polymer.
A = Hydral-710, alumina trihydrate.
C = Limestone-325M, calcium carbonate.
S = HiSil-233, hydrated silica.
Table 6 lists the flame and smoke test results obtained for filled samples of [NP(OC6 H4 --p--sec--C4 H9)2 ]n. Generally, the additives used had little effect upon the OI value, although all additives at the concentrations tested did increase the OI value slightly. The additives used did lower the smoke density values obtained and in general, the values decreased as the filler concentrations were increased.
Table 6
__________________________________________________________________________
Flame and Smoke Test Results of Filled [NP(OC.sub.6 H.sub.4 -4-sec
C.sub.4 H.sub.9).sub.2 ].sub.n
NBS Smoke Density Test
Dm(Avg)
Flaming Mode(F)
Nonflaming Mode(N)
F + N
Additive (phr).sup.1
Dm(corr)
SV/g
Dm(corr)
SV/g
2 OI
__________________________________________________________________________
0 230 59 145 24 188 23.9
10A 383 82 19 4 201 24.2
10C 242 58 48 14 145 25.5
10S 374 85 61 14 218 24.7
25A 268 54 52 11 160 25.8
25C 154 24 13 2 84 26.4
25S 281 47 81 14 181 25.5
50A 148 30 42 9 95 29.1
50C 131 27 9 2 70 26.7
50S 215 48 71 14 143 26.7
__________________________________________________________________________
.sup.1 Additive used per one hundred parts polymer.
A = Hydral-710, alumina trihydrate.
C = Limestone-325M, calcium carbonate.
S = HiSil-233, hydrated silica.
EXAMPLE 22
To 100 parts of the copolymer prepared in accordance with Example 8, there were added 100 parts of alumina trihydrate, 5 parts of magnesium oxide, 5 parts of zinc stearate, 10 parts of Celogen AZ (1,1'azobisformamide), 3 parts of oil-treated urea as an activator, 7 parts of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane and 3 parts of benzoyl peroxide (78% active, wet with water). The above ingredients were milled to insure homogeneous mixing of all materials and were then free blown at 325°-350° F. for 15 minutes. The resultant foam was light tan in color and was flexible. The foam density was 9.7 pounds per cubic foot. When exposed to an open flame the foam did not burn and produced essentially no smoke. The foam had an Oxygen Index (OI) of 38.7, a flaming mode smoke density (Dm(corr)F) of 48, and a smoke value per gram (SV/g) of 8, each determined in accordance with the procedure set forth in Example 21.
EXAMPLE 23
Preparation of Foamed [NP(OC6 H4 --p--OCH3)(OC.sub. 6 H4 --p--sec--C4 H9)]n
To 100 parts of the copolymer prepared in accordance with Example 7, there were added 100 parts of alumina trihydrate, 5 parts of magnesium oxide, 10 parts of zinc stearate, 2 parts of CUMAR P-10 (p-coumarone-indene resin), 20 parts of Celogen AZ (1,1'azobisformamide), 5 parts of BIK-OT (an oil-treated urea) as an activator, 6 parts of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2 parts of benzoyl peroxide (78% active), and 1 part of dicumyl peroxide. The above ingredients were milled to insure homogeneous mixing of all materials and were then precured in an open sided mold for 10 minutes at 230° F. under 2000 psi. The precured copolymer was then free expanded in a circulating air oven for 30 minutes at 300° F. The resultant foam was light tan in color and was flexible. The foam density was 9.2 pounds per cubic foot. When exposed to an open flame the foam did not burn and produced essentially no smoke. The foam had an OI of 34.9, a Dm(corr)F of 67 and a SV/g of 12.
EXAMPLE 24
A series of foams containing the copolymer prepared in accordance with Example 7 were prepared with varying amounts of alumina trihydrate filler by the procedure set forth in Example 23. The amount of alumina trihydrate, the foam density, the Oxygen Index, and smoke values for the resulting series of foams are set forth in Table 7.
Table 7
______________________________________
Foam
Den-
Parts of Alumina Trihydrate
sity NBS Flaming Mode
per 100 Parts Copolymer
lbs/ft.sup.3
OI Dm(corr)F
SV/g
______________________________________
50 6.8 29.6 80 20
62.5 4.3 31.0 78 20
75 8.3 32.8 109 22
112.5 8.2 41.8 121 18
125 6.1 45.9 104 19
137.5 15.9 47.9 87 8
150 17.4 48.4 85 8
175 22.2 59.0 94 8
______________________________________
EXAMPLE 25
Preparation of Foamed [NP(OC6 H4 --p--O--nC4 H9) (OC6 H4 --p--iso C3 H7)]n
To 100 parts of the copolymer prepared in accordance with Example 13, there were added 100 parts of alumina trihydrate, 5 parts of magnesium oxide, 10 parts of zinc stearate, 2 parts of CUMAR P-10, a p-coumarone-indene resin, 20 parts of Celogen AZ (1,1'azobisformamide), 5 parts of BIK-OT, an oil treated urea, 7 parts of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane and 3 parts of benzoyl peroxide 78% active, wet with water). The above ingredients were milled to insure homogeneous mixing of all materials. The resultant mix was precured between plates having spacers under 2000 psi pressure for 10 minutes at 230° F. This material was then free expanded in a circulating air oven for 30 minutes at 300° F. The final foam was dark tan in color and was quite flexible. The foam density was 4.7 pounds per cubic foot. When exposed to an open flame the foam did not burn and produced essentially no smoke. The foam had an OI of 32.2 a Dm(corr)F of 33, and an SV/gF of 9.
What is claimed is:
1. A copolymer having randomly distributed repeating units represented by the formulas: ##STR7## wherein R1 is C1 -C4 linear or branched alkyl, and R2 is hydrogen, C1 -C10 linear or branched alkyl or C1 -C4 linear or branched alkoxy, with the proviso that when R2 is alkoxy, OR1 and R2 are different, the ratio of (OC6 H4 --OR1):(OC6 H4 -R2) being from about 1:6 to about 6:1.
2. Copolymers, as in claim 1, having randomly distributed repeating units represented by the formulas ##STR8## wherein R1 is individually CH3 or n--C4 H6, R2 is individually hydrogen, C1 -C10 alkyl or C1 -C4 alkoxy with the proviso that when R2 is alkoxy, OR1 and R2 are different, and W represents a monovalent radical containing a group capable of a cross-linking chemical reaction at moderate temperatures, said group being attached to a P atom by a --O-- linkage, the ratio of (OC6 H4 --OR1):(OC6 H4 --R2) being from about 1:6 to about 6:1, and the ratio of W:[(OC6 H4 --OR1)+(OC6 H4 --R2)] being less than about 1:5.
3. The process of curing the copolymers of claim 2 where W is present which comprises heating said copolymers at temperatures ranging from 200° to 350° F. utilizing sulfur-type curing agents.
4. The polymer of claim 2 cured with a sulfur-type curing agent.
5. The process of curing the copolymers of claim 1 which comprises heating said copolymers at temperatures ranging from 200° to 350° F. utilizing peroxide-type curing agents.
6. The polymer of claim 1 cured with a perioxide curing agent.
7. The process of curing the copolymers of claim 2 which comprises heating said copolymers at temperatures ranging from 200° to 350° F. utilizing peroxide-type curing agents.
8. The polymer of claim 2 cured with a perioxide curing agent.
9. Poly(aryloxyphosphazene) copolymers having the general formula: [NP(OC.sub.6 H.sub.4 --OR.sub.1).sub.a (OC.sub.6 H.sub.4 --R.sub.2).sub.b (W).sub.c ].sub.n
wherein R1 is individually C1 -C4 linear or branched alkyl; R2 is individually hydrogen, C1 --C10 linear or branched alkyl or C1 --C4 linear or branched alkoxy, with the proviso that when R2 is alkoxy, OR1 and R2 are different; W represents a monovalent radical containing a group capable of a cross-linking chemical reaction at moderate temperatures, said group being attached to a P atom by a --O-- linkage; n is from 20 to 2000, c≧o, a+b+c=2, the ratio of a:b is from about 1:6 to 6:1, and the ratio of c: (a+b) is less than about 1:5.
10. The copolymers of claim 9 wherein c=o and R1 is CH3.
11. The copolymers of claim 9 wherein c=o and R1 is n--C4 H9.
12. The copolymers of claim 10 wherein the ratio of a:b is from 1:4 to 4:1.
13. The copolymers of claim 11 wherein the ratio of a:b is from 1:4 to 4:1.
| 1976-02-27 | en | 1977-10-11 |
US-39521864-A | Filter press
FUMIO KAGA Dec. 26, 1967 FILTER PRESS 5 Sheets-Sheet 1 Filed Sept 9, 1964 F uMro- KAGA BMW/W A 774 M5 vs Dec. 26, 1967 FUMO KAGA 3,360,130
FILTER PRESS A mews vs Dec. 26, 1967 FUMIO KAGA 7 3,360,130
FILTER PRESS Filed Sept. 9, 1964 5 Sheets-Sheet C5 LYVENI'OR. Fuwro KAGA ,MZW /k ATTORNEKS Dec. 26, 1967 FUMIOYKAGA FILTER PRESS Filed Sept. 9, 1964 5 Sheets-Sheet 4 JAVA-X1012.
MIG K I 02M ATTORNEYS FUMIO KAGA FILTER PRESS 5 Sheets-Sheet. 5
Filed Sept. 9, 1964 m 7 Q ML w 5. GIG CW: 6. 2s a m y 5 E 44W% a I] ,::v 33 P Ila Q 3 a M 7 4 uunu I BY MM ATTOEIVEVS United States Patent 3,360,130 FILTER PRESS Fumio Kaga, Osaka, Japan, assignor to Noritake Iron Works Co., Ltd., Osaka, Japan Filed Sept. 9, 1964, Ser. No. 395,218 3 Claims. (Cl. 210-225) ABSTRACT OF THE DISCLOSURE A filter press having clearing assemblies mounted on filter plate supporting arms with chain driven pawls engaging the clearing assemblies to move the filter plates. The clearing assemblies having spring biased hooks holding adjacent plates together in closed assembly. The hooks are released one at a time by interaction of the pawls and engaging pieces in the clearing assemblies.
This invention relates to a filter press, and particularly to an automatic separation mechanism for filter plates or filter plates and frames.
Included under filter presses are a single type filter press comprising a plurality of filter plates alone and a double type filter press comprising a plurality of .filter plates and filter frames in alternate combination, and since the two types are structurally the same, this invention is applicable to both of them. It is to be understood that what is referred to as filter plates in this specification and claims means filter plates alone or both filter plates and filter frames.
A plurality of filter plates are pressed collectively in filtering work that is carried out on a filter press having a plurality of filter plates arranged parallel to each other, and after the material to be filtered has been pressed, the plurality of filter plates must be separated one by one and restored to their normal positions in order to remove cakes staying between filter plates.
A primary object of this invention is to provide a new type of filter press whereby a plurality of filter plates can be separated automatically one by one and restored to their normal positions.
Another object of this invention is to provide an automatic filter plate separation mechanism for a filter press whereby a plurality of filter plates are separated intermittently and at fixed intervals.
Still another object of the invention is to provide a drive chain having a feed pawl to be used in the automatic-filter plate separation mechanism.
A further object of the invention is to provide a filter plate for the filter press having on a hanger an engaging piece meshable with the feed pawl for'the drive chain.
A still further object of the invention is to provide an engaging piece lifting mechanism wherein the engaging piece rises or falls in accordance with coupling or separation of filter plates. I
A still further object of the invention is to provide a filter plate locking mechanism in the filter press whereby automatic separation of each plate will not cause another plate to be moved.
A still further object of the invention is to provide an automatic cake removing mechanism in the filter press whereby filter cakes may be shaken off in conjunction with automatic separation of the filter plates.
In short, the filter press provided by this invention comprises parallel drive chains disposed on the outer sides of a train of filter plates and having feed pawls at fixed intervals, an engaging piece movable up and down and meshable wiht the feed pawl fixed to each filter plate, and a lever actuating the engaging piece which is constantly biased downward by a depressing spring and on which is provided a transversal slot in which the front arm 3,360,130 Patented Dec. 26, 1967 of the lever fits, the rear arm thereof being caused to move up and down in accordance with reciprocal movement of the filter plates through coupling and separation. There is provided on a lever shaft a hook which, drawn by a lift spring, catches a lever shaft disposed in the adjacent front.
To the upper part of each filter plate is vertically secured a spring hanging frame on which a plurality of springs are suspended, a filter cloth made of one sheet of cloth turned back like a reversed U-shape on the top thereof, being fitted on both of the filter plates adjacent to each other, and the upper end of the filter cloth being connected to both filter plates in front and rear by means of said spring.
The structure and operation of this invention together with other objects and advantages will be more fully understood from the following detailed description made with reference to the accompanying drawings, wherein:
FIG. 1 is a partial side view of a new filter press according to the present invention;
FIG. 2 is a partial plan view of the filter press shown in FIG. 1;
FIG. 3 is a front view of the filter press shown in FIG. 1;
FIG. 4 is a front view of the filter press equipped with cake removing mechanism with filter cloth artly removed. 1
- FIG. 5 is an enlarged partial sectional view of an automatic separationmechanism and cake removing mechanism of the filter press shown in FIG. 1;
FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 5; and
FIG. 7 is a sectional view taken along line 7-7 of FIG-6.
The filter press of this invention shown in FIGS. 1 and 3 comprises a first head 1, a movable head 2, a rear head 3, a pair of side bars or side rails 4 disposed on the right and left sides, and a plurality of filter plates 5. The first head 1 and the rear head 3 include stands 6 and 7. The rear head 3 includes an oil pressure cylinder 9 incorporating a piston 8, and the end of the rod 10 of the piston 8 is secured to the movable head 2. Two rollers 11 are fitted respectively on the upper right and left sides of the movable head 2, which is supported on the surfaces of the side rails 4 and movable back and forth thereon. A cake hopper 12 is fitted inside a pair of U-shaped frames 13 provided endwise and parallel to each other on the outer side of the stands 6 and 7 and is disposed face to face with the underside of a plurality of filter plates. In the middle of the first head 1 is provided a liquid inlet and in the lower end of both sides thereof is a filter liquid outlet 84 (FIG. 3). On the right and left sides of the filter plates 5 are mounted hangers 14, said hangers being disposed on said side bars or side rails 4. Thereby the filter plates 5 are hung so as to be slidable on said side rails.
On the lower side of the right and left hangers 14 and outside of the right and left side bars are spanned a parallel pair of drive chains 15 between front and rear sprockets 16 and 17. The rear sprocket 17 is moved clockwise by a motor 18 through an interlocking device in the form of sprocket 19, chain 20, sprocket 21, and gears 22 and 23. The drive chain 15 comprises conventional chain pieces 2 chain pieces 26 having feed pawls 25 and chain pieces 27 of the same height with feed pawls 25 connected therewith. (See FIG. 5.)
The chain pieces 26 having the feed pawls are disposed at the separated intervals when filter plates are separated to drop off filter cakes staying therebetween. A drive chain guide 28 shown in FIGS. 5 and 6 comprises .U-shaped frames 31 and 32 having rails 29 and 30 respectively on the upper surface of said guide and having their upper and lower sides disposed opposite to each other, the inner vertical section 31a of the upper frame 31 being secured to the side bar 4 in the longitudinal direction with a plurality of set screws 33, and the inner vertical section 32a of the lower frame 32 being welded to the side bar 4 at the lower end in the longitudinal direction. The upper and lower ends of a transparent cover plate 34 made of synthetic resin are secured to the outer vertical section 31b of the upper frame 31 and the outer vertical section 32b of the lower frame 32 with a plurality of set screws 35. The rail 29 is secured to the upper surface of the horizontal section 310 of the upper frame 31 with a plurality of set screws 36 from underside, and running on said rail are rollers 38 set in chain piece connecting pins 37 of a drive chain 15. On the upper side of the rollers 38 of the drive chain and on the upper side of the inner chain pieces 24 is provided an L-section cover 39 covering the upper side of those parts, and the vertical section 39a is secured to the upper end of the side bar 4 in the longitudinal direction with a plurality of set screws 40. To the underside of the end of the level section 3911 of the cover 39 is secured a rail 41 disposed opposite to the aforementioned rail 29 with a plurality of set screws 42. An underside rail 30 whose section is T-shaped, is welded to the upper surface of the level section 32c of the lower frame 32.
As shown in FIGS. 5, 6 and 7, the hanger 14 is provided with a longitudinal slit 43 and furthermore with a recess 83 extending from the back side to the front with its bottom 83a concave. An engaging piece 44, T-shaped in vertical section, is inserted in the longitudinal slit 43 and a transversal slit 45 is formed in the middle of the engaging piece 44. In the transversal slit 45 is inserted the front arm 46a of the lever 46 from the recess 83 of the hanger 14 and the rear arm 46b of the lever 46 extends downward toward the rear part of the hanger 14. The shaft 47 of the lever 46 is supported by a shaft bearing 48 protruding from the rear surface of the hanger 14. Slightly inside of the end of this lever shaft 47 is loosely fitted the base 49a of a hook 49 and the hook is bent in the middle 49b outwardly and aslant so that each end 49c of the hook may catch the lever shaft 47 of the filter plate 5 adjacent to and in front of it.
On the lateral side of the upper end of the hanger 14 is provided a convex section 51 having a longitudinal slot 50 in the middle, and a pin 52 is horizontally fixed to the convex section 51 and a pin 53 is horizontally fixed to the outside section slightly back of the end 49a of the hook 49, and between the upper pin 52 and the lower pin 53 is spanned a pull spring 54 which constantly pulls the hook 49 upward. On the outer lateral side of the upper end of the engaging piece 44 is fitted a reverse L-shaped hook depressing bar 55, which has its lower end extending through the slot 50 of the aforementioned convex section 51 to the upper surface of the hook 49. Above the upper part of the longitudinal slot 43 is provided a reverse U- shaped spring receptacle 56 and level lugs 57 on the right and left sides of the lower end of the receptacle are secured to the upper surface of the hanger 14 with set screws 58. In the middle of the outside vertical section 56a of the spring receptacle 56 is provided a longitudinal slot 86 which allows the level section 5501 of the hook depressing bar 55 to move up and down. The level section 56b on the upper end of the spring receptacle 56 is formed thick, and in the middle of the level section 5612 is provided an internal thread 59 into which an adjustable screw stock 60 is screwed and the adjustable screw stock is then tightened with a nut 61. A concave spring bearing 62 is formed on the engaging piece 44 and a push spring 63 is supported by the spring bearing 62 and the underside 60a of the adjustable screw stock 60.
To the respective tops of the first head 1, the filter plate 5 and the movable head 2 is secured a nearly rectangular spring hanging frame 64. In the middle of this frame 64 is provided a V-shaped reinforcement frame 65 on the 4 right and left sides of which the upper end of springs 66 and 67 for fixing front and rear filter cloths are fixed to a hanging ring 71 attached to the underside of the adjustable screw stock 70 piercing through the top 64a of the frame 64 and which is secured with nuts 68 and 69 in the upper and under sides of the frame 64.
As shown in FIGS. 3 and 5, filter cloth 72 is formed of one sheet of cloth common to adjacent filter plates 5 and 5 and folded back in a reverse U-shape. A front sheet 72a covers the concavo-convex back side 5a of the filter plate 5 and a rear sheet 72b covers the concave-convex front side 5b of the filter plate 5. In the middle of the filter plate 5 is bored a hole 73 and corresponding holes 72c each are bored in the front sheet 72a and the rear sheet 72b of the filter cloth 72. Firstly an internal thread member 74 is fitted in the hole 73 of the filter plate 5, then an external thread member 76 is screwed thereinto, the external thread member 76 having a liquid inlet 75 which narrows towards the center of the filter plate so that the filter cakes will split at the narrow point when the filter plates are separated and drop easily from the inlet, and the front side 72a of the filter cloth 72 and the rear side 72b thereof respectively are fixed in the middle of the filter plates 5 by tightening the flange 74a of the internal thread member 74 and the flange 76a of the external thread member 76 applied to the brim 73a of the hole 73. The upper side 72d of the filter cloth 72 is covered by filter cloth reinforcement material 77 made of a material such as fiat leather covering the upper surface and part of the front and rear sides of the filter cloth 72. At the front and rear ends of the upper part 72d of the filter cloth 72 an iron bar 78 having the width of the filter cloth is sealed between the filter cloth 72 and the filter cloth reinforcement material 77. At the upper ends of the front sheet 72a and rear sheet 72b of the filter cloth 72 are fitted metal connection fittings 79 each connecting the filter cloth with the springs 66 and 67, the metal connection fitting being fixed by setting a stop ring at either end of the two inside and outside members 79a and 7% whose lengths slightly exceed the width of the filter cloth and between which the filter reinforcement cloth is sandwiched. At the upper end of the metal connection fitting 79 is provided a ring 81 to which the lower ends of springs 66 and 67 respectively are fastened.
A filter cloth liquid outlet 82 is provided in both corners of the lower end of the filter plate 5.
The apparatus of the invention works in the following manner. In FIGS. 1 and 2 filter plates 5 and movable head 2 are in a position of pressing. In this position each hanger 14 of filter plates 5 and movable head 2 thrusts itself against the rear arm 46b of the lever 46 and depresses the rear arm 46b centering around the lever shaft 47, with the result that the front arm 46a of this lever 46 raises the engaging piece 44 against the recoiling power of a push spring 63 and places the lower end thereof in a high position in which the lower end does not thrust itself against a feed pawl 25 of the chain piece 26 of a drive chain 15 and two chain pieces 27 of the same height with its succeeding feed pawl 25. At this time a hook depressing bar 55 is also raised by the engaging piece 44 cooperatively and the hook 49 is released so that the hook 49 springs up, drawn by a pull spring 54, and the end 49c of the book 49 hangs on the front end of the lever shaft 47. Consequently, one filter plate 5 is successively connected with another filter plate by means of the hook 49.
When the pressing and filtering stage of the process is over and the movable head 2 is moved backward by a piston 8, the rear arm 46b of the lever 46 of the first filter plate 5 in the rear is released, so that the supporting power of. the front arm 46a acting on the engaging piece 44 is lost and in consequence the recoiling power of a push spring 63 works on lowering the engaging piece 44, extending its lower end toward the underside of the hanger 14. At the same time a hook depressing bar 55 is lowered and depresses a hook 49 against the power of a pull spring 54, so that the end 490 of the hook 49 is separated from the lever shaft 47 of the second filter plate 5, thereby the connection of the first filter plate 5 with the second filter plate 5 being cut off to put the former in a movable state. The push spring 63 and the pull spring 54 are so made that the former is stronger in spring power than the latter.
When the recession of the movable head 2 is over, a motor 18 is energized to move sprockets 16 and 17 on the right and left sides respectively in a clockwise direction, thereby the upper side of both drive roller chains positioned parallel to each other and located on the outer sides of the side bars or side rails 4 on the right and left sides respectively are guided by a rail 29 and moved toward the right as shown in FIG. 1. Then the feed pawl 25 of the drive chain 15 thrusts itself against the lower end of the engaging piece 44 which was earlier lowered and catches the lower end and pushes it, thereby separating the first filter plate 5 from the second filter plate 5 and moving the first filter plate 5 to a position where it abuts against the movable head 2 that was moved backward and is brought to a standstill in the rear.
As filter cakes which stayed between filter plates 5 in the pressing stage of process are sticky, the second filter plate is stuck to the first plate 5 through filter cakes therebetween and tends to recede together with the first filter plate 5 when the filter plates are operated in the manner described above. This is because the rear arm 46b of the lever 46 of the second filter plate 5 is disengaged by the filter plate 5 moving slightly, thereby the support given the engaging piece 44 by the front arm 46a is lost and consequently the engaging piece 44 is lowered to disconnect the hook 49. If the filter plate 5 that is to be moved back is not separated exactly from the second filter plate, filter cakes of which descriptions will be given hereafter will not be removed in a perfect state. Two chain pieces 27 succeeding a feed pawl 25 and which are the same height therewith prevent the engaging piece 44 of the second filter plate 5 from lowering and consequently preclude the incidental moving of said filter plate 5.
The rear arm 46b of the lever 46 of the thus moved first filter plate 5 thrusts itself against the hanger 14 of the movable head 2 and lowers, while the front arm 46a is raised by the reaction caused by the just described thrust of the rear arm 46b against the hanger 14 of the movable head 2 and the engaging piece 44 is hung up, so that the engaging piece 44 is disengaged from the feed pawl 25 of the drive chain 15 and the first filter plate 5 is brought to a halt in a position where it abuts the movable head 2 (See FIG. 5).
The engaging piece 44 of the second filter plate 5 is held in raised position by the chain piece 27 while the first plate 5 is separated far enough from the second filter plate 5 as to break the junction due to sticky filter cakes therebetween and when said chain piece 27 has finished passing under the engaging piece 44, the engaging piece 44 lowers, and the next feed pawl 25 thrusts itself against said engaging piece 44 and the second filter plate 5 is separated from the third filter plate 5 and is moved to a position, where it abuts against the first filter plate 5 that was earlier moved backward, and is brought to a halt.
The operation described above is repeated successively between the filter plates 5, and the plates are separated one after another. The relationship between the engaging piece 44 and the lever 46 is adjusted in such a manner that suitable clearance is provided between the movable head 2, the filter plate 5 and its succeeding filter plates respectively, when the filter plates are in a halted position. The clearance is provided so as to prevent shocks between the filter plates.
In a state in which the filter plates 5 abut against each other, filter cloth 72 is suspended vertically by springs 66 and 67, and the front sheet 72a and the rear sheet 72b of the filter cloth 72 respectively run along the concavo-convex backside surface 5a of the front filter plate 5 and the concavo-convex front side surface 5b of the rear filter plate 5. When the filter plates 5 are moved apart one after another by the feed pawl 25 of a drive chain 15 after pressing is over, the top end of the filter cloth 72, as shown in FIG. 5, is stretched by front and rear springs 67 and 66 drawn aslant in such a manner that the front sheet 72a. and the rear sheet 7211 form a slant between the front and rear filter plates 5 and 5 being separated while at the same time the vibration of springs 67 and 66 caused by the moving of the rear filter plate 5 is conducted to the front sheet 72a and the rear sheet 725 of the filter plate 72, whereby cohered filter cakes are shaken ofl".
When the rear filter plate 5 is sufficiently separated from the front filter plate 5, the top of the filter cloth 72 is stretched horizontally and consequently a vibrational means may be additionaly provided whereby strong forced vibration is induced by tapping and may be transmitted to the top 72a of the filter cloth in case the quality of cakes make it hard for the cakes to be shaken off the filter cloth 72.
As described above, the filter plates 5 are automatically separated and moved backward one after another from the position in which the press is operated, and filter cakes are automatically removed in conjunction with the backward movement of the filter 5, whereby filtering efficiency is greatly improved.
Description being made of the invention as above, it is apparent that this invention is not limited to the foregoing description alone wherein a single type filter press comprising filter plates alone is illustrated vvith reference to the drawings but that the benefits and advantages of the invention may be derived from provision of the aforementioned engaging piece lifting mechanism on the filter plates and frames thereof in the case of a double type filter press having a plurality of filter plates and frames each in alternate combination.
I claim:
1. A filter press comprising a fixed first head, a fixed rear head, a movable head disposed therebetween, a plurality of plate elements and filter cloths alternately arranged in parallel between said first head and said movable head, said plate elements and said movable head having hangers protruding horizontally from both sides thereof, side rails extending between both sides of said first head and both sides of said rear head and on which said hangers are slidable, drive chains having feed pawls at fixed intervals parallelly arranged below said hangers on the outer sides of both side rails, said hangers each being provided with a longitudinal slot and a recess that extends from the rear part to the front part, an engaging piece in said longitudinal slot, a reverse L-shaped hook depressing bar on the outer lateral side of the engaging piece, the engaging piece having a transverse slot in the middle, said engaging piece being arranged to be stopped at the upper edge of the longitudinal slot when the engaging piece is lowered, a lever shaft on the rear part of each of said hangers, a lever having a front arm and a rear arm at an obtuse angle to each other is swingably fitted on the lever shaft, the front arm of said lever extending into the transverse slot of the engaging piece and engageable with the edge of said transverse slot, the rear arm of said lever protruding behind the hanger and engageable with the next adjacent plate so as to raise the engaging piece to its highest point when the adjacent plates are abutting, a reverse U-shaped spring receptacle "having an outer vertical part with a longitudinal slot therin, the hook depressing bar having a horizontal part movable up and down in the upper part of the longitudinal slot of the hanger and operatively connected to the engaging piece, a push spring between the lower surface of the top part of said spring receptacle and the upper surface of the engaging piece, the hook depressing bar of the engaging piece protruding outwardly from said spring receptacle, a hook loosely fitted at the end of the lever shaft, a pull spring extending between said hook,
and the upper end of the lateral side of each of the hangers, said pull spring being weaker than the said spring pushing against the engaging piece so that the hook catches the lever shaft of the next adjacent plate element when the engaging piece is raised by he lever, the hook depressing bar of the engaging piece being above the upper surface of said hook.
2. A filter press as claimed in claim 1 in which said reverse U-shaped receptacle has a threaded hole in the transverse upper portion thereof, a spring adjusting screw in said threaded hole, said push spring being engaged with the lower end of said spring adjusting screw, the upper surface of said engaging piece having a concave recess in the upper surface thereof in which the other end of said spring is engaged, said hanger having a projection, a pin in said projection, said hook having an outwardly curved section at about the middle thereof, and a further pin at the end and on the outside of the hook from the hanger, said pull spring extending between said pins. 7
3. A filter press as claimed in claim 1 further comprising cake removing mechanism by which to remove filter cakes from the filter cloth and comprising a spring hanging frame secured to the tops of the first head, each of the filter plates and the movable head, and at least two swingable filter cloth fitting springs suspended from the top of each of said frames, the filter cloth on the back side of one filter plate and filter cloth on the front side of the next adjacent filter plate being connected with each other at the upper ends thereof, each filter cloth being fixed to the two springs on the respective frames, and filter cloth fitting means connecting each filter cloth to the respective filter plate at a position at least as low as the middle thereof.
References Cited UNITED STATES PATENTS 447,024- 2/ 1891 Coes et a1. 2102i31 2,932,399 4/ 1960 Emele 210-225 3,153,630 10/ 1964 Green 210-4130 3,232,435 2/ 1966 Fismer 210-23 6 X 3,289,844 12/ 1966 Emele 210230 X REUBEN FRIEDMAN, Primary Examiner.
C. M. DITLOW, Assistant Examiner.
1. A FILTER PRESS COMPRISING A FIXED FIRST HEAD, A FIXED REAR HEAD, A MOVABLE HEAD DISPOSED THEREBETWEEN, A PLURALITY OF PLATE ELEMENTS AND FILTER CLOTHS ALTERNATELY ARRANGED IN PARALLEL BETWEEN SAID FIRST HEAD AND SAID MOVABLE HEAD, SAID PLATE ELEMENTS AND SAID MOVABLE HEAD HAVING HANGERS PROTRUDING HORIZONTALLY FROM BOTH SIDES THEREOF, SIDE RAILS EXTENDING BETWEEN BOTH SIDES OF SAID FIRST HEAD AND BOTH SIDES OF SAID REAR HEAD AND ON WHICH SAID HANGERS ARE SLIDABLE DRIVE CHAINS HAVING FEED PAWLS AT FIXED INTERVALS PARALLELLY ARRANGED BELOW SAID HANGERS ON THE OUTER SIDES OF BOTH SIDE RAILS, SAID HANGERS EACH BEING PROVIDED WITH A LONGITUDINAL SLOT AND RECESS THAT EXTENDS FROM THE REAR PART TO THE FRONT PART, AN ENGAGING PIECE IN SAID LONGITUDINAL SLOT, A REVERSE L-SHAPED HOOK DEPRESSING BAR ON THE OUTER LATERAL SIDE OF THE ENGAGING PIECE, THE ENGAGING PIECE HAVING A TRANSVERSE SLOT IN THE MIDDLE, AND ENGAGING PIECE BEING ARRANGED TO BE STOPPED AT THE UPPER EDGE OF THE LONGITUDINAL SLOT WHEN THE ENGAGING PIECE IS LOWERED, A LEVER SHAFT ON THE REAR PART OF EACH OF SAID HANGERS, A LEVER HAVING A FRONT ARM AND A REAR ARM AT AN OBTUSE ANGLE TO EACH OTHER IS SWINGABLY FITTED ON THE LEVER SHAFT, THE FRONT ARM OF SAID LEVER EXTENDING INTO THE TRANSVERSE SLOT OF THE ENGAGING PIECE
| 1964-09-09 | en | 1967-12-26 |
US-31845781-A | Electrolysis cell with intermediate chamber for electrolyte flow
ABSTRACT
The economy of production of hydrogen and sulfuric acid in a three chamberlectrolysis cell in which an electrolyte flows through the intermediate chamber (11) which is bounded by ion exchanger membranes (9,10) can be improved by the provision of a porus supporting framework or skeleton (12) of graphite or of ion exchanger material against which the separators with the electrodes (7, 8) on them, can be pressed. The overall internal resistance of the cell can thus be reduced and its mechanical behavior improved. Substantial through passage porosity is desired in the supporting structure, which may be of graphite, but porous aggregates of ion exchanger material with fixedly applied or welded on separators in the form of stacked layers or rolled mats, are preferred for the relative simplicity of their provision in practice.
This invention concerns an electrolysis cell for the production of hydrogen and sulfuric acid out of water and sulfur dioxide, the cell having an intermediate chamber through which an electrolyte flows, which chamber separates the anode space from the cathode space and is bounded by separators constituted by ion exchange membranes. The invention relates particularly to an electrolysis cell of this kind that is designed to operated as economically as possible in the so-called "sulfuric acid hybrid closed-cycle process."
New concepts regarding energy sources have highlighted hydrogen as an energy carrier, the most economical recovery of which is a matter now under intensive investigation. The electrolytic separation of hydrogen from aqueous sulfuric acid, accompanied by anodic oxidation of sulfur dioxide to surfur trioxide is now regarded as an interesting method of production, in which the sulfur trioxide is then catalytically retransformed back into sulfur dioxide with the splitting off of oxygen which is usefully recovered.
An important objective of this process is, further, an electrolysis under favorable energy conditions which is as trouble-free as possible. That is, operation at as low a cell voltage as possible with avoidance or suppression of the transport of sulfur dioxide into the cathode space. In order to avoid this last named source of trouble, a process has already been developed by the assignee of this application in which the anode space is separated from the cathode space by an intermediate chamber bounded by two separators between which an electrolyte flows through the chamber. See U.S. patent application Ser. No. 945,693, filed Sept. 25, 1978 now U.S. Pat. No. 4,191,619. In a further development, separators for such a three chamber cell were constituted of special ion exchange membranes having an electrical conductivity that is relatively high and only slightly dependent upon the sulfuric acid concentration. See U.S. patent application Ser. No. 228,796, filed Jan. 26, 1981 now U.S. Pat. No. 4,391,682.
Further improvement of this process can be obtained by a contact that is as close as possible between the electrodes or collectors with the adjacent separators of the intermediate chamber. Difficulties arise in this case, however, because the mechanical stability of the separators is not very high, so that the use of raised application pressures is practically out of the question.
Supporting grids or frameworks (between the separators) made of polyethylene or teflon as recommended generally for aqueous electrolysis in German Pat. No. 1,546,717 would in themselves be useful for the application of pressure laterally in a three chamber cell for the recovery of hydrogen, but these structures substantially raise the overall resistance of the cell, so that such supporting frameworks have heretofore been rejected.
SUMMARY OF THE INVENTION
It is an object of the invention to provide mechanical support for the separators of a three chamber cell, to enable the electrodes to be pressed against them without the disadvantage of substantial increase in the resistance of the cell because of the presence supporting structures.
It has been found that the internal resistance of such three chamber electrolysis cells designed for hydrogen recovery is reduced and the manner of operation of the cell can be improved if a supporting framework is used which itself conducts ions and/or is of high porosity. Briefly, in the electrolysis cell of this invention a permeably porous supporting structure, of graphite or of ion exchange material is interposed between the two separators.
The porous supporting structure should take up the necessary lateral pressure (for a flat juxtaposition of the separators on the supporting structure), but nevertheless and a free volume as high as possible is desirable in between the supporting material. Holes and gaps, even when large enough to be easily visible to the unaided eye, are to be considered "pores."
Preferably the separators lie immediately against the adjacent electrodes and hence against the porous supporting framework which fills out the entire intermediate chamber while maintaining sufficient gaps for passage of an electrolyte.
In one embodiment the separators and the immediately adjacent electrodes are pressed against a supporting porous graphite body, which last should have a through-going porosity that is as high as possible, so that the intermediate electrolyte flow is not excessively limited. Porous graphite or graphite felt with about 95% "particularly useful for this purpose. In practice the through-penetrating porosity of the graphite material used should be at least 80%. This means that reticulated, or mat-like or hard-sponge bodies with the necessary stiffness are to be included in the concept of "porous" bodies, as here used.
As a result of mechanical stiffening by the supporting framework, relatively high lateral pressures are usable. The ohmic resistance of the electrolysis cell can be kept low in this manner as the result of the low specific resistance of supporting frameworks made of easily wettable graphite.
At present supporting bodies of ion exchange material seem particularly favorable, especially if this material is the same as that of the separators and can be heat-welded to the separators.
In this manner an intermediate chamber structure is provided that can be completely produced as a "sandwich" in a continuous strip, which facilitates the assembly of the cell and lowers its overall price.
On the other hand, the separators can again be simply put adjacent to the electrodes as in the case of a graphite supporting structure. The supporting framework should, with sufficient mechanical solidity, have a sufficiently through-going porosity in the direction of flow of the electrolyte between the separators (i.e. parallel to them).
Perpendicular to the separators, on the contrary, the inherently ion-conducting ion exchanger material can support electric charge transport across the intermediate chamber, so that in the case of a supporting framework of ion exchanger material a high through-going porosity is not necessary in this direction.
THE DRAWING
The advantage of the manner of operation according to the invention can best be understood with preference to an illustrative example which is described below with reference to the annexed drawing, the single FIGURE of which shows schematically (in section) a cylindrical three-chamber electrolysis cell, the axis of the cylinder being vertical on the drawing.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
A cell, which is essentially constructed in axially symmetrical form, is held together by external plastic discs 1 and 2 (made for example, from polyvinylidene fluoride), which are adjacent on their respective internal sides to the casing halves 3 and 4 made of graphite. Two copper rings 5 and 6 reinforce the graphite and at the same time provide the electric current connections. The casing halves 3 and 4, and their respectively associated copper rings 5 and 6 are separated from each other electrically by the intermediate chamber frame of plastic containing the support body 12. The cathode 7 and the anode 8 are constituted as flow-through electrodes and lie against the separators 9 and 10 which bound the intermediate chamber 11 and are constituted of cation exchange membranes. The supply of the electrolyte flows is shown in the drawing.
The separators 9 and 10 between the individual cell chambers in the illustrated case were cation exchanger membranes of the type known as NEOSEPTA C 66-5T, on one of which a platinized graphite felt is laid as the cathode and on the other of which a graphite felt is laid as the anode.
Between the parallel membranes a porous body is provided as the supporting framework. The membrane spacing was 5 mm. Sulfuric acid (conc. 50% by weight) served as the electrolyte in the cathode chamber, 50% by weight sulfuric acid plus 0.15% by weight hydriodic acid (as homogeneous catalyst) plus SO2 saturated (saturated at 1 bar) in the anode chamber and, in the intermediate chamber, 30 to 35% by weight sulfuric acid. The temperature was 90° C.
The ohmic internal resistance of the electrolysis cell can be calculated from the current-voltage characteristics of the cell and of the individual electrodes (measured against a comparison electrode). This internal resistance consists substantially entirely of the resistances of the cation exchanger membranes, of the resistance of the electrolyte in the intermediate chamber and of the transition resistances which arise through the low applied pressure of the electrodes against the membranes or of the collectors against the electrodes. In addition, as a result of the use of a supporting framework evenly distributed in the intermediate chamber, the ohmic resistance of the intermediate chamber through which the electrolyte flows, is on the one hand raised. By the use of a graphite felt with about 95% free volume as the supporting framework, this rise of the internal ohmic resistance, however, is only large enough to be fully compensated by reduction of the ohmic internal resistance by the pressing on of the electrodes or collectors against the cation exchanger membranes. Thus, the ohmic resistance of the electrolysis cell without supporting framework is about 1 ohm·cm2 and with supporting framework of graphite felt, likewise about 1 ohm·cm2. The electrolysis voltage is reduced from 625 mV to 565 mV at a current density of 200 mA/cm2 as the result of the improved catalytic effect of the platinized graphite felt more strongly pressed as the cathode against the cathode-side cationic exchanger membrane.
In the case of a preliminary experiment with a filling of course cuttings of a cation exchanger membrane of type NEOSEPTA C 66-5T serving as a supporting framework (free volume about 30%) an ohmic internal resistance of the electrolysis cell of about 1 ohm·cm2 was obtained again, in spite of the small free volume. This ohmic internal resistance can be further reduced by completing the supporting framework with cation exchanger material and thereby enhancing further the reduction of the free volume, when the specific resistance of the cation exchanger membrane is greater than the specific resistance of the electrolyte flowing through the intermediate chamber. Thus, for example, the specific resistance of 30% by weight H2 SO4 at 80° C. is about 0.8 ohm·cm, while the specific resistance of the already highly conducting material NEOSEPTA C 66-5T in 30% H2 SO4 is about 4 ohm·cm at 80° C.
The considerations of ohmic internal resistance of the electrolysis cell therefore provide no obstacle to the manufacture and use of a porous supporting structure of cation exchanger material which is bounded on opposite sides of the strip of material by two fixedly applied or welded-on sheets or films of the same or similar ion exchanger material.
As noted above, when the across-chamber support in the intermediate chamber is a single porous body, the body may be spongy, perforated, reticulated or in the form of a mat, provided that it is sufficiently stiff. When the support is provided by a structure composed of a number of bodies, these bodies do not need to be fastened together, since they act in compression, and may be pieces of any suitable size and shape for maintaining considerable open space between them, for example a packing of balls, and the bodies so packed may themselves be porous. The term "permeably porous" is used to designate a pore structure that is "open" or "through-going." The supporting body or structure may be thought of as a supporting skeleton.
I claim:
1. An electrolysis cell for the production of hydrogen and sulfuric acid from water and sulfur dioxide having an anode chamber, an intermediate chamber and a cathode chamber and means for causing an electrolyte to flow through said intermediate chamber as well as means for supplying electrolytes respectively to said anode and cathode chambers, said intermediate chamber being bounded on opposite sides by separators constituted of cation-exchanger membranes separating said intermediate chamber respectively from said anode and cathode chambers, said cell further comprising a permeably porous and stiff structure or body (12) of graphite extending across said intermediate chamber for supporting said separators against pressure tending to push them towards each other.
2. An electrolysis cell as defined in claim 1 in which said permeably porous and stiff structure or body (12) has a permeability or through-going porosity which, at least in a direction parallel to said separators is as great as practically possible.
3. An electrolysis cell for the production of hydrogen and sulfuric acid from water and sulfur dioxide having an anode chamber, an intermediate chamber and a cathode chamber and means for causing an electrolyte to flow through said intermediate chamber as well as means for supplying electrolytes respectively to said anode and cathode chambers, said intermediate chamber being bounded on opposite sides by separators constituted of cation-exchanger membranes separating said intermediate chamber respectively from said anode and cathode chambers, said cell further comprising a permeably porous and stiff structure or body (12) which substantially completely fills said intermediate chamber and is made either of graphite or of cation-exchanger material, said cell anode and cathode electrodes (7,8) lying directly and flush against the respective separators (9,10) bounding the anode and cathode chambers, and said porous and stiff structure or body supporting said separators against pressure tending to push them towards each other.
4. An electrolysis cell as defined in claim 3 in which said electrodes are pressed against said separators.
5. An electrolysis cell for the production of hydrogen and sulfuric acid from water an sulfur dioxide having an anode chamber, an intermediate chamber and a cathode chamber and means for causing an electrolyte to flow through said intermediate chamber as well as means for supplying electrolytes respectively to said anode and cathode chambers, said intermediate chamber being bounded on opposite sides by separators constituted of cation-exchanger membranes separating said intermediate chamber respectively from said anode and cathode chambers, said cell further comprising a permeably porous and stiff structure or body (12) being made of the same cation-exchanger material as the separators, being firmly bonded to said separators, and extending across said intermediate chamber for supporting said separators against pressure tending to push them towards each other.
6. An electrolysis cell as defined in claim 5 in which said permeably porous and stiff structure or body (12) is fused or welded with the cation-exchanger membranes constituting said separators.
7. An electrolysis cell for the production of hydrogen and sulfuric acid from water and sulfur dioxide having an anode chamber, an intermediate chamber and a cathode chamber and means for causing an electrolyte to flow through said intermediate chamber as well as means for supplying electrolytes respectively to said anode and cathode chambers, said intermediate chamber being bounded on opposite sides by separators constituted of cation-exchanger membranes separating said intermediate chamber respectively from said anode and cathode chambers, said cell further comprising a permeably porous and stiff structure or body (12) consisting either of graphite or of cation-exchanger material and extending across said intermediate chamber for supporting said separators against pressure tending to push them towards each other, the spacing between said separator membranes (9,10) being as small as practically possible while still allowing a sufficient electrolyte flow to pass through said porous and stiff structure or body for preventing passage of sulfur dioxide from said anode chamber to said cathode chamber.
| 1981-11-05 | en | 1984-04-17 |
US-80283377-A | Programmable calculator including a key for performing either a subtraction or a unary minus function
ABSTRACT
An adaptable programmable calculator is provided by employing modular read-write and read-only memory units capable of being expanded to provide the calculator with additional program and data storage functions oriented towards the environment of the user, a central processing unit, and an input-output control unit capable of bidirectionally transferring information between the memory or central processing units and a number of input and output units. The memory, central processor, and input-output control units are controlled by a microprocessor included in the central processing unit. The input and output units include a keyboard input unit with a plurality of sections capable of being defined by plug-in read-only memory modules and stored programs added by the user, a magnetic card reading and recording unit capable of bidirectionally transferring information between an external magnetic card and the calculator, a solid state display unit capable of displaying every alphabetic and numeric character and many other symbols individually and in a line of one or more alphameric statements, and a printer unit capable of printing on thermally sensitive paper every alphabetic and numeric character and many other symbols individually and in alphameric statements or messages. The keyboard input unit includes a MINUS arithmetic operator key that initiates either the unary minus function or the subtraction function, as the context of an entered algebraic statement employing the MINUS arithmetic operator requires.
CROSS REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 510,921, filed on Sept. 30, 1974, now U.S. Pat. No. 4,028,538, which is in turn a division of application Ser. No. 212,581, filed on Dec. 27, 1971, now issued as U.S. Pat. No. 3,839,630. The subject matter of U.S. Pat. No. 3,839,630 is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates generally to calculators and improvements therein and more particularly to programmable calculators that may be controlled both manually from the keyboard input unit and automatically by a stored program loaded into the calculator from the keyboard input unit or an external record member.
Computational problems may be solved manually, with the aid of a calculator (a dedicated computational keyboard-driven machine that may be either programmable or nonprogrammable), or a general purpose computer. Manual solution of computational problems is often very slow, so slow in many cases as to be an impractical, expensive, and ineffective use of the human resource, particularly when there are other alternatives for solution of the computational problems.
Nonprogrammable calculators may be employed to solve many relatively simple computational problems more efficiently than they could be solved by manual methods. However, the keyboard operations or language employed by these calculators is typically trivial in structure, thereby requiring many keyboard operations to solve more general arithmetic problems. Programmable calculators may be employed to solve many additional computational problems at rates hundreds of times faster than manual methods. However, the keyboard language employed by these calculators is also typically relatively simple in structure, thereby again requiring many keyboard operations to solve more general arithmetic problems.
Another basic problem with nearly all of the keyboard languages employed by conventional programmable and nonprogrammable calculators is that they allow the characteristics of the hardware of the calculator to show through to the user. Thus, the user must generally work with data movement at the hardware level, for example, by making sure that data is in certain storage registers before specifying the operations to be performed with that data and by performing other such "housekeeping" functions.
SUMMARY OF THE INVENTION
The principal object of this invention is to provide an improved programmable calculator that has more capability and flexibility than conventional programmable calculators, that is smaller, less expensive and more efficient in calculating elementary mathematical functions than conventional computer systems, and that is easier to utilize than conventional programmable calculators or computer systems.
Another object of this invention is to provide a programmable calculator employing a directly usable high-level keyboard language that completely eliminates most of the operator "housekeeping" requirements typically associated with the languages of conventional programmable calculators and computers.
Another object of this invention is to provide a programmable calculator in which a MINUS key performs either subtraction or unary minus, as the context of the statement requires.
These objects are accomplished according to the illustrated preferred embodiment of this invention by employing a keyboard input unit, a magnetic card reading and recording unit, a solid state output display unit, an output printer unit, an input-output control unit, a memory unit, and a central processing unit to provide an adaptable programmable calculator having manual operating, automatic operating, program entering, magnetic card reading, magnetic card recording, and alphameric printing modes. The keyboard input unit includes a group of data keys for entering numeric data into the calculator, a group of control keys for controlling the various modes and operations of the calculator and the format of the output display, and a group of definable keys for controlling additional functions that may be added by the user. All of the data keys and nearly all of the control keys may also be employed for programming the calculator, many of the control keys being provided solely for this purpose.
The magnetic card reading and recording unit includes a reading and recording head, a drive mechanism for driving a magnetic card from an input receptacle in the front panel of the calculator housing past the reading and recording head to an output receptacle in the front panel, and reading and recording drive circuits coupled to the reading and recording head for bidirectionally transferring information between the magnetic card and the calculator as determined by the control keys of the keyboard input unit. It also includes a pair of detectors and an associated control circuit for disabling the recording drive circuit whenever a notch is detected in the leading edge of the magnetic card to prevent information recorded on the magnetic card from being inadvertently destroyed. Such a notch may be provided in any magnetic card the user desires to protect by simply pushing out a perforated portion thereof.
The output printer unit includes a stationary thermal printing head with a row of resistive heating elements, a drive circuit for selectively energizing each heating element, and a stepping mechanism for driving a strip of thermally-sensitive recording paper past the stationary thermal printing head in seven steps for each line of alphameric information to be printed out. Each alphabetic and numeric character and many other symbols may be printed out individually or in messages as determined by the control keys of the keyboard input unit or by a program stored within the calculator.
The input-output control unit includes a sixteen-bit universal shift register serving as an input-output register into which information may be transferred serially from the central processing unit or in parallel from the keyboard input and magnetic card reading and recording units and from which information may be transferred serially to the central processing unit or in parallel to the solid state output display, magnetic card reading and recording, and output printer units. It also includes control logic responsive to the central processing unit for controlling the transfer of information between these units. The input-output control unit may also be employed to perform the same functions between the central processing unit and peripheral units including, for example, a digitizer, a marked card reader, an X-Y plotter, a magnetic tape unit, a disc, and a typewriter. A plurality of peripheral units may be connected at the same time to the input-output control unit by simply plugging interface modules associated with the selected peripheral units into receptacles provided therefore in a rear panel of the calculator housing.
The memory unit includes a modular random-access read-write memory having a dedicated system area and a separate user area for storing program steps and/or data. The user portion of the read-write memory may be expanded without increasing the overall dimensions of the calculator by the addition of a program storage module. Additional read-write memory made available to the user is automatically accommodated by the calculator, and the user is automatically informed when the storage capacity of the read-write memory has been exceeded.
The memory unit also includes a modular read-only memory in which routines and subroutines of basic instructions for performing the various functions of the calculator are stored. These routines and subroutines of the read-only memory may be expanded and adapted by the user to perform additional functions oriented toward the specific needs of the user. This is accomplished by simply plugging additional read-only memory modules into receptacles provided therefor in the top panel of the calculator housing. Added read-only memory modules are automatically accommodated by the calculator and may be associated with the definable keys of the keyboard input unit or employed to expand the operations associated with other keys. An overlay is employed with each added read-only memory module associated with the definable keys of the keyboard input unit to identify the additional functions that may then be performed by the calculator.
Plug-in read-only memory modules include, for example, a trigonometric module, a peripheral control module, and a definable functions module. The trigonometric module enables the calculator to perform trigonometric functions, logarithmic functions, and many other mathematical functions. The definable functions module enables the user to store subprograms of his own choosing in the program storage section of the read-write memory, associate them with some of the definable keys of the keyboard input unit, and protect them from subsequently being inadvertently altered or destroyed. These subprograms may have their own line numbering dequence and may be any of three types: an immediate execute type wherein the subprogram may be run upon depressing a DEFINE key; a subroutine utilizing parameters; a function having parameters that may be employed as any other keyboard function.
The memory unit further includes a pair of recirculating sixteen-bit serial shift registers. One of these registers serves as a memory address register for serially receiving information from an arithmetic-logic unit included in the central processing unit, for parallel addressing any memory location designated by the received information, and for serially transferring the received information back to the arithmetic-logic unit. The other of these registers serves as a memory access register for serially receiving information from the arithmetic-logic unit, for writing information in parallel into any addressed memory location, for reading information in parallel from any addressed memory location, and for serially transferring information to the arithmetic logic unit. It also serves as a four-bit parallel shift register for transferring four bits of binary-coded-decimal information in parallel to the arithmetic-logic unit.
The central processing unit includes four recirculating sixteen-bit serial shift registers, a four-bit serial shift register, the arithmetic logic unit, a programmable clock, and a microprocessor. Two of these sixteen-bit serial shift registers serve as accumulator registers for serially receiving information from and serially transferring information to the arithmetic logic unit. The accumulator register employed is designated by a control flip-flop. One of the accumulator registers also serves as a four-bit parallel shift register for receiving four bits of binary-coded-decimal information in parallel from and transferring four bits of such information in parallel to the arithmetic logic unit. The two remaining sixteen-bit serial shift registers serve as a program counter register and a qualifier register, respectively. They are also employed for serially receiving information from and serially transferring information to the arithmetic-logic unit. The four-bit serial shift register serves as an extend register for serially receiving information from either the memory access register or the arithmetic-logic unit and for serially transferring information to the arithmetic-logic unit.
The arithmetic-logic unit is employed for performing one-bit serial binary arithmetic, four-bit parallel binary-coded-decimal arithmetic, and logic operations. It may also be controlled by the microprocessor to perform bidirectional direct and indirect arithmetic between any of a plurality of the working registers and any of the storage registers of the data storage section of the read-write memory.
The programmable clock is employed to supply a variable number of shift clock pulses to the arithmetic logic unit and to the serial shift registers of the input-output, memory, and central processing units. It is also employed to supply clock control signals to the input-output control logic and to the microprocessor.
The microprocessor includes a read-only memory in which a plurality of microinstructions and codes are stored. These microinstructions and codes are employed to perform the basic instructions of the calculator. They include a plurality of coded and non-coded microinstructions for transferring control to the input-output control logic, for controlling the addressing and accessing of the memory unit, and for controlling the operation of the two accumulator registers, the program counter register, the extend register and the arithmetic logic unit. They also include a plurality of clock codes for controlling the operation of the programmable clock, a plurality of qualifier selection codes for selecting qualifiers and serving as primary address codes for addressing the read-only memory of the microprocessor, and a plurality of secondary address codes for addressing the read-only memory of the microprocessor. In response to a control signal from a power supply provided for the calculator, control signals for the programmable clock, and qualifier control signals from the central processing and input-output control units, the microprocessor issues the microinstructions and codes stored in the read-only memory of the microprocessor as required to process either binary or binary-coded-decimal information entered into or stored in the calculator.
In the keyboard mode, the calculator is controlled by keycodes sequentially entered into the calculator from the keyboard input unit by the user. The solid state output display unit displays either the mnemonic representation of the keys as they are depressed or a numeric representation of output data or alphameric user instructions or program results. The output printer unit may be controlled by the user to selectively print out a numeric representation of any numeric data entered into the calculator from the keyboard input unit, a numeric representation of any result calculated by the calculator, or a program listing on a line-by-line basis of the mnemonic representation of the keys entered. The output printer unit may also be controlled by the user to print out labels for inputs to and outputs from the calculator and any other alphameric information that may be desired.
When the calculator is in the keyboard mode, it may also be operated in a trace alphameric printing mode. The output printer unit then prints out a mnemonic representation of each program line as it is entered by the user.
In the program running mode, the calculator is controlled by automatically obtaining compiled keycodes stored as steps of a program in the user storage section of the read-write memory. During automatic operation of the calculator, data may be obtained from the memory unit as designated by the program or may be entered from the keyboard input unit by the user while the operation of the calculator is stopped for data either by the program or by the user.
When the calculator is in the program running mode, the user may also employ a TRACE key to check the execution of the program line by line in order to determine whether the program, as entered into the calculator, does in fact carry out the desired seqence of operations.
In the program entering mode, keycodes are sequentially entered by the user into the calculator from the keyboard input unit and are compiled into Polish notation and stored as steps of a program in the user storage section of the read-write memory.
In the magnetic card reading mode, the magnetic card reading and recording unit may be employed by the user to separately load either data or programs into the calculator from one or more external magnetic cards.
In the magnetic card recording mode, the magnetic card reading and recording unit may be employed by the user to separately record either data or programs stored in the user section of the read-write memory onto one or more external magnetic cards. Programs may be coded by the user as being secure when they are recorded onto one or more external magnetic cards. The calculator detects such programs when they are reloaded into the calculator and prevents the user from re-recording them or obtaining any listing or other indication of the individual program steps.
DESCRIPTION OF THE DRAWINGS
The following figures have been numbered in correspondence with the same figures of U.S. Pat. No. 3,839,630, cited above as being incorporated herein by reference.
FIG. 1 is a front perspective view of an adaptable programmable calculator according to the preferred embodiment of this invention.
FIGS. 3A-B are a simplified block diagram of the adaptable programmable calculator of FIGS. 1 and 2.
FIG. 7 is a plan view of the keyboard input unit employed in the adaptable programmable calculator of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
GENERAL DESCRIPTION
Referring to FIG. 1, there is shown an adaptable programmable calculator 10 including both a keyboard input unit 12 for entering information into and controlling the operation of the calculator and a magnetic card reading and recording unit 14 for recording information stored within the calculator onto one or more external magnetic cards 16 and for subsequently loading the information recorded on these and other similar magnetic cards back into the calculator. The calculator also includes a solid state output display unit 18 for displaying alphameric information stored within the calculator. It may also include an output printer unit 20 for printing out alphameric information on a strip of thermally-sensitive recording paper 22. All of these input and output units are mounted within a single calculator housing 24 adjacent to a curved front panel 26 thereof.
Referring to the simplified block diagram shown in FIGS. 3A-B, it may be seen that the calculator also includes an input-output control unit 44 (hereinafter referred to as the I/O control unit) for controlling the transfer of information to and from the input and output units, a memory unit 46 for storing and manipulating information entered into the calculator and for storing routines and subroutines of basic instructions performed by the calculator, and a central processing unit 48 (hereinafter referred to as the CPU) for controlling the execution of the routines and subroutines of basic instructions stored in the memory unit as required to process information entered into or stored within the calculator. The calculator also includes a bus system comprising an S-bus 50, a T-bus 52, and an R-bus 54 for transferring information from the memory and I/O control units to the CPU, from the CPU to the memory and I/O control units, and between different portions of the CPU. It further comprises a power supply for supplying DC power to the calculator and peripheral units employed therewith and for issuing a control signal POP when power is supplied to the calculator.
The I/O control unit 44 includes an input-output register 56 (hereinafter referred to as the I/O register), associated I/O gating control circuitry 58, and input-output control logic 60 (hereinafter referred to as the I/O control). I/O register 56 comprises a universal sixteen-bit shift register into which information may be transferred either bit-serially from CPU 48 via T-bus 52 or in parallel from keyboard input unit 12, magnetic card reading and recording unit 14, and peripheral input units 28 such as the marked card reader via twelve input party lines 62. Information may also be transferred from I/O register 56 either bit-serially to CPU 48 via S-bus 50 or in parallel to magnetic card reading and recording unit 14, solid state output display unit 18, output printer unit 20, and peripheral output units 28 such as the X-Y plotter or the typewriter via sixteen output party lines 64.
I/O gating control circuitry 58 includes control circuits for controlling the transfer of information into and out of I/O register 56 in response to selected I/O qualifier control signals from CPU 48 and selected I/O control instructions from I/O control 60. It also includes an interrupt control circuit 65, a peripheral control circuit 66, a magnetic card control circuit 67, a printer control circuit 68, and a display control circuit 69 for variously controlling the input and output units and issuing control signals QFG and EBT to I/O control 60 via two output lines 71 and 72. These last mentioned control circuits variously perform their control functions in response to control signal POP from the power supply, I/O qualifier control signals from CPU 48, I/O control instructions from I/O control 60, and control signals from keyboard input unit 12. Interrupt control circuit 65 initiates the transfer of information into I/O register 56 from keyboard input unit 12 or interrupting peripheral input units 28 such as the marked card reader and issues a qualifier control signal QNR to CPU 48 via output lines 73. Peripheral control circuit 66 enables interface modules 30 plugged into the calculator to respond to information from I/O register 56, control associated peripheral units 28, transfer information to and/or receive information from associated peripheral units 28, and in some cases initiate the transfer of information to I/O register 56 from the interface modules themselves. Magnetic card control circuit 67 enables magnetic card reading and recording unit 14 to respond to information in I/O register 56 and either read information into I/O register 56 from a magnetic card 16 or record information onto a magnetic card 16 from I/O register 56. Printer control circuit 68 and display control circuit 69 enable output display unit 18, and output printer unit 20, respectively, to respond to information from I/O register 56.
When a basic I/O instruction obtained from memory unit 46 is to be executed, CPU 48 transfers control to I/O control 60 by issuing a pair of I/O microinstructions PTR and XTR thereto. In response to these I/O microinstructions from CPU 48, control signal POP from the power supply, control signals QFG and EBT from I/O gating control circuitry 58, and I/O qualifier and clock control signals from CPU 48, I/O control 60 selectively issues one or more I/O control instructions to gating control circuitry 58 as required to execute the basic I/O instruction designated by CPU 48 and issues control signals, TTX, XTR, QRD, and SCB to CPU 48 via output lines 74-77. The I/O qualifier control signals issued to I/O control 60 and gating control circuitry 58 by CPU 48 are derived from the basic I/O instruction to be executed. Those qualifier control signals issued to I/O control 60 designate the specific I/O control instructions to be issued by I/O control 60, while those issued to gating control circuitry 58 designate selected control circuits to be employed in executing the basic I/O instruction.
Memory unit 46 includes a modular random-access read-write memory 78 (hereinafter referred to as the RWM), a modular read-only memory 80 (hereinafter referred to as the ROM), a memory address register 82 (hereinafter referred to as the M-register), a memory access register 84 (hereinafter referred to as the T-register), and control circuitry 85 for these memories and registers. RWM 78 and ROM 80 comprise MOS-type semiconductor memories.
Routines and subroutines of basic instructions for performing the basic functions of the calculator and constants employed by these routines and subroutines are stored in these portions of ROM 80. An additional 3,072 sixteen-bit words of ROM may also be added on pages 4, 5, and 6 in steps of 512 and 1,024 words. This is accomplished by simply inserting plug-in ROM modules 92 into receptacles 94 provided therefor in top panel 90 of the calculator housing as illustrated in FIG. 1 by the partially-inserted plug-in ROM module on the left. As each plug-in ROM module 92 is inserted into one of these receptacles a spring-loaded door 95 at the entrance of the receptacle swings down allowing passage of the plug-in ROM module. Once the plug-in ROM module is fully inserted as illustrated by the plug-in ROM module on the right, a printed circuit terminal board 96 contained within the plug-in ROM module plugs into a mating edge connector mounted inside the calculator. A handle 98 pivotally mounted at the top end of each plug-in ROM module 92 facilitates removal of the plug-in ROM module once it has been fully inserted into one of the receptacles 94.
Routines and subroutines of basic instructions (and any needed constants) for enabling the calculator to perform many additional functions are stored in each plug-in ROM module 92. The user himself may therefore quickly and simply adapt the calculator to perform many additional functions oriented toward his specific needs by simply plugging ROM modules of his own choosing into the calculator. Added plug-in ROM modules are automatically accommodated by the calculator by momentarily interrupting power or by depressing an ERASE MEMORY key, and they are associated with definable section 91 of keyboard input unit 12 or employed to expand the functions perfomed by this and other sections of the keyboard input unit.
Referring again to FIGS. 3A-B, M-register 82 of the memory unit comprises a recirculating sixteen-bit serial shift register into which information may be transferred bit-serially from CPU 48 via T-bus 52 and out of which information may be transferred bit-serially to CPU 48 via S-bus 50. Information shifted into M-register 82 may be employed to address any word in RWM 78 or ROM 80 via fifteen output lines 106.
T-register 84 of the memory unit comprises a recirculating sixteen-bit serial shift register into which information may be transferred either bit-serially from CPU 48 via T-bus 52 or in parallel from any addressed word in RWM 78 and ROM 80 via sixteen parallel input lines 108. Information may be transferred from T-register 84 either bit-serially to CPU 48 via S-bus 50 or in parallel to any addressed word in RWM 78 via sixteen parallel output lines 110. The four least significant bits of information contained in T-register 84 may comprise binary-coded-decimal information and may be transferred from the T-register in parallel to CPU 48 via three parallel output lines 112 taken with S-bus 50.
The control circuitry 85 of the memory unit controls these transfers of information into and out of M-register 82 and T-register 84, controls the addressing and accessing of RWM 78 and ROM 80, and refreshes RWM 78. It performs these functions in response to memory microinstructions, memory clock pulses, and shift clock pulses from CPU 48.
CPU 48 includes a register unit 114, an arithmetic-logic unit 116 (hereinafter referred to as the ALU), a programmable clock 118, and a microprocessor 120. Register unit 114 comprises four recirculating sixteen-bit shift registers 122, 124, 126, and 128 and one four-bit shift register 130. Shift registers 122 and 124 serve as sixteen-bit serial accumulator registers (hereinafter referred to as the A-register and the B-register, respectively) into which information may be transferred bit-serially from ALU 116 via T-bus 52 and out of which information may be transferred bit-serially to ALU 116 via R-bus 54. The four least significant bit positions of A-register 122 also serve as a four-bit parallel accumulator register into which four bits of binary-coded-decimal information may be transferred in parallel from ALU 116 via four parallel input lines 132 and out of which four bits of binary-coded-decimal information may also be transferred in parallel to ALU 116 via three parallel output lines 134 taken with R-bus 54.
Shift register 126 serves as a sixteen-bit system program counter (hereinafter referred to as the P-register) into which information may be transferred bit-serially from ALU 116 via T-bus 52 and out of which information may be transferred bit-serially to ALU 116 via R-bus 54. Information contained in the least significant bit position of P-register 126 may also be transferred as a qualifier control signal QPO to microprocessor 120 via output line 135.
Shift register 128 serves as a sixteen-bit qualifier register (hereinafter referred to as the Q-register) into which information may be transferred bit-serially from ALU 116 via T-bus 52 and out of which information may be transferred bit-serially to ALU 116 via R-bus 54. Information contained in the five least significant bit positions of Q-register 128 is transferred to I/O gating control circuitry 58 as five one-bit I/O qualifier control signals Q00-Q04 via five parallel output lines 136, and information contained in the six next least significant bit positions of the Q-register is transferred to I/O control 60 as six one-bit I/O qualifier control signals Q05-Q10 via six parallel output lines 138. Similarly, information contained in the seven least significant, the ninth and eleventh least significant, and the most significant bit positions of Q-register 128 and information derived from the thirteenth, fourteenth, and fifteenth bit positions of the Q-register may be transferred to microprocessor 120 as eleven one-bit microprocessor qualifier control signals Q05-Q06, Q08, Q10, Q15, and QMR via eleven output lines 140. Information contained in the twelfth through the fifteenth least significant bit positions of Q-register 128 may be transferred to microprocessor 120 as a four-bit primary address code via four parallel output lines 142.
Shift register 130 serves as a four-bit serial extend register (hereinafter referred to as the E-register) into which information may be transferred bit-serially either from ALU 116 via T-bus 52 or from the least significant bit position of T-register 84 via input line 144. Information may also be transferred out of E-register 130 to ALU 116 via R-bus 54.
Register unit 114 also includes control circuitry 146 for controlling the transfer of parallel binary-coded-decimal information into and out of A-register 122 and the transfer of serial binary information into and out of A-register 122, B-register 124, P-register 126, Q-register 128, and E-register 130. This is accomplished in response to register microinstructions from microprocessor 120, control signals TTX and XTR from I/O control 60, and shift clock control pulses from programmable clock 118. Control circuitry 146 includes a flip-flop 148 (hereinafter referred to as the A/B flip-flop) for enabling the transfer of information into and out of either the A-register 122 or the B-register 124 as determined by the state of the A/B flip-flop. The state of A/B flip-flop 148 is initially determined by information Q11 transferred to the A/B flip-flop from the twelfth least significant bit position of Q-register 128 but may be subsequently complemented one or more times by microinstruction CAB from microprocessor 120.
ALU 116 may perform either one-bit serial binary arithmetic on data received from T-register 84 or M-register 82 via S-bus 50 and/or from any register of register unit 114 via R-bus 54 or four-bit parallel binary-coded-decimal arithmetic on data received from T-register 84 via output lines 112 taken with S-bus 50 and/or from A-register 122 via output lines 134 taken with R-bus 54. It may also perform logic operations on data received from memory unit 46 and/or register unit 114 via any of these lines. The arithmetic and logic operations performed are designated by ALU microinstructions from microprocessor 120 and are carried out in response to these microinstructions, shift clock control pulses from programmable clock 118, and control signal SCB from I/O control 60. Information is also transferred from ALU 116 to A-register 122 via output lines 132 or to I/O register 56, M-register 82, T-register 84, or any register of register unit 114 via T-bus 52 in response to microinstructions and control signals applied to these registers. If a carry results while ALU 116 is performing either one-bit serial binary arithmetic or four-bit parallel binary-coded-decimal arithmetic, the ALU issues a corresponding qualifier control signal QBC and QDC to microprocessor 120 via one of two output lines 152 and 154.
Programmable clock 118 includes a crystal-controlled system clock 156, a clock decoder and generator 158, and a control gate 160. System clock 156 issues regularly recurring clock pulses to clock decoder and generator 158 via output line 162. In response to these regularly recurring clock pulses from system clock 156 and to four-bit clock codes from microprocessor 120, clock decoder and generator 158 issues trains of n shift clock pulses to ALU 116, M-register 82, T-register 82, and all of the registers of register unit 114 via output line 164. These trains of n shift clock pulses are employed for shifting a corresponding number of bits of serial information into or out of any of these registers or for shifting a carry bit in the ALU. The number n of pulses in each of these trains may vary from one to sixteen as determined by the number of bits of serial information required during each operation to be performed. In response to a control signal CCO from microprocessor 120, control gate 160 prevents any shift clock pulses from being applied to the ALU or any of these registers. Upon completion of each train of n shift clock pulses, clock decoder and generator 158 issues a ROM clock pulse to microprocessor 120 via output line 166 and an I/O clock pulse to I/O control 60 via output line 168. In response to the regularly recurring clock signal from system clock 56, clock decoder and generator 158 also issues correspondingly regularly recurring memory clock pulses to memory unit 46 via output line 170.
Microprocessor 120 selectively issues two I/O microinstructions to I/O control 60 via two output lines 172, six memory microinstructions to memory unit 46 via six output lines 174, thirteen register microinstructions to register unit 114 via thirteen output lines 176, and five ALU microinstructions to ALU 116 via five output lines 178. It also issues a four-bit clock code associated with each of these microinstructions to clock decoder 158 via four output lines 180. These microinstructions and associated clock codes are issued as determined by the control signal POP from the power supply, the eleven microprocessor qualifier control signals from Q-register 128, the four-bit primary address codes from Q-register 128, and the five microprocessor qualifier control signals from I/O control 60, interrupt control 65, ALU 116, and P-register 126.
KEY OPERATIONS
All operations performed by the calculator may be controlled or initiated by the keyboard input unit and/or by keycodes entered into the calculator from the keyboard input unit, the magnetic card reading and recording unit, or peripheral input units such as the marked card reader and stored as program steps in this program storage section of the RWM. An operational description of the keyboard input unit is therefore now given with specific reference to FIG. 1, except as otherwise indicated.
TURN-ON PROCEDURE
When the OFF/ON switch located on the front of the calculator is set to the ON position, the following display appears:
φ : END
the calculator is then ready for operation.
INITIALIZING THE CALCULATOR
The ERASE key has the same effect as switching the calculator off and then on again. It erases all stored data and programs from memory and clears the results of any previous calculation or operation.
THE FUNDAMENTAL USER OPERATION
Communication with the calculator is through the display. In general, there are two basic steps to follow when performing operations:
1. A set of directions is written into the display by actuating the appropriate keys.
2. The calculator is then instructed to follow these directions, and the result of any numerical operation is automatically displayed. When making keyboard calculations, this step consists solely of actuating the EXECUTE key.
These two basic steps form the fundamental user operation. With a few exceptions, all operations such as making calculations, loading or running programs, giving directions to the printer, etc., consist of some variation of the fundamental user operation.
DIAGNOSTIC NOTES
In addition to displaying numbers, directions, and the results of operations, the calculator also displays diagnostic notes to inform the user of operational errors or of special situations. The basic notes are numbered from 01 to 16 (higher numbered notes are associated with the various plug-in ROM's). The note number indicates the type of error or situation. For example, NOTE 01 indicates that the calculator was given a direction which it could not understand; NOTE 16 indicates that the printer paper supply has been exhausted. A list of the basic notes and a brief description of their meanings is given in the appendix at the end of Key Operations.
When a note condition occurs in a program execution is halted. The display then indicates the note as well as the number of the program line in which the note condition occurred; e.g.,
NOTE φ2 IN 4
indicates that a note 02 condition occurred during line 4.
KEYING DIRECTIONS AND NUMBERS
Directions are written into the display by actuating the appropriate keys. Suppose, for example, that the user desires to add 2 to 4 and print out the result. The keys PRINT 2+4 are actuated. The calculator does not, however, follow these directions until it is instructed to do so by actuating EXECUTE. It then prints (and displays) the result, 6. Numbers are keyed into the display, as on any standard office-machine, by actuating the number keys (0 through 9) and the decimal point key in the required order. If a number is negative the minus sign should be keyed first before the number is keyed. Use of commas (such as in 32,341.6) is not allowed. As is the case with a direction, even though the keyed number is displayed, it will not be executed by the calculator until the EXECUTE key is actuated. It is not normally desirable to execute just a single number. The number would usually be included within some set of directions, and then the directions would be executed.
USE OF CLEAR
The CLEAR key clears the display, but leaves the memory unaltered. It operates immediately and does not have to be followed by EXECUTE. An end-of-line symbol () appears in the display when CLEAR is actuated, which indicated that the calculator is idle. It is not necessary to clear the display before keying the next direction as long as the previous direction has been executed. In this case use of CLEAR is optional. If no subsequent execution has taken place since the last direction was keyed, then CLEAR must be used. These keys will be printed, and subsequent tracing will cease.
MAKING ARITHMETIC CALCULATIONS
For arithmetic, the fundamental user operation consists of writing an arithmetic expression into the display and then actuating the EXECUTE key, to instruct the calculator to evaluate that expression. An arithmetic expression is written into the display by pressing keys in the same order as they would be written on paper, one key per character or symbol. The arithmetic expression may then be executed by simply pressing the EXECUTE key. This is illustrated by the keying sequences and displayed answers given below.
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Keying Sequence Displayed Answers
______________________________________
3 + 6 EXECUTE 9.φφ
9 . 3 - 6 EXECUTE 3.3φ
- 7 EXECUTE -7.φφ
6 * ( - 7 ) EXECUTE -42.φφ
8 . 2 5 * 4 EXECUTE 33.φφ
6 * 3 / ( 1 1 - 2 ) EXECUTE
2.φφ
√ 3 EXECUTE 1.73
√ 4 + 5 EXECUTE
7.φφ-√( 4 + 5 ) EXECUTE 3.φφ
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As in the above examples, quantities in parentheses are treated as one quantity. Thus √(4+5) is equivalent to √9, whereas, √4+5 adds 5 to the square root of 4. The expression 4(3+2) is the equivalent of the expression 4*(3+2). Use of the multiplication operator is implied and is therefore optional in such cases. Parentheses can be nested (i.e., parentheses inside parentheses, etc.) but they must always be balanced, that is, there must be the same number of left-handed parentheses as there are right-handed.
THE ARITHMETIC HIERARCHY
When an arithmetic expression contains more than one operator, as do several of the preceding examples, there is a prescribed order of execution. An expression must be properly written or the answer will be wrong. The order of execution, known as the hierarchy is shown below:
1. Mathematical functions such as square root;
2. Implied multiplication;
3. Multiplication and division; and
4. Addition and subtraction.
Where an expression contains two or more operators at the same level in the hierarchy, they will be executed in order from left to right. The use of parentheses enables the order of execution to be changed. Thus, in the expression √(4+5) the addition operator is executed before the square root operator even though the addition operator occupies a lower level in the hierarchy.
The arithmetic operators are used to indicate arithmetic operations among variables and constants. The minus sign (-) is used as in ordinary mathematical notations to indicate the subtraction operation (e.g. 2-3, A-B, 5-R1). The special usage of placing a minus sign in front of a quantity to indicate that the negative of that quantity is intended is called unary minus. The term unary comes from the fact that in this usage there is only one number or quantity associated with the operation. A binary operation is one that involves two quantities.
EXCEEDING THE LENGTH OF THE DISPLAY
The length of an expression is not limited to the length of the display. As each excess symbol is keyed, the display shifts left to make room. The maximum allowable length for an expression varies between 35 and 69 keystrokes, depending upon the nature of the expression. If too many keys are pressed the display shows NOTE 09 (see the section on diagnostic notes below). Depending upon the nature of the expression the note may appear either before or after the EXECUTE key is pressed. In either case, the operator must press CLEAR and write a shorter expression.
MAKING CORRECTIONS
The BACK and FORWARD keys enable a displayed expression to be altered or corrected without re-keying the entire sequence. If a wrong key is pressed when writing an expression, it can be corrected immediately by pressing the BACK key followed by the correct key, as illustrated below:
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Keying Sequence Display
______________________________________
2 + BACK * 4 2 * 4
______________________________________
A displayed expression can be blanked, key by key in reverse order, by pressing BACK once for each displayed key. The blanked keys can then be returned to the display one at a time by pressing FORWARD. If an expression contains a wrong key, press BACK until that key is blanked, press the correct key and then press FORWARD to return each subsequent key (or, if extra keystrokes are required, key in the remainder of the expression). For example, if the number 123456789 is keyed incorrectly into the display as 123444789, the error may be corrected as indicated by the following steps:
______________________________________
Keying Sequence Display
______________________________________
BACK BACK BACK BACK BACK 1234
5 6 FORWARD FORWARD FORWARD
123456789
______________________________________
If the incorrect expression has been executed but no key has since been pressed, the expression can be returned to the display (by pressing BACK), corrected as before, and then again executed.
Any line of a stored program may be recalled into the display and then completely blanked by repeatedly actuating the BACK key. One additional actuation of the BACK key will bring the entire next preceding line of the stored program into the display. It is then possible to backstep through that line and bring its predecessor into the display, etc. Analogously, the FORWARD key may be repeatedly actuated to bring those lines succeeding the current line into the display.
To remove a portion of a line the BACK key is repeatedly actuated until the right most character, symbol or mnemonic of the portion to be deleted becomes the right most item in the display. The DELETE key is then actuated once for each character, symbol or mnemonic to be removed. Then, if the right most item of the line is not visible in the display, the FORWARD key is repeatedly actuated. The user may then continue writing the line, execute it, or store it, as appropriate. For example, assume it is desired to delete the underlined portion from the following line:
FXD 2;X→Y;PRT (A+B)/A;GTO 4
this is accomplished by repeatedly actuating the BACK key until the display appears as follows:
;X→Y;PRT (A+B)/A
next, the DELETE key is actuated thirteen times. At first the display shifts to the right to bring the first part of the line into view, which in this case is FXD 2. However, FXD will not appear until there is room in the display for all four characters plus the space between D and 2. After this first part of the line comes into view, the line appears to shorten by losing an item from the right-hand side of the display each time the DELETE key is actuated, while the rest of the line remains stationary. After the segment has been deleted, the FORWARD key is repeatedly actuated until the end of the now modified line comes into view as follows:
FXD 2;GTO 4
the user may now continue writing this line, execute it, or store it, as he desires.
To add a segment to the interior of a line the BACK key is repeatedly actuated until the right most item visible in the display is the character, symbol or mnemonic immediately preceding the segment sought to be added. The INSERT key is then actuated and followed by the keys which describe the desired segment. The FORWARD key is next repeatedly actuated until the end of the line is in view. As the keys following INSERT but preceding FORWARD are actuated their mnemonics are inserted into the line with no loss of any other items in the line. The right-hand portion of the line is shifted to the right to make room for the additional items being inserted. This action continues until one of the keys, BACK, FORWARD, DELETE, CLEAR, EXECUTE or STORE is actuated. Generally the insertion of a portion of a line is terminated with the FORWARD key to return to the end of the line. For example, assume it is desired to insert the portion
2φ→B
into the line
1φ→A;3φ→C
to accomplish the insertion, the BACK key is repeatedly actuated until the semicolon becomes the right most item in the display. The INSERT key is then actuated and followed by the key sequence 2φ→B. Next, the FORWARD key is actuated until the entire line is visible as follows:
1φ→A;2φ→B;3φ→C
if an error is made by the user during the entry of a portion of the line being inserted into an existing line, the erroneous items may be removed by actuating the DELETE key. The user may then continue writing the desired line portion after actuating the INSERT key.
In addition to modifying individual lines of a program as discussed above, it is also possible to insert entire lines into or delete entire lines from, the interior of a program stored in memory. If it is desired to add a line between existing lines 4 and 5, the added line would become new line 5 while the old line 5 would become new line 6. Similarly, if it is desired to remove line 3 from a program, the old line 4 would become the new line 3, the old line 5 would become the new line 4, etc. In both cases the number of available R registers is automatically adjusted after the change.
To insert a line into a program the program line counter is first set to the line number which will be associated with the new line. This may be accomplished, for example, by actuating the GO TO key followed by the number keys representing the line number followed by the EXECUTE key. The new line is then written into the display and followed by sequential actuation of the INSERT and STORE keys. The new line becomes stored, and all succeeding lines of the program together with their line numbers are shifted to provide room.
To delete a line from a program the program line counter is first set to the line number of the line to be deleted. Sequential actuation of the RECALL and DELETE keys will remove the line and shift all succeeding lines and their line numbers to close the gap.
THE DATA MEMORY
The basic calculator contains 179 registers: six storage and working registers (A, B, C, X, Y and Z) and 173 program and data storage registers (R0 through R172). An additional 256 R-registers (R173 through R428) may be added giving a total of 435 registers.
The A, B, C, X, Y and Z registers are selected by pressing the A, B, C, X, Y and Z keys, respectively, while the R registers are selected by pressing the R() key followed by the appropriate number keys 0 through 172 or 428. The argument of the R() key may be a computed quantity. For example, sequentially pressing the R(), (, 7, 0, /, 2, and ) keys denotes the R35 register. The argument of the R() may also be a variable. Then, if register A contains the number 15, sequentially pressing the R() and A keys denotes R15 register. Similarly, if the R5 register contains the number 10 and the C register contains the number 25, sequentially pressing the R(), (, R(), 5, +, C, and ) denotes the R35 register.
The register denoted by the keying sequence R(), R(), R() . . . R() followed by one or more number keys is determined by the number designated by the number keys and by the numbers contained in the various registers. For example, the keying sequence R(), R(), 2 denotes the R8 register if R2 contains the number 8.
When the number following the R() key does not have a strictly integral value, the fractional part of the value is ignored. Thus, the keying sequence R(), 3, 5, 6, ., 6 denotes the R35 register. A plus sign immediately following the R() key is dropped when the line containing it is stored. Thus, the keying sequence R(), +, /, % is stored as R() 35. A minus sign immediately following the R() key is not permitted, and causes a syntax error (NOTE φ1) If the R() key is followed by a quantity whose value is either negative, or greater than the number of available R registers, an error during execution results (the indication will be either NOTE φ5 or NOTE φ6, depending upon the exact circumstances).
Some of the plug-in read-only memory modules require part of the memory for their own use. When one of these modules is installed, it automatically takes the required registers, starting at the highest numbered register and working downwards. Those registers are then temporarily not available for program or data storage, until the module is removed.
When programs are stored they start in the highest-numbered available R-register and sequentially fill the memory downwards. Programs cannot be stored in the A, B, C, X, Y and Z registers. It is, therefore, most convenient to store data first in the A, B, C, X, Y and Z registers and then in the lower numbered R-registers. If the memory contains no program (i.e. at turn-on, or if ERASE has been pressed), then all registers (except those required by a plug-in read-only memory module will be available for data storage. If the memory does contain a program, then the higher-numbered registers will not be available for data diagnostic NOTE φ6 will be displayed if the operator attempts to store data in a register which is not available.
The number of available R-registers can be determined at any time by pressing CLEAR LIST STOP. The printer will start to list the program (the STOP saves having to wait for the whole program to be listed). At the bottom of the list will be a number preceded by the letter R indicating the number of R-registers available. (The lowest-numbered register is R0; subtract 1 from the number printed to obtain the name of the highest-numbered register available for data storage).
STORING DATA
One register can contain one data-number. It is not necessary to clear a register before storing a number in it because the number being stored automatically substitutes for the existing stored number. The entire memory is, however, cleared at turn-on or if ERASE is pressed. Storing data requires use of the → key. For example, pressing
1, 2 . 6→A EXECUTE
stores 12.6 in the A register. Similarly, pressing
6→X EXECUTE
stores 6 in the X register, and pressing
1 9→R() 1 2 EXECUTE
stores 19 in register R12. A stored number may be viewed by using either the DISPLAY or the PRINT keys. For example, pressing
DISPLAY A EXECUTE
displays the number currently stored in A (the number remains stored in A). Similarly, pressing
PRINT R() 1 2 EXECUTE
prints the contents of R12 (the number remains stored in R12).
IMPLIED Z
In general, if a stored number is to be kept for any length of time it should not be stored into the Z register because the result of any arithmetic expression is automatically stored in Z if no other storage location is specified, thus
1 4 . 2 EXECUTE
is equivalent to
1 4 . 2→Z EXECUTE
both expressions result in a display 14.2 which is also stored in the Z register. Similarly,
3 * 4 + 1 6 / 3 EXECUTE
is equivalent to
3 * 4 + 1 6 / 3 → Z EXECUTE
a statement involving numerical activity usually contains an instruction, such as PRT, DSP, or →. If there is no such instruction, the form <quantity> →Z; or <mathematical expression> →Z, is usually automatically assumed when the line is executed or stored.
The automatic addition of Z onto the end of a statement is called the `implied store in Z`.
For instance, if the operator presses A EXECUTE to view the contents of A, the line A→Z is what is actually executed. The contents of A are seen because that is the numerical quantity associated with the last assignment instruction executed in the line. Meanwhile, the contents of Z have been replaced by those of A, and are lost. The recommended procedure for viewing the contents of a register is to use the PRINT or DISPLAY statements, as they do not disturb the contents of any registers.
Because of the implied store into Z, the Z register is not recommended for storing data during calculations performed from the keyboard, except in certain situations. For instance, suppose the operator wished to add a series of numbers: n1, n2, n3, . . . To do this, the register is first set to zero by executing the line 0→Z. Then, the numbers ae added in the following manner:
n.sub.1 +Z
n.sub.2 +Z
n.sub.3 +Z
because of the implied store into Z, this is what is actually happening:
______________________________________
n.sub.1 + Z→Z
n.sub.1 + 0→Z
n.sub.2 + Z→Z
n.sub.2 + n.sub.1→Z
n.sub.3 + Z→Z
n.sub.3 + (n.sub.1 + n.sub.2)→Z
. .
. .
. .
______________________________________
REGISTER ARITHMETIC
Arithmetic expressions may be written using register names instead of actual numbers. When the expression is executed, the values currently stored in those registers will be automatically substituted for the register names in order to evaluate the expression. For example, assume the user has made the following storage assignments:
______________________________________
12.6 in A
6 in X
19 in R12
______________________________________
With the above values stored, the keying sequence
A + R() 1 2 - X EXECUTE
would be equivalent to the keying sequence
1 2 . 6 + 1 9 - 6 EXECUTE
other values stored in these registers would, of course, give a different result for the same expression.
Numbers and register-names may be mixed in an expression, as follows:
3 * 1 2 . 6 + 4 - 6 EXECUTE
fixed- and floating-point numbers
numbers can be keyed into the display and displayed in either fixed point or floating point notation. In fixed-point notation, a number appears in the display as commonly written, with the decimal point correctly located. Floating-point numbers are written with the decimal point immediately following the first digit (discounting leading zeros) and with an exponent. The exponent, which represents a positive or negative power of ten, indicates the direction, and the number of places, that the decimal point should be moved, to express the number as a fixed-point number. In the calculator the exponent may be any integer within the range -99 to +99. Examples of fixed point and floating point notation following: ##STR1##
The FIXED N key selects fixed point display of displayed results. The letter N indicates that the key must be followed by one of the number keys (0 through 9) to select the number of digits to be displayed to the right of the decimal point.
The FLOAT IN key operates in the same way as FIXED N except that floating point display is selected, with N designating the required power of ten. (When the calculator is turned on, FLOAT 9 is automatically assumed.) For example, the number 123.456789 in float 9 notation would be displayed as 1.234567890EφZ. The letter E in the display indicates that the next two digits constitute the exponent. If the exponent is negative a minus sign follows the E, as illustrated below.
______________________________________
Keying Sequence Display
______________________________________
0 0 1 2 3 4 EXECUTE 1.234φφφφφφE-φ3
______________________________________
No more than ten significant digits can be displayed; therefore if a number becomes too large to be properly displayed as a fixed point number, it will be automatically displayed as a floating point number. If the number becomes too small, only zeros are displayed but the number may still be seen if floating point notation is then selected.
The ENTER EXPONENT key is used to designate the E (exponent) when numbers are being keyed in floating point form, as illustrated below:
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Keying Sequence Display
______________________________________
FLOAT N 4 EXECUTE
2 . 5 6
ENTER 2 EXECUTE 2.56φφE φ2
EXP
4 . 7 3
ENTER - 2 EXECUTE 4.73φφE-φ2
EXP
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RANGE OF CALCULATION
The range of the calculator is from ±10-99 to ±9.999999999×1099 ; when this range is exceeded during a calculation diagnostic NOTE 10 is displayed. Calculations which normally result in zero, such as subtracting a number from a number equal to itself, do not exceed the range.
OPERATING THE PRINTER
The print key is used to print both numerical values and alphameric messages (the form of a numerical printout is changed by the FIXED N and FLOAT N keys in the same way as the display is changed). This is illustrated by the following examples (in which it is assumed the FIXED N key, 2 key and EXECUTE key have previously been pressed to determine the form of the printout):
______________________________________
Printing Operation
Keying Sequence Printout
______________________________________
Print A Number
PRINT 1 2 3 EXECUTE
123.φφ
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Print result of a calculation
PRINT 6 + 8 / 2 EXECUTE 10.φφ
print contents of a storage register
PRINT A EXECUTE (CONTENTS OF A)
to print an alphanumeric message requires the use of the quote key (") to both start and end the message (the quote symbol is not printed) as illustrated by the following example:
______________________________________
Keying Sequence
PRINT " MESSAGE SPACE N 0 . 2 " EXECUTE
Printout
MESSAGE NO. 2
______________________________________
no more than sixteen characters (including spaces) can be printed on one line of a message, and each line must be enclosed in quotes. When following the same PRINT instruction, lines must be separated by commas, as indicated below:
PRINT "--------" , "--------" EXECUTE
this prints two lines. If messages and values are to be mixed, they must be separated by a comma as illustrated by the following example in which it is assumed that the number 456 has been stored in the A register.
PRINT " A = " , A EXECUTE A=456.φφ
pressing the SPACE N key followed by one or more number keys designating any one of the numbers 0 through 15 causes the printer to space vertically (the number key specified in the number of lines spaced). This is illustrated by the following example:
______________________________________
Keying Sequence Printout
______________________________________
PRINT " DAYS " EXECUTE DAYS
SPACE N 2 EXECUTE
PRINT 4 EXECUTE 4.00
______________________________________
When used in a message, most keys result in the character printed being the same as the character on the key. The following keys are the exceptions:
1. SPACE prints one blank character-space
2. GO TO prints
3. R() prints :
4. STOP prints !
5. ENTER EXP prints ↑
The following keys either cannot be used in a message or they result in some meaningless character being printed:
1. All of the half-keys at the top of the keyboard and the four blank keys in the left-hand keyblock.
2. The EXECUTE key, RUN PROGRAM key, and STORE key.
3. The JUMP key, END key, IF key, GO TO/SUB key, FLAG N key, RETURN key, and SET/CLEAR FLAG N key.
PROGRAMS
A program enables the calculator to automatically execute the keys necessary to solve a particular problem. First the program must be loaded into the calculator's memory to teach the calculator which key sequences are required and the order in which they are to be executed. Once loaded, the calculator can remember that program until a new one is loaded over it or until the calculator is switched off. A program need not be keyed into the calculator more than once because a loaded program can be recorded on magnetic cards. Recorded programs may then be loaded back into the calculator any time in the future. Once the program has been loaded, it is initialized, and then execution is commenced by actuating RUN PROGRAM key.
A complete program consists of lines of program information, each of which may be separately loaded into the calculator memory from the keyboard by actuating the STORE key when the line has been completed. An end-of-line symbol is automatically displayed at the end of each line after that line has been stored. A program line counter keeps track of which line of a program is currently being executed or is about to be executed or stored next. Before storing a line into the calculator memory, it may be edited with the aid of the BACK, FORWARD, CLEAR, DELETE and INSERT keys. After all lines of the program have been stored, individual lines may be recalled into the display for editing or other purposes. Recall is accomplished by sequentially actuating the CLEAR and GO TO keys followed by the number keys representing the line number of the line to be recalled followed, finally, by the RECALL key. When restoring the recalled line or the edited version thereof it is only necessary to actuate the STORE key.
MAGNETIC PROGRAM CARDS
A magnetic card 16 such as that shown in FIG. 1 is used to permanently or temporarily store programs or data. The card has two sides that may be used independently to store either data or programs (however, data and programs cannot be mixed on the same side of the card). Once a recording has been made on a card-side, that card-side can be protected from erasure by tearing out a corresponding protect tab on the card. The recording on a protected card side cannot be changed.
A program loaded into the memory may be recorded on a magnetic card 16 by pressing
END EXECUTE RECORD EXECUTE
to start the card-reader motor and by then inserting an unprotected card into the card reader. The program from the card may be loaded back into the memory by first sequentially pressing the ERASE key to clear the memory, by then pressing the END, EXECUTE, LOAD and EXECUTE keys, and by thereupon inserting the card into the card reader.
THE PROGRAM LINE
Even though the lines of a program are stored in the same memory as data, the length of individual lines bears no relationship to the length of a register. The calculator simply uses however many registers are necessary to accommodate a particular line. The length of a line is determined by the programmer and depends upon the requirements of his program. However, the length is limited by machine requirements, in the same way that an individual expression is limited (see Exceeding the Length of the Display). Diagnostic NOTE 09 appears either before or after STORE is pressed, if the line is too long. When NOTE 09 appears the operator should press CLEAR and key in a completely new (shortened) line.
Line numbers are automatically assigned, by the calculator, in strict numerical sequence, beginning with line 0. The operator must know what line numbers will be assigned if there are any GO TO statements in his program. The line numbers are not strictly a part of the program because they will automatically change if the program is moved to a different location in memory. For example, suppose a program (No. 1) is a ten-line program (lines 0 through 9) and is already stored in the memory. If a second program (No. 2) is now loaded below program No. 1, then the first line of program No. 2 will be line 10, whereas, if program No. 2 had been the only program in the memory, then its first line would have been line 0. (Any GO TO statements must be corrected, by the programmer, to reflect any such line number changes.)
A line can have one or more statements, separated by semicolons. The actual number of statements on any one line is generally not significant, it being more important to have the statements in the correct order rather than on a particular line. Position of a statement does become significant where a line contains an IF statement or where a branch is to be made. In the former case, those statements which are to be conditionally executed must be on the same line as the IF statement and must come after the IF. In the latter case, a branch is always made to the beginning of a line. Therefore, the first statement to be executed after a branch must be the first statement of the line to which the branch is made. It is recommended that not too many statements be put on one line because a short line is easier to change (once stored) than a long line.
THE DATA ENTRY STATEMENT
Program statements resulting from actuations of the ENTER key are used to halt the program during execution so that the user can key in data. The simplest statement contains only a register name, which is displayed when program execution is halted. The data keyed during the halt is stored, into the register designated, when RUN PROGRAM is subsequently pressed. For example, ENT A; results in the keyed data being stored in register A. An enter statement may contain several register names (which must be separated by commas). The program will halt for each register in turn. For example, ENT A, R13, X; is the equivalent of the three separate statements ENT A;ENT R13;ENT X;. A label (followed by a comma) may precede the register name. In this case the label will be displayed, instead of the name, when the halt occurs. For example, ENT "A=?",A; displays A=? and stores the subsequent data entry into register A.
BRANCHING
Program lines are normally executed in numerical sequence. However, some statements cause the sequence of execution to be changed. This is known as branching (instead of the program going to the next sequential line, it branches to some other specified line and continues program execution there). There are two kinds of branching, conditional and unconditional. Unconditional branching is accomplished with the GO TO, JUMP and GO TO SUB keys while conditional branching is done with the IF key.
There are three types of unconditional branching with GO TO. The first type is an absolute GO TO. On absolute GO TO statements take the form GO TO N, where N is an integer that refers to a particular program line. The second type is a relative GO TO. The form of the relative GO TO statement is GO TO + N or GO TO - N, where N is an integer. This means to skip forward or backward N program lines. The third type is a GO TO label. This type of GO TO statement takes the form GO TO "LABEL", where LABEL is any unique alphameric group of characters and must be enclosed in quotes. The number of characters in the label is virtually unlimited, however, the calculator will only look at the last four characters in the label. When a GO TO "LABEL" statement is executed the program will branch to a program line with "LABEL" as the first statement of that line, where LABEL has the identical last four characters as the original GO TO "LABEL" statement. If two lines have the same label branch execution will always go to the first label.
In a program, a GO TO statement causes program execution to continue with the line whose number is specified. When a GO TO statement is entered from the keyboard and followed by the RUN PROGRAM key, the GO TO statement causes program execution to start at the line whose number is specified. However, when a GO TO statement is entered from the keyboard and followed by the EXECUTE key, the GO TO statement causes the calculator to go to the line specified but not to start program execution. Any subsequent activity then depends upon the next key pressed. A line number is valid only if a currently stored program has a line identified by that number, or if it is the next higher number after the number identifying the last stored line. All other numbers are non-valid and, if used in a GO TO statement, will cause diagnostic NOTE 08 to be displayed.
JUMP allows relative branching. But, unlike the GO TO, can have a numeric constant, a register or any legitimate calculator expression as a parameter. JUMP-6 on execution would go back six lines in the program. If the contents of A were 6.23 then JUMP A would jump the integer value of A lines, or in this case 6 lines in the program. If A were 6.23 and B were 2, then JMP (A+B) would be acceptable and would jump eight lines on execution.
Often it is desirable to execute the same operations at several places in a program. One could simply repeat a group of program lines as needed, but this can be time consuming and error prone. More important, unnecessary repetition of program lines wastes memory space. The calculator has the capability to store a set of program lines once, and allow a program to execute this set of lines many times. Such a group of program lines is called a subroutine.
Once a subroutine has been written and stored in memory, execution may branch to the subroutine from a program. This is known as calling a subroutine. The program which calls the subroutine is usually referred to as the mainline program or calling program. When the subroutine execution is completed a branch is made back to the calling program and mainline execution is resumed where it was interrupted by the subroutine call. The branch from the subroutine to the mainline program is called a return. Note that if a subroutine is called in line N; the return is made to line N+1.
Branching to a subroutine is accomplished by using the GO TO SUB. GO TO SUB works almost exactly like GO TO and may branch to an absolute, relative or "LABEL" address. The difference between GO TO and GO TO SUB is that when a GO TO SUB is used for a branch, the calculator stores the line number for the return branch address. To make the return branch RETURN is stored at the end of the subroutine. The calculator itself will provide the address for the return branch.
The IF statement allows the powerful feature of conditional branching in the calculator enabling the calculator to decide whether or not to execute the succeeding statement(s) on the same line as that IF statement. The general form of the IF statement is IF followed by a condition completing the statement. (For Example, IF A-B;). The line in which the IF statement appears may be completed with any other statements. The operation will be as follows. First the condition immediately following the IF will be evaluated to check the truth of the condition. If the condition is true, the statements following the IF statement are executed, and if the condition is false, execution immediately goes to the next line. Thus, in the example given above, A=B is first computed to determine whether the contents of the A register equal the contents of the B register. If this condition is true, the rest of the line would be executed. If it is false, the rest of the line would be ignored and execution would go immediately to the next line.
The conditions in IF statements all use one of the following keys to test the relationship of any two values, registers, arithmetic expressions, or flags:
1. > (greater than)
2. ≦ (less than or equal to)
3. = (equal to)
4. ≠ (not equal to)
If the relationship is the same as that indicated by the key used an answer of true (one) will be given and if not an answer of false (zero) will be given. For example, if the contents of A and B were 2 then
A=B→C
would store 1 in C,
a≠b→c
would store 0 in C, and
A+B=A→C
would store 0 in C.
again, these can be used in any expression A+B (A=B)+AB (A≦B)+(A+B+C) (A>B)→C would store 2+2(1)+4(1)+6(0) which is 8 in C.
THE STOP AND END STATEMENTS
The STOP key, used as a statement in a program or pressed while a program is running, halts program execution. STOP should be used only to abort a program (in the sense that it is no longer desired to run the program, or that it is desired to start execution again at the beginning).
The END key serves the dual purpose of halting program execution and of initializing the calculator for commencing program execution at line 0.
THE FLAGS
The calculator makes sixteen flags available to the user as selected by the FLAG N key followed by numeric keys to designate one of the flags 0 through 15. For example, actuation of the FLAG N 4 selects flag 4. Flags are used generally as part of an IF statement to enable the user to define some special condition.
The calculator terminology used to describe flags is quite simple: If a flag is raised, it is set; a set flag is considered to have the value 1. If a flag is lowered, it is cleared; a cleared flag is considered to have the value 0.
Flags are set and cleared by means of the SET/CLEAR FLAG N key. This key is actuated once to set a flag and twice to clear it. For example, a single actuation of the SET/CLEAR FLAG N key followed by the 1 and 2 number keys sets flag 12. Similarly, a double actuation of the SET/CLEAR FLAG N key followed by the 7 key cleared flag 7. Once set, a flag remains set until it is deliberately cleared. However, all flags are automatically cleared at turn-on, or when ERASE is pressed, or when an END statement is executed.
As long as no program is being executed, the state of any flag can be examined actuating the FLAG N key followed by number keys representing the flag in question followed by the EXECUTE key. The state (value) of the flag will then be displayed. Such a test will not change the state of any flag.
In addition to their normal use, flags 0 and 13 also have a special purpose. Flag 0 may be set from the keyboard while a program is actually running, by pressing the SET/CLEAR FLAG N key. Flag 13 is set automatically if the program halts for an ENTER statement and the RUN PROGRAM key is then actuated without any data being keyed.
LIST MODE
The LIST key facilitates printing by means of the calculator printing unit a program listing of an internally stored program. The listing includes the line number of each line together with an alphameric mnemonic representation of the line. An indication of the number of storage registers remaining is printed at the end of the listing.
Program listing is accomplished by first setting the program line counter to the line at which listing is to commence. This may be done by actuating the GO TO key followed by the number keys representing the line number followed by the EXECUTE key. Next, the LIST key is actuated to begin the listing operation, which will terminate at the last program line stored.
TRACE MODE
A trace mode of the calculator enables the user to obtain a printed record of its operation. The form of this printed record is a function of the type of operation in progress.
The calculator may be placed in the trace mode by actuating the TRACE key followed by the EXECUTE key or by program execution of a TRACE command. The calculator may be returned to normal mode by actuating the NORMAL key followed by the EXECUTE key or by program execution of a NORMAL command. The calculator is automatically placed in the normal mode when it is turned on.
While in the trace mode, the calculator prints a representation of each line execution from the keyboard and the results of those executed statements which produce a quantity that is considered a result. A few keys, such as CLEAR, are not printed.
The following example is illustrative of the printout obtained when the calculator is operating in the trace mode:
______________________________________
φ→A;φ→B
φ.φφ
φ.φφ
A+1→ A;B+1φ→B
1.φφ
1φ.φφ
A+1→A;B+1φ→B
2.φφ
2φ.φφ
PRT "A=",A,"B=",
A= 2.φφ
B= 2.φφ
______________________________________
While running a program in the trace mode the calculator prints the line number of each line as it is executed, and below that, any quantities that were stored into registers by that line. Running a program in the trace mode may be very helpful in debugging a program by analyzing the numbers stored during the execution of the program. A program may, without alteration, be run in the trace mode simply by sequentially actuating the TRACE and EXECUTE keys before execution of the program is begun. In addition, the calculator may be placed in the trace mode during execution of any program which does not contain a NORMAL statement by simply actuating the TRACE key. It is not necessary to halt execution of the program first.
We claim:
1. An electronic calculator comprising:keyboard input means including a plurality of operand and operator keys for entering a line of at least one algebraic statement into the calculator, one of said plurality of keys being operative for entering a minus arithmetic operator into the calculator; memory means for storing a line of at least one algebraic statement entered into the calculator from said keyboard input means; processing means, coupled to said keyboard input means and memory means, for processing a line of at least one algebraic statement entered into the calculator and stored in said memory means to perform the algebraic operations specified in that line of at least one algebraic statement; and output means, coupled to said processing means, for providing a visual indication of the results of algebraic statements processed by said processing means; said processing means being responsive to the combination of the minus arithmetic operator followed by an operand, encountered during processing of an algebraic statement, for negating that operand, said processing means being further responsive to the combination of a first operand followed by the minus arithmetic operator followed by a second operand, encountered during processing of an algebraic statement, for subtracting the second operand from the first operand.
| 1977-06-01 | en | 1979-08-07 |
US-40972982-A | Shoring frame
ABSTRACT
A right-angled triangular shoring or scaffolding frame unit having its acute apices blunted at right angles to the adjacent side and having multiple holes therein adapted for bolt assembly in a plurality of positions. Said triangular units preferably are made from aluminum and used in identical pairs assembled symmetrically to brace a pair of vertical load-bearing aluminum legs, said triangular units having adjacent legs of different lengths whereby the widths of the assembled frames can be varied by bolting the pair(s) of triangular units to each other edge-to-edge between the vertical legs with either the shorter, or alternatively the longer, of the adjacent legs oriented horizontally.
This is a continuation of patent application Ser. No. 339,726 filed Jan. 15, 1982 and now abandoned.
This invention relates to a versatile shoring frame of the type utilized in the construction industry preferably made from aluminum or similar light weight non-ferrous metals. It is also adaptable for use in scaffolding and other similar frames useful in the construction and similar industries.
An example of conventional steel shoring, adapted for use with extendable frames, is illustrated in U.S. Pat. No. 3,190,405, issued June 22, 1965. Welded steel shoring base frames have long been the conventional standard in the construction industry. Mechanically assembled shoring frames have been generally thought to be less desirable, but nonetheless have found acceptance in various forms. Similarly, in recent years the use of aluminum in shoring equipment has found some favor on the basis of more convenient light-weight handling with resultant labor-saving costs on larger construction jobs. Among the known prior art are bolted steel shoring frames wherein the legs have welded-on tabs to which are bolted (from the four corners thereof) a rectangularly shaped bracing element having diamond shaped internal bracing within the rectangle. This system was designed so that the rectangle could be bolted to the legs via the tabs in either the vertical or horizontal direction, thus giving a two-width option on assembly. This system had several drawbacks including the usual concern about loosening of bolts. Storage of this design was not particularly compact because of the large size rectangle involved. The manufacture was quite costly, particularly in view of the welded-on plurality of the tabs.
More recently there exist bolted aluminum shoring frames, for example utilizing Z-shaped bracing requiring special fittings for bolting to the leg and not having the versatility of variable widths. Such asymmetrical frames are particularly difficult to design and successfully make and use because of the need to hold close tolerances with these holes; and the potential for hole elongation. The resulting "racking" in stacked shoring frames will result in derating the load capacity of such a system.
It is an object of the present invention to provide apparatus for successfully incorporating the foregoing advantages and avoiding the disadvantages; and more particularly, to provide such a device in the form of a bolted shoring frame, preferably made of aluminum, having great versatility in adjustability of widths, and having high rated capacity; being light-weight; being capable of being shipped dismounted with resulting comparatively low bulk for substantial cost savings; having the advantage of replacement of individual components without having to scrap the whole frame; and being advantageously and uniquely developed from many already existing components not requiring specialized fittings or substantial development and retooling costs.
These and other objects will become apparent from the following description of the invention.
In this specification and in the accompanying drawings, we have shown and described preferred embodiments of our invention and have suggested various alternatives and modifications thereof; but it is to be understood that these are not intended to be exhaustive and that many other changes and modifications can be made within the scope of the invention. The suggestions herein are selected and included for purposes of illustration in order that others skilled in the art will more fully understand the invention and the principles thereof and will thus be enabled to modify it in a variety of forms, each as may be best suited to the conditions of a particular use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a preferred embodiment of the present invention showing a bolted shoring frame in the four foot wide and six foot high configuration;
FIG. 2 is a perspective view of a right triangular non-isosceles brace showing a preferred embodiment of an inventive element of the shoring frame illustrated in FIG. 1;
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 1 particularly showing the joinder of the brace to the integral parallel flanges of the shoring frame leg;
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 1 showing the joinder at the blunted apices of a symmetrically joined pair of braces according to the present invention;
FIG. 5 is a view similar to FIG. 1 on a smaller scale showing the use of two pairs of braces for heavy duty use;
FIGS. 6 to 9 are similar to FIG. 5 but show modifications in the orientation of the braces to achieve different heights and widths, all showing the versatility of the basic triangular brace unit;
FIG. 10 is a front elevational view of a conventional slide lock with a special mounting clip providing adjustable positioning thereof on said triangular braces;
FIG. 11 is a vertical cross-section taken along lines 11--11 in FIG. 10;
FIG. 12 is a horizontal cross-section taken along lines 12--12 in FIG. 11; and
FIGS. 13 to 16 are simplified front elevational views showing alternative asymmetrical methods of assembly for achieving bolted shoring of still different widths in the load-bearing legs (these may require some additional bolt holes in the load-bearing legs from those of the embodiments illustrated above).
In co-pending applications filed by applicants' co-workers, there were disclosed aluminum shoring frames having extruded legs with longitudinal integral parallel flages formed therewith. The purpose of these flanges was specifically for improved welding techniques. This method, and apparatus using this method, are described in application Ser. No. 187,520, filed Sept. 15, 1980, and in application Ser. No. 298,474, filed Sept. 1, 1981.
Applicants have surprisingly seized upon the unique idea of utilizing the structure developed for welding instead for a versatile bolted shoring frame system employing at least one pair of identical triangular braces. According to the present invention, these triangular braces have been designed so as to be combinable in various different orientations to give considerable versatility to the size and rating strengths achievable with a minimum of parts. These triangular braces can be utilized exclusively or together with horizontal beam braces or the like.
Referring first to FIGS. 1 to 3, it will be seen that the frame legs 20 are formed with a pair of parallel flanges 22 (differentiated as 22a and 22b).
The particular shape of the leg is not critical and may be conventionally round or may take the shape shown in FIG. 3, or any other appropriate shape. See applicants' co-pending joint application Ser. No. 298,474 for a detailed discussion of the particular shape shown and the advantages thereof.
A basic aspect of applicants' invention is the right triangular brace 24. As particularly illustrated, this is in itself uniquely inventive. This brace 24 is most advantageously made from aluminum and is designed to be symmetrically aligned with an identical brace 24' to give an effective cross beam brace with angular knee braces. Thus referring to FIG. 1, the short leg 26 is aligned with and bolted to the corresponding short leg 26' of the symmetrically aligned triangular brace 24' to give an effective horizontal beam brace. The hypotenuse members 28 and 28' function as knee braces in the assembly as shown in FIG. 1. The longer legs 30 and 30' complete the triangle giving the triangular brace its structural integrity and strength and in the orientation shown in FIG. 1 are utilized to fasten the brace to the respective leg 20.
The brace is preferaby made entirely of aluminum rectangular tubing. By reason of the extrusion process, the flanges 22 run the length of the legs 20 and therefore fastening means such as bolts can be positioned anywhere theralong so long as there is sufficient spacing between adjacent bolts. Therefore as an added safety precaution each fastening point is preferably formed with a pair of bolts through corresponding bolt holes in the flange mating with bolt holes through the legs of the brace.
Comparing FIGS. 1 and 8, it can be seen that the respective pair of braces 24, 24' can be rotated to give a wider bracing member. Thus if the legs 26 and 30 of the brace are approximately respectively 2 feet and 3 feet, one can modify the frame to a width of between 4 and 6 feet. The lower beam brace beam 32 can either be formed as an extendable member, or as illustrated merely be replaced by a longer beam member 32a.
Referring again to FIG. 2, it will be seen that on the outer portion of each leg 26 or 30 (where the flange 22 overlaps such leg; compare overlap of stub 74 in FIG. 3) a pair of holes is drilled at either end of said legs 26 and 30. Each pair of such holes is respectively identified as 34, 36, 38 and 40, numbered counterclockwise in FIG. 2. The remaining bolt holes on legs 26 and 30 are for securing the slide lock fastener 42 (see FIGS. 10 to 12). These are attached in conjunction with respective legs 20 for securing cross-bracing between one shoring frame 18 and an adjacent shoring frame. Bolt holes 44 and 46 adjacent to the right angle are for use with longer legs 20 (such as on five or six foot high frames, e.g. see FIGS. 1, 5, and 8). The adjacent pairs of holes 48 and 50 are for use with the shorter frame legs 20 (such as on three and a half foot high frames, see FIG. 9). The pairs of holes 52 and 54 are for use in securing the fasteners 42 for joining the cross-bracing to the lower portion of the frame of the latter shorter type.
In order to permit the triangular braces 24, 24' to be symmetrically bolted together with one pair of legs aligned and with the other pair of legs parallel (for bolting to respective frame legs 20), the apices of the triangular braces opposite the right angle thereof are blunted so as to form short blunted portions 56 and 58, respectively adjacent to legs 26 and 30. Pairs of lateral holes 60 and 62 are formed respectively through each of said portions 56 and 58 whereby said braces 24 and 24' can be symmetrically joined by bolts 64 (see particularly FIGS. 1 and 4).
As shown in FIGS. 13 to 16, these braces 24 and 24' utilized in pairs can be symmetrically joined individually between frame legs 20 if holes 66, 68 are formed in the outer part of said blunted portions 56 and 58 respectively (shown in dotted outline in FIG. 2). Similarly, on the inner part of the same blunted portions 56, 58 can be formed respectively holes 70, 72 for use in mounting said slide locks 42. In the situation where the blunted portions 56, 58 would have six relatively closely spaced holes, these portions would preferably be made from solid aluminum, rather than aluminum tubing.
The holes illustrated in the flanges 22 of leg 20 in FIG. 1 are such as to accommodate any of the configurations shown in FIGS. 1, 5, or 8. Similarly, the hole orientation along flanges 22 in FIG. 9 are compatible with either the orientation shown in FIG. 7 or 9. The configuration in FIGS. 5 and 6 are particularly strong (and the latter has the advantage of providing a "walk through" feature, which is also partially true of the configurations in FIGS. 1 and 8).
Beam brace 32 in FIG. 1 can be made thicker (as indicated by the dash-dot line below beam 32), if necessary to accommodate heavier loading. In that case if the legs are shortened from the six foot configuration to the five foot configuration, it may be necessary to reorient the beam upside down to the position indicated by 32'. Attached at right angles to the end of the beam brace 32 are stubs 74 having at least one hole drilled at either end thereof. As illustrated in FIG. 1, two sets of holes are drilled in the flanges, but only two bolts 76 per stub are actually utilized. In lighter-weight applications, or with shorter legs, the stub 74 on the beam 32 can be omitted and instead holes can be drilled in the end of the beam 32 (see FIG. 16). On the shorter legs as shown in FIG. 9, a beam 32b can be utilized by bolting directly to the free blunted portions 58 by bolts 64.
The slide lock 42 in FIGS. 10 to 12 is of a conventional type and will be described only with respect to the mounting strap 78 which has bolt holes 80 for bolt holes 82. As shown in FIGS. 9 and 12, this slide lock 42 is mounted on leg 30' through holes 50' of brace 24'.
For use with light loads and/or for use as scaffolding, the lower beam brace 32 etc. can be omitted entirely. This facilitates the size and adjustment capability by avoiding having to stock different size beams for such applications.
We claim:
1. A shoring frame brace, comprising said brace being constructed substantially from aluminum rectangular tubing in the form of a right non-isosceles triangle with the acute angled apices formed with short blunted portions at right angles to the respective adjacent leg, each such portion having a pair of lateral bolt holes extending therethrough in a direction parallel to its adjacent leg, and additional pairs of bolt holes perpendicular to the plane of the triangular surface of said brace and through each of said legs at both the outer and the inner portion of each end thereof, all of said pairs of bolt holes being aligned along the length of said legs or of said portions, said outer pairs of holes being adapted for use in bolting said brace to flanges on a shoring frame leg, and said inner pairs of holes being adpated for use in bolting to a bracing stud mount.
2. A brace according to claim 1, wherein said inner perpendicular pairs of holes are each slightly offset away from the end of its respective leg relative to the corresponding outer pair of holes whereby any weakening effect of overlapping such holes is diminished, and a third pair of inner holes for use in mounting said stud mount when used with shorter frame legs is provided on each leg spaced slightly longitudinally removed from the other inner pair of holes at that end of a respective leg which intersects at right angles with the other leg.
3. A brace according to claim 1 or claim 2, wherein said blunted portions are made from a block of aluminum and additionally have inner and outer pairs of perpendicular holes therethrough.
4. A disassemblable, size adjustable, shoring frame system comprising the following structural elements capable of being assembled in the field as a shoring frame:a pair of load-bearing tubular frame legs each having an integral pair of parallel longitudinally-extending flanges; bracing means for extending between and fastening to each of the frame legs by the respective flanges thereof with said frame legs parallel to each other, said bracing means including at least a pair of substantially identical right triangular braces, wherein at least the two apices of the triangular braces adjacent a hypotenuse thereof are blunted so as to form short blunted portions parallel to a brace leg opposite the blunted apex; and disconnectable fastening means for demountably joining said bracing means to the flanges of said legs.
5. A shoring frame system according to claim 4, wherein said bracing means has upper and lower portions, each portion being adapted to extend between and fasten to each of said legs by the respective flanges thereof with said legs parallel to each other.
6. A shoring frame system according to claim 5, wherein said triangular braces are non-isosceles, said fastening means comprise bolt holes in said flanges and perpendicular bolt holes in both ends of both legs of each of said triangular braces corresponding to selected ones of said holes in said flanges whereby said braces are adapted to be fastened to said flanges by either leg of each brace; the apex of each triangular brace is blunted at right angles to its adjacent leg and has at least one bolt hole through each blunted apex in a direction parallel to such adjacent leg whereby said braces are adapted to be fastened together as a pair at facing apices with the adjacent leg of one brace in line with the adjacent leg of the other brace.
7. A shoring frame system according to claim 6, wherein the blunted apices of said triangular braces also have perpendicular bolt holes therethrough adapted to align with selected ones of said holes in said flanges of said frame legs.
8. A shoring frame system according to claim 6, wherein said legs and braces are aluminum, and said bolt holes occur in pairs.
9. A shoring frame system according to claim 8, wherein said braces are made substantially from rectangular tubing.
10. A shoring frame system according to claim 9, wherein said upper bracing means comprise said pair of triangular braces, said lower bracing means comprise a rectangular aluminum tubular beam of a length determined by symmetrically aligning the legs of said pair of braces, said beam having stubs extending at right angles from either end with a bolt hole at each end of each stub and spaced to correspond to selected ones of said holes in said flanges.
11. A shoring frame comprising the components recited in claim 4 and assembled in accordance therewith, wherein said bracing means extends between parallel frame legs and is joined to said pairs of flanges.
12. A shoring frame according to claim 11, wherein bracing means consists of a single pair of non-isosceles triangular braces, which braces having said blunted portions at right angles to the respective brace leg braces are symmetrically fastened at said respective blunted apices with the adjacent legs in line and with the respective remaining legs each seated in between and fastened to a pair of flanges on the respective frame legs; said legs and braces being made of aluminum.
13. A shoring frame according to claim 11, wherein said bracing means has upper and lower portions, each portion being adapted to extend between and fasten to each of said legs by the respective flanges thereof with said legs parallel to each other.
14. A frame according to claim 13, wherein said triangular braces are non-isosceles.
15. A frame according to claim 14, wherein said upper bracing means consists of said pair of triangular braces which are symmetrically fastened together at said respective blunted apices with the adjacent legs in line and with the respective remaining legs each seated in between and fastened to a pair of flanges on respective frame legs.
16. A frame according to claim 15, wherein said bracing fastening means comprise bolt holes in said flanges and perpendicular bolt holes in both ends of both legs of each of said triangular braces corresponding to selected ones of said holes in said flanges and bolts removably securing said braces to said flanges through overlapping selected ones of said holes; said apex fastening means comprising at least one lateral bolt hole through each blunted apex portion of each triangular brace in a direction parallel to its adjacent brace leg.
17. A frame according to claim 16, wherein said bracing fastening means further comprises perpendicular bolt holes through the blunted apex portions of said triangular braces.
18. A frame according to claim 15, comprising at least four adjustably mountable bracing stud means secured to said each of said upper and said lower bracing means adjacent said frame legs.
19. A frame according to claim 18, wherein said legs and braces are aluminum and said braces are made substantially from rectangular tubing.
20. A frame according to claim 19, wherein said lower bracing means consists of a second pair of substantially identical triangular braces similarly symmetrically mounted as a bracing unit aligned between and fastened to the pairs of flanges of said respective frame legs.
21. A frame according to claim 20, wherein said bracing fastening means comprise bolt holes in said flanges and perpendicular bolt holes in both ends of both legs of each of said triangular braces corresponding to selected ones of said holes in said flanges and bolts removably securing said braces to said flanges through overlapping selected ones of said holes; said apex fastening means comprising at least one lateral bolt hole through each blunted apex portion of each triangular brace in a direction parallel to its adjacent brace leg; bolts fastening said triangular braces together in pairs through respectively aligned pairs of said lateral bolt holes.
22. A frame according to claim 19, wherein said lower bracing means consists of a rectangular aluminum tubular beam of a length determined by said aligned legs of said pair of braces, stubs extending at right angles from either end of said beam with each fastened in a respective pair of flanges such that said beam extends between said frame legs.
23. A frame according to claims 18, 19, or 22, wherein said bracing fastening means comprise bolt holes in said flanges and perpendicular bolt holes in both ends of both legs of each of said triangular braces corresponding to selected ones of said holes in said flanges and bolts removably securing said braces to said flanges through overlapping selected ones of said holes; said apex fastening means comprising at least one lateral bolt hole through each blunted apex portion of each triangular brace in a direction parallel to its adjacent brace leg; at least one bolt fastening said triangular braces together in a pair through at least one aligned pair of said lateral bolt holes.
24. A frame according to claim 23, wherein bolt holes occur in pairs.
25. A frame according to claim 22, wherein said bracing fastening means further comprises a bolt hole at each end of each stub, said holes on each stub being spaced to correspond to selected ones of said holes in said flanges, and bolts securing said stubs to said respective flanges.
26. A frame according to claim 22, wherein said beam is extendable in length so as to accommodate said pair of triangular braces being fastened with either their respective short legs aligned or their respective longer legs aligned.
27. A frame according to claim 14, wherein said bracing fastening means comprise bolt holes in said flanges and perpendicular bolt holes in both ends of both legs of each of said triangular braces corresponding to selected ones of said holes in said flanges and bolts removably securing said braces to said flanges through overlapping selected ones of said holes; said apex fastening means comprising at least one lateral bolt hole through each blunted apex portion of each triangular brace in a direction parallel to its adjacent brace leg.
28. A frame according to claim 27, wherein said bracing fastening means further comprises perpendicular bolt holes through the blunted apex portions of said triangular braces.
29. A frame according to claim 28, wherein said bracing fastening means further comprises bolts removably securing said triangular braces to a frame leg by passing through said perpendicular holes in said blunted portions and through overlapping holes in a pair of the frame leg's flanges.
30. A frame according to claims 21, 27, or 28, wherein bolt holes occur in pairs.
31. A disassemblable, size adjustable, shoring frame system comprising the following structural elements capable of being assembled in the field as a shoring frame:a pair of load-bearing tubular frame legs each having an integral pair of parallel longitudinally-extending flanges; bracing means for extending between and fastening to each of said legs by the respective flanges thereof with said legs parallel to each other, said bracing means including at least a pair of substantially identical right triangular braces, wherein at least the two apices of the triangular braces adjacent a hypotenuse thereof are blunted so as to form short blunted portions parallel to a brace leg opposite the blunted apex, the blunted portions and the brace legs each being of an appropriate width to fit between the two parallel flanges of the frame legs; and disconnectable fastening means for demountably joining said bracing means to the flanges of said legs, including bolt holes in said flanges, corresponding perpendicular bolt holes in the brace legs of each of the triangular braces by which the flanges of either leg of each brace can be fastened to said flanges, and perpendicular bolt holes through the blunted portions of said triangular braces to be aligned with selected ones of the bolt holes in the flanges of said frame legs.
| 1982-08-20 | en | 1985-09-17 |
US-26053063-A | Defluorination process
INVENTORS G.R. HETTICK JOE VAN POOL C.C. CHAPMAN G. R. HETTICK ETAL DEFLUORINATION PROCESS Filed Feb. 25, 1965 Aug. 31, 1965 A TTORNEYS United States Patent 3,204,011 DEFLUORINATIGN PROCESS George R. Hettick, Joe Van Pool, and Charles C. Chapman, all of Bartlesville, Okla, assignors to Phillips Petroleum Company, a corporation of Delaware Filed Feb. 25, 1963, Ser. No. 260,530 6 Claims. (Cl. 260-68342) This invention relates to the treatment of organic compounds with liquid hydrogen fluoride (HF). In one aspect it relates to the removal of organic fluorides from organic materials containing the same. In one specific aspect it relates to an improved process for the removal of alkyl fluorides from a low-boiling hydrocarbon such as propane.
In processes wherein fluorine-containing catalyst such as hydrogen fluoride and boron-trifluoride are used, small proportions of organic fluorine-containing by-products are formed. These processes can involve such reactions as isomerization, polymerization, alkylation and disproportionation of relatively low-boiling hydrocarbons.
In those processes wherein propylene is a component of the feed to the HF catalyzed reaction, alkyl fluorides are formed which are practically impossible to remove from the propane by-product by conventional distillation steps and the presence of these alkyl fluorides in the product propane is objectionable for many of the end uses of the propane. Growing uses for propane have required more complete removal of alkyl fluorides from the propane and these increased demands for more complete removal of the alkyl fluorides have become an acute problem in the HF catalyzed hydrocarbon conversion processes. The problem of the propane by-product occurs only when propylene is included with the butylene in a process such as the alkylation of isobutane with an olefin because when only butylene is employed the propane by-product is insignificant and usually is not recovered separately. We have found that when the propylene-to-butylene ratio in the feed is about 65 to 35, the organic fluorine compounds in the hydrocarbon phase of the reactor efiiuent amount to about 1000 ppm. and when the propylene-to-butylene ratio in the feed to the reactor is about 40 to 60 the organic fluorine compounds in the hydrocarbon reactor effluent amount to about 140 ppm.
Various proposals have been made for the removal of organic fluorides from the by-product propane in a process such as HF catalyzed alkylation and some of these proposals have been adequate to meet the specification requirements of the past; however, such processes as have been proposed do not remove organic fluorides sufliciently to meet present-day requirements or else are unsatisfactory for continued use because of corrosion problems introduced into the process as a result of handling free HF or because of continuing chemical costs. For example, it has been proposed to remove alkyl fluorides by the use of dehydrofluorination agents such as bauxite, various metals and metal salts. HP is lost from the process in such system. The agents tend to lose their effectiveness after a period of continued use and must be replaced periodically. It has also been proposed to treat the contaminated hydrocarbon with a mixture of hydrogen fluoride and acid soluble oil (a hydrocarbon sludge produced in the process) to remove ethyl fluoride. This process appears to be a solvent extraction operation because there is no source of isobutane to be alkylated by the alkyl radical of the organic fluoride.
The present invention provides a method for reducing the fluorine compound content of propane to below that obtained by any known prior art process so as to produce a premium grade of propane without introducing a problem of corrosion to the equipment employed in the process.
3,204,011 Patented Aug. 31, 1965 "ice The present invention provides a method whereby alkyl fluorides are removed from the hydrocarbon by what amounts to a secondary alkylation reaction. According to the process of the invention the overhead product obtained by distillation of the alkylation reactor hydrocarbon eflluent is contacted with about an equal volume of liquid HF under alkylation conditions and in the presence of isobutane so that the isobutane is alkylated with the alkyl radical of the alkyl fluoride with the concomitant formation of HF.
It is an object of the present invention to contact a hydrocarbon containing an organic fluoride with about an equal volume of liquid HF under alkylation conditions so as to catalyze the decomposition of the alkyl fluoride with concomitant alkylation of isobutane with the olefin resulting from the decomposition of the organic fluoride. It is also an object of this invention to produce premium grade by-product propane from an HP catalyzed alkylation reaction wherein propylene is a component of the feed to the alkylation reaction. Other objects and advantages of the present invention will be apparent to one skilled in the art upon study of this disclosure, including the detailed description of the invention and the appended drawing wherein:
The sole figure is a schematic flow diagram illustrating a specific embodiment of the invention as applied to the treatment of hydrocarbons containing alkyl fluorides resulting from an alkylation process.
The process of the invention will now be described with reference to the drawing. It is to be understood that numerous items of equipment such as pumps, valves, etc., have been omitted from the drawing so as to simplify the description of the invention. Those skilled in the art will realize that such conventional equipment can be employed if desired.
A suitable hydrocarbon charge, such as a mixture of isobutane, propylene and butylene, is passed via conduit 10 to reactor 11 along with a recycle stream containing isobutane introduced via conduit 12. A hydrogen fluoridecontaining catalyst is passed via conduit 13 to reactor 11. The efiluent from the reactor is passed via conduit 14 to a settler 15 wherein separation is made between a liquid hydrocarbon phase and a liquid HF phase. The hydrocarbon phase Will be saturated with HF and the HF phase will be saturated with hydrocarbon. The liquid HF phase is removed via conduit 16 and can be returned at least in part to reactor 11 via conduit 13. Generally it is desirable to pass a portion of the used catalyst to purification equipment (not shown) via conduit 17. Make-up HF is added via conduit 18 as required. The hydrocarbon phase is passed from settler 15 via conduit 19 and heater 21 to fractionator 22 wherein a fractionation distillation is conducted which distills HF, propane and alkyl fluorides, boiling in the propane range, overhead along with some isobutane. The major portion of the isobutane along with the alkylate and other higher boiling hydrocarbons is removed via conduit 23 for further treatment.
The overhead stream from fractionator 22 is passed via conduits 24, cooler 25, conduit 26, containing pump 27, to eductor 28 and thence through conduit 29 to liquidliquid contactor 30. In contactor 30 the free HF, which represents the HF in excess of that required to saturate the hydrocarbon stream in conduit 26 forms a separate liquid phase below the hydrocarbon liquid phase in contactor 30 and a body of liquid HF is accumulated in the inlet portion of contactor 30 by means of baflle 31. Liquid HF flows over baffle 31, accumulate in leg 32 and is passed via conduits 33 and 34 to eductor 28 so that liquid HF is admixed with the hydrocarbon in eductor 28 and the mixture is passed via conduit 29 to contactor 30. Conduit 29 is shown as introducing the mixture of liquid HF and liquid hydrocarbon to about the interface of the hydro- 3 carbon and HF phases in contactor 30 but if desired the mixture can be introduced at a point below the HF surface by means of conduit 35.
A stream of hydrocarbon is removed from the hydrocarbon layer of contactor 30 and passed via conduit 36 to fractionator 22 as reflux. A stream of hydrocarbon is removed from conduit 36 and passed via conduit 37, flow controller 38 and heater 39 to depropanizer 40. The hydrocarbon removed from contactor 30 via conduit 36 contains dissolved HF but no free HF. Excess HF is withdrawn from contactor 30 in response to liquid level controller 41 via conduits 33 and 42 and returned to reactor 11. The kettle roduct from depropanizer 40, comprising isobutane, is passed via conduit 12 to reactor 11 as recycle isobutane.
The overhead from depropanizer 40 is passed via conduit 43, cooler 44 and conduit 45 to accumulator 46. Liquid HF is withdrawn from accumulator 46 in response to liquid level controller 47 and is passed via conduit 48 to conduit 42 for return to reactor 11 or can be passed via conduits 48 and 49 to conduit 26 for introduction to contactor 30. The hydrocarbon phase is withdrawn from accumulator 46 via conduit 51 containing pum 52 and passed to depropanizer 40 as reflux. A portion of this stream is removed via conduit 53 containing flow controller 54 and passes as feed to stripper 55. The overhead vapors from stripper 55 are passed via conduit 56 to cooler 44 and thence to accumulator 46. Propane product depleted of organic fluorides is recovered from stripper 55 via conduit 57.
Liquid HF withdrawn from accumulator 46 by means of conduit 48 can be passed to conduit 26 and thenzto contactor 30 by closing valve 58 and opening valve 59. Usually this procedure will be employed only upon those ocon the part of the liquids better than does steel. It is pos sible to employ .a pump instead of the eductor 28; however, a pump the same size as that of pump 27 would be required because substantially equal volumes of hydrocarbon and liquid HF are handled at this point. The eductor will handle a 1:1 ratio of liquid hydrocarbon and liquid HF with only a small increase in the back pressure to pump 27. Furthermore, it is advisable to avoid using a pump where more than a minor amount of liquid HF is involved because of problems introduced to packing glands and bearings. A hydrocarbon flush on all packing glands and bearings would be required in a pump handling liquid HF.
When operating according to prior art proposals, the removal of organic fluorides ha never been known to exceed 90 percent whereas according to the process of this invention organic fluoride removal 01594-97 percent is obtained.
The temperatures and pressures of the distillation steps will be substantially the same when the process of the invention is practiced as those of the prior art processes. The fractionat/or 22 is ordinarly operated at about 200 p.s.i. with a bottom temperature of about'220 F. and a top temperature of about 135 F. Depropanizer is operated at a pressure of about 285 p.s.i. with a bottom temperature of about 230 F. and a top temperature of about 140 F. Stripper is operated at a pressure of about 290 psi. with a bottom temperature of about 150 F. and a top temperature of about 143 F. A stripping gas ordinarily is not used.
Data obtained in the operation of a typical system such as shown in the drawing is presented in the material balance of the following table wherein the materials in the numbered columns represent the materials at the locations of corresponding numbers on the drawing.
Table I Stream 19 36 26 34 36 42 37 51 Component Feed to Reflux to Eductor Contactor Partial Partial Motive Eductor Contactor HF to DeC DeC DeCa DeO; Fluid HF Eflluent Reactor Feed Reflux Propane, bJhr 117 177 177 so 198 Isobutane, b./hr. 1,056 217 328 328 111 z n-Butane. b./hr 39 16 25 9 Total alkylate, b./h 130 Total hydrocarbon 1, 300 350 0 530 180 200 Soluble HF, lb./l1r 2,683 973 1, 480 1, 480 507 795 Liquid HF, lb./ 2,176 2, 176 Organic F, p.p.m 142 3 100 3 3 7 Stream 4s 53 57 56 4s 60 23 12 Component HF Make Total Partial DeC; Feed to Stripper Stripper trom HF DeC DeC OH Stripper Bottoms OH Stripper Make Bottoms Bottoms Propane, b.1111 247 64 49 15 15 11 Isobutane, bJhr 3 1 1 945 n-Butane, b.lhr 3O 9 Total alkylate, b./hr 130 Total hydrocarbon 250 65 50 15 1,
Soluble HF, lb. lhr 1, 302 341 341 Li uid HF, lb./hr 507 2,683 Organic F, p.p.m 8 7 5 l0 31 1 casions when the liquid HF level is contactor 30 is lower The organic fluorides have been reduced from 142 th de i d, p.p.m. 1n the feed to fractlonator 22 to 5 p.p.m. in strip- We have found that the fluoride content of the propane per 55 bottoms. This is more than 96 percent removal product can be drastically reduced by practicing our in- 65 of organic fluorides. When the feed to fractionator 22 vention at ordinary temperatures, for example, at 100 F. contains about 1000 p.p.m. organic fluorides, e.g., when It more thorough removal of combined fluorine from the the olefin feed to the alkylation reactor contains about propane is desired, the contact step in contactor 30 can be 65 percent propylene, the organic fluoride content of the conducted at a higher temperature, for example, rtemperastripper 55 bottoms is about 40 to 50 p.p.m. tures up to and including about F. Ordinarily it is 70 The above process provides savings over the prior art preferred to operate at a temperature of about 100 degrees because corrosion of steel equipment is not a problem at these temperatures.
The eductor 28 is made with a Monel metal throat and is referred to in the trade as a Monel trim educator. The
Monel metal resists erosion at this point of high velocity 75 practices in the HF recovered, reduction in the amount of defluorination bauxite required if an after treatment is necessary to provide a substantially completely fluoride free product, and in time saved in recharging the bauxite defluorinators.
The process of the invention provides an increased acid-to-hydrocarbon ratio in the treatment of the fluoridecontaining hydrocarbon stream over the processes proposed in the prior art.
That which is claimed is:
1. A process for treating hydrocarbon materials to remove therefrom organically combined fluorine comprising:
(l) passing a liquid hydrocarbon material containing an alkylatable material, free HF, and a minor quantity of organically combined fluorine to a contactor to separate the liquid into a liquid hydrocarbon phase and a liquid HF phase;
(2) withdrawing liquid HF from said liquid HF phase in said contactor;
(3) intimately admixing at least one volume of said withdrawn liquid HF with each volume of said liquid hydrocarbon material passing to said contactor; and
(4) withdrawing liquid hydrocarbon of reduced organically combined fluorine content from the liquid hydrocarbon phase in said contactor.
2. The process according to claim 1 wherein said alkylatable material is isobutane.
3. In a hydrogen fluoride catalyzed reaction wherein organic compounds are treated with hydrogen fluoride in a reaction zone and an organic fluoride is formed as a by-product which is contained in the effluent from said reaction zone, the improvement comprising:
(1) passing the eflluent from said reaction zone to a settler to form a liquid hydrocarbon phase and a liquid HF phase;
(2) passing liquid hydrocarbon from the liquid hydrocarbon phase in said settler to a distillation zone to produce a vaporized overhead product;
(3) condensing the overhead product from said distillation zone to form a liquid hydrocarbon material containing an alkylatable material, free HF, and a minor quantity of organically combined fluorine;
(4) passing said liquid hydrocarbon material to a contactor to separate the liquid into a liquid hydrocarbon phase and a liquid HF phase;
(5) withdrawing liquid HF from the liquid HF phase in said contactor;
(6) admixing at least one volume of said withdrawn liquid HF with each volume of said liquid hydrocarbon material passing to said contactor; and
(7) withdrawing liquid hydrocarbon of reduced organic fluoride content from the liquid hydrocarbon phase in said contactor.
4. The process according to claim 3 wherein said alkylatable material is isobutane.
5. In a process for the conversion of hydrocarbons in the presence of a hydrogen fluoride-containing catalyst wherein the reaction product is distilled in a distillation zone and the overhead product contains an organic fluoride as an impurity, the improvement comprising the following sequential steps:
(1) condensing the overhead product from said distillation zone to form a liquid hydrocarbon material containing an alkylatable material, free HF, and a minor quantity of organically combined fluorine;
(2) passing said liquid hydrocarbon material to a contactor to separate the liquid into a liquid hydrocarbon phase and a liquid HF phase such that the liquid hydrocarbon material enters the contactor within the liquid HF phase;
(3) withdrawing liquid HF from the liquid HF phase in said contactor;
(4) intimately admixing at least one volume of said withdrawn liquid HF with each volume of said liquid hydrocarbon material passing to said contactor; and
(5) withdrawing liquid hydrocarbon of reduced organic fluoride content from the liquid hydrocarbon phase in said contactor.
6. The process according to claim 5 wherein said alkylatable material is isobutane.
References Cited by the Examiner UNITED STATES PATENTS 2,451,568 10/48 Linn 208-262 2,542,927 2/51 Kelley 260683.42 2,832,812 4/58 Belden 260-683.42 3,073,878 1/63 Johnson 260683.42
ALPHONSO D. SULLIVAN, Primary Examiner.
1. A PROCESS FOR TREATING HYDROCARBON MATERIALS TO REMOVE THEREFROM ORGANICALLY COMBINED FLUORINE COMPRISING:
1. PASSING A LIQUID HYDROCARBON MATERIAL CONTAINING AN ALKYLATABLE MATERIAL, FREE HF, AND A MINOR QUANTITY OF ORGANICALLY COMBINED FLUORINE TO A CONTACTOR TO SEPARATE THE LIQUID INTO A LIQUID HYDROCARBON PHASE AND A LIQUID HF PHASE;
2. WITHDRAWING LIQUID HF FROM SAID LIQUID HF PHASE IN SAID CONTACTOR;
3. INTIMATELY ADMIXING AT LEAST ONE VOLUME OF SAID WITHDRAWN LIQUID HF WITH EACH VOLUME OF SAID LIQUID HYDROCARBON MATERIAL PASSING TO SAID CONTACTOR; AND
4. WITHDRAWING LIQUID HYDROCARBON OF REDUCED ORGANICALLY COMBINED FLUORINE CONTENT FROM THE LIQUID HYDROCARBON PHASE IN SAID CONTACTOR.
| 1963-02-25 | en | 1965-08-31 |
US-35027394-A | Apparatus for guiding a wire
ABSTRACT
An apparatus for guiding a wire including a device for producing a washing jet and a device for removing washing mist generated from the washing jet which has a suction box. The suction box is located on an opposite side of the wire from the device for producing a washing jet. The suction box has a duct through which the mist produced in the washing of the wire is passed into an inlet chamber. The duct is arranged at an angle, preferably at an acute angle, relative to the running direction of the wire. In conjunction with, a mist suction device, there is provided a list which is in contact with the wire and deflects the wire so that the direction of arrival of the wire at the list differs from the direction of departure of the wire from the list.
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for guiding a wire.
In the prior art, Finnish Patent Application No. 902000 which corresponds to U.S. Pat. No. 5,120,401, describes a mist suction apparatus used in association with a wire in which an oscillating washing jet is positioned on one side of a wire and a suction box is positioned on the other side of the wire. A washing mist produced by the washing jet during washing operation of the wire is gathered in the suction box by the effect of negative pressure therein. In association with the rotation of the wire, a separate mobile tension roll is used to adjust the tension of the wire. When the tension roll is moved, the inlet angle of the wire relative to the suction box of the mist suction apparatus also changes. Thus, in this prior art apparatus, it is a significant disadvantage that the wire may therefore be moved too far from the suction box and out of contact therewith.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to eliminate the disadvantage of the prior art apparatus discussed above, in particular to ensure that the suction box does not become overly distanced from the wire.
Accordingly, in the present invention, a wire is brought in contact with a list, i.e., a band or strip of material, in association with the mist suction means, whereby the list serves as a folding or deflecting element for the wire so that the direction of the wire is changed at the list. The wire remains in contact with the list in various adjustment positions of the wire tension roll, and thus, operation of the mist suction means is not disturbed during movement of the tension roll.
The list may also be used in separation activities, in which case it can replace the guide roll. The procedure is advantageous particularly in renewing machines which need a lot of space so that a narrow list in accordance with the invention will not take a lot of space, and it may be placed in the vicinity of machine beams.
In a preferred embodiment, the list is made of a ceramic material, e.g., SiC, SIN4, A12 O3, ZrO2 and mixtures thereof.
An application of the invention is to use a crownable list, i.e., one in which the profile in a direction transverse to the machine direction can be varied. The list can thus be made arched in order to guide the wire. The crowning of the list can be accomplished, e.g., by an actuating cylinder located in the center area of the list while ends of the list are fixed in place.
Briefly, the apparatus in accordance with the invention for guiding a wire comprises a list positioned in association with mist suction means and in contact with the wire. The direction of the wire moving to the list deviates from the direction of the wire moving away from the list, so that the list serves to fold the wire and provide a non-linear running path from the preceding and subsequent stationary press elements, e.g., tension adjustment roll and guide roll, respectively.
In a preferred embodiment, the list is fixedly connected to the suction box of the mist suction means and is arranged in front of an inlet opening of a duct connecting to the inlet chamber in the suction box in the running direction of the wire. Also, the list is preferably in continuous contact with the wire.
The invention is described below by referring to certain preferred embodiments of the invention presented in the figures of the accompanying drawings. However, the invention is not intended to be exclusively confined to these illustrated embodiments alone.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIG. 1 is a prior art tension adjustment arrangement for a wire in association with mist suction means.
FIG. 2 is an apparatus in accordance with the present invention.
FIG. 3 is a view in the direction of arrow K1 shown in FIG. 2.
FIG. 4 is an illustration of the attachment of the list in the apparatus in accordance with the invention on the front edge of a frame beam of the mist suction means.
FIG. 5 is another embodiment of the apparatus in accordance with the invention in which the guide roll is replaced by a list, and is a view taken along the section line I--I in FIG. 6.
FIG. 6 is a view in the direction of arrow K2 shown in FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a prior art arrangement and particularly the area in which the wire separates from association with the suction box during movement of the tension adjustment roll. A wire H is conducted via rolls 10, 11 and 12. Roll 11 is a tension adjustment roll and roll 12 is a tension measurement roll of the wire H. When adjusting the tension of the wire, i.e., during running thereof, the tension adjustment roll 11 of the wire is moved in direction L1 or L2 as shown in FIG. 1. The tension thus achieved is measured by the tension measurement roll 12. However, it is evident that this adjustment of tension roll 11 causes a displacement X of the wire H thereby detaching the wire from being in connection with mist suction equipment and specifically a suction box 14. The mist suction equipment 13 also comprises means 13a for producing an oscillating washing jet arranged on an opposite side of the wire from the suction box, and on the other side of the wire, means 13b to remove the washing mist., e.g., suction box 14. The washing jet is directed at the wire H to cleanse the same and then the washing mist thus produced is drawn by a vacuum, i.e., negative pressure, into the suction box 14. The mist is conducted into a duct 15 opening at one end into a washing mist inlet chamber 16 within the suction box 14 and opening at an opposite end in the vicinity of the wire in a lower surface of the suction box 14.
When the position of the wire H in the wire tensioning adjustment is changed, the distance of the wire H from the suction box 14 also changes thereby disturbing the discharge of the washing mist into the suction box 14. There is an acute angle α between the longitudinal axis X' of the duct 15 and the principal direction of travel, i.e., the running direction, L of the wire H. The angle opens in the running direction L of the wire H and is preferably in the range of between about 20° and about 70°. The oblique positioning of the duct 15 makes it possible to utilize the velocity component imparted by the wire H to the washing mist and to guide the mist efficiently into the suction box and further away from the washing point.
FIG. 2 illustrates the apparatus in accordance with the invention wherein the arrangement comprises a list 17 arranged in association with a front edge 14a of the suction box 14. List 17 is in contact with the wire H. A list fabricated from ceramic material is advantageously used because the ceramic material withstands wearing. The suction box 14 of the mist suction means 13 and the list 17 are positioned close to the wire H so that the entry direction of the wire H to the list 17 is not the same as the exit direction of the wire H from the list 17. Thus, the list 17 folds or deflects the wire H, i.e., provides the wire with a non-linear path. At the least, the list 17 contacts the wire H.
As shown in FIG. 2, during tension adjustment when the tension adjustment roll 11 is displaced (as shown by the broken line), the tension roll 12 of the wire H is maintained in its position. As a result of this arrangement, during tension adjustment of the wire H, the wire H is kept close to the list 17 and thus to the suction box 14.
In the invention, the passage of the wire H is adjustable and can be further guided with the list 17 in a manner similar to the guiding obtained by the use of crowned rolls. This is made possible by arranging actuating means 18 for crowning the list 17, e.g., in a center area of the list 17 in the length direction thereof. The crowning is accomplished by tensioning the suction box 14 in the center area thereof so that the list 17, which is attached to the suction box 14 is arched in the center area. The crowning can be either negative or positive, i.e., the center area of the list can be adjusted to provide either a concave or convex surface, depending on the manner desired to affect the passage of the wire H.
FIG. 3 shows the apparatus of FIG. 2 in the direction of arrow K1. The suction box 14 is attached at its ends by attachment members M2 and M2 to a transverse beam P of the paper-making machine. An actuator 18 is placed in the center of the suction box 14 of the mist suction means 13, with respect to the length of a frame R of the suction box 14, in an area F between the transverse beam P of the paper-making machine and the frame R of the suction box 14, and also between the attachment members M1 and M2. The actuator 18 may be for instance a claw crane, whereby by rotating a screw 18a, a connection point D is displaced in direction S and in that manner, the frame R of the suction box 14 of the mist suction means 13 is arched. In view of the connection between the suction box 14 and the list 17, the list 17 is also arched to provide the negative or positive crown-variation.
FIG. 4 illustrates the fixing arrangement of the list to the front edge 14a of the suction box 14 of the mist suction means 13 utilizing a T-rail joint 19. In this construction, the list 17 comprises a T-groove 19a which is disposable in counter-joining means 19b, preferably a rail having a corresponding cross-sectional shape, located in the frame R. The connection between the list 17 and the front edge 14a of the suction box 14 may also be a so called dovetail joint. Both the T-rail joint and the dovetail joint enable quick replacement of list 17 when necessary and thus constitute means for removably connecting the list to the suction box. A locking screw may be used to fixedly connect the rail 19b to the front edge 14a of the suction box 14.
As shown in FIG. 4, the list 17 comprises a large face N which lies against the wire H. The list 17 has preferably a rectangular cross-sectional shape and extends over substantially the entire width of the wire. The width of the face N is preferably about 10 to about 60 mm. One purpose of the list 17 is to improve the generation of suction in the suction box and to prevent the flow of air into the suction box from locations other than from that portion of the list which is situated on the side of the duct 15. Accordingly, the list 17 serves as a certain kind of closing part. Another purpose of the list is to serve as a member deflecting the wire. Thus, the face N of the list 17 is against the wire H, and the list 17 functions as a wire-deflecting member so that between the direction of arrival of the wire H at the list 17 and the direction of departure of the wire H from the list 17, there is an angle β that is about 0.5° or preferably even larger. When the tension of the wire is then adjusted by means of the roll 11, the wire H is always maintained in contact with the list 17 and the list 17 thus always has a precise position relative to the wire independently of the adjustment of the tension of the wire. Thus, the list 17 has a wide face N in a direction transverse to its longitudinal direction adapted to contact the wire and also projects from a lower surface of the suction box 14 to define a space between the wire H and the opening of the duct 15 in the lower surface of the suction box 14, as shown in FIG. 4.
FIG. 5 illustrates the list 17 of the invention placed between frame beams P1 and P2 of a paper-making machine replacing a folding or deflecting roll of the wire H. The illustration is a sectional view taken along the line I--I from FIG. 6. FIG. 6 shows a view in the direction of arrow K2 shown in FIG. 5. The list 17 can be crowned with an actuator 18, e.g., with a cylindrical means or, as shown in FIG. 6, with a claw crane. The actuator is located in the center area of the list 17 between the frame beam P2 of the paper making machine and the list 17. The list 17 is attached at its ends by attaching members M1 and M2 to the beam P2. The claw crane 18, which is situated in the center area of the list between the list 17 and the frame beam P2, is positionable by turning a screw 18a of the claw crane 18 on the service side of the paper-making machine. The actuator 18 may also be a double-acting hydraulic cylinder or a pneumatic cylinder, or an electrically driven actuator.
According to the invention, the list 17 is preferably made of a ceramic material, e.g., SiC, SiN4, Al2 O3, ZrO2, or a combination thereof, such as ZrO2 +Al2 O3. The list 17 may also be made of spray coated steel, a carbon fiber compound or plastic.
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within tile scope of the appended claims.
We claim:
1. In an apparatus for washing and guiding a wire comprising means for producing and directing a washing jet at a wire and means for removing washing mist from the wire including a suction box situated on an opposite side of the wire from said washing jet producing and directing means, said suction box including an inlet chamber and a duct through which washing mist produced from the washing jet is passed into said inlet chamber, said duct being arranged at an angle relative to a running direction of the wire over said suction box and having an opening in a lower surface of said suction box facing the wire, the improvement comprisingan elongate list arranged in conjunction with said means for removing washing mist, said list having a wide face in a direction transverse to its longitudinal direction such that at least a portion of said list continuously contacts the wire, said list projecting from said lower surface of said suction box to define a space between the wire and said opening of said duct in said lower surface of said suction box and to deflect the wire such that a direction of arrival of the wire at said list differs from a direction of departure of the wire from said list.
2. The apparatus of claim 1, wherein an angle of deflection of the wire about said list is defined between the direction of arrival of the wire at said list and the direction of departure of the wire from the list, said deflection angle being greater than or equal to about 0.5°.
3. The apparatus of claim 1, wherein said list is fixedly connected to said suction box, said duct having an inlet opening, said list being arranged in front of said inlet opening in a running direction of the wire.
4. The apparatus of claim 1, further comprising a rail arranged on said suction box and having a T-profile cross-sectional shape, said list comprising a groove having a corresponding shape to enable said list to engage with said suction box via a connection between said T-profile rail and said groove.
5. The apparatus of claim 1, further comprising actuator means for providing said list with a crown.
6. The apparatus of claim 5, further comprising attachment means for attaching said suction box to a machine frame while maintaining a space therebetween, said list being connected to said suction box, said actuator means being arranged to operate in said space to bend said suction box such that when said suction box is bent, said list connected thereto is provided with a curved profile.
7. The apparatus of claim 6, wherein said suction box has first and second ends, said attachment means comprising attachmeant members arranged at said first and second ends of said suction box, said actuator means being arranged in a center region of said suction box between said attachment members.
8. The apparatus of claim 6, wherein said actuator means comprise a claw crane.
9. The apparatus of claim 1, wherein said list is made of plastic.
10. The apparatus of claim 1, wherein said list is made of a ceramic material.
11. The apparatus of claim 1, wherein the length of said face is from about 10 mm to about 60 mm in a running direction of the wire.
12. The apparatus of claim 1, further comprising means for removably connecting said list to said suction box.
13. The apparatus of claim 1, wherein said list is positioned at a front edge of said lower surface of said suction box, said space being defined after said list in a running direction of the wire.
14. An apparatus for washing and guiding a wire, comprisingmeans for producing and directing a washing jet at a wire, said means being positioned on a first side of the wire, means for removing washing mist generated from the washing jet from the wire, said means for removing washing mist including a suction box situated on a second side of the wire opposite from said first side, said suction box including an inlet chamber and a duct through which the washing mist is passed into said inlet chamber, said duct having an opening in a lower surface of said suction box facing the wire, and p1 a list coupled to said means for removing washing mist and having a wide face in a direction transverse to its longitudinal direction such that at least a portion of said list continuously contacts the wire, said list projecting from said lower surface of said suction box to define a space between the wire and said opening of said duct in said lower surface of said suction box and to deflect the wire such that a direction of arrival of the wire at said list differs from a direction of departure of the wire from said list.
15. The apparatus of claim 14, wherein said list is fixedly connected to said suction box.
16. The apparatus of claim 14, further comprisingactuator means for providing said list with a crown, and means for attaching said suction box to a machine frame while maintaining a space therebetween, said actuator means being arranged to operate in said space to bend said suction box such that when said suction box is bent, said list is provided with a curved profile.
17. The apparatus of claim 14, wherein the length of said face is from about 10 mm to about 60 mm in a running direction of the wire.
18. The apparatus of claim 14, further comprising means for removably connecting said list to said suction box.
| 1994-12-05 | en | 1996-11-12 |
US-32616889-A | Hydrophobic attachment site for adhesion peptides
ABSTRACT
The invention provides a method of attaching peptides containing a biologically active site, for example RGD-containing adhesion peptides, to a solid surface through a hydrophobic domain, and peptides so attached. The hydrophobic domain can contain either hydrophobic amino acids, such as leucine, valine, isoleucine or phenylalanine, or fatty acids, such as, for example, myristic acid, palmitic acid, arachidic acid or other fatty acids. Additionally, spacers, such as amino acids, between the hydrophobic domain and the biologically active domain can improve the presentation of the biologically active site. Specific peptides of the invention include
GRGDSPASSKG.sub.4 RL.sub.6 RNH.sub.2 ;
GRGDSPASSKS.sub.3 RL.sub.6 RNH.sub.2 ;
and
GRGDSPASSKSSKRL.sub.6 RNH.sub.2.
BACKGROUND OF THE INVENTION
This invention relates to peptides and, more specifically, to peptides having a hydrophobic domain to facilitate their attachment to a solid substrate.
A variety of assays and purification techniques require that a ligand, such as a peptide, be immobilized on a solid support. Generally, two methods have been used to accomplish such immobilization. The peptide may be applied to the surface in solution, which is then evaporated off, leaving the peptide dried to the surface. Such non-specific attachment is inefficient for small peptides and applicable only to methods which do not require a large concentration of immobilized peptide, as much will be resolubilized subsequently in the presence of solution. Moreover, because the attachment is non-specific, peptides will be attached in random and variant orientations. Where presentation of a particular active site is critical, such variance can further reduce the specificity of the bound peptide.
In the more common two-step chemical coupling process, the solid surface is first passively coated with a large protein, such as an immunoglobulin or bovine serum albumin. A hetero-bifunctional cross-linking agent, such as SPDP or glutaraldehyde, is attached to the protein and used to capture peptide from solution. Such a method, while time consuming, is currently used, for example, in cell culture procedures which require a high concentration of bound peptide.
It is now recognized that many cell-cell and cell-matrix interactions are mediated by an arginine-glycine-aspartic acid (Arg-Gly-Asp or RGD) amino acid domain which is common to various adhesion proteins. This binding site is recognized by receptors. Synthetic peptides containing such a domain may be used in a variety of applications, including the coating of tissue culture plates or prostheses and immobilization for the purpose of the purification of adhesion receptors on a column. Achieving the attachment of an RGD-containing peptide to the solid substrate entails the same problems as do other peptides. In addition, because the adhesion domain is small, it is important that the domain be accessible to ligands, as by using a spacing group to distance the tripeptide from the surface that is being coated. Moreover, where the coating is for in vivo use, such as with a prosthesis, it is important that the coats be non-immunogenic and non-cytotoxic
There thus exists a need for a rapid and reproducible one step-process for attaching peptides, such as RGD containing peptides, to a solid surface. Ideally, such a method should be easy to perform and efficient. In addition, it should preferably result in appropriate presentation of critical epitopes, such as the RGD domain. The present invention satisfies these needs and provides related advantages as well.
SUMMARY OF THE INVENTION
The invention provides a method of attaching peptides containing a biologically active site, for example RGD-containing adhesion peptides, to a solid surface through a hydrophobic domain, and peptides so attached. The hydrophobic domain can contain either hydrophobic amino acids, such as leucine, valine, isoleucine or phenylalanine, or fatty acids, such as, for example, myristic acid, palmitic acid, arachidic acid or other fatty acids. Additionally, spacers, such as amino acids, between the hydrophobic domain and the biologically active domain can improve the presentation of the biologically active site. Specific peptides of the invention include
GRGDSPASSKG.sub.4 RL.sub.6 RNH.sub.2 ;
GRGDSPASSKS.sub.3 RL.sub.6 RNH.sub.2 ; and
GRGDSPASSKSSKRL.sub.6 RNH.sub.2.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to the use of hydrophobic domains, such as hydrophobic amino acids or fatty acids, on peptides to facilitate the attachment of the peptide to solid substrates. Such methods of specifically attaching synthetic peptides using hydrophobic domains is useful for localizing a broad range of synthetic peptides to a variety of surfaces. The methodology is of particular utility with RGD-containing adhesion peptides. The method, which bypasses the conventional two-step chemical coupling process, provides a rapid and reproducible method for presenting the RGD active site, for binding both with specific receptors as well as with specific cell types. Moreover, the coating can be relatively non-immunogenic and non-cytotoxic, particularly when naturally occurring amino acids and fatty acids are used.
RGD is known to comprise the binding site of various extracellular matrix proteins, such as fibronectin. RGD containing peptides coated on a substrate promote cell attachment. Alternatively, in soluble form, RGD containing peptides inhibit attachment or promote detachment of cells from a substrate. The arginine residue can be in the D- or L-configuration. See U.S. Pat. Nos. 4,578,079, 4,614,517 and 4,792,525 and Ser. No. 738,078, all of which are incorporated herein by reference.
A peptide is constructed to have a hydrophobic domain, preferably at the carboxyl terminus of the biologically active site of interest. The hydrophobic domain can comprise either multiple hydrophobic amino acid residues, such as leucine, valine, isoleucine or phenylalanine or fatty acids such as myristate CH3 (CH2)12 COO--, palmitate CH3 (CH2)12 COO--, CH3 (CH2)12 COO--, arachidate CH3 (CH2)12 COO--, etc. In one embodiment, the hydrophobic domain comprises multiple leucine residues, such as L6 NH2 or L4N H2. Alternatively, amino acid sequences such as phenylalamine, isoleucine or valine may be used.
In order to have sufficient hydrophobicity to facilitate attachment, the hydrophobic domain must have at least the hydrophobicity of the sequence L4. As used herein, "hydrophobic domain" refers to a domain having a hydrophobicity at least equivalent to the degree of hydrophobicity exhibited by the amino acid sequence L4.
The addition of amino acid spacers between the active site and the hydrophobic domain can improve active site presentation. These spacers can be amino acids, for example glycine or serine. Preferably more than one residue is used, such as S2, S3, or G4. In addition, other organic compounds such as sugars, or other carbon containing, non-hydrophobic moieties can be used.
Less specific cell attachment can be achieved using as the attachment site certain positively charged amino acids known to promote attachment, such as arginine, lysine, homoarginine or ornithine in combination with the hydrophobic domain. For example, both R6 GL6 NH2 and RL6 RNH2 have been shown to have some cell attachment promoting activity.
When in solution, the peptide can be used to coat surfaces such as tissue culture apparatus, prosthetic implant devices, columns for cell or receptor isolation and surfaces for ELISA. The surfaces can by hydrophobic or hydrophilic. The hydrophobic domain will adhere to such surfaces spontaneously as it is driven from solution in an aqueous environment. Greater peptide coating can be achieved by drying the peptide solution down onto the surface. Appropriate surfaces include Millicell™-CM, Immobilon™, Polystyrene, Polycarbonate, Teflon (polytetrafluoroethylene), Silicone, Polyurethane, Polylactic Acid, Titanium, Polyethylene, Gortex (expanded polytetrafluorethylene), tooth dentine and cementum.
Where the peptide has cell adhesion promoting activity, the method provides an improved means of cell culture in serum free conditions. This method also has application for prosthetic devices where it is desirable to have cells attach to the implanted device. Additionally by reproducing a natural extracellular matrix binding site on the substrate, the production of cellular proteins requiring such a substrate can be increased. Using a hydrophobic domain in conjunction with an RGD binding site facilitates the isolation of receptors which recognize the RGD site.
The use of naturally occurring amino acids or fatty acids is preferable to other hydrophobic moieties when coating prosthetic devices to be used in humans because they are relatively non-immunogenic and non-toxic.
The following standard abbreviations are used herein to identify amino acid residues.
TABLE I
______________________________________
Three-letter
One-letter
Amino Acid Abbreviation
Symbol
______________________________________
Alanine Ala A
Arginine Arg R
D-Arginine D-Arg dR
Asparagine Asn N
Aspartic acid Asp D
Cysteine Cys C
Glutamine Gln Q
Glutamic acid Glu E
Glycine Gly G
Histidine His H
Isoleucine Ile I
Leucine Leu L
Lysine Lys K
Methionine Met M
Phenylalanine Phe F
Proline Pro P
Serine Ser S
Threonine Thr T
Tryptophan Trp W
Tyrosine Tyr Y
Valine Val V
______________________________________
nMe refers to an nMethyl group.
All amino acids are in the L-configuration unless otherwise specified.
The following examples are intended to illustrate but do not limit the invention.
EXAMPLE I
Production of the Peptides
Peptides were synthesized using an automated peptide synthesizer (Model 430A; Applied Biosystems, Foster City, Calif.), using the instructions provided by the manufacturer, and purified by reverse phase HPLC on a Biogel TSK SP-5-PW cation exchange column (Bio-Rad Laboratories, Richmond, Calif.).
EXAMPLE II
Attachment of Peptides
The following peptides were tested for their ability to spontaneously adhere to the plastic wells and subsequently promote cell attachment: XG (R) GDS PASSKL2 NH2, XG(R)GDSPASSKL4 NH2, XG(R)GDSPASSKL6 NH2, XG(R)GDSPASSK6, XG(R)GDSPASSE6, where X is NH2, nMe, acetyl or other amino acid. The peptides were solubilized in 70% EtOH at a starting concentration of 1 mg/ml. 200 μl was then added in duplicate to the first two wells of ninety-six well polystyrene microtiter plates that had not been treated for tissue culture. The remaining wells contained 100 μl of 70% EtOH. Taking 100 μl from the lmg/ml solution in the first two wells, a serial dilution was performed out to 0.15 μg/well for each peptide. The plates were allowed to dry overnight at 37° C. in the presence of a desiccator.
The following day the peptide coated plates were used in a standard adhesion assay as described in Example III, using MG-63 cells, an osteosarcoma cell line available from American Type Tissue Culture.
EXAMPLE III
Cell Adhesion Assay
The plates were washed IX using PBS, (150mM NaCl/10mM sodium phosphate, pH 7.4). The plates were incubated with DMEM (0.1 ml/well) containing bovine serum albumin (BSA 2.5mg/mI; Sigma Chemical Co., St. Louis, Mo.) for one hour. Two×105 cells/ml (MG-63) were suspended in DMEM, and BSA (2.5mg/ml). 100μl of cell suspension was added per well and the plates are incubated at 37° C. in 7.5% CO2 /92.5% air for one hour. Afterwards, the plate was washed once in PBS. Attached cells were then fixed with 3% paraformaldehyde and stained overnight with 1% toluidine blue in 10% formaldehyde. The following day, the excess stain was removed and the plates were washed with H2 O; 100μl of a 1% sodium dodecyl sulfate (SDS) solution was added to each well. The level of cell attachment was then measured, using a kinetic microplate reader (Molecular Devices,) by assessing the optical density at 630 nm.
The results are presented in Table II. XG(R)GDSPASSKL6 NH2 promoted significant cell attachment out to a 3 μg/well. XG(R)GDSPASSKL4 NH2 promoted marginal cell attachment only at the highest concentration of 100μg/well. The other peptides nMeG(dR)GDSPASSKL2 NH2, nMeG(dR)GDSPASSK6, nMeG(dR)GDSPASSE6 did not promote significant cell attachment (Table II).
TABLE II
______________________________________
μg/well
Peptide
100 50 25 12 6 3 1.5
______________________________________
K.sub.6
3 2 2 2 2 3 2
E.sub.6
8 5 3 3 2 2 2
L.sub.2
6 6 3 2 1 1 1
L.sub.4
44 12 16 10 2 1 1
L.sub.6
100 76 60 60 60 5 3
______________________________________
The values represent percentage of maximum binding.
EXAMPLE IV
Phenylalanine as a Hydrophobic Carrier
The hydrophobic attachment of RGD containing peptides can be achieved with other hydrophobic amino acids. The following peptide, nMeG(dR)GDSPASSKRF4 RNH2 was solubilized in 70% ETOH and used in an adhesion assay as described previously. This experiment also demonstrated the increase in cell binding by using an S3 spacer on an RF6 RNH2 tail. GRGESPS8 L6 NH2 was used as a negative control, in that RGE is known not to have cell binding activity. The results are presented in Table III.
TABLE III
______________________________________
PHENYLALANINE AS A HYDROPHOBIC DOMAIN
μg/well 100 50 25 12 6 3 1.5
______________________________________
nMeGRGDSPASSKS.sub.3 RF.sub.6 RNH.sub.2
69 69 60 66 65 70 70
nMeGRGDSPASSKRF.sub.6 RNH.sub.2
70 75 56 52 57 54 50
nMeGRGDSPASSKL.sub.6 NH.sub.2
80 78 58 66 60 56 47
nMeGRGDSPASSKRL.sub.5 RNH.sub.2
72 68 58 66 60 44 34
nMeGRGDSPASSKRF.sub.4 RNH.sub.2
70 73 60 59 56 50 34
GRGESPS.sub.8 L.sub.6 NH.sub.2
27 17 16 10 16 8 3
______________________________________
The values represent percentage of maximum binding.
EXAMPLE V
Myristic Acid as a Hydrophobic Carrier
Fatty acids can also be used to promote the hydrophobic attachment of RGD containing peptides. Myristic acid was attached to the peptide, nMeG(dR)GDSPASSK via the epsilon amino group of the lysine. Cell attachment activity was determined as in Examples II and III.
TABLE IV
______________________________________
μg/well 100 50 25 12 6
______________________________________
Myristic acid 33 30 50 75 45
nMeGDRGDSPASSKL.sub.6 --NH.sub.2
100 100 100 50 35
______________________________________
The values represent percentage of maximum binding.
EXAMPLE VI
Cell attachment can also be promoted using positive charge alone on a hydrophobic tail, such as the peptide R6 GL6. The peptides were coated as in Example II and used in the assay of Example III.
______________________________________
μg/well 300 150 75 25 12 6
______________________________________
R.sub.6 GL.sub.6 70 60 50 50 50 43
nMeG(dR)GDSPASSKL.sub.6 NH.sub.2
100 85 65 50 50 45
______________________________________
The values represent percentage of maximum binding.
EXAMPLE VII
The addition of amino acid spacers between the hydrophobic domain in the RGD binding site enhances the presentation of the RGD peptide for cell binding. The peptides were coated as in Example II, for four hours.
______________________________________
ASSAY 10/14/88
Peptides 23 μg/well
10 5 2.5 1.25 6
______________________________________
nMeg(dR)GDSPASSKS.sub.4 RL.sub.6 RNH.sub.2
57 76 100 92 76
nMeg(dR)GDSPASSKS.sub.2 RL.sub.6 RNH.sub.2
34 53 57 46 38
nMeg(dR)GDSPASSKL.sub.6 NH.sub.2
-- 65 65 12 9
______________________________________
The values represent percentage of maximum binding.
Although the invention has been described with reference to the presently-preferred embodiment, it should be understood that various modifications can be made by those skilled in the art without departing from the invention. Accordingly, the invention is limited only by the following claims.
We claim:
1. A substantially pure active adhesion peptide comprising a cell attachment promoting binding site and a hydrophobic attachment domain having hydrophobicity between those exhibited by the amino acid sequences L4 or L6, wherein said substantially pure active adhesion peptide, when adsorbed to a solid surface, can effect the attachment of cells to the solid surface, said cell attachment promoting binding site containing RGD.
2. A substantially pure active adhesion peptide comprising a cell attachment promoting binding site and a hydrophobic attachment domain having hydrophobicity between those exhibited by the amino acid sequences L4 or L6, wherein said substantially pure active adhesion peptide, when adsorbed to a solid surface, can effect the attachment of cells to the solid surface, said cell attachment promoting binding site containing positively charged amino acids.
3. The substantially pure active adhesion peptide of claim 2 wherein said amino acids are selected from the group consisting of arginine, lysine, homoarginine or ornithine.
4. The substantially pure active adhesion peptide of claim 1 wherein said hydrophobic domain comprises fatty acids.
5. The substantially pure active adhesion peptide of claim 1 wherein said hydrophobic domain comprises hydrophobic amino acids.
6. The substantially pure active adhesion peptide of claim 1 wherein said hydrophobic amino acids are selected from the group consisting of leucine, isoleucine, phenylalanine and valine.
7. A substantially pure adhesion peptide comprising a cell attachment promoting binding site and a hydrophobic attachment domain having hydrophobicity between those exhibited by the amino acid sequences L4 or L6 and a spacer sequence between said cell attachment promoting site and said hydrophobic domain, wherein said spacer comprises between about two to four residues of serine or glycine.
8. A peptide having the amino acid sequence X-GRGDSPASSKG.sub.4 RL.sub.6 RNH.sub.2, wherein X is NH2, nMe, acetyl or other amino acid.
9. A peptide having the amino acid sequence X-GRGDSPASSKS.sub.3 RL.sub.6 RNH.sub.2, wherein X is NH2, nMe, acetyl or other amino acid.
10. A peptide having the amino acid sequence X-GRGDSPASSKSSKRL.sub.6 RNH.sub.2, wherein X is NH2, nMe, acetyl or other amino acid.
| 1989-03-20 | en | 1992-06-09 |
US-49716995-A | Externally-applied medicine for curing black foot disease
ABSTRACT
An externally-applied medicine for curing black foot disease comprising a basis part consisting of equal amount of ground, powdered, and mixed clove, frankincense, myrrha, rhizama arisaematis, pinellia, monkshood (root) or kusnezoff monkshood (root), and tuber of bamboo-leaved orchid, and an adjuvant part consisting of equal amount of round, powdered, and mixed borneol, powdered soy bean, borax, coptis root and/or phellodendron amureuse, and sepia aculeata. The medicine is used in such a manner that the powdered basis part is mixed and stirred with tea water until it becomes plaster-like, and the adjuvant part is scattered in dry form onto the wound or swollen area caused by the black foot disease before the plaster-like basis part is applied to the wound or swollen area about 0.5 cm in thickness. The wound is then bandaged and the medicine is renewed once to twice a day until fresh flesh appears in the wound. Thereafter, the medicine is continuously applied but in a dry form until the wound is completely healed.
This application is a Continuation of application Ser. No. 08/135,401, filed Oct. 13, 1993 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an externally-applied medicine for curing a special disease found in southern Taiwan area which is usually known as the black foot disease.
The black foot disease is an endemic disease caused by a kind of arsenism, and is normally found in Taiwan coastal areas having highly salty land, such as the Pei-Man Hsian of Tainan Hsien and the Pu-Dai Town and Tong-Shih Hsian of Chia Yi Hsien. All of these areas are located at southwest coastal plain of Taiwan. However, the same disease is also found in other places through the entire Taiwan.
The symptom of this disease at early stage is some kind of carbuncle, putrilaginous pustule or black pimple-like carbuncle. When such carbuncle or pustule is pierced and broken, the wound is black in color and is sometimes filled with pus and has ropy fluid or thin blood effusing from the wound. After the wound becomes putrefied, it looks like having a layer of black satin thereon. Because such carbuncle or putrilaginous pustule is mostly found on the patient's feet, the disease is usually called as the black foot disease. However, cases that such carbuncle or pustule appears at patient's other areas are found, too. Apart from the black and purulent wound, and the continuous effusion of ropy fluid and thin blood, the black satin-like layer formed on the putrefied wound is a special feature of this disease which will appear again in the next day even if it is removed. The worsened wound gradually expands with unacceptable stink, swelling and pain, seriously bothering the patient who might even suffer long term of insomnia. Since no effective medicine has been developed for the black foot disease up to now, the only way to help the patient to temporarily escape from the agonizing pain is to amputate the suffering foot or feet. However, there is still possibility that the disease appears at other areas of the patient.
It is therefore tried by the applicant based on his years experiences in the research of Chinese medicine and clinical tests to develop a magical prescription to effectively cure the horrible black foot disease.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a curative medicine which is based on a special recipe including several different kinds of Chinese medicine material ground to powder and can be easily applied to the wounds caused by the black foot disease. The curative medicine for curing black foot disease according to the present invention consists of a basis part and an adjuvant part. The basis part is mixed with tea water and stirred to plaster before it is used to cover the wound. The adjuvant part is scattered in a dry form on the wound and/or swollen area before the plaster of basis part is applied to the wound. The curative medicine according to the present invention can immediately kill pain, stop bleeding, stop itching, remove stink, eliminate cacodes, drain pus and help the growth of new tissue around the wound. The patient may get rid of the troublesome insomnia with the gradually stabilized condition. The gangrenous muscle and skin caused by the black foot disease will be gradually healed and the amputation can be avoided.
DETAILED DESCRIPTION OF THE INVENTION
The externally-applied medicine for curing the black foot disease according to the present invention consists of a basis part and an adjuvant part. The basis part of the medicine is the powder ground and mixed from equal amount of clove, frankincense, myrrha, rhizama arisaematis, pinellia, monkshood (root) or kusnezoff monkshood (root), and tuber of bamboo-leaved orchid. The rhizama arisaematis and pinellia must be soaked in water so as to remove their slickness. The monkshood (root) or kusnezoff monkshood (root) can be added only when the wound becomes seriously swollen and can be used alone or combined together. The adjuvant part of the medicine is the powder ground and mixed from equal amount of borneol, powdered soy bean, borax, coptis root, phellodendron amureuse, and sepia aculeata. The borax must be calcined, and the sepia aculeata must be removed of the hard shell and be soaked in water to remove the salt contained therein.
When using the medicine of the present invention, first wash clean the wound with tea water or alcohol, then scatter the dry and powdered adjuvant part of the medicine onto the wound or swollen area on the patient's skin; secondly, mix and stir the powdered basis part of the medicine with tea water until the basis part becomes plaster, then apply the wet plaster of basis part to the wound which has been scattered with the adjuvant part. The entire wound and the swollen area must be covered by the wet plaster of the basis part to a thickness about 0.5 cm. The plastered wound is then bandaged. The wet plastered basis part and the dry powdered adjuvant part are renewed once a day. For worse wound effusing ropy fluid and thin blood, it is preferable to renew the medicine twice a day. When the black slough in the wound is gradually removed and the fresh muscle appears, both the basis part and the adjuvant part are continuously applied to the wound but in a dry form until the wound is completely healed.
Since the rhizama arisaematis and pinellia included in the basis part and the borax in the adjuvant part are of toxicant, the medicine of the present invention is absolutely limited to external use. The medicine of the present invention can not be orally or internally taken.
Moreover, the medicine of the present invention is also an excellent medicine to cure the breast cancer, neck cancer, epactal cartilage, stasis of blood, bruise, swelling, fracture, and other trauma, swelling and pain caused by falling or serious impact.
The medicine of the present invention for curing the black foot disease has been proven to have excellent effect in many clinical experiments and the voluntary revolving medical services sponsored by the Tainan Regiment Control Area Command and the Taitung Division Control Area Command of the Ministry of National Defense of the Republic of China.
What is claimed is:
1. A topical two-part medicinal composition for treating black foot disease which comprises a powdered adjuvant part for sprinkling onto affected portions of an individual suffering from black foot disease and a basis part for adhesion to affected portions of said individual when mixed with tea water; said adjuvant part being a dry powder mixture formed from equal amounts of borneol, soy bean, calcined borax, coptis root, phellodrendron amureuse and de-shelled desalted sepia aculeata; said basis part being a powder mixture containing equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia and tuber of bamboo-leaved orchid.
2. The composition of claim 1 which further includes monkshood root and said basis part is a powder containing equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia, tuber of bamboo-leaved orchid and monkshood root.
3. The composition of claim 1 which further includes kusnezoff monkshood root and said basis part is a powder containing equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia, tuber of bamboo-leaved orchid and kusnezoff monkshood root.
4. The composition of claim 1, wherein the basis part is in admixture with an effective amount of tea water so that said admixture is in the form of a plaster for adhesion to affected portions of said individual.
5. The composition of claim 4 which further includes monkshood root and the basis part includes equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia, tuber of bamboo-leaved orchid and monkshood root.
6. The composition of claim 4 which further includes monkshood root and the basis part includes equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia, tuber of bamboo-leaved orchid and kusnezoff monkshood root.
7. A method for treating black foot disease with a two part topical composition containing a basis part and an adjuvant part; said adjuvant part being a dry powder mixture formed from equal amounts of borneol, soybean, calcined borax, coptis root, philodendron amureuse and de-shelled desalted sepia aculeata and said basis part being a powder mixture containing equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia and tuber of bamboo-leaved orchid; said method comprising the sequential steps of:a) cleaning the diseased tissue of an individual suffering from said disease; b) sprinkling said adjuvant part onto said diseased tissue; c) spreading an adherent coating of a plaster about 0.5 cm thick onto said diseased tissue; said plaster being formed by mixing said basis part with an effective amount of tea water so as to form a wet mixture having a consistency for application to the body by adhesion thereto; d) applying a bandage over said plaster coated diseased tissue; e) periodically replacing said adjuvant part and plaster at least about once a day until the diseased tissue is sloughed off and then; f) maintaining said diseased tissue in contact with said adjuvant part and basis part in dry form until healing is complete.
8. The method of claim 7, wherein the basis part further includes monkshood root and said basis part is a powder containing equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia, tuber of bamboo-leaved orchid and monkshood root.
9. The method of claim 7 wherein the basis part further includes kusnezoff monkshood root and said basis part is a powder containing equal amounts of clove, frankincense, myrrha, de-slicked rhizama arisaematis, de-slicked pinellia, tuber of bamboo-leaved orchid and kusnezoff monkshood root.
| 1995-06-30 | en | 2000-06-20 |
US-49952265-A | Production of sulfuric acid
Oct. 31, 1967y J. B. RINCKHOFF 3,350,169
PRODUCTION OF' SULFURIC ACID Filed oct. 21, 1965 JOHN B. RINCKHOFF INVENTOR.
mgl. M
A G EN T United States Patent O 3,350,169 PRQDUCTIUN F SULFURIC ACID .lohn B. Rinckhoff, Westfield, NJ., assignor to Chemical Construction Corporation, New York, NY., a corporation of Delaware Filed Oct. 21, 1965, Ser. No. 499,522 9 Claims. (Cl. 23-168) ABSTRACT 0F THE DISCLOSURE Sulfuric acid is produced by dividing a sulfur dioxidecontaining process gas stream into two portions. The first portion is subjected to catalytic oxidation of a portion of its sulfur dioxide content to sulfur trioxide. The partially converted gas stream is cooled, scrubbed with concentrated liquid sulfuric acid to remove sulfur trioxide as dissolved sulfuric acid, reheated, and combined with the second portion. The combined gas stream is subjected to complete catalytic oxidation of sulfur dioxide to sulfur trioxide, cooled, and scrubbed with concentrated liquid sulfuric acid to produce further dissolved sulfuric acid.
The present invention relates to the production of sulfuric acid. An improved processing sequence is provided, in which the sulfur dioxide-containing process gas stream is divided into two portions. A first portion is partially converted to sulfur trioxide, and the sulfur trioxide is absorbed in liquid sulfuric acid. The residual first portion is then combined with the second portion, and all of the sulfur dioxide in the combined gas stream is converted to sulfur trioxide, which is subsequently also absorbed in liquid sulfuric acid.
Numerous procedures have been developed for the production of sulfuric acid, all of which involve the basic sequence of combustion of a sulfur-containing feed stream to form a gas stream containing sulfur dioxide, cooling of the gas stream to optimum temperatures, catalytic oxidation of sulfur dioxide to sulfur trioxide, and absorption of the sulfur trioxide in concentrated sulfuric acid to form further sulfuric acid. The sulfur-containing feed stream may consist of elemental sulfur, hydrogen sulfide, pyrites or other sulfides, or sludge acid derived from petroleum refining. Elemental sulfur is the preferred raw material for large-scale commercial facilities, however the other sulfur sources mentioned supra m-ay also be employed within the scope of the present invention. The oxidation of sulfur dioxide to sulfur trioxide is generally carried out in the presence of a vanadium or platinum catalyst, however other catalytic agents known to the art may also be employed in suitable instances. The Oxidation reaction is strongly exothermic. Consequently, in order to avoid overheating of the catalyst, the reaction is generally carried out in a plurality of stages of partial conversion, with cooling of the gas stream being provided between stages. The resultant sulfur trioxide-containing gas stream is then absorbed in concentrated sulfuric acid, either to form further sulfuric acid or oleum, which consists of sulfuric acid containing excess dissolved sulfur trioxide. Both of these alternatives are encompassed within the scope of the present invention.
Numerous alternatives and modifications of the basic process sequence have been proposed in the prior art. Thus, in U.S. Patent No. 2,023,203, the hot sulfur dioxide-containing gas stream is split and a rst portion is passed through a first converter for partial conversion with concomitant cooling. The balance of the hot sulfur dioxide-containing gas stream is then added, in order to compensate for possible over-cooling by providing a heating effect to attain optimum temperature foru further conversion. The combined gas stream is then passed through Patented ct. 31, l1.967
two other conversion stages in series, followed by absorption of sulfur trioxide. In U.S. Patent No. 2,104,858, the sulfur dioxide-containing gas stream is cooledand divided into two portions. A first portion is then reheated to conversion temperature and subjected to partial catalytic conversion without cooling. The resultant hot gas stream is cooled by addition of the cold second portion of the sulfur dioxide-containing gas stream. Finally, U.S. Patent No. 1,789,460 provides a multi-stage sulfur dioxide conversion process in which a recycle gas stream is added to the main gas stream before each stage. The recycle gas stream consists of a portion of the main gas stream which is drawn olf after the first stage of partial conversion, cooled, and scrubbed with a liquid absorbent for sulfur trioxide removal.
In the present invention, a sulfur-containing feed stream is burned with an oxygen-containing gas stream such as air or oxygen-enriched air, in order to produce a hot sulfur dioxide-containing gas stream which also contains excess free oxygen. The hot gas stream is produced at a temperature below 1200 C., in order to prevent furnace deterioration and also to avoid the fixation of atmospheric nitrogen -which could result in stack fumes of nitrogen oxides and nitric acid in the product sulfuric acid. The hot gas stream is cooled and then divided into a first portion and a second portion. In one embodiment of the invention, additional air is added to the first gas stream portion, in order to reduce the sulfur dioxide content to less than 10%. The first portion is passed through a catalytic converter for the oxidation of sulfur dioxide to sulfur trioxide, and a major part of the sulfur dioxide content of the first gas stream portion is converted to sulfur trioxide. The resulting first gas stream portion is cooled and `scrubbed with liquid sulfuric acid, which absorbs the sulfur trioxide content to form further sulfuric acid. The residual first gas stream portion is combined with the second gas stream portion, and the combined gas stream is passed through a second catalytic converter for the oxidation of sulfur dioxide to `sulfur trioxide, in order to convert substantially all of the sulfur dioxide content to sulfur trioxide. The resulting converted combined gas stream is cooled and scrubbed with liquid sulfuric acid, which absorbs the sulfur trioxide content to form further sulfuric acid.
The process sequence of the present invention provides several practical advantages, as compared to the prior art.l In actual application to a commercial sulfuric acid facility, the overall conversion of sulfur dioxide to sulfur trioxide was in excess of 99%, the required process air flow rate was only 50 cubic feet per minute per short ton of acid per day, and the total volume of vanadium catalyst required was only 117 liters per short ton of acid per day. Thus, the present invention provides a process sequence which features high overall conversion of sulfur dioxide to sulfur trioxide, low process air requirement, and low catalyst volume requirement.
It is an object of the present invention to produce sulfuric acid in an improved manner.
Another object is to produce sulfuric acid by dual ab' sorption of sulfur trioxide.
A further object is to produce sulfuric acid by a process which is more efficient than prior art procedures, with respect to higher overall conversion of sulfur dioxide to sulfur trioxide, lower process air requirement, and lower catalyst volume requirement.
An additional object is to produce sulfuric acid from a sulfur dioxide-containing process gas stream by dividing the gas stream into two portions, partially converting the sulfur dioxide content of the first portion to sulfur trioxide, a'bsorbing the sulfur trioxide in sulfuric acid in a first absorber, combining the residual first portion with the second portion, coverting the sulfur dioxide content of the combined gas stream to sulfur trioxide, and absorbing the sulfur trioxide from the combined gas stream into sulfuric acid in a second absorber.
An object is to produce a hot sulfur dioxide-containing gas stream by the combustion of a sulfur-containing feed stream with an oxygen-containing gas stream such as air, while preventing excessive temperature rise and the fixation of atmospheric nitrogen.
These and other objects and advantages of the present invention will become evident from the description which follows. Referring to the figure, process oxygen-containing gas stream 1 usually consists of atmospheric air which has preferably been pre-dried, usually by scrubbing with concentrated sulfuric acid, in order to prevent subsequent mist formation. Stream 1 is preferably divided into the main process air stream 2 and bypass air stream 3. Stream 2 is now reacted with sulfur-containing feed stream 4 in combustion furnace 5, which as described supra is maintained at a temperature below 1200 C. order to prevent furnace deterioration and the formation of nitrogen oxides by the fixation of atmospheric nitrogen. As described supra, stream 4 may consist of any of a variety of sulfur-containing materials, however stream 4 will usually consist of elemental sulfur in large-scale commercial facilities. The resultant sulfur-dioxide-containing gas stream 6 discharged from furnace 5 is thus at a temperature below 1200 C., and is preferably at a temperature in the range of 600 C. to l200 C. Stream 6 usually contains in excess of -by volume of sulfur dioxide content together with excess free oxygen, and will preferably contain in the range of 10% to 14% sulfur dioxide content by volume.
Stream 6 is now cooled to a reduced temperature suitable for subsequent catalytic oxidation of sulfur dioxide to sulfur trioxide. The cooling of stream 6 preferably takes place in boiler 7, with concomitant steam generation. Liquid water stream 8 is passed into unit 7, and the resultant generated steam is removed from unit 7 as stream 9. The cooled process gas stream 10 removed from unit 7 is at a reduced temperature above 400 C. suitable for subsequent catalytic conversion, and is preferably at a temperature in the range of 400 C. to 550 C.
Stream 10 is now divided into first process gas stream portion 11 and second process gas stream portion 12. Stream 11 is combined with bypass process air stream 3, to form process gas stream 13 which preferably contains less than 10% by volume of sulfur dioxide content and typically contains in the range of 6% to 10% by volume of sulfur dioxide content, together with excess free oxygen. Stream 13 is now passed into catalytic converter 14, in order to oxidize a major portion of the sulfur dioxide content to sulfur trioxide. Unit 14 preferably contains two beds 15 and 16 consisting of a suitable catalyst for the reaction, such as platinum or vanadium oxide deposited on a suitable carrier. Each of the 4beds 15 and 16 is of a suitable volume to achieve only partial conversion, in order to avoid excessive temperature rise due to the exothermic nature of the reaction, which could result in catalyst deterioration. The beds 15 and 16 are separated by partition 17, and the partially converted hot gas is withdrawn from below bed 15 as stream 18 for external cooling in an auxiliary steam boiler 19. Liquid water stream 20 is passed into boiler 19 and generated steam is removed via strea-m 21. Other suitable heat exchange mediums may be employed in unit 19 besides water stream 20. The resultant cooled process gas stream 22 is passed from unit 19 into unit 14 below partition 17, and then passes through bed 16 for further catalytic oxidation of sulfur dioxide to sulfur trioxide. The final hot process gas stream 23 withdrawn from unit 14 now contains sulfur trioxide together with a minor proportion of unconverted sulfur dioxide.
Stream 23 is now cooled prior to absorption of its sulfur trioxide content in liquid sulfuric acid. The cooling of stream 23 preferably takes place in heat exchange with the residual gas stream free of sulfur trioxide, prior to recycle of the residual gas stream to the process for further catalytic oxidation of its residual sulfur dioxide content to sulfur trioxide. Stream 23 is thus passed into heat exchanger 24, and the resulting cooled process gas stream 25 is produced at a temperature preferably below 200 C., and typically in the range of C. to 200 C. Stream 25 is now passed into gas scrubbing tower 26, which may be provided with suitable internal means 27 for gasliquid Contact such as Raschig rings or other suitable packing, bubble cap trays, or sieve trays. Concentrated liquid sulfuric acid stream 28 is passed into unit 26 above section 27, and flows downwards countercurrent to the rising gas stream. The sulfur trioxide is absorbed from the gas phase into the liquid stream in section 27 with consequent formation of further sulfuric acid or oleum. The resultant liquid phase containing dissolved sulfur trioxide is withdrawn from unit 26 as stream 29, and may be recycled as stream 28 or passed to product utilization.
The residual gas stream 30 withdrawn overhead from unit 26 is now substantially free of sulfur trioxide, however stream 30 contains sulfur dioxide and is recycled for further catalytic oxidation. Stream 30 is heated in unit 24 to a suitable temperature for recycle and catalytic oxidation of sulfur dioxide to sulfur trioxide by heat exchange with stream 23. The resultant heated residual gas stream 31 is preferably at a temperature above 350 C., and is typically at a temperature in the range of 350 C. to 500 C. Stream 31 is now combined with stream 12, to form combined process gas stream 32 at a temperature preferably above 400 C. and typically at a temperature in the range of 400 C. to 525 C. Stream 32 is now passed into catalytic converter 33, which is similar in configuration and function to unit 14 described supra, except that substantially all of the sulfur dioxide content of stream 32 is converted to sulfur trioxide in unit 33. Thus, unit 33 is provided with a plurality of catalyst beds 34, 35 and 36, with interbed cooling to prevent excessive temperature rise being attained by the provision of cooling coils 37 and 38 between beds. A suitable heat exchange fluid is circulated through coils 37 and 38 via streams 39 and 40, which may consist of process air as described in U.S. Patent No. 3,147,074.
The resultant hot process gas stream 41 withdrawn from unit 33 below bed 36 contains sulfur trioxide and is substantially .free of sulfur dioxide. Stream 41 is now cooled in heat exchanger 42 to a suitable temperature for absorption of the sulfur trioxide in concentrated sulfuric acid. A heat exchange fluid such as water is passed into unit 42 via stream 43, and heated fluid is withdrawn via stream 44. The resultant cooled process gas stream 45 withdrawn from unit 42 is preferably at a temperature below 200 C., and is typically at a temperature in the range of 100 C. to 200 C. Stream 45 is now passed into absorber 46, which is a unit having a configuration and function similar to unit 26 described supra. Thus, concentrated sulfuric acid stream 47 is passed into unit 46 above gas-liquid contact section 48, and absorbs substantially all of the sulfur trioxide from the rising gas phase. The resultant liquid phase of higher sulfur trioxide content is withdrawn via stream 49, and may be recycled via stream 47 or passed to product utilization. The residual gas phase stream 50, now substantially free of sulfur oxides, is discharged to atmosphere from unit 46 above section 48.
Numerous alternatives within the scope of the present invention will occur to those skilled in the art. Thus, the limitations and ranges of process variables such as gas stream temperatures enumerated supra merely represent preferred embodiments of the present invention, and it will be evident that the process is operable outside of these ranges and limitations, with the exception of the maximum limitation of the temperature of stream 6. The bypass air stream 3 may be omitted in some instances, in which case the total process oxygen requirement for combustion and sulfur dioxide oxidation-will be admitted to the process via stream 2. Other means of cooling stream 6 instead of steam boiler 7 may be adopted in practice. Thus, in some instances stream 6 may be cooled by heat exchange with a process duid similarly to stream 23, or with a conventional heat exchange medium other than liquid water. Similar considerations apply with respect to the cooling of stream 18, in that other cooling means besides steam boiler 19 may be adopted in practice. Unit 14 may contain only a single bed of catalyst, particularly in cases where stream 13 is of relatively low sulfur dioxide content. In other cases, unit 14 may contain more than two beds. Similar considerations apply with respect to unit 33, however in most cases three beds of catalyst will be sufficient to attain substantially complete sulfur dioxide oxidation in unit 33, and in some instances less than three beds may be provided in unit 33. The hot process gas stream 23 may be cooled prior to sulfur trioxide absorption by heat exchange with other process streams such as streams 1 or 3, or with liquid water or other heat exchange mediums, instead of by heat exchange with stream 30. In this case, stream 30 may be heated by alternative means or heat exchange prior to recycle as stream 31, or in some cases when stream 12 is at a sufficiently elevated temperature, stream 30 may be directly recycled as stream 31, in which case stream 12 will serve to heat stream 31 to requisite temperature for catalytic reaction by direct mixing. Sections 27 or 48 may be omitted in suitable instances, in which case units 26 and 46 would consist of spray towers. In other cases, gas-liquid contact may be attained by injecting streams 25 or 45 into a liquid pool or concentrated sulfuric acid solution. Other alternative gas-liquid contact procedures will occur to those skilled in the art. Interstage cooling between beds 34 and 35 or beds 35 and 36 may alternatively be attained by the provision of an internal partition in unit 33 similar to partition 17 of unit 14, combined with an external steam boiler similar to unit 19. A single sulfuric acid circulating system comprising a pump and acid cooler could be provided to furnish scrubbing acid to both units 26 and 46. In this case, streams 28 and 47 would be derived from a single cooled acid stream, and streams 29 and 49 could be combined prior to cooling and recycle for further gas scrubbing. In some cases streams 30` or 50 may contain entrained acid mist. In this case, the acid mist will be removed and recovered from the gas streams 30 or 50 by passing the gas stream through a suitable mist filter.
Finally, it is apparent that'the process concept and `sequence of the present invention is feasible and applicable in instances where a large-scale facility is required, and stream is of such a large volume that it becomes practical to divide stream 10 into three or more portions. In this case, more than one portion of stream 10 would be subjected to partial catalytic conversion and sulfur trioxide absorption, followed by combination of the residual portions and final complete catalytic conversion of `sulfur dioxide to sulfur trioxide in the combined gas stream. Alternatively, stream 10 may -be divided into three portions, and the sulfur dioxide content of stream 32 may only be partially converted to sulfur trioxide. In this case, stream 50 will contain residual sulfur dioxide, and stream 50 would be combined with the third portion of stream 10, and the combined gas stream would be subjected to further catalytic conversion and sulfur trioxide absorption in additional separate process units. An example of an industrial application of the process of the present invention will now be described. In the example infra, process stream compositions are provided in terms of cubic feet per minute for each constituent.
Example The process of the present invention was applied to a facility producing 200 short tons per day of sulfuric acid. The total catalyst volume required for beds and 16 was Stream Composition, Cubic Feet Per Minute N o. -Sulfur Dioxide Sulfur Trloxde Oxygen Nitrogen In the example supra, overall conversion of sulfur dioxide to surfur trioxide was 99.1%, the required process air flow rate was only 50 cubic feet per minute per short ton of daily acid capacity, and the total volume of vanadium catalyst required was -only 117.25 liters per short ton of daily acid capacity. These operating conditions represent a significant improvement over prior art procedures.
I claim:
I. A process for the production of sulfuric acid which comprises burning a sulfur-containing feed stream with an oxygen-containing gas, whereby a hot gas `stream containing less than about 14% vby volume of sulfur dioxide, and excess free oxygen, is produced at a temperature below 1200 C., cooling said lhot gas stream to a temperature in the range of 400 to 550 C., dividing said gas stream into a first portion and a second portion, passing said first gas stream portion through first catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby a major part of the sulfur dioxide content of said rst gas stream portion is converted to sulfur trioxide, scrubbing said first gas stream portion with concentrated liquid sulfuric acid in first absorption means, whereby sulfur trioxide is 4absorbed into the liquid phase to form further sulfuric acid, combining the residual first gas stream portion with said second gas stream portion, passing the combined gas stream through second catalytic c-onversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially all of the sulfur dioxide content of said combined gas stream is converted to sulfur trioxide, and scrubbing said combined gas stream with concentrated liquid sulfuric acid in second absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid.
2. A process for the production of sulfuric acid which comprises -burning a sulfur-containing feed stream with a first oxygen-containing gas, whereby a hot `gas stream containing less than about 14% by volume of sulfur dioxide, and excess free oxygen, is produced at .a temperature below 1200" C., lcooling said hot gas stream to a temperature in the range of 400 to 550 C., dividing said gas stream into a first portion and a second portion, adding a second oxygen-containing gas to said rst portion, passing said first gas stream portion through first catalytic-conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby a major part of the sulfur dioxide content of said first gas stream portion is converted to sulfur trioxide, scrubbing s-aid first gas stream portion with concentrated liquid sulfuric acid in first absorption means, whereby sulfur trioxide is .absorbed into the liquid phase to form further sulfuric acid, combining the residual first gas stream portion with said second gas stream portion, passing the combined gas stream through second catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially .all of the sulfur dioxide content of said combined gas stream is converted to sulfur trioxide, and scrubbing said combined gas stream with concentrated liquid sulfuric acid in second absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid.
3. A process for the production of sulfuric acid which comprises burning a sulfur-containing feed stream with an oxygen-containing gas, whereby a hot gas stream containing less than about 14% by volume of sulfur dioxide, and excess free oxygen, is produced at a temperature below 1200 C., cooling said hot gas stream to a temperature in the range of 400 to 550 C., dividing the cooled gas stream into a first portion and a second portion, passing said first gas stream portion through first catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby a major part of the sulfur dioxide content of said first gas stream portion is converted to sulfur trioxide, cooling said first gas stream portion, scrubbing said first gas stream portion with concentrated liquid sulfuric acid in first absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid, combining the residual first gas stream portion with said second gas stream portion, passing the combined gas stream through second catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially all of the sulfur dioxide content of said combined gas stream is converted to sulfur trioxide, cooling the resulting combined gas stream, and scrubbing said combined gas stream with concentrated liquid sulfuric acid in second absorption dioxide to sulfur trioxide, whereby a major part of the sulfur dioxide content of said first gas stream portion is converted to sulfur trioxide, cooling said first gas stream portion to a temperature below 200 C., scrubbing said first gas stream portion with concentrated liquid sulfuric acid in first absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid, heating the residual first -gas stream portion to a temperature above 350 C., combining the residual first gas stream portion with said second gas stream portion, whereby a combined gas stream is formed at a temperature above 400 C., passing the combined gas stream through second catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially all of the sulfur dioxide content of said cornbined gas stream is converted to sulfur trioxide, cooling the -resulting combined gas stream to a temperature below 200 C., and scrubbing the combined gas stream with concentrated liquid sulfuric acid in second absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid.
6. A process for the production of sulfuric acid which comprises burning a sulfur-containing feed stream With a first oxy-gen-containing gas, whereby a hot gas stream containing less than about 14% and more than 10% by volume of sulfur dioxide content, and excess free oxygen, is produced at a temperature below 1200 C., cooling said hot gas stream to a reduced temperature below about 550 C. and above 400 C. by heat exchange with liquid means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid.
4. A process for the production of sulfuric acid which comprises burning a sulfur-containing feed stream with a first oxygen-containing gas, whereby a hot gas stream containing less than about 14% lby volume of sulfur dioxide, and excess free oxygen, is produced at a temperature below 1200 C., cooling said hot gas stream to a temperature in the range of 400 to 550 C., dividing the cooled gas stream into a first portion `and a second portion, adding a second oxygen-containing gas to said first portion, passing said first gas stream portion through first catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby a ymajor part of the sulfur dioxide content of said first gas stream portion is converted to sulfur trioxide, cooling said first gas stream portion in heat exchange means, scrubbing said first gas stream portion with concentrated liquid sulfuric acid in first absorption means, whereby sulfur trioxide is absorbed into the liquid phase t-o form further sulfuric acid, passing the residual first gas stream portion through said heat exchange means, whereby said residual first gas stream portion is heated, combining the heated residual first gas stream portion with said second gas stream portion, passing the combined gas stream through second catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially all of the sulfur dioxide content of said combined gas stream is converted to sulfur trioxide, cooling said combined gas stream, and .scrubbing said combined gas stream with concentrated liquid sulfuric acid in second absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid.
5. A process for the production of sulfuric acid which comprises burning a sulfur-containing feed stream with air, whereby a hot gas stream containing less than about 14% by volume of sulfur dioxide, and excess free oxygen, is produced at a temperature below 1200 C., cooling said gas stream to a reduced temperature below about 550 C. and above 400 C. by heat exchange with liquid water, whereby said liquid water is vaporized to steam, dividing the cooled gas stream into a first portion and a second portion, passing said first gas stream portion through first catalytic conversion means for the oxidation of sulfur water, whereby said liquid water is vaporized to steam, dividing the cooled gas stream into a first portion and a second portion, adding a second oxygen-containing gas to said first portion, whereby the sulfur dioxide content of said first portion is reduced to less than 10% by volume, passing said first lgas stream portion through first catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby a major part of the sulfur dioxide content of said first gas stream portion is converted to sulfur trioxide, cooling said first gas stream portion in heat exchange means to a temperature below 200 C., scrubbing said first gas stream portion with concentrated liquid sulfuric acid in first absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid, heating the residual first gas stream portion to a temperature above 350 C. in said heat exchange means, combining the residual first gas stream portion with said second gas stream portion, whereby a combined lgas stream is formed at .a temperature above 400 C., passing the combined gas stream through second catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially all of the sulfur dioxide content of said combined gas stream is converted to sulfur trioxide, cooling the resulting combined gas stream to a temperature below 200 C., and scrubbing the combined gas stream with concentrated liquid sulfuric acid in second absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid.
7. A process for the production of sulfuric acid which comprises burning a sulfur-containing feed stream with air, whereby a hot gas strea-m containing less than about 14% by volume of sulfur dioxide, and excess free oxygen, is produced at a temperature in the range of 600 C. to 1200 C., cooling said hot gas stream to a temperature in the range of 400 C. to 550 C. by heat exchange with liquid water, whereby said liquid Water is vaporized to steam, dividing the cooled gas stream into a first portion and a second portion, passing said first gas stream portion through rst catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby a major part of the sulfur dioxide content of said first gas stream portion is converted to sulfur trioxide, cooling said first gas stream portion to a temperature in the range of C. to 200 C., scrubbing said first gas stream portion with concentrated liquid sulfuric acid in first absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid, heating the -residual first gas stream portion to a temperature in the range of 350 C. 500 C., combining the residual first gas stream portion with said second gas stream portion, whereby 'a combined gas stream is formed at a temperature in the range of 400 C. to 525 C., passing the combined gas stream through second catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially all of the sulfur dioxide content of said combined gas stream is converted to sulfur trioxide, cooling the resulting combined gas stream to a temperature in the range of 100 C. to 200 C., and scrubbing the combined gas stream with concentrated liquid sulfuric acid in second absorption means, whereby sulfur trioxide is absorbed into the liquid phase to form further sulfuric acid.
8. A process for the production of sulfuric acid which comprises burning a sulfur-containing feed stream with a iirst air stream, whereby a hot ygas stream containing in the range of 10% to 14% by volume of sulfur dioxide content and excess free oxygen is produced at a temperature in the range of 600 C. to 1200 C., cooling said hot gas stream to a temperature in the range of 400 C. to 550 C. by heat exchange with liquid water, whereby said liquid water is vaporized to steam, dividing the cooled gas stream into a first portion and a second portion, addin-g a second air stream to said first portion, whereby the sulfur dioxide content of said iirst portion is reduced to the range of 6% to 10% by volume, passing said first gas stream portion through iirst catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby a major part of the sulfur dioxide content of said first Igas stream portion is converted to sulfur trioxide, cooling said lirst -gas stream portion in heat exchange means to a temperature in the range of C. to 200 C., scrubbing said irst gas stream portion with concentrated liquid sulfuric acid in lirst absorption means, whereby sulfu-r trioxide is absorbed into the liquid phase to form further sulfuric acid, heating the residual rst gas stream portion in said heat exchange means to a temperature in the range of 350 C. -to 500 C., combining the residual rst -gas stream portion with said second gas stream portion, whereby a combined gas stream is formed at a temperature in the range of 400 C. to 525 C., passing the combined gas stream through second catalytic conversion means for the oxidation of sulfur dioxide to sulfur trioxide, whereby substantially all of the sulfur dioxide content of said combined -gas stream is converted to sulfur trioxide, cooling the resulting combined gas stream to a temperature in the range of 100 C. to 200 C., and scrubbing the combined gas stream with concentrated liquid sulfuric acid in second absorption means, whereby sulfur trioxide is :absorbed into the liquid phase to form further sulfuric acid.
9. The process of claim 8, in which said sulfur-containing feed stream comprises elemental sulfur.
References Cited UNITED STATES PATENTS 2,023,203 12/1935 Merriam 23-176 3,142,536 7/1964 Guth et al. 23--175 3,259,459 7/ 1966 Moller 23-176 EARL C. THOMAS, Primary Exalmizer. OSCAR R. VERTIZ, Examiner. A. GREIF, Assistant Examiner.
1. A PROCESS FOR THE PRODUCTION OF SULFURIC ACID WHICH COMPRISES BURNING A SULFUR-CONTAINING FEED STREAM WITH AN OXYGEN-CONTAINING GAS, WHEREBY A HOT GAS STREAM CONTAINING LESS FROM ABOUT 14% BY VOLUME OF SULFUR DIOXIDE, AND EXCESS FREE OXYGEN, IS PRODUCED AT A TEMPERATURE BELOW 1200*C., COOLING SAID HOT GAS STREAM TO A TEMPERATURE IN THE RANGE OF 400* TO 550*C., DIVIDING SAID GAS STREAM INTO A FIRST PORTION AND A SECOND PORTION, PASSING SAID FIRST GAS STREAM PORTION THROUGH FIRST CATALYTIC CONVERSION MEANS FOR THE OXIDATION OF SULFUR DIOXIDE TO SULFUR TRIOXIDE, WHEREBY A MAJOR PART OF THE SULFUR DIOXIDE CONTENT OF SAID FIRST GAS STREAM PORTION IS CONVERTED TO SULFUR TRIOXIDE, SCRUBBING SAID FIRST GAS STREAM PORTION WITH CONCENTRATED LIQUID SULFURIC ACID IN FIRST ABSORPTION MEANS, WHEREBY SULFUR TRIOXIDE IS ABSORBED INTO THE LIQUID PHASE TO FORM FURTHER SULFURIC ACID, COMBINING THE RESIDUAL FIRST GAS STREAM PORTION WITH SAID SECOND GAS STREAM PORTION, PASSING THE COMBINED GAS STREAM THROUGH SECOND CATALYTIC CONVERSION MEANS FOR THE OXIDATION OF SULFUR DIOXIDE TO SULFUR TRIOXIDE, WHEREBY SUBSTANTIALLY ALL OF THE SULFUR DIOXIDE CONTENT OF SAID COMBINED GAS STREAM IS CONVERTED TO SULFUR TRIOXIDE, AND SCRUBBING SAID COMBINED GAS STREAM WITH CONCENTRATED LIQUID SULFURIC ACID IN SECOND ABSORPTION MEANS, WHEREBY SULFUR TRIOXIDE IS ABSORBED INTO THE LIQUID PHASE TO FORM FURTHER SULFURIC ACID.
| 1965-10-21 | en | 1967-10-31 |
US-83524686-A | Process for the preparation of 2-alkyl cyclopent-2-enones
ABSTRACT
A process for the preparation of 2-alkyl cyclopent-2-enones having the formula: ##STR1## wherein R is as defined hereinafter. An α-olefin having the formula CH 2 ═CH--CH 2 R is oxidized to the corresponding epoxide. The epoxide is reacted with an alkylating agent having the formula Na + [CH(COOR") 2 ] - , wherein R" is an ethyl, an isopropyl, or an isobutyl radical. An α-carbalkoxy-γ-alkyl lactone is obtained, which, through saponification and decarboxylation, yields a γ-alkyl lactone having the formula: ##STR2## which is reacted with a protic acid, thereby obtaining, by cyclization, the desired 2-alkylcyclopent-2-enone. The obtained products are intermediates for the production of pharmaceutical products and of drugs for veterinary use, in particular prostaglandin.
The present invention relates to a process for preparing 2-alkylcyclopent-2-enones having the formula: ##STR3## wherein R represents one of the following groups: Cn H2n+1 (the chain being linear or branched);
(CH2)n -COOR';
(CH2)n -NR'2 ;
(CH2)n -OR';
(CH2)n X, wherein X=Cl, Br, I or F; or
(CH2)n -CN.
In each of these groups, n ranges from 1 to 20 and R' is an alkyl radical containing up to 5 carbon atoms, a benzyl radical or a phenyl radical, these last two radicals optionally carrying, in the aromatic nucleus, one or more substituent groups (inert under the reaction conditions).
Cyclopentenones (I) are useful intermediates for the manufacture of pharmaceutical products and of drugs for veterinary use, in particular, prostaglandins.
According to a known process, an olefin is reacted, in a first step, with trihydrated manganese acetate, potassium permanganate, acetic anhydride and anhydrous sodium acetate, all in a large excess with respect to the olefin, thereby obtaining a γ-alkyl lactone, which, in a second step, is cyclized by means of polyphosphoric acid, thereby obtaining the final product. Such a process gives rise to low yields and requires particular reactants which are expensive and can be handled only with difficulty; furthermore, the reactions lead to complex mixtures of products from which the γ-alkyl lactone and the final product may be separated only with difficulty.
An object of the invention is to provide a process for the preparation of 2-alkylcyclopent-2-enones having formula (I) with rather good yields, and a second object is to provide a process starting from raw materials which are cheap and can be handled easily. A third object is to provide a process allowing the intermediate products and the final product to be separated easily.
These and still other objects are easily achieved by means of a process characterized by the following steps:
(a) an α-olefin having the formula
CH.sub.2 ═CH--CH.sub.2 --R (II)
is oxidized to the epoxide ##STR4##
(b) epoxide (III) is reacted, under reflux conditions, with an alkylating agent having the formula: ##STR5## (where R" is an ethyl, an isopropyl, or an isobutyl radical) in the presence of a malonic ester having the formula:
COOR"--CH.sub.2 --COOR"
in an alcoholic solvent having the formula R"OH. The alkylating agent is used in a practically equimolar ratio with respect to the epoxide, and said malonic ester is used in a molar ratio with respect to the epoxide of from 0.5 to 2. An α-carbalkoxy-γ-alkyl lactone is thus obtained, having the formula: ##STR6##
(c) said lactone (IV) is saponified in an alkaline medium, thereby obtaining the corresponding acid;
(d) the acid is decarboxylated, at temperatures from 100° to 160° C., thereby obtaining a γ-alkyl lactone having the formula (V): ##STR7##
(e) said lactone (V) is reacted at 20° to 100° C. with a protic acid, thereby obtaining, by cyclization, the desired 2-alkylcyclopent-2-enone having the formula (I).
In the starting olefin (and consequently in 2-allyl cyclopent-2-enone (I) as well), n ranges preferably from 1 to 10. The preferred substituent groups are Cn H2n+1 or (CH2)n -COOR'. When radical R' is a benzyl or a phenyl radical, these groups may be substituted in the aromatic nucleus by one or more inert groups (usually from 0 to 2), selected generally from the class consisting of NR2 '", OR'", X, CN and NO2, where X has the meaning given above and where R'" is an alkyl radical containing up to 5 carbon atoms, a benzyl radical or a phenyl radical.
The oxidation of the olefin CH2 ═CH--CH2 --R to the epoxide ##STR8## may be carried out by means of well-known methods, according to which the substituents, optionally present in group R, remain unaltered. A suitable method resides in oxidizing the olefin by means of m-chloroperbenzoic acid; such method providing the epoxide with yields over 90% and allowing of a very simple working.
Another suitable method resides in oxidizing the olefin with H2 O2 in the presence of a catalyst based on tungstate and phosphate ions; such a method is described, for instance, in an article by C. Venturello et al, on the J. Org. Chem., 48, 13831, 1983. This last method is more economical than the first one, giving rise to good epoxide yields (about 70%), and allowing one to recover much of the non-reacted olefin. It is clear that still other methods may be used, provided that they do not alter the substituents optionally present in group R.
The second step resides in alkylating epoxide (III) by means of an alkylating agent Na+ [CH(COOR")2 ]-, wherein R" is an ethyl, an isopropyl, or an isobutyl radical; the reaction is described, for instance, in an article by C. H. Depuy et al, in the J. Org. Chem., 1964, page 2810, the reaction scheme being: ##STR9## The epoxide is reacted with the above-mentioned alkylating agent in the presence of a malonic ester having the formula
COOR"--CH.sub.2 --COOR".
The alkylating agent should be used in a substantially equimolar ratio with respect to the epoxide, and said malonic ester should be used in a molar ratio with respect to the epoxide of from 0.5 to 2; preferably, such molar ratio should be about 1. The reaction must be carried out under reflux conditions. The alkylation of epoxide (III) turned out to be completely regioselective, providing only the attack product in the non-substituted position.
An intramolecular cyclization, yielding lactone (IV), follows the alkylation. The reaction can be carried out suitably as follows: metal sodium, in a finely subdivided form, is added to anhydrous alcohol R"OH. When the sodium is wholly dissolved, malonic ester COOR"--CH2 --COOR" is added in such an amount as to have in solution both the alkylating agent and the non-reacted malonic ester, according to the molar ratios defined hereinbefore. Alkylating agent Na+ [CH(COOR")2 ]- forms immediately. At this point, the solution is subjected to reflux conditions and the epoxide is added gradually; the whole is made to react for a time ranging from 1 to about 8 hours, depending on the nature of substituent R.
α-carboxy-γ-alkyl lactone (IV) is then saponified in an alkaline medium, thereby obtaining the corresponding acid (VI): ##STR10## This reaction may be carried out as follows: an aqueous solution of sodium carbonate is added to the reaction mixture of the preceding step and the two phases are mixed generally at from 50° C. to the reflux temperature. Acid (VI) may be separated from the reaction mixture as follows: alcohol R"OH is distilled, while leaving the acid in the aqueous phase and separating said acid successively by crystallization or by extraction by means of an organic solvent.
Acid (VI) is then decarboxylated, at 100° to 160° C., thereby obtaining a γ-alkyl lactone having the formula: ##STR11## The decarboxylation should be carried out preferably at 120° to 140° C. Some of the γ-alkyl lactones may be used for perfumes or essential oils.
γ-alkyl lactone (V) is then reacted at 20° to 100° C. (preferably 50° to 60° C.), with a protic acid, thereby obtaining, by cyclization, the desired 2-alkyl-cyclopent-2-enone having the formula (I).
The protic acids are generally selected from the group consisting of polyphosphoric acid, 96% sulphuric acid (weight/volume), and a mixture consisting of CH3 --SO3 H and P2 O5. The mixture consisting of CH3 --SO3 H and P2 O5 turned out to be particularly suitable. In such a mixture, the CH3 --SO3 H/P2 O5 weight ratio usually ranged from 10 to 20, and is preferably equal to about 10. The preparation of the mixture consisting of CH3 --SO3 H and P2 O5 is described, for instance, in an article by P. E. Eaton et al, J. Org. Chem., 38, 4071, 1973, and the cyclization reaction by means of a protic acid is described, for instance in an article by E. Uhlig et al, Adv. Org. Chem., 1, 35, 1960.
The reaction may be carried out as follows: γ-alkyl lactone (V) is added to the protic acid, at room temperature. The resultant solution is heated, as described above, for a time generally ranging between 5 and 24 hours, depending on the nature of substituent R. Then, the solution is poured into water and the resultant solution is extracted by means of an organic solvent immiscible with water. The organic phase is separated, dehydrated and concentrated in order to yield an oil. The product is then isolated by distillation under reduced pressure, by crystallization or by separation on a chromatographic column, or by the combined use of two of these techniques.
The main advantages of the process of the present invention may be summarized as follows:
the operative conditions are very simple;
the starting substrata and the reactants are cheap;
the first four steps give rise to a high yield; therefore, the global or overall yield of the process is good; and
the intermediate products and the final product may be easily separated.
The following examples will still better illustrate the invention, but without limiting the scope thereof.
EXAMPLE 1
Epoxidation by Means of Metachloro-Perbenzoic Acid
53.08 g (0.25 moles) of ethyl 10-undecenoate were introduced into a 1000 cm3 flask provided with stirrer, reflux cooler, thermometer, and dropping funnel. Then, 60.92 g (0.3 moles) of meta-chloroperbenzoic acid (85% concentration), dissolved in 650 cm3 of chloroform, were added drop-by-drop over 2 hours. Once the addition was over, the mixture was kept under reflux conditions for 2 hours, and then the solution was cooled and shaken with a 10% b.w. aqueous solution of sodium bicarbonate. The organic phase was washed with water until neutral, dehydrated over anhydrous sodium sulphate (Na2 SO4), and dried.
The thus-obtained oil was distilled under reduced pressure (108° to 110° C./2.10-1 mm Hg), thereby providing 52.5 g (0.23 moles) of ethyl 10,11-epoxydecanoate, with a yield of 92%.
EXAMPLE 2
Epoxidation with Hydrogen Peroxide
0.360 g (1.08.10-3 moles) of sodium tungstate (Na2 WO4.2H2 O) dissolved in 6 cm3 of water, 0.55 cm3 (2.24.10-3 moles) of 40% phosphoric acid (weight/volume), and 20.5 cm3 (2.11.10-3 moles) of 35% hydrogen peroxide (weight/volume) were added, following this order, to a 250 cm3 flask equipped with mechanical stirrer, reflux cooler, and thermometer. The pH was brought to 1.6 by means of an aqueous solution of 30% sulphuric acid at (weight/volume). At this point, 53.08 g (2.5.10-1 moles) of ethyl 10-undecenoate in 10 cc of 1-2-dichloroethane and 0.179 g (4.48.10-4 moles) of tricaprylmethylammonium chloride were added. The resultant two-phase mixture was heated with vigorous stirring at 70° C. for 4 hours, until the whole amount of hydrogen peroxide was consumed, after which the mixture was treated with a saturated aqueous solution of Na2 SO3 (in order to eliminate possible traces of H2 O2) and NaHCO3. The organic phase was separated, dehydrated over anhydrous sodium sulphate, concentrated and distilled under reduced pressure.
Two fractions were obtained:
at 96° to 98° C./2.10-1 mm Hg: 9.15 g (4.31.10-2 moles) of ethyl 10-undecenoate;
at 108° to 110° C./2.10-1 mm Hg: 39.4 g (1.73.10-1 moles) of ethyl 10,11-epoxyundecanoate. Yield: 69%. Selectivity: 83%.
EXAMPLE 3
Alkylation, Saponification, and Decarboxylation
100 cm3 of anhydrous ethyl alcohol and 1.01 g (4.38.10-2 moles) of finely subdivided sodium were added, in this order, to a 500 cm3 flask provided with magnetic stirrer, reflux cooler, thermometer, and dropping funnel. The mixture was kept at room temperature until the whole amount of sodium was dissolved, after which 14.03 g (8.76.10-2 moles) of diethylmalonate were added. The whole was kept under reflux conditions and 10.0 g (4.32.10-2 moles) of ethyl 10,11-epoxyundecanoate were added, drop-by-drop, over 1 hour. Once the addition was over, the mixture was kept under stirring for about 3 hours. Then, 3.00 g of sodium carbonate in 100 cm3 of water were added and the alcohol was azeotropically distilled. The residual aqueous solution was acidified by means of an aqueous solution of 10% hydrochloric acid (weight/volume) and cooled down.
The precipitation overnight of 12 g of a crystalline white solid was noted, which was separated and decarboxylated in a stream of nitrogen at 140° C., thereby providing 9.66 g (3.98.10-2 moles) of 13-carboxy-γ-tridecalactone in the form of a pure white oil, with a yield of 91%.
EXAMPLE 4
Cyclization
27 cm3 (36 g) of distilled methanesulfonic acid and 4 g of phosphoric anhydride were added, in this order, to a 100 cm3 flask provided with magnetic stirrer and thermometer, pressurized with nitrogen. The whole was kept under stirring for 1 hour at room temperature until a limpid solution was obtained. Then, 1.0 g (4.13.10-3 moles) of 13-carboxy-γ-tridecalactone were added, the temperature was raised up to 60° C., and the whole was made to react for 16 hours. Then, the solution was dripped into 100 cm3 of water and the resultant mixture was kept under stirring for about 10 minutes. After many extractions with chloroform (4×30 cm3), the organic phase was separated, washed with an aqueous solution of sodium bicarbonate until neutral, dehydrated over anhydrous sodium sulphate and dried, thereby obtaining 0.97 g of a red oil.
This oil was treated with diazomethane (CH2 N2) in order to form the methyl ester of the desired product. The resultant oil was conveyed onto a silica gel column, using hexane-ether as eluent in a 1:1 ratio by volume. Two fractions were recovered:
0.094 g (4.2.10-4 moles) of 2-(6'-carbomethoxy-hexyl)cyclohex-2-ene-1-one;
0.380 g (1.69.10-3 moles) of 2-(7'-carbomethoxy-heptyl)cyclopent-2-ene-1-one.
The yield of the latter was 41%. The molar ratio between the cyclohexenone and the cyclopentenone was 4:1.
EXAMPLES 5-8
Following the operating conditions of Examples 1-4, but for the esterification by means of diazomethane, ##STR12## was prepared, starting from CH2 ═CH--(CH2)5 --CH3.
The scheme of the reactions and the yields were as follows: ##STR13## with meta-chloroperbenzoic acid: Yield 92%; with H2 O2 : Yield 50%, selectivity 95%; alkylation, saponification, ##STR14##
EXAMPLES 9-12
Following the operating conditions of Examples 1-4, but for esterification by means of diazomethane, ##STR15## was prepared, starting from CH2 ═CH--(CH2)9 --CH3.
The scheme of the reactions and the yields were as follows: ##STR16## with metachloroperbenzoic acid: Yield 91%; with H2 O2 : Yield 50%, Selectivity 95%; alkylation, saponification, ##STR17##
EXAMPLES 13-16
Following the operative conditions of Examples 1-4: ##STR18## was prepared, starting from CH2 ═CH--(CH2)7 --COOC2 H5.
The scheme of the reactions and the yields were as follows: ##STR19## with meta-chloroperbenzoic acid: Yield 92% with H2 O2 : Yield 70% and Selectivity 85% alkylation, saponification, ##STR20##
What is claimed is:
1. A process for the preparation of a 2-alkylcyclopenten-2-one having formula:where R is Cn H2n+1 (linear or branched); (CH2)n --COOR'; (CH2)n --NR'2 ; (CH2)n --OR'; (CH2)n X or (CH2)n --CN, n ranges from 1 to 20, X is Cl, Br, I or F, and R' is an alkyl group containing up to 5 carbon atoms, a benzyl group, or a phenyl group, the last two groups having optionally one or more substituent groups on the ring, wherein a saturated gamma-alkyl-lactone: ##STR21## is reacted at 20°-100° C. with a protic acid, thereby obtaining, by rearrangement, a 2-alkyl-cyclopenten-2-one (I), characterized in that said gamma-alkyl-lactone (V) is obtained through the following steps: (a) an epoxide: ##STR22## is made to react with an alkylating agent having the formula Na+ [CH(COOR")2 ]- (R" being an ethyl, isopropyl or isobutyl radical), in the presence of the malonic ester COOR"--CH2 --COOR" and of an alcoholic solvent R"OH, the alkylating agent being in substantially equimolar ratio with respect to said epoxide and the malonic ester being in a molar ratio, with respect to said epoxide, of from 0.5 to 2, an alpha-carbalkoxy-gamma-alkyl-lactone being thus obtained having the formula: ##STR23## (b) said carbalkoxy-alkyl-lactone (IV) is saponified in an alkaline medium, thereby obtaining the corresponding acid, and such acid is decarboxylated, at 100°-160° C., thereby obtaining a gamma-alkyl-lactone having formula (V).
2. A process according to claim 1, wherein n ranges from 1 to 10.
3. A process according to claim 1 or 2, wherein R is selected from the class consisting of Cn H2n+1 and (CH2)n --COOR'.
4. A process according to claim 1 or 2, wherein, in the second step (b), the malonic ester is used in a molar ratio, with respect to the epoxide, of about 1.
5. A process according to claim 1 or 2, wherein, in the fourth step (d), the acid is decarboxylated at 120° to 140° C.
6. A process according to claim 1 or 2, wherein the fifth step (e) is carried out at 50° to 60° C.
7. A process according to claim 1 or 2, wherein, in the fifth step (e), the protic acid is selected from the class consisting of a mixture of CH3 --SO3 H and P2 O5, polyphosphoric acid, and sulphuric acid.
8. A process according to claim 7, wherein the protic acid is a mixture consisting of CH3 -SO3 H and P2 O5, in a weight ratio from 10 to 20.
9. A process according to claim 8, wherein said ratio is about 10.
| 1986-03-03 | en | 1987-06-16 |
US-12203880-A | Apparatus for resistance welding of can bodies
ABSTRACT
An apparatus for resistance welding of the longitudinal seam of can bodies by means of electrode rollers which are suspended so as to be oscillatingly drivable transversely with respect to the edges of the can bodies which are to be welded, in order to prevent premature wear of the electrode rollers due to the formation of notches, scoring or the like. The lower electrode roller which is additionally oscillatingly or reciprocatingly suspended in vertical direction provides outstanding accessibility and low dead mass of the moved parts.
CROSS-REFERENCE TO RELATED CASE
This application is a continuation-in-part application of my commonly assigned U.S. application Ser. No. 919,049, filed June 26, 1978, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a new and improved construction of apparatus for resistance welding the seams of can bodies or the like by means of electrode rolls or rollers.
During the welding of can bodies, typically formed of tin plate or sheet metal, in resistance welding machines which weld the seam of such can bodies by means of electrode rolls or rollers and normally employ centering and clamping devices in order to ensure for the complete parallelism of the edges of the can bodies in the Z-rail serving as guide means, there exists the disadvantage that the squeezing together of the overlap seam produces a relatively intensive wear of the welding roll due to the formation of notches or grooves thereat. Therefore there is frequently required a post-machining of the bronze material of the electrode rolls, in order to ensure for the requisite quality of the overlap welding seam. This post-machining work is associated with extremely high material losses.
In order to reduce this post-machining work, there has been proposed according to Swiss Pat. No. 429,982 shifting of the sheet metal guide means, i.e. the Z-rail transversely with respect to the lengthwise axis thereof. Due to these measures there are shifted the contact locations of the overlapping edges of the can body at the electrode rollers, whereby there can be prevented the formation of grooves or notches.
In welding machines where the Z-rail simultaneously assumes the function of the supporting structure for the upper electrode roller, it is not possible to use the previously described apparatus.
Furthermore, it is known from the aforementioned Swiss Pat. No. 429,982 to periodically somewhat axially displace the electrode rollers or rolls by means of handwheels mounted at the shafts or axles of the electrode rollers.
This displacement mechanism is only suitable for use with slowly operating welding machines having low production rates.
SUMMARY OF THE INVENTION
Hence, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved construction of resistance welding apparatus for can bodies and the like which is not associated with the aforementioned drawbacks and limitations of the prior art constructions.
Another and more specific object of the present invention aims at providing a new and improved construction of apparatus for the welding of the longitudinal seam of can bodies which is equipped with a suitable electrode roller-adjustment mechanism which appropriately also does not inhibit the accessibility of the electrode rollers and is of simple construction.
Yet a further significant object of the present invention aims at providing a new and improved construction of roll-resistance welding apparatus which is relatively simple in construction and design, economical to manufacture, extremely reliable in operation, not readily subject to breakdown or malfunction, and requires a minimum of maintenance and servicing.
Still a further significant object of the present invention is directed to devising a novel construction of roll-resistance welding machine having adjustment means for the electrode rollers so as to minimize the undesirable scoring or notching of the rollers.
Now in order implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the apparatus of the present development for the resistance welding of the longitudinal seam of can bodies by means of electrode rollers or rolls, will be seen to comprise guide means, typically in the form of a Z-rail, for guiding and overlapping the edges of the can bodies. According to significant aspects of the invention the lower electrode roller together with its drive shaft is oscillatingly or reciprocatingly suspended for vertical movement, and the lower electrode roller and the upper electrode roller are additionally oscillatingly movable transversely with respect to the edges of the can bodies.
Due to the combination of a pendulum-type or reciprocatable suspension of the lower electrode roller, which already affords appreciable advantages during seam welding in contrast to a rigid mounting or suspension, there is now afforded the additional advantage of axial displacement or shifting of the entire pendulum-type suspension.
By virtue of the arrangement of the center of gravity of the upper electrode roller essentially at the center of the can body, there is produced a uniform contact of the electrode roll at the can body and which electrode roll has a convex outer surface. The curvature approximately corresponds to the curvature of the rolled can body.
Furthermore, it is advantageous to fixedly arrange the upper electrode roller in a pivotable yoke, so that the energy supply can be accomplished to the yoke and/or the stationary shaft by means of an elastic element. It also has been found to be extremely advantageous to move the yoke or equivalent structure by means of an eccentric drive. By virtue of these measures there is dispensed with the use of complicated sliding contacts for the electrode roller.
Due to the reciprocating or oscillating suspension of the lower electrode roller and the energy supply thereof by means of energy in the support or bearing housing externally of the electrode roller, there is realized an exceptional accessibility at the welding zone. At the same time there is also reduced the dead mass of the electrode roller.
Just as was the case for the upper electrode roller it has been found to be advantageous to move the lower electrode roller as a unit together with its shaft and the energy transmitting support or bearing means, transversely with respect to the edges of the can body.
It has been found to be advantageous to synchronize the transverse movements of the upper and lower electrode rollers.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a schematic front view of the electrode rollers of a resistance welding machine or apparatus having a pendulum-type suspension system; and
FIG. 2 is a side view of the electrode rollers or rolls of the arrangement of FIG. 1 with the pendulum-type or oscillating suspension system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the electrode roller-resistance welding machine or apparatus has been shown in order to enable those skilled in the art to readily understand the underlying principles and concepts of the present invention. Turning attention now to the drawings, it will be seen that the upper electrode roller or roll 2 of a pair of resistance electrode rollers 2 and 13 is mounted at the free end 1a of a support or carrier arm 1 which is rigidly connected with the not particularly illustrated frame of a resistance welding machine. In order to be able to compensate for wear of the electrode roller 2 the roller shaft 3 is mounted in a roller support shown in the form of a yoke 4 which is vertically displaceable at the support arm 1 and pivotable about a pivot shaft or pivot point 28. An adjustment device in the form of an adjustment screw 5 serves as the adjustment element for vertical displacement or shifting of this electrode roller or roll 2. The electrode roll 2 together with the yoke 4 is pivotable in axial direction by means of an eccentric shaft 6 having a connecting rod 7 which is connected at location 50 with the yoke 4. The eccentric shaft 6 or equivalent element together with the connecting rod 7 form an eccentric drive for pivoting the yoke 4.
As best seen by referring to FIG. 1, a can body 8 shown in phantom lines and formed of sheet metal or tin plate by way of example, completely encloses the support or carrier arm 1 and is exactly guided at the outer surface thereof by a number of so-called hourglass or calibrating rolls 9.
Now to ensure on the one hand for an exactly defined overlapping of the edges 10 and 11 of the can body 8, and, on the other hand, to obtain an exact guiding of such can body edges 10 and 11, there is mounted at the support arm 1 a so-called Z-rail 12 defining can body guide means, as best seen by referring to FIG. 2. The Z-rail 12 also can simultaneously assume the function of the support or carrier arm 1.
The second electrode roll 13 is suspended vertically in an oscillating or reciprocating, i.e. pendulum-like fashion. The shaft 14 which is fixedly or rigidly connected with the electrode roller 13 defining the lower electrode roller rotates in the bearing or support housings 15 and 16. The housing 15, apart from containing the standard bearings for the shaft 14, also contains a suitable energy transmission device, for instance mercury contacts, by means of which the energy which is infed through the agency of the rather massive current conductor 27 is transmitted from the stationary bearing means with as little loss as possible to the rotating shaft 14. The housing 15 is pivotably connected by means of a rod 17 with a socket or base element 18. This socket 18 is elevationally displaceable by means of a threaded rod 19. On the one hand, the housing 16 is pivotably articulated or hingedly connected with a pendulum or oscillating arm 20, and, on the other hand, is hingedly connected in the pivot plane of the rod 17 by means of a fluid operated i.e. hydraulic or pneumatic piston and cylinder unit 21 with a fixed socket or base 22 which is elevationally displaceable by means of threaded rod 19. The piston and cylinder unit 21 and the rod 17 together with the shaft 14 form a so-called four-bar linkage mechansim or simply a linkage means. A crank 23 or equivalent structure engages at the housing 15. This crank 23 is driven by an eccentric shaft 24 and imparts to the shaft 14 together with the lower electrode roller 13 an axial to-and-fro movement through a few millimeters.
Now this movement is taken-up by a hinge or a pivot means 25, defining two axes located at right angles to one another, at the pendulum or oscillating arm 20. The axial deflections which are produced by the slightly arcuate-shaped movement curves are taken-up in the support or bearing housings 15 and 16 by conventional spherical roller bearings.
The drive of the electrode roller 13 and the shaft 14 can be accomplished by means of a sprocket wheel or gear 26. Of course, it is also conceivable to mount the sprocket wheel 26 externally of the support or bearing housing 15. The axial movement of the sprocket wheel 26 together with the shaft 14 is readily taken-up by the flexibility of the coacting sprocket chain. By means of the pressurized medium operated piston and cylinder unit 21 it is possible to raise the electrode roller 13 from the electrode roller 2 or to press such electrode roller 13 towards the electrode roller 2. The pneumatic piston and cylinder unit 21 serves to reciprocatingly suspend the lower electrode roller 13 for reciprocating movement in the direction of the upper electrode roller 2 during the welding operation. The lower electrode roller 13 is therefore able to reciprocate, i.e. move up and down, when encountering possible irregular can body thicknesses.
Having now had the benefit of the foregoing description of the inventive resistance welding machine, its mode of operation will be considered and is as follows:
During such time as the welding machine is in operation, that is during or after each pass, that is to say, depending upon the spacing of the can bodies from one another, then during or after each welding of a can body or blank 8 the eccentric shafts 6 and 24 rotate, preferably in synchronism, by a small amount and thus displace the electrode rollers 2 and 13 in relation to the Z-rail. With small values of the angular rotation at the eccentric shafts 6 and 24 there can be achieved the result that due to a complete uniform wear of the electrode rollers or rolls 2 and 13 there no longer occurs any disturbing scoring or notch formation which impairs the quality of the weld.
If after a longer service time there is required a machining or turning of the surface of the electrode rollers and as a consequence thereof the roller diameter becomes smaller, then the electrode rollers can be easily positionally readjusted by means of the adjustment screw 5 and the threaded rod 19. It is not necessary to positionally readjust the hourglass rollers or rolls 9.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practised within the scope of the following claims. Accordingly,
What I claim is:
1. An apparatus for the resistance welding of the longitudinal seam of can bodies by means of electrode rollers, comprising:guide means for guiding and overlapping the edges of the can bodies to be welded; a pair of electrode rollers comprising an upper electrode roller and a lower electrode roller; said lower electrode roller having a drive shaft; means for suspending said lower electrode roller together with its drive shaft for movement during the welding operation towards and away from said upper electrode roller in response to variations in the thickness of the can body to be welded; said suspending means simultaneously also serving to normally bias the lower electrode roller toward the upper electrode roller in order to maintain a substantially constant welding pressure during the welding operation; means for mounting said lower and upper electrode rollers for movement transversely with respect to the edges to be welded of the can bodies and in the axial direction of said lower and upper electrode rollers; and said mounting means for said lower and upper electrode rollers enabling transverse movement with respect to the edges to be welded of the can bodies and in the axial direction of the lower and upper electrode rollers during welding of the can bodies.
2. The apparatus as defined in claim 1, wherein:said means for mounting said upper electrode roller comprises a pivotable yoke in which there is fixedly mounted said upper electrode roller.
3. The apparatus as defined in claim 2, wherein:said mounting means comprises pivot means for pivotably mounting said yoke about a pivot point located essentially at the center of the can body.
4. The apparatus as defined in claim 3, further including:eccentric drive means for pivoting said yoke.
5. The apparatus as defined in claim 1, wherein:said mounting means for said lower electrode roller comprises linkage means for enabling movement of said lower electrode roller transversely with respect to the edges of the can body.
6. The apparatus as defined in claim 5, further including:eccentric drive means for controlling the transverse movement of said lower electrode roller and its drive shaft.
7. The apparatus as defined in claim 6, wherein:said means for mounting said upper electrode roller comprises a pivotable yoke at which there is fixedly mounted said upper electrode roller; eccentric drive means for pivoting said yoke; and said eccentric drive means for pivoting said yoke and said eccentric drive means for controlling the transverse movement of the lower electrode roller operating in synchronism with respect to one another.
8. The apparatus as defined in claim 6, wherein:said means for mounting said upper electrode roller comprises a pivotable yoke at which there is fixedly mounted said upper electrode roller; eccentric drive means for pivoting said yoke; and said eccentric drive means of each related electrode roller pivoting each such related electrode roller through a small angular value following welding of a can body.
9. The apparatus as defined in claim 1, wherein:said suspending means includes fluid-operated means for displacing the lower electrode roller towards the upper electrode roller.
10. The apparatus as defined in claim 9, wherein:said fluid-operated means comprise piston and cylinder means activatable by a pressurized fluid medium.
| 1980-02-19 | en | 1982-06-01 |
US-52374195-A | Semiconductor memory and screening test method thereof
ABSTRACT
A semiconductor memory comprises a dynamic type memory cell array arranged to form a matrix and provided with word lines commonly connected to memory cells of respective columns and bit lines commonly connected to memory cells of respective rows, a dummy cell section having a first set of dummy word lines connected to respective complimentary bit line pairs of said memory cell array by way of respective first capacitances and a second set of dummy word lines connected to respective complementary bit line pairs of said memory cell array by way of respective second capacitances, a dummy word line potential control circuit capable of optionally controlling the mode of driving selected dummy word lines when said word lines of said memory cell array are activated and sense amplifiers connected to the respective complementary bit line pairs of said memory cell array for reading data from selected memory cells of the memory cell array onto the related bit line.
This application is a continuation of application Ser. No. 08/311,006, filed Sep. 23, 1994, abandoned which is a divisional of application Ser. No. 07/978,883, filed Nov. 19, 1992 U.S. Pat. No. 5,377,152.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a semiconductor memory and a method for conducting a screening test on semiconductor memories. In particular, the present invention relates to means for controlling the operation of reading out data from memory cells as well as to a method for conducting a screening test for detecting defective memory cells of semiconductor memories in the state of wafers.
2. Description of the Related Art
Althrough the process of manufacturing semiconductor memories is normally held under rigorous control, certain variances are inevitably observed in the quality of manufactured memories. Variances, if slight, produced in each manufacturing step are added up until the end of the course of processing wafers and the accumulated variances end up as varied performances of the memory cells contained in the manufactured semiconductor memories.
FIG. 1 of the accompanying drawings shows a frequency curve of variances in the performance of the memory cells contained in the samples of semiconductor memories which were tested after the completion of wafer processing steps.
As seen from FIG. 1, the samples could be divided into three groups. Group (1) represents sound memory cells while group (2) and group (3) respectively represent totally defective memory cells where no data can be written nor read and those that operate only imperfectly although they afford data reading and writing.
Manufacturers of semiconductor memories normally conduct a screening test on wafers to sort out defective ones for the first time in the entire manufacturing process at a test step (so called die sort test step) that comes after the completion of wafer processing steps. In the die sort test step, the tip of the needle of the probe card is brought to contact with the pad of the memory chip formed on each wafer in order to provide the chip with electric power, addresses, input data, control signals and other signals necessary for the chip to operate. Then, the wafer is judged for good or bad by measuring the electric current flowing into the needle and the output data and other data coming from the chip and comparing them with respective reference values.
While the die sort test comprises a number of test items, they are generally grouped into two categories of (1) current test and (2) operation test.
The current test is a test that is carried out first. In this test, the stand-by supply current, the operating supply current and the input pin leakage current will be tested among others for each wafer. When these currents are found within respective specified allowable limits, the chip will be judged as a good one and forwarded to the next test. If it does not meet any of these requirements, however, it is rejected as a defective chip and no further test will be performed on it.
Chips that have passed the current test are then subjected to an operation test. This test is aimed to check if their memory cells afford correct data write-in/read-out operations. The operation test normally comprises a number of test items, including the supply voltage, the voltage and timing of input data, the voltage and timing of address data and the data patterns to be written on the memory cells (the combinations of "0"s and "1"s to be written on the memory cell plane), which are combined in many different ways for data write in/read-out operations to see if the data patterns that have been written in the memory cells can be correctly read out.
With a conventional die sort test, memory cells of group (2) can be efficiently removed from the product. On the other hand, however, it is rather difficult to detect and reject memory cells of group (3) because of the small amount of data to be read out of them (including the difference of the potentials of the bit line pair for voltage read out and the difference of the currents of the bit line pair for current read out).
A variety of screening tests have been proposed and tried to reject memory cells of group (3) at the die sort test step. They may include, among others, a test of operating memory cells with a supply voltage lower (or higher) than the limit values defined in the product specification, a test of operating cells with timing which is more rigorous than the timing defined in the product specification for control signals, addresses and other data and a test where data are given to the memory cell plane in the form of various data patterns (the combinations of "0"s and "1"s of adjacent memory cells).
However, any of the known screen tests is not successful in removing memory cells of group (3). Besides, memory cells of group (3) are instable in performance, meaning that they may some times be identified as defective ones while they may be not in other times if a same test is conducted on them for several times.
The memory cells of group (3) that have not been rejected in the die sort test should be detected in the final test that will be conducted after they are packaged. The semiconductor memories that are identified as defective in the final test inevitably entail wastes of packaging materials and the cost of the test which are by no means negligible.
The problem of being unable to perfectly reject memory cells of group (3) can become very significant in the case of dynamic random access memories (DRAMs) having a large memory capacity and a three dimensional structure of stuck type cells or trench type cells because it is difficult to secure a sufficient cell capacity for such memories and consequently the ratio of defective memories to the total turnout can rise if the stuck type cells and the trench type cells respectively involve imperfect contact of storage nodes and defective trench holes.
Now, the configuration and the operation of a typical conventional DRAM will be described by referring to FIGS. 2 through 5 of the accompanying drawings that partly illustrate the DRAM.
FIG. 2 is a circuit diagram illustrating the configuration of part of the memory cell array MCA of a conventional DRAM and the connection between the memory cell array and the sense amplifiers SA1 through SAn.
In the circuit diagram of the memory cell array MCA, MC, MC, . . . denote respective DRAM cells arranged to form a matrix and WL1 through WLm respectively denote word lines commonly connecting the cells MC, MC . . . of the respective rows of the matrix, while BL1, /BL1 through BLn, /BLn respectively denote bit lines commonly connecting the cells MC, MC . . . of the respective columns. DCA denotes a dummy cell section and the dummy cells of this section are connected to the respective bit lines BL1, /BL1 through BLn, /BLn on a one by one basis.
In the dummy cell section DCA of the circuit diagram, DWL and /DWL denote dummy word lines, While VPL and VDC respectively denote the dummy cell capacitor plate potential and the dummy cell writing potential.
The sense amplifiers SA1 through SAn are connected to respective complementary bit line pairs (BL1, /BL1) through (BLn, /BLn) to sense amplify the data read out on the bit lines from memory cell of a selected row.
FIG. 3 is a circuit diagram for one of the memory cells of FIG. 2.
In FIG. 3, Q denotes a MOS transistor for a transfer gate, of which the drain is connected to bit line BLi or /BLi and the gate is connected word line WLi. C denotes a capacitance for storing data having one of its terminals connected to the source of the transistor Q and the other terminal connected to the capacitor plate potential VPL.
FIG. 4 is a circuit diagram for one of the sense amplifiers SA1 through SAn.
In FIG. 4, EQ denotes a bit line precharge equalizing circuit and VPR and /φEQ respectively denote the bit line precharge voltage and a precharge equalizing signal. SN and SP respectively denote an N-channel sense amplifier for sensing the bit line potential and a P-channel sense amplifier for restoring the bit line potential, while /φn and φp respectively denote an N-channel sense amplifier activation signal and a P-channel sense amplifier activation signal.
FIG. 5 is a graph showing voltage waveforms of the DRAM of FIG. 2 typically obtained when it operates to read out data.
In FIG. 5, Vcc denotes the supply voltage and Vcc/2 denotes the bit line precharge potential, while WL, DWL and /DWL respectively denote the word line of the selected row, the selected one of the dummy word lines and the other dummy word line that is not selected. BL and /BL respectively denote one of the bit lines connected to the cells of the selected row and the other bit line which is complementary to the former bit line BL (and connected to the dummy cell DC selected by the dummy word line DWL).
Vn denotes the potential attributable to the coupling noise generated on the former bit line BL through the capacitance between the gate and drain of the cell MC of the selected row when the potential of the word line WL of the selected row rises and Vd denote the potential at tributable to the coupling noise generated on the other bit line /BL connected to the dummy cell DC which is selected as a result of the potential rise in the dummy word line DWL. V1 denote the differential in the signal potential that appears when the "1" data of the selected cell MC is read out on the bit line BL while VO denotes the variation in the signal potential that appears when the "0" data of the selected cell MC is read out on the bit line BL.
As DRAMs are made to have a larger capacity and memory cells are highly miniaturized and integrated to consequently reduce the area that can be spared for cells in each memory device, there arises a remarkable tendency of raised threshold voltage and reduced cell capacitance for "1" data due to the substrate bias effect of the cell transistor, making it difficult to write "1" data in the cell to a sufficient level.
Consequently, the variation Δv1 in the bit line signal potential at the time of reading out "1" data tends to be smaller than the variation ΔvO in the bit line signal potential at the time of reading out "0" data. In other words, the "1" data read out margin (or the sense margin of the bit line sense amplifier) and the "0" data read-out margin come to unbalanced to push up the margin soft error rate of the device.
However, a conventional DRAM cannot arbitrarily change the read-out margins of its memory cells for optimization of the margins.
SUMMARY OF THE INVENTION
In view of the above described circumstances, it is therefore an object of the present invention to provide a semiconductor memory that can solve the problem of the difficulty with which any unbalanced condition of the "1" data read-out margin and the "0" data read-out margin of a conventional semiconductor memory is corrected and which becomes increasingly conspicuous as memory cells are more and more miniaturized and integrated.
It is another object of the present invention to provide a method for conducting a screening test on semiconductor memories which is free from the problem of existing similar screening tests of being not able to detect all the defective wafers of the memory cells that operate only imperfectly.
According to the invention, the above first object is achieved by providing a semiconductor memory comprising an array of dynamic type memory cells, sense amplifiers for reading data from selected memory cells of the memory cell array, a dummy cell section having dummy word lines connected to respective complimentary bit line pairs of the memory cell array by way of capacitances and a dummy word line potential control circuit capable of arbitrarily controlling the mode of driving the dummy word lines when the selected word line of the memory cell array is activated.
With a semiconductor memory having a configuration as described above, any unbalanced condition of the "1" and "0" data read-out margins can be corrected without difficulty by controlling the dummy word line potential control circuit.
Therefore, an unbalanced condition of the "1" and "0" data read-out margins of the memory cells of a semiconductor memory according to the invention can be corrected along with that of other memories to which it belongs, whenever required as a result of a soft error test conducted on the semiconductor memory in the course of manufacturing if it is selected as a test specimen from the lot.
Additionally, the dummy word line drive mode to be used for correcting such an unbalanced condition of a semiconductor memory selected as a specimen from a lot can be semi-permanently maintained if the pad formed on the memory chip is connected to a given potential node in such a manner that the dummy word line drive mode can be selectively determined by the potential of the pad. It may be apparent that the reliability and hence the yield rate of the lot are improved by such an arrangement.
According to the invention, the above second object is achieved by providing a method of conducting a screening test on semiconductor memories comprising a step of applying a control signal to a pad formed on the memory chip zone of each semiconductor wafer as data are read out of the memory cells of the memory cell array of the memory circuit of the chip to forcibly reduce the difference of voltages or currents on the selected bits line pair of the memory cell array while data are being read out of the memory cells so that those memory cells having write-in/read-out margins too small to produce a sufficient difference of potentials or currents for the bit line pair may be detected and rejected.
With a method of conducting a screening test on semiconductor memories in the course of processing the wafers of the memories as described above, it is possible to rigorously control the "1" or "0" data read-out margin of the memory cells by applying a voltage to the pad disposed on the memory chip zone of each memories during a screening test.
With such an arrangement, it will be apparent that all memory cells having small data write-in/read-out margins (that operate defectively) can be detected and rejected.
Thus, with the method of the present invention, screening tests on semiconductor wafers can be carried out with an improved efficiency and, at the same time, the ratio of defective semiconductor memories to the entire population of each lot after packaging can be significantly lowered to reduce the wastes of packaging materials and the cost of performing the final test on them.
Additionally, by replacing defective memory cells having small read-out margins identified by a screening test with redundant bits, the overall yield rate of semiconductor memories can be significantly improved.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a graph showing a frequency curve of variances in the performance of the memory cells contained in the samples of semiconductor memories tested after the completion of wafer processing steps;
FIG. 2 is a circuit diagram of part of a conventional DRAM;
FIG. 3 is a circuit diagram for one of the memory cells of FIG. 2;
FIG. 4 is a circuit diagram for one of the sense amplifier of FIG. 2;
FIG. 5 is a graph showing voltage waveforms of the DRAM of FIG. 2 typically obtained when it operates to read out data;
FIG. 6 is a circuit diagram of part of a first embodiment of DRAM of the present invention;
FIG. 7 is a graph showing voltage waveforms of the DRAM of FIG. 6 obtained when it operates to read out data in a dummy word line drive mode;
FIG. 8 is a graph showing voltage waveforms of the DRAM of FIG. 6 obtained when it operates to read out data in another dummy word line drive mode;
FIG. 9 is a graph showing voltage waveforms of the DRAM of FIG. 6 obtained when it operates to read out data in still another dummy word line drive mode;
FIG. 10 is a graph showing voltage waveforms of the DRAM of FIG. 6 obtained when it operates to read out data in still another dummy word line drive mode;
FIG. 11 is a graph showing voltage waveforms of the DRAM of FIG. 6 obtained when it operates to read out data in still another dummy word line drive mode;
FIG. 12 is a circuit diagram of an example of DWL potential control circuit that can be used for the embodiment of FIG. 6;
FIG. 13 is a circuit diagram of another example of DWL potential control circuit that can be used for the embodiment of FIG. 6;
FIG. 14 is a circuit diagram of still another example of DWL potential control circuit that can be used for the embodiment of FIG. 6;
FIG. 15 is a circuit diagram of still another example of DWL potential control circuit that can be used for the embodiment of FIG. 6;
FIG. 16 is a flow chart illustrating the steps of manufacturing a DRAM according to the invention;
FIG. 17 is a circuit diagram of a DRAM obtained by replacing the capacitances of FIG. 6 with capacitances to be used for a dummy DRAM cell;
FIG. 18 is a graph showing voltage waveforms of the DRAM of FIG. 17 typically obtained when it operates to read out data;
FIG. 19 is a circuit diagram of part of a second embodiment of DRAM of the present invention;
FIG. 20 is a circuit diagram of an example of DWL potential control circuit that can be used for the embodiment of FIG. 19;
FIG. 21 is a circuit diagram of another example of DWL potential control circuit that can be used for the embodiment of FIG. 19;
FIG. 22 is a circuit diagram of part of a third embodiment of DRAM of the present invention;
FIG. 23 is a graph showing voltage waveforms of the DRAM of FIG. 22 typically obtained when it operates to read out data;
FIG. 24 is a circuit diagram of part of a fourth embodiment of DRAM of the present invention;
FIG. 25 is a graph showing voltage waveforms of the DRAM of FIG. 24 typically obtained when it operates to read out data;
FIG. 26 is a circuit diagram of part of a fifth embodiment of DRAM of the present invention;
FIG. 27 is a graph showing voltage waveforms of the DRAM of FIG. 26 typically obtained when it operates to read out data;
FIG. 28 is a circuit diagram of part of a DRAM to which the method of conducting a screening test on semiconductor memories of the invention is applied;
FIG. 29 is a graph showing timing waveforms of the DRAM of FIG. 28 typically obtained when it operates to read out data;
FIG. 30 is a circuit diagram of part of another DRAM to which the method of conducting a screening test on semiconductor memories of the invention is applied;
FIG. 31 is a graph showing timing waveforms of the DRAM of FIG. 30 typically obtained when it operates to read out data;
FIG. 32 is a circuit diagram of part of still another DRAM to which the method of conducting a screening test on semiconductor memories of the invention is applied; and
FIG. 33 is a graph showing timing waveforms of the DRAM of FIG. 32 typically obtained when it operates to read out data.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The the present invention will be described in greater detail by referring to the accompanying drawings that illustrate preferred embodiments of semiconductor memory and method of conducting a screening test on semiconductor memories of the invention. Note that the components that are commonly used in these embodiments are denoted by same reference symbols and will not be described repeatedly.
FIG. 6 is a circuit diagram of part of a first embodiment of DRAM of the present invention, which is formed on a semiconductor chip (DRAM chip) 1.
Reference symbol 10 in FIG. 6 denotes a memory cell array of the DRAM circuit comprising DRAM cells MC, MC, . . . arranged to form a matrix, word lines WL1 through WLm connected to the cells MC, MC . . . of the respective rows, bit line pairs BL1, /BL1 through BLn, /BLn commonly connected to the cells MC, MC, . . . of the respective columns.
Reference symbol 11 in FIG. 6 denotes a coupling capacitance type dummy cell section comprising a dummy word line DWL connected to the bit lines BL1 through BLn by way of respective capacitances C and another dummy word line /DWL connected to the bit lines /BL1 through /BLn by way of respective capacitances C. Each of these capacitances can be realized by using a MOS-type capacitance or the interlayer capacitance between a MOS-type capacitance or a plate polysilicon and the material of a gate electrode.
Reference symbols 12 and 13 in FIG. 6 respectively denote a dummy word line drive circuit connected to the dummy word lines DWL, /DWL and a dummy word line drive mode determining circuit for determining the mode in which the dummy word lines are driven. Reference numeral 14 denotes a pad formed on the chip in order to apply a voltage to the dummy word line drive mode determining circuit 13 to control the dummy word line drive mode. The dummy word line drive circuit 12, the dummy word line drive mode determining circuit 13 and the pad 14 constitute a dummy word line potential control circuit (DWL potential control circuit) 15.
Sense amplifiers SA1 through SAn are connected to the respective complementary bit line pairs (BL1, /BL1) through (BLn, /BLn) of the memory cell array 10 and designed to amplify the data read out on the bit lines from the memory cell of the selected row and have a configuration as illustrated in FIG. 4. Note that these sense amplifies may be replaced by a single sense amplifier that can be connected to a bit line pair selected out of a plurality of bit line pairs by switching operation.
FIGS. 7 through FIG. 11 are graphs showing voltage waveforms of the DRAM of FIG. 6 obtained when it operates to read out data in different dummy word line drive modes.
In FIGS. 7 through FIG. 11, reference symbols Vcc and Vcc/2 respectively denote the supply voltage and the precharge voltage of the bit lines, while reference symbols WL, DWL and /DWL respectively denote the word line of the selected column, one of the dummy word lines and the other dummy word line. Reference symbols BL and /BL respectively denote one of the bits lines that is connected to the memory cell of the selected row and the other bit line that is complementary to the former bit line (the bit line to which the capacitance C selected by the dummy word line DWL). Reference symbol vn denotes the voltage attributable to the coupling noise that can be generated on said former bit line BL through the capacitance between the gate and drain of the cell MC of the selected row when the potential of the word line WL of the selected row rises and Vd denote the potential at-tributable to the coupling noise generated on the other bit line /BL when the potential of the dummy word line DWL is raised, while reference symbols v1 and v0 respectively denote the variation in the signal potential that appears when the "1" data in the selected cell MC is read out onto the bit line BL and the variation in the signal potential that appears when the "0" data in the selected cell MC is read out onto the bit line BL.
The drive mode shown in FIG. 7 is a mode that holds both dummy word lines DWL and /DWL inactive when the selected word line WL is activated.
More specifically, after the potentials of the bit line pair (BL, /BL) are released from a precharge equalized condition, the potential of the word line WL of the selected row rises to the step up potential level. As the potential of the word line WL rises, a potential vn attritutable to the coupling noise is generated on the former bit line BL via the capacitance between the gate and the drain of the cell of the selected column. Then, data are read out of the cell of the selected column onto the former bit line BL and, when a difference appears between the bit line pair (BL, /BL), the sense amplifier begins to operate to pull down the potential of the former one of the bit line pair (BL, /BL) and pull up that of the other one of the bit line pair.
With the drive mode of FIG. 7, therefore, a relation ship v1>v0 is held true because, while the potential of the former bit line BL rises by potential vn attributable to the coupling noise generated on the word line WL when the potential of the word line WL is raised, no potential vd attributable to the coupling noise from the dummy word line DWL appear on the other bit line /BL.
The drive mode illustrated in FIG. 8 is same as that of FIG. 7 except that it holds the potential of the dummy word line /DWL to "H" level as long as the selected word line WL is activated and changes the potential of the dummy word line DWL from "H" to "L".
With the drive mode of FIG. 8, therefore, a relationship v1>>vO is held true because the potential of the former bit line BL rises by potential vn attributable to the coupling noise generated on the word line WL when the potential of the word line WL is raised and, at the same time, the potential of the latter bit line /BL is lowered by potential vd (=-vn) attributable to the coupling noise generated on the dummy word line DWL when the potential of the dummy word line DWL falls.
The drive mode illustrated in FIG. 9 is same as that of Fig. 7 except that it holds the potential of the dummy word line DWL to "L" level as long as the selected word line WL is activated and changes the potential of the dummy word line /DWL from "L" to "H".
With the drive mode of FIG. 9, therefore, a relation ship v1>>v0 is held true because the potential of the former bit line BL rises by potential vn attributable to the coupling noise generated on the word line WL when the potential of the word line WL is raised and, at the same time, the potential of the former bit line BL is raised by potential vd (=vn) attributable to the coupling noise generated on the dummy word line /DWL when the potential of the dummy word line /DWL rises.
The drive mode illustrated in FIG. 10 is same as that of FIG. 7 except that it holds the potential of the dummy word line DWL to "H" level as long as the selected word line WL is activated and changes the potential of the dummy word line/DWL from "H" to "L".
With the drive mode of FIG. 10, therefore, a relationship v1=vO is held true because the potential vn attributable to the coupling noise generated on the word line WL when the potential of the word line is raised is offset by the potential vd (=-vn) attributable to the coupling noise generated on the dummy word line /DWL when the potential of the dummy word line /DWL falls.
The drive mode illustrated in FIG. 11 is same as that of FIG. 7 except that it changes the potential of the dummy word line DWL from "H" to "L" when the selected word line WL is activated and also changes the potential of the dummy word line /DWL from "L" to "H".
With the drive mode of FIG. 11, therefore, a relationship v1>>v0 is held true because the potential of the former bit line BL rises by potential vn attributable to the coupling noise generated on the word line WL when the potential of the word line WL is raised and the potential of the former bit line BL is also raised by potential vd (=vn) attributable to the coupling noise generated on the dummy word line /DWL when the potential of the dummy word line /DWL rises, while, at the same time, the potential of the other bit line /BL falls by potential vd (=vn) attributable to the coupling noise generated on the dummy word line DWL when the potential of the dummy word line DWL falls.
FIGS. 12 through 15 show circuit diagrams of different DWL potential control circuit obtained by modifying the DWL potential control circuit 15 of FIG. 6 such that they are adapted to the respective drive modes of FIGS. 7 through 11.
In FIG. 12 illustrating a modified DWL potential control circuit, 14 denotes a pad, 20 a high resistance connected between the pad 14 and a ground potential (Vss) node, 21 an inverter to which the input node of the pad 14 is connected, 22 a double input AND-gate for receiving the output of the inverter 21 and a word line drive timing signal φWL, 23 a double input NAND gate for receiving a row address signal AOR for selecting one of the bit lines BL1 through BLn and the output of the AND-gate 22, 24 an inverter for inverting the output of the NAND gate 23 and supplying it to the dummy word line DWL, 25 a double input NAND-gate for receiving a row address signal /AOR for selecting one of the bit lines /BL1 through /BLn and the output of the AND-gate 22 and 26 an inverter for inverting the output of the NAND-gate 25 and supplying it to the dummy word line /DWL.
With a circuit as illustrated in FIG. 12, if the pad 14 is at Vss potential level, the output of the inverter 21 is at "H" level and the dummy word line DWL or /DWL is activated in response to an address signal AOR or /AOR when the applied word line drive timing signal φWL is activated (or set to "H" level in this example). This operation of the circuit is identical with that of a conventional circuit as illustrated in FIG. 5.
On the other hand, when the output of the inverter 21 is set to "L" level by externally applying a "H" level signal to the pad 14, both dummy word lines DWL, /DWL are kept inactive (or set to "L" level in this example) if the word line drive timing signal φWL is activated so that the circuit operates in a manner as illustrated in FIG. 7.
In FIG. 13 illustrating another modified DWL potential control circuit, 14 denotes a pad, 30 a high resistance, 31 an inverter, 32 a triple input NAND-gate for receiving the output of the inverter 31, a word line drive timing signal φWL and a row address signal AOR for selecting one of the bit lines BL through BLn and supplying its output to the dummy word line DWL and 33 a triple input NAND gate for receiving the output of the inverter 31, a word line drive timing signal φWL and a row address signal /AOR for selecting one of the bit lines /BL1 through /BLn and supplying its output to the dummy word line /DWL.
With a circuit as illustrated in FIG. 13, if the pad 14 is at Vss potential level, the output of the inverter 31 is at "H" level and the dummy word line DWL or /DWL is activated in response to an address signal AOR or /AOR when the applied word line drive timing signal φWL is activated so that the circuit operates in a manner as illustrated in FIG. 8.
On the other hand, when the output of the inverter 31 is set to "L" level by externally applying a "H" level signal to the pad 14, both dummy word lines DWL, /DWL are kept inactive if the word line drive timing signal φWL is activated so that the circuit operates in a manner as illustrated in FIG. 7.
In FIG. 14 illustrating a still another modified DWL potential control circuit, 14 denotes a pad, 40 a high resistance, 41a an inverter and 4lb another inverter for inverting the output of the inverter (control signal φA) to generate an inverted control signal φB.
42 denotes a double input NAND-gate for receiving a row address signal AOR for selecting one of the bit lines BL1 through BLn and a word line drive timing signal φWL, 43 a clocked inverter that receives the output of the NAND-gate 42 and whose action is controlled by the complementary controls signals φA and φB and 44 an inverter for receiving the output of the NAND gate 42.
45 denotes a clocked inverter that receives the output of the inverter 44 and whose action is controlled by the complementary control signals φA and φB, the clocked inverters 45 and 43 being wired OR to the dummy word line DWL so that their outputs are supplied to the line.
46 denotes a double input NAND-gate for receiving a row address signal /AOR for selecting one of the bit lines /BL1 through /BLn and a word line drive timing signal φWL, 47 a clocked inverter that receives the output of the NAND-gate 46 and whose action is controlled by the complementary control signals φA and φB and 48 an inverter for receiving the output of the NAND gate 46.
49 denotes a clocked inverter that receives the output of the inverter 48 and whose action is controlled by the complementary control signals φA and φB, the clocked inverters 47 and 49 being wired-OR to the dummy word line /DWL so that their outputs are supplied to the line.
With a circuit as illustrated in FIG. 14, if the pad 14 is at Vss potential level, the control signals φA and φB are respectively set to "H"/"L" levels in response to that. Thus, the dummy word line DWL or /DWL is activated in response to an address signal AOR or /AOR when the applied word line drive timing signal φWL is activated. This operation of the circuit is identical with that of a conventional circuit as illustrated in FIG. 5.
On the other hand, if the control signals φA and φB are respectively set to "L"/"H" by externally applying an "H" level signal to the pad 14, the circuit operates in a manner as illustrated in FIG. 8 when the word line drive timing signal φWL is activated.
In FIG. 15 illustrating a still another modified DWL potential control circuit, 14 denotes a pad, 50 a high resistance and 51a and 5lb inverters.
52 denotes a CMOS transfer gate that receives a row address signal AOR for selecting one of the bit lines BL1 through BLn through one of its terminals and whose action is controlled by the complementary control signals φA and φB.
53 denotes another CMOS transfer gate that receives a row address signal /AOR for selecting one of the bit lines /BL1 through /BLn through one of its terminals and whose action is controlled by the complementary control signals φA and φB. The output terminals of the CMOS transfer gates 52 and 53 are wired OR.
54 denotes a double input AND-gate for receiving the output of the wired OR CMOS transfer gates 52 and 53 and the word line drive timing signal φWL and supplying its output to the dummy word line DWL.
55 denotes a CMOS transfer gate that receives an address signal AOR through one of its terminals and whose action is controlled by the complementary control signals φA and φB, 56 another CMOS transfer gate that receives an address signal /AOR through one of its terminals and whose action is controlled by the complementary control signals φA and φB. The outputs terminals of the CMOS transfer gates 55 and 56 are wired-OR.
57 denotes a double input AND-gate for receiving the output of the wired-OR CMOS transfer gates 55 and 56 and the word line drive timing signal φWL and supplying its output to the dummy word line /DWL.
With a circuit as illustrated in FIG. 15, if the pad 14 is at Vss potential level, the control signals φA and φB are respectively set to "H"/"L" levels in response to that. Thus, the dummy word line DWL or /DWL is activated in response to an address signal AOR or /AOR when the applied word line drive timing signal φWL is activated. This operation of the circuit is identical with that of a conventional circuit as illustrated in FIG. 5.
On the other hand, if the control signals φA and φB are respectively set to "L"/"H" by externally applying an "H" level signal to the pad 14, the circuit operates in a manner as illustrated in FIG. 9 when the word line drive timing signal φWL is activated.
With the first embodiment of DRAM of FIG. 6, when the DWL potential control circuit 15 is so configured that it can selectively use one (e.g, the circuit configuration of FIG. 12) of the dummy word line drive modes of FIGS. 7 through FIG. 9 and FIG. 11 (e.g., the dummy word line drive mode of FIG. 7), any unbalanced condition that may exist between the "1"and "0" data read-out margins can be corrected even if the "1" data read-out margin of the memory cell and therefore the "1" data read-out signal v1 are small by selecting a drive mode that can enlarge the "1" data read-out margin.
Thus, in the course of manufacturing DRAMs, any unbalanced condition is detected between the "038 and "1" data readout margins of a specimen selected from a lot as a result of a soft error test, the unbalanced condition of the specimen along with that of the other DRAMs of the lot can be corrected whenever necessary.
Additionally, the potential of the pad 14 can be secured to "H" level (for instance by wire-bonding to the supply pad so that the dummy word line drive mode to be used for correcting such an unbalanced condition of the DRAM of the lot by the DWL potential control circuit 15 can be semi-permanently maintained for use.
A dummy word line drive mode can be semi-permanently maintained for use alternatively by using a fuse circuit of a non volatile program circuit or, still alternatively by changing the connection of the wired layers that are being processed.
The method of conducting a screening test of the invention can be used for DRAMs of FIG. 6.
When conducting a screening test on DRAMs in the state of wafers after the completion of wafer processing operation, the "1" data read-out margin or "0" data read-out margin of each of the memory cells can be controlled more rigorously than the "0" data read-out margin or "1" data read-out margin by applying a control signal onto the pad formed on the chip zone where the DRAM circuit is also formed.
If the DWL potential control circuit 15 is so configured that, for instance, the dummy word line drive mode of FIG. 11 can be selectively used, the "0" data read-out margin can be rigorously controlled when a screening test is conducted on the DRAMs of a lot after the completion of wafer processing operation.
Conversely, the "1" data read out margin can be rigorously controlled by selecting a configuration for the DWL potential control circuit 15 that allows rigorous control of the "1" detected read-out margin.
It will be apparent that, with such an arrangement, any memory cell will be detected as defective if it is found to have narrow "1" and/or "0" data read-out margins.
Thus, with the method of conducting a screening test according to the invention, each and every memory cell having narrow write-in and/or read-out margins (or memory cell that operates only defectively) can be detected and rejected out of a lot of memory cells under test.
Therefore, the present invention provides a very effective and efficient method of conducting a screening test that can remarkably increase the yield rate of semiconductor memories after packaging and reduce the cost of packaging materials and the test.
The overall yield rate can be further improved by replacing detected defective memory cells having a narrow read-out margin as a result of the test with redundant bits.
FIG. 16 is a flow chart illustrating the steps of manufacturing a DRAM according to the invention. Refer ring to FIG. 16, firstly in the wafer processing step, a DRAM circuit having a redundant circuit component is formed on each of a plurality of chip zones of a semiconductor wafer along with a pad to which dummy word line potential control signals are applied.
In the next step of chip selection test, a die sort test is conducted on the DRAM circuits to sort out those having acceptable electric characteristics.
In the step of screening test, the read out margins of the memory cells of each DRAM circuit are set to rigorous values to detect any memory cells having narrow data read out margins by applying a dummy word line potential control signal to the pad of the chip zone of the circuit.
In the following redundancy step, the memory cells that are detected as defective ones in the die sort test and the screening test are replaced with redundant circuits to relieve the chip carrying those defective memory cells.
In the wafer dicing step, each chip zone is individually separated from the wafer to produce a DRAM chip.
In the succeeding chip assembly step, the DRAM chips produced in the preceding step are assembled to IC devices.
In the final test step, the manufactured IC devices are subjected to a final test on a lot basis to determine if each lot is good for shipment or not.
FIG. 17 is a circuit diagram of a DRAM obtained by replacing the capacitances of FIG. 6 with capacitances to be used for a dummy DRAM.
One of the terminals of each capacitance C of FIG. 17 is connected to a bit line by way of a MOS transistor Q to be used for a transfer gate and the gate of the MOS transistor Q is connected to the related dummy word lines DWL, or /DWL, while the other terminal (capacitor plate electrode) of the capacitance C is connected to the related dummy cell capacitor plate lines DWL', or /DWL'.
FIG. 18 is a graph showing voltage waveforms of the DRAM of FIG. 17 obtained when it operates to read out data when the word lines and dummy word lines are driven in a selected drive mode.
The drive mode of FIG. 18 is same as that of FIG. 7 except that the DWL drive circuit 12 is so configured that, while the selected word line WL is being activated, the potential of the dummy word line /DWL is held to "L" level, the potential of the dummy word line DWL is changed from "L"to "H" and the potentials of the capacitor plate lines DWL', /DWL' are changed from "H" to "L".
With the above described dummy word line drive mode for the DRAM, the read-out margins of the cell MC can be optionally modified by controlling the potentials of the capacitor plate lines DWL', /DLW'.
Since the coupling noise vn when the potential of the word line rises offset by the coupling noise attributable to the capacitance at the time of the selection of a dummy cell DC, the levels of the bit lines can be defined Only by the coupling noise attributable to the capacitance of the selected cell MC. Therefore, it is possible to clear any unbalanced condition between the capacitances of the bit lines of a bit line pair.
A same signal may be supplied to the capacitor plate lines DWL', /DWL'.
FIG. 19 is a circuit diagram of part of a second embodiment of the DRAM of the present invention. The DRAM of FIG. 19 differs from that of FIG. 6 in that it is capable of selectively use three or more than three dummy word line drive modes by using a plurality of pads (two pads 141 and 142 in this example) and it additionally comprises a dummy word line level determining circuit 16 so that the dummy word lines DWL, /DWL can be driven at a selected level.
In the DRAM of FIG. 19, the DWL potential control circuit 17 is constituted by the dummy word line drive circuit 12, the dummy word line drive mode determining circuit 13, the pads 141 and 142 and the dummy word line level determining circuit 16.
FIG. 20 is a circuit diagram of an example of DWL potential control circuit that can be used for the embodiment of FIG. 19. In FIG. 20, 141 denotes a first pad, 601 a high resistance connected between the pad 141 and the Vss potential node, 61a an inverter having its input node connected to the pad 141 and 6lb an inverter for generating an inverted control signal φB by inverting the output (control signal φA) of the inverter 61a.
142 denotes a second pad, 602 a high resistance connected between the pad 142 and the Vss potential node and 61c a inverter having its input node connected to the pad 142.
62 denotes a triple input NAND-gate for receiving the output of the inverter 61c, a word line drive timing signal φWL and a row address signal AOR for selecting one of the bit lines BL1 through BLn.
63 denotes a clocked inverter that receives the output of the NAND-gate 62 and whose action is controlled by the complementary control signals φB and φA and 64 an inverter for receiving the output of the NAND-gate 62.
65 denotes a clocked inverter that receives the output of the inverter 64 and whose action is controlled by the complementary control signals φB and φA. The output terminal of the clocked inverter 69 and that of the clocked inverter 63 are wired-OR so that their out puts are supplied to the dummy word line DWL.
66 denotes a triple input NAND gate for receiving the output of the inverter 61c, a word line drive timing signal φWL and a row address signal /AOR for selecting one of the bit lines /BL1 through /BLn.
67 denotes a clocked inverter that receives the output of the NAND-gate 66 and whose action is controlled by the complementary control signals φB and φA and 68 an inverter for receiving the output of the NAND-gate 66.
69 denotes a clocked inverter than receives the output of the inverter 68 and whose action is controlled by the complementary control signals φB and φA. The output terminal of the clocked inverter 69 and that of the clocked inverter 67 are wired-OR so that their out puts are supplied to the dummy word line /DWL.
In this example, voltage Vcc is applied to the dummy word line drive circuit 12 as supply voltage for its operation from a dummy word line level determining circuit (not shown).
In the circuit of FIG. 20, the control signals φA and φB are respectively at "H" and "L" levels if the potential of the first pad 141 is at the level of Vss. The output of the inverter 61c is at "H" level if the potential of the second pad 142 is at the level of Vss. Therefore, once the word line drive timing signal φWL is activated, the dummy word line DWL or /DWL is activated in response to the address signal AOR or /AOR. This operation of the circuit is similar to that of the conventional circuit of FIG. 5.
On the other hand, the circuit shows voltage waveforms similar to those of FIG. 7 if the potential of the first pad 141 is held to Vss and the output of the inverter 61c is turned to "L" level by externally applying a "H" level signal to the second pad 142.
Conversely, the circuit exhibits voltage waveforms similar to those of FIG. 8 if the potential of the second pad 142 is held to Vss and the control signals φA and φB are respectively turned to 37 L"/"H" levels by externally applying a "H" level signal to the first pad 141.
FIG. 21 is a circuit diagram of another example of DWL potential control circuit that can be used for the embodiment of FIG. 19.
In FIG. 21, 143 denotes a third pad, 701 a high resistance connected between the pad 143 and the Vcc potential node and 71 a Current Miller load type CMOS differential amplifier circuit having one of its input nodes connected to the pad 143.
72 denotes a P-channel MOS transistor having its source/drain connected between the Vcc potential node and the other input node of the differential amplifier circuit 71 and its gate connected one of the output nodes of the differential amplifier circuit 71 and 73 a resistance connected between the other input node of the differential amplifier circuit 71 and the Vss potential node. With such an arrangement, a voltage Vout obtained by lowering the potential Vcc is applied to the other input node of the differential amplifier circuit 71.
144 denotes a fourth pad, 702 a high resistance connected between the pad 144 and the Vss potential node. 74 an inverter having its input node connected to the pad 144 and 75 a double input AND-gate for receiving the output of the inverter 74 and a word line drive timing signal φWL.
76 denotes a double input NAND gate for receiving the output of the AND-gate 75 and a row address signal AOR for selecting one of the bit lines BL1 through BLn and 77 a CMOS inverter that receives the output of the NAND-gate 76 and to which the lowered voltage Vout is applied as high potential side supply voltage, the output of the inverter 77 being supplied to the dummy word line DWL.
78 denotes a double input NAND-gate for receiving the output of the AND-gate 75 and a row address signal /AOR for selecting one of the bit lines /BL1 through BLn and 79 a CMOS inverter that receives the output of the NAND-gate 78 and to which the lowered voltage Vout is applied as high potential side supply voltage, the output of the inverter 79 being supplied to the dummy word line /DWL.
In this example, a single pad 144 is used as pad for selecting a dummy word line drive mode to be used.
In the circuit of FIG. 21, a potential Vcc appears on the other input node of the differential amplifier circuit 71 if the potential of the third pad 143 is at the level of Vss. The output of the inverter 74 is at "H" level if the potential of the fourth pad 144 is at the level of Vss. Therefore, once the word line drive timing signal φWL is activated, the dummy word line DWL or /DWL is activated in response to the address signal AOR or /AOR. This operation of the circuit is similar to that of the conventional circuit of FIG. 5.
The circuit shows voltage waveforms similar to those of FIG. 7 if the output of the inverter 74 is turned to "L" level by externally applying a "H" level signal to the fourth pad 144.
If, on the other hand, a potential lower than the voltage Vcc is externally applied to the third pad 143, a reduced potential Vout corresponding to the applied potential appears on the other input node of the differential amplifier circuit 71.
With such an arrangement, it is now possible to optimize the read-out margins of each cell and rigorously control the read-out margins of cells at a screening test.
FIG. 22 is a circuit diagram of part of a third embodiment of DRAM of the present invention (showing a column of a cell array and a dummy word line drive system).
In FIG. 22, (BL, /BL) denotes a complementary bit line pair, SA a bit line sense amplifier, MC a plurality of memory cells (only one of the cells is shown) connected to the bit line pair (BL, /BL), WL a word line, VPL the memory cell capacitor plate potential, VBL the bit line precharge potential, 80 a bit line precharge equalizing circuit and /EQL an equalizing signal. It is assumed here that the memory cell has a capacitance of CS and each of the bit line pair (BL, /BL) has a capacitance of CBL.
C1 denotes a coupling capacitance (dummy cell) connected to the bit line BL, CO a coupling capacitance (dummy cell) connected to be bit line /BL, DWL1 a dummy word line connected to the BL side capacitance C1, DWL0 a dummy word line connected to the /BL side capacitance C0, 81 a DWL drive circuit, 82 a DWL switch pad, 83 a data input pad and 84 a DWL potential control circuit which comprises a pair of NAND-gate 85, 86, three CMOS inverters 87 through 89 and a high resistance 90.
The DWL potential control circuit 84 is provided with a first selection feature of capable of either activating one of the dummy word lines DWL1, DWL0 or deactivating both of them when the word line WL is activated and a second selection feature of capable of selecting the one to be activated when either one of the dummy word lines DWL1, DWLO is activated by the first selection feature.
The DWL switch pad 82 is designed to send a switch signal for selecting either the operation of supplying the output of the DWL drive circuit 81 to the dummy word line DWL1 or that of supplying the output to the dummy word line DWLO via the DWL potential control circuit 84 and connected to the Vss potential via the high resistance 90.
The data input pad 83 is designed to supply data for selecting either the dummy word line DWL1 or the dummy word line DWLO as the destination for sending the output of the DWL drive circuit 81.
If a DRAM having a circuit as illustrated in FIG. 22 is packaged without bonding the DWL switch pad 82 and the data input pad 83, the potential of the DWL switch pad 82 is at the level of Vss under the packaged condition and the potentials of the dummy word lines DWL1 and DWLO are turned to "L" level by the output voltage of the DWL potential control circuit 84 whereas the two capacitances C1 and C0 show a same coupling capacitance relative to the bit line pair (BL, /BL).
If, on the other hand, the DWL switch pad 82 is turned to level "H" at the time of the DRAM screening test, the two capacitances C1 and C0 show different coupling capacitances relative to the bit line pair (BL, /BL) according to the input level of the data input pad 83.
If, in this case, the DWL switch pad 82 and the data input pad 83 are turned respectively to "H" and "L" levels, only the potential of the dummy word line DWL0 is raised by the output voltage of the DWL potential control circuit 84. Conversely, if both the DWL switch pad 82 and the data input pad 83 are turned to "H" level, only the potential of the other dummy word line DWL1 is raised by the output voltage of the DWL potential control circuit 84.
FIG. 23 is a graph showing waveforms of some components of the DRAM of FIG. 22 obtained when it operates to read out data.
Since equalizing signal /EQ is at "H" level in a stand by state, the bit line pair (8L, /BL) are connected to the bit line precharge potential VBL. It is assumed here that either data "0" or "1" is written in the memory cell MC in the preceding operation cycle.
When the /RAS (row address strobe) signal is turned to "L" level (activation level) to start a read-out operation, the word line WL is turned to "H" level to read data written in the memory cell MC onto the bit line BL. If data "0" has been written in the memory cell MC in the preceding operation cycle, the DWL switch pad 82 is turned to "H" level and the data input pad 83 is turned to "L" level when the data is read out. Consequently, only the potential of the dummy word line DWLO rises and the potential of the bit line /BL is slightly raised by the coupling capacitance of the capacitance CO connected to the dummy word line DWL0 so that the difference of the potentials of the bit line pair (BL, /BL) and the sense margin are narrowed.
If, conversely, data "1" has been written in the memory cell MC in the preceding operation cycle, the DWL switch pad 82 is turned to "H" level and the data input pad 83 is also turned to "H" level when the data is read out. Then, only the potential of the other dummy word line DWL1 rises and consequently the potential of the bit line BL is slightly raised by the coupling capacitance of the capacitance C1 connected to the dummy word line DWL1 so that the difference of the potentials of the bit line pair (BL, /BL) and the sense margin are narrowed.
As described above, the DWL potential control circuit 84 of the third embodiment of DRAM illustrated in FIG. 22 is provided with a first selection feature of capable of either activating one of the dummy word lines DWL1, DWLO or deactivating both of them when the word line WL is activated and a second selection feature of capable of selecting the one to be activated when either one of the dummy word lines DWL1, DWLO is activated by the first selection feature.
Thus, when DRAMs are subjected to a screening test according to the invention after the completion of a wafer processing operation, the potential or current difference between the bit line pair for the memory cell storing the data to be read out can be forcibly reduced to narrow the data read-out margins of the memory cell by simply activating either the first or the second dummy word line so that the stored data may be read out with difficulty. Consequently, memory cells inherently having narrow write-in/read-out margins can be easily identified as defective memory cells.
The operation of varying the read-out margin can be carried out within a minimum cycle as in the case of ordinary data reading/writing operation.
FIG. 24 is a circuit diagram of part of a fourth embodiment of DRAM of the present invention.
The DRAM of FIG. 24 is same as that of FIG. 22 except that its DWL potential control circuit 91 has a configuration different from that of its counterpart and its DWL switch pad 82 and data input pad 83 operate differently from their counterparts of the DRAM of FIG. 22.
The DWL potential control circuit 91 comprises an exclusive-OR circuit 92, two CMOS transfer gates 93, 94, two COMS inverters 95, 96, two N channel transistors 97, 98 and a high resistance 90.
The DWL potential control circuit 91 is provided with a first selection feature of capable of either activating the two dummy word lines DWL1, DWLO in opposite phases or keeping both of them inactive and a second selection feature of capable of inverting the phases of the two dummy word lines DWL1, DWLO when the two dummy word lines DWL1, DWLO are activated in opposite phase by means of the first section feature.
The DWL switch pad 82 is designed to either transmit the output of the DWL drive circuit 81 and that of the data input pad 83 to both of the dummy word lines DWL1, DWL0 or reduce the potential of the dummy word line DWL1 and that of the dummy word line DWLO to the level of Vss and connected to the Vss potential via the high resistance 90.
The data input pad 83 is designed to send data to the two dummy word lines DWL1, DWLO that inverts the phases of the lines.
If a DRAM having a circuit as illustrated in FIG. 24 is packaged without bonding the DWL switch pad 82 and the data input pad 83, the potential of the DWL switch pad 82 is at the level of Vss under the packaged condition and both of the two transistors 97, 98 are turned on while the potentials of the dummy word lines DWL1 and DWLO are not raised.
If, on the other hand, the DWL switch pad 82 is turned to level "H" at the time of the DRAM screening test, both of the two CMOS transfer gates 93, 94 are turned on so that the output of the DWL drive circuit 81 is transmitted to the dummy word lines DWL1, DWLO in opposite phase after passing through the exclusive OR circuit 92 as a function of the input level of the data input pad 83.
FIG. 25 is a graph showing waveforms of some components of the DRAM of FIG. 24 obtained when it operates to read out data.
Since equalizing signal /EQ is at "H" level in a stand-by state, the bit line pair (BL, /BL) are connected to the bit line precharge potential VBL. It is assumed here that, for example, data "0" is written in the memory cell MC in the preceding operation cycle and the DWL switch pad 82 is set to "H" level whereas the data input pad 83 is set to "L" level. Under this condition, the dummy word line DWLO is at "H" level and the dummy word line DWL1 is at "L" level.
When a read out operation is started, the word line WL is turned to "H" level to read out data "0" that has been written in the memory cell MC onto the bit line BL and the potential of the bit line BL falls. At this time, the dummy word line DWL1 turns from "L" level to "H" level and the dummy word line DWLO turns from "H" level to "L" level. Then, the potential of the BL line is slightly raised by the coupling capacitance of the capacitances C1, CO so that the difference of the potentials of the bit line pair (BL, /BL) and the sense margin are narrowed.
If, conversely, data "1" has been written in the memory cell MC in the preceding operation cycle, the DWL switch pad 82 is turned to "H" level and the data input pad 83 is also turned to "H" level when the data is read out. Then, the relashinship between the potential of the dummy word line DWL1 and that of the dummy word line DWLO is reversed so that, again, the difference of the potentials of the bit line pair (BL, /BL) and the sense margin are narrowed.
As described above, the DWL potential control circuit 91 of the fourth embodiment of DRAM illustrated in FIG. 24 is provided with a first selection feature of capable of either activating the two dummy word lines DWL1, DWLO in opposite phases or keeping both of them inactive and a second selection feature of capable of inverting the phases of the two dummy word lines DWL1, DWLO when the two dummy word lines DWL1, DWLO are activated in opposite phase by means of the first section feature.
Thus, when DRAMs are subjected to a screening test according to the invention after the completion of a wafer processing operation, the potential or current difference between the bit line pair for the memory cell storing the data to be read out can be forcibly reduced to narrow the data read out margins of the memory cell by simply reversing the phase relationship between the first dummy word line and the second dummy word line. Consequently, memory cells inherently having narrow write in/read-out margins can be easily identified as defective memory cells.
FIG. 26 is a circuit diagram of part of a fifth embodiment of DRAM of the present invention.
The DRAM of FIG. 26 is same as that of FIG. 22 except that it does not have dummy cells and employs a sense system where the potential for reading out data from a memory cell is compared with the bit line precharge potential.
In the circuit diagram of FIG. 26, 100 denotes a bit line precharge circuit, /BPC a bit line precharge signal, 101 a bit line precharge potential line on the bit line BL side, 102 a bit line precharge potential line on the bit line /BL side, 103 an internal VBL generating circuit, 104 a VBL switch pad, 105 an external VBL input pad, 106 an external /VBL input pad and 107 an internal VBL.external VBL switch circuit. The internal VBL.external VBL switch circuit 107 comprises four N-channel transistors 108 through 111, a CMOS inverter 112 and a high resistance 90.
The internal VBL.external VBL switch circuit 107 is designed to selectively receive the output (internal VBL) of the internal VBL generating circuit 103 or the input of the external VBL input pad 105 and that of the external /VBL input pad 106 and supply it to the bit line precharge potential lines 101, 102.
The VBL switch pad 104 is connected to the Vss potential via the high resistance 90. When the VBL switch pad 104 is at "L" level, the N-channel transistors 108, 109 are turned on and the N channel transistors 110, 111 are turned off so that the output of the internal VBL generating circuit 103 is transmitted to the bit line precharge lines 101, 102 by way of the N-channel transistors 108, 109.
When, on the other hand, the VBL switch pad 104 is set to "H" level, the N-channel transistors 108, 109 are turned off and the N channel transistors 110, 111 are turned on so that the input of the external VBL input pad 105 and that of the external /VBL input pad 106 are transmitted to the bit line precharge potential lines 101, 102 by way of the N-channel transistors 110, 111.
If a DRAM having a circuit as illustrated in FIG. 26 is packaged without bonding the VBL switch pad 104, the external VBL input pad 105 and the external /VBL input pad 106, the potential of the VBL switch pad 104 is at the level of Vss under the packaged condition and the output of the internal VBL generating circuit 103 is transmitted to the bit line precharge potential lines 101, 102.
If, on the other hand, the VBL switch pad 104 is set to "H" level at the time of the DRAM screening test, the input of the external VBL input pad 105 and that of the external /VBL input pad 106 are transmitted to the bit line precharge potential lines 101, 102.
FIG. 27 is a graph showing waveforms of some components of the DRAM of FIG. 26 obtained when it operates to read out data.
Since bit line precharge signal /BPC is at "H" level in a stand by state, the bit line precharge circuit 100 is turned on. If it is assumed here that, for example, the VBL switch pad 104 is set to "H" level, the bit line BL is connected to the external VBL input pad 105 and the bit line /BL is connected to the external /VBL input pad 106. If data "0" has teen written in the memory cell MC, the relationship [input potential VBL of the external VBL input pad 105>input potential /VBL of the external /VBL input pad 106] will be maintained.
When a read-out operation is started, the word line WL is turned to "H" level to read out data "0" that has been written in the memory cell MC onto the bit line BL and the potential of the bit line BL falls. Since, however, there is skill a difference between the externally applied voltages (VBL, /VBL) and, therefore, the difference of the potentials of the bit line pair (BL, /BL) under this condition as compared with the difference of the potentials under the condition where both bit lines (BL, /BL) are precharged to an equal potential and consequently the sense margin are narrowed.
If, conversely, data "1" has been written in the memory cell MC, again, the difference of the potentials of the bit line pair (BL, /BL) can be made narrower than the difference of the corresponding potentials under the condition where both bit lines (BL, /BL) are precharged to an equal potential and consequently the sense margin are narrowed and consequently the sense margin are narrowed by maintaining the relationship [input potential VBL of the external VBL input pad 105<input potential /VBL of the external /VBL input pad 106].
While precharge voltages (VBL./VBL) are applied to the bit line pair (BL, /BL) respectively via the external VBL input pad 105 and the external /VBL input pad 106 in order to bring the line pair to respective potentials that are different from each other in the above description, such precharge voltages (VBL, /VBL) may alternatively be generated within the memory chip without causing any problem.
The fifth embodiment of DRAM of the invention as described above by referring to FIG. 26 is provided with a precharge circuit 100 for precharging the bit line pair (BL, /BL) with respective voltages that are different from each other.
Thus, when DRAMs are subjected to a screening test according to the invention after the completion of a wafer processing operation, the potential or current difference between the bit line pair for the memory cell storing the data to be read out can be forcibly reduced to narrow the data read out margins of the memory cell by simply precharging the bit line pair (BL, /BL) with respective voltages that are different from each other. Consequently, memory cells inherently having narrow write-in/readout margins can be easily identified as defective memory cells.
Each of FIGS. 28, 30 and 32 is a circuit diagram of part of a DRAM to which the method of conducting a screening test on semiconductor memories of the invention is applied.
The DRAM of FIG. 28 is same as that of FIG. 22 except that it employs a technique of sensing the potential of reading out data from the memory cell by comparing them with the dummy cell data read-out potential and controlling the dummy cell data write in potential.
In FIG. 28, DC denotes dummy cells connected to each bit lines (BL, /BL) on a one by one basis, DWL a dummy word line. 120 a dummy write-in circuit, 121 a dummy write-in potential line, VDC a dummy write-in potential, 113 an internal VDC generating circuit, 114 a VDC switch pad, 115 an external VDC input pad and 116 an internal VDC.external VDC switch circuit. The switch circuit 116 comprises two CMOS switch 117, 118 and a CMOS inverter 119.
It is assumed here that the capacitance of the memory cell MC and that of the dummy cell DC are equal to CS and the capacitance of each of the bit line pair (BL, /BL) is equal to CBL.
The VDC switch pad 114 and internal VDC.external VDC switch circuit 116 are designed to selectively supply the output (internal VDC) of the internal VDC generating circuit 113 or the input (external VDC) of the external VDC input pad 115 to the dummy cell write in potential line 121.
When the VDC switch pad 114 is set to "L" level (Vss potential), the output of the internal VDC generating circuit 113 is transmitted to the dummy cell write in potential line 121 by way of the CMOS switch 117.
When, on the other hand, the VDC switch pad 114 is set to "H" level, the input from the external VDC input pad 115 is transmitted to the dummy cell write-in potential line 121 by way of the CMOS switch 118.
The VDC switch pad 114 is connected to the Vss potential by way of a high resistance R and if a DRAM having a circuit as described above is sealed in a normal package without bonding the VDC switch pad 114 and the external VDC input pad 115, the output of the internal VDC generating circuit 113 is transmitted to the dummy cell write-in potential line 121 under the packaged condition.
If, on the other hand, the VDC switch pad 114 is set to "H" level at the time of the screening test, the input of the external VDC input pad 115 is transmitted to the dummy cell write-in potential line 121.
FIG. 29 is a graph showing waveforms of the circuit of FIG. 28 obtained when it operates to read out data.
Since equalize signal /EQL is at "H" level in a stand-by state, the bit line pair (BL, /BL) are connected to the bit line precharge potential VBL and the dummy cell DC is connected to the dummy cell write in potential VDC. Either data "0" data or "1" data is written in the memory cell MC in the preceding cycle of operation.
When the /RAS (row address Strobe) signal is turned to "L" level (activation level to start a read-out operation, the word line WL and the dummy word line DWL are turned to "H" level to read data respectively written in the memory cell MC and the dummy cell DC onto the respective bit lines BL and /BL.
Since the electric charge is preserved under the stand-by state and during the read-out operation, if the potential of the hit line /BL is assumed to be V/BL' after the data read-out operation, the following formula holds true.
(VDC-VPL)CS+VBL·CBL=(V/BL'-VPL)CS+V/HL'·CBL
Thus, the potential V/BL' of the bit line /BL after the data read-out operation will be expressed by the equation below.
V/BL'=(VBL·CBL+CS·VDC)/(CBL+CS)
If, on the other hand, the potential of the memory cell connected to the bit line BL under a stand-by state is assumed to be VCELL, the value of VCELL will be equal to Vcc when data "1" is read-out and 0 V when data "0" is read-out. If the potential of the bit line BL after the data read out operation is assumed to be VBL' and considering that the electric charge is preserved, the following equation will be obtained.
(VCELL-VPL)CS+VBL·CBL=(VBL'-VPL)CS+VBL'·CBL
Thus, the potential VBL' of the bit line BL after the data read-out operation will be expressed by the equation below.
VBL'=(VBL·CBL+CS·VCELL)/(CBL+CS)
Since the sense margin is defined as the difference of the potentials of the bit line pair (BL, /BL), the following equation can be obtained.
V/BL'-VBL'={CS(VDC-VCELL)}/(CBL+CS) (1)
From the equation (1) above, it will be seen that the sense margin is not related to the bit line precharge voltage VBL nor the capacitor plate voltage VPL and depends solely on the dummy cell write-in voltage VDC.
In other words, the sense margin can be narrowed by bringing the external VDC input close to the supply volt age Vcc when data "1" is read out whereas it can be narrowed by bringing the external VDC input close to 0 V when data "0" is read out so that memory cells inherently having narrow write-in/read-out margins can be identified as defective memory cells.
The DRAM of FIG. 30 is same as that of FIG. 26 except that it employs a technique of applying the potential of the bit line precharge potential VBL to the bit line pair (BL, /BL).
In FIG. 30, 80 denotes a bit line precharge equalizing circuit, 131 a bit line precharge potential line, 134 a VBL switch pad, 135 an external VBL input pad and 116 an internal VBL.external VBL switch circuit. It is assumed here that the capacitance of the memory cell MC is equal to CS and the capacitance of each of the bit line pair (BL, /BL) is equal to CBL.
The VBL switch pad 134 and internal VBL.external VBL switch circuit 116 are designed to selectively supply the output (internal VBL) of the internal VBL generating circuit 103 or the input (external VBL) of the external VBL input pad 135 to the bit line precharge potential line 131.
When the VBL switch pad 134 is set to "L" level, the output of the internal VBL generating circuit 103 is transmitted to the bit line precharge potential line 131 by way of the CMOS switch 117.
When, on the other hand, the VBL switch pad 134 is set to "H" level, the input from the external VBL input pad 135 is transmitted to the bit line precharge potential line 131 by way of the CMOS switch 118.
The VBL switch pad 134 is connected to the Vss potential by way of a high resistance R and if a DRAM having a circuit as described above is sealed in a normal package without bonding the VBL switch pad 134 and the external VBL input pad 135, the output of the internal VBL generating circuit 103 is transmitted to the bit line precharge potential line 131 under the packaged condition.
If, on the other hand, the VBL switch pad 134 is set to "H" level at the time of the screening test, the input of the external VBL input pad 135 is transmitted to the bit line precharge potential line 131.
FIG. 31 is a graph showing waveforms of the circuit of FIG. 30 obtained when it operates to read out data.
Since equalize signal /EQL is at "H" level in a stand by state, the bit line pair (BL, /BL) are connected to the bit line precharge potential VBL. Either data "0" data or "1" data is written in the memory cell MC in the preceding cycle of operation.
When data read-out operation is started, the word line WL is turned to "H" level and the data written in the memory cell MC is read out onto the bit line BL. Since the other bit line /BL of the bit line pair is not connected to the dummy cell, its potential is not changed after the data read out operation. Thus, the potential V/BL' of the bit line /BL will be expressed by the formula below after the data read-out operation.
V/BL'=VBL
If, on the other hand, the potential of the memory cell connected to the bit line BL under a stand-by state is assumed to be VCELL, the value of VCELL will be equal to Vcc when data "1" is read-out and 0 V when data "0" is read-out. Then, the potential VBL' of the bit line BL after the data read-out operation will be expressed by the equation below because of the law of preservation of electric charge.
(VCELL-VPL)CS+VBL·CBL=(VBL'-VPL)CS+VBL'-CBL
Thus, the potential VBL' of the bit line BL after the data read-out operation will be expressed by the equation below.
VBL'=(VBL·CBL+CS·VCELL)/(CBL+CS)
Since the sense margin is defined as the difference of the potentials of the bit line pair (BL, /BL), the following equation can be obtained.
V/BL'-VBL'=(CS(VBL-VCELL))/(CBL+CS) (2)
From the equation (2) above, it will be seen that the sense margin depends on the bit line precharge voltage VBL.
In other words, the sense margin can be narrowed by bringing the external VBL input close to the supply voltage Vcc when data "1" is read out whereas it can be narrowed by bringing the external VBL input close to 0 V when data "0" is read out so that memory cells inherently having narrow margins can be identified as defective memory cells.
The DRAM of FIG. 32 is same as that of FIG. 30 except that it employs a technique of controlling the memory cell capacitor plate potential VPL.
In FIG. 32, 151 denotes a capacitor plate potential line 151, 153 an internal VPL generating circuit, 154 a VPL switch pad, 155 an external VPL input pad and 156 an internal VPL.external VPL switch circuit. It is assumed here that the capacitance of the memory cell MC is equal to CS and the capacitance of each of the bit line pair (BL, /BL) is equal to CBL.
The VPL switch pad 154 and internal VPL.external VPL switch circuit 156 are designed to selectively supply the output (internal VPL) of the internal VPL generating circuit 153 or the input (external VPL) of the external VPL input pad 155 to the capacitor plate potential line 151.
When the VPL switch pad 154 is set to "L" level, the output of the internal VPL generating circuit 153 is transmitted to the capacitor plate potential line 151 by way of the CMOS switch 117.
When, on the other hand, the VPL switch pad 154 is set to "H" level, the input from the external VPL input pad 155 is transmitted to the capacitor plate potential line 151 by way of the CMOS switch 118.
The VPL switch pad 154 is connected to the Vss potential by way of a high resistance R and if a DRAM having a circuit as described above is sealed in a normal package without bonding the VPL switch pad 154 and the external VPL input pad 155, the output of the internal VPL generating circuit 153 is transmitted to the capacitor plate potential line 151 under the packaged condition.
If, on the other hand, the VPL switch pad 154 is set to "H" level at the time of the screening test, the input of the external VPL input pad 155 is transmitted to the capacitor plate potential line 151.
FIG. 33 is a graph showing waveforms of the circuit of FIG. 32 obtained when it operates to read out data.
Since equalize signal /EQL is at "H" level in a stand-by state, the bit line pair (BL, /BL) are connected to the bit line precharge potential VBL. Either data "0" data or "1" data is written in the memory cell MC in the preceding cycle of operation.
when data read-out operation is started, the word line WL is turned to "H" level and the data written in the memory cell MC is read out onto the bit line BL. Since the other bit line /BL of the bit line pair is not connected to the dummy cell, its potential is not changed after the data read out operation. Thus, the potential V/BL' of the bit line /BL will be expressed by the formula below after the data read-out operation.
V/BL'=VBL
On the other hand, it is assumed here that the capacitor plate potential VPL varies between the time of data write-in and that of data read-out, the capacitor plate potential at the time of data write-in being equal to VPLW, the capacitor plate potential at the time of data read-out being equal to VPLR. If the potential of the memory cell connected to the bit line BL under a stand by state is assumed to be VCELL, the value of VCELL will be equal to Vcc when data "1" is read-out and OV when data "0" is read out. Then, the potential VBL' of the bit line BL after the data read-out operation will be expressed by the equation below because of the law of preservation of electric charge.
(VCELL-VPLW)CS+VBL·CBL=(VBL'-VPLR)CS+VBL'·CBL
Thus, the potential VBL' of the bit line BL after the data read out operation will be expressed by the equation below.
VBL'={VBL·CBL+CS(VCELL-VPLW+VPLR)}/ (CBL+CS)
Since the sense margin is defined as the difference of the potentials of the bit line pair (BL, /BL), the following equation can be obtained.
V/BL'-VBL'=CS(VBL-VCELL+VPLW-VPLR)/(CBL+CS) (3)
From the equation (3) above, it will be seen that the sense margin depends on the between the capacitor plate potential VPLW at the time of data write-in and the capacitor plate potential VPLR at the time of data read-out. In other words, the sense margin can be narrowed by making the capacitor plate potential VPLW low at the time of writing in "1" data and the capacitor plate potential VPLR high at the time of reading out "1" data or making the capacitor plate potential VPLW high at the time of writing in "0" data and the capacitor plate potential VPLR low at the time of reading out "0" data so that memory cells inherently having narrow margins can be identified as defective memory cells.
The screening test method of the invention can be applied not only to DRAMs, but also to, for example, memories of any other type.
The present invention is not limited to the embodiment described above with reference to the accompanying drawings. It can be modified within the scope of the present invention.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrated examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
What is claimed is:
1. A method of conducting a screening test on a semiconductor memory device formed on a semiconductor wafer, said semiconductor memory device comprising pairs of bit lines; a plurality of memory cells connected to each pair of bit lines; a plurality of word lines for selecting the memory cells; first and second complementary dummy word lines; first capacitors, each connected between said first dummy word line and one bit line of each of said bit line pairs; second capacitors, each connected between said second dummy word line and the other bit line of each of said bit line pairs; and a dummy word line potential control circuit including a dummy word line drive mode determining circuit for determining a dummy word line drive mode from a plurality of prearranged dummy word line drive modes and a dummy word line drive circuit for driving said dummy word lines in the dummy word line drive mode determined by said dummy word line drive mode determining circuit; said method comprising the steps of:applying a control signal to a pad formed on said semiconductor wafer so that said dummy word line potential drive circuit changes a potential of a terminal of the first and second capacitors as data are read out of said memory cells to forcibly reduce a difference in voltage on said bit line pairs while data are being read out of the memory cells; and detecting memory cells having a read-out margin too small to produce a sufficient difference in potential on said bit line pairs, such that said detected memory cells may be rejected: wherein said screening test is carried out while said semiconductor device is in a wafer state, and said potentials of said terminals of said first and second capacitors are independently varied.
2. A method of conducting a screening test on a semiconductor memory formed on a semiconductor wafer and having memory cells arranged in an array, the memory cells in respective columns of said array being selectively connected to a corresponding one of a plurality of bit lines pairs, said method comprising the steps of:applying a control signal to a pad formed on said semiconductor wafer as data are read out of said memory cells of said memory cell array to forcibly reduce a difference in voltages on the bit line pairs of said memory cell array while data are being read out of the memory cells of said memory cell array; and detecting memory cells in said memory cell array having a read-out margin too small to produce a sufficient difference in potential on said bit line pairs, such that detected memory cells may be rejected; wherein the difference of voltages on the bit line pairs appearing at the time of reading data out of said memory cells is forcibly varied by applying a control signal to the pad to change the potential of a terminal of a first and second capacitor, said first capacitor connecting one bit line of one of said bit line pairs and a first dummy word line of said memory cell array, said second capacitor connecting the other bit line of said one of said bit line pairs and a second dummy word line of said memory cell array; wherein said screening test is carded out while said semiconductor memory is in a wafer state; and wherein said potentials of said terminals of said first and second capacitors are independently varied.
3. A method of conducting a screening test on a semiconductor memory formed on a semiconductor wafer and having memory cells arranged in an array, the memory cells in respective columns of said array being selectively connected to a corresponding one of a plurality of bit lines pairs, said method comprising the steps of:applying a control signal to a pad formed on said semiconductor wafer as data are read out of said memory cells of said memory cell array to forcibly reduce a difference in voltages on the bit line pairs of said memory cell array while data are being read out of the memory cells of said memory cell array; and detecting memory cells in said memory cell array having a read-out margin too small to produce a sufficient difference in potential on said bit line pairs, such that detected memory cells may be rejected; wherein the difference in voltages on one bit line pair of said plurality of bit line pairs appearing at the time of reading data out of said memory cells is forcibly varied by applying a voltage to the pad to change the potential of writing data in a dummy cell connected between a bit line of said one bit line pair and a dummy word line of said memory cell array; wherein said screening test is carried out while said semiconductor memory is in a wafer state; and wherein said potential of writing data in said dummy cell is supplied from an external source, and said potential of writing data is varied.
4. A method of conducting a screening test on a semiconductor memory formed on a semiconductor wafer and having memory cells arranged in an array, the memory cells in respective columns of said array being selectively connected to a corresponding one of a plurality of bit lines pairs, said method comprising the steps of:applying a control signal to a pad formed on said semiconductor wafer as data are read out of said memory cells of said memory cell array to forcibly reduce a difference in voltages on the bit line pairs of said memory cell array while data are being read out of the memory cells of said memory cell array; and detecting memory cells in said memory cell array having a read-out margin too small to produce a sufficient difference in potential on said bit line pairs, such that detected memory cells may be rejected; wherein the difference in voltages on one bit line pair of said plurality of bit line pairs appearing at the time of reading data out of said memory cells is forcibly varied by applying a voltage to a pad to change the plate potential of the electric charge carrying capacitor connected between a bit line of said one bit line pair and a dummy word line of said memory cell array; wherein said screening test is carried out while said semiconductor memory is in a wafer state; and wherein the plate potential of said electric charge carrying capacitor is supplied from an external source, and the plate potential is varied.
5. A method of conducting a screening test on a semiconductor memory formed on a semiconductor wafer and having memory cells arranged in an array, the memory cells in respective columns of said array being selectively connected to a corresponding one of a plurality of bit lines pairs, said method comprising the steps of:applying a control signal to a pad formed on said semiconductor wafer as data are read out of said memory cells of said memory cell array to forcibly reduce a difference in voltages on the bit line pairs of said memory cell array while data are being read out of the memory cells of said memory cell array; and detecting memory cells in said memory cell array having a read-out margin too small to produce a sufficient difference in potential on said bit line pairs, such that detected memory cells may be rejected; wherein the difference in voltages on the bit line pairs appearing at the time of reading data out of said memory cells is forcibly varied by applying a voltage to the pad to change the precharge potential of the bit lines of said memory cell array; wherein said screening test is carried out while said semiconductor memory is in a wafer state; and wherein said bit line pre-charge potential is supplied from an external source, and said pre-charge potential of each of said bit lines of the bit line pairs is independently varied.
| 1995-09-05 | en | 1996-07-02 |
US-18087180-A | Display device of an electronic language interpreter
ABSTRACT
An electronic language interpreter is characterized by having a display device for displaying second words represented in a second language equivalent to a first word in a first language. When the data length of the second words exceeds the capacity of digits contained within the display device, the second words are displayed with shifting or running of the overall data on the display device. Separating means are associated with the display device for separating the second words in response to the presence of a particular mark such as a comma, a part of speech etc. The particular mark is allotted in a certain portion between the second words.
BACKGROUND OF THE INVENTION
The present invention relates in general to an electronic dictionary and language interpreter for providing efficient and rapid retrieval of any desired word stored therein, and more particularly, to a new and effective type of display device for displaying a plurality of words developed from such an electronic dictionary and language interpreter.
Recently, a new type of electronic device called an electronic dictionary and language interpreter has been available on the market. The electronic dictionary and language interpreter differ from any conventional types electronic devices in that the former is of a unique structure which provides for efficient and rapid retrieval of word information stored in a memory. An example of an electronic dictionary and language interpreter was disclosed in Levy U.S. Pat. No. 4,158,236, June 12, 1979, "ELECTRONIC DICTIONARY AND LANGUAGE INTERPRETER".
Although not directed to such an electronic language interpreter device but directed to a conventional electronic apparatus such as an electronic calculator, there have been presented various types of systems for displaying data derived from the electronic apparatus, the length of which is more than the capacity of a display panel in the electronic apparatus. One of them has been a system for advance splitting of the data to be displayed into two or more groups. There have been inherent problems, however, in that the connection between the groups has been indefinite and vague, leading to operator error in recognizing the overall or combined contents being displayed.
Another has been a system for sequentially shifting and running the contents in the display panel one after another or digit by digit. An example of such a system is disclosed in a copending U.S. patent application Ser. No. 058,666 filed on July 18, 1979 by S. Masuzawa et al., assigned to the present assignee, entitled "A DISPLAY DEVICE FOR ELECTRONIC CALCULATORS OR THE LIKE". The disclosure of U.S. patent application Ser. No. 058,666 is incorporated herein by reference.
There have been inherent problems, however, that images being displayed flicker change and flow, with the result that the images displayed have been difficult to read.
It is desirable that the display device make the contents being displayed easily recognized and readable and that the display device form a clear connection between portions of the contents being displayed in a manner suitable for an electronic translator device.
Even in the case where the length of the data to be displayed is not more than the capacity of the display panel, it may be preferable that the data being displayed be separated with a classification symbol if such a classification is available and useful for assisting the recognition of the data displayed.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved display device suitable for an electronic interpreter apparatus.
It is another object of the present invention to provide an improved display device of the type which runs and shifts data displayed by an electronic interpreter apparatus.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, an electronic language interpreter is characterized by having a display device for displaying second words represented in a second language equivalent to a first word written in a first language, such that in the case where the length of the second words exceeds the capacity of the display device, the second words are displayed with shifting or running the overall data on the display device.
A separating device is connected to the display device for separating the second words according to the presence of a particular mark such as a comma, a part of speech etc. The particular mark is allotted in a certain portion between the second words.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein:
FIG. 1 shows a circuit diagram of a control circuit of an electronic language interpreter according to the present invention;
FIG. 2 shows two groups of characters which are displayed in a display of the control circuit of FIG. 1;
FIG. 3 shows steps of displaying the two groups of characters as shown in FIG. 2 in the display;
FIG. 4 shows another group of characters which are also displayed in the display of the control circuit of FIG. 1;
FIG. 5 shows steps of displaying the group of characters as shown in FIG. 4 in the display;
FIG. 6 shows a group of characters which are further displayed in the display of the control circuit of FIG. 1;
FIG. 7 shows steps of displaying the group of characters as shown in FIG. 6 in the display;
FIG. 8 shows a plan view of another embodiment of an electronic language interpreter according to the present invention;
FIG. 9 represents a circuit diagram of a control circuit implemented within the electronic language interpreter shown in FIG. 8;
FIG. 10 shows a more detailed current diagram of a display circuit contained within the control circuit of FIG. 9;
FIGS. 11 and 12 show each flow charts illustrating operation of the control circuit of FIG. 9;
FIGS. 13 and 14 show each parts of the contents of a memory contained within the control circuit of FIG. 9; and
FIG. 15 indicates steps of displaying data generated by the control circuit as shown in FIG. 9 in the display.
DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is illustrated a control circuit comprising an input keyboard 1, an encoder 2, two shift registers 3 and 4, a decoder 5, a display 6, a group display detection circuit 7, a data buffer circuit 8, an AND gate 9, a store detection circuit 10, a flip flop 11, a display start key 12, three OR gates 13, 14 and 16, and a timer 15.
A desired chain of letters is applied to the input keyboard 1 and encoded by the encoder 2 so that the resultant signals are stored in the shift register 3. The signals stored in the shift register 3 are transferred to the shift register 4 as described hereinbelow. The signals stored in the shift register 4 are decoded by the decoder 5 so that the letters are indicated in the display 6.
FIG. 2 shows two groups of letter or characters which are to be indicated in the display 6. The first group of letters consists of 26 capital letters in alphabetical order while the second group of letters consists of 51 Japanese Katakana letters aligned in the Japanese alphabetical order. There is provided a means for indicating separation between the first and the second groups of letters. A preferable indicating means may be a comma ",".
It is assumed that the display 6 has display capacity of n digits (n>1) and each of the first group and the second group of letters has m digits and m is greater than n. It is usual that each of the first group and the second group of letters may be a specific word or a specific sentence written in a desired language. The input keyboard 1 contains a plurality of key switches, preferably, alphabetical key switches each actuated for entering an item of a desirable group of letters. The indicating means, say, a comma "," is also entered by the actuation of the input keyboard 1.
Alternatively, either or both of the first and the second groups of letters as shown in FIG. 2 may be obtained as output generated by an electronic device such as an electronic translator as described below. This modification can be applicable to the embodiments of FIGS. 4 and 6. In such a case, an appropriate change of the circuit of FIG. 1 should be made. Such change is within the knowledge of those skilled in the art as will be evident from the description hereinafter. In this preferred form of the present invention, it is supposed that both groups are entered by means of the input keyboard 1.
The first group and the second group of letters entered by the input keyboard 1 are applied to the shift register 3 through the encoder 2. The signals indicative of the first group and the second group of letters are developed by the shift register 3. The signals developed are transferred in the shift register 4 through the group display detection circuit 7, the data buffer circuit 8, and the AND gate 9. The shift register 4 consists of storage cells of n digits. The store detection circuit 10 is provided for detecting that appropriate signals are stored in the last storage cell of the shift register 4. In such a case, the store detection circuit 10 generates output signals to reset the flip flop 11.
The display start key 12 is provided for initiating operation of the display 6. In response to the actuation of the display start key 12, the flip flop 11 is turned set. Set output signals provided by the flip flop 11 are applied to the AND gate 9 through the OR gate 13. The set output signals are also applied to an input terminal E of the group display detection circuit 7 through the OR gate 14. Reset output signals generated by the flip flop 11 are applied to an input terminal U of the timer 15. Single-pulse signals or one-short pulse signals developed from an output terminal W of the timer 15 are introduced into the two OR gates 13 and 14, and entered to another input terminal V of the timer 15 through the OR gate 16. The OR gate 16 further receives output signals developed from an output terminal F of the group display detection circuit 7.
The set output pulse-like signals developed from the flip-flop 11 by the actuation of the display start key 12 are applied to the input terminal E of the group display detection circuit 7 through the OR gate 14. Hence, the circuit 7 is operated to enable the transference of the stored signals from the shift register 3 to the shift register 4. By the entrance of pulse signals into the input terminal E, the circuit 7 is operated to generate a single pulse from the output terminal F in the case of the following situations.
(a) The letter information of n digits is transferred from the shift register 3 to the shift register 4, wherein the n-th letter information represents the indicating means, the comma ",".
(b) Single-digit letter information is transferred from the shift register 3 to the shift register 4, wherein the single-digit letter information represents the indicating means, the comma ",".
When the next pulse signal is applied to the input terminal E following transfer of the indicating means, the comma ",", as noted above, is operated to enable the transference of the stored signals having n digits from the shift register 3 to the shift register 4 for the time when the pulse signals continue to generate.
The timer 15 is operated when the start input signals developed from the flip flop 11 are admitted to an input terminal U. The one-shot pulse signals are generated from the output terminal W of the timer 15 when a predetermined timer T has elapsed after the reset input signals to the input terminal U or otherwise after the pulse signals are applied to the input terminal V by means of the OR gate 16.
The first and the second groups of letters of FIG. 2 are indicated in the display 6 in a manner described with reference to FIG. 3. The input keyboard 1 is actuated to enter two groups of letter information, A to Z, ",", and the Japanese Katakana letters. Then the display start key 12 is actuated. The flip flop 11 is turned set so that the set output signals are applied to the AND gate 9. Thus the signals stored in the shift register 3 are transmitted to the shift register 4. When a signal is transmitted to the last storage cell of the shift register 4, the store detection circuit 10 allows the flip flop 11 to be made reset. In such a case, the n-digit letters are shown in the display 6 as shown in FIG. 3(1). This displaying condition is continuosly maintained for the predetermined time T after the reset output signals developed by the flip flop 11 are entered to the timer 15.
The output signals generated by the timer 15 are admitted to the AND gate 9 through the OR gate 13 and the group display detection circuit 7 through the OR gate 14. Then, single-digit letter information "O" stored in the shift register 3 is transported into the shift register 4 through the group display detection circuit 7, the data buffer circuit 8, and the AND gate 9. Thus the display changes to that shown in FIG. 3(2) wherein the letters being displayed in the display 6 are shifted to the left by one digit. The display of FIG. 3(2) continues for the predetermined time T before the timer 15 again supplies its output signal.
Similar procedures are repeated to change the displays to those shown in FIGS. 3(3) and 3(4) for the predetermined time T, respectively.
After the display of FIG. 3(4) continues during the predetermined time T, the timer 15 supplies its output signal to transfer the indicating means, the comma "," from the shift register 3 to the shift register 4. The group display detection circuit 7 detects this information so that it goes on providing the output pulses from the output terminal F during the period wherein the timer 15 continues to generate its output signals. This changes the display to that shown in FIG. 3(5) for the predetermined time T.
Thus, each time a new letter is added to the display, the letters indicated in the display 6 are shifted to the left digit by digit each time for predetermined time T controlled by the timer 15 until the last letter "Z" belonging to the first group of letters is displayed within the right portion of the display 6 as shown in FIGS. 3(4) and 3(5). The group display detection circuit 7 then functions to detect the occurrence of the indicating means, the comma "," on the display 6 as shown in FIG. 3(5).
After the display of FIG. 3(5) continues for the predetermined time T, in response to the indicating means, the comma "," being in the n-th position, as described above, the circuit 7 is responsive to the output pulse signals from the timer 15 for transferring the stored information relating to the following n digits from the shift register 3 to the shift register 4.
The first n-digit letters belonging to the second group of letters is then displayed as shown in FIG. 3(6) for the predetermined time T. Thereafter, the remaining letters belonging to the second group of letters are displayed as the display 6 is shifted to the left digit by digit for each predetermined time T as shown in FIG. 3(7).
FIG. 4 shows another type of letter combination. The first group has n-1 digits A through N and is followed by the indicating means, the comma ",". The second group has less than n digits covering O,P,Q,R and a period ".". When the first n signals stored in the shift register 3 are transferred to the shift register 4 in the same manner as described above, the group display detection circuit 7 detects the comma allotted in the last digit of the first n digits. Therefore, after the display indication in FIG. 5(1) continues for the predetermined time T, the signals representing the letters related to the second group of less than n digits are transported from the shift register 3 to the shift register 4. The dispaly of FIG. 5(2) is then shown.
FIG. 6 shows a further type of a group of letters containing the indicating means, the comma "," interposed among the first n letters to be displayed in the display 6. These n-digit letters are also introduced by means of the input keyboard 1 into the shift register 3. The display start key 12 is operated so that the flip-flop is turned set, in which case the signals stored in the shift register 3 are transported to the shift register 4, passing through the group display detection circuit 7. Thus the display of FIG. 7(1) is shown. The store detection circuit 10 does not detect the indicating means, the comma "," in the last position of register 4 since all the first n digits of A through N and the comma "," are introduced in the shift register 4 at once without shifting operation.
As indicated in FIGS. 7(2) and 7(3), the display will therefore shift digit by digit for each the predetermined time T. When the comma "," is contained in the last position of the display 6, the following n digits, namely, "S,T,U . . . X,Y" replace the previous n-digits letters as shown in FIG. 7(4). The display of FIG. 7(5) is then obtained by shifting the display of FIG. 7(4) by one digit the the left.
It will be apparent that the indicating means is not limited to the comma ",". An equivalent means such as a single-digit blank etc. is also available.
The above described display operation with shift control is carried out digit by digit wherein each display is maintained for the predetermined time T which is considerably longer than the time required for the shift of each digit. In another preferred form of the present invention, a running displaying system can be adapted wherein the data displayed sequentially flow and are shifted digit by digit as disclosed in the above referenced U.S. patent application Ser. No. 058,666. This running displaying system is useful for a dot matrix type display. Such running display system may be obtained by making the predetermined time T approximately equivalent to the time required for the shift of each digit.
Attention is directed to another preferred form of the present invention. Purposes of this preferred form of the present invention are as follows:
(1) In accordance with a first word entered by the operator, a translated word equivalent to the first word is obtained. If there are present two or more translated words equivalent to the first word, they are grouped by a certain reference, in particular, a part of speech to which one or more translated words belong. Being separated by the part of speech, the two or more translated words are outputted.
(2) When many translated words are equivalent to the first word, such translated words are displayed by the above described shifting display regardless of whether they continuously flow or not. In such a case, it may be preferable that an additional switch is provided for repeating the display of the many translated words to reread them.
Any kind of languages can be applied to the electronic translator of the present invention. An input "source" word is spelled in a specific language to obtain an equivalent word, or a translated word spelled in a different language corresponding thereto. According to an example of the present invention, it is assumed that the "source" language is English and the translated language is Japanese.
Referring now to FIG. 8, there is illustrated a plan view of the electronic interpreter according to another preferred form of the present invention. The electronic interpreter of FIG. 8 comprises 26 alphabetical key switches 21, a translation key (SK) 22, a display control key 23, a clear key (CL), and a display 24 of the dot matrix type. The display 24 contains an upper display portion for showing the spelling of the input "source" English word and a lower display portion for showing the spelling of the translated Japanese words together with its part of speech.
FIG. 9 shows a circuit diagram of a control circuit implemented within the language interpreter of FIG. 8. The control circuit comprises a input keyboard K equivalent to the 26 alphabetical key switches 21 of FIG. 8, a key SK equivalent to the translation key 22 of FIG. 8, a display control key 23 equivalent to the same of FIG. 8, an encoder EC, a buffer circuit WR, an equivalence detection circuit CP, a register SR, a memory MU, an address decoder AD, an address register AR, a code circuit J, a gate circuit G, a register R, a display control circuit DSC, a display DSP equivalent to 24 of FIG. 8, an address counter AC, and a digit circuit JL.
The encoder EC is provided for encoding input signals entered by the input keyboard K. The buffer circuit WR is provided for temporarily storing output signals from the encoder EC. The memory MU contains a plurality of "source" English words, translated Japanese words, and parts of speech in coded forms.
The register SR functions to temporarily contain spelling code information indicative of the "source" English words developed from the memory MU. The equivalence detection circuit CP is provided for determining the equivalency between spelling code information from the buffer circuit WR representing one of the input "source" words entered and output signals from the register SR corresponding to the spelling code information generated by the memory MU.
The address register AR and the address counter AC are used to activate the memory MU. The address decoder AD is operated to address a plurality of memory cells of the memory MU. The code circuit J functions to detect and determine the kind of codes in which the "source" English words, the translated Japanese words, and the parts of speech, all developed from the memory MU, are identified and separated. The gate circuit G is provided for switching the output signals from the memory MU. The register R stores another type of spelling code information indicative of the translated Japanese words generated by the memory MU. The display control circuit DSC is employed to control operation of the display DSP. The digit circuit J acts to determine the number of characters contained within the register R.
FIG. 13 shows parts of the contents within the memory MY in symbolical letters. In FIG. 13, W denotes a code representing one of the "source" English words, each of T1 through T5 indicates a code representing one of the translated Japanese words, and each of C1 through C5 represents a code indicative of one of parts of speech related to one of T1 through T5. E denotes an end code indicating the end of one or more translated Japanese words. WD designates the length of data including a certain "source" English word, one or more translated Japanese words, and one or more parts of speech. Needless to say, the number of the translated Japanese words and the parts of speech will vary.
FIG. 14 shows a preferable example of parts of contents within the memory MU in association with FIG. 13. The example of FIG. 14 is a particular "source" English word "fly", usual abbreviations used in any dictionary indicative of the parts of speech, and five translated Japanese words. A character "#" denotes that the part of speech is the same as the previous part of speech "vi".
Under the circumstances, a particular "source" English word, e.g., "fly" is assumed to be entered into the control circuit as shown in FIG. 9. The control circuit is responsive to the introduction of the word "fly" for enabling output of the translated words together with the parts of speech as shown in FIG. 15.
Responsive to the activation of the key SK, the input "source" English word "fly" and one or more translated words belonging to the first part of speech are displayed after a certain memory cell of the memory MU containing them as shown in FIG. 14 is detected. This situation is shown in FIG. 15(a). In the case where the translated words require a number of display digits more than the capacity of the lower display portion of the display DSP, e.g. 16 digits, the left shifting display operation is carried out as shown in FIGS. 15(a) through 15(c) either as a continuous flow or by shifting digit by digit.
The key SK is again operated to obtain the translated Japanese word together with a following part of speech "vt". In this case, the translated Japanese word does not require the number of the display digits in excess of the capacity of the display DSP, namely 16 digits. Accordingly, the running shifting display operation is not necessary to be performed. A stationary display of FIG. 15(d) is obtained.
The key SK is further operated to obtain the translated Japanese word together with the following part of speech "n" as shown in FIG. 15(e). At this point all the translated Japanese words which are stored in the memory MU in connection with the "source" English word have been once displayed.
If the key SK is again operated, the display as shown in FIG. 15(f) which is equivalent to that of FIG. 15(a) is obtained. It can be summarized that each time the key SK is activated, one or more translated Japanese words are displayed together with the part of speech pertinent to them.
FIG. 10 shows a more detailed circuit diagram of the display control circuit DSC. With reference to FIG. 10, the contents of the register R are transported to a display register RR under the control by an input circuit IC. A shift circuit SC shifts the contents of the display register RR. The shift circuit SC responds to the condition of a flip flop F3 and stops or enables the shift of the contents of the display register RR leading to the shift of the display. A first driver DR1 is a circuit for causing the contents of the display register RR to be displayed in the lower display portion of the display DSP. A second driver DR2 is a circuit for causing the contents of the buffer circuit WR to be displayed in the upper display portion of the display DSP.
Operation of the control circuit of FIG. 9 will be illustrated referring to flow charts of FIGS. 11 and 12.
In the case where the particular "source" word "fly" is introduced by means of the input keyboard K, the spelling coded information corresponding to the word "fly" is applied to the buffer circuit WR. As soon as the key SK is operated to start translation, the equivalence detection circuit CP selects a leading address after which a certain number of words starting with with "f1" are to be stored.
According to the selected leading address, the address counter AC, the address register AR, and the address decoder AD address a certain address of the memory MU. Therefore, the memory MU delivers a chain comprising the "source" English word, the one or more translated Japanese words, and the parts of speech. Responsive to the code information W as described with FIG. 13, the code circuit J permits the gate circuit G to pass the code information W to the register SR.
Therefore, the circuit CP compares the contents of the register SR and those of the buffer circuit WR. The equivalence detection circuit CP generates signals S1 in the case where the contents of the register SR and the buffer circuit WR are not equivalent. The signals S1 increment the address set in the address counter AC. The memory MU is further addressed according to the new address by means of the address counter AC, the address register AR, and the address decoder AD.
When the equivalence detection circuit CP detects that the contents of the register SR and the buffer circuit WR are equivalent, it generates its output signals S2 applied to the display control circuit DSC. As a result, the one or more translated Japanese words and the one or more parts of speech are entered to the display control circuit DSC through the gate circuit G and the register R. They are displayed in the display DSP together with the "source" English word under the control of the circuit DSC.
In the flow chart of FIG. 11, step n2 is selected from step n1 by the actuation of the key SK. Steps n2 and n3 are executed to detect conditions of flip flops F1 and F2, respectively. The flip flop F1 is used to represent whether a word stored in the memory MU equivalent to the input 37 source" English word has been found or not. The flip flop F2 is used to enable the detection of the end code E.
The two flip flops F1 and F2 are reset and step n4 is selected. Step n4 is used to clear the contents of the register SR. Step n5 is executed to detect whether the code information generated by the memory MU indicates any part of speech, with the help of the code circuit J. When it is not for any part of speech, but for the "source" English word, the spelling code information indicative of the "source" English word is transferred to the register SR in step n6. Step n7 is performed to increment the number of an address for the memory MU by one.
The part of speech code is related to the code C1 as explaiend with FIG. 13. Steps n5 →n6 →n7 →n5 are repeated as long as the part of speech code is not generated. Step n8 is executed to determine whether there is present or not a "source" English word equivalent to the input "source" English word "fly". If not, the program is advanced into step n9 in which the number of an address for the memory MU is incremented. Steps n9 and n10 are repeated until the end code E is generated and detected.
The detection of the end code E advances the program to steps n4 →n5 →n8, whereby a word following the end code E is transferred to the register SR. Step n8 is executed to determine whether there is present or not a "source" English word equivalent to the input "source" English word "fly". When the equivalence is detected, the address at which the equivalent "source" English word has been generated is stored in an address shelter in step n11. Step n12 is used to enable the transference of a part of speech code into the register R, the part of speech code being with respect to a "source" English word following the presently retrieved "source" English word. Steps n13, n14, n15 and n16 are repeated until the following part of speech code or the end code E is generated and detected. Information with respect to one or more parts of speech code and one or more translated Japanese words is stored in the register R.
The character "#" is considered not to be a code indicative of any part of speech. The introduction of the character "#" into the register R leads to the display of a comma "," in the display DSP with the help of the display control circuit DSC. When the part of speech code "Vt" is detected in step n15, the register R contains information of
"Vi # # ".
Step n17 is executed to make the flip flop F1 set, wherein the contents of the register R are transported to the display register RR within the display control circuit DSC. The digit circuit JL determines whether the contents of the register R require 16 digits or more for the display. In the case where digits required are in excess of 16 digits, the program proceeds to step n20 wherein the flip flop F3 is turned set.
After step n20, the display routine is enabled to show the displays of FIG. 15. In such a case, the actuation of the key SK advances the program from step n2 to step n12, wherein the part of speech code detected in step n15 is transported to the register R. One or more translated Japanese words are transported to the register R until next part of speech code is developed and detected, as described previously.
Thus, each time the key SK is actuated, one or more translated Japanese words are retrieved and displayed together with a part of speech. The one or more translated Japanese words are all identified by the part of speech. Where the key SK is actuated when a certain translated Japanese word is displayed, a part of speech code and its translated Japanese word just following the displayed Japanese word are transferred to the register R. When the end code E is detected in step n14, step n22 is executed to make the flip flop F1 reset and step n23 is executed to make the flip flop F2 set.
Under the circumstances, the key SK is actuated to select steps n3 →n24. In step n24, the sheltered address is recovered. That is, the three translated Japanese words with respect to the part of speech "vi" are again transferred from the memory MU to the register R. The display of FIG. 15(a) is obtained again. Each time the key SK is operated, one or more translated Japanese words are displayed and grouped with one of the parts of speech. No additional key is required to retrieve and display one or more translated words which belong to each of parts of speech.
As seen from the flow chart of FIG. 12, the display control key 23 is operated to select steps n25 and n26. The flip flop F3 is placed in set condition while the shifting display is performed. Step n30 is executed to make the flip flop F3 reset, wherein the shifting display is prevented. The display control key 23 is further operated to execute step n27 wherein the contents of the register R are transported to the display register RR. Under the condition that the contents of the register R require the number of digits in excess of 16 digits, step n29 is executed to make the flip flop F3 set. When the contents of the register do not exceed 16 digits, the flip flop F3 is placed in the reset conditions even though the display control key 23 is activated.
That is, the display control key 23 is actuated once for the purpose of stopping the shifting display. It is further actuated to enable display of all the translated Japanese words inclusive of the one or more translated Japanese words at which the shifting display is stopped.
Thus a desired number of repetitions of the display of the one or more translated Japanese words may be obtained with the help of the key SK and the display control key 23.
While only certain embodiments of the present invention have been described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as claimed.
What is claimed is:
1. An electronic dictionary and language interpreter device wherein a first word represented in a first language is entered to obtain a second word or words represented in a second language equivalent to the first word, comprising:input means for entering the first word; memory means for storing a plurality of words of the second language inclusive of the second word or words and at least a mark for separating said second words or groups of said second words; access means responsive to entry of the first word by said input means for addressing said memory means for retrieving the second word or words; display means comprising means for displaying a predetermined number of characters and responsive to said access means for displaying the second word or words; means associated with said display means for shifting the second word or words displayed thereon when the data length of the second word or words exceeds said predetermined number of characters; means for detecting that said mark is displayed in a selected portion within the display means; and means responsive to said detecting means for replacing all characters indicated on said display with a new display of up to said predetermined number of characters.
2. The device according to claim 1, further comprising timer means associated with said shifting means and said replacing means for determining the length of time during which the display means exhibits particular data prior to shifting or replacing the data.
3. The device according to claim 1, wherein said replacing means comprises display switching means responsive to detection of the mark for switching the display of one of the second words to a display of another of the second words.
4. The device according to claim 1, wherein said selected portion within the display means is the position for displaying the last character thereon.
5. An electronic dictionary and language interpreter device wherein a first word represented in a first language is entered to obtain second words represented in a second language equivalent to the first word, comprising:input means for entering the first word; memory words for storing the second words and indicators of parts of speech with respect to at least one of the second words; access means responsive to entry of the first word by said input means for addressing the memory means and for retrieving the second words and indicators of parts of speech; detection means responsive to predetermined data in said memory means which separates the second words according to their respective different parts of speech; and display means responsive to detection of the predetermined data for displaying the second words in groups according to their parts of speech.
6. The device according to claim 5, wherein said display means comprises means for displaying data comprising a predetermined number of characters and means associated with said display means for shifting the displayed data when the data length of the second words and of the indicator of parts of speech exceeds the capacity of the display means, wherein the second words and the indicator of parts of speech are displayed on the display means for a given length of time prior to shifting.
7. The device according to claim 6, further comprising stopping means connected to the display means for stopping the shifting operation of the display means.
8. The device according to claim 6, further comprising repeating means connected to the display means for repeating the shifting operation by the display means, whereby at least one of the second words can be displayed more than once.
| 1980-08-25 | en | 1983-02-08 |
US-64235975-A | Carbon electrodes for an ultraviolet arc lamp for use in a light-fastness tester
ABSTRACT
Upper and lower carbon electrodes for an ultraviolet arc lamp used for light-fastness testing. The upper electrode is in the shape of an elongated cylinder, the cross-section of which has an exterior annular portion consisting of a carbonaceous material and an interior core portion consisting of a mixture of a carbonaceous material and potassium sulfate. The upper electrode has dispersed therethrough potassium chloride as a stabilizing agent. The lower electrode is in the shape of an elongated cylindrical tube having a hollow interior and is of a carbonaceous material having a high electrical conductivity and has dispersed therethrough potassium chloride as a stabilizing agent. When the upper and lower electrodes are placed with their ends opposed to each other and an alternating current at 135V and 16A is discharged thereacross, a stable light is continuously produced.
This invention relates to an improvement in carbon electrodes for an ultraviolet arc lamp for use in a light-fastness tester.
BACKGROUND OF THE INVENTION AND PRIOR ART
A typical structure of a conventional carbon arc lamp is illustrated in FIG. 1. As shown, two carbon electrodes are secured to a lower electrode holder, and one carbon electrode is secured to an upper electrode holder movable in a vertical direction inside the air-tight lamp housing consisting of a light-transmitting glass glove 1 and a substrate board 2. The upper electrode can be ignited and controlled by an iron core inside an electromagnetic coil 3 and a carbon suspension member 4 associated with said iron core.
Generally, the upper carbon electrode has a length of about 305mm and a diameter of about 13mm, and is either a core type or a coreless type. To make the lower carbon electrodes, a 305mm long carbon electrode, such as is used for the upper carbon electrode, has two lengths of 100mm cut therefrom, and the two thus formed electrodes are used as the lower carbon electrodes. The two electrodes are discharged alternately for a continuous combustion period of from about 20 to 22 hours.
As shown in the sectional views of FIGS. 2 and 3, the conventional carbon electrode has been either a coreless type (FIG. 2) or a core type (FIG. 3). The coreless type electrode is made predominantly of an amorphous carbonaceous material, such as carbon black or the like, whereas the core type electrode uses the abovementioned amorphous carbonaceous material for the exterior cylindrical section and a mixture of a stabilizing agent, such as potassium phosphate and the amorphous carbonaceous material for the interior core section.
A piece of material to be tested is mounted on a frame which rotates slowly around the arc lamp, and the piece of material is continuously irradiated by ultraviolet rays from the lamp over a period of several hundred hours to determine the light-fastness thereof.
Since the conventional carbon electrode has a life of only about 20-22 hours for continuous lighting, it would be desirable to extend this life to at least twice this time.
It is evident that if the length or the diameter of the carbon electrodes was increased, the combustion time could naturally be extended. An increase in the length of the carbon electrodes, however, is not economical because it also increases the overall dimension of the lamp apparatus. Although an increase in the diameter of the carbon electrodes does not cause any substantial change in the overall dimensions of the apparatus, stabilized light cannot be obtained if the diameter of the conventional carbon electrodes is increased unless the material is also changed. As shown in FIG. 4, for example, carbon electrodes having such an enlarged diameter do not always discharge from the tip thereof, but instead may discharge from the peripheral portion spaced from the tip. Likewise, the wearing of the carbon electrodes is not always uniform.
In the light of the teachings of my copending U.S. patent application Ser. No. 598,076 filed July 22, 1975, one of ordinary skill in the art would perhaps attempt to replace the carbon electrodes of the conventional lamp with upper and lower carbon electrodes which incorporate a mixture of a carbonaceous material and an illuminating agent as the core. When such carbon electrodes are used in practice in an ultraviolet arc lamp, however, discharge is effected from points spaced from the tip of the upper electrode as shown in FIG. 5. Thus, the discharge of this type of arc lamp has been found to be very unstable in practice.
Presumably this unstability results from the fact that because the carbon in said electrodes in said copending application is for use in an arc lamp for producing light similar to sunshine, and the carbon is burned in an atmosphere wherein oxygen is present, the carbon in the electrodes of the present invention is for use in an arc lamp for producing ultraviolet light, and hence, the combustion takes place in the absence or substantially complete absence of oxygen.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
The primary object of the present invention is to stabilize the discharge of carbon electrodes in a lightfastness tester and increase the combustion time of the electrodes to at least twice the life of conventional electrodes.
Another object of the present invention is to improve the life of the electrodes by adding a particular type of stabilizer and disposing a hollow core section at the central portion of the lower electrode such that evaporation of the stabilizer causes convection resulting in stabilization of the discharge of the electrode.
These objects achieved in accordance with the present invention by impregnating and dispersing a stabilizing agent in both the upper and lower carbon electrodes. The upper carbon electrode having the stabilizer impregnated and dispersed therein has a core section while the lower carbon electrode also having the stabilizer impregnated and dispersed therein has a hollow hole along the longitudinal axis thereof. The upper electrode having the core section and the lower electrode having the hole cause the stabilizer to exhibit its action most effectively and afford a stabilized discharge, and hence stabilized radiation for a longer period of time than with conventional electrodes.
BRIEF DESCRIPTION OF THE FIGURES
The invention will now be described in greater detail in connection with the accompanying drawings, in which:
FIG. 1 is a schematic elevation view of a conventional ultraviolet arc lamp for use in a light-fastness tester;
FIGS. 2 and 3 are sectional views of conventional prior art carbon electrodes;
FIG. 4 is a schematic view showing the discharge between conventional prior art carbon electrodes;
FIG. 5 is a schematic view showing the discharge between prior art carbon electrodes for producing radiation simulating sunshine;
FIG. 6a is a longitudinal sectional view of an upper carbon electrode in accordance with the present invention;
FIG. 6b is a transverse sectional view thereof;
FIG. 7a is a longitudinal sectional view of a lower carbon electrode in accordance with the present invention;
FIG. 7b is a transverse sectional view thereof;
FIGS. 8 and 9 are schematic views showing the discharge between the carbon electrodes of the present invention;
FIG. 10 is a schematic perspective view showing the end of the lower electrode of the present invention;
FIG. 11 is a graph showing discharge voltages of the carbon electrodes of the present invention; and
FIG. 12 is a graph showing discharge voltages of conventional carbon electrodes.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 6a, 6b, 7a and 7b illustrate the structure of the carbon electrodes in accordance with the present invention.
FIGS. 6a and 6b illustrate the upper electrode. The exterior carbonaceous cylindrical portion 5 is made of a carbonaceous material such as, for example, carbon black, and has a predetermined size, e.g. an outer diameter of 23mm, while the interior core portion 6 has a gear-like cross-sectional shape. After the exterior portion 5 of the upper electrode is shaped by baking so as to have a hollow core, a core material consisting of a mixture of the abovementioned carbonaceous material, e.g. carbon black, and potassium sulfate is poured into the hollow core, and the electrode is again baked to form the core portion 6 within the exterior portion 5. Subsequently, a potassium chloride aqueous solution (having a concentration of 10 g/l is impregnated into the electrode to act as a stabilizing agent, and the electrode is then baked once again in order to disperse the stabilizer throughout the electrode. As a result of this process, a typical upper electrode according to the invention has about 61 gm. carbonaceous material and from 0.18 to 0.10 gm of potassium chloride, or about 0.32 to 0.06% by weight potassium chloride.
FIGS. 7a and 7b show the lower electrode which is formed by shaping a carbonaceous material having a good electric conductivity, such as graphite, into a cylindrical member 8 and then baking the same. Thereafter, the electrode is immersed in a potassium chloride aqueous solution (having a concentration of 15 g/l ) as a stabilizing agent until the stabilizer disperses sufficiently inside the electrode. As a result of this process, a typical lower electrode according to the invention has about 42 gm carbonaceous material and from 0.13 to 0.07 gm. of potassium chloride, or about 0.32 to 0.06% by weight potassium chloride. The electrode has an outer diameter of about 18.5mm, and a hollow core 7 having a diameter of about 1-2mm. The tips 5' and 8' of the electrodes are tapered in order to facilitate the discharge at the initial stage, but the tip need not always be tapered.
One each of the abovementioned lower and upper electrodes are mounted in the lamp device shown in FIG. 1. Since the diameter of the carbon electrodes and the number of electrodes used in the present invention are different from the conventional device, the holder section is modified in the present invention to accept the abovementioned upper and lower electrodes.
FIGS. 8 and 9 illustrate the discharge produced with the electrodes of the present device. In FIG. 8, the discharge is shown as being produced between the core section of the upper electrode and the hollow core of the lower electrode to thereby produce a stabilized illumination which varies hardly at all. As the electrodes are consumed gradually, the upper electrode still keeps discharging from the core section, while the discharge from the lower electrode shifts from the center to the periphery, as shown in FIG. 9, smoothly and producing a stabilized discharge in the same manner as when the discharge is at the center. Thereafter, the discharge from the lower electrode moves back to the central position from the periphery. This procedure is repeated continuously.
As shown in FIG. 10, the lower electrode has exterior peripheral portions 9 and 12 and interior peripheral portions 10 and 11 aligned in the transverse direction thereof (indicated by the arrow). In comparison with the conventional solid lower electrode having only two peripheral portions, the lower electrode in accordance with the present invention has four peripheral portions, as described above. For this reason, wearing of the electrode at only one peripheral portion or abnormal wearing can be eliminated effectively by the present electrode.
The operation of the electrodes in accordance with the present invention was compared with conventional electrodes by effecting discharge at a predetermined current of 16A, and the changes in the discharge voltage were measured. The results of the experiments are shown in FIGS. 11 and 12. FIG. 11 shows the voltage change observed with the present electrodes. As can be seen, the electrodes of this invention produce a fluctuation in voltage of only about 1% at a reference voltage of 135V. In contrast therewith, the conventional electrodes produce a fluctuation of several percent.
The reason the discharge in the present device is extremely stable is not fully understood. However, the inventor believes that the stability can perhaps be explained by the fact that the stabilizer impregnated into and dispersed in the electrode evaporates and changes to a gas at a high temperature, and creates an atmosphere of the gas thus formed, in which the discharge is effected. Likewise, the flow of the stabilizer gas passing through the hollow core of the lower electrode acts favorably for the discharge.
Thus, with electrodes in accordance with the present invention, a well stabilized discharge illumination can be produced continuously over a period of 50 hours by the use of carbon electrodes which in terms of size have only an enlarged outer diameter compared with the outer diameter of conventional carbon electrodes in general.
What is claimed is:
1. Carbon electrodes for an ultraviolet arc lamp used for light-fastness testing, said electrodes comprising:an upper electrode in the shape of an elongated cylinder about 23 mm. in diameter, the cross-section of which has an exterior annular portion consisting of a carbonaceous material and an interior core portion consisting of a mixture of a carbonaceous material and potassium sulfate, the upper electrode having dispersed therethrough potassium chloride as a stabilizing agent; and a lower electrode in the shape of an elongated cylindrical tube about 18.5 mm. in diameter and having a hollow interior about 1-2 mm. in diameter and being of a carbonaceous material having a high electrical conductivity and having dispersed therethrough potassium chloride as a stabilizing agent; whereby when the upper and lower electrodes are placed with their ends opposed to each other and an alternating current at 135V and 16A is discharged thereacross, the discharge can be maintained stably for more than 50 hours and a stable light is continuously produced.
2. Carbon electrodes as claimed in claim 1 in which potassium chloride is present in an amount of from 0.32 to 0.06% by weight of the carbonaceous material.
| 1975-12-19 | en | 1977-02-01 |
US-91760278-A | Bis (difluoromaleimide) capped propolymers and polymers
ABSTRACT
End-capping an aromatic diamine or a precursor formed by reaction of an aromatic diamine with an aromatic dianhydride with difluoromaleic anhydride yields prepolymers which thermally cure at temperatures from about 150° to about 200° C. to form polymers which display long-term thermal stability at temperatures up to 300° C. and more.
BACKGROUND OF THE INVENTION
A need has existed for materials which can be cured at temperatures below about 200° C. to yield thermoxidatively stable, structural resins which display long-term stability at temperatures of 300° C. or more. This need exists because of the limitations of processing equipment for fabrication of large forms at elevated temperatures and pressures. The need for greater reduced costs and energy consumption have also been strong motivating factors in the search for high performance resins with increased processability.
The present invention is directed to a family of prepolymers and polymers formed therefrom which satisfy these needs.
SUMMARY OF THE INVENTION
According to the invention there is provided prepolymers of the formula: ##STR1## wherein n has a value of 0 to about 3, each R is independently an aromatic radical, and R' is a tetra functional radical and selected from the group consisting of: ##STR2## wherein R" is a difunctional radical selected from the group consisting of --SO2 --, --O--, --S--, --CO--, ##STR3##
The prepolymers may be formed by a condensation reaction of difluoromaleic anhydride with an aromatic diamine precursor which is preferably in turn the condensation product of about two moles of an aromatic diamine with about one mole of an aromatic dianhydride.
The difluoromaleic anhydride end-capped prepolymers thermally cure at temperatures from about 150° to about 200° C. to yield cured products which display long-term stability on exposure to temperatures of 300° C. or more.
According to our invention, there is also provided the polymers made by thermally curing the above described prepolymer.
DETAILED DESCRIPTION
Thermally curable bis(difluoromaleimide)-capped prepolymers of this invention are of the formula: ##STR4## wherein n has a value from 0 to about 3, each R is independently an aromatic radical of an aromatic diamine, and R' a tetra functional radical of an aromatic dianhydride selected from the group consisting of: ##STR5## wherein R" is a difunctional radical selected from the group consisting of --SO2 --, --O--, --S--, --CO--, ##STR6##
The aromatic diamines used are thermally stable aromatic diamines. Among the utile aromatic diamines there may be mentioned:
bis-2,2-[4-(4-aminophenoxy)phenyl]hexafluoropropane,
meta-phenylene diamine,
4,4'-diamino-diphenyl propane,
4,4'-diamino-diphenyl methane,
4,4'-diamino-diphenyl sulfide,
4,4'-diamino-diphenyl sulfone,
3,3'-diamino-diphenyl sulfone,
4,4'-diamino-diphenyl ether,
1,5-diamino-naphthalene,
2,4-bis-(beta-amino-t-butyl)toluene,
bis-(para-beta-amino-t-butyl-phenyl)ether,
bis-(para-beta-methyl-delta-amino-pentyl)benzene,
bis-para-(1,1-dimethyl-5-amino-pentyl)benzene,
and the like.
Bis-2,2-[4-(4-aminophenoxy)phenyl]hexafluoropropane and 4,4'-diamino-diphenyl methane are presently preferred.
The useful aromatic dianhydrides are selected for thermal stability and to add processability, namely, to impart meltflow characteristics to the prepolymer prior to cure through the difluoromaleic group. Among the utile dianhydrides there may be mentioned:
pyromellitic dianhydride,
benzophenone tetracarboxylic dianhydride,
2,3,6,7-naphthalene tetracarboxylic dianhydride,
3,3',4,4'-diphenyl tetracarboxylic dianhydride,
1,2,5,6-naphthalene tetracarboxylic dianhydride,
2,2',3,3'-diphenyl tetracarboxylic dianhydride,
2,2-bis(3,4-dicarboxyphenyl)propane dianhydride,
3,4,9,10-perylene tetracarboxylic dianhydride,
bis-2,2-[4-(3,4-dicarboxyphenoxy)phenyl]-hexafluoropropane dianydride,
bis(3,4-dicarboxyphenyl)ether dianhydride,
naphthalene-1,2,4,5-tetracarboxylic dianhydride,
naphthalene-1,4,5,8-tetracarboxylic dianhydride,
2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,
2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,
2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,
phenanthrene-1,8,9,10-tetracarboxylic dianhydride,
pyrazine-2,3,5,6-tetracarboxylic dianhydride,
2,2-bis(2,3-dicarboxyphenyl)propane dianhydride,
1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride,
1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride,
bis(2,3-dicarboxyphenyl)methane dianhydride,
bis(3,4-dicarboxyphenyl)methane dianhydride,
bis(3,4-dicarboxyphenyl)sulfone dianhydride,
benzene-1,2,3,4-tetracarboxylic dianhydride,
thiophene-2,3,4,5-tetracarboxylic dianhydride,
bis(3,4-dicarboxyphenoxyphenyl)sulfone dianhydride and the like.
Bis-2,2-[4-(3,4-dicarboxylphenoxy)phenyl]-hexafluoropropane dianhydride is presently preferred.
The prepolymers are conveniently prepared by condensation reactions. If a dianhydride is to be included in the backbone, the first step involves condensation of the diamine with the dianhydride. The molar ratio of diamine to dianhydride must be sufficient to provide a terminal amino group at the ends of the reaction product for difluoromaleic anhydride end-capping purposes. Generally, the molar ratios of diamine to dianhydride will range from 2 to 1 to 4 to 3. The initial addition reaction may be carried out at temperatures from 120° to 150° C. in a suitable solvent such as xylene, toluene, and other high boiling aromatic solvents. The reaction product is normally recovered for subsequent addition of difluoromaleic anhydride.
Whether the reaction is with an aromatic diamine alone or the reaction product of an aromatic diamine and an aromatic diahydride, end-capping also occurs by a condensation reaction but at lower temperatures. Typically, difluoromaleic anhydride is added at temperatures from about 50° to about 100° C. in suitable solvent, preferably in the presence of an otherwise nonreactive agent which will take up the split-off water. Such agents include acetic anhydride, phosphorous pentoxide, and the like. Their use tends to promote the condensation reaction. The reaction is typically carried out in a mutual solvent such as toluene, dimethylformamide and the like.
A schematic route for prepolymer formation based on 4,4'diamino-diphenyl methane (MDA) and bis-2,2-[4-(3,4dicarboxyphenoxy)phenyl]-hexafluropropane dianhydride is depicted below. ##STR7##
One or more prepolymers formed in accordance with the instant invention may be thermally cured at temperatures from about 150° to about 200° C., more typically from about 190° to about 200° C. While not bound by theory, cure is believed to be by a free radical mechanism through the vinyl unsaturation in the difluoromaleimide groups.
They are utile in the preparation of molded products, the forming of composite and adhesive bonded structures and in coating applications. Where it is desired to apply the prepolymers to a substrate in a solvent prior to cure, they may be dissolved in cyclic ethers such as tetrahydrofuran, dioxane and the like; acetone; as well as aprotic solvents such as dimethyl formamide, dimethyl acetamide and the like.
A unique property of the prepolymers is the ability of the prepolymer to melt-flow prior to cure. This enables complete filling of mold cavities and the like and the wetting of substrates such as fibers or surfaces of a laminate before cure is perfected.
Upon cure, the end products display continuous service at prolonged exposure at temperatures up to about 300° C. or more. By contrast, the prepolymers, if end-capped with maleic anhydride, would have an upper limit of continuous thermal stability of only about 230° C. End-capping with other halogenated maleic anhydrides would materially increase cure temperature.
While nowise limiting, the following examples are illustrative of the invention.
EXAMPLE 1
Preparation of Precursor of Prepolymer from MDA and BFDA
In a 100 ml round-bottomed flask, equipped with a magnetic stirring apparatus, a reflux condenser attached to a Dean-Stark trap and an oil bath, there was added 15.70 g (0.025 mole) of bis-2,2-[4-(3,4-dicarboxyphenoxy)phenyl]-hexafluoropropane dianhydride (BFDA) to a contained solution of 10.90 g (0.055 mole) of methylene dianiline (MDA) in a mixture of 50 ml xylene and 5 ml dimethylformamide. The solution was heated to reflux for 24 hours at about 135° C. The water formed and released was removed with the Dean-Stark trap. The resulting diamine was isolated by stripping off the solvent at a reduced pressure to yield 24.3 g (99% yield) of a reactive addition product having a melting point of 90°-100° C.
EXAMPLE 2
Difluoromaleic Anhydride End-Capping
To a three-necked flask fitted with a magnetic stirrer and maintained under a nitrogen atmosphere, there was added 4.95 g (0.005 mole) of the reaction product of Example 1 to 1.48 g (0.011 mole) of difluoromaleic anhydride in a contained mixture 40 ml toluene and 5 ml dimethylformamide. After 20 minutes of stirring, 3.30 g of acetic anhydride and 0.25 g (p.003 mole) of sodium acetate was added and the mixture stirred for an additional 60 minutes. The reaction mixture was heated to 50° C. for 16 hours before pouring into 500 ml of ethanol. The resulting precipitate was collected by filtration and washed with ethanol and water. The product was dried for 24 hours under vacuum at 60° C. The reaction product weighed 4.85 g for a yield of 89.3%. It had a melting point between 170° and 173° C. as measured in a Fisher-Johns apparatus.
The product had as the principal component the compound of the structure: ##STR8## When subject to Differential Scanning Calorimetry (DSC) analysis in air, the material displayed a melting point endotherm of approximately 175° C. Cure of the prepolymer can be initiated between 190° and 200° C. When thermally cured, the resin was found to have a major decomposition temperature in air of about 520° C. as measured by Thermal Gravimetric Analysis (TGA).
EXAMPLE 3
Using the procedure of Examples 1 and 2, there was formed a difluoromaleic anhydride end-capped prepolymer by the condensation reaction of meta-phenylene diamine (MPD) with BFDA. The principal component of the product formed had the structure: ##STR9##
The composition recovered had a melting point of approximately 200° C. (DSC) and cured at about 138° C. The TGA decomposition temperature in air was found to be approximately 480° C.
EXAMPLE 4
To a 100-ml round-bottomed flask equipped with a magnetic stirrer, condenser and Dean-Stark trap there is added 2.07 g (0.004 mole) of 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane (BDAF), 50 ml of toluene and 5 ml of dimethylformamide (DMF). To this solution there is added 1.26 g (0.002 mole) of 2,2-bis[4-(3,4-dicarboxyphenoxy) phenyl] hexafluoropropane dianhydride (BFDA). The solution is heated at reflux for 16 hours during which time the water from imidization is removed. The mixture is allowed to cool to room temperature and then 0.268 g (0.002 mole) of difluoromaleic anhydride is added and 30 minutes later 3.3 g of acetic anhydride and 0.25 g of sodium acetate are added to the reaction flask. The mixture is heated at 50° C. for 16 hours and then added to 300 ml of ethanol. The resulting precipitate was collected by filtration and washed with an ethanol/water (1:1 by volume) mixture. The main constituent of the product is a prepolymer of the formula: ##STR10## The product is heat curable to furnish a heat stable resin.
EXAMPLE 5
A 2.0 g sample of the prepolymer prepared in Example 2 is cured by heating the sample from 50° C. to 200° C. over a 30 min. period followed by continued heating at 200° C. for about 2 hours. The resultant polymer is a consolidated glassy substance that is thermally stable in air to 320° C. as assessed by thermal gravimetric analysis. The polymer is completely insoluble in boiling dimethyl formamide demonstrating a high degree of the desired crosslink formation resulting from cure of the prepolymer to a thermoset structure.
What is claimed is:
1. Thermally curable prepolymers of the formula: ##STR11## wherein n has a value from 0 to about 3, each R is independently an aromatic radical and R' is a tetra functional radical selected from the group consisting of: ##STR12## wherein R" is a difunctional radical selected from the group consisting of --SO2 --, --0--, --S--, --CO--, ##STR13##
2. A thermally curable prepolymer as claimed in claim 1 in which R is a aromatic radical of an aromatic diamine selected from the group consisting of 4,4'-diamino-diphenyl methane, meta-phenylene diamine and bis-2,2,-[4-(4-aminophenoxy) phenyl] hexafluoropropane.
3. A thermally curable prepolymer as claimed in claim 1 in which R' is a radical of bis-2,2-[4-(3,4 dicarboxyphenoxy)phenyl]-hexafluoropropane dianhydride.
4. A thermally curable prepolymer as claimed in claim 2 in which R' is a radical of bis-2,2-[4-(3,4 dicarboxyphenoxy)phenyl]-hexafluoropropane dianhydride.
5. A thermally curable prepolymer of the formula: ##STR14##
6. A thermally curable prepolymer of the formula: ##STR15##
7. A thermally curable prepolymer of the formula: ##STR16##
8. A polymer made by the step of thermally curing the prepolymer defined in claims 1, 2, 3, 4, 5, 6 or 7.
| 1978-06-21 | en | 1979-11-06 |
US-3619330D-A | Adjustable clamp used in a tube splicing machine
ABSTRACT
A machine for splicing unvulcanized inner tubes. The machine employs a clamp which is adjustable for holding various size inner tubes. The clamp has a pair of end sections with configured recesses for receiving opposing edges of the inner tube and a pair of intermediate sections which are removably positionable in abutting relation between the end sections. Means are provided for varying the spacing between the end sections to accommodate different intermediate sections.
United States Patent Inventor Glenn D. Kerr Akron, Ohio Appl. No. 14,101
Filed Feb. 25, 1970 Patented Nov. 9, 1971 Assignee The Goodyear Tire & Rubber Company Akron, Ohio ADJUSTABLE CLAMP USED IN A TUBE SPLICING MACHINE 20 Claims, 4 Drawing Figs.
US. Cl [56/503, 156/507 Int. Cl. B29h 15/04, 603d 15/04 Field of Search [56/502,
[56] References Cited UNITED STATES PATENTS 2,541,696 2/1951 George 156/503 3,087,847 4/1963 Brugger et al. 156/503 X Primary Examiner-Benjamin A. Borchelt Assistant Examiner.l. J. Devitt Attorneys-F. W. Brunner and Harlan E. Hummer ABSTRACT: A machine for splicing unvulcanized inner tubes. The machine employs a clamp which is adjustable for holding various size inner tubes. The clamp has a pair of end sections with configured recesses for receiving opposing edges of the inner tube and a pair of intermediate sections which are removably positionable in abutting relation between the end sections. Means are provided for varying the spacing between the end sections to accommodate different intermediate sections.
PATENTEnunv 9 Ian SHEET 1 BF 3 IN VENTOR. GLENN D. KERR ATTORNEY PATENTEUunv 9 I97! SHEET 2 [IF 3 INVENTOR. GLENN D. KERR ATTORNEY PATENTEU 9 SHEET 3 [1F 3 INVENTOR. GLENN D. KERR ATTORNEY BACKGROUND OF THE INVENTION A tube splicer is a machine for joining the exposed ends of a flat, sleevelike, unvulcanized rubber inner tube, which has been cut into predetermined lengths according to the size of the tube desired. The opposing ends of the inner tube are clamped in position on the machine and freshly cut. As soon as the cut is completed, the tube ends are brought together and held in compressive engagement for a predetermined period of time to complete the splice. The tube is then unclar'nped and removed from the machine.
Some machines employ clamps which are designed to hold only one particular size tube. This means that a large number of clamps must be kept on hand since many different size tubes are manufactured. Moreover, such clamps generally have side sections which are integral with the bottom section making them cumbersome to store and use. The invention is directed to providing and adjustable clamp which is readily adapted for use with a number of different size tubes, and whose component parts are easily stored.
Briefly stated, the invention is an adjustable clamp comprising a pair of end sections having configured recesses for receiving adjacent sides or edges of an inner tube, and a pair of intermediate sections, which are removably positioned in abutting relation between the end sections. The mechanism for mounting the end sections on the tube splicer is adjustable to vary the spacing between the end sections to accommodate different intermediate sections for various size tubes.
DESCRIPTION OF THE DRAWING The following description of the invention will be better understood by having reference to the annexed drawing wherein:
FIG. 1 is a front view of a tube splicer showing the most essential features thereof;
FIG. 2 is a perspective view of one of the clamping assemblies used on the tube splicer;
FIG. 3 is a section viewed from the line 3-3 of FIG. 4 with one of the top clamp sections and other portions removed; and
FIG. 4 is a section viewed from the line 4-4 of FIG. 3.
DESCRIPTION OF THE INVENTION Referring more particularly to FIG. 1 of the drawing, there is shown a machine 6 for splicing inner tubes, e.g. tube 7. The tube splicer 6 essentially comprises a clamp assembly 8 for holding the exposed ends 9 and 10 of the inner tube 7 in overhanging position for cutting, a squeeze assembly 11 for bringing the exposed tube ends 9 and'l0 into compressive splicing engagement immediately after the ends are cut, and a cutting assembly including a pair of cutting knives l2 and 13 (FIGS. 2-4) for cutting the tube ends 9 and I0, and cooperating cam followers 14 and 15 for guiding the knives l2 and 13 along a tube cutting pathway.
SQUEEZE ASSEMBLY The squeeze assembly 11 (FIG. 1) comprises a pair of squeeze tables 18 and .19 slidably mounted in spaced, aligned relation on a pair of guide rods, e.g. guide rod 20, which are mounted in parallel relation on a horizontally disposed platform 2] of the machine frame 22. The squeeze table 19, although fixed during normal operation of the tube splicer 6, is adjustable about one-fourth inch along the guide rods 20 to vary the position of the tube end 10 slightly in relation to the cutting knife I3. An adjusting screw 23 and manually operated hand crank 24 are used to change the axial position ofthe squeeze table 19.
The opposing squeeze table 18 is movable to bring the freshly cut tube ends 9 and 10 into compressive splicing engagement. A pneumatic cylinder 25 is provided for operating or reciprocating the squeeze table 18 along the guide rods 20.
A conventionally designed linkage system 26 is interposed between the squeeze table 18 and pneumatic cylinder 25 for exerting axial force against the squeeze table 18 in response to movement of the piston within the pneumatic cylinder 25.
CLAMP ASSEMBLY The clamp assembly 8 (FIGS. 1-4) comprises a pair of clamps 30 and 31 which are carried by the squeeze tables 18 and 19. A set of upstanding clamp presses 32 and 33 are mounted for unitary movement with the squeeze tables 18 and 19 and clamps 30 and 31.
Each of the clamps 30 and 31 (FIG. 2) comprises a pair of end sections 34 and 35 and intermediate, or top and bottom sections 36 and 37, which are positionable in abutting relation between the end sections 34 and 35. All of the clamp sections 34-37 are removable from the squeeze tables 18 and 19. Each of the clamp sections 34-37 includes a rigid portion 38 and a resilient portion 39, the rigid portion 38 being any suitable metal, e.g. steel, and the resilient portion 39 being a band of elastomeric material, e.g. rubber, which is molded and bonded to the metal portion 38. The exposed edges of the rubber bands 39 adjacent the tube ends 9 and I0, are in aligned, planar relation, when the clamp sections 34-37 are in clamping engagement with the inner tube 7.
Each of the end sections 34 and 35 include a specially configured recess 40 for receiving and surrounding the adjacent curved edges or sides 41 and 42 of the inner tube 7, when the tube is positioned in the clamps 30 and 31. Each of the end sections 34 and 35 are slidably keyed to adjacent guide blocks 43 and 44 to permit removal and replacement of the end sections 34 and 35. The end sections 34 and 35 and the guide blocks 43 and 44 form guideways, e.g. guideway 45, for receiving similar guide rails 46 extending in parallel relation from the squeeze tables 18 and 19. Each of the guide rails 46 extends between a pair of brackets 47 and 48 secured in upstanding relation on each of the squeeze tables 18 and 19. Thus, each pair of end sections 34 and 35are movable along a common axis, or adjacent guide rails 46.
An adjusting screw 49 is journaled for rotation in each pair of brackets 47 and 48, and a lug 50 projecting from each guide rail 46 intermediate the brackets 47 and 48. Each pair ofguide blocks 43 and 44 are adjustably mounted by any suitable means, e.g. slot 51 and bolt 52, on movers, e.g. mover 53, which are coupled to the adjusting screws 49 for movement therealong in response to rotation of the screws 49. Thus, the end sections 34 and 35 and attached guide blocks 43 and 44, are simultaneously moved toward or away from each other in response to rotation of the adjusting screws 49.
The abutting ends between each pair of end sections 34 and 35 and the bottom sections 37, as indicated at 54, are angularly disposed relative to the plane of the bottom sections 37 and converge in a direction above said sections, such that the end sections 34 and 35 compressively engage and hold the bottom section 37 firmly in position against the squeeze tables 18 and 19. The abutting edges of the top sections 36 and each pair of end sections 34 and 35, on the other hand, converge in an opposing direction or toward the lower sections 37 to permit moving the top sections 36 between the end sections 34 and 35 into and out of compressive clamping engagement with the tube 7 resting on the bottom sections 37.
An elongated slot 58 is disposed in the side 59 of each of the squeeze tables 18 and 19. A pair of slides 60 and 61 are disposed in each slot 58 in juxtaposed relation. Each pair of slides 60 and 6l carry specially configured projections 62 and 63, which are coupled to the movers 53 for unitary movement. Thus, the projections 62 and 63 and attached slides 60 and 61 are movable in unison with the guide blocks 43 and 44 and attached end sections 34 and 35.
The slides 60 and 61 and projections 62 and 63 define a guide pathway or cam surface along which the cam followers 14 and 15 roll to guide the knives l2 and 13 along a predetermined tube cutting pathway. The tube cutting pathway is generally concave, and the slides 60 and 61 act as a straight edge between the projections 62 and 63. Each pair of slides 60 and 61 are keyed together for relative axial movement. For example, the upper slide 60 is provided with an axial keyway 64 (FIG. 4) for slidably receiving a key 65 extending axially from the lower slide 61. A threaded screw 66 is provided for clamping the upper and lower slides 60 and 61 firmly together in cases where a great number of similar size tubes are being spliced.
The inner tube 7 is looped over a pair of upper jaws 68, which carry the top sections 36. The upper jaws 68 are slidably mounted on the clamp presses 32 and 33 by any suitable means. For example, the upper jaws 68 of clamp presses 32 and 33 (FIG. 1), are secured to a pair of parallel guides 69 and 70, which are each slidable along a pair of similar guide rods 71 and 72. A pneumatic cylinder 73, mounted on each clamp press 32 and 33, is coupled to the upper jaws 68 for moving the top sections 36 into and out of compressed clamping engagement with the tube 7 positioned on the bottom sections 37 between the end sections 34 and 35.
The knives l2 and 13 and their associated cam followers 14 and 15 are first moved to a position, indicated at A, adjacent the molds or clamps 30 and 31. The knives 12 and 13 are then moved transversely between the clamps 30 and 31 in cutting relation with the overhanging tube ends 9 and to a position, indicated at B, which is beyond the clamps 30 and 31. As seen in dotted line in FIG. 3, the cam followers 14 and guide the knives 12 and 13 along a predetermined tube cutting pathway as the knives 12 and 13 move transversely between the clamps and 31. A shoulder 74 is cut in the tube 7 adjacent each side 41 and 42 and extends beyond the intermediate concave section. The distance or width (D) of each shoulder 74 is varied slightly by adjusting the guide blocks 43 and 44 relative to the movers 53 and attached projections 62 and 63. This is accomplished by first loosening the bolt 52, slightly moving or adjusting the guide blocks 43 and 44 and then retightening the bolt 52 to reclamp the guide blocks 43 and 44.
The width (W) of the clamp sections 34-37 is generally the same. The cavities or recesses 40 for encompassing the tube sides 41 and 42, can be designed to accommodate individual tubes, or a number of different tubes, such that the end sections 34 and need not be removed and replaced every time different size tubes are spliced.
Thus, there has been provided a new and novel adjustable clamp for accommodating different size tubes.
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.
We claim:
1. A clamp for holding an unvulcanized inner tube in a tube splicing machine comprising:
a. a pair of end sections, including configured recesses for receiving adjacent opposing edges of an inner tube; and
b. a pair of intermediate sections removable from positions in abutting relation between the end sections and having solid planar surfaces between opposing ends thereof for contacting an inner tube between opposing edges of the tube in said recesses. I I
2. The clamp of claim I, which includes a band of elastomeric material bonded to each of the sections, the bands having exposed aligned ends when the clamp is assembled.
3. The clamp of claim 2, wherein the elastomeric material is rubber.
4. The clamp ofclaim 3, which includes:
c. means for holding the end sections in spaced, aligned relation on a tube splicing machine;
d. means for securing one of the pair of intermediate mold sections between the end sections on the machine; and
e. means for moving the otherof the pair of intermediate sections relative to the intermediate section secured between the end sections.
5. The clamp of claim 4, wherein the securing means includes:
f. means for varying the spacing between the end sections to accommodate different intermediate sections.
6. The clamp of claim 5, which includes:
g. means associated with the clamp for guiding a knife along a predetermined tube cutting pathway adjacent the exposed ends of the bands.
7. The clamp of claim 6, wherein the guiding means includes:
h. a straight edge having opposing ends;
i. a pair of configured projections extending from the straight edge adjacent the opposing ends thereof; and
j. means for varying the spacing between the projections in corresponding relation to the spacing between the end sections.
8. The clamp of claim 7, wherein the means for varying the spacing between the projections includes:
k. a pair of slides in juxtaposed relation for carrying the projections; and
m. means for mounting the slides for relative axial movement.
9. The clamp of claim 8, which includes:
ii. an elongated slot for at least partially receiving the slides and maintaining the slides in parallel sliding relation to the intermediate section secured between the end sections; and
0. means associated with the slot for clamping the slides together to maintain the projections in fixed spaced relation after the spacing therebetween has been adjusted in corresponding relation to the spacing between the end section.
10. The clamp of claim 9, wherein the means for mounting the slides for relative axial movement includes:
p. a key projecting in axial relation from one of the pair of slides; and
q. a keyway axially disposed in the other of the pair of slides and matingly configured to slidably receive the key.
11. The clamp of claim 7, wherein the means for varying the spacing between the end sections includes:
r. a pair of guide blocks for holding the end sections;
s. means for guiding the blocks along an axial pathway; and
t. an adjusting screw coupled to the blocks for moving the blocks simultaneously along the pathway when the screw is rotated.
12. The clamp of claim 11, which includes:
u. means for mounting the guide blocks and projections for unitary movement.
13. The clamp of claim 12, which includes:
v. means for adjusting the axial position of the end sections relative to the projections to vary the tube cutting pathway along which the knife moves.
14. The clamp of claim 13, which includes:
w. means for removably mounting the end sections on the guide blocks.
15. The clamp ofclaim 13, wherein the means:
w. includes l. a key projecting from each end section; and 2. a keyway disposed in each guide block and matingly configured to slidably receive a key of an end section.
16. The clamp of claim 13, wherein the means (e) for moving the other of the pair of intermediate sections includes:
x. means for raising and lowering the other section into and out of abutting relation between the end sections to clamp and unclamp a tube resting on the intermediate section secured between the end sections.
17. The clamp of claim 12, which includes:
y. means for moving the sections with a tube clamped therein relative to a similar axially aligned clamp carried by the machine.
18. A machine for splicing inner tubes, comprising in combination:
a. a pair of clamps for holding exposed ends of an inner tube in spaced relation, each clamp including:
l. a pair of end sections including a configured recess for receiving and surrounding adjacent edges of the tube, and a band of elastomeric material facing the sections adjacent the end of the tube.
2. a pair of intermediate sections removably positionable in abutting relation between the end sections for engaging the inner tube between its edges, the sections also including a facing band of elastomeric material adjacent the tube ends;
. means for moving one of each pair of intermediate sections into and out of compressive, clamping engagement with an inner tube positioned in the clamps;
means for varying the spacing between the end sections of the clamps, said means including:
3. a pair of guide blocks for carrying each pair of end sections;
4. means for guiding each pair of guide blocks along an axial pathway; and
5. means for moving each pair of guide blocks toward and away from each other in unison,
a pair of knives for cutting the tube ends adjacent the clamps;
means for moving the knives transversely between the clamps;
means for guiding each knife along a predetermined tube cutting pathway as it moves between the clamps, said means including:
6. a pair of spaced configured projections extending in a direction toward the knives as they move between the clamps;
7. a straight edge extending between the projections and defining a guide pathway therewith;
8. means for varying the spacing between the projections in corresponding relation to the spacing between the end sections of the clamp; and
9. a cam follower associated with each knife for rolling engagement along the guide pathway defined by the projections and straight edge to guide the knife along a corresponding cutting pathway;
g. means for moving the clamps towards each other in response to retraction of the knives out of interfering relation with the moving clamps, to bring the freshly cut tube ends into compressive splicing engagement.
19. The machine of claim 18, which includes:
h. means for coupling each guide block and corresponding projection together for unitary movement; and
i. means for adjusting the axial position of each guide block relative to its corresponding projection.
20. The machine of claim 19, which includes:
k. means for removably mounting each end section on an adjacent guide block, said means including a key projecting from the end section and a keyway disposed in the guide block for slidably receiving the key.
2. The clamp of claim 1, which includes a band of elastomeric material bonded to each of the sections, the bands having exposed aligned ends when the clamp is assembled.
2. a pair of intermediate sections removably positionable in abutting relation between the end sections for engaging the inner tube between its edges, the sections also including a facing band of elastomeric material adjacent the tube ends; b. means for moving one of each pair of intermediate sections into and out of compressive, clamping engagement with an inner tube positioned in the clamps; c. means for varying the spacing between the end sections of the clamps, said means including:
2. a keyway disposed in each guide block and matingly configured to slidably receive a key of an end section.
3. a pair of guide blocks for carrying each pair of end sections;
3. The clamp of claim 2, wherein the elastomeric material is rubber.
4. The clamp of claim 3, which includes: c. means for holding the end sections in spaced, aligned relation on a tube splicing machine; d. means for securing one of the pair of intermediate mold sections between the end sections on the machine; and e. means for moving the other of the pair of intermediate sections relative to the intermediate section secured between the end sections.
4. means for guiding each pair of guide blocks along an axial pathway; and
5. means for moving each pair of guide blocks toward and away from each other in unison, d. a pair of knives for cutting the tube ends adjacent the clamps; e. means for moving the knives transversely between the clamps; f. means for guiding each knife along a predetermined tube cutting pathway as it moves between the clamps, said means including:
5. The clamp of claim 4, wherein the securing means includes: f. means for varying the spacing between the end sections to accommodate different intermediate sections.
6. The clamp of claim 5, which includes: g. means associated with the clamp for guiding a knife along a predetermined tube cutting pathway adjacent the exposed ends of the bands.
6. a pair of spaced configured projections extending in a direction toward the knives as they move between the clamps;
7. a straight edge extending between the projections and defining a guide pathway therewith;
7. The clamp of claim 6, wherein the guiding means includes: h. a straight edge having opposing ends; i. a pair of configured projections extending from the straight edge adjacent the opposing ends thereof; and j. means for varying the spacing between the projections in corresponding relation to the spacing between the end sections.
8. The clamp of claim 7, wherein the means for varying the spacing between the projections includes: k. a pair of slides in juxtaposed relation for carrying the projections; and m. means for mounting the slides for relative axial movement.
8. means for varying the spacing between the projections in corresponding relation to the spacing between the end sections of the clamp; and
9. a cam follower associated with each knife for rolling engagement along the guide pathway defined by the projections and straight edge to guide the knife along a corresponding cutting pathway; g. means for moving the clamps towards each other in response to retraction of the knives out of interfering relation with the moving clamps, to bring the freshly cut tube ends into compressive splicing engagement.
9. The clamp of claim 8, which includes: n. an elongated slot for at least partially receiving the slides and maintaining the slides in parallel sliding relation to the intermediate section secured between the end sections; and o. means associated with the slot for clamping the slides together to maintain the projections in fixed spaced relation after the spacing therebetween has been adjusted in corresponding relation to the spacing between the end section.
10. The clamp of claim 9, wherein the means for mounting the slides for relative axial movement includes: p. a key projecting in axial relation from one of the pair of slides; and q. a keyway axially disposed in the other of the pair of slides and matingly configured to slidably receive the key.
11. The clamp of claim 7, wherein the means for varying the spacing between the end sections includes: r. a pair of guide blocks for holding the end sections; s. means for guiding the blocks along an axial pathway; and t. an adjusting screw coupled to the blocks for moving the blocks simultaneously along the pathway when the screw is rotated.
12. The clamp of claim 11, which includes: u. means for mounting the guide blocks and projections for unitary movement.
13. The clamp of claim 12, which includes: v. means for adjusting the axial position of the end sections relative to the projections to vary the tube cutting pathway along which the knife moves.
14. The clamp of claim 13, which includes: w. means for removably mounting the end sections on the guide blocks.
15. The clamp of claim 13, wherein the means: w. includes
16. The clamp of claim 13, wherein the means (e) for moving the other of the pair of intermediate sections includes: x. means for raising and lowering the other section into and out of abutting relation between the end sections to clamp and unclamp a tube resting on the intermediate section secured between the end sections.
17. The clamp of claim 12, which includes: y. means for moving the sections with a tube clamped therein relatIve to a similar axially aligned clamp carried by the machine.
18. A machine for splicing inner tubes, comprising in combination: a. a pair of clamps for holding exposed ends of an inner tube in spaced relation, each clamp including:
19. The machine of claim 18, which includes: h. means for coupling each guide block and corresponding projection together for unitary movement; and i. means for adjusting the axial position of each guide block relative to its corresponding projection.
20. The machine of claim 19, which includes: k. means for removably mounting each end section on an adjacent guide block, said means including a key projecting from the end section and a keyway disposed in the guide block for slidably receiving the key.
| 1970-02-25 | en | 1971-11-09 |
US-92864278-A | Transfer and inverter machine
ABSTRACT
A machine is positioned in the line of a gypsum board manufacture to provide lifting arms, which are actuated up through the line to remove board sections, invert and transfer them to an adjacent area for subsequent drying. The lifting arms are reciprocated, end for end, during the elevating and inverting action to subsequently approach the board from beneath. The lifting arms are actuated through slider boxes, attached to a shaft, and a cam is provided to control the ends of the lifting arms, as each end is pivoted at the inverter shaft to which its slider box is attached.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the necessary inversion and transfer of green gypsum board from its line of manufacture to orient it for the drying ovens. More specifically, the present invention relates to a transfer machine in its control of lifting arms, so they will approach the live rolls from beneath, and remove the green board from the live rolls.
2. Prior Art
The green plaster board is formed by sandwiching a hot, wet slurry of gypsum between a cream face paper and a gray backing paper. After being formed, the board is conveyed along a belt for several hundred feet to allow set up of the wet slurry before cutting to length. After the boards are cut to length, they are arranged in groups of 1, 2, 3 or 4, (depending on their individual length) to be inverted so they go through the dryer with the cream face up. They are grouped by means of an accelerating section of the conveyor belt. The accelerating section pulls gaps between the groups to allow time for them to be inverted. After being inverted, the boards are transferred onto a tipple table, which feeds a multi-decked dryer.
Present inverting and transferring machines are positioned near the live rolls section of the conveyor system, on which the boards to be inverted come to rest. A series of arms have previously been pivoted down into position beneath the plane of the live rolls. After the board has come to rest on the live rolls, with the inverter arms below their plane, the arms have been pivoted by an inverter shaft at right angle to the live rolls and the boards are elevated, inverted and caught by a second group of arms, which lower the boards, inverted, to be made up into the groups for drying.
It is obvious that in the prior art system, inverting arms must be positioned below the live rolls prior to the approach of the board. Time must be allocated for the lifting arms to be pivoted back into position before the next board to be inverted can come onto the live rolls. This is a lost segment of time. If the lifting arms can be consistenly raised from beneath, rather than being lowered from above, the boards can be more or less continuously flowed to their elevating position.
Additionally, if the lifting and transfer machine can be arranged to consistantly raise the lifting arms from beneath the live rolls, there is the possibility that the space required to accommodate the machine in the line of manufacture could be reduced. Therefore, there are two possibilities for improving green board transfer and inversion. In the first instance, time can be saved if the lifting arms are properly manipulated. Secondly, the space required for the machine could be reduced.
SUMMARY OF THE INVENTION
The present invention contemplates an inverter shaft at right angles to live rolls on which are received green board to be inverted and transferred. The inverter shaft has a series of slider boxes attached to it. An elongated lifting arm structure is positioned in each slider box and reciprocated therein. A cam structure is positioned beneath each slider box and the live rolls to receive, retain and guide the ends of the lifting arm. As the inverter shaft rotates, the slider box forces its lifter arm to pivot up through the line of lifting rolls. The end of the lifting arm at the slider box is received by, and controlled by, the lower cam structure to begin pulling the lifting arm down through the slider box, after the lifting arm has delivered the inverting green board to a catcher arm. Continued rotation of the inverter shaft forces the cam-caught end of the lifting arm to be pulled up and toward the live rolls from beneath. Therefore, the opposite side of the lifting arms are brought upward to contact a new green board needed to be elevated, inverted and transferred.
The cycle of alternate ends of the lifting arms engaging the cam structure and being guided through the rotated slider box alternately brings the two faces of the lifting arm into alternate engagements with the train of green boards sequentially arriving at the live roll position.
Other objects, advantages and features of the invention will become apparent to one skilled in the art upon consideration of the written specifications, appended claims, and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the live rolls of a conveyor system and transfer system at the live rolls, in which the present invention is embodied:
FIG. 2 is a sectioned elevation at slider boxes mounted on the inverter shaft, with its lifting arm at one of its two extreme positions:
FIG. 3 is a section of FIG. 2, along lines 2--2:
FIGS. 4-7 show, in sequence, the cycle of lifting arm 12 actuation, to elevate, invert and transfer green gypsum board.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a set of live rolls 10, which form a platform in a conveyor system, to which thin, sheet-like material is brought to rest. In this preferred embodiment, this sheet-like material will be described as wallboard, or gypsum board, which has been conveyed to the live rolls after its initial formation. The pre-cut sections of this board 11 have emerged from the manufacturing process, and have been given their initial set up by cooling. The must be transferred to an oven to complete their curing into the final product. Therefore, these boards must be elevated from their conveyor line, inverted for oven drying and transferred to an area adjacent the live roll platform 10.
Prior to the present invention, multiple lifting arms have been pivoted down into positions below the plane of the live rolls. The highly frangible wet boards have been elevated by the pivoted arms and flopped over to be caught on catcher arms, which then tenderly lower them to the adjacent area for transfer into an oven. In the prior art, the lifting arms were simply pivoted back down between the live rolls from above, so the next board could be brought into position over the arms for the next lift. In contrast, the present invention shuttles each lifting arm into position beneath the live rolls to avoid being pivoted into their lift position from above the live rolls.
In FIG. 1, lifting arms 12 are generally depicted as actuated from one end by inverter shaft 13. The means for rotating both the live rolls 10 and inverter shaft 13 is not disclosed in detail. Obviously, a motor is connected to the rolls and shaft by belts or gears to rotate them. Also, the control system for limiting and reversing the rotation of these rolls and shafts, as needed, is necessary to overall operation. However, the control system and its motor need not be set forth specifically to disclose the present invention.
As inverter shaft 13 rotates clock-wide, away from the upper surface of the board, it pivots lifting arms 12 upward to elevate a green wallboard from the plane of the live rolls. At the same time, catcher arms 14 are also pivoted from shaft 13 up to that position where they will gently receive the delicate wallboard and ease it down upon a second conveyor system, which sends it on its way to the drying holocaust of ovens.
In FIG. 1, the prior art problem of manipulating the lifting arms can be inferred, as well as the solution provided by the present invention.
Obviously, if the prior art lifting arms need not be pivoted from their elevated position back down through the plane of the live rolls, time for the arrival of the boards to be elevated can be shortened. The present invention solves this problem by shuttling the lifting arms at their inverter shaft 13, end-for-end, and sneaking them up under the plane of the live rolls. How this accomplished, will become evident by inspection of subsequent figures.
FIG. 2 provides the critical analyses of cooperation between slider box 20 keyed to inverter shaft 13. In general, slider box 20 is a framework, which is firmly fixed to shaft 13 to provide support, manipulation and rolling contact with its lifting arm 12.
Now it can be seen that each lifting arm 12 is essentially two parallel beams 31 and 32, held in their relation to each other by end beams 33 and 34. Each of these beams, 31 and 32, engage slider box 20 through a set of rollers. As can be discerned readily in FIG. 2, roller 31-A roller 31-B on slider box 20 directly contact beam 31. In similar fashion, roller 32-A and 32-B, on the other side of slider box 20, directly contact beam 32.
Again, in FIG. 2, it can be clearly discerned that lifting arm 12 is shown in one of its two extreme positions relative to slider box 20. As viewed in FIG. 2, lifting arm 12 is moved to its extreme lifting range of movement. The lifting arm 12 can readily slide to the right until slider box 20 limits its movement.
At each end of lifting arm 12 is a cam-engaging arm, with which sliding force can be applied to move the arm relative to slider box 20. More specifically, cam-engaging arm 35 is on one end of the lifting arm 12, and cam-engaging arm 36 is on the other end of lifting arm 12. Each of these cam-engaging arms is equipped with rolling devices to specifically contact a cam, which will conrol the reciprocation of the lifting arm in slider box 20.
FIG. 3 is a sectioned elevation of FIG. 2 to expand the understanding of how the two beam lifting arms 12 rides on the rollers of the slider box 20 to maintain rolling contact between the arm and inverter shaft 13, carrying out the objects of the invention.
FIGS. 4-7 now disclose how all of the embodying structures come together and cooperate to delicately pluck green boards from live rolls 10, and deposite them as delicately as a mother's kiss upon adjacent conveyor 40. This ancient and honorable result is now achieved with astounding simplicity by the implementation of the concepts of the present invention.
FIGS. 4-7 give us a sequence of this cooperation of structure with clarity that rivals that of a motion picture.
Now the live rolls 10, inverter shaft 13 and catcher arms are shown in elevation. The manner in which the catcher arms are manipulated is essentially the same as in the prior art. Therefore, little drawing disclosure is devoted to actuation of these arms. It is sufficient to disclose how the catcher arms 14 are brought, pivoting, upward to receive the transfer board from the lifting arms of the invention.
The FIGS. 4-7 give us little view of the live rolls, actually, the first of the live rolls is not shown to give full disclosure to the first of the lifting arms 12, as it is controlled by its slider box on shaft 13.
FIG. 4 shows lifting arms 12 horizontally disposed just below the board 11. Catcher arms 14 are also horizontal beneath the surface of conveyor 40, upon which the inverted board 11 is placed. Actuation of live rolls 10 is indicated by motor 41. Motive means for inverter shaft 13 is not shown as it would unnecessarily clutter the drawings and obscure understanding of the information. Hydraulic cylinder 42 is disclosed as linked to arms 14 to raise and lower the catching arms pivoted from shaft 13. Thus, FIG. 4 is a good place to begin the cycle of operation.
The disclosure is dominated by cam structure 43. Each of the slider boxes and their lifting arms attached to shaft 13 has a cam 43 mounted beneath them. Cam 43 is a retaining tract, which receives the ends of its lifting arm 12 at 44. As inverter shaft 13 rotates clockwise, slider box 20 forms a link between the shaft and its lifting arm 12 to pivot the lifting arm from its right hand end as disclosed in FIG. 4.
The cam is shaped to cooperate with the end of the lifting arm to the end that the lifting arm is first pivoted about the axis of shaft 13, and then drawn down through box 20, until the opposite end of shaft 13 is engaged with a cam at point 44. This progressive actuation of the lifting arm can be followed through the four simple FIGS. 4-7.
FIG. 5 discloses the lifting arm pivoting through an angle, which elevates the board from the plane of the live rolls, while the catcher arms 14 begin their pivoting upward to receive the board. Incidentally, the board is held on a bracket 45, so it will not slip down the length of the lifting arm.
FIG. 6 shows the meeting of the lifting and receiving arms at the top of the arcs, through which they pivot. Of course, the timing and spacing and travel of these structures must be precise, in order to gently throw the board from the lifting arms to the catching arms. It is not within the scope of this disclosure to further dwell on these practical, important problems of adjustment.
The inventive concept is dramatically embodied in the control of lifting arms exerted by cam 43. FIG. 6 shows the first part of cam 43 bringing the lifting arms up to the transfer position. Essentially, this much has been done in the prior art. Now we go down on the other side of the hill with inventive concept.
FIG. 7 shows how the lifting arm 12 is carried down through the slider box by the lower end of the lifting arm, being pulled in a downward arc of the cam 43. At this point in the cycle, the catcher arms 14 have begun to lower their precious cargo toward the conveyor belt 40, while the lifting arm 12 begins its descent into the depths beneath the plane of the live rolls. While it may be said that beam 31 of arm 12 has lifted the first board and inverted it into the catcher arms, cam 43 has now directed the entire assembly of the lifting arm beneath the live rolls, and is ready to move the opposite side, i.e. 32, into position to elevate and invert the subsequent board on the live rolls.
Back we go to FIG. 4, only now, the lifting arm has been turned over. Again, the lifting arm is pivoted, only now from its end opposite that shown in FIG. 4. It would be useless and deadly to repeatedly describe this cycle.
It should now be glaringly apparent that the invention formulates an entirely new form and action for lifting arms to elevate and invert delicate thin, sheet-like forms of material. Specifically, green boards, hot off the assembly line, are handled with aplomb, sent on their way to ovens, which impart to them sturdiness derived from oven drying.
A continuous train of these articles are fed onto the platform of live rolls and flipped therefrom, like flapjacks, into the tempering ovens that await them. It is clear that a notable advance has been made in this art of material handling and transfer of the reduction in force base and time, when compared with the prior art.
From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and inherent to the apparatus.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the invention.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted in an illustrative and not in a limiting sense.
This invention having been disclosed, what is claimed is:
1. A machine with which to invert a body with a thin flat configuration including,a set of live rolls arranged in parallel and in a single plane on which rests a thin flat body requiring inversion, an inverter shaft extending at a right angle to the set of live rolls and spaced from one end of the live rolls, a series of slider boxes spaced along the shaft opposite selected spaces between the live rolls and keyed to the shaft at these positions to turn with the shaft, a lifting arm extended through each slider box wherein each lifting arm includes two beams held in parallel by end pieces to engage its box through rollers mounted in the box and arranged to reciprocate end for end through its slider box as the boxes are rotated with the shaft, a series of cams extending and arranged beneath the live rolls and inverter shaft with the arrangement for each cam to alternately receive the ends of the lifting arms as the inverter shaft rotates and guide and control its arm in its reciprocation through the slider box with the result that the lifting arms pivot at the inverter shaft to elevate the thin flat body from the live rolls and transfer it to a station laterally adjacent the live rolls, and a set of receiving arms positioned to receive the thin flat body and lover it to the transfer station.
2. The machine of claim 1 wherein:each cam is shaped to maintain a constant relation between the end of its lifting arm and the inverter shaft as the lifting arm is pivoted through the arc, which will invert the flat body and then slide the lifting
3. The machine of claim 1, wherein:the receiving arms are pivoted from the inverter shaft by means of linkage with a hydraulic cylinder which pivots the receiving arms to meet the lifting arms and receive the inverted body and then lower the received body to a conveyor system.
4. An inverting machine for flat sheets or relatively thin material, including,a flat sheet of relatively thin material positioned in a first horizontal plane, a shaft extended in a first horizontal plane adjacent the flat sheet, means for rotating the shaft in a direction away from the upper surface of the flat sheet, at least one slider box fixed on the shaft to rotate therewith, an elongated arm journaled through the slider box and engaging the slider box through rollers mounted in the slider box to reciprocate end for end in the slider box as the shaft is rotated, a cam structure fixed beneath the first horizontal plane and shaped and arranged to alternately receive the ends of the elongated arm as each end extends from its slider box to cause the lifting arm to pivot from the shaft through a pre-determined angle and subsequently slide through its box and bring its alternate end into engagement with the cam structure and repeat the cycle as the shaft rotates, and a catcher arm pivoted from the shaft through an angle complimental to the angle through which the lifting arm pivots to receive the flat sheet and deliver it to a second horizontal plane laterally removed from the first horizontal plane, wherein the sheet of material is elevated by the lifting arm through the pre-determined angle and at least one catcher arm is pivoted at the shaft from the second horizontal plane through the angle complemental to the pre-determined angle of the lifting arm to receive the inverted sheet of material and subsequently lower it to the second horizontal plane.
| 1978-07-27 | en | 1980-09-02 |
US-13259693-A | Spreading device for a binding apparatus and combined punch and binding apparatus
ABSTRACT
A spreading device is provided for a spreading and binding machine, to which several fixed spreading fingers are arranged at the side. These spreading fingers cooperate with corresponding spreading hooks of a movable plate, in order to move the spreading hooks from the spreading fingers in a spreading direction by moving the plate. The plate is connected through two pivotable and movable arms with an intermediate bar connected so that the arms and bar can move in both a spreading direction and in a direction perpendicular to the spreading direction in parallel movement. The bar is pivotally connected at each end with the two arms.
BACKGROUND OF THE INVENTION
The invention relates to a spreading device for spreading clamping backs used in the binding of sheet and especially for a spreading device in a combined punch and binding machine.
Binding machines for binding paper sheets are highly desirable and useful office machines. Such binding apparatuses are widely utilized in professional offices for binding sheets utilized in reports, presentations and the like. These machines generally include a hole punching assembly and a binding section for binding with various types of binding strips such as the Personal VeloBinder or Douvry-type binding elements. These are described in U.S. Pat. No. 5,143,502. The binding apparatus for paper sheets illustrated in U.S. Pat. No. 5,143,502 includes binding blades for bending flexible studs of one binding strip which fit into grooves on a second aperatured binding strip through which the studs pass. This apparatus is complex, in that it includes a plurality of racks and gears. Accordingly, it is desirable to provide a binding apparatus including a spreading device of simplified construction.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the invention, a spreading device for spreading a spline or clamping back for sheets to be bound is provided. The spreading device includes a base with a plurality of parallel spreading fingers mounted thereon and a plurality of spreading hooks mounted on a movable ratchet in order to move the spreading hooks from the spreading fingers in a spreading direction by moving the ratchet. Each end of the ratchet is pivotally connected through two flexible and movable arms with a connecting bar so that the connecting bar and pivoting arms move in both a spreading direction and in a direction perpendicular to the spreading direction in parallel movement.
The object of the invention is that of creating a spreading device and binding apparatus including the device of the type mentioned, which is inexpensive and can easily be integrated into binding machines, especially office binding machines.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in greater detail by a drawing, given as an example. The following features are represented:
FIG. 1 is a perspective representation of a combined punch and binding machine with installed spreading device according to the invention;
FIG. 2 is a side view of another design of a punch and binding machine with a spreading device according to the invention;
FIG. 3 is a view from the other side of this punch and binding machine of FIG. 2, to illustrate an additional function of same to close clamping backs;
FIG. 4 is a schematic top view of the spreader device according to the invention; and
FIG. 5 is a cross-sectional representation of another variant of such a combined punch and binding machine constructed and arranged in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A combined punch and binding machine 1 shown in FIG. 1 includes a base or bottom element 2 which serves as a support for carrying the various elements of machine 1. A spreader lever 3 is arranged on one side of bottom element 2. The elements of machine 1 are covered by a carrier casing 4. Casing 4 is formed with an elongated opening 5 aligning with the upper surface of bottom element 2, in which a wire binding back can be locked. In order to be able to produce holes conveniently in a stack of paper to be bound, machine 1 is provided with a strong punch lever 6. The axis of rotation of lever 6 is arranged in one end area of elongated carrier casing 4, parallel to the surface of bottom element 2.
The spreading device activated by spreader lever 3 projects from the other side of bottom element 2 and therefore is not visible in FIG. 1.
The spreading device includes a projecting element 11 which extends parallel to the bottom plane and is shown in FIG. 2. It can be seen that this design includes a carrier flange 12 connected with bottom body 2. This can be designed as an angle section, for example. Punch lever 6 is pivotally connected with the left upper end area of flat elongated angle section 12 by a first shaft 13, and by a second shaft 14 with a first lever arm 15 of a lever system which includes five other lever arms 16, 17, 18, 19, 20. Shaft 14 is connected to a connecting piece firmly attached to punch lever 6. One end of lever arm 18 is connected to lever arms 15, 16 and 17 by another shaft 21, and its other end with lever arms 19 and 20 by another shaft 22. Vertical guides 23 or 24 are attached to each of the left and right sides of the end areas of angle section 12, which permit a vertical movement of punching element 25 provided with N punch teeth 26.
Such a punching element can include twenty-one teeth for use in Europe and nineteen teeth for use in the United States. The sharp cutting edges of punch teeth 26 are not represented, to simplify the figure. Lever arms 17 and 20, through one of shaft 27 or 28 each, are thereby pivotally connected with the lower area of punching element 25, but above punch teeth 26. Lever arms 16 and 19 each through one of shaft 29 or 30 are connected with the upper area of angle section 12 in parallelogram form, since both the longitudinal axes of lever arms 17 and 20 and the longitudinal axes of lever arms 16 and 19 always run parallel.
Bottom element 2 includes an upper aligning floor plate 2a, which is provided with N punch holes, into which N punch teeth 26 penetrate during holing. To simplify the drawing, these known punch holes are not shown in FIG. 2.
In the case of the device constructed and arranged in accordance with FIG. 2, punching element 25 is located in an upper position, in which punch level 6 is pulled up, as shown in the figure. In this position, the longitudinal axes of lever arms 16 and 17 or lever arms 19 and 20 form an angle of more than 90°. When punch lever 6 is rotated downward around axis of rotation 13, lever arms 15 and 18 move to the left (FIG. 2) and somewhat downward. Punching element 25 is thereby pressed downward through shafts 27 and 28 by levers 17 and 20, so that punch teeth 26 are introduced into the punch holes.
The spreading lever is not shown in FIG. 3 to simplify the drawing. It should be present at this side of bottom element 2, if the machine is provided with the type of spreading device shown in FIG. 1. The edge of the elongated horizontally flat part 31 of angle section 12 designed in L-shape is visible in FIG. 3 in cross-section. Guide block 32 at the left and thrust block 33 at the right are attached to the end areas of part 31, for example by means of screws not shown in the figure. Guide block 32 includes a groove 34, which serves as a guide for the left side of a pressing element 35, and thrust block 33 together with a sheet attached to it at the rear form a groove 36, provided for the right side of pressing element 35.
Pressing element 35 is an angle section, L-shaped in cross-section, with a vertical part visible in FIG. 3, and a horizontal part, whose length, in horizontal direction, is somewhat shorter than the length, in horizontal direction, of the vertical part, so that the ends of this vertical part can glide in grooves 34 and 36. In FIG. 3, pressing element 35 partially covers another lever system, including two triangular levers 37, 38, two curved levers 39, 40, and two flat bars 41, 42. Triangular levers 37, 38 each have three shafts 43, 44, 45 or 46, 47, 48. Shafts 43 and 46 are arranged rotating only at angle section 12. Rotating shafts 44 and 47 each represent a rotating and movable connection between triangular levers 37 or 38 and a curved lever 39 or 40. Rotating shafts 45 and 48 each represent a rotating and movable connection between triangular levers 37 or 38 and one end of flat bar 41 or 42, whereby the other end of flat bar 42 is also connected to shaft 45, and the other end of flat bar 41 is connected to shaft 14. Flat curved levers 39 and 40 are severely curved, in order to provide a free space for the heads of shafts 45 or 48. The other ends of curved shafts 39, 40 each rotate around another shaft 49, 50 and are flexibly connected with contact 35.
The binding machine constructed in accordance to FIG. 3 functions as follows.
When punch lever 6 is in an upper position, corresponding to the position represented in the figure, rods 41 and 42 are moved to the left, and shafts 44 and 47 are located in their highest position. Preferably, shafts 44 and 47 are located on the fixed plane defined by shafts 43 and 46, or even a little higher. On rotating punch lever 6 downward around firmly attached shaft 13, shaft 14 and rods 41 and 42 connected with it (FIG. 3) are moved to the right. This causes triangular lever 37 and 38 to rotate around firmly supported shafts 43 and 46, whereby curved levers 39 and 40 and pressing element 35 connected to them are pressed downward.
This part of the machine accordingly serves to press a clamping back, especially made of wire, lying on part 31, located under pressing element 35.
The design of the actual spreading device according to the invention is partially shown in FIG. 4. N Vertical fingers 51 shown in FIG. 5 are permanently attached to bottom element 2 shown in FIG. 2. Each finger 51 is formed in its lower area with a short horizontal pin 52' (FIG. 5). Fingers 51 are not shown in FIG. 4, to simplify the drawing.
FIG. 4 shows movable ratchet plate 61, consisting of a flat elongated sheet part, provided with N hooks 62 in its front area on its longitudinal edge. As is seen in FIG. 2 and 4, these hooks 62 are designed three-dimensionally, so that, in reference to the view according to FIG. 2, they present a first short section extending horizontally to the front, a second short section extending vertically upward, and a third short section extending horizontally to the left. The horizontal part 52 of hooks 62 corresponds in dimensions to the horizontal pin of fingers 51 (FIG. 2). Horizontal part 52 is therefore located precisely in front of the horizontal part of corresponding stationary finger 51, invisible in FIG. 2.
The spreading device of FIG. 4 includes a lever system with an elongated flat bar 63 and four arms 64, 65, 66 and 67 pivotally connected with it. Arms 64 and 65 are jointly connected through a shaft 68 with one end and arms 66 and 67 are jointly connected through a shaft 69 with the other end of flat bar 63. Arms 64 and 66 are each pivotally connected at their other end to shafts 70 or 71 which are firmly attached to bottom element 2. The anchoring of shafts 70 and 71 to bottom element 2 is not shown, to simplify the figure. Arms 65 and 67 are each pivotally and movably connected at their other free end, through shafts 72 and 73, with one end of the rear area of ratchet plate 61, which is formed with elongated openings 74, 75 and 76, which serve for guiding ratchet plate 61 in a movement from back to front and vice versa.
Ratchet plate 61 is accordingly mounted by means of bolts and screws with ring sliding in bottom element 2. Flat bar 63 is provided with teeth which form toothed rack 77, which collaborates with pinion 78, mounted on a pinion shaft 79 which is supported at bottom element 2 (FIG. 1) in a way not illustrated in detail, to simplify the drawing. In another modification of the design in accordance with the invention, a brake 80 can be present. This is to prevent the return movement of shaft 79 of pinion 78, which can act against the spring force of a clamping back. Shaft 79 of the pinion is rotated manually by spreading lever 3. Brake 80 can include, for example, a sleeve 81 made of elastic material, with an inside recess and a strip spring 82 rolled outside on the sleeve. Due to the pressure of strip spring 82, sleeve 81 is deformed in its central area, which produces a braking effect by friction against the rough surface of shaft 79. This brake can be useful with the use of ridge-shaped punched plastic binder backs.
The spreading device as shown in FIGS. 2 and 4 functions as follows. When spreading lever 3 is rotated upward, pinion 78 moves toothed rack 77 and therefore also shafts 68 and 69 to the right. This causes a shift of ratchet plate 61 to the rear and, accordingly, also a spreading of fingers 51 and hooks 62. A crescent-shaped clamping back held in a closed state between fingers 51 and hooks 62 can therefore quite easily be spread with a simple movement of spreading lever 3, to open it and then bind the sheets of pages. Instead of a pinion, flat bar 63 can also be activated by means of a preferably vertical movable handle rigidly connected to it. Such a handle can be connected at the side, as illustrated in FIG. 4, or at the front with an longation of flat bar 63. Flat bar 63 can also be moved by means of a crank and screw with an axis running parallel to the longitudinal axis of flat bar 63.
FIG. 5 illustrates a design for a combined punch and binding machine with punch lever 6 designed in a U-shape, bottom element 2 with punch holes 90, L-shaped angle section 12, plate bent at right angle with fingers 51, ratchet 61 with hooks 62, pinion 78 with toothed rack 77, punching element 25 with punch teeth 26, L-shaped contact 35, and spreading lever 3. It is seen from FIG. 5 that, for example, shaft 70 (and 71) is firmly attached to bottom element 2. A box 91 is provided to take up the holed paper residues. Box 91 can be pulled out from the rear of bottom element 2. Punch holes 90 can be located in a punch hole plate 92 to facilitate a change in size or shape.
It is also seen from FIG. 5 that shaft 45 (FIG. 3) can be an extension of shaft 21 (FIG. 2), or shaft 48 (FIG. 3) an extension of shaft 22 (FIG. 2), if corresponding recesses 92 are present in angle section 12, to make movement of the shafts (21, 45 or 22, 48) possible.
Punch lever 6 (FIG. 5 and FIG. 1) could also be somewhat bent in the area of its shaft.
To simplify the drawing, the ends of punch teeth 26 represent a straight line in FIG. 1. However, these ends preferably form a stepped line. For example, the teeth can be shorter in the central area of punching element 25 in the end areas.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction(s) without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing(s) shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
What is claimed is:
1. A spreading device for a binding apparatus comprising;a plurality of parallel spaced apart spreading fingers (51) arranged rigidly in a row on a base body (2); a movable plate (61) having a plurality of parallel spreading hooks (62) cooperating with the spreading fingers in order to remove the spreading hooks from the spreading fingers in the spreading device by moving the plate in a spreading direction (A); an elongated bar (63) and movable arm (65, 67) having first ends and second ends, said first ends being pivotally connected to each end of the bar and said second ends being pivotally connected to said plate, thereby connecting said plate (61) to the bar (63) through the two movable arms (65, 67) so that the arms and plate can move in the spreading direction (A) and in a direction perpendicular to the spreading direction; and two arms (64, 66) having first ends and seconds ends, said first ends being pivotally connected to each end of said bar (63) at essentially the same point as said movable arms (65, 67) and said second ends of said arms (64, 66) being pivotally connected to said base body (2).
2. A spreading device for a binding apparatus comprising:a plurality of parallel spaced apart spreading fingers (51) arranged rigidly in a row on a base body (2); a movable plate (61) having a plurality of parallel spreading hooks (62) cooperating with the spreading fingers in order to remove the spreading hooks from the spreading fingers by moving the plate in a spreading direction (A); an elongated bar (63) and a movable arm (65, 67) pivotally connected to each end of the bar and said plate (61) connected with the bar 63 through the two movable arms (65, 67) so that the arms and plate can move in a spreading direction (A) and in a direction perpendicular to the spreading direction; two arms (64, 66) having first and second ends, said first ends of said arms (64, 67) being pivotally connected to each end of said bar (63) and said second ends of said arms (64, 67) being pivotally connected to base body (2); and an operating lever (3) and a pinion (78) rotatable about an axis and mounted on the lever, said bar (63) having a toothed rack (77) for cooperating with the pinion (78), said toothed rack (77) being movable along said pinion axis without separating from said pinion, said pinion being rotatably attached to said base body (2).
3. The spreading device of claim 2, wherein said pinion (78) includes a shaft (79) connected to the lever (3) and a braking device (80) mounted to the shaft (79).
4. A combined punch and binding apparatus for binding a plurality of sheets, comprising:a bottom element (2); punch means including a vertically movable punching element (25) mounted on said bottom element (2) for punching openings in the sheets to be bound; a spreading device including a plurality of parallel spaced apart spreading fingers arranged rigidly in a row on the bottom element; a movable plate having a plurality of parallel spreading hooks for cooperating with the spreading fingers in order to move the spreading hooks from the spreading fingers in a spreading direction (A) by moving the plate; a bar (63) and moveable arms (65, 67) having first ends and second ends, said first ends being pivotally connected to each end of the bar and said second ends being pivotally connected to said plate (61), thereby pivotally connecting said plate to the bar (63) by the two rotatable and movable arms (65, 67) so that the arms can move in the spreading direction (A) and in a direction perpendicular to the spreading direction; and two arms (64, 66) having first ends and second ends, said first ends being pivotally connected to each end of said bar (63) as essentially the same point at said movable arms (65, 67) and said second ends of said arms (64, 66) being pivotally connected to said bottom element (2).
5. The binding apparatus of claim 4, further including vertically displaceable pressing means (35) for pressing clamping elements and a carrier for vertically guiding said pressing means.
6. The binding apparatus of claim 4, further including two shafts (29, 30) and levers (16, 19) connected to said shafts, and a carrier flange (12) connected with said bottom element (2) by said levers (16, 19) to which said punching element (25) is held.
7. The binding apparatus of claim 6, wherein the carrier flange (12) is an angle section having an L-shaped cross-section.
8. The binding apparatus of claim 4, further including a removable elongated box (91) located beneath the punch means.
9. The binder apparatus of claim 4, further including a curved lever (6) for operating said punch means.
| 1993-10-06 | en | 1995-07-11 |
US-24230662-A | Method and apparatus for the production of crumb shells
Aug. 24, 1965 J. K. CAMERON ETAL 3,202,114
METHOD AND APPARATUS FOR THE PRODUCTION OF CRUMB SHELLS Filed Dec. 4, 1962 6 Sheets-Sheet 1 F|G-I INVENTORS JAMES K. CAMERON PARKER WELCH BY ATTORNEYS Aug. 24, 1965 J. K. CAMERON ETAL 3,202,114
METHOD AND APPARATUS FOR THE PRODUCTION OF CRUMB SHELLS Filed Dec. 4, 1962 6 Sheets-Sheet 2 FIG.3 FIG. 4
INVENTOR. JAMES K. CAMERON PARKER WELCH Mar M41,
ATTORNEYS Aug. 24, 1965 J. K. CAMERON ETAL 3,202,114
METHOD AND APPARATUS FOR THE PRODUCTION OF CRUMB SHELLS Filed Dec. 4, 1962 6 Sheets-Sheet 3 5 I F'IGI INVENTOR. JAMES K. CAMERON PARKER WELCH BY ATTORNEYS 1965 J. K. CAMERON ETAL 3,202,114
METHOD AND APPARATUS FOR THE PRODUCTION OF CRUMB SHELLS Filed Dec. 4. 1962 6 Sheets-Sheet 4 INVENTORS JAMES K, CAMERO N PARKE R WELCH ATTORNEYS Aug. 24, 1965 .1. K. CAMERON ETAL 3,202,114
METHOD AND APPARATUS FOR THE PRODUCTION OF CRUMB SHELLS Filed Dec. 4, 1962 6 Sheets-Sheet 5 7 6 9 10 I1 12 13 I4 I! 76 77 I5 )9 Z9 Z1 IN VEN TOR.
ATTGRNEYS Aug. 24, 1965 METHOD AND APPARATUS FOR THE PRODUCTION OF CRUMB SHELLS Filed Dec. 4, 1962 .1. K. CAMERON ETAL 3,202,114
6 Sheets-Sheet 6 ATTOR N EYS United States Patent 3,202,114 METHOD AND APPARATUS FOR THE PRODUCTION OF CRUMB SHELLS James K. Cameron and Parker C. Welch, Charlottesville, Va., assignors to Continental Baking Company, Rye, N.Y., a corporation of Delaware Filed Dec. 4, 1962, Ser. No. 242,306 Claims. (Cl. 107-54) The present invention relates to a novel and improved method and apparatus for the production of baked goods, and, more particularly, to a novel method and apparatus for the production of a graham cracker pie crust.
Pies having graham cracker crust are becoming more popular with the general public, especially cream pics with a graham cracker crust. The significant feature of a good graham cracket crust is its crum-like texture. The problem, however, in connection with the commercial preparation of such graham cracker pie crusts, has been to produce a high quality crust which retains the crumbly texture of the graham crackers, but which is sufficiently knit together to withstand the successive handling and operations entailed in the mass production of pics.
Heretofore, commercial graham cracker pie crusts have been prepared by employing a fiowable wet mix of graham, graham chacker crumbs shortening and water. The wet mix was plastic enough to be shaped into proper arrangement in the pie plate by conventional means. However, such a wet" mix crust loses its crum-like quality and is a poor substitute for a good graham cracker pie crust.
Another method employed heretofore was the preparation of a dough-like mass of the type used for making the graham crackers themselves. This graham dough was sheeted or rolled thin and placed in its respective pie tins and then baked. The resultant crust, again, failed to have the crumb-like quality of a good graham cracker pie crust.
The present invention has for its object the preparation of a good, crumbly graham cracker pie crust, and is characterized by the preparation of a mixture of graham cracker crumbs and shortening in a relatively dry non-flowable mixture. The mixture is then distributed evenly in a predetermined amount over the bottom and side surfaces of an associated pie plate. The graham cracker mix thus disposed in an associated plate is subjected to a compression force which is operative to knit the graham cracker mix into a cohesive crust ready to withstand subsequent manufacturing operations.
To accomplish this object, the graham cracker mix is preferably placed in a supply hopper having a foraminous depositor grill at the bottom thereof, shaped in the general contour of a pie plate. A depositor blade, shaped for cooperative movement along the inner periphery of the depositor grill, is rotatably mounted in the hopper. With the pie plate disposed beneath the depositor grill and in spaced relation therewith, the depositor blade is rotated a predetermined number of revolutions to effect desposit of the required amount of graham cracker mix on the plate. The pie plate with graham mix thereon is withdrawn from deposit position adjacent the depositor grill in timed relationship with the rotation of the depositor blade, such that the plate moves away from the depositor grill just before the blade stops rotating. This ensures that no graham cracker mix will adhere to the bottom of the grill.
The finished crust should have a firmer texture at the top exposed edge of the crust than elsewhere to prevent damage to the crust at its edges during the manufacture of the finished pie. To accomplish this, the sides of the depositor grill are preferably slanted more 3,202,114 Patented Aug. 24, 1965 steeply than the sides of the pie plate. This results in more graham cracker mix being deposited around the side edges of the plate than on the other portions thereof.
The pie plate, with the controlled amount of graham mix deposited thereon, is then subjected to a gentle compression force, preferably in a form of a hydraulic press. This compressive force completes the formation of the graham cracker pie crust by condensing the graham mix into the form of a pie crust. It will be understood that since more mix is disposed around the sides of the plate, when compressed, the sides and top portions of the crust will have the desired firmer texture.
In order to maintain a sufiicient production rate for commercial operation, the apparatus for carrying out the invention includes a rotatable turret having a deposit station and a compression station. Pie plates are mounted on the turret at one station and passed intermittently through and to the deposit and compression stations to a discharge station, with the operations at the several stations being carried on generally concurrently on the plates travelled thereto, thus assuring highspeed commercial production of graham cracker crusts having the proper crumb-like texture heretofore only achieved in home-baked pies.
Objects and advantages of the invention will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.
In the drawings:
FIG. 1 is a front view of an embodiment for the present invention.
FIG. 2 is a plan view of the turret table and associated mechanisms.
FIG. 3 is a detailed front elevation, partly in section, of the mixture deposit mechanism.
FIG. 4 is an enlarged, detailed view (partly in section) of the mixture deposit mechanism in operation with one configuration for the depositor grill.
FIG. 5 is a sectional view illustrating the mixture distribution from the configuration of depositor grill illus trated in FIG. 4.
FIG. 6 is an enlarged sectional detail view of another configuration of depositor grill.
FIG. 7 is a sectional view of the mixture distribution from the configuration of depositor grill shown in FIG. 6.
FIG. 8 is a plan view, partly in section, of the agitator member.
FIG. 9 is a plan view of a portion of depositor grill illustrating the spacing of the grill perforations.
FIG. 10 is a detailed front elevation, partly in section, of the compression die mechanism and associated elements.
FIG. 11 is an enlarged detailed sectional view of the die shown in operative compressing position.
FIG. 12 is a sectional view of a pie plate and finished crust produced by the present invention.
FIG. 13 is a plan view of the die and cap plate with deflector plate removed.
FIG. 14 is a schematic view of the plate lifter mechanism.
FIG. 15 is a schematic diagram of a suitable pneumatic control system for the present invention.
FIGS. 16 and 17 are schematic diagrams of a suitable electrical control system for the present invention.
General description Referring specifically to FIGS. 1 and 2, there is disclosed a preferred embodiment for carrying out the steps of the invention which includes a rotatable indexing table designated generally 10.
Table 10 is comprised of a support plate 12 having a plurality of spaced openings 14 therein. In the embodiient illustrated, plate 12 is provided with six openings although this number may be varied Without adversely affecting the operation of the invention.
hlounted on support plate 12, concentric with each opening 14, is a pie plate or cup holder 16 having an inner surface 17 corresponding to the general configuration of the conventional round pie plate, and adapted to hold an associated pie plate during the operations of forming a graham cracker pie crust therein.
Each cup holder 16 includes a bottom cup plate It upon which its associated pie plate rests. Cup plate 18 rests freely in a groove 20 formed in holder 16 and is provided with cup plate stem section 22 slidably carried in bottom hub 23 of holder 16 seated in opening 14 of plate 12.
Conventional pie plates P are individually placed in each cup holder 16 by the machine operator for travel to and through the deposit station D and the compression station C on indexing table 10.
When a cup holder 16 and associated pie plate are delivered to deposit station D, a litter rod 24 is raised upwardly in the direction of the arrow, FIG. 4, engaging the terminal end of stem section 22 lifting bottom plate 18 and the pie plate P supported thereon from a position inside cup holder 16 as shown in full lines, FIG. 3, to an elevated position as shown in phantom, FIG. 3.
in this elevated position, plate P is positioned adjacent the bottom 26 of graham cracker mix supply hopper 28. Hopper 28 is provided with a foraminous bottom grill section 39, also formed in the general shape of a conventional pie plate. An abutment 32, adapted to engage the lip of plate P in its raised position, maintains the interior of plate P in spaced relation with the outside face 3! of grill 3%.
With plate P in this raised position, an agitator member 34 rotatably mounted in hopper 28 is actuated, revolving in hopper 23 to force the graham cracker mix through perforations 29 in grill 30 and onto the interior surface of plate P (see FIG. 4). The number of revolutions of agilator 34 is controlled to effect the proper deposit of mix onto plate P.
Referring to FIG. 4, it will be noted that agitator 34 is so constructed that the surface 34A thereof corresponds generally to the shape of grill 3t) and is adapted for travel in close relationship with the several sections of the grill 30 to ensure proper deposit of the mix over the entire inside face of plate P to a controlled depth.
When the proper amount of mix has been deposited onto raised plate P, lifter rod 24 is lowered, returning bottom plate 18 and plate P to position in cup holder 16, and the rotation of agitator 34 is interrupted.
Table 10 is then travelled stepwise to present the next successive cup holder 16 with a plate P thereon to station C while a plate P having graham mix deposited thereon is travelled to compression station C where the mix is formed by pressure into a cohesive pie crust.
At station C, a compression member 36, comprising a hydraudually-operated piston 33 and crust-forming die 4% is actuated upon delivery of a cup holder 16 and plate P thereto on table 10. The die 40, shaped in the general configuration of a conventional pie plate, is travelled as selected distance into cup holder 16 and against plate P therein. Die thus exerts a compressive force on the graham mix deposited on the bottom and sides of plate P. This compressive pressure exerted by die 40 forms the mix into a cohesive pie crust strong enough to withstand subsequent pie manufacturing operations, yet having the desired crumbly texture.
When the crust has been so formed the die 40 is retracted and the plate P with the finished pie crust thereon is delivered by table 10 to a discharge station where the operator removes the plate P with the crust thereon from its holder 16 and replaces it with an empty plate P for the next cyclic operation of the machine. It
(i ll Turret table u'zecl'icmism Table 19 comprises a support plate 12 fixed to indexing head 76 of indexing unit 78. Head 76 is mounted for rotation about a central vertical axis. Shaft 77 rotatably r supports head 76 and, in turn, is mounted in suitable hearings in base plate 79 seated on an extension 81 of the main machine frame F. To actuate unit 78 periodically to rotate head 76 in timed relationship to the machine, operator unit '73 is provided with a hydraulic actuating cylinder 8%] and a position-locking cylinder 82. Cylinder 8% effects intermittent rotation of head 76 and plate 12 in timed relationship with other portions of the invention. while cylinder 82 ensures that head 76 and plate 12 are stopped in precise, registered position at the several machine working stations so that the graham mix is properly deposited and compressed on an associated plate P.
Unit '78, including head 76, plate 79, and the hydraulic actuating and locking cylinders 80 and 82, is preferably utilized as a unit and is commercially available as a unit from Air Hydraulics Incorporated, Jackson, Michigan, ldozlel 1509 index table.
Mix deposit mechanism At deposit station D, hopper 23 includes a generally cylindrical housing 42 with a suitable cover 44. A dry" nonllowable mix of graham cracker crumbs, shortening, some water and sugar is prepared and periodically placed in housing 42 by the operator when the supply becomes depleted somewhat. If desired, suitable flavoring may likewise be added to the mix. It has been found that a proper mix can be obtained by adding preferably about 2% 70 to 3% by weight of water to the mix. However, a suitable, non-flowable dry mix can be obtained by adding crumbs and shortening only, the only requirement being that the mix does not normally flow.
As described hcreinabove, hopper 28 has a foraminous bottom grill section 30 with closely spaced openings 29 therein of about one-quarter inch diameter in the preferred embodiment. Section 30 is formed in the conventional pie plate shape or in the general form of an inverted, frustum of a right circular cone having a flat lowermost section 46 and an inclined lateral side surface 48 and a lip section 50 (see FIG. 4).
Since the graham mix in hopper 28 is non-fiowable, the mix remains in hopper 28 and does not pass through openings 29 until urged therethrough by agitator 34.
Agitator 34 in turn includes a pair of opposed elongated spider arms 35 and 37, each having a top section 52 coacting with lip 50 of grill 30, an inclined section 54 adapted for coaction with surface 48, and a bottom section 56 cooperating with section 46 of grill 30.
Supporting agitator 34 in hopper 28 for concentric rotation about a vertical axis in spaced relation with grill section 30 is an operating shaft 58 fixed at one end to agitator 34 at the point where arms 35 and 37 thereof are joined in common. A sleeve 59 enshrouds shaft 58 in hopper 28 to prevent contamination of the mix. The other end of shaft 58 is fixed to and rotates wtih output shaft 60 of right angle gear drive member 62. The transverse input shaft 64 of member 62 is secured by flexible coupling 66 to a drive shaft 68 carried by suitable bearing mounts 71 and 72 on machine frame F. Drive shaft 68, in turn, is connected through clutch coupling to gear reducer 72 and a power source, such as, motor 74.
Clutch coupling 70 is preferably of the SF400 type manufactured by Warner Electric Brake and Clutch Co. of Beloit, Wisconsin.
In one embodiment of the invention, shown in FIG. 6, the side surface 33 of grill 30 is disposed at the same angle generally as is the inclined side surface of the conventional pie plate P. In this arrangement, a generally uniform depth B of mix is deposited over the entire inside surface of the plate (see FIG. 6).
In the embodiment illustrated in FIG. 4, the side surface 33 of grill 30 is inclined more toward the vertical than is the inclination of the sides of plate P. This configuration results in more mixture being deposited along the sides of plate P, and especially the top edges of the sides, as at A (FIG. 5). When this mixture distribution is compressed by die 40, greater density of crust is realized along the top edges of the finished crust where the greater amount of mix was deposited. This produces a finished pie crust with a stronger top edge section, which is the portion of the crust most generally damaged in subsequent pie manufacturing operations.
Mix compressing mechanism At station C, compression member 36 includes, in addition to inverted frustro-conical die member 40, a cap plate 84 fixed to the top of die 40. Die 40 is preferably formed with a hollow internal cavity 86. An electrical heating element 88, such as the type commercially known as Cal-Rod" unit, is disposed in cavity 86 as shown in FIG. 11. Element 88 is suitably connected to a source of electrical potential. Element 88 is effective to heat die 40 to an elevated temperature, preferably about 130 F. This heating of die 40 assists in ensuring release of the die 40 and mix after the compaction cycle.
To further ensure release of the die 40 and mix so that none of the compacted crust adheres to the die 40 after wtihdrawal of the die 40 from the plate P positioned at station C, the outside operative surface 41 of die 40 is provided with a coating 90 of material having a low coefiicient of friction. It has been found that a coating 90 of silicone rubber for die 40 provides satisfactory results. It will be understood that if any portion of the compacted crust clings to die 40 as the die moves out of the plate P, a defective crust will result. However, heating die 40 and providing the silicone rubber coating therefor ensures proper release without any adhering of the crust to the die.
Crumb excess remover Die 40 is also provided with means for removing any excess crumbs after compaction. To accomplish this, there is provided a crumb deflector plate 92 seated on cap 84 with peripheral sections 94 extending beyond the outside edge 96 of die 40. Sections 94 are provided at their outermost edges with a transverse lip section 98.
The annular side wall 100 of die 40 is provided with a groove or slot 102 therein. A plurality of closely-spaced outlet openings 104 are formed in side wall 100 and extend through side wall 100 into edge 96 while communicating wtih slot 102 as shown in FIG. 11 and FIG. 13. In the preferred embodiment, for the nominal seven-inch diameter pie, there are approximately eighty openings 104 disposed about die 40. For simplicity, FIG. 13 merely illustrates a selected few. Suitable spaced air inlet bores 106 through cap 84 connect slot 102 to a suitable regulated source of compressed air (not shown),
In operation, when, during the cyclic operation of the invention, die 40 has entered its associated plate P at station C, air under pressure is introduced into bores 106 and slot 102, and thence through openings 104. The air discharging through openings 104 blows away any excess graham crumbs onto support table 12 and/or against sections 94 of deflector plate 92 and thence onto plate 12.
Pneumatic and electrical control system FIGS. 15, 16 and 17 disclose a suitable schematic pneumatic and electrical control system for selectively actuating the several machine elements in predetrmined, timed cyclic operation.
At the start of the machine operations, the machine operator actuates line control switch 108 and two-pole start-stop buttons 110 and 112 to complete circuits to the hydraulic pump motor 114 and the agitator motor 74 through their appropriate starter motors 116 and 118, respectively. The circuits energizing motors 114 and 74 remain completed until buttons 110 and 112 are suitably actuated by the machine operator at the end of the machine operations. It will be understood, therefore, that motors 114 and 74 remain energized at all times during the cyclic operation of the several machine elements.
The cyclic operations of the machine are effected by a pair of suitable timer motors 120 and 122. Timer 122 controls the cyclic operation of lifter rod 24, while timer 120 controls the cyclic operation of die member 40. The machine operator sets timers 120 and 122 for the desired timed operation of their associated mechanisms.
At the start of the cyclic operation of the machine, agitator 34 is uncoupled from its associated motor 74. During the timed operation thereof, timer 122, through its associated relay 123 and current converter 125, completes a circuit energizing hydraulic solenoid control valve 124. This, in turn, actuates the hydraulic cylinder 126, extending rod 128 thereof. Rod 128 at its terminal end is attached to lifter rod 24, so that extension of rod 128 raises rod 24 upwardly to dispose a pie plate P in the elevated position shown in phantom in FIG. 4.
As lifter rod 24 is moved upwardly, a collar thereon engages the actuating arm 132 of a normally open switch 134, closing switch 134 and completing a circuit energizing clutch coupling 70. The energizing of clutch coupling 70, in turn, effects rotation of agitator member 34 to deposit mix on raised plate P.
At the end of the timing cycle, as determined by timer 122, the circuit energizing solenoid valve 124 is interrupted, deactuating hydraulic cylinder 126 which is preferably of the spring-return type. Deactuation of cylinder 126 effects retraction of rod 128 and lifter rod 24, returning plate P with mixture deposited thereon into its associated cup holder 16 on table 10. The return or lowering of rod 24 effects disengagement of switch actuating arm 132 and collar 130, opening switch 134 and thus interrupting the circuit energizing clutch coupling 70. This, in turn, decouples agitator member 34 from motor 74 and stops rotation of member 34 in hopper 28.
It will be noted from the foregoing that the control members are so constructed and arranged that agitator member 34 cannot be actuated until a plate P is in proper elevated position adjacent grill 30. In like manner, agitator 34 continues to rotate as plate P moves away from its elevated position until arm 132 is completely released by collar 130. This continued rotation of agitator 34, as plate P is moving downwardly, ensures that no graham cracker mix intended to be deposited on the plate P will inadvertently adhere to the bottom of grill 30.
It will be understood that while the foregoing operations are occurring at deposit station D, substantially simultaneously at station C the crust compression operations are occurring. At station C, die member 40 is moved downwardly as soon as table 10 has completed its indexing operation. At the end of the indexing stroke of the turret table indexing cylinder 80, the piston rod thereof (not shown) activates a two-pole microswitch 138. Activation of microswitch 138 completes a circuit energizing timer motor 120. The relay 136 associated with timer 120, in turn, completes a circuit actuating hydraulic solenoid control valve 140, actuating hydraulic cylinder 142. This, in turn, extends the piston rod 144 thereof to travel die member 40, secured by cap plate I 84 to the terminal end of piston 144, into operative compressing position in a filled plate P, positioned at station D on table 10. It will be noted that activation of switch 138 also energizes timer motor 122 to raise lifter rod 24 at station D.
To ensure that the table is in proper registered position during the compression and deposit operations, there is provided another microswitch 146, disposed in the path of travel of a bracket 148 and slidable rod 149 mounted for travel with piston 144. Bracket 148 and rod 149 are adapted to engage the actuating arm 150 of switch 146 (preferably two-pole), moving arm 150 thereof in the direction to complete a circuit energizing hydraulic solenoid control valve 152 to actuate the hydraulic locking cylinder 82, to retain head 76 and table in fixed position, thus ensuring that the table 10 is in precise registry on the compression stroke of cylinder 142, thereby preventing any damage to the machine elements by misalignment. In like manner, this ensures that plate P and holder 16 are properly disposed for plate elevation at station D.
Adjacent the bottommost extent of travel of piston 144 and bracket 148 and rod 149, bracket 148 and rod 149 engage actuating arm 154 of a second microswitch 156. This completes a circuit energizing pneumatic solenoid control valve 158, admitting air under pressure to bores 106 to etlect removal of excess crumbs.
In addition, the piston rod of locking cylinder 82 is adapted to activate a microswitch 162 upon movement of the locking cylinder piston rod toward locking position. Activation of switch 162 completes a circuit energizing hydraulic solenoid control valve 164 to activate hydraulic cylinder 80 for returning the piston thereof from its indexing stroke preparatory to the next movement of table 10.
At the end of the compression cycle, as determined by timer 120, the circuits energizing locking cylinder control valve 152 and hydraulic cylinder control valve 140 are interrupted while a circuit energizing hydraulic sole noid control valve 160 is completed. This circuit effects retraction of piston 144 of cylinder 142, preferably of the double-acting type, moving die away from the plate P at station D.
Upon interruption of the circuit energizing valve 152, hydraulic locking cylinder 82 is deactuated, releasing table 10 for indexing. This also completes a circuit through switch 162 and valve 164 to efiect indexing of table 10. By this arrangement, it is assured that table 10 does not index until die 40 has been retracted from operative compressing position in holder 16 at station C. Upon completion of the indexing stroke of cylinder 80, the timed operations controlled by switch 138 are repeated.
To control the temperature of heating element 88, there is provided a suitable detachable thermostatic control member 166, including a temperature sensing probe 168, an adjustable thermostat 170, electrical connector 172, which connects element 88 to the source of electrical potential through heater 174 and its associated control relay 176.
Probe 163 is adapted to respond to the temperature of die 40 and interrupt the current to element 88 when the temperature of die 40 exceeds the limit set on thermostat 173. When the temperature falls below this limit, the circuit to element 88 is re-established. Thus, the temperature of die 40 can be suitably maintained at the desired temperature.
For operator convenience, the several control elements are mounted on a control panel G on the main machine frame F, as shown in FIG. 1.
It should be understood that while the process and apparatus of the present invention are disclosed in connection with graham cracker pie crusts, other materials, such as other types of crackers, cookies, cereal flakes and the like, can be employed with the present process and apparatus with equal facility to form crumb shells for pies.
Thus, there is disclosed a novel method and mechanism for the high-speed production of graham cracker crusts having the desired crumbly texture not possible heretofore in commercially prepared baked goods.
It should be understood that the above description has been made with reference to the preferred embodiment illustrated in the drawings and that modifications and alterations can be made therein without departing from the invention, except as expressly limited hereinafter in the claims.
What is claimed is:
1. The method of. preparing a graham cracker pie crust comprising the steps of preparing a relatively dry, nonflowable mixture of at least graham cracker crumbs, shortening, sugar and water, said water being added in an amount less than 3% by weight of the mixture, containing said mixture at a source of supply in a container, subjecting said contained mixture to a controlled discharge force and directing the same to etlect deposit of a pro-selected amount of said mixture along the sides and on the bottom of an associated pie plate, and subjecting the entire surface of said deposited mixture at one time to a compressive force to form said crust.
2. The method as defined in claim 1, including the step of depositing more of said mix on the sides of said plate than on the bottom thereof whereby there is formed a firmer texture on the top edge of said finished crust.
3. The method of preparing a graham cracker pie crust as defined in claim 1, comprising the steps of withdrawing said pie plate from adjacent said container in timed relation to deposit to prevent adherence of the mix to the bottom of the container.
4. The method of preparing graham cracker pie crusts comprising the steps of preparing a relatively dry, nonflowable mixture of at least graham cracker crumbs, shortening, sugar and water, containing said mixture in a supply hopper having a foraminous bottom section, travelling a plurality of pie plates seriatim to and past said hopper, moving each of said pie plates positioned thereat and said hopper relatively toward each other to dispose said plate adjacent said foraminous bottom section of said hopper, urging a controlled amount of mixture through said foraminous bottom section and onto the sides and bottom of said pie plate, moving said plate and container relatively away from each other, travelling said filled plate intermittently to and past a compression station, and subjecting said plate to an axial compressive force to form said crust.
5. The method as defined in claim 4, wherein said plate at said compression station is subjected to both heat and an axial compressive force to form said crust.
6. The method as defined in claim 4, including removing any excess mixture from the formed crust upon application of said compressive force.
7. The method of preparing graham cracker pie crusts comprising the steps of preparing a relatively dry, nonfiowable mixture of at least graham cracker crumbs, shortening, sugar and water, said water being added in an amount of 2/2% by weight of the mixture, containing said mixture in a supply hopper having a bottom section, travelling a plurality of pie plates seriatim to and past the bottom of said hopper, moving each of said pie plate upwardly toward said hopper to dispose said plate adjacent said bottom section of said hopper, subjecting said contained mixture to a controlled amount of rotary action to discharge a selected amount of mixture through said bottom section and onto the sides and bottom of said pie plate, moving said plate downwardly away from said hopper, travelling said filled plate intermittently to and past a compression station, and subjecting said plates at said compression station to heat and an axial compressive force to form said crust.
8. Apparatus for the production of graham cracker pie crusts comprising a container for holding a supply of relatively dry, non-flowable graham cracker mix, a grill, means mounting said grill on the bottom of said. container with the openings in said grill communicating with the interior, means for disposing a plurality platessenstint in adjacent spaced relation with said grill, a travelling element, means mounting said element for travel in said container adjacent said grill to urge said mix in said container through said grill and onto said adjacent pie piatenlneans for travelling said element a prc-oclccted amount thereby controlling the amount of mixdeposited onto said plate,fmeans for operating saidelernent in timed relation with disposition of a pie plate adjacent said grill, and presnrre means for eohesively binding said mixttu'einsaid plates intoaformed piecrust.
9. The apparatus as defined in claim 8, including heat means with said pressure means for facilitating complete release of said pressure means and said formed crust. 1
l0. Apparatus for the production of cracker pie crusts comprising a container for holding a supply of relatively dry, non-flowable graham cracker mix,-a mill, means mounting said grill onthe bottom of saidcontainer with the openings in said grill communicating viithtltc interior, means for disposing a plurality of pie plates seriatim in adjacent spaced relation with said grill, a rotatable impeller element, means mounting said impeller for travel in said container adjacent said grill to urge said mix in said container through said grill and onto said adjacent pic plates, means for rotating said element a preselected number of revolutions for controlling the amount of mix deposited onto said plate, means for operating said impeller in timed relation with the disposition of a pie plate adjacent said grill, a die member, means for positioning said filled pie plates seriatim adjaccnt said die member, means mounting said die for travel into and out of said filled pie plates disposed adjacent thereto to cohesively bind said mixture on said plates into a finished pie crust.
It. The invention as defined in claim 10, including heat means opcmtively associated with said die member for maintaining said die at an elevated temperature to t acilitate complete release of said die and finished crusts upon withdrawal of said die from said plates.
12. The invention as defined in claim 10, including a coating of plastic material on the mixture-engaging face of said die, said plastic material having a low coefficient of friction to onset with said heat means to ensure completerelease of said die and finished crusts.
13. Apparatus for the production of graham cracker pie crusts comprising a container for holding a supply of relatively dry, non-flowable mixture of at least graham cracker crumbs, shortening, sugar and water, said water beingadded in an amountup to3% by weightofsaid mixture, a grill, means mounting said grill on the bottom of said container with the openings in said grill communieating with the interior of said container, an intermittently-travelling turret member, means on said turret for loosely and individually holding a plurality of pie plates, means for indexing said turret about a central vertical axis to travel each of said plates individually to and through a plurality of work stations including a filling and a compression station, means for disposing a pie plate on said turret at said filling station in adjacent spaced relation with said grill, a rotatable impeller, means mounting said impeller for rotation in said container adjacent said grill to urge said mix in said container through grill and onto said adjacent pie plates, means for rotating said element a pro-selected amount for controlling the amount of mix deposited onto said plate, means for interrupting the operation of said impeller until the disposition of a pie plate adjacent said grill, a die member at said compression station, means mounting said die member for travel into and out of tilled pic plates on said turret indexed to said compression station, said die member being operative to cobesively bind ssld mixture in said pie plates into a tlnisbcd pie crust.
llrjhe invention defined in claim 13, lo -hiding operating means inter-relating the movement of said turret, said plate disposing means, said impeller and said die for effecting hlgh speed production of .said pie crusts.
15. Apparatus for the high-speed production of graham cracker piecrusts comprisingin combination ,a container for bolding a supplyof relatively dry, non-flowable mixture of at least graham cracker crumbs, shortening, sugar and water, said water being addedln an amount bill 4% by weight of said mixture, a grill, means mounting'said grill on the bottom of saldcontainer with vthe openings in said.;grillcommunicating with the interior of saidcontainer, a rotatable turrettnc'mbcr, means for indexing .said turret about a central vertical axis, holders on turret for loosely and individually retainmg a pluralityof pie plates contemporaneously on said turret, said turret being operative holders and an associated pie plate to and through a plurality of work stations, including a filling and a compressiois' station, plate lifter means at said filling station for and lowering assoeiatedtholders and into and out of adjacent spaced relationship with said grill, is rotatable impeller in said container, means for rotating said impeller to force said mixture from said container through said grill into an adjacent, elevated pie plate, control means for said impeller rotating means to control the amount of mixture deposited onto an elevated plate, means for interrupting the operation of said impeller until a plate is disposed adjacent said grill, operating means for said plate lifter means, a die member at said compression station, means mounting said die member for travel into and out of filled pie plates on said turret in their associated holders registered at said compression station, said die member being operative to cohesively bind said mixture in said plates into a finished pie crust.
16. The invention as defined in claim 15. including operating means inten'elating the movement of said turret, said plate disposing means, said impeller and said die for elfecting high-speed production of said pic crusts.
11. The invention as defined in claim 15, including heater means opetatively associated with said die memberforheatingsaiddie to facilitate release ofsaiddie and formed pie crust.
18. 111: invention as dcfimd in claim 15, including a coating on said die of a plastic material, said plastic material having a low coefficient of friction to enact with said but means to ensure complete release of said die and finished crusts.
19. The invention as defined in claim 15, including means for removing excess mixture from said finished pie crusts comprising a deflector plate mounted on said die member for movement therewith, extensions on said defleetor plate extending beyond and spaced from the pe riphery of a plate holder at said compression station, air outlet means in said die directed to the periphery of said holder where said tion, means for admitting air under premure to said outlet means when said die is in operative position for blowing excess mixture particles against said deflector plate extensions and away from said finished pie crust.
20. The method of preparing crumb shells for pics from materials such as, crackers, cookies and the like comprising the steps of preparing a relatively ry. noullowable mixture of at least said material crumbs and shortening, containing said mixture in a supply hopper having a foraminoos bottom section, travelling a pluralily of pie plates seriatim to and past said hopper, moving each of said pie plates positioned thercat and said hopper relatively toward each other to dispose said plate adjacent said forsminous bottom section of said hopper. urging a controlled amount of mixture through said ioraminous bottom section and onto the sides and hotto travel each of said pie plates from and to their die is in operative compressing posi- 11 tom of said pie plate, moving said plate and container relatively away from each other, travelling said tilled plate intermittently to and ast a compression station, and subjecting said plate to an axial compressive ioroe to form said crust.
21. line method as defined in claim 20, wherein said plate at said compression station is subjected to both heat and an axial compressive force to form said'crust.
22. The method as defined in claim 20, including removing any exces mixture from the formed crust upon application of said compressive force.
23. The method of preparing a crumb shell for pics from materials such as crackers, cookies and the like comprising the steps of preparing a relatively dry, nonilowable mixture of material crumbs, depositing a controlled amount of said mixture along the sides and on the bottom of the pie plate, and subjecting the entire surface 7 of said deposited mixture to heat and a compressive force attheseme time to formsaid crust, saidheatcusuring complete release of said finished crust and said compreseive force. v
24. Apparatus for the production of crumb shells for pies comprising a container for holding a supply of relatively dry, non-flowabie crumb mix, a grill, means mountingsaidgrilionthebottomofsaid containerwiththe openings in said grill communicating with the interior,
means for disposing! plurality of pie plates serlatim in adjacent spaced relation with said grill. a travelling element. means mounting said element for travel in said container adjacent said grill to urge said mix in said container through said grill and onto said adjacent pie plates. means for travelling said element a pro-selected amount thereby'controlling the amount of mix deposited ontosaid plate, means toroperatingsaid element intimed solution with the disposition oi a pie plaleidlflcent said grill, and pressure means for cohesively ture in said plates intoa formed pie crust.
25. The apparatus as defined in claim-24, incuding' heat means associated with said pressure means for facilitating complete release of said pressure means and said formed crust.
mum w mu Erma UNIIED STATES PATENTS 8i7,488 4/06 l-lutchison 101-1.: 1,330,01s 2/20 Wiilcox 107-5428 1,725,835 8/29 Smith tor-1.5 2,111,021 s/ss Bemis 107-5428 2,220,324 4/42 Tracy tor-1.5 3,022,151 2/62 Dohring 101-5420 WALTER A. SCHEEL, Examiner.
h d s aid 'm x-
23. THE METHOD OF PREPARING A CRUMB SHELL FOR PIES FROM MATERIALS SUCH AS CRACKERS, COOKIES AND THE LIKE COMPRISING THE STEPS OF PREPARING A RELATIVELY DRY, NONFLOWABLE MIXTURE OF MATERIAL CRUMBS, DEPOSITING A CONTROLLED AMOUNT OF SAID MIXTURE ALONG THE SIDES AND ON THE BOTTOM OF THE PIE PLATE, AND SUBJECTING THE ENTIRE SURFACE OF SAID DEPOSITED MIXTURE TO HEAT AND A COMPRESSIVE FORCE AT THE SAME TIME TO FORM SAID CRUST, SAID HEAT ENSURING COMPLETE RELEASE OF SAID FINISHED CRUST AND SAID COMPRESSIVE FORCE.
| 1962-12-04 | en | 1965-08-24 |
US-64160875-A | Method and apparatus for aligning read/write heads in a disc recorder
ABSTRACT
In a magnetic disc recorder utilizing a servo head to generate a feedback signal for the positioning of the heads on the recording disc, a method for aligning the read/write heads with the servo heads by eliminating substantially all of the effects of head movement occurring during the head alignment procedure.
BACKGROUND OF THE INVENTION
In present day recording devices and particularly in disc drives there is employed a plurality of recording discs on which data can be recorded in binary form. These discs are usually referred to as a disc pack and are stacked one above the other to be addressed by a plurality of heads in vertical alignment and positioned by a single actuator.
In one embodiment of disc drives used today, one head and one disc surface are dedicated to the generation of a position signal for the servo system. Usually a plurality of servo tracks are recorded in concentric circles on the servo disc surface and the servo head generates a signal responsive to the relative position of the head and each servo track. Thus if the servo head is aligned over a desired track and the other heads are aligned with the servo head, they also will be aligned over a corresponding track on the respective cooperating disc surfaces.
For interchangeability of the disc packs, the various tracks recorded on each of the disc surfaces must be closely aligned with the prerecorded servo track so that the readback of the data from each disc pack is possible on recorders other than the one in which the data was recorded. Thus the normal procedure for assuring that the heads are in alignment vertically is to place on the drive a disc pack having prerecorded and precisely positioned servo tracks on all of the disc surfaces. Such prerecorded disc packs are referred to as CE or Customer Engineer Packs and are commercially available with disc drives for use in aligning the heads. Thereafter the actuator is energized to position the servo head at a desired track. By reading the signals from the individual heads and feeding such signals to a readout means, usually a visual type such as a signal strength meter, it can be detected whether or not that particular head is in close alignment with the data track corresponding to the track the servo head is positioned over. Thereafter provision is made for adjusting the position of each head/arm assembly relative to the carriage and therefore relative to the servo head. By making the necessary adjustment on each head to maximize the signal, the heads are brought into alignment with the servo head.
However problems have developed which make the alignment procedure just described either very difficult to perform or make the results less than satisfactory. For instance, the presence of the technician around and in contact with the disc drive results in vibrations being transmitted throughout the mechanism thereby making the servo signal hard to read. In addition the various normal vibrations in the building in which the drive is located are sensed by both the servo head and the read/write heads causing the position signal to be modulated by all types of other signals and even more difficult to read. Also there are other forces being exerted on the positioning system such as the force of the electrical leads running to the head and the pressure of the technician's tools while making the necessary adjustments, which forces tend to move the servo system off track sufficiently such that alignment of the head to that position will not align the head directly over the track once the force is removed since the servo system head has been moved off track slightly during the adjustment by the force. Thus after such adjustment the servo head will return to a center position and in doing so will move the read/write heads somewhat off track.
It is thus the object of this invention to provide an improved method and apparatus for aligning the read/write heads relative to the servo system in a disc drive assembly.
SUMMARY OF THE INVENTION
A method of aligning the read/write heads and the servo head in a disc drive wherein the servo system detects predetermined positions and in which the heads are aligned therewith by use of a prerecorded servo pack having closely aligned tracks prerecorded for each head, comprising the steps of moving the carriage assembly to position the servo system at a desired track, detecting the signal read by a first read/write head being adjusted and subtracting from that signal another signal detected by a second read/write head to generate a differential signal having the extraneous signal modulations deleted, and utilizing that differential signal while adjusting the position of the first read/write head for maximum signal output from the read/write head and a minimum differential signal. In addition, means are provided for stiffening the response of the servo positioner so as to resist the normal forces tending to move the heads off of the track during the adjustment of the head position relative to the servo system.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side plan view partially in cross-section of a typical disc drive apparatus;
FIG. 2 shows in enlarged detail one method of mechanically adjusting the head/arm positioning; and
FIG. 3 shows a partial disc drive apparatus in perspective view with the circuit in block diagram for aligning the read/write heads with the servo system in accordance with the present invention.
DESCRIPTION OF THE INVENTION
In the drawings are shown some of the major components of a disc drive to which the invention is particularly applicable. The drive is utilized to read and record data on a disc pack 10 and includes a read/write head assembly 11 and a linear motor 12 mounted on a baseplate assembly 14 for the purpose of reading and writing information in digital form on the individual surfaces of the discs 15. The disc pack 10 serves as a memory device and comprises a plurality of discs having a magnetic coating on the upper and lower surfaces (not shown) on which data in digital form can be recorded magnetically. The discs are mounted in a support 16 having an opening 17 in a lower plate 16A into which a spindle shaft 18 extends. The spindle shaft, lower plate and disc pack include abutting machined surfaces such that when mounted on the shaft the disc pack is precisely positioned relative to the baseplate assembly 14. The spindle shaft is supported by bearings 19 and 20 fixed to the baseplate so as to permit rotation of the spindle shaft and the associated disc pack. A motor 21 drives the spindle shaft and the disc pack through a drive means including a drive belt 22 and a pulley 22a on the spindle shaft.
For reading and writing information on the disc pack surfaces, a read/write head 24 is supported on an arm 25 in close proximity to an associated disc magnetic surface. The arms are mounted on a support assembly 26 comprising a T/block 27 fixed to a carriage having a plurality of rollers 28 for movement along a rail 29 fixed to the baseplate. Linear movement of the support assembly shifts the heads in a direction radially of the disc surfaces. By proper energization of the read/write heads, information in digital form can be transferred to and from the disc surfaces as the disc pack is rotated past the head. Thus data is recorded and read back from tracks in concentric circular locations on the disc surfaces. For a more complete explanation of such an apparatus, reference can be made to the U.S. Pat. No. 3,587,075 entitled Carriage Mechanism For Direct Access Data Storage Device, Brown et al. as inventors and issued on June 22, 1971, and U.S. Pat. No. 3,768,083 entitled Baseplate Assembly For A Disc Drive, Ivan Pejcha as inventor and issued on Oct. 23, 1973.
To effect movement of the support assembly 26 along the rail 29, the electromagnetic linear motor 12 includes an outer pole piece 30 fixed in a stationary position for magnetic interaction with a movable coil 32 attached to the T/block 27 of the support assembly 26. With proper energization of the coil by passage of electric current therethrough, a magnetic interaction between the coil and stationary pole piece 30 will cause the support assembly to move along the extending rail 29 in a direction lateral to the axis of rotation of the disc pack 10. Thus by moving the support assembly in a direction towards and away from the axis of rotation of the disc pack, the heads are positioned adjacent the concentric data tracks on the disc surface. In this manner the head 24 is moved across the disc surface and positioned over the desired data track for the transfer of information in digital form between the head and the disc surface. Electrical signals carrying this information are transmitted through the electrical leads 34 for transmittal to computers and other apparatus (not shown) utilizing the information.
As an illustration of one means for detecting the position of the heads, there is provided a servo system including one servo head 35 positioned adjacent the bottom disc 15B (FIG. 1). This head is dedicated to the detection of the position of the carriage and heads and normally is not utilized to write information. Prerecorded tracks on the surface of the disc 15B are provided for indicating the various track locations at which data can be recorded on the other disc surfaces. Thus with movement of the head 35 and the carriage, the signal from the surface of the disc 15B is detected and fed into a servo system for determining the location of the servo head 35. By detecting the location of this servo head, the location of all of the read/write heads stacked vertically relative thereto is also indicated.
The servo signal is transmitted through the conductor 37 to a preamplifier 38 and on to a noise-limiting band-width filter 39 and a dibit servo-pattern demodulator 40. From there the signal in modified form is transmitted through the conductor 41 to a servo compensation circuit 42 similar to that disclosed in U.S. Pat. No. 3,808,486 entitled Selective Frequency Compensation For A Servo System, Cuda et al., issued on Apr. 30, 1974. To complete the position servo loop the circuit includes a power driver 44 such as that disclosed in U.S. Pat. No. 3,582,750 entitled Power Driver For Regulating A Servo Motor, Martin Halfhill, Inventor, and issued on June 1, 1971.
Thus the position servo loop is utilized to develop a signal for comparison with a signal indicative of the desired position of the head and received at the terminal 45 for generation of a position error signal to energize the actuator through the conductor 46 and locate the head at the desired track. With the head at the desired track, data can be read by use of one of the heads such as the read/write head 24, which data is transferred through the conductor 50 to a preamplifier 51, a noise-limiting band-width filter 52 and a dibit pattern demodulator 54 for supplying a signal to the conductor 55 leading to a data readout channel. These circuit components are of standard design and commonly used in such data channels. Thus data can be read from the desired track or data can be recorded on a desired track with the track location being sensed by the position servo loop.
The disc packs 10 are removable and replaceable with other disc packs. Thus it is necessary to closely control the position of all of the read/write heads relative to the associated servo head or servo system such that data recorded on one disc pack can be detected and read back on any disc drive or vice-versa. Obviously if the heads are misaligned relative to the servo system positions or tracks, the data can be read back on the same disc drive but other disc drives not having the heads in a similar misalignment cannot read back the data. Thus in the embodiment shown it is necessary to closely align the read/write heads with the servo head in a single vertical plane.
For alignment of the heads, there is utilized a special recording medium or prerecorded disc pack having data tracks prerecorded on each of the disc surfaces and closely aligned in a vertical plane. Such a pack utilized in aligning the read/write heads is commonly referred to as a CE pack or a Customer Engineer Pack. The packs are made available to customers by disc drive manufacturers for head alignment purposes. For instance one such pack is sold by the Sperry Rand Corporation, Part Number 9023567-00. Such a disc pack is placed on the drive and the signal from each read/write head is detected individually. Thereafter as shown in FIG. 2, a screw 56 is loosened on each arm assembly, and a head alignment tool 58 is inserted with the studs 59 fitting into cooperating openings 60 and 61 in the T/block and arm respectively. The radial position of that head/arm assembly thus can be shifted in the horizontal plane by rotation of the screw 57 on the head alignment tool thereby causing the studs 59 to move clear or further apart to shift the arm until a maximum signal is detected. However experience has shown that the pressure on the screw 57 tends to hold the carriage assembly and associated heads off center from the recorded track. In addition the force of the conductors 34 (FIG. 1) is sufficient also to bias the carriage laterally a short distance away from the track. Further, the cooling air supplied to the disc pack tends to bias the heads away from the center position over the track. All of these conditions tend to shift the position of the carriage such that the servo head is not positioned directly over the servo track even though the servo system indicates this position, therefore adjustment of the position of the read/write head to a maximum signal position will result in some misalignment between the adjusted head and the servo head. With the recording densities being increased with each generation of magnetic disc recorders, such misalignment can become more critical as the recorded data tracks become narrower and closer together.
In addition, since the adjustment of the head is usually accomplished by a visual observation of the signal detected by the read/write head being adjusted, problems of vibration in the disc drive can complicate the proper reading of that signal. For instance, the adjusting tool held by the technician will tend to cause the head to shake or vibrate due to the natural movement of the hand. In addition, any contact with the drive or any vibration transmitted through the floor will tend to modulate the signal detected by the head by causing movement of the head relative to the disc surface. It therefore becomes very difficult to detect just when the signal indicates the head is centered over the data track. In accordance with the present invention, a method is provided for substantially reducing the preceding problems for permitting a more correct alignment of the servo head with the read/write heads.
In accordance with one feature of the invention, the signal generated within the servo system is subtracted from the signal generated in each read/write head circuit and the resultant differential signal is observed and used for adjusting the position of the read/write head. Such is accomplished by the transmission of the read/write head signal through the conductor 58 to a junction 59 which receives also through the conductor 60 servo head signal. The juncture subtracts the servo signal from the data signal and the resultant signal is fed to a suitable readout device 61 which in most instances is a signal strength meter of suitable design and commonly used in the industry. In the alternative, one read/write head signal can be subtracted from that of another read/write head to eliminate the common modulations of the signals.
By subtracting the signals, most of the extraneous modulations of the signal due to carriage movement are removed. For instance, the signal modulations due to vibrations being transmitted to the drive through the floor on which it is setting, vibrations transmitted to the carriage by the tools used to adjust the head/arm position, and vibrations within the drive due to the operation of the drive motor for the disc pack, the cooling air, et cetera, are substantially eliminated making the signal much easire to observe. Thus a less modulated signal is fed to the readout device and the readout device indicates in a more precise and readable manner the signal actually generated by the read/write head responsive to the track prerecorded on the special disc used for such adjustments. Since the position of the head is only adjusted to generate the minimum relative signal the subtraction of the servo signal from the read/write head signal has little or no other effect on the operation other than eliminating the common modulating signals therefrom.
In accordance with another feature of the invention the servo system is greatly stiffened -- that is, adjustment is made to the system such that a much greater force is necessary for moving the head, arm and carriage assembly off-track by an external force than is normally encountered during standard operation of the disc drive. By this adjustment of the operation of the servo system, the forces previously described, and specifically the force of the tools exerted during adjustment of the head/arm position, are rendered insufficient for moving the head/arm assembly and carriage off track.
For this purpose, there is provided in the position servo loop a switch S which when opened, connects a lag-lead compensator circuit in the position servo loop circuit. When the switch S is closed, the compensator capacitor is shorted out and has no effect on the operation of the servo circuit. The use of such a circuit tends to substantially leave the higher frequency signals unaffected because the capicator in effect becomes a short at higher frequencies thereby tending to react to the higher frequency signals as a switch acts when closed. Lower frequency signals result in charging or discharging the capacitor, thereby changing the command signal to the actuator. Thus a low frequency signal, such as results from an offset from track center, causes the capacitor to charge and thereby command the actuator in such a manner as to drive the low frquency signal towards zero, when the low frequency signal reaches zero, the capacitor will neither charge nor discharge and therefore the charge on the capacitor continues to command the actuator. In this manner the capacitor develops the charge that is required to exactly cancel the low frequency disturbance.
The invention claimed is:
1. In a recording device for recording data on a medium and having a plurality of read/write heads and a servo head mounted for simultaneous movement on a carriage effected by energization of an actuator acting responsive to a servo signal detected by the servo head, and wherein the read/write heads are mounted in a manner to allow fine position adjustment relative to the servo head;the method of aligning the read/write heads relative to the servo head comprising the steps of: placing on the recording device a medium having prerecorded aligned signals positioned to be detected by the read/write heads and servo head simultaneously to indicate track positions; detecting the signals read by the servo head and the read/write heads; subtracting the signals of one read/write head from the signal of the servo head to generate a differential signal; and manually fine adjusting the position of said one read/write head to minimize said differential signal.
2. In the method of aligning the read/write heads as defined in claim 1 including providing means for supplying only the low frequency servo signals to the actuator to thereby make said actuator more resistant to movement resulting from external forces acting on said carriage; andenergizing said means to make the actuator more resistant to movement when the position of said one read/write head is being adjusted.
3. In the method as defined in claim 2, said means to make said actuator more resistant to movement comprising a circuit for receiving and storing the servo signal when said servo signal is in the lower frequency ranges and for supplying said lower frequency signals to control energization of said actuator when the position of said one read/write head is being adjusted.
| 1975-12-17 | en | 1978-02-21 |
US-63918357-A | Therapeutic compositions containing heat-treated attapulgite
Zeus
other clay minerals.
United States Patent Otiice 2,918,405 Patented Dec. 22, 19 59 THERAPEUTIC COMPOSITIONS CONTAINING HEAT-TREATED ATTAPULGITE Martin Barr, Philadelphia, and Anthony L. Monaco, Norristown, Pa., assignors to American Home Products Corporation, New York, N.Y., a corporation of Delaware No Drawing. Application February 11, 1957 Serial No. 639,183
Claims. (Cl. 167-65) This invention relates to therapeutic compositions intended for internal use which contain heat-treated Attapulgus clay as an adsorptive agent. More particularly,
our invention is concerned with therapeutic compositions which contain attapulgite clay, which has been subjected to heat treatment as an ingredient replacing the kaolin whichis frequently present in these medicinal or therapeutic suspensions having effective adsorptive action. By
heat-treated Attapulgus clay is meant that modified form of the naturally occurring clay product which, previous to its incorporation in the medicinal or therapeutic suspension, has been subjected to heating at a temperature silicate. De Lapparent has suggested for this hydrous magnesium aluminum silicate the empirical formula: (OH) H Al Mg Si H O X-ray diifraction data and diiferential thermal analysis curves give definite support to the conclusion that attapulgite is a distinct species, distinguished from mica, montmorillonite and other clay minerals.
Attapulgite particles have a lath-like character with long double chains of composition Si O running parallel to the fibre axis. The double chains of Si O are joined by magnesium and calcium, as well as through shared oxygen atoms. A complete planar sheet of oxygen atoms is thus produced, arranged exactly as in the micas and However, as contrasted with the micas, the silicon atoms in attapulgite form long strips alternately on the two sides of the oxygen sheet. The magnesium-aluminum-oxygen units are also placed in strips parallel to the fibre axis. Channels which have a free cross-section of 3.7 to 6.0 Angstrom units, i.e. large enough to admit molecules of considerable size, run parallel to the fibre axis. These channels, however, have no interconnections of comparable size. In the natural Attapulgus clay loosely-retained water molecules occupy a considerable part of this space. On dehydration of the attapulgite by heating at moderate temperatures such as those which are utilized in the preparation of heat- ,'treated attapulgite which -we incorporate in therapeutic compositions, water molecules present in the raw clay material are removed, but the structure of the mineral remains substantially intact.
Attapulgus clay is hygroscopic and is readily dispersed in water. The naturally occurring clay has marked ,adsorptive properties, which are, however, usually enhanced by thermal activation such as by heating within the'range 250-900" F., for a period of time ranging from 15 to minutes. Particles of attapulgite have a diameter of from 10 to 50 millimicrons and a surface area calculated as 150 square meters per gram, this latter figure giving an index as to the high adsorptive properties of the mineral. The superior. adsorptive properties of attaplllgite'are yattribute'dto its needle-like crystal struc- In contrast, kaolin occurs as scales or plates, either rhombic or hexagonal, which are non-porous and therefore possess less surface area on an equal weight basis.
In addition to attapulgite, Attapulgus clay as commercially supplied contains some free silica, calcite and iron minerals. Spectrographic analysis shows traces of manganese, nickel, chromium, zinc, copper, lead, tin, vanadium and silver.
While Attapulgus clay, being a natural product, may vary to some extent in chemical composition depending on the source and other factors, the chemical composition of a typical attapulgite may be illustrated by the following summary giving compositions of three commerciallyavailable clays. i
TABLE I Percentage Constituent Oomposi- Composi- Composition A tion 13 tion 0 uents 3. 0 Balance Balance Many therapeutic compositions intended for internal use, usually termed intestinal adsorbent compositions, are characterized by the presence therein of an adsorptive clay as one of the adsorptive agents. In the past it has been customary to utilize kaolin as the clay. Kaolin, which is included in the most recent edition of the National Formulary, has important aclsorptive properties for bacterial toxins and other poisons. But therapeutic compositions containing the usual ingredients including, however, the hydrous magnesium aluminum silicate, Attapulgus clay, which has previously been subjected to heating at a temperature within the range 250- 900 F. for a period of time ranging from 15 to 30 minutes in place of the kaolin, in accordance with our invention, will exhibit much superior adsorptive activity.
Compositions containing an adsorptive and, generally, an alkaline agent such as alumina gel, are frequently administered internally for combating bacterial infections. They are particularly effective for adsorbing toxins produced in the patients stomach and intestines by bacteria. They are also effective as adsorbents for other toxic substances which find their way into the human gastroenteric tract, whether produced by food decomposition, or otherwise. Among microorganisms that are frequently causative agents in infections of the gastrointestinal tract and whose toxins are adsorbed when these pharmacological preparations containing clay are taken internally may be mentioned the following: Staphylococcus aureus, Proteus morgnnii, Proteus vulgar-is, Salmonella typhimurinm, Salmonella enteritidis, Salmonella montevideo, Shigella dysenteriae, Shigella paradysenteriae, Shigella .alkalescens, and Shz'gella dispar.
Therapeutic compositions of this general type frequently contain other active ingredients, such as one or more of the antibiotics. One or more antispasmodic agents, which are especially beneficial in preparations intended to be eflective in the gastrointestinal tract, are also frequently present. These therapeutic compositions often contain other active ingredients in addition, such as pectin, inorganic silicates such as the product sold commercially under the trademark name Veegum, etc., as Well as sweetening, flavoring and coloring agents, preservatives, and other ingredients. (Veegum is purified colloidal magnesium aluminum silicate effective as a suspending and emulsifying agent which is sold under this trademark by R. T. Vanderbilt Co. of 230 Park Avenue, New York, N.Y.)
Specific compositions of this type which contain heattreated Attapulgus clay as the primary adsorptive agent,
and which are intended to be taken into the gastrointestinal tract for the purpose of adsorbing toxins and other toxic products which may be present therein, are
' subsequently described.
We have discovered that it Attapulgus clay which has been subjected to heat-treatment at a temperature within the range 250-900 F. for a period of time ranging from 15 to 30 minutes is used in place of the usual kaolin constituent of these therapeutic preparations, the adsorptive properties are greatly increased. Our invention is there- 'fore directed to the utilization as the clay ingredient, in
place of the usual kaolin, of one or more forms of the naturally occurring hydrous magnesium aluminum silicates known as attapulgite, which has previously been subjected to heat-treatment within the temperature range specified for a period of time ranging from 15 to 30 minutes.
One of the commercially-available attapulgites that has been found especially suitable for use in our improved therapeutic compositions intended for internal use is supplied by Minerals and Chemicals Corporation of America under the trademark name Attasorb. This product, which is prepared by a heat treatment which involves heating the clay to a temperature within the range 250900 F. for a period of time ranging from 15 to 30 minutes utilizes as the Attapulgus clay a product Attapulgus clay product known as Attasorb LVM is prepared by activating the attapulgite by heating within the temperature range 700 F. to 900 F. The grade known as Attasorb RVM is prepared by heating within the temperature range 400 F. to 700 F. That known as Attasorb HVM is prepared by heating within the range 250 F. to 350 F. The duration of the heating period, in each instance, may vary somewhat, but in all cases it is between 15 minutes and 30 minutes after the charge of Attapulgus clay being heated has reached a temperature within the indicated range.
When heating Attappugus clay within the temperature range 250 F.350 F, employed in the preparation of Attasorb HVM, destruction of the colloidal properties of the mineral occurs at these temperatures. Attapulgite activated by heating within this temperature range exhibits the greatest dispersibility in water. While adsorptive properties are somewhat less than the maximum characteristic of the other grades of Attasorb, i.e. heattreated Attapulgus clay, the difference appears to have no practical significance.
Attasorb RVM, prepared by heat treatment of the Attapulgus clay within the temperature range 400 F. to 700 F. exhibits optimum adsorption characteristics. Its water-dispersibility is less than that of Attasorb HVM.
The grade of the heat-treated product known as Attasorb LVM is characterized by adsorption properties somewhat less than the maximum obtainable. Its waterdispersibility is less than that of the other two grades.
As illustrative of the water content of these three prod-i ucts, after completion of the activation by heating, with: in the specified temperature ranges, the following percentages are typical:
When incorporated in therapeutic compositions, espeicially intestinal adsorbent compositions, in accordance with our invention, all three grades of heat-treated Attapulgus clay, Attasorb LVM, Attasorb RVM, and Attasorb HVM, will give improved products exhibiting properties much superior to those of the usual types of these compositions containing kaolin as the adsorbent clay. However, where dispersibility in aqueous systems is of importance, superior activity will be secured when the therapeutic compositions contain either the HVM or the RVM grades of the Attasorb heat-treated Attapulgus clay product;
The thermal treatment of the attapulgite removes the water from the channels previously described, thereby increasing the effective surface area and augmenting the adsorptive capacity. The particle sizes of the three grades of Attasorb vary within the range 0.3-3.0 microns, but this has no practical significance with respect to adsorption.
A typical chemical composition on the volatile-free basis of Attasorb heat-treated Attapulgus fullers earth as supplied by Minerals and Chemical Corporation of America, whether the LVM, RVM or HVM grades, follows. The percentages specified are by weight.
TABLE III Typical composition Percent SiO 67.0 A1 0 12.5 MgO 11.0 F6203 40 CaO 2.5
K 0 0.6 TlO 0.5 Miscellaneous 1.9
It may be remarked that the form of heat-treated Attapulgite clay commercially available and sold as Attasorb is particularly suitable, in that its use results in a pharmaceutical product of superior elegance, since Attasorb is a dry, light-colored material of extreme fineness, and of a character such that its dispersions are free from the presence of objectionable gritty constituents.
By means of comparative experiments it can be readily demonstrated that a heat-treated attapulgite (as, for example, one of the Attasorb products of Minerals and Chemicals Corporation of America) which has been heated within the temperature range of 250 F.900 F. for a period of time ranging from 15 to 30 minutes, thereby driving out a large proportion of the water and other volatile constituents, will adsorb in a given period of time about four to five times as much of a typical toxin as will kaolin.
The therapeutic compositions intended for internal use, particularly for use in the gastrointestinal tract of human beings, in which we have observed that the use of heattreated Attapulgus fullers earth as the clay ingredient will greatly increase the adsorptive activity of the medicament for poisonous constituents which may be present in the stomach and gastrointestinal tract may also include estates various other active agents in addition to the heat-treated Attapulgus clay. Usually, in addition to the clay (now ordinarily kaolin), an antacid agent such as alumina gel, magnesium hydroxide or magnesium trisilicate will also be present. Compositions of this type are disclosed in Bird patent, No. l,949,266. Pectin is frequently also present for its therapeutic activity, and suspending agents such as mineral oil or synthetic hydrated aluminum silic'ate (e.g. Veegum of Vanderbilt Company) are frequently present. Antibiotics, especially streptomycin (or dihydrostreptomycin), polymyxin and neomycin, are usual constituents of these intestinal adsorbent compositions. One or more of those therapeutic agents having antispasmodic activity may also be incorporated. Preservatives, such as sodium benzoate, sodium propionate, sorbic acid, one or more of the parabens, etc. are also usual constituents. The parabens are salts of the alkyl esters of p-hydroxybenzoic acid.
In all compositions it has been found that the use of heat-treated attapulgite as the clay constituent will provide a very satisfactory medicament of greatly improved therapeutic properties, having adsorptive properties great- 1y exceeding those of the same composition containing kaolin N.F. in place of the attapulgite. Moreover, the use of heat-treated attapulgite, such as any of those grades sold under the trademark name Attasorb, has been found to impart greater smoothness and stability to the medicinal suspension.
Ordinarily the effective range for the heat-treated attapulgite content of the improved internal therapeutic preparations with which this invention is concerned will vary from attapulgite percentages of from 0.5 percent to 17.0 percent by weight, based on the total weight of the medicament. Anv amount of heat-treated attapulgite exceeding about 20 percent by weight is usually not desirable, since at this concentration of heat-treated attapulgite the therapeutic suspension begins to take on a semi-solid character and great difliculty in pouring is experienced. Within the specified range for heat-treated attapulgite content, however, it has been found that the use of this heat-treated clay product in place of kaolin NF. imparts to the resulting medicinal suspension, on an equal weight basis, improved adsorptivity, both for toxins and alkaloids, to a truly remarkable degree.
The fact that heat-treated attapulgite also possesses valuable antacid properties to a degree not possessed by the usual kaolin N.F. used in these preparations is shown by the following experiment. In eight hours it was found that l grams of kaolin NF. adsorbed 5 milliliters of 0.1 N hydrochloric acid, its pH being changed in the process from 7.6 to 3.0. At the end of the same period of time, on the other hand, grams of heat-treated attapulgite consumed 83.5 milliliters of the same 0.] N hydrochloric acid, the pH during the eight hour interval going from 7.9 to 4.0. The remarkable superiority of heat-treated attapulgite as an antacid is apparent.
'The following are examples of typical intestinal adsorbent compositions prepared in accordance with our invention.
Y EXAMPLE 1 This intestinal adsorbent composition contained the antibiotic dihydrostreptomycin (or streptomycin) and polymyxin. The composition included the following ingredients, per 100 milliliters of therapeutic preparation:
Sodium hydroxide solution or citric acid, depending upon the pH of the preparation as prepared without this basic or acidic constituent, is added to the preparation in amount suificient to bring the pH within the range 5.5 to 6.5.
The use of heat-treated attapulgite (specifically Attasorb HVM) in this formula in place of the usual kaolin as the clay constituent was found to greatly increase its adsorptive properties for toxins.
EXAMPLE 2 The ingredients in this composition on a percentage basis (weight per volume) were as follows:
Dihydrostreptomycin sulfate percent-.. 1.4709 Polymyxin B sulfate, 6,500 u/cc. do 0.03077 Heat-treated attapulgite do 10.00 Alumina gel do 36.0 Pectin do 1.00 Veegum, plain ..do.. 0.75 Sodium benzoate ..do 0.25 Sodium propionate do 0.25 Sorbic acid do 0.20 Sodium hydroxide (or citric acid) enough to adjust to pH 5.5-6.5 Sucrose ..percent 35.0 D 8.: C Red Color #33 do 0.002 Imitation custard flavor do 0.011 Imitation butter-vanilla flavor do 0.011 Imitation raspberry flavor do 0.225 Imitation cherry flavor do 0.150 Imitation lime flavor do 0.0004 Imitation pineapple flavor ..do 0.0004
Distilled water, enough to make mls.
As compared with a similar composition containing kaolin NF. in place of heat-treated attapulgite in the same proportionate content (10 percent on a weight per volume basis) our improved preparation containing heattreated attapulgite (Attasorb) showed greatly increased adsorptive properties for toxins.
EXAMPLE 3 An intestinal adsorbent composition containing heattreated attapulgite, alumina gel and pectin (but no antibiotic) was prepared having the following composition:
Distilled water, enough to make 100 ml.
Percentages as given, are on a weight per volume basis. As compared with the identical composition containing,
however, the same percentage of kaolin in place of the heat-treated attapulgite clay, it was found that the adsorptive properties of the composition for diphtheria toxin had been increased approximately seven times by the use of the heat-treated attapulgite.
EXAMPLE 4 An intestinal adsorbent composition similar to that,"
described in Example 3 was prepared, this preparation having the following composition:
Heat-treated attapulgite percent 10.0 Alumina gel (2% A1 do 36.0 Pectin N.F. do 0.90 Sodium benzoate do 0.363 Mineral oil, heavy do 5.0 Vanillin do 0.00834 Benzoic acid do 0.222 Glycerine do 1.35 Sa'ccharin do 0.009l4 Water, enough to make 100 ml. of preparation.
All percentages are on a weight per volume basis.
When the same composition containing, however, 10.0 percent of kaolin NE. in place of the heat-treated attapulgite was tested, it was found to have an adsorptive value for diphtheria toxin, per milliliter of preparation, equal to 250 units. The composition containing heattreated attapulgite, on the other hand, showed adsorption for diphtheria toxin per milliliter of preparation equal to 1750 units. This seven-fold improvement in adsorptive properties for a typical bacterial toxin results from the use of the heat-treated attapulgite clay (Attasorb HVM) in the composition.
EXAMPLE 5 An intestinal adsorbent composition which contained both dihydrostreptomycin and polymyxin, as well as heat-treated attapulgite in place of the usual kaolin, was prepared to contain the following:
Dihydrostreptomycin base (as sulfate) grams 1.015 Polymyxin B sulfate units 100,000 Heat-treated attapulgite (Attasorb HVM) grams 10.0 Pectin do 0.90 Methyl paraben ....do 0.05 Propyl paraben do 0.01 Butyl paraben do 0.04 Sucrose do 20.0 Color, q.s.
Flavor, q.s.
Distilled water, q.s. ad 100.0 ml.
It showed superior adsorbent action for toxins normally present in the human gastrointestinal tract.
EXAMPLE 6 This intestinal adsorbent composition contained the antispasmodic agent, ambutonium bromide, as well as the heat-treated attapulgite.
Distilled Water, q.s. ad 100 ml.
Ambutonium bromide is an antispasmodic agent which is chemically identified as a,a-diphenyl-' -dimethylaminobutyramide ethobromide. See the article by Cheney et al.j in Jour. Org. Chem, 17, pp. 770777 (May 1952).
Its' antispasmodic activity is reported in the article by Judge et al., Journal of Laboratory and Clinical Medicine, 47, pp. 950-959 (June 1956).
This intestinal adsorbent composition could of course contain any other antispasmodic agent, although superior results weresecured by the inclusion of ambutonium bromide. When taken internally, ,it' exhibited OlltStanding 8 adsorptive action for poisons present in the gastrointestinal tract.
EXAMPLE 7 This following intestinal adsorbent composition contained antacids, but no antibiotics. It is particularly effective as an antacid-adsorbent:
- Grams Heat-treated attapulgite (Attasorb" HVM) 2.0 Pectin 0.90 Methyl paraben 0.05 Propyl paraben 0.01 Butyl paraben 0.04 Color, q.s. Flavor, q.s. Sodium benzoate 0.50 Magnesium hydroxide 2.0 Hydrated alumina powder (Wyeth) 5.0
Distilled water, q.s. ad ml.
EXAMPLE 8 Our improved intestinal adsorbent compositions may also contain an amoebacide in addition to the heattreated attapulgite and other adsorptive agents. The following is an example of such a composition containing as the amoebacide bismuth glycolylarsanilate:
Distiller water, q.s. ad 100 ml.
When taken internally this composition exhibited superior adsorptive activity and the amoebacide was effective against microorganisms present in the gastrointestinal tract.
Various changes and modifications may be made in our invention, as herein described, without departing from the spirit and scope thereof. To the extent that such changes and modifications are within the scope of the appended claims, they are therefore to be regarded as part of our invention.
We claim:
1. An intestinal adsorbent composition which comprises alumina gel and at least 10 percent of attapulgite clay which has been subjected to heating at a temperature within the range 250900 F. for a period of time ranging from 15 to 30 minutes.
2. An intestinal adsorbent composition which comprises at least 10 percent of attapulgite clay which has been subjected to heat treatment at a temperature within the range 250900 F. for a period of time ranging from 15 to 30 minutes, alumina gel and pectin.
3. An intestinal adsorbent composition which comprises at least 10 percent of attapulgite clay which has been subjected to heating at a temperature within the range 250900 F. for a period of time ranging from 15 to 30 minutes, alumina gel, pectin and at least one antibiotic selected from the group which consists of streptomycin, dihydrostreptomycin, polymyxin and neomycin.
4. An intestinal adsorbent composition which cornprises at least 10 percent of attapulgite clay which has been subjected to heating at a temperature within the range 250900 F. for a period of time ranging from 15 to 30 minutes, alumina gel, pectin, hydrated aluminun; ilicate and at least one antibiotic selected from the group which consists of streptomycin, dihydrostreptomycin, polyrnyxin and neomycin.
S. An intestinal adsorbent composition which comprises at least 10 percent of attapulgite which has been subjected to heating at a temperature within the range 250-900" F. for a period of time ranging from 15 to 30 minutes, pectin, dihydrostreptomycin, polymyxin and an antispasmodic agent.
6. An intestinal adsorbent composition comprising at least 10 percent of attapulgite which has been subjected to heating within the temperature range 250900 F. for a period of time ranging from 15 to 30 minutes, pectin, dihydrostreptomycin, polymyxin and a,u'-diphenyl-'y-dimethylamino-butyramide ethobromide.
7. An intestinal adsorbent composition having improved adsorptive action for toxins and other poisons which comprises pectin, alumina gel, dihydrostreptomycin, polymyxin, and as an adsorbent clay from 10.0 percent to 17.0 percent by weight of attapulgite which has been subjected to heating Within the temperature range 250-900 F. for a period of time ranging from 15 to 30 minutes.
8. An intestinal adsorbent composition having increased adsorptive action for bacterial toxins, said composition being in the form of a stable suspension and comprising approximately 36 percent by weight of alumina gel, approximately one percent by weight of pectin, and from 10.0 to 17.0 percent by weight of attapulgite which has been subjected to heat treatment within the temperature range 250-900 F. for a period of time ranging from 15 to 30 minutes, said composition also containing preservatives, sugar, flavoring and coloring agents, and water.
9. An intestinal adsorbent composition having improved adsorptive action for toxins and other poisons and which comprises pectin, alumina gel, dihydrostreptomycin, a amoebacide, and from 10.0 percent to 17.0 per cent by weight of attapulgite which has been subjected to heating within the temperature range 250-900" F.
10. An intestinal adsorbent composition having improved adsorptive action for toxins and other poisons which comprises pectin, alumina gel, dihydrostreptomycin, bismuth glycolylarsanilate, and at least 10 percent of attapulgite which has been subjected to heat treatment at a temperature range within 250900 F.
Judge et al.: J. Lab. and Chem. Med., 47, pp. 950- 959, June 1956.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,918,405 December 22, 1959 Martin Barr et a1,
It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 4, line 49, left-hand side of Table III, seventh item thereof, for "T10 read TiO column 8, line 39, Example 8, for "Distiller" read Distilled column 10, lines 9 and 15, after "250-900 F." each occurrence, insert for a period of time ranging from 15 to 30 minutes. same column 10, list of References Cited, under UNITED STATES PATENTS, the issue date, for "Feb. 27, 1944" read Feb. 27, 1934 Signed and sealed this 19th day of July 1960,
(SEAL) Atte'st:
KARL H; AXL INE ROBERT C. WATSON Attesting Officer Commissioner of Patents
1. AN INTESTINAL ADSORBENT COMPOSITION WHICH COMPRISES ALUMINA GEL AND AT LEAST 10 PERCENT OF ATTAPULGITE CLAY WHICH HAS BEEN SUBJECTED TO HEATING AT A TEMPERATURE WITHIN THE RANGE 250-900*F. FOR A PERIOD OF TIME RANGING FROM 15 TO 30 MINUTES.
| 1957-02-11 | en | 1959-12-22 |
US-78555247-A | Hydrocarbon synthesis process and the production of synthesis gas
Aug. 18, 1953 M. BENEDICT ET Al.
BON SYNTHESIS P HYDROCAR ROCESS AND THE PRODUCTION OF' SYNTHESIS GAS Filed NOV. l2, 1947 patentedV Aug. 18,
HYDROCARBON SYNTHESIS PROCESS AND THE PRODUCTION OF SYNTHESIS GAS Manson Benedict, Westeld, Albert C. Faatz, Jr., Maplewood, and Herman N. Woebcke, North Bergen, N. J., assignors to Hydrocarbon Research, Inc., New York New Jersey N. Y., a corporation of Application November 12, 1947, Serial No. 7 85,552
4 Claims.
This invention relates to the production of hydrocarbons, oxygenated hydrocarbons and the like from solid carbonaceous materials such as coal, lignite, peat, oil shale, coke, and the like.
The invention broadly contemplates subjecting solid carbonaceous materials, such as those mentioned, while in particle, granular, or other divided form, to contact in a gasification zone with an oxidizing gas, namely, oxygen which is supplemented with steam, under conditions so as to convert combustible constituents of the material into gas comprising a substantial amount of compounds containing both carbon and hydrogen atoms in the same molecule, including gaseous hydrocarbons. Resulting gasifled products, including the aforesaid compounds, are conducted, at least in part, to a reforming zone wherein they are subjected to contact with oxygen at an elevated temperature to convert the compounds in question into carbon monoxide and hydrogen. The gaseous effluent material from the gasification zone may be treated rst with oxygen at elevated temperature to effect conversion of the compounds in question into carbon monoxide and hydrogen and thereafter treated with steam in the presence of a shift catalyst also at elevated temperature so as to form additional hydrogen. Steam may be admitted to the reforming zone in which case subsequent treatment With steam may be omitted. The gas stream containing carbon monoxide and hydrogen is treated to remove CO2 and sulphur compounds and subsequently passed to a synthesis reaction zone. Provision may be made for removing CO2 both `before and after the shift conversion. Sulphur compounds may be removed before or after the shift conversion,
The synthesis reaction is preferably carried out under elevated pressure at a temperature in the range of about 500 to 700 F. with an iron type synthesis catalyst, so as to convert carbon monoxide and hydrogen into a product comprising mainly Ca and higher molecular Weight hydrocarbons. Gaseous constituents, including gaseous hydrocarbons such as methane, are separated from the synthesized products and are conducted in substantial amount to the previously mentioned reforming zone.
Residual gases, including hydrocarbon gases resulting from the further processing of the Ca and higher molecular weight hydrocarbons produced in the synthesis, may also be conducted to the reforming step.
( An important feature of the invention distinguishing it from the prior art is that of treat- (Cl. Zim-449.6)
ing the gasifed material containing volatiles in addition to some carbon monoxide and hydrogen in a separate or reforming zone with oxygen so as to convert the volatile constituents containing both carbon and hydrogen atoms in the same molecule into carbon monoxide and hydrogen and thereby produce synthesis gas of improved quality and having the desired proportions of hydrogen and carbon monoxide. The conversion of hydrocarbons and other volatilized constituents by partial combustion with oxygen, preferably oxygen of at least about purity, in the separate reforming zone is realized -with a high degree of efficiency and economy.
A further feature involves converting tar, oils, and resinous compounds by such reforming into valuable synthesis gas constituents. The reforming step is also advantageous from the standpoint of converting sulphur compounds, particularly organic sulphur compounds, into a form more readily removable from the synthesis gas by scrubbing.
A still further feature of the process is that of recycling to the reforming zone residual gases containing C1 and C2 hydrocarbons removed from the synthesis effluent and also obtained from 4the further processing of Ca and higher molecular weight hydrocarbon products of the synthes1s operation. This further processing usually involves treatment of at least a portion of the hydrocarbons, particularly those falling in the gasoline range, with clay or other contact material at an elevated temperature, and the catalytic polymerization of Cs-Ci hydrocarbons. These treating operations and the accompanying fractionating steps result in the production of substantial amounts of hydrocarbon gas.
The ratio of hydrogen to carbon in these hydrocarbon gases recycled to the reforming zone 1s relatively high. Therefore, the addition of these gases to the reformer is productive of synthesis gas containing a higher ratio of hydrogen to carbon monoxide than would otherwise be the case, and therefore reduces the amount of steam used in the reformer or the amount of subsequent shift conversion that otherwise might be necessary to produce synthesis gas containing about one mol of carbon monoxide to two moles of hydrogen, for example.
These and other advantages will be apparent f rom the subsequent description of the invention in connection with the accompanying drawmg.
The drawing is a diagrammatic illustration of a preferred method of carrying out the process of the present invention. This preferred method is described in detail to clearly illustrate various features of the invention. A number of modifications are possible, some of which are suggested herein. In describing the flow illustrated in the drawing, reference will be made to the treatment of coal.
The method of flow contemplated in the draw-r ing involves gasication of the coal while in a crushed or vdivided form, the bull; of the particles ranging in diameter from about two to i'lfteen millimeters.
As indicated in the drawing, the coal in divided form is conducted from a source Vnot shown through conduit I into the upper portion of a gasifier 2 while oxygen and steam are introduced at the base of the gasiiier through a pipe i3. The oxygen and steam may be introduced as a mixture in the proportion of about ten volumes of steam to one volume of oxygen at a temperature of about l,000 F. Suicient oxygen is added so that the resulting exothermic reaction heat liberated will be suicient for the gasification of the coal. A minimum quantity of steam is added to complete the gasification of the coal, and frequently an excess of steam is added to prevent excessive temperatures. Oxygen and steam flow countercurrently to the mass of coal particles moving downwardly through the gasier.
The gasifier is maintained under a pressure ranging from atmospheric to fifty atmospheres or more and usually about to 30 atmospheres. Elevated pressures are conducive to the production of methane. The methane is converted by the present process to more valuable products. The temperature at the point of product gas discharge from the gasier is generally within the range of from about 400 to 1200 F. rI he temperature increases toward the base of the gasier and may be as high as 25009 to 2800 F. Satisfactory operation of the gasier is not generally obtained unless a temperature of 1200 F. or above exists at some point in the gasier. The temperature may be regulated by control of the rate of feed of oxygen and steam to the gasifler.
The base of the gasier is provided with means for discharging ash or non-volatile non-carbonaceous components of the feed therefrom either as ash or as a molten slag.
The product gas is removed through pipe to a cooler 5 wherein Water, oils, and tar are condensed. The cooled gaseous effluent is passed to a separator l wherein condensed water, oils and tar are separated from the gas stream. The residual gas is then passed via line 8 to a carbon dioxide separator 9 wherein :carbon dioxide is removed and discharged through pipe I I.
The scrubbed gas is removed through pipe I2 and introduced to reformer I3 wherein hydrocarbon constituents and other volatized components of the coal are subjected to partial combustion with oxygen.
Oils and tars separated from the gaseous effluent in separator l are passed via line I4 to the reformer I3. If desired, a portion or all of the oils and tar may be withdrawn from the system through line I6 for the recovery of valuable organic constituents therefrom. Water is discharged from separator 'I through line I1.
Oxygen is introduced to the reforming zone I3 from pipe I8. Conditions are maintained so that the :conversion consists essentially of partial combustion of compounds containing both carbon and hydrogen atoms into carbon monoxide and hydrogen at a temperature of about 2200 to 2300 F. or in the range of about 2000 to 2500 The reforming zone advantageously comprises an unpacked chamber with suitable means for effecting thorough mixing of the oxygen and gas upon introduction to the interior of the vessel. Oxygen is advantageously preheated to an elevated temperature of 600 F. or higher before being introduced to the reforming vessel. Gases to be reformed are also advantageously preheated, preferably to 900 or higher.
The resulting product gas is continuously discharged from the reforming zone through a cooler I9 which may take the form of a waste heat boiler wherein sensible heat of the product gas is used to generate steam. The gas is thus cooled to a temperature of about 600 F.
Since it may be desired to obtain a synthesis gas containing about two mols of hydrogen per mol of carbon monoxide, provision is made for subjecting the gas to a shift conversion wherein steam is reacted with a portion of the carbon monoxide in the presence of a shift catalyst at a temperature of about 600 rto 850 F. A suitable catalyst for this purpose comprises iron oxide promoted with small amounts of chromium oxide and magnesium oxide. The iron oxide content of the catalyst may amount to from 60 to 90% F6203.
After cooling of the gas in cooler I9. it is passed to a shift converter ZI to which steam is introduced from pipe 22. In the shift converter, steam and carbon monoxide are reacted in the presence of a catalyst to produce hydrogen and carbon dioxide. The hydrogen-:carbon monoxide ratio can thus be adjusted to provide a synthesis gas feed containing approximately two mols of hydrogen per mol of carbon monoxide.
This shift conversion may be effected in the reforming zone I3 by the introduction of a suit.- able amount of steam thereto, together with the oxygen. In such an instance, the converter 2l may be omitted, or the amount of conversion car.- ried out in the shift converter greatly reduced. In a preferred embodiment, no steam is admitted to the reformer I3 and carbon monoxide Vand steam are reacted in the presence of a specific catalyst in a shift converter 2I to increase the hydrogen content of the stream. Obviously, a portion of the gas may bypass the shift converter 2I if desired and a conventional recycle may be employed if so desired.
The resulting gas mixture from shift converter ZI is passed through pipe 23 to a scrubbing unit 24. Car-bon dioxide and most of the hydrogen sulphide present in the gas are removed by scrubbing with water or other suitable reagents. scrubbing may be effected, for example, with cold Water at a temperature of 45 F. and below.
The scrubbed synthesis gas retaining about 1/2% by volume of carbon dioxide and a small amount of hydrogen sulphide is conducted to a nal purifying zone 26 wherein the gas is sub.- jected to contact with spong-y iron oxide (Luxmasse) at a temperature of about QQte F. so as to efect removal of the remainder 0f the hydrogen sulphide, as well as. carbonyl sulf phide. The purified synthesis .gas is thereafter conducted through pipe 21 to a synthesis reactor 28. In the reactor 2 8, the synthesis gas is subjected to contact with a fiuidized powdered synf thesis catalyst of the iron type, for example, a catalyst comprising iron and small amounts of silica, alumina and alkali metal oxide. The contact between the synthesis catalyst is effected at a temperature in the range of about 500 to 700 I5. and preferably at about 600 to 650 F. The pressure may range from about to 40 atmospheres, preferably, about to 30 atmospheres.
Under these conditions, of the carbon monoxide converted (usually 95 to 98%), about '10 to '75% is converted to C3 and higher molecular weight compounds, includihg oxygenated hydrocarbons. The latter may amount to from about 5 to 8% of the C3 and higher hydrocarbons produced. In addition, about 15% of the carbon monoxide may be converted to C1 and Cz hydrocarbons, while the remainder of the carbon monoxide may be converted to carbon dioxide in the synthesis reaction.
A stream of synthesis products, including water vapor, is continuously removed through pipe 29 and passed through heat exchanger 3| to a receiving drum 32 maintained under substantially synthesis reaction pressure, and Wherein separation into gas and liquid phases occurs.
The gas phase is removed through pipe 33 and recycled in part through exchanger 3| and pipe 34 to the synthesis reaction zone.
The remainder of this gas is conducted through pipe 36 to a gas separator 31, suitably an absorption unit wherein it is subjected to contact with an absorption oil such as a normally liquid fraction of the synthesis product, in order to absorb liquefiable hydrocarbons comprising butanes, butenes, Ipentanes, etc. The resulting dry gas is removed through pipe 38.
Nitrogen is present in the system as an impurity in the oxygen stream and as a constituent of the coal. In order to avoid a build-up of nitrogen in the system, provision is therefore made for purging through line 39 a portion of the dry gas leaving separator 31 through pipe 38. Purged gas may be discharged into a fuel gas system. The gas so purged may amount to about of the total dry gas.
The remainder of the dry gas is conducted through pipe 3B to the carbon dioxide separator 9 for recycle to the reformer I3.
Separator 32 is maintained at a temperature which may be in the range of about 60 to 150 F. and superatmospheric pressure. Under these conditions, separation of condensate into liquid hydrocarbon and aqueous layers occurs, the aqueous layer containing mainly oxygenated compounds produced by the synthesis reaction. This aqueous layer is discharged through pipe 42 and subjected to further treatment for the recovery of oxygenated compounds.
The liquid hydrocarbon layer is removed through pipe 43 and conducted to a hydrocarbon processing unit or plant 44. Hydrocarbons separated from the recycle gas in the gas separator 31 are conducted through pipe 45 to plant 44.
The plant 44 may comprise conventional equipment for treating, rening and fractionation of the synthesis hydrocarbons. For example, the liquid products of the synthesis reaction are advantageously subjected to contact with a solid absorbent material such as clay, bauxite, etc. at an elevated temperature in the range of about 700 to 950 F. and under substantially atmospheric pressure so as to effect dehydration of oxygenated compounds contained therein and to improve the octane rating of the gasoline hydrocarbons.
The C3 and C4 fraction of the synthesized products is advantageously subjected to catalytic polymerization as, for example, by contact with a polymerization catalyst, such as phosphoric acid type, at a temperature of 300 to 500 F..and
under pressure ranging from abut O to 1'00 atmospheres.
Either before or after the aforesaid clay treating, the liquid hydrocarbons may be fractionated to remove a fraction higher boiling than gasoline and lsuitable for the manufacture of diesel oil.
By way of example, the products resulting from the various processing steps in the plant 44 may comprise synthesized gasoline removed through pipe 50, polymer gasoline removed through pipe 5|, fuel oil, e. g., diesel oil, removed through pipe 52, higher boiling oil removed through pipe 53, and polymer tar removed through pipe 54.
In addition to the foregoing products, there is also produced from plant 44 residual gas containing light hydrocarbons, hydrogen, and carbon dioxide. This residual gas is conducted through pipe 55 and pipe 38 to the carbon dioxide separator 9 and, after removal of carbon dioxide therefrom, it is returned to the reforming zone |3. Residual gas not so recycled may be discharged through pipe 56 and is suitable for use as fuel gas.
Instead of effecting the previously mentioned shift conversion prior to purification of the gas stream, it may be effected at a subsequent point after removal of carbon dioxide and combined sulfur from the gas stream. An advantage in eifecting the shift conversion at this latter point in the system is that the previous removal of carbon dioxide reduces the concentration of carbon dioxide in the feed to the convertor which thus facilitates the shift conversion.
In the operation of the overall process, the individual unit operations of reforming, catalytic shift conversion, impurity removal, and synthesis, etc, can be carried out at pressures substantially the same as or not greatly lower than that prevailing in the gasification zone 2. The pressure may be progressively lower in each succeeding stage of the process as a result of pressure diiferential through each succeeding unit. For example, the pressure prevailing in the gasier 2 may be about 350 pounds per square inch gage; in reformer I3, 340 pounds; in scrubber 24, 320 pounds; in purifier 26, 310 pounds; and in synthesis unit 28, 300 pounds. Pumps and compressors may be provided at intermediate points to compensate for pressure losses in the system.
The drawing is merely schematic and does not show the usual auxiliary equipment, including pumps, compressors, heaters, coolers, heat exchangers, etc. Likewise, it will be understood that the scrubbing and absorbing units referred to in the drawing will include strippers for denuding the scrubbing or absorbing liquid of absorbed materials.
In the operation of the gasi'er, a small amount of coke nes and ash may be carried over in the eiiluent gas stream. This entrained solid material is removed in the separator 1 and, therefore, provision may be made for removing the solid material from the liquid by ltration, settling, or a combination of such operations.
In a modification of this invention, the oils and tar contained in the effluent stream from the gasiiier 2 are passed in the vapor state to the reformer I3. In this instance it is not advisable to cool the gaseous eiiluent. The stream of gaseous eiiiuent from the gasier may be heated to preclude the possibility of deposition of tar in the flow line. A preferred mode of supplying heat to the gas stream comprising compounds containing both hydrogen and carbon atoms', e. g., the gaseous eluent from the gasi'fter 2, is by the addition of oxygen to the gas stream. The resulting reaction at the elevated temperature is effective to increase the stream temperature and effect a partial conversion of said components to carbon monoxide and hydrogen. In the reforming operation, the reaction of oils, tars, and other hydrocarbons and substituted hydrocarbons With oxygen serves to convert substantially all such components to carbon monoxide and hydrogen with incidental formation of carbon dioxide. Carbon dioxide may be readily removed from the resulting gas.
It is also contemplated that the gasification of the solid carbonaceous feed may be carried out in a manner other than that speciiically mentioned. For example, the fluidization technique may be employed in the gasifier wherein the feed material, in finely divided or powdered form, is maintained in a fluidized state during contact with steam and oxygen.
Example A bituminous coal is processed in accordance with this invention. The ultimate analysis is as follows:
Percent Carbon 62.1 Hydrogen 4.0 Oxygen 12.6 Nitrogen 0.8 Sulphur 1.4 Ash 19.1
The coal is crushed to 2-10 mesh and charged to a gasier of the Lurgi type equipped with a rotating grate for discharge of ash. The gasier is operated at 350 pounds per square inch gauge. A mixture of superheated steam at 1000 F. and
oxygen of 95% purity is supplied tothe base of Hydrogen CO 18 CO2 18- CH4 12 H2O 29 Light hydrocarbons and impurities 1 After removal of tar, oils, and Water, the gas stream is compressed and most of the carbon dioxide is scrubbed from it.. The residual gas is reacted with oxygen at 2300" F. and 5175 pounds per square inch gauge. The raw gas, is preheated to 1000 F. before introduction into the reformer; the oils containing tar in solution are atomized by injection into the reformer.
The gaseous eiuent from the reformer is passed. toI a shift converter wherev it is contacted with. a chromia-magnesia-iron oxide catalyst at 800 E. and 560 p. s. i. g. The gaseous eiuent from the shift converter is scrubbed with di.- ethyl amine solution at 530 p. s. i. g. and atmospheric temperature, then passed over a bed of spongy iron oxide at '770 F'. and 515 p. s. i. g.
The purified synthesis gas so prepared is essentially a mixtureof hydrogen and carbon monoxide and' hasvthe following composition:
y Y Percent by volume Hydrogen 62.8
Carbonmonoxide 30.0 Carbon dioxide 0.5 Nitrogen 6.5 Water 0.2
Percent by volume CO 2.5 CO2` 12.1 CHA; '7.1 C2 hydrocarbons Y 3.8 Ca hydrocarbons 0.3 Hydrogen 4.1.2 Nitrogen 33 About 20 per cent of thisv dry gasv stream. isv vented to prevent nitrogen build-up in the system. The remainder of the stream, after removal of ca:- bon dioxide is passed to the reformer for conversion of the hydrocarbons to carbon monoxide and hydrogen for recycle to the synthesis reactor.
The foregoing exam-plie is oered by Way of illustration only and is not to; be construed as in any way limiting the invention.
Gbviously, many modifications. and variations` of the invention as above set forth may be made withoutdeparting from the spirit and scopel thereof, and therefore only suchk limitations should be imposed as are indicatedy in. the appended claims.
We claim:
1. In a process for the. generation of carbon monoxide and hydrogen from coal wherein coal is reacted with oxygen and steam to produce a gas stream rich in carbon monoxide and hydrogen and containing carbon dioxide and: hydrocarbons, the improvement which comprises separating carbon dioxide. from. said. gas. stream and thereafter converting the hydrocarbons to additional' carbon monoxide and hydrogen by reacting said hydrocarbons in admixture with said carbon monoxide and hydrogen in said gas stream with substantially pure oxygen in arl-.amount sufficient only for reaction with said hydrocarbons at a temperature within the range of from about 2,000 to about 2,500 and a pressure above about .20 atmospheres in an. unpacked reaction zone and. in theabsence of a. catalyst to prod-ucc carbon monoxide and hydrogen substantially free from hydrocarbons and carbon dioxide.
2.. In a process for thev synthesis of normally liquid hydrocarbons and thel like from carbon monoxide and hydrogen wherein coal is subjected to reaction. with oxygen` and. steam to produce a gas stream rich in carbonv monoxide and hydrogen and containing carbon dioxide and hyd-ro carbone, and: carbon monoxide4 and hydrogen are subjected to a hydrocarbon synthesis reaction producing a synthesis eiiiuent comprising normally liquid hydrocarbons and a gaseous residue including normally gaseous hydrocarbons ad'- mixedi with hydrogen, carbon: monoxide and car'- borr dioxide; the improvement which comprises separating carbon dioxide from said gasl stream and from a portion of said gaseous residue, and thereafter converting the hydrocarbons in said gas stream and in said portion of said gaseous residue to additional carbon monoxide and hydrogen by reacting said hydrocarbons in admixture with said carbon monoxide and hydrogen with substantially pure oxygen in an amount sufcient only for reaction with said hydrocarbons at atemperature within the range of from about 2,000 to about 2,5 F. and at a pressure above about 20 atmospheres in an unpacked reaction zone and in the absence of a catalyst to produce a mixture comprising carbon monoxide and hydrogen substantially free from hydrocarbons and carbon dioxide.
3. In a process for the generation of carbon monoxide and hydrogen from coal wherein coal is reacted with oxygen and steam at an elevated temperature to produce a hot gas stream rich in carbon monoxide and hydrogen and containing hydrocarbons including tarry vapors distilled from the coal, the improvement which comprises adding oxygen to said hot gas stream in an amount suiiicient for reaction with -only a portion of said hydrocarbons whereby additional heat is added to said gas stream due to the resulting exothermic reaction therein between said oxygen and hydrocarbons and condensation of said tarry vapors in said hot gas stream is substantially precluded; subsequently separating carbon dioxide from said gas stream; thereafter converting hydrocarbons in said gas stream to additional carbon monoxide and hydrogen by reacting said hydrocarbons in admixture with carbon monoxide and hydrogen in said gas stream with substantially pure oxygen in an amount sufficient only for reaction with said hydrocarbons at a temperature within the range of from about 2,000 to about 2,500 F. and a pressure above about 20 atmospheres in an unpacked reaction zone and in the absence of a catalyst to produce carbon monoxide and hydrogen substantially free from hydrocarbons and carbon dioxide.
4. In a process for the generation of carbon monoxide and hydrogen from coal wherein coal is reacted With oxygen and steam to produce a gas stream rich in carbon monoxide and hydrogen and containing carbon dioxide and hydrocarbons, the improvement which comprises separating carbon dioxide from said gas stream and thereafter converting said hydrocarbons to additional carbon monoxide and hydrogen by reacting said hydrocarbons in admixture with said carbon monoxide and hydrogen in said gas stream with substantially pure oxygen in an amount sufficient only for reaction with said hydrocarbons at a temperature within the range of from about 2,000 to about 2,500 F. in an unpacked reaction Zone and in the absence of a catalyst to produce carbon monoxide and hydrogen substantially free from hydrocarbons and carbon dioxide.
MANSON BENEDICT.
ALBERT C, FAATZ, JR.
HERMAN N. WOEBCKE.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,921,856 Wietzel et al Aug. 8, 1933 1,960,912 Larson May 29, 1934 1,971,728 Perry Aug. 28, 1934 2,013,699 Richardson Sept. 10, 1935 2,121,733 Cottrell June 21, 1938 2,243,869 Keith, Jr., et a1 June 3, 1941 2,274,064 Howard et al Feb. 24, 1942 2,324,172 Parkhurst July 1-3, 1943 2,346,754 Hemminger Apr. 18, 1944 2,347,682 Gunness May 2, 1944 2,349,438 Koppers May 23, 1944 2,375,500 Silver et al. May 8, 1945 2,431,632 Brandt Nov. 25, 1947 2,436,938 Scharmann Mar. 2, 1948 2,482,284 Michael et a1. Sept. 20, 1.949 2,493,454 Hagy Jan. 3, 1950 2,537,153 Nelson et al. Jan. 9, 1951 OTHER REFERENCES Rambush, Modern Gas Producers, pp. 315-317, 1 page of dwg., December 11, 1923.
2. IN A PROCESS FOR THE SYNTHESIS OF NORMALLY LIQUID HYDROCARBONS AND THE LIKE FROM CARBON MONOXIDE AND HYDROGEN WHEREIN COAL IS SUBJECTED TO REACTION WITH OXYGEN AND STEAM TO PRODUCE A GAS STREAM RICH IS CARBON MONOXIDE AND HYDROGEN AND CONTAINING CARBON DIOXIDE AND HYDROCARBONS, AND CARBON MONOXIDE AND HYDROGEN ARE SUBJECTED TO A HYDROCARBON SYNETHESIS REACTION PRODUCING A SYNTHESIS ELLUENT COMPRISING NORMALLY LIQUID HYDROCARBONS AND A GASEOUS RESIDUE INCLUDING NORMALLY GASEOUS HYDROCARBONS ADMIXED WITH HYDROGEN, CARBON MONOXIDE AND CARBON DIOXIDE; THE IMPROVEMENT WHICH COMPRISES SEPARATING CARBON DIOXIDE FROM SAID GAS STREAM AND FROM A PORTION OF SAID GASEOUS RESIDUE, AND THEREAFTER CONVERTING THE HYDROCARBONS IN SAID GAS STREAM AND IN SAID PORTION OF SAID GASEOUS RESIDUE TO ADDITIONAL CABON MONOXIDE, AND HYDROGEN BY REACTING SAID HYDROCARBONS IN ADMIXTURE WITH SAID CARBON MONOXIDE AND HYDROGEN WITH SUBSTANTIALLY PURE OXYGEN IN AN AMOUNT SUFFICIENT ONLY FOR REACTION WITH SAID HYDROCARBONS AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 2,000 TO ABOUT 2,500* F. AND AT A PRESSURE ABOVE ABOUT 20 ATMOSPHERES IN AN UNPACKED REACTION ZONE AND IN THE ABSENCE OF A CATALYST TO PRODUCE A MIXTURE COMPRISING CARBON MONOXIDE AND HYDROGEN SUBSTANTIALLY FREE FROM HYDROCARBONS AND CARBON DIOXIDE.
| 1947-11-12 | en | 1953-08-18 |
US-62311584-A | Process for preparing ZnSe single crystal
ABSTRACT
A process for preparing a large ZnSe single crystal, comprising vacuum sealing polycrystalline ZnSe prepared by a chemical vapor deposition in a capable and hot isostatically pressing polycrystalline ZnSe in the capsule, by which the ZnSe single crystal having such high qualities as to be used as a substrate on which an epitaxial layer of ZnSe can be grown.
FIELD OF THE INVENTION
The present invention relates to a process for preparing a ZnSe single crystal. More particularly, it relates to a process for preparing a large ZnSe single crystal having high qualities.
BACKGROUND OF THE INVENTION
A ZnSe single crystal is expected to be used, for example, as a blue light emitting diode. However, conventional ZnSe single crystals are neither large nor of high quality to be used as such diode. A ZnSe single crystal prepared by chemical vapor deposition tends to have crystal defects such as the formation of twin crystals and are not large enough. A ZnSe single crystal prepared by the Bridgman method also tends to have crystal defects such as bubbles, twin crystals and compositional deviations.
In order to grow an epitaxial layer of ZnSe on a substrate, a single crystal of a different material having a similar lattice constant such as GaAs, GaP and Ge is used as the substrate, but an epitaxial layer possessing high qualities cannot be prepared due to the difference between the lattice constants of the ZnSe and the substrate.
SUMMARY OF THE INVENTION
One object of the invention is to provide a large ZnSe single crystal having less crystal defects and compositional deviations, than conventional ZnSe crystals.
Another object of the invention is to provide a process for preparing a large ZnSe single crystal having such high quality as to be used as a substrate on which an epitaxial layer is grown, which process comprises vacuum sealing polycrystalline ZnSe prepared by a chemical vapor deposition in a capsule and subjecting the polycrystalline ZnSe to a hot isostatic pressing in the capsule.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a cross-sectional schematic view of an apparatus for high isostatic pressing.
DETAILED DESCRIPTION OF THE DRAWING
Firstly, polycrystalline ZnSe is synthesized by the conventional chemical vapor deposition (hereinafter referred to as "CVD"). CVD comprises charging Zn vapor and gaseous H2 Se in a tubular reactor having a suitable temperature distribution and reacting Zn and H2 Se to form polycrystalline ZnSe on a substrate.
The thus prepared polycrystalline ZnSe is then treated in an apparatus for hot isostatic pressing (hereinafter referred to as "HIP") as shown in the FIGURE.
Polycrystalline ZnSe 1 is vacuum sealed in a capsule 2 and placed in a container 3. The container 3 serves to make the temperature distribution in the capsule homogeneous and has a hole (not shown) through which interior gas is exchanged with exterior gas. The container 3 is made, for example, of carbon. The container 3 is placed on a supporting bed 5 in a pressure container 4 and heated with a heater 6. Numerals 7, 8 and 9 denote a thermal insulator, a thermister which monitors the temperature in the apparatus and a power source for the heater, respectively.
The capsule 2 is usually made of heat-resistant glass such as fused silica and Pyrex (trade mark) glass. The pressure container 4 should be able to withstand a high pressure of 2,000 atm or higher. The pressure is raised by supplying high pressure argon gas through a tube 10 for supplying argon gas.
HIP is carried out at a temperature of at least 1,000° C., preferably from 1,000° to 1,200° C., more preferably from 1,000° to 1,1000° C. The pressure in the pressure container 4 is at least 2,000 atm, preferably from 2,000 to 2,300 atm, more preferably from 2,000 to 2,100 atm. When the temperature is lower than 1,000° C., polycrystalline ZnSe is not transformed to the single crystal even if the pressure is higher than 2,000 atm. When the pressure is lower than 2,000 atm, polycrystalline ZnSe is not transformed to a single crystal either, even if the temperature is higher than 1,000° C. Usually, the HIP treatment time varies with other conditions such as the temperature and the pressure and usually is at least two hours.
According to the process of the invention, polycrystalline ZnSe is transformed to the large single crystal having less crystal defects and compositional deviation. The size of the single crystal prepared by the process of the invention varies with the size of the apparatus used and is usually from 10 to 75 mm in diameter.
The present invention will be hereinafter explained further in detail by following examples.
EXAMPLE
Used polycrystalline ZnSe was prepared by CVD and had a diameter of 50 mm and a weight of 50 g. It was hot isostatically pressed by the apparatus shown in FIGURE at a pressure of 2,000 atm at a predetermined temperature and for predetermined period of time. The crystalline growth was observed and evaluated according to the following criteria:
x: Not crystallized
Δ: Partially crystallized
0: Crystallized
The results are shown in Table.
TABLE
______________________________________
Treating
time Temperature (°C.)
(hr) 900 950 1,000
______________________________________
1 x x Δ
2 x Δ
0
3 x Δ
0
______________________________________
From the results shown in Table, it is understood that, at 950° C., single crystal is not grown after a longer treating time and, at 1,000° C., the treating time shorter than one hour does not afford a single crystal. Thus, HIP is preferably effected at a temperature of at least 1,000° C. for at least two hours.
For comparison, the above procedures were repeated with using a sintered ZnSe powder in place of polycrystalline ZnSe prepared by a CVD method. The thus prepared single crystal had many crystal defects including powder and bubbles and was not suitable for a substrate on which the epitaxial layer is grown.
What is claimed is:
1. A process for preparing a large ZnSe single crystal, comprising vacuum sealing polycrystalline ZnSe prepared by a chemical vapor phase deposition in a capsule and hot isostatically pressing the polycrystalline ZnSe in the capsule at a temperature of at least 1,000° C. and a pressure of at least 2,000 atm for at least one hour.
2. A process according to claim 1, wherein the polycrystalline ZnSe in the capsule is hot isostatically pressed at a temperature of from 1,000° to 1,200° C. and a pressure of from 2,000 to 2,300 atm.
3. A process according to claim 1, wherein the polycrystalline ZnSe in the capsule is hot isostatically pressed at 1,000° C. and 2,000 atm for two hours.
4. A process according to claim 1, wherein the capsule is made of heat-resistant glass.
| 1984-06-22 | en | 1986-04-22 |
US-24081162-A | Controls for heat pumps having air exposed outdoor air coils
R. T. PALMER Filed NOV. 29, 1962 May 19, 1964 CONTROLS FOR HEAT PUMPS HAVING AIR ExPOsED OUTDOOR AIR cOILs Izweraorf Raew TPaZmea United States Patent O CONTRGLS FOR PRAT PUMPS HAVING AER EXPSED UUTDOR AIR COILS Robert T. Palmer, Sharon, Mass., assigner to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Nov. 29, 1962, Ser. No. 240,811
6 Claims. (Cl. 62-16tl) This invention relates to controls for heat pumps having air-cooled, outdoor air coils.
Heat pumps that are used for cooling or heating indoor air usually consist of motor driven refrigerant compressors that are connected through solenoid adjusted, refrigerant reversal valves to indoor air coils and to outdoor air coils. When indoor air cooling is required, a reversal Valve is adjusted to route refrigerant from a compressor through an outdoor air coil acting as a condenser coil, and then through refrigerant expansion means into an indoor air coil acting as an evaporator coil. When indoor air heating is required, the reversal valve is adjusted to route refrigerant from the compressor through the indoor air coil acting as a condenser coil, and then through expansion means into an outdoor air coil acting as an evaporator coil.
Due to the lack of suicient water in many locations to water cool the outdoor coils of heat pumps when such outdoor coils are operating as condenser coils, and due to the cost of water cooling such coils when suicient water is available, air-exposed, outdoor air coils are widely used. In many heat pump systems for buildings containing delicate equipment such as computers, it is the practice to operate heat pumps for indoor air cooling during such low outdoor temperatures that the refrigerant pressure from the outdoor coils acting as condenser coils, may be insuicient to properly operate the expansion devices connected between the outdoor and indoor air coils. An automatically controlled liquid pump can be placed in the liquid line between the Outdoor air coil and the expansion device of such a heat pump when it is operating to cool indoor air, for boosting the liquid pressure, when required, at low outdoor air temperatures. But the outdoor temperature may decrease further to the point that the indoor air may have to be heated by the heat pump. The necessity for the liquid pump no longer exists when the heat pump operates to heat the indoor air since the indoor air coil would be operating as a Vcondenser coil, but the liquid pump and its controls would prevent the operation of the heat pump in indoor air heating.
An object of this invention is to maintain desired liquid pressures at the expansion means of a heat pump when the latter is operating to cool indoor air without aifecting the operation of the heat pump in heating indoor alr.
This invention will now be described with reference to the annexed drawing which is a diagrammatic view of a heat pump system embodying this invention.
A hermetic refrigerant compressor C, driven by an electric motor CM, has its discharge side connected through a tube 10 to a four-way, refrigerant reversal valve which may be of the type disclosed in the U.S. Patent No. 2,672,734. The valve RV is adjustable by a solenoid S1 to indoor air cooling or to indoor air heating positions. The Valve RV is connected by a tube 11 to one end of an outdoor air coil 12, the other end of which is connected by a tube 13 to the inlet of a liquid pump P which is driven by an electric motor PM. The outlet of the pump P is connected by tube 15, three-way valve 17 and capillary tube 18 to one end of an indoor air coil 20, the other end of which is connected by a tube 21 to the reversal valve RV. The valve RV is connected by a tube 22 to the interior of the casing of the motor CM,
ICC
which interior is connected to the suction side of the compressor C as is usual in hermetic compressors. The Valve 17 is connected by a capillary tube 25 to the tube 13, and is adjustable by a solenoid S2 to a position where it routes refrigerant from the tube 1S into the tube 1S or to a position where it routes refrigerant from the coil 20 into the tube 25.
A tube 27 containing a check-valve CV is connected to the tubes 13 and 15 as a by-pass around the pump P when the latter is not operating.
A capillary tube 3i) connects the tube 13 to a pressure bellows 31. A capillary tube 32 may be used to connect the tube 21 to a suction bellows 33. The bellows 3@ is connected by linkage 35 to a pivoted switch arm 37, and the bellows 33, if used, is connected by linkage 36 to the switch arm 37. The switch arm 37 is opposite a contact 38. The bellows 31 responds to refrigerant pressure at the outlet of the outdoor air coil when the latter is operating as a condenser coil, and when such pressure is reduced by a reduction in outdoor air temperature to a pressure insuicient to properly operate the capillary tube 18 as an expansion means, the switch arm 37 moves against the contact 33 closing a circuit that will be described later. The suction bellows 33 may be used with the pressure bellows 31 in a more sensitive, differential control.
The capillary tubes 1S and 25 serve as refrigerant eX- pansion means as disclosed in the G. L. Biehn Patent No. 2,785,540, and the tube 25 may have the greater length so as to add additional restriction as does the check-valve restrictor of this patent during indoor air heating operation when the tube 25 is the expansion means.
The compressor motor CM is connected by a wire 4t) to electric supply line L1, and is connected by a wire 41, switch 42 of a motor starter relay MSR, and a wire 43 to electric supply line L2. The pump motor PM is connected through a wire 45, the switch arm 37, the contact 38, switch 46 of relay 47 and wire 48 to one side of the motor CM, and through wires 49 and 41 to the other side of the motor CM so that the pump motor PM operates when the compressor motor operates provided the switch arm 37 is against the Contact 38, and the switch 46 is closed. i
A heat thermostat HT has a switch arm 50 connected to the supply line L1, and has a Contact 51 connected by wire 53 to the solenoid S1`which is connected by wire 54 to the supply line L2. The thermostat HT has another contact 55 connected by wire 56 to contact 57 of cool thermostat CT. The thermostat CT has a switch arm 59 connected to the supply line L1. Its contact 57 is connected by wire 60 to one end of energizing coil 61 of the relay MSR, the other end of which is connected by the wire 43 to the supply line L2. The relay MSR is energized and closes its switch 42 to energize the compressor motor CM when either of the switch arms 50 or 59 of the thermostats HT or CT respectively, touch the contacts 55 or 57 respectively. The solenoid S1 is energized when the switch arm S0 of the thermostat HT touches the contact 51 at the same time it touches the contact 55.
The relay 47 has an energizing coil 64 connected by wires 65, 66, 67 and 68 across the solenoid S1. The solenoid S2 is connected by the same wires across the solenoid S1. Thus, when the solenoid S1 is energized by the thermostat HT, the relay 47 and the solenoid S2 are energized.
During the operation of the heat pump in indoor air cooling, the solenoid S1 is deenergized, and the valve RV is in position to route refrigerant from the compressor C iirst to the outdoor air coil 12 and then to the indoor air coil 20 as shown by the solid line arrows on the drawing. At this time the relay 47 is deenergized and its switch 46 is closed. At this time the solenoid S2 is deenergized, and
53 the valve 17 is in position to route refrigerant through the capillary tube 18 into the indoor air coil 2d, and to close off the capillary tube 25.
During the operation of the heat pump in indoor air heating, the solenoid S1 is energized and places the valve RV in position to route refrigerant from the compressor C first to the indoor air coil 2t) and then to the outdoor air coil 12 as shown by the dashed line arrows on the drawing. At this time the relay 47 is energized and its switch 46 is open. At this time the solenoid S2 is energized and places the valve li in position to route refrigerant from the indoor air coil 26 into the capillary tube 25, and to close off the capillary tube 18.
Operation Assume that the cool thermostat CT has called for indoor air cooling so that its switch arm 59 is against its contact 57, energizing the relay MSR and through the latter the compressor motor CM. The pump motor PM normally would not be energized due to the condensing pressure normally being sufficient to operate the capillary tube 1S as an expansion means so that the switch arm 37 of the pressure bellows 31 is spaced from the contact 3S in the energizing circuit of the pump motor. The check valve CV is open, and the by-pass around the pump P is open. Refrigerant flows from the compressor through the outdoor air coil 12, the tube Z7 and check-valve CV, the tube 15, the capillary tube L', serving as an expansion device, the valve 17, the indoor air coil 20 and the tube 2l back to the compressor. The outdoor air coil 12 operates as a condenser coil.
The refrigerant pressure within a condenser coil decreases With decreases in the temperature of the coil so that at low outdoor temperatures, the pressure within the coil 12 may be insuiiicient to expand the refrigerant through the capillary tube 1S into the indoor air coil Ztl. When this happens, the pressure within the bellows 3l decreases, causing the switch arm 37 to move against the contact 38, connecting the pump motor through the closed switch 46 and the wires d5, 49, di and 4S across the energized compressor motor CM, starting the pump P which boosts the liquid pressure. The pressure from the pump through the tube 27 closes the check valve CV. When the thermostat CT is satisfied, it stops the compressor motor CM and the pump motor PM.
If the outdoor temperature decreases to the point that indoor air heating is required, the switch arm Si) of the heat thermostat HT moves against the contacts 51 and S, closing through the contact 55, the energizing circuit of the motor starter relay MSR, and closing through the contact Si, the energizing circuits of the solenoids S1 and S2, and of the relay 47. The solenoid S1 adjusts the valve RV to its indoor air heating position. The solenoid S2 adjusts the valve 17 to close off the capillary tube liti, and to route refrigerant from the indoor air coil acting as a condenser coil, through the capillary tube acting as an expansion means, into the outdoor coil 12 acting as an evaporator coil. The pressure within the coil 12 at this time is much lower than when the latter is operating as a condenser coil so that the switch arm 37 of the bellows 31 is against the contact 38, but the pump motor cannot be started at this time since the now energized relay 47 has opened its switch 4e which is in series with the switch arm 37 and the contact 3S in the energizing circuit of the pump motor.
What is claimed, is:
1. A heat pump comprising an indoor air coil, an outdoor air coil, a refrigerant compressor, a refrigerant reversal valve connected to the suction and discharge sides of said compressor and to said coils, means including a liquid pump, a three-way valve and first refrigerant expansion means in series for connecting said outdoor air coil to said indoor air coil, by-pass tubing including a check-valve connected across said pump, means for driving said pump, means including second refrigerant expansion means for connecting said three-way valve to said outdoor air coil, means for adjusting said three-way valve to route refrigerant from said outdoor air coil through said first expansion means into said indoor air coil and for concurrently adjusting said reversal valve to route refrigerant from said compressor directly into said outdoor air coil, or for adjusting said three-way valve to route refrigerant from said indoor air coil through said second expansion means into said outdoor air coil and for concurrently adjusting said reversal valve to route refrigerant from said compressor directly into said indoor air coil, and control means including means responsive to a predetermined drop in refrigerant pressure caused by a reduction in the temperature of said outdoor aii. coil when said reversal valve is adjusted to route refrigerant from said compressor directly to said outdoor air coil, for energizing said pump driving means.
2. A heat pump comprising an indoor air coil, an outdoor air coil, a refrigerant compressor, a refrigerant reversal valve connected to the suction and discharge sides of said compressor and to said coils, means including a liquid pump, a three-way valve and first refrigerant expansion means in series for connecting said outdoor air coil to said indoor air coil, by-pass tubing including a check-valve connected across said pump, means for driving said pump, means including second refrigerant expansion means for connecting said three-Way valve to said outdoor air coil, means for adjusting said three-Way valve to route refrigerant from said outdoor air coil through said first expansion means into said indoor air coil and for concurrently adjusting said reversal valve to route refrigerant from said compressor directly into said outdoor air coil, or for adjusting said three-Way valve to route refrigerant from said indoor air coil through said second expansion means into said outdoor air coil and for concurrently adjusting said reversal valve to route refrigerant from said compressor directly into said indoor air coil, control means including means responsive to a predetermined drop in refrigerant pressure caused by a reduction in the temperature of said outdoor air coil when said reversal valve is adjusted to route refrigerant from said compressor directly to said outdoor air coil, for energizing said pump driving means, and means for disabling said control means when said reversal valve is adjusted to route refrigerant from said compressor directly to said indoor air coil.
3. A heat pump comprising an indoor air coil, an outdoor air coil, a refrigerant compressor, a refrigerant reversal valve connected to the suction and discharge sides of said compressor and to said coils, means including a liquid pump and tirst refrigerant expansion means in series for connecting said outdoor air coil to said indoor air coil, by-pass tubing including a check-valve connected across said pump, means for driving said pump, means including second refrigerant expansion means for connecting said indoor air coil to said outdoor air coil, means for adjusting said reversal valve to route refrigerant from said compressor directly to said outdoor air coil, or to route refrigerant from said compressor directly to said indoor air coil, control means responsive to a predetermined drop in refrigerant pressure caused by a reduction in the temperature of said outdoor air coil when said reversal valve is adjusted to route refrigerant from said compressor directly to said outdoor air coil for energizing said pump driving means, and means for disabling said control means when said reversal valve is adjusted to route refrigerant from said compressor directly to said indoor coil.
4. A heat pump comprising an indoor air coil, an outdoor air coil, a refrigerant compressor, a refrigerant reversal valve connected to the suction and discharge sides of said compressor and to said coils, means including a liquid pump and first refrigerant expansion means for connecting said outdoor air coil to said indoor air coil, by-pass tubing including a check-valve connected across said pump, means for driving said pump, means including second refrigerant expansion means for connecting said indoor air coil to said outdoor air coil, means for routing refrigerant from said outdoor air coil through said first expansion means into said indoor air coil and for concurrently adjusting said reversal valve to route refrigerant from said compressor directly to said outdoor air coil, or for routing refrigerant from said indoor air coil through said second expansion means into said outdoor air coil and for concurrently adjusting said reversal valve to route refrigerant from said compressor directly to said indoor air coil, control means responsive to a predetermined drop in refrigerant pressure caused by a reduction in the temperature of said outdoor air coil when said reversal valve is adjusted to route refrigerant from said compressor directly to said outdoor air coil, for energizing said pump driving means, and means for disabling said control means When said reversal valve is adjusted to route refrigerant from said compressor directly to said indoor air coil.
5. A heat pump comprising an indoor air coil, an outdoor air coil, a refrigerant compressor, a refrigerant reversal valve connected to the suction and discharge sides of said compressor and to said coils, means including a liquid pump and rst refrigerant expansion means in series for connecting said indoor coil to said outdoor coil, by-pass tubing including a check-valve connected across said pump, means for driving said pump, means including second expansion means for connecting said indoor coil to said outdoor coil, means for routing refrigerant from said outdoor air coil through said rst expansion means into said indoor air coil or for routing refrigerant from said indoor air coil through said second expansion means into said outdoor air coil, a solenoid for adjusting said routing means, a second solenoid for adjusting said reversal valve to route refrigerant from said compressor directly from said compressor into said outdoor air coil or directly from said compressor into said indoor air coil,
means including thermostatic means for energizing said solenoids, and control means responsive to a predetermined drop in refrigerant pressure caused by a reduction in the temperature of said outdoor air coil when said reversal valve is adjusted to route refrigerant directly from said compressor to said outdoor air coil, for energizing said pump driving means.
6. A heat pump comprising an indoor air coil, an outdoor air coil, a refrigerant compressor, a refrigerant reversal valve connected to the suction and discharge sides of said compressor and to said coils, means including a liquid pump and first refrigerant expansion means in series for connecting said indoor air coil to said outdoor air coil, by-pass tubing including a check-valve connected across said pump, means for driving said pump, means including second expansion means for connecting said indoor air coil to said outdoor air coil, means for routing refrigerant from said outdoor air coil through said rst expansion means into said indoor air coil or for routing refrigerant from said indoor air coil through said second expansion means into said outdoor air coil, a solenoid for adjusting said routing means, a second solenoid for adjusting said reversal valve to route refrigerant from said compressor directly into said outdoor air coil or directly into said indoor air coil, means including thermostatic means for energizing said solenoids, control means responsive to a predetermined drop in refrigerant pressure caused by a reduction in the temperature of said outdoor coil, and means for disabling said driving means when said reversal valve is adjusted to route refrigerant from said compressor directly to said indoor air coil.
References Cited in the tile of this patent UNITED STATES PATENTS
3. A HEAT PUMP COMPRISING AN INDOOR AIR COIL, AN OUTDOOR AIR COIL, A REFRIGERANT COMPRESSOR, A REFRIGERANT REVERSAL VALVE CONNECTED TO THE SUCTION AND DISCHARGE SIDES OF SAID COMPRESSOR AND TO SAID COILS, MEANS INCLUDING A LIQUID PUMP AND FIRST REFRIGERANT EXPANSION MEANS IN SERIES FOR CONNECTING SAID OUTDOOR AIR COIL TO SAID INDOOR AIR COIL, BY-PASS TUBING INCLUDING A CHECK-VALVE CONNECTED ACROSS SAID PUMP, MEANS FOR DRIVING SAID PUMP, MEANS INCLUDING SECOND REFRIGERANT EXPANSION MEANS FOR CONNECTING SAID INDOOR AIR COIL TO SAID OUTDOOR AIR COIL, MEANS FOR ADJUSTING SAID REVERSAL VALVE TO ROUTE REFRIGERANT FROM SAID COMPRESSOR DIRECTLY TO SAID OUTDOOR AIR COIL, OR TO
| 1962-11-29 | en | 1964-05-19 |
US-6279993-A | Method for treating neurological disorders
ABSTRACT
A method for ameliorating a neurological disorder in a human by administration to the cerebrospinal fluid (CSF) of a therapeutic agent in a dispersion system which allows the therapeutic agent to persist in the cerebro-ventricular space.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for treating a neurological disorder using a slow-release vehicle for delivery of a therapeutic agent to the cerebrospinal fluid (CSF) of a human.
2. Description of the Related Art
Neurological disorders are among the most difficult diseases to treat. A major complicating factor in treating such disorders is the inability of many drugs to penetrate the blood-brain barrier when the agent is administered systemically. This ineffectiveness of classical drug delivery to address this need is particularly problematic with respect to chronic neurological disorders, such as those caused by benign or malignant cell proliferation or various viral etiologic agents.
Among the most difficult chronic neurological disorders to treat are those derived from metastatic infiltration, such as neoplastic meningitis. Neoplastic meningitis results from the metastatic infiltration of the leptomeninges by cancer, and is most commonly a complication of acute leukemia, lymphoma, or carcinoma of the breast and lung. Autopsy studies indicate that 5 to 8 percent of solid tumor patients develop metastasis to the leptomeninges during the course of disease. Evidence suggests that the incidence of neoplastic meningitis may be increasing, in part due to increased survival from effective systemic therapies. (Bleyer, Curr. Probl. Cancer, 12:184, 1988).
Standard treatment for neoplastic meningitis includes single agent or combination intrathecal chemotherapy and radiation therapy. Radiotherapy to the entire neuraxis often produces severe marrow depression and has not been satisfactory in controlling active leptomeningeal disease except in leukemic meningitis. (Kogan, in Principle and Practice of Radiation Oncology, Perez, et al. eds., Lippincott, Philadelphia, Pa., pp. 1280-1281, 1987). Systemic chemotherapy likewise is not generally effective in active meningeal malignancy because of poor drug penetration through the blood-brain barrier. (Biasberg, et al., Can. Treat. Rep., 61:633, 1977; Shapo, et al., New Eng. J. Med., 293:161, 1975). Cytarabine, one of the three chemotherapeutic agents most commonly used for intrathecal therapy of neoplastic meningitis, is a cell-cycle phase specific agent that kills cells only when DNA is being synthesized. Consequently, optimal tumor kill with agents such as cytarabine requires constant infusion or frequent daily injections to maintain therapeutic concentrations for extended periods in CSF. This procedure is uncomfortable for patients, time consuming for physicians, and associated with an increased risk of infectious meningitis. Therefore, there is a need for a slow-releasing depot formulation which can allow a therapeutic agent to persist in contact with a neurological disorder in order to achieve an ameliorative effect. The present invention addresses this need.
SUMMARY OF THE INVENTION
The present invention arose from the seminal discovery that the clinical effectiveness of therapeutic agents in the treatment of neurological disorders in humans could be greatly enhanced if the therapeutic agent was administered as part of a dispersion system. This therapeutic approach allows effective dose levels of the agent to be maintained over a relatively long period of time such that the neurological disorder is continuously exposed to the agent. Surprisingly, the dispersion system containing the therapeutic agent can be effectively administered intralumbar even though the primary foci of the neurological disorder are centered in the cranium region, such as the ventricles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the ventricular CSF pharmokinetics of intraventricularly administered DTC 101 as a function of dose from 12.5 to 125 mg.
FIG. 2 shows the maximum CSF cytarabine concentration [Panel A] and AUC [Panel B] as functions of dose.
FIG. 3 shows a comparison of the ventricular (closed circles) and lumbar (open circles) cytarabine concentrations [total and free, Panels A and B, respectively] and DTC 101 particle count [Panel C] as functions of time following intraventricular administration of DTC 101.
FIG. 4 shows cytarabine concentration in the ventricular CSF as a function of time (solid lines), and lumbar CSF cytarabine concentration at 3 minutes and 14 days (broken lines), following intralumbar administration of DTC 101.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is directed to a method for ameliorating neurological disorders which comprises administering a therapeutic agent to the cerebral spinal fluid (CSF). The surprising ability of the therapeutic agent to ameliorate the neurological disorder is due to the presentation of the therapeutic agent in a dispersion system which allows the agent to persist in the cerebro-ventricular space. The ability of the method of the invention to allow the therapeutic agent to persist in the region of the neurological disorder provides a particularly effective means for treating those disorders which are chronic and, thereby, are particularly difficult to achieve a clinical effect.
The term "neurological disorder" denotes any disorder which is present in the brain, spinal column, and related tissues, such as the meninges, which are responsive to an appropriate therapeutic agent. Among the various neurological disorders for which the method of the invention is effective are those which relate to a cell proliferative disease. The term "cell proliferative disease" embraces malignant as well as non-malignant cell populations which often appear morphologically to differ from the surrounding tissue. Thus, the cell proliferative disease may be due to a benign or a malignant tumor. In the latter instance, malignant tumors may be further characterized as being primary tumors or metastatic tumors, that is, tumors which have spread from systemic sites. Primary tumors can arise from glial cells (astrocytoma, oligodendroglioma, glioblastoma), ependymal cells (ependymoma) and supporting tissue (meningioma, schwannoma, papilloma of the choroid plexus). In children, tumors typically arise from more primitive cells (medulloblastoma, neuroblastoma, chordoma), whereas in adults astrocytoma and glioblastoma are the most common. However, the most common CNS tumors in general are metastatic, particularly those which infiltrate the leptomeninges. Tumors that commonly metastatically invade the meninges include non-Hodgkin's lymphoma, leukemia, melanoma, and adenocarcinoma of breast, lung, or gastrointestinal origin.
The method of the invention is also useful in ameliorating neurological disorders which arise as a result of an infectious disease. Aseptic meningitis and encephalitis are CNS diseases which are caused by a virus. Among the viral infections which may benefit most from the ability of the method of the invention to allow the therapeutic agent to persist are those viral diseases caused by a slow virus or a retrovirus. Of particular interest among the retroviruses are the Lentivirus, which include HTLV-I, HTLV-II, HIV-1 and HIV-2.
Neurological disorders which arise due to an infectious disease caused by a prokaryote can also be treated according to the method of the invention. Typically, the procaryotic etiologic agent is a bacteria such as Hemophilus influenzae, Neisseria meningitidis, Streptococcus pneumonia, Pseudomonas aeruginosa, Escherichia coli, Klebsiella-Enterobacter, Proteus, Mycobacterium tuberculosis, Staphylococcus aureus, and Listeria monocytogenes. Alternatively, the infectious disease can be caused by a eukaryote, such as a fungus. Important fungi which can be treated according to the method invention include Cryptococcus, Cocoidioides immitis, Histoplasma, Candida, Nocardia, and Blastomyces.
The therapeutic agents used according to the method of the invention are administered to the CSF in a delivery system such as synthetic or natural polymers in the form of macromolecular complexes, nanocapsules, microspheres, or beads, and lipid-based systems including oil-in-water emulsions, micelies, mixed micelies, synthetic membrane vesicles, and resealed erythrocytes. These systems are known collectively as dispersion systems. Typically, the particles comprising the system are about 20 nm-50 μm in diameter. The size of the particles allows them to be suspended in a pharmaceutical buffer and introduced to the CSF using a syringe. The administration may be intraventricularly or, more preferably, intrathecally. Most preferred is injection of the particles by intralumbar puncture.
Materials used in the preparation of dispersion systems are typically sterilizable via filter sterilization, nontoxic, and biodegradable, for example, albumin, ethylcellulose, casein, gelatin, lecithin, phospholipids, and soybean oil can be used in this manner. Polymeric dispersion systems can be prepared by a process similar to the coacervation of microencapsulation. If desired, the density of the dispersion system can be modified by altering the specific gravity to make the dispersion hyperbaric or hypobaric. For example, the dispersion material can be made more hyperbaric by the addition of iohexol, iodixanol, metrizamide, sucrose, trehalose, glucose, or other biocompatible molecules with high specific gravity.
One type of dispersion system which can be used according to the invention consists of a dispersion of the therapeutic agent in a polymer matrix. The therapeutic agent is released as the polymeric matrix decomposes, or biodegrades, into soluble products which are excreted from the body. Several classes of synthetic polymers, including polyesters (Pitt, et al, in Controlled Release of Bioactive Materials, R. Baker, Ed., Academic Press, New York, 1980); polyamides (Sidman, et al, Journal of Membrane Science, 7:227, 1979); polyurethanes (Maser, et al., Journal of Polymer Science, Polymer Symposium, 66:259, 1979); polyorthoesters (Heller, et al., Polymer Engineering Science, 21:727, 1981); and polyanhydrides (Leong, et al., Biomaterials, 7:364, 1986) have been studied for this purpose. Considerable research has been done on the polyesters of PLA and PLA/PGA. Undoubtedly, this is a consequence of convenience and safety considerations. These polymers are readily available, since they have been used as biodegradable sutures, and they decompose into non-toxic lactic and glycolic acids (see, U.S. Pat. No. 4,578,384; U.S. Pat. No. 4,765,973; incorporated by reference).
Solid polymeric dispersion systems can be synthesized using such polymerization methods as bulk polymerization, interfacial polymerization, solution polymerization, and ring opening polymerization (Odian, G., Principles of Polymerization, 2nd ed., John Wiley & Sons, New York, 1981). Using any of these methods, a variety of different synthetic polymers having a broad range of mechanical, chemical, and biodegradable properties are obtained; the differences in properties and characteristics are controlled by varying the parameters of reaction temperatures, reactant concentrations, types of solvent, and reaction time. If desired, the solid polymeric dispersion system can be produced initially as a larger mass which is then ground, or otherwise processed, into particles small enough to maintain a dispersion in the appropriate physiologic buffer (see, for example, U.S. Pat. No. 4,389,330; U.S. Pat. No. 4,696,258; incorporated by reference).
The mechanism of release of therapeutic agent from biodegradable slabs, cylinders, and spheres has been described by Hopfenberg (in Controlled Release Polymeric Formulations, pp. 26-32, Paul, D. R. and Harris, F. W., Eds., American Chemical Society, Washington, D.C., 1976). A simple expression describing additive release from these devices where release is controlled primarily by matrix degradation is:
M.sub.t /M.sub.∞ =1-[1-k.sub.0 t/C.sub.0 a].sup.n
where n=3 for a sphere, n=2 for a cylinder, and n=1 for a slab. The symbol a represents the radius of a sphere or cylinder or the half-thickness of a slab. Mt and M.sub.∞ are the masses of drug release at time t and at infinity, respectively.
Most preferred as a dispersion system according to the invention are synthetic membrane vesicles. The term "synthetic membrane vesicles" denotes structures having one or more concentric chambers, commonly known as liposomes, as well as structures having multiple non-concentric chambers bounded by a single bilayer membrane.
When phospholipids are dispersed in aqueous media, they swell, hydrate, and spontaneously form multilamellar concentric bilayer vesicles with layers of aqueous media separating the lipid bilayer. Such systems are usually referred to as multilamellar liposomes or multilamellar vesicles (MLVs) and have diameters ranging from about 100 nm to about 4 μm. When MLV's are sonicated, small unilamellar vesicles (SUVs) with diameters in the range of from about 20 nm to about 50 nm are formed, which contain an aqueous solution in the core of the SUV.
The composition of the synthetic membrane vesicle is usually a combination of phospholipids, particularly high-phase-transition-temperature phospholipids, usually in combination with steroids, especially cholesterol. Other phospholipids or other lipids may also be used.
Examples of lipids useful in synthetic membrane vesicle production include phosphatidyl compounds, such as phosphatidylglycerol, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, sphingolipids, cerebrosides, and gangliosides. Particularly useful are diacylphosphatidylglycerols, where the lipid moiety contains from 14-18 carbon atoms, particularly from 16-18 carbon atoms, and are saturated. Illustrative phospholipids include egg phosphatidylcholine, dipalmitoylphosphatidylcholine, and distearoylphosphatidylcholine.
In preparing vesicles containing a therapeutic agent, such variables as the efficiency of drug encapsulation, lability of the drug, homogeneity and size of the resulting population of vesicles, drug-to-lipid ratio, permeability instability of the preparation, and pharmaceutical acceptability of the formulation should be considered. (Szoka, et al, Annual Reviews of Biophysics and Bioengineering, 9:467, 1980; Deamer, et al., in Liposomes, Marcel Dekker, New York, 1983, 27; Hope, et al., Chem. Phys. Lipids, 40:89, 1986).
If desired, it is possible to produce synthetic membrane vesicles with various degrees of target specificity. The targeting of vesicles has been classified based on anatomical and mechanistic factors. Anatomical classification is based on the level of selectivity, for example, organ-specific, cell-specific, and organelle-specific. Mechanistic targeting can be further distinguished based upon whether it is passive or active. Passive targeting utilizes the natural tendency of vesicles to distribute to cells of the reticulo-endothelial system (RES) in organs which contain sinusoidal capillaries. Active targeting, on the other hand, involves the alteration of the vesicle by coupling the vesicle to a specific ligand such as a monoclonal antibody, sugar, glycolipid, or protein, or by changing the composition or size of the vesicles in order to achieve targeting to organs and cell types other than the naturally occurring sites of localization. Alternatively, vesicles may physically localize in capillary beds.
Another dispersion system which can be used according to the invention is resealed erythrocytes. When erythrocytes are suspended in a hypotonic medium, swelling occurs and the cell membrane ruptures. As a consequence, pores are formed with diameters of approximately 200-500 Å which allow equilibration of the intracellular and extracellular environment. If the ionic strength of this surrounding media is then adjusted to isotonic conditions and the cells incubated at 37° C., the pores will close such that the erythrocyte reseals. This technique can be utilized to entrap the therapeutic agent inside the resealed erythrocyte.
The surface of the dispersion system may be modified in a variety of ways. Non-lipid material may be conjugated via a linking group to one or more hydrophobic groups, for example, alkyl chains from about 12-20 carbon atoms. In the case of a synthetic membrane vesicle delivery system, lipid groups can be incorporated into the lipid bilayer in order to maintain the compound in stabilize association with the membrane bilayer. Various linking groups can then be used for joining the lipid chains to the compound.
Whether a ligand or a receptor, the number of molecules bound to a synthetic membrane vesicle will vary with the size of the vesicle, as well as the size of the molecule to be bound, the binding affinity of the molecule to the target cell receptor or ligand, as the case may be, and the like. In most instances, the bound molecules will be present on the vesicle from about 0.05 to about 2 mol %, preferably from about 0.1 to about 1 mol %, based on the percent of bound molecules to the total number of molecules in the outer membrane bilayer of the vesicle.
In general, the compounds to be bound to the surface of the targeted delivery system will be ligands and receptors which will allow the dispersion system to actively "home in" on the desired tissue. A ligand may be any compound of interest which will specifically bind to another compound, referred to as a receptor, such that the ligand and receptor form a homologous pair. The compounds bound to the service of the dispersion system may vary from small haptens from about 125-200 molecular weight to much larger antigens with molecular weights of at least about 6000, but generally of less than 1 million molecular weight. Proteinaceous ligands and receptors are of particular interest. In general, the surface membrane proteins which bind to specific effector molecules are referred to as receptors. As presently used, however, most receptors will be antibodies. These antibodies may be monoclonal or polyclonal and may be fragments thereof such as Fab, F(ab')2, and Fv, which are capable of binding to an epitopic determinant. Techniques for binding of proteins, such as antibodies, to synthetic membrane vesicles are well known (see, for example, U.S. Pat. No. 4,806,466 incorporated by reference).
The term "therapeutic agent" as used herein for the compositions of the invention includes, without limitation, drugs, radioisotopes, and immunomodulators. Similar substances are known or can be readily ascertained by one of skill in the art. There may be certain combinations of therapeutic agent with a given type of dispersion system which are more compatible than others. For example, the method for producing a solid polymeric dispersion may not be compatible with the continued biological activity of a proteinaceous therapeutic agent. However, since conditions which would produce an uncompatible pairing of a particular therapeutic agent with a particular dispersion system are well known, or easily ascertained, it is a matter of routine to avoid such potential problems.
The drugs which can be incorporated in the dispersion system include non-proteinaceous as well as proteinaceous drugs. The term "non-proteinaceous drugs" encompasses compounds which are classically referred to as drugs such as, for example, mitomycin C, daunorubicin, vinblastine, AZT, and hormones. Of particular interest are anti-tumor cell-cycle specific drugs such as cytarabine, methotrexate, 5-fluorouracil (5-FU), floxuridine (FUDR), bleomycin, 6-mercapto-purine, 6-thioguanine, fludarabine phosphate, vincristine, and vinblastine. Similar substances which can also be used according to the invention are within the skill of the art.
The proteinaceous drugs which can be incorporated in the dispersion system include immunomodulators and other biological response modifiers as well as antibodies. The term "biological response modifiers" encompasses substances which are involved in modifying the immune response in such manner as to enhance the particular desired therapeutic effect, for example, the destruction of tumor cells. Examples of immune response modifiers include such compounds as lymphokines. Examples of lymphokines include tumor necrosis factor, the interleukins, lymphotoxin, macrophage activating factor, migration inhibition factor, colony stimulating factors and the interferons. Interferons which can be incorporated into the dispersion systems include α-interferon, β-interferon, and γ-interferon and their subtypes. In addition, peptide or polysaccharide fragments derived from these proteinaceous drugs, or independently, can also be incorporated. Those of skill in the art will know, or can readily ascertain, other substances which can act as proteinaceous drugs.
In using radioisotopes to treat cell proliferative disorders, such as tumors, certain radioisotopes may be more preferable than others depending on such factors, for example, as tumor distribution and mass, as well as isotope stability and emission. Depending on the type of malignancy present some emitters may be preferable to others. In general, α and β particle-emitting radioisotopes are preferred in immunotherapy. For example, if a patient has solid tumor foci a high energy β emitter capable of penetrating several millimeters of tissue, such as 90 Y, may be preferable. On the other hand, if the malignancy consists of single target cells, as in the case of leukemia, a short range, high energy α emitter such as 212 Bi may be preferred. Examples of radioisotopes which can be incorporated in the dispersion system for therapeutic purposes are 125 I, 131 I, 90 Y, 67 Cu, 212 Bi, 211 At, 212 Pb, 47 Sc, 109 Pd, and 188 Re. Other radioisotopes which can be incorporated are within the skill in the art.
When an antibody is incorporated into the dispersion system, the antibody, whether monoclonal or polyclonal, may be unlabeled or labeled with a therapeutic agent. The term "antibody" or "immunoglobulin" as used herein, includes intact molecules as well as fragments thereof, such as Fab, F(ab-)2, and Fv, which are capable of binding to an epitopic determinant on a cell proliferative or infectious neurological disorder etiologic agent. When coupled to an antibody, the therapeutic agent can be coupled either directly or indirectly. One example of indirect coupling is by use of a spacer moiety. These spacer moieties, in turn, can be either insoluble or soluble (Diener, et al., Science, 231:148, 1986) and can be selected to enable drug release from the antibody molecule at the target site. Examples of therapeutic agents which can be coupled to the antibody for immunotherapy are drugs and radioisotopes, as described above, as well as lectins and toxins.
Lectins are proteins, usually isolated from plant material, which bind to specific sugar moieties. Many lectins are also able to agglutinate cells and stimulate lymphocytes. However, ricin is a toxic lectin which has been used immunotherapeutically. This is preferably accomplished by binding the alphapeptide chain of ricin, which is responsible for toxicity, to the antibody molecule to enable site specific delivery of the toxic effect.
Toxins are poisonous substances produced by plants, animals, or microorganisms that, in sufficient dose, are often lethal. Diphtheria toxin is a substance produced by Corynebacterium diphtheria which can be used therapeutically. This toxin consists of an α and β subunit which under proper conditions can be separated. The toxic α component can be bound to an antibody and used for site specific delivery to a target cell for which the antibodies are specific. Other therapeutic agents which can be coupled to the monoclonal antibodies are known, or can be easily ascertained, by those of ordinary skill in the art.
The labeled or unlabeled antibodies can also be used in combination with other therapeutic agents such as those described above. Especially preferred are therapeutic combinations comprising a monoclonal antibody and an immunomodulator or other biological response modifier. Thus, for example, a monoclonal antibody can be used in combination with α-interferon. This treatment modality enhances monoclonal antibody targeting of carcinomas by increasing the expression of monoclonal antibody reactive antigen by the carcinoma cells (Greiner, et al., Science, 235:895, 1987). A dispersion system based on the use of a synthetic membrane vesicle with multiple non-concentric chambers is particularly useful with combination therapy, since the non-concentric chambers can be loaded with different therapeutic agents. Those of skill in the art will be able to select from the various biological response modifiers to create a desired effector function which enhances the efficacy of the monoclonal antibody or other therapeutic agent used in combination.
When the monoclonal antibody of the invention is used in combination with various therapeutic agents, such as those described herein, the administration of the monoclonal antibody and the therapeutic agent usually occurs substantially contemporaneously. The term "substantially contemporaneously" means that the monoclonal antibody and the therapeutic agent are administered reasonably close together with respect to time. Usually, it is preferred to administer the therapeutic agent before the monoclonal antibody. For example, the therapeutic agent can be administered 1 to 6 days before the monoclonal antibody. The administration of the therapeutic agent can be daily, or at any other interval, depending upon such factors, for example, as the nature of the neurological disorder, the condition of the patient and half-life of the agent.
The term "therapeutically effective" as it pertains to the compositions of the invention means that the therapeutic agent is present at a concentration sufficient to achieve a particular medical effect for which the therapeutic agent is intended. Examples, without limitation, of desirable medical effects which can be attained are chemotherapy, antibiotic therapy, and regulation of metabolism. Exact dosages will vary depending upon such factors as the particular therapeutic agent and desirsable medical effect, as well as patient factors such as age, sex, general condition and the like. Those of skill in the art can readily take these factors into account and use them to establish effective therapeutic concentrations without resort to undue experimentation.
The foregoing is meant to illustrate, but not to limit, the scope of the invention. Indeed, those of ordinary skill in the art can readily envision and produce further embodiments, based on the teachings herein, without undue experimentation.
EXAMPLE 1
PRODUCTION OF DEPO/ARA-C (DTC101)
This example describes the production of a synthetic membrane vesicle having multiple non-concentric chambers containing ara-C which are bounded by a single bilayer membrane.
Dioleoyl lecithin (8.3 g), dipalmitoylphosphatidyl glycerol (1.66 g), cholesterol (6.15 g), and triolein (1.73 g) were mixed with 800 ml of chloroform (the lipid phase) in a 13-liter glass homogenizer vessel fitted with a 2-inch mixing blade. Next, Cytosine arabinoside (33 mg/ml) was dissolved in 0.151N HCI (at a final volume of 1.2 liters) and added to the homogenizer vessel. To form a water-in-oil emulsin, the mixing blade was rotated at 8000 rpm for 10 minutes.
Low ionic strength aqueous component comprising free base lysine (40 mM) and glucose (3.2%) was added to the homogenizer to form the chloroform spherules and the mixing blade was rotated at 3500 rpm for 90 seconds. To remove the chloroform, nitrogen gas was bubbled through the mixture at 62 liters per minute for 30 minutes while the vessel was heated to 35° C. The resulting product was purified and concentrated by diafiltration using polysulfone hollow-fiber with 0.1μ pore size and 8 ft2 surface area.
EXAMPLE 2
INTRATHECAL AND INTRAVENTRICULAR TREATMENT WITH
ENCAPSULATED DEPO0/ARA-C
A. PATIENTS AND METHODS
Twelve patients with a histologically proven diagnosis of cancer and radiological or cytologic evidence of neoplastic meningitis were treated. This human investigation was performed after approval by the UCSD Human Subjects Committee. There was no performance status requirement and prior intra-CSF chemotherapy was allowed. The patients were given 47 total doses of DTC 101. There were 4 patients with hematological malignancies and 8 with solid tumors (TABLE 1). Concurrent systemic chemotherapy was given to 5 patients.
TABLE 1
______________________________________
PATIENT CHARACTERISTICS
______________________________________
Total Number of Patients 12
Male 7
Female 5
Ages (range, years) 6-73
Median 38
Diagnoses
Chronic myelogenous leukemia in blast crisis
1
AIDS-related non-Hodgkin's lymphoma
2
Multiple myeloma 1
Breast cancer 2
Non-small cell lung cancer
1
Head and neck cancer 1
Renal cell tumor 1
Melanoma 1
Primitive neuroectodermal tumor
2
Prior Therapy for Meningeal Disease
With prior therapy 9
Without prior therapy 4
Types of Prior Therapy
Methotrexate 6
Cytarabine 3
ThioTEPA 3
Interferon 1
______________________________________
An Ommaya reservoir was placed in the right lateral ventricle in all but one patient with chronic myelogenous leukemia in blast crisis. Therapy consisted of DTC 101 suspended in a preservative-free 0.9% NaCl solution administered intraventricularly or by the lumbar intrathecal route as a single injection once every 2-3 weeks. The reservoir was flushed with autologous CSF after DTC 101 dosing and at each CSF sampling.
B. TREATMENT
The initial dose of 12.5 mg was escalated (25, 37.5, 50, 75, 125 mg) after at least 3 cycles in 2 patients who were available for evaluation. Treatment was continued until disease progression or to a maximum of 7 doses. Initial work-up included history and physical examination and complete neurological examination; CBC and platelet count; CSF sample for cytology; serum chemistries; CT or MR brain scan with and without appropriate contrast agents and Indium-DTPA CSF flow studies (Chamberlain, et al., Neurol., 40:435-438, 1990; Chamberlain, et al., Neurol., 41:1765-1769, 1991). Before each cycle of DTC 101, complete neurological history and examination, blood counts, and chemistries were done, and CSF samples were obtained for cytologic examination. Complete cytologic response was defined as two consecutive negative CSF cytology examinations at least one week apart; anything less than a complete response was considered as no response. Progressive disease was defined as conversion from negative to positive cytology. Changes in parenchymal CNS lesions or lesions outside the CNS were not used as part of response determination since these were not expected to be influenced by intra-CSR therapy. Treatment-induced toxicities were scored using the "Common Toxicity Scale" of the National Cancer Institute.
FIG. 1 shows the CSF pharmacokinetics of cytarabine following intraventricular administrations of DTC 101 at various doses ranging from 12.5 to 125 mg, where CSF samples were obtained from the same ventricle into which DTC 101 had been injected. Panel A, total cytarabine concentration; panel B, free cytarabine concentration. Each data point is an average from at least three courses and the error bars represent standard errors of mean. Following intraventricular administration of a maximum tolerated dose (75 mg), the ventricular concentration of free cytarabine (cytarabine that had been released from DepoFoam particles into the CSF) decreased biexponentially with an average initial (α) half-life of 9.4±1.6 hrs (SEM), and terminal (β) half-life of 141±23 hrs (SEM). The total ventricular concentration (free plus encapsulated cytarabine) decreased in a similar biexponential manner.
Pharmacokinetic Studies
Ventricular CSF and blood samples were obtained immediately before injection and at 1 hr and then 1, 2, 4, 7, 14, and 21 days following injection. Lumbar CSF samples were obtained in selected patients as a part of evaluation for lumbar CSF cytology at one of these same time points. For intralumbar injections, a sample from the lumbar sac was obtained 3 minutes after injection in lieu of the 1 hr sample. All CSF and blood samples were collected in tubes containing tetrahydrouridine at a final concentration of 40 μM to prevent in vitro catabolism of cytarabine to uracil arabinoside (ara-U) by cytidine deaminase. The heparinized blood samples were immediately placed on ice and plasma was separated from blood cells by centrifugation. The CSF samples were centrifuged at 600×g for 5 minutes to separate DepoFoam particles from the free cytarabine fraction (the supernate). The DepoFoam pellet was lysed by vortexing sequentially in 200 μl methanol and in distilled water. The free cytarabine fractions of CSF were analyzed without further processing. The plasma was ultrafiltered (YMT membrane, No. 4104; Amicon Corp., Danvers, Mass.). The CSF and plasma samples were stored frozen at -20° until analysis by a modification of previously described method (Kaplan, J. G., et al., J Neuro-Onc, 9:225-229, 1990). The samples were analyzed on a high performance liquid chromatography system (Waters Associates, Milford, Mass.) with 254 and 280 mm UV detectors, two Pecosphere C-18 reverse-phase columns (3×3C Cartridge; Perkin-Elmer, Norwalk, Conn.) in tandem, and 6.7 mM potassium phosphate/3.3 mM phosphoric acid mixture (pH 2.8) as an isocratic mobile phase at a flow rate of 1.0 ml/min. Retention time for cytarabine was 6 minutes and that for the major metabolite, ara-U, was 7 minutes. There were no interfering peaks.
The pharmacokinetic curves were fit to the biexponential function C(t)=Ae-αt +BE-βt, where C(t) is the concentration at time 5, A and B are constants and α and β are the initial and terminal rate constants. The RSTRIP program (MicroMath Scientific Software, Salt Lake City, Utah) was used to perform the curve fitting by iterative non-linear regression. The area under the concentration-versus-time curve (AUC) was determined by the linear trapezoidal rule up to the last measured concentration and extrapolated to infinity. CSR clearance of cytarabine was determined by dividing the dose of cytarabine by the AUC. The initial volume of distribution of cytarabine in CSF (Vd) was calculated by dividing the dose of cytarabine by the concentration measured at 1 hr.
TABLE 2 shows the detailed pharamcokinetic parameters as a function of dose. The half-lives (T1/2), volumes of distribution (Vd), and clearances (CI) did not change significantly as the dose was escalated from 12.5 to 125 mg.
TABLE 2
__________________________________________________________________________
PHARMACOKINETIC PARAMETERS AS A FUNCTION OF DOSE
__________________________________________________________________________
Dose 12.5
mg 25 mg 37.5
mg 50 mg 75 mg 125 mg
Cycles 3 6 5 6 7 3
Total Cytarabine
C.sub.max (μg/ml)
161
± 35
263 ± 51
308
± 98
468
± 112
554
± 146
1373
± 740
α T.sub.1/2 (hr)
2.3
± 5
8.0 ± 1.5
6.0
± 1.7
5.0
± 1.0
7.6
± 1.5
8.4 ± 1.5
β T.sub.1/2 (hr)
47 ± 22
229 ± 70
75 ± 16
87 ± 15
95 ± 16
161 ± 75
AUC (μg-hr/ml)
2210
± 452
5910
± 1550
4820
± 1230
7390
± 1150
9090
± 1750
20800
± 9400
Cl (ml/min)
.11
± .02
.09 ± .02
.18
± .04
.13
± .02
.27
± .07
.18 ± /07
V.sub.d (ml)
91 ± 21
112 ± 22
206
± 64
150
± 35
275
± 95
286 ± 154
Free Cytarabine
C.sub.max (μg/ml)
25 ± 12
77 ± 17
55 ± 12
73 ± 11
66 ± 31
282 ± 111
α T.sub.1/2 (hr)
5.5
± 7
7.6 ± 1.6
4.6
± 1.4
5.5
± 1.4
9.4
± 1.6
7.3 ± .1
β T.sub.1/2 (hr)
71 ± 13
123 ± 22
112
± 31
80 ± 18
141
± 23
129 ± 46
AUC (μg-hr/ml)
355
± 151
± 1595
± 234
853
± 210
1327
± 135
1343
± 465
4525
± 1775
Cl (ml/min)
1.2
± .6
.30 ± .1
1.1
± .3
.66
± .06
1.7
± .4
.73 ± .25
__________________________________________________________________________
Abbreviations:
C.sub.max, maximum concentration; α T.sub.1/2, initial halflife;
β T.sub.1/2, terminal halflife; AUC, area under the curve; Cl,
clearance; V.sub.d, volume of distribution
FIG. 2 depicts the maximum ventricular cytarabine concentration (Panel A) measured at 1 hr following DTC 101 administration, and the CSF drug exposure (AUC, Panel B) as a function of dose administered intraventricularly. Open and closed circles represent total and free cytarabine, respectively. Each data point is an average from at least three courses nd the error bars represent standard errors of mean. There was a linear relationship between these pharmacokinetic parameters and dose, indicating that there was no saturation of clearance process over the dose range examined. The total ara-U AUC averaged 3.7±0.9% (SEM) of the total cytarabine AUC in the CSF. No cytarabine or ara-U was detected in the plasma (detection limit=0.25 μg/ml for both) at any time point.
Lumbar CSF samples were obtained during five courses in two patients following intraventricular administration of DTC 101 at the maximum tolerated dose (75 mg). FIG. 3 compares the ventricular drug concentration and DTC 101 particle count with that in the lumbar subarachnoid space. Comparison of the ventricular (closed circles) and lumbar (open circles) cytarabine concentrations (total and free, Panels A and B, respectively) and DTC 101 particle count (Panel C) as functions of time following intraventricular administration of DTC 101. The initial ventricular free cytarabine concentration decreased in an exponential fashion with a half-life of 6.8 hrs; cytarabine became detectable in lumbar CSF at 1.25 hrs and then increased rapidly with a doubling time of 0.53 hrs. Subsequently, the lumbar and ventricular concentrations of free and total cytarabine decreased in parallel fashion, with the lumbar drug concentrations remaining comparable to those in the ventricle throughout the terminal phase of the decay curve.
Both ventricular and intralumbar CSF samples were obtained from four patients given DTC 101 intrathecally by lumbar puncture. FIG. 4 shows that a therapeutic concentration of free cytarabine (>0.1 μg/ml) was maintained for 3 to 6 days in ventricular CSF following intrathecal lumbar injection, and a significant concentration of total cytarabine was found in the ventricular CSF for 14 days following intralumbar administration. Cytarabine concentration in the ventricular CSF as a function of time (solid lines), and lumbar CSF cytarabine concentration at 3 minutes and 14-days (broken lines), following intralumbar administration of DTC 101. Open squares and circles represent total cytarabine concentrations and closed squares and circles represent free cytarabine concentrations. A therapeutic concentration of free cytarabine was maintained for more than 14 days in the lumbar subarachnoid space following intralumbar injection.
TABLE 3 summarizes the toxicities of DTC 101 as a function of dose. The toxicities were transient and in no instance did drug-related toxicity delay therapy with a subsequent dose of DTC 101. There was one death due to the occurrence of a toxic encephalopathy that developed 36 hours following intraventricular administration of 125 mg of DTC 101. This patient was also receiving concurrent whole brain irradiation (20 Gy in 5 fractions) for partial blockage of CSF flow at the base of brain. There were no hematological toxicities attributable to DTC 101 except in one patient who had an autologous bone-marrow transplant two months prior to DTC 101 administration. The maximum tolerated dose of DTC 101 was 75 mg; dose limiting toxicity occurred a dose of 125 mg, at which there was excessive vomiting and encephalopathy (TABLE 3).
TABLE 3
______________________________________
TOXICITY OF DTC 101 AS A FUNCTION OF DOSE
______________________________________
Dose (mg) 12.5 25 37.5 50 75 125
Patients 2 6 5 4 8 4
Courses 3 7 7 6 20 4
Fever 1 (1)* 0 (4) 0 (1) 0 (3)
0 (5)
0 (1)
Headache 0 (1) 0 (7) 0 (2) 2 (2)
0 (4)
1 (2)
Neck/back pain
0 (0) 0 (0) 0 (0) 0 (1)
0 (3)
0 (0)
Nausea/vomiting
0 (3) 1 (2) 1 (3) 0 (4)
2 (4)
3 (1)
Cerebellar 0 (1) 0 (0) 0 (0) 0 (0)
0 (0)
0 (0)
Tinnitus 0 (0) 0 (1) 0 (0) 0 (0)
0 (0)
0 (0)
Encephalopathy
0 (0) 1 (1) 0 (0) 1 (0)
0 (0)
1 (1)
Hyponatremia
0 (0) 0 (0) 0 (0) 0 (0)
0 (1)
0 (0)
______________________________________
*The numbers in the columns represent toxicities greater than grade 2.
The numbers in parenthesis represent toxicities of grade 1 or 2.
TABLE 4 shows that oral dexamethasone in doses of 2 to 4 mg twice per day had a major effect on blunting toxicities associated with DTC 101. Fever, headache, and nausea/vomiting were all reduced. There were three patients who received the same doze of DTC 101 with and without oral dexamethasone. All three patients manifested toxicity without dexamethasone and in each patient the toxicity was almost completely suppressed with concurrent oral dexamethasone.
TABLE 4
______________________________________
EFFECT OF CONCURRENT ORAL DEXAMETHASONE
ADMINISTRATION ON DTC 101 TOXICITY
(-) Dexamethasone
(+) Dexamethasone
______________________________________
Number of courses
9 12
% with toxicity grade
1-2 3-4 1-2 3-4
Fever 44 0 8 0
Headache 44 0 8 0
Back/neck pain
33 0 0 0
Nausea/vomiting
22 22 17 8
Encephalopathy
0 0 0 0
______________________________________
Intraventricular and intralumbar routes were combined.
Four patients were treated with DTC 101 by the lumbar intrathecal route. The toxicities were similar to those observed following intraventricular administration except 4 of 9 cycles were associated with grade 1 to 2 low back pain.
Nine of 12 patients had a positive CSF cytology immediately prior to treatment. Seven of these 9 cytologically evaluable patients cleared their CSF of malignant cells with DTC 101 treatment (TABLE 5). The duration of response ranged from 2 to 26 weeks with a median of 16 weeks. One non-responding patient had an AIDS-related non-Hodgkin's lymphoma and the other had a prima brain tumor. Survival time for all patients on study ranged from 3 to 64 weeks (median: 21 weeks).
TABLE 5
______________________________________
CSF CYTOLOGIC RESPONSE TO DTC 101
______________________________________
Number of Patients 12
Number with positive CSF cytology
9
Cleared CSF with DTC 101
7
Responders
Breast cancer 1
Non-small cell lung cancer
1
Multiple Myeloma 1
CML in blast crisis 1
Melanoma 1
AIDS-related non-Hodgkin's lymphoma
1
Primitive neuroectodermal tumor
1
Non-Responders
AIDS-related NHL 1
Primitive neuroectodermal tumor
1
______________________________________
Three of twelve patients had evidence of neoplastic meningitis by CT or MRI scan, but had negative CSF cytology prior to therapy and were not evaluable for cytologic response. However, none of these three patients developed a positive CSF cytology while on treatment.
Surprisingly, responses were observed at all dose levels and were not limited to the higher doses. One patient with multiple myeloma relapsed following an initial cytologic response at the 25 mg dose level, then responded again to a higher dose (37.5 mg) of DTC 101. Three of five patients presenting with headache responded clinically to DTC 101 therapy. No clinical improvement was observed in patients with focal (ophthalmoplegia or paraparesis) or diffuse (acute confusional state) neurologic deficits at the start of therapy.
A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiment, but only by the scope of the appended claims.
We claim:
1. A method for ameliorating a cell proliferative disease which comprises intralumbar administration to the cerebrospinal fluid (CSF) of a human with the disease of a therapeutically effective amount of an antitumor drug in a synthetic membrane vesicle such that the antitumor agent persists in the cerebro-ventricular space for a time sufficient to ameliorate the disease.
2. The method of claim 1, wherein the synthetic membrane vesicle is a liposome.
3. The method of claim 2, wherein the liposome contains multiple concentric chambers.
4. The method of claim 1, wherein the synthetic membrane vesicle contains multiple non-concentric chambers.
| 1993-05-14 | en | 1995-10-03 |
US-90499178-A | Method for purifying phosphate containing waste waters
ABSTRACT
Process for purifying phosphate containing waste waters in which aluminum oxide is used as the sorption material. The waste water is brought into contact with fine-grained aluminum oxide in a grain size range from 0.05 to 0.2 mm. Simultaneously, a gas is blown in, which is inert with respect to Al 2 O 3 and with respect to phosphate ions.
BACKGROUND OF THE INVENTION
The present invention relates to a method for purifying phosphate containing waste waters in which aluminum oxide is used as the sorption material.
For the removal of phosphates from waste waters, for example, from waste discharges from biological clarification systems, the prior art practice has been flocculation with iron or aluminum salts. A drawback of the flocculation process is that there is a great consumption of salts and possibly of means or agents which aid flocculation. Moreover, in the flocculation process, a large quantity of mud or sludge is produced which must be disposed of. Possible recovery of the phosphates from these muds has not as yet been effected and is very costly because of the relatively low concentration in the mud.
There are literature references which indicate that phosphate ions are sorbed by aluminum oxide. Two process principles have become known in this connection.
In the first process, the percolation of the waste water is effected through a column filled with coarse Al2 O3 grains, for example, grain sizes of from 1 to 5 mm. In the second process, a fluidized bed is used with fine-grained Al2 O3 having grain sizes of, for example, 0.05 to 0.2 mm.
These methods which employ aluminum oxide so far have not as yet been used, other than in laboratories, and have a number of drawbacks. With respect to the first process principle where use is made of a fixed bed, the columns are clogged very quickly due to the development of mud. The columns must therefore be rinsed out very often. Moreover, abrasion of the coarse grained Al2 O3 produces relatively heavy losses. With respect to the second process principle where use is made of a fluidized bed, the mode of operation of fluidized bed reactors is very irregular. Further, it happens that unpurified or incompletely purified water breaks through and so-called bubble formation takes place. In addition, the adsorption kinetics in the fluidized bed are very poor due to great film thicknesses of the materials to be removed at the individual grains of the sorption agent. Moreover, the start of operation after shut-down in a fluidized bed is very difficult since the fine-grained Al2 O3 cakes together when settling and renewed fine distribution is very difficult.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a process with which phosphate containing waste waters can be freed of the phosphates while avoiding the drawbacks of the known processes.
A further object of the present invention is to provide a process which is safe and continuous, as well as discontinuous, while employing a sorption agent that can easily be desorbed again.
Additional objects and advantages of the present invention will be set forth in part in the description which follows and in part will be obvious from the description or can be learned by practice of the invention. The objects and advantages are achieved by means of the processes, instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing objects and in accordance with its purpose, the present invention, as embodied and broadly described, provides a process for purifying a phosphate containing waste water in which aluminum oxide is used as the sorption material, comprising: bringing the waste water into contact with fine-grained aluminum oxide having a grain size range from 0.05 to 0.2 mm, and simultaneously blowing in a gas which is inert with respect to Al2 O3 and with respect to phosphate ions.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the practice of the present invention, the medium to be treated is a waste water which contains phosphates, and can, for example, be industrial waste water containing chemicals or waste water from domestic sewage and especially can be discharge from a biological clarification system.
The process of the present invention employs inexpensive finely grained aluminum oxide particles having a grain size of between 0.05 and 0.2 mm as sorption agent. Abrasion losses do not occur to any significant extent and no longer play a part in the present invention with the use of this finely grained material.
The waste water to be treated is brought into contact with the finely grained aluminum oxide, and simultaneously a gas is blown in which is inert with respect to Al2 O3 and with respect to phosphate ions.
Advantageously, the inert gas is air. Preferably, the air is blown in with a flow rate in the range between 1 and 10 liters of air per liter of waste water being treated. The process according to the present invention can also be used successfully, however, with nitrogen, or carbon dioxide, or oxygen as the inert gas. The same flow rate ranges as for air are used in such cases.
By blowing in air or the above-mentioned gases, an additional purification effect occurs which is unexpected with the use of aluminum oxide. Moreover, the aluminum oxide sorption agent can be charged higher.
The phosphate loading of the Al2 O3 is increased by bubbling air or other gases through the suspension of the waste water and the oxide according to the invention. On the other hand the phosphate concentration of the purified water is decreased compared with experiments done without bubbling gases.
The process of this invention can be either continuous or discontinuous, with reference to the contact of the Al2 O3 with the waste water. From the point of view of the apparatus, this can be handled in two ways: either a certain amount of the oxide is contacted with the water until exhaustion and then replaced by fresh Al2 O3 or the Al2 O3 is fed in counter current stream to the waste water.
The advantages of the process according to the present invention compared to purification effected without aeration can be seen in that the same discharge quality of the water is attained in the process of the present invention with a smaller quantity of Al2 O3 since purification in the present invention is more uniform in the stirrer reactor in which the process is conducted and the sorption agent is able to accept about twice or three times the phosphate quantity as a result of the aeration.
The difference between the stirrer reactor system and the fluidized bed system lies in the fact that in the latter the state of suspension of the solid oxide is caused by flowing in of the waste water whereas in the former it is effected by using stirrers. The particles of the oxide are agitated in the whole reactor volume independent on the material density and leads to a better adsorption kinetics of the phosphate on the oxide. In a conventional fluidized bed the technique of bubbling gases cannot be used. The application of the described technique in a fixed bed reactor was not investigated.
We conducted investigations on ortho-phosphate (PO4 3-); di-phosphate (P2 O7 4-); triphosphate (P3 O1o 5-); dibutyl-phosphate; monobutyl-phosphate; sodium poly-phosphate (NaPO3)x ; calgon (Na10 P8 O25, ca. 64% P2 O5); secondary effluent, containing one or more of the phosphate compounds listed above.
The following examples are given by way of illustration to further explain the principles of the invention. These examples are merely illustrative and are not to be understood as limiting the scope and underlaying principles of the invention in any way. All percentages referred to herein are by weight unless otherwise indicated.
EXAMPLE 1
The discharge from a biological clarification system was introduced into a three-stage stirrer reactor system and was aerated in accordance with the present invention. In an identical parallel system, the same type of waste water was purified without aeration. Each stirrer reactor received 100 g of so-called acid aluminum oxide in a 2.5 percent by weight suspension.
A comparison of the resulting values is set forth in the following Tables 1 and 2.
TABLE 1
______________________________________
Elimination of Phosphates as a
pecentage (%) of the original
phosphate content
Waste Water Throughput
of the waste water.
(Liters) With aeration
Without aeration
______________________________________
100 79 70
200 55 18
300 54 16
400 55 16
700 38 0
______________________________________
TABLE 2
______________________________________
Resulting charge on the Al.sub.2 O.sub.3
(% P)
With aeration
Without aeration
______________________________________
Reactor 1 2.5 1.2
Reactor 2 2.1 1.0
Reactor 3 1.8 1.2
______________________________________
The charges were measured at the end of the experiments after a throughput of 700 liters.
The correspondance of the 4 elimination values given in table 1 and the oxide load lists above (table 2) cannot be seen exactly as the phosphate concentration of the influent was not constant, but in the range of 16.5 mg P/l to 20.4 mg P/l.
The grain size of the Al2 O3 used was in the range of 0.05-0.2 mm, the flow rate of the air 10 l/h using reactors of 4.2 l volume and a throughput of 4 l/h water. Analogous experiments with the same purification effects were done with throughputs between 0.5 and 6 l/h, i.e. a contacting time between 15 minutes and 1 hour depending on the rate of suspension of the oxide reaching from 2.5 to 20% by weight of the oxide and the phosphate concentration of the inlet.
EXAMPLE 2
The procedure was the same as in Example 1, with the only exception that instead of an acid aluminum oxide, a so-called alkali Al2 O3 was used which additionally had a higher specific surface than the acid Al2 O3 of Example 1.
A comparison of the resulting values is set forth in the following Tables 3 and 4.
TABLE 3
______________________________________
Elimination of Phosphates as a
percentage (%) of the original
phosphate content of the waste
Waste Water Throughput
water.
(Liters) With aeration
Without aeration
______________________________________
100 82 82
200 53 45
300 54 33
400 41 15
1000 42 0
1200 25 0
______________________________________
TABLE 4
______________________________________
Resulting charge on the Al.sub.2 O.sub.3
(% P)
With aeration
Without aeration
______________________________________
Reactor 1 1.9 1.3
Reactor 2 3.2 1.2
Reactor 3 2.1 1.2
______________________________________
The charges were measured at the end of the experiments after a throughput of 1200 liters. The correspondance of the % elimination values given in table 3 and the oxide load listed above (table 4) cannot be seen exactly as the phosphate concentration of the influent was not constant, but in the range of 13.8 mg P/l to 19.9 mg P/l.
EXAMPLES 3 to 5
In single-stage beaker glass experiments, charges of 3 liters each of a discharge from a clarification system containing waste water with 16 mg P/l were each stirred together with 5 g aluminum oxide and gasified with a gas stream of 20 liters per hour in accordance with the present invention. Three different gases were tested, namely, N2, CO2, and O2. Samples of treated waste water were taken at various time intervals and were analyzed to determine the percent of phosphate eliminated. A comparison experiment was conducted under identical conditions, but in which no gas was blown in. Table 5 below shows the elimination values in percent of the originally present phosphorus. The grain size of the Al2 O3 used in the examples 3 to 5 was in the range between 0.05 and 0.2 mm.
TABLE 5
______________________________________
Comparison
Example 3 Example 4
Example 5
Sample example Gasifica- Gasifica-
Gasifica-
taken without in-
tion with tion with
tion with
after put of gas.
20 l/h N.sub.2.
20 l/h CO.sub.2.
20 l/h O.sub.2.
gasification
% P % P % P % P
(min) eliminated
eliminated
eliminated
eliminated
______________________________________
2.5 38.75 50.0 43.1 51.25
5 45.6 56.25 46.9 59.4
10 45.6 58.1 50.0 61.9
30 52.5 59.5 57.5 65.0
40 56.25 60.6 61.25 65.0
50 57.5 61.9 63.75 65.0
______________________________________
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
What is claimed is:
1. Process for purifying a phosphate containing waste water in which aluminum oxide is used as a sorption material, comprising: bringing the waste water into contact in a stirrer reactor, with stirring, with fine-grained aluminum oxide having a grain size range from 0.05 to 0.2 mm, and simultaneously blowing in a gas which is inert with respect to Al2 O3 and phosphate ions.
2. Process as defined in claim 1 wherein the inert gas is air.
3. Process as defined in claim 2 wherein the air is blown in at a flow rate in the range between 1 and 10 liters air per liter of waste water being treated.
4. Process as defined in claim 1 wherein the inert gas is nitrogen.
5. Process as defined in claim 1 wherein the inert gas is carbon dioxide.
6. Process as defined in claim 1 wherein the inert gas is oxygen.
| 1978-05-11 | en | 1980-10-28 |
US-60665490-A | Dryer apparatus
ABSTRACT
A dryer apparatus is disclosed for drying a pressed web. The apparatus includes a plurality of single tier dryer sections in which successive sections dry alternate sides of the web, the web being transferred between successive sections without any open draw of the web such that the web is uniformly dried on both sides thereof while the web is restrained against cross-machine directional shrinkage. Each of the sections includes a single tier of dryers with an intermediate roll disposed between each adjacent dryer. A dryer felt extends in serpentine configuration around each dryer and roll such that the web is disposed between the felt and each dryer for drying one side of the web. The felt is also disposed between the roll and the web with the felt in direct contact with an alternate side of the web. The intermediate roll defines a plurality of circumferential grooves for diffusing boundary air following the felt that would otherwise tend to lift the web from the felt extending around the roll. The arrangement is such that inherent machine directional shrinkage of the web during drying thereof inhibits crossmachine directional shrinkage of the web during movement of the web between successive dryers.
CROSS-REFERENCE TO RELATED APPLICATIONS
The subject application is a continuation-in-part of co-pending patent application Ser. No. 07/431,961 filed Nov. 3, 1989 now U.S. Pat. No. 5,101,577, which is a continuation-in-part of Ser. No. 07/014,569 filed Feb. 13, 1987, which issued as U.S. Pat. No. 4,934,067 Jun. 19, 1990. All the subject matter of Ser. Nos. 07/431,961 and 07/014,569 are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a dryer apparatus for drying a pressed web. More specifically, the present invention relates to a dryer apparatus which includes a plurality of single tier dryer sections in which successive sections dry alternate sides of the web as the web is transferred between successive sections without any open draw.
2. Information Disclosure Statement
In the papermaking art, a formed web of paper is pressed in a press section in order to remove as much water as possible from the formed web. Subsequently, the pressed web is guided around a plurality of heated drying cylinders in order to remove remaining water from the web.
Preferably, alternate sides of the web are successively brought into direct contact with the heated surfaces of the drying cylinders as the web moves through the dryer apparatus. Such successive drying of alternate sides of the web tends to enhance the uniform drying characteristics of the resultant dried roll.
U.S. Pat. No. 4,934,067 to Skaugen et al teaches the aforementioned drying apparatus which also permits transfer of the web between successive drying sections without open draw of the web. Consequently, the apparatus disclosed in U.S. Pat. No. 4,934,067 enables the restrained drying of the web not only in the wet section of the dryer apparatus, but along the entire length of the dryer apparatus.
More particularly, because the web is constrained by the dryer felt during transit of the web around the dryer and because vacuum is applied to hold the web on the felt during movement around an intermediate roll, cross-machine directional shrinkage of the web during drying is inhibited.
Also, during the transfer of the web between successive dryer sections, vacuum means is used to restrain the web against such cross-machine directional shrinkage and to prevent cross-machine directional shrinkage that would occur in such a transfer if an open draw transfer were utilized.
Therefore, the aforementioned disclosure of U.S. Pat. No. 4,934,067 not only enabled enhanced runnability, but also provided improved resultant sheet quality because due to the sheet being restrained against cross-machine directional shrinkage, edge curl of the web was inhibited.
However, in certain applications, it has been discovered that the provision of intermediate vacuum rolls and the like are unnecessary provided means are supplied for diffusing boundary air following the felt adjacent to such intermediate rolls.
More particularly, the present invention provides a dryer apparatus having a plurality of single tier dryer sections in which successive sections dry alternate sides of the web, the web being transferred between successive sections without any open draw, and in which the web is guided between adjacent dryers by an intermediate roll defining a plurality of circumferential grooves for diffusing the aforementioned boundary air.
Therefore, it is a primary objective of the present invention to provide a dryer apparatus which provides a significant contribution to the art of drying a pressed web.
Another object of the present invention is the provision of a dryer apparatus including an intermediate roll which defines a plurality of circumferential grooves for diffusing boundary air following a dryer felt that would otherwise tend to lift the web from the felt extending around the intermediate roll.
Another object of the present invention is the provision of a dryer apparatus having an intermediate roll defining a plurality of grooves such that inherent machine directional shrinkage of the web during drying thereof inhibits cross-machine directional shrinkage of the web during movement of the web between successive dryers.
Another object of the present invention is the provision of a dryer apparatus in which each intermediate roll has a diameter which is substantially less than the diameter of adjacent dryers such that the machine directional shrinkage increases the tension of the web between successive dryers so that the pressure exerted by the web against the dryer felt during movement of the web around the intermediate roll is increased in conformity with an equation PS=TW/RI, where PS is the pressure exerted by the web on the felt, TW is the machine direction tension of the web, and RI is the radius of the intermediate roll.
Other objects and advantages of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description contained hereinafter taken in conjunction with the annexed drawings.
SUMMARY OF THE INVENTION
A dryer apparatus is disclosed for drying a pressed web. The apparatus includes a plurality of single tier dryer sections in which successive sections dry alternate sides of the web. The web is transferred between successive sections without any open draw of the web such that the web is uniformly dried on both sides thereof while the web is restrained against cross-machine directional shrinkage.
Each of the dryer sections includes a single tier of dryers. An intermediate roll is disposed between each adjacent dryer of the single tier dryers. A dryer felt extends in serpentine configuration around each dryer and intermediate roll such that the web is disposed between the felt and each dryer of the single tier of dryers for drying one side of the web. Also, the felt is disposed between the intermediate roll and the web so that the felt is disposed in direct contact with an alternate side of the web.
The intermediate roll defines a plurality of circumferential grooves for diffusing boundary air following the felt that would otherwise tend to lift the web from the felt extending around the intermediate roll.
The arrangement is such that inherent machine directional shrinkage of the web during drying thereof inhibits cross-machine directional shrinkage of the web during movement of the web between successive dryers.
In a more specific embodiment of the present invention, the dryer apparatus includes a first single tier dryer section for drying one side of the web. A second single tier dryer section is disposed immediately downstream relative to the first dryer section for drying an alternate side of the web.
A transfer means is disposed between the first and second dryer sections for transferring the web without open draw between the first and the second dryer sections.
The transfer means includes a felt roll which is disposed between the first and the second dryer sections such that the dryer felt extends from the first dryer section to and around the felt roll. The felt is disposed between the felt roll and the web.
A further felt roll is disposed between the felt roll and the first dryer section, and a further felt extends around the further felt roll such that the further felt is disposed between the further felt roll and the web. The further felt thereafter extends around the second dryer section so that the web disposed between the felt and the further felt is guided without open draw from the first to the second dryer section.
Means are disposed adjacent to the felt roll for urging the web to follow the further felt when the felt and the further felt diverge relative to each other adjacent to the felt roll.
More specifically, the means is a blow box disposed on the opposite side of the second felt relative to the web. The blow box is connected to a source of pressurized air such that a curtain of air is blown from the blow box onto the further felt so that the web is drawn towards the further felt due to a Coanda effect of the curtain of air relative to the further felt.
Each of the intermediate rolls has a diameter which is substantially less than the diameter of the adjacent dryers such that the machine directional shrinkage increases the tension of the web between successive dryers. The arrangement is such that the pressure exerted by the web against the dryer felt during movement of the web around the intermediate roll is increased in conformity with the equation PS=TW/RI pounds per square inch, where PS is the pressure exerted by the web on the dryer felt extending around the intermediate roll, TW is the machine direction tension of the web induced by the machine directional shrinkage of the web during drying, and RI is the radius of the intermediate roll.
In a preferred embodiment of the present invention, the plurality of grooves are spaced in a cross-machine direction along the entire length of the intermediate roll.
Each groove of the plurality of circumferential grooves extends around the circumference of the intermediate roll so that air pumped into each groove by the dryer felt converging relative to the intermediate roll flows through and around each groove so that a build-up of air pressure at a converging nip defined between the dryer felt and the intermediate roll is inhibited.
In an alternative embodiment of the present invention, the dryer apparatus includes a vacuum box which is disposed closely adjacent to an unfelted end portion of the intermediate roll. The vacuum box is selectively connected to a source of partial vacuum such that in use of the apparatus, during a tail threading operation thereof, the vacuum box is connected to the source of partial vacuum such that air flows in a direction from a tail of the web towards and through the dryer felt and into the circumferential grooves disposed adjacent to the vacuum box and into the vacuum box such that the tail is urged into close conformity with the dryer felt moving around the intermediate roll during the tail threading operation.
In one embodiment of the present invention, the intermediate roll is a shell roll, the shell defining a plurality of circumferential grooves.
More specifically, the shell roll includes a rotatable shell and an internal baffle disposed within the shell. The shell and baffle define a tail threading chamber which is disposed adjacent to one end of the intermediate roll.
Circumferential grooves disposed in the vicinity of the tail threading chamber define aperture means such that the tail threading chamber is disposed in fluid communication with the circumferential grooves disposed in the vicinity of the chamber such that when the tail threading chamber is connected to a source of partial vacuum, air flows from a tail of the web towards and through the dryer felt, through the grooves disposed in the vicinity of the threading chamber, and through the aperture means into the threading chamber so that the tail is urged into close conformity with the dryer felt during a tail threading operation of the dryer apparatus.
Many modifications and variations of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description contained hereinafter taken in conjunction with the annexed drawings. However, such modifications and variations fall within the spirit and scope of the present invention as defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side-elevational view of a dryer apparatus according to the present invention;
FIG. 2 is a perspective view of an intermediate roll according to the present invention showing a plurality of circumferential grooves defined thereby;
FIG. 3 is a fragmentary sectional view of one embodiment of the present invention showing a portion of an intermediate roll together with an adjacent vacuum box; and
FIG. 4 is a fragmentary sectional view of an alternate embodiment of the present invention showing an intermediate roll including a shell and a baffle defining a tail threading chamber.
Similar reference characters refer to similar parts throughout the various embodiments of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side-elevational view of a dryer apparatus generally designated 10 according to the present invention for drying a pressed web W.
The dryer apparatus 10 includes a plurality of single tier dryer sections 12 and 14, respectively, in which successive sections 12 and 14 dry alternate sides 16 and 18 of the web W.
The web W is transferred between successive sections 12, 14 without any open draw of the web W such that the web W is uniformly dried on both sides 16 and 18 thereof while the web W is restrained against cross-machine directional shrinkage.
Each of the dryer sections 12 and 14 includes a single tier of dryers indicated by the arrow 20 and 22, respectively.
More specifically, the dryer section 12 includes a single tier of dryers 24, 25 and 26.
An intermediate roll 28 is disposed between each adjacent dryer 25 and 25 of the single tier of dryers 20.
A dryer felt 30 extends in serpentine configuration around each dryer 24 to 26, and intermediate rolls 28 such that the web W is disposed between the felt 30 and each dryer 24 to 26 of the single tier of dryers 20 for drying one side 16 of the web W.
The felt 30 is also disposed between the intermediate roll 28 and the web W so that the felt 30 is disposed in direct contact with an alternate side 18 of the web W.
The intermediate roll 28 defines a plurality of circumferential grooves as shown more clearly in FIG. 2 which is a perspective view of one of the intermediate rolls 28.
As shown in FIG. 2, the intermediate roll 28 defines a plurality of circumferential grooves 32, 33, 34, 35, 36 and 37 for diffusing boundary air as indicated by the arrows 38 following the felt 30 as shown in FIG. 1 that would otherwise tend to lift the web W from the felt 30 extending around the intermediate roll 28.
The arrangement is such that inherent machine directional shrinkage, as indicated by the arrow MD, during drying thereof inhibits cross-machine directional shrinkage, as indicated by the arrow CD, during movement of the web W between successive dryers 24 and 25.
More specifically, with reference to FIG. 1, the dryer apparatus 10 includes a first single tier dryer section 12 for drying the one side 16 of the web W.
A second single tier dryer section 14 is disposed immediately downstream relative to the first dryer section 12 for drying the alternate side 18 of the web W.
Transfer means generally designated 40 is disposed between the first and the second dryer sections 12 and 14 respectively for transferring the web W without open draw between the first and the second dryer sections 12 and 14.
More specifically, the transfer means 40 includes a felt roll 42 which is disposed between the first and second dryer sections 12 and 14 such that the dryer felt 30 extends from the first dryer section 12 to and around the felt roll 42. The felt 30 is disposed between the felt roll 42 and the web W.
A further felt roll 44 is disposed between the felt roll 42 and the first dryer section 12.
Also, a further felt 46 extends around the further felt roll 44 such that the further felt 46 is disposed between the further felt roll 44 and the web W. The further felt 46 thereafter extends around the second dryer section 12 so that the web W disposed between the felt 30 and the further felt 46 is guided without open draw from the first dryer section 12 to the second dryer section 14.
More particularly, as shown in FIG. 1, means 48 is disposed adjacent to the felt roll 42 for urging the web W to follow the further felt 46 when the felt 30 and the further felt 46 diverge relative to each other adjacent to the felt roll 42.
As shown in FIG. 1, the means 48 is a blow box 50 which is disposed on the opposite side of the further felt 46 relative to the web W. The blow box 50 is connected to a source of pressurized air 52 such that a curtain of air indicated by the arrow 54 is blown from the blow box 50 onto the further felt 46 so that the web W is drawn towards the further felt 46 due to a Coanda effect of the curtain of air 54 relative to the further felt 46.
As clearly shown in FIG. 1, each of the intermediate rolls 28 has a diameter d which is substantially less than the diameter D of adjacent dryers 24 to 26 such that the machine directional shrinkage MD increases the tension of the web W between successive dryers 24 and 25 so that the pressure, as represented by the letter P, exerted by the web W against the dryer felt 30 during movement of the web W around the intermediate roll 28 is increased in conformity with the equation PS=TW/RI pounds per square inch, where PS is the pressure exerted by the web W on the dryer felt 30 extending around the intermediate roll 28, TW is the machine direction tension of the web W induced by the machine directional shrinkage of the web W during drying, and RI is the radius of the intermediate roll 28.
FIG. 2 shows in more detail the intermediate roll 28 which defines a plurality of circumferential grooves 32 to 37. The grooves are spaced in a cross-machine direction CD along the entire length of the roll 28.
As shown in FIG. 2, each groove of the plurality of grooves 32 to 37 extends around the circumference of the roll 28 so that air 38 pumped into each groove by the dryer felt 30 converging relative to the roll 28 flows through and around each groove so that a build-up of air pressure at a converging nip N defined between the dryer felt 30 and the intermediate roll 28 is inhibited.
FIG. 3 shows an alternative embodiment of the present invention in which a vacuum box 56 is disposed closely adjacent to an unfelted end portion 58 of the intermediate roll 28. The vacuum box 56 is selectively connected to a source of partial vacuum 52A such that in use of the apparatus, during a tail threading operation thereof, the vacuum box 56 is connected to the source of partial vacuum 52A such that air 60 flows in a direction from a tail T of the web W towards and through the dryer felt 30A and into the circumferential groove 32A disposed adjacent to the vacuum box 56 into the vacuum box 56 such that the tail T is urged into close conformity with the dryer felt moving around the intermediate roll 28A during the tail threading operation.
In an alternative embodiment of the present invention, the intermediate roll 28B is a shell roll with the shell defining a plurality of grooves 32B,33B,34B,35B, and 36B and includes a rotatable shell 62 and an internal baffle 64 disposed within the shell 62. The shell 62 and the baffle 64 define a tail threading chamber 66 disposed adjacent to one end 68 of the intermediate roll 28B.
Circumferential grooves 32B to 36B disposed in the vicinity of the tail threading chamber 66 define aperture means 70 such that the tail threading chamber 66 is disposed in fluid communication with the circumferential grooves 32B to 36B disposed in the vicinity of the chamber 66.
The arrangement is such that when the tail threading chamber 66 is connected to a source of partial vacuum 52B, air 60B flows from a tail TB of the web web towards and through the dryer felt 30B, through the grooves 32B to 36B disposed in the vicinity of the threading chamber 66, and through the aperture means 70 into the threading chamber 66 so that the tail TB is urged into close conformity with the dryer felt 30B during a tail threading operation of the dryer apparatus.
In operation of the apparatus according to the present invention, machine directional shrinkage of the web as the web dries increases the pressure exerted by the web against the felt during movement of the web and felt around each intermediate roll so that cross-machine directional shrinkage of the web is inhibited throughout the drying operation.
More specifically, in the prior art single tier dryer sections, special vacuum rolls are utilized to improve sheet runnability and sheet restraint and in some cases to provide the ability to thread the dryer section without the use of rope threading devices.
Such prior art configurations, as disclosed in U.S. Pat. No. 4,934,067, have been shown commercially to be an effective design to achieve the aforementioned objectives.
However, a primary disadvantage of the aforementioned design of U.S. Pat. No. 4,934,067 is the high cost of vacuum rolls and the need for a vacuum system for such rolls.
The present invention overcomes the aforementioned problem by the provision of special felt rolls which replace the aforementioned intermediate vacuum rolls. Such special felt rolls require no internal center shaft, internal seals, and extensive drilled through holes which are required in the prior art vacuum rolls. Specifically, these special felt rolls have grooved surfaces to help diffuse boundary layer air which follows the inside surface of the dryer felt. The single tier dryer section arrangement according to the present invention is further characterized by having the single tier concept extending beyond the wet end of the dryer section into the dry end portion without the need for the aforementioned costly vacuum rolls.
One of the novel features of the present invention resides in the recognition that the basic geometry of the single tier dryer section can have a significant and perhaps controlling influence on the shrinkage restraint which is applied to the web, in some cases without the use of an intermediate vacuum roll.
The following includes an analysis which highlights the essential features of the inventive concept according to the present invention.
The web is restrained in the entire apparatus according to U.S. Pat. No. 4,934,067 by a combination of felt pressure on the web as it passes over the dryers, and the vacuum restraint applied by the vacuum rolls as the web passes around the vacuum rolls. Such combination of restraint mechanisms has proven to be effective on lightweight grades at high machine speeds.
The frictional contact developed between the web and the felt and dryer in the first case and between the web and the felt in the second case inhibits the web from contracting in the cross-machine direction. Such is distinctly different from the more common two-tier dryer section arrangements in which the web experiences very little cross-machine directional restraint in the open draws between dryer cylinders.
In the first case, the pressure applied to the web is given by the equation P1=T/RD, pounds per square inch, in which T represents the effective tension in the felt in pounds per linear inch, and RD represents the radius of the dryer cylinder in inches.
In the second case, the pressure applied to the web is given by the equation P2=PV, pounds per square inch, in which PV is the vacuum inside the vacuum roll expressed in pounds per square inch.
The above analysis describes the restraint mechanisms which have been recognized to be operative in the dryer sections according to U.S. Pat. No. 4,934,067 and the various modifications thereof.
However, it has been discovered that the machine directional shrinkage of the sheet also has an effect on cross-machine directional restraint. In the single tier geometry of the present invention, the web is always supported by a felt, and, therefore, does not experience the stretching effects of external flows of air in open draws of the web and will, accordingly, according to the present invention, actually shrink in a machine direction.
Such inherent or natural machine directional shrinkage of the web depends on the formation, furnish and fiber orientation but is typically in the range of 2 to 4 percent. In a typical dryer section with 40 dryers, the sheet length in the dryers at any one time is about 600 foot. The aforementioned 600 foot of web has a natural tendency to shrink in the machine direction by 12 to 24 foot. Such shrinkage in the range of 12 to 24 foot means that the web shrinks on an average between 3.6 and 7.2 inches between successive dryers if there are 40 dryers in the dryer apparatus. The aforementioned shrinkage is largely inhibited by the pressure applied to the web by the tensioned felts as the web wraps the dryer cylinders.
Effectively, the web is held both machine directional ends by the dryer felt as it passes over each intermediate roll. The increased tendency for the web to shrink in a machine direction then translates into an increase in the machine directional web tension. Such web tension then translates into a pressure on the fabric as the web wraps the intermediate roll. Such pressure is given by the equation PS=TW/RI, pounds per square inch, in which TW is the machine directional tension induced by the machine directional shrinkage tendency, and RI is the radius of the intermediate vacuum roll.
The pressure PS results in a normal force on the felt which, when coupled with the friction between the felt and the web, will prevent or inhibit cross-machine directional shrinkage.
It has been further noted that the effective web tension TW depends on the amount of natural shrinkage that the web exhibits, as well as any plastic relaxation that may occur. The total web tension may be further reduced by the centrifugal forces that the web must counter as it passes around the intermediate roll.
If DL represents the shrinkage tendency of the web in inches, and "e" represents the amount of relaxation of the web, expressed in inches, and if "E" represents the effective modulus of the web, expressed in pounds per square inch, then the total tension developed in the web between cylinders would be Tt=(DL-e) E, pounds per linear inch.
The loss in effective tension as applied by the web to the dryer felt due to centrifugal forces can be approximated.
More specifically, for intermediate rolls that have a wrap angle of 180 degrees, the aforementioned approximation is represented by the equation T1=C(B n RI) V2 /RI, pounds per linear inch, where B is the wet weight of the web expressed in pounds per square foot, and V is the velocity of the web expressed in feet per minute, and RI is the radius of the intermediate roll expressed in inches.
It is to be noted that n equals 3.1415, and that C is an appropriate conversion factor.
Consequently, it has been noted that the loss in tension due to the centrifugal force does not depend on the radius of the intermediate roll.
From the above and by combining the above equations, an expression for the pressure applied by the web to the fabric is:
______________________________________
PS = TW / RI
PS = (Tt - T1) / RI
PS = ((DL - e) E - C(B n V.sup.2)) / RI, pli
______________________________________
From the aforementioned equation, it was discovered that the natural tendency of the web to shrink in a machine direction can be utilized for inhibiting cross-machine directional shrinkage by generating pressure on the dryer felt, and that this inhibition of cross-machine directional shrinkage will be larger for the following conditions:
1) Small diameter intermediate roll (small RI)
2) Low speed machines (low V)
3) Minimum web relaxation (small e)
4) High wet web modulus (high E)
5) High natural machine directional shrinkage rates (high DL)
It has also been observed that the relaxation of the web stress (e) is a time related phenomenon. In other words, there will be less relaxation if the time is short. For a given machine speed, such will be achieved with a small diameter intermediate roll, with short felt tangent lengths between the dryers and associated intermediate rolls.
Accordingly, the present invention has particular application to the manufacture of linerboard and other board at speeds less than 3,000 feet per minute.
The present invention provides a no-draw dryer apparatus for uniformly drying both sides of a web which utilizes machine directional shrinkage to inhibit cross-machine directional shrinkage of the resultant web.
What is claimed is:
1. A dryer apparatus for drying a pressed web, said apparatus comprising:a plurality of single tier dryer sections in which successive sections dry alternate sides of the web, the web being transferred between successive sections without any open draw of the web such that the web is uniformly dried on both sides thereof while the web is restrained against cross-machine directional shrinkage; each of said dryer sections including;a single tier of dryers; an intermediate roll disposed between each adjacent dryer of said single tier of dryers; a dryer felt extending in serpentine configuration around each dryer and intermediate roll such that the web is disposed between said felt and each dryer of said single tier of dryers for drying one side of the web, said felt being disposed between said intermediate roll and the web so that said felt is disposed in direct contact with an alternate side of the web; said intermediate roll defining a plurality of circumferential grooves for diffusing boundary air following said felt that would otherwise tend to lift the web from said felt extending around said intermediate roll, the arrangement being such that inherent machine directional shrinkage of the web during drying thereof inhibits cross-machine directional shrinkage of the web during movement of the web between successive dryers; said dryer apparatus further including:a first single tier dryer section for drying said one side of the web; a second single tier dryer section disposed immediately downstream relative to said first dryer section for drying said alternate side of the web; transfer means disposed between said first and second dryer sections for transferring the web without open draw between said first and second dryer sections; said transfer means including;a felt roll disposed between said first and second dryer sections such that said dryer felt extends from said first dryer section to and around said felt roll, said felt being disposed between said felt roll and the web; a further felt roll disposed between said felt roll and said first dryer section; a further felt extending around said further felt roll such that said further felt is disposed between said further felt roll and the web, said further felt thereafter extending around said second dryer section so that the web disposed between said felt and said further felt is guided without open draw from said first to said second dryer section; and means disposed adjacent to said felt roll for urging the web to follow said further felt when said felt and said further felt diverge relative to each other adjacent to said felt roll.
2. A dryer apparatus as set forth in claim 1 wherein said means is a blow box disposed on the opposite side of said further felt relative to the web, said blow box being connected to a source of pressurized air such that a curtain of air is blown from said blow box onto said further felt so that the web is drawn towards said further felt due to a Coanda effect of said curtain of air relative to said further felt.
3. A dryer apparatus for drying a pressed web, said apparatus comprising:a plurality of single tier dryer sections in which successive sections dry alternate sides of the web, the web being transferred between successive sections without any open draw of the web such that the web is uniformly dried on both sides thereof while the web is restrained against cross-machine directional shrinkage; each of said dryer sections including:a single tier of dryers; an intermediate roll disposed between each adjacent dryer of said single tier of dryers; a dryer felt extending in serpentine configuration around each dryer and intermediate roll such that the web is disposed between said felt and each dryer of said single tier of dryers for drying one side of the web, said felt being disposed between said intermediate roll and the web so that said felt is disposed in direct contact with an alternate side of the web; said intermediate roll defining a plurality of circumferential grooves for diffusing boundary air following said felt that would otherwise tend to lift the web from said felt extending around said intermediate roll, the arrangement being such that inherent machine directional shrinkage of the web during drying thereof inhibits cross-machine directional shrinkage of the web during movement of the web between successive dryers; and a vacuum box disposed closely adjacent to an unfelted end portion of said intermediate roll, said vacuum box being selectively connected to a source of partial vacuum such that in use of the apparatus, during a tail threading operation thereof, said vacuum box is connected to said source of partial vacuum such that air flows in a direction from a tail of the web towards and through said dryer felt and into said circumferential grooves disposed adjacent to said vacuum box and into said vacuum box such that said tail is urged into close conformity with said dryer felt moving around said intermediate roll during said tail threading operation.
| 1990-10-31 | en | 1993-09-07 |
US-3744414D-A | Dampening device for lithographic presses
ABSTRACT
A dampening system for a printing press which includes a resilient metering roller which is concave in plan profile, having a diameter at its ends which is larger than the diameter over the central portion so as to develop relatively higher contact pressure at its ends for blocking off flow of dampening fluid in the end regions when printing a sheet of small size. Means are provided for skewing the metering roller to selectively reduce the pressure at the ends for securing a more nearly uniform axial distribution for the printing of sheets of full roller width. The skewing may be augmented to compensate for any bowing which may occur in the rollers. The skewing is effected by mounting the metering roller on individually swingable arms with means for differential adjustment of the arms. Eccentrics at the ends of the metering roller enable adjustment of the pressure.
United States Patent v [1 1 Krochert et al.
[ DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES inventors: Karl Heinz Kriichert, Offenbach;
Karl Zimmermann, Darmstadt, both of Germany Roland Offsetmaschineenfabrik Faber & Schleicher AG, Offenbach/Main, Germany Filed: Oct. 19,1971
Appl. No.: 190,491
[73] Assignee:
[30] Foreign Application Priority Data A Nov. 6, 1970 Germany P 20 54 678.5
US. Cl. 101/148, 101/350 I Int. Cl. B4lf 7/26, B4lf 7/40 Field of Search 101/148, 348-352, 101/206, 207, 208
References Cited UNITED STATES PATENTS 10/1919 Linder 101/148 UX 9/1941 Knowlton 118/262 9/1956 Varga et al. 101/148 UX 11 3,744,414 1 July 10, 1973 3,343,484 9/1967 Dahlgren 101/148 3,433,155 3/1969 Norton 101/148 I Primary Examiner-J. Reed Fisher [57] ABSTRACT A dampening system for a printing press which includes a resilient metering roller which is concave in plan profile, havinga diameter at its ends which is larger than the diameter over the central portion so as to develop relatively higher contact pressure at its ends for blocking off flow of dampening fluid in the end regions when printing a sheet of small size. Means are provided for skewing the metering roller to selectively reduce the pressure at the ends for securing a more nearly uniform axial distribution for the printing of sheets of full roller width. The skewing may be augmented to compensate for any bowing which may occur in the rollers. The skewing is effected by mounting the metering roller on individually swingable arms with means for differential adjustment of the arms. Eccentrics at the ends of the metering roller enable adjustment of the pressure.
7 Claims, 6 Drawing Figures PAIENTED JUL 1 men SHEEI 1 OF 2 SOURCE OF wk 36 IN vsu'ran Mez-k/wzWa/ur he: Z/MMEkM/M/V @,%%m4% 1 I'TYS.
PAIENTEU JUL 1 0 I973 sum 2 or 2 SOURCE OF INK INVENTOR 1 ,M MJ, ',wam
0% Arrr .DAMPENING DEVICE FOR LITHOGRAPHIC PRESSES Dampening devices are normally constructed so as to produce even distribution of water or other dampening fluid over the entire width of the applicator roller and plate cylinder. Where sheets of narrower than standard size are to be printed the water fed from the ends of the applicator roller is not consumed and tends to accumulate to produce a flooding condition. Steps have been taken in the past to reduce the flow of dampening fluid at the ends or in other localized regions of the applicator roller but this has required troublesome conversion when the press is again set up for the printing of full size sheets. Steps have also been taken to compensate for axial variations .in feed due to slight bowing of rollers running in pressure engagement.
Accordingly it is an object of the invention to provide a dampening system which is capable of feeding a film of dampening fluid uniformly along the length of an applicator roller for theprinting of full size sheets.
It is a related object to provide a dampening system which may be used universally for narrow sheets as well as sheets of full width, which may be switched from one width condition to the other, which is consistent permitting original operating conditions to be precisely reestablished, and which is inherently inexpensive both for inclusion in new presses and for conversion of presses in the field to incorporate the inventive features. It is yet another object to provide means for controlling the width of a wetted path which serves also to achieve effective bowing compensation.
Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings in which:
FIG. 1 is an elevational view of a dampening system incorporating the present invention.
FIG. 2 is a-fragmentary plan view of the system set forth in FIG. 1.
FIG. 3 is an elevational view'of the system shown in FIG. 1 but with the metering roller skewed for feeding of an axially uniform film of fluid.
FIG. 4 is a plan view corresponding to FIG. 3.
FIGS. 5 and 6 are fragmentary elevations showing means for calibrating the skew and pressure adjustments.
While the invention has been described in connection with a preferred embodiment, it will be understood that we do not intend to be limited to the particular embodiment as shown but intend, on the contrary, to cover the various alternative and equivalent constructions included within the spirit and scope of the appended claims.
Turning now to the drawings there is disclosed a portion of a lithographic printing press including a dampening system generally indicated at 10 which cooperates with a plate cylinder 11. As is well known in the operation of a lithographic press it is necessary to apply to the surface of the plate on the plate cylinder a film of ink which adheres to the ink receptive areas and a film of dampening fluid which adheres to the non-ink receptive areas. For applying a film of ink to the plate an ink applicator or form roller 12 is used, fed, for example, through a series of rollers (not shown), from a suitable source of ink 13. For the purpose of transmitting a film of dampening fluid to the plate, a water fountain 20 is provided having a body 21 of water or other dampening fluid and having a fountain roller 22. The fountain roller 1 22 which is preferably hardsurfaced is rotated in the fountain, preferably at a speed lower than press surface speed, by a drive mechanism 23. The fountain roller 22 is rotated in the direction of the arrow to provide an ascending or feed side 24, to which the fluid clings, and a descending or return side 25. Each roller in a series has such feed side and return side. lnterposed between the fountain roller 22 and the plate cylinder is a resiliently surfaced applicator roller 26 which issometimes referred to as a water form roller. If desired, a transfer roller-(not shown) may be interposed between the fountain roller and the applicator roller.
In accordance with the present invention a metering roller is provided running in pressing engagement with the feed side of the fountain roller or other rollers in the fluid system, the metering roller having a concave plan profile with a larger diameter at the ends than over the central portion so as to relatively augment the pressure applied at the ends thereby to block passage of fluid at the ends for printing of sheets of less than full roller width, the metering roller having means for adjustably skewing it with respect to the fountain roller so as to reduce the pressure applied at the ends of the metering roller for achieving substantially uniform axial distribution of fluid for printing of sheets of full roller width and to compensate for any bowing tendency. More specifically the metering roller is journaled in a pair of arms which are independently swingable about the axis of the engaged roller and having independent adjusting means coupled to the press frame for adjusting the degree of skew. Thus, referring to the, drawings, a resilient metering roller 30 is provided having a central portion 31 and end portions 32. Projecting from the metering roller are stub shafts 33, 33a which are journaled in bearings 34, 34a. The bearings are mounted in levers 35, 350 which are mounted for independent swinging movement coaxially with respect to the fountain roller 22.
When the levers 35, 350 are alined, as shown in FIGS. 1 and 2, the metering roller.30 is parallel to the axis of the fountain roller 22 which it engages. To adjust the pressure between the metering roller and fountain roller, eccentrics 36, 36a having adjusting arms 37, 37a are interposed between the levers and the bearings of the metering roller.
The metering roller is so formed as to be concave in plan profile, having a diameter d] over its central portion and a diameter d2 at the ends. As a result, when the eccentrics 36, 36a are symmetrically adjusted so that the metering roller applies pressure to the fountain roller, the pressureat the ends of the metering roller is augmented by reason of the larger diameter and is greater than that'which exists over the central portion of the metering roller. The high pressure at the ends of the metering roller effectively blocks passage of a film of dampening fluid in the end positions so that a film of fluid is transmitted (as indicated by the stipp ling) only over the central portionof the fountain roller, via the central portion of the applicator roller, to the central portion of the plate cylinder for printing of sheets having a width N less than the width of the rollers. This prevents the flooding at the endsof the dampening rollers which is usually encountered in presses where the film is fed more or less uniformly over the entire axial width of the rollers in the dampener system.
In carrying out the invention means are provided for differentially adjusting the swingable levers 35, 35a so that the metering roller is skewed relative to the axis of the fountain roller which it engages, such skewing serving to move the ends of the metering roller relatively away from the axis of the fountain roller thereby to reduce the pressure exerted by the ends of the metering roller and permitting a more uniform flow of dampening fluid over the entire length of the metering roller for printing of sheets of full roller width. To accomplish this a linkage including a threaded element is interposed between each of the levers 35, a and the press frame. Taking the lever 35 by way of example, a link is pinned to the lever at one end 41. At its opposite end 42 the link is pinned to a non-rotatable screw 43. The screw is threaded into a nut 44 which is rotatable by a knob 45 but which is captive, in the endwise direction, in the press frame indicated at 46. Corresponding elements, with subscript a, are provided for adjusting the remaining lever 35a.
With the arms differentially adjusted as shown in FIGS. 3 and 4, the metering roller 30 is skewed into the position shown thus reducing the pressure applied by the ends of the metering roller upon the fountain roller. The degree of skew may be so adjusted that the pressure applied by the metering roller is uniform along the entire length of the metering roller so that a film of dampening fluid of constant thickness, indicated by the stippling, is fed to a wide printing area indicated at W for printing of sheets of wide, i.e., standard, width.
' It will be seen then that when switching the press from printing of narrow sheets to printing of sheets of standard width it is a simple matter to adjust the control knobs 45, 450 from a symmetrical condition, in which the metering roller is parallel to the other rollers in the system, to a differential condition in which the metering roller is skewed. For convenience in making the adjustment, and for enabling a given adjustment to be reproduced when returning to a particular mode of operation, the skew control knobs may be calibrated as shown in FIG. 5, the calibration being such as to account for turning of the knob through a number of revolutions. As shown in this figure the knob 45 is provided with a pinion which engages a gear 51 having a pointer 52 which cooperates with a scale 53. To establish the condition shown in FIGS. 1 and 2, both of the pointers may be set to the zero reference position. To achieve skew, one or both of the control knobs may be rotated to predetermined scale positions. If desired, the eccentrics 36, 36a may be calibrated, as shown in FIG. 6. A scale 55 may be secured to the lever 35 and cooperating directly with the eccentric adjusting arm 37.
While the invention has been described in connection with a metering roller which cooperates directly with the fountain roller, it will be apparent that the present invention is not limited thereto but contemplates use of a metering roller of concave profile mounted for skewing adjustment with respect to the feed side of any roller in the fluid feeding system. For example the metering roller may be mounted for pressing engagement with the applicator roller 26, with the ends swingable, for skewing purposes, about the axis of the applicator roller. Alternatively, the metering roller may be mounted in pressing engagement with any transfer roller which may be interposed between the fountain roller 22 and applicator roller 26. Accordingly, as used herein, the term roller means is intended to be sufficiently broad as to include any roller within a dampening system which consists of a number of rollers interposed in the path of fluid transfer.
While the invention has been described above in connection with rollers which are sufficiently stiff as to substantially resist bowing, it is one of the further features of the present invention that use of a metering roller of concave profile with provision for skew may be utilized without change or addition to compensate for the effects of bowing. As is well known, bowing occurring in any one ofa series of rollers by reason of the total pressure load between them results in a nonuniform distribution of the unit pressure. Thus the middle of the roller which is supported less stiffly than the ends tends to have a lower per unit pressure at the region of engagement. As a result there is a tendency to feed a thicker film of fluid at the center of a bowed roller than at the ends. This center feeding tendency may be readily overcome in the present construction by skewing the metering roller to an angle beyond that which would apply if the rollers were perfectly stiff and unbowing. Using the present invention, axial uniformity of fluid or standard width, even where relatively thin and flexible rollers are used, simply by turning the skew knob, or knobs, an augmented amount to provide even less per unit pressure, relatively speaking, at the ends of the metering roller and with the desired total pressure being restored, if desired, by touch-up adjustment at the eccentrics. The skew setting and eccentric adjustment corresponding to the condition of uniform feeding of fluid for the printing of a sheet of full width may be noted and the settings reestablished at any future time upon the calibration scales without any special tailoring adjustment and by a press operator who is relatively unskilled but capable of resetting the adjustment on the scales as a purely routine or mechanical procedure.
In the preferred embodiment of the invention the me tering roller is made of resilient material, for example, synthetic rubber running in engagement with a hard surfaced roller, for example, the fountain roller in the fluid feed system. If desired, and without departing from the invention, the metering roller may be of hard surfaced construction cooperating with the feeding side of a resilient roller in the fluid feed system. A hard surfaced metering roller could, for example, engage the undersurface of the form roller 26. If this were done, the arms 35,35a and the associated adjusting means could be retained, with the arms swiveling about the stubshafts of the form roller rather than about the stubshafts of the fountain roller.
Also while the invention is particularly applicable to the supplying of dampening fluid, it will be apparent that the invention in its broader aspect is not limited to use with dampening fluid but is applicable wherever there is need for adjusting the axial distribution of a film of fluid fed between a set of cooperating rollers. For example, the invention may be employed in the feeding of ink in an ink supply system entirely analogously to the feeding of water or the like in a dampening system and where it is desired to ink only the central section of a printing cylinder for the printing of sheets of narrow width or for the purpose of compensating for the bowing of the ink-feeding cylinders. Thus, the term dampening fluid as used herein is not to be limited to water or the like but may be construed to cover any fluid which is to be fed in the form of a film to a printing plate or other cylindrical receiving surface.
What we claim is:
1. In a dampening system for lithograph press having a frame journaling a plate cylinder, the combination comprising a source of dampening fluid, roller means including a plurality of serially arranged rollers coupled to the source for forming and transferring a film ofdampening fluid to the plate cylinder, a metering roller running in pressing engagement with the feeding side of one of the serially arranged rollers for determining the thickness of the film, at least the metering roller or the roller which it engages being resiliently surfaced, the metering roller being concave in plan profile having a larger diameter at its ends than over its central portion so as to relatively augment the pressure applied by the metering roller at its ends thereby to block transfer of dampening fluid at the ends of the roller means when the metering roller and roller means are substantially parallel for printing of sheets of narrow width, means for mounting the metering roller for adjustable skewing movement thereby to enable adjustment of the metering roller to a skewed position relative to the roller means in which the ends of the metering roller are moved relatively away from the roller which it engages to achieve substantially uniform axial distribution of the pressure exerted by the metering roller for printing of sheets of substantially full roller width.
2. The combination as claimed in claim 1 in which the metering roller is formed of resilient material and the roller which it engages is hard surfaced.
3. The combination as claimed in claim 1 in which the rollers exert a substantial degree of pressure upon one another and in which the mounting means for the metering roller has a range of adjusting movement for skew to produce a degree of skew beyond the amount theoretically required for even distributionof the fluid thereby to compensate for non-uniform distribution of pressure between the rollers resulting from the tendency of the rollers to flex or bow by reason of their pressure engagement with one another.
4. In a dampening system for lithograph press having a frame journaling a plate cylinder, the combination comprising a fountain roller rotatably driven in a fountain having a supply of dampening fluid, an applicator roller interposed between the fountain roller and the plate cylinder for conveying a film of dampening fluid to the plate cylinder, a resilient metering roller running in pressing engagement with the feeding site of the fountain roller for determining the thickness of the film on the fountain roller which is available for transfer to the applicator roller, the metering roller having a concave plan profile with a larger diameter at the ends than over the central portion so as to relatively augment the pressure applied by the metering roller at its ends thereby to block passage of fluid at the ends when the metering roller is substantially parallel to the fountain roller while providing a substantially even axial distribution of fluid over the central portion of the applica tor roller for the printing of sheets of less than the full roller width, and means for adjustably skewing the metering roller with respect to the fountain, roller to reduce the pressure applied at the ends of the metering roller for achieving substantially uniform distribution of fluid along the axis of the applicator roller for the printing of sheets of full roller width.
5. In a dampening system for lithograph press having a frame journaling a plate cylinder, the combination comprising a source of dampening fluid, roller means comprising a plurality of serially arranged rollers coupled to the source for forming a film of dampening fluid and including an application roller for applying the fluid to the plate cylinder, a metering roller running in engagement with the feeding side of one of the serially arranged rollers for determining the thickness of the film, at least the metering roller or the roller which it engages being resiliently surfaced, the metering roller fluid at the ends of the roller means when the metering roller and roller means are substantially parallel for printing of sheets of narrow width, the metering roller being journaled in a pair of independently swingable.
levers coaxial with the engaged roller and having means for differentially adjusting the angular positions of the levers thereby to enable swinging of the metering roller to a skewed position relative to the engaged roller for more uniform axial distribution of the pressure exerted by the metering roller to-equalize flow of dampening fluid along the axis of the applicator roller when printing sheets of substantially full roller width.
6. In the combination as claimed in claim 5, the levers each having journals for engaging the ends of the metering roller and eccentrics interposed between the levers and the respective journals for varying the pressure applied by the metering roller against the engaged roller.
7. The combination as claimed in claim 5 in which linkages including respective threaded elements are interposed between the press frame and the levers for individual adjustment of the angular positions of the levers.
1. In a dampening system for lithograph press having a frame journaling a plate cylinder, the combinaTion comprising a source of dampening fluid, roller means including a plurality of serially arranged rollers coupled to the source for forming and transferring a film of dampening fluid to the plate cylinder, a metering roller running in pressing engagement with the feeding side of one of the serially arranged rollers for determining the thickness of the film, at least the metering roller or the roller which it engages being resiliently surfaced, the metering roller being concave in plan profile having a larger diameter at its ends than over its central portion so as to relatively augment the pressure applied by the metering roller at its ends thereby to block transfer of dampening fluid at the ends of the roller means when the metering roller and roller means are substantially parallel for printing of sheets of narrow width, means for mounting the metering roller for adjustable skewing movement thereby to enable adjustment of the metering roller to a skewed position relative to the roller means in which the ends of the metering roller are moved relatively away from the roller which it engages to achieve substantially uniform axial distribution of the pressure exerted by the metering roller for printing of sheets of substantially full roller width.
2. The combination as claimed in claim 1 in which the metering roller is formed of resilient material and the roller which it engages is hard surfaced.
3. The combination as claimed in claim 1 in which the rollers exert a substantial degree of pressure upon one another and in which the mounting means for the metering roller has a range of adjusting movement for skew to produce a degree of skew beyond the amount theoretically required for even distribution of the fluid thereby to compensate for non-uniform distribution of pressure between the rollers resulting from the tendency of the rollers to flex or bow by reason of their pressure engagement with one another.
4. In a dampening system for lithograph press having a frame journaling a plate cylinder, the combination comprising a fountain roller rotatably driven in a fountain having a supply of dampening fluid, an applicator roller interposed between the fountain roller and the plate cylinder for conveying a film of dampening fluid to the plate cylinder, a resilient metering roller running in pressing engagement with the feeding site of the fountain roller for determining the thickness of the film on the fountain roller which is available for transfer to the applicator roller, the metering roller having a concave plan profile with a larger diameter at the ends than over the central portion so as to relatively augment the pressure applied by the metering roller at its ends thereby to block passage of fluid at the ends when the metering roller is substantially parallel to the fountain roller while providing a substantially even axial distribution of fluid over the central portion of the applicator roller for the printing of sheets of less than the full roller width, and means for adjustably skewing the metering roller with respect to the fountain roller to reduce the pressure applied at the ends of the metering roller for achieving substantially uniform distribution of fluid along the axis of the applicator roller for the printing of sheets of full roller width.
5. In a dampening system for lithograph press having a frame journaling a plate cylinder, the combination comprising a source of dampening fluid, roller means comprising a plurality of serially arranged rollers coupled to the source for forming a film of dampening fluid and including an application roller for applying the fluid to the plate cylinder, a metering roller running in engagement with the feeding side of one of the serially arranged rollers for determining the thickness of the film, at least the metering roller or the roller which it engages being resiliently surfaced, the metering roller being concave in plan profile having a larger diameter at its ends than over its central portion so as to relatively Augment the pressure applied by the metering roller at its ends thereby to block transfer of dampening fluid at the ends of the roller means when the metering roller and roller means are substantially parallel for printing of sheets of narrow width, the metering roller being journaled in a pair of independently swingable levers coaxial with the engaged roller and having means for differentially adjusting the angular positions of the levers thereby to enable swinging of the metering roller to a skewed position relative to the engaged roller for more uniform axial distribution of the pressure exerted by the metering roller to equalize flow of dampening fluid along the axis of the applicator roller when printing sheets of substantially full roller width.
6. In the combination as claimed in claim 5, the levers each having journals for engaging the ends of the metering roller and eccentrics interposed between the levers and the respective journals for varying the pressure applied by the metering roller against the engaged roller.
7. The combination as claimed in claim 5 in which linkages including respective threaded elements are interposed between the press frame and the levers for individual adjustment of the angular positions of the levers.
| 1971-10-19 | en | 1973-07-10 |
US-66697291-A | Oxyhydrochlorination catalyst
ABSTRACT
An improved catalyst and method for the oxyhydrochlorination of methane is disclosed. The catalyst includes a pyrogenic porous support on which is layered as active material, cobalt chloride in major proportion, and minor proportions of an alkali metal chloride and of a rare earth chloride. On contact of the catalyst with a gas flow of methane, HCl and oxygen, more than 60% of the methane is converted and of that converted more than 40% occurs as monochloromethane. Advantageously, the monochloromethane can be used to produce gasoline boiling range hydrocarbons with the recycle of HCl for further reaction. This catalyst is also of value for the production of formic acid as are analogous catalysts with lead, silver or nickel chlorides substituted for the cobalt chloride.
CONTRACTUAL ORIGIN OF THE INVENTION
The U.S. Government has rights in this invention pursuant to the employee/employer relationship of the inventor to the U.S. Department of Energy at the Pittsburgh Energy Technology Center.
This is a division of application Ser. No. 516,611 filed Apr. 30, 1990, now U.S. Pat. No. 5,019,652.
BACKGROUND OF THE INVENTION
The present invention relates generally to catalysts and methods for converting light hydrocarbons into monohaloalkanes and other useful products. In particular, the invention is directed to the production of monochloromethane and formic acid from methane. As has been described in the inventors' prior U.S. Pat. No. 4,769,504, entitled "Process for Converting Light Alkanes to Higher Hydrocarbons", issued Sep. 6, 1988, monochloromethane so produced can be further processed to form gasoline boiling range hydrocarbons. This prior U.S. patent is hereby incorporated by reference for describing this process.
The need to supplement petroleum supplies has stimulated research and the production of chemicals and fuels from other sources. Methane from natural gas and from the conversion of coal is a source of considerable interest for such production.
It is well known that methane can be converted to methanol by reformation with steam and that the methanol thus produced can be further processed over a crystalline aluminosilicate catalyst to form gasoline boiling range hydrocarbons. Such a process is described in U.S. Pat. No. 3,928,483 to Chang et al.
Monohalomethanes can be prepared as disclosed in European Patent Application No. 0117731 and as suggested in PCT Publication No. W085102608, converted to higher hydrocarbons over crystalline aluminosilicates. It has long been thought that the monohalides are much preferred in such processes with only low levels of polyhalogenated alkanes tolerated for effective conversion. Such monohalomethanes can be produced by reaction of chlorine or other halogens with methane which requires elevated temperatures above 450° C. or by the oxyhalogenation of methane using a suitable catalyst such as the halide salts of copper, nickel, iron or palladium. Such procedures as are described in the above cited European Patent Application are characterized by low conversions, generally less than about 35%.
An oxyhydrochlorination catalyst containing copper chloride, potassium chloride and a rare earth chloride is disclosed in U.S. Pat. No. 4,123,389 to Pieters et al. This catalyst is reported to provide substantially higher values of methane conversion, but to result in substantial polychlorination. Previously, this catalyst was of particular interest in the production of carbon tetrachloride as a feed stock for chlorofluorocarbon-refrigerants.
This invention also relates to the production of formic acid as a co-product to monohalide alkanes. Typically, formic acid is produced by the reaction of sulfuric acid with sodium formate in the presence of 85-90% formic acid. Adequate cooling of the reaction mixture and the presence of the added formic acid as a reaction medium limits decomposition of the product. Sodium formate is formed by the reaction of sodium hydroxide and carbon monoxide, such as from producer gas that is carefully cleaned and compressed to 12-18 atmospheres. The sodium formate crystals are obtained by drying the reaction product prior to reaction with the sulfuric acid.
The major commercial use of formic acid is in the textile and leather industries as an effective disinfectant and preservative. It acts as a dye exhausting agent for various fabrics and for other functions in dying and treating textiles. Formic acid serves as an intermediate in the preparation of various esters and amides. Methyl and ethyl formate have value as solvents, fumigants and pesticides. Formamide is of particular interest as it has considerable value in the manufacture of pharmaceuticals, agricultural chemicals and dyes.
SUMMARY OF THE INVENTION
Therefore, in view of the above, it is an object of the present invention to provide a process for the co-production of monohalomethanes and formic acid.
It is also an object of the invention to provide a method for the production of monochloromethane with recoverable concentrations of formic acid.
It is a further object of the invention to provide a catalyst for the production of monochloromethane with limited production of polychloromethanes.
It is likewise an object of the invention to provide a two-stage conversion process of methane to gasoline range hydrocarbons with a co-product of formic acid.
It is a further object of the invention to provide oxyhydrochlorination catalysts for the co-production of monochloromethane and formic acid.
It is also an object of the invention to provide an improved oxyhydrochlorination catalyst for the conversion of methane to monochloroalkanes with enhanced methane conversion and reduced production of polychloromethanes.
In accordance with the present invention, a catalytic method for the production of monochloromethane with recoverable concentrations of formic acid in aqueous solution with limited polychloromethane production includes providing an oxyhydrochlorination catalyst with a pyrogenic support material carrying a first layer of catalyst including a metal chloride deposited on the support. The metal chloride selected is from the group of chlorides including cobalt, lead, nickel and silver. A second catalyst layer includes alkali metal chlorides and permissibly a rare earth chloride deposited on the support. The catalyst is contacted with a reactant gas mixture containing methane, HCl and oxygen at reactant conditions to produce a normalized carbon-product distribution of at least 20 mol% formic acid and with monochloromethane in excess of the total polychloromethane production.
In other aspects of the invention, the formic acid is separated from other carbon products by condensation in a formic acid-water solution and concentrated to a constant boiling composition of formic acid and water. Concentrations in the range of 75-90% formic acid are obtained by fractional distillation, azeotropic distillation and solvent extraction.
In one other aspect of the invention, the gas mixture contacts a catalyst at a temperature of about 300° C. to 450° C. for a residence time of about 7-10 seconds.
After separating the monochloromethane from aqueous formic acid, it can be dried and reacted over a crystalline aluminosilicate catalyst to produce hydrocarbons in the C5 to C10 gasoline boiling point range. HCl produced in the second reaction can be recycled to the oxyhydrochlorination catalysts for further production of monochloromethane.
The invention also comprehends an oxyhydrochlorination catalyst for the co-production of monochloromethane and formic acid from methane. The catalyst in major proportion is a metal chloride selected from the chlorides of cobalt, nickel, lead and silver along with a minor proportion of alkali metal chlorides permissibly including a rare earth chloride. The active catalyst materials are supported on a pyrogenic carrier selected from silica titania and alpha alumina. Preferably, the catalyst employs cobaltous chloride in about 40-60 weight % along with 10-20 weight % of a mixture of potassium chloride and lanthanum chloride supported on a silica carrier at about 20-40 % by weight.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated in the accompanying drawings wherein:
FIG. 1 is a flow diagram of a hydrocarbon reforming process in which methane is converted to monochloromethane, formic acid and higher hydrocarbons.
FIG. 2 is a bar chart illustrating reactant conversion for various catalysts.
FIG. 3 is a normalized product distribution for the oxyhydrochlorination reaction with various catalysts.
FIG. 4 is a bar chart showing the reaction product distribution expressed as methane conversion times normalized product distribution for the various catalysts.
FIG. 5 is a graph showing reactant conversion as a function of time for the cobalt catalyst.
FIG. 6 is a graph showing normalized product distribution as a function of time for the cobalt catalyst.
FIG. 7 is a graph showing reactant conversion as a function of temperature for the lead catalyst.
FIG. 8 is a graph showing normalized product distribution as a function of temperature for the lead catalyst.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 wherein oxyhydrochlorination reactor 11 is provided with a feed of HCl 13, methane 15 and oxygen 17 for reaction over an oxyhydrochlorination catalyst. The catalyst is selected particularly for the co-production of monochloromethane and formic acid with limited production of polychloromethanes such as dichloromethane, trichloromethane and carbon tetrachloride. The inventors have found that the chlorides of cobalt, nickel, lead and silver are particularly advantageous for this purpose. Preferably, for the balanced production of monochloromethane and formic acid, cobaltous chloride is selected as the catalyst. The active metal chloride is supported on a pyrogenic oxide such as silica, titania or alpha alumina as a first layer and is coated with a second layer of an alkali metal chloride such as potassium chloride and permissively a minor proportion of the rare earth chloride. The resulting product containing monochloromethane, formic acid and water in principal amounts along with minor amounts of dichloromethane, trichloromethane and carbon dioxide is passed into a separator 19 wherein the formic acid and water is condensed from the monochloromethane and other carbon containing products.
As is described in the above cited U.S. Pat. No. 4,769,504, the monochloromethane is thoroughly dried and passed on to a second reactor 21 containing a zeolite catalyst for producing gasoline boiling range fraction products 23 (within the C-5 and C-10 range) and light hydrocarbons 25 (C-3 and C-5 range). HCl released in this reaction is separated and recycled to the oxyhydrochlorination reactor 11 for reaction with additional methane and oxygen. Permissibly, the light hydrocarbons or a portion thereof, also may be recycled to the oxyhydrochlorination reactor for further processing.
It is advantageous to include minor proportions of polychloromethanes or other polychloroalkanes to be condensed over the zeolite catalysts as they may promote formation of aromatic and branched-chain hydrocarbons in the product. However, the inventors have found that polychloroalkanes approaching the concentration of the monochloromethane can have a deleterious effect on the zeolite catalyst. This has been a disadvantage of the copper based oxyhydrochlorination catalysts as they tend to produce polychlorinated alkanes up to and in excess of the monochloromethane product. Accordingly, it is preferred that the normalized product distribution based on carbon include monochloromethane in excess of the total molar concentration of the more highly chlorinated hydrocarbons.
Water and formic acid separated from the chlorinated hydrocarbons at 29 are passed on to a fractionation process 31 in which water 33 is separated from the more highly concentrated formic acid product 35. Typically, formic acid concentration of 20-30% in water can be separated by condensation from the reaction products produced with a cobalt chloride catalyst. In contrast, the condensation product corresponding to flow 29 in a process using a copper-based oxyhydrochlorination catalyst will include economically unrecoverable concentrations of formic acid of only about 0.5-2%. With the copper catalyst not only is less formic acid produced, but also a greater proportion of water is produced in the reactions leading to the polychloroalkanes.
The following four reactions show the conversion of methane to monochloromethane, dichloromethane, trichloromethane and to formic acid. It is seen that the production of the polychloromethanes adds increasing amounts of water into the product stream that must subsequently be removed.
METHANE CONVERSION REACTIONS
CH.sub.4 +HCl+1/2 O.sub.2 →CH.sub.3 Cl+H.sub.2 O
CH.sub.4 +2HCl+O.sub.2 →CH.sub.2 Cl.sub.2 +2H.sub.2 O
CH.sub.4 +3HCl+3/2 O.sub.2 →CHCl.sub.3 +3H.sub.2 O
CH4 +3/2 O2 →CH2 O2 +H2 O
Advantageously, nickel, lead and silver catalysts provide even higher concentrations of formic acid typically in excess of 40 mol%.
These aqueous solutions of formic acid can be readily concentrated to constant boiling mixtures of formic acid containing between 75 and 85% acid depending on the pressure of fractionation. Azeotropic distillation with propyl formate gives a non-aqueous phase which can be further distilled to yield anhydrous formic acid. The separated aqueous phase typically will contain less than about 1% formic acid. Such methods for separating formic acid are described in Louderback, Formic Acid and Derivatives, KIRK-OTHMER ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY, 2nd ED., Vol. 10, pages 99-113.
The following examples are presented merely by way of illustration and are not intended to limit the invention beyond that defined in the claims.
EXAMPLE I
An oxyhydrochlorination catalyst containing cobalt chloride was prepared by thoroughly dissolving cobaltous chloride, CoCl, in acetonitrile, CH3 CN. Particulate silicon dioxide (Cab-O-Sil® HS-5) was added to the solution with swirling followed by standing overnight to thoroughly impregnate the cobaltous chloride into the silicon dioxide support. The acetonitrile was then slowly evaporated under aspiration with slow rotation over a period of about four hours. The temperature was increased slowly to 60° C. and then held to prevent any rapid boiling that could interfere with the uniform distribution of the catalyst into the support. The resulting blue solid was then slowly dried under vacuum overnight at a temperature of 90°-110° C. Potassium chloride (KCl) and lanthanum chloride (LaCl3) were dissolved in 98% formic acid and this solution was added to the cobaltous chloride-silica powder and allowed to stand overnight. The formic acid was then evaporated under aspiration with rotation until a tacky solid was formed. The rotation was stopped and the temperature slowly increased to 60° C. and held until all of the formic acid was removed. The resulting blue solid was dried overnight under vacuum at a temperature of 90° to 110° C. The blue powder as thus formed included a first layer of crystalline cobaltous chloride uniformly distributed on the silica support with a second layer of potassium chloride and lanthanum chloride deposited over the cobaltous chloride.
Scanning Electron Photomicrography has shown that the catalysts in their most active forms have crystalline materials on their surfaces and that catalysts of the same chemical composition with lesser activities have less crystalline materials on their surfaces. It has been found that the surface topography of these catalysts, and thus their activities, is directly related to the method of preparation. In order to make the more active catalysts with highly crystalline surfaces, great care must be taken during the evaporation of the various solvents when layering the supports with the metal chlorides. High solvent evaporation rates and rapid tumbling during evaporation lead to materials with lower surface crystallinity and lower catalytic activity.
EXAMPLE II
A lead oxyhydrochlorination catalyst was prepared in much the same way Example I except lead acetate (Pb(OAc)2) was dissolved in methanol to be deposited onto the silica support. After drying the resulting white solid it was exposed to gaseous hydrochloric acid (HCl) for sufficient time to convert the lead acetate to lead chloride (PbCl2). A second catalytic layer of potassium chloride and lanthanum chloride was then deposited in much the same manner as described in Example I.
Various other oxychlorination catalysts in accordance with the present invention as well as copper chloride and blank catalysts were prepared for comparison in a manner similar to that described in Examples I and II. The catalysts compositions are given below in Table I.
TABLE I
______________________________________
CONSTITUENTS BY WEIGHT
% METAL
CATALYST CHLORIDE % SiO.sub.2
% KCl % LaCl.sub.3
______________________________________
Cu 41.66 37.50 11.46 9.38
Co 55.17 28.82 8.81 7.20
Ni 58.46 26.70 8.16 6.68
Pb 66.96 21.24 6.49 5.31
Ag 44.73 35.53 10.86 8.88
Pt 41.66 37.50 11.46 9.38
Cr 56.24 28.12 8.61 7.03
BLANK 0.00 64.29 19.64 16.07
______________________________________
EXAMPLE III
An oxyhydrochlorination catalyst as described in Example I with cobaltous chloride in an amount of about 3 grams was exposed to equal flows of methane and HCl (4.0 milliliters/minute) and about one half that flow (2.0 milliliters/minute) of oxygen diluted with 2 milliliters per minute of nitrogen at about 340° C. and a residence time of 8.3 seconds. The flow was continued for over 48 hours resulting in a methane conversion of about 61%, HCl conversion of about 53% and an oxygen conversion of about 85%.
Similar runs made with various other catalysts were conducted and the reactant conversions given below in Table II.
TABLE II
______________________________________
REACTANT CONVERSION
% CH.sub.4 % HCl % O.sub.2
CATALYST CONV CONV CONV
______________________________________
Cu 47.69 80.08 83.86
Co 61.03 52.54 85.48
Ni 19.31 19.81 11.11
Pb 5.51 14.86 9.41
Ag 4.54 7.95 14.03
Pt.sup.a 54.34 0.01 3.10
Pt.sup.b 7.36 3.29 6.56
Cr 13.15 3.54 33.21
BLANK 16.16 6.63 25.31
______________________________________
Each of the catalysts, other than platinum, maintained nearly constant conversion over the full period. The platinum catalyst was found to degrade substantially after hours of reaction. Subsequent tests with the other catalysts conducted for over 400 hours showed the cobalt, nickel, lead and silver catalysts to be stable over the full time period. FIG. 5 illustrates the constant conversion rates for the cobaltous chloride catalyst. The lower conversion percentages are attributed to a more rapid stripping of the acetonitrile than that described in Example I resulting in less crystalline CoCl, deposited.
Unexpectedly, the cobalt chloride catalyst was found to have higher selectivity for monochloromethane in preference to polychloromethanes of any of the catalysts tested (see FIG. 6). In addition, this catalyst produced substantial amounts of formic acid within the aqueous phase.
Nickel, lead and silver catalysts also produced advantageous results with high selectivity for formic acid and good selectivity of monochlormethane over the polychloromethanes. The performance of the PbCl2 catalyst is illustrated in FIGS. 7 and 8 where increased conversion of methane with good selectivity for monochloromethane is obtain at temperatures of 350°-450° C.
The results of the normalized carbon distribution of the various catalysts are listed below in Table III.
TABLE III
__________________________________________________________________________
NORMALIZED CARBON PRODUCT DISTRIBUTION
CATALYST
CH.sub.3 Cl
CH.sub.2 Cl.sub.2
CHCl.sub.3
CCl.sub.4
CO CO.sub.2
HCOOH
__________________________________________________________________________
Cu 30.03
39.42
9.39
0.14
0.00
12.44
8.58
Co 44.31
12.44
1.32
0.00
0.00
3.67
38.26
Ni 23.03
3.78 0.00
0.00
0.00
0.00
73.19
Pb 20.97
3.49 0.37
0.00
0.00
0.00
75.17
Ag 12.71
1.37 0.09
0.00
0.00
14.52
71.31
Pt.sup.a
31.26
3.49 0.30
0.18
0.00
17.35
47.42
Pt.sup.b
28.96
3.28 0.42
0.14
0.00
10.75
56.45
Cr 10.92
2.66 0.60
0.00
64.77
21.05
0.00
BLANK 10.10
0.45 0.09
0.00
69.55
7.02
12.78
__________________________________________________________________________
.sup.a After 24 hours.
.sup.b After 48 hours.
As stated above, it is of advantage to minimize the polychloromethane production in order to protect the catalysts. It is also of note that limiting the polychloromethane production also limits water production that must be removed in recovering the formic acid product.
It is therefore seen that the present invention provides an improved method for the production of monochloromethane and other chlorinated alkanes from methane. The methane can be provided from natural gas supplies or from that which ordinarily is removed in a coal gasification process. Through use of one of the selected oxyhydrochlorination catalysts in accordance with the invention increased selectively of monochloromethane over polychloromethanes is achieved along with the production of economically recoverable quantities of formic acid. Using a straight forward condensation separation, formic acid concentrations of 20-30% and higher can be obtained for subsequent further concentration by fractionation or azeotropic distillation. Improved conversions of the methane are achieved through use of the cobaltous chloride catalyst to enhance productivity in a second reaction over zeolite for the production of gasoline boiling fractions with recycle of released HCl.
Although the invention is described in terms of specific embodiments and process parameters, it will be clear to one skilled in the art that various modifications in the procedures and materials can be made within the scope of the following claims.
The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows:
1. An oxyhydrochlorination catalyst for the co-production of monochloromethane and formic acid from methane comprising as catalytic material, a major proportion of a metal chloride selected from the group consisting of chlorides of cobalt, nickel, lead and silver, as a first layer; a minor proportion of an alkali metal chloride and optionally a minor proportion of a rare earth chloride, as a second layer; said first and second layers of catalyst materials are supported on a pyrogenic carrier selected from the group consisting of silica, titania and alpha alumina.
2. The catalyst of claim 1 wherein said metal chloride is selected from the group consisting of chlorides of cobalt, nickel and lead.
3. The catalyst of claim 1 wherein the cobalt chloride is essentially in the cobaltous form as CoCl2.
4. The catalyst of claim 3 wherein minor proportions of potassium chloride and lanthanum chloride are included as promoter with the cobaltous chloride as active catalytic material.
5. The catalyst of claim 3 including a carrier of silica in about 20% to 40% by weight, about 40% to 60% by weight cobalt chloride, essentially as cobaltous chloride, as a first layer on the carrier and about 10% to 20% total by weight of a mixture of potassium chloride and lanthanum chloride as a second layer over the cobalt chloride on the silica carrier.
6. An oxyhydrochlorination catalyst for the co-production of monochloromethane and formic acid comprising a major proportion of a metal chloride selected from the group consisting of chlorides of cobalt, nickel, lead and silver, as a first layer, and a minor proportion of an alkali metal chloride, as a second layer, supported on a pyrogenic carrier selected from the group consisting of silica, titania and alpha alumina, said selected metal chloride having a surface topography characterized by crystalline material.
7. The catalyst of claim 6 wherein said selectee metal chloride surface is prepared by impregnating an organic solution of the metal chloride into the pyrogenic carrier and slowly evaporating the organic solvent without rapid boiling followed by applying a solution of alkali metal chloride, gently evaporating the solvent to form a first layer of crystalline selected metal chloride uniformly distributed on the pyrogenic carrier and a second layer of alkali metal chloride deposited over the selected metal chloride layer.
8. The catalyst of claim 7 wherein the second layer of alkali metal chloride includes a minor proportion of rare earth chloride.
9. The catalyst of claim 7 wherein said selected metal chloride is cobalt chloride essentially in the cobaltous form as CoCl2.
10. The catalyst of claim 9 wherein minor proportions of potassium chloride and lanthanum chloride are included as promoters with the cobaltous chloride as active catalytic material.
11. The catalyst of claim 9 including a carrier of silica in about 20% to 40% by weight, about 40% to 60% by weight cobalt chloride, essentially as cobaltous chloride, as a first crystalline layer on the carrier and about 10% to 20% total by weight of a mixture of potassium chloride and lanthanum chloride as a second crystalline layer over the cobalt chloride.
| 1991-03-11 | en | 1992-08-18 |
US-95907097-A | Method for releasing call in cordless telephone
ABSTRACT
A cordless telephone releases a telephone call, in case that a handset unit is engaged in the telephone call over a predetermined time even though a telephone conversation has been completed. During the telephone conversation, a base unit periodically transmits busy state inquiry data to the handset unit, and checks whether response data thereto is received or not within a predetermined time. If the response data is not received within the predetermined time, the speech loop is automatically cut off. Therefore, in case that the handset unit misoperates due to the damage or the discharge of the battery, the base unit forcefully releases the call so that the user may make a telephone call with the base unit or another handset unit.
CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application for METHOD FOR RELEASING CALL IN CORDLESS TELEPHONE earlier filed in the Korean Industrial Property Office on Oct. 28, 1996 and there duly assigned Ser. No. 49240/1996.
1. Field of the Invention
The present invention relates to a call release method in a cordless telephone, and more particularly to a method for releasing a call if a handset unit is continuously engaged in the call after completion of a telephone conversation.
2. Description of the Related Art
A cordless telephone includes a base unit connected to a telephone fine, and a handset unit with which a user can make a telephone call. The handset unit makes a radio communication with the base unit. Generally, the base unit continues to hold a speech loop between the handset unit and the telephone line, unless a call completion signal is received from the handset unit. Further, the base unit includes a carrier intensity sensing circuit for sensing an intensity of the carrier to release the call, in case that, for example, the handset unit runs out of the battery in the midst of the telephone call. For example, U.S. Pat. No. 5,535,429 for a Method of Disconnecting an Established Communication Connection in a Mobile Radio System to Bergenlid et al and U.S. Pat. No. 5,497,415 for an Automatic Release Device For Automatically Releasing the Hond-On Setting of an Outside Line Call, and Transfer Method for an Outside Line Call to Kagi discuss releasing a telephone line. However, if the carrier intensity sensing circuit misoperates for somewhat reasons, the base unit will misconceive that the handset unit is continuously in use. In that case, the base unit can not receive an incoming call, if any.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method for cutting off a speech loop, in case that a handset unit is continuously engaged in a call over a predetermined time even though a telephone conversation has been completed.
It is also an object of the present invention to provide a cordless telephone unit having a base unit and a handset, such that if call completion data is not received by the base unit within a first predetermined time, the base unit transmits to the handset a busy state inquiry signal.
It is yet another object of the present invention to disconnect the speech loop should the base unit fail to receive from the handset a response to its request for busy state inquiry.
According to an aspect of the present invention, a method for releasing a call in a cordless telephone including a base unit and a handset unit comprises the steps of checking whether the base unit has received call completion data from the handset unit; transmitting busy state inquiry data to the handset unit, if the call completion data is not received within a first predetermined time; and cutting off a speech loop, if response data which is responsive to the busy state inquiry data is not received from the handset unit within a second predetermined time.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
FIG. 1 is a block diagram of a base unit in a cordless telephone to which the present invention is applicable;
FIG. 2 is a block diagram of a handset unit in a cordless telephone to which the present invention is applicable;
FIG. 3 is a flow chart for controlling the base unit of FIG. 1 according to an embodiment of the present invention; and
FIG. 4 is a flow chart for controlling the handset unit of FIG. 2 according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a base unit of a cordless telephone includes a controller 32 for controlling an overall operation of the base unit. In accordance with the present invention, the controller 32 transmits busy state inquiry data when a handset unit engages a call over a predetermined time, and cuts off a speech loop upon receiving response data from the handset unit. A memory 33 is composed of a ROM (Read Only Memory) for storing a program, and a RAM (Random Access Memory) for temporarily storing data generated during executing the program. Further, the memory 33 stores a password for the handset unit and has a region for setting various functions. A key input section 34 includes a plurality of function keys for setting various functions and modes, and a plurality of numeric keys for performing a dialing function. The key input section 34 generates key data according to depression of the keys and provides the controller 32 with the key data. A transmitter 36 modulates an input signal and transmits the modulated signal via an antenna 58, under the control of the controller 32. A receiver 38 demodulates the signal received through the antenna 58 into a voice signal and provides the controller 32 with various control data. A transmission/reception controller 40 controls the transmitter 36 and the receiver 38 by using a transmitting/receiving frequency based on channel data generated from the controller 32. A dialing circuit 42 generates a DTMF (Dual Tone Multi-Frequency) or pulse dialing signal under the control of the controller 32. A line interface 46 interfaces between a telephone line (T, R) and the base unit, under control of the controller 32. A network controller 48 is connected to the transmitter 36, the receiver 38, the dialing circuit 42, and the line interface 46, so as to form a speech loop according to the control of the controller 32. A display 56 displays the key input status and an operational status of the base unit.
Referring to FIG. 2, there is shown a block diagram of the handset unit, in which a controller 12 controls an overall operation of the handset unit. A memory 14 stores a password for the handset unit, and temporarily stores data generated during executing a program. A key input section 10 is composed of a plurality of function keys for setting various functions and modes, and a plurality of numeric keys for dialing telephone numbers, to generate key data to the controller 12 according to key inputs by the user. A transmitter 20 transmits a transmittal voice signal generated from a microphone 18 through an antenna 22, under the control of the controller 12. A receiver 24 demodulates the signal received through the antenna 22 to provide a speaker 26 with the demodulated signal, and provides the controller with various control data. A transmission/reception controller 28 controls the transmitter 20 and the receiver 24 using the transmitting/receiving frequency based on the channel data generated from the controller 12. A display 30 displays the key input status and an operational status of the handset unit.
Now, referring to FIGS. 1 through 4, operation of the preferred embodiment of the present invention will be described in detail hereinbelow. First, if a user depresses a call button of the handset unit to make a telephone call, the controller 12 of the handset unit checks, at a step 101, whether or not the call button is depressed. If the call button is depressed, the transmitter 20 transmits call start data to the base unit, at a step 102. At this moment, the controller 32 of the base unit checks, at a step 201, whether or not the receiver 38 has received the call start data through the antenna 58. If the call start data is received, the transmitter 36 transmits call response data responsive to the call start data to the handset unit, at a step 202. Then, at a step 103, the controller 12 of the handset unit checks whether or not the receiver 24 has received the call response data from the base unit. If the call response data is not received, the controller 12 checks, at a step 104, whether or not a response time has elapsed. If the response time has not elapsed, the process returns to the step 103 to wait for the call response data. In a little while, if the response time has elapsed, the controller 12 abandons the call at a step 105. However, if the call response data is received at the step 103, the controller 12 forms a speech loop to the base unit at a step 106. Meanwhile, after transmission of the call response data at the step 202, the controller 32 of the base unit forms the speech loop to the handset unit and the telephone line, at a step 203, so as to start the telephone call. Thereafter, the controller 32 of the base unit initializes a call time counter to recount the call time, at a step 204. The controller 32 of the base unit checks, at a step 205, whether or not the call time has exceeded a predetermined time. If the call time has not exceeded the predetermined time, the controller 32 checks whether call completion data is received or not, at a step 210. If the call completion data is not received, the process returns to the step 205. However, if the call completion data is received, the controller 32 transmits call completion response data to the handset unit at a step 211, and completes the call at a step 212.
Meanwhile, upon completion of the telephone conversation, the user depresses a call completion button prepared in the key input section 10 of the handset unit. Then, the controller 12 of the handset unit checks, at a step 107, whether or not the call completion button prepared in the key input section 10 is depressed. If the call completion button is depressed, the controller 12 transmits the call completion data to the base unit at a step 110. Thereafter, the controller 12 checks, at a step 111, whether or not the call completion response data is received from the handset unit. If the call completion response data is received, the call is completed at a step 113. However, if the call completion response data is not received, the controller 12 checks, at a step 112, whether or not a call completion response time has elapsed. If the call completion response time has not elapsed, the process returns to the step 111.
Further, if the call completion data is not received over a predetermined time after starting the call at the step 205, the controller 32 of the base unit transmits the busy state inquiry data at a step 206. The busy state inquiry data is for checking whether the handset unit engages the call. Then, the controller 12 of the handset unit checks, at a step 108, whether the busy state inquiry data is received. If the busy state inquiry data is received, the controller 12 transmits busy state response data to the base unit at a step 109 and then, returns to the step 107. The busy state response data is for notifying that the handset unit is currently engaged in the call. Meanwhile, after transmission of the busy state inquiry data at the step 206, the controller 32 of the base unit checks, at a step 207, whether or not the busy state response data is received. If the busy state response data is received, the process returns to the step 204 and initializes the call time counter to recount the call time. However, if the busy state response data is not received, the controller 32 checks, at a step 208, whether or not a busy state response time has elapsed. If the busy state response time has not elapsed, the process returns to the step 207. However, if the busy state response time has elapsed, the call is completed at a step 209.
In other words, if the base unit does not receive the call completion data from the handset unit within a predetermined time, for example, 60 minutes, then the base unit transmits the busy state inquiry data to the handset unit. Then, in response to the busy state inquiry data, the handset unit transmits the busy state response data within the busy state response time, for example, 10 seconds. However, if the busy state response data is not received over the busy state response time, i.e., 10 seconds, it is judged that the handset unit is out of order or runs out of the battery. Then, at the step 209, the controller 32 of the base unit cuts off the speech loop to complete the call.
As described in the foregoing, during the telephone conversation, the base unit periodically transmits the busy state inquiry data to the handset unit, and checks whether the response data thereto is received or not within the predetermined time. If the response data is not received within the predetermined time, the speech loop is automatically cut off. Therefore, in case that the handset unit misoperates due to the damage or the discharge of the battery, the base unit forcefully releases the call so that the user may make a telephone call with the base unit or another handset unit.
Although a preferred embodiment of the present invention has been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught which may appear to those skilled in the art will still fall within the spirit and scope of the present invention.
What is claimed is:
1. A method for releasing a call in a cordless telephone including a base unit and a handset unit, comprising the steps of:checking whether said base unit has received call completion data from said handset unit; transmitting busy state inquiry data to said handset unit to check whether said handset unit is engaged with a call, when said call completion data is not received within a first predetermined time; and cutting off a speech loop, when busy state response data, notifying that the handset unit is currently engaged in the call, and being responsive to said busy state inquiry data, is not received from said handset unit within a second predetermined time.
2. A method for releasing a call in a cordless telephone including a base unit and a handset unit, comprising the steps of:transmitting call start data to the base unit upon depressing a call button prepared in the handset unit, so as to form a speech loop between the handset unit and a telephone line; checking whether or not the base unit has received call completion data from the handset unit within a first predetermined time; transmitting busy state inquiry data to said handset unit to check whether said handset unit is engaged with a call, when said call completion data is not received within said first predetermined time; and cutting off said speech loop between the base unit and the telephone line, when busy state response data, notify that said handset unit is currently engaged in the call and being responsive to said busy state inquiry data, is not received from said handset unit within a second predetermined time.
3. A method for releasing a call in a cordless telephone according to claim 2, further comprising the step of initializing a call time count to count a call time, when said response data is received from said handset unit within said second predetermined time.
4. A method for releasing a call in a cordless telephone including a base unit and a handset unit, comprising the steps of:forming a speech loop between the handset unit and a telephone line, upon receiving call start data from the handset unit; initializing a call time count value to count a call time; checking whether or not the base unit has received call completion data from the handset unit; transmitting busy state inquiry data to said handset unit to check whether said handset unit is engaged with a call, when said call completion data is not received from the handset unit within a predetermined time; transmitting busy state response data to the base unit to notify that the handset unit is currently engaged in the call, when said handset unit has received busy state inquiry data from the base unit; and cutting off said speech loop between the base unit and the telephone line, when said response data that is responsive to said busy state inquiry data is not received from said handset unit.
5. An apparatus for releasing a call in a cordless telephone, comprising:a base unit comprising a controller, a transmitter, a receiver, and a key input section; a handset comprising a controller, a transmitter, a receiver, and a key input section containing a call completion button, wherein when said base unit is not in receipt of a call completion data signal transmitted from said key input section of said handset, said base unit, checking whether said handset unit is engaged with a call, transmits to said handset a busy state inquiry signal.
6. The apparatus of claim 5, wherein said base unit releases said call if said base unit is not in receipt of a busy state response in response to said busy state inquiry, said busy state response for notifying said handset is currently engaged in the call.
7. An apparatus for releasing a call in a cordless telephone, comprising:a base unit comprising:a controller for sending and receiving information to and from a handset, a receiver receiving a call completion signal and a busy state response signal from said handset, notifying that said handset is currently engaged in said call, and a transmitter transmitting a busy state inquiry signal to said handset, checking whether said handset is engaged with said call; said handset unit comprising:a controller sending and receiving information from said base unit, a key input section allowing a user to input a call completion signal, a receiver receiving a busy state inquiry signal from said base unit, and a transmitter transmitting both said call completion signal and a busy state response signal to said base unit, wherein said busy state response signal is in response to said busy state inquiry signal and said busy state inquiry signal is in response to failing to receive said call completion signal from said handset.
| 1997-10-28 | en | 2000-03-07 |
US-55762575-A | Attachment for reflectors for spoke wheels
ABSTRACT
An attachment for combination with wheel reflectors attached to and/or carried by the spokes of spoke wheels. Wheel reflectors normally provide increased visibility from only right angles to the direction of travel. The attachment, of double-faced reflectorized construction in its preferred embodiment, is carried by the wheel reflector at substantially right angles thereto and is of a size to pass between the wheel supporting frame members to which the wheel is attached. Being disposed normal to the wheel reflector, the attachment increases visibility in directions more or less parallel to the direction of travel and in use moves up and down with rotation of the wheel thereby providing the maximum degree of visibility from both forwardly and rearwardly directions-directions from which side reflectors are totally invisible.
United States Patent [191 Trimble Dec. 9, 1975 ATTACHMENT FOR REFLECTORS FOR SPOKE WHEELS Robert C. Trimble, 258 Main St., Northboro, Mass. 01532 [22] Filed: Mar. 12, 1975 [21] Appl. No.: 557,625
[76] Inventor:
[52] US. Cl. 350/99; 350/97; 301/37 SA [51] Int. C13... G02B 5/12; 3608 11/00; B60R 7/00 [58] Field of Search 350/97, 99, 97 UX, 303; 301/37 SA; 280/289 [56] References Cited UNITED STATES PATENTS 2,344,542 3/1941 Fike 350/97 2,752,816 H1955 Austing... 350/99 3,809,434 5/1974 Linder 350/99 Primary ExaminerAlfred E. Smith Assistant Examiner-B. W. de los Reyes Attorney, Agent, or Firm-Melvin E. Frederick, Esq.
[57] ABSTRACT An attachment for combination with wheel reflectors attached to and/or carried by the spokes of spoke wheels. Wheel reflectors normally provide increased visibility from only right angles to the direction of travel. The attachment, of double-faced reflectorized construction in its preferred embodiment, is carried by the wheel reflector at substantially right angles thereto and is of a size to pass between the wheel supporting frame members to which the wheel is attached. Being disposed normal to the wheel reflector, the attachment increases visibility in directions more or less parallel to the direction of travel and in use moves up and down with rotation of the wheel thereby providing the maximum degree of visibility from both forwardly and rearwardly directions-directions from which side reflectors are totally invisible.
10 Claims, 8 Drawing Figures US. Patent Dec. 9, 1975 Sheet 1 0f 3 3,924,928
US. Patent Dec. 9, 1975 shw 2 of3 3,924,928
US. Patent Dec. 9, 1975 Sheet 3 of3 3,924,928
ATTACHMENT FOR REFLECTORS FOR SPOKE WHEELS The present invention relates to a novel, decorative and safety attachment for use in conjunction with but disposed normal to reflectors attached to or carried by the spokes of a spoke wheel and lying generally in the plane of the wheel.
In decorative and reflector devices such as are commonly used at present, such devices are generally in the form of small flat faceted glass devices permanently mounted by means of screws and the like to the fenders, frame, spokes or rim of the wheels of the vehicle. Devices of this type are small, are limited in reflection value, and tend to give a false sense of security inas much as the drivers of other vehicles have difficulty seeing the small devices, or see them too late to avoid a collision. Reflectors heretofore used for this purpose are effective only over a narrow angle of view and are generally totally ineffective when viewed from a direction normal to that in which the reflector lies. As noted above, prior reflectors are subject to the particular disadvantage in that they are ineffective in signalling vehicles approaching at right angles. Thus, spoke mounted wheel reflectors now required by law are reasonably visible to a vehicle approaching at right angles. Not only do they reflect light, but due to the rotation of the wheel on which they are mounted, they appear as a highly visible area having both a forward and circular motion. For a more thorough discussion of such required spoke mounted side reflectors, reference is made to U.S. Pat. Nos. 3,768,433 and 3,781,082, the contents of which are incorporated as if set out at length herein.
However, such wheel reflectors are totally ineffective with respect to a vehicle approaching from the front or rear. In this case, reliance for detection must be placed on the presence of non-movable reflectors mounted in conventional manner, i.e., fixedly attached to the rear fender and facing rearward, or perhaps one fixedly attached to the front and facing forward. Alternately, a bicycle or the like might be equipped with a tubular member of the type described in my U.S. Pat. No. 3,834,765, issued Sept. 10, 1974, the contents of which are incorporated as if set out at length herein. If the tubular member is of a cross section greater than that of the tire, then, of course, it does not function solely as a spoke mounted side reflector and a small portion may be visible as a substantially non-movable reflector from, for example, directly in front of the bicycle.
Thus, as may now be seen, various reflectors have been mounted on bicycle fenders, handle bars, and other parts of the bicycle. Such reflectors have been adapted to meet purposes of safety and attractiveness. So far as is known, no reflector has been provided which can be efficiently mounted on a wheel and provide a high degree of visibility from directions both in front of and behind. Both Federal and certain state specifications now in effect require side lighting on bicycles as well as on automobiles and trucks. Such side lighting is attained by using various optic and reflector elements. Such reflectors are variously mounted with or without brackets and may be of the reflex reflector type, including cube corner reflectors. The elements may be comprised entirely of reflector elements or be comprised of both optic and reflector elements.
Side reflex illumination is now commonly provided by conventional side markers or wheel reflectors, attached to the wheels and/or tubular members as set forth in my aforementioned U.S. Pat. No. 3,834,765; rear illumination is commonly provided with a fender mounted electric tail light and/or reflex reflector; and frontal illuminationby an electric light and/or reflex reflector.
It is an important object of the present invention to provide an improved reflector element which can be mounted on a wheel which, in use, moves up and down with rotation of the wheel and provides the maximum degree of visibility from forwardly and rearwardly directions.
Another object of the present invention is to provide, in a manner as hereinafter set forth, a decorative and- /or safety reflective attachment that may be expediously combined with a side reflector for a spoke wheel without structurally altering the side reflector, the wheel, interfering with the use of or servicing of the wheel, or requiring the use of any attaching means such as clamps, screws and the like.
Another object of the present invention is to provide a decorative and/or reflective device for combination with a side reflector for spoke wheels which is of the simplest construction, strong, durable, light-weight, attractive in appearance, unbreakable, easily cleaned, and which may be manufactured at low cost.
A still further object of the present invention is to provide a generally flat reflective member that is easily combined with required side reflectors for spoke wheels and does not require the use of any tools for installation or removal, and which is not substantially affected by either rotation or vibration of the wheel.
A further object of the present invention is the provision of a reflective device for combination with required side reflectors for spoke wheels which rotate with the side reflector and which can be seen from those directions in which the side reflector is invisible.
A still further object of the present invention is the provision of a reflective device which can easily be mounted without requiring the use of tools or without the necessity of making any modifications or providing means to attach the reflective device.
The above objects together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:
FIG. 1 is a fragmentary cross-sectional view of a spoke wheel with a wheel reflector and a device in accordance with the invention;
FIG. 2 is a fragmentary side elevation of the wheel reflector and device in accordance with the invention;
FIG. 3 is a front view of the reflector device shown in FIG. 1 and FIG. 2;
FIG. 4 is a fragmentary view in side elevation of a spoke wheel with a ring reflector and an annular shaped device;
FIG. 5 is a fragmentary side elevation view of that shown in FIG. 4;
FIG. 6 is a fragmentary side elevation view of an alternate embodiment for use with the ring reflector of FIG. 4;
FIG. 7 is a fragmentary side elevation view of a further embodiment for use with the ring reflector of FIG. 4; and
FIG. 8 is a fragmentary view in side elevation of a spoke wheel showing a device in accordance with the invention substantially as shown in FIG. 3 carried by an elongated wide angle wheel reflector.
The present invention is especailly useful with bicycles of the conventional type which includes a frame, a front fork mounted upon the hub of the front wheel, the front fork being pivotally mounted with respect to the frame and adapted to be steered by handle bars. Rear fork members converge at the rear end and are connected to the hub of a rear wheel. The rear wheel hub carries a small sprocket which is connected by a drive chain to a large pedal sprocket. Mounted for rotation with the large sprocket are oppositely extending crank arms carrying pedals. A seat for the rider is carried by the frame. Depending upon the type of construction, a conventional type of coaster brake may be provided in the rear hub or caliper type brakes actuated from the handle bar may be provided on either or both of the wheels.
Directing attention now to the wheels, FIG. 1 and FIG. 2 illustrate by way of example, a portion of a spoke wheel designated generally by the numeral 10 for bicycles and the like comprising a pneumatic tire 11, a rim 12, and spokes l3 and 14. As is well-known, the spokes l3 and 14 are alternately secured to opposite ends 15 and 16 of an axially elongated hub 17. In other words, the spokes 13 are attached to end 15 of the hub 17 of the wheel 10 and define a cone surface converging to the left as shown in FIG. 1, whereas the spokes 14 extend to the other end 16 of the hub and define a second cone surface on the other side of the wheel and extending to the right. As may be seen in FIG. I, the spokes 13 and I4 slope in opposite directions from a plane 18 passing through the center of the rim and halfway between the ends of the hub 17. The wheel 10 is rotatably carried by and between two wheel supporting members 39 and 20 which may comprise a front wheel fork 21.
Disposed on and carried by a pair of adjacent spokes as best seen in FIG. 2, is a wheel reflector generally designated by the number 25. The wheel reflector 25, such as, for example, a GEM 90 reflector meeting Department of Transportation requirements, manufactured and sold by EXCEL Corporation, Franklin Park, "1., may comprise double faced reflector means 26 fixedly disposed in the center of a plastic frame member 27 having opposed end portions 28 and 29. The end portions 28 and 29 are each provided with openings 31 and 32 covered by offset tabs or ear members 33 and.
34 which, in cooperation with the end portions, are adapted to receive and firmly grip a spoke. As is wellknown to those familiar with the repair and maintenance of bicycles, such wheel reflectors are adapted to permit the engagement of one end portion with first one spoke and then engagement of the other end portion with an adjacent spoke.
Such reflectors, while very effective with respect to light coming at right angles to the direction of travel of a bicycle or the like equipped with such a reflector, they are, of course, totally ineffective with respect to one positioned substantially in front of or behind the bicycle.
To simply, economically, and effectively overcome the abovenoted deficiency, in accordance with the invention, there is provided a thin reflector member or device 35 having an opening 36 to receive an end portion of the wheel reflector whereby it may be slid thereover a distance to permit the end portion to be attached to a spoke. The member 35 needs no additional attachments and may be made to fit with little or no movement on a wheel reflector or to permit some movement as suggested by the illustration of member 35 in both solid and broken lines in FIG. 2.
The reflector member 35 is preferably fabricated from any suitable resilient plastic material and provided in any suitable manner with reflectorized surfaces 37 and 38. For use with the type of wheel reflectors illustrated, which are attached to the spokes, the opening 36 must not only be of the proper size to permit it to be mounted on a given wheel reflector, but it must be offset (see FIG. 3) such that when it is mounted in operative position, it will be centered between the wheel supporting members. This is because any wheel reflector carried by the spokes are of necessity themselves offset from the central plane 18. Further, in the case of a reflective member 35 having a circular configuration as shown merely by way of example, its diameter (or dimension normal to the plane of rotation of the wheel) must be sufficiently less than that between the wheel supporting member that it will freely pass between them. However, the reflective member 35 is preferably provided with just sufficient flexibility that should it encounter a wheel supporting member or obstruction, it will not cause the wheel to cease turning or the reflector to break. Excessive or an unnecessarily high degree of flexibility is not desirable because in this case, wind pressure can cause the reflective member 35 to be bent back on itself and thereby reduce, if not destroy, its effectiveness and/or cause it to be flexed back and forth and thereby result in early failure due to fatigue.
While the reflective member 35 may be formed of a number of resilient and/or compressible materials in-.
cluding rubber, conventional synthetic plastics are preferred because of their low cost, the ease with which they may be formed and/or combined with other materials such as fluorescent dyes and light reflective particles or materials. The opposite faces of a reflective member 35 in accordance with the invention may be provided with a light reflective outer surface as by coating or applying under a protective transparent coating a light reflective material or surface having, for example, a large number of small refracting and/or reflecting prismatic surfaces for receiving light and re-directing it generally along its incoming path. Alternately, it may include a fluorescent dye which fluoresces both under sunlight and artificial light.
Reflective member 35 is attached to a wheel by inserting an end portion 28 of a wheel reflector 25 through the opening 36 (see FIG. 2 and FIG. 3) a distance to permit attachment of that end portion to a spoke. The other end portion of the wheel reflector is then attached to the next adjacent spoke in conventional manner and the wheel reflector adjusted to permit minimum free movement of the reflective member 35 and/or the reflective member 35 is moved to contact the spoke.
It will now be apparent that a reflective member 35 in accordance with the invention attached as shown and described needs no separate attaching means, is insensitive to rotation or vibration of the wheel and is inexpensive and simple to manufacture.
Directing attention now to FIG. 4 and FIG. 5, there is shown an embodiment for use in combination with a tubular member 41 shown and described in my abovementioned US. Pat. No. 3,834,765.
For this case, the reflective member 42 is provided with an axial or central opening to permit it to be slid onto the tubular member 41 and located intermediate a pair of adjacent spokes. Of course, one or a plurality of reflective members 42 may be utilized.
FIG. 6 shows a modification wherein the reflective member may be made in the form of a glow worm 44 or the like to provide both decorative and safety features. Any decorative form or shape may be used so long as it will pass between the wheel supporting members.
FIG. 7 shows a still further modification wherein the reflective member is provided with a donut configuration 45 such that it has a substantial dimension paral lel to the plane of the wheel. Preferably, the donut embodiment is of such thickness t as to contact adjacent spokes when mounted on a tubular member 41. Further, it is also preferably of a hollow nature to reduce manufacturer costs and to keep its weight to a minimum.
FIG. 8 shows a portion of a spoke wheel similar to that shown in FIG. 4, but carrying an elongated wide angle wheel reflector 50. This type of wheel reflector, such as, for example, the 1975 model wide angle reflector meeting Department of Transportation requirements manufactured and sold by Gulco Division, Bright Star Industries, Inc. comprises adjacent prismatic reflective surfaces, disposed at an angle to the reflective surface or surfaces adjacent thereto to provide visibility up to 50 from each side of center of a reflector. Opposed ends of the reflector are each provided with grooved screw type fittings to engage and grip a spoke. A further wide angle reflector, also providing visibility up to 50 from each side of center, but having opposed flat outer surfaces, is part number 07730, manufactured and distributed by Schwinn Bicycle Company, Chicago, III. A reflective member 51, which may be of a substantially rectangular or circular configuration depending on the depth of the reflector 50, is provided with an appropriately located opening to receive and pass over one end of the reflector 50. The reflective member 51 is carried on the wheel reflector 50 in much the same manner as the reflector 35 of FIG. 2. Similarly, the wheel reflector 50 is attached to the spokes of a wheel in substantially the same manner as is the reflector 25 of FIG. 2.
As will now be evident, a reflective member formed of a resilient material when combined with a wheel reflector provides a new and novel decorative and reflective member and is of particular additional value from a safety point of view. Such a device does not in any way affect servicing or use of a wheel with which it is combined. Thus, the tire may be inflated or repaired, the wheel removed or attached to the frame, the wheel padlocked, the spokes adjusted, or the wheel trued with the member in place. It is virtually unbreakable; no tools are required for its installation and retention; it may be installed by anyone old enough to ride a bicycle, does not tent to collect dirt, oil and the like; and when it does get dirty, it may be cleaned by simply wiping it with a cloth. It is inexpensive to manufacture and purchase and will snugly fit existing bicycle and motorcycle wheel side reflectors. Reflective members in accordance with the invention may be of any desired shape or configuration including round or rectangular and may be made decorative in the form of faces, flowers, donuts, worms and the like. Even if the reflective member is made from sheet material, its edge or edges as well as the front and rear surfaces may be reflectorized to increase visibility from all directions. A reflective member in accordance with the invention will move through a much greater distance than, for example, pedals having reflective: portions.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.
What is claimed as new is as follows:
1. A safety device in combination with a wheel mounted reflector adapted to be carried by the spokes of a spoke wheel rotatably carried by and between two wheel supporting members, said device comprising:
a. a light reflective member having an opening to receive and engage a wheel reflector, said light reflecting member having a thickness and said opening being of a size that when said light reflecting member is carried by a wheel reflector attached to a spoke wheel, said light reflecting member engages and is substantially held against movement by said wheel reflector and at least one spoke.
2. The device of claim 1 comprising a pair of light reflecting surfaces facing in opposite directions.
3. The device of claim ll wherein said opening is offset from the centers of said light reflective member and said light reflective member has a dimension normal to the greatest dimension of said opening that is less than the distance between said wheel supporting members whereby when said light reflecting member is carried by a side reflector, it will pass between said wheel supporting members during rotation of said spoke wheel.
4. The device of claim 3 comprising a pair of light reflecting surfaces facing in opposite directions.
5. The device of claim 4 wherein the said dimension of said light reflecting member is less than three inches to freely fit between the wheel supporting members of a front wheel bicycle fork.
6. The device of claim 1 wherein said light reflecting member is of a size that when carried by a wheel reflector, it will freely fit between the wheel supporting members.
7. The device of claim 6 wherein said light reflecting member is substantially annular in shape and said opening is centrally located.
8. The device of claim 7 wherein said light reflecting member is substantially donut shaped and of a thickness to engage and contact adjacent spokes.
9. The device of claim 1 wherein said light reflecting member is flexible whereby if it strikes a wheel supporting member during use it will not break or cause the wheel to cease turning.
10. A safety reflector device in combination with a wheel mounted reflector having a reflective center position intermediate opposed end portions adapted for gripping attachment to respectively two adjacent spokes of a spoke wheel rotatably carried by and between two wheel support members, said device comprising:
portion attached to a spoke wheel said light reflecting member engages and is substantially held against movement by said side reflector and the spoke gripped by the side reflector end portion passing through said light reflecting member.
1. A safety device in combination with a wheel mounted reflector adapted to be carried by the spokes of a spoke wheel rotatably carried by and between two wheel supporting members, said device comprising: a. a light reflective member having an opening to receive and engage a wheel reflector, said light reflecting member having a thickness and said opening being of a size that when said light reflecting member is carried by a wheel reflector attacheD to a spoke wheel, said light reflecting member engages and is substantially held against movement by said wheel reflector and at least one spoke.
2. The device of claim 1 comprising a pair of light reflecting surfaces facing in opposite directions.
3. The device of claim 1 wherein said opening is offset from the centers of said light reflective member and said light reflective member has a dimension normal to the greatest dimension of said opening that is less than the distance between said wheel supporting members whereby when said light reflecting member is carried by a side reflector, it will pass between said wheel supporting members during rotation of said spoke wheel.
4. The device of claim 3 comprising a pair of light reflecting surfaces facing in opposite directions.
5. The device of claim 4 wherein the said dimension of said light reflecting member is less than three inches to freely fit between the wheel supporting members of a front wheel bicycle fork.
6. The device of claim 1 wherein said light reflecting member is of a size that when carried by a wheel reflector, it will freely fit between the wheel supporting members.
7. The device of claim 6 wherein said light reflecting member is substantially annular in shape and said opening is centrally located.
8. The device of claim 7 wherein said light reflecting member is substantially donut shaped and of a thickness to engage and contact adjacent spokes.
9. The device of claim 1 wherein said light reflecting member is flexible whereby if it strikes a wheel supporting member during use it will not break or cause the wheel to cease turning.
10. A safety reflector device in combination with a wheel mounted reflector having a reflective center position intermediate opposed end portions adapted for gripping attachment to respectively two adjacent spokes of a spoke wheel rotatably carried by and between two wheel support members, said device comprising: a. a light reflecting member having an elongated opening to receive a side reflector end portion and permit said end portion to pass through it, said light reflecting member having a thickness and said opening being of a length that when said light reflecting member is carried by a side reflector end portion attached to a spoke wheel said light reflecting member engages and is substantially held against movement by said side reflector and the spoke gripped by the side reflector end portion passing through said light reflecting member.
| 1975-03-12 | en | 1975-12-09 |
US-67063384-A | Folder for paper sheets or the like
ABSTRACT
A folder for paper sheets comprising a carrier body (20) is provided, said folder consisting of a bottom (21), a back (22) optionally including a handling hole (36), and a cover (23), said parts being joined to each other by means of permanently foldable creases (26, 27). The bottom (21) is adapted to be provided with a line-up mechanism including U-clamps. At least those regions of bottom (21) and cover (23) which adjoin the back (22) have a greater width than the remaining areas of bottom and cover, so that equal-sized symmetrical lugs (28) are formed which are integral with the carrier body (20). Such a folder may selectively be set up either in upright position, in horizontal position or suspended in a suspension file system.
BACKGROUND OF THE INVENTION
The invention is directed to folders for paper sheets or the like, comprising a carrier body made especially of plastics or metal and consisting of a bottom, a back optionally formed with a handling hole, and a cover, said parts being joined to each other by means of permanently foldable creases, the bottom being adapted to be provided with a line-up mechanism including U-clamps.
Such a folder has been known, for instance, from DE-A No. 2,303,218, in which the folder is made of plastics material but for reasons of greater strength includes regions of increased material thickness which constitute diagonal stiffenings. The cover is formed with slots having unilaterally protruding rigid detents which, when the folder is upright, are capable of engaging behind the U-clamps of the line-up mechanism so as to prevent opening of the folder while in the upright position. Such a folder is not suitable, however, for a suspension file system, so that its uses are limited.
For practical purposes it is, however, desirable to make use of a folder for paper sheets or other documents in a highly versatile manner without any problems when filing such folders. It is furthermore undesirable to be limited to a certain filing system so that, for instance, filing in a suspension file system is impossible such that the space-saving accommodation in cabinets or desks cannot be utilized or binders have to be used instead of folders.
It is therefore the object of the instant invention to provide a folder of the above-specified kind, which is easy to manufacture and particularly versatile in use so that it may be filed selectively in horizontal or upright or suspended position.
SUMMARY OF THE INVENTION
The solution of the above-specified object in accordance with the invention resides in that at least the regions of bottom and cover which adjoin the back, and optionally the back itself, have a greater width on either side than the remaining areas of bottom and cover, and that said wider regions define substantially rectangular, symmetrical lugs of equal size on either side, said lugs being integrally formed with the carrier body and being of stepped configuration.
It is therefore possible to use the folder according to the invention not only in horizontal or upright position, but also directly suspended in a suspension file system without requiring any additional components. The carrier body is constituted by a single blank which is easily produced. The folder may be used with paper sheets of any desired size.
The folder will have increased stability for upright filing and at the same time an attractive appearance provided that, in accordance with a further modification of the invention, the lugs formed at bottom and cover have chamfered side edges which extend from the junctions between the creases and the outer edges of the lugs obliquely in the direction of the outer corner points of bottom and cover, respectively.
When the folder according to the invention is provided at the bottom thereof in the region adjoining the back with lateral support means and the support means are integral with the bottom and project transversely in the direction of the cover substantially perpendicularly to the bottom, the folder according to the invention will have a particularly high stability for placement in suspension file systems.
It has been found advantageous that the support means are flat webs or prisms which, when the folder is closed, include a leg extending substantially parallel to the back, and the support means are formed with stiffenings which are optionally broadened towards the bottom, whereby strength and stability of the folder are further improved.
In one embodiment of the folder the support means are joined to webs formed at the bottom and optionally disposed at right angles, and the webs extend in parallel relationship to the side edge or to the crease, respectively, whereby the stability of the folder is further improved. It is also possible to provide for securing of a paper stack in the folder.
It is an advantageous feature that the support means merge at the underside thereof into the broader region of the bottom to limit the same laterally, and that the support means have L-shaped configuration and include legs which extend in parallel relationship to the side edge and are flush with the side edges of the bottom. Thereby a compact and symmetrical arrangement is formed, which is favourable when the folder has to carry high loads.
In a special embodiment the support means are provided with a hook-shaped protrusion at the outer front edge thereof, whereby slipping of the folder into the suspension file system is prevented when the folder itself has a narrow back.
It is especially advantageous that the folder with its support means and optionally the stiffenings thereof is an integral injection-moulded or moulded article of plastics material. Plastics such as polyethylene, polyvinylchloride, polycarbonate, polyurethane or especially polypropylene are suitable materials, preferably with a wall thickness of 2 to 3 mm, and with a grained or structured outer surface.
When the bottom and/or back and/or cover of the folder include at least one region formed as a smooth surface on which an exchangeable, especially a pressure-sensitive label may be provided, the versatility of the folder in use is further improved, since outdated labels need no longer be pasted over.
In one embodiment of the folder of the instant invention, the smooth surfaces are shallow depressions in the respective walls of the carrier body, and the smooth surfaces are offset or stepped relative to the surrounding areas of the respective walls by a ring or ridge. Thereby the label edges are protected against mechanical wear and undesirable peeling of the label is prevented.
It has been found advantageous that the smooth surfaces are completely surrounded by the continuous elevated ring or ridge and that the ring or ridge is of flat design and forms a slight elevation of a few tenths of a millimetre relative to the respective smooth surface. The smooth surface may be offset in a decorative and functional manner relative to the surrounding areas while the elevation is in no way inconvenient.
Suitably, the smooth surfaces may be integrally formed with the plastics part as the carrier body and may be embossed in the respective region. Thereby the folders with the smooth surfaces may easily be produced in a single operation, for instance as an injection-moulded plastics part.
It has been found appropriate that a respective elongated slot is formed in the cover in parallel relationship to the side edge of the carrier body, each slot being disposed as the mirror image of the respective U-clamp of the line-up mechanism relative to the longitudinal axis of the back and having at least one resiliently bendable tongue which protrudes into the through-opening of the slot. Thereby a space-saving folder is produced, on the one hand, and the folder is effectively closed, on the other hand, because the folder cannot open by itself even if it is placed upright in a cabinet or suspended in a suspension file system.
The slots may have S-shaped configuration with two tabs protruding from opposite sides into the through-opening, and the width of the slots is approximately equal to twice the diameter of the U-clamps. The cover is thereby effectively locked, while the folder may readily be opened due to the spring-elastic properties.
In a special embodiment of the folder of the invention for paper sheets formed with a row of equidistant perforations along their margins, the carrier body is provided with fixtures at the predetermined spacing of the perforations, said fixtures being either integral with the carrier body or permanently joined thereto, and for receiving and locating the paper sheets there are provided U-shaped clamps of metal or a resilient material adapted to be secured in the fixtures, said U-clamps being formed on one leg thereof with a projection extending towards the other leg thereof. With the folder according to the invention the fixtures are either integral with the carrier body or permanently joined to the same, for instance by welding, riveting, glueing, screwing or tacking, while no complex operations are required therefor. The U-clamps are adapted for easy and quick release and renewed securing when papers are to be either removed or inserted.
In one embodiment of the folder of the instant invention the height of the U-clamps is approximately equal to the diameter of the circular arc portions, and the distance between the two legs is an odd multiple of the uniform spacing intermediate the perforation holes. Thereby the folder according to the invention is particularly suitable for EDP paper the marginal feed holes of which are utilized for securing and turning of the paper sheets.
In a special embodiment the fixtures include a first and a second open-topped recess with a transversely disposed lateral opening, the recesses being bores or blind holes optionally provided with countersunk portions in the inlet region. Thereby insertion of the U-clamps into the fixtures is aided and facilitated and a quickly releasable connection is provided.
In this connection it may be advantageous when the second recess formed in the fixture includes a vertical slot merging in the lower portion thereof into a horizontal slot, which is in part covered by the top side of the fixture while an opening is left clear. Such a folder with fixtures may be made by injection moulding in a single operation and ensures the required releasable mounting of the U-clamps.
It has been found suitable that the fixtures are formed with sliding faces extending via a retaining lug from the vertical slot into the clear opening. Thereby an effective locking of the U-clamps to the fixture is made possible.
Generally, the fixtures of the folder according to the invention are provided with locking elements which secure the respective U-clamp in its locked position against withdrawal from the recesses, whereby inadvertent dropping-out of the papers is prevented.
DESCRIPTION OF THE DRAWINGS
Additional features and advantages of the invention will become apparent from the following description of embodiments thereof with reference to the accompanying drawings, in which
FIG. 1 is a diagrammatic plan view of a first embodiment of the folder according to the invention in open condition;
FIG. 2 is a diagrammatic partial plan view of another embodiment of the folder in open condition;
FIG. 3 is a partial side view of the folder shown in FIG. 2 as seen from the right;
FIG. 4 is a diagrammatic partial plan view showing a further embodiment of the folder;
FIG. 5 is a partial side view of the folder shown in FIG. 4 as seen from the right;
FIG. 6 is a diagrammatic side view of the folder according to the invention;
FIG. 7 is a diagrammatic plan view of the folder shown in FIG. 6;
FIG. 8 is a diagrammatic plan view of the back of the folder shown in FIG. 6;
FIG. 9 and
FIG. 10 are diagrammatic sectional views of the folder shown in FIG. 8 along the line IX--IX;
FIG. 11 is a diagrammatic perspective view of the folder including a fixture into which a U-clamp is being inserted;
FIG. 12 is a diagrammatic perspective view in which a stack of paper sheets together with the U-clamp is being inserted into the fixture;
FIG. 13 is a diagrammatic perspective view of the next-following stage, in which the U-clamp is already inserted in the fixture and is just being secured therein;
FIG. 14 is a diagrammatic perspective view, in which the U-clamp is locked in the fixture and one of the legs of the U-clamp locates a stack of paper sheets;
FIG. 15 is a diagrammatic perspective view of the folder filled with paper sheets and being in its closed state;
FIG. 16 is a diagrammatic plan view showing a fixture with its open-topped recesses;
FIG. 17 is a diagrammatic sectional side view of the fixture along the line XVII--XVII of FIG. 16;
FIG. 18 is a diagrammatic sectional side view of the fixture along the line XVIII--XVIII in FIG. 16;
FIG. 19 is a diagrammatic side view of a U-clamp for the folder according to the invention;
FIG. 20 is a diagrammatic perspective view of a further embodiment of a fixture and U-clamp for the folder according to the invention prior to assembly;
FIG. 21 is a diagrammatic perspective view of the fixture and U-clamp according to FIG. 20 in assembled state;
FIG. 22 is a sectional view through the fixture and U-clamp in the assembled state of the arrangement shown in FIG. 21; and
FIG. 23 is a sectional view similar to FIG. 22 showing the arrangement according to FIG. 21 from the opposite side.
FIG. 1 is a diagrammatic plan view showing the folder in the open state, the various parts being indicated only schematically. As will be apparent, a carrier body 20 consists substantially of three approximately rectangular portions, i.e., a bottom 21, a back 22, and a cover 23 disposed symmetrically to a longitudinal axis 29, the bottom 21, the back 22 and the cover 23 being interconnected by means of permanently foldable creases 26 and 27, respectively. The carrier body 20 may be made of metal, of plastics-reinforced paper or only of plastics material, the latter being preferred. The bottom 21 of the carrier body 20 is used for mounting a line-up mechanism of a commercially available type provided with U-clamps. Such line-up mechanisms are normally provided with U-clamps and are secured to the bottom 21, for instance, by means of rivets. In an illustrated embodiment shown in FIG. 1, the bottom 21 of the carrier body 20 is provided with two fixtures 40 which may be made of metal or plastics and are either integral with the carrier body 20 or permanently joined thereto, e.g. by injection-moulding or moulding or, respectively, by welding, riveting, glueing, tacking or the like. Appropriately, the fixtures 40 may also be made of the same material as the carrier body 20 itself. On the one hand, the fixtures 40 are disposed closely adjacent the side edges 25 of the carrier body 20 or the bottom 21, and on the other hand their end edges 51 are disposed in the immediate vicinity of the opposite crease 26 at the transition to the back 22. Each fixture 40 is provided with a U-clamp 70, the legs 71 of which are schematically indicated in FIG. 1. A respective one of the legs 71 of said U-clamps 70 is used for receiving and locating a stack of paper sheets 30 schematically indicated in the lower part of FIG. 1.
These paper sheets 30 may be of rectangular configuration and are provided with perforations 31 near their side edges, said perforations being disposed on a straight connecting line 32 and having the function of feeding and locating the paper sheets 30 in an electronic data processing system (EDP system). The paper sheets 30 extend, on the one hand, right near the lower edge 24 of the bottom 21 and, on the other hand, approximately to the middle of the two fixtures 40, where they may be releasably located by means of the U-clamps 70. The width of the paper sheets 30 is indicated at B5, the spacing between the two rows 32 of perforations 31 is indicated at B6, and the equal spacing between two adjacent perforated holes 31 is indicated at L. The height of the paper sheets 30 is indicated at H5. In one embodiment it is possible, for instance, to use the following dimensions: B5=305 mm, B6=232 mm, H5=9" or 228.6 mm, and L=0.5" or 12.7 mm.
As will be apparent from FIG. 1, the fixtures 40 with their U-clamps 70 or, respectively, the legs 71 are secured to the carrier body 20 at the predetermined spacing B6 and along the lines of the two rows 32 of perforations 31. In this way the U-clamps 70 have the function of accommodating and locating the paper sheets 30, which may be folded about their upper edge, the sheets being accommodated by the respectively opposite legs of the U-clamps.
FIG. 1 furthermore shows lugs 28 on either side of the side edges 25 in the region of the bottom 21, the back 22 and the cover 23. These lugs 28 should be provided at least in the region of bottom 21 and cover 23 so as to form integral support means intended for placing the folder in a commercially available suspension file system. It is also possible to provide recesses or cut-outs 36a, 36b in the region of the back 22 in order to save material and possibly to facilitate handling of the folder. The spacing of the laterally projecting lugs 28 relative to the side edges 25 is indicated at B4, so that the folder or the carrier body 20 has a greater overall width B7 in this region. The lugs 28 have a straight side edge 127 extending in parallel to the side edges 25 and adjoin the latter via a respective shoulder 37 so that the stepped lugs 28 result. Either additionally or alternatively, the back 22 may also be formed with a possibly circular cut-out 36 functioning as a handling hole to facilitate handling of the folder.
As will be apparent from FIG. 1, the wider regions of bottom 21, back 22 and cover 23 are respectively equal-sized and of symmetrical configuration on either side, so that the step-like, substantially rectangular lugs 28 result. Appropriately, the side edges 127 may gradually merge into chamfered side edges 127a, which extend from the junctions between the creases 26, 27 and the straight outer edges 127 of the lugs 28 at an inclination towards the outer corner points P from the bottom 21 and the cover 23, respectively. Thereby the carrier body achieves an attractive exterior, and the slightly chamfered side edges 127a improve the stability of the folder when the latter is placed in upright position in a piece of furniture. The shoulders 37 also may be slightly chamfered or may include a right angle with the side edges 25.
With the embodiment illustrated in FIG. 1, the shoulders 37 of the stepped lugs 28 are disposed approximately at the level of the centre of the fixtures 40 or their U-clamps 70, respectively. This has been found advantageous for placing such a folder in a suspension file system, wherein it will rest with its lugs 37 on the parallel suspension rails of the suspension file system.
In the embodiments shown in FIGS. 2 to 5 the carrier body 20 is provided with reinforcements or supports for the lugs, which in this embodiment are referenced 124. Bottom 21, back 22 and cover 23 are flat members and are interconnected through permanently foldable creases 128 and 129. The bottom 21 has a region 126 intermediate the crease 129 and a dashed line 126a which is used to accommodate and secure a line-up mechanism (not shown) of a commercially available type.
To improve the carrying capacity of the folder or carrier body 20, the region 126 adjoining the back 22 is provided with lateral support members 130 formed integrally with the bottom 21 and projecting transversely, substantially perpendicularly to the bottom 21. When the folder is closed, these support members 130 extend in the direction of the cover 23 and are designed as flat webs or prisms which in the closed condition of the folder extend in substantially parallel relationship to the back 22.
In this embodiment the outer edges 127 of the lugs 124 also may be formed with chamfered side edges 127a which extend, as described above, towards the corner points of either the bottom 21 or the cover 23. In the illustrated embodiment, the support members 130 extend from the outer edge 127 or 127a of the wider portion of the lugs 124, respectively, beyond the side edges 125 of the bottom 21 into the interior region; they may be formed with a slight taper both in the direction of the outer edge 127 or 127a and in the direction of their upper edge. This taper towards the outer edge 127 or 127a is schematically indicated in FIG. 2. To improve the stability, the support members may be provided with reinforcements or stiffenings.
In one embodiment the support members 130 widen towards the bottom 21. In addition to this measure, or as an alternative, the support members 130 may be joined to webs 131 and/or 132 which may be disposed at right angles to each other and appropriately extend in parallel to the side edge 125 and the crease 129, respectively. Thus the webs 131 and 132 have a dual function, because on the one hand they contribute to the stability of the support members 130 and thus of the folder in the suspended position thereof, and on the other hand they form bearing portions for a stack of paper sheets (not shown) accommodated by the carrier body in use.
In another embodiment not illustrated here, the lugs 124 in the region of the bottom 21 and/or of the back 22 and/or of the cover 23 may be omitted, and then the support members 130 increasingly or solely accommodate the weight of the folder when the same is suspended in a suspension file system. As will be apparent from FIG. 2, the support members 130 merge with their underside into the wider region of the bottom 21 and thus form a lateral boundary or limit for the respective lug 124, so that a compact and stable arrangement having an attractive appearance is formed.
From the fragmentary side view of FIG. 3 parts of the bottom 21 and of the back 22 adjoining via the crease 129 will be apparent. One support member 130 of the pair of support members 130 projects from the bottom 21 transversely and substantially upright relative to the bottom 21. Furthermore a web 131 will be apparent, which is joined to both the support member 130 and the bottom 21 so that a triangular connection is obtained which results in increased stability.
From the embodiment illustrated in FIGS. 2 and 3 it is further apparent that the support members 130 each have a protrusion 138 near their front edges 137. These protrusions 138 extend substantially in parallel to the side edge 125 of the bottom 21 and constitute extensions of the respective outer edge 127 or 127a of the wider lug 124. These protrusions 138 are hook-shaped and extend approximately at right angles from the legs 135 of the support members 130 so that they improve placement of the folder in a suspension file system and inhibit the folder from falling completely into the cabinet of the suspension file system when the respective compartment is only slightly filled and/or the back 22 has a small width.
A further embodiment of the folder is illustrated in FIGS. 4 and 5, wherein FIG. 4 only shows a fragmentary plan view of the right-hand part. It will be apparent that the support member 130 includes a leg 135 extending substantially in parallel to the back 22 or to the crease 129 and a leg 136 provided at right angles thereto, so that in the end an L-shaped support member 130 results. Appropriately, the leg 136 extends in flush relationship with the side edge 125 of the bottom 21, so that smooth transitions from the support member 130 to the respective adjoining walls will result. In this embodiment, too, a hook-like protrusion 138 is provided near the front edge 137 of the leg 135 or the support member 130, respectively, the function of said protrusion being similar to that already described.
FIG. 5 is a side view from the right of such an embodiment. It will be apparent that the leg 136 forms a wall in continuance of the leg 135. This triangular or angle structure results in a particularly robust and compact configuration of the support members 130 or the folder intended for a suspension file system, said configuration having a high carrying capacity. Although the height of the leg 136 in the embodiment of FIG. 5 is equal to that of the leg 135, the folder is certainly not limited to such a configuration. Rather, the leg 136 may also be of lesser height, or it may have an oblique upper edge as indicated in dashed lines in FIG. 5. The stability of the support member 130 is not impaired thereby. On the opposite side of the carrier body a complementary support will then be provided on the bottom 21 so as to ensure uniform load accommodation.
In practice, it has been found advantageous to manufacture such a folder with its support members 130 and possibly with the reinforcements therefor in the form of webs or legs as a unitary plastics article, for instance as an injection-moulded or a moulded article. It is then possible to manufacture the folder in a simple way in one operation, and the folder will exhibit the desired good carrying capacity and stability for practical use in a shelf or a suspension file system.
Suitable materials for such office supplies are conventional rigid or possibly elastic plastics such as polyethylene, polyvinylchloride, polycarbonate or polyurethane, or especially polypropylene, although the invention is not limited to the aforementioned plastics. The unitary folder of polypropylene may have a structured or grained outer surface. Small wall thicknesses of only about 2 to 3 mm for the bottom 21, the back 22 and the cover 23 will be sufficient, and no large-area stiffenings for the folder itself, such as used in conventional folders, will be required, because a plastic such as polypropylene exhibits the favourable properties of sufficient rigidity and strength in the region of the flat parts, on the one hand, and on the other hand has the desired elasticity in the region of the hinge-forming creases 128 and 129. Therefore the mentioned stiffenings are provided only for the load-absorbing support members 130 but not for stiffening the folder as a whole. Such a material can be readily processed and the grained or structured outer surface thereof is insensitive to scratches in use.
FIG. 6 is a diagrammatic side view of the folder, in which the carrier body is referenced 20. In the illustrated embodiment the bottom 21, the back 22 and the cover 23 are interconnected by means of permanently foldable creases 26 and 27, respectively, and form flat parts or walls to which labels may be applied, if desired. The inside of the carrier body 20 is referenced 218, while the outside thereof is referenced 220.
FIG. 7 is a diagrammatic plan view showing the cover 23 of the carrier body 20, in which a smooth surface 230, which may be of rectangular shape, is distinctly offset relative to the surrounding area 222. The area 222 may be structured, mottled, rough, grained or the like. The outer edge of this area 222 and thus of the cover 23 is referenced 224, the inner edge of the area 222 is defined by a schematically indicated ring or ridge 226.
On such a smooth surface 230 it is possible to apply an exchangeable label, preferably a pressure-sensitive label which may be removed again, if desired. Of course, such smooth surfaces 230 may be provided not only on the cover 23 of the carrier body 20 but also on other parts of the folder, for instance in the region of the bottom 21 or the back 22 on both the outside 220 and the inside 218.
FIG. 8 shows a further embodiment in a partial view of the back 22, on which a smooth surface 232 is symmetrically provided which is surrounded by a structured area 228. Between the smooth surface and the area 228 there is provided a transitional region in the form of an edge, a ring or a ridge 226. Details will be apparent from FIGS. 9 and 10, which are sectional views of the embodiment illustrated in FIG. 8, wherein a label 234 is applied to the smooth surface 232. In FIG. 9, the smooth surface 232 is a shallow depression in the back 22 and adjoins the somewhat higher surrounding area 228 via the schematically indicated edge 226a. FIG. 9 shows that the label 234 is securely placed in the depression of the smooth surface 232; in particular the outer edges of the label 234 are protected against mechanical wear, dog ears and accidental peeling, because the user of the folder will not normally get caught by the label 234 or the label edge.
In the embodiment illustrated in FIG. 10 a ring or ridge 226b is provided which protrudes outwardly with respect to both the smooth surface 232 and the surrounding area 228. The ring or ridge 226b completely surrounds the smooth surface 232, so that the applied label 234 is protected on all sides.
In the embodiments shown in FIGS. 9 and 10 the height of the edge 226a and of the ring or ridge 226b will amount to only a few tenths of a millimetre by which this part protrudes from the smooth surface 232. As schematically indicated in FIGS. 9 and 10, the height of the edge 226a or of the ring 226b will be chosen such that normally it will somewhat exceed the thickness of conventional labels 234, whereby the desirable protection against inadvertent removal is provided.
According to FIG. 10 the ring or ridge 226b may be of semi-circular cross-section, but it may as well have rectangular, triangular or trapezoidal cross-section. In this respect the design is in no way limited, the various areas may also be offset against each other by different colours, if desired.
Appropriately, at least the region of the smooth surfaces 230 and 232, respectively, will be made of metal or plastics. From the viewpoint of manufacturing it has been found advantageous to make the carrier body 20 entirely from plastics material with the respective smooth surfaces 230 or 232 embossed therein; in an injection-moulded or a moulded plastics part they are, for instance, formed as moulded smooth surfaces 230 or 232. It is thus possible to manufacture the carrier body 20 in a single operation without any secondary processing being required to form the smooth surfaces 230 or 232, respectively.
Such an arrangement has already been found highly satisfactory in practical use, since it is possible on the one hand to apply the labels so that they are protected and, on the other hand, outdated labels may readily be replaced and old ones need not be pasted over.
Below, reference will first be made to FIG. 1. It will be apparent that in the arrangement of FIG. 1 a pair of elongated slots 33 is provided as mirror images of the fixture 40 relative to the longitudinal axis 29 of the back 22, said slots being disposed in parallel to the side edge 25 of the carrier body 20 in the cover 23 and having resiliently bendable tabs 34 protruding into the respective through-openings 35 of the slots 33. The slots 33 have S-shaped configuration including two tabs 34 protruding from opposite sides into the through-opening 35, although the folder is not limited to such an arrangement. If desired, a pair of such tabs 34, which are disposed in the respective slots 33 either in facing relationship or in oppositely directed relationship, will also be sufficient.
These slots 33 with their tabs 34 have the function of coming into engagement with the oppositely disposed U-clamps 70 of the fixtures 40 when the folder is closed, whereby the folder is kept closed, on the one hand, and the stack of paper sheets 30 is urged against the bottom 21 and is thereby secured in the folder, on the other hand. Appropriately, the slots have a width which is approximately equal to twice the diameter of the material of the U-clamps 70, the tabs 34 protruding transversely approximately to the middle of the slots 33. It is thereby possible to achieve reliable locating of the cover 23 in the U-clamps 70, while opening of the folder does not pose a problem because the tabs 34 are capable of being resiliently deflected.
In the arrangement shown in FIG. 1 the following reference characters are additionally used: width and height of the bottom 21 are referenced H1 and B1, respectively; the height of the back 22 is referenced H2; height and width of the cover 23 are referenced H3 and B3, respectively.
The mode of operation of the folder according to the invention will be explained in detail with reference to FIGS. 11 to 15, which are diagrammatic perspective fragmentary views illustrating the various stages during which such a folder is filled with paper sheets and closed. FIG. 11 shows portions of such a folder with bottom 21, back 22 and cover 23, a fixture 40 into which a U-clamp 70 is to be inserted being schematically indicated on the bottom 21.
FIG. 12 shows the next stage, in which a stack of paper sheets 30 having perforations 31 has been threaded onto one of the legs of a U-clamp 70. The U-clamp 70 is placed downwardly onto the fixture 40, as indicated by the arrow, so that it will be brought into engagement with the two open-topped recesses 41 and 42 of the fixture 40.
FIG. 13 shows the next stage, in which the stack of paper sheets 30 is already located on the fixture 40 by means of the U-clamp 70. The two legs 71 of the U-clamp 70 have been inserted into the open-topped recesses, and one of the legs is turned about the axis of the other leg so that the projection thereof may be moved beneath a locating projection of the fixture and secured against dropping out.
The next stage is illustrated in FIG. 14, where the stack of paper sheets 30 together with the U-clamp 70 is completely located in position on the fixture 40. One leg 71 extends through the registering perforations of the paper sheets 30, while the other leg 71a is located in position on the opposite side in the fixture 40.
Finally, FIG. 15 illustrates the closed condition of the folder, in which the bottom 21, the back 22 and the cover 23 define a U-shaped arrangement accommodating the stack of paper sheets 30 in the interior thereof. The cover 23 is pressed downwardly, so that the U-clamp 70 extends with its circular arc portion through the slot 33 in the cover 23, whereby the cover is secured against being opened.
As will be apparent from the various figures of the drawing, the U-clamps 70 are of unitary and U-shaped configuration, and the ends of their legs 71 and 71a are releasably joined to the respective fixture 40. Therefore the U-clamps 70 do not have an edge like conventional U-clamp assemblies, in which the top and bottom part of a U-clamp may be opened for the removal of paper sheets. Due to the continuous smooth surface along the length of the U-clamps 70 any damage to the paper sheets 30 is reliably prevented, especially when single paper sheets 30 of a stack are turned over. Appropriately, the U-clamps are made of metal or some other strong material having a certain degree of elasticity, for instance of iron, wherein the surface thereof may optionally be polished or chromium-plated. These U-clamps may be inserted into the fixtures 40 with their legs 71 and 71a so that they are secured against withdrawal and dropping-out. Further details will be apparent from the following description with reference to the FIGS. 16 to 23.
FIG. 16 is a diagrammatic plan view of a fixture 40 having a first recess 41 and a second recess 42, both recesses being open-topped. The recess 42 is a blind hole or vertical hole, a countersunk portion 44 being formed at the top 40a of the fixture 40, as will be apparent from FIGS. 16 to 18. The other recess 41 is formed as a slot and has hook-like configuration when seen in plan view, as will be apparent from FIG. 16. This second recess 41 includes a linear slot portion facing towards the recess 42, and an arcuate portion which extends from the linear portion via a transitional portion into an opening 47, which likewise forms an open-topped opening 47. Intermediate the linear slot portion of the recess 41 and the opening 47 there is provided a retaining lug 46 having a sliding face 45 somewhat outwardly offset relative to the opening 47. In its lower portion the vertical slot 41 merges into a horizontal slot 43, which is in part covered by the top 40a of the fixture 40, while the opening 47 is left clear. As viewed in cross-section, the retaining lug 46 therefore produces an L-shaped connection between the vertical slot 41 and the horizontal slot 43.
The FIGS. 17 and 18 are diagrammatic sectional side views through the fixture including the two recesses 41 and 42. It will be apparent that the U-clamp 70, which is shown in detail in FIG. 19, may be inserted with its leg 71 into the recess 42 and with its other leg 71a including the projection 73 into the recess 41 in the manner shown in the sectional view of FIG. 17. Thereupon the U-clamp 70 is turned about the axis of its leg 71 while it slides along the sliding face 45 of the recess 41 or the retaining projection 46, respectively, and is elastically deflected outwardly. Then, the elastic U-clamp snaps back with its leg 71a to latch in the opening 47 behind the retaining projection, so that the projection 73 of the U-clamp 70 will then be seated in the slot 43 beneath the retaining projection 46 to be thereby retained against withdrawal and dropping-out.
It is therefore possible in a simple way to locate the U-clamp 70 in the fixture and to release it from its locked position, because nothing but a plugging motion with a subsequent turning motion, or vice versa, is required to close or open the U-clamp assembly. Appropriately, the upper edge of the slot 41 is also provided with a countersunk portion or chamfer 44, as will be apparent from the drawing. The retaining lug 46 with its sliding face 45 forms a kind of snap mounting for the U-clamp.
As will be apparent from FIG. 19, each U-clamp 70 comprises two substantially parallel legs 71 and 71a joined to each other through a circular arc portion 72. The height of each U-clamp 70 is approximately equal to the diameter D of the circular arc portion 72. The distance A between the two legs 71 and 71a suitably is an odd multiple of the uniform spacings L between the perforation holes 31. This distance A between the two legs 71 and 71a also determines the approximate height of the stack of paper sheets 30 that may be accommodated in the folder without any difficulties during turning-over of the sheets and without any damage to the creases in case a concertina-type paper stack is concerned.
Each U-clamp 70 is made of a strong material having elastic properties, for instance of iron, the one leg 71a of the U-clamp 70 having L-configuration at the end thereof and including a projection 73 which merges via a rounded portion 73a into the leg 71a.
Another embodiment of fixture 40 and U-clamp 70 is illustrated in the FIGS. 20 to 23. The perspective view of FIG. 20 shows a fixture 40 including a hole 52 and an elongated slot 53, which form the open-topped recesses. Furthermore, a transverse hole 54, which optionally is a through-hole, is formed at least in the region of the slot 53, said transverse hole 54 extending in spaced relationship above the bottom 59 of the slot 53. For the sake of clarity, the bottom of the slot 53 is shown to be identical with the bottom of the fixture 40. The upper end of this slot is then formed by the upper side of the bottom 21 of the carrier body 20 on which the fixture 40 is either mounted or integrally formed therewith. The spacing 60 of the transverse hole 54 above the bottom of the slot 53 is at least equal to the diameter of the material of the U-clamp 70 or its projection 73, respectively, so that the U-clamp 70 inserted in the fixture 40 may be secured.
The hole 52 and the remote outer edge 61 of the slot 53 in the fixture 40 have a spacing from each other which is at least equal to the distance A between the legs of the U-clamp 70, so that the U-clamp 70 may be inserted from above in a simple manner. For securing purposes a pin 56 is provided, which has a broad head 57 while the opposite end forms a pointed end 58. The pin is made of a strong, possibly flexible, elastic material having such a diameter as to be detachably insertable into the fixture above the projection 73 of the U-clamp 70.
Only one transverse hole 54 is required for insertion of said pin. In the manner shown, however, it is also possible to provide two such transverse holes 54 and 55 in spaced relationship, so that one transverse hole 55 always serves to accommodate the pin 56, whereas the opposite, pointed end 58 thereof is withdrawn, if required, out of the other transverse hole 54 in order to permit insertion or removal of a U-clamp 70. In this way the pin 56 cannot be lost in use, because it is always held captive in the fixture 40. Alternatively, such a pin 56 may also be permanently joined to the fixture 40 or may be integrally formed therewith, so that the pin 56 will always be available.
The FIGS. 21 to 23 show the assembled state of fixture 40 and U-clamp 70 in different views. It will be apparent that the pin 56 is inserted through the one transverse hole 55 so that the head 57 abuts the side edge of the fixture 40. The pin 56 is then drawn out in an arc and inserted through the other transverse hole 54, wherein it extends over the projection 73 of the leg 71a of the U-clamp and thus locks the U-clamp 70 in the fixture 40.
The slot 53 need not necessarily be disposed in register with the perforation holes 31 of the paper sheets; what is important merely is that its outer edge 61 is disposed along the line of the row 32 of perforation holes 31. The projection 73 and the slot 53 together may have any desired orientation, wherein the transverse hole 54 has to be aligned correspondingly so that the pin 56 may extend over the projection 73 to thereby secure the U-clamp 70.
It should be noted that the fixtures 40 may also be formed with a plurality of relatively spaced aligned recesses 42 in the form of open-topped holes so that U-clamps 70 with different spacings between the legs 71, 71a may be accommodated if the U-clamps 70 are to be exchanged or the fixtures 40 are to be used for different types of folders. It should merely be observed that the spacing of the recesses 42 from the opposite recess 41 or the outer edge 61 of a slot 53, respectively, is an odd multiple of the equal spacings of the perforation holes, i.e., said spacing should have the values of L, 3L, 5L, . . . . In accordance with the usual inch-system dimensions of paper sheets used in EDP systems, these spacings between the two recesses in the fixture 40 and the equal-size spacings between the legs 71 and 71a of the U-clamps 70 will be chosen to be either 38.1 mm or 64.5 mm; this corresponds to a spacing L of the perforation holes of 1/2", which is commonly used.
It should be added in respect of the diagrammatic view of FIG. 1 that the fixtures 40 ought to be disposed with their one end face 51 either in the direct vicinity of, or slightly spaced from, the opposite permanently foldable crease 26 so as to achieve a highly compact arrangement. The spacing H7 between this crease 26 and the end face 51 may be about one centimetre. The height H2 of the back 22 is selected to be about equal to the (free) height of the U-clamps 70, i.e., approximately equal to the diameter D of the circular arc portion 72 of the respective U-clamp 70. It is thereby readily possible to close the carrier body 20 to U-shape, so that the U-clamps 70 with their circular arc portions 72 can extend through the slots 33 in the cover 23.
The U-clamps 70 themselves have circular cross-section with a diameter of 1 to 3 mm, preferably about 2 mm, so that the stacks of paper sheets may readily be placed thereon with their perforation holes. The thickness of the material for the carrier body 20 may be selected in a suitable manner and will be about 2 mm in case of a particularly advantageous material such as polypropylene, so that both the required strength and the desired elasticity are provided in the region of the slots 33 and the tabs 34, respectively. Appropriately, these slots 33 are provided at locations which are opposite to the U-clamps 70 and in the same numbers as the U-clamps, wherein it is merely necessary to provide one or two slots 33 with the flexible tabs 34.
When EDP continuous stock of 305 mm×9" (=228.6 mm) is used, a carrier body 20 will be used whose bottom 21 and cover 23 each have a width B1 and B3, respectively, of 320 to 330 mm and a height H1 and H3, respectively, of 250 to 270 mm. The centre of the U-clamps 70 may have a spacing of about 230 mm from the bottom edge 24 of the carrier body 20, so that the paper stack will not protrude from the bottom edge 24. The shoulders 37 of the lugs 28 may be disposed approximately at the level of the centre of the U-clamps 70, as will be apparent from FIG. 1. The distance of the shoulders 37 of the lugs 28 from the next-adjacent crease 26 or 27, respectively, is referenced H6 and amounts to approximately 30 to 40 mm. This will result in the required strength of the arrangement when the folder filled with paper sheets 30 is placed in a suspension file system with these lugs 28 serving as support means. It will be sufficient when the lugs 28 protrude laterally beyond the side edges 25 of the carrier body 20 by a width B4, which is about 10 mm.
With a folder of the kind described above it will be advantageous to fill the U-clamps 70 with paper sheets up to half the height of the U-clamps, because in that case easy closing of the folders by depressing the cover 23 will be ensured. Of course, it will also be possible with a folder of the kind described above to provide an additional clamping strip formed with openings in the region of the two U-clamps 70; said clamping strip may be run onto the U-clamps 70 prior to threading a stack of paper sheets 30 thereon, whereby securing of a stack of paper sheets during storage is aided. However, such a clamping strip is by no means necessary.
Such and further changes and modifications of the explained embodiments which are recognizable to those skilled in the art upon study of the above papers shall also be covered by the present invention as long as they can be subsumed under the subject-matter of the following patent claims and/or the equivalents thereof.
I claim:
1. A folder for paper sheets or the like, comprising a carrier body (20), said body including a bottom (21) and a back (22) and a cover (23) having adjoining portions joined to each other by means including permanently foldable creases (26,27), said bottom (21) having a line-up means for aligning the paper sheets, characterized in that at least the adjoining portions of said bottom (21) and of said cover (23) adjoining said back (22) have a width (B7) in excess of the width of the remaining portions (B1,B3) of said bottom (21) and of said cover (23), and that said adjoining portions having said width define a substantially rectangular configuration and defining symmetrical lugs (28) of equal size on either side of said back (22), said lugs being integrally formed with the carrier body (20) and defining a stepped configuration.
2. A folder as claimed in claim 1, characterized in that the lugs (28) formed at said bottom (21) and said cover (23) have chamfered side edges (127a) which extend from the junctions between the creases (26, 27) and the outer edges (127) of the lugs (28) at an inclination directed towards the outer corner points (P) of the bottom (21) and cover (23), respectively.
3. A folder as claimed in claim 1 characterized in that in a portion (126) of said cover (31) adjoining the back (22) includes lateral support means (130), said lateral support means (130) being integral with the bottom (21) and projecting transversely in the direction of the cover (23) and substantially perpendicularly outwardly of the bottom (21).
4. A folder as claimed in claim 3, characterized in that said lateral support means (130) include flat webs projecting from said bottom, each of said flat webs includes a leg (135) extending substantially parallel to the back (22) with said back folded on said foldable creases (26, 27), and each of said legs includes a stiffening portion which is preferably broadened towards the bottom (21).
5. A folder as claimed in claim 3 characterized in webs (131, 132) generally L-shaped with web portions substantially at right angles, and said web portions (131, 132) extend in parallel relationship to the side edge (125) and to the foldable crease (129), respectively.
6. A folder as claimed in claim 3 wherein said support means (130) is substantially L-shaped and includes a member which merges at the underside thereof into the wider portion of the bottom (21) to limit the same laterally, and support legs (136) which extend in parallel relationship to and are flush with the side edges (125) of the bottom (21).
7. A folder as claimed in claim 3 characterized in that the support means (130) are provided with a hook-shaped protrusion (138) at the outer front edge (137) thereof.
8. A folder as claimed in claim 3 wherein said cover and back and bottom including said lugs and support means is an integral moulded article of plastics material, selected from plastic materials selected from the group consisting of polyethylene, polyvinylchloride, polycarbonate, polyurethane and preferably polypropylene, said cover and back and bottom preferably having a wall thickness of 2 to 3 mm, and having a grained or structured outer surface.
9. A folder as claimed in claim 1 wherein at least one of said bottom (21) and back (22) and cover (23) includes at least one region formed as a smooth surface (230, 232) adapted to releasably receive a label member (234).
10. A folder as claimed in claim 9, characterized in that each said smooth surface (230, 232) is a shallow depression said smooth surface (230, 232) is offset relative to the surrounding areas (222, 228) of the body (21, 22, 23) by a ridge (226, 226a,226b).
11. A folder as claimed in claim 10, characterized in that the ridge (226, 226a, 226b) completely surrounds said surface, and each said ridge (226a, 226b) is of flat design and forms a slight elevation of a few tenths of a millimetre relative to the smooth surface (230, 232).
12. A folder as claimed in claim 9, chracterized in that each smooth surface (230, 232) is integrally formed with the carrier body (20), and the surrounding body is embossed.
13. A folder as claimed in claim 1, wherein said line-up means includes a U-clamp at each side of the bottom, an elongated slot (33) is formed in each side of the cover (23) in parallel relationship to each side edge (25) of the carrier body (20), each said slot defining a through-opening aligned with one of said U-clamps and being disposed as the mirror image of the U-clamp (70) relative to the longitudinal axis (29) of the back (22) and having at least one resiliently bendable tab (34) which protrudes into said through-opening (35) of the slot (33).
14. A folder as claimed in claim 13, characterized in that the slot has an S-shaped configuration with two tabs (34) protruding from opposite sides into the through-opening (35), and said slot (33) having a width approximately equal to twice the thickness of the U-clamps (70), said tabs (34) protruding transversely to about the middle of the slots (33).
15. A folder as claimed in claim 1, for EPD paper sheets formed with a row of equi-distance perforations (31) along their margins, characterized in that fixtures (40) are secured to said body in accordance with predetermined spacing corresponding to the spacing of the perforations (31) and form a permanent part of said folder, U-shaped clamps for receiving and locating of the paper sheets (30), said U-shaped clamps being resilient and (70) adapted to be secured in the fixtures (40) and defining said aligning means, said U-shaped clamps having one leg (71a) with a projection (73) extending towards the other leg (71) and mating with said slot.
16. A folder as claimed in claim 15, characterized in that said U-clamps (70) have a height approximately equal to the diameter (D) of the circular arc portion (72) of the clamp, and the two legs (71, 71a) are spaced by a distance (A) equal to an odd multiple of the uniform spacing (L) intermediate the perforation holes (31).
17. A folder as claimed in claim 15, characterized in that each fixture (40) is formed with a first open-topped recess (42) and a second open-topped recess (41) with a transversely disposed lateral opening (43), the recesses being blind holes.
18. A folder as claimed in claim 17, characterized in that said second open-topped recess (41) is formed in the fixture (40) including a vertical slot (41) merging in the lower portion thereof into said lateral opening (43), said lateral opening (43) having a portion thereof in a top portion of the fixture (40) and having an unrestricted opening (47).
19. A folder as claimed in claim 18, characterized in that the fixtures (40) includes sliding faces (45) extending from a retaining lug (46) between recess (41) and the unrestricted opening (47).
20. A folder as claimed in claim 15, characterized in that the fixtures (40) are provided with locating elements for locking the respective U-clamps (70) in its engaged position against withdrawal from the recesses (41, 42).
| 1984-11-13 | en | 1986-07-15 |
US-70362085-A | Jig apparatus for arraying and supporting works to be soldered
ABSTRACT
A jig apparatus for arraying and supporting work to be soldered wherein a plurality of lower supporting bars for supporting the lower side of a work are arranged so as to extend in a frame designed to be mounted on a conveyor holder of an automatic soldering line, upper supporting bars are arranged so as to extend above and in parallel with the lower supporting bars to press the work from the upper side thereof. The upper supporting bars have one end fitted to the frame. A gate member supports the other end of the upper supporting bars and movable up and down with respect to the frame. Work insertion openings are formed in the frame such as to oppose the gate member. The lower supporting bars are made of elongated channel members with a substantially U-shaped cross-section, each of the elongated channel members having holes formed in the floor thereof.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a jig apparatus for use in application of a solder coat to the lead frames of works such as ICs to be soldered. More particularly, the invention is concerned with a jig apparatus adapted to be mounted on a conveyor line of an automatic soldering line, while arraying and supporting the work.
2. Description of the Prior Art:
As disclosed in Japanese Patent Publication No. 57269/1983, the conventional jig of the kind described is constituted by frames adapted to be retained by the conveyor holder of the soldering line, a plurality of pairs of lower steel wires stretched between adjacent frames and adapted to support the lower part of the work, a plurality of pairs of upper steel wires extended above said lower steel wires along both side surfaces of the body of the work, the upper steel wires being secured at their one end to said frames, gate members supporting the other end of said upper steel wires and movable up and down with respect to the frames, and work insertion openings formed in the frames such as to oppose the gate members. In use, the work such as ICs is inserted through the insertion openings onto two lower steel wires past the space under the gate members in the raised position, and the gate members are lowered so that the work is pressed and held by two upper steel wires.
In this known jig apparatus, the upper steel wires of each pair can be reinforced by an intermediate supporting bar which connects the intermediate regions of these steel wires, thus preventing any deformation of the steel wires. In the case of the lower steel wires, however, it is impossible to reinforce these steel wires by a member such as the intermediate bar connecting mid portions of the wires of each pair, because of a fear that a part such as the lead frame of the IC may interfere with the intermediate supporting bar during the sliding of the IC along the lower steel wires to the innermost position. It is, therefore, quite difficult to maintain the parallelism and linearity of two lower steel wires of all pairs. Lack of linearity of the lower steel wires tend to cause problems such as dropping the ICs.
SUMMARY OF THE INVENTION
An object of the invention is to provide a jig apparatus having lower supporting bars which have a special shape so as to maintain the linearity thereof.
To this end, according to the invention, there is provided a jig apparatus having lower supporting bars and upper supporting bars adapted for arraying and supporting a multiplicity of work units such as integrated circuits, the jig apparatus being adapted to be mounted on a conveyor holder of an automatic soldering line, wherein the improvement comprises that at least the lower supporting bars are made of elongated channel members with a substantially U-shaped cross-section, each of the elongated channel members having holes formed in the floor thereof.
The basic arrangement of the jig apparatus as a whole has, as in the case of a conventional jig apparatus, a frame designed to be mounted on a conveyor holder of the automatic soldering line, a plurality of lower supporting bars extended in the frame and adapted to support the lower side of the works, upper supporting bars extended above and in parallel with the lower supporting bars such as to press the works from the upper side thereof, the upper supporting bars having one end fitted to the frame, gate members supporting the other end of the upper supporting bars and movable up and down with respect to the frame, and work insertion openings formed in the frame such as to oppose the gate members.
According to the invention, after raising the gate member, work units to be soldered are successively brought into the space between the lower supporting bars and the upper supporting bars through the insertion opening. Then, the gate member is lowered so that the insertion opening is closed and the work is clamped between the upper and lower supporting bars. Since the lower supporting bars are channel members having a substantially U-shaped cross-section, they are rigid and resist deformation both in the lateral and the vertical directions so as to maintain good linearity. The lower supporting bars, therefore, can stably hold a number of work units along the length thereof. The work is, for example, integrated circuits having lead frames. The lead frames are dipped in the molten solder together with the lower supporting bars and soldering is conducted on the lead frames.
The invention will be fully described hereinunder with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an embodiment of the jig apparatus in accordance with the invention in the state mounted on a conveyor holder;
FIG. 2 is a sectional view taken along the line II--II of FIG. 1;
FIG. 3 is a sectional view taken along the line III--III of FIG. 2;
FIGS. 4a and 4b are enlarged sectional views of insertion openings;
FIG. 5 is an enlarged perspective view showing the state in which an IC is supported; and
FIG. 6 is an illustration of the soldering work conducted with the assist by the jig apparatus of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 to 3, a jig apparatus 2 for arraying and supporting work to be soldered is put into a conveyor holder 1 and fixed in the same from the upper side. The jig apparatus 2 has a frame 5 made of titanium and provided with a pair of handles 3. The frame 5 is adapted to be retained by supporting portions 4 on both sides of the conveyor holder 1. The jig apparatus further has a plurality of lower supporting bars 7 made of titanium and welded to the lower portion of the frame 5 at a predetermined pitch. The lower supporting bars 7 are adapted to support the lower side of works to be soldered which are in this case integrated circuits (referred to as "IC", hereinunder) 6, in a manner shown in FIG. 5. The jig apparatus further has pairs of upper bars 8 having a circular cross-section and made of titanium. The upper bars 8 constitute upper supporting bars. The upper supporting bars extend above and in parallel with the lower supporting bars 7 such as to retain the ICs from the upper side thereof and are loosely received at one end by the frame 5. The jig apparatus also has a gate member 9 fixed to the other ends of the upper supporting bars 8 and movable up and down with respect to the frame 5. An IC insertion opening 10 is formed in the frame 5 such as to oppose the gate member 9.
As will be seen from FIG. 5, each of the lower supporting bars 7 is an elongated channel member having a substantially U-shaped cross-section with both vertical walls 11 adapted to support the lower face of the IC 6. The floor of the lower supporting bar 7 is provided with holes 12 formed therein at a predetermined pitch. These holes 12 serve as drain holes through which water in the bar 7 is discharged at the time of washing.
The upper bars 8 are held at their mid regions by being fitted in lower grooves 14 formed in intermediate supporting bars 13 so that two upper bars 8 of respective pairs are held linearly and in parallel with each other. The intermediate supporting bars 13 have both ends received by elongated grooves 16 in guide members 15 which are fastened to the inner surfaces of the frame 5 by screws, such as to be moved up and down along the elongated grooves 16.
As shown in FIG. 4a, lever-like stoppers 18 are rotatably secured to the portions of the frame 5 opposing both end surfaces of the gate member 9, by shafts 17, such that the lower ends of the stoppers 18 oppose both ends of the gate member 9.
Then, as shown in FIG. 4b, the stoppers 18 are rotated with the ICs 6 sandwiched between the lower supporting bars 7 and the upper bars 8. In consequence, the gate member 9 is pressed by the lower ends of the stoppers 18 onto the insertion opening 10 and the lower supporting bars 7, thereby locking the gate member 9. For taking out the ICs 6, the stoppers 18 are rotated to the position shown in FIG. 4a thus unlocking the gate member 9.
As shown in FIGS. 1 and 2, the conveyor holder 1 is provided with four wheels 21 and an engaging plate 22 on one side thereof. The wheels 21 are adapted to roll on both rails 23 while the engaging plate 22 is engaged by a conveyor pin 25 on the conveyor chain 24, so that the holder 1 runs along the rails 23 by being toward by pins 25 on the chain 24.
An explanation will be made as to the manner in which the ICs are inserted into the jig apparatus.
When the empty jig apparatus 2 is set on a seesaw type IC shifting device (not shown), the gate members 9 are pushed by pushing pins 31 as shown in FIG. 4a thus opening respective insertion openings 10. In this state, it is possible to insert a multiplicity of ICs 6 into the space between the lower supporting bars 7 and the upper bars 8 through the insertion openings 10 from IC tubes or IC magazines (not shown) connected to the insertion openings. During the insertion, the ICs 6 are moved by the force of gravity as the jig apparatus 2 and the IC magazines are inclined as a unit with each other.
After the insertion of a multiplicity of ICs 6 in the jig apparatus, the jig apparatus is lifted away from the IC shifting device, so that the gate member 9 is disengaged from the pin 31 and lowered so that the upper bars 8 of respective pairs press upper portions of both side surfaces of the bodies of ICs 6. Then, the gate member 9 is locked by the stoppers 18 as shown in FIG. 4b, thus securely holding ICs 6.
The jig apparatus 2 thus loaded with the ICs 6 is mounted on the conveyor holder 1 of a soldering line, so that the ICs are conveyed along the soldering line by the conveyor holder 1. During the conveying, lead frames 32 of the ICs are applied with flux and pre-heated. Then, as shown in FIG. 6, the ICs 6 are made to pass through molten solder 38 jetted from nozzles 37 in a solder cell 36 of jet-flow type, so that the solder is applied such as to form solder coats on the lead frames 32. Then, residual flux is washed away by warm and cold water. The water used in the washing tends to stay in the channel-shaped lower supporting bars 7. The water, however, can be effectively discharged through the holes 12 formed in the bottom wall of the lower supporting bars 7.
ADVANTAGES OF THE INVENTION
According to the invention, the lower supporting bars for supporting the work to be soldered are made of elongated channel members having a substantially U-shaped cross-section, so that the distortion is prevented and high linearity of the lower supporting members is ensured over the entire length thereof, thus eliminating the problem of the work falling through the gap between the upper and lower supporting bars. Also, the undesirable retention of washing water in the channel-shaped lower supporting bars is avoided due to the provision of holes in the bottom wall of each lower supporting bar.
What is claimed is:
1. In a jig apparatus for arraying and supporting work to be soldered, comprising: a frame designed to be mounted on a conveyor holder of an automatic soldering line; a plurality of lower supporting bars extended in said frame and adapted to support the lower side of said work; upper supporting bars extended above and in parallel with said lower supporting bars such as to press said work from the upper side thereof, said upper supporting bars having one end fitted to said frame; a gate member supporting the other end of said upper supporting bars and movable up and down with respect to said frame; and work insertion openings formed in said frame such as to oppose said gate member; the improvement characterized in that the lower supporting bars are made of elongated channel members with a substantially U-shaped cross-section, each of said elongated channel members having holes formed in the floor thereof.
2. The jig apparatus according to claim 1, wherein the lower surface of said each work is supported by both vertical side walls of said lower supporting bar.
3. The jig apparatus according to claim 1, wherein said holes formed in the floor of said lower supporting bar are used for discharging washing water from the lower supporting bar.
| 1985-02-21 | en | 1986-04-08 |
US-29632194-A | Control device for folding and expanding a base portion of a playpen
ABSTRACT
A control device for folding and expanding a base portion of a playpen includes four block members each fixed on a base portion which is mounted on a mediate portion of the playpen and each pivotally engaged with one of four drive posts each of which is mounted on one of the four corners of the playpen, four fastener members each mounted on a mediate portion of one of the drive posts, two transmission assemblies each including a bracket member mounted in a mediate portion thereof, a pair of linking rods each having a first end pivotally engaged with one of the fastener members on associated drive post and having a second end pivotally engaged with the bracket member.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a control device, and more particularly to a control device for folding and expanding a base portion of a playpen.
2. Related Prior Art
A conventional control device for folding and expanding a base portion of a playpen is complex in structure and it is not easy to perform the operation of folding and expanding the playpen.
The present invention has arisen to mitigate and/or obviate the above-mentioned disadvantages of the conventional playpen.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a control device for folding and expanding a base portion of a playpen which comprises four vertical stands respectively mounted on four corners thereof and a base portion mounted on an underside thereof, four drive posts each having a first end connecting to a lower end of one of the four vertical stands and having a second end connecting to the base portion, and a flexible casing enclosed around a peripheral portion of the playpen and having an underside engaged with the base portion, the control device comprising four block members each fixed on the base portion and pivotally engaged with the second end of one of the drive posts, four fastener members each mounted on a mediate portion of one of the drive posts, two transmission assemblies each mounted between two of the four drive posts and opposite to each other, each of the transmission assemblies comprising a bracket member mounted in a mediate portion thereof, a pair of linking rods each having a first end pivotally engaged with one of the fastener members on associated drive post and having a second end pivotally engaged with the bracket member.
Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a playpen in accordance with the present invention;
FIG. 2 is top plan view as shown in FIG. 1 showing the playpen in an expanded status;
FIG. 3 is a partially cross-sectional perspective view showing how a block member engages with a drive post and a base portion;
FIG. 4 is an exploded perspective view showing how a fastener member engages with a drive post and a linking rod;
FIG. 5 is a perspective view showing how a bracket member engages with a pair of linking rods;
FIG. 6 is an enlarged top plan view showing the playpen in a folded status; and
FIG. 7 is front plan view showing the playpen in a folded status.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and initially to FIGS. 1 and 2, a control device in accordance with the present invention is provided for folding and expanding a base portion of a playpen which comprises four vertical stands 93 respectively mounted on four corners thereof and a base portion 20 mounted on a mediate portion of an underside thereof, four drive posts 10 each having a first end pivotally connected to a lower end of one of the four vertical stands 93 and having a second end pivotally engaged to a top plate 201 of the base portion 20 by a block member 21, and a flexible casing 90 (shown in phantom lines) enclosed around a peripheral portion of the playpen and having an underside connected to the top plate 201 of the base portion 20, the control device comprising of four of the block members 21 each fixed-on the top plate 201 of the base portion 20 and pivotally engaged with the second end of one of the drive posts 10, four fastener members 11 each mounted on a mediate portion of one of the drive posts 10, two transmission assemblies 30 each mounted between two of the four drive posts 10 and opposite to each other, each of the transmission assemblies 30 comprising a bracket member 32 mounted in a mediate portion thereof, a pair of linking rods 31 each having a first end pivotally engaged with one of the fastener members 11 on an associated drive post 10 and having a second end pivotally engaged with the bracket member 32.
Referring to FIG. 3, each of the four block members 21 is fixed on the top plate 201 by four rivets 23 each of which extends through a hole 22 defined in the block member 21 which also defines a longitudinal recess 24 having an opening facing downwardly and further define a vertical compartment 27 therethrough which communicates with the recess 24, a pair of aligned holes 25 transversely defined through the block member 21 and communicating with the vertical compartment 27, the second end of one of the drive posts 10 being received in the longitudinal recess 24 and defining a transverse bore 101 therethrough which aligns with the pair of holes 25, a pivot axle 26 extending through the pair of holes 25 and the bore 101 such that the drive post 10 is pivotally engaged with the block member 21 at the pivot axle 26, whereby, the second end of the drive post 10 is received in the vertical compartment 27 when the drive post 10 is rotated about the pivot axle 26.
Referring to FIG. 4, each of the four fastener members 11 defines a recess 15 therein having an opening facing towards the base portion 20 and defines a compartment 18 therethrough which communicates with the recess 15, a pair of aligned holes 16 vertically defined through the fastener member 11 and communicating with the compartment 18, the first end of one of the linking rods 31 being received in the recess 15 and defining a vertical bore 311 therethrough which communicates with the pair of holes 16, a pivot axle 17 extending through the pair of holes 16 and the vertical bore 311 such that the linking rod 31 is pivotally engaged with the fastener member 11 at the pivot axle 17, whereby, the first end of the linking rod 31 is received in the compartment 18 when the linking rod 31 is rotated about the pivot axle 17. A screw hole 13 is defined in each of the drive posts 10 near a corresponding fastener member 11, a bolt 14 extending through a washer 140 is threadedly engaged in the screw hole 13 for biasing against the fastener member 11 so as to inhibit a displacement of the fastener member 11 relative to the drive post 10 towards the base portion 20.
Referring to FIG. 5, each of the two bracket members 32 has two distal ends and defines a substantially U-shaped recess 33 therethrough which has an opening facing opposite the base portion 20, a pair of aligned holes 34 vertically defined through each of the two distal ends of the bracket member 32, the second end of each of the linking rods 31 being received in the recess 33 and defining a vertical bore 312 therethrough which communicates with the pair of holes 34 in a corresponding distal end of the bracket member 32, a pair of pivot axles 35 each extending through the pair of holes 34 and the vertical bore 312 such that each of the linking rods 31 is pivotally engaged with the bracket member 32 at the pivot axle 35. Each of the two bracket members 32 defines a substantially T-shaped slot 36 having an opening facing the base portion 20 and forms two flange portions 360 thereon, a resilient strip 91 has a mediate portion attached to the base portion 20, as shown in FIG. 1, and has two free ends each of which is formed into a loop 92 so as to be fitted on the two flange portions 360 of the bracket member 32 through the opening of the T-shaped slot 36. Preferably, with reference to FIGS. 2 and 3, two pairs of elongated slots 202 are each defined through one side of the top plate 201 of the base portion 20, the resilient strip 91 initially extends through a pair of slots 202 on one side of the top plate 201, then passes through two bores defined in an underside of the flexible casing 90 and finally extends through the pair of slots 202 on the other side of the top plate 201 such that the underside of the flexible casing 90 together with the resilient strip 91 is attached to the top plate 201 of the base portion 20.
In operation, referring to FIGS. 1, 2 and 6, in order to fold the base portion 20 of the playpen, a user may pull the resilient strip 91 upwardly to drive the base portion 20 and the two bracket members 32 upwardly, whereby, each of the drive posts 10 is able to pivot relative the base portion 20 about the pivot axle 26 on the block member 21, each of the linking rods 31 is able to pivot relative to the bracket member 32 about the pivot axle 35 and pivot relative to the fastener member 11 about the pivot axle 17 such that the four vertical stands 93 are driven by the drive posts 10 to displace in parallel towards the base portion 20 so as to fold the playpen. FIG. 7 shows the playpen is in a folded status. Conversely, when expanding, the user just needs to push the base portion 20 downwardly to displace the four vertical stands 93 in parallel outwardly by the drive posts 10, thereby expanding the base portion of the playpen.
It should be clear to those skilled in the art that further embodiments of the present invention may be made without departing from the teachings of the present invention.
I claim:
1. A control device for folding and expanding a base portion of a playpen which comprises four vertical stands (93) respectively mounted on four corners thereof and a base portion (20) mounted on an underside thereof, four drive posts (10) each having a first end pivotally connected to a lower end of a corresponding one of said four vertical stands (93) and having a second end pivotally connected to said base portion (20), and a flexible casing (90) enclosed around a peripheral portion of said playpen and having an underside engaged with said base portion (20), said control device comprising:four block members (21) each fixed on said base portion (20) and each pivotally engaged with the second end of a corresponding one of said four drive posts (10); four fastener members (11) each mounted around a mediate portion of a corresponding one of said four drive posts (10); and two transmission assemblies (30) each pivotally mounted between two of said four drive posts (10) and arranged opposite to each other, each of said two transmission assemblies (30) comprising:a bracket member (32) mounted in a mediate portion of said transmission assembly (30), said bracket member (32) including a substantially T-shaped slot (36) having an opening facing said base portion (20) forming two flange portions (360); a pair of linking rods (31) each having a first end pivotally engaged with a corresponding one of said four fastener members (11) located on associated said drive post (10) and each having a second and pivotally engaged with said bracket member (32); and a resilient strip (91) having a mediate portion attached to said base portion (20) and having two free ends each formed into a loop (92) which is received by said two flange portions (360) of said bracket member (32).
2. The control device in accordance with claim 1, wherein each of said block members (21) defines a longitudinal recess (24) therein having an opening facing downwardly and further defines a vertical compartment (27) therethrough which communicates with said recess (24), a pair of aligned holes (25) transversely defined through said block member (21) and communicating with said vertical compartment (27), the second end of said drive post (10) being received in said longitudinal recess (24) and defining a transverse bore (101) therethrough which aligns with said pair of holes (25), a pivot axle (26) extending through said pair of holes (25) and said bore (101) such that said drive post (10) is pivotally engaged with said block member (21) at said pivot axle (26), whereby, the second end of said drive post (10) is received in said vertical compartment (27) when said drive post (10) is rotated about said pivot axle (26).
3. The control device in accordance with claim 1, wherein each of said fastener members (11) defines a recess (15) therein having an opening facing towards said base portion (20) and defines a compartment (18) therethrough which communicates with said recess (15), a pair of aligned holes (16) vertically defined through said fastener member (11) and communicating with said compartment (18), the first end of said linking rod (31) being received in said recess (15) and defining a vertical bore (311) therethrough which communicates with said pair of holes (16), a pivot axle (17) extending through said pair of holes (16) and said vertical bore (311) such that said linking rod (31) is pivotally engaged with said fastener member (11) at said pivot axle (17), whereby, the first end of said linking rod (31) is received in said compartment (18) when said linking rod (31) is rotated about said pivot axle (17).
4. The control device in accordance with claim 1, wherein each of said bracket members (32) has two distal ends and defines a substantially U-shaped recess therethrough which has an opening facing opposite said base portion (20), a pair of aligned holes (34) vertically defined through each of the distal ends of said bracket member (32), the second end of said linking rod (31) being received in said recess (33) and defining a vertical bore (312) therethrough which communicates with said pair of holes (34) in a corresponding distal end of said bracket member (32), a pair of pivot axles (35) each extending through said pair of holes (34) and said vertical bore (312) such that said linking rod (31) is pivotally engaged with said bracket member (32) at said pivot axle (35).
| 1994-08-25 | en | 1996-03-12 |
US-23716594-A | Beverage container with pull ring
ABSTRACT
A beverage container is provided with a pull ring attached to the outer surface of the cap thereof and with a gas chamber disposed under the inner surface of the cap thereof. The gas chamber has a top lid provided with a whistling hole and a bottom lid provided with a small hole through which the gas produced by the beverage contained in the beverage container enters the gas chamber. As the pull ring of the beverage container is pulled out, the gas contained in the gas chamber is let out via the whistling hole, thereby producing a clear, loud and whistling sound.
BACKGROUND OF THE INVENTION
The present invention relates generally to a beverage container, and more particularly to a beverage container having a top end which is provided with a pull ring to facilitate the opening of the beverage container,
It is a well-known fact that a pop sound is produced at the time when the pull ring of the cap of the can containing a carbonated soft drink such as a cola, or an alcoholic beverage like beer, is pulled out. Such a pop sound as described above is short and light and does not give an added exhilarating excitement in drinking, which is a fun thing to do.
SUMMARY OF THE INVENTION
It is therefore the primary objective of the present invention to provide a beverage container capable of producing a clear, loud and whistling sound at the time when the pull ring of the cap of the beverage container is pulled to open, so as to give an added amusement to drinking.
In keeping with the principle of the present invention, the foregoing objective of the present invention is attained by a beverage container which is provided with a pull ring attached to the outer surface of the cap thereof. The gas chamber has a cover provided with a whistling hole and is filled with the gas produced by the beverage held in the body of the beverage container. As the pull ring of the beverage container is pulled out, the gas contained in the gas chamber is let out via the whistling hole, thereby producing a clear, loud and whistling sound.
The foregoing objective, features and structures of the present invention can be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exploded view of the preferred embodiment of the present invention.
FIG. 2 is an enlarged sectional view showing a body and a gas chamber of the beverage container in combination, according to the present invention as shown in FIG. 1
FIG. 2A is a top plan view of the container of FIG. 1.
FIG. 2B is an enlarged cross-sectional view of a portion of FIG. 2.
FIG. 3 is a schematic view of the preferred embodiment of the present invention and showing that a pull ring of the beverage container of the present invention is pulled to open the container.
FIG. 3A is a top plan view of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1, 2, 2A and 2B, the beverage container of the present invention is shown to comprise a body 1 provided with a top end 2 having a pull ring 3 attached to an outer surface 2A thereof and further having a pour opening 31. Disposed horizontally under an inner surface 2B of the top end 2 is a gas chamber 6, which is provided with a top lid 4 and a bottom lid 5. The top lid 4 has a right end 41 and a left end 42, which are riveted respectively to the inner surface 2B of the top end 2. The top lid 4 of the gas chamber 6 is provided at the center thereof with a through whistling hole 4A while the bottom lid 5 of the gas chamber 6 is provided at the center thereof with a small hole 5A through which the gas chamber 6 communicates with the body 1. As a result, the gas produced by the beverage contained in the body 1 is able to enter the sealed gas chamber 6 via the small hole 5A.
As shown in FIG. 3, as soon as the pull ring 3 pulled out to open up the pour opening 31, a clear, loud and whistling sound is produced by the gas which has already been collected in the gas chamber 6 and is let out via the whistling hole 4A. Such a clear, loud and whistling sound described above gives an added amusement to the joy of drinking. Accordingly, the beverage container of the present invention can be instrumental in promoting the sale of the beverage.
The embodiment of the present invention described above is to be regarded in all respects as merely illustrative and not restrictive. Accordingly, the present invention may be embodied in other specific forms without deviating from the spirit thereof. The present invention is therefore to be limited only by the scope of the following appended claim.
What is claimed is:
1. A beverage container comprising a body provided with a top end having a pull ring attached to an outer surface thereof and further having a pour opening; wherein said top end has an inner surface under which a gas chamber of a dimension and a shape is disposed, said gas chamber having a top lid riveted at a left end thereof and at a right end thereof to said inner surface of said top end, said gas chamber further having a bottom lid, said gas chamber being sealed off except that said top lid of said gas chamber is provided at a center therof with a whistling hole corresponding in location to said pour opening of said top end, and that said bottom of said gas chamber is provided at a center thereof with a small hole through which a quantity of gas produced by a beverage contained in said body is allowed to enter said gas chamber.
| 1994-05-03 | en | 1995-02-14 |
US-80934559-A | Production of powdered polycarbonates
Unite States Patent M 2,989,503 PRODUCTION OF POWDERED POLYCARBONATES Bart Paul Jibben, Arnhem, Netherlands, assignor, by
mesne assignments, to N.V. Onderzoekingsinstituut Research, Arnhem, Netherlands, a corporation of the Netherlands No Drawing. Filed Apr. 28, 1959, Ser. No. 809,345 Claims priority, application Netherlands May 19, 1958 8 Claims. (Cl. 260-47) This invention relates to a process for the preparation of polycarbonates and more particularly to a process for the preparation of macromolecular polycarbonates in powdered or granular form.
Polycarbonates may be prepared by reacting 2,2-(4,4'- dihydroxydiphenyl)-propane with phosgene or chlorocarbonic acid esters of 2,2-(4,4-dihydroxydiphenyl)propane in the presence of dichloromethane, trichloromethane or mixtures thereof. The polycarbonate is then obtained in solution in the dichloromethane, trichloromethane or mixtures thereof.
The known method of obtaining the polycarbonate in powdered form is to evaporate this solution which on evaporation yields a hard tough mass. This mass is then ground into a powder. It is very difficult to remove all of the solution from the mass, thereby necessitating high temperatures and prolonged evaporation which materially increases the cost of the operation. In addition, the hard mass of polycarbonate is very difficult to handle while grinding, which also adds to the cost of the operation.
Therefore, it is an object of this invention to overcome the difliculties of the prior art.
It is a further object of this invention to provide a process for the preparation of macromolecular polycarbonate in powdered or granular form.
Another object of this invention is to provide an economical and simple process for the preparation of macromolecular polycarbonates in powdered or granular form.
These and other objects will become apparent from the following detailed description.
In accordance with the present invention, the foregoing objects are accomplished by adding to the solution of the polycarbonate in dichloromethane, trichloromethane, or mixtures thereof, water and at least 2 cc. of dimethylbenzene per gram of polycarbonate. Upon evaporation of this mixture, the polycarbonate is obtained in the form of a powder or a coarsely divided brittle mass which may be easily triturated to a powder. The powdered form is retained even after the polycarbonate is subjected to a drying operation.
The polycarbonate in powder form may readily be used for coating objects or for preparing spinning solutions to be used in the production of threads and filaments. Also, it finds utility in the preparation of solutions for the production of films and foils.
The polycarbonates in powdered form are not very suitable for use in conventional injection molding and extrusion apparatus. The conventional method for preparing polycarbonate powder for such use is to compress the powder into pellets. However, it has been found that pellets or granules of polycarbonates suitable for extrusion may be obtained by agitating the mixture of polycarbonate solution, water and dimethylbenzene during the evaporation of the mixture. Upon completion of the evaporation, the polycarbonate is obtained in granular form.
The bulk density of the powdered polycarbonate is less than 0.4 g./cc. Whereas the bulk density for the granulated polycarbonate is approximately 0.6 g./cc. Thus there is a considerable difference in size between the Patented June 20, 1961 powder and granules which renders the granules suitable for extrusion.
The dimethylbenzene that is added'to the polycarbonate solution may be l,2-dimethylbenzene, 1,3-d'imethylbenzene, 1,4-dimethylbenzene, or the commercial product referred to as dimethylbenzene, which is a mixture of the foregoing. Whenever dimethylbenzene is used, it is to be understood that it is to be interpreted as including the foregoing.
The amount of dimethylbenzene that is used should be at least 2 cc. per gram of polycarbonate because less than that amount will cause the mixture to agglutinate on evaporation. Thus if 2 to 25 cc., and preferably 10-20 cc., of dimethylbenzene per gram of polycarbonate is used, the polycarbonate is obtained directly in powdered form. If larger quantities, for example 40 cc. per gram, are used the polycarbonate will be obtained as a coarsely divided, brittle mass. This mass may easily be triturated into a powder but the added step and large quantity of dimethylbenzene add to the cost.
The water that is added to the polycarbonate solution along with the dimethylbenzene will normally be present in an amount of 50 cc. to 300 cc. per cc. of dimethylbenzene.
It has been found that for the best results, the amount of polycarbonate in solution in dichloromethane, trichloromethane, or mixtures thereof should be between 2040 grams per 100 grams of solvent. If the concentration of polycarbonate is too high, it will be difiicul-t, if not impossible, to obtain the polycarbonate in powdered form.
The mixture may be evaporated by heating. However, the preferred method is to pass steam through the mixture to expel the solvents. Thus if steam is used, it is not necessary to add water to the polycarbonate solution because sufiicient water Will be supplied by the condensation of the steam.
To illustrate the manner in which this invention may be carried out, the following examples are given. It is to be understood, however, that the examples are for the purpose of illustration and the invention is not to be regarded as limited to any of the specific materials or conditions recited therein.
Example I A solution containing 34.4 g. of 2,2-(4,4-dihydroxydiphenyl)-propane, 17.2 g. of sodium hydroxide, 35.0 mg. of sodium dithionite, 240 cc. of water and 60 cc. of dichloromethane was prepared and maintained at a temperature of 25 C. Phosgene in an amount of 17.9 g. was passed through this solution for 45 minutes. The solution was stirred while the phosgene was passed therethrough. The stirring was continued and 0.75 g. of triethylbenzyl ammonium chloride and cc. of dichloromethane were added to the solution. After three hours of stirring, 160 cc. of dichloromethane was again added to the solution. The total stirring after the introduction of phosgene was for five hours. At this point, the solution separated into two layers, one being polycarbonate in dichloromethane and the other an alkaline layer of water. The polycarbonate layer was removed and washed successively with water, dilute sulfuric acid and water. The dichloromethane solution was then mixed with 760 cc. of dimethylbenzene and 800 cc. of water. The mixture was then evaporated to remove all of the organic solvents. The polycarbonate was obtained as a white powder by filtration and drying in a vacuum at 60 C. The dry powder weighed 0.35 g./cc. and could then. b processed into a colorless, clear foil. 7
Example II A solution of the type described in Example I was treated in a similar manner except that the two additions of dichloromethane consisted of 65 cc. each rather than 160 cc. each. After the three washings, 380 cc. of 1,3- dimethylbenzene and 800 cc. of water were added to the dichloromethane solution of the polycarbonate. After evaporation, filtration, and drying as in Example I, the dry polycarbonate powder thus obtained weighed 0.13 g./cc.
Example 111 A mixture of 22.8 g. of 2,2-(4,4'-dihydroxydiphenyl)- propane and 35 cc. of pyridine was prepared. While stirring this mixture, a solution containing 7.0 g. of phosgene in 40 cc. of trichloromethane was added dropwise to this mixture over a period of 22 minutes and at a temperature of between -2 to C. Then 155 cc. of dichloromethane was added to the reaction mixture. Thereafter a solution of 3.5 g. of phosgene in 20 cc. of trichloromethane was added dropwise for 15 minutes at a temperature of 0 C. The reaction mixture was then stirred for 40 minutes and the temperature was gradually raised to 16 C. At this point, 200 cc. of dichloromethane was added and the mixture was shaken successively with water, dilute hydrochloric acid and water. A neutral solution of polycarbonate in a mixture of dichloromethane and trichloromethane was thus obtained. This solution was mixed with 400 cc. of dimethylbenzene and 500 cc. of water. Steam was passed through this mixture to remove the solvents from the solution. After filtration and drying in a vacuum at 60 C., the polycarbonate was obtained as a white powder.
Example IV A solution containing 6.66 g. of bis-chlorocarbonic acid ester of 2,2-(4,4-dihydroxydiphenyl)-propane and 50 cc. of trichloromethane was prepared. A solution of 4.29 g. of 2,2-(4,4'-dihydroxyphenyl)-propane in g. of pyridine and 50 cc. of trichloromethane was added to this solution dropwise for 45 minutes. The solution was stirred and maintained at 0 C. during this addition. Stirring was continued for two hours at room temperature, after which the mixture was shaken successively with water, dilute hydrochloric acid, and water. A solution containing the polycarbonate in trichloromethane was obtained and to this solution was added 100 cc. of dimethylbenzene and 75 cc. of water. Steam was passed through this mixture to evaporate the organic solvents, after which the polycarbonate was obtained as a white powder which was dried in a vacuum at 60 C.
Example V A solution of 2 kg. of polycarbonate, obtained by reacting 2,2-(4,4'-dihydroxydiphenyl)-propane with phosgene, in liters of dichloromethane was mixed with 25 liters of dimethylbenzene and 20 liters of water. Steam was passed through the mixture to remove the organic solvents. During this steam passage, the mixture was stirred. The polycarbonate thus obtained was in granular form, each granule being about 2 mm. in diameter. After drying in vacuum at 60 C., the granules had a bulk density of 0.55 g./ cc.
It is apparent from the foregoing that polycarbonates in either powder or granular form may be prepared easily and economically. The product thus obtained is suitable for coating objects or extrusion.
Since many embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the above specific illustrations, except to the extent of the following claims.
What is claimed is:
1. A process for the preparation of powdered macromolecular polycarbonates comprising the steps of reacting 2,2-(4,4'-dihydroxydiphenyl) propane with a compound of the group consisting of phosgene and chlorocarbonic acid esters of 2,2-(4,4-dihydroxydiphenyl)-propane in the presence of a compound of the group consisting of dichloromethane, trichloromethane and mixtures thereof, obtaining the polycarbonate in solution in said compound, said polycarbonate being present in an amount of 20-40 grams per grams of said compound, mixing said solution with water and at least 2 cc. of dimethylbenzene per gram of polycarbonate, said water being present in an amount of 50 to 300 cc. per 100 cc. of dimethylbenzene, and evaporating said mixture to obtain the polycarbonate in powder form.
2. A process according to claim 1 wherein said dimethylbenzene is present in an amount of 10 to 20 cc. per gram of polycarbonate.
3. A process for the preparation of powdered macromolecular polycarbonates comprising the steps of reacting 2,2-(4,4'-dihydroxydiphenyl)-propane with phosgene in the presence of dichloromethane, obtaining the polycarbonate in solution in said dichloromethane, said polycarbonate being present in an amount of 20 to 40 grams per 100 grams of said dichloromethane, mixing said solution with water and at least 2 cc. of dimethylbenzene per gram of polycarbonate, said water being present in an amount of 50-300 cc. per 100 cc. of dimethylbenzene, and evaporating said mixture to obtain the polycarbonate in powdered form.
4. A process for the preparation of powdered macromolecular polycarbonates comprising the steps of reacting 2,2-(4,4-dihydroxydiphenyl)-propane with phosgene in the presence of trichloromethane, obtaining the polycarbonate in solution in said trichloromethane, said polycarbonate being present in an amount of 20 to 40 grams per 100 grams of said trichloromethane, mixing said solution with water and at least 2 cc. of dimethylbenzene per gram of polycarbonate, said water being present in an amount of 50 to 300 cc. per 100 cc. of dimethylbenzene, and evaporating said mixture to obtain the polycarbonate in powdered form.
5. A process for the preparation of powdered macromolecular polycarbonates comprising the steps of reacting 2,2-(4,4'-dihydroxydiphenyl)-propane with chlorocarbonic acid esters of 2,2-(4,4'-dihydroxydiphenyl)- propane in the presence of dichloromethane, obtaining the polycarbonate in solution in said dichloromethane, said polycarbonate being present in an amount of 20 to 40 grams per 100 grams of said dichloromethane, mixing said solution with water and at least 2 cc. of dimethylbenzene per gram of polycarbonate, said water being present in an amount of 50 to 300 cc. per 100 cc. of dimethylbenzene, and evaporating said mixture to obtain the polycarbonate in powdered form.
6. A process for the preparation of powdered macromolecular polycarbonates comprising the steps of reacting 2,2-(4,4-dihydroxydiphenyl)-propane with chlorocarbonic acid esters of 2,2-(4,4-dihydroxydiphenyl)- propane in the presence of trichloromethane, obtaining the polycarbonate in solution in said trichloromethane, said polycarbonate being present in an amount of 20 to 40 grams per 100 grams of said trichloromethane, mixing said solution with water and at least 2 cc. of dimethylbenzene per gram of polycarbonate, said water being present in an amount of 50 to 300 cc. per 100 cc. of dimethylbenzene, and evaporating said mixture to obtain the polycarbonate in powdered form.
7. A process for the preparation of powdered macromolecular polycarbonates comprising the steps of reacting 2,2-(4,4'-dihydroxydiphenyl)-propane with a compound of the group consisting of phosgene and chlorocarbonic acid esters of 2,2-(4,4'-dihydroxydiphenyl)- propane in the presence of a compound of the group consisting of dichloromethane, trichloromethane and mixtures thereof, obtaining the polycarbonate in solution in said compound, said polycarbonate being present in an amount of 20 to 40 grams per 100 grams of said compound, mixing said solution with at least 2 cc. of dimethylbenzene per gram of polycarbonate, said water being present in an amount of 50 to 300 cc. per 100 cc. of dimethylbenzene, and passing steam through said mixture to evaporate the mixture whereby the polycarbonate is obtained in powdered form.
8. A process for the preparation of granular, macromolecular polycarbonates comprising the steps of reacting 2,2-(4,4'-dihydroxydiphenyl)-pr0pane with a compound of the group consisting of phosgene and chlorocarbonic acid esters of 2,2-(4,4-dihydroxydiphenyl)- propane in the presence of a compound of the group consisting of dichloromethane, trichloromethane and mixtures thereof, obtaining the polycarbonates in solution in said compound, said polycarbonate being present in an amount of to grams per 100 grams of said compound, mixing said solution with water and at least 2 cc. of dimethylbenzene per gram of polycarbonate, said water being present in an amount of to 300 cc. per cc. of ldimethylbenzene, evaporating said mixture and during said evaporation, agitating said mixture whereby the polycarbonate is obtained in granular form.
References Cited in the file of this patent FOREIGN PATENTS 578,585 Canada June 30, 1959
1. A PROCESS FOR THE PREPARATION OF POWDERED MACROMOLECULAR POLYCARBONATES COMPRISING THE STEPS OF REACTING 2,2-(4,4''-DIHYDROXYDIPHENYL)PROPANE WITH A COMPOUND OF THE GROUP CONSISTING OF PHOSGENE AND CHLOROCARBONIC ACID ESTERS OF 2,2-(4,4''-DIHYDROXYDIPHENYL)-PROPANE IN THE PRESENCE OF A COMPOUND OF THE GROUP CONSISTING OF DICHLOROMETHANE, TRICHLOROMETHANE AND MIXTURES THEREOF, OBTAINING THE POLYCARBONATE IN SOLUTION IN SAID COMPOUND, SAID POLYCARBONATE BEING PRESENT IN AN AMOUNT OF 20-40 GRAMS PER 100 GRAMS OF SAID COMPOUND, MIXING SAID SOLUTION WITH WATER AND AT LEAST 2 CC. OF DIMETHYLBENZENE PER GRAM OF POLYCARBONATE, SAID WATER BEING PRESENT IN AN AMOUNT OF 50 TO 300 CC. PER 100 CC. OF DIMETHYLBENZENE, AND EVAPORATING SAID MIXTURE TO OBTAIN THE POLYCARBONATE IN POWDER FORM.
| 1959-04-28 | en | 1961-06-20 |
US-17381671-A | Device for recording weaving faults
ABSTRACT
Device for recording weaving faults in fabric being manufactured on weaving machines in which a recording card is fixed to a drum means and has associated therewith writing means that are initiated through an electro-magnet and circuitry connected to at least one stop motion on the stop circuit of the weaving machine.
The drum which supports the recording card is rotated at the same speed as the advancing fabric being manufactured on the weaving machine through a transmission coupling the drum to means on the weaving machine such as the withdrawal cylinder.
BACKGROUND OF THE INVENTION
The present invention relates to a device for recording weaving faults in fabric being manufactured on weaving machines. The faults are made on a recording card, the mark recorded indicating the reason for the fault, such as stoppage of the machine by the attendant, breakage of warp or weft threads or similar faults.
The correlation between the quality of woven goods and the number of weaving machine stoppages is well known, particularly in those kinds of fabrics in which each stoppage of the machine leaves a visible trace. Similarly, the correlation between the number of weaving machine stoppages for whatever reason and the efficiency of the weaving machine is known. In order to improve quality and efficiency, there is interest in recording and assessing the reasons of weaving machine stoppages. Consequently, in certain weaving mills the weaving faults are recorded in such a manner that they are noted only upon inspection of the machines and the cause for stoppage is eliminated. At that time, a record is made concerning the weaving faults and one copy is left at the weaving machine for use by the foreman and attendants. However, this method is too time consuming and disadvantages for other reasons also. For example, both the foreman and the attendants of the weaving machine get the record too late, that is after considerable production has already been completed.
Devices for recording and assessing faults in which separate weaving machines are centrally controlled are also known. Devices of this type include a recording apparatus for making a record and means for generating a signal for the recording apparatus, the devices being connected to the separate weaving machines and further provided with means which serve for their connection and interruption of activity. With such types of devices, the record is generated centrally either on one card for all machines controlled thereby or by a series of cards, one belonging to each machine. Such devices are very advantageous in connection with the overall assessment of the records by the dispatcher. For the shop crew, that is, the foreman and the attendants of the weaving machine, however, these records are already disadvantageous, since the information is communicated to them, as in the preceding case, too late, that is, after the final processing of the record. Such devices are also disadvantageous since they are very expensive, and require close attendance and maintenance. In addition, expensive devices for assessing the records made are necessary, too. Without the assessing devices, however, the recording devices are not practical. Consequently smaller plants cannot afford them. There is a need, therefore, for a device for recording weaving faults in fabric made on weaving machines that is relatively simple in construction and which provides immediate data to the foreman and operators and which can be further used for additional processing.
Accordingly, it is an object of this invention to provide a device for recording weaving faults in fabric being manufactured on weaving machines which is of a relatively simple and inexpensive design.
It is still a further object of this invention to provide such a device wherein the recorded data is immediately available to the machine operators and still can be later used for further assessment of the data by a dispatcher or other personnel in another physical location.
It is still another object of the invention to provide such a device in which a recording card is fixed to a drum means having writing means associated therewith and which drum means is linked through a transmission to means on the weaving machine such as the withdrawal cylinder so that the drum and recording card thereon rotate at the same speed as the advancing fabric being manufactured on the weaving machine.
Numerous other objects of the invention will be apparent from the following description and the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention provides a device which mitigates the disadvantages of the known methods and devices to a substantial extent and provides a record that is made directly in the weaving machine and which is also suitable for further processing. In accordance with the invention, there is provided a device in which a recording card is mounted on a drum means that is rotatably fixed on a threaded end of a stationary shaft which is coupled through a transmission means with an element of the weaving machine which moves at a speed identical to that of the advancing fabric, the drum means being provided on its circumference below the recording card with a threaded groove which has the same pitch as the threaded end of the shaft and recording means controlled by electromagnetic means being mounted opposite said groove and connected to circuit means and switch means coupled to at least one stop motion or the stop circuit of the weaving machine.
In order to understand the invention more fully, reference is directed to the following description thereof which is to be taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, diagrammatic arrangement of a device in accordance with the invention and its relationship to a weaving machine;
FIG. 2 is a view partially in section showing in detail the drum means, writing means and the threaded shaft on which the drum means is mounted; and
FIG. 3 is a view of a recording card suitable for use with the device and used to record three different types of stoppage date.
It is to be understood that the device of this invention can be used on any known weaving machine, such as, for example, those shuttless looms disclosed in U.S. patent application Ser. No. 79,035 filed Oct. 8, 1970 and U.S. patent application Ser. No. 79,478 filed Oct. 9, 1970. Consequently, the weaving machine is shown in the drawings only in broad detail in order to illustrate the operative relationship between the device of this invention and such a machine and to avoid the inclusion of complex extraneous subject matter in the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is now directed to FIG. 1 wherein a typical weaving machine is generally shown and in which the shed 1 formed by the system of warp threads 2 by means of healds 3 suspended in the heald shaft frames 4, is ready to receive a weft thread (not shown) in the known manner. The weft thread constitutes, after beat-up by the reed 5, together with the bound warp threads 2, the fabric 6. The fabric 6 passes over the breast beam 7 and is withdrawn by means of a pair of withdrawing cylinders 8, the operation of which is controlled by a cloth regulator (not shown).
Fabric 6 is next wound on to a cloth beam (not shown). The movement of fabric 6 is recorded best be means of an element of the weaving machine moving at an identical speed as fabric 6, such as one of the withdrawing cylinders 8 and is transmitted through transmission means either intermittently or continuously to a recording device.
The recording device is constituted by a rotatably mounted drum means 9 and at least one recording element. The record is made on a recording card 10. The drive of drum means 9 is illustrated in the form of an intermittent drive.
Drum means 9 is mounted on a threaded end 11 of a stationary shaft 12, and upon turning of the drum, it is simultaneously axially traversed, along the shaft in the direction of the longitudinal axis thereof, similar to a nut being rotated on a screw. About the circumference of drum means 9, there is provded a helical groove 13 having the same pitch as the threaded end 11 of shaft 12. The helical groove 13 on the surface of the drum 9 enables the writing element or elements, three being shown in FIG. 2 and one being identified by numeral 28 to pierce the record card 10 with the tip or tips, three being shown in FIG. 2 and one tip being identified by numeral 29. Consequently, the lead of the groove 13 is made so that it cooperates with the lead of the thread of shaft 12, so that upon rotation of drum 9 the tip 29 or tips of the writing element 28 or pluraltiy thereof are continuously pointed against the groove 13 and move within its confines when the elements are swingably actuated and thus pierce the record card 10. The housing of drum means 9 is further cut by a groove 14 in the direction of the axis of shaft 12 for insertion of the ends off the recording card 10. The length of the helical groove 13 is proportional to the length of the woven goods.
As already mentioned above, an intermittent drive is used for the recording device and is conveniently arranged as follows. On shaft 15 of the withdrawing cylinder 8, a cam 16 provided with at least one projection, is mounted. The drive of fabric 6 is scanned by the cam. A roller 18 is pressed against the circumference of cam 16 by means of spring 17, the roller being mounted on a swingably mounted lever 19, to which one end of the resilient cable 20 is fastened, the other end being firmly connected to an arm 21, on which pawl 24 is swingably mounted by means of pin 22 and screw connection 23. Pawl 24 is pressed by means of spring 25 on pin 22 into engagement with teeth 26 on drum means 9. Arm 21 is mounted swingably on shaft 12 carrying drum means 9.
One or more recording elements, three being shown in FIG. 2, are carried by a holder 27 fixed to shaft 12 of which one end is bent above drum means 9.
Each recording element includes a writing means 28 which may be of different color, provided with a tip 29 and each writing means 28 is attached to an electro-magnet 30, and an associated electric circuit 31 having a switch 32. In the embodiment shown, the switch 32 is attached to one recording element and to the warp stop motion 33. Where a plurality of recording elements are used the switch of each can be attached to the weft stop motion (not shown) or be connected to the stop circuit of the weaving machine.
The writing means on elements 28 of the separate recording elements are mounted swingably beside each other with their tips 29 pointing against the helical groove 13 of drum means 9 on holder 27 by means of pin 34 and are spring loaded by spring 35. Pin 34 is mounted on the holder by a screw connection 36 which also supports a swingably mounted stopping pawl 37 which cooperates with the teeth of the drum means 9 in order to assure the rotation of drum means 9 in only one direction.
The electro-magnets 30 attached to the writing means or elements 28 are mounted directly to the bent part of holder 27 at the respective writing element 28. In FIG. 2, however, as mentioned above, only one electro-magnet 30 is shown.
The device of the present invention operates in the following manner.
The warp beam regulator rotates the withdrawing cylinders 8 and thus also cam 16. The motion of cam 16 is transmitted to roller 18 and by means of a swingably mounted lever 19 and resilient cable 20 to arm 25 and pawl 24, which intermittently rotates drum means 9 and moves it simultaneously in an axial direction about the threaded end 11 of shaft 12 until the weaving machine is stopped at which time the movement of drum means 9 is also interrupted. In the embodiment illustrated, when the weaving machine is stopped due to warp thread breakage, the warp stop motion closes simultaneously with the stopping of the weaving machine and drum means 9 thereby actuating switch 32, which deflects writing element 28 towards drum means 9 and the tip 29 pierces an opening in the record card 10. After eliminating the reason for stoppage of the weaving machine, the warp stop motion 33 is returned to its original position, the electric circuit 31 of electro-magnet 30 is opened, writing element 28 returned to its original position and drum means 9 being started to move once again with re-starting of the weaving machine.
The record due to weft thread breakage, or stoppage of the weaving machine is recorded in a like manner except that the record is made on the recording card by writing element 28 of the recording element attached to the weft stop motion or the stop circuit of the weaving machine.
It is advantageous when the recorded data are preprinted on the recording card 10 to make an easy evaluation of the record. Card 10, as shown in FIG. 3, is divided into sections by transverse lines 39, which symbolize the number of meters of woven goods during one revolution of drum means 9, and vertical lines 40 which symbolize the number of revolutions of drum means 9. In addition, card 10 is divided by longitudinal lines 41 into three sections indicating the reasons for the weaving machine stoppages, such as weft thread breakage, warp thread breakage and intervention of the attendant. On card 10, data are recorded, also, to indicate on which weaving machine the card was used and which woven piece was made on the machine.
For better guidance of the machine operators, it is advantageous to provide the device with a light signalling means which indicates that a woven piece is finished. In such a case shaft 12 is hollow and lamp 38 and its associated circuitry is located in the end thereof in a known manner.
The present device presents many advantages. For example, it provides a relatively simple, inexpensive design which can be used on known weaving machines without making any overall design changes in the machine. It provides immediate data to the machine operator, as well as data which can be later used by a dispatcher or other personnel in making further assessment of study thereof. Moreover, the device of the invention because of the simplicity of design and relatively small number of moving parts is less susceptible to breaking down and relatively easily repaired when breakdown does occur. Numerous other advantages of the invention will be apparent to those skilled in the art.
It is to be understood that many variations of the embodiments of this invention may be made without departing from the spirit and scope thereof. Therefore, the invention is not limited except as defined in the appended claims.
What is claimed is:
1. Device for recording weaving faults in fabric being manufactured on weaving machines having a withdrawal cylinder by making a written record of said faults on a recording card with symbols indicating the reason for the particular weaving faults comprising drum means mounted on a threaded end of a stationary shaft, a recording card mounted circumferentially on said drum means, transmission means connected to said withdrawal cylinder and coupling said drum means thereto and which transmission means moves at the same speed as advancing fabric being manufactured on said weaving machine and comprises a cam having at least one projection and which is mounted on the shaft of the withdrawing cylinder of the weaving machine, a roller mounted on a swingable lever means and bearing against said cam and a resilient cable connected to said swingable lever at one end and to the drum means at the opposite end, said drum means being provided with a helical, circumferential groove of the same pitch as the threaded end of said stationary shaft, writing means being mounted opposite the helical groove of said drum means and electromagnetic means, including circuit means and switch means connecting said electromagnetic means to at least one stop motion on the stop circuit of said weaving machine.
2. The device as defined in claim 1 including spring means connected to the swingable lever and biasing the roller against the cam.
3. The device as defined in claim 1 including a spring biased pawl connected to the resilient cable and toothed drum means, said pawl engaging the teeth on the drum means.
4. The device as defined in claim 1 wherein the writing means are mounted on a holder fixed to the stationary shaft which supports the drum means.
5. The device as defined in claim 4 wherein the writing means includes a plurality of writing elements.
6. The device as defined in claim 5 wherein the writing elements are of different colors.
| 1971-08-23 | en | 1976-08-31 |
US-44773095-A | White balance control device for use in both an outdoor and indoor mode
ABSTRACT
A white balance control device is provided for use in a video camera or a still video camera in which white balance control signals are controlled so that an object may be photographed without the occurrence of color failure. A microcomputer of the white balance control device detects a difference between integral averaged values for two color difference signals R-Y and B-Y and a reference value. Depending on the difference, values of the white balance control signals Rcont and Bcont may be changed when the brightness of an object is changed by more than a predetermined amount. In an indoor mode, the values of the white balance control signals Rcont and Bcont are positioned within a region corresponding to various artificial light sources. In an outdoor mode, the values of the white balance control signals are positioned within a region corresponding to natural light.
This application is a divisional of application Ser. No. 08/245,689, filed on May 18, 1994, now U.S. Pat. No. 5,448,292 which is a divisional of application Ser. No. 07/922,488, filed Jul. 31, 1992, now U.S. Pat. No. 5,392,361, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a white balance control device of a video camera and a video still camera, and particularly to a white balance control device for properly controlling white balance by a method of inside light measurement without color failure occurring, a white balance control device for accurately controlling white balance by reducing the white balance converging period, a white balance control device for properly controlling white balance control by a method of inside light measurement without color failure occurring when photographing indoors and outdoors, a white balance control device with a device for selecting a light source by manual operation in order to prevent deterioration of reproduced colors caused by a difference between a data of a selected light source and an actual color temperature of the selected light source.
2. Related Art
In conventional video cameras and video still cameras, a white balance control is utilized in order to reproduce a white object as a white colored material. The white balance control is operated by controlling a gain of a red signal circuit and a gain of a blue signal circuit in the camera based on a green signal as a reference value.
In the white balance control, it is necessary to measure a tint (color temperature) of a photographing working field for operating the white balance control. As methods of the white balance control, there are an outside light measuring method and an inside light measuring method, which are different from each other in measuring the color temperature of the photographing working field.
In the outside light measuring method, a color temperature is directly detected by a color temperature sensor. A white balance control signal for a red signal and a white balance control for a blue signal are produced based on reference data detected by the color temperature sensor in order to control the white balance. The color temperature sensor is integrally formed with photosensors, for example, a photo sensor with a red filter, a photo sensor with a green filter and a photo sensor with a blue filter. The white balance control for the blue signal are produced by an output voltage of each photo sensor, respectively.
In the inside light measuring method, a color temperature is indirectly detected by a color temperature sensor. If a white balance is matching in a picture, an averaged color of whole colors in a picture becomes achromatic color (grey). The inside light measuring method utilizes this theory. That is, an integrated averaged value of color difference signals R-Y and B-Y at a reference color temperature that an averaged color for all of the colors in a picture becomes an achromatic color is designated as a reference value for each signal. Thus, gains of the red signal and the blue signal are controlled in order to match the integrated averaged value with the reference value.
The above described values of the white balance control for a red signal and the white balance control for a blue signal are calculated by a device, such as a microcomputer and then white balance control signals for a red signal and a blue signal are output from the microcomputer to a white balance circuit. In the white balance circuit, gains of a red signal and a blue signal are controlled based on values of the white balance control signals.
On the other hand, in a manual white balance method, an operator detects a kind of light source (for example, sunshine, electric bulb, fluorescent lamp and so on) in a photographing field by himself and then the operator selects the kind of the light source by manually operating a device for selecting a light source, such as a switch. In accordance with a selection of the light source, gains of the red signal circuit and the blue signal circuit are set at specific gains corresponding to the kinds of the light sources.
The condition in which an averaged color becomes an achromatic color (grey) in a picture is achieved when the video camera takes a photograph of an ordinal sight in which various colors are mixed randomly. However, when the video camera takes a photograph of an object having a background of a blue sky, a blue ocean or a red wall, the above described condition cannot be accomplished. An averaged color for all of the colors in a picture is not an achromatic color, the averaged color becomes a color with a blue tint or a red tint. If the video camera takes a photograph of a sight dominated by a mono-colored background, the averaged color of the picture is recognized as the achromatic color by a white balance control in the inside light measuring method, although an averaged color in a picture is not an achromatic color. As a result, a reference white level is only slightly different from the true white level. The color of the background is discolored and a color of a main object (person) is controlled to be shifted to its additive complementary color (additive complementary color against the background), and a so called "color failure" occurs.
As a result, in an inside light measurement control, a video camera with a white balance control unit takes a photograph of an ordinal sight in which various colors are mixed randomly, so that the white balance control is operated properly. On the other hand, when the video camera takes a photograph of a specific sight in which a specific color dominates, the above described color failure occurs.
In a conventional automatic white balance control device, white balance control signals are output with predetermined intervals. If the predetermined intervals of the output white balance control signals are too short, the White balance control signals are not accurately converged by the occurrence of hunting. On the other hand, if the predetermined intervals of the output balance control signals are too long, the device spends a large amount of time to converge, although the white balance control signals are accurately converged. Therefore, some of the following problems arise for example. Such as, if a color temperature is suddenly changed or a light source is turned on, the device needs to spend a long time for operating white balance normally in the case when the white balance control signals should be converged as early as possible.
In the above described conventional manual white balance method, gains of the red signal circuit and the blue signal circuit are set to the specific value which depends on the kinds of the light sources. Even if the same kind of the light source is selected, a deterioration of reproduced colors occurs by a difference between a predetermined value of a selected light source and an actual color temperature, because there are various fluorescent lamp types and colors associated with a camera which have undesirable influences.
OBJECTS OF THE PRESENT INVENTION
Upon reviewing the conventional art, one object of the present invention is to provide a white balance control device for photographing a sight in which one specific color dominates without color failure occurring.
Another object of the present invention is to provide a white balance control device for photographing a sight in which one specific color dominates without color failure occurring, and particularly to a white balance control device for properly controlling white balance when an object is photographed under a light source or without a light source.
A further object of the present invention is to provide a white balance control device for accurately controlling white balance simultaneously with shortening a converging period.
A still further object of the present invention is to provide a white balance control device for photographing a sight in which one specific color dominates without color failure occurring, and particularly to a white balance control device for properly controlling white balance when an object is photographed indoors or outdoors.
Another object of the present invention is to provide a white balance control device for properly controlling white balance with a manual operation.
SUMMARY OF THE INVENTION
To accomplish the above objects, a white balance control device in an inside light measurement control method of an embodiment of the present invention comprises
white balance control means for controlling white balance by controlling an amplification degree of a red elementary color signal and a blue elementary color signal of red-, green-, and blue- elementary color signals,
color matfixing means for outputting first and second color difference signals by processing the elementary color signal white balance controlled by said white balance control means,
processing means for detecting a brightness of an object simultaneously with transmitting white balance control signals to the white balance control means, wherein the white balance control means is actuated in order to equalize integral averaged values of the first and second color difference signals, and reference values and predetermined integral averaged values for each first and second color difference signal are set as the reference values when an averaged color of all colors in a picture becomes an achromatic color at a reference color temperature, and
controlling means for stepping up and down values of the white balance control signals after a battery source is turned on and values of the white balance control signals converge in a condition that the values of the white balance control signals are varied within a variable region of which a center point is the previous converged value or a value of a previous fixed time, when the differences between the integral averaged values for the first and second color difference signals and the reference values are more than predetermined values and a present brightness value is changed more than a predetermined value with respect to a value of the previous brightness or a brightness at a previous fixed time,
wherein the processing means fixes the values of the white balance control signals while the stepped up and down values of the white balance control signals become a boundary value or the values of the white balance control signals are fixed or converged within the variable region, and the variable region is renewed to a new variable region of which a center point is the present fixed values or present converged values.
A white balance control device of another embodiment of the present invention comprises processing means for detecting whether a photographing condition is suitable for a telescope condition or a wide condition and narrowing a variable region in the telescope condition and enlarging the variable region in the wide condition.
To accomplish the above object, a structure of a white balance control device of a different embodiment in an inside light measurement control method of the present invention comprises
white balance control means for controlling white balance by controlling an amplification degree of a red elementary color signal and a blue elementary color signal out of red-, green-, and blue- elementary color signals,
color matfixing means for outputting first and second color difference signals by processing elementary color signals white balance controlled by said white balance control means,
processing means for transmitting white balance control signals to the white balance control means, wherein the white balance control means is actuated in order to equalize integral averaged values of the first and second color difference signals, and reference values and predetermined integral averaged values for each first and second color difference signals are set as the reference values when an averaged color of all colors in a picture becomes an achromatic color at a reference color,
controlling means for inputting zoom information after a battery source is turned on and a value of white balance control signals converges, wherein the processing means increases the reference values when a zooming position is in a telescope condition or a brightness value of an object is high, the processing means decreases the reference values when the zooming position is in a wide condition or the brightness value of an object is low so that a recognize level for changing a brightness value can be determined and the values of the white balance control signals are changed in order to equalize the integral averaged values of each first and second color difference signal and the respective reference values when a difference between a present brightness value and a brightness value at the last converged time is more than the recognize level for changing the brightness value.
To accomplish the above objects, a structure of a white balance control device of another embodiment of the present invention comprises
white balance control means for controlling white balance by controlling an amplification degree of a red elementary color signal and a blue elementary color signal out of red-, green-, and blue- elementary color signals,
color matfixing means for outputting first and second color difference signals by processing elementary color signals white balance controlled by said white balance control means, and
processing means for transmitting white balance control signals to the white balance control means, wherein the white balance control means is actuated in order to equalize integral averaged values of the first and second color difference signals, and reference values and predetermined integral averaged values for each first and second color difference signal are set as the reference values when an averaged color of all colors in a picture becomes an achromatic color at a reference color temperature,
the processing means outputting an interval of a white balance control signal of which a value is changed by one step value longer after a difference between the integral averaged values of the first and second color difference signals and the reference values are less than a predetermined level for changing or values of the white control signals are converged once.
To accomplish the above objects, a structure of a white balance control device of a different embodiment in an inside light measurement method of the present invention comprises,
brightness detecting means for detecting a brightness value of an object and for selecting an outdoor mode for photographing properly outdoors when the brightness value of the object is higher than a level for changing modes, and an indoor mode for photographing properly indoors under an artificial light such as a fluorescent lamp and an incandescent lamp when the brightness of the object is less than the level for changing modes, controlling means for controlling white balance within a selected restricted region by detecting a color temperature of sunshine in the outdoor mode and white balance within a selected restricted region by considering a color temperature of the respective artificial light in the indoor mode, and after the values of white balance control signals converged to a value corresponding to the outdoor mode, and changing means for changing values of white balance control signals to a value corresponding to the indoor mode after the values of the white balance control signals converge to a value corresponding to the outdoors mode when a brightness value of an object is less than a value for mode changing and the differences between integral averaged values of the first and second color difference signals and the reference values are more than a level for detecting an expanding/converging value, and changing values of the white balance control signals to a value corresponding to the outdoor mode after the values of the white balance control signals converge to a value corresponding to the indoor mode when a brightness value of an object is higher than a value for changing and differences between the integral averaged values of the first and second color difference signals and the reference values are more than a level for detecting the expanding/converging value.
To accomplish the above objects, a structure of the white balance control device of a different embodiment of the present invention comprises,
light source selecting means for manually selecting light sources,
white balance control means for controlling an amplification degree of a red elementary color signal and a blue elementary color signal out of red, green and blue elementary color signals,
color matfixing means for outputting first and second color difference signals by processing white balance controlled elementary color signals by said white balance control means, and
processing means for transmitting white balance control signals to the white balance control means, wherein the white balance control means is actuated in order to equalize integral averaged values of the first and second color difference signals and reference values and predetermined integral averaged values for each color difference signal are set as the reference values when an averaged color of all colors in a picture becomes an achromatic color at a reference color temperature,
the processing means determining outputs of initial values of the white balance control signals and a variable region in order to control the values of the white balance control signals within the variable region.
In the present invention, values of white balance control signals are changed step by step when differences between integral averaged values of color difference signals and the reference values are more than the predetermined level value and a brightness value of an object is changed more than a predetermined level with a movable area of the values being restricted within the variable region.
In the present invention, values of white balance control signals are changed in order to equalize integral averaged values of color difference signals and the reference values when a difference between a present brightness value and a brightness value at the last converged time is more than a recognition level for changing brightness. In addition,
(i) if a zooming position is in a telescope condition, the recognizing level for changing brightness is relatively high and if a zooming position is in a wide condition, the recognition level for changing brightness is relatively low, and
(ii) if a brightness value of an object is high, the recognition level for changing brightness is relatively large and if the brightness value of an object is low, the recognition level for changing brightness is relatively low.
In the present invention, the values of the white balance control signals can be rapidly and accurately converged by controlling the outputting intervals of the white balance control signals. That is, if the outputting intervals become shorter, a converging time can be shortened. If the outputting intervals become longer, the values of the white balance control signals can be converged accurately.
The spectral characteristics of natural light and the spectral characteristics of artificial light are quite different from each other. Therefore, it is necessary to widen the controllable area in order to control white control corresponding to both kinds of light sources because color failure sometimes occurs. On the contrary, if the controllable area is narrowed in order to prevent color failure from occurring, it is insufficient to control white balance.
On the other hand, in the present invention, the controllable area is separated to an area for an outdoor mode and an area for an indoor mode so that white balance control is properly operated in both modes. Since the controllable area is restrictly specified, for example, even if green grass is photographed outdoors, white balance is controlled properly without over adjusting to have color failure occur. Switching the area of the outdoor mode and the area of the indoor mode is determined by the brightness value of an object and differences between the integral averaged values of color difference signals and the reference values, so that the switching is done accurately.
In the present invention, the amplification degree of the red signal and the blue signal does not have a fixed gain thereof. Values of white balance control signals are limited within some region and are changed in order to equalize the integral averaged values of the color difference signals and the reference value. Thereby, in a manual white balance method, even if there are differences between the predetermined color temperature of a selected light source and the actual color temperature of the selected light source, it is possible to prevent deterioration of reproduced colors without ignoring an operator's selection of a light source.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows a block diagram of a video camera according to an embodiment of the present invention;
FIG. 2 shows initial values of white balance control signals and their variable region;
FIG. 3 shows a flow chart for the operation of a first embodiment according to the present invention;
FIG. 4 shows values of white balance control signals at an initial photographing time;
FIG. 5 shows white balance control signals and their variable region;
FIG. 6 shows a variation of white balance control signals;
FIG. 7 shows variation of white balance control signals and its renewed condition of a variable region;
FIG. 8 shows a condition of converging the white balance control signals;
FIG. 9 shows a flow chart for the operation of a second embodiment of the present invention;
FIG. 10 shows a flow chart for the operation of a third embodiment of the present invention;
FIG. 11 shows a flow chart for the operation of a fourth embodiment of the present invention;
FIG. 12 shows a relation between the brightness value of an object and a recognize level for changing brightness;
FIG. 13 shows a flow chart for the operation of a fifth embodiment of the present invention;
FIG. 14 shows a flow chart for the operation of a sixth embodiment of the present invention;
FIG. 15 shows a control region of a control device;
FIG. 16 shows a flow chart for the operation of a seventh embodiment of the present invention; and
FIG. 17 shows a flow chart for the operation of an eighth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments for the present invention will be described with reference to drawings as follows.
FIG. 1 shows a block diagram of a video camera of the first embodiment of the present invention. Although each operation as claimed in the respective claims are different from each other, the structure of the video camera is common. The equipment structure will be explained first. As shown in FIG. 1, a picture image of an object is formed by a lens 1 and the picture image is input to a charge coupled device (CCD) 3 through an iris. Additive complementary color (cyanogen, magenta, yellow, green) filters are provided at an image pick up surface of the charge coupled device 3. A charge signal E indicates that the object is input to a signal processing circuit 5 through a sample hold (S/H) and automatic gain control (AGC) circuit 4. The signal processing circuit 5 outputs a brightness signal Y and elementary color signals R, G and B by processing the charge signal E. The elementary color signals R, G and B are white balance controlled in a white balance control device 6, γ-adjusted in a γ adjustment circuit 7 and input to a matrix circuit 8. In the matrix circuit 8, the elementary color signals R, G and B are matrix processed and the color difference signals are output. In an encoder 9, the color difference signals are orthogonally two phase modulated and the brightness signal Y is added to the signals and then the signal is output as a video signal by the NTSC method.
An output from the S/H and AGC circuit 4 is digitally converted in an analog/digital (A/D) converter 18, integrated in an integral circuit 19 and then input to a microcomputer 10. In the microcomputer 10, an AGC control signal is transmitted to the S/H and AGC circuit 4 through a digital/analog converter 11 based on an integrated value output from the S/H and AGC circuit 4. In the microcomputer 10, a zoom information P1 is transmitted from a lens driver and an iris data P2 for indicating an opening degree of an iris is transmitted from a hole element 12 for detecting an iris degree.
The microcomputer 10 computes a brightness of an object based on the opening degree of the iris 2, the gain and the electronic shutter speed from the S/H and AGC circuit 4. That is, the higher that the brightness of an object becomes, the narrower that an opening degree of the iris 2 becomes. On the other hand, the lower that the brightness of an object becomes, the wider that an opening degree of the iris 2 becomes. When the iris 2 is opened, the lower that the brightness of an object becomes, the greater that a gain of the S/H and AGC circuit 4 becomes. At that time, when the electronic shutter is actuated at high speed, the opening degree of the iris 2 and the gain information from the S/H and AGC circuit 4 becomes dark. The microcomputer 10 computes this information so that the brightness of the object can be detected.
On the other hand, the color difference signals R-Y and B-Y output from the matrix circuit 8 is averaged in low pass filters 13 and 14. The signals are converted to digital signals in analog/digital converters 15 and 16 and then output to the microcomputer 10, respectively. In the microcomputer 10, integral averaged values of the color difference signals R-Y and B-Y, which are computed in a condition that an averaged color of all colors at a reference color temperature, are designated as reference values, respectively.
A white balance control signal (Rcont) for a red signal, which equalizes the integral averaged value of the color difference signals R-Y and the reference value of the color difference signal R-Y, and a white balance control signal (Bcont) for a blue signal, which equalizes the integral averaged value of the color difference signal B-Y and the reference value of the color difference signal B-Y, are output from the microcomputer 10. The signals Rcont and Bcont are analog converted in a digital/analog converter 17 and then transmitted to the white balance control device 6. In the white balance control device 6, the gain of an elementary red color signal R and an elementary blue color signal B is controlled in accordance with the value of the white balance control signals Rcont and Bcont, respectively and a feed back control of the white balance is actuated. A timing and an area of the white balance control with respect to the white balance control signals Rcont and Bcont will be described.
A device for manually selecting a light source with a switch 20 is connected to the microcomputer 10. The switch 20 can select three kinds of light sources, that is, sunshine, electric bulb and fluorescent lamp. As shown in FIG. 2, in accordance with the selected light source, an initial value r-0 of a white balance control signal Rcont for a red color signal, an initial value b-0 of a white balance control signal Bcont for a blue color signal and a variable area β for these control signals Rcont and Bcont are preset in the microcomputer 10 corresponding to each kind of light source.
The first embodiment of the present invention will be described next with an explanation for the operation of the microcomputer 10. As shown by a flow chart in FIG. 3, a battery source is turned on in a step 1 and then an initial operation for white balance control is actuated in a step 2. As shown in FIG. 4, at first, a value r-0 as a white balance control signal Rcont for a red signal and a value b-0 as a white balance control signal Bcont for a blue signal are output from the microcomputer 10. The values r-0 and b-0 are preset values. Then, integral averaged values of white balance controlled color difference signals R-Y and B-Y, which correspond to the values r-0 and b-0 of the white balance control signals Rcont and Bcont, are input to the microcomputer 10 and the integral averaged values of the color difference signals and the reference values are compared. As a result of the comparison, if differences between the integral averaged values of the color difference signals and the reference values are more than predetermined values, the values of the white balance control signals Rcont and Bcont are stepped up or down and then output. The values of the white balance control signals Rcont and Bcont are successively stepped up or down and then output until the differences between the integral averaged values of the color difference signals and the reference values are less than the predetermined values. When the differences are less than the predetermined values (for example, 10LSB [Least Significant Bit]), the values of white balance control signals Rcont and Bcont become constant, which is called "converging".
FIG. 5 shows step values r-1 and b-1 of the white balance control signals Rcont and Bcont, which are stepped up four times from the initial values r-0 and b-0 of the white balance control signals Rcont and Bcont as shown in FIG. 4.
The values of the white balance control signals Rcont and Bcont are increased or decreased step by step. Therefore, eight variations can be obtained by changing at least one of the values one step toward one of the bidirections as shown in FIG. 6.
Again as shown in FIG. 3, after the initial operation is finished, present values r-1 and b-1 (c.f. as shown in FIG. 5) of the white balance control signals Rcont and Bcont are memorized and a brightness value at a converged time is detected and then memorized in a step 3. Further, a variable region α as shown in FIG. 5 is determined. In this example, an upper boundary line and a lower line of the variable region α is determined by increasing or decreasing the converged value b-1 four steps, respectively. A right end boundary line and a left end boundary line of the variable region α is determined by increasing or decreasing the converged value r-1 four steps, respectively.
The integral averaged values of the color difference signals are input in a step 4. It is judged whether or not differences between the integral averaged values and the reference values are less than the predetermined value in a step 5. If the differences are more than the predetermined value, it means that the white balance control is improper. Then, in a step 6, it is computed whether the values of the white balance control signals Rcont and Bcont should be increased or decreased in order to control white balance properly.
In a step 7, it is judged whether a displacement of the present brightness is more than the predetermined value (for example, 0.4BV: Brightness Value) with respect to a previously memorized brightness value (memorized in the step 3). If a displacement amount is more than the predetermined value, it is considered that an object is changed and the operation goes to a step 8. One of the characteristics of the present embodiment is to detect whether an object is changed or not in response to a displacement of the brightness value of an object.
In the step 8, it is detected whether the present values of the white balance control signals Rcont and Bcont are within a predetermined variable region α. If the values are within the variable region α, the operation goes to a step 9. In the step 9, the values of the white balance control signals Rcont and Bcont, which are increased or decreased by one step, are output. In the step 6, it is already determined whether the values are increased or decreased.
By repeating a control operation of the steps 4, 5, 6, 7, 8 and 9 in the flow chart, the values of the white balance control signals Rcont and Bcont are successively changed. FIG. 7 shows that the values of the white balance control signals Rcont and Bcont are successively stepped up three times and changed from the values r-1, b-1 to the values r-2, b-2 by repeating the operation control of the steps 4 through 9 in the flow chart.
On the other hand, for example as shown in FIG. 7, when the values of the white balance control signals Rcont and Bcont are converged at the values r-2 and b-2, that is, the difference is determined to be less than the predetermined value in the step 5 in the flow chart of the control operation as shown in FIG. 3, the operation returns to the step 3. In the step 3, the converged values r-2 and b-2 of the white balance control signals Rcont and Bcont are memorized and the brightness value at the time are memorized. Further, a new variable region α-1 is determined. An upper boundary line and a lower boundary line of the new variable region α-1 are determined by increasing and decreasing the converged step value b-2 by four steps, respectively. A right end boundary line and a left line boundary line of the new variable region α-1 are determined by increasing and decreasing the converged step value r-2 by four steps, respectively. Thus, a variable region is renewed from the region α to the region α-1.
In the present embodiment, as shown in FIG. 8, when the values r-1 and b-1 of the white balance control signals Rcont and Bcont are changed to the values and b-3 by stepping up four times and the values r-3 and b-3 become border values of a variable area α, the values of the white balance control signals are fixed without varying, although a difference between integral averaged values of the color difference signals and the reference values are more than the predetermined values. In the flow chart as shown in FIG. 3, an operation does not go to the step 9 in the case when it is determined that the values of Rcont and Bcont are not within a variable region in the step 8. If the values of the white balance control signals become the boundary values of the variable area, the values of the white balance control signals are fixed although the differences between the integral averaged values of the color difference signals and the reference values are more than the predetermined values. It is a so called "fixing" that the values of the white balance control signals Rcont and Bcont are controlled not to be changed when the values become the boundary values. In case of the "fixing" and the "converging", the values of the white balance control signals are not changed. In the case of the fixing, the differences between the integral averaged values of the color difference signals and the reference values are more than the predetermined values. In the case of the converging, the differences are less than the predetermined values.
If it is determined that the values of Rcont and Bcont are not within a variable region in the step 8 and the values of the white balance control signals Rcont and Bcont are fixed, the operation returns to the step 3. In the step 3, the fixed values (r-3, b-3 as shown in FIG. 8) of the white balance control signals Rcont and Bcont are memorized and the brightness value at the time is also memorized, and a new variable region α-2 having a horizontal width equalizing with + four step value and a vertical length equalizing with + four step value with respect to step values r-3 and b-3.
In an embodiment according to the present invention, a movable area of the values of the white balance control signals Rcont and Bcont is restricted and specified within the variable area. Even if a mono-colored object is suddenly photographed, the values of the white balance control signals Rcont and Bcont are not significantly changed. Therefore, an occurrence of color failure can be prevented. This feature is one of the most important characteristics of the present embodiment. A practical photographic action will be described as follows.
In the step 7 as shown in FIG. 3, if it is judged that brightness value is not changed by more than the predetermined value from the value at the previous converged time or the brightness value at the last fixed time, the operation returns to the step 4.
The practical photographic action with reference to the flow chart of the control operation as shown in FIG. 3 will be explained. For example, a beach side is photographed at first and then a bright blue ocean is photographed.
When turning on a battery switch at a beach side, the values of the white balance control signals Rcont and Bcont are converged by initially operating white balance control (steps 1 and 2). The converged values and the brightness at the beach side are memorized and then a variable region is specified.
Generally, the white balance control at the beach side is not significantly changed. When the operation goes to the step 5, the difference is determined to be less than the predetermined value. Therefore, the operation does not go to the step 9 and the values of the white balance control signals Rcont and Bcont are not changed. If a red swimming wear is photographed, the differences between the integral averaged values of the color difference signals and the reference values become large and the difference is determined to be Greater than the predetermined value in the step 5. However, it is determined that the brightness value does not change by a predetermined amount in the step 7 in the case that a displacement of the brightness is less than the predetermined value as a result, the operation does not go to the step 9 so that the values of the white balance control signals Rcont and Bcont are not changed and color failure does not occur.
If a bright blue ocean is rapidly photographed for a whole scope of a picture, the differences between the integral averaged values of the color difference signals and the reference values become large and the difference is determined to be greater than the predetermined value in the step 5. If the brightness value of the ocean becomes much higher than the brightness value of the beach side and the brightness value is determined to change by a predetermined amount in the step 7, the step values of the white balance control signals Rcont and Bcont are stepped up (down) one time and output in the step 9. After repeating the steps 4 through 9 several times, the values of the white balance control signals Rcont and Bcont become boundary values and the values of Rcont and Bcont are determined to be outside of the variable region in the step 8, and the values of the white balance control signals Rcont and Bcont are fixed without going to the step 9.
As described above, although a difference between the integral averaged values of the color difference signals to be photographed for a blue ocean in a full scope of a picture and the reference values are large, the values of the white balance control signals Rcont and Bcont are fixed when the values become the boundary values of the variable region. Thus, even if a blue ocean is photographed, the values of the white balance control signals Rcont and Bcont are not significantly changed and color failure does not occur.
Unless the variable region is predetermined, the values of the white balance control signals Rcont and Bcont are changed by a large amount. Although an averaged color of all colors in a picture is blue, the averaged color is recognized as an achromatic color and the white balance control is operated so that a blue ocean becomes grey and color failure occurs.
A structure of the first embodiment of the present invention specifies a variable region so as to provide a limit of the displacement of the values of the white balance control signals Rcont and Bcont.
When an ocean is photographed, the fixed values of the white balance control signals Rcont and Bcont and the brightness of the ocean are memorized and then a new variable region is determined with respect to the memorized values (step 3). In the step 7, the brightness value is determined not to change by a predetermined amount, since the ocean brightness value at this time is the same as the ocean brightness value at the previous time. The operation does not go to the step 9 and the values of the white balance control signals Rcont and Bcont are not changed.
Next, the second embodiment according to the present invention will be described with respect to FIG. 9. In comparison with the first embodiment according to the present invention (as shown in FIG. 3), the steps of the second embodiment of the present invention are the same as the steps of the first embodiment of the present invention except for the addition of a step 2-1.
In the step 2-1 as shown in FIG. 9, zoom information P1 is input. When the camera is shifted to a telescope condition, an area of the variable region determined in the step 3 becomes narrow (for example, the width and the length of the variable region are +2 step value). When the camera is shifted to a wide condition, an area of the variable region determined in the step 3 becomes normal space (for example, the width and the length of the variable region are +4 step value).
A reason why the variable region becomes narrow in the telescope condition is as follows. When photographing in the telescope condition, a picture would be dominated by one object. If the color of the object is mono-color, it is recognized that a color temperature is changed and color failure occurs although the color temperature does not change. Therefore, the camera is shifted to a telescope condition, and displacement values of the white balance control signals are strictly specified by narrowing the variable region in order to prevent the color failure from occurring.
Next, the third embodiment according to the present invention along a description of an operation of the microcomputer 10 will be described. As shown in a flow chart in FIG. 10, a battery source is switched on in a step 101 and an initial operation of the white balance control is actuated in a step 102. The initial operation is the same as the step 2 shown in FIG. 3.
After finishing the initial operation, the operation goes to a step 103 and the zoom information is input. Next, in a step 104, the present values r-1 and b-1 (see an example as shown in FIG. 5) of the white balance control signals Rcont and Bcont are memorized simultaneously with memorizing the brightness value at a converging time. Further, as shown in FIG. 5, a variable region α is determined. A recognition level for changing the brightness value is specified corresponding to the zoom information.
The recognition level for changing brightness will be explained as follows.
(1) In the telescope condition, the recognition level for changing the brightness value is 0.8 Bv (Brightness value) with respect to a plus direction and 1.4Bv with respect to a minus direction.
(2) In the wide condition, the recognition level for changing the brightness value is 0.4Bv with respect to a plus direction and 0.8Bv with respect to a minus direction.
The value of the recognition level for changing brightness increases slightly from the wide condition to the telescope condition.
In a step 105, the color difference signals are input and it is judged whether the differences between the integral averaged values of the color difference signals and the reference values are less than the predetermined values in a step 106. If the differences are more than the predetermined value, then the white balance is controlled improperly. Then, the operation goes to a step 107 and it is determined whether the values of the white balance control signals Rcont and Bcont should be increased or decreased in order to control white balance properly.
In a step 108, it is judged whether a difference between the present brightness value and the previous memorized brightness value (memorized in the step 104) is more than the recognition level for changing brightness detected in the step 104. If the difference is more than the recognition level for changing brightness, it is judged that an object is changed and an operation goes to a step 109.
If a following equation is assumed;
(present brightness)+(previous memorized value)-(brightness value)=d,
(1) in the telescope condition, it is judged that an object is changed in the case that the difference d is more than 0.8Bv or less than -1.4Bv, and
(2) in the wide condition, it is judged that an object is changed in the case that the difference d is more than 0.4Bv or less than -0.8Bv.
The technique according to the third embodiment of the present invention is on the premise that a change of an object is base detected by a displacement of the brightness value of the object.
In a step 109, it is judged that the present values of the white balance control signals Rcont and Bcont are within the variable region α determined in the step. 104. If the present values are within the variable region α, the operation goes to a step 110. In the step 110, the values of the white balance control signals Rcont and Bcont are stepped up or down by one step and then output. The judgement of whether the values are increased or decreased is determined in the step 107.
While the control operation of the steps 105, 106, 107, 108, 109 and 110 of the flow chart are repeated, the values of the white balance control signals Rcont and Bcont are successively changed. As shown in FIG. 7, the values of the white balance control signal Rcont are stepped up three times and changed from the value r-1 to the value r-2 and the value of the white balance control signal Bcont is stepped up three times and changed from the value b-1 to the value b-2 by repeating the control operation of the steps 105 through 110 of the flow chart three times.
On the other hand, when the values of the white balance control signals Rcont and Bcont are converged to the values r-2, b-2, respectively, in FIG. 7, that is, the difference is determined to be less than a predetermined value in the step 106 in a flow chart as shown in FIG. 10, the operation returns to the steps 103 and 104 and the converged values of the white balance control signals Rcont and Bcont r-2, b-2 are memorized and the brightness value at the time is also memorized. Further, a new variable region α-1 having a ± four step horizontal width and a ± four step vertical length with respect to the step values r-2 and b-2 is used as a central point. That is, the variable region is renewed from the region α to the region α-1. Further, the recognition level for changing, which corresponds to the zoom information, is set again.
Further, in the embodiment according to the present invention, as shown in FIG. 8, in the case that the values of the white balance control signals Rcont and Bcont are positioned in the variable region α, when the values are stepped up four times, changed from the values r-1 and b-1 to the values r-3 and b-3 and become boundary values of the variable region α, the values of the white balance control signals are fixed without changing, although the integral averaged values of the color difference signals and the reference value are more than the predetermined value. In the flow chart as shown in FIG. 10, the values of Rcont and Bcont are determined to be outside of the variable region in the step 109 so that an operation does not go to the step 110. As described above, when the values of the white balance control signals Rcont and Bcont become the boundary values of the variable region, the values are fixed, although the differences between the integral averaged values for color difference signals and the reference values are more than the predetermined values.
If the values of Rcont and Bcont are determined to be outside the variable region and the values of the white balance control signals Rcont and Bcont are fixed in the step 109, the operation goes back to the steps 103 and 104, the fixed values of the white balance control signals r-3 and b-3 (for example, in FIG. 8) are memorized and the brightness values at the time is also memorized. A new variable region α-2 is specified having a + four step horizontal width and a + four step vertical length with respect to the step values r-3 and b-3 as a central point of the variable region. The recognition level for changing brightness is set again.
As described above, in the embodiment according to the present invention, the area where the values of the white balance control signals Rcont and Bcont can be varied is limited within a variable region, so that the values of the white balance control signals Rcont and Bcont cannot be significantly changed, even if a mono-colored object is suddenly photographed. Therefore, it is possible to prevent color failure from occurring.
In this embodiment according to the present invention, a recognition level for changing brightness is changed depending on the telescope condition and the wide condition. When the camera is shifted to the telescope condition, the present brightness value is the brightness value at the last converged time and the values of the white balance control signals Rcont and Bcont are changed only when the brightness values are significantly changed. When the camera is shifted to the wide condition, the brightness value is changed when the present brightness value is changed by a small amount from the (fixed) value at the last converged time. The sensitivity for the brightness value is changed corresponding to the telescope condition and the wide condition, which is one of the most important features of the present embodiment.
As described above, a reason why the recognition level for changing brightness becomes higher in the telescope condition in order to avoid a change of the values of the white balance control signals Rcont and Bcont will be described as follows. When an object is photographed in the telescope condition, a part of a picture may occasionally be dominated by one object. If a color of one object is mono-color, a recognition of changing the color temperature may be mistaken and color failure occurs, although the color temperature is not changed. Therefore, an object is determined to have changed only when the brightness value is significantly changed in the telescope condition. Thus, the values of the white balance control signals Rcont and Bcont are changed and a recognition of changing color temperature is prevented from being mistaken. In a view of a different point, a displacement of brightness value in a whole scope of a picture in the telescope condition is generally larger than the displacement of the brightness value in the wide condition. Therefore, in the telescope condition, the recognition level for changing the brightness value is made higher.
In the step 108 as shown in FIG. 10, it is judged that a brightness value is not changed more than a predetermined value from the brightness value at the last converged time or the previous fixed value and then the operation returns to the step 105.
The fourth embodiment of the present invention will be explained next with reference to a flow chart as shown in FIG. 11. An operation of a flow chart as shown in FIG. 11 is the same as the operation control of the flow chart as shown in FIG. 10 except for the operation of steps 103 and 104. The differences of these steps will be described.
After a battery source is switched on and an initial operation of the white balance control is finished (steps 101, 102), a brightness data of an object is input in the step 103 and a recognition level for changing brightness corresponding to the brightness value of the object is specified in the step 104.
FIG. 12 shows a relation between the brightness value of an object and a predetermined recognition level for changing brightness. As shown in FIG. 12, in the embodiment according to the present invention, if the brightness value of the object is more than L1, the recognition level for changing brightness is sex as β1. If the brightness value of the object is less than L1, the recognition level for changing brightness is set as 0.
The recognition level for changing brightness is set as shown in FIG. 12, so that variations of changing the values of the white balance control signals Rcont and Bcont are divided to two variations on a border of the brightness value of the object L1 in the present embodiment.
(1) When the brightness value of the object is equal to or more than L1, a difference between integral averaged values of color difference signals and the reference values is more than the predetermined values and the white balance control is operated improperly (the decision is judged to be YES in the step 106). When a difference between the present brightness value and a brightness value at the previous converged time (or the last fixed brightness value) is more than β1 (the decision is judged to be YES in the step 108), the values of the white balance control signals Rcont and Bcont are changed by one step value and then output (step 110), while the values are in a variable region (the decision is judged to be YES in the step 109). As a result, if the brightness value is much more than the value L1, an object is recognized as being changed and the values of the white balance control signals Rcont and Bcont are changed on a premise that the other conditions are satisfied.
(2) On the other hand, when the brightness value of the object is less than L1, the decision is always judged to be YES in the step 108. If differences between integral averaged values of the color difference signals and the reference values are more than the predetermined values (the decision is judged to be NO in the step 106), and the values of the white balance control signals Rcont and Bcont are within a variable region (the decision is judged to be YES in the step 109), that is, if the two conditions are satisfied, the values of the white balance control signals Rcont and Bcont are changed. As a result, if the brightness value of the object is less than L1, the values of the white balance control signals Rcont and Bcont are changed on a premise that the above described two conditions are satisfied (steps 106, 109) and the detection of a change of the brightness value of an object is stopped because a photographic circumstance is dark and it becomes difficult to detect a change of the brightness value of an object. Accordingly, even if the photographic circumstance is dark, white balance control is always operated properly.
A control operation of the fifth embodiment will be explained next according to the present invention with reference to FIG. 13. A battery source is switched on in a step 201, and a value of the white balance control signal for a red signal as an initial value and a value of a white balance control signal for a blue signal as an initial value are output from the microcomputer 10. Accordingly, the initial values are preset. Next, the microcomputer 10 inputs integral averaged values for color difference signals which are white balance controlled depending on the values of the white balance control signals Rcont and Bcont as the initial values in a step 203. In a step 204, it is judged whether differences between the integral averaged values of the color difference signals and the reference values are more than the predetermined values (for example, 10LSB [Least Significant Bit]). If the judgement is NO, it is recognized that the values are not converged and the operation goes to a step 205. In the step 205, it is computed whether the values of the white balance control signals Rcont and Bcont should be increased or decreased in order to control white balance.
In a step 206, it is judged whether the differences between integral averaged values of the color difference signals and the reference values are more than switching values. The switching values are more than the predetermined values determined in the step 204. If the differences between the integral averaged values and the reference values are more than switching values, the operation goes to a step 207 and the values stepped up (down) once of the white balance control signals Rcont and Bcont are output because the values of the white balance control signals Rcont and Bcont are quite different from the converged values.
When the values of the white balance control signals Rcont and Bcont are different from the converged values and the difference between the integral averaged values of the color difference signals and the reference values are more than the switching values, the steps 203 through 207 of the control operation are repeated and values of the white balance control signals Rcont and Bcont renewed at intervals of 0.5 second are output. Thus, the values of the white balance control signals Rcont and Bcont are renewed by intervals of a short period and then output, so that the values will quickly converge.
As the value of the white balance control signals Rcont and Bcont approach the converged values and the differences between the integral averaged values of the color difference signals and the reference values become less than the switching value (the decision is judged to be NO in a step 206), the number of the cases is counted up in a step 208. Unless the number of the cases that the difference is less than the switching value becomes a predetermined number of times (for example, four times), the operation goes to a step 207 and the values of the white balance control signals stepped up (down) by one time value are output and the counted times are reset.
As a result, when the values of the white balance control signals Rcont and Bcont approach the converged values, the output of the white balance control signals Rcont and Bcont are thinned out and output intervals become longer. Thus, the values can be converged accurately without the occurrence of any hunting.
If the differences between the integral averaged values of color difference signals and the reference values are more than the predetermined values, that is, if the decision is judged to be YES in the step 204, the operation returns to the step 203. In this case, the values of the white balance control signals Rcont and Bcont are renewed.
The sixth embodiment of the present invention will be explained next. In the present embodiment, after the values are converged once, a converging speed becomes late by making the intervals for outputting the white balance control signals Rcont and Bcont longer.
A control operation of the sixth embodiment of the present invention will be explained with reference to FIG. 14. When a battery source is switched on in a step 301, an initial operation of white balance control is actuated in a step 302. At first, the microcomputer 10 outputs a value of a white balance control signal for a red signal Rcont as an initial value and a value of a white balance control for a blue signal as an initial value so that the initial values are preset. Next, the microcomputer 10 inputs integral averaged values of color difference signals white balance controlled corresponding to the white balance control signals Rcont and Bcont as the initial values, respectively and these values are compared with the integral averaged values of the color difference signals and the reference values. Upon comparing the values, if the differences between the integral averaged values of the color difference signals and the reference values are more than the predetermined values, the values of the white balance control signals Rcont and Bcont stepped up (down) by one step value (increased or decreased) are output. If the differences between the integral values of the color difference signals and the reference values are less than the predetermined values (for example, 10LSB [Least Significant Bit]), the values of the white balance control signals Rcont and Bcont become constant.
In the initial operation as described above, in the case that intervals for outputting the white balance control signals Rcont and Bcont are fixed at 0.5 second, the intervals may become shorter when the values are much different from the converged value and the intervals may become longer when the values become same as the converged values.
After the values converge once, the integral averaged values of the color difference signals during a photographing period are input in a step 303. In a step 304, it is judged whether the difference between the integral averaged values of the color difference signals and the reference values are less than the predetermined values. If the decision is judged to be YES, the white balance is controlled properly, the operation returns to the step 303 and the present values of the white balance control signals are maintained. If the decision is judged to be NO, the white balance is controlled improperly, and the operation goes to a step 205. In the step 305, a number of cases that the difference of the integral averaged values and the reference values are more than the predetermined value is counted.
In a step 306, it is judged whether the counted number approaches the predetermined count number (for example, four times). If the decision is judged to be NO, the operation returns to the step 303 and the present values of the white balance control signals are maintained. If the decision is judged to be YES, varying directions of the value of the white balance control signals Rcont and Bcont are computed in a step 307 and the value stepped up (down) by one step value of the white balance control signals Rcont and Bcont are output in the step 308.
Until the detecting number of the changed color temperatures becomes the count number, the values of the white balance control signals Rcont and Bcont are not renewed. Accordingly, even if a mono-colored object is photographed in a full scope of a picture, the values of the white balance control signals Rcont and Bcont are not changed and a proper white balance control can be maintained.
When the color temperatures are changed during a photographing period, the values of the white balance control are renewed only for a few number of times. That is, after the values converge in the initial condition once, it is seldom that the color temperatures change suddenly. Thereby, the object can be photographed while the values of the white balance control are slightly changed. An occurrence of color failure which happens in the case that a mono-colored object is photographed can be prevented as much as possible unless one object is photographed for a long time.
Next, the seventh embodiment of the present invention will be described. In the seventh embodiment, an indoor mode and an outdoor mode are set in a microcomputer 10 as shown in FIG. 15. In the indoor mode, the values of the white balance control signals Rcont and Bcont are positioned within a region X surrounded with a real line in FIG. 15. When a white paper is photographed under an electric bulb, a cool white fluorescent lamp, a natural fluorescent lamp, and a day light fluorescent lamp, values of the white balance control signals Rcont and Bcont are positioned at points A, B, C, and D, respectively as shown in FIG. 15. In the region X of the indoor mode, each of the converged values of the white balance control signals photographed on a white paper under a respective artificial light are included and the region X becomes narrow. On the other hand, in the outdoor mode, the values of the white balance control signals Rcont and Bcont are positioned within a region Y surrounded with a long and short dotted line in FIG. 15.
The microcomputer 10 detects brightness values of an object by judging from an iris data P8 and judges the outdoor mode if the detected brightness value is more than a mode switching value and the indoor mode if the detected brightness value is less than the mode switching value. As shown in Table 1, the fact that an outdoor brightness value is generally more bright than an indoor brightness is used.
TABLE 1
______________________________________
unit
(lux)
______________________________________
snow mountain
sky slope
beach side, fine day in summer
100,000 sunshine, fine day in the afternoon
(100,000)
sunshine, fine day at three o'clock
(35,000)
sunshine, cloudy (32,000)
10,000
sunshine, cloudy, one hour after sunrise
(2,000)
1,000 window side at the office under
fluorescent
lamp (1,000)
sunshine, fine day, one hour after sunset
(1,000)
shopping space in department store (500-700)
500 ticket gate at station (650)
office under fluorescent lamp (400-500)
eight mat space under two fluorescent
(30 W) lamp (300))
300 subway platform (300)
arcade in the night (150-200)
100
movie theater, intermisson time (15-35)
candle light (10-15)
10
______________________________________
In the microcomputer 10, white balance is controlled as follows. The microcomputer 10 increases (decreases) the values of the white balance control signals Rcont and Bcont step by step in order to make the difference between the integral averaged value of the color difference signals R-Y and B-Y and the reference values less than a value for judging convergence (for example, 10LAB [Least Significant Bit]). When the differences between the integral averaged values of the color difference signals and the reference values are less than the values for judging convergence for operating white balance control signals at the most suitable color temperature, the values of the white balance control signals Rcont and Bcont become constant.
In the outdoor mode, the values of the white balance control signals are positioned within the region Y. In the indoor mode, the values of the white balance control signals are positioned within the region X. If the values of the white balance control signals Rcont and Bcont are converged to constant values within the region X, white balance control is properly operated.
In addition, when white balance is automatically controlled and an occurrence of color failure is reduced regardless of natural light and artificial light in the outdoor and indoor modes, a controlled region of the white balance control signals Rcont and Bcont is widened as shown by a region X surrounded with a broken line in FIG. 15. To widen the controlled region, an occurrence of color failure is increased, since the other factors, except for the information of color temperature, effect the white balance control. The seventh embodiment of the present invention provides the outdoor mode and the indoor mode. In the outdoor mode, white balance is controlled within a region corresponding to a respective value of color temperature under natural light. In the indoor mode, white balance is controlled within a region corresponding to a respective value of color temperature under artificial light. Therefore, the region of the white balance control is restrictively limited. Even if green grass and a red wall is photographed of which the averaged color of all colors in a picture is not an achromatic color, an occurrence of color failure is remarkably reduced and white balance is controlled properly.
In the seventh embodiment of the present invention, after the values of the white balance control signals Rcont and Bcont are converged to values within the region Y, the values of the white balance control signals Rcont and Bcont are shifted to the region X in the indoor mode, only when the following two conditions are satisfied.
(1) The brightness values of the object are less than a value for the switching modes.
(2) The difference between integral averaged values for color difference signals R-Y and B-Y and the reference values is more than the widened converged value for judging (for example, 30LSB), where the widened converged value for judging (30LSB) is slightly greater than the converged value for judging (10LSB).
When an object is photographed outdoors, even if the above condition (1) is satisfied by photographing a dark object, the values of the white balance control signals Rcont and Bcont are not shifted to the region X in the indoor mode because the condition (2) is not satisfied. Thus, when a dark object is photographed outdoors, the white balance is properly controlled by the values of the white balance control signals within the region Y for the outdoor mode so that the object is photographed properly. If a region is changed by only having condition (1) satisfied, when a dark object is photographed outdoors, the values of the white balance control signals are shifted to the region X for the outdoor mode, so that the white balance cannot be controlled properly. On the other hand, when a person who is photographing outdoors enters into a house with a camera, the above conditions (1) and (2) are satisfied, so that the values of the white balance control signals Rcont and Bcont are shifted to the region X for the indoor mode and white balance is properly controlled indoors.
In the seventh embodiment of the present invention, after the values of the white balance control signals Rcont and Bcont are converged at the values within the region X for the indoor mode, the values of the white balance control signals Rcont and Bcont are shifted to the values within the region Y for the outdoor mode, only when the following conditions are satisfied.
(3) The brightness values of an object are greater than a value for the switching modes
(4) The difference between integral averaged values for color difference signals R-Y and B-Y and the reference values is more than the widened converged value for judging (for example, 30LSB) where the widened converged value for judging (30LSB) is slightly greater than the converged value for judging (10LSB).
When an object is photographed indoors, even if the above condition (3) is satisfied by photographing with a light source such as an electric bulb, the values of the white balance control signals Rcont and Bcont are not shifted to the region Y in the indoor mode, since the condition (4) is not satisfied. Thus, when a light source such as an electric bulb is used for photographing indoors, the white balance is properly controlled by the values of the white balance control signals within the region X for the indoor mode so that the object is photographed properly. If a region is changed by only having condition (3) satisfied, when a light source such as an electric bulb is used for photographing indoors, the values of the white balance control signals are shifted to the region Y for the indoor mode, so that the White balance cannot be controlled properly. On the other hand, when a person who is photographing indoors goes outdoors with a camera, the above conditions (3) and (4) are satisfied, so that the values of the white balance control signals Rcont and Bcont are shifted to the region Y for the indoor mode and white balance is properly controlled outdoors.
When the values are shifted from the region X to the region Y, the values change to values located in the region Y nearest to the region X. Similarly, when the values are shifted from the region Y to the region X, the values change to converged values located in the region X nearest to the region Y.
In the present embodiment, the indoor and outdoor modes are changed depending on a brightness value for switching, that is, a value for switching modes may be selected for the most suitable value in accordance with the type of video camera. The regions X and Y may be optionally selected in accordance with a design of a video camera.
Next, a control operation of the seventh embodiment will be explained according to the present invention with reference to FIG. 16. A battery source is switched on in a step 401, a value of the white balance control signal for a red signal as an initial value and a value of a white balance control signal for a blue signal as an initial value are output from the microcomputer 10 so that the initial values are preset. Next, the microcomputer 10 inputs integral averaged values for color difference signals R-Y and B-Y which are white balance controlled depending on the values of the white balance control signals Rcont and Bcont as the initial values in a step 403. In a step 404, it is judged whether a difference between the integral averaged values of the color difference signals R-Y and B-Y and the reference values are more than the predetermined values (for example, 10LSB [Least Significant Bit]). If the judgement is YES, the values converge and the operation returns to the step 403. If the judgement is NO, the values do not converge and the operation goes to a step 405.
In the step 405, brightness values are detected by inputting brightness data. In a step 406, if the brightness value of an object is more than a value for the switching mode, the region Y is selected for the outdoor mode and if the brightness value of an object is less than a value for the switching mode, the region X is selected for the indoor mode. In a step 407, it is judged whether a selected region is different from a previous region. If the selected region is the same as the previous region, the operation returns to a step 409.
In a step 408, a region is selected which is the same as the previous region and a varying direction of the white balance control is computed in a step 409. If the values of the white balance control signals Rcont and Bcont are within the region (the decision is to be judged YES in a step 410), the white balance control signals Rcont and Bcont are output of which the values are changed by one step value. If the values of the white balance control signals Rcont and Bcont are not within the region (the decision is judged to be NO in the step 410), renewed values of the white balance control signals Rcont and Bcont are not output.
If it is judged that the selected region is different from the previous region in the step 407, it is judged whether the values converge once in a step 412. After the values converge once (the decision is judged to be YES in the step 412), when a difference between integral values of the color difference signals R-Y and B-Y and the reference values are more than enlarged converged values, the operation goes to the step 408. Therein, the selected region is not utilized and the previous region is still utilized. Such an operation is operated when a light source is photographed indoors and a dark object is photographed outdoors.
When the decision is judged to be NO in a step 412 or the values of the white balance control signals Rcont and Bcont are converged once (the decision is judged to be YES in the step 412) and a difference between integral averaged values of color difference signals R-Y and B-Y and the reference values are more than enlarged converged values, the operation goes to a step 414. In the step 414, a region is changed to the region which is selected in the step 406, and the white balance control signals of which the values are positioned in the selected region are output. Such an operation is operated when a person who is photographing indoors goes outdoors or a person who is photographing outdoors goes indoors.
Next, the eighth embodiment of the present invention will be described with an explanation of an operation of the microcomputer 10. As shown by a flow chart in FIG. 17, a kind of a light source is selected in step 501 and then an initial operation for white balance control is actuated in step 502. As shown in FIG. 4, an initial value r-0 as the white balance control signal Rcont for a red signal and an initial value b-0 as the white balance control signal Bcont for a blue signal are output from the microcomputer 10. In a step 503, a variable region B is set. Then, integral averaged values of color difference signals white balance controlled R-Y and B-Y, which correspond to the values r-0 and b-0 of the white balance control signals Rcont and Bcont, are input to the microcomputer 10 and the integral averaged values of the color difference signals R-Y and B-Y and the reference values are compared in a step 504. As a result of a comparison, if differences between the integral averaged values of the color difference signals and the reference values are more than predetermined values, values of the white balance control signals Rcont and Bcont are stepped up (down) and then output. The values of the white balance control signals Rcont and Bcont are successively stepped up (down) and output until the differences between the integral averaged values of the color difference signals R-Y and B-Y and the reference values are less than the predetermined values. When the differences are less than the predetermined values (for example, 10LSB [Least Significant Bit]), the values of the white balance control signals Rcont and Bcont become constant. However, the values of the white balance control signals Rcont and Bcont are limited within the variable region β in accordance with the kind of selected light source.
Further, the operation of steps 504 through 508 as shown in FIG. 17 will be explained. As described above, integral averaged values of the color difference signals R-Y and B-Y are input in the step 504 and then it is judged whether the integral averaged values of the color difference signals R-Y and B-Y and the reference values are less than the predetermined values in a step 505. If the difference is more than the predetermined values, then the white balance control is improper and the operation returns to the step 504 and the integral averaged values of the color difference signals R-Y and B-Y are input.
In the step 507, it is judged whether the present values of the white balance control signals Rcont and Bcont are within the variable region β selected in the step 503. If the values are within the variable region β, the operation goes to a step 508. In the step 508, the white balance control signals Rcont and Bcont are increased or decreased by one step value. In the step 506, it is judged whether the values should be increased or decreased. If the values are positioned out of the variable region β, the white balance control signals Rcont and Bcont are not output and the operation returns to the step 504.
After repeating an operation of the steps 504, 505, 506, 507, and 508 of a flow chart, the values of the white balance control signals Rcont and Bcont are successively changed within the variable region B. Gains of a red signal circuit and a blue signal circuit are changed within a variable region so that a deterioration of the reproduced color does not occur even though there is a difference between a selected light source and an actual color temperature.
As described above, according to the first embodiment of the present invention, a variable amount of white balance control signals are limited in the variable region so that color failure is prevented from occurring even if an object is photographed in which one specific color dominates.
The variable region can be renewed by the values of the white balance control signals converged or fixed. Thereby, a proper white balance is controlled even if the color temperature of the object is actually changed.
According to the second embodiment of the present invention, a variable region becomes narrow in a telescope condition for zooming. Thereby, color failure is prevented from occurring in the telescope condition.
According to the third- and fourth- embodiments of the present invention, values of white balance control signals are changed in order to equalize integral averaged values of color difference signals and the reference values when a difference between a present brightness value and a brightness value at the last converged time is more than a recognition level for changing brightness. Thereby, the white balance control device can control white balance properly without having color failure occur when an object is photographed under a light source or without a light source.
According to the fifth embodiment of the present invention, when a difference between the integral averaged values of color difference signals and the reference values is more than the switching values, that is, the values of the white balance control signals are quite different from the converged values, a converging period becomes shorter since output intervals of the white balance control signals are-made to be shorter. When the difference between the integral averaged values and the reference values are less than the switching values, that is, the values of the white balance control signals are near to the converged values, the values are accurately converged without the occurrence of any hunting since output intervals of the white balance control signals are made to be longer.
According to the sixth embodiment of the present invention, after the values are converged once, output intervals of white balance control signals are made to be longer. When a color of an object is suddenly changed, white balance can be continuously controlled without changing the control condition of the white balance.
According to the seventh embodiment of the present invention, an outdoor mode and an indoor mode are provided and controllable regions are set for each mode in order to control white balance in the best condition.
In the seventh embodiment, after the white balance control signals converge once, a change from the outdoor mode to the indoor mode occurs responsive not only to the brightness value of an object but also to a difference between integral averaged values of color difference signals and the reference values. Therefore, a region for a corresponding mode is not changed even if a light object is photographed indoors and a dark object is photographed outdoors so that white balance is properly controlled. The region for the corresponding mode is changed when a color temperature is actually changed from an indoor condition to an outdoor condition.
According to the eighth embodiment of the present invention, when a light source is manually selected, a variable region is changed in accordance with a light source selected from white balance control signals, so that the white balance is properly controlled without a deterioration of the reproduced color even if there is a slight difference between a selected light source and an actual color temperature.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modification as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
We claim:
1. A method for controlling white balance control signals, comprising the steps of:(a) controlling white balance by controlling an amplification degree of a red elementary color signal and a blue elementary color signal out of red-, green- and blue-elementary color signals; (b) outputting first and second color difference signals by processing elementary color signals white balance controlled by said step (a); (c) detecting a brightness value of an object; (d) selecting between an outdoor mode for properly photographing under natural light and an indoor mode for properly photographing under an artificial light in accordance with said brightness value; (e) controlling means for controlling white balance within a first selected restricted region by considering color temperature of natural light in said outdoor mode and white balance within a second selected restricted region by considering each color temperature of respective artificial light in said indoor mode; and (f) changing values of white balance control signals to a value corresponding to one of said indoor mode and said outdoor mode in accordance with said brightness value of said object an integral averaged values of said first and second color difference signals.
2. The method as recited in claim 1, wherein said selecting step (d) comprises selecting said outdoor mode when said brightness value of said object is higher than a level for changing modes and selecting said indoor mode when said brightness value of said object is less than said level for changing modes.
3. The method as recited in claim 2, wherein said changing values step (f) comprises, after said white balance control signals converge to a value corresponding to said outdoor mode and said brightness value of said object is less than said value for changing modes and differences between said integral averaged values of said first and second color difference signals and reference values are more than a level for detecting convergence, changing values of white balance control signals to a value corresponding to said indoor mode, and, after said values of white balance control signals converge to a value corresponding to said indoor mode and said brightness value of said object is higher than said value for changing modes and differences between said integral averaged values of said first and second color difference signals and said reference value are more than said level for detecting convergence, changing values of white balance control signals to a value corresponding to a said outdoor mode.
4. The method as recited in claim 1, further comprising, prior to said selecting step (d), integrally averaging said first and second color difference signals, determining whether integral averaged value of said first and second color difference signals exceed a convergence value, and, if said convergence value is exceeded, returning to said controlling step (a) for a next input signal.
5. The method as recited in claim 1, further comprising determining whether a mode selected by said selecting step (d) is the same as a previous mode.
6. The method as recited in claim 5, further comprising computing, when said mode is the same as said previous mode, a varying direction of said first and second color difference signal, determining whether said first and second color difference signals are within a region corresponding to said mode, and, when said first and second color difference signals are within said region, altering said white balance control signals in accordance with said varying direction.
7. The method as recited in claim 5, wherein, when said mode is different from said previous mode said changing step (f) includes determining if said previous mode was selected and determining whether a difference between reference values and said integral averaged values of said first and second color difference signals is less than an expanded convergence value.
8. The method as recited in claim 7, wherein said changing values step (f) comprises, when said difference is greater than said expanded convergence value, changing values of white balance control signals to a value corresponding to said mode selected by said selecting step (e).
9. The method as recited in claim 7, comprising, when said difference is less than said expanded convergence value, maintaining said previous mode and values of white balance control signals.
10. The method as recited in claim 9, further comprising, when said mode is the same as said previous mode, computing a varying direction of said first and second color difference signal, determining whether said first and second color difference signals are within a region corresponding to said mode, and, when said first and second color difference signals are within said region, altering said white balance control signals in accordance with said varying direction.
11. A white balance control device comprising:first white balance control means for controlling white balance by controlling an amplification degree of a red elementary color signal and a blue elementary color signal out of red-, green-, and blue-elementary color signals; matrixing color means for outputting first and second color difference signals by processing elementary color signals white balance controlled by said first white balance control means; detecting means for detecting a brightness value of an object; mode selecting means for selecting between an outdoor mode for properly photographing under natural light and an indoor mode for properly photographing under an artificial light in accordance with said brightness value; second white balance controlling means for controlling white balance within a first selected restricted region by considering color temperature of natural light in said outdoor mode and white balance within a second selected restricted region by considering each color temperature of respective artificial light in said indoor mode; and value changing means for changing values of white balance control signals to a value corresponding to one of said indoor mode and said outdoor mode in accordance with said brightness value and integral averaged values of said first and second color difference signals.
12. A white balance control device as recited in claim 11, wherein said mode selecting means selects said outdoor mode when said brightness value of said object is higher than a level for changing modes and selects said indoor mode when said brightness value of said object is lower than said level for changing modes.
13. A white balance control device as recited in claim 12, wherein said value changing means changes values of white balance control signals to a value corresponding to said indoor mode after said values of white balance control signals converge to a value corresponding to said outdoor mode when said brightness value of said object is less than a level for changing modes and differences between reference values and said integral averaged values of said first and second color difference signals are more than a level for detecting convergence.
14. A white balance control device as recited in claim 13, wherein said value changing means changes values of white balance control signals to a value corresponding to said outdoor mode after said values of white balance control signals converge to a value corresponding to said indoor mode when said brightness value of said object is higher than a level for changing modes and differences between reference values and said integral averaged values of said first and second color difference signals are more than said level for detecting convergence.
15. A white balance control device as recited in claim 11, wherein said value changing means changes values of white balance control signals to a value corresponding to said indoor mode after said values of white balance control signals converge to a value corresponding to said outdoor mode when said brightness value of said object is less than a level for changing modes and differences between reference values and said integral averaged values of said first and second color difference signals are more than a level for detecting convergence.
16. A white balance control device as recited in claim 15, wherein said value changing means changes values of white balance control signals to a value corresponding to said outdoor mode after said values of white balance control signals converge to a value corresponding to said indoor mode when said brightness value of said object is higher than a level for changing modes and differences between reference values and said integral averaged values of said first and second color difference signals are more than said level for detecting convergence.
17. A white balance control device as recited in claim 11, wherein said value changing means changes values of white balance control signals to a value corresponding to said outdoor mode after said values of white balance control signals converge to a value corresponding to said indoor mode when said brightness value of said object is higher than a level for changing modes and differences between reference values and said integral averaged values of said first and second color difference signals are more than a level for detecting convergence.
| 1995-05-23 | en | 1996-10-15 |
US-23513762-A | Process of using shellac-compositions
United States Patent 3,215,551 PROCESS OF USING SHELLAC-COMPOSITIONS Irving Skeist, Summit, N.J., Rock F. Martel, Stamford,
Conn., and Werner R. Kuebler, Ho-Ho-Kus, N..l., assiguors to Gillespie-Rogers-Pyatt Co., Inc, New York, N.Y., a corporation of Delaware No Drawing. Filed Nov. 2, 1962, Ser. No. 235,137 12 Claims. (Cl. 106-236) T his invention relates to coating compositions of shellac and blocked organic isocyanates and certain applications thereof. In particular, this invention refers to coating compositions prepared from shellac and blocked organic isocyanates which are applied to a substrate and then cured by heat.
The reactivity of the isocyanate radical with compounds containing labile hydrogen is known. For example, organic polyisocyanates react with certain polyols to form compositions useful for surface coatings. In the preparation of these compositions a polyol is reacted with the polyisocyanate to give a cross-linked structure.
Shellac is a natural resin having several free hydroxyl groups. Moreover, the shellac molecule has other reactive groups such as the carboxy. Shellac will also form cross-linked structures with itself on continued heating. Therefore, when using shellac, in order to obtain crosslinked products which are suitable for surface coatings it is possible to use monoisocyanates as well as polyisocyanates.
For coating on substrates which later can be heated, for example, in wire coating, it is possible to blend together in the proper proportions solutions of the two active ingredients just before use, apply the mixed composition to the substrate, allow the solvent to dry to a film and then cure the film by heating. However, for ease of operation and convenience it is desirable to have these materials available in one package which requires no mixing or blending at the time of use.
In these chemical reactions, the marked reactivity of the organic isocyanate compounds with the shellac results in certain difficulties with regard to stability. In carrying out reactions with the isocyanates, care must be exercised to prevent undesirable reactions by carefully controlling the various steps such as order of addition, temperature, presence of moisture and the like in order to avoid undesirable side reactions. This invention provides a means for controlling the reactivity of the isocyanate with the shellac so that one-package systems can be used.
In our co-pending application Serial No. 235,138, filed November 2, 1962, stable one-package coating compositions are described in which the reaction of the shellac with the isocyanate has taken place prior to applying the coating composition on the substrate, and also onepackage stable coating compositions in which an excess of isocyanate is used and the terminal isocyanate groups of an intermediate prepoylmer are cured after applying the coating composition on the substrate by the action of moisture from the air. Neither of these systems require a heat cure after application.
This invention describes stable one-package coating compositions which are useful for substrates which can be heated. After the film is applied, these compositions have the advantage that a more uniform curing rate and greater product control are possible, since the cure is not dependent upon ambient temperature and humidity conditions.
According to our invention stable one-package coating compositions are prepared from shellac and organic isocyanates in which the reactive isocyanate groups are hindered or blocked to render them relatively inactive with the shellac at lower temperatures, but reactive with the shellac at higher temperatures.
3,215,551 Patented Nov. 2, 1%65 The reaction between the isocyanate and the blocking agent is a reversible reaction, the direction of which is controlled by temperature:
Room temp.
Nil-150 C The adduct is formed at relatively low temperatures, while the dissociation into the isocyanate and the blocking agent takes place at relatively high temperatures. The preferred temperature range for formation and dissociation of the organic isocyanate adduct varies with the particular isocyanate and the blocking agent employed. The formation of adducts is also a useful means for controlling the tendency of polyisocyanates to self-polymerize since the inactivation of the isocyanate group will retard such polymerization.
When no blocking agent is used, almost immediately after the addition of the isocyanate, and before the coating composition can be applied to the surface, the isocyanate groups react at room temperature with the shellac molecule, causing premature cross-linking and gelation. However, when the isocyanate adduct is used as the crosslinking agent under otherwise strictly comparable conditions the composition remains in very satisfactory condition and after storage is applied without difliculty to the surface at room temperature by the conventional spraying techniques. A simple heat curing treatment produces on the coated surfaces a uniformly hardened film of outstandingly good properties.
The blocking agents which are useful for preparing stable shellac-isocyanate coating compositions include certain alcohols, cyclic alcohols, phenols, mercaptans, lactams, imides, imines and compounds containing methylene hydrogen. Among the compounds which may be employed are acetoacetic ester, dimethyl malonate, 2-mercaptobenzothiazole, succinimide, phthalimide, naphthalimide, glutarimide, tertiary amyl alcohol, dimethyl phenyl carbinol, tertiary butyl phenol, and diphenylamine. The preferred blocking agents are cyclohexanol and phenol.
Dewaxed, decolorized shellac may be considered as representative of pure shellac resin, and is used in the examples unless otherwise indicated. Other types of shell-ac may be employed. Natural shellac contains wax, red coloring matter and moisture. Generally, when the natural resin is used the solution of the shellac in the solvent can be decanted off from the wax which settles out. Orange shellac is unbleached shellac which may be in the form of flakes, sheets, buttons and the like. It may be employed in any formulations where the color is unobjectionable.
A wide variety of organic isocyanates may be employed, ranging from simple monoisocyanate compounds up to polymeric materials containing isocyanate groups. Examples of isocyanate compounds include the monoisocyanates, such as the alkyl isocyanates; ethyl isocyanate, butyl isocyanate and octadecyl isocyanate; the aryl monisocyanates, such as phenyl isocyanate, ot-naphthyl isocyanate, and the like; the diisocyanates, such as the polymethylene diisocyanates, for example ethylene diisocyanate, trimethylene diisocyanate, 2-chl-orotrimethylene dissocyanate, tetramethylene diisocyanate, pentamethylene disocyanate, and hexamethylene diisocyanate; alkylene diisocyanates, for instance propylene-l,2-diisocyanate, butylene-LZ-diisocyanate and butylene-l,3-diisocyanate; alkylidene diisocyanates, such as ethylidene diisocyanate and methylene bis(p-phenylene isocyanate) which is known as MDI and polymethylene polyphenylisocyanate (PAPI); p-phenylene diisocyanate, l-methylphenylene- 2,4-diisocyanate, naphthylene-1,4-diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, xylene-1,3-diisocyanate, 4,4'-diphenylene methane diisocyanate, 4,4'-diphenyllenepropane diisocyanate, benzidine dissocyanate, tolidine diisocyanate, and the like; corresponding tri, tetra, etc. isocyanates, such as 1,2,4-benzene triisocyanate, triphenylmethane triisocyanate, diphenylmethane tetraisocyanate, and the like. The aromatic nucleus of an aryl isocyanate is preferably the benzene ring. The aromatic ring may be substituted with groups which are non-reac tive with isocyanate groups, such as alkyl or halogen. For simplicity, the term isocyanate is used throughout this specification to mean organic isocyanates.
The toluene diisocyanate referred to in the discussion and in the examples is an 80/20 mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. This mixture is generally the preferred reactant because of its low cost. The 2,4-isomer may be used if lower viscosity materials are desired. The 80/20 isomeric mixture is the product naturally resulting from the dinitrating of toluene, reducing this product to the diamine, and then treating it with phosgene.
Superior coatings utilizing shellac as a basic material are prepared by incorporating other reactive organic materials. For example, polyols with less functionality than shellac may be added to increase flexibility and toughness, or to impart other special properties, such as gloss or adhesion. Addition agents which have been found to be particularly useful for this purpose are the polyoxyalkylene condensate polyols which are commercially available from the reaction of a variety of polyols with alkylene oxides, especially propylene oxide and ethylene oxide. Typical of these base chemicals are the diols, diethylene glycol, propylene glycols; triols such as glycerine, trimethylolpropane and hexanetriol-l,2,6, as well as polyols such as sorbitol, pentaerythritol, methyl glucoside, sucrose and tetra(hydroxypropyl)ethylenediarnine.
Polyether-polyols are known under various trade names such as Pluracol, Pluronic and NIAX. In the examples Pluracol TP-440 is a 400 molecular weight product which is made by the addition of propylene oxide to trimethylolpropane; Pluronic L-61" is a diol of equivalent weight 1000 having terminal primary hydroxyl groups, which contains the sequence polyethylene oxide-polypropylene oxide-polyethylene oxide; NIAX 2025 is a polypropylene diol of the above described type. Polyesterpolyols are also useful as addition agents for the compositions of this invention. Polyols of moderately high molecular Weight are made by the reaction of low molecular weight polyols, in excess of stoichiometric amounts, with dibasic acids. A typical polyester-diol of this type is prepared by esterifying adipic acid with a slight excess of ethylene glycol.
The particular polyol used in a given formulation may be varied to suit a special use. Combinations of polyols may be employed. Thus a wide selection and combination of properties may be obtained by the addition of comparatively low cost polyols in the shellac-isocyanate coatings. The outstanding properties of these coatings are a combination of hardness and flexibility, abrasion resistance, and good water and chemical resistance. Excellent Weather resistance is found in many of the coatings.
It is an advantage that the polyol can serve also, wholly or in part, as a solvent for the shellac, making unnecessary the addition of other shellac solvents, such as methyl ethyl ketone. Thus polyols can be used to afford a solvent-free system which can be used for castings as well as coatings. Systems pigmented for example, with titanium oxide, red iron oxide, ferrite yellow, and the like may be prepared by ball milling the pigment with the polyol. Compositions containing color may also be prepared by dissolving a soluble dyestuff, previously dried to remove moisture, in the solvent which is used for dissolving the shellac.
The first step in the preparation of the coatings of our invention is to prepare an anhydrous solution of shellac in a solvent which is inert to shellac and to organic isocyanates. Any inert solvent, or mixture of solvents, may be used that will afford clear solutions of shellac which can be made anhydrous, which will have physical characteristics suitable for coatings, especially with regard to viscosity, and which are sufficiently stable that the shellac will not reprecipitate on standing at room temperature. The preferred solvents for our invention are methyl ethyl ketone, cyclohexanone, and mixtures of the two. Dioxane can also be employed.
Shellac dissolves in hot methyl ethyl ketone, but as some concentrations the shellac tends to reprecipitate on standing at room temperature. Cyclohexanone dissolves shellac at C., giving crystal clear shellac solutions which remains stable on cooling. The addition of only about 5 parts of cyclohexanone to about parts of methyl ethyl ketone results in a stable shellac solution and this is a preferred solvent mixture for shellac-isocyanate coatings. Other mixtures of cyclohexanone and methyl ethyl ketone can also be used.
Any instability of shellac in methyl ethyl ketone can also be overcome by the incorporation of certain polyols. Although 30 parts of shellac is soluble in 70 parts of Plu racol TP-440 (a 400 molecular weight product made by the addition of propylene oxide to trimethylolpropane) to give a stable solution, the use of lesser amounts of Pluracol produces a more viscous solution which, although clear, requires high temperatures for fluidity. It is important that the shellac solution be made anhydrous due to the reaction of water with isocyanates. The amount of water in a shellac solution can be reduced to less than about 0.02% by having present another liquid as a carrier for the water vapor, which liquid will not boil at too high a temperature, so that on distillation the shellac will not lose plasticity through a heat activated reaction. The preferred liquids are those which form lower boiling azeotropes with water, such as benzene, toluene, xylene, ethylbenzene, and aliphatic hydrocarbons from C to C Using toluene, for example, the shellac is dissolved in a solvent such as methyl ethyl ketone (or a mixture of methyl ethyl ketone and cyclohexanone) toluene is added, and the mixture is then distilled, the water being carried off with the first distillate in the form of a toluene-water azeotrope.
The adduct of the organic isocyanate with a blocking agent is prepared by mixing the two ingredients at a temperature below the decomposition temperature of the desired adduct, and preferably at a temperature within the range of approximately 20 to 35 C. In most instances the reaction will proceed satisfactorily at room temperature. Since the reaction is exothermic it may be necessary to apply cooling to maintain a controlled lower temperature. The time required for the adduct to form will vary from a few minutes to several hours depending upon the particular reactants used. Usually a slight excess of the isocyanate is preferred. A solvent such as toluene, methyl ethyl ketone or o-dichlorobenzene which is inert to both the shellac and the isocyanate may be employed.
The shellac solution is then mixed with the isocyanate adduct in approximately equal stoichiometric proportions of the isocyanate to the shellac hydroxyl. A stable coating composition results. The coating is applied to a substrate in the usual manner by brush, spray or dip methods. The solvent is permitted to evaporate and the film which. forms is cured by heating, for example, in an oven. The temperature of the cure will vary with the particular isocyanate adduct employed, but is generally in the range of 80 to 250 C.
The following are examples that serve to illustrate but do not limit my invention. In the following examples the hydroxyl equivalent of shellac has been taken as 225, but it must be understood that shellac, being a natural product, may have a greater or lesser hydroxyl equivalent weight depending on its origin or its processing history.
1 Parts per hundred solids.
The shellac is dissolved in dry methyl ethyl ketone by heating at about 65 C. A cyclohexanol-toluene diisocyanate adduct is prepared by mixing the toluene diisooyanate with cyclohexanol while cooling so as to keep the temperature below 32 C. The two compositions are mixed and stirred. The final composition is then applied to wood and the coating is cured by heating in an oven at about 120 C. The coating has good water resistance.
In accordance with the above procedure, but using an equivalent weight of polymethylene polyphenylisocyanate (PAPI) or an equivalent weight of methylene bis(pphenylene isocyanate), (MDI), in place of the toluene diisocyanate, a coating composition is obtained which cures on heating to form coatings having greatly improved water resistance.
Example 2 Two moles of phenol are added to one mole of toluene diisocyanate and the product is heated to about 80 C. for about 5 minutes. A solution of shellac in methyl ethyl ketone is then added in a 1/ 1 ratio of shellac to the toluene diisocyanate/phenol. The mixture is stirred at room temperature and then coated on a glass slide. The coating is cured by heating for 5 minutes at 150 C. It has excellent water resistance.
In accordance with the above procedure, but using an equivalent amount of acetoacetic ester, or diethyl malonate, in place of phenol a stable coating composition is obtained which cures on heating to form coatings having improved water resistance.
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.
We claim:
1. A process of coating a surface which comprises applying to said surface a coating composition, which is stable at ambient temperatures, comprising shellac, a blocked organic isocyanate and an inert anhydrous organic solvent; exposing the resulting coating surface to the air to permit the solvent to evaporate and a coating film to form on said surface; and then curing said coating film by heat.
2. A process of coating a surface which comprises applying to said surface a coating composition which is stable at ambient temperatures consisting essentially of a solution of approximately stoichiometric proportions of shellac and a blocked isocyanate in an inert anhydrous organic solvent; exposing the resulting coated surface to the air to permit the solvent to evaporate and a coating film to form on said surface; and then curing said coating film by heat.
3. The process of claim 2 wherein said organic isocyanate is blocked with an agent selected from the group consisting of cyclohexanol, phenol, acetoacetic ester and diethyl malonate, and said curing takes place at a temperature of about to C.
4. The process of claim 3 wherein said organic isocyanate is blocked with phenol.
5. The process of claim 3 wherein said organic isocyanate is blocked with cyclohexanol.
6. The process of claim 2 wherein said solvent is selected from the group consisting of dioxane, methyl ethyl ketone, cyclohexanone, and mixtures of methyl ethyl ketone and cyclohexanone.
7. The process of claim 3 wherein said solvent is methyl ethyl ketone.
8. The process of claim 2 wherein said organic isocyanate is an admixture of 2,4-toluenediisocyanate and 2,6- toluenediisocyanate.
9. The process of claim 2 wherein said organic isocyanate is polymethylene polyphenylisocyanate.
10. The process of claim 2 wherein said organic isocyanate is methylene bis(p-phenylene isocyanate).
11. The process of claim 2 wherein said solution of shellac and blocked isocyanate contains a polyalkylene condensate polyol.
12. The process of claim 11 wherein said polyalkylene condensate polyol is derived from an alkylene oxide having from 2 to 3 carbon atoms and a diol having from 2 to 3 carbon atoms.
References Cited by the Examiner UNITED STATES PATENTS 2,041,733 5/36 Werntz 106-37 2,409,712 10/46 Schweitzer 260453 2,853,397 9/58 Seibert et al. 106-237 3,061,557 10/62 Hostettler et a1. 2602.5 3,084,182 4/63 McElroy 260482 3,108,084 10/63 Whitehill 260-22 OTHER REFERENCES Paint, Oil and Chemical Reviews, volume 116, No. 26, 1953 (pages 28 and 29 relied upon).
ROBERT F. WHITE, Primary Examiner.
MORRIS LIEBMAN, Examiner.
1. A PROCESS OF COATING A SURFACE WHICH COMPRISES APPLYING TO SAIS SURFACE A COATING COMPOSITIONM, WHICH IS STABLE AT AMBIENT TEMPERATURES, COMPRISING SHELLAC, A BLOCKED ORGANIC ISOCYANATE AND AN INERT ANHYDROUS ORGANIC SOLVENT; EXPOSING THE RESULTING COATING SURFACE TO THE AIR TO PERMIT THE SOLVENT TO EVAPORATE AND A COATING FILM TO FORM ON SAID SURFACE; AND THEN CURING SAID COATING FILM BY HEAT.
| 1962-11-02 | en | 1965-11-02 |
US-11817893-A | Electronic circuit device having a series connection of resistor and capacitance as a noise reducing circuit connected to a power source wiring
ABSTRACT
A power source wiring supplies power to individual electronic circuits constituting an electronic circuit device. Load circuits are connected to the power source wiring within the range of an arrival time of a voltage noise occurring in the power source wiring in a time of about a half of a pulse width of a noise current at the time of the operation of the electronic circuit. Each of these load circuits includes a series circuit of a resistance and a capacitance.
BACKGROUND OF THE INVENTION
This invention relates to a power source wiring system in an electronic circuit device comprising a plurality of electronic circuits. More particularly, the present invention relates to a noise reduction structure for reducing a voltage noise on a power source wiring resulting from a current noise that occurs as a result of operation of an electronic circuit.
In electronic circuit devices comprising a plurality of electronic circuits such as electronic computers, a higher integration density has been sought in recent years with a higher operation speed of individual electronic circuits so as to improve processing speed and obtain reduction in size.
A current noise (an a.c.-like noise current) flows through a power source wiring for feeding power to electronic circuits with the operation of the electronic circuits, and this noise current generates a voltage noise in the power source wiring system. The resulting voltage noise changes the power source voltage of a group of electronic circuits in the vicinity of the electronic circuit in which the current noise occurs, and invites an erroneous operation of these electronic circuits.
SUMMARY OF THE INVENTION
A higher operation speed of the electronic circuits and a higher integration density of the electronic circuit device drastically increase the quantity of the noise current due to a noise current quantity per electronic circuit (a peak value of the noise current) with the higher operation speed, and due to a noise source (electronic circuit) itself with a higher integration density. Because a propagation speed of the noise is constant, the higher integration density invites expansion of a range of the noise influence.
Accordingly, reduction of the power source noise and prevention of noise propagation become very important in light of the higher operation speed of electronic circuits and the higher integration density of the electronic circuit device which is expected in future.
It is an object of the present invention to provide a structure of a power source wiring system which reduces a voltage noise occurring in the power source wiring system due to a current noise at the time of the operation of an electronic circuit particularly in an electronic circuit device having electronic circuits mounted thereto in a high integration density, and to prevent propagation of the voltage noise.
To accomplish the object described above, an electronic circuit device according to the present invention includes load circuits for reducing noise, connected to power source wirings between junctions of two electronic circuits and the power source wirings.
Each of the load circuits comprises a series circuit of a resistor element and a capacitance element connected between the power source wiring and a ground potential.
The relation between the resistance value RL of the resistance element and the capacitance value CL of the capacitance element is set as follows, by assuming the operation frequency of the electronic circuit as fo :
(1) When noise reaches the distal end of the power source wiring with a time which is 1/8 of the cycle of the operation frequency fo : ##EQU1## where k is set to 1.4; (2) When noise reaches only a distance Le of the power source wiring with the time of 1/8 of the cycle of the operation frequency fo :
CL>k.sub.2 ·2/(π.sup.2 ·ZO·Ne·f.sub.o) (2)
where k is set to 1.4;
(3) When noise reaches the distal end of the power source wiring with the time of 1/8 of the cycle of the operation frequency fo, the value k in the formula (1) is set to 1.0 and the load resistance RL is set as follows:
CL·RL.sup.2 >Lt·L·N (3)
or, when noise reaches only the distance Le of the power source wiring with the time of 1/8 of the cycle of the operation frequency fo, the value k in the formula (2) is set to 1.0 and the load resistance RL is set as follows:
RL>π·ZO·Ne/4 (4)
Here, Le is the distance which the noise can reach with the time of 1/8 of the cycle of the operation frequency f, and is expressed by the following formula: ##EQU2## Further, Lt is the wiring length of the power source wiring, L and C are the inductance and the capacitance per unit length of the power source wiring, CL is the capacitance of the load circuit, N is the number of load circuits, and Ne is the total number of load circuits disposed within the distance Le from the noise occurring point.
As a result, the voltage noise is damped whenever it passes through the load point, and the influences of the voltage noise on other electronic circuits can be reduced.
Particularly when the load circuit is disposed within the range of the power source wiring in which the noise propagates within the time of 1/2 of a pulse width of the voltage noise occurring from the junction between the power source circuit and the electronic circuit with the operation of the electronic circuit, a reflection wave occurring at this load point propagates towards the noise generation point and offsets the voltage noise at the noise generation point. Accordingly, the voltage noise at the noise generation point can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a planar structural view of power source wirings of a semiconductor integrated circuit chip to which a noise reduction structure of the present invention is applied;
FIG. 1B is an electric equivalent circuit diagram of a part of the power source wiring shown in FIG. 1A;
FIG. 2 is a structural view showing an embodiment wherein a load circuit of the noise reduction structure shown in FIG. 1A is constituted by a series circuit of a resistor and a capacitance;
FIG. 3A is a plan view showing the series connection of a resistor element and a capacitance element formed on a semiconductor substrate according to the present invention;
FIG. 3B is a structural sectional view of the series connection shown in FIG. 3A;
FIG. 4 is a diagram showing a noise damping ratio at a load junction point;
FIG. 5A is a diagram showing an initial noise waveform at an occurrence point of a voltage noise;
FIG. 5B is a diagram showing a reflection waveform when the voltage noise shown in FIG. 5A is incident into the load junction point;
FIG. 6A is a perspective view showing the structure of the power source wiring on the semiconductor substrate;
FIG. 6B is an equivalent circuit diagram of the power source wiring on the semiconductor substrate;
FIG. 6C is a schematic view showing the equivalent circuit of the power source wiring;
FIG. 7A is a diagram showing the relationship between a characteristic impedance of the power source wiring formed on the semiconductor substrate and a wiring width; and
FIG. 7B is a diagram showing the relationship between a propagation time on the power source wiring formed on the semiconductor substrate and the wiring width.
FIG. 8 is a diagram showing a noise damping ratio at a load junction when the resistance element of the load circuit does not exist;
FIG. 9A is a diagram showing a noise damping ratio at a load junction when a load circuit comprises a series circuit of a resistance element and a capacitance element;
FIG. 9B is a diagram showing the relation of a boundary frequency and a resonance frequency when the power source wiring is handled as a concentrated constant circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A and 1B are structural views each showing a noise reduction structure according to an embodiment of the present invention.
FIG. 1A illustrates a planar structure of a power source wiring of a semiconductor integrated circuit chip to which a noise reduction structure according to the present invention is applied. This chip represents a structural example of a master slice type semiconductor integrated circuit having electronic circuits which are regularly arranged on a semiconductor substrate. Reference numerals 117 and 101 denote power source wirings, respectively. Reference numeral 117 denotes a power source wiring of a ground potential, which is electrically connected to the substrate inside the semiconductor integrated circuit chip or inside a package for mounting the semiconductor integrated circuit chip. Portions encompassed by dash lines, such as portions 103, 104 and 115, represent the electronic circuits. Symbol x, e.g. 121 and 122, denote feeding points at which a voltage is supplied to the electronic circuits 103 and 104. Black circles, e.g. 105, 106, 107 and 116, denote load circuits. Each load circuit is interposed between the feeding points of the electronic circuits adjacent to one another on the same power source wiring so as to prevent the propagation of a power source noise. For example, the load circuits 105, 106, 107 are disposed between the feeding points 121 and 122 in order to prevent any fluctuation of the potential of the feeding points 121 when the electronic circuit 103 starts operating, or, in other words, to prevent the propagation of a voltage noise to the electronic circuit 104.
FIG. 1B shows an electric equivalent circuit for a part of the power source wiring system in FIG. 1A. The power source wiring 101 can be handled as a distributed constant line having a characteristic impedance, and in this embodiment, the characteristic impedance is set to ZO. Reference numerals 103 and 104 denote electronic circuits having various electric functions, and power is supplied to them through the power source wiring 101. Reference numerals 105, 106 and 107 denote the load circuits described already, which reduce the voltage noise resulting from the noise current that occurs due to the operation of the electronic circuits 103, 104.
Incidentally, FIG. 1B shows the case where the electronic circuit 103 operates and then the noise current occurs, and the generation source of the noise current is equivalently expressed by the current source 102. The load circuits 105, 106 and 107 are interposed between this electronic circuit 103 and the electronic circuit 104 adjacent to the former, on the power source wiring. A great effect of the noise reduction can be obtained by disposing the load circuits particularly within the range of the distance, in which the noise propagates within the time about 1/2 of the pulse width of the noise from the power feeding point 108 to the electronic circuit 103 as the noise source on the power source wiring, that is, within the travelling distance of the noise propagating through the power source wiring 101 within the time of about 1/2 of the noise pulse width.
As shown in FIG. 2, each of the load circuits 105, 106 and 107 can be constituted by a series circuit of a resistor and a capacitance.
The power source wirings on the semiconductor integrated circuit chip are equivalently expressed as in FIG. 5, and are determined by the width of the power source wirings and the distance between the power source wiring 801 and the substrate 804, that is, the thickness of the dielectric, as shown in FIGS. 6A to 6C.
FIG. 6A shows the structure of the power source wiring, FIG. 6B does an equivalent circuit and FIG. 6C does symbols. The power source wiring is expressed as a distributed constant line comprising an inductance L per unit length and the capacitance C. Generally, the width of the power source wiring is increased so as to reduce its resistance component. Reference numeral 802 denotes SiO2 as the dielectric and reference numeral 803 denotes an active layer in which transistors, etc, and formed and an iron implantation layer. The numeral 806 is made of Al, for example.
The relation of the characteristic impedance ZO, which represents electrical characteristics of the power source wiring at this time, or the propagation time tpd, with the inductance L and the capacitance C per unit length described already is expressed by the following formulas: ##EQU3## FIG. 7A shows the characteristic impedance and FIG. 7B shows the propagation time. In FIG. 7A, thickness of the dielectric member may be defined as the distance between the wiring 801 and the substrate 804, for example.
When the noise current 102 flows due to the operation of the electronic circuit 103, the voltage noise 202 occurs at the noise generation point 108 as shown in the drawing. When this voltage noise 202 reaches the junction 109 of the first load circuit 105, a reflection wave 404 having an opposite polarity to this voltage noise occurs at this junction 109 due to mismatching of the impedance by the load circuit 105. This reflection wave 404 operates in such a direction as to offset the voltage noise 403, and the voltage noise at this point is reduced.
In other words, the reflection wave 404 reflects at this load point 109 towards the noise generation point, and the voltage noise 405 attenuated by the reflection wave 404 transmits. When this reflection wave 404 reaches the noise generation point 108 before the voltage noise 403 is extinguished at the noise generation point 108 (within the pulse width from the occurrence of the noise), the voltage noise at the noise point 108 is offset by this reflection wave 404, and the voltage noise 403 itself at the noise generation point 108 is reduced, too. In this embodiment, when the voltage noise 403 (the noise current) is a square wave as shown in FIG. 3A, for example, the reflection wave 404 at the load point 109 becomes such as shown in FIG. 3B. At this time, the peak value Vr of the reflection wave 402 is determined in accordance with the following equation:
Vr=Vi/(1+2·RL/ZO)·EXP(-T/β) (8)
with the provision that a time constant β is given by:
β=CL·(ZO/2+RL) (9)
Here, Vi is the peak value of the voltage noise 403, T is the pulse width of the voltage noise 403 (the noise current), RL is the resistance value of the resistance 401 of the load circuit 105, CL is the capacitance value of the capacitance 402 of the load circuit 105, and ZO is the characteristic impedance when the power source wiring is handled as the distributed constant line. As already described, a greater reduction effect of the voltage noise can be obtained by increasing the reflection wave 402. As can be understood from equations (8) and (9), the reflection wave 402 can be increased by making the time constant β greater than the noise current pulse width T. Accordingly, a greater noise reduction effect can be obtained by increasing the capacitance value CL and the resistance value RL so as to increase the time constant. When the resistance value RL is excessively increased, however, the time contant β can certainly be made greater, but the reflection wave becomes smaller because the term Vin/(1+2·RL/ZO) becomes smaller, so that the noise reduction effect cannot be obtained, on the contrary.
Next, the quantitative relation between the pulse width of the voltage noise (frequency component) described above, the inductance L and the capacitance C per unit length of the power source wiring, and the capacitance CL and the resistance value RL of the load circuit will be explained.
The following description will represent the case where the electronic circuit 103 operates and the voltage noise occurs at the feeding point 121 when the width of the power source wiring is 20 μm, the distance between the power source wiring and the substrate is 3 μm, the distance from the feeding point 121 to the branch point 118 is 10 mm, the gap between the load points is 1 mm and the total number of the load circuits is 10. To demonstrate the noise damping effect by the load circuits, the impedances of the electronic circuits 103 and so forth are hereby assumed to be infinite.
The frequency component of the noise occurring when the electronic circuit operates at the operation frequency fo exists in a frequency band within the range which is higher by one figure (=10·fo) than the operation frequency fo. Therefore, there is the possibility that the noise of this frequency band propagates and causes an erroneous operation of the electronic circuit in the load circuit. In other words, the noise damping effect must be secured in the frequency range which is higher by one figure than the operation frequency fo. Incidentally, in electronic circuit devices operating in synchronism with clock signals in general, the operation frequency is equal to the frequency of the clock signal.
FIG. 8 shows the noise damping ratio at the load point 105 using the capacitance value CL as a parameter about the case where the load circuit is not provided with the resistance element but is provided with the capacitance element alone. As can be understood from this diagram, the noise damping effect can be obtained by the use of the capacitance element alone with a frequency fα, at which the noise frequency component exists, being a boundary. Accordingly, this boundary frequency fα must be set below the operation frequency fo. This boundary frequency fα is approximately twice the resonance frequency by the total inductance (=Lp·L) and the total capacitance (=Lp·C+CL) of the power source wiring from the noise generation point to the load point, and is substantially expressed by the following formula: ##EQU4## Here, Lp is the distance from the noise generation point to the load point, L is the inductance per unit length of the power source wiring, C is the capacitance per unit length of the power source wiring, and CL is the capacitance of the load circuit.
To obtain satisfactory damping characteristics to the noise of the frequency band higher by one figure than the operation frequency fo described above, therefore, it is necessary to increase the capacitance CL and to set the boundary frequency fα to be smaller than the operation frequency fo, as can be appreciated from the formula (10), as well. When the operation frequency fo is 100 MHz, for example, a capacitance CL as great as dozens of nF becomes necessary to obtain the noise damping effect. In the integrated circuit chip formed on the semiconductor substrate, however, fabrication of such a large capacitance by the capacitances between parallel flat plates and by the junction capacitance shown in FIG. 3 requires an extremely large area and is not practical.
FIG. 9 shows the noise damping ratio at the load point 109 when the load circuit 105 is constituted by the series circuit of the capacitance element and the resistance element. As can be understood from FIG. 9A, the noise damping effect can be obtained when the load circuit comprising the series circuit of the capacitance element and the resistance element according to the present invention is used, too, with a certain frequency fα being the boundary. When the resistance RL of the load circuit is 5Q and its capacitance CL is 1,000 pF, for example, this boundary frequency fα is 66 MHz, and the noise damping effect can be obtained above this frequency. In this case, too, the noise of the frequency component, which renders the problem, can be damped by setting the boundary frequency fα below the operation frequency fo. The noise damping effect can be obtained by using the capacitance, which is lower by one figure than when the capacitance element is used alone as described already, that is, 1,000 pF, in the operation frequency band. For, all the load circuits existing time-wise before the peak-attaining time of the noise amplitude, or in other words, existing at those positions at which the reflection wave occurring at the load points returns to the noise generation point within the time of 1/4 of the noise cycle, effectively function to reduce the noise. The range in which the load circuits are effective for damping the noise, that is, the distance Le in which the reflection wave occurring at the load point from the noise generation point returns to the noise generation point within the time of 1/4 of the noise cycle, is determined by the following formula and depends on the operation frequency: ##EQU5## Here, L and C are the inductance and the capacitance per unit length of the power source wiring, and fo is the operation frequency of the electronic circuit. Incidentally, all the load circuits effectively operate when the wiring length Lt of the power source wiring is shorter than Le.
The boundary frequency fα at this time is determined by the inductance and the capacitance of the power source wiring within the range in which the load circuits remain effective for damping the noise, that is, within the distance Le in which the reflection wave occurring at the load point can return to the noise generation point within the time of 1/4 of the noise cycle, and by the capacitance of the load circuits. The inductance within the distance Le and the capacitance of the load circuits can substantially be handled as concentrated constants. As shown in FIG. 9B, therefore, this boundary frequency fα is below about 1.4 of the resonance frequency fβ when the inductance and the capacitance falling within the distance Le are handled as the concentrated constants. In conjunction with the relation between the length of the power source wiring and the operation frequency, this resonance frequency fβ includes the following two cases, and can be expressed as follows:
(1) When the noise can reach only the distance Le expressed by the formula (11) within the time of 1/8 of the cycle of the operation frequency, that is, when the operation frequency fo is within the range of the formula (12), the resonance frequency fβ can be substantially expressed by the formula (13): ##EQU6## (2) When the noise reaches the distal end of the power source wiring within the time of 1/8 of the cycle of the operation frequency, that is, when the operation frequency fo is within the range of the formula (14), the resonance frequency fβ can be substantially expressed by the formula (15): ##EQU7## Here, Lt is the wiring length of the power source wiring, L and C are the inductance and the capacitance of the power source wiring, CL is the capacitance of the load circuit, N is the total number of the load circuits disposed in the power source wiring, and Ne is the total number of the load circuits existing in the distance Le, in which the refelection wave occurring at the load point can return to the noise generation point within the time of 1/4 of the cycle of the noise from the noise generation point.
Accordingly, the resistance elements and the capacitances of the load circuits may be set in such a manner that boundary frequency fα is below the operation frequency fo when the operation frequency of the electronic circuit is fo, that is the resonance frequency fβ is below 11/4 times the operation frequency fo,
f.sub.o >fβ·k (16)
where k is set to 1.4.
When a plurality of noise generation points exist or in other words, when the number of load circuits existing within an effective distance from the electronic circuit for reducing the noise is different, the resistance element and the capacitance of the load circuit must be so set as to match with the case where the resonance frequency fβ attains the highest frequency, that is, where Ne becomes minimal, in order to cause the load circuit to effective operate in all cases.
Further, depending on the combination of the resistance RL and the capacitance CL, there is the case where the noise damping ratio is positive or in other words, where the noise is amplified, such as when the resonance frequency fβ is about 130 MHz with the resistance RL of the load circuit being 5Q and its capacitance being 1,000 pF, as represented by dash lines in FIG. 9A. This is because the impedance of the capacitance CL of the load circuit is higher than the resistance RL in this frequency band and consequently, the load circuits do not much contribute to the reduction of the noise. Accordingly, in-order to let the load circuits function in this frequency band and to render the noise damping ratio negative, the impedance of the capacitance CL must be lowered below the resistance RL. In other words, the resistance and the capacitance of the load circuit are so set as to satisfy the following relation (17):
RL>1/(2·π·fβ·CL)) (17)
Here, RL and CL are the resistance value and the resistance value of the load circuit, and fβ is the resonance frequency already described. In FIG. 9A, solid line represents the case where the resistance RL and the capacitance C are so set as to satisfy the formula (17), and satisfactory damping characteristics can be obtained in either case. So long as the resistance element and the capacitance of the load circuit satisfy the relation (17) at the operation frequency fo of the electronic circuit, the resonance frequency may be set to be below the operation frequency fo or in other words, in such a manner that k in the formula (16) becomes 1.0.
Further, when a plurality of noise generation points exist or in other words, when the number of load circuits existing within an effective distance from the electronic circuit for reducing the noise is different, the resistance RL of the load circuit must be so set as to match with the case where the resonance frequency fβ is the lowest, that is, Ne becomes maximal, in order to cause the load circuit to effectively operate.
After all, it can be understood by putting the formulas (11) to (17) in order that the resistance and the capacitance of the load circuit may be set to the following case (1) or (2).
(1) When the noise reaches only the distance Le of the power source wiring within the time of 1/8 of the cycle of the operation frequency as represented by the formula (11), that is, when the operation frequency fo exists within the range of the formula (12), they may be set as in the following case (1A) or (1B):
(1A)
RL>π·ZO·Ne,max/4 (18)
and
CL>3.92/(π.sup.2 ·ZO·Ne,min) (19)
or
(1B)
RL>π·ZO·Ne,max/4 (20)
and
CL>2/(π.sup.2 ·ZO·Ne,min) (21)
(2) When the noise reaches the distal end of the power source wiring within the time of 1/8 of the cycle of the operation frequency, that is, when the operation frequency fo exists within the range of the formula (14): ##EQU8##
Here, Lt is the wiring length of the power source wiring, L and C are the inductance and the capacitance per unit length of the power source wiring, N is the total number of the load circuits, and Ne is the total number of the load circuits disposed within the distance Le from the noise generation point represented by the formula (11).
When a plurality of noise generation points exist or in other words, when the number of load circuits existing within an effective distance from the electronic circuit for reducing the noise, the value Ne,max in the formulas (18) and (20) must be set to the maximum value of the number of load circuits existing within an effective distance from the noise generation points for reducing the noise, while the value Ne,min in the formulas (19) and (21) must be set to the minimum value of the load circuits existing within an effective distance from the noise generation points for reducing the noise.
Furthermore, when the operation frequency fo is extremely high, there is the case where satisfactory damping characteristics cannot be obtained depending on the ratio of the resistance RL and the characteristic impedance ZO of the power source wiring even when the boundary frequency fα is set to be smaller than the operation frequency fo.
FIG. 4 shows the noise damping ratio for each frequency component of the noise at the junction 109 of the load circuit 105 using the ratio of the resistance value RL to the characteristic impedance ZO as a parameter.
Reference numeral 130 denotes the noise source and reference numeral 131 does an equivalent impedance of the noise source, which is hereby equal to the characteristic impedance. Reference numeral 132 denotes an equivalent impedance at the branch point 118 of the power source wiring, which is hereby equal to the characteristic impedance of the power source wiring. The capacitance of each load circuit 105, 107 is 10 pF. This diagram shows an example where the boundary frequency fα is set to approximately 500 MHz.
When the operation frequency fo is 6 GHz as shown in FIG. 4, for example, the reflection wave occurring at the junction of the load circuits drops with a greater resistance RL in a frequency band of about 10 GHz, though the boundary frequency fα is lower than the operation frequency f, so that the load circuits fail to function, the damping ration becomes smaller, and the noise is amplified in a certain frequency band.
It can be appreciated from the diagram that damping can be attained in any frequency band above several GHz within the range of the ratio α of the resistance RL to the characteristic impedance ZO of not greater than 4.5 times. In other words, it can be understood that the ratio α of the resistance RL to the characteristic impedance may be set to the range of up to 4.5 times. Though not shown in the drawing, it is effective to set the ratio α of the resistance RL to the characteristic impedance ZO to the range of from 4.5 to 5.0 times. Accordingly the ratio α of the resistance RL to the characteristic impedance ZO may be set to the range of not greater than 5.5 times.
FIGS. 3A and 3B show a structural example of the capacitance element when the noise reduction structure of the present invention is applied to the power source wiring system inside a semiconductor integrated circuit device. FIG. 3A is a plan view and FIG. 3B is a sectional view taken along a line A-A'.
In FIGS. 3A and 3B, a junction capacitance of the diode formed between an electrode 707 and an n-type ion implantation layer 702 is used as the capacitance element, whereas a diffusion resistance of a high concentration n-type ion implantation layer 702 is used as the resistance element. In this embodiment, the diode used as the capacitance element is fabricated by forming a high concentration n-type implantation layer 701, an n-type implantation layer 702 and a p-type implantation layer 703 on a semiconductor substrate 706. Reference numeral 705 denotes an insulating film for electrically insulating the power source wiring 101 from the electrode 707 and reference numeral 710 denotes an insulating film for insulating the substrate 706 from the electrode 708 and a metal layer 707. Reference numeral 711 denotes an insulating film for isolating the devices. The anode 707 of the diode is electrically connected to the substrate 707 by the high concentration p-type ion implantation layer 704. The cathode 708 is electrically connected to the power source wiring 101 through a through-hole 709. Here, the junction capacitance between the n-type implantation layer 702 and the p-type implantation layer 703 is used as the capacitance. The numerals 101, 707, 708, 709 are made of Al, for example. The numeral 710 is made of SiO2, for example.
The explanation given above deals with the case where the load circuits 105, 106 and 107 are disposed within the arrival time range of about 1/2 of the noise pulse width or 1/4 of the period of the noise frequency component. Needless to say, however, even when the load circuits are not disposed within this range, the voltage noise is damped at the junction of the load circuits due to mismatching of the impedance at the junction and consequently, the noise propagating to the adjacent electronic circuit 104 can be reduced. Particularly according to this structure, the power source wiring is cut off d.c.-wise from the ground potential by the capacitance 402 and the d.c. current does not flow through the load circuit 105. In other words, the increase of power consumption can be inhibited. Generally, the resistance element can be miniaturized much more than the capacitance element. Therefore, the present invention is particularly effective for a semiconductor integrated circuit having electronic circuits mounted thereto in a high mounting density. The effect of the present invention can be obtained likewise in a semiconductor integrated circuit of the type wherein the electronic circuits and the power source wirings are disposed irregularly, by disposing the afore-mentioned load circuits in the electronic circuits connected to the same power source wiring or between the electronic circuit groups.
In the explanation given above, the load circuits 105, 106 and 107 are disposed within the range of the arrival time range of about 1/2 of the noise pulse width. However, even though they are disposed outside this range, the voltage noise is damped at the junction of the load circuits due to mismatching of the impedance at this junction, and the noise propagating to the adjacent electronic circuit 104 can be reduced.
The construction of the present invention can be accomplished in a power source wiring system of an electronic circuit device having semiconductor integrated circuits on a printed circuit board, too, by using resistance elements and capacitance elements.
As described above, the present invention can reduce the voltage noise occurring in the power source wiring system due to the current noise at the time of the operation of the electronic circuit in the electronic circuit device having the electronic circuits mounted thereto in a high mounting density, can prevent the propagation of the voltage noise, and can effectively prevent the erroneous operation of the electronic circuit resulting from the voltage noise occurring in the power source wiring system.
We claim:
1. An electronic circuit device comprising:a plurality of electronic circuits; a common power source wiring connected to said plurality of electronic circuits at a plurality of junctions; and a plurality of series circuits for reducing noise, each of said series circuits including a resistance and a capacitance connected in series, wherein said plurality of series circuits are connected to said power source wiring between adjacent junctions at which adjacent electronic circuits are respectively connected to said power source wiring; wherein assuming conditions of the operation frequency fo of said adjacent electronic circuits, a wiring length Lt of said power source wiring, an inductance L and a capacitance C per unit length of said power source wiring, a characteristic impedance ZO of said power source wiring, and a smaller number Ne,min of said series circuits and a greater number Ne,max of said series circuits among the total number of said series circuits disposed within the range of distance 1/(8·fo ·√/(L·C) from each of said adjacent electronic circuits, when the operation frequency fo of said adjacent electronic circuits is in the following relation f.sub.o >1/(8·L.sub.t ·√(L·C), then values of RL and CL of the resistance and the capacitance of said each series circuit satisfy the following relations RL<π·ZO·Ne,max/4, and CL>3.92/(π.sup.2 ·ZO·Ne,min), and wherein said plurality of electronic circuits, said power source wiring and said plurality of series circuits are formed on a surface of a common semiconductor substrate.
2. An electronic circuit device comprising:a plurality of electronic circuits; a common power source wiring connected to said plurality of electronic circuits at a plurality of junctions; and a plurality of series circuits for reducing noise, each of said series circuits including a resistance and a capacitance connected in series, wherein said plurality of series circuits are connected to said power source wiring between adjacent junctions at which adjacent electronic circuits are respectively connected to said power source wiring; wherein assuming conditions of the operation frequency fo of said adjacent electronic circuits, a wiring length Lt of said power source wiring, an inductance L and a capacitance C per unit length of said power source wiring, characteristic impedance ZO of said power source wiring, and a smaller number Ne,min of said series circuits and a greater number Ne,max of said series circuits among the total number of said series circuits disposed within the range of 1/(8·fo ·√(L·C) from each of said adjacent electronic circuits, when the operation frequency fo of said adjacent electronic circuits is in the following relation f.sub.o >1/(8·L.sub.t ·√(L·C), then values of RL and CL of the resistance and the capacitance of said each series circuit satisfy the following relations RL>π·ZO·Ne,max/4, and CL>2/(π.sup.2 ·ZO·Ne,min), and wherein said plurality of electronic circuits, said power source wiring and said plurality of series circuits are formed on a surface of a common semiconductor substrate.
3. An electronic circuit device comprising:a plurality of electronic circuits; a common power source wiring connected to said plurality of electronic circuits at a plurality of junctions; and a plurality of series circuits for reducing noise, each of said series circuits including a resistance and a capacitance connected in series, wherein said plurality of series circuits are connected to said power source wiring between adjacent junctions at which adjacent electronic circuits are respectively connected to said power source wiring; wherein assuming conditions of the number N of said series circuits connected to said power source wiring between said adjacent electronic circuits, the operation frequency fo of said adjacent electronic circuits, a wiring length Lt of said power source wiring, and an inductance L and a capacitance C per unit length of said power source wiring, when the operation frequency fo of said adjacent electronic circuits is in the following relation f.sub.o <1/(8·L.sub.t ·√/(L·C), then values of RL and CL of the resistance and the capacitance of said each series circuit satisfy the following relations CL>1.96/(2·π·f.sub.o ·√(L.sub.t ·L·N)).sup.2, and CL·RL.sup.2 <L.sub.t ·L·N, and wherein said plurality of electronic circuits, said power source wiring and said plurality of series circuits are formed on a surface of a common semiconductor substrate.
4. An electronic circuit device comprising:a plurality of electronic circuits; a common power source wiring connected to said plurality of electronic circuits at a plurality of junctions; and a plurality of series circuits for reducing noise, each of said series circuits including a resistance and a capacitance connected in series, wherein said plurality of series circuit are connected to said power source wiring between adjacent junctions at which adjacent electronic circuits are respectively connected to said power source wiring; wherein assuming conditions of the number N of said series circuits connected to said power source wiring between said adjacent electronic circuits, the operation frequency fo of said adjacent electronic circuits, the wiring length Lt of said power source wiring, and an inductance L and a capacitance C per unit length of said power source wiring, when the operation frequency fo of said adjacent electronic circuits is in the following relation f.sub.o <1/(8·L.sub.t ·√(L·C), then values of RL and CL of the resistance and the capacitance of said each series circuit satisfy the following relations CL>1/(2·π·f.sub.o ·√(L.sub.t ·L·N)).sup.2, and CL·RL.sup.2 >L.sub.t ·L·N, and wherein said plurality of electronic circuits, said power source wiring and said plurality of series circuits are formed on a surface of a common semiconductor substrate.
5. An electronic circuit device comprising:a plurality of electronic circuits; a common power source wiring connected to said plurality of electronic circuits at a plurality of junctions; and a plurality of series circuits for reducing noise, each of said series circuits including a resistance and a capacitance connected in series, wherein said plurality of series circuits are connected to said power source wiring between adjacent junctions at which adjacent electronic circuits are respectively connected to said power source wiring; wherein a resistance value of said resistance is at least 1/2 times and not greater than 5.5 times a characteristic impedance of said power source wiring, and wherein said plurality of electronic circuits, said power source wiring and said plurality of series circuits are formed on a surface of a common semiconductor substrate.
| 1993-09-09 | en | 1995-03-07 |
US-3731242D-A | Method of forming plural strip-shaped magnetic poles
ABSTRACT
To form strip-shaped poles in a preferably resilient magnet an electric conductor is provided in the direction of current flow with a plurality of parallel soft-iron strips on which the object to be magnetized is placed. A current pulse is passed through the conductor; the resulting magnetic field is highly directed by the strips. The device by means of which this method may be carried out is very simple and may comprise a hollow conductor on the inner or outer surface of which the strips are arranged.
United States Patent 1 Hofman 51 May 1,1973
[54] METHOD OF FORMING PLURAL STRIP-SHAPED MAGNETIC POLES [75] Inventor: Wytze Hofman, Emmasingel, Eindhoven, Netherlands [73] Assignee: U.S. Philips York,N.Y.
[22] Filed: Aug. 23, 1971 [21] Appl. No.: 173,904
Corporation, New
[30] Foreign Application Priority Data Aug. 31, 1970 Netherlands ..7012889 [52] U.S. Cl ..335/284, 335/306 [51] Int. Cl. ..H0lf 13/00 [58] Field of Search ..335/284, 302, 303
[56] References Cited UNITED STATES PATENTS 3,158,797 11/1964 Andrews ..335/284 3,335,377 8/1967 Kohlhagen ..335/284 3,474,368 10/1969 Seely ..335/284 3,191,106 6/1965 Baermann ..335/303 X Primary Examiner-George Harris Att0rneyFrank R. Trifari [57] ABSTRACT To form strip-shaped poles in a preferably resilient magnet an electric conductor is provided in the direction of current flow with a plurality of parallel soft-iron strips on which the object to be magnetized is placed. A current pulse is passed through the conductor; the resulting magnetic field is highly directed by the strips. The device by means of which this method may be carried out is very simple and may comprise a hollow conductor on the inner or outer surface of which the strips are arranged.
8 Claims, 5 Drawing Figures METHOD OF FORMING PLURAL STRIP-SHAPED MAGNETIC POLES The present invention relates to a method of forming a plurality of strip-shaped magnetic poles of alternating polarities on the surface of a permanent magnet to be magnetized, which surface is placed near a conductor, after which an electric current is passed through the conductor.
Such a method is described in a published German Patent application (Auslegeschrift) No. 1,489,805. In this method, the electric conductor comprises a plurality of parallel tortuous paths which are embedded in a synthetic resin. The effect is based on the presence of a magnetic field around this conductor. The magnet body which is to be magnetized is placed on the conductor and is polarized under the influence of this magnetic field.
The invention is characterized in that a plurality of strips of a soft -magnetic material are arranged parallel to one another in the direction of current flow and are interposed between the surface of the magnet and the surface of the conductor.
The conductors may have various shapes. A flat strip-shaped conductor may be used on one surface of which identical strips of soft-iron may be arranged across its full width.
Alternatively the conductor may be cylindrical, the soft-iron strips being arranged internally or externally along the entire circumference.
The advantage of this method is that the length of the current-carrying conductor is kept to a minimum, i.e., the conductor has a low electrical resistance. This is an important feature in view of the large values of the current pulses required to magnetize the magnet body (from 40 to 50 RA). The resulting accuracy of the polarization is high and the method may be carried out in a simple manner.
A device for carrying out the method which comprises a conductor through which an electric current may be passed according to the invention is characterized in that the conductor is provided with strips of a soft magnetic material which are arranged parallel to one another in the direction of current flow.
The invention also relates to a permanent magnet produced by the method. The permanent magnet preferably consists of a yielding synthetic material in which a permanent-magnetic powder is embedded.
Embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:
FIGS. 1 and 2 show a device for carrying out the method according to the invention,
FIG. 3 shows a detail of the magnetization and FIGS. 4 and 5 illustrate a cylindrical magnetizing device according to the invention.
Referring now to FIG. 1, the device shown comprises a flat copper electric conductor 1 on which a plurality of soft-iron strips 2 have been arranged parallel to one another. The magnetization of flat permanent magnets is effected as follows:
An object 3 to be magnetized, for example, a plastoferrite strip, is placed on or over the strips 2. A
current pulse, the direction of which corresponds to the arrow I, is passed through the conductor 1. In FIG. 3,
which shows such an arrangement in greater detail the current flows in a direction at right angles to the plane of the drawing and recedes from the reader. The current produces a magnetic field H, the direction of which is indicated by an arrow in the Figures. The softiron strips are magnetized by this magnetic field and have poles disposed as shown in FIG. 3. The field within the object 3 to be magnetized is indicated by broken arrows and produces magnetic poles at the boundaries of the strips 2.
A cylindrical conductor 1 also may be used. In FIG. 4, the strips 2 are arranged on the outer surface, and in FIG. 5 on the inner surface, of this conductor.
What is claimed is:
1. A method of magnetizing a permanent magnet to form a plurality of strip-shaped magnetic poles of alternating polarities on the surface of said permanent magnet which comprises, placing said magnet surface near an electric conductor, arranging a plurality of strips of a soft-magnetic material in parallel with one another between the surface of the magnet and the surface of the conductor, and passing an electric current through the conductor in a direction parallel to the magnetic strips.
2. A method as claimed in claim 1, characterized in that the conductor comprises a flat strip member on one surface of which identical strips of soft-iron are arranged across its full width.
3. A method as claimed in claim 1, characterized in that the conductor is cylindrical and the soft-iron strips are externally arranged along the entire circumference.
4. A method as claimed in claim 1, characterized in that the conductor comprises a hollow cylinder and the soft-iron strips are arranged along its entire inner circumference.
5. A method as claimed in claim 1 wherein said conductor comprises a flat member and said strips of softmagnetic material comprise identical strips of a softiron material juxtaposed across one surface of the flat conductor.
6. A method of magnetizing a magnetizable body to form a permanent magnet with a plurality of stripshaped magnetic poles of alternating polarity on the surface thereof which comprises, arranging a plurality of strips of a soft-magnetic material in a parallel between the surface of an electric conductor and the surface of the magnet, and passing an electric current through the conductor in a direction parallel to the magnetic strips.
7. A method as claimed in claim 6 wherein the magnetic strips are first arranged in parallel adjacent the surface of said electric conductor and then the magnetizable body is placed adjacent thereto so as to sandwich the magnetic strips between the electric conduction and the magnetizable body.
8. A method as claimed in claim 6 wherein prior to the step of arranging said magnetic strips between the conductor and the magnetizable body there is included the further step of impregnating a resilient synthetic material with permanent-magnetic powder to form said magnetizable body.
1. A method of magnetizing a permanent magnet to form a plurality of strip-shaped magnetic poles of alternating polarities on the surface of said permanent magnet which comprises, placing said magnet surface near an electric conductor, arranging a plurality of strips of a soft-magnetic material in parallel with one another between the surface of the magnet and the surface of the conductor, and passing an electric current through the conductor in a direction parallel to the magnetic strips.
2. A method as claimed in claim 1, characterized in that the conductor comprises a flat strip member on one surface of which identical strips of soft-iron are arranged across its full width.
3. A method as claimed in claim 1, characterized in that the conductor is cylindrical and the soft-iron strips are externally arranged along the entire circumference.
4. A method as claimed in claim 1, characterized in that the conductor comprises a hollow cylinder and the soft-iron strips are arranged along its entire inner circumference.
5. A method as claimed in claim 1 wherein said conductor comprises a flat member and said strips of soft-magnetic material comprise identical strips of a soft-iron material juxtaposed across one surface of the flat conductor.
6. A method of magnetizing a magnetizable body to form a permanent magnet with a plurality of strip-shaped magnetic poles of alternating polarity on the surface thereof which comprises, arranging a plurality of strips of a soft-magnetic material in a parallel between the surface of an electric conductor and the surface of the magnet, and passing an electric current through the conductor in a direction parallel to the magnetic strips.
7. A method as claimed in claim 6 wherein the magnetic strips are first arranged in parallel adjacent the surface of said electric conductor and then the magnetizable body is placed adjacent thereto so as to sandwich the magnetic strips between the electric conduction and the magnetizable body.
8. A method as claimed in claim 6 wherein prior to the step of arranging said magnetic strips between the conductor and the magnetizable body there is included the further step of impregnating a resilient synthetic material with permanent-magnetic powder to form said magnetizable body.
| 1971-08-23 | en | 1973-05-01 |
US-40419673-A | Diphenylsulfides as hypolipidemics
ABSTRACT
1. A PHARMACEUTICAL COMPOSITION IN THE FORM OF A TABLET, CAPSULE, DISPERSIBLE POWDER, GRANULE, SYRUP OR ELIXIR USEFUL IN THE TREATMENT OF LIPIDEMIA IN MAMMALS COMPRISING AS AN ACTIVE INGREDIENT THEREOF A COMPOUND OF THE FORMULA HO-(1,4-PHENYLENE)-S-(1,4-PHENYLENE)-OH OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF, AND A PHARMACEUTICALLY ACCEPTABLE CARRIER THEREFOR, SAID COMPOUND BEING PRESENT IN SAID COMPOSITION IN AN AMOUNT SUFFICIENT TO PROVIDE A DAILY DOSAGE O FROM ABOUT 150 MILLIGRAMS TO ABOUT 4000 MILLIGRAMS OF SAID COMPOUND.
3,851,064 DIPHENYLSULFIDES AS HYPOLIPIDEMICS Mario G. Buzzolini, Convent Station, N.J., assignor to Sandoz-Wander, Inc., Hanover, NJ.
No Drawing. Continuation-impart of abandoned application Ser. No. 318,030, Dec. 26, 1972. This application Oct. 9, 1973, Ser. No. 404,196
Int. Cl. A61k 27/00 US. Cl. 424337 11 Claims ABSTRACT OF THE DISCLOSURE Certain hydroxy diphenylsulfides, e.g., 4,4-thiodiphenol,
- are useful as hypolipidemic agents.
This application is a continuation-in-part of US. patent application Ser. No. 318,030, filed Dec. 26, 1972, now abandoned.
This invention relates to the pharmaceutical activity of diphenyl sulfide derivatives. More particularly, this invention concerns the use of hydroxy substituted diphenylsulfides in the treatment of lipidemia in mammals. The invention also relates to pharmaceutical compositions containing the above compounds as an active ingredient thereof.
The active agents with which this invention is concerned may be represented by the following structural formula:
or pharmaceutically acceptable salts thereof.
Preferred compounds of formula I are 4,4-thiodiphenol and its sodium salt.
The compounds of formula I above are known and may be prepared according to methods disclosed in the literature from known materials. The pharmaceutical acceptable salts include the alkali metal salts, in particular, the sodium and potassium salts and the alakline earth metal salts, such as the magnesium and calcium salts. These salts may also be prepared by methods disclosed in the literature. The present invention contemplates only the novel use of such compounds in pharmaceutical applications, particularly as hypolipidemic agents.
As previously indicated, the compounds of formula (I) are useful because they possess pharmacological activity in animals, e.g., mammals. In particular, the compounds of formula (I) are useful as hypolipidemic agents in the treatment of lipidemia, in particular, hyperlipoproteinemia as indicated by the fall in cholesterol and/or triglyceride levels in male albino Wistar rats weighing 110130 g. initially. The rats are maintained on drug-free laboratory chow diet for seven days and then divided into groups of 6 to 10 animals. Each group with the exception of the control is then given the compound orally at a dose of 7.5, 30, 250 or 500 milligrams per kilogram of body weight per day, p.o. for six days. At the end of this period, the animals are anesthetized with sodium hexobarbital and bled from the carotid arteries. Serum or plasma samples are then extracted with isopropanol, and the cholesterol and triglyceride content of the extracts is estimated on a Technicon Autoanalyzer by standard methodology. For example, 1.0 ml. of serum is added to 9.0 ml. redistilled isopropanol. Two autoanalyzer cupsful of a mixture of zeolite-copper hydroxide and Lloydds reagent (Kersler, E., and Lederer, -H., 1965, Technicon Symposium, Madiad Inc., New York, 345-347) are added, and the mixture is shaken for 1 hour. Cholesterol levels are determined using this sample by the standard Technicon N 24A (cholesterol) methodology. The mean total serum cholesterol levels are then computed and the hypo- United States Patent 3,851,064 Patented Nov. 26, 1974 cholesterol-emic activity is expressed as the fall in cholesterol levels as a percentage of the control level. For the triglyceride determination, blood samples are collected as above and 1.0 ml. samples of the serum are added to 9.0 ml. redistilled isopropanol. Two autoanalyzer cu-psful of a mixture of zeolite-copper hydroxide and Lloydds reagent (Kessler, G., and Lederer, H., 1965, Technicon Symposium, Mediad Inc., New York, 345-347) are added, and the mixture is shaken for one hour. After centrifugation, 2 ml. of the clear supernates are evaporated to dryness and saponified by addition of 0.1 ml. 10% KOH in 90% ethanol and 1.0 ml. Skelly B (petroleum ether b.p. 6070). After acidification and the removal of fatty acids with petroleum ether, the aqueous phases are neutralized, suitably diluted with water, and
' analyzed for glycerol by the method of Lofland (Anal.
Biochem. 9, 393, 1964) using the Technicon Autoanalyzer. The change in serum triglyceride levels induced by the drug is computed as a percentage of the control triglyceride levels.
For such usage, the compounds are administered orally as such or admixed with conventional pharmaceutical carriers. They may be administered in such forms as tablets, dispersible powders, granules, capsules, syrups and elixirs. The compositions may contain one or more conventional adjuvants, such as sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide an elegant and palatable preparation. Tablets my contain the active ingredient in admixture with conventional pharmaceutically acceptable excipients, e.g., inert diluents, such as calcium carbonate, sodium carbonate, lactose and talc, granulating and disintegrating agents, e.g., starch and alginic acid, binding agents, e.g., starch, gelatin and acacia, and lubricating agents, e.g., magnesium stearate, stearic acid and tale. The tablets may be uncoated or coated by known techniques to delay disintergration and absorption in the gastro-intestinal tract and thereby provide a sustained action over a longer period. Similarly, oral liquids, e.g. suspensions may contain the active ingredient in admixture with any of the conventional excipients utilized for the preparation of such compositions, e.g., suspending agents (methylcellulose, tragacanth and sodium alginate), Wetting agents (lecithin, polyoxyethylene stearate and polyoxyethylene sorbitan mono-oleate) and preservatives (ethyl-o-hydroxybenzoate). Capsules may contain the active ingredient alone or admixed with an inert solid diluent, e.g., calcium carbonate, calcium phosphate and kaolin. These pharmaceutical preparations may contain up to about of the active ingredient in combination with the carrier or adjuvant.
The hypolipidemic efiective dosage of the compounds of formula I employed for the alleviation of lipidemia may vary depending on the particular compound employed and the severity of the condition being treated. However, in general, satisfactory results are obtained when the compounds of formula I are administered at a daily dosage of from about 2 milligrams to about 500 milligrams per kilogram of animal body weight, preferably given in divided doses two to four times a day, or in sustained release form. For most large mammals, the total daily dosage is from about to about 4000 milligrams preferably 600 to 2000 milligrams. Dosage forms suitable for internal use comprise from about 37.5 to about 2000 milligrams preferably 150 to 2000 milligrams of the active compound in intimate admixture with a solid or liquid pharmaceutically acceptable carrier or diluent.
The preferred pharmaceutical compositions from the standpoint of preparation and ease of administration are solid compositions, particularly hard-filled capsules and tablets containing from about 50 to 300 milligrams of the active ingredient.
3 EXAMPLES 1- AND 2 Tablets and capsules suitable for oral administration Tablets and capsules containing the ingredients indicated below may be prepared by conventional techniques and are useful in treating lipidemia at a dose of one or two tablets or capsules 2 to 4 times a day.
Weight (mg.)
Similarly, tablets and capsules can be prepared using 4 EXAMPLE 6 The following formulations for syrups or elixirs containing an effective amount of active compound may be formulated using conventional methods and are administered 2 to 4 times a day in the treatment of lipidemia.
Percent by weight Ingredient Syrup Elixir Disodium salt of 4,4-thiodiphenol 0. 5-3. 5 0. 5-3. 5 Bufiering system Quantity suflieient to adjust pH Sodium benzoate 0. 1-0. 5 1-0.
Flavoring agent- 0 01-0. 5 Water 5-2 Simple syrup U.S.P 0 Sorbitol solution (70%) -60 Certified dye 0.5-0 Alcohol 2. 5-22 Methyl paraben- 0. 05-0. 0 Propyl paraben- 0. 05-0. 1 Sodium saceharin 0 01-0. 01
Analogous compositions to those of Examples 5 and 6 the disodium salt of 4,4'-thiodiphenol in place of the 4,4- 20 I thiodiphenol at the same dosage level and used in treating are formulated l Y EI 111 P 0 dlsodlum Salt i id i form of 4,4 thiodiphenol the dipotassium salt form EXAMPLES 3 AND 4 thereof- EXAMPLES 7 AND 8 Sterile suspension for in ection and oral liquid suspension D Tablets and capsules suitable for oral administration I The following pharmaceutlcal compos1t1ons are formulated with the indicated amount of active agent using (2011- Tablets and capsules contalnlng the lpgredlents ventional techniques. The injectable suspension and the cated below y be P 'P Q Y c'onvel'ltlonal technlqlles oral liquid suspension represent formulations useful as and are useful I t a g 1P 1dm1a at a dose of one or unit doses and may be administered in the treatment of tWO tablets of ap u es 2 t0 4011185 aday. hyperlipidemia. The injectable suspension is suitable for I administration once a day whereas the oral liquid suspenweght (mg) sion is suitable administered 2 to 4 times per day for this Ingredient Tablet Capsule Purpose' 4,4-thiodiphenol (or the disodium form thereof)-.- 300 Tragacanth 1g Lactose 297. 5 Weight (mg) Corn starch 25 Talcum- Sterile Oral Magnesium stear 2.5 injectable liquid Ingredients suspension suspension Total 650 Methyl paraben, U.S.P Propyl paraben, U.S.P Polysorbate 80 (e.g. Tween 80), U.S.P Sorbitol solution, 70% U.S.P Bufie agent to adjust pH for desired sta- 1 For injection q.s. to 1. ml. 2 Q.s. to 51111.
Similar injectable suspensions and oral liquid suspensions for use in the treatment of lipidemia may be prepared by conventional techniques using the calcium or magnesium salt of 4,4'-thiodiphenol at the above dosage levels.
EXAMPLE 5 Sterile solution for injection Ingredient: Weight (mg) Disodium salt form of 4,4'-thiodiphenol 100. Sodium alginate 0.5. Buffer system As desired. Lecithin 0.5. Sodium chloride As desired.
Water for injection sq.s. to 1 milliliter.
EXAMPLES 9 AND 10 Sterile suspension for injection and oral liquid suspension The following pharmaceutical compositions are formulated with the indicated amount of active agent using conventional techniques. The injectable suspension and the oral liquid suspension represent formulations useful as unit doses and may be administered in the treatment of hyperlipidemia. The injectable suspension is suitable for administration twice a day whereas the oral liquid suspension is suitable administered 2 to 4 times per day for this purpose.
Weight (mg.)
Sterile Oral injectable liquid Ingredients suspension suspension 4,4-thiodiphenol (or the disodium form thereof) 300 300 Sodium carboxy methyl cellulose U.S.P 1. 25 12. 5 Methyl cellulose 0. 4 Polyvinylpyrrolidone Lecithin Benzyl alcohol Magnesium aluminum silicate Flavor- Color Methyl paraben, U.S.P Propyl paraben, U.S.P Polysorbate (eg. Tween 80), U.S. Sorbitol solution, 70% U.S.P Buffer agent to adjust pH for desired stability 1 For injection q.s. to 1 ml. 2 Q.s. to 5 ml.
Compositions useful in treating lipidemia analogous to those of Examples 9 to 12 may be formulated by employing, in place of the sodium salt form of 4,4'-thiodiphenol, the dipotassium, calcium or magnesium salt form thereof.
What is claimed is:
1. A pharmaceutical composition in the form of a tablet, capsule, dispersible powder, granule, syrup or elixir useful in the treatment of lipidemia in mammals comprising as an active ingredient thereof a compound of the formula or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier therefor, said compound being present in said composition in an amount sufficient to provide a daily dosage of from about 150 milligrams to about 4000 milligrams of said compound.
2. The pharmaceutical composition of claim 1 wherein said active ingredient is present in said composition to the extent of from about 37.5 milligrams to about 2000 milligrams per unit dosage.
3. A composition according to claim 1 wherein the carrier is a solid orally ingestible carrier and the active ingredient is present in said composition to the extent of from about 50 to 300 milligrams per unit dosage.
4. A composition accordingto claim 1 in which the active ingredient is 4,4-thiodiphenol.
5. A tablet according to claim 1 useful in the treatment of lipidemia in mammals comprising a hypolipidemic effective amount of a compound of the formula or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier therefor.
6. A capsule according to claim 1 useful in the treatment of lipidemia in mammals comprising a hypolipidemic effective amount of a compound of the formula or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier therefor.
7. A method for treating lipidemia, which comprises orally administering to a mammal in need of said treatment a hypolipidemic efiective amount of a compound of the formula or a pharmaceutically acceptable salt thereof.
8. A method according to claim 7 wherein the compound is administered at a daily dose of from about milligrams to about 4000 milligrams.
9. A method according to claim 7 wherein the compound is administered in a unit dosage form comprising said compound to the extent of from about 37.5 milligrams to about 2000 milligrams per unit dosage.
10. A method according to claim 7 wherein the compound is administered in a unit dosage form comprising said compound to the extent of from about 150 milligrams to about 2000 milligrams per unit dosage.
11. A method according to claim 7 in which the compound is 4,4'-thiodiphenol.
References Cited Chem. Abst. 68-20483S (1968).
STANLEY J. FRIEDMAN, Primary Examiner
1. A PHARMACEUTICAL COMPOSITION IN THE FORM OF A TABLET, CAPSULE, DISPERSIBLE POWDER, GRANULE, SYRUP OR ELIXIR USEFUL IN THE TREATMENT OF LIPIDEMIA IN MAMMALS COMPRISING AS AN ACTIVE INGREDIENT THEREOF A COMPOUND OF THE FORMULA
| 1973-10-09 | en | 1974-11-26 |
US-18339488-A | Infrared-sensitive electrophotoconductive element comprising an anthanthrone, a phthalocyanine and an oxadiazole compound in admixture
ABSTRACT
An electrophotoconductor is disclosed, comprising a conductive support having provided thereon a photoconductive layer comprising a resin binder having dispersed therein an anthanthrone compound, a phthalocyanine compound, and an oxadiazole compound. The electrophotoconductor exhibits high sensitivity in the wavelength region of from 760 to 850 nm and high negative charge retention and is suitable for use in a recording device using a semiconductor laser as a light source.
This application is a continuation of application Ser. No. 018,556 filed Feb. 25, 1987, now abandoned.
FIELD OF THE INVENTION
This invention relates to an electrophotoconductor having high sensitivity in the near infrared region which is suitable for use in electrophotographic devices, and particularly, recording devices employing a semiconductor laser as a light source for recording, such as a laser beam printer, a laser printing plate making system, and the like.
BACKGROUND OF THE INVENTION
In an electrophotographic recording system, a light source for recording is chosen according to spectral sensitivity of a photoconductor used. Systems using a gas laser, e.g., an Ar laser, an He-Ne laser, etc., as a light source for recording achieves image formation in a relatively short time because of the high output of the laser. However, since use of a gas laser is associated with a complicated optical system and requires techniques for maintenance therefor, it is difficult to reduce the size and cost of devices. Therefore, studies are being made on a recording system using a semiconductor as a light source which would meet the demands for small-sized and unexpensive devices.
Semiconductor lasers have recently received a marked development. Of conventionally proposed semiconductor lasers, those having their oscillation wavelengths in the region longer than 780 nm have been put into practical use. For particular use in printers or printing plate making systems, semiconductor lasers having their oscillation wavelengths in the region of from 780 nm to 850 nm are commonly employed.
Since state-of-the-art semiconductor lasers have lower outputs than other lasers, photoconductors to be used in semiconductor laser printers, semiconductor laser printing plate making systems, etc. are required to have sufficiently high sensitivity in the wavelength region of from 780 to 850 nm. For practical purposes, sensitivities of 10 erg/cm2 or less in terms of E1/2 (exposure required to reduce the charge by half its initial value) are demanded.
Known electrophotoconductors include those containing inorganic compounds, e.g., zinc oxide, copper phthalocyanine compounds, oxadiazole compounds, etc., as photosensitive substances, but none of them exhibits sufficiently high sensitivity in the longer wavelength region of from 780 to 850 nm.
SUMMARY OF THE INVENTION
Accordingly, one object of this invention is to provide an electrophotoconductor having high sensitivity in the longer wavelength region and suitable for use in recording devices using a semiconductor laser as a light source for recording.
It has now been found that the above object can be accomplished by an electrophotoconductor comprising a conductive support having provided thereon a photosensitive layer in which (a) an anthanthrone compound, (b) a phthalocyanine compound, and (c) an oxadiazole compound are dispersed in (d) a resin binder.
DETAILED DESCRIPTION OF THE INVENTION
The anthanthrone compound which can be used in the present invention may be selected arbitrarily from compounds known to have electrophotoconductivity, such as anthanthrone, dibromoanthanthrone, dichloroanthanthrone, dimethoxyanthanthrone, diethoxyanthanthrone, C.I. VAT Black 29, iodized dibromoanthanthrone, etc. Particularly preferred among them are compounds represented by formula ##STR1## wherein X1 and X2 each represents a halogen atom; and n represents 0 or an integer of from 1 to 4.
The phthalocyanine compound which can be used in the present invention includes metallo-phthalocyanine or metal-free phthalocyanine compounds and derivatives thereof with the aromatic nucleus being substituted. Examples of preferred phthalocyanine compounds include metallo-phthalocyanine compounds having formulae (II) to (VI) shown below, in which at least part of the four benzene nuclei may be substituted by a halogen atom, a nitro group, an amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group. ##STR2##
The oxadiazole compound which can be used in the present invention may be selected arbitrarily from conventional oxadiazole compounds known to have electrophotoconductivity, such as 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole, 2,5-bis(4-diethylaminophenyl)-1,3-4-oxadiazole, 2,5-bis(4-dipropylaminophenyl)-1,3,4-oxadiazole, 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole, 2-(4'-aminostyryl)-5-phenyl-1,3,4-oxadiazole, 2-(4'-aminostyryl)-5-(4"-methylphenyl)-1,3,4-oxadiazole, etc. Particularly preferred among them are those represented by formula ##STR3##
The oxadiazole compound of formula (VII) may be used in combination with an N-alkylcarbazole compound, e.g., N-methylcarbazole, N-ethylcarbazole, N-propylcarbazole, etc., or a dialkylaminobenzoic acid compound, e.g., dimethylaminobenzoic acid, diethylaminobenzoic acid, dipropylaminobenzoic acid, etc.
The binders to be used in the photosensitive layer of the invention are not particularly restricted, and any known binder resin commonly employed in electrophotographic materials can be selected. Examples of preferred resins to be used as binders include acrylic resins, polyester resins, polycarbonate resins, polystyrene resins, phenolic resins, epoxy resins, urethane resins, phenoxy resins, and the like.
The electrophotoconductors according to the present invention can be prepared by dissolving a resin binder in an appropriate organic solvent, uniformly dispersing the aforesaid compounds (a) to (c) in the binder solution by means of a ball mill, a paint shaker, a sand mill, a ultrasonic dispersing machine, etc. to prepare a coating composition, and coating the composition on a conductive support, followed by drying. Coating is usually carried out by roll coating, wire bar coating, doctor blade coating, and the like.
Solvents which can be used for dissolving the binder include aromatic hydrocarbons, e.g., benzene, toluene, etc.; ketones, e.g., acetone, butanone, etc.; halogenated hydrocarbons, e.g., methylene chloride, chloroform, etc.; ethers, e.g., ethyl ether, etc; cyclic ethers, e.g., tetrahydrofuran, dioxane, etc.; and esters, e.g., ethyl acetate, methyl cellosolve acetate, etc. These solvents may be used either alone on in combination of two or more thereof.
The photosensitive layer is preferably coated to a dry thickness of from 3 to 50 μm, and more preferably from 3 to 15 μm.
In the photosensitive layer, the anthanthrone compound (a) and the phthalocyanine compound (b) each is preferably used in an amount of from 0.5 to 90% by weight, and more preferably from 10 to 40% by weight, based on the resin binder (d). The oxadiazole compound (c) is preferably used in an amount of from 0.1 to 90% by weight, and more preferably from 1 to 80% by weight, based on the resin binder (d).
The conductive support on which a photosensitive layer is formed usually includes a metal sheet or foil, e.g., an aluminum sheet or foil, a plastic film having deposited thereon a metal, e.g., aluminum, and paper having been rendered electrically conductive.
If desired, an adhesive layer or a barrier layer may be provided between the conductive support and the photosensitive layer. Materials for the adhesive or barrier layer include polyamide, nitrocellulose, casein, polyvinyl alcohol, etc.
A laser printing plate making system has been developed, in which a printing plate is produced by using an electrophotoconductor having high sensitivity to laser beams, and has already been applied to practical use in U.S.A. The electrophotoconductors in accordance with the present invention can be suitably utilized in this system because of their high sensitivities to laser beams. For use in this system, a metal sheet, and preferably an aluminum sheet, having a grain surface is used as a conductive support, and an alkali-soluble resin is used as a binder. The alkali-soluble resin includes a styrene-maleic acid copolymer, a copolymer of a polymerizable monomer (e.g., acrylic esters, methacrylic esters, vinyl acetate, styrene, vinyl chloride, etc.) and a carboxyl-containing polymerizable monomer (e.g., acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, etc.), and the like. The photoconductor prepared by using these materials is irradiated with a laser beam to form a toner image thereon. After fixation of the toner image, the photoconductor is developed with an aqueous alkali solution containing an alkali agent (e.g., sodium hydroxide, sodium silicate, etc.) whereby non-image areas are dissolved and removed, while the toner image remains. On printing, the remaining toner image serves as image areas, and the exposed metal surface forms non-image areas. The thus produced printing plate can be used as a lithographic printing plate using fountaining solution.
The sensitization mechanism of the electrophotoconductor according to the present invention will be briefly explained below.
Conventionally reported phthalocyanine compounds are hole transport substance. A photosensitive layer obtained by uniformly dispersing such a phthalocyanine compound in a resin binder shows satisfactory sensitivity only when positively charged but has an inferior charge retention when negatively charged because it receives injection and transport of holes from the support electrode. Such behavior is unfavorable particularly in the laser scan plate making system. Even if the phthalocyanine compound is dispersed in an ordinary charge carrier transporting material, such as a hole transport substance, e.g., oxadiazole compounds, hydrazone compounds, pyrazoline compounds, etc., it has a considerably high residual potential when negatively charged.
To to contrary, the system according to the present invention in which an appropriate amount of an anthanthrone compound is added to a phthalocyanineoxadiazole system, i.e., a phthalocyanine hole transporting material system, exhibits surprisingly improved negative charge retention and increased sensitivity, thus realizing a single-layer photoconductor which shows high sensitivity even when negatively charged.
Considering the fact that an anthanthrone compound-oxadiazole-resin binder dispersion system photoconductor containing no phthalocyanine compound exhibits substantially no sensitivity in the wavelength region longer than 780 nm, it is believed that in the photoconductor of the invention an electronical interaction is produced among the three components, i.e., anthanthrone compound, phthalocyanine compound, and oxadiazole compound, and the phthalocyanine compound is excited to generate the transport charge carriers thereby to show high sensitivity.
The present invention will now be illustrated in greater detail by way of examples, but it should be understood that the present invention is not limited thereto. In these examples, all the parts are by weight unless otherwise indicated.
EXAMPLE 1
A mixture consisting of 120 parts of dibromoanthanthrone of formula ##STR4##10 parts of titanyl phthalocyanine of formula (II), 150 parts of the oxadiazole compound of formula (VII), 660 parts of a polyester resin as a binder ("Vylon 200" produced by Toyo Spinning Co., Ltd.), and 5500 parts of a methyl ethyl ketone-methylene chloride mixed solvent was uniformly dispersed in a paint shaker. The resulting coating composition was coated on an aluminum sheet with a wire bar coater, followed by drying to preparea photoconductor having a 13 μm thick photosensitive layer. The resulting electrophotoconductor was determined for charging characteristics and photosensitivity according to the following proceduresby means of "Paper Analyzer SP-428" manufactured by Kawaguchi Electric Works Co., Ltd.
The photoconductor was charged to a negative voltage of 6 kV, and the surface potential immediately after charging (initial potential: V0) and after 10 seconds from the charging (V10) were measured to obtain a surface potential retention (V10 /V0). The photoconductor was then exposed to white light emitted from a tungsten lamp at an illumination of 5 lux, and the photosensitivities E1/2 and E1/5 (lux·sec), i.e., the exposure required for the surface potential to drop to half or one-fifth of the initial value, were measured. Further,the surface potential retained after 15 seconds from the commencement of exposure (VR 15) was measured. In the same manner, the spectral photosensitivity E1/2 (μJ/cm2) of the photoconductor when exposed to light of 830 nm was measured. Evaluation of photosensitivity ofthe photoconductor was made based on these measured values. The results obtained are shown in Table 1.
COMPARATIVE EXAMPLES 1 TO 3 AND EXAMPLES 2 TO 5
Photoconductors were produced in the same manner as described in Example 1 except for using compositions shown in Table 1. The resulting photoconductors were evaluated in the same manner as in Example 1, and theresults obtained are shown in Table 1.
TABLE 1
__________________________________________________________________________
Comparative
Comparative
Comparative
Example 1
Example 1
Example 2
Example 3
Example 2
Example 3
Example
Example
__________________________________________________________________________
5
Composition (part):
Dibromoanthanthrone
120 120 -- -- 120 120 120 120
Titanyl Phthalocyanine
10 0 10 10 20 30 60 120
Oxadiazole of (VII)
150 150 150 -- 150 150 150 150
Vylon 200 660 660 660 660 660 660 660 660
Methyl Ethyl Ketone/
5500 5500 5500 5000 5500 5500 5500 5500
Methylene Chloride
Electrostatic
Characteristics:
V.sub.0 (V) -530 -600 -700 -650 -630 -720 -580 -430
V.sub.10 (V)
-500 -580 -630 -600 -600 -660 -520 -380
V.sub.10 /V.sub.0
0.94 0.97 0.90 0.92 0.94 0.97 0.93 0.74
E.sub.1/2 (lux · sec)
1.8 12.0 500.0 180.0 2.0 1.80 1.40 1.40
E.sub.1/5 (lux · sec)
2.4 24.0 -- -- 4.5 4.0 4.0 5.0
V.sub.R15 (V)
0 -- -- -- 0 0 0 0
E.sub.1/2 at 830 nm
0.6 -- -- 60.0 0.99 0.90 0.60 0.4
(μJ/cm.sup.2)
__________________________________________________________________________
EXAMPLE 6
The photoconductor as prepared in Example 1 was determined for sensitivity E1/2 in the same manner as in Example 1 except for using monochromatic light having various wavelengths as shown in Table 2 selected by a combination of an interference filter and a band pass filterin place of white light as used in Example 1. The results obtained are shown in Table 2.
TABLE 2
______________________________________
Wavelength E.sub.1/2
(nm) (μJ/cm.sup.2)
______________________________________
400 0.7
450 0.70
480 0.80
500 0.81
520 0.80
560 0.90
580 0.92
600 1.0
630 0.9
660 0.8
700 0.75
750 0.75
780 0.70
800 0.65
830 0.68
850 0.65
890 0.68
______________________________________
EXAMPLES 7 TO 11
Photoconductors were produced in the same manner as in Example 1 except forreplacing the titanyl phthalocyanine as used in Example 1 with compounds shown in Table 3. The resulting photoconductors were evaluated in the samemanner as in Example 1, and the results obtained are also shown in Table 3.
TABLE 3
__________________________________________________________________________
Phthalocyanine Dark Decay
E.sub.1/2
E.sub.1/2 at λ.sub.max
Example No.
Compound
λ.sub.max
V.sub.0
Rate (lux · sec)
(μJ/cm.sup.2)
__________________________________________________________________________
7 (III) 810
-550
0.89 2.0 0.7
8 (IV) 800
-500
0.82 2.0 0.7
9 (V) 850
-600
0.79 2.3 0.8
10 metal-free
780
-600
0.90 3.0 0.9
phthalocyanine
11 (VII) 778
-600
0.92 6.0 1.2
__________________________________________________________________________
EXAMPLE 12
The photoconductor as produced in Example 1 was evaluated for stability on repeated use by means of Paper Analyzer SP-428. The photoconductor was charged to a negative voltage of 6 kV and exposed to light at an illumination of 50 lux. The characteristics in the initial stage and aftercopying 6000 prints were measured, and the results obtained are shown in Table 4.
TABLE 4
______________________________________
V.sub.O V.sub.10 E.sub.1/2 E.sub.1/5
V.sub.15
(V) (V) (lux. · sec)
(lux.sec)
(V)
______________________________________
Initial
-530 -500 1.8 2.4 0.0
State
After -550 -500 1.7 2.2 0.0
Copying
6,000
Prints
______________________________________
It can be seen from the results of Table 4 that the photoconductor according to the present invention has excellent stability on repeated use.
EXAMPLE 13
A photoconductor was produced in the same manner as in Example 1 except forusing a styrene-maleic acid copolymer resin ("ISM-7" produced by Gifu Shellac Seizosho K.K.) as a resin binder and a grained aluminum sheet as aconductive support. As a result of evaluation, the initial potential V0 and photosensitivity E1/2 of the resulting photoconductor were found to be 300 V and 2.5 lux.sec, respectively.
An electrostatic latent image was formed on the photoconductor by the use of a laser printing plate making apparatus, and the latent image was developed with a liquid developer ("CBR-100" produced by Dai-Nippon Ink & Chemicals Inc.), followed by heating at 180° C. for 5 seconds to fix the toner image. Then, the photosensitive layer on the areas where a toner was not adhered was removed by dissolving in a mixed aqueous alkali solution of sodium hydroxide and sodium silicate adjusted to a pH of 13 thereby to produce a lithographic printing plate having a toner image thereon. When the resulting printing plate was actually used for printing,more than 100,000 clear prints were obtained.
As described above, the electrophotoconductors in according with the present invention, in which (a) an anthanthrone compound, (b) a phthalocyanine compound, and (c) an oxadiazole compound are incorporated in a photosensitive layer, exhibit markedly increased sensitivity to lightof longer wavelengths of from 760 nm to 860 nm and greatly improved negative charge retention. The photoconductors of the invention are, therefore, suitable for use in recording device using a semiconductor laser as a light source for recording.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
What is claimed is:
1. An electrophotoconductor having high sensitivity in the near infrared region comprising a conductive support having provided thereon a photosensitive layer comprising a resin binder having dispersed therein from 0.5 to 90% by weight of an anthanthrone compound, from 0.5 to 90% by weight of a phthalocyanine compound, and from 0.1 to 90% by weight of an axadiazole compound.
2. An electrophotoconductor as in claim 1, wherein said anthanthrone compound is a compound represented by formula ##STR5## wherein X1 and X2 each represents a halogen atom; and n represents 0 or an integer of from 1 to 4.
3. An electrophotoconductor as in claim 1, wherein said oxadiazole compound is a compound represented by formula ##STR6##
4. An electrophotoconductor as in claim 1, wherein said anthanthrone compound is present in an amount of from 10 to 40% by weight based on the resin binder.
5. An electrophotoconductor as in claim 1, wherein said phthalocyanine compound is present in an amount of from 10 to 40% by weight based on the resin binder.
6. An electrophotoconductor as in claim 1, wherein said oxadiazole compound is present in an amount of from 1 to 80% by weight based on the resin binder.
7. An electrophotoconductor as in claim 1, wherein said conductive support is an aluminum sheet having a grain surface and said resin binder is an alkalisoluble resin.
| 1988-04-13 | en | 1989-09-19 |
US-60389684-A | Strainer for submergible pump
ABSTRACT
A strainer for use in a submergible pump is constructed by a plurality of stoppers arranged on a plate member and each of the stoppers is disposed and extended in the direction of liquid flow passing from the peripheral portion of the plate member towards the central portion of the same or the suctioning opening of the pump. Each of the members is provided with a slanted edge near the center portion, an upright edge near the outer periphery and a tip edge parallel to the plate member and coupling the slanted edge. The upright edge and the height of the tip edge is made shorter in its axial length so that the liquid flow may freely pass between the adjacent stoppers as well as the portion between the tip edge and the pump body.
The stoppers or entire strainer may be made of elastic material to give flexibility to the stoppers so as to make the flow passage larger by the deflection thereof to allow smooth backward flow and give facility for cleaning when the pump is de-energized.
FIELD OF INVENTION
The present invention relates to a pump construction and more specifically to a strainer for use in a submergible pump.
BACKGROUND OF INVENTION
A strainer used in a submergible pump of prior art has usually been made in a cylindrical tube form having a plurality of longitudinal slits or a plurality of perforations on the cylindrical surface through which the liquid is sucked into the pump. Such strainer has been generally made by a casting process or of a sheet metal and directly attached to a pump body at its suction opening.
The slits or perforations are choked with foreign materials during use and, when soft items such as fibrous foreign materials are caught in the slits or perforations, the ends of foreign fibrous materials may become entangled with each other thereby making it difficult and troublesome to remove them from the strainer. Also, such strainer is likely to be choked with other foreign materials and, therefore, the length of slits or number of perforations is generally increased to provide some surplus operating time whereby the axial length of the strainer is lengthened which causes a condition wherein the water cannot be satisfactorily pumped out close to the water bottom because the position of the suction opening is made higher due to the increased axial length of the strainer.
Also, when the operation of the submergible pump is stopped, the delivery water containing foreign materials may flow backward to cause clogging of the strainer so that further actuation of the pump becomes impossible.
Such clogging of the strainer due to backward flow of the delivery water is difficult to clear if the foreign materials trapped these contain fibrous items because pulling the trapped fibrous materials from the outside of the strainer will cause them to be tightly pushed into the slits or perforations together with other foreign materials. Therefore, it is necessary to dismantle the strainer for the purpose of cleaning the trapped materials therefrom.
SUMMARY OF INVENTION
Accordingly, it is an object of the present invention to provide a strainer used in a submergible pump free from the drawbacks noted above.
Thus, it is an object of the present invention to provide a strainer in which trapping of the fibrous materials is prevented, suctioning the water close to the water bottom is possible, the chance of clogging by the backward flow at the time of stopping operation of the pump is minimized and removal of the trapped materials is made easy.
The above objects are accomplished according to the present invention wherein a plurality of stopping elements are circumferentially disposed on the strainer of a plate or disk form and each of these elements is elongated in the radial direction and parallel to the axial direction so that the radial flow passages are formed at opposite radial sides of the elements between the adjacent elements and the axial tip of each element is spaced from the pump body around the suction opening thereof.
Further objects and advantages of the present invention will be made clear when the detailed description of the preferred embodiments is reviewed in conjunction with the accompanying drawings, the brief description of which is summarized below.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side view of a submergible pump partly in cross section which includes a strainer according to the present invention;
FIG. 2 is a plan view of the strainer shown in FIG. 1;
FIG. 3 is a cross-sectional view of a stopper of the strainer taken along the line III--III in FIG. 2;
FIG. 4 is a cross-sectional view taken along the line IV--IV in FIG. 2;
FIG. 5 is a cross-sectional view of a bushing employed in the strainer shown in FIGS. 1 and 2;
FIG. 6 is an end view of the bushing;
FIG. 7 shows the situation where a fastening bolt is received in the bushing shown in FIGS. 5 and 6;
FIG. 8 is an end view of the situation shown in FIG. 7; and
FIG. 9 is a perspective view of an alternative embodiment of the strainer according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a side view of a submergible pump assembly partly in section which is provided with a strainer 15 (also referred to as a "pump support 15") according to the present invention.
The motor section of the submergible pump assembly comprises a motor frame 1 in which a motor is housed, a motor cover 2 attached to the upper part of the motor frame 1, a handle 3 secured to the motor cover 2, a cable connector 5, a submergible cable 4 coupled to the stator of the motor through the connector 5, and a shaft 6 attached to the rotor of the motor and journalled by means of bearings (not shown). At the lower portion of the motor frame 1, an intermediate casing 9 is mounted with a seal ring 11 disposed therebetween and is secured to the motor frame 1 by bolts 12 screwed into the frame to form a shaft seal chamber 7. The shaft 6 extends downwardly through a shaft seal means 8 such as a mechanical seal disposed at the lower part of the intermediate casing 9.
A pump section comprises a pump casing 14 abutting against the lower end of the intermediate casing 9 with a seal packing 13 interposed therebetween, a pump support 15 abutting against the lower surface of the pump casing 14 and an impeller 17 mounted at the distal end of the motor shaft 6 extending into the pump casing 14.
The intermediate casing 9, the pump casing 14 and the pump support 15 are tightly fastened by means of bolts 16 and nuts 16b associated therewith. The upper portion of the pump support 15 serves as means for straining foreign materials from the incoming liquid into the pump section and, therefore, the pump support 15 may also be referred to as a strainer in, the present specification and claims. The pump casing 14 is provided with a suction opening 21 at the lower wall of the casing and a discharge opening 22 leading to the vortex chamber of the casing.
Within the pump casing 14, the impeller 17 is secured to the distal end of the motor shaft 6 by conventional means such as the key on the shaft 6, the keyway on the internal bore of the impeller 17 and a fastening nut 18. In this preferred embodiment of the submergible pump, the impeller 17 is of a semi-open type and is disposed within the pump casing 14 which is not provided with an impeller chamber as is usually provided in the ordinary vortex pump. Thus, the impeller is not placed in such impeller chamber but the open side of the impeller 17 is spaced from the inner lower surface of the pump casing 14.
A front surface 19a of a main shroud 19 of the impeller 17 is arranged to be coplanar with an inner upper surface 14a of the pump casing 14. In the conventional submergible pump, there is possibility that the fibrous foreign materials may get into the recess between the outer periphery of the impeller and the impeller chamber; however, in the preferred embodiment shown in FIG. 1, the fibrous foreign materials will not clog such recess and such foreign materials easily move to the outside of the impeller towards the vortex chamber. The nut 18 tightening the impeller 17 to the shaft 6 may be given a single plate vane 18a which extends through the suction opening 21 slightly beyond the lower wall of the pump casing 14. At the discharge opening 22, a delivery conduit 23 is attached by fastening means 24 such as bolts and nuts.
In FIG. 2, a plan view of the pump support or strainer 15 is illustrated. For attaching the strainer to complete the pump assembly by bolts 16 and nuts 16b as hereinfore explained in connection with FIG. 1, a plurality of fastening pads 27 are circumferentially provided on a pump base 26 and, in each of the pads, a bushing 25 is installed so as to provide a through hole for the fastening bolt 16. Also, a plurality of stabilizing seats 28 are circumferentially arranged on the base 26 so that the upper surfaces of the fastening pads 27 and the stabilizing seats abut against the outer lower surface of the pump casing 14 when the pump support 15 is tightened together with the motor section and the intermediate casing 9 by bolts 16 and nuts 16b. Also, on the same side of the support 15 as those of the pads 27 and seats 28, a plurality of stoppers 29 for foreign materials are circumferentially disposed so as to prevent foreign materials from being sucked into the pump casing 14 through the suction opening 21.
The stabilizing seats 28 is the upright protrusions on the upper surface of the base 26. Each of the seats are extended radially from the periphery of the base 26 towards the center but terminates at a certain point so that the inner end of the seat may not interfere with the suction opening when the support 15 is assembled. Stoppers 29 are rather small pieces compared to the seats 28 and each of them also extends radially in the respective intermediate portions between the pad 27 and the seat 28. Each stopper 29 is also upright and is made of a thin piece elongated in the radial direction or from the central portion to the peripheral portion.
In FIG. 3 and FIG. 4, there are shown schematic illustrations of the stopper 29 in cross sections along the lines III--III and IV--IV, respectively in FIG. 2. As shown in FIG. 3, the outer side of each stopper 29 forms an upright edge 29a and the opposite inner side forms a slanted edge 29b, both edges being connected by a top edge 29c. The top edge 29c is arranged to have a gap "S0" between the top edge 29c and the inner surface 14b of the lower wall of the pump casing 14.
As illustrated in FIG. 2, stoppers 29 are arranged radially and equally spaced from each other, and the flow passages formed between the adjacent stoppers are gradually narrowed in the direction from the periphery of the strainer to the central portion.
Thus, the relationship
S2 >S1
is given wherein
S1 is a circumferential distance between the adjacent stoppers at the inner ends thereof; and
S2 is the circumferential distance between the adjacent stoppers at the outer ends thereof.
There are given similar gap distance S3 between each pad 27 and its adjacent stopper 29 at the outer end of the stopper and similar gap distance S4 between the seat 28 and its adjacent stopper 29 at the outer end of the stopper.
The dimensions of the gaps "S1", "Sl", "S2", "S3" and "S4" are determined by the pump design with consideration being given to such matters as what liquid is to be handled and what size of foreign material is to be anticipated in such liquid.
The pump support 15 having the construction as above explained will serve as the strainer under the operation of the pump.
When the pump is energized through the cable 4, the impeller 17 is rotated to suck the liquid through the passages (S1, S2, S3, S4 and S0) of the strainer 15 and the suction opening 21. Within the pump casing 14, a vortex flow "α" identified in FIG. 1 is generated on each of the blades of the impeller 17 and this vortex flow is moved together with a larger vortex having its center coinciding with the axis of the shaft 6 and along the internal surface of the vortex chamber of the pump casing so as to be discharged through the discharge opening 22. During the movement of the liquid through the flow gaps "S0", "S1", "S2", "S3" and "S4", the foreign materials are trapped by the stoppers 29. When the motor of the pump is de-energized, the liquid in the delivery conduit will flow backward into the pump chamber with a pressure head larger than the ordinal suctioning pressure and will pass backwards through the suction opening 21 towards the strainer 15 where the liquid will pass through the gap passages "S0", "S1", "S2", "S3" and "S4" in the backward direction.
When the foreign materials in the backward flow lodge against the slanted surfaces 29b of the stoppers 29, such foreign materials rise along the slanted surfaces 29b and enter the gap "S0" and are forcibly returned to the original pond or pool.
Thus, due to the presence of slanted surfaces 29b and the free gap 37 S0", such foreign materials may be easily passed backwards through the strainer 15.
In the foregoing explanation, the strainer or pump support 15 has been explained with respect to its configuration and the effects derived therefrom. The effects of the strainer are further enhanced if the stopper 29 is made to be flexible. Such may be accomplished by molding the entire strainer 15 (excluding the bushings 25) from an elastic material such as rubber or plastic, etc. The bushings 25 may be positioned in place during the molding or they may be inserted after the molding. Alternatively, the stoppers 29 above may be made flexible by appropriately mounting the flexible stoppers 29 on the base 26.
Due to the configuration of the stoppers 29, the stoppers 29 are relatively rigid in the direction A shown in FIG. 3, even if they are made flexible, compared to the direction B shown in FIG. 4. During the operation of the pump, the liquid containing foreign materials is moved in the direction A from the side of the upright edge 29a towards the slanted edge 29b, and the stopper 29 exhibits stiffness in this direction whereby the foreign materials are trapped by the stoppers 29. In the case where the pump is de-energized and backward flow of the liquid from the delivery conduit towards the outside of the pump through the strainer 15 takes place, foreign materials which have once passed through the strainer 15 towards the delivery conduit may lodge against the stoppers 29 during the backward flow. However, on such occasion, the foreign materials firstly come against the slanted edges 29b, explained before, and rise along the slanted edges 29b and are then freed at the gap "S0" into the backward flow even if the foreign materials are elongated ones which span the opposite radial side surfaces of the stoppers. If the foreign materials are agglomerated into a mass and become lodged at the stoppers 29, flexible stoppers will warp in the direction B shown in FIG. 4 to make the dimension of "S0" larger so that such agglomerated foreign materials may pass therethrough. Further, if the stoppers 29 are made flexible, they may oscillate when the backward flow passes the stoppers so that, if any foreign material becomes attached to the stoppers, it is subjected to such oscillation by the backward flow every time the pump is de-energized and, thus, the strainer 15 is cleaned by the backward flow. Further, if it is found that some foreign materials are suspended on the stoppers at the time when the pump is not being operated, such foreign materials may be manually removed with the deformation of the stoppers by pulling such materials from outside.
If the whole support or strainer 15 is made elastic, it may also serve as an anti-shocking member when the pump is sunk to the bottom of the liquid or water. In actual operation, the pump is used for liquid which may not be clear due to the foreign materials contained therein and it would be difficult to determine when the pump reaches the bottom. Therefore, elasticity of the pump support gives the advantage of protecting the pump body from shock on hitting the bottom.
The pump or support is given further advantage in that each of the bushings 25 is slotted at one end as illustrated in FIGS. 5 thru. 8. As shown in FIGS. 5 and 6, one end of each bushing 25 is cut off to provide a slot having parallel opposite surfaces 25a which serve to prevent rotation of the head 16a of the bolt 16 as illustrated in FIGS. 7 and 8. Therefore, for fastening nuts 16b for the bolts 16, only a single tool may suffice to rotate the nuts 16b whereby assembling and disassembling the pump is made simple and easy.
The height of the support or strainer 15 measured in the axial direction is made smaller according to the present invention since such height is the sum of the thickness of the base 26, the height of the stopper 29 and the axial gap "S0", and the stoppers 29 are made thin in the circumferential direction thereby providing enough suctioning space even when the height of the strainer 15 is made small. Therefore, it is possible for the total height of the pump to be made small and suctioning liquid is effectively performed to a level close to the bottom.
As an alternative configuration of the strainer 15, another embodiment 15' is illustrated in FIG. 9. This strainer 15' comprises a base 26', an annular ring 31 having perforated ears or bushings and stoppers 29' circumferentially suspended downwardly from the ring 31, the ring 31 and the base 26' being connected by an appropriate number of columns 32. This strainer may also be unitarily molded from elastic material.
The invention has been explained in detail referring to the preferred embodiment. However, the present invention is not limited to what has been explained above and it may be modified by those skilled in the art within the sprit and scope of the present invention defined in the appended claims.
What is claimed is:
1. A strainer for use in a submergible pump wherein suctioning flow is generally directed from the peripheral portion to the central portion of the strainer, said strainer comprising:(a) a base member and (b) a plurality of stoppers disposes perpendicularly relative to said base member at the peripheral portion thereof, each said stoppers extending in the direction of the suctioning flow, the height of said stoppers being short of the total height of the strainers so that a flow passage is provided at the axial tip of each of said stoppers communicating the passages at the opposite side surfaces of said stopper with each other, each of said stoppers being given a slanted edge at the portion near the central poriton of the stainer, an upright edge parallel to a pump axis near the outer periphery of the strainer, and a tip edge connecting said slanted edge and said upright edge while leaving a space between said tip edge and the outer surface of the pump casing within the range of the total height of the strainer.
2. A strainer so claimed in claim 1 wherein said stoppers are mounted on said base member.
3. A strainer as claimed in claim 1 wherein said strainer further comprises an annular ring member disposed parallel to said base member and coupled to said base member through plural column members disposed therebetween, said stoppers being suspended from said ring member leave space between the tips and said base member.
4. A strainer as claimed in any one of claims 1, 2, and 3 wherein said strainer is made of elastic material.
5. A strainer as claimed in any one of claim 1, 2, and 3 wherein said base member is circular and said stoppers are arranged circumferentially so as to extend in the radial direction.
| 1984-04-25 | en | 1985-12-24 |
US-92336486-A | Electrochemical generator utilizing solid polymer-salt complex
ABSTRACT
An electric current producing primary electrochemical cell and a process for producing electric current at an ambient temperature of about 20° C. to about 100° C. in a primary electrochemical cell using a polymer electrolyte which is a solid at a temperature of about 20° C. to about 100° C.
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation in part of application Ser. No. 799,699, now abandoned filed Nov. 19, 1985.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to primary electrochemical cells utilizing an electrolyte comprising a solid polymer.
2. Description of the Prior Art
Aqueous electrolytes conventionally used as electrolytes in primary batteries can be disadvantageous in that degradation of the electrodes can result by contact with said electrolytes. In addition, aqueous electrolytes can be difficult to handle. Therefore, solid electrolytes have been developed which have certain advantages including thermostability, absence of corrosion of the electrodes, and a wide range of redox stability which permits their combination with highly energizing couples to obtain electrochemical generators of high energy per unit of weight. Solid electrolytes are also advantageous because they can be prepared in thin layers which makes it possible to decrease the internal resistance of the electrochemical generator. Commercially available solid electrolyte battery systems utilize lithium iodide as the solid electrolyte since the lighter alkali metals, in particular lithium are the most attractive commercially utilized anode materials. Much research has been concentrated on lithium ion conductors as electrolytes but only little work has been done using alkaline earth metal ion conductors since the alkaline earth metal salts are poorly ionized. In a battery, the overall resistance of the fabricated electrolyte element limits the rate capability. In addition the volume taken up by a solid electrolyte such as lithium iodide is wasted space which could otherwise be devoted to active electrode components. Therefore, in order to maximize volumetric energy density and rate capability, the ability to fabricate a solid electrolyte as a thin element is important. Because, upon cell discharge, there is often a substantial redistribution of material in the cell and, in general, an overall volume change may occur, cell design must accommodate or minimize the stress on a thin, solid electrolyte element. In addition, the electrolyte must be compatible with the electrodes, both in the sense of being unreactive and also of making and maintaining electrical contact.
Solid polymer-salt complexes for use as electrolytes in electrochemical generators are known from U.S. Pat. No. 4,579,793, Armand et al in which there are disclosed electrolytes of cross linked organometallic polymers in which lithium salts are dissolved. The solid polymer-salt electrolytes of U.S. Pat. No. 4,578,326 to Armand et al are polyether copolymers which have been found to have improved conductivity over certain polyether homopolymers. The solid complexes of poly(eythylene oxide) and magnesium chloride which are disclosed by Yang et al in J. Electrochemical Society, July 1986, pp. 1380-1385 appear to be principally anion conductors when used as electrolytes. Preferably sodium or lithium salts can be utilized as the ionic compound to be used in admixture with the polymer. Cross linked solid polymers of a cyclic ether in admixture with alkali metal salts of weak bases are disclosed in U.S. Pat. No. 4,357,401 to Andre et al. In addition, solid polymer electrolytes containing salts the anion of which is a residue derived from a strong acid and the cation of which is derived from an alkali metal or the ammonium ion are disclosed in U.S. Pat. No. 4,303,748 to Armand et al.
Novel alkali metal based ionic compounds are disclosed in U.S. Pat. No. 4,505,997 to Armand et al in admixture with solid polymers as electrolytes. The polymers are derived from monomer units which include at least one heteroatom, particularly oxygen or nitrogen, in the structure. Solid electrolytes are disclosed in U.S. Pat. No. 4,556,614 to Mehaute et al which include a first complexing polymer, an ionizable alkaline salt, and a second polymer having cross-linkable functions, for instance, a polymer of polyoxyethylene containing lithium perchlorate in admixture with a polymer of an acrylic modified polybutadiene-nitrile.
Complexes of lithium, sodium, or potassium salts and solid crown polyethers are disclosed as electrolytes in U.S. Pat. No. 3,704,174 to Berger. In U.S. Pat. No. 4,060,674 and U.S. Pat. No. 4,139,681 to Klemann, electrolytes consisting of an organic solvent and an organometallic alkali metal salt are disclosed.
There is no indication in any of these references that useful electrolytes can be obtained from triphenylmethylhalo-borate, -arsenate, -antimonate, or -phosphate salts and solid polymers which provide anionic conductance at ambient temperature, i.e., 20° to 100° C.
It is an object of the invention to provide a solid electrolyte comprising a polymer-salt complex which provides anionic conductance. This is especially important where alkaline earth metal anodes are utilized in electrochemical cells in conjunction with the solid polymer-salt complex electrolytes since most salt solutions containing alkali metals are strongly ionized as compared with salt solutions containing alkaline earth metals. The solid polymer-salt complex electrolytes are suitable for primary electrochemical cells operating at ambient temperatures such as 20° to 100° C. The electrolytes are particularly useful in combination with an alkaline earth metal anode such as an anode of magnesium or calcium.
The polymer-salt complex electrolytes of the invention have good flexibility and provide high anionic conductivity when the ionic salt utilized in combination with the solid polymer is a triphenylmethylhalo-borate, -arsenate, -antimonate, or -phosphate compound.
SUMMARY OF THE INVENTION
There is disclosed a primary electrochemical cell having an anode of an alkali or alkaline earth metal and a solid polymer-salt electrolyte complex. The electrolyte is particularly useful in electrochemical cells having an alkaline earth metal anode which operate at ambient temperatures of about 20° C. to about 100° C. The active cathode material of the cell is selected from at least one of the sulfides, halides, haloborates, haloarsenates and halophosphates of metals from groups Ib, IIb, IVa, Va, IVb, Vb, VIb, VIIb, and VIII of the Periodic Table of the Elements, quaternary tetraalkylammonium polyhalides, or an element selected from the group consisting of sulfur and iodine. The cathode can be, but need not be, a compound which intercalates the cation of which the anode is formed.
A useful method of forming the solid polymer-salt complex electrolyte is to form the polymer from a suitable monomer using a Lewis acid catalyst in the presence of an ionizing salt compound which is selected from at least one of a salt of the formula:
(R).sub.3 CMX.sub.n,
wherein M is selected from the group consisting of at least one of boron, phosphorus, antimony, and arsenic, and wherein X is halogen, n is 4 or 6, and R is aryl of 6-18 carbon atoms, alkyl of 1-8 carbon atoms, or alkaryl of 7-26 carbon atoms. R is preferably phenyl.
The polymer is formed from a monomer comprising at least one heteroatom in the monomer unit such as a heteroatom selected from at least one of the group consisting of oxygen, nitrogen, sulfur, and phosphorus. Alternatively, the polymer-salt complex can be formed by dissolving said salt in a preformed polymer either by means of a solvent or by fusion techniques, if the polymer is thermoplastic.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 and 2 of the drawings show a schematic representation of a cell using a magnesium anode, one embodiment of a solid electrolyte of the invention prepared by polymerizing a mixture of triphenylmethyltetrafluoroborate, magnesium metal and tetrahydrofuran, and a cathode consisting by weight of 50% WS2, 30% carbon black, and 20% polytetrafluoroethylene powder.
FIG. 3 is a graph showing current densities for a solid polymer electrolyte when used in a cell operating at normal room temperature ranges or approximately between about 20° C. and about 80° C., using a cathode, consisting by weight of 50% WS2, 30% carbon black and 20% polytetrafluoroethylene powder.
FIG. 4 is a graph showing current densities for one embodiment of the solid polymer electrolyte of the invention operating in a cell at normal room temperature ranges using a cathode consisting by weight of 80% CuS and 20% polytetrafluoroethylene.
FIG. 5 is a graph showing current densities for the solid polymer electrolyte operating in a cell at normal room temperature ranges using a cathode consisting by weight of 50% AgBF4, 30% graphite and 20% polytetrafluoroethylene.
DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTS
According to the present invention, there is provided an electric current producing primary electrochemical cell containing an alkali or alkaline earth methal anode, a cathode and an electrolyte which is a solid at ambient temperature, defined as a temperature of about 20° C. to 100° C. Said electrolyte comprises an electrolytically active polymer and salt complex derived from at least one monomer comprising at least one heteroatom in the monomer unit and said salt is at least one of a salt of the formula:
(R).sub.3 CMX.sub.n
wherein M is selected from the group consisting of at least one of boron, phosphorus, antimony, and arsenic, wherein X is halogen, n is 4 or 6 and R is aryl of 6-18 carbon atoms, alkyl of 1-8 carbon atoms, or alkaryl of 7-26 carbon atoms. R is preferably phenyl.
The cell of the invention provides a solid electrolyte which can be used in a primary cell assembled, for instance, using a magnesium anode, a cathode comprised of a mixture of WS2, graphite or carbon black, and polytetrafluoroethylene (PTFE). A solid electrolyte is prepared by first adding a sufficient amount of triphenylmethyltetrafluoroborate ((C6 H5)3 CFB4) to tetrahydrofuran to make a 1 molar solution. Magnesium turnings are added in excess to the mixture while stirring until the (C6 H5)3 CBF4 is completely dissolved and a dark liquid is formed. This liquid polymerizes to provide a black, rubbery solid polymer of empirical formula C70 H110 MgBF4 O12. The solid polymer has an electrical conductance of about 10-4 ohm-1 cm-1 at room temperature.
When this rubbery solid polymer is compressed between a magnesium anode and a cathode made of WS2, carbon black, and PTFE powder to form a cell, the cell generates an open circuit potential of about 2 volts, and currents of at least about 100 microamperes/cm2 can be withdrawn at voltages greater than 1 volt.
Placing a small piece of the rubbery solid polymer material between a Mg ribbon and a piece of copper mesh results in the generation of an open circuit voltage of about 2 V. The AC conductivity at 1000 Hz of the solid polymer when compressed between copper and aluminum rods held apart by a fluorocarbon O-ring (using externally applied voltage) was 9.5×10-5 ohm-1 cm-1, according to the formula: ##EQU1##
Comparison of the S:W ratio for the used cathode material with that for unused WS2 indicates a decline from 1.97 to 1.54, and the magnesium anode was coated with magnesium sulfide. The rubbery solid polymer electrolyte allows S-- ions formed at the cathode to migrate through the electrolyte to the anode. The electrolyte maintained its physical integrity as the anode and cathode volumes changed. It is clear from this that the solid electrolyte is an anionic conductor rather than the usual cationic conductor.
The polymer which forms a portion of the solid electrolyte of the invention is generally any homopolymer or copolymer, solid at ambient temperature, derived from at least one monomer comprising at least one heteroatom in the monomer unit such as oxygen, nitrogen, sulfur, and phosphorus. Preferred are monomers containing oxygen or nitrogen heteroatoms in the monomer unit and most preferred are the polymers of cyclic ethers or cyclic acetals such as tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, ethylene oxide, propylene oxide, 1,2- or 2,3-butylene oxide. Useful monomer units include: ##STR1## in which R' represents a hydrogen atom or one of the groups R3, --CH2 --O--R3, --CH2 --O--R4 --R3, --CH2 --N═(CH3)2, with R3 representing an alkyl or a cycloalkyl radical including particularly 1 to 16, preferably 1 to 5 carbon atoms, R4 representing a polyether radical of the general formula:
--CH.sub.2 --CH.sub.2 --O).sub.p,
p having a value of 1 to 100, particularly from 1 to 2, or by the following formula: ##STR2## in which R" represents, R3, --R4 --R3, with R3 and R4 having respectively one of the above-indicated meanings, or by the following formula: ##STR3## in which R3 and R4 have respectively one of the above indicated meanings, or by the formula: ##STR4## in which R1 and R2 are identical or different and each represent one of the groups R4, R4 --R3 with the above meanings, and R4 can then represent also a polyether of the formula: ##STR5## Preferably, the electrolyte comprises a cyclic ether copolymer particularly one derived from tetrahydrofuran and at least one of ethylene oxide or propylene oxide. The polymer can also be derived from cyclic acetals such as 1,3-dioxolane and 1,4-dioxane. Copolymers of tetrahydrofuran and any of the cyclic acetals listed above are also suitable.
The polymers are preferably formed from the defined monomers in the presence of a metal or a Lewis acid catalyst, that is, any molecule or ion (also called an electrophile) that can combine with another molecule or ion by forming a covalent bond with two electrons from the second molecule or ion. An acid is thus an electron acceptor. Hydrogen ion (proton) is the simplest substance that will do this, but many compounds, such as boron trifluoride, BF3, and aluminum chloride, AlCl3, exhibit the same behavior and are therefore properly called acids. Such substances show acid effects on indicator colors and when dissolved in the proper solvents. The solid electrolyte can be formed by adding said salt to a preformed polymer, as disclosed above, in the presence of a solvent or diluent for said polymer and subsequently removing said solvent or diluent or by adding said salt to said polymer rendered fluid by heating above its melting point. Generally, the useful catalysts are selected from the group consisting of metals or metal containing compounds. The preferred catalysts are metals selected from the group consisting of the alkali and alkaline earth metals, aluminum, and zinc. The polyhalides of aluminum, boron, vanadium, tantalum, titanium, zirconium, and niobium are less preferred as catalysts.
As is well known in the prior art, the preferred polyether compounds of the invention can be produced by first reacting an initiator compound having active hydrogen atoms. By use of the term "active hydrogen atoms" there is meant any compound which gives a positive Zerewitinoff test. The term active hydrogen atoms is well known and clearly understood by those skilled in the art. However, to remove any possible ambiguity in this regard, the term active hydrogen atoms, as used herein includes any hydrogen atom fulfilling the following two conditions:
(1) It is sufficiently labile to open the epoxide ring of 1,2-propylene oxide, and
(2) It reacts with methyl magnesium iodide to liberate methane in the classical Zerewitinoff reaction (see Niederl and Niederl, Micromethods of Quantitative Organic Analysis, p. 263, John Wiley and Sons, New York City, 1946).
In utilizing the prior art procedures for making heteric or block copolymer polyethers, the 1,2-propylene oxide used therein can be replaced with tetrahydrofuran. The preferred initiators are those having up to 3 active hydrogen atoms and one to about eight, most preferably three to about eight, carbon atoms. Representative examples of such compounds are water, monohydric alcohols such as phenol, cresol, ethyl alcohol, methyl alcohol, polyhydric alcohols such as hydroquinone, ethylene glycol, butylene glycol, diethylene glycol, glycerol or trimethylolpropane. A wide variety of suitable initiators and general procedures for making polyethers are illustrated, for instance, in U.S. Pat. Nos. 2,674,619 and 2,677,700, incorporated herein by reference.
As is well known from the prior art, particularly U.S. Pat. No. 4,578,326, solid polymers of ethylene oxide, because of the regular oxygen atom sequence in the polymer and the favorable oxygen/carbon atom ratio, have good solvation properties with respect to useful ionic salts which are dissolved therein so as to provide high conductivities for such solid electrolytes. But ethylene oxide polymers have a tendency to form crystalline structures at temperatures even above ambient temperature; the formation of crystallites occurring more easily as the concentration of the ionic salt dissolved therein is increased. The formation of crystallites in ethylene oxide polymers reduces the ionic conductivity of the solid polymer electrolyte and thus renders such polymers inappropriate for use at ambient temperatures in electrolytic cells. As disclosed in U.S. Pat. No. 4,578,326, useful polyether polymers can be prepared having lower crystallizing temperature and increased conductivity at ambient temperature than the homopolymers of ethylene oxide by the formation of copolymers of ethylene oxide and methyl glycidyl ether or propylene oxide. The polymer electrodes of the invention include homopolymers of substituted and non-substituted tetrahydrofuran and copolymers of said tetrahydrofuran with other cyclic ethers as disclosed herein.
The molecular weight of the homopolymers or copolymers forming the solid polymer electrolyte utilized in the electric current producing primary electrochemical cell of the invention is at least about 50,000, preferably the molecular weight is about 100,000 to 1,000,000.
The ionic compound which is utilized in admixture with the polymer of a cyclic ether or cyclic acetal in the formation of the solid electrolyte is an ionic compound generally defined as a organohalo-borate -phosphate, -antimonate, or -arsenate having the formula:
(R).sub.3 CMX.sub.n
wherein M is selected from the group consisting of at least one of boron, phosphorus, antimony, and arsenic and wherein X is halogen n is 4 or 6, and R is aryl of 6-18 carbon atoms, alkyl of 1-8 carbon atoms, or alkaryl of 7-26 carbon atoms. R is preferably phenyl. Preferably the ionic compound salt is incorporated with the monomer or monomers and the mixture polymerized.
Alternatively, the ionic compound salt can be incorporated into a preformed polymer by mixing a solvent or diluent, which is subsequently removed, into the polyether polymer at ambient temperatures so as to solvate the polymer and thereby allow the incorporation of the ionic compound salt in admixture with the polymer.
Alternatively, a fusion process can be utilized to incorporate the ionic compound salt into a preformed polymer. In this process the polymer is raised in temperature until it melts and becomes sufficiently fluid so as to permit the uniform mixture of the ionic compound salt therein. Preferably, the ionic compound salt is incorporated by forming the polymer from a mixture of at least one monomer and the ionic compound salt. The concentration of the ionic compound salt in the polymer is generally about 0.1 to about 5.0 molar, preferably about 0.5 to about 2 moles, and most preferably about 0.5 to about 1.0 molar of the ionic compound are utilized in admixture with the polymer.
An electric current producing primary electrochemical cell can contain an anode comprising an anode active metal selected from group Ia and IIa of the Periodic Table of the Elements, or aluminum. The anode active metal preferably is an alkali or alkaline earth metal and, most preferably is an alkali metal selected from the group consisting of sodium, potassium, lithium, or an alkaline earth metal, selected from the group consisting of magnesium and calcium. The anode active metal may be present in the anode in the form of an alloy of the metal with at least one other metal chosen from the groups Ia and IIa of the Periodic Table of the Elements.
The cathode of the electric current producing primary electrochemical cell of the invention has a cathode active material comprising a compound selected from the group consisting of the sulfides, halides, haloborates, and halophosphates of elements from groups Ib, IIb, IVa, Va, IVb, Vb, VIb, VIIb, and VIII of the Periodic Table of the Elements or an element such as sulfur or iodine, or a tetra-alkylammonium polyhalide, having 1,-6 carbon atoms in the alkyl group. While the anode active material can be in the form of a metal or an alloy thereof, as indicated above, the cathode is formed of cathode active materials which can be formed of compressed powders which may include a binder and particles of an electron conductor, such as carbon or graphite, dispersed therein in order to improve conductivity. The cathode binder can be polytetrafluoroethylene or other inert polymeric materials known to those skilled in the art.
Generally, the cathode active materials for a primary electric current producing electrochemical cell using the electrolyte of the invention are composed of those materials which do not give rise to a topochemical reduction reaction in which the preferred alkali metal or alkaline earth metal ions find their way into the structure of the cathode and are regenerated by chemical or electrochemical reduction. But the use of such materials as cathode active materials is not excluded. The materials which do not give rise to a topochemical reduction reaction generally provide considerably higher specific capacities than those which do and therefor these materials are well adapted to the manufacture of high energy density primary cells.
In practice, a primary electric current production electrochemical cell and constitute a pile of compressed solid electrolyte pellets each slidably sandwiched between a pellet of the anode material and the cathode and separated by a thin film of the solid electrolyte disclosed herein.
In the preparation of the cathode of the primary electric current producing electrochemical cell, conventional methods are used in which powders of the cathode active material, graphite and/or carbon are pressed together in combination with a binder such as polytetrafluoroethylene or other polymeric binders known to those skilled in the art. Typically, from about 2% to about 30% by weight of such additives are used, including carbon or graphite and those additives employed as binders. The cathodes can be fabricated by pressing a mixture including such additives against a support structure such as a nickel or copper wire mesh.
The anode is fabricated in a conventional manner by attaching the anode active material to a supporting grid structure made of a material such as aluminum or nickel.
The following examples illustrate the various aspects of the invention. Where not otherwise specified throughout this specification and claims, temperatures are given in degrees centigrade and parts, percentages, and proportions are by weight.
EXAMPLE 1
A primary electric current producing electrochemical cell was assembled utilizing a magnesium anode and a cathode made by pressing together powdered tungsten disulfide, carbon black and polytetrafluoroethylene powder. The proportions by weight of the cathode were 50% tungsten disulfide, 30% carbon black, and 20% polytetrafluoroethylene. The solid electrolyte was prepared by reacting triphenylmethyltetrafluoroborate with tetrahydrofuran in the presence of magnesium in accordance with the following procedure:
A sufficient amount of triphenylmethyltetrafluoroborate ((C6 H5)3 CBF4) is added to tetrahydrofuran to make a 1 molar solution. Magnesium turnings were added in excess to the mixture while it was being stirred. After about 2 hours, the (C6 H5)3 CBF4 was completely dissolved and a dark liquid was formed. This liquid polymerized in about 48 hours to form a black rubbery solid having an electrical conductance of about 10-4 ohm-1 cm-1 at room temperature. The electrolyte is compressed in a thin layer between the magnesium anode and the cathode material in a disc area equal to approximately 0.713 cm2, as shown by FIG. 1.
After preparing the electrolyte, the activity of the electrolyte was determined by placing a small piece of the solid electrolyte between a magnesium ribbon and a piece of copper mesh. An open circuit voltage of about 2.0 V was observed. The conductivity was measured by compressing a piece of the solid electrolyte between copper and aluminum rods held apart by a fluoroelastomer O-ring. An external voltage is applied across the gap between the two metals to measure the AC conductivity at 1000 Hz. The conductivity was 9.5×10-5 ohm-1 cm-1, according to the formula: ##EQU2## S=0.131 cm A=0.519 cm2
R1000 Hz 2.66K ohm ##EQU3##
The solid electrolyte polymer battery generated an open circuit potential of about 2 volts, and a current of at least about 100 microamperes/cm2 Mg were withdrawn at voltages of 1 volt.
______________________________________
Current - Voltage data for this cell was:
I, microamperes
i, microamperes/cm.sup.2
V, volts
______________________________________
10 14.0 1.88
20 28.1 1.81
30 42.1 1.69-1.73
40 56.1 1.50-1.69 erratic
50 70.2 1.46-1.60
______________________________________
The graph of FIG. 3 portrays some of this data.
The current densities shown are good for solid electrolyte cells operating at room temperature. While the cell was capable of current reversal, no evidence of a recharge capability was seen, although this resulted in an increased open-circuit potential. The cell was then discharged across a 100 ohm resistor for three days, with the cell voltage commencing at 0.25 V and slowly falling to 0.03 V at the end of this time. The open-circuit potential at this point was 1.49 V, and indicated a slow degradation of either the electrolyte (possible air oxidation), the cathode, or the anode (possible passivation).
The appearance of the cathode and electrolyte were unchanged upon cell disassembly, but the Mg anode was covered with a yellow-white powder. The deposit on the anode surface and the used cathode material were analyzed via Energy Dispersive Spectroscopy (EDS), and yielded an X-ray spectrum which showed a comparison of the S:W ratio for the used cathode material with that for WS2 which declined from 1.97 (for WS2) to 1.54 (for used cathode). The anode deposit appeared to be magnesium sulfide. From this data, it is clear that the solid electrolyte allowed S-- ions formed at the cathode to migrate to the magnesium anode and react and therefore the electrolyte is an anion conductor, as opposed to most solid electrolytes (with the exception of F- conductors such as CaF2) which are cation conductors.
EXAMPLE 2
A battery was assembled as in Example 1, using 80% by weight of CuS and 20% by weight of PTFE as the cathode material.
Current density-voltage data for the first discharge of this battery is as follows:
______________________________________
i, microamperes/cm.sup.2
V, volts
______________________________________
0 1.10
14.0 0.78
28.1 0.58
42.1 0.46
56.1 0.35
70.2 0.24
______________________________________
After an overnight "charge" @ 3.5 microamperes/cm2 the current density-voltage data for the second discharge is:
______________________________________
i, microamperes/cm.sup.2
V, volts
______________________________________
0 1.30
14.0 0.69
28.1 0.39
______________________________________
The graph of FIG. 4 sets forth the data for this battery using by weight 80% CuS/20% PTFE as the cathode material.
The main mode of discharge for this reaction is probably Mg+CuS→MgS+Cu. E° for this reaction is 1.5 V. Therefore, the open circuit voltage of this cell was somewhat lower than E° for the proposed reaction, and this cell also polarized more than the Mg/WS2 cell; therefore, the cathode appears to be a poorer conductor than the cathode in Example 1. After disassembly, the Mg surface again showed a yellow-white coating, which looked identical to that seen in the previous cell, but this coating was not analyzed.
An attempt was made in assemble a Mg/S solid electrolyte battery, where the cathode was made by making a depression in the end of a 1/2" graphite rod, filling it with powdered graphite, and dripping S dissolved in CS2 onto it and allowing the CS2 to evaporate. While this produced an adherent cathode and an open circuit voltage (O.C.V.) of 1.29 V, the cell polarized severely.
EXAMPLE 3
A battery was assembled as in Example 1, using 50% by weight of AgBF4, 30% by weight of graphite and 20% by weight of PTFE as the cathode material.
Current density--Voltage data for this battery is shown in FIG. 5.
The open circuit voltage and the polarization characteristics were better than the cells in Examples 1 and 2, however, after several hours, the voltage became erratic, apparently because of decomposition of the cathode. (The cathode material shows a hygroscopic character after standing in air several days).
The cell voltage was still stable during a relatively-high rate discharge (about 70 microamperes/cm2), but would always become erratic on open circuit or at low discharge rates.
Based upon the above examples, it is apparent that the battery operates by generating anions at the cathode which are transported through the electrolyte. The anions react with the Mg anode to form a Mg salt, and electrons are released to flow through an external circuit.
Preferably, the solid electrolytes of the invention useful in a primary battery are prepared by adding a sufficient amount of a triphenylmethyl compound from the group (C6 H5)3 CBX4, (C6 H5)3 CPX6, (C6 H5)CSbX6, and (C6 H5)3 CAsX6, where X is a halogen, to a suitable monomer, preferably a cyclic ether, to make a 1 molar solution. A metal, such as alkali or alkaline earth metal turnings, are added in amounts equal to or greater than the quantity of triphenylmethyl compound as the mixture is being stirred. The triphenylmethyl compound is completely dissolved in about 2 hours, and this is evidenced by the formation of a dark liquid. The liquid is allowed to stand at normal room temperature ranges, whereupon it polymerizes into a black rubbery solid in about 2 days. The electrical conductance of these solids is about 10-4 ohm-1 cm-1, which is within the acceptable range of room temperature operational solid electrolytes. These can have a conductivity greater than about 10-3 ohm-1 cm-1 at room temperature down to a conductivity of about 10-7 ohm-1 cm-1.
While any of the mentioned triphenylmethyl compounds are useful, a triphenylmethyltetrahaloborate is preferred. Among the triphenylmethyltetrahaloborates, triphenylmethyltetrafluoroborate is most preferred.
In addition to cyclic ethers and cyclic acetals, straight chain aliphatic and aromatic ethers, such as dialkoxyalkanes and acetals are useful. However, the cyclic ethers and cyclic acetals are preferred. Tetrahydrofuran is most preferred.
While any of the alkali and alkaline earth metals will work as anodes in the inventive battery, the alkaline earth metals are preferred. Among the alkaline earth metals, magnesium and calcium are most preferred.
Normal or surrounding room temperatures, as intended within the purview of the invention, will range from about 20° C. to about 100° C. and the capacity of the cell to exhibit anionic conductance is operable when the electrolyte and cell temperatures are within this range; however, it is preferred that the temperatures be within the range of between about 25° C. to about 50° C.
It is to be understood that the foregoing disclosure relates to specifically preferred embodiments of the instant invention, and it is intended to cover in the appended claims all of the variations and modifications of the invention which do not depart from the spirit and scope of the invention.
The embodiments of the invention in which an exclusive priviledge or property is claimed are defined as follows:
1. In an electric current producing primary electrochemical cell comprising an anode, a cathode, and an electrolyte which is a solid at a temperature of about 20° C. to 100° C., the improvement comprising using as said electrolyte an electrolytically active solid polymer and salt complex, said polymer derived from at least one monomer comprising at least one heteroatom and wherein said salt is at least one of a salt of the formula: (R).sub.3 CMX.sub.n wherein M is selected from the group consisting of at least one of boron, phosphorus, antimony, and arsenic, and wherein X is halogen, n is 4 or 6, and R is aryl of 6-18 carbon atoms, alkyl of 1-8 carbon atoms, or alkaryl of 7-26 carbon atoms.
2. The cell of claim 1 wherein said polymer is derived from an ether, said heteroatom is selected from the group consisting of oxygen, nitrogen, sulfur, and phosphorus, said anode comprises a metal selected from the group consisting of an alkali metal, an alkaline earth metal, and aluminum, and R is phenyl.
3. The cell of claim 2 wherein said polymer is a homopolymer or copolymer derived from at least one monomer selected from the group consisting of tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, ethylene oxide, propylene oxide, and butylene oxide.
4. The cell of claim 3 wherein said polymer is polymerized by reacting at least one of said monomers in the presence of a catalyst comprising a metal or a Lewis acid.
5. The cell of claim 4 wherein the M in said formula is boron, said halogen is fluorine, and said anode comprises a metal selected from the group consisting of a metal of Group IIa of the Periodic Table of The Elements, and aluminum.
6. The cell of claim 5 wherein said polymer comprises a polymer of tetrahydrofuran or 1,3-dioxolane and said catalyst is selected from metals or metal containing compounds wherein the metal is selected from the group consisting of at least one of the alkali and alkaline earth metals, aluminum, and zinc.
7. The cell of claim 6 wherein said anode comprises a metal selected from the group consisting of magnesium, calcium, aluminum, and alloys thereof.
8. The cell of claim 7 wherein said cathode comprises a compound selected from the group consisting of sulfides, halides, haloborates, haloarsenides, and halophosphates of elements from groups Ib, IIb, IVa, Va, IVb, Vb, VIb, VIIB, and VIII of the Periodic Table of the Elements or an element selected from the group consisting of sulfur, iodine, and tetraalkyl ammonium polyhalides.
9. A process for producing electric current at ambient temperature in a primary electrochemical cell comprising an alkali metal, aluminum or an alkaline earth metal anode, a cathode, and an electrolyte which is a solid at a temperature of about 20° C. to 100° C., comprising using as said electrolyte an electrolytically active solid polymer and salt complex, said polymer derived from at least one monomer comprising at least one heteroatom in the monomer unit and said salt comprising at least one of a salt of the formula: (R).sub.3 CMX.sub.n wherein M is selected from the group consisting of at least one of boron, phosphorus, antimony, and arsenic; X is halogen; n is 4 or 6; and R is aryl of 6-18 carbon atoms, alkyl of 1-8 carbon atoms, or alkaryl of 7-26 carbon atoms; and said electrolyte is further characterized by anionic conductance.
10. The process of claim 9 wherein said polymer is an ether; said heteroatom is selected from the group consisting of oxygen, nitrogen, sulfur, and phosphorus; said R is phenyl; and said anode comprises a metal selected from the group consisting of an alkali metal, an alkaline earth metal, and aluminum.
11. The process of claim 10 wherein said polymer is a cyclic ether homopolymer or copolymer; said monomer is selected from at least one of the group consisting of tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, ethylene oxide, propylene oxide, and butylene oxide.
12. The process of claim 11 wherein said polymer is polymerized by reacting at least one of said monomers in the presence of a metal or a Lewis acid as a catalyst.
13. The process of claim 12 wherein the M in said formula is boron, said halogen is fluorine, and said anode comprises a metal selected from the group consisting of a metal of Group IIa of the Periodic Table of the Elements, and aluminum.
14. The process of claim 13 wherein said polymer comprises a polymer of tetrahydrofuran or 1,3-dioxolane and said Lewis acid is selected from metal containing Lewis acid compounds wherein the metal is selected from the group consisting of at least one of an alkali or an alkaline earth metal, aluminum, and zinc.
15. The process of claim 14 wherein said anode comprises a metal selected from the group consisting of magensium, calcium, aluminum, and alloys thereof.
16. The process of claim 15 wherein said cathode comprises a compound selected from the group consisting of sulfides, halides, haloborates, haloarsenides and halophosphates of elements from groups Ib, IIb, IVa, Va, IVb, Vb, VIb, VIIb, and VIII of the Periodic Table of the Elements or an element selected from the group consisting of sulfur and iodine and tetraalkyl ammonium polyhalides.
| 1986-10-27 | en | 1987-10-27 |
US-32837889-A | Schmitt-trigger circuit having no discrete resistor
ABSTRACT
A schmitt-trigger circuit includes a differential amplifier (1), formed of at least two transistors (2, 3) having their emitters coupled to at least a first current source (4). The differential amplifier (1) has a first input for receiving an input signal (Ue) and has one output coupled, via a first current mirror (5) and a feedback transistor (8), to the second input, from which output an output signal is taken. The second input of the differential amplifier (1) is coupled to a second current source (9) as well as to a diode array which comprises at least two diode elements (10, 11) and which is arranged in parallel with the first current mirror (5) and the feedback transistor (8).
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a Schmitt-trigger circuit for converting an input signal on an input terminal into an output signal on an output terminal, which circuit comprises a differential amplifier comprising a first transistor and a second transistor, each having a base, an emitter and a collector, the emitters of the first and the second transistor being coupled to a first current source, the base of the first transistor being coupled to the input terminal, the collector of the second transistor being coupled to an input of a first current mirror, and the base of the second transistor being coupled to an output of the first current mirror.
2. Description of the Prior Art
A Schmitt-trigger circuit comprising two emitter-coupled transistors is known from Japanese Kokai No. 60-136413(A). The input voltage is applied to the base of one transistor (first input). The second input, i.e. the base of the second transistor, is connected to the collector of the second transistor by a current mirror. The first and second transistor have their emitters connected to a current source.
The known Schmitt-trigger circuit cannot readily be fabricated in integrated circuit technology, because resistors, in particular those having high values, are difficult to integrate.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a Schmitt-trigger circuit which does not employ any resistors.
In a Schmitt-trigger circuit of the type defined in the opening paragraph this object is achieved in that at a first coupling point the base of the second transistor is coupled to a second current source, and at a second coupling point to the output of the first current mirror via a semiconductor junction and to a first diode array, which diode array comprises at least two diode elements and is arranged in parallel with the first current mirror and the semiconductor junction.
In this Schmitt-trigger circuit a current will flow into the first current source via the input stage of the first current mirror and the differential amplifier if the input signal is small enough. The current reproduced by the first current mirror flows from the output stage of this current mirror into the second current source via the semiconductor junction. No current will flow into the first diode array because the voltage across the current-mirror output and the semiconductor junction is smaller than two diode voltages. If the input signal is large enough there will be no current in the first current mirror and the semiconductor junction. The current which flows into the second current source is supplied by the first diode array.
If the semiconductor junction is a base-emitter junction of a feedback transistor which has its base coupled to the output of the first current mirror and its emitter to the base of the second transistor, the current gain from the output of the first current mirror to the base of the second transistor will be higher, which causes the trigger circuit to change over more rapidly.
The output signal can be derived by means of, for example, a further current mirror coupled to the first diode array. The output signal changes from a low to a high level at a first threshold, which depends upon the voltage of the output stage of the first current mirror and the base-emitter voltage of the feedback transistor. The second switching threshold, at which a change from a high to a low level takes place, depends upon the sum of the forward voltages of the diode elements in the first diode array.
The first diode array should comprise at least two series-connected diode elements. The diode elements are poled in the forward direction for the current which flows to the second current source.
The hysteresis width, i.e. the spacing between the two switching thresholds, is dictated by the number of diode elements in the first diode array. The switching thresholds can be reduced, while maintaining their spacing, in that a second diode array is arranged between the first and the second coupling point.
Preferably, the output signal is taken from the first diode array by means of a current mirror. The first diode array is then arranged in the input-current path of an input stage of a second current mirror having an output stage connected to the output terminal.
In the currentless state temperature variations or crystal defects may give rise to a leakage current in the output stage of the first current mirror. In order to drain (absorb) this leakage current the collector of the first transistor is connected to an input of a third current mirror which has an output coupled to an input of a fourth current mirror having an output connected to the base of the feedback transistor. The leakage current is then drained by the output stage of the fourth current mirror. Moreover, the loop gain is increased, which improves the edge steepness of the output signal at the upper switching thresholds.
In order to prevent the first transistor of the differential amplifier from being driven into saturation for high input voltages the input terminal is coupled to the base of the first transistor via an input diode array.
In a further embodiment of the invention the input of the first current mirror is preceded by an input stage of a fifth current mirror, which has an output stage coupled to to an input stage of a sixth current mirror having an output stage connected to the output terminal. This embodiment may be used to drain the leakage current of the output stage of the second current mirror in the currentless state. The output stages of the second and the sixth current mirror are then interconnected.
Said further embodiment may also serve to apply the output signal to a circuit in I2 L-technology. The second current mirror can then be dispensed with and the first and the second current source each form an output stage of a current-source array which is constructed in I2 L technology and which comprises transistors whose bases are connected to a common injector or control means.
Embodiments of the invention will now be described in more detail, by way of example, with reference to the accompanying drawings. In the drawings:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified circuit diagram of a Schmitt-trigger circuit,
FIG. 2 shows the transfer characteristic of the Schmitt-trigger circuit, and
FIGS. 3 and 4 show more detailed circuit diagrams of embodiments of the Schmitt-trigger circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Schmitt-trigger circuit whose simplified circuit diagram is shown in FIG. 1 comprises a differential amplifier 1 comprising two NPN transistors 2 and 3, whose emitters are connected to a current source 4. The other terminal of the current source 4 is connected to the negative supply-voltage terminal of a voltage source (not shown). The collector of the transistor 2 is connected to the positive supply-voltage terminal 50 of the voltage source, and an input voltage Ue on the input terminal 52 is applied to the base of the transistor 2. The collector of the transistor 3 is connected to the input stage of a first current mirror 5. The input stage comprises a PNP transistor 6, which has its emitter connected to the positive supply-voltage terminal 50 and which has its base and its collector connected to the collector of the transistor 3. The output stage of the current mirror 5 is formed by a transistor 7 whose base is connected to the base of the transistor 6 and whose emitter is also connected to the positive supply-voltage terminal 50. The collector of the transistor 7 is connected to the base of an NPN-type feedback transistor 8 whose collector is connected to the positive supply-voltage terminal 50 and whose emitter is connected to the emitter of an NPN transistor 10 connected as a diode element and via a coupling means 60 comprising a conductor to a second current source 9 and to the base of the transistor 3 the emitter of an NPN transistor 10 connected as a diode element. The other terminal of the current source 9 is connected to the negative supply-voltage terminal 51. The base and the collector of the transistor 10 are connected to the collector and the base of a PNP transistor 11, which constitutes the input stage of a second current mirror 12. The emitter of the transistor 11 as well as the emitter of a PNP transistor 13 are connected to the positive supply-voltage terminal 50. The base of the transistor 13 is connected to the base of the transistor 11. The collector of the transistor 13 constitutes the output 53 of the Schmitt-trigger circuit.
The operation of the Schmitt-trigger circuit will now be explained by means of the transfer characteristic shown in FIG. 2. When the input signal Ue is negative the transistor 2 is cut off and the transistor 3 is conductive. A current flows into the current source 4 via the transistor 6 of the current mirror 5 and the collector-emitter junction of the transistor 3. The conductive feedback transistor 8 feeds a substantially equal current to the current source 9. The transistor 7 in the output stage of the current mirror 5 is saturated. Since the transistor 8 is conductive the diode junctions of the two transistors 10 and 11, which are connected as diode elements, are short-circuited. As a result of this, the current mirror 12 is in a currentless state and the output voltage Ua min supplied to the output is approximately zero relative to the negative supply voltage terminal 51.
The output voltage Ua changes from a low level Ua min to a high level Ua max when the input voltage is equal to Us1. The transistor 3 is then turned off and the transistor 2 is turned on. No current flows via the current mirror 5 and the transistor 8 is cut off. The current source 9 draws its current via conductor 60 from the current mirror 12 and the transistor 10. Now the output voltage is equal to the product of the current from the current source 9 and a load resistance, not shown. The output voltage Ua changes from a high level Ua max to a low level Ua min at a switching threshold Us2. The switching threshold Us1 is higher than the switching threshold Us2. The switching threshold Us1 is determined by the satuartion voltage of the transistor 7 and the base-emitter voltage of the transistor 8. The switching threshold Us1 complies with the following equation:
Us1=Up-Usat7-Ube8,
where Up is the voltage on the supply-voltage terminal 50, Usat7 is the saturation voltage of the transistor 7, and Ube8 is the base-emitter voltage of the transistor 8.
The switching threshold Us2 is dictated by the base-emitter voltages of the transistors 10 and 11. The switching threshold Us2 complies with the following equation:
Us2=Up-Ube10-Ube11,
where Ube10 is the base-emitter voltage of the transistor 10 and Ube11 is the base-emitter voltage of the transistor 11.
The spacing between the two switching thresholds Us1 and Us2 can be increased by means of further transistors arranged as diode elements. The transistors arranged as diode elements must be connected in series with the transistor 10. The position of the switching hysteresis can also be changed by means of further transistors connected as diode elements. The spacing between the two switching thresholds then remains the same. The transistors connected as diode elements should be arranged between the junction point between the emitters of the transistors 8 and 10 and the junction point between the base of the transistor 3 and the current source 9.
In the off-state of the transistor 3, when the current mirror 5 should be currentless, crystal defects or temperature changes may give rise to leakage currents from the transistor 7. The output stage of the second current mirror 12 may also produce a leakage current. In comparison with the embodiment shown in FIG. 1 the embodiment shown in FIG. 3 comprises some additional current mirrors, which ensure that the leakage currents are absorbed. The collector of the transistor 2 is connected to the input stage of a third current mirror 14, whose output stage is coupled to a fourth current mirror 15. The input stage of the current mirror 14 comprises a PNP transistor 16 having its emitter connected to the positive supply-voltage terminal and having its base and its collector connected to the collector of the transistor 2. The PNP transistor 17, which constitutes the output stage of the current mirror 14, also has its emitter connected to the positive supply-voltage terminal and its base to the base of the transistor 16. The collector of the transistor 17 constitutes the output of the current mirror 14. This output is connected to the base and the collector of an NPN transistor 18, which constitutes the input stage of the current mirror 15. The emitter of the transistor 18 is connected to the negative supply-voltage terminal. The output stage of the current mirror 15 is constituted by an NPN transistor 19 having its collector coupled to the base of the feedback transistor 8 and to the collector of the transistor 7. The emitter is connected to the negative supply-voltage terminal and the base of the transistor 19 is connected to the base of the transistor 18. A leakage current supplied by the collector of the transistor 7 is drained by the transistor 19. In addition, the third and the fourth current mirror provide a higher loop gain and hence steeper edges of the output signal obtained at the switching threshold Us1.
A fifth current mirror 21 is arranged between the collector of the transistor 3 and the input stage of the first current mirror 5 and comprises the PNP transistors 22 and 23. The base of the transistor 22 and the base of the transistor 23 are connected to the collector of the transistor 3 and the collector of the transistor 22. The emitters of the two transistors are connected to the base of the transistor 6. The collector of the transistor 23 is connected to the input stage of a sixth current mirror 24. The input stage of this current mirror comprises an NPN transistor 25 which has its emitter connected to the negative supply-voltage terminal and its base and collector to the collector of the transistor 23. The output stage of the sixth current mirror 24 is constituted by an NPN transistor 26 whose collector together with the collector of the transistor 13 constitutes the output. The emitter is also connected to the negative supply-voltage terminal and the base to the base of the transistor 25. The transistor 26 drains the leakage current produced by the collector of the transistor 13 when this transistor should be in a currentless state.
The current sources 4 and 9 are formed by the output stages of a current-source array 28. The two output stages each comprises an NPN transistor 29 and 30 respectively, whose emitters are connected to the negative supply-voltage terminal and whose bases are connected to the base of an NPN transistor 31. The collector of the transistor 29 is connected to the emitters of the transistors 2 and 3 and the collector of the transistor 30 is connected to the base of the transistor 3. The emitter of the transistor 31 is also connected to the negative supply-voltage terminal and the collector of the transistor 31 is connected to its base and to a further current source 32. The other terminal of the current source is connected to the negative supply-voltage terminal.
In order to prevent the transistor 2 of the differential amplifier 1 from being saturated for high input voltages, a transistor 33 arranged as a diode element is connected to the base of the transistor 2. The input signal Ue is applied to the base and to the collector of the transistor 33, whose emitter is connected to the base of the transistor 2. As a result of this, the two switching thresholds Us1 and Us2 are, each time shifted by one base-emitter voltage.
The Schmitt-trigger circuit can also be used in an I2 L circuit. FIG. 4 shows an embodiment suitable for this purpose. This embodiment differs from that shown in FIG. 3 in that the transistor 13 is dispensed with and an injector or control means comprising a PNP transistor 40 operating in common-base arrangement supplies base currents to the current source array 28. The transistor 40 has its collector connected to the base of the transistor 31 and its emitter to the current source 32. The base of the transistor 40 is connected to earth. The output of the circuit arrangement is constituted by the collector of the transistor 26.
The switching thresholds Us1 and Us2 in the present embodiment have also changed because further diode-element transistors are arranged between the emitter connection of the transistor 8 and the base connection of the transistor 3 and between the the emitter connection of the transistor 8 and the emitter connection of the transistor 10. An NPN transistor 41 has its collector and its base connected to the emitter of the transistor 10 and has its emitter connected to the base and the collector of a further NPN transistor 42. The emitter of the transistor 42 is connected to the emitter of the transistor 8 and, via a coupling means 61 comprising the series combination of further NPN transistors 43 and 44 connected as diodes, to the base of transistor 3 and to current source 9. An upper end of coupling means 61 comprises the commoned emitter of the transistor 43 is connected to the base and the collector of an NPN transistor 44, which has its emitter connected to the base of the transistor 3 and to the collector of the transistor 30. The switching threshold Us1 satisfies the following equation:
Us1=Up-Usat7-Ube8-Ube43-Ube44+Ube33,
and the switching threshold Us2 complies with the equation:
Us2=Up-Ube11-Ube10-Ube41-Ube43-Ube44+Ube33,
where Ube33, Ube41, Ube42, Ube43 and Ube44 are the base-emitter voltages of the transistors 33, 41, 42, 43 and 44.
I claim:
1. A Schmitt-trigger circuit comprising:an input terminal (52); a first current source (4); a second current source (9); a first current mirror (5) having an input and an output; a coupling means; a differential amplifier comprising a first transistor (2) and a second transistor (3), each having a base, an emitter and a collector, the emitters of the first and the second transistors being coupled to the first current source (4), the base of the first transistor being coupled to the input terminal, the collector of the second transistor being coupled to the input of the first current mirror (5), and the base of the second transistor being coupled to the output of the first current mirror, characterized in that the coupling means is coupled to the base of the second transistor, to the second current source (9), to the output of the first current mirror via a semiconductor junction (8), and to a first diode array (10, 11), which diode array comprises at least two diode elements in a first current-path which is arranged in parallel with a second current-path comprising the output of the first current mirror and the semiconductor junction.
2. A Schmitt-trigger circuit as claimed in claim 1, characterized in that the semiconductor junction is a base-emitter junction of a feedback transistor (8) which has its emitter coupled to the coupling means.
3. A Schmitt-trigger circuit as claimed in claim 1, characterized in that said coupling means comprises a second diode array (43,44).
4. A Schmitt-trigger circuit as claimed in claim 1, further comprising an output terminal and wherein the first diode array comprises an input of a second current mirror (12), said second current mirror having its output coupled to the output terminal.
5. A Schmitt-trigger circuit as claimed in claim 4, further comprising third and fourth current mirrors each having an input and an output and wherein the collector of the first transistor (2) is coupled to the input of said third current mirror (14), the output of said third current mirror is coupled to the input of said fourth current mirror (15), and the output of said fourth current mirror is coupled to the base of the feedback transistor (8).
6. A Schmitt-trigger circuit as claimed in claim 5, characterized in that the input terminal (52) is coupled to the base of the first transistor (2) via a second diode array (33).
7. A Schmitt-trigger circuit as claimed in claim 5, further comprising fifth and sixth current mirrors each having an input and an output and wherein the input of the first current mirror (5) is in series with the input of said fifth current mirror (21), the output of said fifth current mirror is connected in series with the input of said sixth current mirror (24), and the output of said sixth current mirror is coupled to the output terminal (53).
8. A Schmitt-trigger circuit as claimed in claim 7, wherein the outputs of the second and sixth current mirrors are in series with each other.
9. A Schmitt-trigger circuit as claimed in claim 8, wherein the first and second current sources (4, 9) respectively comprise first and second outputs of a controllable current-source array which is constructed in I2 L Technology and which comprises a common control means (40, 32, 31).
| 1989-03-23 | en | 1990-12-11 |
US-27950663-A | Device for displacing couplings having a plurality of chain sections and anchor members with a thrust member to move a pipe
Oct. 26, 1965 J. B. GILL 3,213,529
DEVICE FOR DISPLACING COUPLINGS HAVING A PLURALITY OF CHAIN SECTIONS AND ANCHOR MEMBERS WITH A THRUST MEMBER TO MOVE A PIPE Filed May 10, 1963 3 Sheets-Sheet l INVENTOR JOHN B. GILL P E 3 BY I FIE|.I-3- Fl fi A TTORNEYS Oct. 26, 1965 J. B. GILL 3,213,529 DEVICE FOR DISPLACING COUPLINGS HAVING A PLURALITY OF CHAIN SECTIONS AND ANCHOR MEMBERS WITH A THRUST MEMBER TO MOVE A PIPE Filed May 10, 1965 5 Sheets-Sheet 2 JOHN sf e L f BY 5M ATTORNEYS Oct. 26, 1965 J. B. GILL 3,213,529
DEVICE FOR DISPLACING COUPLINGS HAVING A PLURALI'IY OF CHAIN SECTIONS AND ANCHOR MEMBERS WITH A THRUST MEMBER TO MOVE A PIPE Filed May 10, 1963 5 Sheets-Sheet 5 FI[E| ll FIE-.12
INVENTOR.
JOHN B. G/LL BY 51%; a%%
A 7" TORN' Y5 United States Patent DEVICE FOR DISPLACING COUPLINGS HAVING A PLURALITY OF CHAIN SECTIONS AND AN- CHOR MEMBERS WITH A THRUST MEMBER TO MOVE A PIPE John B. Gill, Box 2127, Torrance, Calif. Filed May 10, 1963, Ser. No. 279,506 8 Claims. (Cl. 29237) This invention relates to a device for displacing couplings relative to adjacent sections of pipe and more particularly to a coupling displacer that is adjustable for use on different sizes of pipe.
The present invention has been found particularly useful in handling asbestos-cement pipe, wherein two couplings are used in conjunction with a short section of pipe to join two runs of pipe into a line. In joining the runs of pipe, the couplings are first pulled over either end of the short section of pipe. The section of pipe is then placed in alignment with the two runs and the couplings are pushed along the pipe, over the gap, to close the line.
Preferably the couplings carry chevron type gaskets which act as a seal. These gaskets, because of their chevron configuration, wedge against the pipe making axial movement difiicult. The gaskets are so positioned that they engage both the pipes and the couplings when the coupling is in place.
To assemble the couplings on the pipes the resistance of the chevron gasket has to be overcome. A lubricant is used initially but it is substantially squeezed off by the initial movement of the gasket. Moreover, after the pipes have been in use for a time the lubricant becomes ineffective. When it becomes necessary to disassemble the line practice has been to break or split the coupling. This procedure is time consuming and expensive, in that the split coupling cannot be reused. v The present invention contemplates a coupling displacing device composed of a plurality of chain sections alternating with a plurality of anchor members to define a loop adapted to encircle a pipe with the anchor members substantially equally spaced about the pipe circumference, together with tightening means interposed in the connection between one of the chain sections and an adjacent anchor member and formed for pulling the loop tightly around the pipe so that the loop cannot be displaced by axial force exerted against the coupling by thrust members carried by each of the anchor members. In this manner, the axial forces exerted against the coupling by the individual thrust members are evenly distributed around the circumference of the pipe, resulting in an even application of the comparatively large forces necessary to move the coupling on the pipe.
It is a principal object of the present invention to provide a device for displacing couplings along the sections of pipe, without injury to the pipe or coupling.
Another object of the present invention is to provide a device of the character described whereby the coupling may be pushed from or pulled onto a section of pipe with an even axial force without subjecting the coupling or pipe to uneven or impact forces that might distort or break either the pipe or coupling.
A further object of the present invention is to provide a device that is readily adjustable for use on diiferent sizes of pipe affording great flexibility in field use.
Further objects of my invention will be apparent as the specification progresses and the new and useful feaice tures of my device for displacing couplings will be fully defined in the claims attached hereto.
The preferred form of my invention is illustrated in the accompanying drawings, forming part of this specification, in which:
FIGURE 1 is an elevational view of a coupling displacer constructed in accordance with the present invention and shown mounted in operative position on a section of pipe prior to displacing a coupling therealong;
FIGURE 2, an enlarged sectional view taken substantially on the plane of line 2-2 of FIGURE 1;
FIGURE 3, a further enlarged sectional view taken substantially on the plane of line 3-3 of FIGURE 2;
FIGURE 4, a sectional view taken substantially on the plane of line 44 of FIGURE 3;
FIGURE 5, a fragmentary elevational view taken substantially on the plane of line 5-5 of FIGURE 2;
FIGURE 6, an elevational view taken substantially on the plane of line 66 of FIGURE 5 FIGURE 7, a view similar to FIGURE 2 but wherein the device is mounted on a pipe of smaller diameter showing how the device accommodates different sizes of pipe;
FIGURE 8, a view similar to FIGURE 2 but wherein the device is enlarged to accommodate a larger pipe;
FIGURE 9, a view similar to FIGURE 8 but wherein a still larger size of pipe is accommodated;
FIGURE 10, an elevational view showing the device as it is used for pulling a coupling onto a section of pipe;
FIGURE 11, an elevational view of the lower end of the lever arm of FIGURE 10; and
FIGURE 12, a side elevational view of FIGURE 11.
While I have shown only the preferred form of my invention it should be understood that various changes or modifications may be made Within the scope of the claims attached hereto without departing from the spirit of the invention.
Referring to the drawings in detail, FIGURE 1 shows a typical installation problem with the device 16 in position to push a coupling 17 from a short closure section of pipe 18 onto a confronting pipe 19 and thus close a pipe line. At the right side of FIGURE 1 a second coupling 21 is illustrated in installed position similar to the position coupling 17 will assume when the pushing action is completed.
The device 16 consists essentially of an assembly 24, having a link chain 26 formed for securing in encircling relation around a pipe 18, an anchor unit 27 selectively engageable with individual links of the chain ends 28 and 29 whereby the total length of the assembly 24 may be adjusted to conform to the size of the pipe 18, tightening means 31 interposed in the chain 26 medially of its length and formed for pulling the assembly 24 taut in binding relation around the pipe 18, and means 32 operatively connected to the chain 26 and formed for exerting axial force between the pipe 18 and an adjacent coupling 17.
Basically the assembly 24 acts as an anchor from whence means 32 may bear against the coupling 17 and exert an axial force thereon.
In accordance with the preferred form of my invention I have found it desirable to bring the assembly 24 into firm contact with a large part of the circumference of pipe 18 to offer greater frictional engagement and to distribute the radial force acting on the pipe 18. I have found a double roller chain, having links 33 joined by transverse pins 34, provides minimum sag and side flexing and the links 33 provide good engagement with the pipe. In the form illustrated in FIGURES 1 and 2, chain 26 includes two chain sections 26a and 26b joined together at their ends 38 and 39 by tightening means 31. In this way, the chain sections and tightening means not as a single chain, and this chain is joined at its effective ends 28 and 29 by anchor unit 27.
The tightening means 31 is used for drawing the chain ends 38-39 together to bind the assembly 24 on the pipe 18 and in such function acts essentially as a contractible link interposed in chain 26. Tightening means 31 is also used for making small adjustments of the assembly 24 over varying pipe sizes.
As here shown, the tightening means 31 includes a body portion 41 having projections 42 extending from one side thereof. The projections 42 fit between the links of chain end 38 and are secured thereto by pin 43 and cotter pin 44. Extending from the body portion 41 opposite the projections 42 are hook shaped lugs 46. The lugs 46 are spaced along the body portion 41 to form a slot 47 therebetween.
A bolt 48, connected to chain end 39 by pin 50, is adapted to enter slot 47 and be pulled therethrough. The bolt 48 carries a seat 49 and an elongated nut 51. To pull the bolt 48 through slot 47 and thereby bring the chain ends 38-39 together, the nut 51 is rotated on bolt 48 urging seat 49 against lugs 46. The seat 49 bridges the slot 47 between the lugs 46 and is made complementary to hook shaped lugs 46 to allow for alignment of the bolt 48.
Gross adjustment of the assembly 24 is made at the anchor unit 27, where any link of the chain 26 may be engaged with the anchor unit and thus vary the effective length of the assembly 24. To make this possible, the anchor unit 27 has a body portion 52 provided with ears 53 extending from either side thereof. The ears 53 are formed with lobes 54 and 56 defining a narrow neck portion 57 and recessed sockets 58 and 59. To engage the anchor unit a pin 34a of link chain 26 is placed in socket 59 and the link 33a is swung over the ear 53 until the adjoining pin 34b falls in socket 58. The links 33a may be retained on ears 53 by inserting cotter pins 61 in holes 62 to allow the assembly to be snaked out from under one pipe and used on a similar sized pipe Without readjustment.
In accordance with the present invention and as a principal feature thereof, the engaged link 33a is forced toward the periphery of the pipe 18 at the immediate edges 7 of the anchor unit 27 to insure full engagement of the chain 26 with the pipe 18. The lobes 56 are formed to provide diverging inclined cam surfaces 63 that act on pin 34a and force such pins, and engaged link 33a, in-
ward toward the pipe surface as the chain 26 is pulled around the pipe 18 by tightening means 31.
The links 33 and anchor unit 27 are so dimensioned that, as the link 33a is about to engage the pipe 18, the outer pin 34b in socket 58 will engage the neck portion 57 and pull the anchor unit 27 against the periphery of the pipe (see FIGURE 4).
The body portions 41 and 52 of tightening means 31 and anchor unit 27 are similar in that they both have depending ribs 64 with recessed portions 66 therebetween, this construction insuring alignment of the body portions 41 and 52 on the pipe surface. Likewise, body portions 41 and 52 both serve as anchor members to which the chain sections 26a and 26b are attached to complete the looping of the assembly 24 around the pipe.
In accordance with the present invention the device can be used either for pushing couplings from pipes or for pulling couplings onto pipes. In each case the thrust force is distributed equidistant around the pipe to obviate cocking of the coupling.
The pusher is illustrated in FIGURES l-6 and includes thrust members in the form of rods 67 threadably con nected to body portions 41 and 52 through bores 68 formed through such body portions. The threaded rods 67 extend from assembly 24 and are adapted to engage the coupling and exert an axial force thereon by rotating the rods 67 through the bores 68. A swiveled head 69 is attached to the rod 67 at the coupling engaging end 71. The end of the rod 67 opposite the head 69 is formed to receive a wrench 72 or similar tool in order to rotate the rod 67 in bore 68. Preferably, the wrench 72 is of the ratchet drive type and has a configuration whereby it can also be used on the elongated nut 51 of tightening means 31.
Due to the necessity of elevating the rod 67 away from the pipe to allow room for the wrench while still permitting engagement of the coupling near or below its periphery, the head 69 is preferably somewhat larger than the rod 67. The swiveled head 69 is further formed in the shape of a square with concave faces 73 to receive the convex surface of the pipe 18. This allows the corners 74 of the head 69 to extend radially inwardly to afford better engagement with smaller sizes of couplings.
The pipe puller is illustrated in FIGURES 10-12 wherein the coupling 17 is shown being pulled onto a pipe 18 prior to being used in the mode of operation illustrated in FIGURE 1. As here shown, the pipe puller includes an elongated lever 76 having a lower portion 77 formed with upturned bifurcated hooks 78, and an upper end 79 having a handle 81. The bifurcated hooks are formed to engage the chain 26 of assembly 24 and provide a fulcrum point therewith. A clamp 82 is slidably carried on the lever '76 and is secured to any point therealong by tightening wing nut 83 on screw 84.
Pivotally carried on screw 84 and extending therefrom is a connector chain 85, illustrated in FIGURE 10 as a roller chain. An engagement member 86 is selectively engageable with the connector chain 85 by finger 87. The member 86 is adapted to engage the distal end of coupling 17 so when the lever 76 is fulcrumed around the assembly 24 the connector chain 85 will pull the coupling onto the pipe 18. The effective length of connector chain 85 can be varied by utilizing the finger 87 of engagement member 86 to engage different links of chain 85. The connector chain 85 is fastened at its far end to engagement member 86 by screw 88.
As shown by the phantom line 89 in FIGURE 10 the head 69 of pusher rod 67 can be used as a stop for the coupling 17 and thereafter is in the correct position to push the coupling along the .pipe, thus providing an efiicient mode of operation.
In pulling the coupling 17 onto the pipe 18, lubricant is smeared over the end of the pipe to offer less resistance to the chevron gasket. The coupling 17 is pulled part way on the pipe with the consequence that most of the lubricant is scraped or squeegeed off by the first gasket 91. The pulling is interrupted before the second gasket 92 engages pipe 18 so more lubricant can be used and so the skirt of the second gasket may be tucked in between the coupling and the pipe in the usual manner.
The assembly is adjusted to accommodate different sizes of pipe by varying the effective length of the chain. Further, the assembly can be enlarged by adding more anchor units 27 and chain sections (see FIGURES 7, 8 and 9). As shown, when additional chain sections and anchor units 27 are added, they should be arranged so that the anchor units, etc., carrying the thrust members 67 are equally spaced circumferentially.
When more than two pushers are used on the larger sizes of pipe the wrenches 72 are alternated between adjacnt pusher rods 67 to obviate cocking the coupling, or the wrenches could be used on two opposed pushers, with the other pushers being advanced by hand to avoid cocking.
From the foregoing it will be seen that I have provided a novel device for displacing couplings onto and off of adjacent pipe sections in a novel manner greatly speeding up the assembly or disassembly of pipe lines and permitting re-use of the couplings.
I claim:
1. A device for displacing couplings relative to adadjacent pusher rods 67 to obviate cocking the coupling, link chain formed for securing in encircling relation around a pipe, an anchor unit selectively engageable with individual links of the chain ends whereby the total length of the assembly may be adjusted to conform to the size of the pipe, tightening means interposed in said chain medially of its length and formed for pulling said assembly taut in binding relation around said pipe, and means operatively connected to said chain and formed for exerting axial force between said pipe and an adjacent coupling, said anchor unit being provided with cam surfaces bearing against the engaged links of said chain and formed for urging said links tightly against the periphery of said pipe.
2. A device for displacing couplings relative to adjacent sections of pipe, comprising an assembly having a plurality of sections of roller chain formed for securing together in end to end relation for encircling the outer periphery of a pipe, an anchor unit interposed between adjacent chains and selectively engageable with the individual links thereof, tightening means connected to said chains and formed for pulling said assembly taut in binding relation around said pipe, and means connected to said chain and formed for exerting axial force between said section of pipe and an adjacent coupling, said anchor unit having cam surfaces formed for bearing against the rollers of the engaged links of said roller chain for displacing said rollers and their links inwardly toward the periphery of said pipe.
3. A device for displacing couplings relative to adjacent sections of pipe, comprising an assembly having a link chain formed for securing in encircling relation around a pipe, an anchor unit selectively engageable with individual links of the chain ends whereby the total length of the assembly may be adjusted to conform to the size of the pipe, tightening means interposed in said chain medially of its length and formed for pulling said assembly taut in binding relation around said pipe, and means operatively connected to said chain and formed for exerting axial force between said pipe and an adjacent coupling, said anchor unit having spaced ribs defining a relieved portion therebetween and formed for engaging the periphery of said pipe so as to effect a longitudinal alignment of the anchor unit with respect to the pipe, said anchor unit being formed with laterally extending ears having lobes defining diverging inclined cam surfaces adapted for engaging selected links of said chain for urging said links inwardly against the periphery of said pipe adjacent to said ribs of said anchor unit.
4. A device for displacing couplings relative to adjacent sections of pipe, comprising an assembly having a plurality of sections of roller chain formed for securing in end to end relation for encircling a pipe, an anchor unit interposed between adjacent chains and selectively engageable with the links thereof whereby the total length of the assembly may be adjusted to conform to the size of pipe, said anchor unit having spaced ribs defining a relieved portion therebetween and formed for engaging the periphery of said pipe so as to effect a longitudinal alignment of the anchor unit with respect to the pipe, tightening means connected to said chains and formed for pulling said chains taut for urging the chains and anchor unit in binding relation around said pipe, said anchor unit formed with laterally protruding ears having lobes defining diverging inclined cam surfaces formed for hearing against the rollers of the engaged links of said roller chains for displacing said rollers and their links inwardly toward the periphery of said pipe when the tightening means pulls the chain taut, the portions of said lobes opposite to said cam surfaces being formed to engage and retain the opposite ends of the links engaged by said cam surfaces, said anchor unit and said tightening" means having bores therethrough, thrust members threadably engaged in said bores and extending therefrom along the pipe, and wherein the outer end of each thrust member is provided with a swiveled head portion larger than the threaded portion of the the thrust member so as to allow the head to engage an adjacent coupling near or below the periphery of the coupling and exert an axial force thereon upon rotation of said thrust member relative to said anchor member and said tightening means.
5. A device for displacing couplings relative to adjacent sections of pipe, comprising an assembly having a plurality of sections of roller chain formed for securing in end to end relation for encircling a pipe, an anchor unit interposed between adjacent chains and selectively engageable with the links thereof whereby the total length of the assembly may be adjusted to conform to the size of pipe, said anchor unit having spaced ribs defining a relieved portion therebetween and formed for engaging the periphery of said pipe so as to effect a longitudinal alignment of the anchor unit with respect to the pipe, tightening means connected to said chains and formed for pulling said chains taut for urging the chains and anchor unit in binding relation around said pipe, said anchor unit formed with laterally protruding ears having lobes defining diverging inclined cam surfaces formed for bearing against the rollers of the engaged links of said roller chains for displacing said rollers and their links inwardly toward the periphery of said pipe when the tightening means pulls the chain taut, the portions of said lobes opposite to said cam surfaces being formed to engage and retain the opposite ends of the links engaged by said cam surfaces, a pulling member formed for pulling a coupling onto a pipe, said pulling member having an elongated lever arm formed with a bifurcated hook at one end thereof and formed for engaging said assembly, a clamp releasably retained on said lever arm and formed for slidable positioning along its length, a connector link pivotally carried on said clamp, and having a series of longitudinal holes, a coupling engaging member formed for engaging the coupling at its distal end, said coupling engaging member having a finger selectively engageable with said connector link so that as the lever is fulcrumed about the assembly the connector link will pull the engaged coupling onto the pipe.
6. A device for displacing couplings relative to adjacent sections of pipe, comprising a plurality of link chain sections, a plurality of anchor members formed for engagement between said link chain sections to define a loop adapted for encircling a pipe and having said anchor members substantially equally spaced about the pipe circumference, tightening means interposed in the connection between one of said link chain sections and an adjacent anchor member and formed for pulling said loop taut so as to urge said chain sections and said anchor members in binding relation against the periphery of said pipe, and thrust members carried by said anchor members and formed for exerting axial force with respect to said pipe between said anchor members and an adjacent pipe coupling.
7. A device for displacing couplings relative to adjacent sections of pipe, as described in claim 6, and in which one of the anchor members engaging each of said link chain sections is formed for selective engagement with individual links of such link chain sections whereby the total length of said loop may be adjusted to conform to the size of the pipe While maintaining substantially equal circumferential spacing of said anchor members.
8. A device for displacing couplings relative to adjacent sections of pipe, as described in claim 7, and in which each of said thrust members includes a rod threadably engaged through said anchor members, an enlarged head portion swiveled on similar ends of said rods and formed for extending closer to the periphery of the pipe than said rods so as to provide for engagement of said 7 i 8 enlarged head portions with said adjacent coupling radi- 1,767,451 6/30 Hedge 24230.5 X ally inwardly of the outer periphery of the coupling. 2,670,174 2/54 Lucker 29237 2,691,211 10/54 Leiber 29237 References Cited by the Examiner 2,7 0, 1/55 Waller 59-85 5 2,759,235 8/56 Rea 24--230.5
UNITED STATES PATENTS 1 99 6 14 d 59 5 X WI IAM FELDMAN, Primary Examlmer.
1,588,002 6/26 Bishop 24230.5 MYRON C. KRUSE, Examiner.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 213, 529 October 26, 1965 John B Gill ror appears in the above numbered pat- It is hereby certified that er rs Patent should read as ent requiring correction and that the said Lette corrected below.
line 5, strike out "adjacent pusher rods 67 to and insert instead jacent bly having a Column 5, obviate cocking the coupling, sections of pipe, comprising an assem Signed and sealed this 16th day of August 1966.
(SEAL) Attest:
ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents
1. A DEVICE FOR DISPLACING COUPLINGS RELATIVE TO ADADJACENT PUSHER RODS 67 TO OBVIATE COCKING THE COUPLING, LINK CHAIN FORMED FOR SECURING IN ENCIRCLING RELATION AROUND A PIPE, AN ANCHOR UNIT SELECTIVELY ENGAGEABLE WITH INDIVIDUAL LINKS OF THE CHAIN ENDS WHEREBY THE TOTAL LENGTH OF THE ASSEMBLY MAY BE ADJUSTED TO CONFORM TO THE SIZE OF THE PIPE, TIGHTENING MEANS INTERPOSED IN SAID CHAIN MEDIALLY OF ITS LENGTH AND FORMED FOR PULLING SAID ASSEMBLY TAUT I BINDING RELATION AROUND SAID PIPE, AND MEANS OPERATIVELY CONNECTED TO SAID CHAIN AND FORMED FOR EXERTING AXIAL FORCE BETWEEN SAID PIPE AND AN ADJACENT COUPLING, SAID ANCHOR UNIT BEING PROVIDED WITH CAM SURFACES BEARING AGAINST THE ENGAGED LINKS OF SAID CHAIN AND FORMED FOR URGING SAID LINKS TIGHTLY AGAINST THE PERIPHERY OF SAID PIPE.
| 1963-05-10 | en | 1965-10-26 |
US-50408383-A | Vise
ABSTRACT
The present invention relates to a vise for securely supporting a workpiece relative to a fixed support. The vise includes a base member which is secured relative to the fixed support. A clamp assembly is rotatably mounted with respect to the base member and includes a pair of jaw members one member of which, except for the relative rotative movement between the clamp assembly and the base member, is fixed relative to the base member. The second jaw member is pivotally interconnected to the first jaw member. Both jaw members have a workpiece engaging surface formed thereon with the engaging surfaces arranged in a facing relation to one another. The vise further includes a threaded handle pivotally mounted on the second jaw member and cooperating with the fixed jaw member for pivoting the jaws relative to one another to move the workpiece engaging surfaces toward one another whereby a workpiece positioned between the surfaces will be securely supported. A vise of this construction is specially suitable for supporting automotive components such as a MacPherson strut suspension assembly or a rack and pinion steering assembly, for example.
This is a continuation of application Ser. No. 242,379 filed 3/10/81 now abandoned.
BACKGROUND OF THE INVENTION
One type of vehicle suspension system which is becoming increasingly popular is the MacPherson strut suspension system. The MacPherson strut is an integral coil spring-shock absorber assembly which provides a lightweight, compact vehicle suspension system. The MacPherson strut suspension system is disclosed in more detail in U.S. Pat. No. 2,624,592 to E. S. MacPherson.
One of the problems associated with the MacPherson strut assembly is that the shock absorber unit typically wears out before the associated coil spring. In repairing the shock absorber unit, it is often necessary to remove the entire strut assembly from the vehicle. Once removed, it is desirous for the mechanic to support the assembly in some manner during the repair procedure.
Two companies, Branick Manufacturing of Fargo, North Dakota and Walker Manufacturing of Jonesboro, Arkansas have vises which have been specifically designed to support a MacPherson strut suspension assembly. Both of these vises include a support which is bolted to a work table and clamp assembly secured to the support. The clamp assembly includes a fixed member secured to the support and a pivoted member pivotally connected to the fixed member. The MacPherson strut assembly is placed between these two members and a latch pivotally connected to the fixed member is moved into engagement with the pivoted member to pivot the clamping members toward one another to secure the strut assembly.
One of the problems with the above-described type of MacPherson strut vise is that the pivoted clamping member and the latch are both independently pivoted to the fixed clamping member. This type of construction typically requires the mechanic to utilize two hands to operate the vise. Consequently, it is difficult for a mechanic to hold the strut assembly with one hand while operating the vise with the other. Another problem associated with the above-described vise is that, since one clamping member is fixed relative to the support, the strut assembly can only be supported in a single position.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus for securely supporting a workpiece relative to a fixed support. Although the apparatus is specially suitable for supporting a MacPherson strut suspension assembly, it is also suitable for supporting other workpieces such as a rack tube of a rack and pinion steering assembly, for example. The apparatus includes a base member which is secured relative to a fixed support. A clamp means is rotatably mounted with respect to the base member. Means are provided for releasably securing the rotatable clamp means relative to the base member at predetermined intervals to militate against any relative rotative movement therebetween. The clamp means includes a pair of jaw members one member of which, except for the relative rotative movement between the clamp means and the base member, is fixed relative to the base member. The second jaw member is pivotally interconnected to the first jaw member. Both jaw members have a workpiece engaging surface formed thereon with the engaging surfaces arranged in a facing relation to one another.
The apparatus further includes means mounted on the second jaw member and cooperating with the fixed jaw member for pivoting the jaws relative to one another to move the workpiece engaging surfaces toward one another whereby a workpiece positioned between the surfaces will be securely supported.
Such a vise construction provides several advantages over the above-discussed prior art. First, because the clamp means of the vise is rotatably mounted with respect to the fixed base member, the vise can be used in a variety of applications which require a workpiece to be supported in different positions. Secondly, since the means for pivoting the jaw members is located on the pivoted jaw, the operation of the vise is simplified by permitting a mechanic to operate the vise with one hand while positioning the workpiece with the other.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, as well as other objects and advantages of the invention, will become readily apparent to one skilled in the art when reading the following detailed description of the invention when considered in light of the accompanying drawings, in which:
FIG. 1 is a top plan view of a vise embodying the features of the present invention;
FIG. 2 is a side elevational view of the vise shown in FIG. 1 illustrating in phantom the position of the clamp means after it has been rotated 90° with respect to the fixed support;
FIG. 3 is a front elevational view of the vise shown in FIG. 1;
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 2, illustrating in phantom the position of one of the jaw members of the clamp means after it has been pivoted to release the workpiece; and
FIG. 5 is a sectional view taken along the line 5--5 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 2, and 3, there is shown a vise generally indicated by reference numeral 10 embodying the features of the present invention. The vise 10 includes a base member 12 having flage portions 14 adapted to receive a plurality of bolts 16 for securely mounting the base member to a fixed support 18. The base member 12 has a longitudinally and centrally disposed cylindrical aperture 20 formed therein for receiving a cylindrical end portion 22 of a support member 24.
As shown in FIG. 5, the base member 20 includes a pair of apertures 26 and 28 generally perpendicular and centrally located relative to the central aperture 20. A pair of perpendicularly disposed apertures 30 and 32 of the same diameter as the apertures 26 and 28 are formed in the cylindrical portion 22. The apertures 30 and 32 are formed such that, when the support 24 is rotated to align the apertures 30 and 32 with the apertures 26 and 28, respectively, a securing pin 34 can be inserted in the pair of aligned apertures to prevent any relative rotative movement between the support 24 and the base member 12. Since the aperture 30 is perpendicular to the aperture 32, the support member 24 can be rotated and secured relative to the base member 12 at 90° intervals. It will be appreciated that, in some instances, it may be desirous to secure the support member 24 and base member 12 at intervals other than 90° . An annular groove 36 formed in the cylindrical end 22 cooperates with a set screw 38 mounted within an internally threaded aperture 40 in the base member 12 to prevent relative axial movement of the support 24 with respect to the base member 12 when the securing pin 34 is removed.
The vise 10 further includes a clamp means, generally indicated by the numeral 42, comprising a pair of pivotally interconnected jaw member 44 and 46. Each of the jaw members 44 and 46 includes a pair of spaced apart arm plates. The jaw member 44 includes arm plates 48 and 50, while the jaw member 46 includes arm plates 52 and 54. The jaw member 42 is secured to a block end 56 of the support 24 by means of a pair of threaded bolts 58 extending through apertures formed in the plate 48, the block end 56, and the plate 50. The lower ends of the bolts 58 have fastening nuts 60 attached thereto. The jaw member 46 is pivotally connected to the jaw member 44 by means of a threaded bolt 62 extending through apertures formed in the plates 48 and 52, down through a cylindrical spacer sleeve 63 and through apertures formed in the plates 50 and 54. A fastening nut 64 is tightened to a point which permits the jaw member 46 to pivot relative to the jaw member 44. A pair of spaced apart bolts 66 are provided along with cylindrical spacer sleeves 68 and retaining nuts 70 to maintain the arm plates 52 and 54 in a spaced apart relationship.
The jaw members 44 and 46 are each provided with workpieces engaging surfaces in facing relation to one another, such as gripping teeth 72 and 74, respectively. Both the upper and lower arm plates of each jaw member can be provided with gripping teeth. The gripping teeth provide an effective means to secure a workpiece such as a cylindrical member 75, shown in phantom in FIG. 1 or a MacPherson strut assembly 76, as shown in phantom in FIG. 3. The gripping teeth 72 and 74 are specially effective when utilized to support automotive assemblies which are often coated with undercoating, road tar, etc.
As clearly shown in FIG. 1, the generally arcuate workpiece engaging surfaces defined by the gripping teeth 72 and 74 are formed with a radius substantially equal to the radius of the cylindrical workpiece 75. The workpiece engaging surfaces of the jaw members 44 and 46 are interrupted at an intermediate area by notched portions 45 and 47 respectively which extend generally radially outwardly from the workpiece engaging surfaces. Such a construction enables the jaw members 44 and 46 to securely engage a cylindrical workpiece having a radius smaller than the radius of the workpiece 75. For example, when the jaw members are utilized to clamp a cylindrical workpiece having a radius smaller that the workpiece 75, the jaw members 44 and 46 would engage the smaller workpiece at points 45a, 45b, 47a, and 47b. This four point contact substantially increases the holding ability of the vise when used to clamp such smaller cylindrical workpieces. Also, in the event the vise is utilized to support a rack tube of a rack and pinion steering unit, the notched portions 45 and 47 provide a space for accommodating the power steering lines which typically run along the outside of the tube.
The end of the jaw member 46, which is opposite the end where the gripping teeth 74 are formed, is provided with a means generally indicated at 77, for pivoting the jaw member 46 relative to the jaw member 44 to move the gripping teeth towards one another. The pivoting means 77 includes a threaded actuating handle 78 and a cooperating internally threaded cylindrical handle support 80. The handle 78 includes gripping portions 82 which are fixed to the end of an elongate shaft 84 having external threads 86 formed on the one end proximate the gripping portions 82, and having a reduced diameter portion 88 at the opposite end. The extreme outer end of the reduced diameter portion 88 is provided with a rounded end 89. The support 80 has reduced diameter end portions 92 which extend through apertures formed in the plates 52 and 54. A pair of snap rings 94 cooperate with annular grooves formed in the ends 92 to permit the support 80 to rotate about its longitudinal axis. The support 80 has internal threads 96 formed therein to engage the threads 86 formed on the shaft 84.
The jaw member 44 includes a cylindrical spacer 98 positioned between arm plates 48 and 50. The spacer 98 has reduced diameter end portions 100 which extend through apertures in the plates 48 and 50 and are fixedly attached to each of the plates to prevent rotation of the spacer 98. The spacer 98 has a quarter section cut out or pocket 102 formed therein having a recessed portion 104 adapted to receive the rounded end 89 of the threaded shaft 84.
In operation, the clamp means 42 is first rotated with the support member 24 relative to the base member 12 to the desired working position. The securing pin 34 is then placed in either the aperture 26 or the aperture 28 and through the respective aperture 30 or 32 formed in the support member 24 to secure the clamp means relative to the base member. The user then grasps the gripping portion 82 of the handle 70 with one hand and, while pivoting the rounded end 89 out of engagement with the spacer 98, also pivots the jaw member 46 in a direction to move the gripping teeth 72 and 74 away from one another. This open position is illustrated in phantom in FIG. 4. Next, the user grasps the workpiece 75 to be supported with his other hand and positions it between the gripping teeth 72 and 74 of the two jaw members 44 and 46, respectively. while still holding the workpiece with one hand, the user pivots the jaw member 46 to move the gripping teeth toward one another while simultaneously pivoting the handle 78 about the support 80 to move the rounded end 89 into engagement with the recessed portion 104. The handle 78 is then rotated about the longitudinal axis of the shaft 84 to screw the shaft into the support 80. As the rounded end 89 engages the recessed portion 104, the jaw member 46 is pivoted relative to the jaw member 44 to cause the gripping teeth 72 and 74 to move toward one another and securely grasp the workpiece.
It will be appreciated that once the workpiece is secured, the user can rotate the workpiece to another position by removing the securing pin 34. It will also be appreciated that the workpiece can be quickly removed from the clamp means 42 by merely unscrewing the handle 78 a few turns sufficiently to permit the handle to pivot from the quarter section cut out 102. It should be noted that, in addition to supporting a MacPherson strut assembly, that vise 10 can also be effectively used to support a rack tube of a rack and pinion steering assembly (not shown).
In accordance with the provisions of the patent statutes, the principle and mode of operation of the invention have been explained in what is considered to represent its best embodiment. It should, however, be understood that the invention may be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
What is claimed is:
1. An apparatus for securely supporting a generally cylindrical workpiece relative to a fixed support comprising:a base member; means for securing said base member to the fixed support; clamps means rotatably mounted on said base member including a pair of jaw members pivotally interconnected, each of said jaw members including a pair of spaced apart, generally parallel plates and means for maintaining said plates in a generally parallel spaced apart relationship, each of said plates having a workpiece engaging surface thereon with said engaging surfaces of one of said jaw members in facing relation to said engaging surfaces of the other one of said jaw members, each of said workpiece engaging surfaces having a generally arcuate portion interrupted at an intermediate area by a notched portion extending generally radially outwardly from said arcuate portion; means for releasably securing said rotatable clamp means relative to said base member to militate against any relative rotative movement therebetween; and means mounted on said clamp means for effecting pivotal movement of said jaw members relative to one another to move said workpiece engaging surfaces toward and away from one another whereby a workpiece positioned between said surfaces may be securely supported relative to the fixed support.
2. An apparatus according to claim 1 wherein said jaw members of said clamp means includes a fixed jaw member secured to said base member and a pivoted jaw member pivotally connected to said fixed jaw, and means mounted on said pivoted jaw and cooperating with said fixed jaw for effecting pivotal movement of said jaw members relative to one another to move said workpiece engaging surfaces toward and away from one another.
3. An apparatus according to claim 2 wherein said pivoted jaw member is pivoted to said fixed jaw member at a point intermediate said workpiece engaging surface and said means for effecting pivotal movement.
4. An apparatus according to claim 3 wherein said means for effecting pivotal movement of said jaws includes a threaded shaft for threaded engagement with a threaded shaft support mounted on said pivoted jaw member, said shaft including means on one end thereof for rotating said shaft about its longitudinal axis and means on the opposite end thereof for engagement with said fixed member whereby relative rotation of said threaded shaft about its longitudinal axis in one direction will effect axial movement of said shaft to pivot said jaw members relative to one another to move said workpiece engaging surfaces toward one another.
5. An apparatus according to claim 4 wherein said threaded shaft support is pivotally mounted on said pivoted jaw member to permit said threaded shaft to be pivoted about an axis perpendicular to the longitudinal axis of said shaft, said threaded shaft being pivoted to one position to engage the one end of said shaft with a cooperating pocket on said fixed jaw member whereby said threaded shaft can be rotated about its longitudinal axis to move said workpiece engaging surfaces toward one another, said threaded shaft being pivoted to a second position to move said threaded shaft out of engagement with said pocket on said fixed jaw member whereby said jaw members can be pivoted relative to one another to move said workpiece engaging surfaces away from one another without rotating said threaded shaft.
6. An apparatus according to claim 1 wherein said means for rotatably mounting said clamp means includes a support having one end securely mounted to at least one of said jaw members and having an opposite cylindrical end rotatably mounted to said base member.
7. An apparatus according to claim 6 wherein said releasably securing means includes a securing pin for insertion through a first aperture in said base member and into a cooperating first aperture in said cylindrical end for supporting said clamp means in a first position, said securing pin also insertable through a second aperture in said base member and into a cooperating second aperture in said cylindrical end for supporting said clamp means in a second position.
| 1983-06-16 | en | 1984-03-06 |
US-62236696-A | Test media and quantitative method for identification and differentiation of biological materials in a test sample
ABSTRACT
A test method and medium for quantitatively identifying and distinguishing biological materials in a test sample. A first biological material has enzyme specificity for a first chromogenic substrate, a second biological material has enzyme specificity for a second chromogenic substrate, and a third biological material has specificity for one of the substrates. The chromogenic substrates form respective first and second colored water insoluble compounds upon reaction with specific enzymes. The first and second biological materials are capable of fermenting a sugar, and the third material does not ferment sugar. The test medium is adjusted to a pH conducive for color change of a pH indicator upon acidification due to fermentation, resulting in the formation of a zone of a third color around the water insoluble compounds of the sugar-fermenting materials. The sample is incubated, and examined for the presence of colonies of the first biological material, having the first color and an encircling zone of the third color; for colonies of the second material, having the second color and the encircling colored zone; for colonies of a third material having the first color, and not having the colored zone; and for colonies having neither color, with or without the colored zone, representing colonies of other biological materials.
BACKGROUND OF THE INVENTION
The present invention relates to a method for the quantitative identification and differentiation of biological materials in a sample containing a plurality of different biological materials, and a test medium for use in the method.
The invention further relates to a quantitative method for detecting and identifying Escherichia coli 0157, with simultaneous quantitative detection and identification of other strains of Escherichia coli (E. coli), general coliforms and non-coliform Enterobacteriaceae in mixed microbial samples.
There has been an ongoing need to screen meat, dairy, water, and other food samples for the presence of offending substances such as bacteria, other microbes, and cells and tissues of other organisms. This need has taken on additional significance as a result of the discovery of the enteropathogenic E. coli 0157 in the early 1980s. Additional impetus was given by the public notoriety in more recent instances of disease and death from the ingestion of poorly cooked ground beef. As a result, much emphasis has been put into the development of test methods to determine the presence and quantities of such offending substances in biological materials such as food, dairy products, beverages and water, as well as in medical and veterinary test materials. This is important both to identify potential hazards in materials, and for diagnostic purposes.
In addition to the aforementioned need to determine the presence and quantities of E. coli 0157 in a test sample, there remains an ongoing need for faster and more reliable test methods to determine the presence in a test sample of many other biological materials which are known to affect the quality and safety of a product. A determination of the presence or absence of such biological materials provides an additional basis upon which the quality and safety of various substances may be evaluated.
The use of indicator organisms in biotechnology, diagnostic chemistry, microbiology, molecular biology and related fields as a basis upon which to determine product or test sample quality is well known. For example, the amount, or count, of E. coli or other coliforms present in water is considered a significant indicator of the cleanliness and safety of that water. Similarly, the presence of E. coli or other coliforms in food and dairy products is considered a significant indicator of the quality of these products. Also, quick and accurate identification of specific entities in medical test samples is important in the diagnosis of disease conditions. Improved test methods to effectively identify, separate and enumerate such bacterial types are needed, and there is a continuing search for faster, more accurate and more versatile test methods in this area.
Numerous test methods have been utilized to determine, identify and enumerate one or more indicator organisms. Some of these test methods only indicate the presence or absence of the microorganism, while others also attempt to quantify one or more of the particular organisms in the test sample. For example, a test referred to as the Presence/Absence (or P/A) test, may be utilized to determine the presence or absence of coliforms and E. coli in a test sample. A test medium comprising the β-galactosidase substrate O-nitrophenyl-β-D-galactopyranoside (ONPG), and the β-glucuronidase substrate 4-methyl-umbelliferyl-β-D-glucuronide (MUG), is inoculated with the test sample. To differentiate the general coliforms from E. coli, this test relies on the fact that generally all coliforms produce β-galactosidase, whereas only E. coli also produces β-glucuronidase in addition to β-galactosidase. If any coliforms are present (including E. coli), the broth medium turns a yellow color due to the activity of the galactosidase enzyme on the ONPG material, causing the release of a diffusible yellow pigment. If E. coli is present, the broth medium will demonstrate a blue fluorescence when irradiated with ultraviolet rays, due to the breakdown of the MUG reagent with the release of the fluorogenic dye caused by the production of the glucuronidase enzyme. These reactions are very specific, and allow the presence of both coliforms in general, as well as E. coli to be identified in a single sample. A disadvantage of this test is that it is not directly quantitative for either bacterial type, since both reagents produce diffusible pigments. The test also requires specific equipment for producing the ultraviolet rays. Further, this test may only be used to detect coliforms and E. coli. Other important microorganisms, such as the strain E. coli 0157 which is glucuronidase negative, are not detected, nor are other non-galactosidase-glucuronidase producing microorganisms.
The Violet Red Bile Agar (VRBA) method has been used to determine the quantity of both coliform and E. coli in a test sample. The test medium used in this method includes bile salts (to inhibit non-coliforms), lactose and the pH indicator neutral red. As coliforms (including E. coli) grow in the medium, the lactose is fermented with acid production, and the neutral red in the area of the bacterial colony becomes a brick red color. The results of this test are not always easy to interpret, and in order to determine the presence of E. coli, confirming follow-up tests, such as brilliant green lactose broth fermentation, growth in EC broth at 44.5° C. and streaking on Eosin Methylene Blue Agar (EMBA), must be performed.
The Membrane Filter (MF) method utilizes micropore filters through which samples are passed so that the bacteria are retained on the surface of the filter. This method is used most often when bacterial populations are very small, and a large sample is needed to get adequate numbers. The filter is then placed on the surface of a chosen medium, incubated, and the bacterial colonies growing on the membrane filter surface are counted and evaluated. This method is widely used and provides good results when combined with proper reagents and media. A disadvantage of this method is that it is expensive and time-consuming. It also does not work well with solid samples, or with samples having high counts of microorganisms. The MF method can be used in conjunction with the inventive method described in this application.
The reagent 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal) is a known test compound for identifying coliforms. When acted on by the β-galactosidase enzyme produced by coliforms, X-gal forms an insoluble indigo blue precipitate. X-gal can be incorporated into a nutrient medium such as an agar plate, and if a sample containing coliforms is present, the coliforms will grow as indigo blue colonies. X-gal has the advantage over the compound ONPG, described above, in that it forms a water insoluble precipitate rather than a diffusible compound, thereby enabling a quantitative determination of coliforms to be made, when the test sample is incorporated into or onto a solidified medium.
A similar compound, 5-bromo-4-chloro-3-indolyl-β-D-glucuronide (X-gluc) is a known test compound for identifying E. coli. When acted on by the β-glucuronidase enzyme produced by most E. coli, X-gluc forms an insoluble indigo blue precipitate. X-gluc has the advantage over the compound MUG, described above, in that it forms a water insoluble precipitate, rather than a diffusible compound, thereby enabling a quantitative determination of E. coli to be made when the test sample is incorporated into or onto a solidified medium. Further, it does not require the use of ultraviolet light. X-gluc and its ability to identify E. coli are described in Watkins, et al, Appl. Environ. Microbiol. 54: 1874-1875 (1988). A similar compound, indoxyl-β-D-glucuronide, which also produces sharp blue colonies of E. coli, was described in Ley, et al, Can. J. Microbiol. 34: 690-693 (1987).
Although X-gal and X-gluc are each separately useful in the quantitative determination of either coliforms (X-gal) or E. coli (X-gluc), these indicator compounds have the disadvantage that they each contain the same chromogen. Therefore, they cannot be used together to identify and distinguish both E. coli and general coliforms in a single test with a single sample, since they both generate identically hued indigo blue colonies. A person using both reagents together would be able to quantitatively identify the total number of coliforms, the same as if X-gal was used alone, but would not be able to indicate which of the colonies were E. coli and which were other coliforms besides E. coli.
A recently developed test method for quantitatively identifying and differentiating general coliforms and E. coli in a test sample is described in U.S. Pat. No. 5,210,022, assigned to the assignee herein. This method improves upon prior art methods by allowing the quantitative identification of general coliforms and E. coli in a single sample. Additional confirmatory tests are not necessary. The test sample is added to a medium containing a β-galactosidase substrate, such as 6-chloroindolyl-β-D-galactoside, and a β-glucuronidase substrate, such as 5-bromo-4-chloro-3-indolyl-β-D-glucuronide (X-gluc). The β-galactosidase substrate is capable of forming a water insoluble precipitate of a first color upon reacting with β-galactosidase, and the β-glucuronidase substrate is capable of forming a water insoluble precipitate of a second color, contrasting with the first color, upon reacting with β-glucuronidase. As a result, general coliforms may be quantified by enumerating the colonies of the first color (having β-galactosidase activity), and E. coli may be quantified by enumerating the colonies of the second color (having both β-galactosidase and β-glucuronidase activity). Although the method described in the patent provides excellent results for the differentiation and identification of general coliforms and E. coli, it is unable to establish and quantify the presence of E. coli 0157 strains and non-coliform Enterobacteriaceae.
Other known methods to identify and differentiate certain microorganisms are based upon the differences exhibited by the microorganisms with regard to their ability to ferment certain carbohydrates, such as the sugar sorbitol. For example, general coliforms and most strains of E. coli are known to have the ability to ferment sorbitol. E. coli 0157 and most non-coliform Enterobacteriaceae do not ferment sorbitol. As a result, when a test sample is added to a fermentable medium containing sorbitol as the sole carbon source, such as MacConkey Sorbitol agar, in the presence of an appropriate pH indicator such as neutral red, the general coliforms and most E. coli strains grow as red colonies due to acid production from sorbitol fermentation. Non-sorbitol fermenters such as E. coli 0157 grow as colorless colonies on this medium. However, since there are also many non-sorbitol fermenting Enterobacteriaceae, it is virtually impossible to identify E. coli 0157 with any certainty on this medium. In addition, the test is incapable of distinguishing E. coli from general coliforms.
Therefore, a need exists to provide a test method that is effective for differentiating a wider variety of biological materials in samples containing mixed populations than may be accomplished with existing methods. Further, this need exists for methods that are faster, simpler and more versatile than prior methods.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of prior art methods by providing a test method for quantitatively identifying and differentiating biological materials in a test sample having a plurality of different biological materials, and a medium for use in the test method.
The present invention, in one form thereof, comprises a method for detecting the presence of and quantitatively identifying and differentiating specified biological materials in a test sample comprising a plurality of different biological materials, wherein a first biological material has enzyme specificity for a first chromogenic substrate, and a second biological material has enzyme specificity for a second chromogenic substrate, and wherein at least some of the biological materials are capable of fermenting a carbohydrate, such as a sugar. A test medium capable of forming a matrix or a solid surface with the test sample is provided. The test medium comprises a first chromogenic substrate, a second chromogenic substrate, a fermentable carbon source such as a specific sugar, a pH indicator and a nutrient base medium. The first chromogenic substrate is capable of forming a water insoluble compound of a first color upon reacting with an enzyme produced from or present in the first biological material, and the second chromogenic substrate is capable of forming a water insoluble compound of a color contrasting with the first color upon reacting with an enzyme produced from or present in the second biological material. The fermentable carbon source is capable of acidifying a portion of the medium upon fermentation by sugar-fermenting components of the test sample. The pH indicator causes a third color to be formed upon reaction to the acidification, which third color comprises a colored zone around the sugar-fermenting components and is visually distinguishable from the general background color of the medium. The nutrient base medium preferably comprises a solid, a gel or a solution for forming a solid. The pH of the test medium is adjusted to a range conducive for color change of the pH indicator upon acidification of the medium, and the test sample is thereafter inoculated into the test medium. The test medium containing the inoculated test sample is then incubated under conditions conducive for growth of colonies of the biological materials. The incubated test sample may then be examined for the presence of colonies having the first color, and having the third colored zone visibly discernable and distinguishable thereabout, which colonies represent sugar-fermenting colonies of the first biological material; for the presence of colonies having a second color and having the third colored zone visibly discernable and distinguishable thereabout, which colonies represent sugar-fermenting colonies of the second biological material; for the presence of colonies having the first color, and not having the second color or the third colored zone discernable and distinguishable therewith, such colonies representing colonies of a third biological material; for the presence of colonies not having either of said first and second colors, with or without the third colored zone, such colonies being colonies of at least a fourth biological material; and for the presence of colonies having a fourth color, with or without the third colored zone, such colonies being colonies of at least a fifth biological material. Each of the respective colonies is then enumerated to provide a count of each of the specified biological materials present in the test sample.
The present invention, in another form thereof, comprises a method for detecting the presence of and quantitatively identifying and differentiating E. coli 0157, other E. coli strains not including E. coli 0157, general coliforms and non-coliform Enterobacteriaceae in a test sample. A test medium capable of forming a matrix or a solid surface with the test sample is provided. The test medium comprises a chromogenic β-galactosidase substrate capable of forming a water insoluble compound of a first color upon reacting with β-galactosidase, a chromogenic β-glucuronidase substrate capable of forming a second water insoluble component of a color visibly contrasting with the first color upon reacting with β-glucuronidase, sorbitol as the sole fermentable carbon source, a pH indicator for causing a third color to be formed upon acidification resulting from sorbitol fermentation, the third color comprising a colored zone around the sorbitol-fermenting components which contrasts with the normal background color of the medium, and a nutrient base medium. The pH of the test medium is adjusted to a range conducive for color change of the pH indicator upon acidification of the medium, and the sample is thereafter inoculated into the test medium. The test medium containing the sample is incubated under conditions conducive for growth of general coliforms, E. coli, E. coli 0157 and non-coliform Enterobacteriaceae, to thereby produce first and second colored precipitates corresponding to said colonies, and to produce a zone of the third color around the sorbitol-fermenting components. The test medium may then be examined for the presence of colonies having the first color and the third colored zone visibly discernable and distinguishable thereabout, these colonies being colonies of general coliforms having β-galactosidase activity but not β-glucuronidase activity, and being sorbitol fermenters; for the presence of colonies having a second color and the third colored zone visibly discernable and distinguishable thereabout, such colonies being colonies of E. coli having β-glucuronidase activity and β-galactosidase activity, and being sorbitol fermenters; for the presence of colonies having the first color, and not having the second color or the third colored zone discernable and distinguishable therewith, such colonies being colonies of E. coli 0157 having β-galactosidase activity but not β-glucuronidase activity, and being sorbitol non-fermenters; for the presence of colonies not having either of the first and second colors, with or without the third colored zone, such colonies being non-coliform Enterobacteriaceae having neither β-galactosidase activity nor β-glucuronidase activity, with or without the ability to ferment sorbitol; and for the presence of colonies having a fourth color, with or without the third colored zone, such colonies representing certain strains of some genera such as Salmonella or Shigella not having β-galactosidase activity but having β-glucuronidase activity, with or without the ability to ferment sorbitol. Each of the colonies may then be enumerated to provide a count of each of the selected microorganisms. Alternatively, only the particular colonies of interest in the particular test sample need be enumerated.
The present invention, in yet another form thereof, comprises a test medium for detecting the presence of biological materials in a test sample. The test medium comprises a first chromogenic substrate, a second chromogenic substrate, a fermentable carbon source such as a sugar, a pH indicator and a nutrient base medium. The first chromogenic substrate is capable of forming a water insoluble compound of a first color upon reacting with an enzyme from said first biological material, and the second chromogenic substrate is capable of forming a water insoluble compound of a second color contrasting with the first color upon reacting with an enzyme from the second biological material. The fermentable carbon source is capable of acidifying a portion of the medium upon fermentation by sugar-fermenting components of the test sample. The pH indicator causes a third color to be formed upon reaction to the acidification, which third color comprises a colored zone around the sugar-fermenting components. The nutrient base medium may comprise a solid, a gel or a solution for forming a solid.
The method and media of the present invention allow the simultaneous growth, isolation, quantification and identification of biological substances, such as general E. coli strains, E. coli 0157, other coliforms and non-coliform members of the Enterobacteriaceae family from a sample incorporated into the test medium in a single petri plate. No pre-enrichment of the sample is required, although pre-enrichment may be utilized if desired. The test results are available within 24-48 hours, and the test essentially comprises the mere addition of the test sample to the medium in the plate, the incubation of the test medium and the enumeration of the respective colonies in the test sample. Most other tests require more steps, and generally require a longer period of time in which to obtain the test results. In addition, the inventive method is not dependent upon one carefully controlled incubation temperature.
DETAILED DESCRIPTION OF THE INVENTION
The method and medium of the present invention allow the simultaneous quantitative identification and differentiation of a variety of selected biological materials in a sample of mixed populations of biological materials.
The inventive method and medium are particularly useful for the quantitative identification and differentiation of E. coli 0157 in mixed microbial samples, with the simultaneous quantitative identification and differentiation of other strains of E. coli, general coliforms, and non-coliform Enterobacteriaceae.
Microorganisms having β-galactosidase activity include those commonly known by the designation "coliform." There are various definitions of "coliform," but the generally accepted ones include bacteria which are members of the Enterobacteriaceae family, and have the ability to ferment the sugar lactose, with the evolution of gas and acids.
Microorganisms having β-glucuronidase activity in addition to β-galactosidase activity primarily include most strains of coliform of the species E. coli, with the exception of E. coli 0157. E. coli 0157 is one of about 3% of E. coli strains that exhibit β-galactosidase activity but do not exhibit β-glucuronidase activity.
The term "general coliforms" as used in this application refers to coliforms other than the various strains of E. coli. These "general coliforms" are gram-negative, non-sporeforming microorganisms having β-galactosidase activity (i.e., lactose fermenters), but not having β-glucuronidase activity, and having the ability to ferment the sugar sorbitol.
The term "non-coliform Enterobacteriaceae" as used in this application refers to microorganisms of the family Enterobacteriaceae not having β-galactosidase activity.
The term "β-galactosidase substrate" as used herein refers to a β-galactoside comprising galactose joined by a β-linkage to a substituent that forms an insoluble colored precipitate when liberated by the action of β-galactosidase on the substrate.
The term "β-glucuronidase substrate" as used herein refers to a β-glucuronide comprising glucuronic acid joined by a β-linkage to a substituent that forms an insoluble colored precipitate when liberated by the action of β-glucuronidase on the substrate.
The β-galactosidase substrates and compounds described herein as "galactosides," as well as the β-glucuronidase substrates and compounds described herein as "glucuronides," each may comprise carboxylate salts formed by reacting a suitable base with the appropriate galactosidase or glucuronic carboxyl group. Suitable bases include alkali metal or alkaline earth metal hydroxides or carbonates, for example, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, and corresponding carbonates; and nitrogen bases such as ammonia, and alkylamines such as trimethylamine, triethylamine and cyclohexylamine.
The method of the present invention is designed to take advantage of distinguishing characteristics found in certain microorganisms, so that the microorganisms may be quantitatively identified and differentiated from each other. The method is particularly suitable for the quantitative identification and differentiation of the different classes of microorganisms described previously, i.e., general coliforms, E. coli, E. coli 0157 and non-coliform Enterobacteriaceae. Although the inventive method is particularly suitable for the microorganisms described above, it is not limited to the quantitative identification and differentiation of those particular microorganisms, as the techniques have application to the quantitative identification and differentiation of a wide variety of biological materials.
The separation and identification of E. coli 0157 from other strains of E. coli has been particularly problematic, as all E. coli strains share many common characteristics. However, there are three primary differences which provide a basis upon which to distinguish E. coli 0157 from the other E. coli strains. These are the unthrifty growth of E. coli 0157 at temperatures above 42° C., the inability of E. coli 0157 to produce the enzyme glucuronidase, and the inability of E. coli 0157 to ferment the sugar sorbitol. Although these differences provide a general backdrop for use in identifying and separating the two E. coli types, additional factors complicate this identification and separation.
In mixed populations of microorganisms found in nature, such as those including both E. coli and E. coli 0157, many other closely related organisms are also normally present. Many of these microorganisms are capable of living and metabolizing under the same or similar conditions as the E. coli strains. Most of the closely related organisms are members of the family Enterobacteriaceae, as are all species of E. coli. The Enterobacteriaceae are gram-negative, non-sporeforming, rod-shaped bacteria. Some of the most well known genera are Citrobacter, Edwardsleila, Enterobacter, Escherichia, Klebsiella, Proteus, Salmonella, Shigella and Yersinia. Within this family are those genera which are commonly designated the coliform bacteria. Coliform bacteria retain the general generic characteristics, but in addition produce the enzyme galactosidase, which is instrumental in the fermentation of the sugar lactose. The coliform genus Escherichia also produces the enzyme galactosidase, and in addition, most strains of this genus also produce the enzyme glucuronidase. However, the strain E. coli 0157 is one of only about 3% of Escherichia coli strains that do not have the ability to produce glucuronidase.
Due to the characteristic similarities of these closely related bacteria, it has proven difficult to identify and separate E. coli 0157 from other members of the Enterobacteriaceae family. As a result, easy to read and formulate test media to accomplish this identification and separation have not been available, and it has generally been necessary to go to complex and expensive methods utilizing antigen-antibody matching or DNA probes to determine the presence of the E. coli 0157 in mixed microbial populations. Such techniques are not only expensive and time-consuming, but often give false positive or false negative results.
The method described in U.S. Pat. No. 5,210,022, incorporated herein by reference, allows the quantitative identification and differentiation of general coliforms and E. coli. The differentiation of these two microorganisms is based upon the characteristic ability of general coliforms to produce galactosidase, and thereby form a water insoluble precipitate of a first color upon reaction with a β-galactoside, and the characteristic ability of E. coli to produce glucuronidase in addition to galactosidase, and thereby form a water insoluble precipitate of a color contrasting with the first color upon reaction with a β-glucuronide.
The present invention goes beyond the method taught in U.S. Pat. No. 5,210,022. With the inventive method, a quantitative identification and differentiation may be made of not only general coliforms and E. coli, as in the patent, but also of the enteropathogenic E. coli 0157 as well as various species of non-coliform Enterobacteriaceae. Sorbitol and a suitable pH indicator are incorporated into a test medium with the chromogenic agents. Since one of the differences between E. coli 0157 and other E. coli is the inability of E. coli 0157 to metabolize the sugar sorbitol, the use of sorbitol in the test medium provides a means to distinguish these two E. coli strains. The chromogenic agents are selected to provide a basis for a quantitative differentiation of coliforms having β-galactosidase activity from those strains of E. coli having β-galactosidase activity in addition to β-glucuronidase activity. The inclusion of sorbitol and the pH indicator in the medium does not affect this quantitative differentiation of coliforms from E. coli, but additionally allows the quantitative detection and differentiation of E. coli 0157 and non-coliform Enterobacteriaceae from general coliforms and most other E. coli. E. coli 0157 may be distinguished from the non-coliform Enterobacteriaceae due to the β-galactosidase activity of E. coli 0157, which activity is not present in the non-coliform Enterobacteriaceae.
The specific β-galactosidase substrate (β-galactoside) and the specific β-glucuronidase substrate (β-glucuronide) for use in the test medium are selected so that the precipitates formed by each of the substrates are of contrasting colors, thereby providing a means to distinguish general coliforms from E. coli. As a result, colonies of microorganisms having β-galactosidase activity but not β-glucuronidase activity, and colonies of microorganisms having either β-glucuronidase activity alone, or both β-galactosidase and β-glucuronidase activity, can be visually distinguished. The exact color of each type of microorganism colony is not crucial as long as each type can be distinguished. The precipitates should be insoluble in the test medium so that the colonies of microorganisms producing each precipitate can be visually counted. Further, the β-galactoside and β-glucuronide should be compounds that are approximately colorless or are not deeply colored, so that they do not interfere with the detection of the colored insoluble precipitates produced by the action of β-galactosidase and β-glucuronidase. The β-galactosides and β-glucuronides should be compounds that can be made soluble in the test medium.
The determination of whether a given β-galactoside or β-glucuronide is operable in the test medium can be made by a simple test. The β-galactoside or β-glucuronide is incorporated in a solid test medium which is then inoculated with general coliforms or E. coli. If colored colonies grow in the test medium, the particular β-galactoside or β-glucuronide may be used, subject to the following test. The determination of whether a given β-galactoside and β-glucuronide can be used together can be made by incorporating the two compounds together in a solid medium which is then inoculated with a mixture of both general coliforms and E. coli, and incubated at a suitable temperature. If the colonies of E. coli and the colonies of general coliforms can be visually differentiated by a contrast in color of each type of colony, then the particular combination of β-galactoside and β-glucuronide is suitable.
A suitable chromogenic compound for the practice of the method of this invention is 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal). X-gal is a commercially available β-galactosidase substrate that produces an insoluble precipitate having an approximately indigo blue color when reacted upon by β-galactosidase. Permissible β-glucuronides that can be used with X-gal include compounds that produce an insoluble precipitate having a color such as red or yellow that contrasts with indigo blue and is not totally masked by the indigo blue color. One such example is the compound 6-chloroindolyl-β-D-glucuronide. This compound produces an insoluble precipitate having a magenta color contrasting with and visually distinguishable from indigo blue. The preparation of this compound and other suitable compounds for use herein is described in the aforementioned incorporated by reference U.S. Pat. No. 5,210,022.
Another suitable chromogenic compound for the practice of the method is 5-bromo-4-chloro-3-indolyl-β-D-glucuronide (X-gluc). X-gluc is a commercially available β-glucuronide that produces an insoluble precipitate having an approximately indigo blue color when reacted upon by β-glucuronidase. Indoxyl-β-D-glucuronide is a similar compound, the preparation of which is described in the aforementioned article by Ley et al., in Can J. Microbiol., the disclosure of which is incorporated by reference. Permissible β-galactosides that can be used with X-gluc or indoxyl-β-D-glucuronide include substrates that produce an insoluble precipitate having a color such as red or yellow that contrasts with indigo blue. An example of a suitable β-galactoside is the compound 6-chloroindolyl-β-D-galactoside. This compound produces an insoluble precipitate having a magenta color contrasting with and visually distinguishable from indigo blue. The preparation of this compound is described in the aforementioned U.S. Pat. No. 5,210,022. Other suitable chromogenic compounds are also specified in the patent.
It is preferred that the β-galactoside and the β-glucuronide are selected so that the β-glucuronide produces an insoluble precipitate that is darker in color than the insoluble precipitate produced by the β-galactoside. This allows the precipitate produced by the β-glucuronide to mask the precipitate produced by the β-galactoside in colonies of E. coli, and makes it easier for colonies of E. coli to be differentiated from colonies of general coliforms. Alternatively, the precipitate produced by the β-galactoside may be masked by using more of the β-glucuronide and less of the β-galactoside. In a preferred embodiment, 6-chloro-3-indolyl galactoside is used as the β-galactoside and 5-bromo-4-chloro-3-indolyl glucuronide is used as the β-glucuronide. When these substrates are used in the medium, coliforms are identified by the presence of red colonies formed due to the presence of the enzyme galactosidase. E. coli is identified by the formation of purple (red+blue) colonies, formed due to the presence of both galactosidase (which produces red colonies) and glucuronidase (which produces blue colonies) in these strains of E. coli.
Other β-galactosides and β-glucuronides that may be utilized include those that fall into the general category of substituted indolyl β-galactosides and β-glucuronides. While it is not intended to limit the invention to any particular theory or mechanism, it is believed that when β-galactosidase and β-glucuronidase substrates having substituted indolyl substituents are reacted upon by their respective enzymes, the substituted indolyl substituents released by action of the enzyme convert in situ to insoluble indigo analogs. For example, when 6-chloroindolyl-β-D-galactoside is acted upon by β-galactosidase, the released 6-chloroindolyl reacts with itself and forms 6,6'-dichloroindigo, a magenta-colored precipitate. This suggests that other compounds similar to 6-chloroindolyl-β-D-galactoside or 6-chloroindolyl-β-D-glucuronide could be made and utilized based upon symmetrical indigo analogs having a color similar to 6,6'-dichloroindigo. The synthesis and absorption spectra of symmetrical chloroindigos were reported by Sadler et al., JACS 78, 1251-1255 (1956), the disclosure of which is incorporated herein by reference. It appears therein that the compounds 4,4',6,6'tetrachloroindigo, 6,6',7,7'tetrachloroindigo, and 4,4',6,6',7,7'hexachloroindigo are similar in color to 6,6'-dichloroindigo. Thus, the respective β-galactosides, namely 4,6-dichloroindolyl-β-D-galactoside, 6,7-dichloroindolyl-β-D-galactoside and 4,6,7-trichloroindolyl-β-D-galactoside, and salts thereof, could be made and used as β-galactosidase substrates in the same manner as 6-chloroindolyl-β-D-galactoside. Other galactosidase substrates suitable for use in the invention to form reddish-colored precipitates include 5-bromo-6-chloro-3-indolyl-β-D-galactoside and 6-chloro-3-indolyl-β-D-galactoside. It has additionally been found that certain naphthyl substituted galactosides, such as 2-naphthyl-β-D-galactoside, may also be utilized as galactosidase substrates, since these naphthyl-substituted compounds form a red precipitate under the conditions specified in the inventive method.
Similarly, the respective β-glucuronides, namely 4,6-dichloroindolyl-β-D-glucuronide, 6,7-dichloroindolyl-β-D-glucuronide and 4,6,7-trichloroindolyl-β-D-glucuronide, and salts thereof, as well as naphthyl-substituted glucuronides such as naphthol-AS-BA-β-D-glucuronide, could be made and used as β-glucuronidase substrates in the same manner as 6-chloroindolyl-β-D-glucuronide. Other suitable glucuronidase substrates that form reddish-colored precipitates include 5-bromo-6-chloro-3-indolyl-β-D-glucuronide and 6-chloro-3-indolyl-β-D-glucuronide. However, in practice, the above-listed glucuronides would not be used with the listed galactosides because the colored precipitates formed by each of the respective substrates would not be readily distinguishable, since they each contain the same chromogen. Rather, in such instances wherein a reddish precipitate is formed by the galactosidase substrate, glucuronides such as 5-bromo-4-chloro-3-indolyl-β-D-glucuronide, indoxyl-β-D-glucuronide, 4-chloro-3-indolyl-β-D-glucuronide, 5-bromo-3-indolyl-β-D-glucuronide and N-methyl-3-indolyl-β-D-glucuronide, and their salts, may be utilized, since the precipitates formed by these substrates are of a color (generally blue or green) that contrasts with the color formed by these galactosides (generally a reddish color).
Similarly, if the glucuronides specified above that form a reddish-colored precipitate are utilized, the galactosides selected would be those that form precipitates having a color distinguishable from the color of the precipitates formed by the glucuronidase substrate. In this event, suitable galactosides would include 5-bromo-4-chloro-3-indolyl-β-D-galactoside, 4-chloro-3-indolyl-β-D-galactoside, 5-bromo-3-indolyl-β-D-glucuronide and N-methyl-3-indolyl-β-D-galactoside, and their salts. Most of the above-listed compounds, or their salts, may be obtained from commercial sources such as Inalco Pharmaceuticals, Inc., of Horsham, Pa., and Diagnostic Chemicals Limited, of Oxford, Conn.
A suitable carbon source and an appropriate pH indicator are also incorporated into the test medium. In the preferred embodiment the sugar sorbitol is utilized as the carbon source to enable the differentiation of sorbitol-fermenting microorganisms, such as general coliforms and E. coli, from non-sorbitol fermenters, such as E. coli 0157 and some non-coliform Enterobacteriaceae. Although sorbitol is utilized in the preferred embodiment, other sources of carbon such as complex carbohydrates, other sugars, proteins and long chain lipids may also be used under appropriate conditions and with appropriate pH indicators to react biochemically with substrates to produce organic acids, and therefore also fall within the scope of the present invention.
The pH indicator causes a colored zone to be created around those colonies which ferment sorbitol with the production of acid. No zone is created around those colonies that do not ferment sorbitol. The pH of the final medium is critical to the effectiveness of this method, as the pH must be such that the pH indicator turns the medium the desired color. Although various pH indicators may be used, phenol red is the preferred indicator when the method is utilized to identify and differentiate E. coli 0157 from the microorganisms specified above. When phenol red is used as the pH indicator, the pH should be adjusted within the range of about 7.0 to 7.6, and preferably about 7.2. With the use of phenol red at this pH, a yellow zone is created around the sorbitol fermenters due to the production of acid upon fermentation. The area around the non-sorbitol fermenters remains colorless, or in some cases red due to a small amount of color leakage from precipitates formed due to the presence of galactosidase. Other indicators such as Brom Thymol Blue (BTB) have also been used to detect and distinguish E. coli 0157 from E. coli. When other pH indicators are utilized, the reaction conditions must be adjusted to the appropriate pH for the particular indicator chosen. In addition, when selecting a pH indicator, it is important to select an indicator that produces colors upon acidification or alkalinization that are distinguishable from the colors of the particular chromogens used in the test medium.
It is important to control the amount of the sugar incorporated in the medium. For example, too high a concentration of sorbitol will result in excessive acid production. In such event, a relatively small number of acid producing colonies may cause the medium in the entire petri plate to turn yellow, and thereby mask the non-sorbitol using colonies. Preferably, the amount of sorbitol should be between about 2 and 7 grams per liter of medium, most preferably about 5 g/l.
In addition, for best results, an overlay of medium should be placed over the sample to lock the bacteria into the matrix of the medium. Since colonies growing on an air exposed surface of a medium may not respond in exactly the same way as those embedded in the medium, the addition of an overlay of medium provides more consistent and accurate test results.
Preparation of Test Medium
The preparation of a test medium for use in the quantitative identification and differentiation of E. coli 0157, with simultaneous quantitative detection and identification of E. coli, general coliforms and non-coliform Enterobacteriaceae in mixed microbial samples will be described.
The test medium is formed by combining the selected chromogens, i.e., the β-galactoside and the β-glucuronide, sorbitol and the pH indicator with a nutrient base medium. Sorbitol is the only sugar added to the medium, as the test method depends upon the fermentation or nonfermentation of sorbitol as one of the differentiation processes. When phenol red is used as the pH indicator, this indicator is red at neutral or alkaline conditions, and yellow in acidic conditions created upon fermentation of sorbitol. In a preferred embodiment, bile salts are also added to the medium to inhibit the growth of many bacteria other than members of the Enterobacteriaceae, thus making the test more selective.
The nutrient base medium may be any one of many culture medium formulations known in the art for growing microorganisms. Generally such media include growth nutrients, buffers, water, and a gelling agent. Possible gelling agents include agars, pectins, carrageenans, alginates, locust bean, xanthins, guars and gellens, among others.
The following example describes the preparation of a test medium suitable for use in the present invention. The amounts of the respective ingredients listed are per liter of test medium:
______________________________________
peptone (casein digest) 10 g
yeast extract 5 g
sodium chloride 3 g
bile salts 1 g
sorbitol 5 g
phenol red 25 mg
5-bromo-4-chloro-3-indolyl glucuronide
75 mg
6-chloro-3-indolyl galactoside
150 mg
bacteriological quality agar
17 g
______________________________________
The above ingredients are blended in about one liter of deionized water heated to 90°-100° C. The pH of the solution is then adjusted to about 7.2 with NaOH or tartaric acid (10% solutions). The medium is sterilized at 121° C. and 15 pounds pressure for 15 minutes, cooled to 45° C., and poured into sterile Petri plates (20 mL/plate) for use.
A pectin-based test medium may be prepared using the same steps described above except that 25 gm of low methoxyl pectin is used as the solidifying agent in place of the agar gum. This medium is poured at room temperature into petri plates containing a thin gel layer containing calcium ions, which combine with the pectin to form a solid gel. A suitable pectin culture medium is described in U.S. Pat. No. 4,241,186 and U.S. Pat. No. 4,282,317, the disclosures of which are incorporated herein by reference. A pectin-based medium is preferred over a standard agar medium because it has the advantages of convenience and temperature independence for the user. The use of pectin media has been well described in the literature, and has been accepted as a result of AOAC collaborative studies, as well as other published and in-house investigations. A suitable pectin medium for use in the inventive method is commercially available from RCR Scientific, Inc., of Goshen, Ind.
Although the method has been described as utilizing a solid pectin or agar medium in its preferred embodiment, the medium need not necessarily be in solid form. For example, an absorbent pad may be placed in a petri dish, and a liquid medium containing all of the necessary nutrients and reagents previously described is added in a manner such that it is absorbed by the pad. The absorbent pad provides a solid surface upon which the microorganisms can grow as discrete colony-forming units similar to those that develop on a medium solidified with agar or other solidifying agents.
Inoculation of the Test Medium with the Sample
The test medium may be inoculated with the sample to be tested by any method known in the art for inoculating a medium with a sample containing microorganisms. For example, the sample to be tested may be added to the petri plates prior to adding the medium, or the sample may be added to the unsolidified medium prior to pouring in the plates (pour plate technique). When the pour plate technique is utilized, an overlay layer is added after the medium has solidified in the plate. Alternatively, the test sample may be spread on the surface of the plates after the plates have cooled and solidified, and then covered with an overlay layer (swab or streak plate technique).
The inventive method may also be used in combination with the Membrane Filter (MF) method described above. In this method, the sample, which in most cases comprises an aqueous solution containing the biological material to be identified, is filtered through a micropore filter so that the biological materials are captured on the surface of the filter. The filter is then placed in a petri dish on the surface of the medium for incubation, to enable the biological materials on the surface to grow into visible colonies. The medium in the petri dish may be presolidified agar or pectin based medium, or alternatively, may be an absorbent pad soaked with liquid medium containing the necessary nutrients and reagents. This latter approach allows the inventive methods to be used without a separate solidifying agent in the medium, but still provides a hard surface for the biological materials to develop on so that they can grow as distinct, discrete colony-forming units similar to those that develop on a medium solidified with agar or other agents.
Incubation of the Test Medium
The inoculated test medium is incubated for a sufficient period of time and at a temperature sufficient to enable the individual microorganisms present in the sample to grow into detectable colonies. Suitable incubation conditions for growing microorganisms in a medium are well known in the art. Preferably, in the quantitative identification and differentiation of E. coli 0157 as described, the test medium is incubated for about 24-48 hours at a temperature of about 300°-40° C.
If desired, the selectivity of the method may be further improved by controlling the incubation temperature at 42° C., rather than between 300°-40° C. E. coli (including the strain 0157) grows well at 42° C., however, this temperature is inhibitory to the growth of many other related microbes. Utilizing this higher temperature may provide improved results for certain microorganisms by improving the selectivity, but at the same time will diminish the overall versatility of the general medium, since it does not give an accurate indication of the presence of certain other microbial types.
Unless inhibitors of the general microbial population are used, the general microbial population, (in addition to the non-coliform Enterobacteriaceae, general coliforms, E. coli and E. coli 0157) will also grow in the incubated test medium. Because microorganisms other than general coliforms and the various E. coli strains rarely produce β-galactosidase or β-glucuronidase, most of the general microbial population will normally show on a standard agar pour plate as white or colorless colonies.
Examination of the Test Medium and Enumeration of Microorganisms
General coliforms produce β-galactosidase, which acts upon the β-galactoside in the test medium, causing the β-galactoside to form an insoluble precipitate having a color in accordance with the particular β-galactoside used. Because the precipitate formed is insoluble in the test medium, it remains in the immediate vicinity of the β-galactosidase-producing microorganisms. As these microorganisms reproduce to form colonies, the colonies have the color produced by the β-galactoside.
Since most strains of E. coli also produce β-galactosidase and β-glucuronidase, insoluble precipitates of both the β-galactoside and β-glucuronide are formed by the action of the respective enzymes. The colonies of E. coli show as colonies having a color different from and contrasting with the color of the colonies of general coliforms, due to the presence of the contrastingly colored insoluble precipitate of the β-glucuronide. E. coli 0157, since it is one of the 3% of strains of E. coli that is glucuronidase negative, reacts in the same manner as the general coliforms and causes the formation of an insoluble precipitate having the same color as the precipitate formed by the general coliforms.
The colonies of those microorganisms that are sorbitol fermenters are further modified as a result of the acid produced from the sorbitol fermentation. A zone is created around these sorbitol-fermenting colonies, which zone is colored in accordance with the particular pH indicator utilized and the pH of the reaction medium. No zone is created around colonies that do not ferment sorbitol, such as E. coli 0157.
Since the specific chromogens, namely the β-galactoside and the β-glucuronide, and the specific pH indicator are selected so that the colors resulting from the incubation provide a visible contrast, the colonies of each type of microorganism present can be visually differentiated. Thus, for example, if 6-chloro-3-indolyl galactoside is used as the β-galactoside, 5-bromo-4-chloro-3-indolyl glucuronide is used as the β-glucuronide, and phenol red is used as the pH indicator in the test medium, E. coli 0157 colonies appear in the incubated medium as red colonies (CFU) surrounded by a noticeably reddish haze around the colony. The reddish haze around these colonies is caused by a small amount of enzyme leakage into the medium surrounding the colony, which leakage produces a slightly colored red "halo" around the colony, and is not formed as a result of a color change of the pH indicator. Other E. coli colonies appear as purple (resulting from the combination of red and blue colonies) colonies (CFU) surrounded by a yellow zone, which yellow zone is formed due to the reaction of the pH indicator to the acid produced upon fermentation. General coliforms appear as red colonies (CFU) surrounded by a yellow zone. Some non-coliform Enterobacteriaceae such as most Salmonella strains appear as colorless or white colonies (CFU) surrounded by a yellow zone, since most Salmonella ferment sorbitol with acid production, but do not produce either galactosidase or glucuronidase. Certain strains of some genera such as Salmonella or Shigella grow as light blue colonies due to glucuronidase (but not galactosidase) production. Other Enterobacteriaceae such as Proteus appear as colorless colonies without any zone surrounding these colonies, due to the lack of either enzyme production or acid fermentation of the sorbitol.
The colonies of each type of microorganism may then be enumerated by counting the colonies of each color combination, or by other methods known in the art for enumerating microorganisms on a test plate. The number of colonies of each type indicates the number of microorganisms of each type originally present in the sample before incubation. The versatility of the inventive method enables the quantitative identification and differentiation of as many of the biological materials as may be of interest in the particular test sample. For example, if only general coliforms, E. coli and E. coli 0157 are of interest in a particular sample, the colonies representing these bacteria may be enumerated, and in this event it is not necessary to also enumerate the colonies of other biological materials, such as Salmonella, Shigella and Proteus.
Thus, it will be appreciated that the invention as described may be used to quantitatively identify and differentiate multiple types of microorganisms in a single test sample simply by distinguishing various color combinations formed as a result of controlled reactions involving said microorganisms.
Optional Ingredients
The method of the present invention does not require inhibitors. However, as stated, the medium may be made more selective when used for the identification and differentiation of biological materials such as general coliforms, E. coli and E. coli 0157 by the addition of various compounds that are known to be inhibitory to the general microbial population, but have little or no effect on coliforms. For example, substances such as bile, sodium lauryl sulfate, desoxycholates and/or polyglycol ethers may be incorporated into the medium to inhibit the growth of bacteria not of interest to the particular test. Suggested concentrations of these compounds per liter of medium are: a) bile salts, about 1.0 g/liter, b) sodium lauryl sulfate, about 0.2 g/liter, c) sodium desoxycholate, about 0.2 g/liter, d) polyglycol ether, about 0.1 ml/liter. The addition of one or more of these compounds may reduce the background (non-Engerobacteriaceae) microorganisms present, thereby making a less cluttered plate, and may reduce the possibility of inhibition or interference by the non-Enterobacteriaceae organisms in the sample. It is also possible to eliminate the presence of some non-E. coli Enterobacteriaceae and/or coliforms by the addition of chemicals such as acriflavine, and/or antibiotics such as cefsulodin, cefoxime, novobiocin and similar inhibitory compounds known in the art. However, as with the inhibitors above, this approach reduces the ability of the medium to screen for and quantify those microorganisms inhibited or eliminated by these materials.
It is also possible to enhance the enzyme production of the general coliforms by the addition to the medium formulations of very small amounts of enzyme inducers. For example, a specific inducer for β-galactosidase is commercially available and is known chemically as isopropyl-β-D-thiogalactopyranoside (IPTG). Adding approximately 150 mg IPTG per liter of medium has a positive and noticeable effect on the speed of enzyme production for some species of coliforms.
EXAMPLE
Test plates were prepared containing the ingredients listed in the formula provided above, but with pectin substituted for agar as the gelling agent. The medium was inoculated with the respective bacteria as indicated in the following Table.
The Table describes the manner in which E. coli 0157, general coliforms, E. coli and the non-coliform Enterobacteriaceae, Proteus and Salmonella, may be distinguished when using the test medium described in the example above. As shown in the Table, when the inventive test medium is used in a test for the identification or differentiation of E. Coli 0157 in a sample containing general coliforms, or the E. coli and the non-coliform Enterobacteriaceae, Proteus and Salmonella, visual distinctions may be recognized for each of the specific colonies of the respective microorganisms. The versatility of the inventive method is not possible with the other test media described in the Table.
______________________________________
COMPARATIVE MEDIA
Media No.
(1) (2) (3) (4) (5) (6)
______________________________________
EC0157 red red white white blue white
red red no
haze zone zone
Other E. coli
purple red blue red blue blue
(most) yellow yellow yellow
zone zone zone
Coliforms
red red white red blue white
(most) yellow yellow yellow
zone zone zone
Proteus white white white white white white
(most) no no no
zone zone zone
Salmonella
white white white white or
white or
white or
(most) yellow yellow yellow
red red red
zone zone zone
______________________________________
(1) Media formula provided above.
(2) Media formula provided above, less 5bromo-4-chloro-3-indolyl
glucuronide.
(3) Media formula provided above, less 6chloro-3-indolyl galactoside.
(4) MacConkey sorbitolstandard formulation.
(5) MacConkey sorbitol plus 5bromo-4-chloro-3-indolyl galactoside.
(6) MacConkey sorbitol plus 5bromo-4-chloro-3-indolyl glucuronide.
While this invention has been primarily described in terms of its preferred embodiment, one skilled in the art will appreciate that the present invention can be further modified within the spirit and scope of this disclosure to enable the identification and differentiation of other biological materials present in samples of mixed populations. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. For example, the inventive technique may be used to quantitatively identify and differentiate any of a wide variety of biological materials, as long as those biological materials exhibit differences in enzyme specificity, and at least some of the biological materials exhibit differences in their respective abilities to ferment various carbohydrates at a selected pH in the presence of a suitable pH indicator for use at the pH. In the practice of the present invention, one need only determine that the particular chromogens to be utilized for the visual differentiation produce distinguishable colors upon reaction with the respective enzymes, and select an appropriate carbohydrate and pH indicator such that yet another visually distinguishable color is produced upon fermentation of the carbohydrate under the appropriate reaction conditions for the pH indicator.
In addition to the foregoing, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
What is claimed is:
1. A method for quantitatively identifying and differentiating specified biological materials in a test sample comprising a plurality of different biological materials, wherein a first one of said biological materials has enzyme specificity for a first chromogenic substrate, and a second one of said biological materials has enzyme specificity for a second chromogenic substrate, and wherein at least some of said biological materials in said test sample are capable of fermenting a carbohydrate, said method comprising the steps of:providing a test medium capable of forming a matrix or a solid surface with said test sample, said test medium comprising said first chromogenic substrate and said second chromogenic substrate, said first chromogenic substrate capable of forming a water insoluble compound of a first color upon reacting with an enzyme from said first biological material, and said second chromogenic substrate capable of forming a water insoluble compound of a color contrasting with said first color upon reacting with an enzyme from said second biological material; a fermentable component capable of acidifying a portion of the medium upon fermentation, said component comprising a carbohydrate, and said fermentation caused by carbohydrate-fermenting components of said test sample; a pH indicator for causing a third color to be formed upon reaction to said acidification, said third color comprising a colored zone around said carbohydrate-fermenting components; and a nutrient base medium; adjusting the pH of said test medium to a range conducive for color change of the pH indicator upon acidification of said portion of the medium; inoculating said test medium with said test sample; incubating said test medium under conditions conducive for growth of colonies or activity of said biological materials, to thereby produce said contrasting colored water insoluble compounds; examining said test medium for the presence of colonies having said first color, and having said third colored zone discernable and distinguishable thereabout, said colonies being colonies of said first biological material, and being carbohydrate fermenters; for the presence of colonies having a second color, contrasting with said first color, and having said third colored zone discernable and distinguishable thereabout, such colonies being colonies of said second biological material, and being carbohydrate fermenters; and for the presence of colonies having said first color, and not having said second color or said third colored zone discernable and distinguishable therewith, such colonies being colonies of a third biological material; and enumerating each of said colonies.
2. The method of claim 1, including the step of further examining said test medium for the presence of colonies having a color other than said first and second colors, or being colorless, with or without said third colored zone, such colonies being colonies of at least a fourth biological material.
3. The method of claim 1, including the step of further examining said test medium for the presence of colonies not having either of said first and second colors, with or without the third colored zone, such colonies being colonies of at least a fourth biological material; and for the presence of colonies having a fourth color, with or without the third colored zone, such colonies being colonies of at least a fifth biological material.
4. The method of claim 1, wherein said first chromogenic substrate comprises 6-chloro-3-indolyl galactosidase, said second chromogenic substrate comprises 5-bromo-4-chloro-3-indolyl glucuronidase, said carbohydrate comprises sorbitol and said pH indicator comprises phenol red.
5. The method of claim 1, wherein the test medium further comprises at least one growth inhibitor.
6. The method of claim 5, wherein said at least one growth inhibitor comprises bile, sodium lauryl sulfate, sodium desoxycholate or polyglycol ether.
7. The method of claim 1, wherein the test medium further comprises at least one of acriflavine and antibiotics.
8. The method of claim 1, wherein the test medium further comprises a reaction inducer.
9. The method of claim 1, wherein said reaction takes place at an incubation temperature of 30°-40° C., and said incubation continues for 24-48 hours, and wherein said pH of the test medium is about 7.2.
10. A test medium for detecting the presence of specified biological materials in a test sample comprising a plurality of different biological materials, said test medium comprising:a nutrient base medium; a first chromogenic substrate capable of forming a water insoluble component of a first color upon reacting with an enzyme from a first biological material; a second chromogenic substrate capable of forming a water insoluble compound of a color contrasting with said first color upon reacting with an enzyme from a second biological material; a fermentable component capable of acidifying a portion of the test medium upon fermentation, said fermentable component comprising a carbohydrate, and said fermentation caused by carbohydrate-fermenting biological materials in said test sample; and a pH indicator for causing a third color to be formed upon reaction to said acidification, said third color comprising a colored zone around said carbohydrate-fermenting biological materials.
11. The test medium of claim 10, wherein said nutrient base medium comprises a solid, a gel, a solution for forming a solid or an absorbent substrate having nutrients absorbed thereto.
12. The test medium of claim 10, wherein said nutrient base medium comprises a gelling agent selected from the group consisting of agars, pectins, carrageenans, alginates, locust bean, xanthin, guar and gellen.
13. The test medium of claim 10, wherein said test medium further comprises an enzyme inducer.
14. The test medium of claim 10, wherein said test medium includes a growth inhibitor.
15. The test medium of claim 10, wherein said first chromogenic substrate comprises a β-galactoside, said second chromogenic substrate comprises a β-glucuronide, said fermentable component comprises sorbitol, and said pH indicator comprises phenol red.
16. The test medium of claim 10, wherein said nutrient base medium comprises peptones.
17. A method for detecting the presence of and quantitatively identifying and differentiating E. coli 0157, other E. coli strains not including E. coli 0157, general coliforms and non-coliform Enterobacteriaceae in a test sample, comprising the steps of:providing a test medium capable of forming a matrix or a solid surface with said test sample, said test medium comprising a chromogenic β-galactoside capable of forming a water insoluble compound of a first color upon reacting with β-galactosidase; a chromogenic β-glucuronide capable of forming a second water insoluble compound of a color contrasting with said first color upon reacting with β-glucuronidase; a fermentable component capable of acidifying a portion of the medium upon fermentation, said fermentable component comprising sorbitol, and said fermentation caused by the action of sorbitol-fermenting components of said test sample with sorbitol; a pH indicator capable of causing a third color to be formed in response to said acidification, said third color comprising a colored zone around said sorbitol-fermenting components; and a nutrient base medium; adjusting the pH of said test medium to a range conducive for color change of the pH indicator upon acidification of said portion of the medium; inoculating said test medium with said test sample; incubating said test medium under conditions conducive for growth of colonies of general coliforms having β-galactosidase activity but not β-glucuronidase activity, colonies of E. coli having both β-glucuronidase activity and β-galactosidase activity, colonies of E. coli 0157 having β-galactosidase activity but not β-glucuronidase activity, and colonies of non-coliform Enterobacteriaceae, to produce contrasting colored precipitates corresponding to said activity; examining said test medium for the presence of colonies having said first color and having said third colored zone visibly discernable and distinguishable thereabout, said colonies being colonies of general coliforms having β-galactosidase activity but not β-glucuronidase activity, and being sorbitol fermenters; for the presence of colonies having a second color, and having said third colored zone discernable and distinguishable thereabout, said colonies being colonies of E. coli having both β-glucuronidase activity and β-galactosidase activity, and being sorbitol fermenters; for the presence of colonies having said first color, and not having said second color or said third colored zone discernable and distinguishable therewith, said colonies being colonies of E. coli 0157 having β-galactosidase activity but not β-glucuronidase activity, and being sorbitol non-fermenters; and for the presence of colonies not having either of said first and second colors, with or without said third colored zone discernable and distinguishable thereabout, said colonies being non-coliform Enterobacteriaceae having neither β-galactosidase activity nor β-glucuronidase activity; and enumerating each of said colonies.
18. The method of claim 17, wherein said non-coliform Enterobacteriaceae colonies having neither β-galactosidase activity nor β-glucuronidase activity are separately enumerated dependent upon the presence of said third colored zone discernable and distinguishable thereabout, said colonies having said third colored zone thereabout being substantially colonies of Salmonella, and said colonies not having said third colored zone thereabout being substantially colonies of Proteus.
19. The method of claim 18, wherein said test medium is further examined for the presence of colonies of a fourth color, with or without said third colored zone discernable and distinguishable thereabout, said colonies being substantially Shigella and some strains of Salmonella.
20. The method of claim 17, wherein said chromogenic β-galactosidase substrate comprises 6-chloro-3-indolyl galactosidase.
21. The method of claim 17, wherein said chromogenic β-glucuronidase substrate comprises 5-bromo-4-chloro-3-indolyl glucuronidase.
22. The method of claim 17, wherein said pH indicator is phenol red, and wherein the medium is adjusted to a pH of about 7.2.
23. The method of claim 17, wherein the test medium further comprises growth inhibitors.
24. The method of claim 23, wherein said inhibitors comprise at least one member selected from the group consisting of bile, sodium lauryl sulfate, sodium desoxycholate and polyglycol ether.
25. The method of claim 17, wherein the test medium further comprises at least one of acriflavine and antibiotics.
26. The method of claim 17, wherein said test medium further comprises a reaction inducer.
27. The method of claim 26, wherein said reaction inducer comprises isopropyl-β-D-thiogalactopyranoside.
28. The method of claim 22, wherein said reaction takes place at a temperature of 30°-40° C., and said incubation continues for 24-48 hours, and wherein the pH of said test medium is about 7.2.
29. The method of claim 17, wherein said nutrient medium comprises a solid, a gel or a solution for forming a solid.
30. The method of claim 29, wherein the nutrient medium forms a solid support from a gelling agent, said gelling agent selected from the group consisting of agar and pectin.
31. A test medium for detecting the presence of E. coli 0157, other E. coli strains not including E. coli 0157, general coliforms and non-coliform Enterobacteriaceae in a test sample, comprising:a nutrient base medium, said nutrient base medium comprising a solid, a gel or a solution for forming a solid; a chromogenic β-galactosidase substrate capable of forming a water insoluble component of a first color upon reacting with β-galactosidase, said chromogenic β-galactosidase substrate selected from the group consisting of 6-chloroindolyl-β-D-galactoside, 5-bromo-6-chloro-3-indolyl-β-D-galactoside, 6-chloro-3-indolyl-β-D-galactoside, 4,6-dichloroindolyl-β-D-galactoside, 6,7-dichloroindolyl-β-D-galactoside, 4,6,7-trichloroindolyl-β-D-galactoside, 2-naphthyl-β-D-galactoside, and salts thereof; a chromogenic β-glucuronidase substrate capable of forming a water insoluble component of a color contrasting with said first color upon reacting with β-glucuronidase, said chromogenic β-glucuronidase substrate selected from the group consisting of 5-bromo-4-chloro-3-indolyl-β-D-glucuronide, indoxyl-β-D-glucuronide, 4-chloro-3-indolyl-β-D-glucuronide, 5-bromo-3-indolyl-β-D-glucuronide and N-methyl-3-indolyl-β-D-glucuronide, and salts thereof; a pH indicator; and sorbitol.
32. The test medium of claim 31, wherein said nutrient base medium comprises a gelling agent selected from the group consisting of agars, pectins, carrageenans, alginates, locust bean, xanthin, guar and gellen.
33. The test medium of claim 31, wherein said test medium further comprises an enzyme inducer.
34. The test medium of claim 33, wherein said enzyme inducer comprises isopropyl-β-D-thiogalactopyranoside.
35. The test medium of claim 31, wherein said pH indicator is phenol red.
36. The test medium of claim 31, wherein said medium includes an inhibitor selected from the group consisting of bile salts, sodium lauryl sulfate, sodium desoxycholate, polyglycol ethers and mixtures thereof.
| 1996-03-26 | en | 1998-03-10 |
US-80659391-A | Flexible non-planar graphite sealing ring
ABSTRACT
A flexible non-planar graphite sealing ring is used to control leakage in a fluid handling device that is caused by a shaft extending through the wall of the device. The flexible graphite sealing ring comprises a chevron-shaped non-planar cross section having approximately complementary inner and outer end faces that are made from laminating sheets of graphite foil in layers transverse to the ring's axis. A plurality of flexible graphite rings are inserted over the shaft and into the stuffing box, occupying the space area between the shaft and the stuffing box. The flexible graphite sealing rings are oriented so that each ring's inner end face adjoins the outer end face of another ring. Upon application of a compressive force, either by internal pressure or by externally applied mechanical loading, the interaction between the dissimilar end faces cause an enhanced interference fit between the shaft and the stuffing box forming a seal.
FIELD OF INVENTION
This invention relates to a non-planar flexible graphite sealing ring used to minimize fluid leakage in a valve stuffing box that occurs between the valve stem and the stuffing box housing.
BACKGROUND OF THE INVENTION
In a fluid handling device, such as a pump or a valve, where a moving stem or shaft extends through a wall of the device, a seal is required at that point to prevent the fluid from leaking from the device. Leakage from such fluid handling devices is undesirable for obvious health, air quality, and safety reasons. For example, a leak of a toxic or flammable fluid could pose a direct threat to human life. Today's heightened environmental consciousness is another influential driving force behind minimizing leaks of toxic or other potentially harmful liquids or gasses onto the ground or into the atmosphere.
Accordingly, such fluid handling devices are often sealed by placing a formed packing material around the shaft, and containing the packing material in the compressed state in a stuffing box. Ideally, the packing material selected should be resilient such that it deforms under compression to conform to the interior of the stuffing box and forms a tight interference seal against the shaft. The packing material should also present a low friction surface to the moving shaft and be stable under the environmental conditions to which it may be exposed. It is also desirable that the packing material act to keep the shaft clean and clear of debris by wiping the surfaces of the shaft as the shaft is passed through the stuffing box. Preferably, the packing is a self energized seal, i.e., that it seals by application of pressure on the seal. It is also desirable that the packing material itself be resistant to fire since many applications are for petrochemical service where fire may be a concern.
Flexible graphite is known in the art and has long been employed as a packing material to form seals for the stuffing box assembly of pumps, valves and like fluid handling devices. Flexible graphite refers to graphite which has been exfoliated and recompressed to a coherent body. The advantages of using graphite as a packing material lies in its excellent thermal stability and chemical resistance. Graphite is also a low friction composition that has commonly been used as a lubricant in certain applications. However, as practiced in the art, flexible graphite has not always proven to be an adequate sealing material due to the lack of resiliency inherent in the particular form used.
One such form of flexible graphite is that of a preshaped ring made by compressing in a closed die a ribbon or tape of graphite that has been wrapped circumferentially in several layers around a shaft. This spiral wrapped form of flexible graphite comprises an anisotropic structure having its bonding planes oriented parallel to the shaft axis. Such flat rings may also be made by laminating exfoliated graphite particles or sheets in a flat sheet and cutting flat gaskets from such a sheet.
The rings are used by stacking several rings over the stem of the fluid handling device such that the rings occupy the annular space between the shaft and the stuffing box housing. A metal collar is then inserted over the stem and is tightened to compress the graphite rings so that the rings deform laterally. An interference fit is formed against the shaft and the interior wall by applying a compressive force to the top of the ring stack.
A shortcoming of this form of flexible graphite lies in its limited resiliency when subjected to an axial compression force. The ends of the ring are flat and they spread laterally only a small amount in response to compression. This lateral spreading is controlled by Poisson's ratio for the material. High compressive forces are required to maintain a good seal. In addition, only the rings near where the force is applied seal due to poor transfer of load between the rings. In one type of valve, a compressive force of about 400 kg/cm2 (5600 psi) may be required to get an interference fit. Even so, traces of leakage may be detected immediately or after limited use.
Flexible graphite seals made from exfoliated graphite have also included braided graphite yarns. Such seals are typically made by wrapping the braided graphite around a shaft. Individual rings may be formed by cutting a helix of braided graphite.
A somewhat self energizing seal is made with a stack of rings, each of which has a wedge shaped transverse cross section. Alternating rings have greater thickness at the inside diameter and outside diameter, respectively. Longitudinal compression on a stack of such rings in a seal tends to wedge alternating rings inwardly and outwardly for sealing against the shaft and stuffing box, respectively.
A self energizing seal which is better than a flat ring has been made of materials such as polytetrafluoroethylene (Teflon). In cross section each side of the ring has a chevron shape. The angles of the chevron are different on the opposite end faces of the ring. When the rings are compressed, the concave side of the chevron is spread laterally by the convex side and the edges of the chevron tightly engage the shaft and stuffing box, forming a tight seal. Teflon forms a good seal, but has temperature limitations and cannot be used above about 260° C.
It would be desirable to form graphite chevron seals, but they have never been made satisfactorily. When such seal rings are formed from circumferentially wound graphite, the planes of weakness extend in the direction of the shaft axis and the rings break apart during the forming operation or when stressed during use.
It is, therefore, highly desirable to provide a flexible graphite packing ring that is sufficiently resilient to allow the degree of deformation necessary to provide a tight interference fit under compression and be strong enough to resist compressive forces. It is also desirable that the flexible graphite packing material be both simple to install and operate.
BRIEF SUMMARY OF INVENTION
There is, therefore, provided in practice of this invention according to a presently preferred embodiment, a flexible non-planar graphite sealing ring capable of sealing a shaft that extends beyond the wall of a fluid handling device and is contained in a stuffing box housing. The sealing ring comprises a non-planer configuration having approximately complementary top and bottom end faces. The cooperation of these end faces, when stacked end-to-end and subjected to a compressive force, causes each ring to expand and force itself against both the shaft and interior wall of the stuffing box.
The flexible non-planar graphite sealing ring has planes of lamination bonding transverse to the shaft axis and the applied compressive force. The graphite sealing ring is made from exfoliated graphite by compressing the graphite particles into sheets of foil, stacking the foil, and then laminating the graphite foil stacks by applying a compression force transverse to the planes of the foil sheets. The flexible graphite sealing ring produced in this manner is better able to accommodate the degree of lateral deformation, under compression, inherent in the ring's non-planar configuration and provide the interference fit needed to form an adequate seal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross section of a valve and the flexible non-planar graphite sealing rings provided in practice of this invention.
FIG. 2 is a cross section of the stuffing box housing, the shaft and the flexible non-planar graphite sealing rings provided in practice of this invention.
FIG. 3 and 4 are cross sections of alternative non-planar ring configurations.
DETAILED DESCRIPTION
In an exemplary embodiment the graphite packing of the present invention is used to minimize leakage in fluid handling devices caused by the insertion of a shaft through the wall of the device and into the fluid. An exemplary fluid handling device is a globe valve 10 as illustrated in FIG. 1. The valve comprises a body 12 having a fluid passage through which the liquid or gas can flow. A shaft or stem 14 extends from outside into the body and is attached to a plug 16 within the valve body which selectively opens or closes the fluid passage through the valve. The shaft exits the body by passing through a bonnet 18 comprising a stuffing box 20.
The stuffing box comprises a cylindrical housing having a narrowed inner end 22 near the body and an open outer end 24 at the outer surface (FIG. 2). A plurality of graphite packing rings 26 fit around the shaft and reside between the shaft and the stuffing box's interior wall 28. A packing gland 30 fits on top of the graphite packing rings and serves to apply a compressive force to the packing rings when tightened to the bonnet.
In such a valve the liquid or gas flow being controlled is generally at a pressure significantly greater than atmospheric pressure. Accordingly, since the shaft passes from the body to the atmosphere, leakage occurs at that point where the shaft enters the bonnet. The leakage is controlled though an interference fit achieved by applying a compressive force to the non-planar graphite packing rings contained in the stuffing box.
The illustrated valve is conventional and merely exemplary of a variety of valves in which the novel sealing rings may be employed. Thus, the packing is equally applicable to gate valves, butterfly valves, control valves, or other rising stem or quarter turn valves where a shaft seal is required. Such a packing may also be used in the more dynamic seals of a pump or other rotating machinery or in hydraulic or pneumatic actuators. It is particularly useful for high temperature applications or in the presence of corrosive materials.
In an exemplary embodiment, a flexible graphite packing material used in controlling leakage in fluid handling devices comprises a plurality of non-planar graphite pressure packing rings 32 having a chevron-shaped cross section with approximately complementary inner 34 and outer end faces 36, a graphite bottom packing ring 38 having a cross section with a convex V-shaped outer end face 40 and a planar inner end face 42 , and a graphite top packing ring 44 having a cross section with a concave V-shaped inner end face 46 and a planar outer end face 48 as better seen in the larger longitudinal cross section of FIG. 2.
The graphite packing rings of the present invention are made from exfoliated graphite particles. Exfoliated graphite is made by treating graphite flakes with an intercalation agent, typically a mixture of sulfuric and nitric acids, and exposing the treated graphite flakes to an elevated temperature, typically in excess of 1000° C. A typical process for making exfoliated graphite is shown in U.S. Pat No. 3,404,061. These materials and products made from them are available from Polycarbon, Inc., for example.
To make the flexible graphite rings of this invention, the exfoliated graphite particles are compressed into graphite foil sheets having a size at least as large as the diameter of the desired ring. The compressing can be carried out either by passing the exfoliated graphite particles through a series of calender rolls or by compacting the exfoliated graphite in a hydraulic press. Rolling is preferred since it appears to be important to have orientation of the graphite in the plane of the foil as obtained in rolling for good strength. The compression of the graphite serves to reduce the thickness and raise the density of the precompact to the desired graphite foil properties. It is desirable that the resulting graphite foil have thickness in the range of from 0.2 mm to 2.0 mm, while the density of the finished foil is in the range of from 0.5 gm/cm3 to 1.5 gm/cm3.
The graphite foil sheets are stacked in layers and configured into a donut shape by cutting a hole through the middle of the sheets and trimming the outer marginal edge to conform to the size of the ring desired. The configured sheets are then laminated and bonded together by compressing the sheets together in the axial direction of the ring. The graphite sheets are introduced into a closed die mold comprising the particularly desired non-planar shape and compressed in the direction of its axis at a pressure in the range of from 100 kg/cm2 to 550 kg/cm2. It is desired that such a compressive force produce a flexible graphite laminate ring having a density in the range of from 1.2 gm/cm3 to 2.3 gm/cm3. Typically, the compression of the sheets in the final pressing to obtain good bonding between adjacent sheets and raise the total density of the material is about ten to one.
The laminated sheets need not be of uniform thickness through the stack. Thus, for example, it may be desirable to have sheets near the top and bottom which are relatively thinner and intermediate sheets which are relatively thicker. The sheets may also be of different densities through the stack to be laminated. Such variations in thickness and density may provide better formability and properties of the ring.
Each graphite pressure ring produced in this manner comprises a chevron-shaped cross section having a convex circumferential ridge located on the outer end face of the ring, a complementary V-shaped groove located on the ring's inner end face, and cylindrical inside and outside surfaces. The ring's outer end face comprises two cones, one converging and the other diverging, descending from the chevron's apex at an approximately 90 degrees included angle from one another. The ring's inner end face comprises an approximately complementary circumferential V-shaped groove having an included angle of approximately 70 degrees. The dissimilarity between the included angle of the outer and inner end face assures a space between the outer end face of one pressure ring and the inner end face of an adjacent ring upon stacking the pressure rings face to face with each other in the stuffing box.
The top graphite packing ring produced in this manner has a planar outer end face, an inner end face having a circumferential V-shaped groove, and cylindrical inside and outside surfaces. The V-shaped groove has an included angle of approximately 70 degrees and intersects the ring's inside and outside surfaces, being deeper in the middle of the ring cross section.
The graphite bottom packing ring produced in this manner comprises a outer end face having a convex circumferential ridge similar to the ridge around the pressure packing rings, a planar inner end face, and cylindrical inside and outside surfaces. The circumferential ridge has an included angle of approximately 90 degrees. The two end rings of the stack may be formed from die trimmed braided graphite packing material in a similar geometry.
The flexible graphite rings have an inside diameter approximately equal to the diameter of the shaft and an outside diameter approximately equal to the inside diameter of the stuffing box housing. A exemplary embodiment of the flexible non-planar graphite sealing rings has an inside diameter of approximately 3.5 cm, an outside diameter of approximately 6.0 cm, and a height of approximately 1.3 cm.
A graphite ring produced in this manner comprises sheets of an anisotropic graphite structure having planes of lamination bonding transverse to its axis and the axis of the shaft. In a chevron ring, the bonding faces are in chevron shapes themselves, parallel to the end faces of the ring. A structure having planes of bonding transverse to the direction of a compressive force has greater strength preventing longitudinal splitting and is capable of elastic deformation and lateral spreading for forming an interference fit around a shaft and within a stuffing box to form a fluid tight seal.
Non-planar graphite rings made from circumferentailly wound graphite ribbon have their planes of lamination parallel to the shaft axis. Such rings are subject to longitudinal fissure under compression. The spiral rings split longitudinally at the apex of the chevron.
The flexible graphite non-planar sealing rings are used to control leakage in a fluid handling device by first inserting the graphite bottom ring over the shaft and sliding it inside the stuffing box oriented such that the ring's planar inner end face lies flatly against the inner face of the stuffing box and the ring's circumferential convex ridge is directed upwards toward the stuffing box's open outer end. Next, a graphite pressure ring is inserted over the shaft and slid inside the stuffing box oriented such that the V-shaped groove or other non-planar inner end face of the ring is directed downwardly and rests against the bottom ring's outer end face having an approximately complementary circumferential convex ridge.
A plurality of identical graphite pressure rings are then inserted over the shaft and slid inside the stuffing box oriented such that the V-shaped groove of the inner end face of each ring is directed downwardly (inwardly toward the pressure within the packing) and rests against the approximately complementary convex ridge of the outer end face of each adjoining pressure ring. Finally, the graphite top ring is inserted over the shaft and slid inside the stuffing box. The top packing ring is oriented such that its V-shaped interior end face is directed against the approximately complementary convex ridge of outer end face of the last pressure packing ring. The top packing ring's planar outer end face is directed towards the stuffing box's outside open end.
After all of the graphite packing rings are inserted into the stuffing box the packing gland 11 is inserted over the shaft and placed against the planar outer end face of the graphite top packing ring. The packing gland is then bolted to the top of the bonnet 18 and tightened. This tightening draws the packing gland toward the body of the valve and imposes a compressive force upon all of the graphite sealing rings. This compression forces the V-shaped groove of each ring's inner end face against the convex ridge of each adjoining ring's outer end face. Since the convex ridge of each outer end face has an included angle greater than that of the V-shaped groove of each adjoining outer end face the effect of such compression causes the V-shaped groove to flare and expand in a direction transverse to its axis. This expansion forces the pressure ring's inside surface against the fluid device's shaft and forces the pressure ring's outside surface against the interior wall of the stuffing box, thus sealing the device through an interference fit. Accordingly, further tightening of the packing gland increases the compressive force upon the pressure rings which results in a greater interference fit and a better seal. Additionally, due to the geometry of the seal, increases in internal pressure increase the effectiveness of sealing.
Flexible graphite seal rings as described can provide excellent sealing to elevated temperatures, much higher than the 260° C. limit of Teflon. When protected from oxidation, graphite seals may be used to temperatures over 800° C. Even when exposed to oxidation they may be used temperatures near 550° C. The seal is compliant and self energizing under relatively low compressive forces. For example, to obtain sealing with flat graphite sealing rings, pressures of about 400 kg/cm2 are needed to effect a good seal. A pressure of only about 110 kg/cm2 is needed for a very tight seal with a flexible graphite chevron seal as provided in practice of this invention.
This is not a trivial difference. The lower compression stress means that a much smaller valve operating motor or gear is needed as compared with a prior flat seal. The friction on the shaft due to the seal is much smaller, typically about one third as much as with flat seal rings. The valve operator may be as much as one third of the cost of a large valve and cost savings can be significant.
In an exemplary embodiment, only three sealing rings and a pair of mating end rings are used in a valve seal. Larger numbers of seal rings may be used for redundancy. Three rings has been shown to be adequate in a volatile organics fugitive emissions test. In such a test three rings retained methane at a pressure of about 31 kg/cm2 (300 psi) with no detectable leakage. As can be readily realized, such a tight seal is quite significant when toxic materials are being handled. Furthermore, because of its high temperature resistance, such a seal can be relied on to maintain its integrity in fire situations where lower temperature materials might fail.
It might also be noted that the rings may be diagonally split at one side so that they may be placed around a shaft by twisting the ring open rather than placed over the end of the shaft. This is needed at times since it may not be possible to completely disassemble structure from the end of the shaft for replacing the seal rings. Such a split ring may be used since the sealing is at the lip of the chevron and multiple rings in the seal minimize potential leakage paths.
The flexible graphite used for forming the seal rings may not be pure exfoliated graphite. It is sometimes desirable to introduce corrosion inhibitors in the graphite, such as zinc, barium molybdate or various proprietary phosphate inhibitors. Such corrosion inhibitors may be commingled with the graphite particles used for forming the sheets, or may be provided on the surfaces of the completed rings.
Although but only one exemplary embodiment of non-planar flexible graphite sealing rings for sealing the shaft of a fluid handling device has been described above, many variations will be apparent to those skilled in the art. For example, FIG. 3 illustrates a flexible graphite sealing ring comprising an alternative non-planer cross section having approximately complementary curved inner and outer end faces. In this embodiment the cross section comprises a convex outer end face having a larger radius than that of the ring's concave inner end face. When subjected to a compression force the interaction of the packing ring's adjoining inner and outer end faces causes an enhanced interference fit, forming a seal in much the same manner as the chevron cross-section of the exemplary embodiment.
FIG. 4 illustrates a flexible graphite sealing ring comprising an alternative cross section having approximately complementary planar inner and outer end faces. In this embodiment the cross section comprises a conical outer end face that descends from the outside surface towards the inside surface. The conical inner end face descends from the outside surface toward the inside surface in an approximately complementary fashion. The outer end face descends from the outside surface at a greater angle than that of the inner end face. The cross section of the ring is, therefore, somewhat wedge shaped. When subjected to a compression force the interaction between adjoining inner and outer end faces causes the inside surface adjacent to the outer end face to be forced against the shaft and outside surface near the inner end face to be forced against the interior wall of the stuffing box, thus generating an enhanced interference fit and providing the necessary seal. Another pair of rings with opposite wedging action may be used for sealing against the wall of the stuffing box.
Since many such modifications may be made, it is to be understood that within the scope of the following claims, this invention may be practiced otherwise than specifically described.
What is claimed is:
1. A shaft seal comprising:a shaft; a stuffing box around the shaft; a packing between the shaft and stuffing box comprising a graphite ring having at least one non-planar end face; and means engaging each face of the ring for biasing at least one edge of the non-planar face of the ring toward the shaft or stuffing box for sealing against the shaft or stuffing box respectively; and wherein the ring is formed substantially entirely of axially compressed exfoliated graphite having bonded faces transverse to the axis of the shaft.
2. A shaft seal as recited in claim 1 wherein the non-planar end face of the ring comprises a concave V-shaped chevron in transverse cross section, and wherein the means for engaging the concave V-shaped face of the ring comprises a convex V-shaped face having an included angle greater than the included angle of the concave chevron face of the ring for biasing the chevron in a spreading direction.
3. A shaft seal as recited in claim 1 wherein the end faces of the ring comprise a chevron in transverse cross section, one end face of the chevron being convex and the other end face being concave, the included angle of the convex chevron being greater than the included angle of the concave chevron.
4. A shaft seal as recited in claim 1 wherein the end faces of the ring each comprise an arc in transverse cross section, one arc being convex and the other concave, the curvature of the convex arc being greater than the curvature of the concave arc.
5. A shaft seal as recited in claim 1 wherein the graphite ring has a density in the range of from 1.2 gm/cm3 to 2.3 gm/cm3.
6. A flexible graphite shaft packing for sealing a shaft extending through the wall of a fluid handling device, the shaft packing comprising a sealing ring made substantially entirely of exfoliated graphite having non-planar end faces and made by pressing and laminating sheets of exfoliated graphite foil having faces of lamination between adjacent sheets of graphite transverse to the shaft axis.
7. A graphite shaft packing as recited in claim 6 wherein the non-planar sealing ring comprises a cross section having approximately complementary curved or toroidal shaped inner and outer end faces.
8. A graphite shaft packing as recited in claim 6 wherein the non-planar sealing ring comprises a chevron shaped cross section having approximately complementary inner and outer end faces.
9. A graphite shaft packing as recited in claim 8 wherein the ring comprises an outer end face having a convex circumferential ridge with an included angle of approximately 90 degrees and a inner end face having an approximately complementary V-shaped circumferential groove with an inside angle of approximately 70 degrees.
10. A graphite shaft packing as recited in claim 9 wherein the graphite ring has a density in the range of from 1.2 gm/cm3 to 2.3 gm/cm3.
11. A flexible graphite shaft packing for sealing the shaft of a fluid handling device, the shaft packing comprising a sealing ring having a chevron-shaped cross section with approximately complementary inner and outer end faces, the sealing ring being made substantial entirely from sheets of laminated graphite foil having planes of lamination between adjacent sheets of graphite extending in a chevron pattern parallel to the end faces of the ring.
12. A valve comprising:a valve body including a fluid flow passage through the valve; means for closing the fluid flow passage; a shaft for actuating the means for closing the fluid flow passage; and a seal between the shaft and valve body, the seal comprising:an annular cavity surrounding the shaft; a plurality of packing rings in the cavity, each of the packing rings having a concave non-planar end face and a convex non-planar end face, and being formed substantially entirely of axially compressed exfoliated graphite having lamination bonded faces transverse to the axis of the shaft; and means engaging each face of the rings for biasing at least one edge of a concave non-planar face of each ring toward the shaft for sealing against the shaft.
13. A valve as recited in claim 12 wherein each of the packing rings has a chevron cross section with a convex V-shaped end face and a concave V-shaped end face approximately complementary to the convex end face, and wherein the lamination bonded faces of the ring are V-shaped and approximately parallel to the end faces of the ring.
| 1991-12-12 | en | 1993-04-13 |
US-61285590-A | Medical ultrasound contrast agent and method of using same
ABSTRACT
A medical ultrasound contrast agent and method of using the same wherein the contrast agent comprises a pharmaceutically acceptable carrier in combination with a substantially solid, radioactively opaque, biodegradable particle. The particle is of a size allowing it to be passed through the lungs to the left side of the heart where it may be visualized by conventional medical ultrasound.
FIELD OF THE INVENTION
The present invention relates to a medical ultrasound contrast agent and method of using the same, and more particularly to a medical ultrasound contrast agent that is completely biodegradable and that is capable of passing through the small blood vessels of the lungs to allow ultrasonic imaging of the left side of the heart.
BACKGROUND OF RELATED ART
In a normal human being, blood flows from the veins of the body to the right heart chambers. The blood then passes through the lungs (where the red cells pick up oxygen), back to the left heart chambers, and then out of the left heart through the aorta. This sequence of blood flow and the passage through which the blood moves through the body can be studied by ultrasonic imaging, a conventional technique which translates the reflection of sound waves into a visual image. Over the past decade, there has been an interest in cardiology in the development of an ultrasonic contrast agent that is capable of passing through the small vessels of the lungs. An ultrasound contrast agent capable of passing through the small blood vessels of the lungs would allow study of the left side of the heart with conventional medical ultrasound technology, e.g. echocardiography or vascular ultrasound.
One common and clinically useful method of studying the right heart chambers involves the injection of small bubbles, created by shaking or agitating liquid, into the cardiovascular system. These bubbles are generally larger than 10 microns. Although these microbubbles are easily visualized by ultrasound in the right heart chambers, they are filtered out by the capillaries of the lungs and, thus, are not transferred to the left heart chambers. Therefore, they can not and do not enhance ultrasound imaging of the left heart chambers. Two contrast agents are currently under investigation in the United States which also create small microbubbles that are allegedly able to pass through the lungs. However, these microbubbles have been known to pass back into solution under the high pressure of the left heart, and neither agent has been approved by the FDA for general use. See, Shapiro, J. R. et al., "Prospects of Transpulmonary Contrast Echocardiography," The American College of Cardiography, No. 0735-1097 (1989).
Another example of an ultrasound contrast agent is described in PCT International Application No. PCT/US84/00135 by Feinstein. This application discloses a method of ultrasonic imaging which comprises injecting microparticles or sonicated microbubbles into the circulatory system of an animal or human. The microparticles are formed from an amino acid polymer matrix with magnetic particles embedded therein to reflect intense patterns of ultrasonic waves. While such particles may enhance ultrasonic imaging, they are not biodegradable.
Similarly, a paramagnetic contrast agent for nuclear magnetic resonance and ultrasound is disclosed in European patent application, publication nos. 0186947 and 0184899. This agent uses as a carrier, a water-insoluble macro molecular material comprising a polymeric or polymerized carbohydrate or a polymerized sugar alcohol or derivative therof. These disclosures do not disclose an ultrasonic contrast agent that is biodegradable.
One important use of a left heart ultrasonic imaging agent is in the diagnosis of coronary artery disease, the major cause of death in developed countries. The coronary arteries arise from the aorta and feed the heart muscle. When coronary artery disease blocks blood flow to a portion of the heart, that portion of the heart is in danger. Currently, thallium nuclear scintigraphy is the only noninvasive method of evaluating myocardial blood flow. Thallium scintigraphy is expensive, requires a nuclear isotope, and does not give an evaluation of cardiac performance (as an ultrasound image does).
Thus, the need exists for an ultrasound contrast agent that is safe, reliable, biodegradable and that enhances visualization of vascularized organs and typcially the left heart.
SUMMARY OF THE INVENTION
The present invention is directed to methods for enhancing ultrasound images of vascularized organs within an animal body using biodegradable, echogenic, size-selected particles, and pharmaceutical compositions for effecting same. In a preferred embodiment, the biodegradable, echogenic, size-selected particles are starch microspheres having a diameter of 7 to 8 microns and find particular utility in ultrasonic visualizing of the heart, and preferably the left chambers of the heart.
With the ultrasonic contrast agent of the present invention, myocardial contrast is possible through simple intravenous injection. Furthermore, because the contrast imaging agent of the present invention is capable of passing through the lungs, it is possible to observe areas of the heart exhibiting different amounts of blood flow by examining their different intensities under ultrasonic imaging.
The contrast agent of the present invention, therefore, has a number of uses. One example is the study of the effects of exercise or medications on the blood supply to the heart. In addition, this agent is useful for diagnosis of many congenital abnormalities in the cardiac structure. Other uses include visualizing the left ventricle or heart chamber; and visualizing the myocardium or heart muscle as the contrast agent enters the blood vessels of the heart muscle (commonly termed perfusion imaging).
BRIEF DESCRIPTION OF THE DRAWING
The foregoing and other objects, aspects, features and advantages of the present invention will be more fully appreciated as the same become better understood from the following detailed description of the present invention when considered in conjunction with the accompanying drawing, in which:
FIG. 1 is a schematic diagram of the cardiovascular system of a human being showing how the contrast agent of the present invention is introduced into the system and how an image of the system is created.
DETAILED DESCRIPTION
With reference to FIG. 1, the present invention comprises a contrast agent for introduction into the circulatory system of a patient P. Although a human patient is shown in the drawing, it should be understood that the present invention is not limited to use in a human being but is adapted for use with all animals having a circulatory system. The present invention enhances a ultrasonic imaging of blood flow through the circulatory system of an animal.
In particular, the contrast agent of the present invention comprises inert particles or microspheres in combination with a pharmaceutically acceptable carrier which is adapted for introduction into the circulatory system of the animal. Each particle, as shown in the drawing Figure as 10, is echogenic (i.e. opaque to ultrasound and capable of reflecting sound waves), and therefore, acts as a contrast agent when visualized using conventional medical ultrasound techniques, for example echocardiography and vascular ultrasound at a frequency of 2.5 to 5 MHZ. The particles are preferably spherical shaped, although other shapes are possible. In a preferred embodiment, the particles comprise a cross-linked starch, for example potato starch. However, other suitable substances for forming the particles exist. European patent application nos. 0184899 and 0186947, which are incorporated in their entirety herein by reference, describe several examples of suitable polymeric or polymerized carbohydrate or polymerized sugar alcohol or derivative suitable for use as an echogenic particle in the present invention. The entire particle is completely biodegradable in the body, typically by serum amylase, a naturally occurring enzyme found in the body.
The particles are substantially solid and may in some instances be completely solid. The preferred diameter of spherically shaped particles is four (4) to nine (9) microns, most preferred being seven (7) to eight (8) microns. Tests have successfully been performed using particles having a diameter as small as three (3) microns to six (6) microns. One example of an acceptable microsphere is DSM (degradable starch microsphere) available from Pharmacia LEO Therapeutics AB in Uppsala, Sweden. Microshperes having a diameter of 5.6 microns are available from Pharmacia under the designation of DSM Batch No. BR71B06B. Other than experiments related to the present invention and those described in European patent application nos. 0184899 and 0186947 described above, it is believed that similar microshperes have been used experimentally mentally as a means of controlled drug delivery to cancers (e.g. tumors).
As mentioned above, the particles are suspended in a carrier or fluid that is capable of being introduced into the circulatory system of an animal. The microspheres swell in the carrier and exhibit gel characteristics making them slightly deformable. Thus, they can adapt their shape to the vascular cavities of the body. Any pharmaceutically acceptable carrier may be employed for this purpose. Examples include conventional saline, water and intravenous fluid. The concentration of particles to carrier should preferably be within the range of 25 to 1,000 micrograms per milliliter, with the most preferred concentration for the average human being 250 micrograms per milliliter.
In use, the contrast agent is prepared by mixing a predetermined amount of bio-degradable particles in a suitable amount of carrier. The agent may be prepared in advance of the procedure and stored until use, or may be prepared in contemplation of the procedure and used immediately. In either case, the prepared agent is transferred to a conventional syringe or other suitable apparatus for administering fluid to the circulatory system (e.g. a catheter). If a syringe is used, the contrast agent is introduced into the circulatory system by injecting the needle into a vein. When the patient is a human, as shown in the Figure, introduction is preferably through an arm vein V using a conventional syringe S.
Referring to the Figure in which the cardiovascular system of a human is shown in a detailed schematic, the contrast agent travels through the circulatory system towards the heart. Upon reaching the heart, the contrast agent first enters the superior vena cava 16 which leads to the right side of the heart. The contrast agent enters the right side of the heart through the right atrium 18 and passes through the tricuspid valve into the right ventricle 22. From the right ventricle, the contrast agent is passed to the lungs 26 through the pulmonary artery 24. In the lungs 26, the contrast agent is passed through the capillaries and back into the pulmonary vein 28. This is an important feature of the present invention because it allows the contrast agent to aid in visualization of the left side of the heart. In order to enhance an ultrasonic image of the left side of the heart, it is important that the particles be of a size that allows them to pass through the capillaries to the pulmonary vein and ultimately to the left side of the heart. From the pulmonary vein 28, the contrast agent is passed to the left atrium 30. From the left atrium, the contrast agent passes through the mitral valve 32 to the left ventricle 34. From the left ventricle 34, the contrast agent passes to the left coronary artery 36 and the aorta 38 into the veins of the body where it is eventually degraded by serum amylase.
While the contrast agent is making its way through the circulatory system of patient P, a conventional medical ultrasound device U is preferably disposed adjacent the chest C of the patient. The medical ultrasound device U is positioned to provide ultrasonic images of the heart of patient P.
The contrast agent of the present invention is capable of providing enhanced visualization of vascularized organs of the body, and in particular, the chambers of the heart (i.e. the right atrium, the right ventricle, the left atrium and the left ventricle) because they are opaque to ultrasonic signals and they are able to conform to the vascular contours. When the contrast agent of the present invention is used to image the cardiovascular system, the shape and contour of the heart chambers are revealed, as well as an indication of any abnormalities and, or blockages in the system.
In most patients diagnosed with heart disease, the left ventricle of the heart exhibits the greatest irregularities. Therefore, it is an especially beneficial feature of the present invention that the particles of the contrast agent are of a size that allows them to be passed to the left side of the heart and into the left ventricle to permit enhanced visualization of the left ventricle. As noted above, this feature is possible with the present invention because the particles of the present invention are of a size capable of passing safely through the lungs, while at the same time being echogenic.
In addition, the present invention also allows enhanced visualization of vascularized organs, for example, the myocardium or heart muscle. That is, the contrast agent present within the blood in the heart muscle has been shown to give a sparkling appearance when visualized using conventional medical ultrasound. This perfusion imaging technique allows study of problems associated with the heart muscle itself.
Furthermore, the present invention can be used to study the effect of exercise or medication on the blood supply to the heart. To accomplish such a study, one fellows the method outlined above with regard to administering the contrast agent to the circulatory system and preserves the ultrasound image, for later comparison, by any known technique. The patient is then exposed to exercise or medication that is believed to have an effect on blood flow in the circulatory system. The method of administration and imaging is repeated and the first image taken before exposure to the blood flow effecting activity is compared to the second image taken after such activity. Any blockage present in the heart chambers due to the activity would be apparent by comparing the two images. For example, during exercise, a portion of the heart may not develop an ultrasonic contrast appearance because blood is not flowing to that portion of the heart during exercise. After waiting for the cardiovascular status to return to a rest condition, a second image might reveal that that same portion of the heart does have an ultrasonic contrast appearance at rest. This comparison would be evidence that that portion of the heart is not receiving blood during exercise, although it does receive blood at rest. Such a finding would be because most patients with coronary artery disease have adequate blood flow to the heart at rest, but have inadequate blood flow to certain regions of the heart during exercise.
In addition to enhancing ultrasonic imaging of the cardiovascular system, the present invention may also be used to image other bodily organ systems such as the liver, spleen, and kidney.
It should be understood that the foregoing disclosure relates only to presently preferred embodiments, and that it is intended to cover all changes and modifications of the invention herein chosen for the purpose of the disclosure which do not constitute departures from the spirit and scope of the invention as set forth is the appended claims.
What I claim is:
1. A method of enhancing ultrasonic imaging of a vascularized organ in an animal, comprising the steps of:introducing a contrast composition into the circulatory system of said animal, said contrast composition consisting essentially of a pharmaceutically acceptable carrier and an effective amount of an insoluble cross-linked starch particle of a size to produce ultrasonic imaging; and ultrasonically imaging said particle within said vascularized organ.
2. The method set forth in claim 1, further including the step of:suspending said particle in said pharmaceutically acceptable carrier before it is introduced into said animal.
3. The method set forth in claim 2, further comprising the step of:ultrasonically imaging said particle within a portion of the cardiovascular system of said animal to observe passage of the particle through the circulatory system into the left atrium and left ventricle of the heart.
4. The method set forth in claim 3, further comprising the step of:altering the blood flow in said circulatory system after said step of ultrasonically imaging said particle within the said portion of the cardiovascular system. re-introducing said contrast composition into said circulatory system; re-imaging said particle within said portion of the cardiovascular system; and comparing the observations made during the step of imaging, with those made during the step of re-imaging, to study the effect of altering the blood flow on said cardiovascular system of said animal.
5. The method set forth in claim 1, wherein said step of ultrasonically imaging said particle is performed simultaneously with said step of introducing said contrast composition.
| 1990-11-14 | en | 1993-08-17 |
US-2187460-A | Process for oxyalkylating solid polyols
United States Patent Office I 319327. Patented June 22, 1965 PROCESS FOR OXYALKYLATING SOLID POLYOLS John T. Patton, Jr., Wyandotte, and Walter F. Schulz,
Southgate, Mich., assiguors to Wyandotte Chemicals Corporation, Wyandotte, Mich., a corporation of Michigan No Drawing. Filed Apr. 13, 1960, Ser. No. 21,874 6 Claims. (Cl. 260-615) This invention relates to a process for oxyalkylating solid polyols. In a more specificaspect, this invention relates to a method for producing high molecular weight products by reacting a normally-solid polyol with an alkylene oxide to produce products that are substantially free of glycols or homopolymers of the alkylene oxideused.
Methods for reacting solid polyols,- such as pentaerythritol,,with alkylene oxides, such as ethylene oxide, proa considerable period of time, but the problems in this area are quite apparent from a review of the pertinent patents that have issued. Thus, Schmidtet al., US. 1,922,459 (1933), disclose the reaction of pentaerythritol with ethylene oxide by heating the reactants in an autoclave in the presence of boric anhydride for about 20 hours at 125 C. The incompleteness of the reaction a paste or suspension which can be stirred in an autoclave along with the basic oxyalkylation catalyst; however, De Groote notes that there would be a problem in large-scale manufacture in handling such an initial pasty suspension or mass. ,A recent suggestion for helping to solve the difiiculties in reacting a normally-solid polyol with an alkylene oxide is given by Anderson, US. 2,902,- 478 (1959), who discloses that high-melting, heat-sensitive polyols that are substantially insoluble in alkylene oxides can be oxyalkylated at temperatures below their melting points and decomposition temperatures and in the absence of solvent by the use of trimethylamine as a catalyst. Anderson discloses that trimethylamine catalyzes the reaction of alkylene oxides with hydroxyl compounds and also solvates or activates the solid polyols so that they react readily with alkylene oxides at low temperatures. The use of amine catalysts is not the solu tion the art is seeking, either, because it is well known that pylene oxide andbutylene oxide, have been known for is shown by the disclosure by Schmidt et al. that unreacted ethylene oxide was removed from the reaction products. Further development in catalysts for this reaction is disclosed by Bowman et al., US. 2,401,743 (1946), who disclose the, reaction of pentaerythritols with alkylene oxides in the presence of a broad group of organic acids and organic acid anhydrides, such as acetic acid or acetic anhydride. Again reaction times were long and incomplete since Bowman et al. disclose that unreacted ethylene oxide was removed from the reaction product.
Brown, US. 2,450,079 (1948), discloses the reaction of polyhydric alcohols having at least 3 hydroxyl groups, such as pentaery-thritol, with alkylene oxides by mixing the polyol with a substantial proportion of water and then reacting the mixture with an olefin oxide. The wellrecognized reaction of water with an alkylene oxide interferes in this process and the productvis a mixture of glycols, polymers of the alkylene oxide used, adducts of the polyol and the alkylene oxide and water. The whole problem of reacting normally-solid polyols with alkylene oxides is discussed in Monson et al., US. 2,766,292 (1956). Monson et a1. point out that the polyols under consideration, although inherently oxyalkylation-susceptible, are solids which are substantially insoluble in any of the oxyalkylation-resistant solvents available for use in the preparation of oxyalkylated derivatives. Monson et al. point out that water is not an acceptable solvent for use in oxyalkylation processes because water reacts With such alkylene oxides to produce polyglycols during oxyalkylation. The problem is further complicated by the fact that the normally-solid, oxyalkylation-susceptible solids cannot be used in undiluted form in the oxyalkylation processes known to date or simply by liquefying such solid polyols by heating prior to introduction of the oxyalkylating agent because they undergo partial decomposition as they' melt.
The problems inherent in using oxyalkylation-resistant solvents, such as xylene, in these processes is disclosed by De Groote, US. 2,554,667 (1951), who notes that powdered dipentaerythritol is not soluble in xylene. De Groote suggests that dipentaerythritol can be reacted with an alkylene oxide by employing enough xylene to give free of polymers of the alkylene oxide used and substanv,
tially free of glycols are produced. A still further object is to provide a method for reacting the normally-solid polyols with alkylene oxides that does not require the use of an oxyalkylation-resistant solvent.
A still further object is to provide a method for reacting normally-solid polyols with alkylene oxides which accomplishes the foregoing objectives while making use of basic oxyalkylation catalysts that are necessary to produce high molecular weight products.
These objectives and others have been accomplished by the method of the invention which is based on the discoveries that an adduct of 1 to 4 mols of at least one alkylene oxide and a high-melting, oxyalkylation-susceptible, organic polyol is a completely suitable solvent or reaction medium for said polyol, itself, and that the polyol and the alkylene oxide reactant can be added to the adduct in the presence of an oxyalkylation catalyst in the absence of oxyalkylation-resistant solvents or water and, under apof 1 to 4 mols per mol of polyol of at least one alkylene oxide and said polyol and an oxyalkylation catalyst.
The process of the invention in commercial practice amounts to a generally two-stage process. The first stage of the process involves contacting a high melting, oxyalkylation-susceptible, organic polyol having from 3 to 8 hydroxyl radicals per molecule with water, an oxyalkylation catalyst and at least one alkylene oxide at a low oxyalkylation temperature. The conditions observed and proportions of reactants in the first stage are very important. About 1 to 4 mols of the alkylene oxide are used per mol of the polyol. The product of the first stage is the adduct that is used thereafter as the solvent and reaction medium for subsequent reaction with the alkylene oxide to produce the high molecular weight product that is desired. Although, as stated, the adduct produced in the first stage is usually the adduct that is used as the reaction medium for further reaction between the polyol and alkylene oxide, a low molecular weight adduct of one polyol, such as pentaerythritol and 2 mols of propylene oxide, can be used as the reaction medium for reaction of a diflerent polyol of the type contemplated herein, such as dipentaerythritol, and an alkylene oxide. Although the melting point of the polyols under consideration is relatively high, that is, greater than 100 C., an adduct of such a polyol with 1 to 4 mols of an alkylene oxide has a greatly reduced melting point and is usually a liquid under normal conditions. The reason for this is probably that the symmetry of the polyol molecule is broken when such an adduct of the polyol is formed resulting in a lower melting product. It is desirable to use the lowest possible proportion of alkylene oxide in the first stage that is necessary to reduce the melting point of the polyol so that the alkylene oxide reacts with the hydroxyl groups of the. polyol rather than with water which is present in the system or with itself to form polymers or glycols.
After the initial adduct is prepared as described above, water and volatile materials are stripped from the adduct. The catalyst concentration may have been adequate in the first stage for subsequent reaction between the alkylene oxide and additional polyol. If so, additional catalysts need not be added; if not, additional catalyst is mixed with the adduct, fresh and additional polyol is mixed with the adduct and the alkylene oxide reactant is introduced under appropriate oxyalkylation conditions and the reaction is carried forward.
The advantages of this process should be quite apparent.
"Only small amounts of glycol or alkylene oxide polymers,
that are undesired by-products, are formed in the first stage because of the proportions of reactants used and the lowoxyalkylation temperature that is employed. The small amount of such undesired by-products that is produced is diluted to an insignificant amount by the additional reactants, polyol and alkylene oxide, that are used in the second and any subsequent stages of the reaction. The second and subsequent stages of the reaction are carried out with no water or other solvent which contribute to impurities and undesired by-products.
The polyols that are used in the process are high-melting, oxyalkylation-susceptible, organic polyols having from 3 to 8 hydroxyl radicals per molecule. Pentaerythritol is a prime example since it has a melting point of 261 C. and has 4 hydroxyl groups. Other examples of such polyols are trimethylolethane having a melting point of 202 C. and 3 hydroxyl groups, dipentaerythritol having a melting point of about 222 C. and 6 hydroxyl groups, tripentaerythritol having a melting point of 248250 C. and 8 hydroxyl groups, inositol having 6 hydroxyl groups, the dextro form of which having a melting point of 247 C. and the levo form of which having a melting point of 238 C., disaccharides such as sucrose having a melting point of 160 C. and 8 hydroxyl groups, monosaccharides such as glucose having a melting point of 147 C. and hydroxyl groups, sorbitol having a melting point of 111 C. and 6 hydroxylgroups and fructose having a melting point of 105 C. and 5 hydroxyl groups, and the like. The advantage of the process for the oxyalkylation of saccharides such as sucrose is apparent when one considers that when one heats to a good oxyalkylation temperature, such as 125 C., a sugar, such as sucrose, together with sodium hydroxide, a basic oxyalkylation catalyst, the result is caramelization of the sugar producing a brown color which is undesirable in oxyalkylated products of sucrose. Also, when sugar is heated with caustic, fragmentation occurs to form saccharinic acids and other decomposition products.
The alkylene oxides that are used are the vicinal oxides, that is, those in which the oxygen atom is attached to two adjacent aliphatic carbon atoms. Mixtures of such alkylene oxides can also be used and examples of the alkylene oxide reactants are ethylene oxide, 1,2,-propylene oxide, 1,2- and 2,3-butylene oxides, isobutylene oxide, butadiene monoxide, styrene oxide, cyclohexene oxide, butadiene dioxide, methyl glycidyl ether, phenyl glycidyl ether, and the like. A distinction is made, however, between the use of ethylene oxide and any other of the vicinal alkylene oxides listed and referred to. Ethylene oxide can be used in the process of the invention but it is less desirable than the alkylene oxides having at least 3 carbon atoms because, when ethylene oxide reacts with the polyol, the hydroxyl group produced when the ethylene oxide ring opens is a primary hydroxyl group whereas the hydroxyalkyl product obtained using the higher alkylene oxides under basic catalysis contains secondary hydroxyl groups. The efficacy of the first stage of the process is based, to a large extent, on the higher reactivity of alkylene oxides with the primary hydroxyl groups of the polyol, itself, and, when ethylene oxide is used, it is just as likely to react with the primary hydroxyl group of a hydroxyethyl radical as with the primary hydroxyl group of the polyol. The use of higher alkylene oxides insures even distribution about the molecule of the starting polyol of the hydroxyalkyl groups since the higher alkylene oxides preferentially react with the primary hydroxyl group of the starting polyol rather than the secondary hydroxyl groups in the hydroxalkyl radicals resulting from ring opening of the higher alkylene oxides. This preferential reaction of alkylene oxides with primary hydroxyl groups provides the basis for a continuous process embodiment of the invention using alkylene oxides having at least 3 carbon atoms in which the first stage of the process need only be carried out once and, thereafter, the desired adduct which is needed as a solvent for the second stage and high molecular weight oxyalkylation products are produced continuously in separate reaction zones.
The catalyst that is used is a conventional oxyalkylation catalyst that generates secondary hydroxyl groups when the oxirane ring of higher alkylene oxides is opened. These are, in general, basic catalysts, such as amines, alkali metal hydroxides, alkali metals and alkali metal alcoholates. The preferred catalysts are sodium hydroxide and potassium hydroxide. Amines are suitable although, as pointed out hereinabove, they are not adequate for producing products having a molecular weight of higher than about 400 to 600. If products having molecular weights below this range are desired, amine catalysts are quite suitable, such as trimethylamine, triethylamine, tripropylamine and other tertiary alkylamines, N-benzyl-N,N-dimethylamine, N methylmorpholine, and the like.
The concentration of catalyst in any stage of the process depends on the molecular weight of product that is desired. It a relatively high molecular weight product is desired, such as one having a molecular weight of 1000 to 10,000 or higher, a higher catalyst concentration is used in the first stage of the process than would otherwise be necessary -since the catalyst would not be removed and would be effective in subsequent reaction of the polyol with the alkylene oxide. Thus, the catalyst concentration can range from about 1 mol percent of alkali metal hydroxide, based on the polyol, to as high as 10 to 15 mol percent. A concentration of about 4 to 5 mol percent of alkali metal hydroxide is usually effective. It may be noted that amine catalysts must be replaced when the adduct formed in the first stage is stripped of water because such amine catalysts will be removed along with the water. Other basic oxyalkylation catalysts, such as sodium hydroxide, are not removed by the stripping operation and, therefore, need only be supplemented in subsequent stages to the end that the proper catalyst concentration is present to produce the molecular weight of product that is desired.
The first stage of the process is carriedout using water as a solvent for the polyol. Only that amount of water need be used that permits agitation or mixing and conpentaerythritol with propylene oxide.
tacting of the solid polyol with catalyst and alkylene oxide. It is not necessary that the polyol be completely dissolved in the water. The amount of water used should be that amount which permits a significant amount, such as approximately 2 to weight percent, of the polyol to dissolve in the water.-'; It will be satisfactory, of course, i i-a greater proportion "of the polyol dissolves in the water, but it is desirable to keep the amount of water used at a minimum. This amount of water will dissolve a sufficient amount of the polyol and produce a stirrable mixture to facilitate the reaction with 1 to 4 mols of the alkylene oxide reactant. The reaction with the alkylene oxide proceeds in the aqueous solution phase of the mixture and, as the alkylene oxide reacts with the polyol in the aqueous solution phase, an additional amount of polyol dissolves in the aqueous solution phase,
to permit further reaction with the alkylene oxide reactant.
A low oxyalkylation temperature is employed in the first stage of the process. The low temperature is employed in order to minimize reaction of the alkylene oxide with water in the system. For this reason, the temperature is desirably not above about 100 C. to 115 C. in the first stage of the process. The broad temperature range for oxyalkylation reactions is about 85-170 C., on the other hand. If the polyol to be oxyalkylated is difficultly soluble in water, the temperature can be raised to 110 C. or 115 C. in the first stage. The low oxyalkylation temperature, such as about 100 C., isetfec- :tive for producing the adduct of 1 to 4 mols per mol of polyol of alkylene oxide and the polyol. .When this adduct has been formed, the adduct is'stripped in a vacuum stripping operation and subsequent reaction of fresh polyol and alkylene oxide is carried out at conventional oxyalkylation temperatures, such as about 125 C.
All of the reactions carried out in the process of this invention are carried out in closed reaction zones and the pressure need only be the autogenous pressure developed by the reactants under the conditions of the reaction. The reaction zone is purged with nitrogen or any other inert gas to remove air containing oxygen from the system, as is conventional in oxyalkylation reactions, because the polyol and the polyol adduct are oxidized to aldehydes f and colored polymers if oxygen is present under the conditions of the oxyalkylation reaction.
The reaction time for the first or any subsequent stage of the process is that time required for introducing the proper amount of alkylene oxide to the system while controlling the reaction temperature at the desired level. oxyalkylation reactions are exothermic and so the alkylene oxide must be introduced at a controlled rate so that the desired reaction temperature is not exceeded. When the pressure of the reaction systems falls to and remains at a constant value after all of. the alkylene oxide reactant has been introduced, the reaction is complete.
As has been pointed out, the proportion of alkylene oxide to polyol that is employed in the first stage is very important. Desirably the lowest proportion of alkylene oxide should be used that produces an adduct with the polyol having a sufficiently reduced melting point such that it can act as a solvent and reaction medium for further reaction of fresh polyol and additional alkylene oxide. Usually a proportion of 1 to 2 mols of alkylene oxide per mol of polyol is preferred.
The process of the invention is further described by the following examples which are supplied in order to illustrate but not limit the process.
Example 1 A run was carried out for the purpose of oxyalkylating The reactor was a steam heated autoclave and the autoclave was charged with 816 grams (6 mols) of pentaerythritol, 12 grams of potassium hydroxide, and 405.7 grams of distilled water. The autoclave was purged three times with nitro- Propylene oxide was then introduced into the autoclave and 696 grams (12 mols) of propylene oxide were introduced over a period of about 3% hours. The maximum pressure developed by the reactants was 41 p.s.i.g. and the reactants were heated and stirred at 110 C. for about 25 minutes after the propylene oxide was completely added to the autoclave.
Thereafter, the reaction mixt'nrewas cooled to 42 C. and the liquid product containing no suspended solid material was blown into a clean glass vessel. The product was stripped at 5 mm. Hg pressure at 125126 C. for about 2 /2 hours. After cooling, the product wasa clear liquid containing only a small amount of solid precipitate.
The product of the first stage of the run was an adduct of 2 mols of propylene oxide and pentaerythritol having a molecular weight of 252.
The pentaerythritol-propylene oxide adduct prepared v added as catalyst and the reaction mixture was heated and stirred for 30 minutes at C. and then the temperature was raised to 135 C. Propylene oxide was then introduced in the amount of 2018 grams (34.8 mols) over a period of about 8 hours.
The product of the reaction between pentaerythritol and propylene oxide, after cooling and stripping, was a clear liquid which had a molecular weight of 600.
x 1 Example 2 Dipentaerythritol-and propylene oxide were reacted in the same reaction system as described in Example 1. The amount of dipentaerythritol used was 508 grams (2.0 mols), the amount of water used was 500 grams and the amount of potassium hydroxide catalyst was 4 grams which corresponds to 0.8 mol percent based on the dipentaerythritol.
The reaction with propylene oxide was carried out at -112 C. and 464 grams (8.0 mols) of propylene oxide were introduced to the reactor over a period of about 3% hours.
The product was removed from the autoclave and subjected to vacuum stripping to remove water. The prodnot was an adduct of dipentaerythritol and 4 mols of propylene oxide.
The initial adduct of dipentaerythritol and 4 mols of propylene oxide was employed in a second stage as the solvent and reaction mediu'mfor further reaction of dipentaerythritol and propylene oxide. There was charged to the autoclave 468 grams (1.0 mol) of the dipentaerythritol-propylene oxide adduct produced in the first stage, 381 grams (1.5 mols) of fresh dipentaerythritol and 22 grams of additional potassium hydroxide catalyst.
Pr pylene oxide was introduced at about C. overa period of 3% hours during which time 1651 grams (28.4 mols)-of propylene oxide was introduced to the system. 4 I
The product was cooled and subjected to vacuum stripping. The product was a liquid having a molecular weight by hydroxyl number test of 980. The theoretical molecular weight of the product was 1000.
Example 3 The solubility of pentaerythritol in an adduct of 2 mols propylene oxide and pentaerythritol was demonstrated. A 20 gram sample of an adduct of 2 mols propylene oxide and 1 mol of pentaterythritol, prepared as described in Example 1, was placed in a 125 ml. flask and heated to 125 C. grams of pentaerythritol was added and it dissolved readily. An additional 5 grams of pentaerythritol was added and it dissolved readily, also.
A total of 20 grams of pentaerythritol was added to the 20 grams of adduct in the flask and all of the materials were in solution at 160 C. When a total of 40 grams of pentaerythritol were added to the 20 grams of adduct, the resulting mixture was very fluid at 170 C.
These runs demonstrate the suitability of an adduct of 2 mols of propylene oxide and 1 mol of pentaerythritol as a solvent and reaction medium for reactions of pentaerythritol and an alkylene oxide.
Example 4 A run was carried out to react trimethylolethane with propylene oxide by the process of the invention. An adduct of 2.8 mols of propylene oxide per mol of trimethylolethane was prepared in the first stage and this adduct was then used as the solvent and reaction medium for preparing the timethylolethane-propylene oxide reaction product having a molecular weight of 750.
In the first stage, 648 grams (5.4 mols) of trimethylolethane, 400 grams of distilled water and 45 grams (13.3 mol percent) of potassium hydroxide catalyst were charged to the autoclave. 870 grams mols) of propylene oxide were introduced over a period of 3% hours at 124-126 C.
After cooling and vacuum stripping the product, the product was a yellow liquid having a molecular weight by hydroxyl number test of 211. The theoretical molecular weight'of the product is 282.
The adduct of trimcthyolethane and 2.8 mols of propylene oxide was used in a second stage by charging 506 grams (1.8 mols) of the adduct and 108 grams (0.9 mol) of trimethylolethane to the autoclave. No additional catalyst was employed. 1636 grams (28.2 mols) of propylene oxide were introduced over a period of 6% hours at 124-126" C.
After cooling and vacuum stripping the product, the product was a liquid having a molecular weight by hy droxyl number test of 684. The theoretical molecular weight of the product is 750.
Example 5 A run was carried out to react sorbitol with propylene oxide by the process of the invention. An adduct of 3 mols of propylene oxide per mol of sorbitol was prepared in the first stage of the process and this adduct was employed as the solvent and reaction medium for producing a reaction product of propylene oxide and sorbitol having a theoretical molecular weight of 874.
In the first stage of the process, 900 grams (4.9 mols) of sorbitol, 500 grams of water and 3 grams (1.1 mol percent based on the sorbitol) of potassium hydroxide catalyst were charged to the autoclave. Propylene oxide was introduced to the autoclave over a period of about 5 hours at 108110 C. during which time 870 grams (15.0 mols) of propylene oxide were introduced to the system.
After cooling and vacuum stripping the product, the adduct was found to have a molecular weight of 328 by hydroxyl number. The product was a clear liquid containing no solid residue on visual inspection.
The adduct prepared as described above was employed as the solvent and reaction medium for further reaction of sorbitol and propylene oxide by charging 712 grams (2.0 mols) of the adduct, 364 grams (2.0 mols) of sorbitol and 6 grams (5.35 mols percent based on the polyol) of additional potassium hydroxide catalyst to the autoclave. Propylene oxide was introduced over a period of 9 hours at 125 C. in the amount of 1384 grams (23.8 mols).
After cooling and vacuum stripping the product, the product was a liquid having a molecular weight by bydroxyl number test of 618.
The process of the invention can be expressed as a continuous process in which the 2 to 4 mol alkylene oxide adduct of the solid polyol is continuously preparedin one reaction zone and a portion of that adduct is used in a second reaction zone as the solvent and reaction medium for preparing high molecular weight reaction products of the polyol and alkylene oxide in a system in which no water is present. The higher alkylene oxides having at least 3 carbon atoms should be used when the process is carried out continuously because such alkylene oxides preferentially react with the primary hydroxyl groups of the polyol, itself, instead of the secondary hydroxyl groups in the 2 to 4 mol alkylene oxide adduct of the polyol that is used as the solvent and reaction medium in the first reaction zone.
In order to employ the process of the invention in a continuous system, a 2 to 4 mol higher alkylene oxide adduct of the solid polyol is prepared, initially, in the same manner that has been described hereinabove, employing a low oxyalkylation temperature and a sutficient amount of water such that a significant amount, e.g. about 2 to 10 weight percent, or more, of the solid polyol is in solution in the water to facilitate reaction with the alkylene oxide. After preparing such a 2 to 4 mol adduct, the adduct is placed in a first reaction zone together with a catalytic amount of an oxyalkylation catalyst. The polyol that is to be the basis of the product that is desired (which can be the same as or different from the polyol used to produce the adduct that serves as the reaction medium in the first reaction zone) is passed into the first reaction zone and a stream of the alkylene oxide to be used, such as propylene oxide, is passed into the first reaction zone. The flow rate of the alkylene oxide stream into the first reaction zone is adjusted so that the molar ratio of the alkylene oxide and the additional polyol passing into the first reaction zone is about 2 to 4 mols of alklene oxide per mol of polyol. The temperature in the first reaction zone is a low oxyalkylation temperature, such as C. to C., and the reactants in the first reaction zone are mixed and heated to continuously produce an adduct of the polyol and 2 to 4 mols of the alkylene oxide.
The adduct produced in the first reaction zone is withdrawn from the first reaction zone and separated into a recycle product stream and a second reaction zone polyol feed stream. The recycle product stream is returned to the first reaction zone to serve as the solvent and reaction medium for further preparation of a 2 to 4 mol alkylene oxide adduct with the polyol. The portion of the first reaction zone product that is designated the second reaction zone polyol feed stream is passed into a second reaction zone together with a stream of alkylene oxide to produce the desired high molecular weight adduct. Fresh polyol is not added to the second reaction zone since the purpose here is to build up chains of oxyalkylene groups on the polyol adduct that is passed into the second reaction zone as the second reaction zone polyol feed stream. Usually, no additional catalyst will be required in the second reaction zone since the catalyst will be carried into the second reaction zone by the second reaction zone polyol feed stream. However, catalyst can easily be added to adjust its concentration in the event that this is required.
The reactants are heated and stirred in the second reaction zone at an oxyalkylation temperature which can be in the range of 110-160 C. We prefer about C. in the second reaction zone.
Product from the second reaction zone is withdrawn and subjected to conventional purification steps, such as vacuum stripping, before passing same to storage.
It is believed that the concept of employing a low molecular weight adduct of a normally-solid polyol and an alkylene oxide as the reaction medium and solvent for the polyol, itself, when preparing high molecular weight adducts together with the concept of employing an alkylene oxide having at least 3 carbon atoms so that advantage can be' taken of the preferential reaction of such an alkylene oxide with the primary hydroxyl groups of the polyol provide, for the first time, a completely practical process that can be carried out on large scale for producing high molecular weight adducts of normallysolid polyols and alkylene oxides that are substantially free of undesired by-products, such as glycols or polymers of the alkylene oxide that is used.
We claim:
1. A process for oxyalkylating a normally solid polyol,, which comprises, mixing and heating to from 85 C. to 170 C. in the presence of a basic oxyalkylation catalyst (1) a vicinal alkylene oxide, (2) a normally solid organic polyol having 3 to 8 hydroxyl radicals per molecule and \(3) a substantially water-free adduct of a normally solid organic polyol having 3 to 8 hydroxyl radicals per molecule with from 1 to 4 mols of a vicinal alkylene oxide per mol of said polyol, said organic polyol having a melting point of at least 100 C. and being selected from the v igroup consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, trirnethylolethane, inositol, monosaccharides and disaccharides, said alkylene oxide being selected from the group consisting of ethylene oxide, propylene oxide, 1,2-butylene oxide,'2,3-butylene oxide, isobutylene oxide, butadiene monoxide, styrene oxide, cyclohexene oxide, butadiene dioxide, methyl glycidyl ether, phenyl glycidyl ether and mixtures thereof, said oxyalkylation catalyst being selected from the group consisting of alkali metal hydroxides, alkali metals and alkali metal alcoholates,.the amount of said adduct employed being sufficient so that it is the solvent and reaction medium cfor the process and the amount of said solid organic polyol that is employed being at least sutficient so that the polyol is oxyalkylated by the vicinal alkylene oxide under the conditions of the process. I 2. A process according to claim 1 wherein said polyol (2) is pentaerythritol, said adduct (3) is an adduct of pentaerythritol and propylene oxide and said alkylene oxide (1) is propylene oxide.
3. A process for oxyalkylating a normally solid polyol,
which comprises, contacting a solid organic polyol having from 3 to 8 hydroxyl radicals per molecule with water, an oxyalkylation catalyst and a vicinal alkylene oxide at from 85 C. to 115 C. to produce therefrom a polyoladduct-solvent, said polyol being soluble in the water at least to the extent of about 2 weight percent based on the weightof the water and the molar proportions of said polyol and said alkylene oxide being in the range of about 1 to 4 mols of said alkylene oxide per mol of said polyol, said polyol havinga melting point of at least 100C. and being selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolethane, inositol, monosaccharides and disaccharides, said alkylene oxide being selected from the group consisting of ethylene oxide, propylene oxide, 1,2- butylene oxide, 2,3-butylene oxide, isobutylene oxide, butadiene monoxide, styrene oxide, cyclohex-ane oxide, butadiene dioxide, methyl glycidyl ether, phenyl glycidyl ether and mixtures thereof, and said oxyalkylation catalyst being selected from the group consisting of alkali metal hydroxides, alkali metals and alkali metal alcoholates, removing water from said polyohadduct-solvent, adding and mixing additional amounts of a solid organic polyol, herein-above defined, and a vicinal alkylene oxide,
hereinabove defined, to and with said polyol-adduct-solvent in the presence of an oxyalkylation catalyst, hereinabove defined, at from 85 C. to 170 C., the additional amounts of said polyol and vicinal alkylene oxide added to said polyol-adduct-solvent being sutficient to enable the preparation of an oxyalkylated solid organic polyol having a molecular weight up to about 10,000.
4. A process for oxyalkylating a normally solid polyol, which comprises, contacting a solid organic polyol having from 3 to 8 hydroxyl radicals per molecule with water, an oxyalkylation catalyst and a vicinal alkylene i0 oxide at from C. to 110 C. to produce therefrom a polyol-adduct-solvent, said polyol being soluble in the water at least to the extent of about 2 weight percent based on the weight of the water and the molar proportions of said polyol and said alkylene oxide being in the range of about 2 to 4 mols of said alkylene oxide per mol of said polyol, said polyol having a melting point of at least C. and being selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolethane, inositol, monosaccharides and disaccharides, said alkylene oxide being selected from the group consisting of ethylene oxide, propylene oxide, 1,2- butylene oxide, 2,3-butylene oxide, isobutylene oxide, bu- .tadiene monoxide, styrene oxide, cyclohexene oxide, butadiene dioxide, methyl glycidyl ether, phenyl glycidyl ether and mixtures thereof, and said oxyalkylation catalyst being selected from the group consisting of alkali metal hydroxides, alkali metals and alkali metal alcoholates, removing water from said polyol-adduct-solvent, adding and mixing additional amounts of said polyol and J said alkylene oxide to and with said polyol-adduct-solene oxide and pentaerythritol in a substantially water-free pentaerythritol-adduct-solvent, said pentaerythritol-adductsolvent consisting essentially of an adduct of pentaerythritol and propylene oxide in the proportion of about 2 to 4 mols propylene oxide per mol pentaerythritol.
6. A continuous process for oxyalkylating a normally solid polyol, which comprises, heating and mixing at from 90 C. to C. in the presenceof a basic oxyalkylation catalyst a vicinal alkylene oxide, water and a solid organic polyol having 3 to 8 hydroxyl radicals per molecule and a melting point of at least 100 C., the proportions of water and said polyol being such asto .produce a stirrable slurry of polyol and alkylene oxide in water and to dissolve in the water at least 2 weight percent, based on the weight of water, of said polyol and the proportions of said polyol and said alkylene oxide being about 2 to 4 mols of said alkylene oxide per mol of said polyol, thereby producing a polyol-adduct-solvent having from 2 to 4 hydroxyalkyl radicals per molecule, said solid organic polyol being selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolethane, inositol, .monosaccharides and disaccharides, said alkylene oxide being selected from the group consisting of ethylene oxide, propylene oxide, 1,2- butylene oxide, 2,3-butylene oxide, isobutylene oxide, butadiene monoxide, styrene oxide, cyclohexene oxide, butadiene dioxide, methyl glycidyl ether, phenyl glycidyl ether and mixtures thereof, said oxyalkylation catalyst being selected from the group consisting of alkali metal hydroxides, alkali metals and alkali metal alcoholates, removing water from said polyol-adduct-solvent, transferring said polyol-adductsolvent into a first reaction zone together with a catalytic amount of said oxyalkylation catalyst, passing additional amounts of said polyol and said alkylene oxide into said first reaction zone in the proportion of from 2 to 4- mols of alkylene oxide per mol of polyol while withdrawing from said first reaction zone a first reaction zone product stream subsequently defined, heating to 90 C. to 110 C. and stirring in said first reaction zone the polyol-adducbsolvent, catalyst,
said first reaction zone product stream into a recycle product stream and a second reaction zone polyol feed stream, returning said recycle product stream to said first reaction zone to serve as said polyol-adduct-solvent therein, passing into a second reaction zone said second reaction zone polyol feed stream and a stream of said alkylene oxide and stirring and heating same to 110 C. to 160 C. in the presence of a catalytic amount of said oxyalkylation catalyst, the proportions of said last-mentioned alkylene oxide stream and second reaction zone polyol feed stream being such as to produce the desired oxyalkylated polyol having a molecular weight up to about 10,000.
References Cited by the Examiner UNITED STATES PATENTS 2,450,079 I 9/48 Brown. 2,766,292 10/56 Monson et a1. 260--6l5 2,902,478 9/59 Anderson 260-209 2,987,489 6/61 Bailey et a1 260-615 XR- FOREIGN PATENTS 736,991 9/55 Great Britain.
LEON ZITVER, Primary Examiner. I
LEON ZITVER, Examiner.
UNITED STATES 'VPATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,190,927 June 22, 1965 John T. Patton, Jr. et a1.
It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 9, line 57, for "cyclohexane" read cyclohexene Signed and sealed this 17th day of January 1967.
(SEAL) Attest:
ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioxrer of Patents
1. A PROCESS FOR OXYALKYLATING A NORMALLY SOLID POLYOL,, WHICH COMPRISES, MIXING AND HEATING TO FROM 85*C. TO 170*C. IN THE PRESENCE OF A BASIC OXYALKYLATION CATALYST (1) A VICINAL ALKYLENE OXIDE, (2) A NORMALLY SOLID ORGANIC POLYOL HAVING 3 TO 8 HYDROXYL RADICALS PER MOLECULE AND (3) A SUBSTANTIALLY WATER-FREE ADDUCT OF A NORMALLY SOLID ORGANIC POLYOL HAVING 3 TO 8 HYDROXYL RADICALS PER MOLS CULE WITH FROM 1 T/ 4 MOLS OF A VICINAL ALKYLENE OXIDE PER MOL OF SAID POLYOL, SAID ORGANIC POLYOL HAVING A MELTING POINT OF AT LEAST 100*C. AND BEING SELECTED FROM THE GROUP CONSISTING OF PENTAERYTHRITOL, DIPENTAERYTHRITOL, TRIPENTACRYTHRITOL, TRIMETHYLOLETHANE, INOSITOL, MONOSACCHARIDES AND DISACCHARIDES, SAID ALKYLENE OXIDE BEING SELECTED FROM THE GROUP CONSISTING OF ETHYLENE OXIDE, PROPYLENE OXIDE, 1,2-BUTYLENE OXIDE, 2,3-BUTYLENE OXIDE, ISOBUTYLENE OXIDE, BUTADIENE MONOXIDE, STYRENE OXIDE, CYCLOHEXENE OXIDE, BUTADIENE DIOXIDE, METHYL GLYCIDYL ETHER, PHENYL GLYCIDYL ETHER AND MIXTURES THEREOF, SAID OXYALKYLATION CATALYST BEING SELECTED FROM THE GROUP CONSISTING OF AKALI METAL HYDROXIDES, ALKALI METALS AND ALKALI METAL ALCHOLATES, THE AMOUNT OF SAID ADDUCT EMPLOYED BEING SUFFICIENT SO THAT IT IS THE SOLVENT AND REACTION MEDIUM FOR THE PROCESS AND THE AMOUNT OF SAID SOLID ORGANIC POLYOL THAT IS EMPLOYED BEING AT LEAST SUFFICIENT SO THAT THE POLYOL IS OXYALKYLATED BY THE VICINAL ALKYLENE OXIDE UNDER THE CONDITION OF THE PROCESS.
| 1960-04-13 | en | 1965-06-22 |
US-16994093-A | Process for the production of stable high wax content vinyl latices
ABSTRACT
Stable, compatible, resin fortified aqueous vinyl polymer emulsions that are rich in wax are prepared in a method comprising a first polymerization of a mixture containing wax and monomers that include carboxylated monomers such as acrylic acid. The first polymerization or terpolymerization is carried out under conditions sufficient to produce a relatively low molecular weight resin. A portion of the wax rich resin from the first polymerization is neutralized and used as a cosurfactant in a second aqueous emulsion polymerization of vinyl monomers to produce a fortified vinyl latex that is rich in wax. Coatings prepared from the latex exhibit superior moisture barrier properties and are also useful as surface preservatives.
FIELD OF THE INVENTION
This invention relates to a novel process for production of stable aqueous emulsions of vinyl polymers, herein referred to as vinyl latices, that are rich in paraffinic wax and fortified with low molecular weight, carboxylated resins. The vinyl latices are prepared by addition polymerization of vinyl monomers in an aqueous emulsion mixture containing the aqueous reaction product of the addition polymerization of a mixture of monomers which also contain a carboxylated vinyl monomer and a substantial quantity of paraffinic wax. The resultant paraffin-rich, resin-fortified vinyl latices are useful for the preparation of coatings having especially low moisture permeability.
BACKGROUND OF THE INVENTION
The free radical initiated polymerization of vinyl monomers in aqueous emulsions is a process well known in the polymer field and described in such classic references as "Emulsion Polymerization" by F. A. Bovey, et al., Interscience Publishers, N.Y., 1955 and in the Encyclopedia of Polymer Science and Technology. The vinyl latices are prepared by suspending one or more monomers in water in contact with a surfactant and a free radical initiator such as ammonium persulfate. Surfactants commonly employed include ethoxylated polypropylene glycol, ethoxylated nonyl phenol, etc. Mixtures of various surfactants can be employed including the ammonium or alkali salts of low molecular weight polymers containing carboxy groups. The use of such low molecular weight carboxylated polymers as cosurfactant typically leads to the characterization of the resultant polymer vinyl latex as a fortified or resin-fortified latex.
Artisans engaged in the development of inks and surface coatings derived from polymer latices are continually challenged by the need to modify the latex formulations to enhance properties required for the end-user application. Of these modifications, the inclusion of wax in the latex formulation is commonly employed and is well known in the art. Wax, it has been found, functions well as a component of a vinyl latex to provide key properties in the coating produced therefrom. As will be described in more detail hereinafter, a wide variety of waxes can be and have been included in vinyl latex. These waxes, generally added in low concentrations to the vinyl latex, provide coatings with improved mar resistance, anti-blocking properties, slip and formability improvement, anti-settling, coating flatting, abrasion resistance and metal marking resistance.
As practiced in the art heretofore, waxes are added to the latex polymerization reaction mixture just before, during, or after the emulsification polymerization step. A major problem found within the latices prepared by this technique is a propensity for the wax to separate from the emulsion mixture, or otherwise cause the emulsion to break. Separation can occur as a function of the work preformed during application, during post-treatment of the coating formed in the application, as a result of ambient temperature swings or progressive chemical incompatibility. For whatever cause, the emulsion instability and resultant wax separation destroys the utility of the latex product. The problem of emulsion stability becomes particularly aggravated when higher concentrations of wax are required in the emulsion in order to confer a particularly desirable property on the resultant coating. The higher the wax loading, the more difficult it is to prepare a stable emulsion.
One of the more desirable coating properties sought after in the field of inks and synthetic surface coatings is moisture impermeability. It is highly advantageous for coatings such as those used on food and detergent containers to be very resistant to, if not impermeable to, moisture. One way to produce such moisture impermeability in vinyl latex derived coatings is to include relatively high loadings or concentrations of wax in the latex. However, a wax concentration high enough to render the subsequent coating a moisture barrier intrudes into the zone of those latex/wax mixtures that comprise highly unstable emulsions. Accordingly, workers in the field are critically challenged by the need to discover a means to prepare vinyl latices that are both stable as formulated but also contain high concentrations of wax so that coatings can be produced having improved moisture barrier qualities.
U.S. Pat. No. 4,151,143 describes a two stage process for the preparation of fortified, surfactant-free polymer emulsion. The first stage comprises the polymerization of a mixture of monomers including carboxylic containing monomers followed by neutralization of the polymer product. In a second stage a mixture of monomers including acrylate monomers and a polymerization catalyst are added to the emulsion produced in the first stage. No cosurfactant is utilized and the process does not teach the incorporation of high concentrations of wax.
U.S. Pat. No. 4,820,762 describes the preparation of a fortified latex composed of a preformed soluble resin, a cosurfactant and latex forming monomers. The soluble resin is dispersed in water or alkali and comprises a resin having a low molecular weight. The process does not teach the incorporation of high wax concentration in a fortified latex.
U.S. Pat. No. 4,293,471 teaches the production of a fortified emulsion polymer by first preparing an aqueous dispersion of an alkyd resin neutralized to a pH of about and then forming an emulsion polymer from one or more vinyl monomers in aqueous dispersion. The patent does not teach the production of high wax content emulsions.
U.S. Pat. No. 4,569,896 teaches the production of a toner composition which includes resin particles of styrene methacrylate copolymer grafted or containing a low molecular weight wax plus a second resin composed of a terpolymer of styrene, acrylate and acrylonitrile. The developer also contains magnetite particles and carbon black.
Japanese Patent JP 59,191,706 (CA vol. 102:62720t) teaches styrene grafted polyolefin waxes useful as release agents for molded plastics. The polymers are prepared by melt polymerization. The patent does not teach the preparation of fortified emulsions for moisture barrier coatings.
It is an object of the present invention to provide a process for the production of a stable vinyl latex that contains a high concentration of wax and is suitable for the formation of coatings that exhibit superior moisture barrier properties.
Another object of the present invention is the preparation of high wax content aqueous emulsions by the emulsion polymerization of vinyl monomers in the presence of a soluble resin cosurfactant containing said wax.
Yet another object of the present invention is the production of a high wax content soluble resin useful as a cosurfactant in aqueous emulsion polymerization wherein the soluble resin is prepared in the presence of wax under graft polymerization conditions.
SUMMARY OF THE INVENTION
A method has been discovered for the preparation of stable, compatible, resin fortified aqueous vinyl polymer emulsions that are rich in wax. The method involves two consecutive polymerization steps comprising a first polymerization of a mixture containing wax and monomers that include carboxylated monomers such as acrylic acid. The first polymerization or copolymerization is carried out under conditions sufficient to produce a relatively low molecular weight resin. All or at least a portion of the wax rich resin from the first polymerization, after neutralization of a major portion of the carboxylic acid moieties in the resin, is used as a cosurfactant in a second aqueous emulsion polymerization of vinyl monomers to produce a fortified vinyl latex that is rich in wax. Coatings prepared from the latex exhibit superior moisture barrier properties and are also useful as surface preservatives.
The process of the invention more specifically comprises a process for the production of a stable, wax-rich aqueous emulsion of vinyl polymers by a first step comprising copolymerizing under addition copolymerization conditions a wax-rich mixture comprising vinyl monomers containing at least one carboxylated vinyl monomer in contact with a free radical initiator. The resin or copolymerization product produced comprises a carboxylated vinyl copolymer resin rich in wax. A major portion of the copolymer is treated with ammonium hydroxide or aqueous alkali to produce an alkaline aqueous copolymerization product. In a second step, at least a portion of the alkaline aqueous copolymerization product is introduced into an aqueous emulsion polymerization mixture containing at least one vinyl monomer and a cosurfactant in contact with a free radical initiator under addition polymerization conditions whereby a stable, wax-rich aqueous emulsion is produced, referred to herein as a fortified latex.
A preferred embodiment of the invention comprises a process for the production of a stable, paraffin wax-rich vinyl latex useful in the production of coatings having low moisture permeability. The process includes two sequential steps comprising a first copolymerization step involving copolymerizing in an organic solvent under addition copolymerization conditions, for a time sufficient to produce a paraffin wax-rich copolymer product. The first step copolymerization mixture contains 32-33 wt. % of solvent, 10-30 wt. % of a paraffinic wax and 37-58 wt. % of a mixture of at least three vinyl monomers having a combined acid number between 150 and 250 and selected from vinyl monomers capable of providing homopolymers that exhibit glass transition temperatures greater than 70° C., plus about 10 wt. % (based on monomer) of a free radical initiator. The first step reaction mixture product is distilled to recover the copolymer product and the copolymer product is treated with aqueous alkali in an amount sufficient to provide an aqueous paraffin wax-rich copolymer product having a pH between 7.5 and 9.5.
All or a portion of the foregoing first step aqueous copolymer product is introduced into a second step aqueous latex emulsion copolymerization mixture under emulsion copolymerization conditions. The amounts of the latex reagents, including the first step product, are chosen so as to provide a final latex non-volatile solids composition of 45-75 wt. %, preferably 60-70 wt. %, of at least two vinyl comonomers, one of which comonomer comprises stearyl methacrylate; 2-10 wt. %, preferably 4-6 wt. %, of nonionic surfactant; 3-20 wt. %, preferably 7-10 wt. %, of wax from step one; and 20-50 wt. %, preferably 26-38 wt. %, of resin from step one. The copolymerization product comprises a stable, paraffin wax-rich vinyl latex.
DETAILED DESCRIPTION OF THE INVENTION
Two distinct polymerization reactions are carried out sequentially to produce the stable, wax-rich, fortified vinyl latex that satisfies a primary objective of the invention. The first is a polymerization process to produce a wax enriched, low molecular weight, water soluble resin; the second is an aqueous emulsion polymerization process that uses the soluble resin as a surfactant or cosurfactant to produce the stable, wax-rich fortified vinyl latex. As to the useful methods of polymerization, obviously the second polymerization is limited to methods known in the art for aqueous emulsion addition polymerization of vinyl monomers to form a latex, preferably by free radical initiation or catalysis. The first polymerization, however, in not so constrained. The production of a soluble resin rich in wax can be carried out by any of a variety of methods or mechanisms including ionic catalysis, coordination catalyst or free radical initiated addition polymerization, polycondensation, cyclopolymerization and the like. The first polymerization may be carried out in bulk, as by melt or neat polymerization, in solution, or in aqueous or organic emulsion. Preferably, the first polymerization is carried out in solution in an organic solvent.
The polymerization method to be used to prepare the wax-rich soluble resin is dictated largely by the selection of monomers to be polymerized or copolymerized, the desired molecular weight range and the type of wax to be incorporated in the soluble resin. Although not intending to be bound by theoretical considerations, the inclusion of a high concentration of wax in the soluble resins prepared by the process of the instant invention is believed to occur, in part, by graft polymerization of wax molecules onto the resin backbone as that backbone is formed during the course of polymerization. This event, wax grafting, tends to enhance the compatibility of the resin and non-grafted wax such that the carrying ability of the soluble resin for wax, i.e., the ability of the soluble resin to maintain a homogeneous mixture, is substantially increased.
In view of the foregoing theoretical considerations, the selection of monomers and polymerization methods useful for the preparation of soluble resins in the instant invention is restrained to those monomers and methods conducive to the formation of copolymers containing or carrying wax and/or having wax molecules grafted onto the resin backbone that can still be used effectively as a surfactant or cosurfactant in the subsequent vinyl emulsion polymerization step. It has been discovered that the judicious selection of monomers and methods for the production of soluble resins can lead to a substantial increase in the wax carrying capabilities of these resins and a subsequent increase in the stability of the wax containing aqueous emulsions or latices prepared using the soluble resins of the invention. Monomers and methods employed in the production of the soluble resin of the invention are particularly taken from those that produce vinyl polymers and/or alkyds having free carboxylic acid groups, described herein as carboxylated polymers or resins. For vinyl monomers, the preferred method for the production of the vinyl copolymers comprising the soluble resin is free radical initiated polymerization in solution.
PREPARATION OF SOLUBLE RESIN
Monomers for the first copolymerization step are selected to produce a low molecular weight, water soluble resin of low crystallinity and high glass transition temperature (Tg). Water solubility of the resin is necessary to permit the resin to function as a surfactant or cosurfactant in the subsequent aqueous emulsion polymerization and can be achieved by including an ethylenically unsaturated acid functional comonomer in the resin polymerization or an ethylenically unsaturated comonomer containing a water soluble polyether moiety.
Preferably, monomers suitable for the first polymerization preparation of a soluble resin include at least one monomer having an acid moiety or functionality in an amount sufficient to provide a soluble resin having an acid number of 150-250, based on total monomer weight. Acid functional monomers include acrylic acid (preferred), methacrylic acid, maleic acid or anhydride, half esters of maleic anhydride and the like. At least two other ethylenically unsaturated monomers are included in the first polymerization. Such monomers include styrene, α-methylstyrene, para-methylstyrene, parachlorostyrene, vinylnaphthalene, vinyl toluene, vinyl halides such as vinyl chloride, and acrylonitrile; vinyl esters including vinyl acetate, vinyl propionate, vinyl benzoate and the like; vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether, vinyl ethyl ether, and the like; vinyl ketones, vinylidene halides and N-vinyl pyrrolidone; acrylamide and C1 to C18 linear and branched esters of acrylic acid and methacrylic acid, particularly isobutyl methacrylate. The monomers are preferably selected so as to provide a soluble resin copolymer or terpolymer having a glass transition temperature of 70°-80° C., as calculated by the Fox equation.
The most preferred mixture of monomers to produce the preferred terpolymer soluble resin of the invention comprises acrylic acid, styrene and isobutyl methacrylate in a weight ratio of about 1:1.23:1.61.
Preferably, the selected monomers are dissolved in an organic solvent and the polymerization is carried out by free radical initiated solution polymerization. However, it is within the scope of the invention to carry out the polymerization to produce the soluble resin by free radical initiated bulk polymerization or aqueous emulsion polymerization. Useful solvents for the first polymerization include 4-methyl-2-pentanone, butyl acetate, propylacetate, 2-butanone, 2-heptanone, or mixtures thereof. MIBK or butyl acetate are most preferred.
Free radical initiators useful for the preparation of soluble resin comprise any peroxyester or peroxyacid soluble in the selected system. For solution polymerization, tert-butyl peroctoate is preferred. Others that could be used include benzoyl peroxide, t-butyl peroxyisobutyrate, t-butyl peroxyacetate, di-t-butylperoxide, t-butyl peroxybenzoate and azo-bisisobutyronitrile. Preferably, a relatively high concentration of initiator is used in the soluble resin polymerization step in order to produce a resin having a low molecular weight between about 1000 and 12,000, but preferably between about 4,000 and 8,000. The preferred molecular weight range can be achieved by using 8-10 wt. % of initiator, based on the total weight of monomers.
A key element of the instant invention is the discovery that stable fortified vinyl latices rich in wax can be prepared when the fortifying soluble resin that is added to the vinyl latex polymerization step is prepared in the presence of wax. While the wax concentration in the soluble resin polymerization reaction can be 10-60 wt. % based on solvent, the preferred range is 24-48 wt. %, with a most preferred wax content of about 37 wt. %.
While a wide range of waxes can be used to achieve the objective of the instant invention, the preferred wax is a neutral paraffin wax, Rosswax 145, which has a melting point of 51°-93° C., a flash point of 204°-243° C., a specific gravity at 25° C. of 0.88-0.92 and a molecular weight of about 500. Neutral paraffin wax is produced from petroleum from the neutral distillate overhead taken during crude refining and is predominantly a straight chain hydrocarbon.
Waxes, their definition and properties, are described in the Encyclopedia of Polymer Science and Technology, 1971, 14, pp 768-778, and in an article in the J. Oil & Colour Chem. Assoc. 1989, 72(8), pp 297,300 and 312 to which reference is made for a more detailed description of waxes useful in the instant invention. Waxes useful in invention are classified as natural, modified natural or synthetic waxes. Natural waxes include Beeswax and Carnauba wax. Modified waxes, derived from fossil fuels, include paraffin wax, microcrystalline wax and montan wax. Synthetic wax includes polyethylene wax, oxidized polyethylene wax and Fisher Tropsch Amide Wax.
The soluble resin polymerization mixture is typically prepared to contain 10-30 wt. % wax, 32-33 wt. % solvent and 37-58 wt. % of a mixture of monomers. Initiator is added at about 10 wt. %, based on monomer weight and the mixture heated for a time sufficient to complete the copolymerization, i.e., about 4-5 hours. Solvent is removed by evaporation or distillation and the residue is treated with aqueous alkali such as ammonium hydroxide or aqueous potassium hydroxide to neutralize 85-100 mol % of the carboxylic acid present in the resin. The aqueous product preferably contains about 30 wt. % of soluble resin and wax and preferably has a pH of 8.0-8.5. Non-volatiles comprise about 15-45 wt. % wax and 85-55 wt. % of copolymer or terpolymer.
PREPARATION OF WAX-RICH FORTIFIED VINYL LATEX
The second copolymerization is carried out basically according to aqueous emulsion polymerization methods well known for the production of vinyl latices. However, the method departs from known art in that a high wax content soluble resin is added as surfactant or cosurfactant and the comonomers are selected from those that will provide a calculated Tg of 50°-90° C., preferably 70°-85° C. The second copolymerization step of the process can be carried out in the same reaction vessel employed for the preparation of the soluble resin or an alternate vessel can be used with soluble resin added to the copolymerization process. In one embodiment, the soluble resin product is diluted with additional water in the reaction vessel and the aqueous emulsion polymerization carried out in the same vessel that contains all the soluble resin product.
Monomers useful in the preparation of the fortified vinyl latex include styrene, α-methylstyrene, para-methylstyrene, para-chlorostyrene, vinylnaphthalene, vinyltoluene, vinyl halides such as vinyl chloride, and acrylonitrile; vinyl esters including vinyl acetate, vinyl propionate, vinyl benzoate and the like; vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether, vinyl ethyl ether, and the like; vinyl ketones, vinylidene halides and N-vinyl pyrrolidone; acrylamide and C1 to C18 linear and branched esters of acrylic acid and methacrylic acid. Stearyl methacrylate is a particularly preferred comonomer for the production of vinyl latex. A particularly preferred comonomer pair is 70 wt. % styrene and 30 wt. % stearyl methacrylate.
In the instant invention, the soluble resin acts as surfactant for the vinyl monomer emulsion copolymerization. However a small amount of a cosurfactant can be added to enhance latex stability, reduce grit and foaming. A preferred cosurfactant is Igepal CO-977 (GAF Corp.). Other useful cosurfactants include Pluronic L-61 (BASF Corp.), Surfynol-104 and Surfynol-465 (Air Products and Chemicals, Inc.).
As free radical initiator for the vinyl polymerization, any water soluble initiator can be used with ammonium persulfate preferred.
The emulsion polymerization is carried out preferably at 20°-100° C., but most preferably at about 82° C. The amounts of reagents are chosen so as to give a final preferred non-volatile solids composition of 40-45 wt. % and containing 3-20 wt. wax. The remainder of the solids, i.e. 80-93 wt. %, is composed of 20-50 wt. % soluble resin from the first polymerization, but preferably 26-38 wt. %; 2-10 wt. % cosurfactant, but preferably 4-6 wt. %; and 45-75 wt. % latex-forming vinyl monomers, but preferably 60-75 wt. %.
The final latex product from a preferred aqueous emulsion polymerization contains about 41 wt. % total nonvolatile solids with an acid number of about 50. The Brookfield viscosity of the emulsion, measured at 25° C. and 20 RPM is 3-20 poises. The non-volatile composition is 9 wt. % wax and 91 wt. % non-wax solids. The non-wax solids consist of about 28 wt. % of a soluble resin of acrylic acid, styrene and isobutyl methacrylate, 5 wt. % of Pluronic L-61 and a vinyl copolymer comprising 47 wt. % styrene and 20 wt. % stearyl methacrylate.
Employing in sequence the foregoing methods for step 1, i.e. the preparation of the wax-rich soluble resin, and step 2, i.e. the preparation of the wax-rich resin fortified latex, a variety of wax enriched fortified laticies can be produced containing relatively low to relatively high wax concentrations. Generic examples of the process provided to illustrate the range of the invention are presented as Example A (low wax), Example B (intermediate wax) and Example C (high wax). Parts are expressed in parts by weight.
Example A (Low Wax)
The first step copolymerization is carried in a mixture containing 15.8 parts of wax and 84.2 parts of comonomers comprising 26 parts of acrylic acid (AA), 32 parts of styrene (S) and 42 parts of isobutyl methacrylate (IBMA) plus 10 wt. % of initiator, based on monomers. The second step fortified latex is prepared by emulsion polymerization of a mixture containing 32.6 parts of the foregoing copolymerization product, 4.7 parts of a surfactant and 63.7 parts of monomers comprising 70 parts of styrene and 30 parts of stearyl methacrylate. On a solids basis, the stable, fortified latex product contains 5 parts of wax and 95 parts of a mixture consisting of 5 parts of a surfactant, 28 parts of the polymeric residue from the polymerization of step 1 monomers and 67 parts of the polymeric residue from the polymerization of step 2 monomers.
Example B (Intermediate Wax)
A preferred wax rich resin fortified latex is prepare as follows:
The first step copolymerization is carried in a mixture containing 26.1 parts of wax and 73.9 parts of comonomers comprising 26 parts of acrylic acid (AA), 32 parts of styrene (S) and 42 parts of isobutyl methacrylate (IBMA) plus 10 wt. % of initiator, based on monomers. The second step fortified latex is prepared by emulsion polymerization of a mixture containing 34.5 parts of the foregoing copolymerization product, 4.5 parts of a surfactant and 61 parts of monomers comprising 70 parts of styrene and 30 parts of stearyl methacrylate. On a solids basis, the stable, fortified latex product contains 9 parts of wax and 91 parts of a mixture consisting of 5 parts of surfactant, 28 parts of the polymeric residue from the polymerization of step 1 monomers and 67 parts of the polymeric residue from the polymerization of step 2 monomers.
Example C (High Wax)
For a high wax content product the first step copolymerization is carried in a mixture containing 47.2 parts of wax and 52.8 parts of comonomers comprising 26 parts of acrylic acid (AA), 32 parts of styrene (S) and 42 parts of isobutyl methacrylate (IBMA) plus 10 wt. % of initiator, based on monomers. The second step fortified latex is prepared by emulsion polymerization of a mixture containing 42.4 parts of the foregoing copolymerization product, 4.0 parts of a surfactant and 53.6 parts of monomers comprising 70 parts of styrene and 30 parts of stearyl methacrylate. On a solids basis, the stable, fortified latex product contains 5 parts of wax and 95 parts of a mixture consisting of 5 parts of surfactant, 28 parts of the polymeric residue from the polymerization of step 1 monomers and 67 parts of the polymeric residue from the polymerization of step 2 monomers.
The following specific Examples 1, 5, 8 and 10 are presented herein to illustrate the process of the invention and the properties of the fortified latex product of the invention. Examples 2, 4, 7 and 9 are presented to provide comparisons with methods to prepare wax containing fortified latices and properties of those latices wherein the wax is added at some point subsequent to the preparation of the soluble resin. Examples 3 and 6 contain no wax. In all Examples where a wax was included (Examples 1, 2, 4, 5, 7, 8, 9 and 10), the wax was a neutral paraffin wax (Rosswax 145). The latex prepared in Examples 1-4 comprised an acrylic acid/styrene/isobutyl methacrylate soluble resin and a 70/30 styrene/stearyl methacrylate latex. Examples 5-7 comprised an acrylic acid/vinyl toluene/isobutyl methacrylate soluble resin and a 30/70 vinyl toluene/stearyl methacrylate latex. Examples 8-9 comprised an acrylic acid/vinyl toluene/isobutyl methacrylate soluble resin and a 70/30 vinyl toluene/stearyl methacrylate latex. Example 10 is identical to Example 1, with the exception that the soluble resin was neutralized with sodium hydroxide instead of ammonia. The results of the Examples show clearly that the product of the invention provides superior moisture barrier properties. The results of Examples 1-10 are summarized in Table 1. The moisture vapor transmission rate (MVTR) values reported in Table 1 and in the Examples were obtained after dilution of the corresponding reaction product with water to a viscosity of 20-25 sec Zahn cup number 2 and application with a number 5 Meyer Rod to the substrate.
Unless otherwise indicated, component parts of the Examples 1-10 are expressed in parts by weight.
TABLE 1
______________________________________
EX. NO. PROCESS SUMMARY MVTR.sup.1
______________________________________
1 (SR).sup.2,3
9% wax.sup.4 + AA/S/IBMA
0.4
(latex) S/SMA
2 (SR) AA/S/IBMA Coagulum and grit
(latex) 9% wax.sup.5 + S/SMA
3 (SR) AA/S/IBMA 3.0
S/SMA
4 (SR) AA/S/IBMA 2.5
(latex) S/SMA + 9% wax.sup.6
5 (SR) 17% wax + AA/VT/IBMA
0.6
(latex) VT/SMA
6 (SR) AA/VT/IBMA 2.5
(latex) VT/SMA
7 (SR) AA/VT/IBMA 4.0
(latex) VT/SMA + 17% wax.sup.6
8 (SR) 9% wax + AA/VT/IBMA
0.4
(latex) VT/SMA
9 (SR) AA/VT/IBMA 0.7
(latex) 9% wax.sup.5 + VT/SMA
10 (SR).sup.2,7
9% wax + AA/S/IBMA 0.4
(latex) S/SMA
______________________________________
.sup.(1) MVTR moisture vapor transmission rate, g/100 sq. in./day,
measured by Permatram W1A Water Vapor Transmission Rate Tester according
to ASTM F1249-89.
.sup.(2) soluble resin
.sup.(3) neutralization with aqueous 28% ammonia.
.sup.(4) weight percent of nonvolatile portion in final latex.
.sup.(5) Wax added prior to latex formation.
.sup.(6) Wax added to preformed latex.
.sup.(7) Neutralization with aqueous sodium hydroxide.
EXAMPLE 1
Step 1: Preparation of Wax/Soluble Resin Dispersion
A stirred flask was charged with 47.5 parts of methyl isobutyl ketone (MIBK) and 28.0 parts of Rosswax 45 (Frank B. Ross Co.). The mixture was heated to reflux temperatures, at which point a clear solution was formed. Over a 4-hour period, a solution of 20.0 parts acrylic acid, 25.2 parts styrene, 32.8 parts iso- butyl methacrylate, 8.0 parts t-butyl peroctoate and 8.0 parts MIBK was added at a constant rate. The batch was maintained at reflux temperatures throughout the addition period (120°-126° C.). After the addition, a further portion of 0.5 parts t-butyl peroctoate in 2.5 parts MIBK was added, and the reaction mixture was kept at reflux temperature for an additional 4-hour period. The apparatus was then fitted for azeotropic distillation, and MIBK solvent was removed until a batch temperature of 135° C. was reached. The batch was then allowed to cool below 100° C. then a solution of 24 0 parts of aqueous ammonia solution (28%) in 223.0 parts of deionized water was added gradually under vigorous stirring. After reheating to azeotropic distillation temperatures, the top-layer of distilled MIBK was removed and the bottom layer of water was returned to the reaction vessel. Upon reaching 100° C. the batch was maintained at that temperature for 30 minutes; then it was allowed to cool to 45° C. and discharged to give 347.7 parts of colorless dispersion, having a solids content of 30.0%, a pH of 8.86, an acid value of 144.0, and a Brookfield viscosity, at 25° C., of 203 poises (spindle No. 6, at 20 rpm).
Step 2: Wax/Fortified Latex Dispersion
A stirred flask was charged with 165.0 parts of the product from step-1, 6.5 parts Pluronic L-61 (BASF Corp.), 0.7 parts sodium bicarbonate, and 64.9 parts deionized water. The mixture was heated to 80° C. under a nitrogen blanket, and a solution of 0.7 parts ammonium persulfate in 11.4 parts water was added, followed by the addition, at a constant rate over a 4-hour period, of a solution of 61.2 parts styrene and 26.1 parts stearyl methacrylate. The reaction temperature was maintained at 80°±2° C. throughout the addition. Thirty minutes thereafter, a solution of 0.6 parts ammonium persulfate in 5.7 parts water was added, and the reaction mixture was maintained at 80°±2° C. for an additional 3-hour period. The mixture was cooled to 45° C. and filtered through a 150μ mesh nylon cloth to give 339.4 parts of colorless emulsion having a solids content of 42.61%, a pH of 8.05, and a Brookfield viscosity, at 25° C. of 21 poises (Spindle No. 3, 20 rpm). A drawdown of this product on a glass plate gave a clear, glossy, and tack-free film. Moisture barrier properties were 0.4 g/100 sq. in./day.
EXAMPLE 2 (COMPARATIVE)
The soluble resin was prepared from 77.2 parts acrylic acid, 95.8 parts styrene, 127.2 parts isobutyl methacrylate and 30 parts t-butyl peroctoate in 160 parts MIBK, followed by solvent interchange with a solution of 90 parts aqueous ammonia (28%) in 660 parts deionized water, as described in Example 1, part 1. The product, 1034.2 parts, had a solids content of 29.70%, a pH of 8.72, an acid value of 211 (based on solids content) and a Brookfield viscosity of 808 poises (spindle no. 7, 20 rpm). To 122.2 parts of this material were added 6.5 parts Pluronic L-61 (BASF Corp.), 0.7 parts sodium bicarbonate, 97.0 parts deionized water and 13.7 parts Rosswax-145. The mixture was then treated successively with a solution of 0.65 parts ammonium persulfate in 10.0 parts water, then with a mixture of 61.0 parts styrene and 26.1 parts stearyl methacrylate, followed with a solution 0.5 parts ammonium persulfate in 5.0 parts water, as described in Example 1, step 2. After completion of the reaction, filtration of this product gave 339.8 parts of colorless emulsion having a solids content of 41.15%, a pH of 8.03 and a Brookfield viscosity, at 25° C. of 14 poises (Spindle No 2, 20 rpm.). The air-dried residue from the filtration of this material amounted to 10.0 parts of wax and coagulum.
EXAMPLE 3 (COMPARATIVE)
To a stirred portion of 471.0 parts of the aqueous ammoniacal solution of the acrylic acid-styrene/isobutyl methacrylate copolymer described in Comparative Example 2 were added 25.0 parts Pluronic L-61 (BASF Corp.), 3.0 parts sodium bicarbonate, and 230.0 parts deionized water. The reaction mixture was treated with a solution of 3.0 parts ammonium persulfate in 25.0 parts water, followed by a mixture of 235.0 parts styrene and 100.0 parts stearyl methacrylate as described in the preceding examples. Filtration of this wax-free latex gave virtually no residue and gave 1113.6 parts of colorless latex having a solids content of 45.11%, a pH of 8.29, and a Brookfield viscosity, at 25° C., of 32 poises (Spindle No. 4, 20 rpm.). Moisture barrier properties of this product: 3.0 g/100 sq. in./day.
EXAMPLE 4 (COMPARATIVE)
A portion of 200.0 parts of wax-free fortified latex, prepared as described in Comparative Example 3, having a solids content of 52.55% and a pH of 8.69, was stirred and heated to 80° C.; then 10.4 parts Rosswax-145 were added portion-wise, followed by the slow addition of 61.5 parts deionized water, while maintaining the reaction temperature at 80°±2°; then cooled to 45° C. and filtered through a 150μ mesh nylon cloth to give 271.3 parts of colorless emulsion having a solids content of 42.10%, a pH of 8.56, and a Brookfield viscosity of 0.6 poise at 25° C. using a No. 2 spindle at 20 rpm. Moisture barrier properties of this product: 2.5 g/100 sq. in./day.
EXAMPLE 5
Step 1: Preparation of Wax/Soluble Resin Dispersion
The reaction vessel was charged with 30.0 parts MIBK and 28.0 parts Rosswax 145. While stirred, the mixture was heated to reflux temperatures (118° C.). A mixture of 10.0 parts acrylic acid, 12.6 parts vinyltoluene, 16.4 parts isobutyl methacrylate, 4.0 parts t-butyl peroctoate and 5.0 parts MIBK was added to the clear solution at a constant rate over a 3.5-4.0 hour period, while the reaction mixture was maintained at reflux temperature (120°-123° C.). One half hour after the addition, a further portion of 0.5 part t-butyl peroctoate in 2.5 parts MIBK was added, and the reaction mixture was maintained at reflux for an additional 3.5 hour period. The vessel was then fitted for azeotropic distillation and MIBK solvent was removed until a batch temperature of 135° C. was reached. After cooling to below 100° C., a mixture of 12.0 parts 28% aqueous ammonia in 144.0 parts deionized water was added under vigorous stirring. After reheating to azeotropic distillation temperatures, MIBK in the upper distillate layer was removed, and the bottom aqueous layer was returned to the reaction mixture. The batch was held at a vapor temperature of 100° C. for 30 minutes then cooled to 45° C. and discharged to give 244.0 parts of colorless dispersion, having a solids content of 29.9%, a pH of 9.11, an acid value of 116 a Brookfield viscosity at 25° C. of 4.6 poises (Spindle No 2, 20 rpm)
Step 2: Wax/Fortified Latex Dispersion
To a stirred flask was charged 161.0 parts of the product from step-1, followed by 5.0 parts Pluronic L-61 (BASF Corp.), 0.5 parts sodium bicarbonate, and 37.6 parts deionized water. The mixture was heated to 80° C. under a nitrogen blanket, and a solution of 0.5 parts ammonium persulfate in 10.0 parts water was added, followed by the addition, at a constant rate over a 4-hour period, of a solution of 47.0 parts stearyl methacrylate and 20.0 parts vinyltoluene. The reaction temperature was maintained at 80°±2° C. for an additional 3-hour period. The mixture was cooled to 45°-50° C. and filtered through a 150μ mesh nylon cloth to give 286.0 parts of colorless emulsion having a solids content of 42.38%, a pH of 8.81, and a Brookfield viscosity, at 25° C. of 32 poises (Spindle No 3, 20 rpm) A film of this material on a glass plate gave a clear, glossy, and tack-free film. Moisture barrier properties: 0.6 g/100 sq.in./day); gloss: 56.6.
EXAMPLE 6 (COMPARATIVE)
A fortified latex, prepared as described in Example 5, steps 1 & 2, except for the omission of Rosswax-145, having a solids content of 45.21%, an acid value of 56, a pH of 8 28 and a Brookfield viscosity, at 25° C. of 77 poises (Spindle No. 5 at 20 rpm), gave a clear, glossy and tack-free film. The moisture barrier properties were 2.5 g/100 sq. in./day.
EXAMPLE 7 (COMPARATIVE)
A portion of 90.0 parts of fortified latex, prepared as described in Example 5, steps 1 & 2, except for the omission of Rosswax 145, having a solids content of 45.41%, a pH of 8 74 and a Brookfield viscosity, at 25° C. of 51 poises (Spindle No. 5, 20 rpm), was heated to 65-70° C. while stirring with a high speed blender. Molten Rosswax 145, 10.0 parts, was slowly added to the stirred mixture. After the wax addition, the mixture was stirred for an additional hour at 65°-70° C. A film cast from the cooled product was found to be hazy and granular. Moisture barrier properties: 4.0 g/100 sq. in./day.
EXAMPLE 8 Step 1: Preparation of Wax/Soluble Resin Dispersion
A mixture of 28.0 parts Rosswax 145 and 47.5 parts MIBK was treated with 20.0 parts acrylic acid, 25.2 parts vinyltoluene, 32.8 parts isobutyl methacrylate, 8.0 parts t-butyl peroctoate and 8.0 parts MIBK as described in Example 5, step-1. The resultant dispersion was neutralized with 24.0 parts aqueous ammonia (28%) in 223.0 parts deionized water to give after MIBK removal, 349.7 parts of colorless dispersion, having a solids content of 29.95%, a pH of 9.13, an acid value of 152 and a Brookfield viscosity of 306 poises (Spindle No.6, 20 rpm).
Step 2: Wax/Fortified Latex Dispersion
A mixture of 165.0 parts of the product from the Example 7, 6.5 parts Pluronic L-61 (BASF Corp.), 0.7 parts sodium bicarbonate, and 64.9 parts deionized water was treated with a mixture of 61.2 parts vinyltoluene and 26.1 parts stearyl methacrylate as described in Example 5, step 2 After filtration at 45° C. 340.0 parts of colorless emulsion were obtained, having a solids content of 42.15%, a pH of 8.34 and a Brookfield viscosity of 30 poises at 25° C. (Spindle No. 3, 20 rpm). A film of this material on a glass plate was clear, glossy, and tack-free. Moisture barrier properties: 0.4 g/100 sq. in./day.
EXAMPLE 9 (COMPARATIVE)
The soluble resin was prepared from 77.2 parts acrylic acid, 95.8 parts styrene, 127.2 parts isobutyl methacrylate and 30 parts t-butyl peroctoate in 160 parts MIBK, followed by solvent interchange with a solution of 90 parts aqueous ammonia (28%) in 660 parts deionized water, as described in Example 1, part 1. The product, 1026.5 parts, had a solids content of 30.35 %, a pH of 8.55 and a Brookfield viscosity of 3800 poises (spindle no. 7, 20 rpm). To 92.3 parts of this material were added 5.0 parts Pluronic L-61 (BASF Corp.), 0.5 part sodium bicarbonate, 84.0 parts deionized water and 13.0 parts Rosswax 145. The mixture was treated with a solution of 47.0 parts vinyltoluene and 20.0 parts stearyl methacrylate as described in Comparative Example 6, to give 276.0 parts of a colorless emulsion having a solids content of 41.04%, a pH of 8.48 and a Brookfield viscosity of 5.0 poises at 25° C. (Spindle No. 3, 20 rpm.). A film of this material on a glass plate was hazy and tack-free. Moisture barrier properties: 0.7 g/ 100 sq. in./day.
EXAMPLE 10
Step 1: Preparation of Wax/soluble Resin Dispersion
A reaction vessel was charged with 100 parts MIBK and 52 parts Rosswax 145. The mixture was heated to reflux temperatures at which point a clear solution was formed. Over a 4-hour period, a solution of 43.6 parts acrylic acid, 53.8 parts styrene, 70.6 parts isobutyl methacrylate, 16.8 parts t-butyl peroctoate and 20 parts MIBK was added at a constant rate. The batch was then treated as described in Example 1, step 1, and neutralized with a solution of 18.3 parts sodium hydroxide in 394 parts deionized water. The product, 722.6 parts, had a solids content of 31.24 %, a pH of 7.9, a Brookfield viscosity of 80 centipoises (spindle no. 2, 20 rpm) and a residual acid number of 31.
Step 2: Wax/Fortified Latex Dispersion
A reaction vessel was charged with 156.7 parts of the product from step 1, 7.1 parts Pluronic L-61 (BASF Corp.), 0.8 parts sodium bicarbonate, and 104.3 parts deionized water. The mixture was heated to 80° C., and a solution of 0.8 part ammonium persulfate in 10.0 parts deionized water was added, followed by the addition of a mixture of 62.5 parts of styrene and 26.8 parts stearyl methacrylate at a constant rate over a 3-hour period at a reaction temperature range of 80°±2° C. The reaction mixture was then treated as described in Example 1, step 2, to give 372.4 parts of a colorless emulsion having a solids content of 42.3%, a pH of 7.9, an acid value of 14, and a Brookfield viscosity of 84 centipoises (spindle no. 2, 20 rpm). Moisture barrier properties were 0.4 g/100 sq. in./day.
As described herein before, the preferred wax for use in the process of the invention is a neutral paraffin wax such as Rosswax 165. However, other waxes can be used with varying degrees of success when, particularly when they are incorporated into the latex by the method described in Example 1. Examples 11-20 were carried out using various waxes under the graft polymerization and non-graft polymerization conditions depicted in Examples 1-10 and the properties of the resultant latex were measured. The waxes tested and the properties of the resultant product are presented in Table 2.
TABLE 2
______________________________________
WAX.sup.1
MP Acid
Exam. Name °C.
No. Type
______________________________________
11 Rosswax 165 74 0 paraffin
12 Paraffin wax 112/118
46 0 paraffin
13 Cardis 320 91 36 Oxid. HC. microcry.
14 Cardis 320 " " "
15 Petrolite C8500
95 9 "
16 Ceramer-67 97 48 Modified HC
17 Ceramer-67 " " "
18 Polywax 500 88 0 Polyethylene
19 Vybar 373.sup.(2)
110 0 Fischer Tropsch
20 Vybar-103.sup.(2)
71 0 Fisher Tropsch
______________________________________
PRODUCT PROPERTIES
Total % Brook.
Exam. Non-Vol. Vis. (P) MVTR.sup.(4)
GLOSS.sup.(5)
______________________________________
11 39 55
12 42 17 4.8 30
13 40 2 50
14 unstable latex non-graft.sup.(3)
15 40 19 3.3 57
16 40 100 3.5 53
17 unstable latex non-graft.sup.(3)
18 38 100 0.6 43
19 41 190 1.2 49
20 45 114 1.1 50
______________________________________
.sup.(1) All waxes constitute 9-10% of the nonvolatile portion of the
final latex.
.sup.(2) Equal weight mixtures with Rosswax 145.
.sup.(3) Wax added after formation of soluble resin, as in comparative
Examples 2 and 9.
.sup.(4) MVTR moisture vapor transmission rate, g/100 sq. in./day,
measured by Permatram W1A Water Vapor Transmission Rate Tester, according
to ASTM F1249-89.
.sup.(5) Determined by BYK Gardner, Inc. Gloss Meter at reflected light o
60° angle.
What is claimed is:
1. A process for the production of a stable, paraffin wax-rich vinyl latex useful in the production of coatings having low moisture permeability comprising the steps of:a) copolymerizing in an organic solvent under addition copolymerization conditions for a time sufficient to produce a paraffin wax-rich soluble resin a component mixture comprising: (1) a paraffinic wax and (2) a monomer mixture of at least three vinyl monomers having a combined acid number between 150 and 250 and selected from vinyl monomers capable of providing homopolymers that exhibit glass transition temperatures greater than 70° C., and a free radical initiator; b) distilling the copolymerization reaction mixture to recover said soluble resin; c) treating the soluble resin with aqueous alkali in an amount sufficient to provide an aqueous paraffin wax-rich soluble resin having a pH above 7.5; d) introducing a portion of said aqueous soluble resin into an aqueous emulsion copolymerization component mixture under emulsion copolymerization conditions, said mixture comprising at least two vinyl monomers, one of which monomer comprises stearyl methacrylate, a nonionic surfactant, and a free radical aqueous emulsion polymerization initiator; whereby said stable, paraffin wax-rich vinyl latex is produced.
2. The process of claim 1 wherein the step a) vinyl monomers are selected from the group consisting of acrylic acid, methacrylic acid, styrene, vinyltoluene, α-methylstyrene, vinyl chloride, acrylonitrile, acrylamide, vinyl acetate, esters of acrylic acid, esters of methacrylic acid and stearyl methacrylate.
3. The process of claim 1 wherein said soluble resin contains about 9 wt. % paraffinic wax and comprises a terpolymer of acrylic acid, styrene and isobutyl methacrylate.
4. The process of claim 1 wherein the step d) vinyl monomers are selected from the group consisting of, styrene, vinyltoluene, α-methylstyrene, vinyl chloride, acrylonitrile, acrylamide, vinyl acetate , esters of acrylic acid, esters of methacrylic acid and stearyl methacrylate.
5. The process of claim 1 wherein the step a) component mixture contains 10-30 wt.% said wax and 37-58 wt. % said vinyl monomers; and the step d) component mixture contains 45-75 wt. % of said vinyl monomers, based on total solids.
| 1993-12-20 | en | 1995-03-07 |
US-75172585-A | Stirling engine
ABSTRACT
A Stirling engine wherein a pressure variation is provided by a reciprocative movement of a displacer and is effected upon a power piston to obtain an output motive force. A first elastic film is provided at the displacer rod projecting into the crankcase so as to produce a first hermetically sealed space bounded by the expansion cylinder. A second elastic film is provided at the power piston rod so as to produce a second hermetically sealed space below the power piston. A pressure adjusting device equalizes the mean pressure of a reactive space, which includes the first and the second hermetically sealed spaces, and that of the crankcase.
FIELD OF THE INVENTION
The present invention relates to a Stirling engine, and more particularly, to an improvement of the mechanism for sealing the working gas.
BACKGROUNO OF THE INVENTION
In order to explain a prior art Stirling engine, reference will be particularly made to FIG. 1:
FIG. 1 is a schematic diagram of a displacer type Stirling engine as a typical example of a Stirling engine. The reference numeral 1 designates an expansion cylinder, the numeral 2 designates a heater tube, the numeral 3 designates a regenerator, the numeral 4 designates a cooler tube, the numeral 5 designates a displacer, and the numeral 6 designates a displacer rod. The numeral 7 designates a first rod seal for sealing the sliding gap between the expansion cylinder 1 and the rod 6. The numeral 8 designates a compression cylinder. The numeral 9 designates a first communicating pipe located between the compression cylinder 8 and the expansion cylinder 1. The numeral 10 designates a power piston. The numeral 11 designates a power piston rod. The numeral 12 designates a second rod seal for sealing the sliding gap between the compression cylinder 8 and the power piston rod 11. The numeral 13 designates a first connecting rod for converting the rotating force of a crankshaft to the reciprocative movement of the diplacer 5. The numeral 14 designates a second connecting rod for converting the reciprocative movement of the power piston 10 to a rotating force of the crankshaft. The numeral 15 designates the crankshaft which utilizes the reciprocative movement of the displacer 5 and that of the power piston 10 while keeping a predetermined phase difference therebetween to obtain a rotating force. The numerals 16 and 17 designate main bearings for the crankshaft 15. The numeral 100 designates a crankcase for supporting the components 1 to 17 arranged at respective predetermined positions. The numeral 18 designates a buffer chamber.
In this Stirling engine, the heater tube 2 is continuously heated by such as a burner, and the cooler tube 4 is continuously cooled by such as water to generate a pressure variation in the cylinder. Thus the power piston 10 moves up and downwards to generate a motive force.
It is common practice to use hydrogen or helium as the working gas contained in the expansion cylinder 1 and the compression cylinder 8 in order to operate the Stirling engine at a high efficiency and a high output motive force. Accordingly, one of the most important problems in utilizing the Stirling engine resides in the hermetical sealing of the hydrogen or helium.
In the prior art device, however, a lip seal or an O-ring is used as the first rod seal 7 and the second rod seal 12, and it was difficult to seal the hydrogen or helium perfectly for a long period of time.
Regarding another prior art Stirling engine, there is an article "DEVELOPMENT OF A STIRLING ENGINE ROD SEAL" by SHORT, M. G. 17th IECEC, LOS ANGELES, p 1881 to 1884, 1982, wherein there is described a construction and a function of a sliding seal made of PTFE or the like used as a Stirling engine rod seal. According to this article, it was impossible to perfectly seal the working gas or the oil in the moving state.
SUMMARY OF THE INVENTION
The present invention is directed to solving the problems pointed out above, and has for its object to provide a Stirling engine capable of sealing the working gas in the cylinder perfectly, and furthermore capable of enhancing the sealing life to a great extent.
Other objects and advantages of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific embodiment are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
According to the present invention, there is provided a Stirling engine where a pressure variation is provided by a reciprocative movement of a displacer and it is effected upon a power piston to obtain an output motive force, which comprises: a first elastic film which is provided at the displacer rod projecting into the crankcase so as to produce a first hermetically sealed space with the expansion cylinder; a second elastic film which is provided at the power piston rod so as to produce a second hermetically sealed space below the power piston; and a pressure adjusting means which equalizes the mean pressure of the reactive space, which includes the first and the second hermetically sealed spaces, and that of the crankcase.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing a typical example of a prior art Stirling engine;
FIG. 2 is a schematic diagram showing a first or γ type Stirling engine as a first embodiment of the present invention;
FIG. 3 is a schematic diagram showing a concrete example of the pressure adjusting means of the engine FIG. 2;
FIG. 4 is a schematic diagram showing a second or β type Stirling engine as a second embodiment of the present invention; and
FIG. 5 is a schematic diagram showing a third or α type Stirling engine as a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to explain a first embodiment of the present invention in detail, reference will be particularly made to FIG. 2 wherein the same reference numerals are used to designate the same elements as those shown in FIG. 1.
The reference numeral 101 designates a pressure containing crankcase for supporting the expansion cylinder 1 and the compression cylinder 8 arranged at respective predetermined positions. The crankcase 101 can be subjected to a pressure application up to the same pressure as the mean pressure of the working gas in the expansion cylinder 1 and the compression cylinder 8. The reference numeral 23 designates a rotating axis seal for preventing the sealed gas in the crankcase 101 from leaking out from the gap between the crankcase 101 and the crankshaft 15. The numeral 19 designates a first elastic film such as a bellows provided below the expansion cylinder 1 inside the crankcase 101. One end of the elastic film 19 is fixed to the bottom of the expansion cylinder 1 and the other end thereof is fixed to the displacer rod 6 projecting into the crankcase, thereby constituting a first hermetically sealed space 19a surrounded by the first rod seal 7 and the first elastic film 19 which space is perfectly separated from the crankcase. The numeral 20 designates a second elastic film for partitioning the compression cylinder 8 from the crankcase. One end of the second elastic film 20 is fixed to the bottom of the expansion cylinder 8 and the other end thereof is fixed to the power piston rod 11, thereby constituting a second hermetically sealed space 20a surrounded by the lower surface of the power piston 10, the internal wall of the compression cylinder 8, and the second elastic film 20 which space is perfectly separated from the crankcase. The numeral 21 designates a second communicating pipe for communicating the first hermetically sealed space 19a and the buffer chamber 18 which pipe is connected to the connecting portion 22 of the buffer chamber 18. The second hermetically sealed space 20a is directly connected to the buffer chamber 18.
The reference numeral 24 designates a pressure difference meter for detecting the pressure difference between the pressure in the buffer chamber 18 and that in the crankcase. As shown in FIG. 3, the pressure difference meter 24 comprises a diaphragm device 24h constituted by a diaphragm 24f and a diaphragm spring 24g, and a transformer 24i constituted by a primary coil 24d, a secondary coil 24e, and a core 24c. The numeral 24b designates an inlet pipe for introducing the pressure in the crankcase, and the numeral 24a designates an inlet pipe for introducing the pressure in the buffer chamber 18.
The numeral 25 designates an operational control circuit intended to generate a signal in accordance with the pressure difference. The numeral 26 designates an electro-magnetic valve which is opened or closed by the signal, and this valve is controlled by the operational control circuit 25 so that the pressure difference from the pressure difference meter 24 may become 0. The numeral 27 designates a pressure control apparatus having a secondary controlled pressure which is equal to the mean pressure in the reactive space which includes the buffer chamber 18, space 19a, space 20a and pipe 21.
The numeral 29 designates a third communicating pipe for supplying gas to the crankcase.
This Stirling engine is operated as follows:
The working space is constituted by the expansion cylinder 1, the heater tube 2, the regenerator 3, the cooler tube 4, the compression cylinder 8, and the first communicating pipe 9. The reactive space which decides the mean pressure of the working space is constituted, as noted previously by the buffer chamber 18, the first hermetically sealed space 19a, the second hermetically sealed space 20a, and the second communicating pipe 21. The mean pressure of the working space, that of the reactive space, and the pressure in the crankcase can be held at an approximately equal pressure. That is, when the pressure in the crankcase is lowered, for example, by about 0.5˜2 kg/cm2 by the leakage of the gas in the crankcase from the rotating axis seal 23 of the crankshaft, the pressure difference meter 24 converts the pressure difference between the pressure in the buffer chamber 18 and that in the crankcase into a displacement of the core 24c by the diaphragm device 24h, and further converts that displacement into the variation of the impedance of the transformer 24i to obtain an electric quantity in accordance with the pressure difference, and the operational control circuit 25 compares the electric quantity from the pressure difference meter 24 and the reference electric quantity at 0 pressure difference, and supply gas from the high pressure gas tank 28 to the crankcase through the pressure control apparatus 27 (pressure adjusting means) by opening the electro-magnetic valve 26 until the pressure difference becomes approximately equal to 0. Hereupon, the pressure control apparatus 27 operates to reduce the pressure in the high pressure gas tank 28 to become equal to that in the buffer chamber 18. Thus, the gas is automatically supplied to the inside of the crankcase from the high pressure gas tank 28, and the mean pressures in the three spaces are held approximately equal to each other.
Accordingly, the gas pressures applied to the elastic films 19, 20 can be regarded as 0 because the pressures in the first and the second sealed space 19a, 20a and the pressure in the crankcase are equal to each other. The elastic films 19 and 20 can be designed by only taking into consideration the exhaustion by the expansion and contraction thereof which corresponds to the both strokes of the displacer and the power piston.
Furthermore, hydrogen or helium having a low viscosity, a low molecular weight, and a high thermal conductivity is sealed in the working space and the reactive space which are pertinent to the engine efficiency, and it becomes capable of using a gas having a high molecular weight and a high viscosity such as air or nitrogen as a gas in a crankcase which does not directly have any influence upon the engine efficiency. So, the leakage of gas from the rotating axis seal between the crankcase 100 and the crankshaft is lowered to approximately 1/10 as compared with the case of using hydrogen or helium, thereby realizing the practical use of the engine.
In the illustrated embodiment shown in FIG. 2, a displacer and a power piston are provided separately, but the present invention can also be applied to a second type Stirling engine which has a displacer and a power piston in a cylinder.
This second type Stirling engine is employed in a second embodiment of the present invention and is shown in FIG. 4 wherein the same reference numerals designate the same elements as those shown in FIG. 2. The reference numeral 102 designates a cylinder which operates as both of the expansion cylinder and the compression cylinder in FIG. 2. In this engine construction the gas supply piston 5 and the power piston 10 are arranged on a same axis line. The numeral 103 designates a first elastic film provided between the power piston 10 and the gas supply piston rod 6. The mumeral 104 designates a first rod seal for sealing the sliding gap between the power piston 10 and the gas supply piston rod 6. The numeral 105 designates a communicating opening for communicating between the second hermetically sealed space 20a and the space produced between the first rod seal 104 and the first elastic film 103 at the side space of the power piston rod 6. This communicating opening 105 has the same function as that of the second communicating pipe 21 in FIG. 2.
In the second type Stirling engine under such a construction, the first and the second elastic film can be designed by only taking into consideration the exhaustion by the expansion and compression thereof which corresponds to the both strokes of the displacer and the power piston by the function of the apparatus constituted by the components 29, 24, 25, 26, 27, and 28 shown in FIG. 2. Of course, the same operation and effects are obtained as those of the first embodiment.
Furthermore, the present invention can be applied to a third type Stirling engine which has two cylinders, and has confronting pistons.
This third type Stirling engine is utilized in a third embodiment of the present invention and is shown in FIG. 5 wherein the same reference numerals designate same elements as those shown in FIG. 2. In this embodiment the displacer 5 is also called as an expansion piston. Similarly as the first and the second embodiments the first and the second elastic film can be designed by only taking into consideration the exhaustion by the expansion and compression thereof which corresponds to the both strokes of the displacer and the power piston by the function of the apparatus constituted by the components 29, 24, 25, 26, 27, and 28 shown in FIG. 2, and the same operation and effects are obtained as those of the first embodiment.
As described above, according to the present invention, an elastic film is used to seal between each cylinder and each rod related to the cylinder, and the working space, the reactive space, and the crankcase are sealed respectively so as to obtain a mean pressure equal to each other.
Furthermore, a gas having a large molecular weight and a high viscosity such as air or nitrogen is used in the crankcase which cannot be perfectly sealed, thereby lowering the leakage from the rotating axis seal to about 1/10 as compared with the case of using hydrogen or helium. This is quite advantageous in the practical use of the Stirling engine.
What is claimed is:
1. A Stirling engine wherein a pressure variation is provided by reciprocative movement of a displacer and is utilized by a power piston to obtain an output motive force, which comprises:a pressurized crankcase, an expansion cylinder having a seal carrying wall, a displacer located in said expansion cylinder, a displacer rod connected to said displacer and projecting through said seal and into said crankcase, a first elastic film attached to said displacer rod and to said seal carrying wall so as to produce a first hermetically sealed space, a compression cylinder, a power pistion having a power pistion rod located in said compression cylinder, a second elastic film attached to said power piston rod and to said compression cylinder so as to produce a second hermetically sealed space below said power piston, said first and said second hermetically sealed spaces being included in a pressurized reactive space, a pressure adjusting means for equalizing the mean pressure within said reactive space and the mean pressure within said crankcase, a heater tube, a regenerator, and a cooler tube are connected to said expansion cylinder, and are included in a working space, as is the expansion cylinder and the compression cylinder, and a first gas having a low viscosity, a low molecular weight and a high thermal conductivity is sealed in said working space and said reactive space, and a second gas having a high viscosity and a high molecular weight is sealed in said crankcase.
2. A Stirling engine as set forth in claim 1, wherein said first gas is helium.
3. A Stirling engine as set forth in claim 1, wherein said pressure adjusting means comprises:pressure difference meter for detecting the pressure difference between the means pressure in said reactive space and that in said crankcase; an operational control circuit means for generating an electric signal in accordance with the pressure difference; an electro-magnetic valve intended to be opened or closed by the electric signal; and a pressure controlling apparatus for supplying a second gas having a pressure equal to the mean pressure in the reactive space through the valve.
4. A Stirling engine as set forth in claim 1, wherein said first gas is hydrogen.
| 1985-07-03 | en | 1986-11-04 |
US-77190377-A | Circuit for simultaneous display of separately broadcast video signals
ABSTRACT
A circuit system for a television receiver, said system operating to repl a changing quadrant of the picture of a main transmitted program with an equivalent-size sector of a second transmitted program.
BACKGROUND OF THE INVENTION
The present invention concerns a circuit system for a television receiver on which a first transmitted program is reproduced and including means by which at least a portion of the picture of a second transmitted program is made simultaneously visible replacing a portion of the initially reproduced program.
Prior art television receivers in which more than one program can be viewed simultaneously have been constructed with an additional smaller television screen being placed adjacently to the main screen. However, that method of construction is very expensive because it requires a complete duplication of parts, including the television picture tube.
A method for elimination of the additional television tube has been accomplished in television studios where the co-joining or mixing of at least one part of an additional television picture into a blanked sector of the main picture is common practice. However, the method of combining a plurality of television images taken by different in-station television cameras and reproduced together on the same receiver screen is simplified by the fact that the deflection signals for the different television camera tubes have identical timing. Thus, the method is limited to television studio systems operating under closed-circuit conditions. The same limitation also applies to known methods for the simultaneous showing of several video signals originating from different in-station television cameras in which different saw-tooth signals are applied to the different television cameras, but where the frequencies of the signals are related to each other by integral fraction.
The simultaneous reproduction of television picture signals beamed by various television stations onto one television receiver screen has been accomplished by the blending of a reduced image of a second program into the televised picture of the main program. However, that method requires memory capability for the purpose of reducing the size of the picture of the second program and for the purpose of overcoming the difference in time between the synchronizing signals broadcast by the two stations. The size reduction of the picture of the second program has been achieved by designing the output speed for the memory to be greater than the input speed and by limiting reproduction to only every fourteenth line of the second program. The reduced picture consequently has a diminished resolution in the vertical direction.
SUMMARY OF THE INVENTION
The present invention utilizes a television receiver circuit system which operates without the previously described memory and associated circuitry. This invention is based on the fact that it is often sufficient to replace part of the picture of the main program with a mere part of the picture of the second program, since the viewer wishes merely to be informed as to whether the second program is of interest to him or her or whether is has already begun. This can be readily accomplished by viewing merely a sector of the picture transmitted for the second program. The circuit system of this invention replaces a quadrant of the picture of the main program with a sector of the picture of the second program. The sector of the second picture is not reduced in size, nor is the resolution changed. Both the remaining part of the main picture and the sector of the second picture are displayed exactly as broadcast.
Accordingly, the present invention provides a television receiver with a picture screen on which a first program is televised, said television receiver having a circuit system by means of which at least a segment of a second transmitted video signal is made visible simultaneously, said segment replacing a segment of the simultaneously broadcast first transmitted video signal. Said circuit system includes a means for receiving, tuning and amplifying the video signals at intermediate frequency, a means for extracting from each signal the respective horizontal-frequency and vertical-frequency synchronizing pulses. The phase positions of the respective sync signals from each transmitter are compared by a phase-comparison means, said phase-comparison means providing a bi-level switching signal with timing dependent on the relative phase position of both the horizontal and the vertical synchronizing pulses. The phase-comparison means chooses a rectangular portion of the picture of the second program to replace an equivalent size rectangular quadrant of the main program. The quadrant of the main program is continually re-selected to be free from synchronizing pulses of the second program. The bi-level ouput signal of the phase-comparison means is used to drive a switching means which alternately transmits first and second picture signals to the video-display means.
BRIEF DESCIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the circuit system of this invention;
FIG. 2 is a detailed block diagram of a phase-comparison means for use in the circuit system of the present invention;
FIG. 3 is a pulse diagram for use in explaining operation of the phase-comparison means of FIG. 2;
FIG. 4 indicates a picture frame divided into sectors for the purpose of explanation of the circuit system of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is based on the fact that transmitters using standard color television signals for the NTSC and PAL systems transmit a video signal which has fixed ratios between the horizontal and vertical scanning frequencies and the color sub-carrier frequency. Since the frequency of the color sub-carrier is required to have an accuracy on the order of 10 -6, a very close agreement between the horizontal and vertical scanning frequencies from transmitter to transmitter is ensured. It is therefore possible to mix the video information of a transmitter A with that of a transmitter B, or to co-join the information of transmitter B with the information of transmitter A. However, due to very slight differences of frequency, the synchronizing pulses of transmitter B are generally shifting in phase with respect to the synchronizing pulses of transmitter A, and this phase shift results in the picture of transmitter B slowly shifting its position in relation to the picture of transmitter A. In addition, a fixed or non-time-varying phase displacement between the received synchronizing pulses of two transmitters may also result from relative geographical distances between the receiver and the transmitters. The synchronizing and blanking pulses contained in the video information of transmitter B, when super-imposed on a signal displayed from transmitter A, show themselves as broad black horizontal and vertical bars which move vertically and laterally as the phase of the two signals shift with respect to each other. If the screen is divided into four sectors, I, II, III, and IV, it will be seen from FIG. 4 that at any instant one sector of the picture from transmitter A is always free from the moving broad black horizontal and vertical bars caused by the shifting phase of the blanking pulses of transmitter B. The circuit system of the present invention automatically selects this bar-free sector and reproduces therein a part of the picture transmitted from transmitter B.
In the circuit system of FIG. 1, the television video signals of first and second transmitters, A and B, pass through means for receiving, tuning and amplifying said signals at intermediate frequency. Said means may include an antenna 1 connected to antenna filter 2, which in turn is connected to two intermediate frequency amplifiers 4 and 9 through separate tuners 3 and 5. It is assumed here that tuner 3 is tuned to transmitter A and tuner 5 is tuned to transmitter B. The signal from transmitter A is processed and reproduced on the picture tube 8 as the first or main program. The signal is processed in the usual manner through an IF amplifier 4 from which it passes through switching means 12, described later, to a video-display means comprised of luminance amplifier 6, television tube 8 and deflection unit 10. The synchronizing pulses from transmitter A are simultaneously processed in the sync-separating means 7 from which the deflection signals for the deflection unit 10 are obtained. In the circuit system of a color television receiver, the color signals pass through chrominance processor 11. The additional program from transmitter B is received by tuner 5, then processed through IF amplifier 9 from which it passes to the luminance amplifier 6 via switching means 12 to which the other program is also connected. In addition, the transmitter B signal of IF amplifier 9 is applied to sync-separating means 13 which delivers the horizontal frequency and vertical frequency synchronizing pulses to phase-comparison means 14, said pulses being compared with the transmitter A vertical-frequency and horizontal-frequency synchronizing pulses from the sync-separating means 7. The phase-comparison means 14 causes switching means 12 to operate dependent on the relative phase position of the synchronizing pulses, so that a part of the picture from the signal of transmitter B appears on the screen of the television tube 8. Switching means 12 thus transmits to luminance amplifier 6 that part of the picture transmitted by transmitter B which is free from horizontal and vertical synchronizing and blanking pulses. Where used in a color television receiver, the chrominance processor 11 may be blocked by a blocking pulse which inhibits processor 11 during display of the part of the picture from transmitter B. The circuit system of this invention may, of course, also be used with a black and white television receiver, in which case chrominance processor 11 is eliminated from the circuit system indicated in FIG. 1.
One embodiment of phase-comparison means 14 and production of the bi-level signal required for operation of switching means 12 will now be described with reference to FIG. 2 and FIG. 3.
The transmitter A horizontal-synchronizing pulses H1 and vertical-synchronizing pulses V1 from sync-separating means 7 of the receiver arrive at the inputs of frequency-dividing bi-stable flip-flops 15 and 16, causing them to switch to a first state for start of the horizontal or the vertical sweep. The flip-flops shown are those in which a positive pulse on one input switches the indicated output to a positive potential and a positive pulse on the other input switches the other output to a positive potential. Simultaneously, half-sweep one-shot multivibrator 17 or 18 is triggered. Multivibrators 17 and 18 are timed such that the electron beam, after said one-shot multivibrators switch back, has not reached the center of the picture either in the horizontal or in the vertical direction. Center-blanking-triggering one-shot multivibrators 19 and 20 and half-sweep-pulsing one-shot multivibrators 21 and 22 are connected in tandem pairs to one-shot multivibrators 17 and 18 and, during operation, switch the output of flip-flops 15 and 16 to a second state after a half-sweep delay determined by the one-shot multivibrators 17 and 19 as well as 18 and 21. The outputs of flip-flops 15 and 16 are passed through AND gates 23L, 23R, 24T and 24B. The outputs of AND gates 23L, 23R, 24T and 24B are inhibited by H1, output of multivibrator 20, output of multivibrator 22 and V1 respectively. The effect of said inhibited AND gates is to delay the leading edge of the output of flip-flops 15 and 16 by the duration of the synchronizing pulses H1 and V1 or by the length of the pulse output of one-shot multivibrators 20 and 22. One-shot multivibrators 20 and 22 have pulse lengths substantially equal to the lengths of pulses H1 and V1. The time delays, which could also be accomplished by use of exclusive OR gates, are necessary in order to produce stable switching conditions in the center of the respective horizontal and vertical sweeps as well as at the top and left side of the picture. The outputs of the AND gates 23L and 23R are then compared with the synchronizing pulses H2 of the television signal from transmitter B, said outputs and pulses being applied to horizontal-comparison AND gates 25 and 26. Similarly, the outputs of AND gates 24T and 24B are compared with the synchronizing pulses V2 at the inputs of vertical-comparison AND gates 27 and 28. The outputs of AND gates 25, 26, 27, and 28 are applied to respective inputs of horizontal-locking bi-stable flip-flop 29 and vertical-locking bi-stable flip-flop 30. Flip-flop 29 has first and second outputs 29R and 29L. Flip-flop 30 has first and second outputs 30T and 30B. The bi-stable flip-flops 15, 16, 29 and 30 are connected to first-, second-, third-, and fourth-quadrant-comparison AND gates 31, 32, 33 and 34. The flip-flop outputs 29R, 15L, 16T and 30B are connected to the inputs of AND gate 31. The flip-flop outputs 29L, 15R, 16T and 30B are connected to the inputs of AND gate 32. The flip-flop outputs 29R, 30T, 15L and 16B lead to the input of AND gate 33. The flip-flop outputs 29L, 30T, 15R and 16B lead to the inputs of AND gate 34. The outputs of AND gates 31, 32, 33 and 34 are applied through switch-sequencing OR gate 35, then to optional AND gate 36, the bi-level output of which is normally at a first level, changing to its second level only during times during which the simultaneous requirements of each of AND circuits 31, 32, 33 and 34 are met. AND gate 36 is inhibited by a signal from either or both of one-shot multivibrators 37 and 38. Thus AND gate 36 is opened only when all of the following conditions are met:
a. The electron beam is in the proper quadrant.
b. No horizontal blanking pulse is applied.
c. No vertical blanking pulse is applied.
d. The electron beam is not near the center of a line.
e. The electron beam is not near the center of the vertical scan.
The bi-level output of AND gate 36 remains at its first level during the middle of the picture scan both in a horizontal and a vertical direction because of inhibiting pulses which are produced by one-shot multivibrators 37 and 38. One-shot multivibrators 37 and 38 are triggered by the outputs of one-shot multivibrators 17 and 18. The pulse lengths of multivibrators 37 and 38 extend across the center of the corresponding horizontal and vertical deflection sweep signals. The bi-level signal taken from AND gate 36 is of such duration and phase that it operates switching means 12 to interrupt the video signal of the main program with correct timing. That is, during the "bar-free" sector of the television field switching means 12 links the signal of the second program B to the video display means rather than linking the signal of the first program to said video display means. However, replacement of the first program by the second program is prevented during passage of the electron beam through the hatched area of FIG. 4. That is, the switching can take place only in the parts of sectors I, II, III or IV which are not hatched. During operation, AND gate 36 may also switch off the chrominance processor 11 so that color errors caused by a different color frequency for program 8 are avoided.
The operation of the phase-comparison means 14 shown in FIG. 2 may be illustrated with reference to the pulse diagrams indicated in FIG. 3. For example, in FIG. 4 it is assumed that the phase position of the horizontal and vertical synchronizing pulses V2 and H2 of the second television signal are disposed in the bottom and left parts of the raster of the first television signal. For illustration purposes, the screen is divided into four quadrants, I, II, III, and IV. As may be seen, only the quadrant II is free of synchronizing pulses H2 and V2. The first synchronizing pulse H1 places the output of the bi-stable flip-flop 15 in the switching condition indicated in FIG. 3 for the horizontal frequency pulse. If, as is assumed, a synchronizing pulse H2 occurs during the first line half, it is compared at AND gates 25 and 26 with the outputs of flip-flop 15 as said outputs are delayed by inhibiting AND gates 23L and 23R. In the first line half the output of AND gate 23L is high and the output of AND gate 23R is low. Therefore, in the first line half, the AND conditions for AND gate 26 are fulfilled by the pulse H2 causing flip-flop 29 to initially switch to the condition such that output 29L is high and output 29R is low. The outputs of flip-flop 29 remain constant so long as pulse H2 occurs during the left half of the electron beam sweep. Through identical reasoning, it may be shown that flip-flop output 30B is high so long as pulse V2 occurs in the top half of the vertical beam sweep.
When the electron beam reaches sector II during its horizontal sweep, flip-flop 15, as indicated in the diagram of FIG. 3, is switched by one-shot multivibrator 20 while flip-flop output 29L remains in its high state. Switching of flip-flop 15 continues during each horizontal sweep of the beam. The switching conditions of the outputs of flip-flops 29, 30, 15 and 16 are compared with each other in AND gates 31, 32, 33 and 34. In the quadrant II example illustrated, only the AND conditions for AND gate 32 are fulfilled. The AND conditions for AND gates 31, 32, 33 and 34 are each fulfilled only during the absence of transmitter B synchronizing pulses from those quadrants and during the presence of the electron beam in those quadrants. The operation results in the fact that the switching means 12 is changed over only during a completely defined switching time. The control signal from AND gates 31, 32, 33 and 34 is transmitted via OR gate 35 and AND gate 36 to the switching means 12 which, in the proper quadrant, alternately links the video signal of transmitter A and the video signal of the transmitter B with the video display means. As soon as the transmitter B synchronizing pulses migrate into another quadrant and begin to be visible there, another AND condition for either gate 31, 32, 33, or 34 is fulfilled so that the video signal of transmitter B replaces that of transmitter A in another quadrant of the picture. The AND circuits consequently represent the time control for program switching and determine at what moment the signal of transmitter A is to be replaced by the signal of transmitter B at the input to the video display means.
Since, as is well known, the horizontal synchronizing pulses are narrower than the blanking pulses because of front and back porches, the front or rear of the moving vertical bar of FIG. 4 will project at times into the picture of the bar-free quadrant. It is necessary to avoid this and to ensure that a stable changeover from quadrant to quadrant can take place not only when the synchronizing and blanking pulses from the two transmitters coincide but also when the pulses occur at half-intervals. These objects are achieved by causing AND gates 23L and 23R to be inhibited by the synchronizing pulse of transmitter A or by the synchronizing pulse of the same duration produced by the one-shot multivibrator 20, the latter having been delayed by one-shot multivibrators 17 and 19. A similar result is obtained for the vertical synchronizing pulses by inhibiting AND gates 24T and 24B by the vertical synchronizing pulse V1 or by the artificially developed synchronizing pulse of one-shot multivibrator 22.
When the blanking intervals of transmitter B are precisely between two quadrants, switching means 12 may not receive precise information concerning the proper quadrant location. In order to avoid this problem, the synchronizing pulses from transmitter B may be made somewhat shorter than those of transmitter A. For example, the transmitter A pulses might include front and back porches of that signal. The resultant effect is to produce a slight delay in switching between the quadrants. Thus the synchronizing pulse information of transmitter B disappears between quadrants and switching is controlled by the synchronizing pulses of transmitter A. Since the position of the transmitter B picture is stored in flip-flops 15, 16, 29 and 30, a particular condition is maintained until blanking pulses definitely appear in another quadrant. At that time, comparison between the synchronizing pulses resumes and switching means 12 operates in the new bar-free quadrant.
The pulses shown in FIG. 3 apply to the horizontal scanning of the electron beam. Similar conditions occur for the pulses in the vertical scanning direction. The color sub-carrier signals radiated by the transmitters have a standardized tolerance of ±10Hz for both NTSC and PAL specifications. Since the horizontal and vertical synchronizing pulse frequencies are rigidly coupled, fractional sub-harmonies of the frequencies of the color sub-carriers, and since the horizontal and vertical frequencies are much smaller in value, they coincide with much greater accuracy than the ±20Hz tolerance between station color sub-carriers. However, in general, a slight difference in the synchronizing pulse frequencies of two broadcast transmitters will always be present. In the present invention the slight difference is regarded as an advantage, because the resulting phase change not only causes shifting of the sector of the second picture from quadrant to quadrant of the main picture but also causes all parts of the second picture to be periodically seen by the viewer, thus considerably increasing viewer information concerning the content of the second program.
While a particular embodiment of the present invention has been described and shown, it will be obvious to those who are skilled in the art to which the invention pertains that changes and modifications may be made without departing from the spirit and scope of the invention as set forth in the appended claims. More specifically, it is well known that equivalent logic functions may be obtained by interchanging AND gates and OR gates with appropriate input inhibitions and output inversions. For example, the function of inhibited AND gates 23L, 23R, 24T and 24B could be performed by inhibited NOR gates wherein the outputs of flip-flops 15 and 16 are inhibited.
What we claim is:
1. A circuit system for a television receiver wherein a quadrant of a first transmitted video signal is replaced by a sector of a second transmitted video signal comprising:means for receiving, separating and amplifying at intermediate frequencies a first and a second transmitted video signal; sync-separating means for separately extracting the vertical and the horizontal synchronizing pulses from said first and second transmitted video signals; phase-comparison means for processing said vertical and horizontal pulses to provide a bi-level switching signal in which a second level is activated only during time periods corresponding to transmission of a quadrant of said second transmitted video signal, said time periods coinciding with time periods during which no synchronous pulses occur during transmission of said first transmitted video signal; video display means; and switching means responsive to said bi-level switching signal, said switching means linking said second transmitted video signal to said video display means during activation by said second level of said switching signal and linking said first transmitted video signal to said video display means during activation by the first level of said switching signal.
2. The circuit system of claim 1 in which said first transmitted video signal is connected to a chrominance processor after amplification at intermediate frequency, the output of said chrominance processor being transmitted to said video display means.
3. The circuit system of claim 2 in which said chrominance processor is inhibited by blocking pulses transmitted from the output of said phase-comparison means during said first-level activation of said bi-level signal.
4. The circuit system of claim 1 in which said phase-comparison means further comprises:a horizontal-and a vertical-frequency-dividing bi-stable flip-flop, one input of each of said dividing flip-flops connected respectively to said horizontal and vertical synchronizing pulses of said first transmitted video signal, the second input of each of said dividing flip-flops connected respectively to the outputs of half-sweep-pulsing one-shot multivibrators, the inputs of said pulsing multivibrators connected to outputs of half-sweep-delay one-shot multivibrators, the inputs of said delay multivibrators connected respectively to said horizontal and vertical synchronizing pulses of said first transmitted video signal; two horizontal-comparison AND gates, one input of each of said horizontal-comparison gates connected to said horizontal synchronizing pulses of said second transmitted video signal, the second input of each of said horizontal-comparison gates connected to opposite outputs of said horizontal-frequency-dividing flip-flop; two vertical-comparison AND gates, one input of each of said vertical-comparison gates connected to said vertical synchronizing pulses of said second transmitted video signal, the second input of said vertical-comparison gates connected to opposite outputs of said vertical-frequency-dividing flip-flop; a horizontal-locking bi-stable flip-flop, each input of said horizontal-locking flip-flop connected to the output of one of said horizontal-comparison AND gates; a vertical-locking bi-stable flip-flop, each input of said vertical-locking flip-flop connected to the output of one of said vertical-comparison AND gates; a first-quadrant-comparison AND gate, the four inputs of said first-quadrant-comparison gate connected respectively to a first output of said horizontal-locking flip-flop, to a second output of said vertical-locking flip-flop, to a first output of said horizontal-frequency-dividing flip-flop and to a first output of said vertical-frequency-dividing flip-flop; a second-quadrant-comparison AND gate, the four inputs of said second-quadrant-comparison gate connected respectively to a second output of said horizontal-locking flip-flop, to a second output of said vertical-locking flip-flop, to a second output of said horizontal-frequency-dividing flip-flop and to a first output of said vertical-frequency-dividing flip-flop; a third-quadrant-comparison AND gate, the four inputs of said third-quadrant-comparison gate connected respectively to a first output of said horizontal-locking flip-flop, to a first output of said vertical-locking flip-flop, to a first output of said horizontal-frequency-dividing flip-flop and to a second output of said vertical-frequency-dividing flip-flop; a fourth-quadrant-comparison AND gate, the four inputs of said fourth-quadrant-comparison gate connected respectively to a second output of said horizontal-locking flip-flop, to a first output of said vertical-locking flip-flop, to a second output of said horizontal-frequency-dividing flip-flop and to a second output of said vertical-frequency-dividing flip-flop; and a switch-sequencing OR gate, the four inputs of said switch-sequencing gate connected respectively to the outputs of said first-, second-, third- and fourth- quadrant-comparison gates, the output of which is connected to said switch means.
5. The circuit system of claim 4 in which the switched outputs of said frequency-dividing bi-stable flip-flops are time-delayed by transmission of said outputs through inhibiting AND gates, said inhibiting AND gates inhibited by respective switching inputs to said flip-flops, said half-sweep pulsing one-shot multivibrator outputs having pulse lengths substantially equal to horizontal and vertical pulse lengths respectively.
6. The circuit system of claim 4 in which the output of said switch-sequencing OR gate is transmitted through an inhibiting AND gate, said inhibiting AND gate being inhibited by impulses from blanking one-shot multivibrator outputs, the impulses of said blanking one-shot multivibrators beginning prior to the respective impulses of said secondary one-shot multivibrator and ending after said respective impulses, the input of said blanking one-shot multivibrators being triggered by a center-blanking triggering one-shot multivibrator.
7. The circuit system of claim 4 in which the switched outputs of said frequency-dividing bi-stable flip-flops are time-delayed by transmission of said outputs through inhibiting NOR gates, one input of each of said inhibiting NOR gates connected to the respective switching inputs to said flip-flops and the second inhibiting input of each of said NOR gates connected to the respective outputs of said flip-flops, said half-sweep pulsing one-shot multivibrator outputs having pulse lengths substantially equal to horizontal and vertical pulse lengths respectively.
8. The circuit system of claim 4 in which the switched outputs of said frequency-dividing bi-stable flip-flops are time-delayed by transmission of said outputs through exclusive OR gates, one input of each of said exclusive OR gates connected to the respective switching input to said flip-flops and the second input of each of said exclusive OR gates connected to the respective outputs of said flip-flop, said half-sweep pulsing one-shot multivibrator outputs having pulse lengths substantially equal to horizontal and vertical pulse lengths respectively.
| 1977-02-25 | en | 1978-01-24 |
US-30002289-A | 1.4-dihydro pyridines
ABSTRACT
Compounds are described of the formula ##STR1## wherein R 1 and R 4 independently represent a C 1-4 alkyl group;
R 2 and R 3 independently represent a C 1-6 straight or branched alkyl chain which may be interrupted by an oxygen atom;
R 5 represents a straight or branched chain C 1-13 alkyl group or a C 5-8 cycloalkyl group which may be substituted by a C 1-3 alkyl substitutent;
The compounds represented by formula (I) reduce intracellular calcium ion concentration by limiting transmembranal calcium ion influx and thus may be useful for the treatment of cardiovascular disorders such as hypertension.
This is a divisional of co-pending application Ser. No. 767,593 filed Aug. 20, 1985 now U.S. Pat. No. 4,801,599 issued Jan. 31, 1989.
This invention relates to novel heterocyclic derivatives which have an effect on the transmembranal influx of calcium ions into the cells of cardiac and smooth muscle, to processes for the preparation thereof, to pharmaceutical compositions containing them and to their use in therapeutics.
The role of intracellular calcium ions in the control of the contractile system of cardiac and smooth muscle is well known. Furthermore it has been established that compounds which limit the intracellular calcium ion concentration by preventing or reducing the transmembranal calcium ion influx in cells of the contractile system of cardiac and smooth muscle are useful in the treatment of cardiovascular disorders.
We have now found a new group of compounds which reduce intracellular calcium ion concentration by limiting transmembranal calcium ion influx and thus may be useful for the treatment of cardiovascular disorders such as hypertension, angina pectoris, myocardial ischaemia, congestive heat failure, cerebral vascular and peripheral disorders.
The invention thus provides for compounds of the general formula (I). ##STR2## wherein
R1 and R4 independently represent a C1-4 alkyl group;
R2 and R3 independently represent a C1-6 straight or branched alkyl chain which may be interrupted by an oxygen atom;
R5 represents a straight or branched chain C1-13 alkyl group or a C5-8 cycloalkyl group which may be substituted by a C1-3 alkyl substitutent;
The compounds represented by formula (I) can exist in more than one isomeric and/or enantiomeric form and the invention includes all such isomers, enantiomers and mixtures thereof. Thus the group --CH═CHCO2 R5 is compounds of formula (I) can exist in the cis (Z) or the trans (E) configuration and the invention includes both isomers and mixtures thereof.
Examples of suitable groups for R2 and R3 independently include C1-4 straight or branched alkyl such as methyl, ethyl, isopropyl, isobutyl, t-butyl or C1-4 alkyl (such as methyl, ethyl or n-propyl) substituted by a C1-3 alkoxy e.g. methoxy or propoxy group.
When the group R5 represents a C1-13 alkyl group this may for example include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec butyl, tert butyl, pentyl, isopentyl, neopentyl, hexyl, 2,6-dimethyl-4-heptyl, octyl and tridecyl groups. When R5 represents a cycloalkyl group, conveniently this represents cyclopentyl, cyclohexyl and cycloheptyl, which cycloalkyl groups may be substituted by a C1-3 alkyl group e.g. a methyl group. Preferred compounds of formula (I) are those in which the group CH═CHCO2 R5 exists in the (E) configuration.
Preferred meanings for the groups R1 and R4 independently include ethyl or more particularly methyl.
R2 and R3 preferably independently represent C1-4 alkyl e.g. methyl, ethyl, isopropyl or isobutyl or ethyl substituted by C1-3 alkoxy e.g. methoxy or propoxy.
R5 preferably represents C3-9 straight or branched alkyl such as isopropyl, tert butyl, 2,6-dimethyl-4- heptyl or octyl, or C5-7 cycloalkyl e.g. cyclopentyl or cyclohexyl which may be substituted by a methyl group.
A particularly preferred class or compounds of the invention are those of formula I wherein R1 and R4 represent methyl, R2 and R3 independently represent methyl, ethyl, isopropyl, isobutyl, propoxyethyl or methoxyethyl and R5 represents C3-9 alkyl, more particularly isopropyl, tert butyl, 2,6- dimethyl-4-heptyl or octyl, or a cyclohexyl group which may be substituted by a methyl group.
Within this particularly preferred class of compounds those where R5 represents a tertiary butyl group are especially preferred.
A particularly preferred compound according to the invention is 4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1-propenyl) phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester and more especially the E isomer thereof.
Other preferred compounds according to the invention are
4-(2-(3-(1,1-dimethylethoxy)-3,5-oxo-1-propenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5 -pyridinedicarboxylic acid, 3-methyl ester, 5-(2-methylpropyl) ester;
4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1propenyl)phenyl)-1,4-dihydro -2,6-dimethyl-3,5-pyridinedicarboxylic acid, dimethyl ester;
4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1-propenyl)phenyl-1,4-dihydro -2,6-dimethyl-3,5-pyridinedicarboxylic acid, 3-methyl ester 5-ethyl ester;
and more particularly the E isomers thereof.
The compounds of the invention limit intracellular ion concentrations by preventing or reducing the transmembranal calcium ion influx in cells. Thus for example the compounds limit or inhibit the effect of calcium ion on the tone of depolarised vascular smooth muscle.
The antihypertensive activity of the compounds of the invention was demonstrated by intravenous and/or oral administration of the compound to male spontaneously hypertensive rats. In these tests compounds of the invention and more especially the specific compounds named above have been found to have a particularly advantageous profile of activity including a relatively long duration of action.
The compounds of the invention are thus of interest in the treatment of hypertension. They are also potentially useful for the treatment of other cardiovascular disorders including angina pectoris, myocardial ischaemia, congestive hat failure, cerebral vascular and peripheral disorders. They may be formulated in a conventional manner with one or more pharmaceutical carriers.
Thus a further aspect of the invention includes pharmaceutical compositions of the compounds of formula (I) formulated for oral, sub lingual, transdermal, parenteral or rectal administration.
For oral administration the pharmaceutical composition may take the form of for example tables, which may be film or sugar coated, capsules, powders, granules, solutions including syrups, or suspensions prepared by conventional means with acceptable excipients. For sub lingual administration the composition may take the form of tablets or lozenges formulated in conventional manner.
For parenteral administration the compounds of formula (I) may be given as a bolus injection or by continuous infusion. The compositions may take such forms as suspension, solutions or emulsions in oily or aqueous vehicles and may contain formulatory agents such as suspending, stabilising and/or dispersing agents. For administration by injection these may take the form of a unit dose presentation or as a multidose presentation preferably with an added preservative.
Alternatively for parenteral administration the active ingredient may be in powder form for reconstitution with a suitable vehicle.
The compounds of formula (I) may be formulated as ointments and creams for transdermal administration and as suppositories or retention enemas for rectal administration.
A proposed daily dosage of active compound of the invention for the treatment of man is in the range of 0.005 mg to 50 mg for example 0.01 mg to 20 mg, which may conveniently be administered in one or more doses. The precise dose employed will depend on the age and condition of the patient as well as the route of administration.
For oral use the compounds of the invention are conveniently administered to the human patient at a dose in the range 0.01 to 50 mg, more preferably 0.1 to 20 mg per day. For parenteral use the compounds of the invention are conveniently administered at a dose in the range of 0.005 to 1 mg, more preferably 0.01-0.5 mg per day.
For oral use the compound is preferably administered twice or more particularly once a day.
Methods for preparing the compounds of formula (I) are described below and for the intermediates described below R1, R2, R3, R4, and R5, have the meanings defined above for compounds of formula (I) or are such groupings in a protected form.
Thus compounds of formula (I) and more particularly the E isomers thereof, may be prepared by reaction the α,β-unsaturated ketone (II) with the aminoester (III). The reaction is conveniently carried out in a solvent such as an alkanol, e.g. ethanol or isopropanol and preferably with heating e.g. 40°-150° C. ##STR3## The α, β-unsaturated ketone (II) may be prepared by reacting the aldehyde (IV) with the ketoester (V), in a solvent such as an alkanol e.g. ethanol or isopropanol, preferably with heating e.g. 40°-150° C. Conveniently this reaction is carried out in the presence of a catalyst such as piperidine acetate. ##STR4##
In a modification of this process for preparing compounds of formula (I), the aldehyde (IV) may be reacted with a mixture of the aminoester (III) and the ketoester (V) under the conditions previously described for the reaction of the α,β-unsaturated ketone (II) with the aminoester (III).
Compounds of formula (I) and in particular the E isomers thereof in which R1 and R4 are the same and R2 and R3 are the same may be prepared by reacting the aldehyde (IV) with the aminoester (III) in the presence of a suitable acid catalyst. Examples of suitable acid catalysts include organic acids such as oxalic acid, alkanoic acids e.g. acetic acid or haloalkanoic acids such as trichloroacetic acid or trifluoroacetic acid or pyridinium salts thereof, or a sulphonic acid such as an alkanesulphonic acid e.g. methanesulphonic acid or an arylsulphonic acid e.g. benzenesulphonic acid or p-toluenesulphonic acid or a tetrahaloboric acid such as tetrafluoroboric acid. The reaction is preferably carried out in the presence of a solvent and at a temperature within the range of -70° to 30° preferably -30° to 10° C. Suitable solvents for the reaction include aprotic solvents such as hydrocarbons, e.g. hexane or cyclohexane, acetonitrile or ethers such as tertiary butyl methyl ether, dioxan or tetrahydrofuran, or protic solvents such as an alkanol e.g. methanol, ethanol, propanol, isopropanol or butanol.
Compounds of formula (I) and more particularly the E isomers thereof in which R1 and R4 are the same and R2 and R3 are the same may also be prepared by reacting the aldehyde (IV) with the ketoester (V) and ammonium acetate. This reaction is conveniently carried out in a solvent such as pyridine with heating at 50°-120° C., conveniently at reflux.
In a further process of the invention compounds of formula (I) may be prepared by esterifying the corresponding acid of formula (I) in which R5 is hydrogen. Thus is one embodiment of this process compounds of formula (I) may be prepared by treating a compound of formula (I) in which R5 is hydrogen with an alkylating agent R5 X where R5 is as defined in formula (I), and X is a leaving group such as chloride, bromide, iodide or mesylate. The reaction is preferably carried out in the presence of a base such as an alkali or alkaline earth metal carbonate e.g. potassium carbonate in a polar aprotic solvent such as dimethylformamide or dimethylsulphoxide optionally with heating. Thus for example the reaction may be carried out a temperature within the range 10°-100°.
In a further embodiment of this process compounds of the invention may be prepared from the corresponding carboxylic acid of formula (I) in which R5 is hydrogen, via an activated derivative thereof such as a mixed anhydride, by reaction with an appropriate alcohol R5 OH, where R5 is as defined in formula (I), or the corresponding alkoxide thereof.
The compounds of formula (I) wherein R5 represents hydrogen may be prepared by hydrolysis of a compound of formula (I) wherein R5 represents a tertiary butyl group. The hydrolysis may be carried out using hydrogen bromide in acetic acid, in the presence of a solvent such as dichloromethane. Preferably the reaction is carried out at low temperatures e.g. -78°-35° C.
In yet another process of the invention the E isomers of compounds of formula (I) may be prepared by treating a compound of formula (VI) ##STR5## (where Hal represents a bromine or iodine atom) with an acrylic ester CH2 ═CHCO2 R5 (VII), in the presence of a catalytic amount of a palladium salt such as palladium acetate, in the presence of a suitable organic base such as a trialkylamine e.g. triethylamine or tri-n-butylamine. The reaction is also preferably carried out in the presence of a triarylphosphine such as tri-o-tolyphosphine, or more preferably, triphenylphospine.
The reaction is conveniently carried out in a suitable solvent such as xylene or t-butyl acetate, or more conveniently in dimethylformamide or in a mixture of solvents e.g. xylene/dimethylformamide, preferably with heating. The reaction mixture is preferably heated within the temperature range of 80° C. to 150° C., more preferably at 100° C. to 110° C.
The carboxylic acids represented by the compounds of formula (I) wherein R5 represents hydrogen are new compounds and useful chemical intermediates for preparing the compounds of formula (I) and represent a further feature of the invention.
Compounds of formula (IV) may be prepared by reacting the bis aldehyde (VIII) with the triphenylphosphorane (IX) in solvent such as methylene chloride or toluene. ##STR6## Compounds of formula (IV) may also be prepared by reacting a 2-halobenzaldehyde (X) ##STR7## (where Hal represents a bromine or iodine atom) with an acrylic ester (VII). The reaction takes place under the conditions previously described for the reaction between the compound of formula (VI) and the acrylic ester (VII).
The compounds of formula (VI) may be prepared by reacting the 2-halobenzaldehyde (X) with the aminoester (III) and/or the ketoester (V) according to the conditions described above for the reaction between the compound of formula (IV) and the aminoester (III) and/or the ketoester (V).
The compounds of formulae (III), (V), (VII), (VIII), (IX) and (X) are either known compounds or may be made by analogous processes to those used for known compounds.
Compounds of formula (I) in which the group --CH═CHCO2 R5 is in the cis (Z) configuration may be prepared by irradiating a solution of the corresponding trans (E) isomer. Thus when a solution of the E isomer in dichloromethane under a atmosphere of nitrogen is exposed to daylight a mixture of the E and Z isomers are obtained and these may be separated by standard techniques such as fractional crystallisation and/or chromatography.
Compounds of formula (I) may also be prepared from the reaction of the compound (XI) with the phosphorane (IX) in a suitable solvent such as dichloromethane, tetrahydrofuran or toluene. Preferably the reaction is carried out with heating for example 40°-120° C., conveniently at reflux. ##STR8##
The intermediate (XI) may be prepared by aqueous acid hydrolysis of the corresponding acetal (XII; in which R6 represents an alkyl group)
the compound of formula (XII) may be prepared from the aldehyde (XIII) by reaction with a compound of formula (III) and/or (V) under the conditions described above for preparing compounds of formula (I) from the intermediate (IV). The intermediate (XIII) may be prepared from the bromobenzene derivative (XIV) by reaction with butyl lithium in solvent followed by addition of dimethylformamide. ##STR9##
The following examples illustrate the invention. Throughout the example reference to t.l.c. means thin layer chromatography on Merck silica gel 60F-254. All temperature refer to °C.
INTERMEDIATE 1
1a. (E)-3-(2-Formylphenyl)-2-propenoic acid, 1,1-dimethyl ethyl ester
A solution of triphenylphosphoranylidene acetic acid 1,1-dimethylethyl ester (54.7 g) in dry dichloromethane (100 ml) was added to a solution of ortho phthaldehyde (19.3 g) in dry dichloromethane at 0° C. in 15 minutes. The solvent was evaporated and the oil taken up with diethyl ether. The solid triphenylphosphine oxide was filtered, washed with ether and the filtrate evaporated to dryness to give a yellow oil (36 g), which was eluted on a silica gel column (petrol ether/diethylether, 7:3), to give the title compound as a colourless oil (21.4 g). T.l.c. (Petrol Ether/diethyl ether, 1:1) Rf=0.45.
1b.
In a similar manner (E)-3-(2-formylphenyl)-2-propenoic acid, ethyl ester (12 g) was prepared from o-phthaldehyde (13.4 g) and triphenylphosphoranylidene acetic acid ethyl ester (34.8 g).
T.l.c. (Petrol ether/diethyl ether, 1:1) Rf=0.40.
INTERMEDIATE 2
2-(Diethoxymethyl)bromobenzene
A mixture of 2-bromobenzaldehyde (33.2 g), triethyl orthoformate (29 g) and powdered ammonium chloride (0.379 g) in ethanol (30 ml) was stirred for eight hours at room temperature. The resulting suspension was filtered and the filtrate evaporated. The resulting yellow oil was distilled at reduced pressure to give the title compound (31 g). b.p. 63° C. 0.3 mm Hg. T.l.c. (Petrol/diethyl ether, 6:1) Rf=0.6.
INTERMEDIATE 3
2-(Diethoxymethyl)benzaldehyde
To a solution of tetrahydrofuran (250 ml) and ether (250 ml) was added a 1.2M solution of butyl lithium in hexane (160 ml). The mixture was stirred and cooled to -70° C. and then Intermediate 2 (50 g) was added dropwise. After the addition the mixture was stirred at -70° for 30 minutes and then a solution of dimethylformamide (165 ml) in tetrahydrofuran (75 ml was added slowly dropwise keeping the temperature at -65°. A saturated aqueous solution of ammonium chloride (150 ml) was added, the organic phase separated and the aqueous phase extracted with ether (2×70 ml). The combined organic phase was dried (MgSO4) and evaporated. The resulting brown oil was distilled at reduced pressure to give the title compound (30 g) as a white waxy solid. b.p. 87° C. 0.9 mm Hg. T.l.c. (Petrol/diethyl ether, 7:3) Rf=0.6.
INTERMEDIATE 4
4-(2-Formylphenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinecarboxylic acid, diethyl ester
To a stirred solution of ethyl-3-aminocrotonate (9.3 g) in glacial acetic acid (5 ml) at 0° was added dropwise Intermediate 3 (5 g). After two hours the reaction was poured into ethyl acetate (100 ml) and shaken with 10% hydrochloric acid. The organic phase was separated, dried (MgSO4) and evaporated. The residual brown oil was purified by column chromatography (silica gel, dichloromethane/ethyl acetate 7:3) and crystallized from diethyl ether to give the title compound (0.200 g) as a yellow solid. m.p. 172°-173°. T.l.c. (Petrol/ethyl acetate, 7:3) Rf=0.4.
INTERMEDIATE 5
4-(2(2-Carboxyethenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
To a solution of the compound of Example 1 (10 g) in dichloromethane (70 ml), at -78° C. was added slowly, a solution of HBr/CH3 COOH 33% in dichloromethane (70 ml). The mixture was then warmed to -35° C. and after 10 minutes poured into ice/water. The pH was adjusted at 6 and the mixture extracted with ethyl acetate, washed with water and dried over Na2 SO4. Evaporation of the solvent gave a solid which was recrystallized from petrol ether/ethyl acetate (1:1) to give the title compound as a white solid (6.5 g). T.l.c. (CH2 Cl2 /CH3 CO2 C2 H5 /CH3 COOH, 8:2:1) Rf=0.4. m.p. 175°-178°
INTERMEDIATE 6
6a. 2,6-Dimethyl-4heptylmethanesulphonate
A solution of methanesulphonyl chloride in diethyl ether was added dropwise to a solution of 2,6-dimethyl-4-heptanol and triethylamine in ether at 0° C. The mixture was then stirred for 2 hrs at room temperature, then poured into water and extracted with ether. The organic phase was washed with dilute hydrochloric acid, then water and dried over Na2 SO4. Evaporation of the solvent gave the title compound (2.6 g) as a colourless oil. T.l.c. (Ethyl acetate/cyclohexane, 4:6). Rf.=0.55. Similarly prepared was:
6b. 2-Methylcyclohexylmethanesulphonate
T.l.c.(methylene chloride/Ethyl acetate, 7:3) Rf.=0.75. From methanesulphonyl chloride and 2-methylcyclohexane
INTERMEDIATE 7
4-(2-Bromophenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinecarboxylic acid, diethyl ester
(a) A solution of 2-bromobenzaldehyde (83.7 g) in absolute ethanol (1350 ml) was cooled to -10° under stirring. To the solution trifluoroacetic acid (108 g) was added quickly followed by a solution of ethyl 3-aminocrotonate (146 g) in ethanol (750 ml) added dropwise during 1 hour. Stirring was continued for a further 1 hour at -10° and the mixture was then added dropwise to a 0.3% solution of hydrochloric acid (7000 ml) under vigorous stirring. The solid was collected by filtration, washed with water and petroleum ether and dried in vacuo at 60° to give the title compound (156 g). m.p. 142°-143°. T.l.c. (ethyl acetate/petroleum ether, 8:2) Rf=0.5
(b) A solution of 2-bromobenzaldehyde (10.8 g), ethyl 3-aminocrotonate (9.36 g) and ethyl acetoacetate (9.12 g) in absolute ethanol (50 ml) was heated at reflux for 15 hours. The mixture was then cooled, diluted with absolute ethanol (250 ml) and added dropwise to a 0.2% solution of hydrochloric acid (2000 ml) under vigorous stirring. The solid was collected by filtration, washed with petroleum ether (150 ml) and dried in vacuo to give the title compound (19.3 g) m.p. 142°-143°.
INTERMEDIATE 8
4-(2-Iodophenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinecarboxylic acid, diethyl ester
Following the procedure in Intermediate 7(a) 2-iodobenzaldehyde (46.4 g) and ethyl 3-aminocrotonate (73 g) gave the title compound (54.8 g) m.p. 178°. T.l.c. (dichloromethane/ethyl acetate, 9:1) Rf=0.5.
INTERMEDIATE 9
2-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1-propenyl)phenyl)methylene-3-oxo-butanoic acid, methyl ester
A solution of piperidine (0.11 g) and acetic acid (0.078 g) in iospropanol (1 ml) was added to a solution of 3-(2-formylphenyl)propenoic acid 1,1-dimethylethyl ester (5.2 g) and methyl acetoacetate (2.55 g) in isopropanol (15 ml). The mixture was stirred at 60° C. for 1h, then the solvent was evaporated and the residue taken up with ether (100 ml). The solution was washed with 1N HCl, water, with saturated bicarbonate solution, then water again and dried over Na2 SO4. Evaporation of the solvent gave an oil which was purified by column chromatography (gradient Petrol/Ether, 7:3 -1:1) to give the title compound as a pale oil (4.2 g; mixture E/Z isomers).
Example 1
(E)-4-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1-propenyl)phenyl) -1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
Ethyl 3-aminocrotonate (24 g) was added to a solution of Intermediate 1a (21.4 g) in acetic acid, at room temperature. The red solution was stirred at room temperature for 5 hrs, then poured into water and extracted with ethyl acetate. The organic phase was washed with 5% aqueous sodium bicarbonate solution, then with water and dried over Na2 SO4. Evaporation of the solvent gave a dark oil, which was eluted on a silica gel column (CH2 Cl2 /Ethyl acetate, 9:1). The title compound was obtained as a white solid (3.6 g) and recrystallized from ethyl acetate, m.p. 173°-175° C. T.l.c. (methylene chloride/Ethyl acetate, 9:1) Rf.=0.4
EXAMPLE 2
4-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1-propenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
To a solution of Intermediate 4 (0.1 g) in dichloromethane (0.5 ml) was added triphenylphosphoranylidene acetic acid 1,1-dimethylethyl ester (0.1 g) in dichloromethane (0.5 ml) at room temperature. After 12 hours reflux in dichloromethane, tetrahydrofuran was added and refluxing continued for 12 hours. Then toluene was added and the mixture refluxed for a further 5 hours. The mixture was evaporated and the residue purified by column chromatography and crystallized from petrol to give the title compound (120 mg) as a mixture of E and Z isomers.
EXAMPLE 3
(E)-4-(2-(3-Ethoxy-3-oxo-1-propenyl)phenyl)-1,4-dihydro-2,6dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
Ethyl 3-aminocrotonate (13 g) was added to a solution of Intermediate 1b (10.2 g) in acetic acid (150 ml), at room temperature. The red solution was stirred at room temperature for 3 hrs., then poured into water and extracted with ethyl acetate. The organic phase was washed with 5% aqueous sodium bicarbonate solution, then with water and dried over Na2 SO4. Evaporation of the solvent gave a dark oil (20 g), which as eluted on a silica gel column (CH2 Cl2 /Ethyl acetate, 7:3). The title compound was obtained as a white sole (4.5 g) and recrystallized from petrol ether/diethyl ether (9:1); m.p. 130°-131° C.; T.l.c. (methylene chloride/Ethyl acetate, 8:2) Rf=0.50
EXAMPLE 4
4a. (E)-4-(2-(3-(1,1-dimethylethoxy-3-oxo-1-propenyl)phenyl)-1,4-dihydro -2,6-dimethyl-3,5-pyridinedicarboxylic acid 3-methyl ester, 5-ethyl ester
Intermediate 1a (0.5 g), ethyl 3-aminocrotonate (0.27 g) and methyl acetoacetate (0.24 g) in ethanol were refluxed for 14 hrs. The solvent was then evaporated and the crude oil was eluted on a silica gel column (diethyl ether/petrol ether 7:3) to yield the title compound as a pale yellow solid (0.25 g), m.p. 165°-167° C. (petrol ether). T.l.c. (Diethyl ether/petrol ether, 9:1) Rf=0.3
Similarly prepared were:
4b. (E)-4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1-propenyl)phenyl) -1,4-dihydro-2,6-dimethyl-3,5pyridinedicarboxylic acid 3-methyl ester, 5-(2-methylpropyl) ester
m.p. 147°-149° (petrol ether) T.l.c. (Petrol ether/ethyl acetate 6:4) Rf=0.35 From Intermediate 1a, methyl 3-aminocrotonate and 2-methylpropyl acetoacetate
4c. (E)-4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1-propenyl)phenyl) -1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, 3-(1-methylethyl) ester, 5-(2-methoxyethyl) ester
m.p.=156°-157° C. (petrol ether)
T.l.c. (ethyl acetate/cyclohexane, 1:1) Rf=0.35 From Intermediate 1a, 1-methylethyl 3-aminocrotonate and 2-methoxyethyl acetoacetate
4d. (E)-4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1-propenyl)phenyl -1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, dimethyl ester
m.p.=158°-162° (petrol ether/diethyl ether, 100:1). T.l.c. (petrol/ethyl acetate, 6:4) Rf=0.25 From Intermediate 1a, methyl 3-aminocrotonate and methyl acetoacetate
4e. (E)-4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1-propenyl)phenyl) -1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, bis-2-n-propoxyethyl ester
m.p.=115-116 (petrol/ether)
T.l.c. (ethyl acetate/cyclohexane 1:1) Rf=0.40 From Intermediate 1a, n-propoxyethyl 3-aminocrotonate and n-propoxyethyl acetoacetate
4f. (E)-4-(2-(3-Ethoxy-3-oxo-1-propenyl)phenyl)-1,4-dihydro -2,6-dimethyl-3,5-pyridinedicarboxylic acid ethyl (1,1-dimethyl)ethyl ester
From Intermediate 1b, 3-oxobutanoic acid ethyl ester and 3-aminobutenoic acid 1,1-dimethylethyl ester.
EXAMPLE 5
5a. (E)-4-(2-(3-Octyloxy-3-oxo-1-propenyl)phenyl)-1,4-dihydro -2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethylester
A suspension of the Intermediate 5 (0.5 g), octyl bromide (0.38 g) and potassium carbonate (10 g) was stirred at room temperature for 20 hrs. The mixture was poured into water and extracted with ethyl acetate, washed thoroughly with water and dried over Na2 SO4.
Evaporation of the solvent gave an oil which was triturated with petrol ether and recrystallized from petrol ether to give the title compound as a white solid (0.3 g), m.p. 110-°112°. T.l.c. (methylene chloride/ethyl acetate, 9:1) Rf=0.5
Similarly were prepared:
5b. (E) -4-(2-(3-Methoxy-3-oxo-1-propenyl)phenyl)-1,4-dihydro-2,6-dimethyl -3,5-pyridinedicarboxylic acid, diethyl ester
m.p. 138°-140° (petrol ether). T.l.c. (methylene chloride/Ethyl acetate 8:2) Rf=0.40 From Intermediate 5 and methyl bromide.
5c. (E)-4-(2-(3-(1-Methylethoxy)-3-oxo-1-propenyl)phenyl)1,4-dihydro-2,6-dimethyl -3,5-pyridinedicarboxylic acid, diethyl ester
m.p. 145°-147° C. (petrol ether) T.l.c. (methylene chloride/Ethyl acetate, 8:2) Rf=0.45
From Intermediate 5 and 1-methylethyl bromide.
5d. (E)-4-(2-(3-(2-Methylpropyloxy)-3-oxo-1-propenyl)phenyl)-1,4-dihydro -2,6-dimethyl-3,5pyridinedicarboxylic acid, diethyl ester
m.p. 172°-174° C. (petrol ether). T.l.c. (methylene chloride/Ethyl acetate, 8:2) Rf=0.55
From Intermediate 5 and 2-methylpropylbromide.
5e. (E)-4-(2-(3-Cyclohexyloxy-3-oxo-1-propenyl)phenyl)1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid diethyl ester
m.p. 175°-177° C. (petrol ether) T.l.c. (methylene chloride/Ethyl acetate, 9:1) Rf=0.40
From Intermediate 5 and cyclohexyl bromide.
5f. (E)-4-(2-(3-Tridecyloxy-3-oxo-1-propenyl)phenyl-1,4dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
m.p.=87°-89° C. T.l.c. (Petrol ether/ethyl acetate, 6:4) Rf.=0.40.
From Intermediate 5 and tridecyl bromide at room temperature
5g. (E)-4-(2-(3-Cycloheptyloxy-3-oxo-1propenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
m.p.=192°-194° C. T.l.c. (methylene chloride/Ethyl acetate, 8:2) Rf.=0.45
From Intermediate 5 and cycloheptyl bromide
5h. (E)-4-(2-(3-Cyclopentyloxy-3-oxo-1-propenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
m.p.=182°-184° c. T.l.c. (Ethyl acetate/cyclohexane, 1:1) Rf.=0.42
from Intermediate 5 and cyclopentyl bromide.
EXAMPLE 6
(E)-4-(2-(3-Octyloxy-3-oxo-1-propenyl)phenyl)-1,4-dihydro-2,6-3,5-pyridinedicarboxylic acid diethyl ester
A suspension of the intermediate 5 (0.1 g), octyl methanesulphonate (0.077 g) and potassium carbonate (2 g) in dimethylformamide (5 ml) was stirred at room temperature for 20 hrs. The mixture is poured into water and extracted with ethyl acetate, washed thoroughly with water and dried over Ns2 SO4. Evaporation of the solvent gave an oil which was triturated with petrol ether and recrystallized from petrol ether to give the title compound as a white solid, (0.04 g). m.p. 110°-112° C. T.l.c. (methylene chloride/Ethyl acetate, 9:1) Rf=0.5
EXAMPLE 7
(E)-4-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1propenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
A suspension of the intermediate 5 (0.2 g) and potassium carbonate (0.07 g) in N,N-dimethylformamide (5 ml) was treated with tert-butyl bromide (0.14 g) and stirred t room temperature for 20 hrs. The mixture was poured into water and extracted with ethyl acetate, washed thoroughly with water nd dried over Na2 SO4. Evaporation of the solvent gave an oil which was crystallized from petrol ether to give the title compound as a white solid (0.005 g) m.p. 173°-175° C.
EXAMPLE 8
(Z)-4-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1-propenyl)phenyl-1,4-dihydro -2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
A solution of the compound of Example 1 (1 g) in dichloromethane (250 ml) was deoxygenated with a stream of nitrogen for 3 min., then left standing, under an atmosphere of nitrogen, in daylight for two weeks. The solution was then evaporated and the solid was recrystallized twice from petrol/diethyl ether (9:1). The white solid obtained (0.2 g) was eluted 5 times on a silica gel plate (CH2 Cl2) to obtain a colourless oil. Crystallization from petrol ether/diethyl ether (9:1) gave the title compound as a white solid (0.05 g) m.p. 143°-145° C. T.l.c. (methylene chloride/Ethyl acetate, 9:1) Rf=0.40
EXAMPLE 9
9a. (E)-4-(2-(3-(2,6-Dimethyl-4-heptyloxy)-3-oxo-1-propenyl)phenyl -1,4-dihydro-2,6-dimethyl-3,5-pyridine -dicarboxylic acid, diethyl ester
A suspension of Intermediate 5 (2 g), 2,6-dimethyl-4-heptylmethanesulphonate (1.6 g) and potassium carbonate (40 g) in dimethylformamide (30 ml) was stirred at 60° C. for 12 hours. The mixture was poured into water and extracted with ethyl acetate, washed thoroughly with water and dried over Na2 SO4. Evaporation of the solvent gave a crude oil (3 g) which was eluted on a silica gel column (Diethyl ether/petrol ether, 8:2) to yield the title compound (0.66 g) as a white solid. m.p. 49°-52° C. T.l.c. (Petrol ether/Ethyl acetate, 6:4) Rf.=0.45.
Similarly prepared were:
9b. (E)-4-(2-(3-(2-Methylcyclohexyloxy)-3-oxo-1-propenyl) phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
m.p. 165°-166° C. T.l.c. (methylene chloride/Ethyl acetate, 8:2) Rf=0.55.
From Intermediate 5 and 2-methylcyclohexylmethanesulphonate.
EXAMPLE 10
(E)-4-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1-propenyl)phenyl)-1,4-dihydro -2,6-diethyl-3,5-pyridinedicarboxylic acid diethyl ester
A solution of Intermediate 1a (3.2 g) in ethanol (25 ml) was cooled to 0° C. and then trifluoroacetic acid (2 ml) added, followed by a solution of ethyl-3-aminocrotonate (10 g) in ethanol (25 ml). The mixture was stirred at 0° C. for 1 hr, then poured into water and neutralized with 10% sodium bicarbonate and extracted with ethyl acetate. The organic layer was washed with 10% hydrochloric acid then with water and dried over Na2 SO4. Evaporation of the solvent gave an oil which was eluted on a silica gel column (gradient Ether/petrol, 3:7-7:3) to give the title compound (2 g) as a pale yellow solid. m.p.=154°-155° C. T.l.c. (Petrol ether/ethyl acetate, 1:1) Rf=0.65
EXAMPLE 11
(E)-4-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1-propenyl)phenyl)-1,4-dihydro -2,6-dimethyl-3,5-pyridinedicarboxylic acid, diethyl ester
(a) A mixture of the intermediate 7 (171.5 g), tertiary butylacrylate (67.0 g), tributylamine (97.6 g), palladium acetate (0.94 g) and triphenylphosphine (4.4 g) in dimethylformamide (200 ml) was heated at 110° for 24 hours under nitrogen. The mixture was then cooled, the catalyst removed by filtration and the organic solvent was evaporated to dryness. The residue was dissolved in acetone (700 ml) and the resulting solution was added dropwise to a 0.5% solution of hydrochloric acid (8000 ml) under vigorous stirring. The solid was collected by filtration, washed with water and petroleum ether and dried in vacuo at 60° to give a yellow solid. The solid was recrystallised twice from ethyl acetate (500 ml) to give the title compound (100 g) m.p. 174°-175°. T.l.c. (dichloromethane/ethyl acetate, 8:2) Rf=0.48. (b) In a similar manner the intermediate 8 (91 g) and tertiary butylacrylate (33 g) gave the title compound (46 g).
EXAMPLE 12
(E)-4-(2-(3-(1,1-Dimethylethoxy)-3-oxo-1-propenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid diethyl ester
A solution of ethyl 3-aminocrotonate (19.5 g) in absolute ethanol (75 ml) was added to a mixture of (E)tert-butyl-2-formyl-cinnamate (11.6 g) and trifluoroacetic acid (11.4 g) in absolute ethanol (90 ml) at -10° to 020 C. The mixture was aged for 1.5 h within this temperature range and then 8% aqueous sodium bicarbonate (150 ml) was added. The product was extracted with tert-butyl methyl ether (3×150 ml), the combined extracts washed with water (2×150 ml) and dried (MgSO4). Filtration followed by evaporation of solvent gave an oil which was triturated with petroleum ether (50 ml) then filtered to give a granular solid. Crystallisation from ethyl acetate (30 ml) to give the title compound (8.5 g). M.p. 174°-175°.
EXAMPLE 13
(E)-4-(2-(3-(1,1-dimethylethoxy)-3-oxo-propenyl)phenyl) -1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylic acid, methyl ethyl ester
Ethyl 3-aminocrotonate (1.3 g) and the intermediate 9 (2.9 g) in ethanol (20 ml) were heated under reflux for 13 hr. The solvent was evaporated and the residual oil was purified by column chromatography (gradient petrol/Ethyl acetate, 7:3-1:1) to give the title compound 0.42 g) as a white solid, m.p.=165°-167° C.
EXAMPLE 14
Pharmaceutical compositions
(a) TABLETS
______________________________________
(I) mq/tablet
______________________________________
Active ingredient 1
Polyvinylpyrrolidone (PVP)
20
Lactose B.P. 127
Magnesium stearate B.P.
2
Compression weight 150
______________________________________
The drug is granulated by a solution of PVP in ethanol, blended with the excipients and compressed using punches to suit.
______________________________________
(II) mg/tablet
______________________________________
Active ingredient 1
Microcrystalline cellulose BPC
40
Lactose B.P. 100
Sodium carboxymethylcellulose
8
Magnesium stearate B.P.
1
Compression weight 150
______________________________________
The drug is sieved through a suitable sieve, blended with the excipients and compressed using punches to suit.
Tables of other strengths may be prepared by altering the compression weight and using punches to suit. The tablets may be film coated with suitable film forming materials, e.g. methyl cellulose, ethyl cellulose or hydroxypropylmethyl cellulose, using standard techniques. Alternatively the tablets may be sugar coated.
(b) SOFT GELATIN CAPSULES
______________________________________
mg/capsule
______________________________________
Active ingredient 1
Polyethylene glycol (PEG) 400
199
Fill weight 200
______________________________________
The drug is dissolved in PEG 400 with stirring and the mix is filled into soft gelatin capsules using a suitable filling machine. Other doses may be prepared by altering the fill weight and if necessary changing the capsule size to accommodate the change in fill weight.
In the above pharmaceutical examples the active ingredient refers to one or more compounds of the general formulae I but is preferably 4-(2-(3-(1,1-dimethylethoxy)-3-oxo -1-propenyl)phenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridine dicarboxylic acid diethyl ester, and more especially the E isomer thereof.
What we claim is:
1. A composition for treating hypertension, comprising an effective amount of at least one compound of the formula: ##STR10## wherein, R1 and R4 independently represent a C1-4 alkyl group;R2 and R3 independently represent a C1-6 straight or branched alkyl chain which may be interrupted by an oxygen atom; R5 represents a straight or branched chain C1-13 alkyl group or a C5-8 cycloalkyl group which cycloalkyl group may be substituted by a C1-13 alkyl group, and a physiologically acceptable carrier.
2. A composition as claimed in claim 1 in a form suitable for oral, sub lingual, transdermal, parenteral or rectal administration.
3. A composition as claimed in claim 2 in the form of a tablet or capsule for oral administration.
4. A composition as claimed in claim 3 wherein the amount of the oral administration is between about 0.01 to about 50 mg per day.
5. A composition as claimed in claim 3 wherein the amount of the oral administration is between about 0.1 to about 20 mg per day.
6. A composition as claimed in claim 2 for parenteral administration in the form of a bolus injection or continuous infusion.
7. A composition as claimed in claim 6 wherein the amount of the parenteral administration is between 0.005 to about 1 mg per day.
8. A composition as claimed in claim 6 wherein the amount of the parenteral administration is between 0.01 to about 0.5 mg per day.
9. A composition as claimed in claim 2 for transdermal administration in the form of ointments or creams.
10. A composition as claimed in claim 2 for rectal administration in the form of suppositories or retention enemas.
11. A composition as claimed in claim 1 wherein the amount of the compound is between about 0.005 to about 50 mg.
12. A pharmaceutical composition comprising an effective amount of 4-(2-(3-(1,1-dimethylethoxy)-3-oxo-1-propenyl)phenyl) -1,4-dihydro-2-6-dimethyl-3,5-pyridinedicarboxylic acid diethyl ester and a physiologically acceptable carrier.
13. A composition as claimed in claim 12 in a form suitable for oral, sub-lingual, transdermal, parenteral or rectal administration.
14. A composition as claimed in claim 13 for oral administration in the form of a tablet or capsule.
15. A pharmaceutical composition of claim 12, for treating cardiovascular disorders resulting from transmembranal calcium ion flux.
16. A pharmaceutical composition of claim 12, for treating hypertension.
17. A composition as claimed in claim 14 wherein the amount of the oral administration is between about 0.01 to about 50 mg per day.
18. A composition as claimed in claim 14 wherein the amount of the oral administration is between about 0.1 to about 20 mg per day.
19. A composition as claimed in claim 13 for parenteral administration in the form of a bolus injection or continuous infusion.
20. A composition as claimed in claim 19 wherein the amount of the parenteral administration is between 0.005 to about 1 mg per day.
21. A composition as claimed in claim 19 wherein the amount of the parenteral administration is between 0.01 to about 0.5 mg per day.
22. A composition as claimed in claim 13 for transdermal administration in the form of ointments or creams.
23. A composition as claimed in claim 13 for rectal administration in the form of suppositories or retention enemas.
24. A composition as claimed in claim 13 wherein the amount of compound is between about 0.005 to about 50 mg.
25. A method of treating cardiovascular disorders arising from transmembranal calcium ion influx comprising administering to a patient in need of such treatment, an effective amount of the composition of claim 12.
26. A method of treating hypertension comprising administering to a patient in need of such treatment, an effective amount of the composition of claim 1.
27. A method for treating hypertension comprising administering to a patient in need of such treatment, an effective amount of the composition of claim 12.
| 1989-01-23 | en | 1991-04-30 |
US-27362781-A | Velocity sensitive keyer control circuit for an electronic musical instrument
ABSTRACT
A touch responsive envelope control system is provided for use in an electronic musical instrument having a multiplexed keyboard, a plurality of assignable tone generators, each being assignable to producing a single note of one or more notes corresponding to one or more actuated keys of the keyboard and a keyer associated with each tone generating means for keying the generated tone with controlled attack time and decay rate and a controllable peak amplitude. The touch responsive system comprises a peak amplitude control system responsive to the actuation of each key for keying the associated tone with a peak amplitude corresponding to the intensity of actuation thereof. The peak amplitude control system includes an encoding circuit responsive to the actuation of each actuated key for producing an encoded intensity signal corresponding to the intensity of actuation thereof and a decoding circuit responsive to each encoded intensity signal for producing a corresponding peak amplitude control signal. An assigning circuit is responsive to the assignment of a given tone generator to production of a note corresponding to an actuated key for assigning the corresponding peak amplitude control signal to the given tone generator for controlling the peak amplitude of the note keyed thereby in accordance with the intensity of actuation of the corresponding key.
BACKGROUND OF THE INVENTION
This invention relates generally to envelope generation in an electronic musical instrument and more particularly to a system for touch-responsive generation of an envelope waveshape in an electronic musical instrument of the keyboard variety.
In the co-pending application of William R. Hoskinson et al, Ser. No. 065,619, filed Aug. 19, 1979, now U.S. Pat. No. 4,299,153, a touch-responsive envelope control for a keyboard musical instrument is disclosed. The present invention represents an improvement upon this system. Accordingly, the present invention is particularly useful with a tone generator and keyer comprising an LSI circuit of the type disclosed in U.S. Pat. No. 4,203,337 to Schwartz et al. This LSI tone generating and keying circuit or chip will be hereinafter referred to as a B-2 chip, in conformity with its designation in the aforementioned patent.
The present invention, like the aforementioned Hoskinson et al co-pending application is directed to producing an envelope characteristic of a keyed tone approximating the response of a conventional percussion-type instrument such as a piano, in response to the velocity or intensity of the actuation of a key. In this regard, it has been found that the generally exponential charge and discharge characteristics of conventional capacitors provide a suitable approximation of both the attack and decay portions of such an envelope waveshape. However, in conjunction with digital LSI tone generating and keying chips of the type disclosed in the aforementioned Schwartz et al patent, it has heretofore been difficult to provide suitable charging and discharging signals corresponding to a relatively broad range of possible intensities of actuations of a key. Moreover, since as many as 16 separate tone generators and associated keyers may be provided in a typical keyboard instrument, it has heretofore proven difficult to assure the proper association of the charging signals generated in response to each key actuation with only the generator and keyer assigned to the production of the tone corresponding to that key.
In the foregoing Hoskinson et al application one such arrangement is disclosed. However, the present invention makes possible the same accuracy of control, while using fewer and less expensive circuit components. Accordingly, the present invention provides a relatively simpler and more economical system than heretofore available while permitting a broad range of peak intensities of an envelope generated for a particular tone, in accordance with the intensity of actuation of the associated key on the keyboard. Hence, a family of similar attack and decay envelope waveshapes may be provided, each having substantially similar attack time and decay rate, but a peak value to accordance with the intensity of key actuation and hence, a decay time in accordance with this peak value.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a new and improved touch-responsive envelope control system for an electronic musical instrument.
A related object is to provide such a control system which is simpler and more economical than heretofore proposed systems and yet highly reliable in operation.
Briefly, the present invention provides a peak amplitude control system for an electronic musical instrument having a multiplexed keyboard, a plurality of assignable tone generating means, each being assignable to produce a single note of one or more notes corresponding to one or more actuated keys of said keyboard and keying means associated with each tone generating means for keying the generated tone with controlled attack time and decay rate and a controllable peak amplitude. The peak amplitude control system is responsive to the intensity of actuation of each key for keying the associated tone with a peak amplitude corresponding to said intensity and comprises encoding means responsive to the actuation of each actuated key for producing an encoded intensity signal corresponding to the intensity of actuation thereof, decoding means responsive to each encoded intensity signal for producing a corresponding peak amplitude control signal, and assigning means responsive to the assignment of a given tone generator to production of a note corresponding to an actuated key for assigning the corresponding peak amplitude control signal to said given tone generator for controlling the peak amplitude of the note keyed thereby in accordance with the intensity of actuation of the corresponding key.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more readily apparent upon reading the following detailed description of the illustrated embodiment, together with the accompanying drawings, in which:
FIG. 1 is a block diagrammatic representation of a control system in accordance with the invention;
FIG. 2 is a schematic circuit diagram of a multiplexing circuit associated with a keyboard instrument with which the invention may be advantageously utilized;
FIG. 3 is a schematic circuit diagram of a first portion of the control system of the invention;
FIG. 4 is a schematic circuit diagram of a second portion of the control circuit in accordance with the invention; and
FIG. 5 is a schematic circuit diagram of a circuit useful with a modified embodiment of the circuit of FIG. 4.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
Referring now to the drawings and initially to FIG. 1, an electronic instrument includes a keyboard designated generally by the reference numeral 10. This keyboard 10 is scanned and preferably multiplexed by a keyboard scanner or multiplexer 12. As will be seen later with reference to FIG. 2, this multiplexer produces a serial pulse train or data stream on a serial signal line 14 representative of the state of each key of the keyboard 10. In other words, each key of the keyboard 10 is assigned a time slot in a serial data stream generated by the scanner 12. Moreover, the signal occurring in this time slot is indicative of the state of the associated key, either undepressed, fully depressed, or in transition between its undepressed and fully depressed conditions. Suitable clocks 16 are provided for controlling the timing of the operation of the keyboard scanner 12, by way of signal lines 18 and also for providing suitable signals to key busses of the keyboard 10 by way of signal lines 20.
As more fully described in Schwartz et al U.S. Pat. No. 4,203,337, this serial data line 14 is normally fed to a first of a series of tone generator and keyer chips 22, 24, 26 and 28. In the illustrated embodiment the line 14 feeds an intensity encoder circuit 30, which feeds a corresponding serial data stream over a line 14a to the chips 22, 24, etc. These tone generator and keyer chips are preferably of the type described in the Schwartz et al patent and designated as B-2 chips. Each of these B-2 chips includes three independent tone generators, each being provided with an associated keyer for keying out the tone generated thereby. Moreover, each of the tone generators on each of these chips is assignable to the production of a single note of one or more notes corresponding to one or more actuated keys of the keyboard 10, in accordance with the corresponding data carried on the serial data line 14a. In this regard, the assignment means of these chips are connected substantially in serial fashion by intervening serial data lines 14b, 14c and 14d to accommodate up to twelve notes which may be simultaneously played on the keyboard 10. More or fewer such B-2 chips may be utilized without departing from the invention.
As also described in the above-referenced Schwartz et al patent, each of the keyers associated with the tone generators of the B-2 chips 22-28, inclusive, includes means (not shown) for keying the generated tone with a controlled envelope. Specifically, this envelope control means provides a controlled attack time and decay rate and a controllable peak amplitude, and hence decay time. Each of these envelope control means is therefore responsive to a suitable control signal for determining the peak amplitude and hence decay time of the note keyed thereby.
In accordance with the invention, a control system is provided which produces a suitable control signal to these keyer and envelope control circuits for controlling the peak amplitude of the envelopes generated thereby in accordance with the intensity of actuation of the associated key. To this end, the intensity encoder circuit 30 receives the serial data line 14 from the keyboard scanner or multiplexer 12. This intensity encoder 30 produces a digitally encoded signal corresponding to the intensity of actuation of each key of the keyboard 10, and feeds this digitally encoded signal by way of data lines 32 to an intensity decoder circuit 34. This intensity decoder circuit preferably comprises digital-to-analog conversion circuits for converting the digitally encoded signal on the signal lines 32 into an analog, peak amplitude control signal.
This analog peak amplitude control signal is fed out on a common line 36 to each of four signal assignment circuits 38, 40, 42 and 44, which are respectively associated with the B-2 chips 22, 24, 26 and 28. Each of these signal assignment circuits 38-44, inclusive, is substantially identical, whereby only the first such circuit 38 will be further described. This circuit 38 is responsive to the peak amplitude control signal on the common signal line 36 and to a note assignment signal generated by the B-2 chip 22 (as described in Schwartz et al U.S. Pat. No. 4,203,337) on a line 46 for assigning the peak amplitude control signal to the tone generator selected for generation of the corresponding note. In other words, the intensity control signal and resulting peak amplitude control signal generated in response to a given note is assigned to the keyer associated with the tone generator assigned to reproduction of that note. Each of the assignment circuits 40, 42, 44 functions in the same fashion to assign the peak amplitude control signal from the line 36 to the proper keyer and tone generator in response to a tone generator assignment signal on the associated line 48, 50 or 52. The peak amplitude control signal is then fed out to the selected or assigned keyer by mean of one of three lines designated generally by the reference numeral 54. Hence, each intensity signal or peak amplitude control signal generated on the line 36 will be assigned to one and only one keyer by way of one and only one of the lines 54, in response to the assignment of one and only one tone generator to the production of the corresponding note.
Referring briefly to FIG. 2, one form of a keyboard scanner or multiplexer system 12 is illustrated in additional detail. Briefly, this scanning or multiplexer system produces a serial data output on the line 14 in which each time slot carries a signal corresponding not only to the identity of a corresponding key of the keyboard 10 but also to the state of that key. In this regard, it will be recognized that each key may be in one of three states: in its undepressed condition, in its fully depressed condition, or in transition between the undepressed and fully depressed conditions. Moreover, it will be recognized that the relative length of time in which the key is in the latter, transition condition, is indicative of the velocity, and hence intensity of actuation of that key.
Accordingly, an upper key bus 20a and a lower key bus 20b carry suitable clock signals from the clocks 16. Preferably, these signals are inversely related, and hence are here designated as φ and φ. For convenience of illustration a single key 10a is here illustrated as a switch movable between the busses 20a and 20b. This key switch 10a forms one input to a first multiplexer 60 which in the illustrated embodiment comprises an 8-bit multiplexer clocked by signals A, B, and C from the clocks 16. Additional such 8-bit multiplexers, clocked by signals A, B, and C, such as multiplexer 62 are also provided. The number of such multiplexers 60, 62 providede depends upon the number of key switches such as the key switch 10a associated with the keyboard 10. In other words, a 61-note keyboard, as is provided on many such keyboard instruments, would utilize eight 8-bit multiplexers such as the multiplexers 60 and 62.
The serial signal output of the multiplexers 60 and 62 is fed to a further multiplexer 64, which in the illustrated embodiment is a 16-bit multiplexer clocked by signals D, E, F and G from the clocks 16. Hence, as many as 16 multiplexers 60 and 62 may be accommodated by this multiplexer 64. In a two-manual instrument having two 61-note keyboards, it will be recognized that a total of 16 multiplexers 60 and 62 will be utilized to feed the 16-bit multiplexer 64. Additionally, other functions may be multiplexed by such a system, as for example function switches or tabs of a typical electronic musical instrument such as an organ. The serial data line 14 comprises the serial output of the multiplexer 64.
The clock signals A, B, C, D, E, F and G are preferably of the type described in the above-mentioned co-pending application of William R. Hoskinson et al, Ser. No. 065,619, filed Aug. 19, 1979, and need not be further described herein. Moreover, as described in this co-pending application, the signals φ and φ on the key busses 20a and 20b provide a recognizable signal on the serial data line 14, which represents the state of each key of the keyboard 10. However, in the illustrated embodiment, these signals φ and φ may comprise DC levels such as digital 1 and 0 levels. Hence, a multiplexed output signal (M.O.) on the serial data line 14a is in an active or digital 1 state when the key switch such as the key switch 10a is in contact with the lower bus 20b, and in an inactive or digital 0 state in all other instances.
Reference is next invited to FIG. 3 wherein the intensity encoder circuit 30 is illustrated in detail. This encoder circuit 30 comprises a digital circuit, including a digital read/write memory 70. In the illustrated embodiment this read/write memory 70 comprises a RAM of the type generally designated 2101. This RAM 70 is addressed by the clock signals A, B, C, D, E, F and G, which are the same signals used to clock the multiplexer system of FIG. 2. Hence, the RAM is addressed simultaneously with the multiplexing of the keyboard 10. Accordingly, each data word of the RAM 70 corresponds to a given key of the keyboard 10, and as will be seen later, stores an encoded intensity signal corresponding to the intensity of actuation of the associated key.
The data output or read terminals D01, D02, D03 and D04 of the RAM 70 are coupled respectively to the "A" inputs of a digital adder circuit 72. In the illustrated embodiment this adder 72 is of the type generally designated 4008 and is a 4-bit adder. These same four data outputs of the RAM 70 are also fed through suitable buffer components designated generally by the reference numeral 74 whose outputs QA, QB, QC and QD form the digitally encoded intensity signal lines 32 of FIG. 1.
The carry in input (Ci) of the adder 72 receives from a suitable source a logic "1" positive voltage, while the "B" inputs thereof are all tied to logic "0" or ground. Accordingly, the sum inputs S1, S2, S3 and S4 of the adder 72 produce a 4-bit digital number which comprises the number received from the RAM 70 at the "A" inputs thereof incremented by one least significant bit, due to the +V at the Ci input. This summed output is fed to one input of each of four two-input OR gates designated generally by the reference numeral 76, which in turn feed the D inputs of four D-type flip-flops circuits designated generally by the reference numeral 78. In the illustrated embodiment these D-type flip-flops 80 preferably comprise a single integrated circuit component of the type generally designated 40174 hex D flip-flop. Each of OR gates 76 receives its second or control input from the carry-out (Co) output of the adder 72. The clock terminal (CL) of the flip-flop circuit 78 is fed from the Q1 output of a dual one-shot circuit 80. In the illustrated embodiment this dual one-shot circuit 80 is of the type generally designated 4098. The reset (R) input of the flip-flop circuit 78 is fed from this same Q1 output of the one-shot 80 by way of an intervening 2-input NAND gate 82. The remaining input of this NAND gate 82 receives the M.O. signal on the serial data line 14 from the multiplexer system of FIG. 2. The Q1, Q2, Q3 and Q4 outputs of the flip-flop circuit 78 feed the data input terminals Di1, Di2, Di3 and Di4 of the RAM 70.
The dual one-shot circuit 80 receives a clock control input signal CL4/4 at its TR1+ trigger input terminal from the clocks 16 of FIG. 1. The Q2 output of the dual one-shot circuit 80 feeds the read/write (R/W) control terminal of the RAM 70. The serial data line 14 also feeds the data input (D) of a RS-type flip-flop 84, whose Q output feeds the serial data line 14a. The clock input (CL) of this flip-flop 84 receives a clock signal CL2/4 from the clock circuit 16 of FIG. 1.
In operation, the circuit of FIG. 3 functions to produce a series of encoded intensity signals on the outputs 32 which correspond to the intensity of actuation of each key of the keyboard 10. In the illustrated embodiment, the RAM 70 is wired to accommodate 128 4-bit words, which is sufficient to accomodate the keys of two 61-note keyboards. Different numbers of keys may be utilized by modifying the addressing of the RAM 70, without departing from the invention.
The CL4/4 signal in a one-quarter duty cycle signal which is produced by the clock circuit 16 in the last one-quarter of each time slot of the multiplexer system of FIG. 2. Hence, as each key of the keyboard 10 is scanned, a CL4/4 signal is produced during the last quarter of the period during which the associated multiplexing signal 14 is in its high or logic 1 state. Accordingly, a clock signal CL4/4 will be produced to the flip-flop circuit 78 for each scan of each key of the keyboard 10 by the multiplexing system of FIG. 2. If the signal on the serial data line 14 is in the high or active state, indicating that the associated key is in contact with the upper bus 20a, the NAND gate 82 will cause the Q1 output from the one-shot 80 to reset the flip-flop 78. Hence, the simultaneously produced Q1 signal to the CL input of the flip-flop 78 will fail to pass the state of the D inputs thereof to the Q outputs thereof which will hence all remain at a low or logic 0 level.
This same CL4/4 signal will also trigger the Q2 output of the dual one-shot 80 which feeds the read/write terminal of the RAM 70. The RAM 70 will therefore be in the read mode until the CL4/4 signal occurs, whereupon it will be actuated to the write mode by the transition of the Q2 output. Accordingly, the CL4/4 signal will cause the D inputs of the flip-flop circuit 78 to be fed to the Q outputs thereof and written into the data inputs of the RAM 70 for any key which is not in the fully undepressed condition, i.e., in contact with the upper bus 20a during its scan time in the multiplex cycle of the circuit of FIG. 2. If the key is in the fully undepressed condition, four 0 bits will be written into the word in the RAM 70 corresponding to that key.
From the foregoing it will be seen that the adder 72 will increment the 4-bit word read from the RAM 70 for a given key for each scan during which that key remains in an active state, that is, not in contact with the upper bus 20a. As mentioned above, the carry-out output (Co) of the adder 72 feeds the remaining input of each of the four OR gates 76. Hence, when the maximum or digital 1111 count is reached by the adder 72 in response to continued depression of a given key over 16 scan periods, this maximum count will be held at the data inputs of the flip-flop 78, rather than rolled over to a 0000 state. Accordingly, a 4-bit binary word having one of 16 possible states will be written into the RAM 70 for each key of the keyboard 10. During each cycle of the keyboard scan the RAM contents for each key will be simultaneously read out on the data lines QA, QB, QC and QD, indicated collectively by the reference numeral 32. It will be noted that tone generator assignment on the B-2 chip does not take place until a key switch contacts the lower bus 20b. Accordingly, the 4-bit word on data lines 32 is fully developed by the RAM 70 by the time generator assignment occurs. If a given key remains undepressed, the associated note and RAM contents are not assigned, and are of no consequence. The data lines 32 feed the input of the intensity decoder circuit 34, shown in detail to FIG. 4, to which reference is now invited.
The 4-bit data word on the lines 32 forms the four control inputs to a 16-bit analog multiplexer 90, whose single output forms the line 36 of FIG. 1 which carries the peak amplitude control signal. The 16 analog inputs of the multiplexer are coupled to respective junctions in a voltage divider chain comprising 16 resistors designated generally by the reference numeral 92. These resistors are coupled in series from a suitable positive voltage source +V to ground. In the illustrated embodiment, the resistor values of the resistors 92b, 92c through 92n are selected to logarithmically increase. Accordingly, the divided voltage fed out due to selection of a given junction between resistors logarithmically increases as the selected junction moves from the bottom-most or "15" input of the multiplexer 90 to the topmost or "0" input thereof.
For purposes of disclosing a specific embodiment, the first resistor 92a is selected to have a resistance on the order of 3.9 K ohms, which defines a minimum voltage to be fed out on the analog data line 36. The next resistor 92b has a value on the order of 200 ohms, while the next series-connected resistor 92c has a value of on the order of 220 ohms, the succeeding resistors logarithmically increasing in this fashion. The selected positive voltage +V is on the order of 9 volts DC. Other positive voltage reference potentials and resistor values which increase logarithmically in this fashion may be utilized without departing from the invention.
From the foregoing it will be seen that the 4-digit digital output from the RAM 70 received at the inputs 32 of the multiplexer 90 will bear an inverse relation to the intensity of actuation of the associated key. That is, the less intense the actuation of a given key, the longer period it will take to reach the lower bus 20b, and hence the higher count that will accumulate in the RAM 70 for that key. Hence, the resistor values of resistors 92 are arranged in logarithmically increasing fashion to produce a logarithmically decreasing analog voltage signal on the output 36 in response to a binarily increasing digital input signal on the inputs 32 of the multiplexer 90.
The resulting analog peak value control signal is fed through a suitable operational amplifier 94 to the common signal line 36. This common signal line 36 feeds all of the signal assignment circuits 38, 40, 42 and 44. As mentioned above, these four circuits are identical, whereby only the first circuit 38 is here described in detail. The peak amplitude control signal on the line 36 is scaled or adjusted by way of a suitable potentiometer 98 which forms the non-inverting input of an operational amplifier 100 whose inverting input is fed back from the output thereof. The potentiometer 98 associated with each of the intensity control or assignment circuits is provided in order to properly scale the analog voltage on the line 36 for use with that particular circuit and its associated B-2 chip. This allows for normal tolerances in both the B-2 chip and the analog circuit components and provides an offset error adjustment.
The output of the op amp 100 feeds three solid state switches 102, 104 and 106 associated with the three tone generators of the first B-2 chip 22. Three one-shots 108, 110 and 112 are provided to respectively actuate each of these electronic switches 102, 104, 106 in response to a note assignment signal from one of the three tone generators of the B-2 circuit chip 22. Actuation of each of these switches causes the intensity of peak amplitude control signal to be fed to a sample and hold circuit 113 associated with the corresponding tone generator of the B-2 circuit chip 22. These sample and hold circuits 113 are identical, whereby only a first such circuit 113 will be described.
The sample and hold circuit 113 associated with the first tone generator of the circuit chip 22 comprises an operational amplifier (op amp) 114 which is provided with a grounded capacitor 116 at its non-inverting input. The inverting input of the op amp 114 receives feedback from the output thereof which feeds a series-connected resistor 118 and diode 120. The diode 120 feeds an envelope decay control circuit comprising a pair of capacitors 122, 124 and a resistor 126 coupled in parallel to the capacitor 124. The keyer circuit associated with the first tone generator of the circuit chip 22 is coupled to these capacitors 122, 124 and resistor 126 to utilize the discharge or decay voltage thereof as a decay portion of the envelope waveform generated thereby. A further control terminal 128 provides the generator assignment signal associated with the first keyer and tone generator pair of the circuit chip 22 to the one-shot 108 and is also coupled by way of a diode 130 to the capacitor 116. This control terminal 128 also discharges the capacitor 16 when the assigned percussive note has been generated and keyed, so that the generator envelope is percussive with the key closure as in a piano type instrument. In the illustrated embodiment, each of the operational amplifiers 94, 100 and 114 is preferably one operational amplifier component of an integrated circuit component generally designated LF347 quad bi-FET operational amplifier, which has a relatively high impedance and rate of response. In the illustrated embodiment, the generator assignment signal on the line 128 is generated substantially in the middle of a 50 microsecond time slot during which the generator assignment takes place. The one-shot active period is thus somewhat less than this one-half of a 50 microsecond time slot and typically less than on the order of 40 microseconds so that the electronic switch 102 and its associated sample and hold circuit 113 is actuated only long enough to receive the associated peak amplitude control signal. In the illustrated embodiment, the electronic switches 102, 104 and 106 preferably comprise a CMOS switch of either of the types generally designated 4016 and 4066. Additionally, the one-shots 108, 110 and 112 preferably comprise one-shot components of a dual one-shot package of the type generally designated CD4098.
Referring briefly to FIG. 5, the multiplexer 90 may also take the form of a pair of 8-to-1 multiplexers 90a and 90b, which may be of the type generally designated CD4051. In this case, the QD bit is additionally fed to an inhibit input of the first multiplexer 90a and inverted through a suitable buffer inverter 140 to the inhibit input of the multiplexer component 90b, to cause these two multiplexers 90a and 90b to function essentially as a 16-to-1 multiplexer as illustrated in FIG. 4.
What has been illustrated and described herein is a novel and improved intensity or velocity responsive envelope control system for an electronic musical instrument. While the invention has been described with reference to a preferred embodiment, it is not limited thereto. Those skilled in the art may devise various changes, alternatives and modifications upon reading the foregoing descriptions. Accordingly, the invention includes such changes, alternatives and modifications insofar as they fall within the spirit and scope of the appended claims.
The invention is claimed as follows:
1. In an electronic musical instrument having a multiplexed keyboard, a plurality of assignable tone generating means, each being assignable to produce a single note of one or more notes corresponding to one or more actuated keys of said keyboard and keying means associated with each tone generating means for keying the generated tone with controlled attack time and decay rate and a controllable peak amplitude, a peak amplitude control system responsive to the intensity of actuation of each key for keying the associated tone with a peak amplitude corresponding to said intensity and comprising: a single encoding means common to all of the keys of said keyboard and responsive to the intensity of actuation of each actuated key for producing an encoded intensity signal corresponding to said intensity of actuation, a single decoding means common to all of said tone generators and responsive to each encoded intensity signal for producing a corresponding analog peak amplitude control signal, memory means for storing the peak amplitude control signal, gate means connected to said memory means, and assigning means interconnected with said tone generating means and responsive to the assignment of a given tone generator for production of a note corresponding to an actuated key for operating said gate means to gate the corresponding peak amplitude control signal to said given tone generator at the onset of attack for controlling the peak amplitude of the note keyed thereby in accordance with the intensity of actuation of the corresponding key.
2. A control system according to claim 1 wherein said encoding means comprises digital circuit means for producing a digitally encoded signal comprising said encoded intensity signal and corresponding to the intensity of actuation of an actuated key.
3. A control system according to claim 2 wherein said decoding means comprises digital-to-analog circuit means for producing an analog signal comprising said peak amplitude control signal in response to said digitally encoded signal, which analog signal varies logarithmically in accordance with said intensity of actuation of an actuated key.
4. A control system according to claim 2 wherein said memory means receives and stores data corresponding to a plurality of said digitally encoded signals and addressing means for individually addressing data corresponding to each of said digitally encoded signals.
5. A control system according to claim 4 wherein said memory means comprises read/write memory means.
6. In an electronic musical instrument having a multiplexed keyboard, a plurality of assignable tone generating means, each being assignable to produce a single note of one or more notes corresponding to one or more actuated keys of said keyboard and keying means associated with each tone generating means for keying the generated tone with controlled attack time and decay rate and a controllable peak amplitude, a peak amplitude control system responsive to the intensity of actuation of each key for keying the associated tone with a peak amplitude corresponding to said intensity and comprising: a single encoding means common to all of the keys of said keyboard and responsive to the intensity of actuation of each actuated key for producing an encoded intensity signal corresponding to said intensity of actuation, a single decoding means common to all of said tone generators and responsive to each encoded intensity signal for producing a corresponding analog peak amplitude control signal, and assigning means responsive to the assignment of a given tone generator for production of a note corresponding to an actuated key for assigning the corresponding peak amplitude control signal to said given tone generator for controlling the peak amplitude of the note keyed thereby in accordance with the intensity of actuation of the corresponding key, said encoding means comprising digital circuit means for producing a digitally encoded signal comprising said encoded intensity signal and corresponding to the intensity of actuation of an actuated key, said digital circuit means including memory means for receiving and storing data corresponding to a plurality of said digitally encoded signals and addressing means for individually addressing data corresponding to each of said digitally encoded signals, said memory means comprising read/write memory means, said read/write memory means comprising a RAM, and gate means connected to said memory means to gate said peak amplitude control signal to said given tone generator at the onset of attack.
7. A control system according to claim 5 wherein said addressing means comprises multiplexing means which simultaneously multiplexes said keyboard in a predetermined order.
8. In an electronic musical instrument having a multiplexed keyboard, a plurality of assignable tone generating means, each being assignable to produce a single note of one or more notes corresponding to one or more actuated keys of said keyboard and keying means associated with each tone generating means for keying the generated tone with controlled attack time and decay rate and a controllable peak amplitude, a peak amplitude control system responsive to the intensity of actuation of each key for keying the associated tone with a peak amplitude corresponding to said intensity and comprising: a single encoding means common to all of the keys of said keyboard and responsive to the intensity of actuation of each actuated key for producing an encoded intensity signal corresponding to said intensity of actuation, a single decoding means common to all of said tone generators and responsive to each encoded intensity signal of producing a corresponding analog peak amplitude control signal, and assigning means responsive to the assignment of a given tone generator for production of a note corresponding to an actuated key for assigning the corresponding peak amplitude control signal to said given tone generator for controlling the peak amplitude of the note keyed thereby in accordance with the intensity of actuation of the corresponding key, said encoding means comprising digital circuit means for producing a digitally encoded signal comprising said encoded intensity signal and corresponding to the intensity of actuation of an actuated key, said digital circuit means including memory means for receiving and storing data corresponding to a plurality of said digitally encoded signals and addressing means for individually addressing data corresponding to each of said digitally encoded signals, gate means connected to said memory means to gate said peak amplitude control signal to said given tone generator at the onset of attack, said memory means comprising read/write memory means, said read/write memory means further including means responsive to a first clock pulse for reading out the addressed data, and said digital circuit means further including adder means for receiving the data read out from said read/write memory means in response to said first clock pulse and for incrementing said read out data and latch means responsive to a second clock pulse occurring after said first clock pulse for reproducing said incremented data from said adder means, said read/write memory means being responsive to said second clock pulse for receiving and writing said reproduced data from said latch means, said digital circuit means further including clock control means responsive to the actuation of each key for producing said first and second clock pulses, the number of said first and second clock pulses produced thereby corresponding to the intensity of actuation of the corresponding key.
9. A control system according to claim 8 wherein said read/write memory means has a capacity for receiving and storing a number of data words at least as great as the number of keys on said keyboard instrument and is addressed in unison with the multiplexing of said keys for receiving and storing a data word corresponding to the intensity of actuation of each of said keys.
10. A control system according to claim 8 wherein said decoding circuit means comprises analog multiplexer means.
11. A system according to claim 1 wherein said assigning means comprises electronic switch means responsive to the assignment of a tone generating means for passing the peak amplitude control signal to the keyer means associated with the assigned generating means.
12. In an electronic musical instrument having a multiplexed keyboard, a plurality of assignable tone generating means, each being assignable to produce a signal note of one or more notes corresponding to one or more actuated keys of said keyboard and keying means associated with each tone generating means for keying the generated tone with controlled attack time and decay rate and a controllable peak amplitude, a peak amplitude control system responsive to the intensity of actuation of each key for keying the associated tone with a peak amplitude corresponding to said intensity and comprising: a single encoding means common to all of the keys of said keyboard and responsive to the intensity of actuation of each actuated key for producing an encoded intensity signal corresponding to said intensity of actuation, a single decoding means common to all of said generators and responsive to each encoded intensity signal for producing a corresponding peak amplitude control signal, and assigning means responsive to the assignment of a given tone generator for production of a note corresponding to an actuated key for assigning the corresponding peak amplitude control signal to said given tone generator for controlling the peak amplitude of the note keyed thereby in accordance with the intensity of actuation of the corresponding key, said assigning means comprising electronic switch means responsive to the assignment of a tone generating means for passing the peak amplitude control signal to the keyer means associated with the assigned generating means, said assigning means further including one-shot means for actuating said electronic switch means momentarily upon assignment of a tone generating means and sample and hold means interposed between said electronic switch means and the associated keying means for holding said peak amplitude control signal after the momentary actuation of said electronic switch means by said one-shot means.
13. A control system according to claim 12 and further including means for resetting said sample and hold means following keying of said tone produced by the associated tone generator means, so as to be in a condition to receive a further peak amplitude control signal for keying a tone generated by said tone generating means in response to a subsequently assigned actuated key.
14. In an electronic musical instrument having a multiplexed keyboard, a plurality of assignable tone generating means, each being assignable to produce a single note of one or more notes corresponding to one or more actuated keys of said keyboard and keying means associated with each tone generating means for keying the generated tone with controlled attack time and decay rate and a controllable peak amplitude, a peak amplitude control system responsive to the intensity of actuation of each key for keying the associated tone with a peak amplitude corresponding to said intensity and comprising: encoding means responsive to the actuation of each actuated key for producing an encoded intensity signal corresponding to the intensity of actuation thereof, decoding means responsive to each encoded intensity signal for producing a corresponding analog peak amplitude control signal, memory means for storing the peak amplitude control signal, gate means connected to said memory means, and assigning means interconnected with said tone generating means and responsive to the assignment of a given tone generator for production of a note corresponding to an actuated key for operating said gate means to gate the peak amplitude control signal corresponding to that key to said given tone generator at the onset of attack for controlling the peak amplitude of the note keyed thereby in accordance with the intensity of actuation of the corresponding key.
15. A control system according to claim 14 wherein said encoding means comprises digital circuit means for producing a digitally encoded signal comprising said encoded intensity signal and corresponding to the intensity of actuation of an actuated key.
16. A control system according to claim 15 wherein said decoding means comprises digital-to-analog circuit means for producing an analog signal comprising said peak amplitude control signal which varies in accordance with the intensity of actuation of a key.
| 1981-06-15 | en | 1983-11-29 |
US-36451564-A | Continuous wave fm radar
Sept. 6, 1966 0. K. NILSSEN CONTINUOUS WAVE FM RADAR Filed May 4, 1964 2 Sheets-Sheet 1 BEAT FREQUENCY TRANSM ITTED SIGNAL j F2 l F I I TIME DELAY,T RECEIVED SIGNAL FIG. 1
I0 I: I7 HTRANSMITTEM MODULATORHINTEGRATOR FREQUENCY METER SCALE OF n COUNTER FIG.3
-- TRANSMITTER MODULATOR INTEGRATOR FREQUENCY METER 1e 22 SCALE OF n COUNTER FIG.4
OLE K. NILSSEN //Vl EN7'OR p 1966 0. K. NILSSEN CONTINUOUS WAVE FM RADAR 2 Sheets-Sheet 2 Filed May 4, 1964 NQK 5:23 mantis? mwkzzouc Qz lo wiuw 55 552 j u U n n nfln Q Q Q Q 9 m 5.52:? Kim mobqmoni 1 1233002 EtEwZ/EP N H E o ATTORNE S United States Patent 3,271,766 CONTINUOUS WAVE FM RADAR Ole K. Nilssen, Livonia, Mich., assignor to Ford Motor Company, Dearhorn, Mich, a corporation of Delaware Filed May 4, 1964, Ser. No. 364,515 9 Claims. (Cl. 343-14) This invention relates to a continuous wave radar system and more particularly to a continuous wave radar system of the frequency modulated type that has reduced transmission bandwidth requirements and no fixed range error.
A well known drawback of standard frequency modulated radar is that a fixed error is caused by the digital or quantized nature of the range reading. As a result of this quantization of the range reading, it is necessary to use a very wide transmission bandwidth in order to achieve accurate range readings, particularly at short ranges.
In standard frequency modulated radar, the frequency of the transmitted signal is varied by a certain amount. Range is obtained by counting how many beat cycles occur as a result of the mixing of the transmitted and reflected signals. As may be readily understood, there will be an inaccuracy in range reading possible corresponding to one beat cycle count. Thus, in order to achieve a sufficiently accurate range measure, a certain minimum number of beat cycles must be produced. This implies a certain minimum frequency swing by the transmitter which for close ranges or high accuracies may become exceedingly large. This in turn requires large transmission bandwidths, with resulting complex and expensive electronic equipment.
The present invention provides a continuous wave radar system in which there is no fixed error, and as a result the system operates with a much reduced transmission bandwidth requirement. This simplifies the electronic equipment required, and provides a very accurate system particularly for measurement of short ranges.
In the invention, the frequency swing of the transmitter required for a given count of beat cycles is determined, rather than determining the number of beat cycles that occur for a given frequency swing as is done in conventional frequency modulated radar. As a result of this, there is no fixed error involved in that the frequency swing of the transmitter can be measured simply and directly in a proportional or nonquantized manner. From this information, range may be computed directly.
In accordance with the invention, a frequency modulated transmitting means is employed for transmitting a signal to the target. Means are provided for receiving and combining the signal transmitted and a signal reflected from the target. This signal is applied to a means that produces a beat signal having a frequency representative of the difference between the transmitted and the received signal. Means are connected to this last mentioned means for determining the frequency change in the transmitting means for a given number of heat cycles. This may be done by a feedback system that reverses the rate of change of frequency of the transmitting means each time a predetermined number of beat cycles is produced. Range may be easily computed by measuring a variable from which the change in frequency between these reversals can be determined.
An object of the present invention is the provision of a continuous wave radar system that has a small transmission bandwidth.
Another object of the present invention -is the provision of a continuous wave radar of the frequency modulated type in which no fixed error of range measurement is produced.
A further object of the invention is the provision of a continuous wave radar system of the frequency modulated 3,271,?65 Patented Sept. 6, 1966 type that is capable of accurately measuring very small ranges and employs a minimum of transmission bandwidth for accomplishing this purpose.
Other objects and attendant advantages of the present invention may be more fully realized when the specification is considered in connection with the attached drawing in which:
FIGURE 1 is a waveform of the transmitted and received signals in a frequency modulated radar system showing the frequency swing of the carrier signal.
FIGURE 2 is a block diagram of one embodiment of the invention.
FIGURE 3 is a partial block diagram of another embodiment of the invention, and
FIGURE 4 is a partial block diagram of still another embodiment of the invention.
In a conventional frequency modulated radar system, the carrier frequency may be modulated by a modulated voltage such that the frequency of the transmitted signal versus time appears in accordance with the solid line waveform shown in FIGURE 1. The dotted line waveform represents the reflected signal from the target delayed in time. This time delay can be used, as: is well known to those skilled in the art, to determine distance or range to the target.
In order to determine range in accordance with the above principles, the frequency difference between the transmitted and the received signal is determined. This is ordinarily done by mixing or beating these two signals together and then amplitude detecting the combined signal. The frequency of this difference or beat signal provides a direct measure of range to the target. In such a case, range may be expressed as In this equation it is a number determined by applying the beat frequency mentioned above to a counter, a is the speed of light, df/dt is the time rate of change of the transmitter frequency, or the slope of the transmitted signal depicted in FIGURE 1, and T is the time allowed for counting.
Since 11, the output from the counter, must be in the form of a whole number, there exists a possiiblity of error corresponding to one count. For very short ranges, this uncertainty may correspond to a great percentage error in the range. In order to obviate this difiiculty in conventional radar systems, the frequency of the transmitter must be deviated very rapidly in order to achieve a sufiiciently large number of counts for short ranges. This implies a very large transmission bandwidth and expensive electronic equipment.
The present invention provides a frequency modulated radar system that has no fixed range error and that has small transmission bandwidth requirements. This is achieved by employing means for measuring the frequency swing required for a given count of beat cycles, rather than counting the number of beat cycles associated with a given frequency swing.
Referring back to FIGURE 1, it can be appreciated that a given change in transmitter frequency is equal to the time delay 1- between the transmitted and received signals multiplied by the slope of the curves or plots shown in FIG- URE l, or in other words,
Rearranging this equation and integrating gives The left-hand side of this equation is equal to the number of beat cycles or n for a given time interval, while the right-hand side gives Therefore,
Substituting this into the range equation 2R='r'C gives n-c .F.
As a result, if n is kept constant, range may be easily determined by measuring the frequency swing of the transmitter involved in bringing about a fixed number of beat gram of one embodiment of the invention for accomplishing this purpose.
In FIGURE 2, a transmitter 10 that may be operated in the microwave region is frequency modulated by a modulator 11. The energy from the transmitter 10 is applied to an antenna 12 through a circulator 13, and is transmitted to a target to determine its range with respect to the system. The echo or received signal from the target is received by the same antenna 12 and is then fed to an amplitude detector 14 through the circulator 13. A portion of the transmitted signal from the transmitter 10 leaks through the circulator 13, as shown by the dotted lines, to the amplitude detector 14. The transmitted signal from the transmitter 10 and the echo signal or received signal from the target are thus mixed and the amplitude detector 14 produces a beat signal which has a frequency equal to the difference between the transmitted signal and the echo or received signal.
The beat signal produced by the amplitude detector 14 may then be fed to an amplifier and an amplitude limiter 15 that produces a rectangular wave, as shown, from the essentially sinusoidal beat frequency signal. This rectangular wave is then applied to a scale of n counter 16 which may be set to change its output after having accepted a certain count n. For example, it may be set to count 2, 3, 4 or beat cycles or any other number that is appropriate and convenient. In the example shown with the waveforms in FIGURE 2, n has been selected as the whole number 1. As shown, the scale of n counter 16 will produce an output voltage having either of two constant voltage levels and it switches from one of these levels to the other after having accepted the count 11.
The rectangular waveform from the scale of n counter 16 is then fed to an integrator 17 that integrates the output voltage waveform from the scale of n counter thereby producing the triangular waveform shown. This triangular waveform is applied to the modulator 11 which will produce a frequency change in the transmitted signal from the transmitter proportional to this voltage. It can readily be appreciated that the frequency change in the transmitter 10 will follow the triangular waveform shown in FIGURE 1. In order to determine range it is only necessary to determine the frequency difference in the transmitted signal corresponding to a given number of beat cycles. This may be done by measuring the peak voltage output of the integrator 17 since it is directly proportional to the frequency difference in the transmitted signal associated with a given number of beat cycles. In order to measure this voltage, it is only necessary that a peak reading voltmeter 18 be connected to read the peak voltage outputs of the integrator 17. It may be seen that range may be easily determined from the previously developed equation since It and c are constants.
cycles; FIGUREQ of the drawing discloses a block diato the scale of n counter 16 as shown in the partial block diagram of FIGURE 3. It should be understood that the remainder of the invention, not shown in FIGURE 3, is the same as that shown in FIGURE 2. Since the waveform produced by the integrator 17 has a constant slope, it is apparent that the time intervals between the reversal of slope will provide an indication of range, and this time may be easily found through computation by using the frequency at which this occurs. This frequency may be measured by the use of the frequency meter 21 connected to the scale of n counter, since the waveform output from the integrator 17 reverses twice during each cycle of the output voltage from the scale of n counter.
The frequency change of the transmitted signal associated with the given count of beat cycles may also be measured directly from the modulator er transmitter by use of a frequency meter 22 that may be connected to the transmitter 10 as shown in FIGURE 4. This frequency difierence, is the difference in frequency between reversals of the rate of change of frequency as represented by the triangular waveform shown in FIGURE 1 and the triangul ar waveform that is produced by the integrator '17.
Another way to measure range would be to measure the time involved for the scale of n counter 16 to flip from one position to the other. As brought out previously in the discussion of the measurement of the frequency difference between the reversals of the rate of change of frequency by use of the frequency meter 21, this time it may be used directly to compute the frequency difference and hence be used to compute range to the target.
The present invention thus provides a continuous wave radar system of the frequency modulated type that operates with no fixed range error and which may be used to determine short ranges accurately with a minimum bandwidth.
It is to be understood that this invention is not to be limited to the exact construction shown and described but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
I claim:
1. A continuous wave radar system for determining range between the system and a target comprising, a transmitting means, modulating means coupled to said transmitting means for frequency modulating said transmitting means, means for receiving and combining a signal transmitted by said transmitting means and a signal reflected from the target, means coupled to said last mentioned means for producing a beat frequency signal that varies as a function of the range between the system and the target and having a frequency equal to the difference between the transmitted signal and the received signal, and means coupled to said last mentioned means and said modulating means for modifying the rate of change of said transmitting means each time a given number of beat cycles is produced, and means connected in circuit with said last mentioned means and said modulating means for determining the frequency swing of said transmitting means required for said given number of said beat cycles whereby range between the system and the target may be determined.
2. A continuous wave radar system for measuring range between the system and a target comprising, a transmitting means, modulating means connected to said transmitting means for frequency modulating said transmitting means, means for receiving and combining a signal transmitted by said transmitting means and a signal reflected from the target, means coupled to said last mentioned means for producing a signal having a frequency equal to the difference between the transmitted signal and the received signal, means coupled to said last mentioned means and said modulating means for reversing the rate of change of frequency of said transmitting means each time a predetermined number of beat cycles is produced.
3. A continuous wave radar system for measuring range between the system and a target comprising, a transmitting means, modulating means connected to said transmitting means for frequency modulating said transmitting means, means for receiving and combining a signal transmitted by said transmitting means and a signal reflected from the target, means coupled to said last mentioned means for producing a signal having a frequency equal to the difference between the transmitted signal and the received signal, means coupled to said last mentioned means and said modulating means for reversing the rate of change of frequency of said transmitting means each time a predetermined number of beat cycles is produced, and means coupled to said last mentioned means for measuring a variable from which range may be determined.
4. A continuous wave radar system for measuring range between the system and a target comprising, a transmitting means, modulating means coupled to said transmitting means for frequency modulating said transmitting means, means for receiving and combining a signal transmitted by said transmitting means and a signal reflected from said target, detecting means connected to said last mentioned means for producing a beat signal having a frequency equal to the frequency difference between the signal transmitted by said transmitting means and the signal reflected from said target, means connected to said detecting means and said modulating means for reversing the rate of change of frequency of said transmitting means each time a given number of beat cycles is produced by said detecting means, and means connected in circuit with said means connected to detecting means and modulating means for determining the frequency swing of said transmitting means required for said given number of beat cycles whereby range between the system and the target may be determined.
5. A continuous wave radar system for measuring range between the system and a target comprising, a transmitting means, modulating means connected to said transmitting means for frequency modulating said transmitting means, means for receiving and combining a signal transmitted by said transmitting means and a signal reflected from the target, detecting means connected to said last mentioned means for producing an output signal having a frequency equal to the difference between the transmitted and said received signals, counter means connected to said detector means for counting the number of output signal cycles from said detecting means and for producing a rectangular wave output signal having a frequency equal to the frequency of the output signal from said detecting means divided by a predetermined whole integer, an integrator coupled to said counter means for producing a triangle waveform from said rectangular wave output signal from said counter means, said integrator coupled to said modulating means for applying said triangular waveform to said modulating means whereby the change of frequency of the signal transmitted by said transmitter follows said triangular waveform, and means 5 coupled to said system for measuring a variable from which the frequency difference of said transmitter means between changes in slope of said triangular waveform may be determined whereby range from the system to the target may be computed.
6. The combination of claim 5 in which said last mentioned means is a frequency meter coupled to said counter means.
7. The combination of claim 5 in which said last mentioned means is a peak voltmeter connected to the output of said integrator.
8. The combination of claim 5 in which said last mentioned means is a frequency meter coupled in circuit with said transmitting means for measuring the frequency difference of said transmitter means between reversals of slope of said triangular waveform.
9. A continuous wave radar system for measuring range between the system and a target comprising, a transmitting means, modulating means coupled to said transmitting means for frequency modulating said transmitting means, means for receiving and combining a signal transmitted by said transmitting means and a signal reflected from said target, detecting means connected to said last mentioned means for producing a beat signal having a frequency equal to the frequency difference between the signal transmitted by said transmitting means and the signal reflected from said traget, means connected to said detecting means and said modulating means for modifying the rate of change of frequency of said transmitting means each time a given number of beat cycles is produced by said detecting means, and means connected in circuit with said means connected to detecting means and modulating means for determining the frequency swing of said transmitting means required for said given number of beat cycles whereby range between the system and the target may be determined.
References Cited by the Examiner UNITED STATES PATENTS 2,543,782 3/1951 Kiebert 34314 FOREIGN PATENTS 525,123 5/1956 Canada.
CHESTER L. JUSTUS, Primary Examiner.
R. E. KLEIN, P. M. HINDERSTEIN,
Assistant Examiners.
1. A CONTINUOUS WAVE RADAR SYSTEM FOR DETERMINING RANGE BETWEEN THE SYSTEM AND A TARGET COMPRISING, A TRANSMITTING MEANS, MODULATING MEANS COUPLED TO SAID TRANSMITTING MEANS FOR FREQUENCY MODULATING SAID TRANSMITTING MEANS, MEANS FOR RECEIVING AND COMBINING A SIGNAL TRANSMITTED BY SAID TRANSMITTING MEANS AND A SIGNAL REFLECTED FROM THE TARGET, MEANS COUPLED TO SAID LAST MENTIONED MEANS FOR PRODUCING A BEAT FREQUENCY SIGNAL THAT VARIES AS A FUNCTION OF THE RANGE BETWEEN TH SYSTEM AND THE TARGET AND HAVING A FREQUENCY EQUAL TO THE DIFFERENCE BETWEEN THE TRANSMITTED SIGNAL AND THE RECEIVED SIGNAL, AND MEANS COUPLED TO SAID LAST MENTIONED MEANS AND SAID MODULATING MEANS FOR MODIFYING THE RATE OF CHANGE OF SAID TRANSMITTING MEANS EACH TIME A GIVEN NUMBER OF BEAT CYCLES IS PRODUCED, AND MEANS CONNECTED IN CIRCUIT WITH SAID LAST MENTIONED MEANS AND SAID MODULATING MEANS FOR DETERMINING THE FREQUENCY SWING OF SAID TRANSMITTING MEANS REQUIRED FOR SAID GIVEN NUMBER OF SAID BEAT CYCLES WHEREBY RANGE BETWEEN THE SYSTEM AND THE TARGET MAY BE DETERMINED.
| 1964-05-04 | en | 1966-09-06 |
US-85014392-A | Brake holding system
ABSTRACT
A brake holding system for a vehicle, comprising a vacuum magnetic member, a brake pedal extension arm which is attached to a push rod which, in turn, is connected to the master cylinder. The brake holding system can be actuated by a vacuum magnetic member when the speed of the vehicle is reduced to 0 mph under activation of a plurality of sensors while the vehicle is completely stopped.
This application is a continuation of application Ser. No. 07/677,419 filed on Mar. 29, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved brake holding system of an automotive vehicle. More particularly, the present invention is directed to a brake holding system for vehicles comprising a vacuum magnetic device operatively associated with a brake pedal extension arm which is attached to a push rod connected to the master cylinder, whereby when the speed of the automobile is reduced to 0 mph such as, for example, at a stoplight, the brake is automatically engaged and maintained and thus the operator does not need to keep his foot on the brake pedal. The brake can then be automatically released when the accelerator pedal is depressed by the operator for advancing the automobile.
2. Description of the Prior Art
In many of the brake holding and releasing systems known in the art, the mechanism are very complicated, rendering them unacceptable for commercial applicability or availability. Such brake controlling systems are shown in U.S. Pat. No. 1,927,209 to Gilmore, U.S. Pat. No. 2,235,424 to Weiss et al, U.S. Pat. No. 2,308,822 to Murphy, U.S. Pat. No. 2,313,232 to Freeman, U.S. Pat. No. 2,642,484 to Price, U.S. Pat. No. 2,690,824 to Forman, U.S. Pat. No. 2,843,235 to Weaver, U.S. Pat. No. 2,849,557 to Long, U.S. Pat. No. 2,904,134 to Cieply, Jr., U.S. Pat. No. 2,938,611 to Cook, U.S. Pat. No. 2,973,844 to Prather, U.S. Pat. No. 3,021,821 to Prather, U.S. Pat. No. 3,315,536 to Caleys, and U.S. Pat. No. 4,446,950 to Wise et al. Also, U.S. Pat. Nos. 4,646,903 and 4,696,222, issued to the present inventor, disclose a brake holding system for vehicles, comprising a vacuum and magnetic device including a brake holder, a moon gear having a plurality of teeth, a push rod connected to a master cylinder, a speed monitoring device having a needle being contacted to a switch member and a brake releasing switch operatively associated with the accelerator. The brake holding system can be placed into position when the speed of the vehicle is reduced to between 0 and 5 mph by application of the brake pedal. The brake is then automatically unlocked by depressing the accelerator pedal. Also, the driver can pull an emergency handle to mechanically release the brake. However, this brake holding system is very complicated to manufacture and cannot be applied to the vehicle conveniently and reliably.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved brake holding system of an automotive vehicle.
Another object of the present invention is to provide a brake holding system which can safely lock a braking system on a vehicle when the speed of the automobile is reduced to 0 mph.
A further object of the present invention is to provide a brake holding system which automatically unlocks the brake when the accelerator pedal is depressed.
Still another object of the present invention is to provide a brake holding system which is easy to operate and does not require the operator to keep a foot on the brake pedal at all times to prevent the vehicle from moving. Accordingly, it is particularly useful when the operator is a woman, a senior citizen, or a young adult.
Yet another object of the present invention is to provide a brake holding system which is simple, and inexpensive to manufacture and can be readily installed on a used car.
Still another object of the present invention is to provide a brake holding system comprising a vacuum magnet unit which is connected to the original vacuum system of the automobile.
A further object of the present invention is to provide a brake holding system which automatically locks a vehicle only when the vehicle is stationary since the brake holding system is deactivated by deactivating a plurality of sensors during the time when the vehicle is moving.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
Briefly described, the present invention relates to a brake holding system for a vehicle, comprising a vacuum magnetic member, a brake pedal extension arm which is attached to a push rod which, in turn, is connected to the master cylinder. The brake holding system can be actuated by the vacuum magnetic member when the speed of the vehicle is reduced to 0 mph under activation of a plurality of sensors during the time when the vehicle is completely stopped.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a perspective view of the brake holding system showing components of the brake holding system of the present invention;
FIG. 2 is a perspective view of the brake holding system of the present invention;
FIG. 3 is a diagrammatic view showing an on/off member of the brake holding system of FIGS. 1;
FIG. 4 shows the electrical circuit of the vacuum and magnetic systems of the brake holding system of the present invention; and
FIGS. 5A and 5B are perspective views of a sensor for an axle shaft and a sensor for an axle of the present invention, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, the brake holding system for a vehicle as shown in FIGS. 1 and 2, comprises a brake pedal extension arm 10 having a brake pedal 11, a vacuum activator 12 connected to the brake pedal extension arm 10 via a connecting steel wire 13 and connected to a vacuum tank 25, and a control box 14 containing a magnetic member 40. The control box 14 is connected to a button or on-off switch through wires 16A and an odometer 17 through a speed monitoring sensor 20. And a push rod 18 is connected to a master cylinder 19 and is also attached to the brake pedal extension arm 10. Also, the connecting steel wire 13 is movably disposed within a pipe 15. The pipe is passed through a partition 51 and is held in place with a pair of adjustable nuts 52.
As shown in FIGS. 1 and 4, the speed monitoring sensor 20 is connected to the odometer 17 and thus senses movement of a needle 37. The sensor is also connected to the control box 14 through sensor wires 22. The odometer 17 is directly connected to the vehicle transmission 23 through the speed monitoring sensor 20 by a odometer cable 21. The speed monitoring sensor 20 is a magnet sensor which includes a permanent magnet 20a wrapped by an electric coil group 20b, and an odometer cover 38 is provided for covering the permanent magnet 20a and the electric coil group 20b, whereby when the odometer 17 is not being activated by the cable 21 electricity is not generated since there is no movement of the permanent magnet 20a within the coil group 20b. In turn, when the odometer 17 is being activated by the cable 21, electricity is generated by the rotation of the permanent magnet 20a within the coil group 20b. Therefore, the speed monitoring sensor 20 produces no signal where there is a reading of 0 mph on the odometer 17.
Also, as shown in FIGS. 5A and 5B, a shaft magnet sensor 29 is positioned in close proximity to a shaft joint 30 where a driven shaft 31 connected to an axle 35 of the rear wheel 48 via a differential gear 47 is mounted to the transmission 23. An axle magnet sensor 33 is positioned in close proximity to an axle joint 34 where the axle 35 of one of the front wheel is mounted to the transmission 23. Thus, through sensor wires 32, 36 and 22 these shaft and axle magnet sensors 29 and 33, and the speed monitoring sensor 20 are connected to a sensor unit 41 which is operatively connected to the circuit of the magnet member 40 of the control box 14 (FIG. 2). In other words, signals are conducted through sensor wires 22, 32 and 36 to sensor unit 41 which senses any conducted signals in sensor wires 22, 32 and 36. That is, when the sensor unit 41 is actuated, the circuit is completed, and on the contrary, when the sensor unit 41 is deactivated, the circuit is not completed. Accordingly, at this time, even though the operator pushes the button 16, the magnet member 40 does not activate. That is, when the vehicle is moving, the brake holding system of the present invention does not work even though the operator pushes the button 16.
As shown in FIGS. 1 and 3, the vacuum activator 12 is connected to an on/off-member 24 including an on-member 24a and an off-member 24b through a hose 26. Also, the on/off-member 24 is connected to the control box 14 through wires 14A and to a vacuum tank 25 through a hose 27 and the vacuum tank 25 is connected to a vacuum system (not shown) of the vehicle via a hose 28.
As shown in FIG. 2, the control box 14 includes a housing 49 containing the magnet member 40, and a plurality of apertures for fixing to a support member through screws 50. The magnet member 40 is a kind of a relay switch so that, when the circuit is complete, the relay switch 40 is in an on-position since the magnet member 40 is actuated to function as a magnet. A battery 39 is connected to the control box 14 by wires 39A.
Diagrammatic FIG. 3 shows on/off-member 24 in the off configuration wherein movable member 24c of on-member 24a is positioned to interrupt communication between hose 26 and hose 27, while movable member 24d of off-member 24b is positioned so that atmospheric air from air inlet 43 will flow into hose 26 and to the actuator 12.
Also with reference to the diagrammatic view of FIG. 3, when then on/off-member 24 is in the on configuration, the movable member 24c of on-member 24a is raised to allow communication between hose 26 and hose 27, while the member 24d is lowered to the dashed line position so that air from air inlet 43 can no longer enter hose 26.
The brake holding system of the present invention operates as follows:
When the vehicle is to be stopped for a fixed period of time such as, for example, at a stoplight, and thus when the speed of the vehicle is reduced to 0 mph by the application of the brake pedal, the vacuum actuator 12 tightly holds the brake pedal extension arm 10 so that the push rod 18 applies brakes through the master cylinder.
As shown in FIGS. 2 and 4, when the needle 37 of the odometer 17 of the vehicle is positioned at 0 mph, the speed monitoring sensor 20 is actuated and simultaneously, when the operator pushes the button 16, the magnet member 40 is actuated, the circuit is completed with the battery 39, and the magnetic member 40 is actuated to function as a magnet.
As shown in FIGS. 3 and 4, at this time, the on-member 24a provides communication through the hose 26 to the vacuum tank 25 or the vacuum system through the hose 27 or the hoses 27 and 28 when the energized coils 42 and 42' are magneted. Simultaneously, the off-member 24b is maintained in a closed position. When the operator does not depress the accelerator, a releasing switch 46 is in an on-position and the on-member 24a is opened to communicate between the hoses 26 and 27.
On the other hand, the off-member 24b is closed to prevent communication with the air through air inlet 43 which contains a filter 44. Because the magnetic coils 42 and 42' are energized, respectively, the vacuum actuator 12 pulls the connecting steel wire 13 together with the brake pedal extension arm 10 and indirectly pushes the push rod 18 to the master cylinder 19 since the connecting steel wire 13 and the push rod 18 are fixed to the brake pedal extension arm 10. At this time, there is no need to apply further pressure to the brake pedal 11 since the push rod 18 is in a fixed state relative to the master cylinder 19.
When the accelerator 47 is depressed, the releasing switch 46 is opened and deenergizes the magnet coils 42 and 42' of the on/off-member 24 which causes the off-member 24b to communicate with the air through the air inlet 43 and the filter 44. Simultaneously, the on-member 24a closes to interrupt the vacuum which causes the brake pedal extension arm 10 to return to its original position due to the bias thereof. Because the magnet coils 42 and 42' of the on/off-member 24 are not energized, the vacuum actuator 12 is not functioning, and therefore, the vacuum actuator 12 cannot now pull the brake pedal extension arm 10. A lamp 45 disposed on the dashboard indicates the operation of both holding and releasing conditions. Also, when the releasing switch 46 is opened by pushing the accelerator, the magnet coil 42 of the on-member 24a is deenergized because the magnet member 40 is not maintained in a continuously closed state.
Also, if the operator applies the brake pedal 11 when the speed of the vehicle is above 0 mph, the holding system of the present invention does not actuate because the needle 37 separates from 0 mph and the speed monitoring sensor 20 deactivates so that the circuit with the battery 39 is interrupted. When the driven shaft 31 and axle 35 rotate, the shaft and axle sensors 29 and 33 do not activate. Therefore, even though the operator pushes the button 16, the circuit with the battery 39 is interrupted.
Accordingly, the brake holding system of the present invention is very simple to manufacture. Also, it is very easy to apply the brake holding system of the present invention to the new cars or used cars conveniently or reliably.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included in the scope of the following claims.
What is claimed is:
1. A brake holding system for a vehicle having in combination, a brake pedal, master cylinder, a vacuum system and a power supply, which comprises:a connecting steel wire connected at one end to a brake pedal extension arm of said brake pedal, a vacuum actuator means connected to the other end of said connecting steel wire for pulling said connecting steel wire when said vacuum actuator is connected to a vacuum source, an on-off member means for selectively connecting said vacuum actuator to said vacuum source when actuated, with connection being made in an on position, but not in an off position, control means for selectively actuating said on-off member means, said control means including a button means operable by a seated operator for setting said on-off member means in the on position to connect said vacuum actuator to said vacuum source, a speed monitoring sensor mounted to sense movement of an odometer cable, and a shaft sensor means mounted to sense rotational movement of a driven shaft, said control means also including means responsive to sensed movement by at least one of said sensors for preventing the operation of said button means from setting said on-off member means in the on position; and said control means also including a releasing switch means which is operated in response to the depression of an accelerator pedal and functions to position the on-off member means in the off position.
2. A brake holding system for a vehicle according to claim 1, wherein said driven shaft is a drive shaft which is connected to rotate rear wheels of the vehicle.
3. A brake holding system for a vehicle according to claim 1, wherein said driven shaft is on axle which is connected to rotate a front wheel of the vehicle.
| 1992-03-12 | en | 1993-06-08 |