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US-51983483-A | Electrode tool storage magazine
ABSTRACT
A tool changer for an EDM apparatus provided with a reciprocable machining head having a tool holder mounted on the end of the machining head. The tool changer comprises a rotatable indexable turret supporting a plurality of electrode tools each integrally provided with a support member for attachment of the electrode tool/support member assembly to the turret. Successive machining operations are effected by the machining head carrying an appropriate electrode tool, and at the end of each machining operation the electrode tool/support member assembly is attached to the turret.
BACKGROUND OF THE INVENTION
The present invention relates to EDM apparatus provided with several electrode tools capable of being used in sequence.
It is known to provide EDM apparatus with an automatic tool changing mechanism, whereby the diverse electrode tools are stored in a magazine and a tool conveyor is provided between the magazine and the tool holder for carrying the electrode tools between the magazine and the tool holder and for returning the electrode tools to the magazine. For example, with the tools stored in a magazine such as a rotatable table, the tool conveyor system comprises, in general, a moving arm arranged such as to take a tool from the rotatable table and carry it to the tool holder of the machining head. After the tool has been installed on the tool holder, the moving arm must be retracted such as to clear the machining head to enable the electrode tool to be displaced to a position proximite the workpiece.
Tool conveyor systems and moving arms take much room and are a hindrance to designing a compact tool changer. In addition, known tool changers and conveyors must achieve motion of the tool along the three axes, which is a requirement that results in complex and costly devices.
SUMMARY OF THE INVENTION
The present invention has for principal object to eliminate the inconveniences of the prior art and to provide a very compact tool changer which may be placed proximate to the machining head of a machine tool such as an EDM apparatus.
One of the objects of the invention is to provide an EDM apparatus having a support member for a workpiece to be machined and a machining head, provided with an electrode tool, axially displaceable relative to the workpiece, the EDM apparatus comprising a rotatable table or turret for storing a variety of electrode tools, which requires no separate conveyor means for carrying the electrode tools from their stored position to the machining head and for returning the electrode tools from the machining head to the storage turret.
The apparatus of the invention is further characterized in that each electrode tool includes an integral support member in the form of a removable portion of the storage turret which remains attached to the electrode tool. The peripheral surface of the rotating turret to which is removably attached the electrode tool support member is located outside of the geometric projection of the machining head during reciprocation of the machining head, once the electrode tool is mounted on the tool holder on the machining head.
The many objects and advantages of the present invention will become apparent to those skilled in the art when the following description of an example of structure of apparatus according to the present invention, given for illustrative purpose only, is read in conjunction with the accompanying drawing wherein like numerals refer to like or equivalent parts and in which:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevation view of an EDM apparatus according to the present invention;
FIG. 2 is a view of a portion of FIG. 1 shown at a larger scale and with portions cut away for illustrating the internal structure; and
FIG. 3 is a top plan view, partly in section, from line 3--3 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, an EDM apparatus according to the present invention comprises a frame 1 integral with, or attached to, a base 2 supporting a table 3 on which is mounted a workpiece 4. The workpiece 4, which is made of electrically conductive material, is immersed in a tank 5 filled with a machining fluid which is generally a dielectric liquid. The frame 1 carries at its top a machining head 6 which is reciprocable along a vertical axis 7 by appropriate servo control means, not shown. An electrode tool 8 is arranged to be removably mounted in a holder 6a affixed to the bottom of the machining head 6 for displacement by the machining head to a position proximate to the workpiece 4 prior to machining the workpiece 4 by electrical discharges, and for feeding the electrode tool into the workpiece by relative motion between the electrode tool 8 and the workpiece 4 during machining of the workpiece.
The machining current pulses are supplied by a generator 9 which is connected across the machining head 6 and the workpiece 4, as is well known in the EDM art.
The EDM apparatus has several electrode tools which are carried by a rotatable storage magazine or turret 10, supported in rotation around an axis 11 substantially parallel to the axis 7 of displacement of the machining head 6. The rotatable turret 10 is supported from the bottom of the frame 1 and is disposed proximate to the machining head 6.
As shown in more details at FIG. 2, the turret 10 comprises a central portion or spindle 12, generally bell-shaped, carrying on its periphery a plurality of generally vertically disposed clamping levers 13 pivotable around a pivot point 14 and biased to a clamping position by a spring 15. Each of the clamping levers 13 permits to hold, on the peripheral surface of the bell-shaped spindle 12 of the turret 10 a generally L-shaped support member 16 carrying an electrode tool 8. In the structure illustrated, there are eight electrode tools, 8a through 8h, mounted on the periphery of the turret bell-shaped spindle 12, each by way of a support member, 16a through 16h, integral with or fixedly attached to its corresponding electrode tool.
The turret bell-shaped spindle 12 is mounted on a shaft 18 journalled, via the intermediary of bearings 19, through a block 20 attached to the frame 1 of the EDM apparatus. The shaft 18 carries at its top a toothed wheel 21 for driving the shaft 18 in rotation and for angularly positioning the shaft 18 by means of a stepping electric motor 22, which drives the toothed wheel 21 keyed on the shaft 18 through a cog belt 23. A disk 24 is mounted on the end of the shaft 18. The disk 24 is provided with peripheral teeth or slits 24a angularly spaced such as to correspond each to the position of one of the support members 16a through 16h. The disk 24 co-operates with a reading transducer 25 detecting the driverse angular positions taken by the disk 24 when rotated and angularly positioned by the shaft 18.
FIG. 2 illustrates the machining head 6 in its raised position enabling tool changing. In the raised position of the machining head 6, an appropriate electrode tool 8, such as electrode tool 8a for example, is brought in register with the machining head 6 through appropriate indexing of the rotating turret 10. The machining head 6 is subsequently displaced downwardly such that the tool holder 6a carried at the bottom of the machining head 6, provided with tool holding means 6b in the form of a conical recess, not shown in detail but well known in the art, as disclosed in U.S. Pat. No. 4,316,071 for EDM Apparatus with Tool Changer, engages the mounting shank 26 of the electrode tool 8a. The mounting shank 26 is provided with a conical portion, a locking groove 27 co-operating with a locking member in the holding means 6b, and an angular position indexing finger 28 which, as a result of engaging a conforming keyway in the tool holder means 6b, enables the electrode tool 8a to be accurately indexed angularly relative to the tool holder 6a.
After the preselected electrode tool 8a has been affixed in the tool holder 6a at the bottom of a machining head 6, the lever clamp 13 maintaining the tool support member 16a attached to the turret spindle 12 is released. For that purpose, the top end portion of each clamping lever 13 is bent over as shown at 29 to enable the clamping lever 13 to pivot around its pivot point 14 under the action of a fluid actuated plunger 30 reciprocably mounted in the block 20 proximate the machining head 6, and located such as to act upon the bent over portion 29 of the appropriate clamping lever 13 when an appropriate tool has been brought to its working position. The end of each clamping lever 13, opposite to its bent over end portion 29, is provided with appropriate interlocking pawl means 31 normally engaged with conforming interlocking means 32, in the form of a recess or groove for example, disposed on the surface of the upright portion 33 of each tool support member 16, proximate its upper edge, under the action of the spring 15. The upright portion 33 of the tool support member 16 has a surface 34 engaged with a mounting surface 35 on the periphery of the turret spindle 12. After the appropriate tool support member, 16a in the example of FIG. 2, is no longer attached to the spindle 12, the machining head 6 may be advanced to its working position, as shown in dashed line, carrying to the working position the electrode tool 8a and its attached support member 16a. It is to be noted that such a displacement is made possible as a result of the peripheral surface of the spindle 12, and more particularly the mounting surfaces 35, being situated outside of the geometric projection of the machining head 6 or, in other words, volume generated by the machining head 6 when it is displaced downwardly for bringing it in its working position, FIGS. 2 and 3.
After machining of the workpiece 4 with an appropriate electrode tool 8, such as electrode tool 8a, is concluded, the machining head 6 is retracted such as to bring the tool holder 6a to an appropriate position proximate to the rotatable turret 10 which, in the example of operation described, presents a vacant space on the spindle 12 corresponding to the tool support member 16a. In the course of the upward displacement of the machining head 6, the upright portion 33 of the tool support member 16a, provided at its edge with the interlocking means 32 is automatically engaged below the end of the clamp lever 13 which is provided with the interlocking pawl means 31 in the example of structure illustrated, such that the electrode tool 8a and its support member 16a are again attached to the spindle 12 as shown at FIG. 2, while the tool shank 26 is simultaneously freed and unlocked from the tool holder 6a. The rotatable turret 10 can thus be rotated to index any appropriate electrode tool 8 relative to the machining head 6 and the tool holder 6a, so as to enable the appropriate electrode tool to be mounted in the tool holder 6a for effecting another machining operation on the workpiece 4.
It will be appreciated that diverse means may be used for attaching the electrode tools 8 to the spindle 12, such as for example, pincers or electro-magnetic chucks. It will also be appreciated that the present invention has many applications to machine-tools, other than EDM apparatus, provided with automatic tool changers.
Having thus described the present invention by way of a structural example thereof, modification whereof will be apparent to those skilled in the art, what is claimed as new is as follows:
1. In an EDM apparatus for effecting a machining operation on a workpiece, said EDM apparatus being provided with an automatic tool changer, said tool changer comprising a rotatable and indexable turret for supporting a plurality of electrode tools, and said EDM apparatus having a reciprocable machining head having a tool holder mounted on the end thereof, the improvement comprising a support member permanently attached to each of said electrode tools, said tool support member having a portion adapted to be removably attached to said turret, means for removably attaching said tool support member to said turret and for individually holding each said tool support member on said turret, said turret having a mounting surface for said tool support member portion, said mounting surface being located outside of the space occupied by said tool support member during reciprocation of said machining head with said electrode tool and tool support member attached to said tool holder, wherein said attaching and holding means comprise a clamping lever for each said tool support member, said clamping lever having pawl means co-operating with engaging means disposed on said tool support member portion for attaching said tool support member portion to said turret mounting surface during a retraction of said machining head from the workpiece causing engagement of said tool support member portion under said pawl means.
2. The improvement of claim 1 further comprising a fluid actuated plunger disposed in a fixed position proximate said machining head for actuating said clamping lever for detaching said tool support member from said turret after mounting said electrode tool on said tool holder.
3. In an apparatus for effecting a machining operation on a workpiece, said apparatus being provided with an automatic tool changer, said tool changer comprising a rotatable and indexable turret for supporting a plurality of tools, and said apparatus having a reciprocable machining head having a tool holder mounted on the end thereof, the improvement comprising a support member permanently attached to each of said tools, said tool support member having a portion adapted to be removably attached to said turret, means for removably attaching said tool support member to said turret and for individually holding each tool support member on said turret having a mounting surface for said tool support member portion, said mounting surface being located outside of the space occupied by said tool support member during reciprocation of said machining head with said tool and tool support member attached to said tool holder, wherein said attaching and holding means comprise a clamping lever for each said tool support member, said clamping lever having pawl means co-operating with engaging means disposed on said tool support member portion for attaching said tool support member portion to said turret mounting surface during a retraction of said machining head from the workpiece causing engagement of said tool support member portion under said pawl means.
4. The improvement of claim 3 further comprising a fluid actuated plunger disposed in a fixed position proximate said machining head for actuating said clamping lever for detaching said tool support member from said turret after mounting said tool on said tool holder.
| 1983-08-03 | en | 1986-01-14 |
US-22871794-A | Video reproducing apparatus with non-repetitive selecting function
ABSTRACT
A video reproducing apparatus includes a video data memory for storing video data and a video data table for storing information about whether or not given items of the video data in the video data memory have been reproduced. A backup power supply unit backs up the information in the video data table when power is removed. A song category designation input unit is provided for inputting the song category designated, a video reproducing unit is provided for reproducing video data, and a background video control unit is provided for controlling the component units configured. On the basis of the information held in the video data table, the background video control unit determines whether or not any unreproduced video data remains in the video data belonging to the song category designated by the song category designation input unit. If unreproduced video data is found to exist, the control unit instructs the video reproducing unit to reproduce that unreproduced video data.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a video reproducing apparatus for reading video data from a video data storage medium on which a plurality of video data are stored, the read-out video data being reproduced when output.
2. Description of Related Art
Commonly known karaoke apparatuses that reproduce background music sound tracks for do-it-yourself vocals can be equipped to play back recorded background music while reproducing corresponding video data. Most of the apparatuses of this kind are operated by superimposing song text (lyrics) on the background video. The storage medium for storing background video data thereon is illustratively a video disc that is played back for a total of one to two hours. The trend today is toward prolonging the total playback time of the storage medium so that customers will better enjoy singing songs accompanied by the increased amount of stored video data.
Some apparatuses are designed to more or less match the reproduced video data with the superimposed song text. For that purpose, the video data is divided into groups that go with different categories of songs: for example, enka music (ballads combining lyrics and melodies that express typical Japanese feelings with Western music) or pop music.
Whether the background video data is grouped or not by song category, generally the apparatus retrieves the video data of a single group (if the video data is not grouped by song category) or of a plurality of groups (where the video data is grouped by song category) in the order in which the video data of each group is stored on the storage medium. The purpose of this scheme is to average the frequencies at which the stored video data is retrieved and output.
Under the above scheme, however, every time the video reproducing apparatus (more specifically, the video disc drive) is turned on, video data retrieval always starts from the beginning. Thus, the video reproduction always commences with the same image.
Even when the video data is grouped by song category, the first image to be reproduced for a given category is always the same. Where the total playback time of the reproducing apparatus is relatively short, the same cycle of a series of video data is output repeatedly from beginning to end during a day's use. Thus, it matters little from which image the retrieval of stored video data starts. On the other hand, suppose that the total playback time is longer than the entire day's business hours and that the apparatus is turned on at the start of the business hours and turned off at the end of each day's work. In that case, the images located toward the end of the sequential order of storage are seldom, if ever, retrieved and output. This has been a considerable impediment to averaging the reproducing frequencies of the stored video data.
With the above conventional scheme in place, customers of karaoke entertainment are more likely to sing songs with the same background video, with a sizable amount of video data left unused. This is a waste of data resources that deprives the customers of the entertainment they could otherwise enjoy.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to overcome the above and other deficiencies and disadvantages of the prior art and to provide a video reproducing apparatus that prevents a limited number of images from being reproduced more frequently than other images. Further, it is an object of this invention to provide a video reproducing apparatus that allows the stored image data to be reproduced randomly and not sequentially for a given song category so that customers will not become bored with repetitive video reproduction.
To achieve the foregoing and other objects of the present invention, according to one aspect thereof, the video reproducing apparatus comprises: input means for inputting information for selecting a given group of video data from a video data storage medium and storage means for storing at least one of two sets of video data, one set having been reproduced and the other set currently being reproduced, in the group of video data selected according to the selection information input through the input means. Determining means determines whether all video data in the selected group of video data has been reproduced on the basis of the contents of the storage means and selecting means selects the unreproduced video data if the determining means finds any video data not yet reproduced. A reproduction designating means designates the reproduction of the video data selected by the selecting means.
In a preferred structure according to the invention, the selecting means may be arranged to select the unreproduced video data in one of two manners, randomly and in a desired sequence.
In another preferred structure according to the invention, the selecting means may be arranged to enter one of two states, one state for randomly selecting the unreproduced video data and the other state for selecting the video data in a desired sequence. The selecting means further includes switching means for switching from one state to the other.
In a further preferred structure according to the invention, the video reproducing apparatus may further comprise second storage means for storing the reproducing sequence selected by the selecting means. Then, the selecting means selects the video data in the sequence stored in the second storing means when the determining means determines that all video data in the currently selected group has been reproduced.
In any of the preferred structures above, the storage means may include data retaining means for retaining the data held in the storage means whenever the video reproducing apparatus is turned off.
These and other objects, features and advantages of the invention will become more apparent upon a reading of the following description and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a typical karaoke system to which the invention is applied;
FIG. 2 is a block diagram of a background video reproducing apparatus in the system;
FIG. 3 is a block diagram of a video data memory in the karaoke system;
FIG. 4 is a memory structure of a video data table provided as part of the system;
FIG. 5A is a flowchart of steps in which a background video control unit of the system operates;
FIG. 5B is a table listing the steps of the flowchart of FIG. 5A;
FIG. 6A is another flowchart of steps in which the background video control unit operates; and
FIG. 6B is a table listing the steps of the flowchart of FIG. 6A.
DESCRIPTION OF PREFERRED EMBODIMENTS
A video reproducing apparatus according to a preferred embodiment of the invention and incorporated into a karaoke system for illustrative purposes is outlined referring to FIGS. 1 and 2.
The karaoke system to which the invention is applied comprises a karaoke control unit 1, a background video reproducing apparatus 5, a television set 8, an amplifier 10, a microphone 11 and speakers 13. The karaoke control unit 1 has a composition memory 1A that stores a plurality of karaoke data coded as per the MIDI (musical instrument digital interface) standards. In operation, the control unit 1 starts orchestral background music for a singer's accompaniment in accordance with the song designated by the singer. The karaoke control unit 1 obtains new-song data 28 by communicating over communication channels with a host computer 27 having a song data-base including the data on newly accommodated songs. When starting the accompaniment of a song, the karaoke control unit 1 outputs song category designating data 4 instructing the background video reproducing apparatus 5 to reproduce the video data relevant to the song. In addition, the karaoke control unit 1 superimposes on a video signal 6, described later, a song text signal generated internally and supplies the television set 8 with a karaoke video signal 7 comprising the song text. The karaoke control unit 1 also outputs an accompaniment signal 9 to the amplifier 10. This assembly is equivalent to that disclosed in U.S. Pat. Nos. 5,233,438, 5,252,775 and 5,131,311, the disclosures of which are expressly incorporated herein by reference.
The background video reproducing apparatus 5 receives the song category designating data 4 from the karaoke control unit 1. In turn, the background video reproducing apparatus 5 sends the video signal 6 of the song category corresponding to the song category designating data 4 to the karaoke control unit 1.
The amplifier 10 receives the accompaniment signal 9 from the karaoke control unit 1 and a vocal signal 12 entered from the microphone 11. The two signals are mixed by the amplifier 10 before being output to the speakers 13.
The background video reproducing apparatus 5, the key component of this invention, is described in detail with reference to FIGS. 2 through 4.
The background video reproducing apparatus 5 comprises a background video control unit 20, a song category designation input unit 21, a video reproducing unit 22, a video data table 23, a backup power supply unit 24, a video data memory 25, a reproduction designation changeover switch 26 and a song category variable memory 29.
The background video control unit 20 controls the video reproducing apparatus 5 as a whole using a CPU 20A. The song category designation input unit 21 admits the song category designation data 4 coming from the karaoke control unit 1.
The video data memory 25, as shown in FIG. 3, is a video data storage medium that has a plurality of blocks of video data grouped by song category and stored on video discs. Under control of the background video control unit 20, the video data memory 25 outputs video data to the video reproducing unit 22. In the memory structure of FIG. 3, there are four video blocks grouped by song category. That is, a pops block 40 comprises m video data (1 to m); an enka block 41 comprises n video data (1 to n); an animation song block 42 comprises j video data (1 to j); and a martial song block 43 comprises k video data (1 to k).
The video reproducing unit 22 converts the video data coming from the video data memory 25 into a video signal 6. The video playback time of each video block is preferably around five minutes so as to comply with the playing time of a single song.
The video data table 23 serves as storage means and is a writable memory structured as shown in FIG. 4. The starting address of the video data table 23 accommodates information as to whether or not video data 1 of the pops block has been reproduced; the end address of the video data table 23 contains information as to whether or not video data k of the martial song block has been reproduced. If video data is already reproduced, "1" is written to the corresponding address location; if the video data has yet to be reproduced, "0" is set to the corresponding address location. In the example of FIG. 4, pops data 2 and 5 as well as martial song data 3 have been reproduced. The video data table 23 is backed up by the backup power supply unit 24 that works as data retaining means for retaining the stored data while power is removed.
The reproduction designation changeover switch 26 acting as switching means is used to select one of two options: to reproduce video data randomly within the song category block designated with reference to the video data table 23 or to reproduce video data sequentially from video data 1 onward within a given song category stored in the video data memory 25. Turning on the reproduction designation changeover switch 26 selects the first option, and turning it off selects the second option.
The song category variable memory 29 stores a song category variable corresponding to the song category designating data 4 output from the karaoke control unit 1 to the song category designation input unit 21.
The foregoing description has centered on the composition of the apparatus embodying the invention. Below is a description of how the background video control unit 20 operates referring to FIGS. 2, 5A, 5B, 6A and 6B.
When the background video reproducing apparatus 5 is turned on, the CPU 20A checks the reproduction designation changeover switch 26 (step S501) for its status. If the switch 26 is found to be on, the process of randomly reproducing video data is selected; if the switch 26 is found to be off, the process of sequentially reproducing video data of a given song category block is selected.
More specifically, when the reproduction designation changeover switch 26 is turned on, the CPU 20A checks to see if the song category designating data 4 is input from the karaoke control unit 1 to the song category designation input unit 21 (step S502). If the song category designating data 4 has yet to be input to the song category designation input unit 21, a check is made to see if the currently reproducing video data is nearing its end (step S510). The determination of the check at step S510 is executed by reading flag data previously written near the end of the video data or by comparing a total reproducing time of the video data with an elapsed time of the same. If the currently reproducing video data is not close to its end, step S502 is reached again. If the currently reproducing video data is nearing its end, step S503 is reached. The video reproducing status held in the video data table 23 is examined by use of the song category variable stored in the song category variable memory 29 at step S503. The song category variable stored in the song category variable memory 29 remains the same as that of the song being currently reproduced. Therefore, the processing for designating a reproduction of the next video data to be reproduced for the currently reproducing song starts if it is determined that the currently reproducing video data is nearing its end at step S510.
If the song category designating data 4 is found to be input in step S502, the designated song category is set in a song category variable memory 29 as the song category variable and the song category designation input unit 21 (step S509) is cleared. Step S509 is followed by step S503 in which the video reproducing status held in the video data table 23 is examined by use of the song category variable stored in the song category variable memory 29. Upon examination, a check is made to see if there still exists unreproduced video data (step S504). If all video data in the designated song category block is found to be reproduced, the reproducing status of that song category block is initialized in the video data table 23 (step S505), and step S506 (described later) is reached. The process of step S504 serves as the determining means for determining whether all relevant video data has been reproduced on the basis of the contents of the video data table 23.
When the CPU 20A finds in step S504 that there exists unreproduced video data, or when the CPU 20A has completed the process of step S505, the CPU 20A using a random function incorporated therein randomly selects some of the unreproduced video data of the currently selected song category (step S506). The video data to be reproduced is set where appropriate in the video data table 23 (step S507). Thereafter, the CPU 20A sends a reproduction command to the video data memory 25 ordering it to reproduce the randomly selected video data (step S508). When the video reproducing unit 22 outputs the video signal to the karaoke control unit 1 for reproduction, step S502 is reached. The process of step S506 serves as the selecting means for selecting the unreproduced video data. The process of step S508 serves as the reproduction designating means for designating the video data selected in step S506 to be reproduced.
The video data of the song category designated by the karaoke control unit 1 is reproduced continuously in the manner described until another song category is designated. If the karaoke control unit 1 outputs an end-of-accompaniment signal, the reproduction process may be interrupted and a standby state may be entered.
If the reproduction designation changeover switch 26 is found to be off, the CPU 20A carries out the following steps shown in FIG. 6A and listed in FIG. 6B. The CPU 20A first initializes the counter of each song category to 1 (step S600). The CPU 20A then checks to see if the song category designating data 4 is input from the karaoke control unit 1 to the song category designation input unit 21 (step S601). If the song category designating data 4 has yet to be input, a check is made to see if the currently reproducing video data is nearing its end (step S602). If the currently reproducing video data is not close to its end, step S601 is reached again. If the currently reproducing video data is found to be close to its end, step S604 (described later) is reached.
If the song category designating data 4 is found to be input in step S601, the designated song category is set in the song category variable memory 29, and the song category designation input unit 21 is cleared like the process of step S509 (step S603). After step S603, or after step S602 wherein the end of the currently reproducing video data is found to be near, the song category counter pointed to by the song category variable is incremented by 1 (step S604). A check is then made (step S605) to see if the counter has exceeded its highest possible count (m for pops block 40, n for enka block 41, j for animation song block 42, k for martial song block 43). If the highest possible count of the counter is found to be exceeded, the counter is reset to 1 (step S606). If the counter value has yet to exceed the highest possible count for the currently selected song category, or if the process of step S606 is terminated, the video data memory 25 is ordered to reproduce the video data pointed to by the counter (step S607). In that case, the video signal is output via the video reproducing unit 22 to the karaoke control unit 1. Then, the CPU 20A checks the reproduction designation changeover switch 26 for its status (step S608). If the switch 26 is found to be on, the process of reproducing video data is changed to the randomly reproducing process and step S608 is followed by step S502. If the switch 26 is found to be off, the process returns to step S601. If, as in the foregoing processing, the karaoke control unit 1 outputs an end-of-accompaniment signal, the reproducing process may be interrupted, and a standby state may be entered.
As described, the background video reproducing apparatus of the invention retains information about the video data already reproduced so as not to reproduce the same images repeatedly. This allows customers of the do-it-yourself vocals to enjoy background video accompaniment without feeling bored watching the repeated video reproduction.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of the presently preferred embodiment of this invention. For example, whereas the storage means of the above embodiment is arranged to store the current status of video data reproduction, an additional memory unit may be provided as a second storage means for storing the sequence in which the video data has been reproduced. The second storage means allows the video data to be again reproduced later in the order in which it was reproduced. With the same video data reproduced at regular intervals, customers are less likely to see the same images repeatedly and are therefore less likely to be bored thereby.
Whereas the storage means of the above embodiment stores information about the selected video data as already reproduced data even before actual reproduction, the storage means may alternatively be arranged to store information about the selected video data as reproduced data only after it is actually reproduced. If the currently selected video data is interrupted during reproduction for some external reason, the control unit when resuming reproduction considers the interrupted video data to be unreproduced and proceeds to select the same data. This makes it possible to better average the reproduction frequencies of the stored video data.
The storage means may alternatively comprise two areas: one area for storing information about the selected video data as currently reproducing data even before actual reproduction, and the other area for storing information about the video data as reproduced data after actual reproduction. The arrangement distinguishes two states: one in which the selected video data is currently reproducing, and the other in which the selected video data has all been reproduced. If the selected video data is interrupted during reproduction for some external reason, the control unit when resuming reproduction selects and reproduces the video data whose status as currently reproducing data was retained by the storage means. This allows customers to enjoy background video accompaniment without feeling awkward as a result of watching different images while singing the previously selected same song.
Whereas the selecting means of the above embodiment is designed to select randomly or in a predetermined sequence the video data of a given song category block stored in the video data memory 25, there may be cases where there are a plurality of video blocks of the same song category. In such cases, the multiple video blocks may be subsumed under a single greater video block from which the blocks may be selected randomly or in a predetermined sequence of these video blocks. When all video data of a given video block has been reproduced, the video data of another block in the same song category may be selected randomly or in a predetermined sequence of that video block.
Whereas the retaining means of the above embodiment is the memory backed up by the backup power supply unit 24 for keeping the stored data retained when power is removed, the backup power supply unit 24 may alternatively be replaced by an EEPROM, a flash EPROM, a magnetic storage unit or some other memory capable of retaining the stored data while power is off. The alternative arrangement makes the circuit constitution simpler than that proposed illustratively above.
As another alternative, the backup power supply unit 24 may be a capacitor arrangement for retaining the stored data in the memory. This arrangement is inexpensive to implement.
Whereas the video data memory 25 of the background video reproducing apparatus 5 is generally an analog type video disc or the like, recent advances in digital animation data compression technology makes it possible to utilize a mass digital data storage medium such as a CD-ROM, a hard disc or a digital audio tape (DAT). Where the storage medium is of an interchangeable type such as the CD-ROM, a plurality of media of this type may be incorporated in the storage unit and changed one after another by an auto changer or the like. The arrangement helps constitute a system that reproduces greater quantities of background video data for longer periods of time than ever before.
One of the benefits of the invention is that the selecting means for selecting the video data permits random video selection. That is, customers cannot predict the background images they will get when singing songs. This prevents the customers from getting bored with the predictable video data reproduction.
The selecting means for selecting the video data may be set to reproduce video data of a given song category block in a desired sequence. This allows the video data to be tested easily for reproduction.
The selecting means may be set selectively either for random video data selection or for specific video data sequence selection of the image data in a given song category block. In this manner, the advantages derived from either option are obtained inexpensively.
With the separate memory provided to store the sequence in which the video data has been reproduced, the video data may again be produced using the memory in the same sequence in which the data was reproduced. This allows the same video data to be reproduced at regular intervals, so that customers are less likely to watch the same images repeatedly and are therefore less likely to be bored thereby.
Because the information about the video data having been reproduced is retained after power is removed, it is possible to exclude the possibility of reproducing the same images until after all stored images have been reproduced and the reproduction-related information is cleared. This averages the reproduction frequencies of the video data and eliminates the cases where specific images are reproduced repeatedly or where certain images are reproduced rarely if ever.
What is claimed is:
1. A video reproducing apparatus for controlling reproduction of video data comprising:a video data storage means for storing video data in groups; a historical storage means for storing at least one of two sets of historical data, one set of historical data corresponding to video data that have been reproduced and the other set of historical data corresponding to video data that is currently being reproduced; a determining means coupled to the video data storage means and the historical storage means for determining whether any video data in a group of the video data stored in the video data storage means has not yet been reproduced based on a comparison between the video data stored in the video storage means and the historical data stored in the historical storage means; a selecting means coupled to the determining means for selecting video data from any of the remaining video data yet to be reproduced in the group of the video data stored in the video data storage means when the determining means determines that any video data remains yet to be reproduced; and a reproduction designating means coupled to the selecting means for designating the reproduction of the video data selected by the selecting means, wherein the comparison between the video data in the video data storage means and the historical data in the historical storage means prevents video data that has already been produced during a session from being produced again unless all video data in the corresponding group has been reproduced, wherein the video data is adapted to be reproduced simultaneously with audio data, the reproduction of the video data being independent of the order in which the audio data is reproduced.
2. A video reproducing apparatus as claimed in claim 1, further comprising an input means coupled to the determining means for inputting selection information for selecting a group of video data, wherein the determining means determines whether any video data in the group selected by the selection information remains yet to be reproduced.
3. A video reproducing apparatus as claimed in claim 1, wherein the selecting means includes switching means for switching between one of two states, one state for randomly selecting the video data and the other state for selecting the video data in a predetermined sequence.
4. A video reproducing apparatus as claimed in claim 3, further comprising an input means coupled to the determining means for inputting selection information for selecting a group of video data, whereinthe determining means determines whether any video data in the group selected by the selection information remains yet to be reproduced and the selecting means selects the video data from the group selected by the selection information of video data.
5. A video reproducing apparatus as claimed in claim 1, further comprising a clearing means coupled to the historical storage means for clearing the historical storage means when the determining means determines that no video data remains yet to be reproduced.
6. A video reproducing apparatus as claimed in claim 5, further comprising an input means coupled to the determining means for inputting selection information for selecting a group of video data, whereinthe determining means determines whether any video data in the group selected by the selection information of video data remains yet to be reproduced, and the clearing means clears the historical data corresponding to the video data in the group selected by the selection information.
7. A video reproducing apparatus as claimed in claim 6, wherein the historical storage means includes data retaining means for retaining the historical data held in the historical storage means whenever the video reproducing controlling apparatus is turned off.
8. A video reproducing apparatus as claimed in claim 7, further comprising a reproducing means for reproducing a video by reading out from the video data storage means the video data designated by the reproduction designating means.
9. A video reproducing apparatus as claimed in claim 8, wherein the input means inputs selection information for selecting a group of video data according to a category of a song indicating data entered into the input means.
10. A video reproducing apparatus as claimed in claim 9, further comprising an audio reproducing means for reproducing an audible signal according to the song indicating data.
11. A video reproducing apparatus as claimed in claim 1, wherein the selecting means is automatic and automatically selects the video data in a predetermined sequence when the determining means determines that no video data remains yet to be reproduced.
12. A video reproducing apparatus as claimed in claim 11, further comprising an input means coupled to the determining means for inputting selection information for selecting a group of video data, whereinthe determining means determines whether any video data in the group selected by the selection information remains yet to be reproduced and the automatic selecting means automatically enters the state for selecting the video data from the group selected by the selection information in the predetermined sequence when the determining means determines that no video data remains yet to be reproduced.
13. A reproducing apparatus that reproduces an output signal, comprising:an input that receives output selection data; a storage memory that stores a plurality of output data; an output data table that stores output signal reproduction data; a reproducing unit that reproduces the output signal by converting stored output data into the output signal; a controller coupled to said input, said storage memory, said output data table and said reproducing unit that selects stored output data from said storage memory based on said output selection data from said input and said output signal reproduction data stored in said output data table so that the selected output data is not repeated during a session unless all other output data has been reproduced, and instructs said reproducing unit to reproduce the output signal; and a reproduction designation changeover switch coupled to said controller that selects a mode of retrieving output data from said storage memory, wherein the output signal is adapted to be reproduced simultaneously with a second output signal, the reproduction of the output signal being independent of the order in which the second output signal is reproduced.
14. The reproduction apparatus of claim 13, wherein said output signal is a video signal.
15. The reproduction apparatus of claim 13, wherein said output data table comprises a writable memory that stores current and past reproduction output signal data.
16. The reproduction apparatus of claim 13, wherein said storage memory includes output data stored in groups based on categories of output signals.
17. The reproduction apparatus of claim 13, wherein said reproduction designation changeover switch selects a mode of random or sequential retrieval.
18. The reproduction apparatus of claim 13, further comprising a back-up power supply unit coupled to said output data table that supplies power to maintain the data stored in said output data table when power is removed from the reproduction apparatus.
19. The reproduction apparatus of claim 13, further comprising a category variable memory coupled to said controller and said input that stores category variables corresponding to input selection data that said controller uses to select stored output data from said storage memory.
20. A method of reproducing output signals comprising the steps of:storing output data in groups; storing historical output data regarding output signals that have been reproduced and are currently being reproduced; inputting selection data corresponding to a group of data; determining output data based on the stored historical data and the input selection data to determine which data in the selected group of data have not been reproduced; selecting output data from only any of the determined output data determined to have not yet been reproduced; and reproducing the selected output data, wherein the selected output data is simultaneously reproduced with a selected one of a plurality of stored second output data, the second output data being reproduced independently of the order in which the second output data is reproduced.
21. The method of claim 20, wherein the step of reproducing the selected output data comprises reproducing video data.
22. The method of claim 20, wherein the step of selecting output data includes randomly selecting output data that has not yet been reproduced from a group of stored data.
23. The method of claim 20, wherein the step of selecting output data includes sequentially selecting output data from a group that has not yet been reproduced.
| 1994-04-18 | en | 1998-07-14 |
US-3656012D-A | Method of generating unipolar and bipolar pulses
ABSTRACT
The method for generating bipolar and unipolar mechanical pulses is described. The unipolar pulses can be in a form of a single unipolar pulse or pairs of unipolar pulses of opposite polarity.
United States Patent Dixon [45] Apr. 11, 1972 [54] METHOD OF GENERATING UNIPOLAR 2,562,450 7/1951 DeLano, Jr. ..3l0/8.1 x AND BIPOLAR PULSES 2,398,701 4/1946 Firestone .1 X 2,920,192 1/1960 Peck .l X 1 Invent Norman DIXOII, Pam, Wash- 3,114,058 12/1963 Lyth [73] Assignee: The United States of America as 3,202,868 8/1965 Blank represented by the United states Atomic 3,004,424 10/1961 Henry Energy Commission Primary Examiner-J. D. Miller [22] Wed: 1971 Assistant Examiner-Mark O. Budd 2 App] 111,957 AttorneyRoland A. Anderson [57] ABSTRACT [52] US. Cl ..3l0/8.l [51] Int. Cl. ,H01 7/00 The method for generatmg blpolar and unipolar mechanical [58] Field of Search ..310/8.1; 340/8; 73/67.8 R; pulses is described- The unipolar Pulses can be in a form of a 333/30 single unipolar pulse or pairs of unipolar pulses of opposite polarity. [56] References Cited 9 C 15 Drawing Figures UNITED STATES PATENTS 2,949,028 8/1960 Joy ...310/8.l Q; l
Patented April 11, 1972 3,656,012
6 Sheets-Sheet l Fig- PRES S URE EI-Z1 25 METHOD OF GENERATING UNIPOLAR AND BIPOLAR PULSES CONTRACTUAL ORIGIN OF THE INVENTION BACKGROUND OF THE INVENTION The invention described herein relates to the generation of mechanical pulses in the form of unipolar and bipolar pulses. In the field of nondestructive testing much effort has gone into improving range resolution, broad band spectral content, penetration capabilities and eliminating near field effects. Innovations such as destructive lenses, matched damping members, single surface operation of very thick transducer elements, broad band amplifiers, frequency diffraction gratings and electronic enhancement of the rising slope of received signals have been developed for obtaining improved resolution response. However, relatively little work has been done to optimize the transmitter pulse for improved response.
Various types of ultrasound pulses have been generated for nondestructive testing. For example, output pulses having a rise time faster or slower than the transducer element half period resonance with exponential decay times have been used. For the faster rise time the transducer rings with a decay rate proportional to the ratio of the transmitter rise time to the transducer half period and the transducer mechanical damping or backing member. For the slower case a low-frequency component is imposed on the leading portion of the pulse and the transducer element resonates with a decay rate similar to that of the fast rise time pulse. These pulses have relatively poor range resolution and low or high spectral band width depending on whether the band width is evaluated from the viewpoint of narrow or broad spectral band width application. These pulse techniques also have relatively poor flaw separation resolution and can miss significant flaws because of interference, orientation and ultrasonic beam field effects.
A brute force fast rise transmitter pulse applied to a highly damped destructivelens transducer element produces an output pulse which is nearly a sinusoidal single cycle with very little resonance ringout. Using a pulse of this nature, resolution down to 0.010 inch longitudinal range resolution in steel has been obtained. This pulse technique has the advantage of high range resolution, relatively broad spectral range and minimization of near field effects. It has disadvantage in that the pulse is difficult to reproduce, particularly with different transducers and pulse systems. The equipment using this system is expensive and this system will not develop unipolar pulses. The receive response characteristics are also not ideal for varying signal types.
Variable length sinusoidal transmitter pulse trains tuned to transducer resonance are also used. This type of pulse is used primarily for attenuation measurement at a single frequency or may also be used for thickness measurements employing destructive resonance. Stable variable-frequency transmitters which are relatively expensive are required for this pulse type. This type wave propagation can be up to continuous and transmitters and transducers can be frequency modulated to cover relatively narrow frequency bands of spectral information. There is, however, very little range resolution using this pulse and the spectral power density is very narrow.
It is therefore an object of this invention to provide an excitation signal for developing a single unipolar pulse from a transducer.
Another object of this invention is to provide an excitation signal for developing a single bipolar pulse from a transducer.
Another object of this invention is to provide an excitation signal for developing a pair of unipolar pulses of opposite polarity from a transducer.
Another object of this invention is to provide signals for developing mechanical pulses having improved range resolution.
Another object of this invention is to provide signals for developing mechanical pulses which have a predictable broad spectral power density distribution.
Another object of this invention is to provide signals for developing mechanical pulses which have little or no transducer beam field effects.
Another object of this invention is to provide signals for developing mechanical pulses which can be approximated by straight lines so that they can easily be used in computer analysis.
SUMMARY OF THE INVENTION In practicing this invention, a method is provided for generating mechanical pulses. An excitation voltage is applied to a transducer to charge the transducer. The amplitude of the voltage increases from an initial value to a predetermined value at a time rate of change which inhibits measurable mechanical pulse generation by the transducer. After the excitation voltage has reached the predetermined value, the voltage is decreased linearly to the initial value during a specific time period to develop a single pulse having a period equal to the resonant sinusoidal period of the transducer. This excitation method develops a single unipolar pulse which is used for nondestructive testing of materials.
The time period required to develop the unipolar pulse is dependent on the backing impedance of the transducer. If the backing impedance is matched, the period of the excitation voltage is one-half the resonant sinusoidal period of the transducer. If the backing impedance is zero or unmatched, the period of the excitation voltage is equal to the resonant sinusoidal period of the transducer. Where the backing impedance is not zero and is unmatched, a dual slope excitation voltage is used.
A bipolar pulse having similar characteristics can also be developed by using an excitation voltage which increases in amplitude from the initial value to the predetermined value in the required time period and then decreases to the initial value in the same period. A pair of unipolar pulses can be developed by increasing the amplitude of the excitation voltage from the initial value to the predetermined value in the required time period to produce the first pulse. The excitation voltage is maintained at the predetermined value for a time period sufficiently long to permit ultrasound generated by the transducer to be reduced below a particular magnitude. The excitation voltage is then reduced to the initial value in the required time period. In this manner, a pair of unipolar pulses of opposite polarity are developed. In the time period between the unipolar or bipolar pulses generated in this manner, a receiver may be connected to the transducer for receiving reflected energy for analysis.
DESCRIPTION OF THE DRAWINGS The invention is illustrated in'the drawings, of which:
FIG. 1 is a curve showing the unipolar pulse;
FIG. 2 is a block diagram showing the equivalent circuit of a transducer;
FIGS. 3, 4 and 5 show the output forces developed by excitation of the transducer equivalent circuit of FIG. 2;
FIG. 6 shows the construction of a unipolar pulse in an air backed transducer;
FIG. 7 shows the unipolar response of a transducer with matched backing impedance;
FIG. 8 shows the dual slope ramp excitation required to develop unipolar pulses from a transducer with unmatched backing impedance other than zero;
FIGS. 9, 10 and 12 show the voltage applied to a transducer to develop desired mechanical pulses;
FIGS. 11 and 13 show the output pulses from a transducer as a result of the voltages shown in FIGS. 10 and 12;
FIG. 14 is a curve showing the power spectral density resulting from the mechanical pulses of FIGS. 1 and 11; and
FIG. 15 is a curve showing the power spectral density resulting from the mechanical pulse of FIG. 13.
DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, there is shown the waveform of a unipolar pulse which is a single triangular pressure wave radiated from a properly excited transducer. The width, T, of the pulse is equal to one period of the transducers natural resonant frequency. The pressure amplitude of this pulse will be of the same order of magnitude as the maximum half-cycle of an exponentially damped oscillatory burst resulting from rapid excitation of the same transducer.
To explain the generation of the unipolar pulse, reference is made to an equivalent circuit of a piezoelectric plate transducer, FIG. 2. The body of the transducer is represented by a three terminal delay line whose time delay is equal to one-half the transducers period at resonance. The velocity of propagation of a mechanical wave in the delay line is v. The lens and backing member impedances are represented respectively by Z and Z Z, is the source impedance and V is the electrode voltage. C, is the electrical capacitance at the terminals and Z, is the characteristic impedance of the delay line (analog of piezoelectric materials acoustic impedance). X is the thickness of the transducer and z is a transfonnation ratio. The voltage appearing at Z is the analog of ultrasonic force (pressure 1: surface area) radiated into the lens, while that appearing at Z is the analog of force radiated into the backing member.
At ultrasonic frequencies a piezoelectric transducer is effectively damped by its mass with the exception of areas immediately adjacent to the electrodes. Therefore the only sources of acoustic waves are at the front and back surfaces. Each surface will radiate waves in both the positive and negative X directions. The initial response to a positive Dirac voltage impulse applied at t= is shown in FIG. 3 with forces (F) labeled. Upon application of the voltage a positive and negative force will be generated at each surface.
The complete impulse response, FIG. 4, of the transducer can be derived through a transmission line treatment of succeeding reflections and radiations in the delay line. Referring back to the circuit of FIG. 2, the reflection coefficient at the front face is 0 =(Z1" Z0)/(ZI Z0) while that at the rear face is After the initial front face radiation F at t 0, no signal leaves the transducer until the force F originally generated at the rear face reaches the front face. A portion of this wave will leave the front face with magnitude (1 7 F That portion of the wave not radiated will be reflected back into the transducer with magnitude T F By subjecting all signals generated to a similar transmission line treatment, the complete train of impulses leaving the front face can be drawn. This impulse train is shown in FIG. 5.
The simplest case for unipolar pulse generation employs an air backed transducer with a water or other low impedance lens medium at the front face. Practical values for this case in an actual transducer are Z 1/20 2,, and Z 0. The driving function required to generate a unipolar pulse in an air backed transducer is a linear voltage ramp. The ramp starts at t O and at t= 2X /v. The duration of the ramp is critical if a clean baseline after t= 2X/v is to be obtained. The amplitude of the unipolar pulse will be directly proportional to the slope of the ramp.
The combination of force pulses responsible for generation of the unipolar pulse in this special case is shown in FIG. 6. Ramp waves of force are radiated from the front face with amplitudes as predicted by the impulse diagram of FIG. 6. At t 0 a positive force or compression ram is radiated in phase with the driving voltage. Its amplitude is established by the values of Z, and Z, to be =(hC, V/20) where V is the time function of voltage describing the input ramp and h is the piezoelectric constant. At t= X/v, the rarefaction force wave F generated at the rear face reaches the front face and will be radiated with amplitude =(2hC V/20). At t 3X/v, force F will have made a round trip in the transducer and will be radiated with approximate amplitude 2hC V/20. The complete series of radiated pulses can be derived in this manner. The algebraic sum of all these is the total force radiated with time from the front face. As can be seen from FIG. 6, this summation of forces is a unipolar pulse with nearly total cancellation of all radiated signals after t= 2X/v.
FIG. 7 shows the models response for matched backing, i.e., Z Z In this case the required ramp length is only X/v. This correlates with theory since the unipolar pulse will be the algebraic sum of only two pressure ramps, F and (l 1- F,,, which are equal and out of phase for any value of Z,. If they are to generate a unipolar pulse the ramp must terminate at t= X/v.
The equivalent circuit of FIG. 2 with linear ramp excitation provides a unipolar output for only the two cases 2 very small, Z 0 and Z any value, Z Z In practice, many transducers have epoxy backing of nonzero impedance and cannot be excited in the unipolar mode with a single linear ramp.
It has been found that a transducer can generate unipolar pulses where the nonmatched backing impedance is not matched or zero if certain conditions are met. These are: (A') that the ramp has a dual slope with a breakpoint at t X/v; (B) the two ramp slopes are of a specific ratio determined by transducer constants; and (C) the impedances Z and Z are equal. Such an excitation ramp is shown in FIG. 11.
By requiring that the time derivative of radiated signals occurring in both even and odd time intervals after t 2X/v is zero, the following relationships hold:
For odd intervals of X/v K2 Z0) k 0 and for even intervals 2 2 ZO/ZI 0) 1 0 where k, and k are the ramp slope coefficients as shown in FIG. 8, and a is the attenuation factor for one trip across the transducer in percent x 100. For both of these relationships to be true simultaneously, Z must equal Z The ramp ratio can then be determined to be 2/ l 0 2/ o 2)- Referring to FIG. 9, there is shown the waveform of a voltage pulse which can be applied to a transducer to develop a unipolar mechanical pulse therefrom. The transducer is charged by a linear ramp voltage 10 which gradually increases from an initial value to a final value 11. The time period over which this increase takes place A is long enough so that the transducer is charged without exciting the transducer to develop mechanical output pulses. After the transducer is charged, the voltage applied to the transducer is reduced to the initial value as shown by the linear ramp voltage 12. This reduction takes place over time period C which is equal to the time period required to develop a full single-cycle sinusoidal output pulse from the transducer.
Time C is variable depending upon the construction of the transducer. For example, an air backed transducer time period C is equal to the full single-cycle sinusoidal period of the transducer 2X/v. With a matched back transducer, the time period C is one-half the full single-cycle sinusoidal period X/v. Where the backing is neither matched nor zero (air, for example), the dual slope signal of FIG. 8 may be used. In either example, time period C is of the proper length to develop the single-cycle sinusoidal output pulse from the transducer. Time period B is arbitrary in length and may be zero, so that the output pulse is developed as soon as the transducer is charged. During the time period E the transducer is connected to a receiver to receive the reflected pulses for analysis. FIG. 1 shows the shape of the transmitted mechanical pulse. The time period T is equal to the full single-cycle sinusoidal period of the transducer.
Referring to FIG. 10, there is shown a waveform which will excite the transducer to develop two unipolar pulses. A linear ramp voltage (or dual linear ramps as required) 15 is applied to the transducer for a period F. When the ramp voltage 15 reaches a predetermined voltage level 16, it is maintained at this level for a time period G. At the end of time period G the voltage applied to the transducer is reduced to the initial value during a time period F at the rate shown by linear ramp voltage 17. (Linear ramp voltage 17 may be a dual linear ramp.) Periods F are of the proper duration to develop the normal full single-cycle sinusoidal pulses from the transducer. Period G is an arbitrary time period during which the initial pulse developed by the linear ramp voltage is transmitted and received. It should also be sufficiently long so that the transducer is quiescent prior to applying ramp 17.
Referring to FIG. 11, there is shown the transmitted pulses from the transducer for the excitation signal shown in FIG. 10. Each of the pulses has a time period T which is equal to the full single-cycle sinusoidal period of the transducer.
Referring to FIG. 12, there is shown the required excitation voltage to develop a single bipolar pulse. The linear ramp voltage 20 rises from the initial value to the predetermined value during a time period I and is immediately reduced to the initial value according to ramp voltage 21 in a time period I. (Ramps 20 and 21 may be dual linear ramps as required.) Time periods I are of the proper time duration to develop a full single-cycle sinusoidal output pulse from the transducer. Referring to FIG. 13, there is shown the output pulse from the transducer. In this example, the time period T is equal tothe full single-cycle sinusoidal period of the transducer.
FIG. 14 illustrates the spectral power density for a 15 MHz unipolar pulse of the kind shown in FIGS. 1 and 11. It can be seen that the power density covers a broad range. In FIG. 15 there is shown the spectral power density for the bipolar pulse of FIG. 13.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A method of generating mechanical pulses from a transducer coupled to a load including the steps of:
a. applying to said transducer an excitation voltage changing in amplitude from an initial value to a predetermined value during a first time period,
b. maintaining said excitation voltage at said predetermined value during a second time period, and
c. changing said excitation voltage across said transducer to a value proximate said initial value during a third time period, said excitation voltage during said third time period being formed of at least one and no more than two linear ramps, said third time period and said ramps being such that the amplitude of the signal from the transducer rear face reaching the load is substantially equal to the magnitude of the second and subsequent cycles of the signal from the transducer front face reaching the load and further is 180 out of phase with said second and subsequent cycles.
2. The method of generating mechanical pulses from the transducer of claim ll wherein:
a. the characteristic impedance of the backing material of said transducer is substantially zero,
b. said excitation voltage is applied to said transducer during said first time period to change the amplitude from said initial value to said predetermined value at a time rate of change to inhibit generation of mechanical pulses from said transducer, and
c. said excitation voltage across said transducer during said third time period is a single linear ramp with a duration equal to the resonant sinusoidal period of said transducer.
3. The method of generating mechanical pulses from the transducer of claim 2 wherein:
a. said second time period is zero.
4. The method of generating mechanical pulses from the transducer. of claim 1 wherein:
a. said excitation voltage across said transducer during said first time period is a single linear ramp with a duration equal to the resonant sinusoidal period of said transducer, and
b. said second time period during which said excitation transducer of is maintained at said predetermined value is sufficiently long to permit mechanical pulses thereby generated to be reduced below a particular magnitude.
5. The method of generating mechanical pulses from the transducer of claim 4 wherein:
a. said second time period is zero.
6. The method of generating mechanical pulses from the transducer of claim 1 wherein:
a. The characteristic impedance of the backing material of said transducer is substantially equal to the characteristic impedance of said transducer,
b. said excitation voltage is applied to said transducer during said first time period to change the amplitude from said initial value to said predetermined value at a time rate of change to inhibit generation of mechanical pulses from said transducer, and
c. said excitation voltage across said transducer during said third time period is a single linear ramp with a duration equal to one-half the resonant sinusoidal period of said transducer.
7. The method of generating mechanical pulses from the transducer of claim 6 wherein:
a. said second time period is zero.
8. The method of generating mechanical pulses of claim 1 wherein:
a. said excitation voltage across said transducer during said third time period is formed of two linear ramps with the duration of each of said ramps being equal to one-half the resonant sinsuoidal period of said transducer, and
b. the ramp ratio k /k is found by the formula 2/ 1 0 Z2/Z0'I'Z2), where k and k are the ramp slope coefficients of each of the two linear ramps, 0- is the attenuation factor for one trip of a pressure wave across the transducer, Z is the characteristic impedance of the transducer and Z is the impedance of the transistor backing material.
9. The method of generating mechanical pulses of claim 8 wherein:
a. said second time period is zero,
b. said excitation voltage across said transducer during said first time period is formed of two linear ramps with the duration of each of said ramps being equal to one-half the resonant sinusoidal period of said transducer, and
c. the ramp ratio K lk is found by the formula 2/ l o 2/ 0 2) where k, and k are the ramp slope coefficients, 0' is the attenuation factor for one trip of a pressure wave across the transducer, 2 is the characteristic impedance of the transducer, Z is the impedance of the transistor backing material.
1. A method of generating mechanical pulses from a transducer coupled to a load including the steps of: a. applying to said transducer an excitation voltage changing in amplitude from an initial value to a predetermined value during a first time period, b. maintaining said excitation voltage at said predetermined value during a second time period, and c. changing said excitation voltage across said transducer to a value proximate said initial value during a third time period, said excitation voltage during said third time period being formed of at least one and no more than two linear ramps, said third time period and said ramps being such that the amplitude of the signal from the transducer rear face reaching the load is substantially equal to the magnitude of the second and subsequent cycles of the signal from the transducer front face reaching the load and further is 180* out of phase with said second and subsequent cycles.
2. The method of generating mechanical pulses from the transducer of claim 1 wherein: a. the characteristic impedance of the backing material of said transducer is substantially zero, b. said excitation voltage is applied to said transducer during said first time period to change the amplitude from said initial value to said predetermined value at a time rate of change to inhibit generation of mechanical pulses from said transducer, and c. said excitation voltage across said transducer during said third time period is a single linear ramp with a duration equal to the resonant sinusoidal period of said transducer.
3. The method of generating mechanical pulses from the transducer of claim 2 wherein: a. said second time period is zero.
4. The method of generating mechanical pulses from the transducer of claim 1 wherein: a. said excitation voltage across said transducer during said first time period is a single linear ramp with a duration equal to the resonant sinusoidal period of said transducer, and b. said second time period during which said excitation transducer of is maintained at said predetermined value is sufficiently long to permit mechanical pulses thereby generated to be reduced below a particular magnitude.
5. The method of generating mechanical pulses from the transducer of claim 4 wherein: a. said second time period is zero.
6. The method of generating mechanical pulses from the transducer of claim 1 wherein: a. The characteristic impedance of the backing material of said transducer is substantially equal to the characteristic impedance of said transducer, b. said excitation voltage is applied to said transducer during said first time period to change the amplitude from said initial value to said predetermined value at a time rate of change to inhibit generation of mechanical pulses from said transducer, and c. said excitation voltage across said transducer during said third time period is a single linear ramp with a duration equal to one-half the resonant sinusoidal period of said transducer.
7. The method of generating mechanical pulses from the transducer of claim 6 wherein: a. said second time period is zero.
8. The method of generating mechanical pulses of claim 1 wherein: a. said excitation voltage across said transducer during said third time period is formed of two linear ramps with the duration of each of said ramps being equal to one-half the resonant sinsuoidal period of said transducer, and b. the ramp ratio k2/k1 is found by the formula k2/k1 sigma (Z0 - Z2/Z0 + Z2), where k1 and k2 are the ramp slope coefficients of each of the two linear ramps, sigma is the attenuation factor for one trip of a pressure wave across the transducer, Z0 is the characteristic impedance of the transducer and Z2 is the Impedance of the transistor backing material.
9. The method of generating mechanical pulses of claim 8 wherein: a. said second time period is zero, b. said excitation voltage across said transducer during said first time period is formed of two linear ramps with the duration of each of said ramps being equal to one-half the resonant sinusoidal period of said transducer, and c. the ramp ratio K2/k1 is found by the formula K2/k1 sigma (Z0 - Z2/Z0 +Z2), where k1 and k2 are the ramp slope coefficients, sigma is the attenuation factor for one trip of a pressure wave across the transducer, Z0 is the characteristic impedance of the transducer, Z2 is the impedance of the transistor backing material.
| 1971-02-02 | en | 1972-04-11 |
US-19802388-A | Triple axis thrust vectoring exhaust nozzle
ABSTRACT
A variable area, convergent-divergent (10) nozzle for directing the flow of exhaust gas from an aircraft turbine engine to achieve thrust vectoring about yaw, pitch and roll axes includes a convergent section (16) and a divergent section (18) each comprised of hingedly connected planar members (201-214, 301-322) selectively positioned by actuators (101-114) for defining deformable gas directing flow ducts.
FIELD OF THE INVENTION
The present invention relates to a thrust vectoring exhaust nozzle for an aircraft gas turbine engine.
BACKGROUND
The control and maneuvering of modern high speed aircraft remains a technical area in which designers continue to press for ever-increasing effectiveness. Such increased control response may require a balancing with increased airframe drag as control surfaces become larger, while in certain flight regimes, such as in supersonic or low-speed flight, the effectiveness of even large surfaces is diminished for certain angles of attack, etc.
One effective method for imparting additional maneuvering force is the use of a thrust vectoring exhaust nozzle. Such nozzles divert the flow of exhaust gas from the aircraft propelling gas turbine engine at an angle from the normal exhaust flow, thereby developing asymmetric thrust (and hence moment) with respect to the airframe center of gravity. Simpler versions of such thrust vectoring nozzles are able to impart thrust vectoring with respect to a single axis, for example the pitch axis. Such simpler versions still require several cooperating gas directing surfaces, especially convergent-divergent thrust vectoring nozzles used in conjunction with gas turbine engines equipped with an afterburner. The convergent section of such nozzles must be adapted to provide a variable throat area for optimization of the engine thrust, while the divergent section directs the exhaust gas selectably in the vertical plane for pitch thrust vectoring.
Yaw and pitch thrust vectoring exhaust nozzles are also known in the art, and are able to divert the exhaust gases in both the horizontal and vertical plane, thus achieving two axis thrust vectoring. Such two axis nozzles require additional structure and complexity over the one axis designs, requiring the advantages of increased maneuverability to be balanced against the additional weight and complexity required.
One advantage which thrust vectoring designs achieve with respect to prior art unvectored engine exhaust systems is the reduced control surface requirement for normal and even emergency maneuvering. The use of thrust vectoring exhaust nozzles in conjunction with automatic attitude control systems can achieve stable aircraft operation and control with reduced external control surfaces. Hence, an airframe having even a pitch thrust vectoring exhaust nozzle may operate with reduced size elevators providing benefits in external drag reduction, weight, etc. Likewise, a nozzle having yaw thrust vectoring capability can provide the necessary yaw maneuvering and stability to the airframe while permitting a reduction in rudder size.
A third axis of control remains which has no been adequately addressed by the prior art nozzle designs. The roll axis, traditionally controlled by ailerons on the aircraft wings, has thus far not been practically addressed by prior art thrust vectoring nozzles. What is needed is a thrust vectoring exhaust nozzle able to provide complete three axis thrust vectoring to an airframe, thereby achieving satisfactory control and stability with a reduced requirement for external control surface action.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a thrust vectoring exhaust nozzle for an aircraft gas turbine engine.
It is further an object of the present invention to provide a thrust vectoring nozzle capable of selectably providing yaw, pitch, and roll thrust vectoring.
It is further an object of the present invention to provide a variable flow area, convergent exhaust duct upstream of the thrust vectoring outlet, for optimizing nozzle performance under a range of engine power levels.
According to the present invention, a plurality of hinged triangular segments define a deformable divergent duct for receiving a flow of exhaust gas from a gas turbine engine and discharging such exhaust gas from the downstream end thereof. The hinged segments are generally planar and elongated with respect to the exhaust gas flow direction. Adjacent segments are hingedly joined longitudinally, forming a gas tight circumferential barrier for directing the exhaust flow.
The present invention further provides a plurality of actuators, each disposed between a fixed frame and the plurality of segments, for selectably positioning the segments and thereby influencing the discharge direction of the exhaust flow from the divergent duct. By properly positioning the individual segments, the exhaust flow can be configured to impart a resultant thrust on the nozzle structure and airframe which is asymmetric with respect to an unvectored, central axis. The deformable divergent duct according to the present invention is thus able not only to develop lateral and vertical thrust in the yaw and pitch directions, but can also achieve a torsional moment about the aircraft central axis, thereby achieving roll thrust vectoring as desired.
The nozzle according to the present invention further provides an upstream, convergent duct defined by a plurality of triangular and rectangular flaps hingedly joined together. The convergent flaps are positioned to define a converging gas flow passage having a variable throat area for discharging the exhaust gases into the downstream divergent duct.
The advantages of the variable area, triple axis thrust vectoring nozzle according to the present invention include enhanced aircraft maneuverability and stability as well as lower aerodynamic drag resulting from a reduced demand for external maneuvering control surfaces. Both these and other objects and advantages of the present invention will be apparent to those skilled in the art upon review of the following specification and the appended claims and drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a convergent-divergent three axis thrust vectoring exhaust nozzle according to the present invention.
FIG. 2 is a perspective view looking forward or upstream as indicated in FIG. 1. The nozzle is in the full flow configuration for providing unvectored, afterburning thrust.
FIG. 3 is a sectional view as indicated in FIG. 1 taken through the divergent section showing the orientation of the flaps. The nozzle is positioned for full, unvectored thrust.
FIG. 4 is a sectional view taken at the throat of the nozzle according to the present invention between the convergent and divergent sections. The throat is shown in a partial thrust configuration.
FIG. 5 shows the geometrically developed divergent flaps and convergent segments laid out in a plane.
FIG. 6 shows an upstream looking perspective view with the nozzle according to the present invention configured to provide normal, unvectored thrust.
FIG. 7 shows the nozzle configured to provide vectored pitch thrust.
FIG. 8 shows the nozzle according to the present invention configured to provide vectored yaw thrust.
FIG. 9 shows the nozzle according to the present invention configured to provide vectored roll thrust.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawing figures, and in particular to FIG. 1 thereof, the nozzle 10 according to the present invention is seen in a side elevation. Engine exhaust gas (not shown) flowing aftward in a cylindrical afterburner duct 12 enters a transition section 14 wherein the flow cross section is changed from cylindrical to hexagonal.
The exhaust nozzle 10 includes a convergent section 16 and a divergent section 18, with a restricted throat 20 located therebetween. A first circumferential static frame 22 and a second circumferential static frame 24 are shown disposed respectively about the nozzle throat 20 and midway along the divergent section 18 as shown. A central axis 26 represents the unvectored thrust direction and is generally coincident with the center axis of the cylindrical afterburner duct 12.
The nozzle 10 as shown in FIG. 1 is configured as to deliver full thrust during full afterburning operation of the gas turbine engine (not shown). The throat section 20 is opened to the widest flow area and the divergent duct 18 defines a gas tight conduit for directing the exhaust gases rearwardly generally coincident with the central axis 26. The details and individual components of the convergent and divergent sections 16, 18 will be explained in detail hereinbelow.
FIG. 2 shows a perspective view of the nozzle according to the present invention looking generally forwardly from a point aftward of the nozzle outlet 28. The nozzle in FIG. 2 is shown configured for full flow, afterburning operation in which the nozzle throat 20 is positioned to define a maximum area, and wherein the nozzle outlet 28 is fully opened as shown. The interior 30 of the transition section 14 may be viewed through the outlet opening 28.
FIG. 2 also shows the second static frame 24 surrounding the divergent section 18, as well as a plurality of linear actuators 101-110. The actuators 101-110 are positioned between the static frame 24 and the hinged divergent flap segments for selectively positioning the segments as discussed below.
It should be noted that the divergent duct 18 defined by the divergent segments moves independently from the convergent section 16 defined by the convergent flaps, with each section 16, 18 moving to accommodate its particular function in providing an efficient thrust vectoring nozzle.
The operation of the convergent section 16 is best appreciated by reviewing the forward looking cross section taken in the nozzle throat plane as shown in FIG. 4. The convergent section is defined by a plurality of triangular and rectangular flaps 201-214 disposed adjacent each other circumferentially about the gas flow path. Rectangular flaps 201, 208 are located on opposite lateral sides of the centerline 26 and are hingedly secured 221, 218 at opposite sides of the hexagonal transition duct opening.
The remainder of the convergent section 16 consists of triangular flaps 202-207 and 209-214 which are disposed on vertically opposite sides of the central axis 26 and hingedly secured for forming a gas tight convergent duct 16 as shown. Of the triangular flaps 202-207 and 209-214, flaps 203, 206, 210 and 213 are isosceles shaped, while 202, 204, 205, 207, 209, 211, 212, and 214 are right triangular shaped. Isosceles segments 203, 206, 210 and 213 are oriented with the base side forward and hingedly secured to one side of the hexagonal shaped outlet opening of the transition duct 14 while the remaining right triangular shaped flaps, each including a hypotenuse, a long leg, and a short leg, are hingedly secured together such that the hypotenuse of each is hingedly joined to one equal length leg of the adjacent isosceles shaped flap, with the short leg of each segment defining the convergent nozzle throat 20 and the long leg of each being secured either to the adjacent rectangular flap or the adjacent right triangular flap, as shown.
The collected convergent flaps 201-214 are positioned by four linear actuators 111-114 disposed between the first static frame 22 (not shown in FIG. 4) and the downstream edge of the first and eighth rectangular convergent flaps 201, 208 and the downstream end of the hingedly joined right triangular flaps 204, 205 and 211, 212. The four linear actuators 111-114 secured as shown and described above, operate in unison to vary the area of the nozzle throat 20 by moving the flaps 201-214 collectively inward and outward with respect to the central axis 26.
The convergent section 16 of the nozzle according to the present invention moves in response to the current engine power level, afterburner heat output, exhaust gas flow, and other parameters to provide a properly sized throat 20 for efficient engine thrust operation. The scheduling of nozzle outlet area to engine power output is well known and will therefore not be discussed further herein.
FIG. 3 shows a cross section of the divergent section 18 of the nozzle 10 according to the present invention looking forwardly as indicated in FIG. 1. The divergent duct 18 comprises 22 triangular shaped flap segments 301-322 hingedly secured and distributed circumferentially so as to define the divergent duct 18 as shown. The divergent triangular segments comprise two isosceles shaped triangular segments 301, 312 hingedly secured at the base thereof to the downstream edge of corresponding rectangular convergent flaps 201, 208. The remaining right triangular shaped segments are disposed adjacently about the circumference of the gas flow path with each segment having a hypotenuse and a long leg extending generally in the direction of the gas stream and secured to a corresponding hypotenuse or long leg of the next adjacent right triangular segment. The short legs of the right triangular segments located at the entrance or upstream end of the divergent section 18 are coincident with the short legs of the right triangular convergent flaps and include sliding, gas tight seals disposed therebetween.
Thus, the eight right triangular convergent flaps 202, 204, 205, 207, 209, 211, 212, and 214 each include a downstream short leg side which lies axially adjacent the short leg side of respective divergent right triangular segments 303, 306, 307, 310, 314, 317, 318, and 321. The sliding seals (not shown) disposed between the right triangular convergent flaps and divergent segments need only accommodate axial displacement as the flaps and segments are positioned and may therefore include simple tongue and groove or bellows type seals.
FIG. 5 shows the convergent and divergent duct sections 16, 18 of the nozzle according to the present invention separated along the circumference and laid out flat for the purpose of illustrating the relative placement and shape of the individual elements. The nozzle according to the preferred embodiment of the present invention may be visualized in three dimensions by matching ends A and B of FIG. 5 together so as to define convergent and divergent ducts 16, 18 about the gas stream as shown generally in FIG. 1.
With regard to the divergent section 18, FIG. 3 shows an upstream facing cross section taken as indicated in FIG. 1 and perpendicular to the central axis 26. Divergent flap sections 301-322 are indicated as visible.
Also shown is the second static frame 24 circumferentially disposed about the divergent duct 18 and having linear actuators 101-110 secured thereto. In the preferred embodiment of the present invention, each divergent actuator 101-110 is operatively connected to the divergent duct 18 at a corresponding hinge joint disposed along the long leg of two adjacent right triangular segments. Hence, divergent actuators 101-110 are disposed at the hinge lines between respective segment pairs 302 and 303, 304 and 305, 306 and 307, 308 and 309, 310 and 311, 313 and 314, 315 and 316, 317 and 318, 319 and 320, 321 and 322.
The nozzle according to the present invention defines a gas directing divergent duct 18 responsive to the position of the divergent segments 301-322 as selected by the action of divergent actuators 101-110. A variety of configurations in addition to the full flow configuration of FIG. 2 may be selected to achieve thrust vectoring about the yaw, pitch, and roll axes as desired.
FIG. 6 shows a forward looking view of the divergent section of the nozzle according to the present invention configured so as to deliver normal, unvectored thrust during operation of the gas turbine engine in a non-afterburning mode. The segments of the divergent section 18 have been configured so as to distribute the exhaust gases in a generally lateral plane with the bulk of the gas exiting the nozzle adjacent the isosceles segments 301, 312. Although the preferred configuration for normal thrust as shown in FIG. 6 imparts an opposing lateral velocity vector to the exhaust gases exiting therefrom, it has been determined that such exhaust pattern enhances the stability of the airframe (not shown) especially during takeoff and/or low speed maneuvering. The important feature of the configuration and exhaust flow resulting from the configuration of FIG. 6 is that the thrust and exhaust mass flow is symmetric about both the vertical and lateral planes.
FIG. 7 shows the exhaust nozzle 10 according to the present invention with the divergent section 18 positioned by the actuators 101-110 so as to deliver asymmetric thrust about the pitch axis. As may be clearly seen in FIG. 7, the divergent flap segments 301-322 are oriented so as to divert substantially all of the flow to one side of a horizontal plane passing through the central axis 26, thereby resulting in either an upward or downward pitch moment being imparted to the airframe. Although shown as diverting the axis so as to deliver a downward pitch to the airframe, it will be appreciated that the divergent flap 18 according to the present invention may be similarly positioned so as to deliver a vertically upward pitch moment to the airframe.
Likewise, FIG. 8 shows the divergent duct 18 according to the present invention configured so as to provide yaw thrust to the airframe. The individual segments 301-322 have been positioned by the divergent actuators 101-110 so as to divert a major portion of the exhaust flow to one side of a vertical plane passing through the nozzle central axis. The asymmetric exhaust flow resulting from the configurations of FIGS. 7 and 8 thus enable the nozzle according to the present invention to provide thrust vectoring about the yaw and pitch axes of the airframe. The thrust vectoring illustrated in FIGS. 7 and 8 can be applied not only during normal thrust operation of the gas turbine engine, but also during full and/or afterburning thrust by similarly diverting the majority of the exhaust gases asymmetrically about the nozzle central axis.
Finally, FIG. 9 shows the divergent duct 18 of the nozzle according to the present invention configured so as to impart a roll moment to the associated airframe. The FIG. 9 configuration is somewhat similar to the unvectored, normal thrust configuration of FIG. 6, however it may be appreciated that the laterally outboard portions 401, 401 of the divergent duct adjacent the equilateral triangular segments 301,312 of the duct 18 are configured so as to discharge a greater portion of the exhaust gas flowing therethrough on opposite sides of a horizontal plane passing through the nozzle central axis 26. The result of these two skewed exhaust flows is to develop a counterclockwise moment about the central axis 26 when viewed in the forward looking direction as in FIG. 9. As with the previous vectored thrust configurations, the roll thrust configuration of FIG. 9 may be achieved both in the clockwise direction as well as in combination with the yaw and pitch thrust vectoring configurations at both normal and full thrust.
The nozzle according to the present invention is thus limited only by the sophistication of the actuator control system in developing a gas directing divergent duct configuration to deliver any individual roll, pitch or yaw thrust vector, or any simultaneous combination thereof.
Another feature of the nozzle according to the present invention is the ability to provide a lightweight, structurally rigid flow directing divergent section without excessive bracing or other weight increasing structure. As will be noted by reviewing FIGS. 2 and 6-9, the adjacent triangular segments of the divergent section 18 are disposed at an angle so as to provide a relatively high bending moment at each hinged connection therebetween, thereby achieving a structurally strong yet extremely flexible movable duct. The attachment of the divergent actuators 101-110 at the hinge connections between adjacent triangular segments thus provides the actuating force at the most structurally rigid points of the divergent duct.
Cooling of the convergent and divergent sections 16, 18 may be achieved by a variety of methods well known in the art, including for example routing of cooling air internally via hollow hinges, external impingement, internal cooling air routes within the individual flaps and/or segments, etc. Likewise, cooling air may be allocated among the various segments and flaps as required, depending on the local heat flux, etc.
Another feature of the nozzle design according to the present invention is the ability to accommodate impaired operation of one or more actuators. Again, based upon the sophistication of the actuator control system, a single actuator which becomes frozen or otherwise limited in mobility may not substantially impair the overall operation of the nozzle according to the present invention and the associated aircraft due to the ability of the remaining actuators and movable nozzle components to configure the exhaust gas stream so as to accommodate the impaired components. Thus, a failed actuator which creates an asymmetric exhaust gas flow could be accommodated by configuring the remaining actuators in such a fashion as to develop a symmetric exhaust gas flow thereby permitting normal and safe operation of the aircraft.
The present invention is thus well adapted to provide a three axis thrust vectoring exhaust nozzle for a gas turbine engine powered aircraft or the like. It should further be noted that the nozzle according to the present invention, described herein with reference to the drawing figures which illustrate the preferred embodiment thereof, may be provided in a variety of equivalent embodiments, with the scope thereof being thus limited only by the claims appearing hereinbelow.
I claim:
1. A thrust vectoring exhaust nozzle for a gas turbine engine, comprising:a deformable flow duct receiving a flow of engine exhaust gas at an upstream end thereof and discharging said exhaust gas at an open, downstream end thereof, wherein the deformable duct includes a plurality of generally planar triangular segments, each segment having one side thereof coefficient with one end of the deformable duct and the other two sides thereof extending the full length of the deformable duct, and wherein each of the other two sides of each planar triangular segment is hingedly joined the length thereof to one of the other two sides of a next circumferentially adjacent triangular segment, the plurality of hingedly joined triangular segments defining the deformable flow duct; a plurality of actuators, each actuator engaged between a static portion of the nozzle exterior to the deformable duct and at least one of the triangular segments, each actuator adapted to selectively position the triangular segment engaged therewith relative to the nozzle static portion for collectively defining one of a plurality of deformable duct configurations for directing the exhaust gases relative to a central nozzle axis.
2. The nozzle as recited in claim 1, further comprising:a convergent duct secured at an upstream end to a static transition duct and receiving said flow of exhaust gas therefrom, the convergent duct further defining a downstream, variable area throat end discharging said exhaust gas into the upstream end of the deformable duct, wherein the convergent duct includes, a plurality of generally planar flap members, each planar flap member having two sides extending the full length of the convergent duct and hingedly joined over the length thereof to one of the two full length extending sides of a next circumferentially adjacently disposed planar flap member, and wherein each planar flap member has a third side disposed coincident with one of the ends of the convergent duct; and a second plurality of actuators engaged between at least one of the planar flap members and the static portion of the nozzle, each actuator adapted to selectively position the planar flap member engaged therewith relative to the nozzle static portion, and wherein the plurality of positioned planar flap members collectively define the variable area nozzle throat.
3. A yaw, pitch, and roll thrust vectoring exhaust nozzle for a gas turbine engine having a central axis, a forwardly disposed convergent section, and a rearwardly disposed divergent section, a flow of exhaust gases passing generally axially through the convergent section and into the divergent section, wherein the convergent section comprises a plurality of generally planar flap segments arranged adjacently and circumferentially to define a first movable convergent duct, the plurality of planar flap segments comprising, in circumferential sequence,a first rectangular shaped flap having a forward edge and a rearward edge, each forward and rearward edge lying in a corresponding radial plane defined with respect to the nozzle central axis, and first and second lateral edges, the first and second lateral edges each lying in a corresponding axial plane defined with respect to the nozzle central axis, a first right triangular shaped convergent flap, the long leg thereof hingedly secured to the first lateral edge of the first rectangularly shaped convergent flap and the short leg thereof disposed axially rearwardly, a third, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the hypotenuse of the second right convergent flap and the base thereof disposed forwardly, a fourth, right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the third isosceles convergent flap and the short leg thereof disposed rearwardly, a fifth, right triangular shaped convergent flap, the long leg thereof hingedly secured to the long leg of the fourth right shaped convergent flap and the base thereof disposed rearwardly, a sixth, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the long leg of the fifth right convergent flap and the base thereof disposed forwardly, a seventh right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the sixth isosceles convergent flap, and the short leg thereof disposed rearwardly, an eighth, rectangular shaped convergent flap having a forward edge and a rearward edge, each forward edge and rearward edge lying in a corresponding radial plane defined with respect to the nozzle central axis, and first and second lateral edges, each lying in a corresponding axial plane defined with respect to the nozzle central axis, the first lateral edge thereof hingedly secured to the long leg of the seventh right convergent flap, a ninth, right triangular shaped convergent flap, the long leg thereof hingedly secured to the second lateral edge of the eighth rectangular convergent flap and the short leg thereof disposed rearwardly, a tenth, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the hypotenuse of the ninth right convergent flap and the base thereof disposed forwardly, an eleventh, right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the tenth isosceles convergent flap and the short leg thereof disposed rearwardly, a twelfth, right triangular shaped convergent flap, the long leg thereof hingedly secured to the long leg of the eleventh right convergent flap and the short leg thereof disposed rearwardly, a thirteenth, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the long leg of the twelfth right convergent flap and the base thereof disposed forwardly, a fourteenth, right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the thirteenth isosceles convergent flap, and the short leg thereof disposed rearwardly and the long leg thereof hingedly secured to the second lateral edge of the first rectangular convergent flap, and wherein the forward edges of the first rectangular convergent flap and the eighth rectangular convergent flap are hingedly secured to a static frame, and the bases of the third, sixth, tenth, and thirteenth isosceles convergent flaps further comprise corresponding gas tight seals, disposed between each base and the static structure for sealing against any flow of exhaust gas therebetween; and wherein the divergent section comprises a plurality of generally planar triangular segments, each segment extending the full axial length of the divergent section, arranged adjacently and circumferentially to define a second movable duct receiving the flow of exhaust gas from the first movable convergent duct, the plurality of divergent planar triangular segments comprising, in sequence, a first, isosceles triangular shaped segment, the base thereof disposed forwardly and hingedly secured to the rearward edge of the first rectangular convergent flap, a second, right triangular shaped segment, the hypotenuse thereof hingedly secured to the first leg of the first isosceles triangular segment and the short leg thereof disposed rearwardly, a third, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the second right triangular segment and the short leg thereof disposed forwardly, a fourth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the third right triangular segment and the short leg thereof disposed rearwardly, a fifth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the fourth right triangular segment and the short leg thereof disposed rearwardly, a sixth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the fifth right triangular segment and the short leg thereof disposed forwardly, a seventh, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the sixth right triangular segment, and the short leg thereof disposed forwardly, an eighth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the seventh right triangular segment and the short leg thereof disposed rearwardly, a ninth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the eighth right triangular segment and the short leg thereof disposed rearwardly, a tenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the ninth right triangular segment and the short leg thereof disposed forwardly, an eleventh, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the tenth right triangular segment and the short leg thereof disposed rearwardly, a twelfth, isosceles triangular shaped segment, the first leg thereof hingedly secured to the hypotenuse of the eleventh right triangular segment and the base thereof disposed forwardly, and hingedly secured to the rearward edge of the eighth rectangular convergent flap, a thirteenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the second leg of the twelfth isosceles triangular segment and the short leg thereof disposed rearwardly, a fourteenth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the thirteenth right triangular segment and the short leg thereof disposed forwardly, a fifteenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the fourteenth right triangular segment and the short leg thereof disposed rearwardly, a sixteenth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the fifteenth right triangular segment and the short leg thereof disposed rearwardly, a seventeenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the sixteenth right triangular segment and the short leg thereof disposed forwardly, an eighteenth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the seventeenth right triangular segment, a nineteenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the eighteenth right triangular segment and the short leg thereof disposed rearwardly, a twentieth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the nineteenth right triangular segment and the short leg thereof disposed rearwardly, a twenty-first, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the twentieth right triangular segment and the short leg thereof disposed forwardly, a twenty-second, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the twenty-first right triangular segment, the short leg thereof disposed rearwardly and the hypotenuse thereof hingedly secured to the second leg of the first isosceles triangular segment; and a plurality of seals, located between the downstream disposed short legs of the second, fourth, fifth, seventh, ninth, eleventh, twelfth, and fourteenth right triangular convergent flaps and the corresponding forwardly disposed short legs of the third, sixth, seventh, tenth, fourteenth, seventeenth, eighteenth, and twenty-first divergent right triangular segments, for preventing the flow of exhaust gases therebetween.
4. The nozzle as recited in claim 3, further comprising:first and second actuator frames, the first frame disposed circumferentially about the convergent section and the second frame disposed circumferentially about the divergent section, further comprising first, second, third, and fourth linear convergent actuators, the first convergent actuator disposed between the first frame and the first rectangular flap rearward edge, the second convergent actuator disposed between the convergent frame and the rearward end of the long leg hinge disposed between the fourth and fifth convergent flaps, the third convergent actuator disposed between the convergent frame and the rearward edge of the eighth rectangular convergent flap, and the fourth convergent actuator disposed between the convergent frame and the rearward end of the long leg hinge disposed between the eleventh and twelfth convergent flaps; and first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, and tenth linear divergent actuators located axially intermediate the upstream and downstream ends of the divergent section, and wherein the first divergent actuator is disposed between the divergent frame and the long leg hinge between the second and third right triangular segments, the second divergent actuator is disposed between the divergent frame and the long leg hinge between the fourth and fifth right triangular segments, the third divergent actuator is disposed between the divergent frame and the long leg hinge between the sixth and seventh right triangular segments, the fourth divergent actuator is disposed between the divergent frame and the long leg hinge between the eighth and ninth right triangular segments, the fifth divergent actuator is disposed between the divergent frame and the long leg hinge between the tenth and eleventh right triangular segments, the sixth divergent actuator is disposed between the divergent frame and the long leg hinge between the thirteenth and fourteenth right triangular segments, the seventh divergent actuator is disposed between the divergent frame and the long leg hinge between the fifteenth and sixteenth right triangular flap segments, the eighth divergent actuator is disposed between the divergent frame and the long leg hinge between the seventeenth and eighteenth right triangular segments, the ninth divergent actuator is disposed between the divergent frame and the long leg hinge between the nineteenth and twentieth right triangular segments, the tenth divergent actuator is disposed between the divergent frame and the long leg hinge between the twenty-first and twenty-second right triangular segments.
5. A yaw, pitch, and roll thrust vectoring exhaust nozzle for a gas turbine engine having a central axis, a rearwardly disposed divergent section, and a flow of exhaust gases passing generally axially into the divergent section, wherein the divergent section comprises:a plurality of generally planar triangular segments, each segment extending the full axial length of the divergent section, arranged adjacently and circumferentially to define a movable duct receiving the flow of exhaust gas, the plurality of divergent planar triangular segments comprising, in sequence, a first, isosceles triangular shaped segment, the base thereof disposed forwardly, a second, right triangular shaped segment, the hypotenuse thereof hingedly secured to the first leg of the first isosceles triangular segment and the short leg thereof disposed rearwardly, a third, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the second right triangular segment and the short leg thereof disposed forwardly, a fourth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the third right triangular segment and the short leg thereof disposed rearwardly, a fifth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the fourth right triangular segment and the short leg thereof disposed rearwardly, a sixth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the fifth right triangular segment and the short leg thereof disposed forwardly, a seventh, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the sixth right triangular segment, and the short leg thereof disposed forwardly, an eighth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the seventh right triangular segment and the short leg thereof disposed rearwardly, a ninth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the eighth right triangular segment and the short leg thereof disposed rearwardly, a tenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the ninth right triangular segment and the short leg thereof disposed forwardly, an eleventh, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the tenth right triangular segment and the short leg thereof disposed rearwardly, a twelfth, isosceles triangular shaped segment, the first leg thereof hingedly secured to the hypotenuse of the eleventh right triangular segment and the base thereof disposed forwardly, a thirteenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the second leg of the twelfth isosceles triangular segment and the short leg thereof disposed rearwardly, a fourteenth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the thirteenth right triangular segment and the short leg thereof disposed forwardly, a fifteenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the fourteenth right triangular segment and the short leg thereof disposed rearwardly, a sixteenth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the fifteenth right triangular segment and the short leg thereof disposed rearwardly, a seventeenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the sixteenth right triangular segment and the short leg thereof disposed forwardly, an eighteenth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the seventeenth right triangular segment, a nineteenth, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the eighteenth right triangular segment and the short leg thereof disposed rearwardly, a twentieth, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the nineteenth right triangular segment and the short leg thereof disposed rearwardly, a twenty-first, right triangular shaped segment, the hypotenuse thereof hingedly secured to the hypotenuse of the twentieth right triangular segment and the short leg thereof disposed forwardly, and a twenty-second, right triangular shaped segment, the long leg thereof hingedly secured to the long leg of the twenty-first right triangular segment, the short leg thereof disposed rearwardly and the hypotenuse thereof hingedly secured to the second leg of the first isosceles triangular segment.
6. The nozzle as recited in claim 5, further comprising:an actuator frame, disposed circumferentially about the divergent section, and first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, and tenth linear divergent actuators located axially intermediate the upstream and downstream ends of the divergent section, wherein the first divergent actuator is disposed between the divergent frame and the long leg hinge between the second and third right triangular segments, the second divergent actuator is disposed between the divergent frame and the long leg hinge between the fourth and fifth right triangular segments, the third divergent actuator is disposed between the divergent frame and the long leg hinge between the sixth and seventh right triangular segments, the fourth divergent actuator is disposed between the divergent frame and the long leg hinge between the eighth and ninth right triangular segments, the fifth divergent actuator is disposed between the divergent frame and the long leg hinge between the tenth and eleventh right triangular segments, the sixth divergent actuator is disposed between the divergent frame and the long leg hinge between the thirteenth and fourteenth right triangular segments, the seventh divergent actuator is disposed between the divergent frame and the long leg hinge between the fifteenth and sixteenth right triangular flap segments, the eighth divergent actuator is disposed between the divergent frame and the long leg hinge between the seventeenth and eighteenth right triangular segments, the ninth divergent actuator is disposed between the divergent frame and the long leg hinge between the nineteenth and twentieth right triangular segments, the tenth divergent actuator is disposed between the divergent frame and the long leg hinge between the twenty-first and twenty-second right triangular segments.
7. A yaw, pitch, and roll thrust vectoring exhaust nozzle for a gas turbine engine having a central axis, a forwardly disposed convergent section, a flow of exhaust gases passing generally axially through the convergent section, wherein the convergent section comprises,a plurality of generally planar flap segments arranged adjacently and circumferentially to define a first movable convergent duct, the plurality of planar flap segments comprising, in circumferential sequence, a first rectangular shaped flap having a forward edge and a rearward edge, each forward and rearward edge lying in a corresponding radial plane defined with respect to the nozzle central axis, and first and second lateral edges, the first and second lateral edges each lying in a corresponding axial plane defined with respect to the nozzle central axis, a first right triangular shaped convergent flap, the long leg thereof hingedly secured to the first lateral edge of the first rectangularly shaped convergent flap and the short leg thereof disposed axially rearwardly, a third, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the hypotenuse of the second right convergent flap and the base thereof disposed forwardly, a fourth, right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the third isosceles convergent flap and the short leg thereof disposed rearwardly, a fifth, right triangular shaped convergent flap, the long leg thereof hingedly secured to the long leg of the fourth right shaped convergent flap and the base thereof disposed rearwardly, a sixth, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the long leg of the fifth right convergent flap and the base thereof disposed forwardly, a seventh right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the sixth isosceles convergent flap, and the short leg thereof disposed rearwardly, an eighth, rectangular shaped convergent flap having a forward edge and a rearward edge, each forward edge and rearward edge lying in a corresponding radial plane defined with respect to the nozzle central axis, and first and second lateral edges, the first lateral edge thereof hingedly secured to the long leg of the seventh right convergent flap, a ninth, right triangular shaped convergent flap, the long leg thereof hingedly secured to the second lateral edge of the eighth rectangular convergent flap and the short leg thereof disposed rearwardly, a tenth, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the hypotenuse of the ninth right convergent flap and the base thereof disposed forwardly, an eleventh, right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the tenth isosceles convergent flap and the short leg thereof disposed rearwardly, a twelfth, right triangular shaped convergent flap, the long leg thereof hingedly secured to the long leg of the eleventh right convergent flap and the short leg thereof disposed rearwardly, a thirteenth, isosceles triangular shaped convergent flap, the first leg thereof hingedly secured to the long leg of the twelfth right convergent flap and the base thereof disposed forwardly, a fourteenth, right triangular shaped convergent flap, the hypotenuse thereof hingedly secured to the second leg of the thirteenth isosceles convergent flap, and the short leg thereof disposed rearwardly and the long leg thereof hingedly secured to the second lateral edge of the first rectangular convergent flap, and wherein the forward edges of the first rectangular convergent flap and the eighth rectangular convergent flap are hingedly secured to a static frame, and the bases of the third, sixth, tenth, and thirteenth isosceles convergent flaps further comprise corresponding gas tight seals, disposed between each base and the static structure for sealing against any flow of exhaust gas therebetween.
8. The nozzle as recited in claim 7, further comprising:an actuator frame disposed circumferentially about the convergent section and first, second, third, and fourth linear convergent actuators, the first convergent actuator disposed between the first frame and the first rectangular flap rearward edge, the second convergent actuator disposed between the convergent frame and the rearward end of the long leg hinge disposed between the fourth and fifth convergent flaps, the third convergent actuator disposed between the convergent frame and the rearward edge of the eighth rectangular convergent flap, and the fourth convergent actuator disposed between the convergent frame and the rearward end of the long leg hinge disposed between the eleventh and twelfth convergent flaps.
| 1988-05-24 | en | 1989-11-07 |
US-35628564-A | Electric wire junction
Jan. 31, 1967 F. L. CHRlSTENSEN 3,391,941
ELECTRIC WIRE JUNCTION Filed March 51, 1964 INVENTOR. Al ey/w: 0 622/5" TEA/SEN IQTTOPA/Y.
United States Patent 3,301,941 ELECTRIC WIRE JUNCTION Frank L. Christensen, Saratoga, Calif., assignor to Tempress Research Co., Sunnyvale, Calif., a corporation of Utah Filed Mar. 31, 1964, Ser. No. 356,285 6 Claims. (Cl. 174-88) pulls and other types of stresses that might otherwise tend to disrupt the electric connections are prevented from being transferred through the electric wires themselves at their point of interconnection.
Another object of the invention is to provide an electric wire junction which can be made in a small size, and still possess comparatively large mechanical strength, low electrical resistance, and high temperature resistance.
An additional object of the invention is to provide a junction between electric wires, and the like, in which good electric connection between adjacent wires, appropriate insulation of the connection, and its protection are secured essentially through mechanically attaching the parts to one another.
This invention possesses many other advantages and has other objects which may be made more clearly apparent from a consideration of a form embodying the invention. This form is shown and described in the present specification and drawings accompanying and constituting a part thereof. They will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.
Referring to the drawings:
FIGURE 1 is a longitudinal section, portions being shown in side elevation, of an electric wire junction embodying the invention;
FIG. 2 is a longitudinal section, parts shown in side elevation, illustrating the initial steps in making the electric junction disclosed in FIG. 1;
FIG. 3 is a view similar to FIG. 2, illustrating additional steps in forming the electric wire junction;
FIG. 4 is a view similar to FIGS. 2 and 3 illustrating yet a further step in manufacturing the electric wire junction disclosed in FIG. 1.
The electric junction illustrated in FIG. 1 provides electric connections between the wires 10, of an electric resistance type of heater and the wires 11, 11 of insulated electric conductors 70 running from a suitable source of current, which is to flow through the resistance heater. As specifically shown, the heater wires 10 are disposed within a stainless steel sheath or tube 12 and are surrounded by insulating material 13 within the sheath or tube, which material may be magnesium oxide. The heater. wires 10 project beyond the terminal or end portion 14 of the stainless steel sheath, which is piloted within a companion central passage 15 through the base portion 16 of a terminal cup 17 which, for example, may be made of stainless steel. This cup has a skirt portion 18 extending forwardly from its base portion, there being a cavity 19 in the cup through which the heater wires 10 can pass. The cavity opens into a counterbore 20 in which an insulated spacer member-or supporting washer 21 is disposed, which may be made of electrical insulation material, such as a suitable ceramic material. This washer engages a shoulder or base 22 of the counterbore and is held in assembled position against the shoulder by ice rolling over or fianging inwardly the terminal portion 23 of the cup skirt 18.
Mounted within the insulated support member 21 are a pair of longitudinally extending and laterally spaced conductive terminal tubes 24, which may be made of nickel or nickel-like material. Each of these tubes has a reduced diameter portion 25 extending within a companion longitudinal passage or bore 26 in the insulated washer, a shoulder 27 On each tube engaging the outer surface of the washer. The inner end of each tube is riveted or flared outwardly to provide a flange 28 engaging the inner surface of the insulated washer, as well as a flaring mouth 29 through which a heater wire 10 can be inserted into the bore or passage 30 in the tube.
The terminal portion of each heater wire is disposed within the cavity 19 and also into the bore 30 of an associated tube 24. Similarly, the terminal portion 11 of each lead wire is inserted into the tube 24 through its opposite end, and may overlie or be disposed adjacent to an associated heater wire 10. The electrically conductive terminal tube 24 is crimped or flattened laterally so that its crimped or flattened portion 31 clamps both the heater wire terminal 10 and the lead wire terminal 11 firmly to the tube, forming a good electrical connection between the heater wire and the lead wire, which may be provided by direct contact of the wires 10, 11 with one another, or by good mechanical contact between the heater wire 10 and tube 24 and the tube 24 and the lead wire 11, or by a combination of the aforementioned types of contact.
The crimped tubes 24 are covered by a flexible tubing 32 of insulating material which, for example, may be a vinyl resin, the tubing extending along a substantial length of the insulated portions 33 of the electric conductors 70, the inner end 32a of the insulated vinyl tubing terminating closely ajdacent to the insulated washer or support 21.
A secure attaching of the terminal cup 17 to the stainless steel sheath 12 is obtained, as by use of silver brazing material 35 integrating the base portion 16 of the cup with the periphery of the stainless steel sheath or tube.
A jacket or housing 36 encloses the terminal cup 17, insulated washer 21, terminal tubes 24, lead wires 11, and a portion of the insulating tube 32, and serves to mechan ically interconnect the insulated conductor members 70 and insulated tubing 32 with the terminal cup. As disclosed in FIG. 1, the jacket or housing 36 includes a main body portion 37 of relatively large diameter and a tail portion 38 of substantially smaller diameter, the tail portion having a passage 39 therethrough adapted to receive the insulated conductor wires 70 and the insulated tubing 32. Forwardly of its tail portion 38, the jacket provides a chamber 40 larger than the lateral dimension of the insulating tubing 32 mounted on the terminal tubes 24, this chamber terminating in a shoulder 41 adapted to abut the forward end 23 of the terminal cup 17. This shoulder merges into an enlarged diameter jacket portion 42 adapted to snugly fit over the periphery of the terminal cup skirt 18. With the shoulder 41 engaging the forward end 23 of the terminal cup, the end of the jacket extends slightly beyond the cylindrical periphery of the cup, the end portion 43 of the jacket being rolled or flanged over in an inward direction against the tapered transverse surface 44 of the cup base 16, so as to firmly secure the jacket to the cup. Part 45 of the tail portion of the jacket is then flattened or crimped inwardly to compress it against the insulating tubing 32 at a location substantially spaced from the terminal tubes 24, the insulating tubing 32 also being flattened to some extent against the insulation or sheath 33 of the conductive wires 70.
In the manufacture of the electric wire junction illustrated in FIG. 1, the terminal tubes 24 are inserted in the bores 26 of the insulated washer 21 and their rear ends 28 then riveted or flared over. The washer and tube subassembly is then inserted in the counterbore 20 of the terminal cup 17 and the forward end 23 of the latter flared over the end of the insulated washer to secure the washer to the terminal cup (FIG. 2). The stainless steel sheath 12 with a pair of heater wires projecting from its forward end is then inserted in the central passage of the cup, each of the heater wires 10 being disposed in its associated bore or passage 30 in a terminal tube 24, after which the terminal cup 17 is secured to the stainless steel tube 12 by silver brazing material disposed between the end of the terminal cup and the periphery of the stainless steel tube.
The exposed lead wires 11 of the pair of conductor members 70 are then each located in its associate bore 30 of a terminal tube 24, with the insulation 33 substantially abutting the outer end of the tube 24, each tube then being crimped or flattened inwardly to mechanically connect the conducting tube 24 with the heater wire 10 and the lead wire 11 disposed in its bore, as disclosed in FIG. 3. The tubing 32 of insulating material is then pulled over the conductive wires 70 and is stretched over the terminal cup 17, the vinyl tubing 32 conforming to the flattened or crimped portions 31 of the tubes, thereby insulating the tubes 24 and preventing external contact therewith by other conducting elements. The partially completed junction assembly is then in the condition illustrated in FIG. 4.
The jacket or housing 36 is then moved over the insulated tubing 32 and the conductor members 70 therewithin, and is shifted over the periphery of the terminal cup 17, until its shoulder 41 engages the end 23 of the cup, the end 43 of the jacket then being rolled or flanged inwardly to engage the tapered end portion 44 of the terminal cup. The tail portion 45 of the jacket is then flattened or crimped inwardly to mechanically secure it to the insulated tubing 32 and to the insulated conductors 70. The entire assembly has thus been completed, being illustrated in FIG. 1.
The electric wire junction illustrated in FIG. 1 prevents mechanical stresses from being imposed upon the connection between each heater wire 10 and its associated lead wire 10 with a tube 24. Any mechanical pulls or other strains imposed on the heater tube 12 or on the electric conductors 70 are transferred through the rigid cup 17 and rigid jacket 36, and do not pass through the junction portions of the wires themselves. Lateral bending or other forces imposed upon the jacket or housing 36 are not transmitted to the wires within the terminal tubes 24, but are resisted by the jacket or housing. The same is true of compressive forces imposed upon the parts. Any longitudinally inwardly directed forces on the conductors 70 or the insulated tubing 32 are transmitted through the crimped or flattened portion 45 of the jacket to the jacket 36, and through its shoulder 41, terminal cup 17, and the silver brazing material 35 to the stainless steel tubing 12. Inwardly directive or compressive forces originating from the heater end of the'apparatus is transmitted in a reverse direction through the cup 17 and housing 36 to the insulated tubing 32 and the conductors 70. The stresses themselves are not transmitted through the electrical connecting portions between each heater wire and its associated lead wire.
The above connection has been found to possess grea mechanical strength, despite the fact the junction, and particularly its heater wires 10 and lead wires 11, are of a relatively small size. The large conductive areas between the heater wires and lead wires and each terminal tube 24 result in very low electrical resistance at the connecting points. The particular connection also enables it to resist high temperatures, such as might be due to conductive flow of heat from the heater wires 10 to the junction. Substantially all contacts are mechanical.
The only nonmechanical connection is the silver brazing connection 35 between the cup 17 and the stainless steel heater tube 12.
The entire assembly is made of parts that are compartively simple, being capable of manufacture on screw machines, or of being molded easily. The assembly of the parts to one another is rapid and inexpensive, particularly in view of their mechanical interconnection. Even the silver brazing of the terminal cup to the heater .tube 12 is effected in a rapid manner. The simplicity of the parts and their essentially mechanical interconnection to one another makes the assembly of the complete junction capable of accomplishment in a rapid and relatively simple manner. Despite the relative low cost of making the junction, it possesses great mechanical strength and has a long life, since electrical contact between the lead wires 11 and the heater wires 10 is retained, not being susceptible to disruption because of transfer or bypassing stresses around the electrical contact location. The electrically conducting parts are fully insulated from one another, minimizing the danger of short-circuiting.
I claim:
1. In an electric wire junction: a terminal member having a passage; an insulated support in said member; a conductive tube secured to said support; a first sheath in said passage secured to said terminal member; a first electrical conductor extending from said sheath and disposed in said tube from one end thereof; a second sheath adjacent to said tube and having a second electrical conductor extending therefrom and disposed in said tube from the opposite end thereof; said tube being mechanically connected to the portions of said first and second electrical conductors disposed therein; insulating means disposed over said tube; and a jacket surrounding said terminal member, tube and second sheath and secured to said terminal member and second sheath to transmit mechanical forces between said first sheath and second sheath.
2. In an electric wire junction; a terminal member having a passage; an insulated support in said member; a conductive tube secured to said support; a first sheath in said passage secured to said terminal member; a first electrical conductor extending from said sheath and disposed in said tube from one end thereof; a second sheath adjacent to said tube and having a second electrical conductor extending therefrom and disposed in said tube from the opposite end thereof; said tube being pressed inwardly to connect it to the portions of said first and second electrical conductors disposed therein; an insulating tube disposed over said tube and second sheath; and a jacket surrounding said terminal member, tube and insulating tubing and secured to said terminal member, said jacket being pressed inwardly against said tubing to press said tubing inwardly against said second sheath, whereby mechanical forces are transmittable between said sheaths without passing through the portions of said first and second conductors disposed in said tube.
3. In an electric wire junction; a terminal cup having a central passage; an insulated support within and secured to said cup; a conductive tube secured to said support; a first sheath in said passage secured to said cup; a first electrical conductor extending from said sheath and disposed in said tube from one end thereof; a second sheath adjacent to said tube and having a second electrical conductor extending therefrom and disposed in said tube from the opposite end thereof; said tube being pressed laterally inwardly to conect it to the portions of said first and second electrical conductors disposed therein; an insulating tubing disposed over said tube and second sheath; and a jacket surrounding said cap, tube and insulating tubing, said jacket having a thrust shoulder engaging an end of said cup remote from said passage to transmit longitudina-l forces in one direction between said jacket and cup, said jacket having an inwardly directed flange engaging another portion of said cup to transmit longitudinal forces in the opposite direction between said jacket and cup.
said jacket being pressed laterally inwardly against said tubing to press said tubing inwardly against said second sheath, whereby mechanical forces are transmittable between said sheaths without passing through the portions of said first and second conductors disposed in said tube.
4. In an electric wire junction; a terminal member having a passage; an insulated support in said member; a plurality of spaced conductive tubes secured to said support; a first sheath in said passage secured to said terminal member; a plurality of first electrical conductors extending from said sheath, each of said conductors being disposed in an associated tube from one end thereof; a plurality of other sheaths adjacent to said tubes and having electrical conductors extending therefrom and each disposed in a tube from the opposite end thereof; each of said tubes being mechanically connected to the portions of said electrical conductors disposed therein; insulating means disposed over said tubes; and a jacket surrounding said terminal member, tubes and plurality of other sheaths and secured to said terminal member and other sheaths to transmit mechanical forces between said first sheath and other sheaths.
5. In an electric wire junction; a terminal member having a passage; an insulated support in said member; a plurality of spaced conductive tubes secured to said support; a first sheath in said passage secured to said terminal member; a plurality of first electrical conductors extending from said sheath, each of said conductors being disposed in an associated tube from one end thereof; a plurality of other sheaths adjacent to said tubes and having electrical conductors extending therefrom and each disposed in a tube from the opposite end thereof; each of said tubes being pressed laterally inwardly to connect it to the portions of said electrical conductors disposed therein; an insulating tubing disposed over said tubes and said other sheaths; and a jacket surrounding said terminal member, tube and insulated tubing and secured to said terminal member, said jacket being pressed laterally inwardly against said tubing to press said tubing inwardly against said other sheaths, whereby mechanical lfOICGS are transmittable between said first sheath and said other sheaths without passing through the portions of said conductors disposed in said tubes.
6. In an electric wire junction; a rigid terminal cup having a central passage; an insulated support within and secured to said cup; spaced conductive tubes secured to said support; a first sheath in said passage secured to said cup; electrical conductors extending from said sheath, each conductor being disposed in an associated tube from one end thereof; a plurality of other sheaths adjacent to said tubes, each of said other sheaths having an electrical conductor extending therefrom and disposed in an associated tube from the opposite end thereof; each of said tubes being pressed laterally inwardly to connect it to the portions of said electrical conductors disposed therein; an insulating tubing disposed over said tubes and other sheaths; and a rigid jacket surrounding said cup, tubes and insulated tubing, said jacket having a thrust shoulder engaging an end of said cup remote from said passage to transmit longitudinal forces in one direction between said jacket and cup, said jacket having an inwardly directed flange engaging another portion of said cup .to transmit longitudinal forces in the opposite direction between said jacket and cup, said jacket being pressed laterally inwardly against said tubing to press said tubing inwardly against said other sheaths, whereby mechanical forces are transmittable between said first sheath and said other sheaths without passing through the portions of said conductors disposed in said tubes.
No references cited.
LEWIS H. MYERS, Primary Examiner.
DIL. CLAY, Assistant Examiner.
1. IN AN ELECTRIC WIRE JUNCTION: A TERMINAL MEMBER HAVING A PASSAGE; AN INSULATED SUPPORT IN SAID MEMBER; A CONDUCTIVE TUBE SECURED TO SAID SUPPORT; A FIRST SHEATH IN SAID PASSAGE SECURED TO SAID TERMINAL MEMBER; A FIRST ELECTRICAL CONDUCTOR EXTENDING FROM SAID SHEATH AND DISPOSED IN SAID TUBE FROM ONE END THEREOF; A SECOND SHEATH ADJACENT TO SAID TUBE AND HAVING A SECOND ELECTRICAL CONDUCTOR EXTENDING THEREFROM AND DISPOSED IN SAID TUBE FROM THE OPPOSITE END THEREOF; SAID TUBE BEING MECHANICALLY CONNECTED TO THE PORTIONS OF SAID FIRST AND SECOND ELECTRICAL CONDUCTORS DISPOSED THEREIN; INSULATING MEANS DISPOSED OVER SAID TUBE; AND A JACKET SURROUNDING SAID TERMINAL MEMBER, TUBE AND SECOND SHEATH AND SECURED TO SAID TERMINAL MEMBER AND SECOND SHEATH TO TRANSMIT MECHANICAL FORCES BETWEEN SAID FIRST SHEATH AND SECOND SHEATH.
| 1964-03-31 | en | 1967-01-31 |
US-64795391-A | Process of preparing molded products using an internal hold release agent
ABSTRACT
A process for preparing molded polymeric products including reacting a polyisocyanate with an active hydrogen-containing composition having internal mold release components. In the process, the active hydrogen-containing composition contains (a) a primary or secondary amine, (b) a metal salt of an organic material having a carboxylic acid group and a siloxane chain wherein, said metal is selected from Groups I-B, II-B, IV-B, V-B, VI-B, VII-B or VIII, and optionally (c) an organic material containing at least one carboxylic acid group, phosphorus-containing acid group or boron-containing acid group wherein said organic material contains a siloxane chain or contains a terminal or pendant aliphatic hydrocarbon chain.
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 369,581, filed Jun. 21, 1989, now U.S. Pat. No. 5,011,647, issued Apr. 30, 1991, which is a continuation-in-part of application Ser. No. 570,141, filed Jan. 12, 1984, now U.S. Pat. No. 4,876,019, issued Oct 24, 1989, and a continuation-in-part of Ser. No. 466,826, filed Feb. 16, 1983, now abandoned, all incorporated herein by reference. It is related to application Ser. Nos. 749,710, 749,849 and 749,850, all filed Jun. 18, 1985, all abandoned, and incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention pertains to internal mold release compositions, to polyol compositions containing same and processes for preparing polymeric products.
Polyether polyurethane moldings are being increasingly used in the manufacture of automobiles, furniture and in home construction. Molded polyether polyurethanes are especially important because they are lightweight and are resistant to moisture, weather, temperature extremes, and aging. As an illustration, molded polyether polyurethane elastomers have become of special interest in the manufacture of force-reducing impact media such as safety impact bumpers for automotive vehicles and impact resistant automotive fascia.
The high demand for molded polyether polyurethane articles requires that they be produced in the largest numbers in the shortest possible time. Polyurethane-forming mixtures are eminently suited for mass production because the reactants are liquid, that is they are pumpable, and are quick-reacting. The problem has existed, however, in providing adequate mold release in the shortest possible time to take fullest advantage of the unique capabilities of the polyurethane systems.
Heretofore, release of molded articles from molds in which they have been formed has been achieved by coating the surface of the mold cavity with an agent which facilitates release of the molded article from the walls of the mold cavity. Procedures such as this are described in U.S. Pat. Nos. 3,694,530; 3,640,769; 3,624,190; 3,607,397 and 3,413,390. This method has certain disadvantages. The agent, after molding, adheres to the surface of the molded article thereby removing such from the surface of the mold. As the mold release agent is removed from the mold surface, it must therefore be replaced so as to provide continued release of the molded articles from the mold. The necessity for repeated additions of mold release agent results in higher costs due to low productivity as a result of the additional time incurred in applying such additional quantities of mold release agents to the mold surfaces.
In addition, mold build-up may become a problem, since a fine film of urethane is left in spot areas of the mold surface. This build-up on the surface of the mold cavity walls eventually covers and obscures any detail on the mold cavity surface desired to be imparted to the molded article. Also, the presence of the release agent adhering to the surface of the molded article can impede subsequent operations on the article, such as painting or adhering operations.
Additionally, the need to reapply the release agent after each molding or a limited number of moldings interrupts the molding operation and slows down output.
The use of internal mold release agents for use in molding polyurethane articles has been disclosed by Boden et al. in U.S. Pat. No. 3,726,952, Godlewski in U.S. Pat. No. 4,024,088, Bonin et al. in U.S. Pat. No. 4,098,731, Sparrow et al. in U.S. Pat. No. 4,130,698, Godlewski in U.S. Pat. No. 4,111,861, Kleimann et al. in U.S. Pat. No. 4,201,847 and Godlewski in U.S. Pat. No. 4,220,727.
Some of these internal mold release agents bleed or creep to the surface of the molded article. Some of these articles cannot be painted even after appropriate preparation steps for painting has been done. Others are incompatible with polyether polyols. Most of them seriously reduce the activity of the catalyst. Almost all show degradation of physical properties such as reduced elongation.
The use of the "salts" described in U.S. Pat. No. 3,726,952 have not been effective release agents for reaction injection molding (RIM). While showing release characteristics per se their use has demonstrated in a screening program wherein hand mixed formulations are cast into an open mold other serious problems, namely: (1) degradation of the tin catalyst employed in the formulation, (2) excessively long gel and cure time, and (3) poor physical properties. These problems are believed to be caused by the presence of free carboxylic acid. It is released from the salt by the reaction of the amine with the isocyanate, and it is believed that the presence of these free carboxylic acids, or any acid, interferes with the cure rate of the hydroxyl-isocyanate reaction to form a urethane structure as disclosed in J. Polymer Science, Polymer Chemistry Edition, Vol. 19, 381-388 (1981) John Wiley & Son, Inc.
The reactivity or catalyst kill problem can be overcome to a certain degree by using tertiary amines in place of primary or secondary amines. Both U.S. Pat. Nos. 3,726,952 and 4,098,731 describe this technique. Since isocyanates cannot react with tertiary amines the salt cannot be split; it thus remains neutral (the carboxylic acid is not free), hence, catalyst kill does not seem evident. The use of tertiary amines, however, often shows bleed out or exudation problems which in turn result in poor paint adhesion. Further, retention of physical properties is seldom possible because of either excess reactivity when using very catalytically active amines, or because of plasticizer effects brought about by excessively long tertiary amine molecules.
The technology of U.S. Pat. No. 4,111,861 states that polar metal compounds can be employed to overcome catalyst kill problems brought on by the presence of fatty carboxylic acids. It states that metal ions must be present in an amount sufficient to neutralize the acid. Reference is made to the use of the Bi, Pb, Na, Li, and K ion, with sodium carbonate, sodium oleate, and potassium laurate being exemplified. They also show sodium oleate alone to be an effective release agent. When evaluated in RIM polyol systems as a single additive, it failed to show adequate release characteristics in a screening program wherein hand mixed formulations were cast into an open mold.
Zinc stearate has long been known to be an effective release agent for most thermoplastics. It is also used in polyester sheet molding compounds. When evaluated in RIM polyol systems containing only hydroxyl groups as the active hydrogen-containing source, zinc stearate as a single additive failed to show adequate release characteristics in a screening program wherein hand mixed formulations were cast into an open mold. Zinc stearate was observed to dissolve in a mixture of oleoyl sarcosine and excess polyoxypropylene diamine of 400 MW and the resultant mixture performed as an effective mold release agent.
The present invention provides for an improvement in one or more of the following: (1) increased multiple release, (2) increased ease of release, (3) effective and very stable catalyst reactivity, and (4) minimally altered physical properties in molded parts.
SUMMARY OF THE INVENTION
One aspect of the present invention pertains to a process comprising reacting a polyisocyanate in a closed mold with an active hydrogen-containing composition comprising
(A) a material having an average of at least about 2 active hydrogen-containing groups per molecule and a weight from about 500 to about 5000 per active hydrogen-containing group, said composition having dissolved therein
(B) from about 0.5 to about 10 parts by weight per 100 parts by weight of component (A) of a metal salt of an organic material containing at least one carboxylic acid group and a siloxane chain wherein said metal is selected from Groups I-B, II-B, IV-B, V-B, VI-B, VII-B or VIII-B of the Periodic Table of the Elements;
said composition containing a sufficient quantity of at least one aliphatic primary and/or secondary amine-containing materials such that component (B) is soluble in said composition, wherein
said composition containing or being devoid of an organic material containing at least one carboxylic acid group, phosphorus-containing acid group or boron-containing acid group or mixture of such materials wherein said organic material contains a siloxane chain or contains at least one terminal or pendant saturated or unsaturated aliphatic hydrocarbon chain containing at least about 7 carbon atoms.
The aliphatic primary and/or secondary amine-containing materials can be component (A), and/or may be a separate component.
In another aspect, this invention is a process comprising reacting a polyisocyanate in a closed mold with an active hydrogen-containing composition comprising
(A) a material having an average of at least about 2 active hydrogen-containing groups per molecule and a weight per active hydrogen-containing group from about 500 to about 5000, said composition having dissolved therein
(B) from about 0.5 to about 10 parts by weight per 100 parts by weight component (A) of a metal salt of an organic material containing at least one carboxylic acid group and a siloxane chain wherein said metal is selected from Groups I-B, II-B, IV-B, V-B, VI-B, VII-B or VIII-B of the Periodic Table of the Elements;
said composition containing a sufficient quantity of at least one primary and/or secondary amine-containing material such that component (B) is soluble in said composition, wherein
said composition containing or being devoid of an organic material containing at least one carboxylic acid group, phosphorus-containing acid group or boron-containing acid group or mixture of such materials wherein said organic material contains a siloxane chain or contains at least one terminal or pendant saturated or unsaturated aliphatic hydrocarbon chain containing at least about 7 carbon atoms.
The primary and/or secondary amine-containing materials can be component (A), and/or may be a separate component.
The term polymer as employed herein means those polymers containing urethane and/or urea groups.
The term effective amount of an internal mold release as employed herein means that quantity which will permit a molded part prepared from reaction of the active hydrogen-containing composition with a composition containing a plurality of -NCO and/or -NCS groups to be easily removed from its mold.
The term total hydrogen equivalent weight as employed herein means the molecular weight divided by the total number of hydrogen atoms in the molecule which are connected to nitrogen, oxygen and sulfur atoms. The term "weight per active hydrogen-containing group" means the molecular weight of the molecule referred to divided by the number of groups containing isocyanate-reactive hydrogen atoms.
The term equivalent ratio as it pertains to the ratio of the acid salt or acid component and the amine component means the ratio of the number of ##STR1## equivalents contained in the acid salt or acid component to the number of amine nitrogen equivalents contained in the amine component. The amine nitrogen equivalents of a compound is equal to the number of primary or secondary nitrogen atoms per molecule of that compound.
By the term lipophilic as employed herein it is meant that the material contains at least one member of the group consisting of R-CH3 wherein R is a saturated or unsaturated aliphatic hydrocarbon group having at least 6 carbon atoms.
All references to "soluble" or "solubility" refer to solubility at a temperature of about 25° C.
Any reference herein to the Periodic Table of the Elements refers to that published by Sargent-Welch Scientific Company as catalog number S-18806, 1968.
DETAILED DESCRIPTION OF THE INVENTION
Suitable carboxylic acids which can be employed herein as a component in the internal mold release composition include any saturated or unsaturated aliphatic or cycloaliphatic carboxylic acid or aromatic carboxylic acid, preferably those carboxylic acids having from about 2 to about 30, preferably from about 2 to about 18, carbon atoms.
Also suitable as carboxylic acids are those represented by the formula ##STR2## wherein R is a hydrocarbyl group having from 1 to about 12 carbon atoms.
Particularly suitable carboxylic acids include, for example, oleic acid, lauric acid, palmitic acid, stearic acid, mixtures thereof and the like.
Suitable carboxylic acids include amido-containing carboxylic acids such as the reaction products of carboxylic acid halides containing from about 1 to about 30, preferably from about 2 to about 18, most preferably from about 5 to about 18, carbon atoms with an amino carboxylic acid having from about 2 to about 4, preferably from about 2 to about 3, carbon atoms per molecule.
Particularly suitable carboxylic acids include amido-containing carboxylic acids such as those represented by the general formula ##STR3## wherein R is a hydrocarbon or substituted hydrocarbon group having from 1 to about 29, preferably from about 2 to about 17, carbon atoms; R' is hydrogen, an alkyl or hydroxyl substituted alkyl group having from 1 to about 3 carbon atoms and R" is a divalent hydrocarbon group having from 1 to about 3, preferably 1, carbon atoms, such as, for example, oleoyl sarcosine, lauryl sarcosine, capryl sarcosine, oleoyl glycine, octanol glycine, oleoyl hydroxyethyl glycine, mixtures thereof and the like. These amido carboxylic acids can be prepared by the Schotten-Baumann acylation reaction wherein an acyl halide is reacted with an amino acid.
Suitable materials containing at least one carboxylic acid group and containing siloxane chains include those described by J. W. Keil in U.S. Pat. No. 4,076,695 which is incorporated herein by reference.
Suitable organic materials containing at least one phosphorus-containing acid group include, for example, monostearyl acid phosphate, cetyl dihydrogen phosphate, monolauryl phosphate, decyl dihydrogen phosphate, monobutyl monodecyl ester of phosphoric acid, mixtures thereof and the like.
Suitable organic materials containing at least one boron-containing acid group include, for example, dioctadecyl ester of boric acid, monododecyl mono(phenylmethyl) ester of boric acid, monododecyl monophenyl ester of boric acid, monoheptadecyl mono(phenylmethyl) ester of boric acid, monodecyl ester of boric acid, mixtures thereof and the like.
Suitable amines which can be employed herein as a component in the internal mold release composition include any aliphatic, cycloaliphatic, or aromatic compound containing at least one primary or secondary amine group with those compounds having at least two primary and/or secondary amine groups being especially preferred.
Suitable amine compounds include, for example, oleyl amine, coco amine, talloil amine, ethanolamine, diethyltriamine, ethylenediamine, propanolamine, aniline, mixtures thereof and the like.
Particularly suitable as the amine component in the internal mold release composition are these aliphatic amines enumerated later on as being low equivalent weight amine-containing active hydrogen-containing materials, and aromatic amines of relatively low molecular weight active hydrogen-containing materials also enumerated later on. Examples of such particularly suitable amines include the compounds of aminated polyoxyalkane glycols, hexamethylene diamine, diethylenetriamine, and hydrocarbyl substituted aromatic amines such as, for example, diethylenetoluenediamine.
Suitable carboxylic acid or amido carboxylic acid salts of metals which can be employed herein as a component in the internal mold release composition include those containing the metal ions from group II metals, lithium, copper, aluminum, iron, cobalt, and nickel. The organic portions of these compounds are suitably saturated or unsaturated having from about 2 to about 30, preferably from about 2 to about 21 carbon atoms. Particularly suitable metal salts of carboxylic acids or amido carboxylic acids include, for example, zinc stearate, zinc oleate, zinc palmitate, zinc laurate, calcium stearate, calcium oleate, calcium palmitate, calcium laurate, magnesium stearate, magnesium oleate, magnesium laurate, magnesium palmitate, nickel stearate, nickel oleate, nickel palmitate, nickel laurate, copper stearate, copper oleate, copper laurate, copper palmitate, zinc stearoyl sarcosinate, zinc oleoyl sarcosinate, zinc palmitoyl sarcosinate, zinc lauroyl sarcosinate, calcium stearoyl sarcosinate, calcium oleoyl sarcosinate, calcium palmitoyl sarcosinate, calcium lauroyl sarcosinate, magnesium stearoyl sarcosinate, magnesium oleoyl sarcosinate, magnesium palmitoyl sarcosinate, magnesium lauroyl sarcosinate, nickel stearoyl sarcosinate, nickel oleoyl sarcosinate, nickel palmitoyl sarcosinate, nickel lauroyl sarcosinate, copper stearoyl sarcosinate, copper oleoyl sarcosinate, copper palmitoyl sarcosinate, copper lauroyl sarcosinate or mixtures thereof and the like. Of particular interest are those represented by the formula: ##STR4## wherein M represents the metal, R represents an organic group containing a terminal or pendant saturated or unsaturated aliphatic hydrocarbon chain containing at least about 7 carbon atoms, and n is equal to the valance of the metal.
Suitable carboxylic acid salts containing siloxane chains herein include the Group II, aluminum, lithium, copper, iron, cobalt or nickel salts of the acids described in the aforementioned U.S. Pat. No. 4,076,695.
The partially or totally reacted, complexed or associated acid or amido acids with the metals of Group II of the Periodic Table of the elements, aluminum, lithium, copper, iron, cobalt or nickel can be prepared by reacting such acids or amido acids with the appropriate quantity of a compound containing the metal such as a hydroxide or if the metal is above hydrogen in the electromotive series, it can be reacted directly with the acid or acid amide.
Also, mixtures of the acids and metal salts of the acids which are available commercially can be employed when partially reacted, complexed or associated materials are desired. Likewise commercially available metal salts of the acids or amido acids can be employed when the totally reacted, complexed or associated materials are desired.
The metal salt advantageously is present in an amount from about 0.1, preferably about 0.25, more preferably about 0.5 and most preferably about 1.0 part by weight, up to about 20, preferably up to about 10, more preferably up to about 6, most preferably up to about 4 parts by weight per 100 parts of the material referred to as component (A) in the claims.
For purposes of the present invention, the total hydrogen equivalent weight is determined by dividing the molecular weight by all of the hydrogen atoms contained in any material derived from --OH, --NH and NH and --SH groups, regardless of whether or not the group reacts with an NCO or NCS group when preparing molded articles.
In some instances the quality of the metal salt of a carboxylic acid or metal salt of an amido-containing carboxylic acid may affect the performance of the internal mold release composition. This is believed to be particularly true with the use of zinc stearate in urethane reaction injection molding systems.
Suitable materials which can be employed herein as relatively high equivalent weight hydroxyl-, primary amine- or secondary amine-containing materials include, for example, those hydroxyl and/or amine materials having an average hydrogen functionality of from 2 to about 8, preferably from 2 to 4 and a weight of from about 500 to about 5000, preferably from about 1000 to about 3000, per active hydrogen-containing group.
Suitable relatively high equivalent weight hydroxyl-containing polyols which can be employed herein include, for example, those polyether and polyester polyols which have an average hydroxyl functionality of from about 2 to about 8, preferably from about 2 to about 4 and most preferably from about 2 to about 3 and an average hydroxyl equivalent weight of from about 500 to about 5000, preferably from about 1000 to about 3000 and most preferably from about 1500 to about 2500, including mixtures thereof.
Suitable relatively high equivalent weight polyether polyols which can be employed herein include those which are prepared by reacting an alkylene oxide, halogen substituted or aromatic substituted alkylene oxides or mixtures thereof with an active hydrogen-containing initiator compound.
Suitable such oxides include, for example, tetrahydrofuran, ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, epichlorohydrin, epibromohydrin, mixtures thereof and the like.
Suitable initiator compounds include water, ethylene glycol, propylene glycol, butanediol, hexanediol, glycerine, trimethylol propane, pentaerythritol, hexanetriol, sorbitol, sucrose, hydroquinone, resorcinol, catechol, bisphenols, novolac resins, phosphoric acid, mixtures thereof and the like.
Also suitable as initiators for the relatively high equivalent weight polyols include, for example, ammonia, ethylenediamine, diaminopropanes, diaminobutanes, diaminopentanes, diaminohexanes, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, ethanolamine, aminoethylethanolamine, aniline, 2,4-toluenediamine, 2,6-toluenediamine, diaminodiphenyloxide (oxydianiline), 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 1,3-phenylenediamine, 1,4-phenylenediamine, naphthylene-1,5-diamine, -diamine, triphenylmethane-4,4',4"-triamine, 4,4'-di(methylamino)-diphenylmethane, 1-methyl-2-methylamino-4-aminobenzene, 1,3-diethyl-2,4-diaminobenzene, 2,4-diaminomesitylene, 1-methyl-3,5-diethyl-2,4-di-aminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,5,3',5'-tetraethyl-4,4'-diaminodiphenylmethane and amine aldehyde condensation products such as the polyphenylpolymethylene polyamines produced from aniline and formaldehyde, mixtures thereof and the like.
Suitable polyester polyols which may be employed herein include, for example, those prepared by reacting a polycarboxylic acid or anhydride thereof with a polyhydric alcohol. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and/or heterocyclic and may be substituted (e.g., with halogen atom) and/or unsaturated. Examples of carboxylic acids of this kind include succinic acid; adipic acid; suberic acid; azelaic acid; sebacic acid; phthalic acid; isophthalic acid; trimellitic acid; phthalic acid anhydride; tetrahydrophthalic acid anhydride; hexahydrophthalic acid anhydride; tetrachlorophthalic acid anhydride; endomethylene tetrahydrophthalic acid anhydride; glutaric acid anhydride; maleic acid; maleic acid anhydride; fumaric acid; dimeric and trimeric fatty acids; such as oleic acid, which may be in admixture with monomeric fatty acids, terephthalic acid dimethyl ester; terephthalic acid bisglycol ester and the like. Mixtures of such acids or anhydrides may also be employed.
Examples of suitable polyhydric alcohols include ethylene glycol, 1,2-propylene glycol; 1,3-propylene glycol; 1,4-, 1,2- and 2,3-butylene glycol; 1,6-hexane diol; 1,8-octane diol; neopentyl glycol; cyclohexane dimethanol (1,4-bis-hydroxymethyl cyclohexane) 2-methyl-1,3-propane diol; glycerol; trimethylol propane; 1,2,6-hexane triol; 1,2,4-butane triol; trimethylol ethane; pentaerythritol; quinitol; mannitol; sorbitol; methyl glycoside; diethylene glycol; triethylene glycol; tetraethylene glycol; polyethylene glycol; dipropylene glycol; polypropylene glycols; dibutylene glycol; polybutylene glycols and the like. The polyesters may contain some terminal carboxyl groups. It is also possible to use polyesters of lactones such as caprolactone, or hydroxy carboxylic acids such as hydroxy caproic acid.
Other suitable relatively high equivalent weight polyols which can be employed herein include polymer-containing polyols such as, for example, those disclosed in U.S. Pat. RE Nos. 29,118 (Stamberger), 28,715 (Stamberger), 29,014 (Pizzini et al.) and 3,869,413 (Blankenship et al.), Hoffman in U.S. Pat. No. 4,394,491 and Hoffman et al. in U.S. Pat. No. 4,390,645 all of which are incorporated herein by reference.
Also suitable as the relatively high equivalent weight polyols are the thiol derivatives of the aforementioned polyols such that all or a portion of the hydroxyl or amine groups are replaced with --SH groups.
Suitable materials which can be employed herein as relatively low equivalent weight active hydrogen-containing materials include one or more of any such materials containing either hydroxyl groups, primary amine groups, secondary amine groups or mixtures of such groups; such materials having an average active hydrogen functionality of from about 2 to about 16, preferably from about 2 to about 8 and an average active hydrogen equivalent weight of from about 15 to about 500, preferably from about 32 to about 200 and when the active hydrogen atoms are derived only from OH groups then the maximum equivalent weight is about 200.
Also suitable relatively high equivalent weight active hydrogen-containing materials are the products resulting from aminating the polyether and polyester polyols described above.
Suitable relatively low equivalent weight polyols which can be employed herein include, for example, ethylene glycol, propylene glycol, trimethylol propane, 1,4-butane diol, diethylene glycol, dipropylene glycol, bisphenols, hydroquinone, catechol, resorcinol, triethylene glycol, tetraethylene glycol, dicyclopentadienediethanol, glycerine, low molecular weight ethylene and/or propylene oxide derivatives of glycerine, ethylenediamine, diethylenetriamine, mixtures thereof and the like.
Suitable relatively low equivalent weight amine-containing active hydrogen-containing materials which can be employed herein include, for example, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, isophoronediamine, diethylenetriamine, ethanolamine, aminoethylethanolamine, diaminocyclohexane, hexamethylenediamine, methyliminobispropylamine, iminobispropylamine, bis(aminopropyl)piperazine, aminoethyl piperazine, 1,2-diaminocyclohexane, polyoxyalkyleneamines, bis-(p-aminocyclohexyl)methane, triethylenetetramine, tetraethylenepentamine, mixtures thereof and the like.
Also suitable relatively low equivalent weight active hydrogen-containing materials are the aminated polyoxyalkylene glycols having an average amino hydrogen equivalent weight of from about 60 to about 110.
Suitable also as the relatively low equivalent weight active hydrogen-containing materials are the thiol derivatives of the aforementioned materials wherein at least one of the hydroxyl or amine groups has been replaced with an --SH group.
The term aliphatic amine as employed herein includes also the cycloaliphatic amines and heterocyclic aliphatic amines so long as they contain at least one primary or secondary amine group.
Suitable aromatic amines which can be employed herein as a relatively low molecular weight active hydrogen-containing material include, for example, 2,4-bis(p-aminobenzyl)aniline, 2,4-diaminotoluene, 2,6-diaminotoluene, 1,3-phenylenediamine, 1,4-phenylenediamine, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, naphthalene-1,5-diamine, triphenylmethane-4,4',4"-triamine, 4,4'-di(methylamino)diphenylmethane, 1-methyl-2-methylamino-4-aminobenzene, polyphenylpolymethylene polyamines, 1,3-diethyl-2,4-diaminobenzene, 2,4-diaminomesitylene, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,5,3',5'-tetraethyl-4,4'-diaminodiphenylmethane, 4,4'-methylene-bis(2,6-diisopropylaniline), mixtures thereof and the like.
Suitable polyisocyanates include the organic aromatic polyisocyanates, aliphatic polyisocyanates or mixtures thereof.
Suitable organic aromatic polyisocyanates which can be employed herein include, for example, any such polyisocyanate having 2 or more NCO groups per molecule such as, for example, 2,4-toluenediisocyanate, 2,6-toluenediisocyanate, p,p'-diphenylmethanediisocyanate, p-phenylenediisocyanate, naphthalenediisocyanate, polymethylene polyphenylisocyanates, mixtures thereof and the like.
Also suitable as organic aromatic and/or aliphatic polyisocyanates are the prepolymers prepared from such polyisocyanates and compounds having 2 or more active hydrogen atoms; as well as such polyisocyanates and/or prepolymers thereof which have been modified to contain uretonimine or carbodiimide linkages.
Suitable organic aliphatic polyisocyanates include, in addition to the hydrogenated derivatives of the above-mentioned organic aromatic polyisocyanates, 1,6-hexamethylenediisocyanate, isophoronediisocyanate, 1,4-cyclohexyldiisocyanate, 1,4-bis-isocyanatomethylcyclohexane, mixtures thereof and the like.
Also suitable are the corresponding polyisothiocyanates.
Preferably, the cross-linker or chain extender component employed herein is a combination comprising
(1) at least one member selected from the group consisting of
(a) hydroxyl-containing materials which are essentially free of aliphatic amine hydrogen atoms, have an average OH functionality of from about 2 to 4 and have an average OH equivalent weight of from about 30 to about 120 and
(b) aromatic amine-containing materials which are essentially free of aliphatic amine hydrogen atoms and which contain at least two aromatic amine hydrogen atoms; and
(2) at least one aliphatic amine-containing material having at least one primary amine group, an average aliphatic amine hydrogen functionality of from about 2 to about 16 and an average aliphatic amine hydrogen equivalent weight of from about 15 to about 500.
Most preferably, the cross-linker or chain extender component is a combination comprising components (1-b) and (2) such as, for example, a combination of an aminated polyoxypropylene glycol having an average molecular weight of about 400 and diethyltoluenediamine.
The polymers can be prepared either in the presence or absence of a catalyst. Those polymers prepared from amine-containing polyols do not usually require a catalyst although catalysts can be employed if desired. On the other hand, those polymers prepared from polyols which do not contain nitrogen atoms are prepared in the presence of a catalyst.
Suitable catalysts which may be employed herein include, for example, organo-metal compounds, tertiary amines, alkali metal alkoxides, mixtures thereof and the like.
Suitable organo-metal catalysts include, for example, organo-metal compounds of tin, zinc, lead, mercury, cadmium, bismuth, antimony, iron, manganese, cobalt, copper, vanadium and the like such as, for example, metal salts of a carboxylic acid having from about 2 to about 20 carbon atoms including, for example, stannous octoate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin diacetate, ferric acetyl acetonate, lead octoate, lead oleate, phenylmercuric propionate, lead naphthenate, manganese naphthenate, copper naphthenate, vanadyl naphthenate, cobalt octoate, cobalt acetate, copper oleate, vanadium pentoxide, mixtures thereof and the like.
Suitable amine catalysts include, for example, triethylenediamine, triethylamine, tetramethylbutanediamine, N,N-dimethylethanolamine, N-ethylmorpholine, bis-(2-dimethylaminoethyl)ether, N-methylmorpholine, N-ethylpiperidine, 1,3-bis-(dimethylamino)-2-propanol, N,N,N',N'-tetramethylethylenediamine, mixtures thereof and the like.
Suitable alkali metal alkoxides which can be employed as catalysts for urethane formation include, for example, sodium ethoxide, potassium ethoxide, sodium propoxide, potassium propoxide, sodium butoxide, potassium butoxide, lithium ethoxide, lithium propoxide, lithium butoxide, alkali metal salts of polyols such as described in U.S. Pat. No. 3,728,308, mixtures thereof and the like.
Preferably, these urethane catalysts are in liquid form, but if they are inherently a solid at the application temperature, then they may be dissolved in an appropriate liquid, such as, for example, dipropylene glycol or they may be dissolved or dispersed in one of the components.
The catalysts, when employed, can be employed in quantities of from about 0.001 to about 5, preferably from about 0.01 to about 1 part per 100 parts of total polyol employed depending upon the activity of the catalyst. Very weak catalysts could possibly be employed in quantities above 5 parts per 100 parts of polyol.
If desired, the polyurethanes can be modified so as to contain isocyanurate or thioisocyanurate groups by employing relatively high NCO or NCS to active hydrogen ratios, e.g., greater than about 1.5:1, preferably greater than about 2:1, and employing a trimerization catalyst. Suitable trimerization catalysts which can be employed herein include, for example, the zwitterions disclosed by Kresta and Shen in U.S. Pat. No. 4,111,914 and the tertiary amines, alkali metal salts of lower alkanoic acids, mixtures thereof and the like as disclosed in U.S. Pat. No. 4,126,741 (Carleton et al.) all of which are incorporated herein by reference.
The zwitterions can also function as a catalyst for urethane formation, i.e., the NCX-OH reaction.
If desired, the densities of the polymers produced herein can be reduced by incorporating a blowing agent into the formulation. Suitable such blowing agents are fully described in U.S. Pat. No. 4,125,487 and in U.S. Pat. No. 3,753,933 and so much of these patents as pertain to blowing agents is incorporated herein by reference. Particularly suitable blowing agents include the low boiling halogenated hydrocarbons such as methylene chloride and trichloromonofluoromethane.
Another suitable method for reducing the density is by frothing by injecting an inert gas into the mixture of urethane or other polymer-forming components. Suitable such inert gases include, for example, nitrogen, oxygen, carbon dioxide, xenon, helium, mixtures thereof such as air and the like.
If desired, cell control agents can be employed, particularly when preparing foams or microcellular products of reduced density and/or to assist in paintability of the polyurethane. Suitable cell control agents which can be employed herein include silicone oils such as, for example, DC-193, DC-195, DC-197 and DC-198 commercially available from Dow Corning Corp.; SF-1034, PFA-1635, PFA-1700 and PFA-1660 commercially available from General Electric Co.; L-520, L-5320 and L-5340 commercially available from Union Carbide Corp.; and B-1048 commercially available from PH. Goldschmidt, AG., mixtures thereof and the like.
The polyurethanes and other polymeric products may additionally contain, if desired, coloring agents, fire-retardant agents, fillers, modifiers and the like.
Suitable liquid and solid modifiers include those disclosed and described in U.S. Pat. Nos. 4,000,105 and 4,154,716 and so much thereof as pertains to suitable modifier substances are incorporated herein by reference. However, any such modifier described therein which fulfills the definition of any of the other components as described in this application are not considered as modifiers but rather as one of the components of the present invention.
Particularly suitable as the modifier or filler substances are fiberglass reinforcement fibers, particularly those having lengths of from about 1/16 inch (0.16 cm) to about 1/2 inch (1.27 cm) and milled glass fibers having a maximum length of 1/16 inch (0.16 cm), 1/8 inch (0.32 cm) and 1/4 inch (0.64 cm) and the like. Other particularly suitable fillers are mica, wollastonite, and the like.
The components which react to form the polymeric products can be shaped or formed into useful articles by injecting the reactive mixture into molds which are capable of withstanding the exotherm of the polymerizing mass and are non-reactive with and are insoluble when in contact with the liquid reactive mixture. Particularly suitable molds are those made of metal such as aluminum, copper, brass, steel and the like. In some instances non-metal molds can be employed such as those made of, for example, polyethylene, polypropylene, polyethylene terephthalate, silicone elastomers and the like.
Particularly suitable injection methods for RIM applications include those disclosed in a paper entitled "THE BAYFLEX 110 SERIES--THE NEW GENERATION OF RIM MATERIAL", by W. A. Ludwico and R. P. Taylor presented at the SOCIETY OF AUTOMOTIVE ENGINEERS PASSENGER CAR MEETING, Detroit, Mich., Sep. 26-30, 1977; a paper entitled "THE PROPERTIES OF HIGH MODULUS RIM URETHANES", by R. M. Gerkin and F. E. Critchfield presented at the above meeting; British Patent No. 1,534,258 titled "PROCESS FOR THE PRODUCTION OF ELASTOMERIC POLYURETHANE-POLYUREA MOULDED PRODUCTS HAVING A COMPACT SURFACE SKIN" and a book by F. Melvin Sweeney entitled INTRODUCTION TO REACTION INJECTION MOLDING, Technomics, Inc., 1979.
When injecting a relatively rapid-setting blend into massive metal molds, it may be necessary in order for the molded article to have good surface characteristics to preheat the molds to an appropriate temperature so that the mold will not abstract the heat of polymerization from the reactive mass and inappropriately delay the solidification time expected of a given formulation. On the other hand, thin wall metal molds could exhibit a minimal "heat sink" effect on relatively large cross section castings and thus, these thin wall metal molds may not require preheating.
The following examples are illustrative of the present invention and are not to be construed as to limiting the scope thereof in any manner.
Following is a list of materials employed in the examples and comparative experiments.
For purposes of simplicity, all of the active hydrogen-containing material employed herein are referred to as polyols regardless of whether the active hydrogen is a hydroxyl group or an amine group.
Polyol A is the reaction product of glycerine and propylene oxide at a molar ratio of about 1 to 6 respectively and having an equivalent weight of about 150.
Polyol B is the reaction product of Polyol A with propylene oxide and subsequently end-capped with ethylene oxide. The amount of ethylene oxide is about 18 percent by weight of the total weight of the polyol. The hydroxyl equivalent weight is about 1635. About 75 percent of the hydroxyl groups are primary hydroxyl groups.
Polyol C is ethylene glycol having an active hydrogen equivalent weight of about 31.
Polyetheramine A is an aminated polyoxypropylene glycol represented by the formula ##STR5## wherein x has a value of about 5.6. This product has an average amine hydrogen equivalent weight of about 100 and is commercially available from Texaco Chemical Co. as JEFFAMINE D-400.
Polyetheramine B is an aminated polyoxypropylene glycol represented by the formula ##STR6## wherein x has a value of about 33.1. This product has an average amine hydrogen equivalent weight of about 500 and is commercially available from Texaco Chemical Company as JEFFAMINE D-2000.
Polyetheramine C is a 5000 molecular weight polyoxypropylene triol which had been aminated to an extent of about 80 percent which is commercially available from Texaco Chemical Co as JEFFAMINE T-5000.
Diamine A is an aromatic diamine consisting principally of diethyl toluene diamine. The material has an active hydrogen equivalent weight of about 89 and is commercially available from Ethyl Corporation.
Catalyst A is an organo-metal catalyst commercially available from Witco Chemical Company as UL-28.
Catalyst B is a 33 percent solution of triethylenediamine in dipropylene glycol commercially available from Air Products Company as DABCO 33LV.
Polyisocyanate A is a liquid, modified diphenylmethanediisocyanate containing carbodiimide linkages commercially available from Rubicon Chemicals, Inc. as RUBINATE LF-168 or Upjohn Chemical Co. as ISONATE 143L. The average NCO equivalent weight is about 143.
Polyisocyanate B is a liquid prepolymer prepared from reacting an excess of methylenediphenyl diisocyanate with tripropylene glycol commercially available from Rubicon Chemicals, Inc. as RUBINATE LF 179. This polyisocyanate has an NCO equivalent weight of about 182.
The following examples are illustrative of the present invention, but are not to be construed as to limiting the scope thereof in any manner.
GENERAL PROCEDURE FOR EXAMPLES 1-4
The reactive mixtures of each formulation were hand mixed with a very low amount of catalyst, 0.05 parts (UL-28, Witco Chemical Co.), in order to extend reactivity time and also to better separate reactivity differences between the various samples tested. These mixtures were then hand cast into a 4 in.×12 in.×1/2 in. (10.16 cm×30.48 cm×1.27 cm) container made from aluminum foil. After casting, the samples were cured for 60 seconds in an oven at 150° F. (65.5° C.). Upon removal from the oven attempts were made to pull the aluminum foil from the casting by peeling a 3-in. (7.62-cm) wide strip which was made by scoring with razor blades in the long direction of the molded parts. Ease of release was then judged and ranked according to the following scale:
______________________________________
8-10 Excellent release:
equates to a pull
force of about 0.01 to
about 0.33 pounds/in.
(1.75 to 57.79 N/m)
6-7 Marginal release:
equates to a pull
force of about 0.34 to
about 1.00 pounds/in.
(59.54 to 175.13 N/m)
1-5 Unacceptable release:
equates to pull force
of about between >1.00
and about 10.00
pounds/in. (>175.13 to
1751.27 N/m)
0 Sticks: release equals to
about 13.00 to 20.00
pounds/in. (2276.65 to
3502.54 N/m)
______________________________________
Several original sample pulls were measured on an Instron machine and adjacent strips were pulled by hand. Once a feel for the ease of peel was established, the Instron comparison pulls were dropped and a subjective rating was given.
Reactivity was measured and identified by two separate points: (1) cream time and (2) cure time. Cream time is observed as the time at which the mixture of B side plus A side goes from liquid to cream, and cure time is observed as the time when the casting becomes tack free.
EXAMPLE 1
Following the general procedure, various polyurethane-forming compositions were prepared and molded. The components and results are provided in Table I.
TABLE I
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
A* B* C* D* E* F* G* H
__________________________________________________________________________
POLYOL B, pbw.sup.1
100
100
100 100 100
100
92.5
92.5
ahe.sup.2 0.061
0.061
0.061
0.061
0.061
0.061
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
0 0 0 0 0 0 7.5
7.5
ahe.sup.2 0 0 0 0 0 0 0.075
0.075
POLYOL C, pbw.sup.1
18 18 18 18 18 18 18 18
ahe.sup.2 0.58
0.58
0.58
0.58
0.58
0.58
0.58
0.58
OLEOYL SARCOSINE, pbw.sup.1
4 3 2 1 -- -- 4 3
equiv..sup.3 0.011
0.008
0.0057
0.0028
-- -- 0.011
0.008
OLEIC ACID, pbw.sup.1
-- -- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- -- --
LAUROYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- -- --
LAURIC ACID, pbw.sup.1
-- -- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- -- --
ZINC STEARATE, pbw.sup.1
-- 1 2 3 4 -- -- 1
POLYISOCYANATE A, pbw.sup.1
91.7
91.7
91.7
91.7
91.7
91.7
96.4
96.4
equiv..sup.3 0.641
0.641
0.641
0.641
0.641
0.641
0.674
0.674
REACTIVITY TIME, cream, sec.
70 65 42 28 15 17 55 20
cure, sec. 120
75 50 32 20 25 60 25
RELEASE VALUE 5 6 7 6 0 0 8 9
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
I J K L* M* N O P
__________________________________________________________________________
POLYOL B, pbw.sup.1
92.5
92.5
92.5
92.5
92.5
92.5
92.5
92.5
ahe.sup.2 0.057
0.057
0.057
0.057
0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5 7.5 7.5
7.5
7.5
7.5
7.5
7.5
ahe.sup.2 0.075
0.075
0.075
0.075
0.075
0.075
0.075
0.075
POLYOL C, pbw.sup.1
18 18 18 18 18 18 18 18
ahe.sup.2 0.58
0.58
0.58
0.58
0.58
0.58
0.58
0.58
OLEOYL SARCOSINE, pbw.sup. 1
2 1 -- -- -- -- -- --
equiv..sup.3 0.0057
0.0028
OLEIC ACID, pbw.sup.1
-- -- -- -- 4 3 2 --
equiv..sup.3 -- -- -- -- 0.014
0.011
0.007
--
LAUROYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- -- 3
equiv..sup.3 -- -- -- -- -- -- -- 0.011
LAURIC ACID, pbw.sup.1
-- -- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- -- --
ZINC STEARATE, pbw.sup.1
2 3 4 -- -- 1 2 1
POLYISOCYANATE A, pbw.sup.1
96.4
96.4
96.4
96.4
96.4
96.4
96.4
96.4
equiv..sup.3 0.674
0.674
0.674
0.674
0.674
0.674
0.674
0.674
REACTIVITY TIME, cream, sec.
12 9 15 12 57 25 20 21
cure, sec. 20 13 17 15 63 40 30 25
RELEASE VALUE 9 9 0 0 8 8 8 9
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
Q R S T* U* V* W*
__________________________________________________________________________
POLYOL B, pbw.sup.1 92.5
92.5
92.5
100
100
100
100
ahe.sup.2 0.057
0.057
0.057
0.061
0.061
0.061
0.061
POLYETHERAMINE A, pbw.sup.1
7.5
7.5
7.5
-- -- -- --
ahe.sup.2 0.075
0.075
0.075
-- -- -- --
POLYOL C, pbw.sup.1 18 18 18 18 18 18 18
ahe.sup.2 0.58
0.58
0.58
0.58
0.58
0.58
0.58
OLEOYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
OLEIC ACID, pbw.sup.1 -- -- -- 4 3 2 1
equiv..sup.3 -- -- -- 0.014
0.011
0.007
0.004
LAUROYL SARCOSINE, pbw.sup.1
2 -- -- -- -- -- --
equiv..sup.3 0.007
-- -- -- -- -- --
LAURIC ACID, pbw.sup.1
-- 3 2 -- -- -- --
equiv..sup.3 -- 0.015
0.01
-- -- -- --
ZINC STEARATE, pbw.sup.1
2 1 2 -- 1 2 3
POLYISOCYANATE A, pbw.sup.1
96.4
96.4
96.4
91.7
91.7
91.7
91.7
equiv..sup.3 0.674
0.674
0.674
0.641
0.641
0.641
0.641
REACTIVITY TIME, cream, sec.
12 21 19 60 40 30 17
cure, sec. 20 45 33 ∞
80 60 31
RELEASE VALUE 9 8 8 0 5 5 5
__________________________________________________________________________
EXAMPLE 2
The general procedure was employed using various components. The compositions and results are provided in Table II.
TABLE II
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
A B C D E F G
__________________________________________________________________________
POLYOL B, pbw.sup.1
92.5
92.5
92.5
92.5
92.5
92.5
92.5
ahe.sup.2 0.057
0.057
0.057
0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5 7.5 7.5 -- 7.5 7.5
7.5
ahe.sup.2 0.075
0.075
0.075
-- 0.075
0.075
0.075
POLYETHERAMINE B, pbw.sup.1
-- -- -- 37.5
-- -- --
ahe.sup.2 -- -- -- 0.075
-- -- --
POLYOL C, pbw.sup.1
18 18 30 30 30 30 30
ahe.sup.2 0.58
0.58
0.967
0.967
0.967
0.967
0.967
ZINC STEARATE, pbw.sup.1
2 -- 2 2 2 2 2
ZINC ACETATE, pbw.sup.1
-- 0.69
-- -- -- -- --
OLEOYL SARCOSINE, pbw.sup.1
2 2 2 2 -- -- --
equiv..sup.3 0.0057
0.0057
0.0057
0.0057
-- -- --
STEAROYL SARCOSINE, pbw.sup.1
-- -- -- -- 2 -- --
equiv..sup.3 -- -- -- -- 0.0057
-- --
LAUROYL SARCOSINE, pbw.sup.1
-- -- -- -- -- 2 --
equiv..sup.3 -- -- -- -- -- 0.007
--
OCTOYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- 2
equiv..sup.3 -- -- -- -- -- -- 0.01
HEXOYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
BEHENIC ACID, pbw.sup.1
-- -- -- -- -- -- --
ahe.sup.2 -- -- -- -- -- -- --
STEARIC ACID, pbw.sup.1
-- -- -- -- -- -- --
ahe.sup.2 -- -- -- -- -- -- --
OLEIC ACID, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
ISOSTEARIC ACID, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
BENZOIC ACID, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
ACETIC ACID, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
POLYISOCYANATE A, pbw.sup.1
96.4
96.4
152 149 152 152
152
equiv..sup.3 0.674
0.674
1.063
1.042
1.063
1.063
1.063
REACTIVITY TIME, cream, sec.
12 9 7 7 9 8 12
cure, sec. 20 12 12 11 14 13 17
RELEASE VALUE 9 8 9 8 9 8 9
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
H I J K L M N
__________________________________________________________________________
POLYOL B, pbw.sup.1
92.5
92.5
92.5
92.5
92.5
92.5
92.5
ahe.sup.2 0.057
0.057
0.057
0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5 7.5 7.5 7.5 7.5
7.5
7.5
ahe.sup.2 0.075
0.075
0.075
0.075
0.075
0.075
0.075
POLYETHERAMINE B, pbw.sup.1
-- -- -- -- -- -- --
ahe.sup.2 -- -- -- -- -- -- --
POLYOL C, pbw.sup.1
30 30 30 30 30 30 30
ahe.sup.2 0.967
0.967
0.967
0.967
0.967
0.967
0.967
ZINC STEARATE, pbw.sup.1
2 2 2 2 2 2 2
ZINC ACETATE, pbw.sup.1
-- -- -- -- -- -- --
OLEOYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
STEAROYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
LAUROYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
OCTOYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- --
equiv..sup.3 -- -- -- -- -- -- --
HEXOYL SARCOSINE, pbw.sup.1
2 -- -- -- -- -- --
equiv..sup.3 0.011
-- -- -- -- -- --
BEHENIC ACID, pbw.sup.1
-- 2 -- -- -- -- --
ahe.sup.2 -- 0.0059
-- -- -- -- --
STEARIC ACID, pbw.sup.1
-- -- 2 -- -- -- --
ahe.sup.2 -- -- 0.008
-- -- -- --
OLEIC ACID, pbw.sup.1
-- -- -- 2 -- -- --
equiv..sup.3 -- -- -- 0.008
-- -- --
ISOSTEARIC ACID, pbw.sup.1
-- -- -- -- 2 -- --
equiv..sup.3 -- -- -- -- 0.008
-- --
BENZOIC ACID, pbw.sup.1
-- -- -- -- -- 2 --
equiv..sup.3 -- -- -- -- -- 0.016
--
ACETIC ACID, pbw.sup.1
-- -- -- -- -- -- 0.33
equiv..sup.3 -- -- -- -- -- -- 0.0055
POLYISOCYANATE A, pbw.sup.1
152 152 152 152 152
152
152
equiv..sup.3 1.063
1.063
1.063
1.063
1.063
1.063
1.063
REACTIVITY TIME, cream, sec.
15 25 27 13 19 12 11
cure, sec. 20 35 40 21 24 22 15
RELEASE VALUE 7 6 6 8 6 6 6
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
O* P Q R
__________________________________________________________________________
POLYOL B, pbw.sup.1
100 92.5 92.5
92.5
ahe.sup.2 0.061
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
-- 7.5 7.5 7.5
ahe.sup.2 -- 0.075
0.075
0.075
POLYETHERAMINE B, pbw.sup.1
-- -- -- --
ahe.sup.2 -- -- -- --
POLYOL C, pbw.sup.1
30 30 30 30
ahe.sup.2 0.967
0.967
0.967
0.967
ZINC STEARATE, pbw.sup.1
2 2 2 2
ZINC ACETATE, pbw.sup.1
-- -- -- --
OLEOYL SARCOSINE, pbw.sup.1
2 -- -- --
equiv..sup.3 0.0057
-- -- --
STEAROYL SARCOSINE, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
LAUROYL SARCOSINE, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
OCTOYL SARCOSINE, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
HEXOYL SARCOSINE, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
BEHENIC ACID, pbw.sup.1
-- -- -- --
ahe.sup.2 -- -- -- --
STEARIC ACID, pbw.sup.1
-- -- -- --
ahe.sup.2 -- -- -- --
OLEIC ACID, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
ISOSTEARIC ACID, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
BENZOIC ACID, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
ACETIC ACID, pbw.sup.1
-- -- -- --
equiv..sup.3 -- -- -- --
TALLOIL SARCOSINE, pbw.sup.1
-- 2 -- --
equiv..sup.3 -- unknown
-- --
ISOOLEOYL SARCOSINE, pbw.sup.1
-- -- 2 --
equiv..sup.3 -- -- 0.0057
--
COCOYL GLYCINE, pbw.sup.1
-- -- -- 2
equiv..sup.3 -- -- -- unknown
POLYISOCYANATE A, pbw.sup.1
147 152 152 152
equiv..sup.3 1.028
1.063
1.063
1.063
REACTIVITY TIME, cream, sec.
20 9 7 16
cure, sec. 25 15 14 22
RELEASE VALUE 4 9 9 8
__________________________________________________________________________
EXAMPLE 3
The general procedure was employed using various components. The compositions and results are provided in Table III.
TABLE III
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
A B C D E F G
__________________________________________________________________________
POLYOL B, pbw.sup.1
92.5
92.5
92.5
92.5 92.5 92.5 92.5
ahe.sup.2 0.057
0.057
0.057
0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5 7.5 7.5 7.5 7.5 7.5 7.5
ahe.sup.2 0.075
0.075
0.075
0.075
0.075
0.075
0.075
POLYOL C, pbw.sup.1
30 30 30 30 30 30 30
ahe.sup.2 0.967
0.967
0.967
0.967
0.967
0.967
0.967
OLEOYL SARCOSINE, pbw.sup.1
2 2 2 2 2 2 2
equiv..sup.3 0.0057
0.0057
0.0057
0.0057
0.0057
0.0057
0.0057
METAL CARBOXYLATE, TYPE
ZnSt.sup.4
MgSt.sup.5
CaSt.sup.6
AlMSt.sup.7
AlDSt.sup.8
AlTSt.sup.9
LiSt.sup.10
pbw.sup.1 2 2 2 2 2 2 2
POLYISOCYANATE A, pbw.sup.1
152 152 152 152 152 152 152
equiv..sup.3 1.063
1.063
1.063
1.063
1.063
1.063
1.063
REACTIVITY TIME, cream, sec.
7 19 20 30 30 35 29
cure, sec. 12 24 24 36 34 45 34
RELEASE VALUE 9 9 8 5 3 9 9
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
H I J K L M N
__________________________________________________________________________
POLYOL B, pbw.sup.1
92.5
92.5
92.5 92.5
92.5 92.5
92.5
ahe.sup.2 0.057
0.057
0.057
0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5 7.5 7.5 7.5 7.5 7.5 7.5
ahe.sup.2 0.075
0.075
0.075
0.075
0.075
0.075
0.075
POLYOL C, pbw.sup.1
30 30 30 30 30 30 30
ahe.sup.2 0.967
0.967
0.967
0.967
0.967
0.967
0.967
OLEOYL SARCOSINE, pbw.sup.1
2 2 2 2 2 2 2
equiv..sup.3 0.0057
0.0057
0.0057
0.0057
0.0057
0.0057
0.0057
METAL CARBOXYLATE, TYPE
NaSt.sup.11
KSt.sup.12
CdSt.sup.13
NiSt.sup.21
FeSt.sup.22
BaSt.sup.23
CuSt.sup.24
pbw.sup.1 2 2 2 2 2 2 2
POLYISOCYANATE A, pbw.sup.1
152 152 152 152 152 152 152
equiv..sup.3 1.063
1.063
1.063
1.063
1.063
1.063
1.063
REACTIVITY TIME, cream, sec.
15 16 15 16 30 20 12
cure, sec. 18 20 18 25 45 30 18
RELEASE VALUE 9 7 5 9 9 9 9
__________________________________________________________________________
EXAMPLE 4
The general procedure was employed using various components. The components except the isocyanate were blended together and stored for various periods of time at 23° C. prior to mixing with the polyisocyanate and molding. The compositions and results are provided in the following Table IV.
TABLE IV
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
A* B* C* D E F* G* H*
__________________________________________________________________________
POLYOL B, pbw.sup.1
92.5
92.5
92.5
92.5
92.5
92.5
92.5
92.5
ahe.sup.2 0.057
0.057
0.057
0.057
0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5
7.5
7.5
7.5 7.5
7.5
7.5
7.5
ahe.sup.2 0.075
0.075
0.075
0.075
0.075
0.075
0.075
0.075
POLYOL C, pbw.sup.1
18 18 18 18 18 18 18 18
ahe.sup.2 0.58
0.58
0.58
0.58
0.58
0.58
0.58
0.58
OLEOYL SARCOSINE, pbw.sup.1
-- 2 -- 2 -- 4 -- --
equiv..sup.3 -- 0.005
-- 0.0057
-- 0.011
-- --
OLEIC ACID, pbw.sup.1
-- -- 2 -- 2 -- 4 --
equiv..sup.3 -- -- 0.008
-- 0.008
-- 0.014
--
ZINC STEARATE, pbw.sup.1
-- -- -- 2 2 -- -- 4
UL 28 CATLAYST, pbw.sup.1
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
POLYISOCYANATE A, pbw.sup.1
96.4
96.4
96.4
96.4
96.4
96.4
96.4
96.4
equiv..sup.3 0.067
0.067
0.067
0.067
0.067
0.067
0.067
0.067
0 Hours Storage
REACTIVITY TIME, cream, sec.
10 22 25 10 15 33 37 15
cure, sec. 15 30 35 15 25 47 49 17
RELEASE VALUE 0 2 4 9 9 5 7 0
24 Hours Storage
REACTIVITY TIME, cream, sec.
22 65 55 10 25 90 90 15
cure, sec. 30 90 90 15 45 120
120
20
RELEASE VALUE 0 0 2 9 9 0 0 0
72 Hours Storage
REACTIVITY TIME, cream, sec.
20 55 45 10 18 90 90 13
cure, sec. 30 90 90 15 45 ∞
120
20
RELEASE VALUE 0 2 2 9 9 0 0 0
312 Hours Storage
REACTIVITY TIME, cream, sec.
25 60 50 17 18 90 90 17
cure, sec. 30 90 90 25 45 ∞
∞
25
RELEASE VALUE 0 0 2 9 9 0 0 0
__________________________________________________________________________
EXAMPLE 5
This example employed a production model (Krauss Maffei PU 40) reaction injection molding machine. The composition and results are given in the following Table V. The mold was a Steel Plaque Tool, 22"×26"×1/8" (55.88 cm ×66.04 cm ×0.3175 cm). The conditions employed were as follows:
______________________________________
B-Side
Temperature 115° F.-120° C. (46.1° C.-48.8°
C.)
Injection Pressure
150 bars (150 kPa)
A-Side
Temperature 120° F. (48.8° C.)
Injection Pressure
150 bars (150 kPa)
Injection Rate ˜150 lb/min (1134 g/s)
Shot Time 1.5-2 secs
Mold Temperature
150° F.-170° F. (65.5° C.-76.6°
C.)
Demold Time 60 secs
Post Cure, Time/Temp
30 min/250° F. (1800 s/121.1° C.)
______________________________________
The components and results are provided in the following Table V.
TABLE V
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
A* B* C* D E* F* G H I
__________________________________________________________________________
POLYOL B, pbw.sup.1
92.5
92.5
92.5
92.5
92.5
92.5
92.5
92.5
92.5
ahe.sup.2 0.057
0.057
0.057
0.057
0.057
0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5
7.5
0 7.5
7.5
7.5
7.5
7.5
7.5
ahe.sup.2 0.075
0.075
0 0.075
0.075
0.075
0.075
0.075
0.075
POLYOL C, pbw.sup.1
18 18 18 18 18 18 18 18 18
ahe.sup.2 0.58
0.58
0.58
0.58
0.58
0.58
0.58
0.58
0.58
OLEOYL SARCOSINE, pbw.sup.1
-- -- -- -- -- -- 3 -- 2
equiv..sup.3 -- -- -- -- -- -- 0.008
-- 0.057
OLEIC ACID, pbw.sup.1
-- 4 3 -- 3 3.3
-- 3 --
equiv..sup.3 -- 0.014
0.011
-- 0.011
0.012
-- 0.011
--
DETA.sup.14, pbw.sup.1
-- -- 2 -- -- -- -- -- --
ahe.sup.2 -- -- 0.097
-- -- -- -- -- --
EDA.sup.15, pbw.sup.1
-- -- -- -- -- 0.7
-- -- --
ahe.sup.2 -- -- -- -- -- 0.047
-- -- --
DEA.sup.16, pbw.sup.1
-- -- -- -- 1.8
-- -- -- --
ahe.sup.2 -- -- -- -- 0.051
-- -- -- --
SODIUM OLEATE, pbw.sup.1
-- -- -- 1 -- -- -- -- --
ZINC STEARATE, pbw.sup.1
-- -- -- -- -- -- 1 1 2
UL 28 CATLAYST, pbw.sup.1
0.2
0.7
0.8
0.2
0.4
0.4
0.2
0.2
0.2
POLYISOCYANATE A, pbw.sup.1
99.3
99.3
99.3
99.3
99.3
99.3
99.3
99.3
99.3
equiv..sup.3 0.694
0.694
0.694
0.694
0.694
0.694
0.694
0.694
0.694
TENSILE STRENGTH, psi
3700
3800
3300
2600
3300
3900
3300
3200
3400
MPa 25.5
26.2
22.7
17.9
22.7
26.9
22.7
22.1
23.4
ELONGATION, % 240
155
165
105
180
195
220
260
240
NO. OF RELEASES.sup.18
2 18 22 22 18 2 23 23 30+
__________________________________________________________________________
EXAMPLE 6
This example employed a different RIM production machine (Cincinnati Milicron RIM-90) and an actual prototype part. The conditions employed were as follows:
______________________________________
B-Side
Temperature 95° F. (35° C.)
Injection Pressure
1800-2100 psi (12.4-14.5 MPa)
A-Side
Temperature 80° F. (26.7° C.)
Injection Pressure
1600-1900 psi (11-13.1 MPa)
Injection Rate 6.0-3.5 lb/sec (2.7-1.6 kg/s)
Shot Time 1.8-3.1 secs
Mold Temperature
130° F.-155° F. (54.4° C.-68.3°
C.)
Demold Time 30-60 secs
Post Cure, Time/Temp
60 min/250° F. (3600 s/121.1° C.)
______________________________________
The plaque mold was constructed of P-20 tool steel. The mold surface was cleaned using "Slide Mold Cleaner" (commercially available from Percy Harms Corp.). No subsequent treatment was made prior to molding.
The components and results are provided in the following Table VI.
TABLE VI
__________________________________________________________________________
EXPERIMENT LETTER.sup.20
COMPONENT AND RESULTS
A B C D*
__________________________________________________________________________
POLYOL B, pbw.sup.1 92.5
92.5 92.5
92.5
ahe.sup.2 0.057
0.057
0.057
0.057
POLYETHERAMINE A, pbw.sup.1
7.5 7.5 0 7.5
ahe.sup.2 0.075
0.075
0 0.075
DETDA.sup.17, pbw.sup.1
18 20 22 22
ahe.sup.2 0.404
0.449
0.494
0.494
OLEOYL SARCOSINE, pbw.sup.1
2 2 2 --
equiv..sup.3 0.0057
0.0057
0.0057
--
ZINC STEARATE, pbw.sup.1
2 2 2 --
POLYISOCYANATE B, pbw.sup.1
54.7
58.9 63.1
63.1
equiv..sup.3 0.303
0.326
0.350
0.350
NO. OF RELEASES.sup.18 (BARE METAL)
35+ 35+ 35+ 0
CONSECUTIVE.sup.19 (BARE METAL)
35+ 70+ 105+
--
TENSILE STRENGTH, psi
2800
2800 3100
--
MPa 19.3
19.3 21.4
--
ELONGATION, % 230 240 240 --
DIE C TEAR STRENGTH, pli
500 500 500 --
kg/m 8928.5
8928.5
8928.5
--
FLEXURAL MODULUS, psi
26000
30000
38000
--
MPa 179.1
106.7
261.8
--
__________________________________________________________________________
FOOTNOTES TO TABLES I-VI
.sup.1 pbw = parts by weight
.sup.2 ahe = active hydrogen equivalents (pbw ÷ molecular weight .div
number of hydrogen atoms attached to either an oxygen atom or a nitrogen
atom))
.sup.3 equiv. = equivalents
.sup.4 ZnSt = zinc stearate
.sup.5 MgSt = magnesium stearate
.sup.6 CaSt = calcium stearate
.sup.7 AlMSt = aluminum monostearate
.sup.8 AlDSt = aluminum distearate
.sup.9 AlTSt = aluminum tristearate
.sup.10 LiSt = lithium stearate
.sup.11 NaSt = sodium stearate
.sup.12 KSt = potassium stearate
.sup.13 CdSt = cadmium stearate
.sup.14 DETA = diethylenetriamine
.sup.15 EDA = ethylenediamine
.sup.16 DEA = diethanolamine
.sup.17 DETDA = diethylenetoluenediamine
.sup.18 NO. OF RELEASES = number of consecutive releases. The run for the
example was stopped after the indicated no. of parts were made with no
mold sticking being observed.
.sup.19 CONSECUTIVE = consecutive releases including previous experiments
which were tested. No mold sticking was observed.
.sup.20 The experiment letters containing an asterisk (*) are comparativ
experiments whereas those without an asterisk (*) are examples of the
present invention.
.sup.21 NiSt = nickel stearate
.sup.22 FeSt = ferrous stearate
.sup.23 BaSt = barium stearate
.sup.24 CuSt = cupric stearate
COMPARATIVE EXPERIMENT A
"B-Side" Formulation
93 parts by weight Polyol B
7 parts by weight Polyetherdiamine A
18 parts by weight Diamine A
PREPARATION
Polyol B (93 lb, 421,848 kg) was weighed into the polyol tank of an Admiral reaction injection molding machine, to it was then added 7 lb (3.28 kg) of Polyetheramine A and 18 lb (8.17 kg) of Diamine A. The tank was then closed and pressured (9 psi, 62 kPa) with dry nitrogen. The stirrer in the tank was turned on, then the low pressure pump, and then the high pressure pump. The fluid was allowed to circulate till a homogeneous solution was obtained, about 40 minutes (2400 s). The system was catalyzed by the addition of 0.1 percent by weight of the B side of each of the following catalysts, Catalyst A and Catalyst B.
The machine was calibrated to give an index of 105 with a "B-side"/"A-side" weight ratio of 1.87 using polyisocyanate B as the "A-side" component.
Sample plaques were prepared under the following conditions. The shot time was 2 seconds and the demold time was 60 seconds.
______________________________________
Polyol Isocyanate
(B side) (A side)
______________________________________
Injection pressure, psi
2000 2000
kPa 13790 13790
Component Temp. °F./°C.
100/37.8 100/37.8
Mold Temp. °F./°C.
150/65.6 150/65.6
______________________________________
The parts were shot into a chrome steel plaque mold which made a plaque 14"×12"×1/2 (35.56 cm×30.48 cm×0.3175 cm) and weight approximately 470 g.
MOLD PREPARATION
Before any parts were shot the mold was meticulously cleaned with a proprietary mold cleaner and all traces of previous polymer removed. The mold was then dried and polished. There was no further preparation of the mold.
RESULTS
Part 1. The plaque released from the mold with a slight pull.
Part 2. A strong pull was required to pull the plaque from the mold.
Part 3. The plaque stuck to the mold, and was removed with great difficulty. The plaque tore and parts were left adhering to the mold. This was quite unsatisfactory.
EXAMPLE 7
"B-side" Formulation
93 parts by weight Polyol B
7 parts by weight Polyetheramine A
18 parts by weight Diamine A
2.5 parts by weight zinc stearate
PREPARATION
Polyol B (63 lb, 28.58 kg) were weighed into a stainless steel, 25-gallon vessel equipped with heating and stirring. To it was added 7 lb (3.18 kg) Polyetheramine A and 2.5 lb (1.134 kg) of zinc stearate. The mixture was heated to about 85° C. with stirring for about 45 minutes (2700 s), after which time a slightly cloudy solution was obtained. The fluid was transferred to the polyol tank of an Admiral reaction injection molding machine, and the remainder of Polyol B, 30 lb (13.608 kg) was added along with 18 lb (8.17 kg) of Diamine A. The tank was closed, pressurized and recirculated as described in Comparative Experiment A. The system was then catalyzed as in Comparative Experiment A. The machine conditions and "B-side"/"A-side" ratio, index, and isocyanate were the same as in Comparative Experiment A as was the preparation of the mold.
RESULTS
Parts 1 through 16 were prepared and removed from the mold with no evidence of sticking or adhesion to the mold. The surface of the finished plaques was excellent. The trial was arbitrarily concluded at Part 16.
EXAMPLE 8
The formulation of Example 7 was changed by substituting 2.5 lb (1.134 kg) of zinc laurate for the 2.5 lb (1.134 kg) of zinc stearate. Method of preparation and all other conditions as in Example 1.
RESULTS
Parts 1 through 19 were prepared and removed from the mold with no evidence of sticking or adhesion. The trial was arbitrarily concluded at Part 19.
EXAMPLE 9
Using the method of preparation and machine condition as in Example 7, but using 0.5 lb (0.2268 kg) of zinc stearate.
RESULTS
Parts 1 through 15 were obtained without sticking or adhesion. The trial was arbitrarily concluded at Part 15.
EXAMPLE 10
Method of preparation and all other conditions as in Example 7 except that 6 lb (2.7216 kg) zinc stearate were added rather than 2.5 lb (1.134 kg) zinc stearate.
RESULTS
Parts 1 through 16 were produced without sticking or adhesion to the mold, arbitrarily concluded at Part 16.
COMPARATIVE EXPERIMENT B
"B-side" Formulation
93 parts by weight Polyol B
7 parts by weight Polyetheramine A
18 parts by weight ethylene glycol
PREPARATION
The system was prepared as in Comparative Experiment A, except that ethylene glycol (polyol C) was used in place of Diamine A.
Polyisocyanate A was employed as the "A-side" component at an index of 103. Catalysts as described in Comparative Experiment A were employed. Machine conditions as in Comparative Experiment A were employed. Mold preparation as in Comparative Experiment A were employed.
RESULTS
Part 1. Part released from mold.
Part 2. Massive adhesion, surface of part was ruined.
EXAMPLE 11
Formulation as in Comparative Experiment B with the addition of 2.5 lb (1.134 kg) zinc stearate.
Method of Preparation as in Example 7 except that Polyol C (ethylene glycol) was used instead of Diamine A.
Machine conditions and isocyanate used as in Comparative Experiment B. Mold preparation was as previously described.
RESULTS
Parts 1-12 were prepared with no sticking or adhesion to the mold. The testing was arbitrarily concluded after Part 12.
EXAMPLE 12
An experiment was conducted employing an Admiral 400-2HP RIM machine and a stainless steel plaque mold measuring 12 in.×14 in.×1/8 in. (30.48 cm×35.56 cm×0.3175 cm). The mold was not treated prior to use. The compositions and conditions were as follows:
Polyisocyanate (A-side)
Polyisocyanate B was employed in a quantity which provided an NCO Index of 103.
Polyol (B-side)
50 pbw Polyetheramine C
50 pbw mixture of 93 wt. percent Polyol B and 7 wt. percent Polyetheramine A
18 pbw Diamine A
0 or 2 pbw zinc stearate
0.05 wt. percent triethylenediamine catalyst (33 wt. percent solution in dipropylene glycol)
0.05 wt. percent dibutyl tin dilaurate (T-12 from M&T Chemical)
Conditions
A/B weight ratio--0.465/1
116° F./46.7° C.--temperature of reactants
2400 psig/16548 kPa--injection pressure
145° F./62.8° C.--mold temperature
60 seconds--demold time
RESULTS
Prior to the addition of the zinc stearate to the polyol (B-side), several plaques were made. These plaques required considerable effort to obtain release of the plaque from the mold. After addition of the zinc stearate to the polyol (B-side) formulation, 17 parts were made with no indication of sticking or polymer buildup before the polyol (B-side) ran low on material causing the experiment to be terminated. Some of these parts literally fell out of the mold upon opening of the mold.
EXAMPLE 13
An experiment was conducted employing an Admiral 400-2HP RIM machine and a stainless steel plaque mold measuring 12 in.×14 in.×1/8 in. (30.48 cm×35.56 cm×0.3175 cm). The mold was treated with external mold release on one side of the mold. After the seventh sample, the external mold release was stripped from that side so that the entire mold was bare steel.
The composition and conditions were as follows:
Polyisocyanate (A-side)
Polyisocyanate B was employed.
Polyol (B-side)
100 pbw Polyol B
25 pbw Diamine A
2 pbw zinc stearate
2 pbw oleoyl sarcosine
0.1 wt. percent catalyst A
0.1 wt. percent catalyst B
Conditions
A/B weight ratio was 0.5/1. Temperature of the reactants was 100° F. (37.8° C.). Temperature of the mold was 140° F. (60° C.). Injection pressure was 2000 psig (13790 kPa). Demold time was 60 seconds.
The formulation provided good release for 17 samples off one bare steel face and 10 releases off both bare steel faces.
We claim:
1. A process for molding a polymeric article with an internal mold release agent comprising reacting a polyisocyanate in a closed mold with an active hydrogen-containing composition comprising(A) a material having an average of at least about 2 active hydrogen-containing groups per molecule and a weight per active hydrogen-containing group from about 500 to about 5000, said composition having dissolved therein (B) from about 0.5 to about 10 parts by weight per 100 parts by weight component (A) of a metal salt of an organic material containing at least one carboxylic acid group and a siloxane chain, wherein said metal is selected from Groups I-B, II-B, IV-B, V-B, VI-B, VII-B or VIII of the Periodic Table of the Elements; said composition containing a sufficient quantity of at least one aliphatic primary and/or secondary amine-containing material such that component (B) is soluble in said composition, wherein said composition is devoid of an organic material containing at least one carboxylic acid group, phosphorus-containing acid group or boron-containing acid group or mixture of such materials wherein such organic material contains a siloxane chain or contains at least one terminal or pendant saturated or unsaturated aliphatic hydrocarbon chain containing at least about 7 carbon atoms.
2. The process of claim 1 which is a reaction injection molding process.
3. The process of claim 2 wherein the polyisocyanate comprises diphenylmethane diisocyanate, diphenylmethane diisocyanate containing carbodiimide linkages, polymethylenepolyphenylisocyanate, prepolymers or quasi-prepolymers prepared therefrom or a mixture thereof.
4. The process of claim 3 wherein component (A) comprises an amine-terminated polymer or copolymer of propylene oxide.
5. The process of claim 4 wherein the metal is zinc.
6. The process of claim 5 wherein said active hydrogen-containing composition comprises a relatively low equivalent weight material having a plurality of hydroxyl, primary amine or secondary amine groups or a mixture of such groups and an active hydrogen equivalent weight of from about 15 to about 500.
7. The process of claim 6 wherein said relatively low equivalent weight material comprises an aromatic amine.
8. A process for molding a polymeric article with an internal mold release agent comprising reacting a polyisocyanate in a closed mold with an active hydrogen-containing composition comprising(A) a material having an average of at least about 2 active hydrogen-containing groups per molecule and a weight per active hydrogen-containing group from about 500 to about 5000, said composition having dissolved therein (B) from about 0.5 to about 10 parts by weight per 100 parts by weight component (A) of a metal salt of an organic material containing at least one carboxylic acid group and a siloxane chain, wherein said metal is selected from Groups I-B, II-B, IV-B, V-B, VI-B, VII-B or VIII of the Periodic Table of the Elements; said composition containing a sufficient quantity of at least one primary and/or secondary amine-containing material such that component (B) is soluble in said composition, wherein said composition is devoid of an organic material containing at least one carboxylic acid group, phosphorus-containing acid group or boron-containing acid group or mixture of such materials wherein such organic material contains a siloxane chain or contains at least one terminal or pendant saturated or unsaturated aliphatic hydrocarbon chain containing at least about 7 carbon atoms.
9. The process of claim 8 which is a reaction injection molding process.
10. The process of claim 9 wherein component (A) is a polymer or copolymer of propylene oxide.
11. The process of claim 10 wherein said primary or secondary amine-containing material comprises an aromatic diamine.
12. The process of claim 11 wherein the metal is zinc.
13. The process of claim 12 wherein said polymer or copolymer of propylene oxide is hydroxyl-terminated.
14. A process for molding a polymeric article with an internal mold release agent comprising reacting a polyisocyanate in a closed mold with an active hydrogen-containing composition comprising(A) a material having an average of at least about 2 active hydrogen-containing groups per molecule and a weight from about 500 to about 5000 per active hydrogen-containing group, said composition having dissolved therein (B) from about 0.5 to about 10 parts by weight per 100 parts by weight of component (A) of a metal salt of an organic material containing at least one carboxylic acid group and a siloxane chain, wherein said metal is selected from Groups I-B, II-B, IV-B, V-B, VI-B, VII-B or VIII of the Periodic Table of the Elements; said composition containing a sufficient quantity of at least one aliphatic primary and/or secondary amine-containing material such that component (B) is soluble in said composition said composition further comprising (C) an organic material containing at least one carboxylic acid group, phosphorus-containing acid group or boron-containing acid group or mixture of such materials wherein such organic material contains a siloxane chain or contains at least one terminal or pendant saturated or unsaturated aliphatic hydrocarbon chain containing at least about 7 carbon atoms.
15. The process of claim 14 wherein component (A) comprises an amine-terminated polymer or copolymer of propylene oxide.
16. The process of claim 15 wherein the metal is zinc.
17. A process for molding a polymeric article with an internal mold release agent comprising reacting a polyisocyanate in a closed mold with an active hydrogen-containing composition comprising(A) a material having an average of at least about 2 active hydrogen-containing groups per molecule and a weight per active hydrogen-containing group from about 500 to about 5000, said composition having dissolved therein (B) from about 0.5 to about 10 parts by weight per 100 parts by weight of component (A) of a metal salt of an organic material containing at least one carboxylic acid group and a siloxane chain, wherein said metal is selected from Groups I-B, II-B, IV-B, V-B, VI-B, VII-B or VIII of the Periodic Table of the Elements; said composition containing a sufficient quantity of at least one primary and/or secondary amine-containing material such that component (B) is soluble in said composition and (C) an organic material containing at least one carboxylic acid group, phosphorus-containing acid group or boron-containing acid group or mixture of such materials wherein such organic material contains a siloxane chain or contains at least one terminal or pendant saturated or unsaturated aliphatic hydrocarbon chain containing at least about 7 carbon atoms.
18. The process of claim 17 wherein component (A) is a polymer or copolymer of propylene oxide.
19. The process of claim 18 wherein said primary or secondary amine-containing material comprises an aromatic diamine.
20. The process of claim 19 wherein the metal is zinc.
21. The process of claim 20 wherein said polymer or copolymer of propylene oxide is hydroxyl-terminated.
| 1991-01-30 | en | 1992-11-17 |
US-20213380-A | Filter bag and method for suppressing electrostatic charges
ABSTRACT
A fabric filter bag, a method of making such a bag, and apparatus using such bags, in which the bag is a tube of yarn knit into stitches defining a ground and stitches defining terry loop pile extending from the ground. In accordance with the present invention, such a fabric filter bag, method of making a bag, and apparatus using a bag is improved by the inclusion of a conductive strand for conducting electrostatic charges otherwise accumulating on the fabric filter bag away from the bag so as to suppress accumulation or build-up of such charges.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 37,286 filed May 9, 1979 now U.S. Pat. No. 4,284,507 issued Aug. 18, 1981 which is a continuation-in-part of application Ser. No. 904,485, filed May 10, 1978.
FIELD AND BACKGROUND OF INVENTION
Bag filter apparatus and fabric filter bags used in such apparatus have been employed for some time for separating particulate material from fluids. One generally known use for such bag filter apparatus and fabric filter bags is in the field of handling grain and grain products such as flour and meal. Fabrics have been manufactured for specific use as fabric filter bags in such fields, in order that separation of solid particulate material from air, gas and the like may be accomplished. Persons familiar with the field of filtration generally will be aware of other uses for such fabrics, filter bags and filter bag apparatus.
Particularly in certain applications for such apparatus, bags and fabrics, a significant risk is presented by the accumulation or build-up of electrostatic charges in the filtering process. Certain fluids and/or particulate substances to be removed from the fluids are or can become explosive. For example, wheat flour being separated from air streams can, under proper circumstances, become explosive. Further, friction involved in such filtration frequently gives rise to electrostatic charges which occur or appear on components of a filter apparatus. Where an explosive or potentially explosive material is being filtered in an apparatus and through the use of bags and fabrics which accumulate electrostatic charges, explosions are possible which are capable of doing severe damage to the apparatus involved and, in certain circumstances, killing persons employed in the area of the filter apparatus.
BRIEF DESCRIPTION OF INVENTION
Realizing the difficulties and deficiencies with prior filter apparatus, bags and fabrics, it is an object of the present invention to improve such structures by providing for suppressing accumulation or build-up of electrostatic charges. In realizing this object of the present invention, electrostatic charges are conducted from the fabric filter bags employed, so as to prevent or suppress accumulation or build-up of such charges. Inasmuch as such charges are suppressed or drained away, the potential of spark ignition of an explosive mixture is significantly reduced or is eliminated altogether.
Yet a further object of the present invention is to accomplish, in a method of making fabric filter bags, an improvement which facilitates safely discharging electrostatic charges otherwise possibly accumulating on fabric filter bags during filtration use. In realizing this object of the present invention, an electrically conductive strand is knitted with filamentary yarn used in forming a filter fabric. In accordance with certain features of this invention, such an electrically conductive strand takes the form of a synthetic monofilament yarn having electrically conductive characteristics, while in accordance with other aspects of this invention such an electrically conductive strand comprises a metallic staple yarn.
Yet a further object of the present invention is to provide, in a bag filter apparatus having a fabric bag which comprises a tube of circularly knitted, crimped, synthetic filamentary yarn knit into stitches defining a ground and stitches defining terry loop pile extending from the ground, a conductive strand formed with the stitches defining terry loop pile and functioning to conduct from the bag electrostatic charges otherwise possibly accumulating thereon.
BRIEF DESCRIPTION OF FIGURES
Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which
FIG. 1 is an elevation view of a fabric filter bag embodying the present invention;
FIG. 2 is an enlarged elevation view of a portion of the bag of FIG. 1, taken generally as indicated in that Figure;
FIG. 3 is a schematic representation of the knit stitch structure of the fabric of FIGS. 1 and 2, particularly showing an electrically conductive strand incorporated into the fabric and bag in accordance with the present invention;
FIG. 4 is a perspective view, from a ground fabric side, of the fabric of FIGS. 1 and 2;
FIG. 5 is a view similar to FIG. 4, from the pile face of the fabric of FIGS. 1 and 2; and
FIG. 6 is a perspective view, partly broken away, of a bag filter apparatus incorporating a filter in accordance with the present invention.
DETAILED DESCRIPTION OF INVENTION
While the present invention will be described hereinafter with particular reference to the accompanying drawings, it is to be understood at the outset that persons skilled in the applicable arts will be able to modify the present invention while accomplishing the favorable result to be described. Accordingly, the following description is to be understood, from the outset, as a broad teaching disclosure directed to persons skilled in the art, and not as being restrictive upon the scope of this invention.
Referring now more particularly to the accompanying drawings, a fabric filter bag is shown in FIG. 1 and is there generally indicated at 10. The fabric filter bag in accordance with the present invention, comprises a tube of yarn having a predetermined denier in the range of from about 70 to about 300 and knit into stitches defining a ground and stitches defining terry loop pile extending from the ground to a predetermined height. The stitches of the fabric forming the tube define predetermined open areas in the range of from about 1 micron to about 100 microns. The tube is then closed at one end to form a bag. The fabric filter bag is useful in apparatus (FIG. 6) having housing means 11 for enclosing and supporting the bag and circulating means including fan means 12 or the like and inlet and outlet means for directing a flow of fluid through the housing means and the bag so as to remove particulate material from the flowing fluid. Such structures are generally known to persons skilled in the arts to which the present invention pertains and specific details of such structures may be readily determined from known prior publications. Preferably, the tube is circularly knit of crimped, synthetic filamentary yarn. Specific ranges for the denier of the crimped synthetic filamentary yarn, the porosity of the filter material as determined by the stitch structure, and the height of the terry loops may be determined by persons skilled in the appropriate arts. For example, the fabric may be formed with filamentary yarn of one hundred denier knit into stitches defining terry loop pile extending approximately two millimeters from a ground and having a porosity such as to pass particles of fifty micron size or less.
In accordance with the present invention, such a fabric filter bag 10 and apparatus using such a bag is improved by a provision of means for conducting electrostatic charges from the fabric filter bag. More particularly, the fabric filter bag includes an electrically conductive strand, as indicated in FIGS. 1 and 2. Preferably, the electrically conductive strand 15 is knitted with the filamentary yarn forming a pile, as indicated generally in FIGS. 3 through 5. In the schematic representation of FIG. 3, the electrically conductive strand 15 is indicated by darker shading than is the case for the filamentary yarn. Similarly, in the fabric views of FIGS. 4 and 5, the conductive strand 15 is knitted with a filamentary yarn forming pile.
One operating embodiment in accordance with the present invention was constructed in accordance with a method in which an electrically conductive strand 15 was knitted with the filamentary yarn forming the fabric. In particular, the electrically conductive strand was fed to an eight feed knitting machine together with a crimped, synthetic filamentary yarn so as to form the strand and the yarn together into the stitches defining terry loop pile as shown in FIGS. 3 through 5. In one embodiment in accordance with this invention, a synthetic monofilament yarn having electrically conductive characteristics due to the inclusion of conductive materials in the yarn was employed as a conductive strand. The present invention additionally contemplates that the electrically conductive strand may comprise a metallic staple yarn, fed into the knitting machine with a synthetic filamentary yarn. Such a metallic staple yarn may be formed using relatively short lengths of metallic strands, and will perform the conductive function required in accordance with the present invention. The electrically conductive strand may also be formed by lamination with vacuum metalized foils.
Where the fabric filter bag 10 is manufactured as a seamless bag, using a circular knitting machine, the electrically conductive strand 15 is knitted into courses of the fabric so as to extend essentially continuously throughout the length of the bag and spiral about the circumference thereof. Thus, electrostatic charges otherwise accumulating at any point on the surface of the bag are conducted through the yarn to a portion of the bag gripped by mounting means which holds the bag in place during use in a filtering apparatus. Where the fabric is formed in a larger diameter which is then slit, opened and sewn into a bag, similar conductance of electrostatic charges to a ground point in the apparatus may be accomplished by seaming the bag with an electrically conductive strand of the same general type knitted into the fabric. In either instance, the risks associated with sparking from accumulated electrostatic charges are eliminated.
In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.
That which is claimed is:
1. In a method of making fabric filter bags which includes circularly knitting crimped, synthetic yarn having a denier in the range of from about 70 to about 300 into a tube of predetermined diameter and at least a predetermined length while forming the yarn into stitches defining a ground and stitches defining terry loop pile extending from the ground to a predetermined height, the stitches defining open areas in the range of from about 1 micron to about 100 microns, and then sewing the fabric into a bag, an improvement which facilitates safely discharging electrostatic charges otherwise accumulating on the fabric filter bags during filtration use, the improvement comprising the step of knitting with the filamentary yarn an electrically conductive strand.
2. A method according to claim 1 wherein the step of knitting an electrically conductive strand comprises feeding the electrically conductive strand with a yarn while forming the strand and the yarn into the stitches defining terry loop pile.
3. A method according to one of claims 1 and 2 wherein the electrically conductive strand comprises a synthetic monofilament strand having electrically conductive characteristics.
4. A method according to one of claims 1 and 2 wherein the electrically conductive strand comprises a metallic staple strand.
5. In a fabric filter bag comprising a tube of circularly knitted, crimped, synthetic yarn having a denier in the range of from about 70 to about 300 and knit into stitches defining a ground and stitches defining terry loop pile extending from the ground to a predetermined height, the stitches defining open areas in the range of from about 1 micron to about 100 microns, the tube being closed at one end, an improvement which facilitates safely discharging electrostatic charges otherwise accumulating on the fabric filter bag during filtration use, the improvement comprising an electrically conductive strand knitted with the yarn for conducting electrostatic charges from the fabric filter bag.
6. A fabric filter bag according to claim 5, wherein the electrically conductive strand is knitted with a yarn into the stitches defining terry loop pile.
7. A fabric filter bag according to one of claims 5 and 6 wherein the electrically conductive strand is a synthetic monofilament strand having electrically conductive characteristics.
8. A fabric filter bag according to one of claims 5 and 6 wherein the electrically conductive strand is a metallic staple strand.
9. In a bag filter apparatus having a fabric bag for filtering material from flowing fluid, housing means for enclosing and supporting said bag, and circulating means including inlet and outlet means for directing a flow of fluid through said housing means and said bag, the bag comprising a tube of circularly knitted, crimped, synthetic yarn having a denier in the range of from about 70 to about 300 and knit into stitches defining a ground and stitches defining terry loop pile extending from the ground to a predetermined height, the stitches defining open areas in the range of from about 1 micron to about 100 microns the tube being closed at one end, an improvement which facilitates safely discharging electrostatic charges otherwise accumulating on the fabric filter bag during filtration use, the improvement comprising an electrically conductive strand knitted with the yarn for conducting from the bag electrostatic charges otherwise accumulating thereon.
10. An apparatus according to claim 9 wherein the electrically conductive strand is knitted with a yarn into the stitches defining terry loop pile.
11. An apparatus according to one of claims 9 and 10 wherein the electrically conductive strand is a synthetic monofilament strand having electrically conductive characteristics.
12. An apparatus according to one of claims 9 and 10 wherein the electrically conductive strand is a metallic staple strand.
| 1980-10-30 | en | 1982-03-30 |
US-3624800D-A | Fluid flow control means
ABSTRACT
A device for controlling the flow of fluids which includes tubing having an axial preflattened section, a clamp and means for orienting the tubing relative to the clamp.
United States Patent Edwin Grant Swick Bartlett, Ill.
Sept. 29, 1969 Nov. 30, 197 1 Illinois Tool Works Inc. Chicago, Ill.
Inventor App]. N 0. Filed Patented Assignee FLUID FLOW CONTROL MEANS 4 Claims, 9 Drawing Figs.
US. Cl 251/4,
, l38l1l8,138/177 Int. Cl Fl6k 7/02 Field of Search 251/4-10;
138/118,119,177,DIG.11
[56] References Cited UNITED STATES PATENTS 1,683,322 9/1928 Annis 251/8 2,701,565 2/1955 Gewecke.... 128/214 FOREIGN PATENTS 142,472 7/1935 Austria 251/5 436,035 10/1926 Germany 251/9 1,040,349 8/1966 Great Britain .1 251/5 Primary Examiner-M. Cary Nelson Assistant Examiner- Richard Gerard Attorneys-Robert W. Beart, Michael Kovac, Barry L. Clark and Jack R. Halvorsen ABSTRACT: A device for controlling the flow of fluids which includes tubing having an axial preflattened section, a clamp and means for orienting the tubing relative to the clamp.
FLUID FLOW CONTROL MEANS BACKGROUND OF THE INVENTION The transport of fluid from one point to another through tubing, be it rigid or flexible, normally requires a control means to regulate the rate and quantity of fluid passing through the tubing. In the case of rigid tubes and pipes, such devices normally take the form of valves while in the flexible tubing the valve-type elements normally are clamps. Such clamps can be categorized generally as screw clamps, lever clamps, cam or wedge clamps or crimp means, all of which categories of clamps tend to flatten or distort the tube so as to close the internal bore and thereby prevent the passage of fluid.
When small diameter plastic tubing is used for transporting a liquid such as in intravenous sets for the introduction of parenteral solutions through venipuncture or when the tubing is used in blood sets where the catheters are utilized in the withdrawal of blood for collection in a container, there exists a problem on ,how to accurately meter the liquid flow. When a round tube is compressed, whereby the wall of the bore is brought into engagement with the opposite wall of the bore i.e., into a virtually straight line relationship, the ends of the bore or corners have a tendency to remain open because of the amountof material that has to be displaced into a tight radius. The material in these areas is under high stress and there is a tendency in the use of plastic materials to relax or cold flow. After a period of time there will be a variation in the internal configuration of this bore and because of this it is difficult to maintain an accurate initial setting with any clamp. In the case of the parenteral solutions it is necessary to maintain a constant drip rate so that the patient will obtain a predetermined quantity over a given period of time. In some instances if this rate is exceeded the patient can literally drown" due to the presence of an excessive amount of solution in the blood. To accomplish this control it is a mandatory rule in most hospitals that a nurse must check the flow control means at least once every minutes until the flow rate is stable and substantially constant. Many times, in the 5-minute interval, the flow of liquid can vary as much as 50 percent from the initial setting. Thus, to ensure an accurate flow requires a constant periodic check by the attending personnel until it is stabilized to ensure that the patient is getting the exact quantity and rate of solution prescribed by the physician. Unfortunately, if a variation in flow rate is required, an additional amount of time must again be allotted for cold flow" in order to obtain a constant flow rate.
SUMMARY This invention relates to the preforming and permanent crimping of an axial portion of an initially circular tubing whereby the opposed axially extending portions of the internal bore wall have adjacent surfaces sealed against one another to form a bore defining in cross section a flattened oval with opposed pointed ends falling substantially on the major dimension of the oval and opposed elongated smooth curved surfaces falling on the minor dimension of the oval. Such a tube is oriented within a clamp means wherein the clamp will apply a transverse force along the minor axis of the oval to incrementally collapse a portion of the tube to reduce the available passageway through the tubing from a maximum until the tubing bore is completely closed. The first flow setting established with this tube and clamp combination will maintain a substantially constant rate of flow through the tubing since the axial precrimping of the tubing eliminates the area in which there is a tendency to relax or cold flow. Thus, with this type oftube the initial setting will remain constant and no further resetting is required.
DRAWINGS FIG. I is a perspective view of the preferred embodiment of this invention;
FIG. 2 is an end view of the device shown in FIG. I;
FIG. 3 is a cross-sectional elevation of a piece of tubing of the prior art in compressed form;
FIG. 4 is a piece of tubing in cross section of the preferred embodiment in compressed form;
FIG. 5 is a cross-sectional view of an ultrasonic horn and anvil used to form the preferred embodiment;
FIG. 6 is an elevational view in partial section of one form of clamp usable with the present invention;
FIG. 7 is a side elevational view of the device shown in FIG.
FIG. 8 is an elevational view in partial section taken along lines 8--8 of FIG. 7; and
FIG. 9 is an elevational view in partial section of a wedgetype clamp capable of being used with the present invention.
DESCRIPTION Referring now to the drawings wherein similar parts are designated by similar numerals throughout the drawings;
FIG. I is a perspective view in partial section of a tube 20 having an axially extending preflattened portion 22. The tube 20 is preferably an extruded plastic tube, such as F.D.A. approved plasticized vinyl, polytetrafluoroethylene, or polyethylene, initially having a circular cross-sectional form and then partially flattened by crimping. The portion 22 includes opposite laterally and axially extending riblike side portions 24 in which the internal opposed surfaces 26, 28 of the wall of the bore 30 have been distorted and brought into juxtaposed relation and then preferably are sealed together. This results in the crimped portion of the tubing being flattened from a circular or cylindrical configuration to an elongated oval with the bore having a cross section at the opposed sealed edges which tapers down to a knife-edgelike sharp line which along with the lateral rib portions 24 falls on the major axis of the oval while the curved opposed surfaces 29 generally fall on the minor axis of the oval.
As best seen in FIG. 3, when a prior art cylindrical tubing 40, shown in phantom, is subjected to a transverse force, diagrammatically represented by the arrows A--A, the tubing can be collapsed to a position whereby the opposed surfaces of the internal wall of the bore abut one another in a flat line. However, due to the nature of the tubing there is a tendency for the extremity of the contacting wall, due to the short radius of curvature in the opposed edges generally designated 42. to leave an unclosed portion of the tubing in the form of teardrops in cross section as designated by the numeral 44.
As has been indicated above it has been found that the tubing will cold flow" or relax and the size and configuration of the openings 44 under compressive load will vary. They will either prevent total closure of the tubing or will close up and eliminate passage of liquids which were intended to be passed. In the instant invention when a transverse force, indicated schematically by the arrows BB in FIG. 2, is applied to the tubing of the instant invention, the tubing will, upon application of sufficient force in the direction of arrows BB, assume a configuration substantially as shown in FIG. 4 when sufficient pressure is applied to completely collapse the tubing. The crimping of portions 24 results in an elimination of the openings 44 and the cold flow" problem. If the tubing, shown in cross section in FIG. 2, is collapsed to an intermediate position between that shown in FIG. 2 and the totally closed position shown in FIG. 4 the tubing will tend to retain the intermediate position under a partial clamping load and to maintain that position without cold flow. Release of the clamping pressure results in a return to the initial configuration of FIG. 2.
Tubing of this type can be crimped and sealed quite readily due to its thermoplastic nature. One proposed form of production shown in FIG. 5, is to utilize an anvil 50 and horn 52 in an ultrasonic sealing machine in which the anvil and horn are recessed and configured to accept a round tube. Application of pressure in the direction of arrows CC to a round tube as well as an ultrasonic impulse through the horn 52 results in the deformation of the tubing as well as the welding or sealing of the opposed surfaces 26, 28 in the rib position 24, if desired. Similarly, an application of radio frequency sealing means or heat and pressure along the limited area 24 of a circular tube will result in a configuration of the desired variety.
The use of a preflattened or crimped tubing will improve the operation of all of the heretofore known clamps used, particularly, in the medical field. For example, in FIG. 6 there is shown in partial section a schematic screw clamp 60 having a frame 62 with a base 64 and screw adjustable pressure means 66. The tubing preferably is maintained in an oriented position by means such as an aperture 68 in an upstanding wall 70 complementary in shape to the flattened or crimped portion of the tubing. This will ensure the application of the transverse force along the minor axis as defined by the arrows BB. Such a clamp can additionally be provided with a total cutoff means, in the present instance, a semirigid slot means 72 into which the tube is inserted after twisting about its longitudinal axis with the edges of the slot 72 acting along the minor axis of the crimped portion to totally compress the tube to the closed configuration shown in FIG. 4.
As further example of the variety of clamps usable with this type of tubing, HO. 9 discloses a wedge-type clamp 80 in which the oriented tube 22b is acted upon by the movable block 82 controlled by the cam or wedge 84 which moves the block 82 and its complementary inclined surface toward the base 86 of the clamp means.
It will be appreciated that many other styles of clamps are available for use in combination with the type of tubing set forth above. The objective of the invention is the establishment of a means capable of maintaining a constant rate of fluid flow with a minimum of adjustment. The described embodiments of an axially crimped tubing, means for orienting the tubing and suitable clamp means for applying a transverse force to the tube have generally resolved the problems which previously have prevented other from reaching the objective.
lclailm:
I. An extruded flexible plastic tubing generally circular in cross section for conveying fluids including a limited axial portion having a generally curved noncircular internal bore, said tubing being initially circular and said limited axial portion being crimped along opposite sides thereof and permanently deformed so that opposed axially extending portions of said bore wall have adjacent surfaces thereof brought into juxtaposition to one another to form a bore defining in cross section a flattened oval having opposed sharply pointed feathered ends falling substantially on the major axis of the oval and opposed smooth curved surfaces falling on the minor axis of the oval, the outer surfaces of said limited axial portion being generally curvilinear in relaxed condition, said tubing when subjected to sufi'icient force along said minor axis collapsing to totallyclose said bore and feathered ends of said oval bore eliminating cold flow in said limited axial portion.
2. Tubing of the type claimed in claim 1 wherein said juxtaposed portions are sealed to one another substantially throughout their length.
3. A device for controlling the flow of fluids including a small, round. flexible plastic tubing for conveying the fluids having a limited axial portion provided with a generally curved noncircular internal bore, said tubing being initially circular and said limited axial portion being crimped along opposite sides thereof opposed axially extending portions of said bore wall having adjacent surfaces thereof brought into permanent juxtaposition to one another to form a limited axial bore defining in cross section a flattened oval having opposed sharply pointed feathered ends falling substantially on the major dimension of the oval and opposed smooth curved surfaces falling on the minor dimension of the oval, clamp means for clamping the flexible tubing and at least one orienting means spaced from said clamp means having a complementary configuration for surrounding and capturing a segment of said limited axial portion ofthe tubing in a predetermined relationship with the minor axis of the tubing bore being positively oriented relative to said clamp means whereby said clamp viating the normal cold flow inherent in the round portion of said plastic tubing.
4. A device of the type claimed in claim 3 wherein said juxtaposed portions are sealed to one another throughout their length.
l I t i
1. An extruded flexible plastic tubing generally circular in cross section for conveying fluids including a limited axial portion having a generally curved noncircular internal bore, said tubing being initially circular and said limited axial portion being crimped along opposite sides thereof and permanently deformed so that opposed axially extending portions of said bore wall have adjacent surfaces thereof brought into juxtaposition to one another to form a bore defining in cross section a flattened oval having opposed sharply pointed feathered ends falling substantially on the major axis of the oval and opposed smooth curved surfaces falling on the minor axis of the oval, the outer surfaces of said limited axial portion being generally curvilinear in relaxed condition, said tubing when subjected to sufficient force along said minor axis collapsing to totally close said bore and feathered ends of said oval bore eliminating cold flow in sAid limited axial portion.
2. Tubing of the type claimed in claim 1 wherein said juxtaposed portions are sealed to one another substantially throughout their length.
3. A device for controlling the flow of fluids including a small, round, flexible plastic tubing for conveying the fluids having a limited axial portion provided with a generally curved noncircular internal bore, said tubing being initially circular and said limited axial portion being crimped along opposite sides thereof opposed axially extending portions of said bore wall having adjacent surfaces thereof brought into permanent juxtaposition to one another to form a limited axial bore defining in cross section a flattened oval having opposed sharply pointed feathered ends falling substantially on the major dimension of the oval and opposed smooth curved surfaces falling on the minor dimension of the oval, clamp means for clamping the flexible tubing and at least one orienting means spaced from said clamp means having a complementary configuration for surrounding and capturing a segment of said limited axial portion of the tubing in a predetermined relationship with the minor axis of the tubing bore being positively oriented relative to said clamp means whereby said clamp means can apply a transverse force to incrementally collapse the bore and reduce the available passageway through said tubing from a maximum until the tubing bore is completely closed, said crimped limited axial portion of said tubing obviating the normal cold flow inherent in the round portion of said plastic tubing.
4. A device of the type claimed in claim 3 wherein said juxtaposed portions are sealed to one another throughout their length.
| 1969-09-29 | en | 1971-11-30 |
US-39273153-A | Seismometer
April 3, 1956 R. H. J. GENEsLAY SEISMOMETER Filed Nov. 17, 1953 25441946 sEIsMoivmrnn Raymond Henri Joseph Geneslay, Viroflay, France, as-
signor to Compagnie Generale de Geophysique, Paris, France, a corporation of France Application November 17, 1953, Serial No.. 392,731 Claims Priority, application France December 16, 1952 4 Claims. (Cl. 340 17) My invention has for its object improvements in seismographs used for geophysical researches. I will first define the problem to be solved by referring to accompanying drawings, wherein:
Fig. l shows a conventional seismograph adapted to transform the movement of a movable system into electric voltages;
Fig. 2 shows an embodiment of my invention as applied to a seismograph including two radial gaps to either side of a plane of symmetry perpendicular to the axis' of revolution of the instrument;
Fig. 3 is an explanatory diagram.
Turning to Fig. 1 which is a diametrical cross-section of va conventional seismograph, it is apparent that the latter includes chiefiy a magnetic field defined by a body of revolution surrounding the axis xy. Said magnetic field includes an outer section 15 made of mild steel and an inner axial section including a permanent magnet 16 and a pole piece 17, also made of mild steel, the parts 15, 16 and 17 being mechanically connected to form a unitary system.
The movable part of said conventional seismograph is constituted by a coil 18 adapted to move inside the annular gap 19 formed in the outer section and surrounding the pole-piece 17. A coil-guiding system similar to that used in loudspeakers is provided and includes a flexible member 20 which allows the movable coil to oscillate freely in the direction of the axis xy while preventing any lateral movement thereof.
Under the action of the vbrations transmitted through the ground, the movable coil vibrates axially, which leads to the production of an electromotive force inside the coil 18 and this in its turn produces the desired transformation of mechanical vibrations into electric voltages.
In such conventional seismographs, the movable coil associated with yielding current-feeding wires forms a weak point, inasmuch as it is not protected and is consequently liable to damage when the instrument is being handled; dismantled, adjusted or the like. Furtherrnore, the necessity of housing the coil inside the gap leads to an increase in the breadth of the latter, whereby the value of the magnetic field is reduced by a corresponding amount, the conditions remainng otherwise identical.
These various drawbacks are avoided by the improvernents according to my invention, which provides for the permanent location of the coil or coils transforming the vibrations of the movable section into electric voltages, on the stationary part of the magnetic circuit, said coil or coils being housed inside notches formed in said stationary section.
In Fig. 2, showing an embodiment of a seismograph according to my invention, there are provided two annular gaps lying in radial planes extending to either side of a plane of symmetry perpendicular to the axis of revolution xy of the magnetic field. The latter includes two flanges 1, 2 connected with each other by means of a cylindrical member 3, while the movable part of the instrument is constituted by a magnet 4, carrying at both ends respectively pole pieces 5 and 6, made preferably of mild steel, and moves, as shown, inside an axial bore passing through the members 1, 2, 3 of the magnetic field.
A portion of the flanges 1 and 2 is constituted, as shown, by extensions of the member 3. There is also provided a guiding system, as precedingly, for the movable section, said guiding system including the symmetrical elastic members 9 and 10.
The coils 3%, 31 are stationary and are housed inside the notches 11, 11' and 12, 12' located as shown in the wall of the bore inside the field, to register with the parts of the bore in which the pole pieces 5 and 6 are adapted to move.
Pafented Apr. 3, 1956 The height h of the pole pieces 5 and 6 measured in closed inside the corresponding bore section defining a gap therewith and the reluctance of the magnetic circuit remains substantially Constant, When the movable part 4, 5, 6 executes movements of a small amplitude therein. In contradistinction, during such movements, the magnetic fiux passing through the coils 30 and 31 varies.
Fig. 3 is a partial enlarged view of the instrument shown in Fig. 2 and examination thereof allows an explanation to be given of such a Variation of the magnetic fiux, said Pig. 3 showing, on an enlarged scale, the upper. gap 'and associated elements. Assuming the movable part 4, 5, 6 is moving upwardly, a number of lines of force, such as 21, 21', which did not Originally surround the annular coil 30, are shifted into a position 22, 22' for which they surround the coil and produce consequently a modification in the fiux entering said coil.
Obviously, if the coils 31) and 31 are wound in opposide directions, the electromotive forces induced in each coil by such modifications in the magnetic flux, as'sume the same direction and add up.
It is immediately apparent that the movable section may, consequently, be executed as a mechanically resistant member, since it includes only metal elements Without any winding thereon.
On the other hand, the coils are premanently secured inside the notches that may be partly or completely closed, along their edges facing the gap, by means of a suitable insulating material so that said coils cannot in practice be submitted to any damage and, furthermore, it is no longer necessary to feed any current to the coils through fiexible wires.
different parts,vit is possible to obtain, in seisrnographs` of this type, the same sensitivity as or even a greater sensitivity than in the case of conventional instruments.
The damping of the instrument is also easy to execute since it is possible to size the different parts of the seismograph within a far wider range than in the case of conventional types; in particular, the cross-sections of the coils 30, 31 are not limited as in the case where they are to be housed inside a gap and, furthermore, the mass of the movable section may be comparatively small by reason of the movements of said movable section being small in practice and consequently, the height h of each pole piece 5 or 6 may be only slightly larger than the thickness, measured in the direction of the axis, of the notch 11, 11' or 12, 12'. Thus, the mass of the steel magnet 4 may be chosen very small, if required.
Obviously, for a predetermined mass of the movable section, it is easier to producc a seismograph of reduced bulk in accordance with my irnproved type, than in accordance with the conventional movable coil type.
' 'A-zfurthr important advantage of my invention consts in that, when the pole pieces 5 and 6 move, the relctance of 'the magnetic circuit actually varies to a light extent, since the flux of the magnetic leaks is not le same for the different relative positions of the poleieces 5 and 6with reference to the corresponding notches 1,11'. and 12, 12'. The consequence is that the movble section is submittcd to an axially directed magnetic orce. It is, therefore, possible to suitably locate the iole pieces 5, 6 With reference to the notches 11, 11'
vnd 12, 1,2' so as to make said magnetic force opposc- :ircuit'remains Constant, atleast as a first approximation;V
this' distinguishes the instrument from those wherein the :lectromotive force is produced inside a stationary coil July through a modification of the magnetic flux due to 1 modificationV in the reluctance of the magnetic Circuit as produced by a movement of the movable section of ile instrument.
Obviously, many modifications may be brought to the :mbodiment described and illustrated, Without unduly widening thereby the scope of the invention as defined in accompanying claims; thus, the Shape of the crosssection of the notches may be modified and the instrument may include a single coil instead of two or again, a plorality Of notehes may be cut in register With the samegap.
What I claim is:
1. In a seismometer; thetcombination of a cylindrical member of magnetic material having annular fianges extending radially inward therefrom at the opposite ends of said'member, a permanent magnet mounted coaxially within said member and vmovable axially relative to the latter, pole pieces at the opposite ends of said magnet and having` cylindrical outer surfaces With the diameters of the latter being only slightly less than vthe inner diameters of said flanges thereby to define narrow annular gaps between the inner edge surfaces of said fianges and the cylindrical surfaces of the related pole pieces,
means securing together said magnet andt'pole pieces' to.
define a movable assembly, at least one of said flanges having an annular groove in the inner edge surface thereofopening radially into the related gap, and a magnetic coil disposed in saidV annular groove, the axial dimension'of at least said one fiange being substantially greater than the axial dimension of the related pole piece, while said axial dimension of the related pole piece is substantially greater than the axial dimension of said groove.
2. In a seismometer; 'the combination according to claim 1; further comprising resilient members extending between the opposite ends of said cylindrical member and the adjacent ends of said movable assembly to normally retain the latter in an aXial position wherein said pole pieces are disposed symmetrically With respect to the radial media] planes of the adjacent flanges.
3. In a seismometer; the combination of a cylindrical member of magnetic material having annular flanges extending radially inward Vtherefrom at the opposite ends of said member, each of said annular flanges having a relatively narrow annular. groove opening radially inward at the inner surface of the flange andsubstantially centrally located With respect to the axial dimension of the latter, a magnetic coil in each of said grooves, a movable assembly including a permanent magnet and pole pieces at the opposite'ends thereof, and resilient means extending between the opposite ends of said cylindrical member and the adjacent ends of the movableassembly and mounting the latter coaxially within the cylindrical member for axial rnovement` With respect to the iatter, said pole pieces having diameters which are only slightly smaller, than the diameters of the inner surfaces of the fianges to define narrow gaps therebetvveen into which said grooves open, said movable assembly being axially dimensionedpso that, in the normal axialiposition thereof as established by said resilient means, said pole pieces are symmetrically located with respect to the radial medial planes of the related fianges, the axial dimensions of said fianges being substantially greater than the axial dimensions of the related pole pieces, while, said axial dimensions of the pole pieces are substantially greater than the axial dimensions of thegrooves in the related fianges.
4. In a seismometer; the combination according to claim 3, wherein the magnetic coils in said grooves of the fianges at opposite ends of the cylindrical member are oppositely wound so that, in response to any axial displacement of the movable assembly from said normal oositions', the variations of the electromotive force induced in said coils are in the same Vdirection and may be added together to provide arelatively strong indication, and any magnetic field outside of the seismometer prof vides opposed reactions in said coils to cancel out each other and thereby maintain the seismometer substantially free of any influence by such outside magnetic fields.
References Cited in the file of this patent UNITED STATES PATENTS
1. IN A SEISMOMETER; THE COMBINATION OF A CYLINDRICAL MEMBER OF MAGNETIC MATERIAL HAVING ANNULAR FLANGES EXTENDING RADIALLY INWARD THEREFROM AT THE OPPOSITE ENDS OF SAID MEMBER, A PERMANENT MAGNET MOUNTED COAXIALLY WITHIN SAID MEMBER AND MOVABLE AXIALLY RELATIVE TO THE LATTER, POLE PIECES AT THE OPPOSITE ENDS OF SAID MAGNET AND HAVING CYLINDRICAL OUTER SURFACES WITH THE DIAMETERS OF THE LATTER BEING ONLY SLIGHTLY LESS THAN THE INNER DIAMETERS OF SAID FLANGES THEREBY TO DEFINE NARROW ANNULAR GAPS BETWEEN THE INNER EDGE SURFACES OF SAID FLANGES AND THE CYLINDRICAL SURFACES OF THE RELATED POLE PIECES, MEANS SECURING TOGETHER SAID MAGNET AND POLE PIECES TO DEFINE A MOVABLE ASSEMBLY, AT LEAST ONE OF SAID FLANGES HAVING AN ANNULAR GROOVE IN THE INNER EDGE SURFACE THEREOF OPENING RADIALLY INTO THE RELATED GAP, AND A MAGNETIC COIL DISPOSED IN SAID ANNULAR GROOVE, THE AXIAL DIMENSION OF AT LEAST SAID ONE FLANGE BEING SUBSTANTIALLY GREATER THAN THE AXIAL DIMENSION OF THE RELATED POLE PIECE, WHILE SAID AXIAL DIMENSION OF THE RELATED POLE PIECE IS SUBSTANTIALLY GREATER THAN THE AXIAL DIMENSION OF SAID GROOVE.
| 1953-11-17 | en | 1956-04-03 |
US-7047960-A | Catadioptric optical systems for cameras and the like
WWWENQE 3,142,235 CATADIOPTRIC OPTICAL SYSTEMS 'FOR CAMERAS AND THE LIKE 2 Sheets-Sheet l Filed Nov. 21, 1960 D N 5 Wu E m VP .T N H I m T% m w Y B July 28, 1964 w. P. SIEGMUND 3,142,235
CATADIOPTRIC OPTICAL SYSTEMS FOR CAMERAS AND THE LIKE Filed NOV. 21, 1960 2 Sheets-$heet 2 IN VENTOB WHLTER R 5/5 MUND I H TTOBNEYS United States Patent f 3,142,235 CATADIOPTRIC OPTICAL SYSTEMS FOR CAMERAS AND THE LIKE Walter P. Siegmund, Woodstock, Conn., assignor to American Optical Company, Southbridge, Mass., a voluntary association of Massachusetts Filed Nov. 21, 1960, Ser. No. 70,479 6 Claims. (Cl. 95-11) This invention relates to image-forming optical systems of the catadioptric type, and more particularly relates to catadioptric systems for use with cameras or the like and provided with fiber optical means for enabling such optical systems to be operated at higher numerical apertures, or at wider angular object fields, or both, than heretofore.
While a reflecting type image-forming optical system for use with a camera or the like and employing a spherical mirror and an aspherically curved Schmidt-type corrector plate for compensating for the inherent spherical aberrations of the mirror is well known, nevertheless, the use of such a reflecting optical system has been considerably restricted in the past because of the limitations imposed thereon by having its primary image formed within the boundaries of the system. Furthermore, even though it has been possible to use, for example, an angularly disposed plane mirror centrally within such a reflecting system to relay the image-forming light rays thereof laterally to a focal plane outside the system, such an additional mirror has not been satisfactory since it can only be used in a system of relatively low numerical aperture or of very limited angular object field.
It has now been found, however, that such a catadioptric type image-forming optical system having the desirable qualities of high light-gathering ability with good imagery, good field coverage, and freedom from chromatic aberrations, astigmatism, distortion and coma, can be employed in a camera or the like and combined with a fiber optical bundle of proper design and suitable location within the system in such a manner as to act as an image relay device capable of receiving the appreciably curved primary image being formed within the system and conducting same at increased optical speed to a flat image plane located outwardly thereof.
Additionally, the invention includes optical components and means in combination with a pair of improved combined systems in such a manner as to direct separate sets of image-forming light rays from the same object field onto opposite sides of a single sensitized film and at such size and in such registry with each other that substantially double light intensity will be supplied the film during a single exposure thereof, whereby shorter exposures and thus pictures at higher rates of speed may be obtained.
The fiber optical image relay bundle may be of either a rigid or flexible construction. It is possible, when the fiber optical image relay means is of a flexible nature to arrange the exit end of at least one or possibly both fiber bundles so as to be movable toward each other. Thus, both exit ends may be pressed into intimate contact with opposite sides of the sensitized film to be exposed. Also, when the bundles are flexible, it is an easy matter to match and align the two images being formed thereby at opposite sides of the single thin film.
Furthermore, the flexibility of the fiber optical image relay means of the present invention may be such that ap- 3,142,235 Patented July 28, 1964 preciable angularity may be had when desired between the catadioptric optical system (or systems) being used to focus the image-forming light rays from an object field upon the forward end of the fiber optical relay means and the associated camera and film supporting structure adjacent the exit end or ends of said relay means.
Other objects and advantages of the invention will become apparent from the detailed description which follows when taken in conjunction with the accompanying drawing in which:
FIG. 1 is a longitudinal sectional view showing a reflecting type image-forming optical system and fiber optical image relay means associated therewith.
FIG. 2 is a longitudinal sectional view showing two associated reflecting image-forming optical systems, fiber optical relay means and reflecting optical components for effecting a combined photographic system;
FIG. 3 is a longitudinal sectional view somewhat similar to FIG. 2 but showing a modified form of combined photographic system; and
FIG. 4 is a view somewhat similar to FIG. 3 but showing a modified form of combined image-forming optical systems for photographic purposes, or the like.
Referring to the drawing in detail and in particular to FIG. 1, it will be seen that a catadioptric optical system is indicated generally by the numeral 10 and comprises a concave spherically curved front surface mirror 12 arranged in optical alignment with a Schmidt-type aspherically curved corrector plate or element 14. As is well known, such a corrector plate is for providing negative spherical aberration of such a value as to compensate to a high degree for the inherent spherical abberation of the spherical mirror 12. Positioned forwardly of the corrector plate 14 is an angularly disposed plane mirror 16 and this mirror, it will be appreciated, is arranged to receive light rays such as rays 18 coming from a distant axial object field, and to reflect same in a direction at thereto so as to pass through corrector plate 14.
The result of such an arrangement is that light rays from a distant object field, such as that of an aerial or astronomical camera, will be brought to a real image by the corrector plate and the mirror at an image surface 20 internally of the optical system and that this real image will have appreciable curvature of field. Even though heretofore a plane mirror has been located within such a catadioptric system for reflecting image-forming rays to a location outwardly of the system, such an arrangement cannot be used by the system of FIG. 1 without necessitating a material reduction in the numerical aperture or the degree of angular field being accommodated by the system. Thus, it will be readily apparent that reflecting optical systems of this type heretofore have been materially restricted.
In order to utilize a reflecting optical system like that of FIG. 1 at very high light-gathering efficiency and also at high angular field, it has been found that a fiber optical image transfer bundle or bundles of the type disclosed in a co-pending Hicks application Serial No. 736,172 which was filed May 19, 1958, may be employed to transfer the image to a location outwardly of the system. Thus at 22 a tapered fiber bundle is shown with its larger spherically curved end 22a within the system and at such a location as to coincide with the curved image field 20 of the reflecting system. This tapered fiber optical bundle has its smaller end 2211 arranged to coincide with one end of an elongated straight-sided fiber optical bundle 24 which extends centrally within the system and passes outwardly through a central aperture 9 26 provided therefor in the aspheric corrector plate 14. An aperture 28 is also provided in the plane angularly arranged reflector 16 and thus the exit end of the bundle 24 may extend to a terminal location 30 outwardly of the system per se but, nevertheless, still within the confines of a camera housing indicated by dotted line 25.
Accordingly, it is an easy matter to arrange photographic film, as diagrammatically indicated at P with its emulsion side in contact with this outer fiber bundle end for photographic purposes, or the like. Even though some of the light rays 18 travelling toward the mirror 16 will be blocked out by the fiber bundle, nevertheless, an image at high optical speed and appreciable angular field will be formed at the curved image plane 20. Also, it should be clear that since the larger end 22a of the fiber optical bundle 22 may be finished so as to have a curvature corresponding closely to the curvature of field of the real image formed by the catadioptric system and since a taper of suitable value may be provided the bundle 22, it is possible to arrange these parts so as to accept and utilize the high light-gathering ability and the relatively large angular object field afforded by the system. Also, since each fiber of the bundle 22 is tapered, the light entering each fiber will be concentrated as it passes through the fiber to the opposite end thereof. This, of course, will effect an increase in intensity of illumination at the smaller exit end of bundle 22 and thereafter for the light rays travelling through the elongated bundle 24 and to the film in contact with the exit end thereof.
In FIG. 2, a spherical mirror 40, a corrector plate 42, a plane mirror 44 and a fiber optical bundle 46 are shown and it will be appreciated that these parts are much like those already discussed in FIG. 1 for conducting the optical image to the emulsion on the film F One difference does exist, however, in that the fiber optical bundle 46 is formed as a single unit instead of two separate fiber optical units. This bundle 46, instead, has an enlarged forward end formed by fibers which are tapered at their forward end 46a, as shown, and are integral with the elongated straight-sided portions extending outwardly of the system so as to terminate in a flat surface 48 adjacent the photographic film F associated therewith. However, in FIG. 2, a second reflecting optical system has been shown and comprises a concave spherical mirror 50, an aspheric corrector plate 52, and a fiber optical bundle 54. This system, however, is of somewhat different construction in that not only do the individual fibers at their forward end 54a taper so as concentrate light being transmitted thereby but also these fibers are curved, as indicated at 56, in such a manner as to transport the image-forming light rays laterally and outwardly of the optical system without passing through the corrector plate 52. The result is that approximately the same amount of light will be blocked out as was the case in the arrangement of FIG. 1.
The outer flat end 5412 of the bundle 54, however, is arranged in contacting engagement with the opposite side of the film F in such a manner as to be in matching relation, so to speak, with corresponding fibers of the fiber optical bundle 46. In this instance, the film F should be relatively thin in order to avoid spreading of the light passing through the film to the emulsion. Since the plane mirror 44 reflects the light rays which it receives toward the left and effects a quarter turn thereof before reaching the corrector plate 42 and the curved fiber bundle 54 for transferring the image formed by the mirror 50 is bent to the left, the end result will be that each unit area of the film emulsion will be simultaneously exposed to corresponding areas of the two images being formed by the left and right-hand parts of the combined optical system. Thus, the amount of light being provided for forming the image on the film will be substantially twice that obtainable for the film in FIG. 1.
In FIG. 3, a somewhat different combined optical system is disclosed but same will accomplish substantially the same end result as that produced by the combined optical system of FIG. 2. While a concave spherical mirror 60, an aspheric corrector plate 62 and a fiber optical bundle 64, in FIG. 3, are like those shown at the right side of FIG. 2, the construction and arrangement of components for the system at the left side of FIG. 3 are different. A concave spherical mirror 66 which forms a real image at the curved focal plane 67 within the optical system receives its light rays from an angularly disposed plane mirror 68 which is aligned with an aspheric corrector element 70. Thus, light rays from a distant object field which pass through plate 70 and are laterally reflected by the mirror 68 before impinging upon the spherical mirror 66 are imaged thereby at focal plane 67. The plane mirror 68, however, is centrally apertured, as indicated at 68a, and disposed within this aperture is a fiber optical bundle 72 which has its tapered forward end 72a convexly spherically curved so as to fit closely the curvature of field of the real image being formed by the optical system. By this arrangement, a somewhat more compact combined optical system may be effected than in FIG. 2 but the results obtained by this modified form of the invention in supplying matching images to the opposite sides of the film F are substantially the same as those obtained in FIG. 2.
In FIG. 4, a further modified construction of combined catadioptric optical system for providing double light intensity upon a photographic film F is shown. In this arrangement, however, even though the reflecting type image-forming systems 76 and 78 thereof are each quite similar to that disclosed at the right side of FIG. 2, nevertheless, in order to have the two images being formed thereby rightly oriented and in proper matching relation with each other but at opposite sides of the film F there is provided, for the left side, an angularly disposed plane mirror 80 and at the right side a first angularly disposed plane mirror 82 and a second angularly disposed plane mirror 84 in properly oriented relation thereto. Thus, by the use of one more mirror in the right side of the combined system than in the left side, it is possible to so oppositely rotate or orient the two real images being supplied to opposite sides of the emulsion surface of the film F; that a proper matching of images with double light intensity will be provided therefor.
Additionally, in FIG. 4, there is indicated by the double arrows 86 and 88 that movement of the exit ends of either or both fiber bundles 90 and 92 toward or away from the film R; can be had and this would be without requiring any movement of either reflective optical system 76 or 78 relative to the other. This would be possible when the intermediate portion 90a of the fiber bundle 90 or the intermediate portion 92a of the bundle 92 is made flexible and arranged to accommodate such movement. Also, the box-like dotted lines 94 are intended to indicate the confines of a camera structure, or the like which, it should be appreciated, may be sufficiently removed from the reflecting image-forming optical systems 76 and 78 of the combined system so that angular movement of the combined image-forming system may be had without necessitating movement of any structure within the box-like camera portions of the device. Also, within this box-like portion, means (not shown) may be provided whereby a suitable liquid or semi-liquid may be applied to opposite sides of the film at exit areas 96 and 98 of the fiber bundles. This liquid or semi-liquid would be to insure complete optical contact between the film and the ends of the fibers of both bundles 90 and 92, with the result that a much higher acceptance angle for the light rays leaving the ends of the fiber and impinging upon the emulsion of the film may be had than would be possible if no such optical contact were provided.
Of course, when considering the angular field to be covered by the high-speed optical systems of the present invention, care must be exercised in the relative positioning and arrangement of the mirrors and other components of the system so that no material vignetting of the more oblique light rays from the object field of the system will occur; and, of course, this is a distinct and separate problem from that of keeping the obscuration ratio of the system as low as conveniently possible, the ratio, of course, being controlled by the size of fiber bundle and image surface being used within the system.
Having described my invention, I claim:
1. A camera or the like having relatively high-speed optical means for forming an image of an object field upon photographic film within said camera, said optical means comprising a pair of catadioptric optical systems each having a concavely curved spherical mirror and an aspheric corrector plate in optical alignment and predetermined spaced relation relative to each other, the corrector plate and spherical mirror of each of said opti cal systems being arranged to receive light rays from a single object field spaced therefrom and to focus said light rays as a pair of real images having appreciable curvature of field at a pair of curved image planes within said systems, respectively, and optically disposed between the mirrors and the corrector plates thereof, a pair of elongated fiber optical image-transfer bundles having their inner ends of predetermined size and of predetermined convexly curved shape and so disposed Within said systems, respectively, as to be in substantial coincidence with said curved image planes of said systems, said elongated fiber optical bundles extending outwardly of said systems and having their outer end surfaces substantially flat and so disposed as to contact opposite sides of a photographic film at a predetermined film exposure position in said camera, and plane mirror means disposed in the path of the light rays of one of said systems so as to intercept said last mentioned light rays and cause a mirror image reversal thereof before reaching the concave mirror associated therewith, whereby the light rays of both systems will form a pair of real images in matching relation upon opposite sides of the photographic film at said exposure position.
2. The combination defined in claim 1 in which at least one of said elongated fiber optical bundles is of such flexibility intermediate its opposite ends as to allow movement of its flat outer end surface between its film contacting position and an out-of-the-way position to thereby allow ready insursion of photographic film between the adjacent flat end surfaces of said bundles at said exposure position.
3. A camera or the like having high-speed optical means for forming an image of an object field upon photographic film within said camera, said optical means comprising a pair of catadioptric optical systems each having a concavely curved spherical mirror and an aspheric corrector plate in optical alignment and predetermined spaced relation relative to each other, the corrector plate and spherical mirror of each of said optical systems being arranged to receive light rays from a single object field spaced therefrom and to focus said light rays as a pair of real images having appreciable curvature of field at a pair of curved image planes within said systems, respectively, and optically disposed between the mirrors and the corrector plates thereof, a pair of elongated fiber optical image-transfer bundles having their ends of predetermined size and of predetermined convexly curved shape and so disposed within said systems, respectively, as to be in substantial coincidence with said curved image planes of said systems, said elongated fiber optical bundles extending outwardly of said systems and having their outer end surfaces substantially flat and so disposed as to contact opposite sides of a photographic film at a predetermined film exposure position in said camera, and plane mirror means disposed in the path of the light rays of each of said systems so as to intercept the light rays thereof and direct same toward the concave mirrors associated therewith, whereby a mirror image reversal of said light rays of one of said systems will be effected and the light rays of both systems will form a pair of real images in matching relation upon opposite sides of the photographic film at said exposure position.
4. A camera or the like having relatively high-speed optical means for forming an image of an object field upon photographic film within said camera, said optical means comprising a pair of catadioptric optical systems each having a concavely curved spherical mirror and an aspheric corrector plate in optical alignment and predetermined spaced relation to each other, the corrector plate and spherical mirror of each of said optical systems being arranged to receive light rays from a single object field spaced therefrom and to focus said light rays as a pair of real images having appreciable curvature of field at a pair of curved image planes within said system, respectively, and optically disposed between the mirrors and the corrector plates thereof, a pair of elongated fiber optical image-transfer bundles having their inner ends of predetermined size and of predetermined convexly curved shape and so disposed with said systems, respectively, as to be in substantial coincidence with said curved image planes of said systems, said elongated fiber optical bundles extending outwardly of said systems and having their outer end surfaces substantially flat, and at least one of said flat end surfaces being movable relative to the other so as to be brought into contacting relation with said film at a predetermined film exposure position in said camera, and plane mirror means disposed in the path of the light rays of one of said systems so as to intercept said last mentioned light rays before reaching the concave mirror associated therewith, whereby, a mirror image reversal of said last mentioned light rays will be effected and the light rays of both systems will form a pair of real images in matching relation upon opposite sides of the photographic film at said exposure position.
5. A camera or the like having relatively high-speed optical means for forming an image of an object field upon photographic film within said camera, said optical means comprising a pair of catadioptric optical systems each having a concavely curved spherical mirror and an aspheric corrector plate in optical alignment and predetermined spaced relation relative to each other, the corrector plate and spherical mirror of each of said systems being arranged to receive light rays from a single object field spaced therefrom and to focus said light rays as a pair of real images having appreciable curvature of field at a pair of curved image planes within said systems, respectively, and optically disposed between the mirrors and the corrector plates thereof, and fiber optical means for transferring said real images from said curved image planes within said systems to a pair of flat exit surfaces thereon outwardly of said systems, respectively, the fiber optical means for each system comprising a tapered fiber optical portion for concentrating the light rays being received at its larger end, and an elongated substantially parallel-sided fiber optical portion aligned therewith and extending outwardly of said system, each tapered portion having its larger end of such a predetermined size and predetermined convexly curved shape and so located within its respective system as to be in substantial coincidence with the curved image plane associated therewith, the flat exit surfaces of said parallel-sided portions being so disposed relative to each other as to be closely adjacent opposite sides of photographic film at a predetermined film exposure position in said camera, and mirror means disposed in the path of the light rays of one of said systems so as to reflect said light rays and cause a mirrorimage reversal thereof before reaching the concave mirror of said one system, whereby said light rays will form a pair of real images in matching relation upon opposite sides of the photographic film at said exposure position.
6. The combination defined in claim 5 in which at least one of said elongated parallel-sided portions is of such flexibility intermediate its opposite ends as to allow movement of its flat exit surface between its film contacting position and an out-of-the-way position to thereby allow ready insursion of photographic film between the adjacent flat end surfaces of said bundles at said exposure position.
References Cited in the file of this patent UNITED STATES PATENTS 1,173,083 Banks Feb. 22, 1916 2,354,591 Goldsmith July 25, 1944 2,697,182 Sheldon Dec. 14, 1954 2,794,380 Rehorn June 4, 1957 2,825,260 OBrien Mar. 4, 1958 OTHER REFERENCES Article: Fiber Optics. Part III, Field Flatteners, Journal of the Optical Society of America, vol. 47, No. 7, July 1957, pages 594598.
1. A CAMERA OR THE LIKE HAVING RELATIVELY HIGH-SPEED OPTICAL MEANS FOR FORMING AN IMAGE OF AN OBJECT FIELD UPON PHOTOGRAPHIC FILM WITHIN SAID CAMERA, SAID OPTICAL MEANS COMPRISING A PAIR OF CATADIOPTRIC OPTICAL SYSTEMS EACH HAVING A CONCAVELY CURVED SPHERICAL MIRROR AND AN ASPHERIC CORRECTOR PLATE IN OPTICAL ALIGNMENT AND PREDETERMINED SPACED RELATION RELATIVE TO EACH OTHER, THE CORRECTOR PLATE AND SPHERICAL MIRROR OF EACH OF SAID OPTICAL SYSTEMS BEING ARRANGED TO RECEIVE LIGHT RAYS FROM A SINGLE OBJECT FIELD SPACED THEREFROM AND TO FOCUS SAID LIGHT RAYS AS A PAIR OF REAL IMAGES HAVING APPRECIABLE CURVATURE OF FIELD AT A PAIR OF CURVED IMAGE PLANES WITHIN SAID SYSTEMS, RESPECTIVELY, AND OPTICALLY DISPOSED BETWEEN THE MIRRORS AND THE CORRECTOR PLATES THEREOF, A PAIR OF ELONGATED FIBER OPTICAL IMAGE-TRANSFER BUNDLES HAVING THEIR INNER ENDS OF PREDETERMINED SIZE AND OF PREDETERMINED CONVEXLY CURVED SHAPE AND SO DISPOSED WITHIN SAID SYSTEMS, RESPECTIVELY, AS TO BE IN SUBSTANTIAL COINCIDENCE WITH SAID CURVED IMAGE PLANES OF SAID SYSTEMS, SAID ELONGATED FIBER OPTICAL BUNDLES EXTENDING OUTWARDLY OF SAID SYSTEMS AND HAVING THEIR OUTER END SURFACES SUBSTANTIALLY FLAT AND SO DISPOSED AS TO CONTACT OPPOSITE SIDES OF A PHOTOGRAPHIC FILM AT A PREDETERMINED FILM EXPOSURE POSITION IN SAID CAMERA, AND PLANE MIRROR MEANS DISPOSED IN THE PATH OF THE LIGHT RAYS OF ONE OF SAID SYSTEMS SO AS TO INTERCEPT SAID LAST MENTIONED LIGHT RAYS AND CAUSE A MIRROR IMAGE REVERSAL THEREOF BEFORE REACHING THE CONCAVE MIRROR ASSOCIATED THEREWITH, WHEREBY THE LIGHT RAYS OF BOTH SYSTEMS WILL FORM A PAIR OF REAL IMAGES IN MATCHING RELATION UPON OPPOSITE SIDES OF THE PHOTOGRAPHIC FILM AT SAID EXPOSURE POSITION.
| 1960-11-21 | en | 1964-07-28 |
US-73669996-A | Technique for efficiently allocating bandwidth to multimedia calls in a communications system
ABSTRACT
In a multimedia communications system where bandwidth of an access facility is limited, the bandwidth is partitioned into three bands dedicated to audio, video and data traffic, respectively, in accordance with blocking probabilities associated with the respective media types. The value of each blocking probability is selected pursuant to the relative importance of the associated media type in a multimedia service. With the blocking probabilities in place, the dominance of traffic of a particular media type, which may be relatively unimportant in the service, would not cause blocking of traffic of other media types, which may be relatively important.
FIELD OF THE INVENTION
The invention relates generally to multimedia communications systems and, more particularly, to a communications system administering control on bandwidth allocation to audio, data and/or video calls therein.
BACKGROUND OF THE INVENTION
Traditional communications have been by telephone involving audio media only. With the advent of technology and ever-demanding communications needs, multimedia services emerge such as video conferencing, CD-ROM applications and Internet services, involving communications on a combination of audio, data and video media.
In the business arena, workstations or personal computers (PCs) having multimedia capabilities are employed to increase productivity. In a business location, the workstations are typically connected to one another via a local area network (LAN) such as the Ethernet LAN to facilitate communications between employees. For communications with a remote location, wide area networking facilities are commonly used. In addition, multimedia servers have been developed to interface a LAN with a wide area network (WAN) to provide multimedia services between two distant locations. However, multimedia calls normally demand more communication bandwidth than traditional telephone calls, and it is costly to allocate much bandwidth to each multimedia call in a limited bandwidth setting, which is usually the case.
Accordingly, there exists a need for a methodology in a multimedia communications system for cost-effectively allocating bandwidth to multimedia calls.
SUMMARY OF THE INVENTION
In accordance with the invention, a multimedia service processor is employed in a communications system to allocate bandwidth for each of the audio, video and data media type communications. The bandwidth allocation is based on at least a predetermined blocking probability associated with each media. The blocking probability is defined as the likelihood that the traffic of the associated media would be blocked because of the unavailability of system resources including the limited bandwidth allocated thereto. The value of the blocking probability varies inversely with the relative importance of the media type of the traffic in the system.
Specifically, before a call is established in the system, the multimedia service processor identifies each media involved in that call. The processor allows the call to go through when the bandwidth allocated to at least one of the identified media is sufficient for communications of the information associated therewith.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing,
FIG. 1 illustrates multimedia communications system in accordance with the invention;
FIG. 2 is a block diagram of a multimedia server in the system of FIG. 1;
FIG. 3 illustrates a first scheme whereby bandwidth of an access facility in the system of FIG. 1 is allocated for use by traffic of different media types;
FIG. 4A illustratively tabulates the number of required channels for a respective media type, given a blocking probability associated therewith in a video intensive service, in accordance with the invention;
FIG. 4B illustratively tabulates the number of required channels for a respective media type, given a blocking probability associated therewith in a data intensive service, in accordance with the invention;
FIG. 5 illustrates a second scheme whereby bandwidth of the access facility is allocated for use by traffic of different media types;
FIG. 6 illustrates a third scheme whereby bandwidth of the access facility is allocated for use by traffic of different media types; and
FIG. 7 is a flow chart depicting the steps of a bandwidth management process run by a multimedia service processor in the system of FIG. 1.
Throughout this disclosure, unless otherwise stated, like elements, components and sections in the figures are denoted by the same numerals.
DETAILED DESCRIPTION
FIG. 1 illustrates multimedia communications system 100 embodying the principles of the invention. In system 100, two distant locations 101 and 109 communicate with each other through standard wide area network (WAN) 107. In location 101, workstations (or PCs) 103-1 through 103-n are connected to multimedia server 105 via local area network (LAN) 111, where n is a positive integer. Each workstation is equipped with a standard data entry facility including a keyboard, and point-and-click device; audio facility including a telephone handset; and video facility including a camera. With these facilities, the workstations in location 101 may communicate through a combination of audio, data and video media with workstations having similar hardware in location 109.
In this illustrative embodiment, LAN 111 is a switched or shared Ethernet LAN which supports real-time communications. Referring to FIG. 2, server 105 is a LAN-based server connected to LAN 111 through Ethernet interface 205. On the other end, server 105 provides, at E1/T1 interface 213, integrated services digital network (ISDN) primary rate interface (PRI) facility 117 for accessing WAN 107. Server 105 also includes LAN/WAN converter 220 which, in one direction, converts information streams from LAN 111 which are in an internet protocol (IP) format to a format compatible to WAN 107. The conversion includes dividing IP streams from LAN 111 into 64 Kbps increments, and inserting proper framing into the fragmented streams, pursuant to a standard point to point and multilayer protocol (PPP/MP). In the other direction, converter 220 performs the inverse function to the LAN-to-WAN conversion, and converts the traffic from WAN 107 to IP streams compatible with LAN 111.
In addition, server 105 includes multimedia service processor 225, which is programmed to orchestrate the operation of server 105 and manage different multimedia service features. In particular, processor 225 administers blocking control on multimedia calls utilizing the limited bandwidth of PRI facility 117, in accordance with the invention. The blocking control operation of processor 225 is fully described hereinbelow.
Referring back to FIG. 1, location 109 includes multimedia server 160 which is structurally identical to server 105. Similarly, server 160 is connected to multimedia workstations 150-1 through 150-v through switched or shared Ethernet LAN 166, where v is a positive integer. On the other end, server 160 provides ISDN PRI facility 165 for accessing WAN 107.
It should be noted at this point that discussions herein regarding location 101 (including server 105 and facility 117) are similarly applicable to location 109 (including server 160 and facility 165) as the latter is a mirror image to location 101.
By way of example, ISDN PRI facility 117 comprises standard T1 lines, which is most likely the case in the United States, and each PRI in facility 117 provides a 1.544 Mbps transport interface. (Alternatively, facility 117 may comprise E1 lines, which is most likely the case in foreign countries, and each PRI then provides a 2.048 Mbps transport interface.) In accordance with the ISDN PRI standard, each T1 line carries 24 B-channels each transporting 64 Kbps audio, data and/or video information. These B-channels may carry clear-channel information, or may use HDLC framing to package multimedia information. One of the 24 B-channels may be used as a D-channel providing ISDN signaling for multimedia call establishment and disconnection, and maintenance control.
In addition, the ISDN PRI standard provides for logically grouping multiple B-channels into a wider band channel of 344 through 1,536 Kbps capacity. With this flexibility, a channel carrying audio, data and/or video information can be dynamically sized in B-channel increments in response to the traffic needs. For example, after a voice call has been established between workstation 103-1 in location 101 and workstation 150-1 in location 109 over a PRI link, server 105 can establish with server 160, as the need arises, additional B-channels for video and data over the same link, and aggregate the additional channels into one or more PPP logical channels, resulting in a synchronized delivery of multimedia information.
Typically, a data connection with bursty traffic has average and maximum bit rates each varying from a few thousand bits per second to a few million bits per second. Calls utilizing a standard transmission control protocol (TCP) typify the data connection. The bit rate required for a voice or audio connection is normally in the range of 32 to 64 Kbps. Similarly, a video connection calls for a variety of bit rates. For example, the bit rate required for video information encoded according to the H.261 standard is p×64 Kbps, where p=2, 4, 6, . . . . In the case of J-PEG encoding, the required bit rate is about 1 Mbps. Unlike data calls, video and audio calls are normally transmitted pursuant to a standard user datagram protocol (UDP).
Point-to-point connections are established between workstations in respective locations 101 and 109 using ISDN signaling over a D-channel pursuant to an ITU Q.931 protocol. The D-channel may control only the B channels associated therewith on a particular PRI link over which a point-to-point connection is made. In an alternative, non-facility associated signaling (NFAS) arrangement, the D-channel may control B-channels on other links as well.
A traditional multimedia server allocates bandwidth of the PRI facility to audio, data and video calls on a per call basis and, more particularly, on a first-come-first-served basis. As each new call arrives, the server attempts to accommodate the call, regardless of its media type. The call is blocked (i.e., denied access to the WAN) only when the bandwidth available on the PRI facility is insufficient for the new call.
However, in multimedia applications in general, the relative importance of the media involved depends on the type of multimedia application invoked by the call. Based on the past experience, we have determined that the audio media is generally essential for each call. However, the relative importance of the video media with respect to the data media is application dependent. For engineering and financial types of multimedia applications for example, the data media normally takes precedence over the video media. On the other hand, in an entertainment type of application, the video media normally takes precedence over the data media. Accordingly, it is desirable to have a multimedia communications system such as system 100 affording the flexibility of allocating limited system resources to each media according to its relative importance. Thus, for example, with this flexibility, in the engineering multimedia application where audio and data media are more important than the video media, system 100 can be arranged in such a way that audio traffic and data traffic are more readily admitted to PRI facility 117 than video traffic.
The cost of system 100 varies directly with the number of PRI's provided in facility 117. In accordance with the invention, a service parameter, referred to as a "Blocking Probability", for traffic of each media type traversing facility 117 is enforced to efficiently utilize the bandwidth thereof. The blocking probability for a particular media type traffic in a multimedia service is defined as the likelihood that such traffic would be blocked because of unavailability of system resources (the bandwidth of facility 117 in this instance) allocated thereto. The value of the blocking probability varies inversely with the relative importance of the type of media traffic in the multimedia service.
To realize the blocking probability for each media type, the bandwidth of facility 117, comprising a number of B-channels, is divided in a manner depicted in FIG. 3. The resulting bands 303, 305 and 307 separated by partitions 311 and 313 are dedicated to the audio, video, and data traffic, respectively. It should be pointed out that the relative width of each band corresponds to a fraction of the bandwidth or number of B-channels on facility 117. The actual amount of bandwidth available on facility 117 and the particular manner in which the bandwidth is partitioned depend on the system user needs and the relative importance of each media type in the multimedia service to which the user subscribes. It is apparent that the lower the blocking probability required for the traffic of a particular type, the wider the band (corresponding to a higher number of B-channels) dedicated to that particular media type is. In implementation, all channels carrying audio information to and from location 101 are multiplexed and derived from band 303; all channels carrying video information are multiplexed and derived from band 305; and all channels carrying data are multiplexed and derived from band 307. Advantageously, with the blocking probabilities in place, the dominance of traffic of a particular media type, which may be relatively unimportant, would not cause blocking of traffic of other media types, which may be relatively important.
FIG. 4A illustratively tabulates the numbers of B-channels required of facility 117 for traffic of the respective media types, given the corresponding blocking probabilities in multimedia service 401. Service 401 includes, for example, video conferencing applications, and is video intensive. In order to maintain satisfactory quality of service, the blocking probability for video traffic is illustratively set at 0.5%. It should be noted that in practice 0.5% is a very low blocking probability for video communications. The corresponding number of B-channels needed in this instance is j, which is a positive number. Since we have determined that audio traffic is generally important in multimedia applications, the blocking probability therefor is illustratively set at 0.1%. The corresponding number of B-channels needed in this instance is i, which is a second positive number. FIG. 4A also enumerates different blocking probabilities for data traffic in service 401, and the corresponding numbers of B-channels required. For example, referring to row 403, a blocking probability of 0.1% for data traffic corresponds to k required B-channels, where k is a third positive number. Referring to row 405, a blocking probability of 1% corresponds to (k-3) required B-channels. It is apparent that by increasing the data blocking probability, the corresponding number of required B-channels decreases. Thus, FIG. 4A is important to a system user who subscribes to service 401 for establishing a communications budget. The user may be satisfied with a relatively high blocking probability for data traffic which is not as important as other media type traffic in service 401, and saves on the cost of B-channels as fewer B-channels would be needed.
Similarly, FIG. 4B illustratively tabulates the numbers of B-numbers required of facility 117 for traffic of the respective media types, given the corresponding blocking probabilities in multimedia service 411. Service 411 includes, for example, data sharing applications and is data intensive. In order to maintain satisfactory quality of service, the blocking probability for data traffic is illustratively set at 0.1% which, in practice, is very low for data communications. Thus, the corresponding number of B-channels needed in this instance is k. Again, the blocking probability for audio traffic is illustratively set at 0.1%, and the corresponding number of B-channels needed is i. FIG. 4B also enumerates different blocking probabilities for video traffic in service 411, and the corresponding numbers of B-channels required. For example, referring to row 413, a blocking probability of 1% for video traffic corresponds to (j-3) required B-channels. Referring to row 415, a blocking probability of 2% corresponds to (j-7) required B-channels. Again, by increasing the video blocking probability, the corresponding number of required B-channels decreases. The user in this instance may be satisfied with a relatively high blocking probability for video traffic which is not as important as other media type traffic in service 411, and saves on the cost of B-channels as fewer B-channels would be needed.
It should be noted that, in FIGS. 4A and 4B, the number of channels required for (or dedicated to) a particular media type only corresponds to the blocking probability associated with that media type, and is independent of the number of channels required for another media type. In particular, the values of i, j and k are independently derived. In other words, once the blocking probability for traffic of a particular media type is determined, the corresponding number of B-channels needed to meet such a blocking probability is defined, regardless of the numbers of channels required for other media types.
Referring briefly back to FIG. 3, each of bands 303, 305 and 307 is permanently allocated to the corresponding media as partitions 311 and 313 are static and do not move over time. Accordingly, the blocking probabilities for the audio, video, and data traffic in the multimedia service is said to be "guaranteed."
In an alternative embodiment, at least one of the above two partitions is not static but dynamic. FIG. 5 illustrates the bandwidth allocation in such an alternative embodiment. As shown in FIG. 5, the bandwidth of facility 117 is divided by partitions 511 and 513 into dedicated audio band 503, non-dedicated video band 505 and dedicated data band 507. Like partitions 311 and 313, partition 511 is static and does not move over time. As such, audio band 503 is dedicated to audio traffic. However, partition 513 is dynamic and may move between positions A and B. As a data traffic need arises, partition 513 may move from position A toward position B and in effect expand the data band into video band 505. Data/video band 520 between positions A and B represents the spare bandwidth to the data traffic at the expense of video band 505. That is, video traffic utilizing the bandwidth represented by data/video band 520 would be blocked in favor of data traffic when the latter requires more bandwidth than dedicated data band 507 can offer.
The bandwidth allocation depicted in FIG. 5 is particularly advantageous to a data intensive service such as service 411 described above. This stems from the fact that in such a service the user is more concerned about the audio and data traffic than the video traffic. In the allocation as illustrated, since the data traffic is allowed to utilize a portion of the video band, but not vice versa, the blocking probability for the video traffic is not guaranteed, and subject to the expansion of the data band. However, the blocking probabilities for the audio and data traffic are guaranteed, and the guaranteed probabilities correspond to dedicated band 503, and dedicated band 507 plus data/video band 520, respectively. A saving on the bandwidth is realized as dedicated data band 507 is narrower than band 307 to achieve the same guaranteed blocking probability.
The converse to the above is true for a video intensive services such as service 401 previously described. In such a service, video traffic may utilize part of the data capacity when the video traffic requires more bandwidth than the dedicated video band can offer.
FIG. 6 illustrates yet another allocation of bandwidth of facility 117 to audio, data and video traffic. In this example, the user requires a guaranteed blocking probability for the audio traffic, but is satisfied with a range of blocking probabilities, say, between 5 and 10 percent for each of the video and data traffic. To that end, band 603 is dedicated to the audio traffic and corresponds to the required guaranteed blocking probability; band 605 is dedicated to the video traffic and corresponds to the upper limit (in this instance 10%) of the blocking probability range associated therewith; and band 607 is dedicated to the data traffic and corresponds to the upper limit (in this instance also 10%) of the blocking probability range associated therewith.
To achieve the lower limits of the two probability ranges (both 5% in this instance), band 610 is instituted for shared use of the data and video traffic according to a first-come-first-served policy. The size of band 610 is determined in such a way that the requirements of both lower limits would be met. For example, let's say 10 B-channels additional to band 605 are needed to reduce the video blocking probability from 10 to 5 percent. Furthermore, let's say three B-channels additional to band 607 are needed to reduce the data blocking probability from 10 to 5 percent. In order to meet the above requirements of lower limits for both traffic, the size of shared band 610 must correspond to the higher of the two numbers of additional channels needed, i.e., 10 channels.
The blocking control operation of multimedia service processor 225 will now be described. Processor 225 allocates bandwidth of PRI facility 117 to incoming and outgoing multimedia calls during the establishment of the calls, and operates in accordance with bandwidth management process 700. As shown in FIG. 7, at step 705 of process 700, before any call establishment, the B-channels provided by facility 117 are designated for use by audio, video and data traffic according to the respective blocking probabilities. For example, where audio, video, and data blocking probabilities are guaranteed, as in the bandwidth allocation of FIG. 3, each media type is assigned with a number of B-channels for use by traffic of that media type only. Where the audio and data blocking probabilities are guaranteed and the video blocking probability is not, as in the bandwidth allocation of FIG. 5, each of audio and data media type is assigned with a number of B-channels for use by traffic of that media type only. In addition, a selected number of B-channels are assigned to video traffic, with a subset of that selected number being assigned as data/video channels which may be borrowed by data traffic when a data traffic need arises. Finally, where the audio blocking probability is guaranteed, and the video and data blocking probabilities are expressed by a range, as in the bandwidth allocation of FIG. 6, each media type is assigned with a number of B-channels for use by traffic of that media type only. An additional number of B-channels are designated for borrowing by video or data traffic on a first-come-first-served basis.
In establishing an incoming or outgoing call involving a combination of media, among other things, processor 225 checks call set-up information for the media involved, as indicated at step 710. In accordance with a standard protocol, this call set-up information is provided by a D-channel on facility 117 if it is an incoming call, and by LAN/WAN data converter 220 if it is an outgoing call. In addition to the media information, the call set-up information includes the destination of the call and a request for bandwidth for each media. At step 715, processor 225 checks the call set-up information for the amount of bandwidth for each media involved. Processor 225 translates at step 720 the amount of requested bandwidth to the number of B-channels needed for one of the media involved. Processor 225 then determines whether the B-channels on facility 117, as designated above, can accommodate the required number of B-channels for the media. To that end, processor 225 first checks the availability of the channels dedicated to the media involved, as indicated at step 725. If the capacity of any unused, dedicated channels does not meet the required number, processor 225 then checks at step 727 for additional, available capacity from any borrowing channels assigned to the media pursuant to the particular bandwidth allocation scheme such as that of FIG. 5 or FIG. 6. Process 700 thereafter returns to step 720 for every other media involved, if any. After the channel requirement for each media involved is checked, process 700 proceeds to step 729. If processor 225 determines at step 729 that the number of channels required for each media involved cannot be accommodated, processor 225 causes a signal indicative of a call rejection to be transmitted to the call-originating workstation, as indicated at step 730. Otherwise if the number of channels for at least one but not all of the media involved can be accommodated, processor 225 at step 733 causes a signal to be transmitted to the call-originating workstation, indicating that the call can be partially accommodated, with the missing media identified. It is up to the caller to accept or reject such an incomplete call. This last feature is important especially where audio communications are normally essential and requested in almost every multimedia call. An incomplete call providing no audio media would be highly undesirable and would most likely be rejected by the caller. Finally, if the number of channels for each media involved can be accommodated, processor 225 proceeds to establish the call, as indicated at step 735.
The foregoing merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise numerous other systems which embody the principles of the invention and are thus within its spirit and scope.
For example, the implementation of a blocking probability in accordance with the invention is not restricted to the illustrative application where the bandwidth of the PRI facility accessing a WAN is limited. Rather, it is generally applicable to communications systems where resources are limited for multiple applications. In one such communications system, a blocking probability is established for each application according to its relative importance, in accordance with the invention.
In addition, the channels used in the disclosed system are illustratively in the unit of an ISDN PRI B-channel. However, the principles of the invention also apply where the channels are subdivisions of the B-channels, or indeed, are not related to the B-channels or ISDN PRI protocol whatsoever, and they may even not be identical to one another in terms of their bandwidth or protocol utilized.
Finally, although the disclosed multimedia communications system is embodied in the form of various discrete electronic blocks and components, the invention could equally well be embodied in a system in which the functions of any one or more of those blocks and components or indeed, all of the functions thereof, are realized, for example, by one or more appropriately programmed processors.
We claim:
1. Apparatus for allowing completion of a call in a communications system having a plurality of channels, said call communicating information through at least one of a plurality of media, comprising:means for dividing said plurality of channels into subsets of channels; means for assigning to each of said plurality of media one of said subsets of channels, the number of channels in each subset assigned to a respective media being a function of at least a predetermined blocking probability associated with said respective media; means for determining an identity of each media involved in the call and the number of channels required for the media involved; and means for allowing the call to be completed when the required number of channels for at least one of the media involved in the call is not greater than the number of available channels assigned to the media.
2. The apparatus of claim 1 wherein the plurality of media include at least one of audio, video and data media.
3. The apparatus of claim 1 wherein each subset of channels assigned to a selected one of the media is for use by traffic of the selected media only.
4. The apparatus of claim 1 wherein at least one subset of channels assigned to a selected one of the media is for use by traffic of the selected media and at least one other media.
5. The apparatus of claim 1 wherein said plurality of channels are not identical.
6. The apparatus of claim 1 wherein said required number of channels are not identical.
7. The apparatus of claim 1 wherein said at least a blocking probability includes a range of blocking probabilities.
8. A system for communicating information involving at least one of a plurality of media comprising:means for allocating bandwidth for communications on each of said plurality of media, the amount of bandwidth allocated to a respective media being a function of at least a predetermined blocking probability associated with said respective media; means for identifying each media which said information involves; and means for allowing communications when the bandwidth allocated to at least one of the identified media is sufficient for communicating information associated therewith.
9. The system of claim 8 further comprising a network over which the communications are achieved.
10. The system of claim 9 wherein said network is a wide area network (WAN).
11. The system of claim 9 wherein said bandwidth is provided by a facility accessing said network.
12. The system of claim 11 wherein said facility comprises a plurality of channels in accordance with an integrated services digital network (ISDN) primary rate interface (PRI) standard.
13. The system of claim 8 wherein said information is provided by a terminal connected to a local area network (LAN).
14. The system of claim 13 wherein said LAN includes an Ethernet LAN.
15. The system of claim 8 wherein said plurality of media include at least one of audio, video and data media.
16. A method for allowing completion of a call in a communications system having a plurality of channels, said call communicating information through at least one of a plurality of media, comprising the steps of:dividing said plurality of channels into subsets of channels; assigning to each of said plurality of media one of said subsets of channels, the number of channels in each subset assigned to a respective media being a function of at least a predetermined blocking probability associated with said respective media; determining an identity of each media involved in the call and the number of channels required for the media involved; and allowing the call to be completed when the required number of channels for at least one of the media involved in the call is not greater than the number of available channels assigned to the media.
17. The method of claim 16 wherein the plurality of media include at least one of audio, video and data media.
18. The method of claim 16 wherein each subset of channels assigned to a selected one of the media is for use by traffic of the selected media only.
19. The method of claim 16 wherein at least one subset of channels assigned to a selected one of the media is for use by traffic of the selected media and at least one other media.
20. The method of claim 16 wherein said plurality of channels are not identical.
21. The method of claim 16 wherein said required number of channels are not identical.
22. The method of claim 16 wherein said at least a blocking probability includes a range of blocking probabilities.
23. A method for communicating information involving at least one of a plurality of media comprising the steps of:allocating bandwidth for communications on each of said plurality of media, the amount of bandwidth assigned to a respective media being a function of at least a predetermined blocking probability associated with said respective media; identifying each media which said information involves; and allowing communications when the bandwidth allocated to at least one of the identified media is sufficient for communicating information associated therewith.
24. The method of claim 23 wherein said plurality of media include at least one of audio, video and data media.
| 1996-10-28 | en | 1998-05-12 |
US-27956188-A | External door handle for a motor vehicle
ABSTRACT
An external door handle for a motor vehicle with a cleaning device for removing dirt and slush which accumulates on the handle when the vehicle is driven on slushy or muddy routes or when the vehicle is stationary.
BACKGROUND & SUMMARY OF THE INVENTION
The invention relates to a handle, useful as an external door handle for a motor vehicle, wherein the handle is a strap handle and has a gripping zone along its length.
Handles of this kind, especially when they are external door handles, can easily become soiled, for example when the vehicle is driven on wet, slushy or muddy roads and tracks.
In the case of external door handles of motor vehicles, the protection of the latter by supplementary devices against soiling caused by the relative wind has therefore already been disclosed. Devices of this kind described, for example, in German Offenlegungsschrift No. 2,214,425, German Pat. No. 2,403,690 and German Pat. No. 3,338,960 the principle of protecting the handle from the accumulation of dirt by elements which deflect the relative wind.
However, in many cases these known measures provide inadequate protection.
In particular, all these measures can only keep dirt away from the handle when the vehicle itself is in motion. In contrast, when the vehicle is stationary, such devices offer virtually no protection against dirt which is thrown against the door handle by other vehicles or which accumulates thereon in some other manner.
An object of the invention provides a cleaning device which provides for a clean condition to a handle for the person who wishes to use it, irrespective of how it became dirty and irrespective of the type of handle used.
This object is achieved on a handle of the generic type by providing a displaceable slide which moves across the gripping portion of the handle and touches, scrapes or brushes the gripping portion.
In contrast to the prior art described above, the solution according to the invention does not aim to prevent deposition of dirt, but rather aims to reliably and completely remove already deposited dirt before each use of the handle. The result, a self-cleaning handle, thus differs not only in structure, but also fundamentally from the known dirt prevention devices.
The slide which effects the cleaning of the door handle is preferably moved from outside the handle by a drive mechanism situated in the vehicle door.
Means are provided for triggering the drive in such a way that the handle is cleaned automatically before being grasped by a person using the handle. Thus initiation of the cleaning action can be in response to a trigger means connected for example to an inside door handle, a door key lock, or a remote control device, etc..
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the view of an external door handle which can be mounted in the handle recess of a motor vehicle door; and
FIG. 2 shows a section through the slide mounted so as to slide on the strap of the door handle, according to line II--II in FIG. 1.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an external door handle 2 fitted in a handle recess 1, of a motor vehicle door (not shown). The grasping zone is formed by a central section of the door handle designed as a strap 3. This strap has an approximately uniform cross-sectional profile along its length as can be seen in FIG. 2.
A slide 4 is arranged on the strap 3 so as to be able to slide over the entire grasping zone accessible to a user.
In the drawing, the slide is illustrated in an end position in which it is not in use. If it is desired to clean the strap 3, the slide 4 is set in motion to be displaced from the above-mentioned end position over the entire length of the strap to the other end of the strap and back again to its original end position. During this process, the slide 4 is guided on the strap 3. The drive (not shown) for the movement of the strap can be based on any desired servomotor and is situated inside the vehicle door associated with the handle recess 1. The slide 4 is linked to the servomotor (not shown) via a rod 5. The slide 4, which fits in annular fashion around the strap 3 has two internal chambers 6, 7 which, in the axial direction, adjoin one another, and are open to the strap surface 3. The chamber 6 contains an annular rubber lamellae 8 which acts like a windscreen wiper. When the slide 4 moves across the strap 3, the lamellae 8 acts in a wiping fashion against the surfaces of the strap 3.
Fluid can be admitted to the chamber 7 at the opposite end face of the slide via a line 9 connected to the rod 5. The fluid fed into the chamber 7 is therein absorbed by a sponge 10. By means of the sponge 10 supplied with fluid, the dirt deposited on the strap 3 of the door handle 2 can be moistened and thus removed more efficiently by the wiping lamellae 8. The wiping lamellae 8 are advantageously oriented so that they develop their full wiping effect only on the return journey of the slide 4 into its inoperative end position.
Instead of the wiping lamellae 8, the slide 4 can be provided with a brush. In this case, a separate chamber for the supply of a cleaning fluid can be omitted.
The drive of the slide 4 can be triggered by pushing the car key into the door lock 11. However, triggering is also possible by remote control. When the vehicle door is opened from inside the vehicle, the drive for the slide 4 can be triggered by actuating the internal door handle.
The direction in which the slide moves backwards and forwards on the strap 3 of the door handle 2 is indicated by the arrow 12. The chain-dotted representation of the slide 4 illustrates an intermediate position of the slide 4 between the two end positions.
Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.
What is claimed:
1. An outside vehicle door handle means for opening a vehicle door comprising:a strap which has a user gripping zone; the strap is attached to the outside of the vehicle door and is formed with an approximately uniform cross-sectional profile along its longitudinal direction; a displaceable slide means is provided and has portions which are arranged over the periphery of the strap for at least one of touching, scraping and brushing the gripping zone of the strap as the slide means is displaced along the strap to remove filth that has accumulated on the strap.
2. A handle mechanism for a vehicle comprising:a strap which has a user gripping zone; the strap is formed with an approximately uniform cross-sectional profile along its longitudinal direction; a displaceable slide means is provided and has portions which are arranged over the periphery of the strap for at least one of touching, scraping and brushing the gripping zone of the strap as the slide means is displaced along the strap, wherein the slide means is linked to a drive means for displacing the slide means which drive means is located externally of the strap.
3. A handle according to claim 2, wherein there is a trigger means for the drive means to initiate a backward and forward movement of the slide means over the gripping zone of the strap.
4. A handle according to claim 3, wherein the drive means is triggered by at least one of a key which can be inserted into the handle and by a remote control signal.
5. A handle according to claim 4, wherein the handle is an external door handle for a motor vehicle and wherein the remote control signal is triggered from an internal door handle for a motor vehicle.
6. A door handle according to claim 1, wherein the strap itself provides a guide path for the slide means.
7. A handle mechanism for a vehicle comprising:a strap which has a user gripping zone; the strap is formed with an approximately uniform cross-sectional profile along its longitudinal direction; a displaceable slide means is provided and has portions which are arranged over the periphery of the strap for at least one of touching, scraping and brushing the gripping zone of the strap as the slide means is displaced along the strap, wherein the portions of the slide means which scrape the gripping zone of the strap are annular rubber wiping lamellae.
8. A door handle according to claim 1, wherein the portion providing scraping of the gripping zone is situated at one end of the slide means and a fluid-distributing means connected to a fluid source outside the handle is situated at the other end of the slide means.
9. A door handle according to claim 8, wherein the fluid-distributing means is a chamber immediately adjoining and open towards the strap.
10. A door handle according to claim 8, wherein the fluid distribution means includes a material means for absorbing fluid.
| 1988-12-05 | en | 1990-07-10 |
US-89715286-A | Alkyl monoperoxysuccinic acid precursors and method of synthesis
ABSTRACT
A number of novel peracid precursors each have the general structure: <IMAGE> wherein: Z is a leaving group, the conjugate acid of the leaving group being in the range of from about 4 to 15; R is a substituted or unsubstituted alkyl or alkenyl group having from about 1 to 18 carbon atoms; and M is hydrogen or an alkali or alkaline earth metal. A method is also disclosed for synthesizing a product as represented above wherein succinic anhydride, including an R constituent as defined above is dissolved in a water-miscible, non-nucleophilic solvent and an acid including a Z constituent as defined above is neutralized and deprotonated to form a nucleophile, the substituted anhydride and the nucleophile being combined to form the product. The product is a component in a dry bleach product, optionally including other adjuncts.
FIELD OF THE INVENTION
The present invention relates to a novel group of peracid precursors which can be combined with a source of hydrogen peroxide in aqueous solution for in situ generation of peracids capable of effective fabric bleaching. The peracid precursors and hydrogen peroxide source may, for example, be combined in a dry bleach product, with or without detergents and other suitable adjuncts.
BACKGROUND OF THE INVENTION
Hypochloride bleaches and, more recently, peroxygen bleaching compounds, such as hydrogen peroxide, sodium percarbonate and sodium perborate monohydrate or tetrahydrate, for example, have been found useful in the bleaching of fabrics, textiles, and other similar materials.
Preformed peracid chemistry has developed more recently and been found to provide bleaching action.
Now, peracid precursor or activated bleach chemistry presents further alternative bleaching compositions. Generally, this chemistry concerns the use of precursors or activators which combine in aqueous solution with a peroxygen bleaching compound to cause effective bleaching action.
There have accordingly been a number of such peracid precursors or bleach activators developed in the prior art.
For example, U.S. Pat. No. 4,283,301 issued Aug. 11, 1981 to Diehl disclosed peracid precursors in the form of esters having different leaving groups specifically identified as either enols, imidazoles or carbon acids. In this regard, the Diehl patent is similar to many other references in using the term "leaving group" to identify a substituent of a precursor molecule which rapidly cleaves off in aqueous solution and promotes formation of the desired peracid. Diehl employed the symbol Z to designate such a leaving agent within a peracid precursor and that practice is also employed in the following disclosure of the present invention.
U.S. Pat. No. 4,412,934 issued Nov. 1, 1983 to Chung et al also disclosed surface active peracid precursors, which were denoted as "bleach activators", having the general configuration or structure RCOL wherein R was an alkyl group with 5 to 18 carbon atoms and L was a leaving group, the conjugate acid of which had a pKa in the range of 6-13. GB No. 864,798, however, appears to have disclosed the same technology at an earlier time.
U.S. Pat. No. 4,483,778 issued Nov. 20, 1984 to Thompson et al disclosed a modification of a peracid precursor to the Chung et al type, particularly for the purpose of reducing or eliminating undesirable odors.
European Patent Publication Nos. 105,672 and 105,673, both published Apr. 18, 1984 upon application by the Proctor & Gamble Company, disclosed methods of synthesizing peracid precursors of the type disclosed by Chung et al.
U.S. Pat. No. 4,473,507 issued Sept. 25, 1984 to Bossu disclosed preformed peroxy acid bleach preferably employed in conjunction with a dry, granular, controlled release laundry bleach product in a water-permeable pouch.
All of the above noted peracid precursors or bleach activators and the peracids resulting in aqueous solution have been found to be effective to one degree or another in terms of bleaching activity.
There has been found to remain a need for peracid precursors having further improved characteristics. For example, in addition to providing increased bleaching action, it is also desirable to provide a peracid precursor capable of providing greater peracid yield in aqueous solution. At the same time, there has also been found to remain a need for new peracid precursors and corresponding methods for effectively synthesizing the precursors.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide novel peracid precursors, a novel method for synthesizing the precursors and a novel bleach composition containing the precursors.
It is a further object of the invention to provide novel peracid precursors having the general structure: ##STR2## wherein Z is a leaving group characterized by a conjugate acid thereof having a pKa value in the range of from about 4 to 15;
R is a substituted or unsubstituted, alkyl or alkenyl group having from about 1 to 18 carbon atoms, the form of the structure indicating that R can be in either the or position; and
M is hydrogen or an alkali or alkaline earth metal.
It is a further object of the invention to provide a peracid precursor compound of the general structure set forth above wherein Z is selected from the group consisting essentially of:
(1) a compound having the general structure ##STR3## wherein Y and R' are optionally substituted at any respective available locations in the structure,
R' is hydrogen or a substituted or unsubstituted alkyl group of about one to about ten carbon atoms, with or without an ether linkage, that is, R' or OR' where R' is otherwise defined as above, and
Y is hydrogen or a halogen or a solubilizing group; and
(2) a compound having the general structure comprising ##STR4## wherein R2 is an alkyl chain containing from about one to about eight carbon atoms,
wherein
R3 is an alkyl group containing from about one to about eighteen carbon atoms,
R4 is H or R2, and
Y' is H or a solubilizing group; and
(3) the group consisting of enols, carbon acids and N-alkyl quaternary imidazoles.
It is a still further object of the invention to provide a novel peracid precursor compound wherein the leaving group Z is identified in subparagraph (2) above and wherein Y' is selected from the group consisting of SO3 - M, CO2 - M, SO4 - M, N+ R3 5 X, ONR2 5 and mixtures thereof wherein R5 is an alkyl chain containing at least one carbon atom, M is a cation and X is an anion.
In accordance with the preceding object of the invention, the specific compound noted above includes the novel base structure of the invention while further including a suitable leaving group.
It is another further object to provide a peracid precursor compound of the type noted above wherein Y is a solubilizing group selected from the group consisting of CO2 - M', SO3 - M', N+ (R)3 and OH, M' being hydrogen or an alkali or alkaline earth metal or mixtures thereof.
Preferably, the peracid precursor compound includes a phenol group or a phenol carboxylate as a leaving group with R being an alkyl group having from about 8 to 12 carbon atoms or an alkenyl group having from about 10 to 14 carbon atoms.
Peracid precursor compounds of the above type, particularly the preferred compounds noted immediately above, have been found to exhibit excellent peracid yields over a wide pH range while also lending themselves to use in bleaching compositions.
Accordingly, it is another related object to provide a dry bleaching composition and method of bleaching wherein a composition is prepared including a source of hydrogen peroxide in aqueous solution and a bleach-effective amount of a peracid precursor compound as noted above.
It is yet another further related object to provide a method for synthesizing peracid precursor compounds of the type noted above in a process wherein: succinic anhydride substituted with an R substituent as defined above is dissolved in a water miscible non-nucleophilic solvent; an acid including a Z constituent as defined above is neutralized in order to deprotonate the acid and convert it into a nucleophile also including Z as a substituent; and the substituted anhydride and nucleophile are combined in an addition reaction to form the peracid precursor compound.
It is also a general object of the invention to provide a peracid precursor compound or compounds capable of effective bleaching in bleach or wash temperatures below about 70° C., more preferably below about 60° C., and most preferably at or below about 50° C.
Additional objects and advantages of the invention are made more apparent in the following description and examples of the invention which, however, are not to be taken as limiting the scope of the invention but rather to facilitate an understanding thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
General Structure of the Peracid Precursor
Compounds of the Invention
As noted above, the present invention generally relates to novel peracid precursor compounds which are effective to provide relatively high bleaching activity in aqueous solution or wash water at temperatures generally below about 70° C., more preferably below about 60° C. and most preferably at or below about 50° C.
The novel peracid precursors of the invention are formed with a succinic anhydride moiety which is combined, in a method of synthesis described in greater detail below, with one of a variety of leaving agents and an alkyl or alkenyl constituent selected for promoting surface activity of the resulting peracid precursor. Accordingly, the invention is based upon peracid or perhydrolysis chemistry as referred to above and dealt with at length in the prior art, for example by Sheldon N. Lewis, in Chapter 5 entitled "Peracid and Peroxide Oxidations" of the publication entitled Oxidation, Volume 1, published by marcel Dekker, Inc., New York, N.Y., 1969 (see pages 213-254). In order to avoid a detailed discussion of basic peracid and perhydrolysis chemistry, even though not believed necessary for an understanding of the invention by those skilled in the art, that reference is incorporated herein as though set out in its entirety.
In accordance with the above description, the preferred peracid precursor compounds of the present invention have the general structure: ##STR5## wherein Z is a leaving group, the conjugate acid of which has a pka in the range of from about 4 to about 15;
R is a substituted or unsubstituted, alkyl or alkenyl group having from about one to about eighteen carbon atoms the form of the structure indicating that R can be in either the alpha or beta position; and
M is hydrogen or an alkali or alkaline earth metal.
A number of peracid precursor compounds corresponding to the above structure of the invention have been found to result in excellent perhydrolysis in aqueous solution, giving particularly high yields of the corresponding or desired peracid. In addition to the excellent yields noted above and discussed in greater detail below, the peracid precursor compounds of the invention have also been found to surprisingly demonstrate pH insensitivity.
In other words, the peracid precursor compounds of the invention defined by the general structure set forth above have been found to achieve increased perhydrolysis yield as compared with peracid precursors available from the prior art. Those high yields can be achieved at pH values in the range of about 8 to 10. It is also to be understood, of course, that very high perhydrolysis yields are accomplished by the peracid precursor compounds of the present invention at higher pH values.
In considering the structure of the peracid precursor compounds of the present invention in greater detail, it was noted above that the general structure includes an alkyl or alkenyl group, either substituted or unsubstituted. This substituent of the basic succinic anhydride structure promotes "surface bleaching" after undergoing perhydrolysis in wash water. The alkyl or alkenyl group, referred to above as R, produces an affinity in the peracid precursor compound for fabrics of the type being subjected to bleach treatment. Bleaching action thus occurs more effectively upon or near the surface of the fabric.
As noted above and discussed in greater detail below, R is selected as an alkyl or alkenyl group having from about 1 to about 18 carbon atoms and more preferably from about 6 to 16 carbon atoms. Most preferably, R comprises an alkyl group having from about 8 to 12 carbon atoms or an alkenyl group having from about 10 to 14 carbon atoms. As will also be noted in greater detail below, these most preferred alkyl and alkenyl groups form a substituent of the peracid precursor compound. At the same time, the leaving group, identified above as Z, preferably comprises either a phenol group or a substituted phenol group such as a phenol carboxylate or sulfonate.
Various solubilizing groups such as the sulfonates (--SO3 -) or carboxylates (--CO2 -) have been found to impart good solubility or dispersion characteristics to the peracid precursors of the present invention. Additionally, a counterpart ion or counterion for the solubilizing group is preferably chosen from the group consisting of hydrogen, alkali metal ions including sodium, potassium and lithium, alkaline earth metal ions and ammonium ions.
Addition of the solubilizing group can be accomplished in a number of ways well known to those skilled in the art. For example, halogen groups may be added by typical halogenation reactions in which a typical source of halogen is combined by addition with a selected starting material in the presence of a Lewis acid. Nitration, on the other hand, occurs when the starting material is reacted with nitric acid in the presence of sulfuric acid. Sulfonation occurs when the starting material is reacted with concentrated sulfuric acid. Amination is generally produced by reacting an amino source with the starting material in the presence of liquid ammonia. Further, acylation and alkylation can readily be carried out by Friedel-Crafts reactions.
As noted above, the general structure of the peracid precursor compounds includes a substituent identified as M and located on the free succinate carboxylate of the succinic anhydride structure. Although M is usually hydrogen, at least initially, it may also be an alkali or alkaline earth metal as noted above. If any of the peracid precursor compounds having the above general structure, with M being hydrogen, are placed in aqueous solution or in wash water, their very high deprotonation values in water (for example, a pKa of about 4) readily cause formation of compounds where M is any of a variety of alkali or alkaline earth metals present in the aqueous solution or wash water. Thus, these variations are considered to be equivalent to the basic hydrogenated structure.
The greatest variation for the peracid precursor compounds of the invention exists within the leaving group identified as Z. As initially noted above, the leaving group Z may be selected from a group of compounds consisting of the following:
(1) Initially, the leaving group Z may be a compound having the general structure: ##STR6## wherein Y and R' are optionally substituted at any respective locations in the structure,
R' is hydrogen or a substituted or unsubstituted alkyl group of about one to about ten carbon atoms, with or without an ether linkage, that is, R' or OR' where R' is otherwise defined as above, and
Y is hydrogen or a halogen or a solubilizing group.
In the above class of leaving group compounds, R' and Y may both be hydrogen with the leaving group structure being a phenol group. Y may also be a halogen or solubilizing group, as described in greater detail below, with R' being a substituted or unsubstituted alkyl group of about 1 to 10 carbon atoms, with or without an ether linkage, that is, R' or OR' where R' is otherwise defined as above. Accordingly, a substantial number of compounds are covered by paragraph (1) above.
Also in connection with the structure of paragraph (1), the Y and R' substituents may be located at any of the unsubstituted positions in the phenol ring. Accordingly, the substituents Y and R' are shown above as being capable of addition at any available location.
It is also to be understood that numerous other substituents disclosed in the general structure of the peracid precursor compounds may similarly be located in a variety of positions. Accordingly, the preceding comments concerning the Y and R' substituents of paragraph (1) also apply to those other substituents.
(2) Yet another group of compounds suitable for forming the Z substituent in the general structure of the peracid precursor compound of the present invention may have any of the following general structures: ##STR7## wherein R2 is an alkyl chain containing from about one to eight carbon atoms,
wherein
R3 is an alkyl group containing from about one to eighteen carbon atoms,
wherein
R4 is H or R2, and
wherein
Y' is H or a solubilizing group.
The class of leaving group compounds set forth in subparagraph (2) is also a substituent of the general structure of the novel peracid precursor compounds identified above.
(3) Finally, yet another class of leaving groups Z is defined as consisting of enols, carbon acids and N-alkyl quarternary imidazoles.
Peracid precursor compounds constructed according to the present invention and including a leaving group Z as defined in subparagraph (3) have been found to exhibit the general advantages of the present invention. However, certain peracid precursor compounds with leaving groups defined in subparagraph (3), particularly those including carbon acids, may be less satisfactory for example by exhibiting lower perhydrolysis yields in aqueous solution.
As noted above, a wide variety of substituents are possible in the general structure of the peracid precursor compounds. However, the most preferred forms of the peracid precursor compounds include R as an alkyl group containing from about 8 to 12 carbon atoms or an alkenyl group containing from about 10 to 14 carbon atoms while the leaving group Z preferably comprises either a simple phenol or a substituted phenol, preferably a sulfonated phenol or a carboxylated phenol as also discussed in greater detail below.
In addition to exhibiting excellent perhydrolysis yields with corresponding pH insensitivity, the peracid precursor compounds of the general structure defined above, particularly those summarized immediately above, have also been found to particularly lend themselves to effective synthesis as disclosed in the following examples.
Surfactants and Other Detergent Adjuncts
Surfactants appear useful in the inventive compositions to improve cleaning performance. Nonionic surfactants appear particularly effective for this purpose. Preferred surfactants include linear ethoxylated alcohols, such as those sold by Shell Chemical Company under the brand name NEODOL. Other suitable nonionic surfactants include other linear ethoxylated alcohols with an average length of from about 6 to 16 carbon atoms and averaging about 2 to 20 moles of ethylene oxide per mole of alcohol; linear and branched, primary and secondary ethoxylated, propoxylated alcohols with an average length of about 6 to 16 carbon atoms and averaging 0-10 moles of ethylene oxide and about 1 to 10 moles of propylene oxide per mole of alcohol; linear and branched alkylphenoxy (polyethoxy) alcohols, otherwise known as ethoxylated alkylphenols with an average chain length of 8 to 16 carbon atoms and averagins 1.5 to 30 moles of ethylene oxide per mole of alcohol; and mixtures thereof.
Further suitable nonionic surfactants include polyoxyethylene carboxylic acid esters, fatty acid glycerol esters, fatty acid and ethoxylated fatty acid alkanolamides, certain block copolymers of propylene oxide and ethylene oxide, and block polymers of propylene oxide and ethylene oxide with propoxylated theylene diamine. Also included are such semi-polar nonionic surfactants as amine oxides, phosphine oxides, sulfoxides, and their ethoxylated derivatives.
Anionic surfactants may also be employed. Examples of such anionic surfactant include the alkali metal and alkaline earth metal salts of C6 -C20 fatty acids and resin acids, linear and branched alkyl benzene sulfonates, alkyl sulfates, alkyl ether sulfates, alkane sulfonates, olefin sulfonates, hydroxyalkane sulfonates, fatty acid monoglyceride sulfates, alkyl glyceryl ether sulfates, acyl sarconsinates and acyl N-methyltaurides.
Suitable cationic surfactants include the quarternary ammonium compounds in which typically one of the groups linked to the nitrogen atom is a C12 -C18 alkyl group and the other three groups are short chained alkyl groups which may have inert substituents such as phenol groups.
Further, suitable amphoteric and zwitterionic surfactants, which may contain an anionic water-solubilizing group, a cationic group and a hydrophobic organic group, include amino carboxylic acids and their salts, amino dicarboxylic acids and their salts, alkylbetaines, alkyl aminopropylbetaines, sulfobetaines, alkyl imidazolinium derivatives, certain quarternary ammonium compounds, certain quaternary phosphonium compounds and certain tertiary sulfonium compounds. Other examples of potentially suitable zwitterionic surfactants can be found in Jones, U.S. Pat. No. 4,005,029, at columns 11-15, which is incorporated herein by reference.
Further examples of anionic, nonionic, cationic and amphoteric surfactants which may be suitable for use in this invention are set forth in Kirk-Othmer, Encyclopedia of Chemical Technology, Third Edition, Volume 22, pages 347-387, and McCutcheon's Detergents and Emulsifiers, North American Edition, 1983, which are also incorporated herein by reference.
As mentioned above, the surfactants may actually assist during perhydrolysis to bring the precursor into more intimate contact with the source of hydrogen peroxide. If so, then certain water soluble or dispersible polymers such as polyvinyl alcohol, polyvinyl pyrrolidine, polyacrylic acid and the like, may also aid in promoting perhydrolysis.
As mentioned hereinabove, other common detergent adjuncts may be added if a bleach or detergent bleach product is desired. In a dry bleach composition, for example, the following ranges (set forth by weight percentages) appear suitable;
______________________________________
Hydrogen Peroxide Source
0.5-50.0%
Peracid Precursor 0.05-75.0%
Surfactant 1.0-50.0%
Buffer 1.0-50.0%
Filler, stabilizers, dyes,
0.5-99.9%
Fragrances, brighteners, etc.
______________________________________
The hydrogen peroxide source may be selected from the alkali metal salts of percarbonate, perboarte, hydrogen peroxide adducts and hydrogen peroxide. Most preferred are sodium percarbonate, sodium perborate mono- and tetrahydrate, and hydrogen peroxide. In liquid applications, it may be necessary to isolate the liquid hydrogen peroxide solution from the precursor prior to use, e.g., to prevent premature decomposition. This can be accomplished by dispensing separate streams of fluid containing, respectively, hydrogen peroxide and precursor and other adjuncts via, e.g., a multiple liquid dispenser. An example of a dispenser of this type is "Multiple Liquid Proportional Dispensing Device," disclosed in U.S. Pat. No. 4,585,150, issued Apr. 29, 1986 to Beacham et al, and assigned to The Clorox Company.
The buffer may be selected from sodium carbonate, sodium bicarbonate, sodium borate, boric acid, sodium silicate, phosphoric acid salts, and other alkali metal/alkaline earth metal salts known to those skilled in the art. Organic buffers, such as succinates, maleates and acetates may also be suitable for use. It appears preferable to have sufficient buffer to attain an alkaline pH.
The filler material which, in a detergent bleach application, may actually constitute the major constituent of the detergent bleach, is usually sodium sulfate. Sodium chloride is another potential fillter. Dyes include anthraquinone and similar blue dyes. Pigments, such as ultramarine blue (UMB), may also be used, and can have a bluing effect by depositing on fabrics washed with a detergent bleach containing the UMB. Monastral colorants may also be included. Brighteners, such as stilbene, styrene and styrylnapthalene brighteners (fluorescent whitening agents), may also be used. Fragrances used for esthetic purposes are commercially available from Norda, International Flavors and Fragrances, Firmenich and Givaudon.
Synthesis of the Peracid Precursors
The novel peracid precursor compounds of the invention are synthesized by the methods summarized below and embodied by the following examples. Additionally, bleaching performance resulting from use of products of those methods are set forth below.
The method for synthesizing peracid precursors of the invention is summarized immediately below and is believed generally applicable for use with a wide variety of peracid precursor products having the general structure: ##STR8## wherein Z, R and M are defined as before. Following the summary of the method of synthesization, a number of examples are then set forth for a preferred peracid precursor products according to the invention.
In discussing the synthesis method of the invention, the procedural steps are divided into seven portions referred to below as Step I through Step VII. The numbering of steps in this manner is merely intended to facilitate a better understanding of the invention and is not intended to indicate relative importance for any of the steps. In fact, as will be noted below, certain of the procedural portions or steps are considered critical to the invention while other of the steps are set froth only for the purpose of demonstrating complete synthesis and separation of the precursor products as contemplated by the invention.
In an initial processing portion referred to as Step I, an acid selected to include Z as a substituent, where Z is defined as above, is neutralized with a selected base catalyst in order to deprotonate the acid and convert it into a nucleophile suitable for entering into an addition reaction disclosed below as Step III.
By way of example, one preferred structure for Z according to the present invention is a phenol carboxylate group. In order to better demonstrate Step I of the invention for that exemplary product, p-hydroxybenzoic acid is selected as the corresponding acid. At the same time, sodium hydroxide is selected for achieving base catalysis in Step I.
Accordingly, for these exemplary materials, Step I is preferably represented as: ##STR9##
In Step I, the base catalysis agent is present in a molar excess relative to the acid, for example, in a molar ratio of 2:1, in order to assure complete conversion of the acid to the nucleophile. At the same time, the nucleophile is conditioned for entering into the addition reaction of Step III (set forth below).
In Step II, which is carried out separately from the procedure of Step I, succinic anhydride substituted with an R substituent as defined above is dissolved in a water-miscible non-nucleophilic solvent in order to assure availability of the substituted succinic anhydride in the addition reaction of Step III as described below.
In this step, it is particularly important that the solvent be non-nucleophilic so that is does not participate in the addition reaction of Step III. At the same time, the solvent must be water-miscible in order to disperse the substituted succinic anhydride, which is hydrophobic in nature, in the water phase of Step III.
As noted above, R is either an alkyl or alkenyl group having from about 1 to 18 carbon atoms, more preferably from about 6 to 16 carbon atoms and most preferably an alkyl group having from about 8 to 12 carbon atoms or an alkenyl group having from about 10 to 14 carbon atoms.
Exemplary non-nucleophilic and water-miscible solvents suitable for use in the dissolution procedure of Step II include but are not limited to tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), ethyl acetate, ketones having from about 1 to 4 or 5 carbon atoms such as methyl ethyl ketone (MEK) and ethers such as dimethyl, diethyl and dipropyl ethers.
The identify of the particular solvent employed in Step II has been found to be of substantial importance within the present invention to assume completion of the substitution reaction in Step III. The above noted solvents have been found generally satisfactory for this purpose. However, tetrahydrofuran has been found to be a most particularly preferred solvent in Step II in order to assure the high yield desired in the present invention as noted above. Of the other solvents, diethyl ether was found to be suitable for use where Z included an unsubstituted phenol group but not where Z was a substituted phenol such as phenol carboxylate.
In Step III, the substituted anhydride dissolved in the water-miscible and non-nucleophilic solvent of Step II, is combined in approximately equal molar amounts with the nucleophile resulting from neutralization of the acid including Z as a constituent, in an addition reaction to form the peracid precursor product of the present invention.
Where the exemplary components discussed above in connection with Step I are employed in the method of the invention, the addition reaction of Step III may be set forth as follows: ##STR10##
In carrying out Step III, the addition time is generally extended to as long as five minutes in the examples set forth below in order to prevent instability from occurring in the products of the addition reaction.
Because of the selection and conditioning of components as described above in Steps I and II, the addition reaction of Step III is made possible in accordance with the present invention.
Step IV of the synthesis method involves agitation or stirring of the components from Steps I and II for an additional period of time after their combination in order to assure completion of the addition reaction of Step III.
In Step V of the synthesis method, a non-nucleophilic organic solvent is added to the combination resulting from Steps III and IV to initiate extraction of an organic phase including the peracid precursor product of the invention. In order to more effectively perform the extraction step noted above, the organic non-nucleophilic solvent is preferably very polar and may be selected from the group including but not limited to non-water soluble ethers, methylene chloride, chloroform, etc.
In Step VI of the synthesis method, an acid is added to the addition reaction product together with the organic solvent from Step V in order to neutralize the excess base catalysis agent and precursor salt from Steps I and III and thereby protonate the peracid precursor product of the invention so that it enters substantially completely into the organic phase formed by the extraction solvent added in Step V.
Hydrochloric acid is a suitable acid for carrying out the function of Step VI. Other inorganic acids which appear suitable for use in the process include sulfuric acid, phosphoric acid and nitric acid.
Steps V and VI are not particularly critical to the invention in terms of forming the peracid precursor product which, as was noted above, is formed by the combined limitations of Steps I-III. However, Steps V and VI are important to the extent that they cause substantially all of the peracid precursor product to enter the organic phase formed by the extraction solvent in order to further facilitate high yield recovery which is an important feature of the invention.
Thereafter, in Step VII, the peracid precursor product contained in the organic phase is dried, for example over magnesium sulfate, and the solvent from Step V removed for example by evaporation in order to result in recovery of the product itself.
As noted above, the procedures provided in Steps I-III are particularly critical to the invention and result in formation of the desired peracid precursor product. At the same time, it is particularly important to note in connection with Steps I-III that the synthesis of the present invention can be carried out in a single container.
In the following examples, specific synthesis techniques are set forth for a number of preferred peracid precursor products according to the present invention.
EXAMPLE 1
α and β-Octyl (Mono p-Carboxy Phenol) Succinate
In this example, 22.1 grams (0.16 moles) of p-hydroxybenzoic acid, obtained from Aldrich Chemical Co., Milwaukee, Wis., was dissolved in 130 milliliters of 15 10% sodium hydroxide contained in a flask immersed in a cold ice bath. In a separate container, 33.9 grams (0.16 moles) of octylsuccinic anhydride were combined with 150 milliliters of tetrahydrofuran (THF), also obtained from Aldrich Chemical Co.
The substituted succinic anhydride dissolved in THF was then added over a period of about five minutes to the p-hydroxybenzoic acid neutralized in a molar excess of sodium hydroxide.
Thereafter, the reaction mixture resulting from combination of the substituted succinic anhydride and the acid was stirred for an additional period of about twenty minutes in order to assure completion of the addition reaction between the substituted succinic anhydride and the acid.
200 milliliters of ether, also obtained from Aldrich Chemical Co., were then added to the reaction mixture followed by the addition of 100 milliliters of a 20% solution of hydrochloric acid. This results in phase separation with the peracid precursor product of the invention entering into the organic phase formed primarily by the ether solvent. The organic phase including the ether solvent and peracid precursor product was then separated from the water phase and dried over magnesium sulfate in order to remove any residual water. Thereafter, the organic phase was subjected to a reduced pressure of about 20 millimeters of mercury (mm. Hg) in order to effect removal of the ether solvent from the product. This resulted in the formation of 52.4 grams of the subject peracid precursor product as a white solid substance. The resulting product included alkyl groups in a mixture of α and β positions as indicated by the title of EXAMPLE 1 and corresponding to the initial octylsuccinic anhydride.
EXAMPLE 2
α and β-Decyl (Mono p-Carboxy Phenol) Succinate
The steps of Example 1 were again followed except that 38.4 grams (0.16 moles) of decylsuccinic anhydride, also obtained from Humphrey Chemical Co., were dissolved in THF in place of the octylsuccinic anhydride of Example 1. Otherwise, the steps of Example 1 were repeated as set forth above resulting in the formation of 56.3 grams of the subject peracid precursor product also in the form of a white substance.
EXAMPLE 3
α and β-Dodecyl (Mono p-Carboxy Phenol) Succinate
The steps of Example 1 were again repeated except that 42.9 grams (0.16 moles) of dodecylsuccinic anhydride were dissolved in the THF. At the same time, the acid was dissolved in 130 milliliters of a 10% solution of sodium hydroxide in order to provide a greater liquid or water volume as discussed above. The dodecylsuccinic acid was also obtained from Humphrey Chemical Co. The steps of Example 3 resulted in the formation of 61.1 grams of the subject peracid precursor product again in the form of a white solid.
EXAMPLE 4
2α or β- Decenyl (Mono p-Carboxy Phenol) Succinate
Again, the steps of Example 1 were repeated except that 38.1 grams of decenylsuccinic anhydride were dissolved in THF in place of the octylsuccinic anhydride in Example 1. The decenylsuccinic anhydride was also obtained from Humphrey Chemical Co.
This resulted in formation of 54.2 grams of the subject peracid precursor product in the form of a white solid.
EXAMPLE 5
2α or β- Dodecenyl (Mono p-Carboxy Phenol) Succinate
The steps of Example 1 were again repeated except that 53.2 grams (0.2 moles) of dodecenylsuccinic anhydride were dissolved in the THF. At the same time, the acid was dissolved in 160 milliliters of a 10% solution of sodium hydroxide as also disclosed above in Example 3.
This resulted in formation of 77.8 grams of the subject peracid precursor product again in the form of a white solid.
EXAMPLE 6
2α or β- Tetradecenyl (Mono p-Carboxy Phenol) Succinate
The steps of Example 1 were again repeated with 47 grams (0.16 moles) of tetradecenylsuccinic anhydride, again obtained from Humphrey Chemical Co., being dissolved in the THF. Also as in Examples 3 and 5, the acid was dissolved in 130 milliliters of a 10% solution of sodium hydroxide in water.
This resulted in a the formation of 64 grams of the subject peracid precursor product again in the form of a white solid.
EXAMPLE 7
α and β-Decyl Monophenol Succinate
The steps of Example 1 were again repeated except that 7.2 grams (0.03 moles) of decylsuccinic anhydride were combined with 150 milliliters of diethyl ether. The decylsuccinic anhydride of this example was also obtained from Humphrey Chemical Co. At the same time, 2.3 grams (0.025 moles) of phenol were dissolved in the sodium hydroxide solution. Otherwise, the steps of Example 1 were repeated as noted above, resulting in formation of 9.3 grams of the subject peracid precursor product in the form of a white solid.
EXAMPLE 8
α and β-Dodecyl Monophenol Succinate
The steps of Example 7 were again repeated except that 7.5 grams (0.08 moles) of dodecylsuccinic anhydride were employed in place of decyl succinic anhydride described as above in connection with Example 7. At the same time, the phenol was dissolved in 32 milliliters of a 10% solution of sodium hydroxide in order to provide greater liquid or water volume as was also disclosed above in connection with Examples 3, 5 and 6. Otherwise, the steps of Examples 7 and 1 were again repeated resulting in the formation of 17.2 grams of the subject peracid precursor product in the form of a white solid.
In addition to setting forth specific procedures for forming preferred peracid precursor products according to the present invention, Examples 1 through 8 to further demonstrate the ability to synthesize other peracid precursor products having the general structure set forth above by similar techniques.
The peracid precursor products formed in accordance with Examples 1-8 above were further tested as described below both in terms of perhydrolysis yield and subsequent bleaching characteristics. Those features of the invention for the respective products are set forth immediately below.
Peracid Yield from Perhydrolysis of Different Precursors
The ability of the peracid precursor products of the invention to produce effective peracid yields is demonstrated in Table I below which sets forth yield data for the products described above in Examples 1-8 and also for two peracid precursor products disclosed in the Chung et al reference for purposes of comparison. Accordingly, in Table I, tests carried out with the products of Examples 1-8 are respectively numbered 1-8 with the two Chung et al peracid precursor prodcuts numbered 9 and 10.
Peracid yeilds for these respective products were determined at a number of pH levels to demonstrate the perhydrolysis effectiveness of the peracid precursors at relatively low pH levels in the range of approximately 8 to 10. Accordingly, tests were initially conducted at relatively high pH levels with additional yield tests being conducted at successively lower pH levels until the resulting yield values became unacceptable for one reason or another.
In carrying out the perhydrolysis yield tests, the respective peracid precursors were introduced into an aqueous solution together with a source of hydrogen peroxide. In these tests, for convenience, liquid hydrogen peroxide was employed in a 2:1 molar ratio relative to the precursor. The use of liquid hydrogen peroxide generally simulates wash water conditions where a compound such as sodium perborate is the normal source of hydrogen peroxide.
In actual wash water applications, the peracid precursor would of course be incorporated in a solid composition with or without various surfactants and other detergent adjuncts. However, the test as set forth above provides an effective test indicating perhydrolysis yield for each of the peracid precursors.
In conducting these tests, peracid yields in the soltuions were determined at a number of time intervals by potassium iodide (KI) titration in order to determine active oxygen yields. Such titration tests are well known in the art and are disclosed for example in the publication titled "Peracid and Peroxide Oxidations" by Sheldon N. Lewis (see above). Accordingly, that reference is incorporated herein as though set forth in its entirety.
Peracid yield tests were carried out at three pH levels including pH values of 8.5, 9.5 and 10.5. Tests were first conducted at the highest pH value and then at successively lower pH values. However, if the perhydrolysis yield values fell below an acceptable level, about 40% of theoretical for example, then tests were not carried out at the lower pH levels.
Further in Table I, below, titration to determine active oxygen (A.O.) was carried out for the products of Examples 2-8 and the Chung et al products numbered 9-10. The yields of peracid given in Table I are the maximum amounts formed.
The two precursor products tested from the Chung et al reference included sodium linear octanoyloxybenzene sulfonate (number 9) and sodium linear decanoyloxybenzene sulfonate (number 10).
TABLE I
______________________________________
Comparative Perhydrolysis Yield for Tests Carried Out at
70° F. (or 21° C.) as a Percentage of Theoretical Peracid
Active Oxygen
% Yield from Titrated A.O.
Precursor pH 8.5 pH 9.5 pH 10.5
______________________________________
2 86 97 100
3 -- 37 72
4 89 87 100
5 41 70 99
6 -- -- 30
7 -- 82 89
8 -- -- 31
9 (Chung et al)
-- 39 83
10 (Chung et al)
-- 26 58
______________________________________
Table I clearly demonstrates advantages in peracid precursor products of the present invention in producing very high perhydrolysis yields which are generally insensitive to pH.
A comparison of the perhydrolysis yields for peracid precursor products of the present invention considered with respect to yields for products as disclosed by Chung et al further demonstrate the superior characteristics of the precursors of the present invention.
Bleach Performance Tests
Performance tests for the precursors of the present invention were also conducted.
Performance tests summarized in Table II below were carried out as follows: stain removal studies were conducted with a tergotometer (operating at 100 rpm and 100° F. (38° C.).
Wash water containing 1.50 grams per liter (g/L) of Tide® detergent and 0.02M sodium carbonate was adjusted to the desired pH indicated in Table II by the addition of sulfuric acid or sodium hydroxide. The pH level was maintained throughout a twelve minute wash cycle. A hydrogen peroxide level of 28 parts per million (ppm), measured as active oxygen (A.O.), was developed. A precursor concentration of 14 ppm theoretical A.O. was established by adding either 332/ppm decyl monophenol carboxylate succinic anhydride precursor of 356 ppm dodecyl monophenol carboxylate succinic anhydride precursor, assuming 100% purity.
TABLE II
______________________________________
Percent Stain Removal
Oxidant pH Ink stain Coffee stain
______________________________________
C.sub.10 MPSAP (Example 2)
8.5 71.4 87.6
9.9 60.5 87.0
C.sub.12 MPSAP (Example 3)
9.9 59.4 87.0
Detergent 9.8 55.8 83.3
LSD* 1.89 1.76
______________________________________
*Least significant difference at a 95% confidence level.
From these tests, the precursors of the invention were found to exhibit significant improvements in bleaching performance in comparison with detergent alone as demonstrated in Table II.
The foregoing description, embodiments and examples of the invention have been set forth for purposes of illustration and not for the purpose of restricting the scope of the invention. Other non-limiting embodiments of the invention are possible in addition to those set forth above in the description and in the examples. For example as was also noted above, peracid precursor products according to the present invention could be formed by similar synthesis techniques for products having leaving groups Z and R groups as defined above in connection with the general structure of the peracid precursors of the invention. Accordingly, the scope of the present invention is defined only by the following claims which are also further illustrative of the invention.
What is claimed is:
1. A dry bleaching composition comprising a bleach effective amount of a peracid precursor compound of the general structure ##STR11## wherein Z is a leaving group, the conjugate acid of which has a pKa in the range of from about 4 to about 15,R is a substituted or unsubstituted, alkyl or alkenyl group having from about one to about eighteen carbon atoms, and M is hydrogen or an alkali or alkaline earth metal; and a source capable of yielding hydrogen peroxide in aqueous solution.
2. The composition of claim 1 wherein the hydrogen peroxide source is selected from the group of alkali metal salts of percarbonate, perborate, persilicate and hydrogen peroxide adjuncts.
3. The composition of claim 2 further comprising a surfactant or polymer.
4. The composition of claim 3 wherein the surfactant is selected from the group consisting of anionic, nonionic, zwitterionic, cationic, amphoteric surfactants and mixtures thereof.
5. The composition of claim 3 wherein the polymer is selected from the group of water soluble polymers consisting of polyvinyl acid, polyacrylic acid and polyvinyl alcohol.
6. The composition of claim 4 wherein Z is selected from the group consisting of:(1) a compound having the general structure ##STR12## wherein Y and R' are optionally substituted at any respective locations in the structure,R' is hydrogen or a substituted or unsubstituted alkyl group of about one to ten carbon atoms, with or without an ether linkage, that is, R' or OR' where R' is otherwise defined as above, and Y is hydrogen or a halogen or a solubilizing group; (2) a compound selected from the group of general structures consisting of: ##STR13## wherein R2 is an alkyl chain containing from about one to eight carbon atoms, whereinR3 is an alkyl group containing from about one to eighteen carbon atoms wherein the longest linear alkyl chain extending from and including the carbonyl carbon contains from about six to ten carbon atoms, whereinR4 is H or R2, and whereinY' is H or a solubilizing group; and (3) the group further consisting of enols, carbon acids and N-alkyl quaternary imidazoles.
7. The composition of calim 6 wherein R is an alkyl group having from about eight to twelve carbon atoms and wherein Z is a compound having the general structure ##STR14## wherein R' and Y are optionally substituted at any available respective locations in the structure.
8. The composition of claim 7 wherein R' is hydrogen and Y is H or CO2 - M', M' being hydrogen or an alkali or alkaline earth metal or mixtures thereof.
9. The composition of claim 6 wherein R is an alkenyl group having from about ten to fourteen carbon atoms and wherein Z is a compound having the general structure ##STR15## wherein R' and Y are optionally substituted at any available respective locations in the structure.
10. The composition of claim 9 wherein R' is hydrogen and Y is H or CO2 - M', M' being hydrogen or an alkali or alkaline earth metal or mixtures thereof.
11. A method for removing soils from fabrics comprising the step of contacting said fabrics in an aqueous solution with a bleaching composition comprising:a source capable of yielding hydrogen peroxide in aqueous solution; and a bleach effective amount of a peracid precursor having the general structure ##STR16## wherein Z is a leaving group, the conjugate acid of which has a pKa in the range of from about 4 to about 15,R is a substituted or unsubstituted alkyl or alkenyl group having from about one to about eighteen carbon atoms, and M is hydrogen or an alkali or alkaline earth metal.
12. The method of claim 11 wherein the hydrogen peroxide source is selected from the group consisting of alkali metal salts of percarbonate, perborate, persilicate and hydrogen peroxide adjuncts.
13. The method of claim 11 further comprising a surfactant or polymer selected for stability of the precursor and surfactant.
14. The method of claim 13 wherein the surfactant is selected from the group consisting of anionic, nonionic, zwitterionic, cationic, amphoteric surfactants and mixtures thereof.
15. The method of claim 13 wherein the polymer is selected from the group of water soluble polymers consisting of polyvinyl acid, polyacrylic acid and polyvinyl alcohol.
16. The method of claim 11 where Z is selected from the group consisting of:(1) a compound having the general structure ##STR17## wherein Y and R' are optionally substituted at any respective locations in the structure,R' is hydrogen or a substituted or unsubstituted alkyl group of about one to about ten carbon atoms, with or without an ether linkage, that is, R' or OR' where R' is otherwise defined as above, and Y is hydrogen or a halogen or a solubilizing group; and (2) a compound selected from the group consisting of: ##STR18## wherein R2 is an alkyl chain containing from about one to about eight carbon atoms,R3 is an alkyl group containing from about one to about eighteen carbon atoms wherein the longest linear alkyl chain extending from and including the carbonyl carbon contains from about six to ten carbon atoms, R4 is H or R2, and Y is H or a solubilizing group; and (3) the group further consisting of enols, carbon acids and N-alkyl quaternary imidazoles.
17. The method of claim 16 wherein R is an alkyl group having from about eight to twelve carbon atoms and wherein Z is a compound having the general structure ##STR19## wherein R' and Y are optionally substituted at any available respective locations in the structure.
18. The method of claim 17 wherein R' is hydrogen and Y is H or CO2 - M', M' being hydrogen or an alkali or alkaline earth metal or mixtures thereof.
19. The method of claim 16 wherein R is an alkenyl group having from about ten to fourteen carbon atoms and wherein Z is a compound having the general structure: ##STR20## wherein R' and Y are optionally substituted at any available respective locations in the structure.
20. The method of claim 19 wherein R' is hydrogen and Y is H or CO2 - M', M' being hydrogen or an alkali or alkaline earth metal or mixtures thereof.
| 1986-08-14 | en | 1988-12-13 |
US-22940088-A | Inflator assembly for life vests
ABSTRACT
Disclosed is an inflator assembly for life vests which includes a one-piece housing heat sealed to the wall of an associated cell of the vest. Exteriorly of the cell, the housing has an end-to-end bore, in one end of which a carbon dioxide cartridge is mounted, in position to be pierced by a plunger slidable within the bore. The bore is stepped to form communicating chambers. Normally the plunger is in a position in which O-rings thereon sealably engage the walls of both chambers, at opposite sides of a port through which the gases are to flow into the cell when the cartridge is pierced. Springs within the respective chambers exert their force in opposite directions. A lever handle has a cam surface, such that when the handle is thrown the cam surface will act upon the springs to bias the plunger to a cartridge-piercing position. Further movement of the handle permits the other spring to partially withdraw the plunger. With the handle cammed to a final position, the escaping gases now bias the plunger to a position in which both O-rings clear the port, for inflating the cell, after which the force exerted by one of the springs returns the plunger to its initial position to prevent backflow of the gases. The construction has the advantage of permitting initial assembly, installation, and full testing, even with the device heat sealed to the vest.
BACKGROUND OF THE INVENTION
1. Field Of The Invention
The present invention relates, in a very general sense, to check valves. More particularly, however, the invention relates to inflator assemblies for life vests of the single or dual flotation cell type. Life vests of this type are used, for example, by commercial airlines, and commonly, each cell has its own inflator assembly. The inflator assembly includes check valve means, so designed that when it is necessary to inflate the vest, the wearer pulls upon a lanyard, operating the inflator assembly in such a way as to pierce a carbon dioxide cartridge attached thereto. Escape and consequent expansion of the gas confined within the cartridge is effective to inflate the associated cell.
2. Description Of The Prior Art
Inflation devices for life vests of the character described require means for attaching the same to the wall of the associated, inflatable cell. Heretofore, one conventional procedure has been to use a mechanical connection, involving threaded elements, nuts, and the like, to clamp the material of the life vest, together with gasket means, between components of the inflator assembly, or more typically, to seal a valve stem with air check to the cell, and then mechanically attach the inflator to the valve stem via a threaded nut and washer.
In devices of this type, governmental regulations must be complied with, with respect to extensive testing procedures to assure reliable operation in the event of an emergency, the prevention of back leakage through the inflator assembly, the leakproof mounting of carbon dioxide cartridges, and the carrying out of other important safety measures.
If a procedure such as heat sealing were used to mount the inflator assembly upon the fabric of the life vest, the attachment would become a permanent one. As a result, should it be necessary to replace the inflator assembly due to the inability thereof to pass certain safety tests, a high expense would result. Conversely, when a mechanical mounting is used, the failure of the device to pass certain tests may permit the device to be removed in its entirety from the cell of the life vest for replacement in whole or in part and for re-testing, but the overall expense is increased due to the inability to utilize heat sealing, as well as the added materials and labor of assembly.
Heretofore, so far as is known, there have been no devices which have been so designed as to facilitate the carrying out of all presently required test procedures, the replacement or repair of any one or more elements of the device, the initial, inexpensive assembly of the device, and the inexpensive installation thereof by heat sealing. The present invention has as its main purpose the overcoming of all of these shortcomings found in inflator assemblies heretofore designed.
SUMMARY OF THE INVENTION
Summarized briefly, the present invention incorporates a one-piece, molded housing of a suitable plastic material adapted to be heat sealed to the material of a modern day life vest such as is used by commercial airlines under government supervision. The housing includes a mounting flange interfacing with the life vest material to permit the heat sealing of the inflator assembly to the vest, a base, and a body having an end-to-end bore. Mounted in the bore is a pivoted handle adapted to be thrown by a pull upon a lanyard. The handle includes a cam surface within the bore, and the cam surface engages a floating spring seat, in particular a ball that engages the base of a first spring coiled about a slidable plunger. The plunger has a piercing tip, so that when urged in one direction it will pierce the end of a carbon dioxide cartridge that is attached to the housing in a position closing the end of the bore remote from the handle. A second spring is also mounted in the bore, receiving the plunger. The plunger has spaced O-rings in leak-preventive contact with the wall of the bore, the O-rings normally being at opposite sides of a port through which gases escaping from the carbon dioxide cartridge will flow into the cell for inflating the same.
The springs are so designed that when the device is in a standby condition, the spring forces are balanced, so that the plunger is not biased in either direction, and is at rest in a position in which the O-rings are located at opposite sides of the port. When, however, the handle is thrown, the movement of the cam surface to a position in which it exerts its maximum cam effect causes the cam to bias the ball into engagement with the plunger, so that there is a direct contact of cam-with-ball and ball-with-plunger, that is to say, there is a direct line of force to cam to ball to plunger effective to bias the plunger to a cartridge-piercing position. Then, further movement of the handle responsive to the continuing pull on the lanyard presents a lower cam surface to the ball, permitting the first spring to cam the handle to its final, fully thrown position and expanding the first spring to an extent sufficient to allow the second spring to exert its own force, to withdraw the tip of the plunger slightly from the cartridge. This frees the confined gases for escape and expansion. The escaping gas exerts a force against the plunger tending to bias it away from the cartridge a distance effective to compress the back spring to an extent that will cause both O-rings to clear the outlet port, allowing the gas to flow into the cell. When the force of the escaping gas is spent, the springs are once again both permitted to return to a balanced condition, with the rear spring urging the plunger forward to re-seat the front O-ring. Thus, the plunger is returned to a static position matching or nearly matching its original position, wherein the O-rings are located at opposite sides of the port once again, to prevent back leakage from the cell through the inflator assembly.
This arrangement is the structural feature that permits the unit to be heat-sealed to a life vest, in a permanently sealed mounting that does not require an air check as a separate item.
The arrangement also has a desirable advantage in locating all components of the device where they can be easily accessed, and this in turn permits ready replacement, repair, or substitution, of one or more of the interior components of the check valve assembly. Further, this permits all testing procedures to be carried out even with the device heat sealed to the fabric of the life vest. The housing of the device can remain attached to the life vest, with all interior components being readily accessible in the event of a test failure. Further, the construction permits equally swift assembly of the relatively few parts of the entire device, and inexpensive, fast installation thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
While the invention is particularly pointed out and distinctly claimed in the concluding portions herein, a preferred embodiment is set forth in the following detailed description which may be best understood when read in connection with the accompanying drawings, in which:
FIG. 1 is a top plan view showing an inflator assembly constructed in accordance with the invention, a life vest cell on which the device is mounted being illustrated fragmentarily and a gas cartridge and lanyard means also being illustrated fragmentarily;
FIG. 2 is a transverse sectional view, substantially on line 2--2 of FIG. 1;
FIG. 3 is a longitudinal sectional view through the inflator assembly, taken substantially on line 3--3 of FIG. 2;
FIG. 4 is a view on the same cutting plane as FIG. 3, in which the handle has been moved from the rest position shown in FIG. 3 to a position effective to cause piercing of the cartridge;
FIG. 5 is a view similar to FIG. 3 in which the handle has been moved still further responsive to a pull on the lanyard, to a position in which the first spring begins to cam the handle to its final position, and the second spring asserts its force enough to partially withdraw the plunger after the cartridge has been pierced;
FIG. 6 is a view similar to FIG. 3 in which the handle has been cammed to its final position, permitting the escaping gases to bias the plunger to a position in which the gases can pass through the port into the cell to be inflated; and
FIG. 7 is a view similar to FIG. 3 in which the handle remains in its final operating position, and the force of the escaping gases has been fully spent, permitting the rear spring means to re-assert a force sufficient to return the plunger to its initial position, preventing back leakage from the inflated cell.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The inflator assembly 10 comprising the present invention is a component of an inflatable life vest 12 having one or more cells 13 receiving a flat, oblong mounting flange 14 formed on the underside of and integrally with an elongated base 16 projecting upwardly through and fitting snugly within a correspondingly shaped opening 17 formed in the wall of cell 13. Integral with base 16 is an elongated cylindrical body 18. The flange, base, and body comprise a single piece of rigid plastic material. The upper surface of the flange underlies the wall of cell 13 in contact therewith, and is heat sealed thereto as at 19, over the entire area of its interface with the wall of the cell. In and of itself, heat sealing a mounting flange to the cell wall is well known as shown, for example, in Moran Pat. No. 3,512,807, the disclosure of which is incorporated herein by reference.
A bore 20, open at both ends, extends end-to-end of body 18 and comprises (FIG. 3) an elongated first spring chamber 22 the inner end of which terminates in a frusto-conical shoulder 24 which steps down the bore diameter to a second spring chamber 26 communicating with a flow passage 28 of still smaller diameter. Passage 28 merges into a threaded counter bore 30 in the inner end of which is an annular, grooved sealing flange 31 molded integrally with the body 18 and sealably engaged with the mating, threaded neck of a carbon dioxide cartridge C. The cartridge is per se conventional, and is of the type having a normally sealed end adapted to be pierced to release its contents.
At the end thereof remote from the cartridge, body 18 is formed with a slot 32 intersecting chamber 22 in communication therewith for mounting of an elongated, flat, right-angular operating handle 34 having one leg normally disposed exteriorly of body 18, and having a shorter, inner leg 35 through which extends a transverse pivot pin 36 mounting the handle for swinging movement between its initial, rest position shown in FIG. 3 to its opposite extreme position shown in FIGS. 6 and 7, to which it is thrown when the life vest is to be inflated.
Formed upon the distal end of leg 35 is a circularly shaped cam 38 eccentric to pin 36. At the opposite end of the handle, that is, the distal end of the elongated outer leg thereof, a lanyard 40 is attached, connected to a pull tab 42.
Leg 35 of the handle bears against a ball 44 providing a movable seat for a main spring 46 interposed between the ball and the rear end of an elongated, one-piece plunger 48 having a circular mounting groove for a first O-ring 50 adjacent the end against which the main spring 46 bears. Forwardly of O-ring 50, the rear portion 51 of the plunger is of a diameter adapted to give it a free sliding fit within the main spring chamber 22. Forwardly of the portion 51, plunger 48 is stepped down in diameter to provide an intermediate portion 52 the diameter of which gives it a free sliding fit within the second spring chamber 26. Formed in intermediate portion 52 is a groove for an O-ring 54. Forwardly of the O-ring 54, plunger 48 is still further stepped down in diameter to provide a forward portion 56 terminating in a piercing tip 57. The O-rings provide seals between the plunger and the walls of the respective spring chambers.
Extending about tip portion 56, and compressible between the intermediate portion 52 and the forward end of chamber 26, is a second spring 58.
Providing means for flow of the expanding gases released by piercing of the cartridge C, is a port 60 of oblong cross-section, extending from the main chamber 22 immediately rearward of the shoulder 24, and opening upon the interior of cell 13 when the inflator assembly is mounted as shown.
Assembly And Testing
An important feature of the invention is the fact that it is heat-sealed to the cell . The body, base, and mounting flange comprise a one-piece housing for all of the remaining components, and this housing is especially designed to permit its attachment to the associated cell by heat sealing.
Devices of this type, being designed for use especially in life vests carried as equipment on commercial airlines, are subject to heavy governmental regulation, with respect to testing procedures. These requirements have militated against certain desirable assembly and mounting techniques, as for example, the use of heat sealing as a means for mounting the assembly upon the material of the life vest proper. Because of a high rate of failure under the stringent testing procedures imposed, it is often necessary to completely disassemble the valve mechanism from the associated components of the housing and mounting means. If a device were heat sealed, and then tested, and if it should happen that the device were to fail in the test, it becomes impossible, in devices heretofore designed, to remove and replace the valve mechanism.
In the present device, all of these difficulties are eliminated, so that heat sealing becomes a viable means for mounting the device upon the material of the life vest cell.
For example, since in operation, a cartridge could be loosely mounted, a test for air retention without the carbon dioxide cylinder installed, is always required. This test is what necessitates a separate air check in all other units, and is the reason why there is an O-ring seal on opposite sides of vent port 60 in this device. Also, due to the low pressure seal nature of these air checks and their being prone to leakage it is necessary to service the air check. Checking for this type of leakage is readily permitted in the present device, without removal of the inflator assembly from the cell, since all of the valve components can be readily removed with the inflator assembly mounted in place by removal of the pin 36. This is a very important feature of the present invention, and is what permits it to be sealed directly to the cell. In all other devices, the separate nature of the air check and the need to service the air check require the removal of the inflator from the life vest cell to access the air check for service. This prevents their being permanently sealed directly to the cell.
By the same token, the entire device can be readily subjected to testing before mounting upon the life vest, and further lends itself to full testing after being heat sealed in the manner described above. In each case, should there be a failure, the pin 36 is readily removed and the various components of the valve can be replaced as necessary.
In assembly of the device, it becomes apparent that all that need be done is to insert the plunger, with the spring 56 and the O-rings 50, 54 assembled therewith, after which the spring 46, ball 44, and lever handle 34 are inserted. Insertion of the pin 36 secures the entire assembly in operating position. All testing procedures can be readily carried out, and at the same time, the device can be heat sealed without concern as to the problem heretofore existing, wherein it has been required that a mechanical connection of the inflator assembly to the life vest be employed, utilizing threaded nuts, etc. in the manner shown, for example, in Ruscigno Pat. No. 4,161,797.
In the present instance, in the event of a test failure either before or after heat sealing of the flange to the material of a life vest cell, quick and easy access to all the interior components of the device is had. In this way, the advantages of inexpensive inflator assembly, inexpensive installation, and the use of a minimum number of simply formed components, are all achieved in the one device.
Operation
The operation of the device is shown to particular advantage in FIGS. 3-7.
In FIG. 3, the device is shown as it appears in a rest or standby condition, as it would appear with the life vest stored and awaiting use. At this time, the handle is in one extreme position thereof, with the long, outer leg lying in close proximity to and in parallel relation with the elongated body 18. It may be assumed that all testing procedures have previously been carried out, and that the device has been found in good condition and available for use in an emergency.
At this time, all the parts are in a static condition, that is, springs 46, 58 are in a fully expanded or at least a substantially fully expanded condition. O-rings 50, 54 are disposed at opposite sides of the port 60, in sealable engagement with the walls of chambers 22, 26 respectively.
Assuming the need to inflate the vest, a pull is exerted upon lanyard 40 in the direction shown by the arrow in FIG. 3. Handle 34 swings counter-clockwise when viewed as in FIGS. 3-7, and moves through an angular distance of 90 degrees to the position shown in FIG. 4 during its initial swinging movement. Eccentric or cam 38 is thus caused to present its cam surface to ball 44 so as to bias the ball 44 toward plunger 48, compressing rear spring 46 and bringing ball 44 into direct contact with the plunger. Further camming of the ball toward the cartridge causes piercing thereof by the resultant cam-to-ball-to-plunger direct contact and the advancement of the ball and plunger as a unit. Spring 58 compresses to permit this movement of the plunger, so that tip 57 is now caused to pierce the end of the cartridge C.
In FIG. 5, the handle continues its movement away from its initial position, and as will be seen, the high point of the cam has passed the ball and the ball is now free to move away from the cartridge. With the plunger in the FIG. 5 position, the movement of the ball 44 away from the plunger occurs under the force of spring 46 as he spring 46 expands. The force of the spring 46 is lessened by reason of its expansion and the spring 58 (which was heavily compressed in the FIG. 4 position of the handle) now overcomes the force of spring 46, and exerts sufficient force to withdraw the tip 57 from the end of the cartridge.
It is only necessary that the tip be withdrawn to a very small extent. This alone permits expansion of the gases within the cartridge or cylinder C. The gases, tending to escape, create a strong force directed against the plunger tending to shift the plunger away from the gas cylinder against the restraint of the spring 46. The force of the escaping gases, as the plunger moves to the position shown in FIG. 5, is exerted against shoulder 62 of the plunger, since it is prevented from exiting the chamber 26 at this particular time by reason of the sealable engagement of the O-ring 54 against the wall of that chamber.
Referring to FIG. 6, the continued retraction of the plunger by the force of the escaping gases causes the plunger to move to the FIG. 6 position, wherein the shoulder 62 has entered the larger chamber 22. The instant the O-ring 54 moves out of sealable engagement with the wall of the chamber 26, the continued force of the escaping gases is now exerted against shoulder 64 of the plunger, simultaneously with passage of the gases through port 60 to inflate the cell of the life vest.
The force of the escaping gases, directed against the shoulder 64, will hold the plunger in the FIG. 6 position, against the opposing force of the compressed spring 46, without need of utilizing the force of the second spring 58. Spring 58, indeed, is now fully expanded, and the entire function of holding the plunger in a position where the gases can inflate the cell is assumed by the force of the escaping gases. It should be noted that the forward O-ring must fully clear the port 60, else it could be blown down into the port. This clearance is a function of the full distance that the plunger is biased rearwardly by the force of the escaping gases.
With the cell inflated and the force of the expanding gases having been spent, and with the operating handle 34 moved fully to its final position of FIGS. 6 and 7, the spring 46 is free to expand, and biases the plunger away from the handle as shown in FIG. 7, to cause the O-ring 54 to once again enter the chamber 26 in sealable engagement therewith, while O-ring 50 is in sealable engagement with the wall of chamber 22. This prevents escape of the gases that have inflated the cell, and the life vest is fully inflated and remains so.
The particular size, force, number of coils, and other elements of spring design can be varied. Such designs can be readily calculated by spring design engineers, given the requirement that initially, the springs be allowed to expand to positions in which the plunger will be left in a static or rest condition, with the O-rings 50, 54 at opposite sides of the port 60 and in sealable engagement with the walls of the first and second spring chambers 22, 26 respectively. The design of the springs would further take into consideration the fact that when the handle 34 is thrown to its middle position shown in FIG. 4, the spring 46, must compress enough to allow ball 44 to make direct contact with the plunger and move it forwardly to pierce the cylinder tip, with spring 58 compressing sufficiently not to inhibit the piercing action.
The spring designs should further be sufficient that when the handle 34 is further moved in a direction toward its fully thrown position, as shown in FIG. 5, the spring 56, having been fully or substantially fully compressed when the cartridge was pierced (see FIG. 4) now exerts its full force tending to retract the plunger to withdraw the tip from the hole it made in the end of the cartridge when the cartridge was pierced. Even a slight withdrawal of the tip from the hole in the cartridge permits the sudden expansion of the gases, whereby the plunger is biased to its fully retracted position of FIG. 6, wherein both the front O-ring 54, and the front plunger shoulder against which spring 58 bears, clear the port 60. Combinations of specific springs that will function as so intended are well within the capabilities of skilled spring design engineers, and hence it is not considered necessary in this application to set forth the dimensions and other mechanical characteristics of specific springs which, in combination, will function as intended.
While particular embodiments of this invention have been shown in the drawings and described above, it will be apparent, that many changes may be made in the form, arrangement and positioning of the various elements of the combination. In consideration thereof it should be understood that preferred embodiments of this invention disclosed herein are intended to be illustrative only and not intended to limit the scope of the invention.
I CLAIM:
1. For use in a life vest of the type having at least one cell inflatable by the expansion of gases escaping from a cartridge in which they have been confined in a compressed condition, an improved inflator assembly comprising:(a) a housing mountable upon said cell and having a bore in which the cartridge is mountable and a gas exit port communicating the bore with the interior of the cell; (b) a plunger sliding in the bore and adapted to pierce the cartridge to allow escape and expansion of the confined gases, the bore having communicating first and second spring chambers and the plunger being normally disposed therein in a standby position, the plunger having first and second seal means engaging, in the standby position of the plunger, the walls of the respective chambers at opposite sides of the port; (c) first and second springs disposed in the first and second chambers respectively, the first spring being tensioned to bias the plunger from its standby position in a direction to pierce the cartridge and the second spring being tensioned to bias the plunger in an opposite direction to at least partially withdraw the same from the cartridge; (d) a handle pivotally mounted in the housing for movement between standby and final operating positions respectively; and (e) a spring seat interposed between the cam surface and the first spring, said cam surface being adapted, when the handle is moved from its standby position, to shift the spring seat to place the springs under tension and effect direct contact of the spring seat with the plunger to bias the plunger to its cartridge-piercing position, the continued movement of the handle being adapted to lower the cam surface for bias of the plunger by the second spring in its opposite direction, to withdraw it from the pierced cartridge and thereby allow escaping gases to bias the plunger away from the cartridge a distance sufficient for both of said seal means to move fully to one side of the port, thus to permit exit of the gases through the port into the cell for inflating the same, the handle when fully thrown to its final operating position having its cam surface located to allow expansion of both springs to return the plunger to a position in which said seal means are again located at opposite sides of the port and will prevent leakage of said gases from the inflated cell through said bore.
2. An improved inflator assembly as in claim 1 wherein said housing includes means interfaced with said cell in heat sealed engagement therewith.
3. An inflator assembly as in claim 2 wherein the means in heat sealed engagement with the cell comprises a flat mounting flange.
4. An inflator assembly as in claim 3 wherein the housing is formed with a body in which said bore is formed, the life vest having an opening about which the mounting flange extends and the body projecting upwardly through said opening to provide access to said bore.
5. An inflator assembly as in claim 4 wherein said housing is formed wholly from a single piece of molded material.
6. An inflator assembly a in claim 1 in which the first chamber is of greater diameter than the second chamber, and said port is in communication with the first chamber at a location adjacent the second chamber, whereby upon movement of the plunger away from the cartridge under the force of the expanding gases the second sealing means will move wholly out of engagement with the wall of the second chamber to permit flow of the escaping gases through the second chamber into the first chamber and through the port.
7. An inflator assembly as in claim 6 wherein the first and second seal means are in the form of O-rings.
8. An inflator assembly as in claim 7 wherein the bore is formed with a frusto-conical shoulder at the juncture of the first and second chambers, for free passage of the O-ring of the second seal means back into the second chamber upon return of the plunger to its standby condition following inflation of the cell.
9. An inflator assembly as in claim 6 wherein the bore is formed open at both ends, said cartridge being mounted in one end of the bore and the handle being mounted in the other end thereof.
10. An inflator assembly as in claim 9 wherein the cam surface is formed on one extremity of the handle located within said bore.
11. An inflator assembly as in claim 10 wherein the cam surface is in the form of a part-circular enlargement formed upon the end of the handle located within the bore.
12. An inflator assembly as in claim 11 wherein said spring seat is in the form of a ball mounted to float freely within said bore in engagement with the cam surface and said first spring.
13. An inflator assembly as in claim 12 wherein the handle is pinned within its associated end of the bore, whereby on removal of said pin said ball, first and second springs, plunger, and first and second seal means can be removed from the bore through the end thereof in which the handle is mounted.
14. An inflator assembly as in claim 2 wherein the means disposed in heat sealed engagement with the cell is located in contact with a wall of the cell and with the remainder of the housing being disposed fully exteriorly of the cell, said handle being removably mounted in one end of the bore with the cartridge being mounted in the opposite end of the bore and said plunger, spring seat, springs, and seal means being confined between the handle and the cartridge, thereby to permit their ready insertion and removal responsive to attachment and detachment of the handle, thus to facilitate assembly, installation, and testing of the inflator assembly with the housing in heat sealed engagement with the wall of the cell.
15. For use in a life vest of the type having at least one cell inflatable by the expansion of gases escaping from a fixedly positioned conventional gas cartridge in which gas has been confined in a compressed condition, an improved inflator assembly comprising:(a) a housing being heat sealably mounted to the inflatable cell, said housing defining a bore therein in fluid flow communication with respect to the cell to facilitate inflation thereof; (b) a plunger means movably mounted within said housing, said plunger means being movable between a piercing position, a filling position and a check valve position, said plunger means including:(1) a piercing means integral with said plunger means and adapted to selectively pierce the cartridge responsive to movement of said plunger means to the piercing position to release the gases therefrom into the cell for inflation thereof; (2) a sealing means on said plunger means to define a one-way valving means allowing filling of the inflation cell responsive to said plunger means being in the filling position after piercing of the cartridge and being further responsive to substantial filling of the cell to urge said plunger means to the check valve position for preventing backflow of gases from the inflated cell into said housing, said plunger means, said piercing means, said sealing means and said one-way valving means being completely removable from said housing while allowing maintenance of the heat sealed engagement between the inflated cell and said housing.
| 1988-08-08 | en | 1990-01-16 |
US-4832279-A | Synthesis of acetylene-terminated compounds
ABSTRACT
Phenolic materials containing propargyl groups are prepared by reacting a polyhydric, phenolic material with propargyl bromide, the reaction being conducted in an aqueous sodium hydroxide solution. The products can be thermally polymerized to polymers which are useful as adhesives and as matrix resins in the fabrication of composites.
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
FIELD OF THE INVENTION
This invention relates to the preparation of aromatic materials containing propargyl groups. In one aspect, it relates to polymers prepared from the aromatic materials.
BACKGROUND OF THE INVENTION
Acetylene-terminated compounds show promise for use in the preparation of matrix resins and adhesives for advanced aircraft and aerospace systems. The compounds can be polymerized thermally without the evolution of volatile by-products, thereby obviating the problem of void formation in composite structures and molded articles.
In Polymer Letters, 8, 97-99 (1970), A. S. Hay et al. describe the preparation of bispropargyl ethers of bisphenols by reacting a bisphenol with propargyl bromide in acetone in the presence of potassium carbonate. The reactions are characterized by long reaction times. For example, when using 4,4'-isopropylidenedi-phenol (bisphenol A) as the bisphenol, the time of reaction at reflux temperature was 72 hours. It would be desirable to have a process for preparing bispropargyl ethers of bisphenols that could be carried out in short reaction periods in a non-polluting reaction medium.
It is a principal object of this invention, therefore, to provide an improved process for preparing bispropargyl ethers of phenolic materials.
Another object of the invention is to provide aromatic compounds containing propargyl and hydroxy groups.
A further object of the invention is to provide polymers prepared from aromatic compounds containing propargyl groups.
Other objects and advantages of the invention will be apparent to those skilled in the art upon consideration of the accompanying disclosure.
SUMMARY OF THE INVENTION
The present invention resides in a process for preparing phenolic materials containing propargyl groups. In accordance with the process, a polyhydric, phenolic material is reacted with propargyl bromide in an aqueous sodium hydroxide solution. The reaction occurs at the interface between the aqueous basic solution of the phenolic material and the propargyl bromide which is insoluble in water. The reaction that occurs is illustrated by the following equation: ##STR1##
As shown by the foregoing equation, an exemplary phenolic material, namely, 4,4'-dihydroxydiphenyl sulfone (I), is reacted with propargyl bromide (II) in an aqueous sodium hydroxide medium. As a result of the reaction, two products are formed, i.e., the dipropargyloxy ether of sulfonyldiphenol (III) and dipropargylsulfonyldiphenol (IV). Compound (III) is insoluble in the aqueous medium whereas compound (IV) is soluble therein. In general, compound (III) is obtained in a major amount that can be separated from the reaction mixture by any suitable means, e.g., by filtration or decantation. The soluble compound (IV) can be recovered by acidifying the basic aqueous solution, which remains after separation of the solid product, with concentrated hydrochloric acid. As a result of this treatment, there is obtained a solid compound (IV) which can be purified by crystallization. In this procedure, the compound is dissolved in an alcohol, such as methanol, after which the solution is poured into water, thereby causing the compound to crystallize.
Various polyhydric, phenolic materials can be utilized in conducting the process of this invention. Examples of such materials include mononuclear, polyhydric phenols, such as resorcinol, hydroquinol, 2,3-dicyanohydroquinone, and the like, as well as polyhydric, polynuclear phenols having the formula: ##STR2## wherein Z is a divalent radical, such as --O--, --S--, ##STR3## It is often preferred to use 4,4'-dihydroxydiphenyl-sulfone and 4,4'-isopropylidenediphenol (bisphenol A).
It is also within the scope of the invention to utilize phenolic resins, such as phenol novolac and resorcinol novolac resins having, respectively, the following formulas: ##STR4## In the foregoing formulas, n is an integer ranging from about 2 to 100. It is generally preferred to use a resin in which n ranges from 5 to 10.
The amount of propargyl bromide used is about equivalent to the hydroxyl content of the polyhydric phenol. Thus, the mole ratio of propargyl bromide to polyhydric phenol is about 2:1. However, it is within the scope of the invention to use an excess of the propargyl bromide so that the mole ratio of propargyl bromide to polyhydric phenol ranges from 2:1 to 2.5:1.
When a novolac resin is used, the amount of propargyl bromide used depends upon the number of hydroxyls available for etherification and the degree of etherification desired. Thus, the amount of propargyl bromide can vary within rather broad limits up to a maximum amount which is the equivalent or slightly in excess, e.g., 5 to 10 percent, of the equivalent to the hydroxyl content of the novolac resin. In general, the higher the degree of etherification the higher is the crosslink density of the cured resin.
The amount of sodium hydroxide used is equivalent to the total number of hydroxyls that it is desired to etherify. Thus, equimolar amounts of sodium hydroxide and propargyl bromide can be advantageously employed in the present process. When using equimolar amounts, a maximum amount of the product containing propargyl ether groups is obtained. A larger amount of the product containing hydroxyl and propargyl groups is produced if an excess of sodium hydroxide is utilized.
As indicated above, the reaction of the phenolic material and propargyl bromide is conducted in an aqueous sodium hydroxide solution. The reaction temperature ranges from about 70° C. to the reflux temperature of the base solution, i.e., about 100° C. The reaction is complete when the aqueous solution is neutral. Under reflux condition a reaction period of about 1 hour is sufficient while at lower temperatures a reaction period up to about 3 hours is required.
In a preferred procedure for carrying out the process, the propargyl bromide is added to the phenolic material dissolved in the basic solution. The propargyl bromide can be added directly by itself or in solution in a suitable solvent. Since the propargyl bromide is often supplied in solution in toluene, it is usually preferred to add it as received from the supplier. However, other solvents can be used so long as they are immiscible with water and have a boiling point of at least 80° C. The product containing propargyl ether groups is insoluble in the reaction medium whereas the product containing hydroxyls is soluble in the medium. The products can be readily recovered in the manner described above.
The products prepared by the process of this invention can be converted to polymers by thermal polymerization of the acetylene groups. A temperature of at least 200° C. is usually required for the polymerization. The polymers obtained are useful as adhesives and as matrix resins in the fabrication of composites. Since volatile by-products are not evolved during the polymerization, the composites are free of undesirable voids.
A more complete understanding of the invention can be obtained by referring to the following illustrative examples which are not intended, however, to be unduly limitative of the invention.
EXAMPLE I
A run was carried out in which the dipropargyloxy ether of sulfonyldiphenol was prepared in accordance with the present process. The following ingredients in the amounts indicated were utilized:
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4,4'-Dihydroxydiphenyl sulfone
25.0 g 0.1 mole
Propargyl bromide 26.18 g. 0.2 mole plus
10% excess
Sodium hydroxide 8.0 g 0.2 mole
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The 4,4'-dihydroxydiphenyl sulfone and sodium hydroxide were dissolved in 200 ml of water in a reaction flask fitted with a stirrer, dropping funnel and reflux condenser. The solution was heated to reflux and the propargyl bromide was added slowly. A vigorous reaction occurred when the propargyl bromide was added, and a white product started to separate. After addition of the propargyl bromide, refluxing was continued for one hour. The product was separated by filtration and then dissolved in hot acetone. Upon cooling the product crystallized, yielding 16.1 g (49.4% yield).
Analysis calc'd for C18 SO4 H14 : C,66.26; S,9.82; H,4.29. Found: C,65.79; S,10.10; H,4.15.
Melting point: 185°-186° C.
The product was thermally polymerized by heating at 210° C. for a period of 12 hours. A hard, black polymer was obtained. During the polymerization there was no evolution of volatile by-products.
EXAMPLE II
A run was conducted in which the dipropargyloxy ether of sulfonyldiphenol was prepared by utilizing the following ingredients in the amounts indicated:
______________________________________
4.4'-Dihydroxydiphenyl sulfone
25.0 g 0.1 mole
Propargyl bromide 26.18g 0.2 mole plus
10% excess
Sodium hydroxide 8.0 g 0.2 mole
______________________________________
The procedure of Example I was followed except that the propargyl bromide was added dropwise at room temperature over a period of 30 minutes. The mixture was stirred at room temperature for 2 hours and very little, if any, reaction occurred as indicated by the absence of product and the basic pH of the aqueous phase. The mixture was heated rapidly to 90° C. and at about 70° C. product began to separate. After 30 minutes at 90° C., the aqueous phase was neutral, indicating completion of the reaction. The product was isolated by filtration. The weight of the dried product was 30.8 g (99.4% yield). The melting point of crystallized product was 185°-186° C.
EXAMPLE III
A run was carried out in which the dipropargyloxy ether of sulfonyldiphenol was prepared with the following ingredients in the amounts indicated:
______________________________________
4,4'-Dihydroxydiphenyl sulfone
73.0 g 0.3 mole
Propargyl bromide 71.4 g 0.6 mole
Sodium hydroxide 24.0 g 0.6 mole
______________________________________
The 4,4'-dihydroxydiphenyl sulfone and the sodium hydroxide were dissolved in 600 ml of water in a reaction flask fitted with a stirrer and condenser. The propargyl bromide was added in one addition as an 80 percent solution in toluene. The mixture was heated rapidly with stirring to 82° C. and maintained at that temperature for one hour at which time the reaction was complete as indicated by the neutral pH of the aqueous phase. The product was separated by filtration and washed twice with methanol. The amount of the solid phase was 67 g for a yield of 68 percent.
The methanol wash was added to water, thereby causing the precipitation of a gummy solid. After separation, the dried product weighed 13.0 g for a yield of 13.3 percent. The infrared spectra of the product confirmed the dipropargyl compound of 4,4'-dihydroxydiphenyl sulfone, and also gave absorption bands confirming the presence of hydroxyl groups.
EXAMPLE IV
A run was conducted in which the dipropargyloxy ether of sulfonyldiphenol was prepared with the ingredients listed below. In this run a large excess of sodium hydroxide was used.
______________________________________
4,4'-Dihydroxydiphenyl sulfone
25.0 g 0.1 mole
Propargyl bromide 23.8 g 0.2 mole
Sodium hydroxide 16.0 g 0.4 mole
______________________________________
The 4.4'-dihydroxydiphenyl sulfone and sodium hydroxide were dissolved in 600 ml of water. The propargyl bromide as an 80 percent solution in toluene was added in one addition to the reaction flask. The mixture was brought rapidly to reflux with stirring and maintained at reflux for 2 hours. The mixture was filtered and 4.2 g (13% yield) of the bispropargyl ether was obtained.
The aqueous filtrate was made acid with hydrochloric acid, and a brown resin was obtained. The dried weight of the resin was 19.5 g for a yield of 60 percent. The resin was dissolved in methanol and then crystallized by pouring the solution into water. The light brown crystalline product obtained had a melting point of 154°-158° C. The infrared spectra of this compound confirmed that it was the dipropargyl compound of the diphenyl sulfone, and showed a strong absorption band for the hydroxyl group.
The compound described in the preceding paragraph was thermally polymerized to a hard polymer by heating at 210° C. During the polymerization there was no evolution of volatile by-products.
EXAMPLE V
A run was conducted in which the bispropargyl ether of 2,3-dicyanohydroquinone was prepared, utilizing the following ingredients in the indicated amounts:
______________________________________
2,3-Dicyanohydroquinone
32.0 g 0.2 mole
Propargyl bromide 47.6 g 0.4 mole
Sodium hydroxide 16.0 g 0.4 mole
______________________________________
The 2,3-dicyanohydroquinone and sodium hydroxide were dissolved in 50 ml of water in a flask fitted with a stirrer and reflux condenser. The propargyl bromide was added to the reaction flask in one addition as an 80 percent solution in toluene. The temperature was raised rapidly to 80° C. with stirring. The product began to separate almost immediately. Heating and stirring was continued for one hour. At this time the aqueous phase was neutral, indicating completion of the reaction. The product was separated by filtration and washed several times with water. The product was a brown powder and after drying weighed 34.7 g (73.5% yield).
Infrared spectra showed absorption bands at 2230 cm-1 for nitrile and at 3300 and 2130 cm-1 for acetylene.
EXAMPLE VI
A run was carried out in which a resorcinol novolac was used as the phenolic material in the process of this invention. The following materials were used in the run:
Resorcinol novolac: 24.4 g
Propargyl bromide: 23.8 g
Sodium hydroxide: 8.0 g
The novolac resin and sodium hydroxide were dissolved in 200 ml of water in a reaction flask and heated to reflux. The propargyl bromide was added dropwise with stirring over a 30 minute period. The aqueous phase was neutral almost immediately, indicating completion of the reaction. Refluxing was continued for 1.25 hours after addition of the propargyl bromide. A dark red product was separated by decantation of the aqueous phase. The product was dissolved in a solution of 300 ml of water containing 8 g of sodium hydroxide and filtered. The filtrate was neutralized with concentrated hydrochloric acid, and the precipitate that formed was separated by filtration. After drying overnight in vacuo at 65° C., the product weighed 21.1 g (66% yield). Infrared spectra confirmed the presence of propargyl ether groups.
The product was thermally polymerized at 200° C. to a hard resin. During the polymerization there was no evolution of volatiles.
EXAMPLE VII
A run was conducted in which bisphenol A was employed as the phenolic material in the present process. The amounts of the materials used were as follows:
______________________________________
Bisphenol A 228 g 1.0 mole
Propargyl bromide 238 g 2.0 moles
Sodium hydroxide 80 g 2.0 moles
______________________________________
The bisphenol A and sodium hydroxide were dissolved in 1 liter of water in a reaction flask. The propargyl bromide was added in one addition as an 80 percent solution in toluene. The mixture was heated rapidly to reflux and refluxed for 2.5 hours. The aqueous phase was neutral at this point, indicating completion of the reaction. The product was separated as a dark resinous liquid by means of a separatory funnel. The toluene was allowed to evaporate and the product was extracted with 500 ml of 2-propanol. The 2-propanol insoluble material was dried and weighed 138.0 g (45.4% yield). The product was the bispropargyl ether of bisphenol A as indicated by a melting point of 84°-85° C. and infrared spectra.
The 2-propanol extract was mixed with water, thereby causing a resinous material to precipitate. After separation and drying, the material weighed 132.5 g (43.6% yield). This product was soluble in hot aqueous sodium hydroxide, indicating the presence of hydroxyl groups. The basic solution was cooled and the solid product filtered and neutralized with concentrated hydrochloric acid. The product upon drying was a very viscous semisolid. The infrared spectra confirmed the presence of propargyl groups as well as hydroxyl groups.
The product described in the preceding paragraph was thermally polymerized at about 200° C. to a hard solid. During the polymerization there was no evolution of volatiles.
As seen from the foregoing, the present invention provides an improved process for preparing phenolic materials containing reactive propargyl groups. The process is characterized by short reaction times and the utilization of an aqueous reaction medium. Since the propargyl groups contain acetylene linkages, the products can be polymerized without the evolution of undesirable, void-forming by-products. The products are as a result eminently suitable for use in forming matrices for fiber-reinforced composites.
As will be evident to those skilled in the art modifications of the present invention can be made in view of the foregoing disclosure without departing from the spirit and scope of the invention.
I claim:
1. A process for preparing a phenolic material containing propargyl groups which comprises reacting a polyhydric, phenolic material with propargyl bromide, the reaction being carried out in an aqueous sodium hydroxide solution.
2. The process according to claim 1 in which the reaction is conducted at a temperature ranging from about 70° C. to reflux temperature of the aqueous solution for a period of about 1 to 3 hours.
3. The process according to claim 2 in which the polyhydric, phenolic material is selected from the group consisting of a polyhydric, mononuclear phenol; a polyhydric, polynuclear phenol; and a phenolic resin.
4. The process according to claim 3 in which the polyhydric, mononuclear phenol is resorcinol, hydroquinol or 2,3-dicyanohydroquinone.
5. The process according to claim 3 in which the polynuclear, polyhydric phenol has the following formula: ##STR5## wherein Z is --O--, --S--, ##STR6##
6. The process according to claim 3 in which the phenolic resin is a phenol novolac resin or a resorcinol novolac resin.
7. The process according to claim 3 in which the amount of propargyl bromide is about equivalent to the hydroxyl content of the phenolic material and the mole ratio of sodium hydroxide to propargyl bromide is about 1:1.
8. A process for preparing a phenolic compound containing propargyl ether groups which comprises reacting propargyl bromide with a polyhydric phenol selected from the group consisting of 4,4'-dihydroxydiphenyl sulfone and 4,4'-isopropylidenediphenol, the reaction being conducted in an aqueous sodium hydroxide solution at a temperature ranging from about 70° C. to reflux temperature of the sodium hydroxide solution for a period of about 1 to 3 hours.
9. The process according to claim 8 in which the mole ratio of propargyl bromide to polyhydric phenol ranges from 2:1 to 2.5:1 and the mole ratio of sodium hydroxide to propargyl bromide is 1:1.
10. A process for preparing a phenolic material containing propargyl groups which comprises reacting propargyl bromide with a polynuclear, polyhydric phenol having the following formula: ##STR7## wherein Z is --0--, --S--, ##STR8## the reaction being conducted in an aqueous sodium hydroxide solution at a temperature ranging from about 70° C. to reflux temperature of the sodium hydroxide solution for a period of about 1 to 3 hours, the mole ratio of propargyl bromide to polyhydric phenol ranging from 2:1 to 2.5:1, and the mole ratio of sodium hydroxide to propargyl bromide being about 1:1.
11. The process according to claim 10 in which the polynuclear, polyhydric phenol is 4,4'-dihydroxydiphenyl sulfone.
12. The process according to claim 10 in which the polynuclear, polyhydric phenol is 4,4'-isopropylidenediphenol.
13. A process for preparing a phenolic material containing propargyl groups which comprises reacting propargyl bromide with a phenolic material selected from the group consisting of resorcinol, hydroquinol, 2,3-dicyanohydroquinone, 4,4'-dihydroxydiphenylsulfone, 4,4'-isopropylidenediphenol, a phenol novolac resin having the following formula: ##STR9## a resorcinol novolac resin having the following formula: ##STR10## wherein n in each formula is an integer ranging from about 2 to 100, the reaction being conducted in an aqueous sodium hydroxide solution at a temperature ranging from about 70° C. to reflux temperature of the sodium hydroxide solution for a period of about 1 to 3 hours, the amount of propargyl bromide being about equivalent to the hydroxyl content of the phenolic material, and the mole ratio of sodium hydroxide to propargyl bromide being about 1:1.
| 1979-06-14 | en | 1980-10-07 |
US-3722496D-A | Concrete cutting hand saw
ABSTRACT
A concrete cutting hand saw has a base plate for engaging a concrete surface to be cut. The saw is driven by a motor having a housing and a rotatable saw blade supporting spindle. A shroud member is adapted to receive a circular saw blade therein and to mount the motor housing thereto with the spindle extending into the shroud member. The shroud member is arranged to enclose opposite sides of the saw blade engaged with the spindle over a substantial portion of the area of the blade. Means connect the shroud member to the base plate for hinging motion about an axis parallel to the spindle axis and spaced therefrom. An elongate shroud guide, having an elongate arcuate slot curved concentric to the hinge axis, is fixed to the base plate. Selectively operable means for fixing the shroud member at a desired angular position relative to the base plate include a connecting member removably positioned through the arcuate slot and matable with a socket defined in the shroud member. The connecting member is fully releasable from the socket and the slot so that the shroud member is hingeable relative to the base member through an arc greater than that subtended by the slot. In this manner the saw blade may be easily inserted into the shroud member into coaxial alignment with the spindle.
United States Patent [1 1 Schuman [52] U.S. Cl. ..125/13 R, 143/43 A [51] Int. Cl. ..B28d 1/04 [58] Field of Search ..143/43 R, 43 A, 43 F, 43 C;
[56] References Cited UNITED STATES PATENTS 1,854,510 4/1932 Haas ..143/43 F 1,830,579 11/1931 Wappat... ...143l43 F 1,806,528 5/1931 Fegley ...l43/43 F 1,803,068 4/1931 McKeage.... ..143/43 C 2,014,229 9/1935 Emmons ..125/13 R 2,502,656 4/1950 Koett ..143/43 X FOREIGN PATENTS OR APPLICATIONS 593,566 5/1959 Italy ..125/13 R Primary ExaminerI-1arold D. Whitehead Attorney-Christie, Parker & Hale 1 Mar. 27, 1973 [57] ABSTRACT A concrete cutting hand saw has a base plate for engaging a concrete surface to be cut. The saw is driven by a motor having a housing and a rotatable saw blade supporting spindle. A shroud member is adapted to receive a circular saw blade therein and to mount the motor housing thereto with the spindle extending into the shroud member. The shroud member is arranged to enclose opposite sides of the saw blade engaged with the spindle over a substantial portion of the area of the blade. Means connect the shroud member to the base plate for hinging motion about an axis parallel to the spindle axis and spaced therefrom. An elongate shroud guide, having an elongate arcuate slot curved concentric to the hinge axis, is fixed to the base plate. Selectively operable means for fixing the shroud member at a desired angular position relative to the base plate include a connecting member removably positioned through the arcuate slot and matable with a socket defined in the shroud member. The connecting member is fully releasable from the socket and the slot so that the shroud member is hingeable relative to the base member through an arc greater than that subtended by the slot. In this manner the saw blade may be easily inserted into the shroud member into coaxial alignment with the spindle.
2 Claims, 5 Drawing Figures PATErlTEmRzvms SHEET 3 BF 5 PATENTEUHARZYISB SHEET l 0F 5 :nllllIIlIllllllllhH! v h A CONCRETE CUTTING HAND SAW BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the cutting of concrete. More specifically, the invention relates to concrete cutting hand saws and to a method for installing a saw blade in same.
2. Description of the Prior Art Recommended procedure in cutting concrete with a hand saw is to start with a small blade and then go to a larger blade. A cut of desired depth preferably is made in multiple passes with progressively larger blades, thereby making frequent blade changing a necessary requirement. Since concrete cutting blades generally have a diamond studded peripheral edge, it is also a requirement that great care be taken in blade changing so as not to damage the diamond cutting surface.
Concrete cutting hand saws generally can be classified into two main groups: (I) converted wood cutting hand saws and (2} hand saws designed specifically for cutting concrete. The former group is not the most efficient for a number of reasons. For one, the axis of saw blade rotation is not readily adjustable relative to the saw base plate. This results in imperfect control over the depth of the cut during each pass and in improper tracking of the saw during each pass. To compound these problems, blade changing is a time consuming and often damaging process. This is true since, in converting a wood cutting hand saw to a concrete cutting one, a water duct must be added along the base plate to discharge water onto the saw blade so that centrifugal force sprays the water into the cut. The presence of the water ducting on the base plate makes it most difficult to change the blade.
In an effort to remedy the difficulties inherent in. converted wood saws, hand saws designed specifically to cut concrete were introduced. These saws generally include a saw shroud pivotally mounted to a base plate by a loosenable bolt to allow the angular position of the shroud relative to the base plate to be varied for control over the cut depth. The saw shroud covers a substantial area of a saw blade, which is necessary to protect the cutter from splatter of the water spray which is used to lubricate the surface between the saw periphery and the concrete; in these saws, the water spray apparatus is located entirely within the shroud. The saw blade is rotatably mounted on a spindle driven by a motor mounted to the shroud. An elongate shroud guide is fixed to the base plate and defines an arcuate slot curved concentric to the pivot axis of the saw shroud relative to the base plate.
A bolt is used to selectively fix the angular position of the shroud member relative to the base plate.'.Specifically, the head of the bolt is permanently disposed within the saw shroud with its shank permanently passed through the saw shroud and the elongate slot in the shroud guide. The other end of the bolt is fastened by a wing nut or the like. Although the saw shroud is selectively pivotable relative to the base plate by loosening the nut, thereby permitting control over the cut depth, the shroud is confined to pivot through an arc less than or equal to that subtended by the elongate slot. This complicates blade changing since the blade has to be first inserted through a longitudinal aperture in the base plate, then into the shroud laterally of the spindle axis, and then positioned over the spindle. The blade cannot be loaded coaxially of the spindle because it must be first passed through the base plate, the saw shroud being specifically designed to cover a substantial portion of the blade for the reasons above described. The result is that the process of changing a saw blade is a time consuming process, often leading to damage of the saw blade and to injury of the operator.
SUMMARY OF THE INVENTION The disadvantages inherent in the concrete cutting hand saws described above have been essentially eliminated in the saw of the present invention, which is among those classified in group (2) above. Specifically, blade changing has been made extremely easy notwithstanding the fact that the shroud covers a substantial portion of the blade. One reason is that a connecting member, such as a bolt, used to fix the angular position of the shroud relative the base plate, by clamping the shroud to the shroud guide, has been reversed end for end so that the bolt head no longer is fixed within the shroud. Now the bolt head is outside the shroud with its shank passing through the shroud and shroud guide arcuate slot. By removing the bolt completely clear of the shroud guide, the shroud may be pivoted through an arc much greater than that subtended by the elongate slot. In this manner, the blade to be installed need not first be passed through a slot in the base plate and then into the shroud. Now, it can be passed directly into the shroud laterally of the motor.
driven spindle and then coaxially onto the spindle.
Generally speaking, therefore, the invention comprises a concrete cutting hand saw having a base plate for engaging a concrete surface to be cut. The-saw is driven by a motor having a saw blade supporting spindle coupled thereto. A shroud member is adapted to receive a circular saw blade therein and to mount the motor thereto with the spindle extending into the shroud member. The shroud member is arranged to enclose opposite sides of the saw blade engaged with the spindle over a substantial portion of the area of the blade.'Means connect the shroud member to the base plate for hinging relative motion therebetween about an axis parallel to the spindle axis and spaced therefrom. An elongate shroud guide, having an elongate arcuate slot curved concentric to the hinge axis, is fixed to the base plate. Selectively operable means, for fixing the shroud member at a desired angular position relative to the base plate, includes a connecting member removably positioned through the elongate slot and matable with a socket defined in the shroud member. The connecting member is fully releasable from the socket and the slot so that the shroud member is hingeable relative to the base member through an are greater than that subtended by the slot for insertion of the saw blade into the shroud member into coaxial alignment with the spindle.
Also disclosed is a method for installing a saw blade onto a saw of the type above described. Basically, the method includes the steps of loosening the connecting member so that it is released from within the socket and the slot; pivoting the shroud member through an are substantially greater than that subtended by the elongate slot; moving the saw blade into the shroud member laterally of the spindle from above the base plate; moving the saw blade into coaxial alignment with the spindle and then laterally toward and onto the spindle; and securing the blade on the spindle so that the former rotates with the latter. 1
BRIEF DESCRIPTION OF THE DRAWING These and other aspects and advantages of the present invention are more clearly described with reference to the accompanying drawing in which:
FIG. 1 is a front elevation view of a concrete cutting hand saw according to the present invention with the motor removed for purposes of illustration;
FIG. 2 is a plan view of the saw taken along lines 2- 2 of FIG. 1;
FIG. 3 is a cross-sectional view of the saw taken along lines 3-3 of FIG. 1;
FIG. 4 is a cross-sectional view of the saw taken along lines 4-4 of FIG. 1; and
FIG. 5 is a perspective view of the saw.
DESCRIPTION OF THE PREFERRED EMBODIMENT A presently preferred concrete cutting hand saw 10, according to the present invention, is shown in FIGS. 1-5. Basically, saw includes an essentially planar base plate 12 having a bottom surface 13 for engaging a concrete surface to becut. The front and rear ends of plate 12 are turned up so as to facilitate movement of the plate along a surface. As best shown in FIG. 5, plate 12 includes a rectangular-shaped aperture 14 which is designed to accommodate the lower portion of a saw disc drive motor. As will be described in greater detail below, by accommodating the lower portion of the saw motor, aperture 14 allows the axes of rotation of a saw blade (not shown) to be lowered closely adjacent the base plate soas to maximize the permissible cut depths by the saw and also to place the center of gravity of the saw 10 as close as possible to the base plate. Base plate 12 further includes a longitudinal aperture 16 located adjacent and parallel to a rear edge 18 of the plate. Aperture 16 is designed to accommodate a saw blade therethrough and to stabilize it from movement in directions parallel with the axis of rotation of the blade.
A saw blade shroud member 20 of essentially semicircular configuration is pivotally mounted to an upper surface of base plate 12. More specifically, shroud includes a semi-circular front plate 22 having a U- shaped peripheral flange 24 to which is bolted an essentially semi-circularly configured rear plate 26. Shroud 20 is designed to enclose opposite sides of a saw blade (not shown) over as much of the area of the blade (about 40%) as possible. The front plate of shroud 20 includes a circular aperture 23 into which is fitted a disc 25 having an aperture 27 adapted to receive and journal a saw disc spindle 52.
As best shown in FIGS. 1 and 3, the lower left extent of front plate 22 includes a circular aperture 28 designed to accommodate the shank of a pivot pin 30 a threaded end 32 of which is located within shroud 20. The other end 33 of pin 30 is engaged within a recess 34 defined in a cylindrical handle 36. The shank of pin 30 is also disposed through an L-shaped mounting bracket 38 having a horizontal leg 40 secured to base plate 12 by a pair of screws 42. A vertical leg 44 of bracket 38 is engaged between shroud front plate 22 and a washer 37 disposed around the pivot pin shank and handle '36; bracket leg 44 includes a circular aperture 46 through which the shank of pin 30 passes. A nut 48 is threaded on pin end 32 within shroud 20 to tighten the shroud and handle 36 against opposite sides of bracket 38.
Shroud 20 may thus be pivoted about a hinge axis defined by the longitudinal axes of pin 30. In this regard, it is noted that shroud 20 is not prevented from pivoting about pin 30 when nut 48 is tightened. Rather, handle 36 is of the type which permits pin end 33 to be turned within recess 34 at all times independently of the state of nut 48, end 33 of pin 30 is maintained in recess 34 by a split roll pin 49 which functions in a manner akin to a cotter pin. As will be described below in greater detail, however, the invention does include means for selectively fixing the pivotal position of shroud 20 relative to base plate 12 so that a cut of a selected depth may be attained.
With reference to FIG. 2, it is noted that bracket 38 is secured to base plate 12 in a position such that the interior of shroud 20 is exposed to and aligned with base plate longitudinal aperture 16. In this manner, a saw blade mounted with shroud 20 may be positioned through aperture 16 for engagement with a surface to be cut.
A saw blade drive motor 50 is shown in FIGS. 2 and 5. Motor 50 is a conventional air motor which drives a saw blade supporting spindle 52 coupled coaxially to the motor shaft, as is conventional. Motor 50 has a housing 51 containing a rear face (not shown). The motor housing rear face is bolted to front plate 22 at spaced points about aperture 23 (FIG. 1) by bolts 54 threaded into holes 55 tapped through the shroud adjacent aperture 23. The motor is bolted in a manner such that spindle 52 is disposed through aperture 27 in disc 25 (see also FIG. 1) to have its threaded end located in the interior of shroud 20. Motor housing 51 has a lower surface 56 which is adapted to be accommodated in base plate aperture 14. This permits the motor to be mounted to shroud 20 with its drive spindle very closely adjacent a lower edge 58 of the shroud. In this manner, when shroud 20 is in a closed position, i.e., with shroud edge 58 parallel to base plate 12 (FIG. 1), the drive spindle is closely adjacent the base plate thereby maximizing the possible cut depth by a saw blade (not shown) carried on spindle 52.
As stated previously, it is desired that water be injected into a out being made by a concrete saw to lubricate the saw and to wet down the masonry duct generated by the cutting action of the saw. In this regard, a water jet assembly is carried by shroud 20. The assembly includes a pair of conduits 60 (FIGS. 1 and 5) for transmitting water from their inlet ends disposed within a manifold block 62 mounted to the exterior of shroud flange 24 to their outlet ends 64 disposed within shroud 20. The conduits are spaced from each other along opposite sides of the interior of the shroud a distance sufficient so that they are situated on opposite sides of a saw blade carried by drive spindle 52. As a saw blade is rotated, water is emitted from the outlet ends of conduits 60 onto the opposite sides of the saw blade adjacent its axis of rotation, the rotating saw blade carrying the water into a cut being made by the saw. In this manner, the cut is sufficiently lubricated.
Water is supplied to conduits 60 through manifold 62 by means of a valve 66 coupled to the manifold inlet. The valve is adapted to be coupled to a source of water (not shown) and is operated manually by the operator.
A hand grip 68 is secured to motor housing 51 by being bolted to a mounting block 70, which is in turn bolted to motor housing 51. Specifically, and as more clearly shown in FIGS. 1, 2 and 5, block 70 includes a set of four circular apertures 72 positioned adjacent the corners of the block and designed to receive a corresponding set of bolts 74. Bolts 74 are further adapted to be mated within a corresponding set of sockets (not shown) defined in a side of motor housing 51. In this manner, block 70 is secured to motor housing 51 and thus to shroud for pivotable movement therewith about hinge 36. Mounting block 70 further includes a pair of apertures 76 (see FIG. 4) positioned adjacent opposite sides of the block and designed to receive corresponding bolts 78. Bolts 78 are further positioned through another pair of apertures defined through a respective pair of flanges 80 (FIG. 2) extending laterally from opposing sides of a front end 82 of hand grip 68. In this manner, hand grip 68 is securely fastened to mounting block 70 and thus to shroud 20.
Hand grip 68 is not only designed to afford a cutter means by which to guide the saw along a desired cutting path, but additionally provides a means for selectively operating air motor 50. More specifically, hand grip 68 includes an air inlet opening 84 (FIG. 5) adapted to receive a fitting 86 by which a compressed air hose may be connected to the saw. A channel (not shown) is formed within hand grip 68 for supplying compressed air through an air valve (not shown, since this is conventional) in the hand grip, as is common, to motor 50 via a passage 90 in mounting block 70 (see FIG. 4). Hand grip 68 further includes an air control trigger lever 94 coupled to the air valve in the hand grip in the conventional manner.
A shroud guide 96, in the shape of an arcuate arm, has a laterally extending leg 97 fixed to base plate 12 by a pair of screws 99 rearwardly of aperture 14 and adjacent aperture 16 (see FIG. 5). Guide 96 is positioned closely adjacent shroud 20 when the latter is in a closed, or down, position as shown in FIG. 1. An elongate arcuate slot 98 is defined in guide 96 and is curved concentric to the hinge axis of shroud 20 at hinge pin 30. In other words, a point on shroud member 20 aligned with slot 98 when the shroud is in a down position will be so aligned all the way along the slot as shroud 20 is pivoted upwardly about handle 36.
With the above in mind, and as best shown in FIG. 4, mounting block 70 has an upper flange 100 having an aperture 102 defined therethrough for receipt of the shank of a connecting member, such as bolt 104, therein. Aperture 102 is aligned with arcuate slot 98 and with an aperture 106 defined through shroud front plate 22. A socket member 108 is secured to the back surface of shroud front plate 22 by means of screws 110. Socket member 108 has a tapped hole 112 defined therein to receive the threaded end 114 of bolt 104. The head 1 16 of bolt 104 is disposed outside shroud 20 and adjacent the front face 118 of flange 100. Tightening of bolt 104, when the bolt passes through shroud guide slot 98 as shown -in FIG. 4, securely clamps shroud 20 to shroud guide 96 and also clamps block 70 to the shroud guide, thereby fixing the position of the shroud relative to base plate 12.
It is clear that any one of a range of angular positions of shroud 20 relative to base plate 12 may be set and used to complete a cut of a desired depth. More specifically, by raising or lowering shroud 20, the shank of bolt 104 rides through slot 98 thereby guiding the hinging movement of the shroud member about pivot pin 30. The limits of travel of the shroud relative to the base plate, during most cutting operations, are thereby defined at either end of slot 98 when the shank of bolt 104 contacts them. At any position of bolt 104 through slot 98 between such limits, the shroud may be clamped thereby presetting a desired cut depth by a saw carried within shroud 20.
An important feature of the present invention is the ability to move shroud 20 upwardly from its down position (FIG. 1) through an are much greater than that' subtended by slot 98 (see FIG. 5) so as to facilitate blade changing and installation. More specifically, by removing bolt 104 from socket member 108 and moving the bolt out of slot 98, shroud 20 may be hinged into the position shown in FIG. 5. This makes blade changing extremely efficient, easy and fast since a blade can be installed within shroud member in a three step procedure as follows: (1) moving the blade into the shroud member laterally of the axis of rotation of spindle 52; (2) moving the blade laterally toward front plate 22 into coaxial alignment and engagement with spindle 52 from above base plate 12; and (3) securing the blade on the spindle by the conventional clamp disc so that the saw disc rotates with the latter.
The above procedure differs from that possible in concrete cutting hand saws of the past which required that the saw blade first be carefully passed through longitudinal aperture 16 in base plate 12 since the shroud member could be pivoted upwardly only until a bolt, fixed through a shroud guide elongate slot engaged the upper limit thereof. More specifically, the head of the bolt used in the past was within the shroud member with its thread end extending outwardly from the elongate slot and being fastened by a wing nut or the like. By loosening the nut, the shroud could be hinged relative to the base plate, but only within the limits defined by the ends of the slot.
Another important feature of the present invention is the ability to position the saw blade supporting spindle very closely adjacent the base plate when the shroud member is in its down or closed position. This enables a cut of maximum possible depth to be made by a saw employed. More specifically, aperture 14 in base plate 12 permits lower surface 56 of motor housing 51 to be accommodated therewithin so that drive spindle 52 is lowered closer to base plate 12. A cut depth could be further maximized by moving the saw downwardly within the shroud out of coaxial relation to the motor and driving the saw through a gear box interposed between the saw blade supporting spindle and the motor drive shaft. In this alternative situation, the minimum distance possible between the saw blade supporting spindle and the bottom surface of the base plate is determined by the diameter of the gear box housing. Such alternative is within the contemplation of the present invention.
What has been described, therefore, is a concrete cutting hand saw which greatly aids in the efficient changing and loading of blades, it being noted that frequent blade changing is a necessary requirement in properly cutting concrete. What has also been described is a method for loading a saw blade onto a saw of the present invention. Although the invention has been described with reference to the specific embodiment disclosed, it will be appreciated that certain modifications may be made without departing from the spirit of the invention as defined in the following claims. Such modifications are considered part of the present invention.
What is claimed is:
l. A motor driven hand saw for cutting concrete and the like comprising:
a. a base plate having a bottom surface for engaging a concrete surface to be cut and defining therethrough an elongate aperture through which a cutting disc extends during use of the saw;
b. a motor having a housing and a rotatable supporting spindle for a cutting disc;
a shroud member for receiving a circular cutting disc therein and mounting the motor housing thereto with said spindle extending into the shroud member, the shroud member being arranged to enclose opposite sides of a cutting disc engaged with the spindle over a substantial portion of the area of the disc;
. means connecting the shroud member to the base plate for hinging relative motion therebetween in the plane of the elongate extent of the base plate aperture only about an axis parallel to the spindle axis and spaced therefrom;
e. means for guiding said hinging motion including an elongate shroud guide fixed to the base plate to ex tend closely adjacent an exterior surface of the shroud member and defining an elongate arcuate slot therethrough curved concentric to said hinge axis; and
f. selectively operable means for securing the shroud member at a desired angular position relative to the base plate including a threaded socket defined in the shroud member, an elongate bolt matable with the socket through the shroud guide elongate slot, and an element carried by the shroud member closely adjacent the side of the shroud guide opposite from the shroud member and defining an elongate hole aligned with the socket for receiving the bolt and for guiding the bolt into the socket, the element being arranged so that the bolt is engageable between the element and the socket through the slot in the shroud guide for clamping the shroud guide between the shroud member and the element thereby to secure the shroud member at the desired angular position relative to the base, the bolt being fully releasable from'the socket and the arcuate slot whereby the shroud member is hingeable relative to the'base member through an are greater than that subtended by the arcuate slot for insertion of a cutting disc into the shroud member into coaxial alignment with the spindle other than through the base plate aperture.
2. The concrete cutting hand saw of claim 1 including water duct means carried by the shroud member for discharging water supplied thereto onto a cutting disc engaged with the spindle.
' a a: a: t s
1. A motor driven hand saw for cutting concrete and the like comprising: a. a base plate having a bottom surface for engaging a concrete surface to be cut and defining therethrough an elongate aperture through which a cutting disc extends during use of the saw; b. a motor having a housing and a rotatable supporting spindle for a cutting disc; c. a shroud member for receiving a circular cutting disc therein and mounting the motor housing thereto with said spindle extending into the shroud member, the shroud member being arranged to enclose opposite sides of a cutting disc engaged with the spindle over a substantial portion of the area of the disc; d. means connecting the shroud member to the base plate for hinging relative motion therebetween in the plane of the elongate extent of the base plate aperture only about an axis parallel to the spindle axis and spaced therefrom; e. means for guiding said hinging motion including an elongate shroud guide fixed to the base plate to extend closely adjacent an exterior surface of the shroud member and defining an elongate arcuate slot therethrough curved concentric to said hinge axis; and f. selectively operable means for securing the shroud member at a desired angular position relative to the base plate inclUding a threaded socket defined in the shroud member, an elongate bolt matable with the socket through the shroud guide elongate slot, and an element carried by the shroud member closely adjacent the side of the shroud guide opposite from the shroud member and defining an elongate hole aligned with the socket for receiving the bolt and for guiding the bolt into the socket, the element being arranged so that the bolt is engageable between the element and the socket through the slot in the shroud guide for clamping the shroud guide between the shroud member and the element thereby to secure the shroud member at the desired angular position relative to the base, the bolt being fully releasable from the socket and the arcuate slot whereby the shroud member is hingeable relative to the base member through an arc greater than that subtended by the arcuate slot for insertion of a cutting disc into the shroud member into coaxial alignment with the spindle other than through the base plate aperture.
2. The concrete cutting hand saw of claim 1 including water duct means carried by the shroud member for discharging water supplied thereto onto a cutting disc engaged with the spindle.
| 1971-01-28 | en | 1973-03-27 |
US-61874990-A | Use of cationic charge modified filter media
ABSTRACT
A process for removing anionic contaminants from an aqueous fluid having a pH up to about 12, the fluid being passed through a filter media whereby the contaminants are electrokinetically captured and adsorbed onto the media, such a media comprising cellulose fiber and silica based particulate or fiber filter elements and a charge modifying amount of a cationic charge modifying system bonded to the surfaces thereof. One component of the charge modifying system is a primary charge modifying agent characterized as a water soluble organic polymer capable of being adsorbed into the filter elements and having a molecular weight greater than about 1000. Each monomer of the polymer can have at least one epoxide group capable of bonding to the surface of the filter elements and at least one quaternary ammonium group. A portion of the epoxy groups on the organic polymer are bonded to the secondary charge modifying agent.
This application is a division of application Ser. No. 335,995, filed Apr. 7, 1989, now U.S. Pat. No. 4,981,591.
FIELD OF THE INVENTION
This invention relates to charge modified filter media and more particularly to cationic charge modified filter sheet media comprising cellulose fibers and silica based particulate and/or fiber filter elements, said sheet having a high capacity for electrokinetic capture and adsorption of anionic contaminants, particularly at elevated pH's, e.g., up to pH 12, and pyrogen removal.
PRIOR ART
Filtration of fine particle size contaminants from fluids has been accomplished by the use of various porous filter media through which the contaminated fluid is passed. To function as a filter, the media must allow the fluid, commonly water, to pass through, while retaining the particulate con taminant. This retention of contaminant is accomplished by virtue of the operation, within the porous media, of one or both of two distinctly different filtration mechanisms, namely (1) mechanical straining and (2) electrokinetic particle capture and adsorption. In mechanical straining, a particle is removed by physical entrapment when it attempts to pass through a pore smaller than itself. In the case of electrokinetic capture mechanisms, the particle collides with a surface within the porous filter media and is retained on the surface by short range attractive forces.
With the exception of microporous polymeric membranes, the porous filter media known to the art as being suitable for the filtration of fine particle size contaminants, e.g., pyrogens, are comprised of fiber filter elements or a mixture of fiber and particulate filter elements formed into sheet, typically by vacuum felting from an aqueous slurry followed by drying. In a fibrous filter media that depends only upon mechanical straining to hold back particulate contaminants, it is necessary that the pore size of the filter medium be smaller than the particle size of the contaminant to be removed from the fluid. Thus, for removal of fine, submicronic contaminant particles by mechanical straining, the filter media must have correspondingly fine pores, and is typically comprised of small diameter fibers.
As the size of the contaminants sought to be removed by filtration decreases, especially into the submicron range, there developed considerable interest in the use of fine particulate filter elements, such as diatomaceous earth, for use in conjunction with fibers. However, in order to utilize particulate filter elements in a filter media it is necessary to provide a matrix to retain such particulate in the media in order to provide a structure for use. Thus, at least one of the component materials in the filter media sheet must be a long, self-bonding structural fiber, to give the sheet sufficient structural integrity. Unrefined cellulose fibers such as wood pulp, cotton, cellulose acetate or rayon are commonly used.
Asbestos fiber has also been used for filtration of fine or very fine particulate and the use thereof has been well-documented. The high filtration efficiency of asbestos fibers has been attributed not only to mechanical straining effects but also to the positive zeta potential exhibited by asbestos, which results in the efficient electrokinetic capture of negatively charged contaminant particles. However, because of health considerations, asbestos cannot be used for many applications, particularly in the filtration of pharmaceuticals and parenterals.
Important improvements in filter media and their effectiveness have been achieved with the use of charge modifying systems which modify the surface charge characteristics of a filter media. Charge modifiers are employed to control the zeta potential of the sheet constituents and maximize performance in the electrokinetic capture of small charged contaminants. In practice, cationic charge modifiers are usually employed since most naturally occurring contaminant surfaces are anionic at fluid pH's of practical interest. For example, U.S. Pat. Nos. 4,007,113, 4,007,114, 4,321,288 and 4,617,128 to Ostreicher, describe the use of a melamine formaldehyde cationic colloid to charge modify fibrous and particulate filter elements; U.S. Pat. Nos. 4,305,782 and 4,366,068 to Ostreicher, et al describe the use of an inorganic cationic colloidal silica to charge modify such elements; U.S. Ser. No. 164,797 filed June 30, 1980, to Ostreicher. et al, now abandoned, describes the use of a polyamido-polyamine epichlorohydrin cationic resin to charge modify such filter elements; and U.S. Pat. No. 4,230,573 to Kiltv, et al describes the use of polyamine epichlorohydrin to charge modify fibrous filter elements, see also U.S. Pat. Nos. 4,288,462 to Hou, et al and 4,282,261 to Greene. Preferred methods of making the aforedescribed filter media are described in U.S. Pat. No. 4,309,247 to Hou, et al. Cationic charge modified fibrous filter media covered by the aforementioned patents and application are being sold by Cuno, Inc. under the trademark ZETA PLUS. Similar attempts at cationic charging of filter elements were made in U.S. Pat. Nos. 3,242,073 and 3,352,424 to Guebert, ct al; and U.S. Pat. No. 4,178,438 to Hasse, et al.
Of particular relevance to this invention is U.S. Pat. No. 4,523,995 to Pall, et al. The patent apparently describes ULTIPOR GF PLUS filters sold by Pall Corporation (Glen Cove, N.Y.). This filter media, in its most relevant and preferred embodiment, is prepared by mixing inorganic microfibers, e.g. glass, with polyamine-epichlorohydrin resin, to form a dispersion, to which a precipitating agent is added to precipitate the resin and coat the microfibers. The preferred precipitating agents are high molecular weight polymers containing anionic charges. The resulting coated microfibers are described as having a positive zeta potential in alkaline media and enhanced particulate removal efficiencies for fine particulate removal, including bacteria and endotoxins (pyrogens). See also, THE ULTIPOR AND ULTIPOR GF PLUS FILTER GUIDE, 1981, Pall Corp.
Carrazone et al, "A New Type of Positively Charged Filter: Preliminary Test Results", Journal of Parenteral Science and Technology, 32:69-74, describes tests on Pall's ULTIPOR GF PLUS filters and states that such filters are effective in microbial removal but only when proteins or negative ions or peptones are not present in the solution. The filter media of this invention, as demonstrated herein, provides effective pyrogen removal in both strong electrolytes and proteinaceous solutions.
Robinson et al (1985), "Depyrogenation by Microporous Membrane Filters", in Technical Report No. 7, Depyrogenation, Parenteral Drug Association, Inc., Philadelphia, Pa.; Mandaro (1987), "Charge Modified Depth Filters: Cationic-Charge Modified Nylon Membranes"; and Meltzer (1987), "Filtrative Particle Removal From Liquids", both in Filtration in the Pharmaceutical Industry, T.H. Meltzer Ed., Marcel Dekker, Inc., New York, N.Y., describe the limitations of prior art cationic charge modified media in terms of general loss of filtration performance at high pH and, more specifically, in Robinson et al the inability of prior art media to achieve useful levels of very fine particle and/or pyrogen removal at high pH. The media of this invention exhibits useful filtration properties at pH values as high as 12.
Cationically charged membranes which are used for the filtration of anionic particulate contaminants are also known in the art. For example, as disclosed in the Assignee's Japanese Patent No. 923649 and French patent No. 7415733, an isotropic cellulose mixed ester membrane, was treated with a cationic colloidal melamine formaldehyde resin to provide charge functionality. Treatment of the nylon membranes prepared by the methods described in U.S. Pat. No. 2,783,894 to Lovell (1957) and U.S. Pat. No. 3,408,315 to Paine (1968) is suggested therein.
U.S. Pat. No. 4,473,475 and 4,743,418 to Barnes, et describes a cationic charge modified microporous nylon membrane having bonded thereto, through a cross-linking agent, a charge modifying amount of an aliphatic amine or polyamine, preferably tetraethylene pentamine. The cross-linking agent is an aliphatic polyepoxide having a molecular weight of less than about 500, preferably 1, 4 butanediol diglycidyl ether. Such a membrane exhibits an advantageously low "flush-out" time.
U.S. Pat. Nos. 4,473,474, 4,673,504, 4,708,803 and 4,711,793 to Ostreicher, et al describe, in the preferred embodiment a nylon membrane charge modified with a charge modifying system of an epichlorohydrin modified polyamide having tertiary amine or quaternary ammonium groups, e.g. Hercules R4308, and a secondary charge modifying agent which may be an aliphatic polyamine having at least one primary amine or at least two secondary amines, e.g. tetraethylene pentamine. There is no teaching or suggestion in these patents that such a charge modifying system may be used to produce the filter media of this invention having the unexpected properties described herein
Cationic charge modified nylon membranes covered by these patents to Ostreicher, ct al and Barnes, et al are now being sold by Cuno, Inc., under the trademark ZETAPOR.
U.S. Pat. No. 4,604,208 to Chu. et al describes an anionic charge modified nylon microporous filter membrane. The charge modifying system is a water soluble polymer having substituents thereon capable of bonding to the membrane and anionic functional groups such as carboxyl, phosphorous, phosphonic, sulfonic groups. A cross-linking agent may also be utilized, e.g., aliphatic polyepoxides.
U.S. Pat. No. 4,381,239 to Chibata et al is relevant in that it describes a method for removing pyrogen from a solution by contacting the solution with an adsorbent to adsorb the pyrogen. The adsorbent comprises a water-insoluble carrier and a nitrogen-containing heterocyclic compound of the formula:
R--A--X
wherein R is a nitrogen-containing heterocyclic group; A is single bond, alkylene or alkenylene; X is hydrogen or a functional group; and the heterocyclic group and alkylene may be optionally substituted by one or more substituents, and the compound being bonded to the carrier directly or through a spacer. Cellulose is described as a preferred carrier.
OBJECTS AND SUMMARY OF THE INVENTION
An object of this invention is to provide a filter media containing cellulosic fibers and silica based particulate or fiber filter elements having high capacity for electrokinetic capture and adsorption of anionic contaminants, particularly at elevated pHs, e.g. up to pH 12.
Another object of this invention is to provide a filter media capable of endotoxin, e.g. pyrogen, removal from fluids, particularly electrolytes or protein containing fluids.
A further object of the present invention is to provide a new and improved method of producing pyrogen-free water which is readily adapted to large scale production.
A still further object of the present invention is to provide a new and improved method of selectively depyrogenating protein containing fluids.
Another object of this invention is to provide a filter media which exhibits excellent performance for pyrogen removal with greater resistance to performance degradation during multiple autoclaving and/or water washing cycles.
It is still a further object of the present invention to provide charge modified filter media sheets of enhanced filtration performance.
These and other objects of this invention are attained by a novel cationic charge modified filter media. The media comprises cellulosic fiber and silica based particulate or fiber filter elements and a charge modifying amount of a cationic charge modifying system bonded to the surfaces thereof.
A component of the charge modifying system is a primary charge modifying agent characterized as a water soluble organic polymer capable of being adsorbed into the filter elements and having a molecular weight greater than about 1000. Each monomer of the polymer can have at least one epoxide group capable of bonding to the surface of the filter elements and at least one quaternary ammonium group. Preferably, the primary charge modifying agent is a polyamido-polyamine epichlorohydrin resin, a polyamine epichlorohydrin resin, or a resin based upon diallyl-nitrogen-containing materials reacted with epichlorohydrin. Such resins typically are the reaction product of a polyamine with epichlorohydrin and have quaternary ammonium groups along the polyamine chain as well as epoxide groups capable of bonding to the surfaces of the filter elements.
Another necessary component of the charge modifying system is a secondary charge modifying agent. Preferably a portion of the epoxy groups on the organic polymer are bonded to the secondary charge modifying agent. This secondary charge modifying agent is an aliphatic polyamine having at least one primary amine or at least two secondary amines.
The invention is further directed to a process for cationically charge modifying said filter media by applying to the aforesaid filter elements the aforesaid charge modifying system. Preferably, the process for charge modifying comprises contacting the filter elements with an aqueous solution of the charge modifying system.
The preferred filter media comprises a filter sheet of cellulosic fibrous filter elements and silica based particulate filter elements having bonded thereto a charge modifying system comprising polyamine epichlorohydrin and tetraethylene pentamine.
The filter elements and filter media of this invention have unexpectedly been found to have a high capacity for electrokinetic capture and adsorption of anionic contaminants, particularly at elevated pH's, e.g., up to pH 12. Further, the filter media of this invention has been found to be particularly useful in depyrogenating strong electrolytes and proteinaceous solutions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of "Membrane Protection Test Time (minutes)" vs. the ratios of the preferred primary and secondary charge modifying agents ("4308/TEPA") (See Examples).
FIG. 2 is a graph of "0.109 micron MDL Test Time (minutes)" vs. "4308/TEPA Ratio" (See Examples)
FIG. 3 is a graph of "Metanil Yellow Dye Test Time (minutes)" vs. "4308/TEPA Ratio" (See Examples).
FIG. 4 is a graph of "Transmittance (%)" vs. "Specific Thruput (Gal/ft2)" demonstrating Dye Removal Characteristics of the filter of this invention compared to the Prior Art (See Examples).
FIG. 5 is a longitudinal partial cross-sectional view of a preferred embodiment of a filter housing and filter cartridge comprised of a plurality of filter cells utilizing the filter media sheet of this invention.
FIG. 6 is a cross-sectional view of an individual filter cell of the filter cartridge of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
The primary charge modifying agent used in the charge modifying system for this invention may broadly and generally be characterized as a water soluble organic polymer having a molecular weight greater than about 1000, is capable of being adsorbed into the filter elements, and the monomer of the polymer has at least one epoxide substituent capable of bonding to the surface of the filter elements and at least one quaternary ammonium group capable of providing a cationic charge site.
The primary charge modifying agent is adsorbed onto the filter elements and bonded to substantially all of the wetted surfaces of the filter elements, i.e., to substantially all of the microporous microstructure of the subsequently formed filter media.
By the use of the term "bonded" it is meant that the charge modifying agent(s) are sufficiently attached to the filter elements and/or to each other so that they will not significantly extract from the filter media under the intended conditions o use. By the use of the term "substantially all of the wetted surface" as used herein it is meant substantially all of the external surface and internal pore surfaces which are wetted by a fluid passing through the filter media or in which the media is immersed, i.e., substantially all of the microporous microstructure of the filter media.
The preferred primary charge modifying agents are selected from a class of quaternary amine containing cationic resins whose general production and structure are described, for example, in the following U.S. Pat. Nos.: 2,926,116 to Keim; 2,926,154 to Keim; 3,224,986 to Butler, et al; 3,311,594 to Earle. Jr.: 3,332,901 to Keim; 3,382,096 to Boardman; and 3,761,350 to et al. The entire disclosures of all of these U.S. patents are incorporated herein by reference.
Broadly, the primary charge modifying agent may be produced by conducting a polymerization of an allyl nitrogen-containing material reacted with epichlorohydrin. Preferred charge modifiers (hereinafter termed "polyamido-polyamine epichlorohydrin or polyamine epichlorohydrin") are produced by reacting a long chain polyamide with epichlorohydrin, i.e. 1-chloro-2,3 epoxypropane having the formula: ##STR1##
The polyamide may be derived from the reaction of a polyalkylene polyamine and a saturated aliphatic dibasic carboxylic acid containing from about 3 to 10 carbon atoms. The polyamide produced is water soluble and contains the recurring groups:
--NH(C.sub.n H.sub.2n HN).sub.x --CORCO--
where n and x are each 2 or more and R is the divalent hydrocarbon radical of the dicarboxylic acid. This polyamide is then reacted with epichlorohydrin to form the preferred water soluble primary charge modifiers used in this invention.
The polyamido-polyamine epichlorohydrin cationic resins are available commercially as Polycup 172, 1884, 2002, or S2064 (Hercules); Cascamide Resin pR-420 (Borden); or Nopcobond 35 (Nopco). Most preferably the preferred polyamine epichlorohydrin resin is Hercules R4308 (hereinafter "4308"), wherein the charged nitrogen atom forms part of a hetorocyclic grouping, and is bonded through methylene to a depending, reactive epoxide group.
A secondary charge modifying agent or anchoring agent is used in the charge modifying system to enhance the cationic charge of the primary charge modifying agent and/or enhance the bonding of the primary charge modifying agent to the filter elements and/or the secondary charge modifying agent.
The secondary charge modifying agent used in this invention is an aliphatic polyamine having at least one primary amine or at least two secondary amines.
Preferably, the secondary charge modifying agent is a polyamine having the formula:
H.sub.2 N--(R.sub.1 --NH--).sub.x --R.sub.2 --NH.sub.2
wherein R1 and R2 are alkyl of 1 to 4 carbon atoms and x is an integer from 0 to 4. Preferably, R1 and R2 are both ethyl.
Preferred polyamines are:
______________________________________
Ethylene diamine
H.sub.2 N--(CH.sub.2).sub.2 --NH.sub.2 --NH.sub.2
Diethylenetri-
H.sub.2 N--(CH.sub.2).sub.2 --NH--(CH.sub.2).sub.2 --NH.sub.2
amine
Triethylenetetra-
H.sub.2 N--(CH.sub.2 --CH.sub.2 --NH).sub.2 --CH.sub.2
--CH.sub.2 --NH.sub.2
mine
Tetraethylene
H.sub.2 N--(CH.sub.2 --CH.sub.2 --NH).sub.3 --CH.sub.2
--CH.sub.2 --NH.sub.2
pentamine
______________________________________
The highly preferred polyamine is tetraethylene pentamine.
The secondary charge modifying agent is essentially bonded to the filter elements by bonding through a portion of the epoxide substituents of the polymeric primary charge modifying agent.
The amount of primary and secondary cationic charge modifying agent utilized in the charge modifying system is an amount sufficient to enhance the electropositive capture potential of the filter media. Such an amount is highly dependent on the specific charge modifying agents utilized and the filter elements.
Broadly, the process of this invention is directed to cationically charge modifying cellulosic fibrous and siliceous particulate or fiber filter elements which are subsequently formed into a filter media sheet. The process comprises applying to the filter elements a charge modifying amount of a charge modifying system comprising the primary cationic charge modifying agent and the secondary charge modifying agent. The charge modifying system is adsorbed onto the filter elements and bonds to the elements through the epoxide substituents of the primary charge modifying agent, to produce charge modified or surface modified filter elements which are subsequently formed into filter media.
Preferably, the process comprises (a) contacting the filter elements with an aqueous solution of the primary cationic charge modifying agent and (b) contacting the filter elements with an aqueous solution of the secondary charge modifying agent. The contacting steps may be performed in any order, i.e. step (a) prior to step (b) or vice versa, or simultaneously, i.e. a mixture of the aqueous solutions is contacted With the filter elements. The filter elements are then vacuum felted and dried to form the filter media.
In order to provide the charge modifying amount of cationic charge system to the filter elements, it is preferred that the aqueous solution of primary charge modifying agent that the filter elements are contacted with contain charge modifying agent sufficient to be at least about 1% of the total weight of the filter elements. The maximum amount of charge modifying agent in the aqueous solution is limited by economic and solubility limitations. For example, an excess of primary charge modifying agent which is not adsorbed into the filter elements may not be economically utilized and might constitute an undesirable extractive from the final filter media. It has been found that the amount of charge modifying agent in the aqueous solution should probably not exceed about 5% by weight of the total weight of the filter elements.
The amount of secondary charge modifying agent used in the aqueous solution is highly dependent on the specific secondary charge modifying agent and the amount and type primary charge modifying agent used, and the cross-linking mechanism between these compounds to provide the bonding of the secondary charge modifying agent to the filter elements. For general guidance however, it has been found that a weight ratio of primary to secondary charge modifying agent of from about 1:1 to about 10:1, with from about 3:1 to about 6:1 in the aqueous solutions contacted with the filter elements, provides sufficient bonding of the cationic charge modifying agents to the filter elements as well as maximum cationic charge modification of the filter elements. It has been found that if the aqueous solution containing the secondary charge modifying agent contains a sufficient amount to provide at least about 0.2% up to a maximum of about 2.5% charge modifying agent of the total weight of the filter elements, when used in conjunction with the aforementioned of primary charge-modifying agent, that adequate bonding of the charge modifying agents to the filter elements is obtained.
The charge modifying system may be contacted with the filter elements by immersing the filter elements in aqueous solutions of the charge modifying agents for a period of time sufficient to effect the desired degree of pick-up. In the preferred embodiment fibrous and particulate filter elements are mixed with an aqueous solution of the charge modifying system, i.e., both primary and secondary charge modifying agent, and a filter sheet media formed by vacuum felting the elements onto a substrate. The sheet is subsequently dried.
Although applicants do not wish to be bound by the following theory, it is believed that in bonding the primary charge modifying agent to the filter elements the epoxide groups on the primary charge modifying agent enter into addition type reactions with the hydroxyl and carboxyl groups which are on the filter elements as well as with the secondary cationic charge modifying agent. For example, the epoxide substituents on the primary charge modifying agent function to (a) cross-link the carboxyl groups on the filter elements to the primary charge modifying agent, (b) cross-link these carboxyl groups to the primary and/or secondary amine groups of the secondary charge modifying agent, and (c) cross-link the primary and/or secondary amines of the secondary charge modifying agent to each other. Due to this extensive cross-linking of the epoxide substituent with various other substituents the final filter media is substantially devoid of epoxide functionality and has a high cationic charge, particularly at high pH's.
Amines are classified as primary, secondary or tertiary, according to the number of substituents attached to the nitrogen atom, i.e. according to the number of hydrogens which have been substituted. Epoxide groups will react with primary and secondary amine groups through the free hydrogens. An epoxide group will not react with a tertiary amine group since there are no free hydrogens.
Amine groups of all three classes, i.e. primary, secondary or tertiary are capable of forming hydrogen bonds with water. As a result, amines of relatively low molecular weight, i.e. short carbon chain length, are quite soluble in water, with borderline solubility in water occurring at about 6 carbon atoms per amine group. In the preferred embodiment of this invention it is highly desirable that the cationic charge modifying agents be soluble in water to provide the desired environment for production of filter media, i.e. elimination of fumes, toxicity, etc.
Amines are basic and generally form salts. The amines are converted into their salts, i.e. charged form, by hydrogen ions and are liberated from their salts by hydroxide ions. It is this latter characteristic, that is undesirable for cationic charge modified media and produces a reduction in adsorptive capacity for anionic contaminants when amine charge modified filter media is exposed to high pHs. It is therefore desirable to use a more basic amine secondary charge modifying agent to produce a filter media having high charge modification and adsorptive capacity for contaminants at a given pH.
It appears, however, that increased cross-linking of the secondary charge modifier with the epoxide substituent increases basicity and filtration effectiveness and thus appears to depend upon the extent to which the primary and secondary amines originally present in, for example, tetraethylene pentamine, are converted to tertiary amines via the reaction with the epoxide.
Preferably, after contacting the filter elements with the charge modifying system, the elements are vacuum felted for a period of time sufficient to remove most of the water and chemical compound not adsorbed into the elements and then dried and cured. Final drying and curing temperatures are preferably from about 120° C. to 140° C. for minimization of drying times without detrimental effects to the media.
The charge-modified media have an improved effective filtration rating relative to untreated media. Such improvement is brought about by charge sites or regions which are effective during filtration to enhance filtration performance through electrokinetic effects, particularly at high pH's, e.g., up to 12.
For so-called sterile filtrations involving biological liquids, the filter media or filter elements are sanitized or sterilized by autoclaving or hot water flushing. The charge-modified media of this invention is resistant to this type treatment, and retains its integrity in use.
The preferred filter media of the present invention is a filter media sheet comprised of filter elements of silica based particulate immobilized in a porous matrix of cellulose fibers. The preferred cellulose fibers are derived from wood pulp. Optionally, cellulose fibers, wherein the cellulose is highly purified alpha-cellulose, provide a filter media, which eliminates false positive tests for pyrogen and is capable of producing filtrates demonstrating very low levels of pyrogen, as tested by the LAL pyrogen test. See U.S. Pat. No. 4,606,824 to Chu, et al incorporated herein by reference.
In the preferred embodiment, in order to provide a matrix which is a coherent and handleable sheet for use, it is desirable that at least one of the components that goes into forming the porous matrix is a long self-binding structural fiber. Such fiber gives the filter sheet media sufficient structural integrity in both the wet "as formed" condition and in the final dried condition. Such a structure permits handling of the filter media during processing and at the time of its intended use. Such fibers are particularly suitable in diameters in the range of 6 to 60 micrometers. Wood pulp, for example, has fiber diameters ranging from 15 to 25 micrometers, and fiber lengths of about 0.85 to about 6.5 mm.
When the amount of particulate immobilized in the porous matrix is low, i.e. less than about 50% by weight of the media, it is preferred that the porous matrix be formed of a self-bonding matrix of normal cellulose pulp having a Canadian Standard Freeness (CSF) of +400 to +800 ml. The state of refinement of wood pulp fibers is determined by means of a "freeness" test in which measurement of the flow rate through the fibers on a standard screen is determined. Two of the most common instruments are the "Canadian Standard Freeness Tester" and the "Shopper-Riegler Freeness Tester". For a more detailed explanation of these tests, see U.S. Pat. No. 4,309,247 to Hou, et al., the entire disclosure of which is incorporated herein by reference. Typical wood pulps show Canadian Standard Freeness values ranging from +400 to +800 ml.
In the preferred embodiment of this invention it is desirable to have a high amount, i.e. greater than about 50% by weight of the filter media, of particulate immobilized in the porous matrix, the remainder being cellulose fiber filter elements. It is thus highly desirable to use the invention described in the aforementioned U.S. Pat. No. 4,309,247 to Hou, et al to maintain such high content of particulate in the filter media. Broadly, a portion of cellulose pulp refined to a Canadian Standard Freeness of between about +100 and -600 ml is incorporated with a portion of the normally dimensioned cellulose pulp (+400 to +800 ml). Generally the weight ratio of unrefined to highly refined pulp will range from about 0.1:1 to about 10:1, preferably 0.2:1 to about 1:1. Such a mixture of pulps permits the retention of fine particulates up to about 80% by weight of the filter media. The higher ratios produce media which are more porous. In any event, it is essential that the cellulose, both refined and unrefined, be a highly pure cellulose. Thus the entire cellulose content of the filtration media comprises a highly pure cellulose, the cellulose with a Canadian Standard Freeness of +400 to +800 ml and the cellulose with a Canadian Standard Freeness of -100 to -600 ml each being highly pure.
Preferably the filter media, and in particular the filter media sheet, is formed by vacuum-felting an aqueous slurry of such normal cellulose fibers, highly refined wood pulp, and particulate with the charge modifying system of primary and secondary charge modifying agent. This forms a charge modified filter media sheet having the particulate immobilized in a porous matrix. The final dried and cured filter media sheet shows a uniformly high porosity and a fine pore-sized structure with excellent filtration flow characteristics.
The amount of particulate in the filter media may be-as little as 20% by weight of the filter media up to about 80% by weight. Generally, levels of about 50 to 70% by weight are employed. Various types of siliceous particulate are suitable for inclusion in the filter media of this invention, including diatomaceous earth, perlite, talc, silica gel, clay, etc. Functionally, the fine particulate should have a specific surface area in excess of one square meter/gram and/or particle diameters of less than 10 microns. In a broad sense, any fine particulate may be suitable, such as J.M. Filter Cel, Standard Super Cel, Celite 512, Hydro Super Cel, Speed Plus and Speed Flow; Dicalite 215 and Dicalite 416 and Dicalite 436, and may be evaluated by techniques well-known to the art. The finer grades of diatomaceous earth, perlite, for example in proportion by weight of from about 80/20 to 20/80, give better filtration performance or better cost-performance characteristics than that achieved by the use of any single type siliceous material. Similarly, mixtures in all proportions of relatively coarse and fine particulates, e.g., 50/50 parts by weight of 10 and 5 micron diameter particulates may be used. Siliceous fibers, e.g., glass fibers, may also be used either alone or admixed with the particulate.
In one embodiment herein, at least some of the particulate material may be "micro-particulate", i.e., has on the average a diameter of less than one micron, (a Gaussian distribution of particle diameters), preferably less than 100 millimicrons, most preferred less than 50 millimicrons, especially between 1 and 25 millimicrons. The micro-particulate is preferably fumed silica or fumed alumina; see U.S. Pat. No. 4,511,473 to Hou, et al, the entire disclosure of which is incorporated herein by reference.
In another embodiment, the cellulose-containing separation media contains, as at least a portion of the particulate, activated carbon particles. The carbon particles have an average diameter of less than about 50 microns; see U.S. Pat. No. 4,404,285 to Hou the entire disclosure of which is incorporated herein by reference.
The sequence of adding the required components to water to form the dispersed slurry of filter elements and cationic charge modifying system appears to be relatively unimportant provided that the slurry is subjected to hydrodynamic shear forces during the mixing process. Preferably, the charge modifying system is added last. Preferably, refined pulp is added to a slurry of unrefined pulp and then the particulate incorporated in the slurry. The slurry is normally prepared at about 4% consistency, i.e., weight percent solids, and then diluted with additional water to the proper consistency required for vacuumfelting sheet formation. This latter consistency value will vary depending upon the type of equipment used to form the sheet. Typically, the slurry is vacuum-formed into a sheet and oven dried in a standard manner. The preferred filter media in sheet form has a thickness of about 0.100 inches (0.25 cm) to about 0.200 inches (0.50 cm) and/or a weight of about 0.7 to 1.3 gm/sq.inch, and most preferably about 1.0 gm/sq.inch.
The process conditions are not critical as long as the charge-modifying system is permitted to contact the filter elements contained in the slurry. The amounts of the dispersion medium, e.g. water, do not seem to be critical. The time required for charge modification of the surface and adsorption into the filter elements does not appear critical and appears to occur instantaneously, with about 0.5 to about 20 minutes being adequate for most purposes. Of course, longer periods of exposure, e.g. up to several hours, can be used to assure relatively complete adsorption, bonding and deposition of the charge modifying system. A period of about 15 minutes up to two hours is typical.
The amount of charge-modifying system added to the filter material is not critical but is merely a matter of functionality. For example, a high surface area filter elements may require more charge-modifying system for optimum filtration than one of lower surface area. Nevertheless as the charge-modifying system is adsorbed into the filter elements and deposited on the surfaces thereof, the filtration efficiency is enhanced, so that even small amounts are effective.
The liquid medium for the present process is a polar medium, advantageously an aqueous medium as mentioned hereinbefore. Water is the simplest, most adequate and most economical and therefore is preferred.
The filter media of this invention are free of extractables and free of discoloration, such that the sheets are usable under any sterilizing conditions and may be employed safely and effectively with potables or ingestables such as food or drugs. Additionally, such filter media has an unexpectedly high capability for removing pyrogen from fluids, particularly electrolytes and proteinaceous solutions, as well as maintaining filtration effectiveness at high pH's, e.g., up to about 12.
A preferred form of utilizing the filter media of this invention is to incorporate the filter media in sheet form in a filter cell which is used to form a filter cartridge. Such filter cartridges are of the type sold by Cuno under the trademark ZETA PLUS. FIGS. 5 and 6 depict, respectively, such a filter cartridge and housing, and the filter cell. Referring to FIGS. 5 and 6, the filter cell 40 is comprised of two filter media 10 and 15, preferably in disc form having the flanges 12 and 17 in intimate face-to-face contact with each other, the filter media 10 and 15 and spacer means 20 all having an axial or central opening 21 of the proper size which forms a vertical conduit 42.
In operation the fluid is filtered by passing through in-take pipe 44 into a housing 46. The fluid passes from the outside of the filter cell 40 through the filter media 10 and 15 to the space 28 formed by spacer means 20. Contaminants, e.g. insolubles and microorganisms, are deposited on the outside and/or within the filter media 10 and 15 and the filtrate discharged through the discharge tube 48. Discharge tube 48 is in fluid connection with vertical conduit 42 which is in fluid connection with space 28 between the media 10 and 15.
Several embodiments of this form of filter cell and cartridges are described in U.S. Pat. No. 4,347,208 to K. Southall; 4,783,262 to Ostreicher, et al; 4,606,824 to Chu, et al; and 4,704,207 to Chu. The entire disclosures of these patents are incorporated herein by reference.
The filter sheet media of this invention is particularly useful in adsorbing and capturing anionic contaminants at high pH's, e.g., up to about 12, and pyrogen removal.
EXAMPLE I
All of the filter medium samples in this EXAMPLE I were prepared from a basic fibre/particulate formulation consisting of the following components:
__________________________________________________________________________
WEYERHAUSER KAMLOOPS KRAFT WOOD PULP
23.6 WT. PERCENT
REFINED (-250 CSF) KAMLOOPS WOOD PULP
6.4 WT. PERCENT
GREFCO DICALITE TYPE 436 PERLITE
70.0 WT. PERCENT
__________________________________________________________________________
The above listed components were sequentially added to water, with agitation, to produce a 4.0 weight percent dispersion. As specified in Table 1, the dispersion pH was either left "as-is" or was adjusted upward to pH 8.0. As further specified in Table 1, varying amounts of the primary charge modifier (Hercules PAE Resin 4308) and secondary charge modifier (Tetraethylene Pentamine) were sequentially added to the fiber/particulate dispersion with agitation, i.e., the primary charge modifier was added first and given time (approximately 15 minutes) to adsorb onto the surfaces of the fiber and particulate in the dispersion, then the secondary charge modifier was added. After approximately an additional 15 minutes, the dispersion was diluted to 2.0 weight percent consistency. The final dispersion pH was either left "as-is" or adjusted downward to pH 7.0 as specified in Table 1.
The samples identified as "30S CONT", i.e., Control, utilized 2.0 weight percent of Hercules Polycup 1884 in place of the primary and secondary charge modifiers mentioned above. As such, the "30S CONT" samples represent the commercially sold filter sheet medium ZETA PLUS manufactured and sold by the Assignee herein using the prior art charge modifier system described in U.S. Ser. No. 164,797 (Ostreicher et al).
Each dispersion was then independently formed into an approximately 24 inch square sheet filter medium by means of vacuum dewatering in a foraminous former followed by drying on a moving belt in a hot air tunnel oven. The resulting sheet filter medium samples had specific weights of approximately 0.75 grams per square inch and a thickness of approximately 0.15 inches.
Each sample filter medium was subjected to a series of three different contaminant removal tests intended to define the electrokinetic capture and adsorption characteristics over a range of anionic particle sizes extending from a maximum of approximately 1.0 micrometer (Hyplar Membrane Protection Test) down to a minimum of approximately 100 Angstroms (Metanil Yellow Dye Test) and including an intermediate particle size of 0.11 micrometers (Monodisperse Latex Test). The test procedures utilized were as follows:
Membrane Protection Test
In this test, a 118 mm diameter disc of the medium sample is installed in a test housing which seals the outside edge of the medium and allows for pressurized flow of the challenge contaminant dispersion through the medium sample. In series with this test housing, and downstream of it, is another housing containing a 47 mm diameter 0.2 micrometer membrane filter. The test contaminant is Grumbacher Hyplar polydisperse acrylic latex (average particle size 0.7 um) dispersed in filtered distilled water to give a turbidity of 50 NTU as measured by a Hach Model 2100A Turbidimeter. The pH of the contaminant dispersion is adjusted to 5.0 with HCl and the resistivity is adjusted with NaCl to a value of 22,000 ohms. The resulting contaminant dispersion is passed through the test medium sample at a constant flow rate of 225 ml/min. The resulting pressure drop across the test medium sample and across the downstream membrane are separately monitored and recorded as a function of time. The test is terminated when the pressure drop across the membrane increases by a value of 5.0 PSID above the initial "clean" pressure drop. In those cases where that contaminant breaks through the sample medium and the membrane plugs, the total elapsed time is a measure of the electrokinetic capture and adsorption capacity of the medium sample for the anionic Hyplar test contaminant.
Monodisperse Latex Test
In this test, a 47 mm diameter disc of the sample medium is installed in a test housing which seals the outside edge of the medium and allows for pressurized flow of the challenge contaminant dispersion through the medium sample. The test contaminant is Dow Diagnostics 0.109 um Monodisperse Latex at a concentration which gives a turbidity of 10 NTU as measured by a Hach Model 2100A Turbidimeter. The pH of the dispersion is adjusted to 7.0 with NaOH and the resistivity is adjusted with NaCl to a value of 22,000 ohms. The resulting contaminant dispersion is passed through the test medium sample at a constant flow rate of 56 ml/min. The pressure drop across the test medium sample, and the effluent turbidity (measured by the Hach Model 2100A Turbidimeter) are continuously monitored and recorded as a function of time. The test is terminated when the effluent turbidity increases to a value of 5.0 NTU. The total elapsed time is a measure of the electrokinetic capture and adsorption capacity of the medium sample for the anionic 0.109 um Monodisperse Latex Contaminant.
Metanil Yellow Dye Test
In this test, a 47 mm diameter disc of the sample medium is installed in a test housing which seals the outside edge of the medium and allows for pressurized flow of the challenge contaminant solution through the medium sample. The test contaminant is Metanil Yellow dye (Molecular Wt. ≈108) at a concentration of 3 ppm giving a transmittance of ≈50 percent as measured at a wavelength of 430 nm using a Coleman 295 Spectrophotometer. The pH of the dispersion is adjusted to pH 7.0 with NaOH and the resistivity is adjusted with NaCl to a value of 22,000 ohms. The resulting contaminant dispersion is passed through the test medium sample at a constant flow rate of 56 ml/min. The pressure drop across the test medium sample, and the effluent transmittance is continuously monitored, as a function of time, using the Coleman 295 Spectrophotometer at a wavelength of 430 nm. The test is terminated when contaminant breakthrough occurs, i.e., the effluent transmittance decreases to a value of 85 percent, or when the pressure drop across the sample medium increases by a value of 5.0 PSID above the initial pressure drop. When the test is terminated because of contaminant breakthrough, the total elapsed time is a measure of the electrokinetic capture and adsorption capacity of the medium sample for the anionic Metanil Yellow Dye.
The results of the EXAMPLE I study are summarized in Table 1.
TABLE I
__________________________________________________________________________
FORMULATION WITH 4308 - TEPA CHARGE MODIFIER SYSTEM
MEM- 0.109 METANIL
BRANE μM MDL
YELLOW
PRO- TEST TEST
SAMPLE
4308
TEPA
INITIAL
FINAL TECTION
TIME TIME
DESIG.
(%)
(%) pH pH (Min.)
(Min.)
(Min.)
__________________________________________________________________________
30S CONT
-- -- -- -- 19.3 46.0 7.4
30S CONT
-- -- -- -- -- 43.8 6.2
30S - 2.500
0.625
6.94(as is)
9.60(as is)
19.9 60.0 67.5
30S - 2.500
0.625
8.70(adj.)
9.60(as is)
15.6 66.5 69.3
30S - 2.500
0.625
6.94(as is)
7.06(adj.)
14.6 66.8 72.5
30S - 2.500
0.625
7.91(adj.)
6.91(adj.)
15.7 74.5 78.0
30S - 2.500
-- 7.02(as is)
5.58(as is)
18.9 71.8 44.5
30S - 2.500
-- 6.87(as is)
7.08(adj.)
21.4 62.9 44.8
30S - 2.500
-- 7.92(adj.)
6.00(as is)
20.0 77.0 38.2
30S - 2.500
-- 8.25(adj.)
6.95(adj.)
19.0 63.3 50.0
30S - 1.250
0.625
7.90(adj.)
8.50(as is)
16.2 52.5 36.2
30S - 10
1.250
0.312
8.23(adj.)
8.34(as is)
18.9 64.6 40.0
30S - 11
1.250
0.156
8.15(adj.)
7.43(as is)
15.2 36.1 31.0
30S - 13
2.500
1.250
8.25(adj.)
8.54(as is)
22.4 48.8 53.0
30S - 2R
2.500
0.625
8.70(adj.)
9.60(as is)
15.6 66.5 69.3
30S - 14
2.500
0.312
8.03(adj.)
7.95(as is)
17.1 42.5 53.0
30S - 16
5.000
2.500
8.50(adj.)
9.04(as is)
17.9 48.8 93.0
30S - 17
5.000
1.250
8.20(adj.)
9.09(as is)
16.0 63.5 79.5
30S - 18
5.000
0.625
8.12(adj.)
8.30(as is)
14.1 37.5 69.0
__________________________________________________________________________
A number of significant conclusions can be drawn from the test results summarized in Table 1 and as shown in FIGS. 1, 2 and 3.
1. As shown in the Membrane Protection Test, there is no significant difference between the prior art samples and the samples of the invention in terms of electrokinetic capture and adsorption capacities for the larger Hyplar contaminant particles. In the samples of the invention, the total charge modifier content and primary to secondary charge modifier ratio (see FIG. 1), or pH history of the media samples do not seem to have any effect o capacity.
2. As shown in the Monodisperse Latex Test, the samples of the invention do appear to have an increased capacity (approximately 50%) for the electrokinetic capture and adsorption of the smaller monodisperse latex particles in comparison to the prior art samples. However, this effect is also demonstrated when the primary charge modifier of the invention is used by itself and it is possible that the enhanced monodisperse latex capacity is due to the differences in charge density between the 1884 and 4308 PAE resins. The results from samples 30S-9 through 30S-18 (see FIG. 2) do show that the ratio of primary to secondary charge modifier does have a significant effect upon the monodisperse latex capacity with a maximum benefit being achieved at an intermediate value of 4:1. On the other hand, the total charge modifier content and pH history of the media did not seem to have any effect.
3. As shown in the Metanil Yellow Dye Test, the samples of the invention do exhibit radically enhanced electrokinetic capture and adsorption capacities for the very small Metanil Yellow particle in comparison to the prior art samples, and a significantly increased capacity compared to those samples using only the primary charge modifier. The results from samples 30S-9 through 30S-18 (see FIG. 3) do show that the primary to secondary charge modifier content does have a significant effect on the Metanil Yellow Dye capacity which again, as previously shown for the monodisperse latex, appears to achieve a maximum value at an intermediate ratio of 4:1. In addition, it is shown that the total charge modifier content has a direct proportional effect on the capacity. Again, the pH history does not seem to have any significant effect.
EXAMPLE II
In EXAMPLE I, the basic fiber/particulate formulation was that of the prior art ZETA PLUS 30S Grade filter medium. It was chosen because it typically produced a filter medium whose pores were large enough not to mechanically strain out the Hyplar, or smaller, particles. As such, all of the particle removal exhibited by the control and sample media was due solely to electrokinetic capture and adsorption. In this example, it was our purpose to compare the electrokinetic capture and adsorption characteristics of the 4308/TEPA charge modifier system, representative of the invention, to that of the previously identified prior art system, in media with finer pore sizes. The sample formulations used in this example are given in Table 2.
TABLE 2
__________________________________________________________________________
The following formulations of filter sheet media were made:
REFINED PULP
PARTICULATE
CONTENT CONTENT CHARGE MODIFIER
PULP CONTENT
(FREENESS &
(TYPE & CONTENT
SAMPLE DESIG.
(TYPE & WEIGHT %)
WEIGHT %) WEIGHT %) (TYPE & WEIGHT
__________________________________________________________________________
%)
90 S CONTROL
KAMLOOPS - 19.0
-250 CSF, 11.0
215 DE, 35.0
1884 PAE, 2.0
416 PERLITE, 35.0
90 S - 1A, B, C
KAMLOOPS - 19.0
-250 CSF, 11.0
215 DE, 35.0
4308 PAE, 5.0
416 PERLITE, 35.0
TEPA, 1.25
60 S CONTROL
KAMLOOPS - 26.3
-250 CSF, 8.9
215 DE, 32.4
1884 PAE, 1.5
416 PERLITE, 32.4
60 S - 1A, B, C
KAMLOOPS - 26.3
-250 CSF, 8.9
215 DE, 32.4
4308 PAE, 5.0
416 PERLITE, 32.4
TEPA, 1.25
50 S CONTROL
KAMLOOPS - 21.0
-250 CSF, 7.0
416 PERLITE, 36.0
1884 PAE, 1.75
436 PERLITE, 36.0
50 S - 1A, B, C
KAMLOOPS - 21.0
-250 CSF, 7.0
416 PERLITE, 36.0
4308 PAE, 5.0
436 PERLITE, 36.0
TEPA, 1.25
30 S CONTROL
KAMLOOPS - 23.6
-250 CSF, 6.4
436 PERLITE, 70.0
1884 PAE, 1.9
30 S - 1A, B, C
KAMLOOPS - 23.6
-250 CSF, 6.4
436 PERLITE, 70.0
4308 PAE, 5.0
TEPA, 1.25
__________________________________________________________________________
Sample filter medium sheets were prepared, using the Table 2 formulations, in the manner described in EXAMPLE 1 except that the dispersion pH before charge modifier addition, and after dilution to the final 2.0% consistency, were left "as-is". The resulting medium specific weights ranged from approximately 0.75 to 0.8 grams per square inch with sheet thicknesses of approximately 0.15 inch. The sample filter media of this EXAMPLE 2 were then subjected to the Metanil Yellow Dye Test previously described in EXAMPLE 1. The results of these tests are summarized in Table 3.
TABLE 3
__________________________________________________________________________
METANIL YELLOW DYE TEST RESULTS
INITIAL INITIAL FINAL
TRANSMITTANCE
P/ TIME
P TRANS-
SAMPLE (%) (PSID)
(Min)
(PSI)
MITTANCE %
__________________________________________________________________________
90S CONTROL
100.0 11.2 11.1
0.8 85.0
90S - 1A 97.0 8.5 48.8
5.0 90.0
90S - 1B 100.0 9.8 42.8
5.0 99.0
90S - 1C 99.0 13.1 30.5
5.0 99.0
60S CONTROL
97.0 8.4 10.9
0.5 85.0
60S - 1A 99.0 8.2 35.3
5.0 91.0
60S - 1B 99.0 7.0 31.6
5.0 98.0
60S - 1C 98.0 8.0 46.8
5.0 94.0
50S CONTROL
99.0 6.3 9.6 0.6 85.0
50S - 1A 100.0 5.5 53.9
5.0 96.0
50S - 1B 100.0 4.8 54.9
5.0 89.0
50S - 1C 100.0 4.8 41.2
5.0 99.0
30S CONTROL
99.0 3.0 10.6
0.4 85.0
30S - 1A 100.0 2.3 13.3
5.0 100.0
30S - 1B 99.0 2.2 67.3
3.8 85.0
30S - 1C 99.0 2.0 73.7
2.7 85.0
__________________________________________________________________________
A number of significant conclusions can be drawn from the results of Table 3, as follows:
1. The use of the high charge modifier content in the samples representative of the invention has no significant effect on the physical formation of the medium, or reduction in pore size, as demonstrated by the fact that the initial pressure drops (INITIAL P) exhibited by the samples of the invention are essentially identical to, or lower than, the initial pressure drops exhibited by the corresponding samples representative of the prior art.
2. The prior art samples exhibit low electrokinetic capture and adsorption capacities as demonstrated by the short time to breakthrough of the Metanil Yellow Dye (85.0% Final Transmittance) and the negligible increase in pressure drop across the sample medium (P) during the course of the test.
3. The samples of the invention, on the other hand, exhibit unexpectedly high electrokinetic capture and adsorption capacities for the Metanil Yellow Dye as demonstrated by the significantly extended test time and the fact that all of the medium samples, with the exception of the most open (largest pore size) 30S-1B and 30S-1C samples, exhibited medium plugging (P=5.0 PSID) prior to breakthrough of the Metanil Yellow Dye. In fact, most of the invention samples were still exhibiting significant electrokinetic capture and adsorption of the dye when the tests were terminated because of pad plugging.
EXAMPLE III
Using full scale production equipment, two different sheet filter medium samples were prepared as follows:
______________________________________
Sample Designation 60LZ
Formulation:
WEYERHAUSER MAC WOOD PULP
16.00 WT. PERCENT
-250 CSF REFINED MAC PUL
24.00 WT. PERCENT
GREFCO DICALITE 215 DE
30.00 WT. PERCENT
GREFCO DICALITE 416 PERLITE
30.00 WT. PERCENT
HERCULES 4308 PAE RESIN
5.00 WT. PERCENT
TETRAETHYLENE PENTAMINE
1.25 WT. PERCENT
SHEET SPECIFIC WEIGHT 0.763/0.842 GMS/IN.sup.2
Sample Designation 90LZ
Formulation:
WEYERHAUSER MAC WOOD PULP
10.00 WT. PERCENT
-250 CSF REFINED MAC PUL
18.00 WT. pERCENT
ACID WASHED GREFCO DICALITE
72.00 WT. PERCENT
215 DE
HERCULES 4308 PAE RESIN
5.00 WT. PERCENT
TETRAETHYLENE PENTAMINE
1.25 WT. PERCENT
SHEET SPECIFIC WEIGHT 0.763/0.842 GMS/IN.sup.2
______________________________________
The process for preparing the sheet samples was essentially as described in EXAMPLE I except that the total weights and volumes of material were considerably higher and the sheet media were formed and vacuum dewatered on a semicontinuous foraminous former. Also, dispersion pH was left "as-is". These samples were subjected to a modified version of the Metanil Yellow Dye Tests as described in EXAMPLE I. The modifications were as follows:
______________________________________
Test Sample Diameter 118 mm
Test Flow Rate 225 ml/min
Dye Concentration 4.0 PPM
Inlet Transmittance 43.7%
pH 7.0 to 12.0
______________________________________
Standard ZETA PLUS 60S prior art medium was used in a comparative example. The results of this testing are summarized in Table 4.
TABLE 4
__________________________________________________________________________
OUTLET TRANSMITTANCE (Percent)
SPECIFIC
Prior Art Invention
THRUPUT
60S 60LZ 90LZ
(Gal/Ft.sup.2)
pH 7.0
pH 7.0
pH 10.0
pH 11.0
pH 12.0
pH 7.0
pH 12.0
__________________________________________________________________________
1.0 99.8
99.9
99.0 99.1 99.4 100.9
100.0
2.5 98.6
99.9
99.8 100.0
99.5 100.5
99.8
5.0 51.0
99.5
99.8 99.9 99.4 99.0
99.6
7.5 -- 99.2
99.5 99.7 96.6 98.0
91.8
10.0 -- 99.5
99.5 98.4 88.2 99.9
87.7
12.5 -- 99.2
99.7 98.9 73.8 99.2
82.6
15.0 -- 98.9
99.7 97.4 -- 99.0
77.2
17.5 -- 99.7
99.6 93.9 -- 98.5
--
20.0 -- 99.4
99.5 85.5 -- 98.9
--
22.5 -- 97.3
99.1 72.1 -- 98.5
--
25.0 -- 99.5
98.8 -- -- 98.9
--
27.5 -- 98.8
96.3 -- -- 98.5
--
30.0 -- 99.2
92.6 -- -- 99.3
--
32.5 -- 98.8
83.4 -- -- 98.3
--
35.0 -- 98.4
72.0 -- -- 98.7
37.5 -- 98.0
-- -- 97.4
--
40.0 -- 94.9
-- -- -- 97.3
--
42.5 -- 87.4
-- -- -- 97.0
--
45.0 -- 76.8
-- -- -- 96.2
--
47.5 -- -- -- -- -- 95.4
--
50.0 -- -- -- -- -- 94.3
--
52.5 -- -- -- -- -- 93.3
--
55.0 -- -- -- -- -- 90.0
--
57.5 -- -- -- -- -- 86.8
--
60.0 -- -- -- -- -- 80.1
--
62.5 -- -- -- -- -- -- --
__________________________________________________________________________
The test results in Table 4 demonstrate that the filter media of this invention demonstrate radically greater capacity for the electrokinetic adsorption of Metanil Yellow Dye than does the prior art media. At pH 7.0, the 60LZ exhibits a capacity 1200 percent greater, and the 90LZ exhibits a capacity 1600 percent greater, than the prior art 60S. More importantly, the filter media of this invention exhibit unexpected useful capacities at higher pH, up to and including 12.0, where the prior art media possess essentially no capacity. In fact, at pH 12.0, the 60LZ exhibits a capacity 200 percent greater, and the 90LZ exhibits a capacity 300 percent greater, than the prior art 60S is capable of achieving at pH 7.0.
EXAMPLE IV
The media of this invention (Sample Designation 60LZ as described in Example III) was fabricated into a 12 inch diameter, 15 cell cartridge of the general configuration shown in FIGS. 5 and 6. This cartridge was installed, in a suitable filter housing, in an industrial process water system in one of the Assignee's plants. This system suffered from pyrogen contamination of a form that had proven to be relatively intractable to useful reduction by means of prior art filter media. Specifically, this process water system attempted to convert municipal water into high purity pyrogen free water by means of sequential treatment through a carbon bed, an anion exchange bed, a ZETAPOR 020ST (0.2 micrometer) charge modified nylon membrane (Cuno, Inc., produced pursuant to U.S. Pat. No. 4,473,474 to Ostreicher et al) and ZETA PLUS 90LP (Cuno, Inc., produced pursuant to U.S. Pat. No, 4,606,824 to Chu et al). The pyrogen removal characteristics of this system, with newly installed prior art filter media, were typically as shown in Table 5.
TABLE 5
__________________________________________________________________________
INCOMING AFTER AFTER AFTER AFTER
CITY CARBON ANION ZETAPOR ZETA PLUS
WATER BED EXCHANGER 020ST 90LP
PYROGEN PYROGEN PYROGEN PYROGEN PYROGEN
SAMPLE
LEVEL LEVEL LEVEL LEVEL LEVEL
DATE (pg/ml)
pH
(pg/ml)
pH
(pg/ml) pH (pg/ml)
pH (pg/ml)
pH
__________________________________________________________________________
9/20/88
5200 7.2
2250 7.4
<6400 7.3
1000 7.3
<1600 7.1
9/21/88
5700 7.2
<6400 7.3
5600 9.4
600 9.3
<3200 8.8
9/22/88
5600 8.3
8800 7.3
4000 7.7
700 9.2
4800 9.4
9/23/88
4100 8.8
5200 7.7
5400 10.4
800 10.2
2700 10.4
9/27/88
8100 7.4
5600 7.3
<12800 10.6
<3200 10.5
<6400 10.3
__________________________________________________________________________
For the testing of the sample medium of this invention, the ZETAPOR 020ST cartridge was removed from the system and the prior art 90LP cartridge was replaced by the 60LZ sample medium cartridge representative of the invention. The results of these tests are summarized, in the form of 60LZ cartridge inlet and outlet pyrogen levels, pH, and total water processed, vs sample date, in Table 6.
The test results given in Tables 5 and 6 clearly demonstrate the superiority of the filter medium (60LZ) of this invention as compared to prior art filter media. The prior art charge modified nylon ZETAPOR 020ST membrane was capable of a pyrogen level reduction that averaged 83.3 percent. The prior art ZETA PLUS 90LP exhibited essentially no pyrogen removal. It is known that, in some applications, both prior art media are capable of useful and essentially quantitative levels of pyrogen removal from water. It would appear that, in the subject process water system used for these tests, the pyrogens are in a form that makes removal particularly difficult for the prior art media. This may be a function of the municipal water treatment methodology, the nature of the gram negative bacteria inhabiting the municipal or in-plant water distribution system, or the specific design of the subject process water treatment system. The media of this invention, on the other hand, exhibited an average pyrogen reduction of 97.3 percent over a period in excess of one month with a treated water total volume in excess of 85000 gallons.
TABLE 6
______________________________________
MEASURED MEASURED
TOTAL INLET OUTLET
WATER CONDITIONS CONDITIONS
SAM- PROCESSED PYROGEN PYROGEN
PLE (GALLONS) LEVEL pH LEVEL pH
______________________________________
12/20/88
603 3200 6.9 <12.5 6.7
12/21/88
3947 2500 6.8 <12.5 6.3
12/22/88
4498 1667 6.7 <12.5 6.3
01/03/89
4666 20000 6.2 50.0 6.1
01/04/89
8913 1250 5.7 17.0 5.6
01/05/89
12772 2000 5.2 12.5 5.4
01/11/89
18248 2500 7.1 50.0 6.9
01/12/89
22488 5000 7.0 50.0 6.8
01/17/89
27178 1250 7.1 25.0 6.8
01/18/89
27178 1667 7.0 100.0 6.7
01/19/89
35081 1250 6.9 67.0 6.6
01/24/89
40528 1250 5.0 100.0 4.6
01/25/89
44541 1250 4.5 50.0 4.8
01/26/89
48616 2500 5.4 267.0 4.9
02/14/89
55509 1250 6.2 12.5 6.4
02/15/89
59218 1250 6.5 50.0 6.5
02/16/89
63145 1333 6.2 <12.5 6.6
02/17/89
63145 1333 5.7 12.5 6.0
02/20/89
78507 1250 5.3 33.0 5.6
02/21/89
82033 500 5.8 <12.5 5.7
02/22/89
85889 667 5.3 <12.5 5.3
02/23/89
-- 2000 5.2 12.5 5.3
______________________________________
EXAMPLE V
Five 10 mm diameter discs of sample medium 60LZ of this invention (see EXAMPLE III) were installed, in a stacked series configuration, in a test housing which seals the outside edge of the medium disc stack and allows for pressurized flow of the challenge contaminant dispersion through the medium sample. The medium sample was equilibrated with 0.02M NaP+0.15M NaCl pH 7.3 buffer solution. Using the same buffer solution, a 20000 pg/ml dispersion of E. coli LPS was prepared, and was flowed through the sample medium at a flow rate of 2.0 ml/min. Effluent fractions were collected at various times and assayed, in duplicate, for pyrogen (LPS) content by means of chromogenic substrate technique (Whittaker Bioproducts QLC-1000). The results were as summarized in Table 7.
TABLE 7
__________________________________________________________________________
CUMULATIVE VOLUME
EFFLUENT PYROGEN
PYROGEN REMOVAL
FILTERED CONCENTRATION
EFFICIENCY
DATE (milliliters) (picograms/ml)
%
__________________________________________________________________________
01/12/89
270 <100 99.5
510 <100 <99.5
720 177 99.1
1000 267 98.7
01/13/89
1200 <100 <99.5
1450 <100 <99.5
1690 123 99.4
1960 179 99.1
01/16/89
2160 363 98.2
2420 519 97.4
2710 576 97.1
02/18/89
3130 256 98.7
3370 261 98.7
3640 335 98.3
01/19/89
3940 496 97.5
4300 687 96.6
01/20/89
4470 379 98.1
4770 410 98.0
4930 464 97.7
__________________________________________________________________________
The data in Table 7 demonstrates the ability of the media of this invention to achieve useful (>1500 gallons/ft2 at a specific flow rate of 0.62 gpm/ft2) levels of depyrogenization in a highly contaminated buffer solution. The test was terminated because of time constraints, but it is evident that the sample medium was maintaining high efficiency for pyrogen removal at the end of the test and was certainly a long way from having exhausted its useful capacity.
EXAMPLE VI
Five 10 mm diameter discs of sample medium 60LZ (see EXAMPLE lII) were installed, in a stacked series configuration, in a test housing which seals the outside edge of the medium disc stack and allows for pressurized flow of the challenge contaminant dispersion through the medium sample. Prior to installation in the test housing, the medium discs were washed with 1.0M NaOH, and then with 1.0M HCl, for 50 minutes each. After installation in the test housing, the medium sample was equilibrated with 0.02M NaP+0.15M NaCl pH 7.3 buffer solution. 400 ml of the buffer containing 2.5 mg/ml HτG (Human Gamma Globulin) and 20000 pg/ml E. coli LPS was flowed through the sample medium at a flow rate of 2.0 ml/min. Effluent fractions were collected and assayed for HτG, and LPS content using the chromogenic technique (Whittaker Bioproducts QCL-1000). The results were as summarized in Table 8.
TABLE 8
__________________________________________________________________________
CUMULATIVE VOLUME
EFFLUENT HτG
EFFLUENT PYROGEN
FILTERED CONCENTRATION
CONCENTRATION
(milliliters) (mg/ml) (pg/ml)
__________________________________________________________________________
20 1.90 800
40 2.40 2800
60 2.40 4200
80 -- 6100
100 2.50 7100
140 2.50 9600
180 -- 10700
220 2.50 11600
260 -- 13400
300 2.50 15700
340 -- 15800
400 2.50 17300
__________________________________________________________________________
The above data demonstrates the ability of the media of this invention to achieve useful levels of depyrogenization in a highly contaminated protein solution, and to do so with minimal nonspecific protein binding.
EXAMPLE VII
The media of this invention (Samples 60LZ and 90LZ from EXAMPLE III) were tested, along with prior art 60 LP and 90LA media, to determine the gravimetric extraction levels in water. For each medium sample, the test consisted of inserting a 90 mm disc of the sample medium into a polysulfone test housing, and recirculating 1.0 Liter of high purity (18 meg-ohm) water through the media sample for a period of 48 hours. At tho end of that time, a 500 ml sample of the water was placed in a preweighed beaker and boiled to dryness and reweighed to determine the total weight extraction. The beaker, containing the dried extraction residue, was then placed in a muffle furnace overnight at a temperature of 550° C., to remove the organic portion of the residue. After cooling the beaker containing the inorganic residue was reweighed to determine the inorganic weight extraction. The organic weight extraction was then calculated by subtracting the inorganic from the total. The results, adjusted back to the full 1 liter water extraction volume, are summarized in Table 9.
TABLE 9
__________________________________________________________________________
CHARGE TOTAL ORGANIC
CHARGE MODIFIER
EXTRACTION
EXTRACTION
SAMPLE
MODIFIER (Wt. %)
(mg) (mg)
__________________________________________________________________________
60LP 1884 PAE RESIN
1.90 8.3 3.2
60LZ 4308 PAE RESIN
5.00 9.5 5.6
TEPA
90LA 1884 PAE RESIN
1.90 11.4 8.0
90LZ 4308 PAE RESIN
5.00 20.2 9.5
TEPA
__________________________________________________________________________
Both the prior art media and the media of this invention exhibited extremely low gravimetric extractions when subjected to extended water contact. Given an average sample medium weight of approximately 7.4 grams, the organic extractions represent less than 0.13 percent of the sample weight. The media of this invention exhibit these very low, and essentially equivalent, organic extraction levels in spite of their significantly higher level of charge modifier.
What is claimed:
1. A process for removing anionic contaminants from an aqueous fluid containing said contaminants, said fluid having a pH up to about 12, comprising passing said fluid through a filter media comprising filter elements of cellulose fiber and silica based particulate or fiber and a charge modifying system bonded to the surfaces of the elements, whereby said contaminants are electrokinetically captured and absorbed onto said media, the charge modifying system including:a primary charge modifying agent which is a water soluble organic polymer capable of being adsorbed onto the elements and having a molecular weight of greater than about 1000, each monomer of the polymer having at least one epoxide group capable of bonding to the surfaces of the elements and quaternary ammonium groups; and a secondary charge modifying agent bonded to a portion of the epoxy groups on the organic polymer, wherein said secondary charge modifying agent is an aliphatic polyamine having at least one primary amine or at least two secondary amines.
| 1990-11-27 | en | 1992-02-04 |
US-79116685-A | Saw carriage stabilizer
ABSTRACT
A longitudinal guide track is arranged to be secured to the elongated supporting frame of a saw mill and a laterally extending arm arranged to be secured to the lower portion of a depending support of a saw carriage has followers arranged for guided movement along the longitudinal guide track for stabilizing the support member and the saw blades. The followers comprise two rollers engageable on opposite sides of the flange. The support for the rollers is spring mounted to provide resilient adjustment to irregularities in the longitudinal flange.
BACKGROUND OF THE INVENTION
This invention relates to new and useful improvements in saw carriage stabilizers for saw mills.
Some saw mills currently in use, such as portable mills, employ an elongated frame arranged to be fixed to the ground or fixed to a log and utilize traveling carriages that move along the frame under operator control. In one form of mill, and to which this invention is concerned, a vertical portion of the carriage is supported in depending relation on one side of the longitudinal frame and a vertical saw blade and one or more horizontal blades are disposed in this overhanging portion of the carriage and operate in combination for making saw cuts. The portion of the carriage that supports the horizontal saws comprises a depending structure which is subject to severe strain and vibrations resulting from tension forces developed by the cutting pull from the saw blades, as well as from other forces. Such forces and vibrations result in damage to shafts, bearings, etc. Prior structures have utilized various types of reinforcement means between the carriage body and the depending support for the purpose of stabilizing the saws but such structures have not been successful in overcoming substantially all the vibrations or other undesirable forces.
SUMMARY OF THE INVENTION
According to the present invention and forming a primary objective thereof, a new and improved stabilizing means is provided for eliminating vibrations and other forces in the carriage whereby to provide long life for shafts, bearings, and other parts.
A more particular object is to provide carriage stabilizing means which utilize a direct connection between the bottom end of the depending portion of the carriage and a longitudinal main frame on which the carriage travels, thus utilizing the reinforced strength and rigidity of the main frame to provide stability to the saw blade supporting portion of the carriage.
A further object of the present invention is to provide stabilizing means of the type described which is simplified in structure, which has automatic spring adjustment means for following irregularities in the saw mill frame, and which is readily installed on existing saw mills.
In carrying out the objectives of the invention, a longitudinal guide track in the form of a depending flange is secured to the elongated main supporting frame adjacent the side on which the carriage travels. A laterally extending arm is secured to the lower end of the depending saw support of the carriage and includes follower means which have guided movement along the depending flange on the main frame for stabilizing the saw blades. The follower means comprise followers engageable on opposite sides of the flange for efficient stabilization. Also, the stabilizing means includes compression spring means which provide resilient follower movement along any irregular path of the frame.
The invention will be better understood and additional objects and advantages will become apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a foreshortened plan view of a saw mill and a log being sawed, this type of mill utilizing a structure with which the present invention may be combined;
FIG. 2 is an enlarged cross sectional view taken on the line 2--2 of FIG. 1 and showing details of the present invention;
FIG. 3 is an enlarged sectional view taken similar to FIG. 2; and
FIG. 4 is a fragmentary sectional view taken on the line 4--4 of FIG. 3.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
With reference first to FIGS. 1 and 2, the present invention is shown in conjunction with a portable saw mill wherein the main frame of the saw mill is anchored securely to a log L and successive cuts are made longitudinally of the log by lateral adjustment of a saw carriage support frame. The numeral 10 designates generally a conventional elongated main frame having longitudinal frame members 12 and suitable horizontal, vertical and angled reinforcing members 14. Frame 10 supports a movable carriage 16, shown in phantom lines in FIG. 1 and in full lines but only fragmentarily in FIG. 2. This carriage supports a vertical saw blade 18 and one or more horizontal saw blades 20. Blades 18 and 20 cooperate upon longitudinal movement of the carriage 16 to provide vertical and horizontal cuts 22 and 24, respectively, on the log. The horizontal saw blades 20 are supported on a shaft 26 having journaled support in suitable bearings 27 on the carriage platform and on vertical support 28 depending from the underside of the carriage 16 on one side of the main frame 10.
With reference to FIG. 1, temporary connection between the frame 10 and the log L is accomplished by laterally disposed rail members 30 secured, as by lag screws or spikes 32 or other suitable means, to the log. Winch means 34 with cables 36 secured to the far end of the rail members 30 are used to adjust the frame toward the log after each cut, and stop means 38 position the carriage for each cut. The structure thus far described is conventional and is shown somewhat diagrammatically.
It is apparent from FIG. 2 that with the depending support 28 providing substantially the entire suspension of the horizontal saw blades, and since the saw blades are located adjacent the bottom of this suspended support, vibrations can readily occur in this area, particularly on tough to saw material and on wide cuts of the vertical saw, whereby damage from such vibrations etc. can occur to the shaft 26, bearings 27, and other parts.
According to the present invention, the bottom of the depending support 28 is provided with stabilizing means 40 which utilize the rigidity of the elongated main frame 10 as a guiding support for the lower end of the carriage as it moves in making a cut. With reference to FIGS. 2, 3 and 4, a guide track 42 is secured longitudinally to the bottom of the frame 10 on the side next to the depending support 28. This guide track has a full length depending flange 44. Secured horizontally to the bottom end of the support 28, as by welding, is a rigid frame or arm 48 having a projecting ear 50 adjacent an outer end thereof and an integral rigid tab or extension 52 projecting in the same direction as the ear 50. The tab 52 supports, by means of an upright shoulder bolt 54, a laterally extending slide plate 56. The tab 52 has a slot 58 therein through which the shoulder bolt 54 extends whereby the slide plate 56 can have a slight amount of lateral adjustment relative to its mounted support on the frame 48, as will be more apparent hereinafter. Slide plate 56 carries a pair of rollers 60 and 62, such rollers being spaced from each other and disposed on opposite sides of the depending flange 44 of the guide track 42. As will be apparent, these two rollers track along the flange 44 and stabilize the lower end of the support 28. One of the rollers 60 or 62, such as the roller 60, is provided with a cam-shaped bearing support 64 for adjustment to the flange 44 during installation.
The outer end of the slide plate 56 has an integral shaft extension 66 which supports a pair of heavy duty compression springs 68 one on each side of the ear 50. One spring 68 is engageable between the ear 50 and a head portion 70 of the shaft 66 and the other spring 68 is engageable between the ear 50 and the slide plate 56. These springs, while holding the slide plate 56 substantially firmly in place, allow the slide plate to adjust slightly in a lateral direction as the carriage moves in its operation now to become apparent.
According to the present invention, the bottom end of the depending support 28 is firmly reinforced against vibration or other undesirable forces by reason of the reinforcement received from the strong main frame 10. That is, as the carriage moves, the rollers 60 and 62 are in firm engagement on opposite sides of the flange 44 and prevent undesirable forces or vibrations from developing in the support 28 and the horizontal saws 20. Springs 68, however, allow the rollers and the slide plate 56 to adjust laterally to any irregularity in the flange 44. With the lower end of the carriage support and the saw blades stabilized by the main frame of the saw mill, the life of the bearings and other parts are prolonged. Also, with the saw blades stabilized, they make a smooth narrow cut, thus allowing the carriage to travel fast and/or with less power.
It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention, or the scope of the subjoined claims.
Having thus described my invention, I claim:
1. A portable saw mill comprising:an elongated supporting frame, a carriage movable longitudinally on said frame and having a vertical saw blade at one side thereof, a depending support on said carriage supporting at least one horizontal saw blade cooperating with the vertical saw blade in sawing boards from a log, a longitudinal depending guide flange secured to the elongated supporting frame, a laterally extending bracket secured to a lower portion of the said depending support, a slide plate slidably mounted on said bracket in a lateral direction, a pair of rollers mounted on said slide plate engageable on opposite sides of said flange and having guided following movement along said longitudinal guide flange for stabilizing the lower portion of said depending support and the horizontal saw blade thereon in a lateral direction, abutment means on at least one of said bracket and slide plate, and compression spring means on both sides of said abutment means engageable with at least one of said bracket and slide plate and providing resilient adjustment of at least one of said bracket and slide plate to adjust to lateral irregularities in said flange.
2. A portable saw mill comprising:an elongated supporting frame, a carriage movable longitudinally on said frame and having a vertical saw blade at one side thereof, a depending support on said carriage supporting at least one horizontal saw blade cooperating with the vertical saw blade in the sawing boards from a log, a longitudinal guide track secured to the elongated supporting frame and having an elongated depending flange, a bracket secured to said depending support, a slide plate slidably mounted on said bracket in the lateral direction, a pair of rollers on said slide plate engageable with opposite sides of said flange, abutment means on said bracket, and compression spring means engageable on both sides of said abutment means and providing resilient adjustment of said slide plate to adjust to lateral irregularities in said flange as said rollers follow said flange.
| 1985-10-24 | en | 1987-12-29 |
US-89384292-A | Process for forming a copolymer-based anticorrosion coating on a metal surface and the products thus obtained
ABSTRACT
The process is characterised according to the invention by the application to the metal surface, especially sheet metal, of a layer of a solution comprising a block copolymer made up of at least two blocks, the first consisting of a unit based on a siloxane monomer and the second consisting of a unit based on acrylic or vinyl monomers.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for forming a coating on a previously pickled metal surface, especially on a metal sheet, and the product obtained by this process, the coating consisting of copolymers based on polydimethylsiloxane imparting anticorrosion and lubricating properties to the surface.
2. Discussion of the Background
The problem of protection of metal surfaces and more particularly of metal sheets against atmospheric corrosion is a continual preoccupation in industry.
In fact, after the operations of hot rolling of flat products and of cold rolling with a view to reducing their thickness, the metal sheets obtained are subjected to a pickling operation and are then stored in a depot or transported to a customer. The metal sheets are then directly subjected to the effects of the environment and corrode as time passes before reaching the user.
It is accepted that atmospheric corrosion represents by far the most important corrosion factor. It acts through the intermediacy of a very thin film of water condensed on the surface of the metal sheets, this film containing chemical species in solution which originate from the atmosphere. The corrosion which arises in this film is of the electrochemical type.
In order to avoid this type of "electrochemical" attack the sheet metal must be isolated from the environment by being coated with a material which is impervious and resistant to this medium such as, for example, by means of oiling. It is also appropriate to endow the surfaces of the metal sheets with a potential for chemical reactivities contrary to those which cause the corrosion.
At present, some products intended for a delayed use are delivered to the customers oiled, the oiling of the products taking place only at the end of the production line, immediately after the pickling. In this case, as soon as the products are received by the customers, the latter must degrease their surfaces before envisaging any use whatsoever.
It is therefore understandable that it is highly advantageous to protect metal sheets temporarily against corrosion for a minimum period of two months while getting rid of the oiling which results in an additional operation by the customer. This period corresponds to the "dead time" between the finishing of the product and its being received by the customer.
Among the known methods for protecting unoiled pickled products can be mentioned corrosion inhibitors, for example amine-based ones, coatings based on a plastic, such as resins or elastomers, and metallic or inorganic coatings.
The major disadvantage linked with the use of conventional anticorrosion products lies in the fact that they exhibit a corrosion resistance which is very limited in time, namely about twenty days. After that, they are no longer effective, the corrosion phenomenon appears and deteriorates the metal sheets.
In another technical field, which is that of the forming of metals by cold plastic deformation, especially by stamping of metal sheets, it is known that the contribution of the frictional forces between a metal sheet and a tool during the deformation represents from 20 to 40% of the total energy absorbed by the operation and is converted entirely into heat energy.
Furthermore, since the deformations applied to the metal sheet are produced under very high pressures during very short times, frictions appear between the metal sheet and the tool during the operation, thus giving rise to adhesions or seizures, that is to say tearing away of metal particles. In extreme cases the sheet metal reaches the limit with mechanical rupture.
Attempts are consequently made to reduce the metal sheet-tool friction coefficient by employing a solid or liquid lubricant which is placed on the sheet metal and/or on the tool and which forms an antifriction layer. It prevents direct contact between the sheet metal to be deformed and the tool and thus reduces the friction.
There are known surface treatments for sheet metal which make it possible to improve the friction coefficient and thus to contribute to a better cold deformation.
Phosphating, in particular, is one of these treatments and the use of zinc phosphates is known to improve the quality of cold deformations. However, phosphating is a chemical conversion process, that is to say that it impairs the chemical properties of the surface of the sheet metal. Now, when the deformation of the sheet metal has been completed, it is possible, depending on the intended industrial application, to apply a chemical treatment to the sheet metal and, when this takes place, reaction incompatibilities may arise and may consequently be detrimental to the performance of the said treatment. In addition, when phosphated metal sheets are to be welded, problems appear as a result of the peculiar behaviour of the sheet metal towards welding products.
There are also known products which are deposited onto a metal sheet with a view to improving the cold deformability of the said sheet, in particular to improve its stamping ductility. In particular, Patent Application FR-88/05334 describes alkali metal salts such as, for example, potassium phosphate, K3PO4, which has lubricating properties when mixed with a lubricating oil at the time of the stamping.
SUMMARY OF THE INVENTION
Faced with the disadvantages and the limitations of the prior art, the present invention is intended to provide a coating for metal surfaces, especially of metal sheets, making it possible to contribute an improved temporary protection against corrosion and to lower the friction coefficient of the surface, as well as the process for applying the coating onto the latter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The subject of the invention is a process for forming a coating on a metal surface, especially on a metal sheet, characterised by the application to the said surface of a layer of a solution containing a block copolymer made up of at least two blocks, the first consisting of a unit based on a siloxane monomer, and the second consisting of a unit based on acrylic or vinyl monomers.
The siloxane monomer is especially dimethylsiloxane. In this case the copolymers employed according to the invention are based on polydimethylsiloxane. The first block may also contain an acrylic or vinyl monomer in addition to the siloxane monomer.
According to a characteristic of the invention the acrylic monomer forming part of the first and/or second block is chosen from methacrylic esters.
The methacrylic esters are preferably chosen from methyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 show the friction coefficient versus normal force for sheet metal coated with a solution comprising the invention copolymer.
A typical copolymer according to the invention comprises (i) a first block made up of three monomers: methyl methacrylate, hydroxyethyl methacrylate and dimethylsiloxane, whose proportions by weight in the said block are between 30 and 50%, 0 and 20%, 40 and 60% respectively and (ii) a second block made up of three monomers: methyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate, whose proportions by weight in the said block are between 30 and 50%, 30 and 50% and 10 and 30% respectively.
This copolymer preferably comprises (i) a first block made up of the monomers methyl methacrylate, hydroxyethyl methacrylate and dimethylsiloxane, whose proportions by weight in the said block are equal to 40, 10 and 50% respectively, the block (i) representing 60% by weight of the copolymer, (ii) a second block made up of the monomers methyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate, whose proportions by weight in the said block are equal to 40, 40 and 20% respectively, the block (ii) representing 40% by weight of the copolymer.
The solvent is chosen from ketones, esters, chloroalkanes and aromatic compounds. These organic compounds have a low surface tension and are chosen for the purpose of avoiding differences in miscibility and to obtain a dispersion of the copolymer in these solvents which is as homogeneous as possible.
Among ketones, acetone, methyl ethyl ketone or cyclohexanone are preferably chosen.
Among esters, ethyl acetate or butyl acetate is preferably chosen.
Among chloroalkanes, 1,1,1-trichloroethane is preferably chosen.
Among the aromatic compounds, toluene or xylene is preferably chosen.
The solution advantageously contains from 2 to 10 g/l of copolymer.
According to a characteristic of the invention the solution is preheated before being applied onto the metal sheet. The heating temperature is in particular between 20 and 400° C.
The application of the layer to the metal surface, especially the face of the sheet metal, may be performed in various way:
by spraying with a gun,
by dipping,
by rotation,
by coating with a paintbrush, brush or roller,
by enamelling as a strip.
According to another characteristic of the process according to the invention, the protective layer is dried after its application to the metal surface. The drying temperature is in particular between 70 and 100°C., depending on the solvent employed, for example approximately 80 C.
Another subject of the invention is the product obtained by the process described above.
Within the scope of this invention the product may be a metal sheet. The layer applied to the sheet has a thickness of between 0.01μm and 3μm. The layer preferably has a thickness of 0.1μm.
The invention will be understood better with the aid of the description which is to follow and which is given solely by way of example.
The process according to the invention, relating to the formation of a coating on a metal surface, applies to a metal sheet which is pickled beforehand, but can also apply to a metal sheet which is previously coated (by phosphating, chromating and the like).
The process is implemented on a treatment line, for example starting with a cold-rolled sheet.
The process also applies to a hot-rolled sheet.
The metal surface may be a wire.
EXAMPLE
Before carrying out the process according to the invention the sheet metal is subjected to a pickling operation in acidic baths, for example in nitric acid, in order to remove the chemical substances which adhere to the surface and which would thereby interfere with the subsequent application of a coating. The sheet metal is then immersed in troughs of rinsing water to remove all traces of acid.
A layer of a solution comprising the following is applied to at least one face of the pickled sheet metal:
copolymer comprising:
(i) a first block made up of three monomers methyl methacrylate, hydroxyethyl methacrylate and a dimethylsiloxane, whose proportions by weight are 40, 10 and 50% respectively, the block (i) representing 60% by weight of the copolymer,
(ii) a second block made up of three monomers methyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate whose proportions by weight in the said block are 40, 40 and 20% respectively, the block (ii) representing 40% by weight of the copolymer, and
solvent defined below.
The acrylic monomers employed according to the invention have a solubility which is higher than that of the siloxane monomer.
The solubility parameter is defined in the "Polymer Handbook" by J. Bandrup (publ. Wiley Interscience 1976).
In the case of the dimethylsiloxane group the solubility parameter has a value of 7.5 (cal/cm3)1/2; the solubility parameters of methyl methacrylate, hydroxyethyl methacrylate and butyl methacrylate respectively assume the following values: 10, 11, 10 (cal/cm3)1/2 respectively, which are thus higher than that of dimethylsiloxane.
Such a copolymer is known as a component of mixtures based on polyurethane resins and elastomers and also as a surface modifier for powders which form part of the composition of paint pigments.
According to the invention is has been possible to ascertain that copolymers comprising a polydimethylsiloxane exhibit a good adhesion to metal sheets.
In this embodiment of the invention the chosen solvent is 1,1,1-trichloroethane. Because of its low boiling point, 74.1° C. at normal atmospheric pressure, this solvent can be evaporated with a low energy, when compared with other industrial solvents.
The solution of the copolymer in trichloroethane is applied in the form of a layer onto the metal sheet at a temperature of 30°C. This heating makes it possible to homogenise the solution and thus to improve the dissolution of the copolymers present.
In a final stage of the process a drying operation is performed on the layer immediately after it has been applied to the sheet metal. The drying is performed by means of hot air driers at approximately 80° C.; this temperature is higher than the boiling temperature of the solvent in order to facilitate its evaporation.
The process described above makes it possible to obtain a product which is a metal sheet coated with the copolymer according to the embodiment of the invention.
The organic coating layer thus obtained has a thickness of 0.1 μgm.
The organic coating endows the metal sheet with properties which make it possible to improve its corrosion resistance. It is nonporous, inert towards the corrosive environment, and adheres sufficiently to the sheet metal to prevent water vapour from penetrating the protective screen formed by the coating and initiating a corrosion reaction at the surface of the sheet metal.
Comparative tests have been carried out with conventional, amine-based corrosion inhibitors and have shown a corrosion resistance of at least 60 days in the case of test pieces of metal sheets treated with the copolymer according to the invention, whether the application had been performed by dipping or by rotation.
On the other hand, the corrosion inhibitors were found to be effective up to 20 days, after which period corrosion commenced.
Thus the metal sheets provided with an organic coating as described above can be left in contact with the surrounding air without the customer having to suffer any degradation of the sheets. Furthermore, the customer is relieved of the operation consisting in the removal of the protective oil with which some sheets are coated at present.
In addition, the coating of the sheet metal according to the invention exhibits lubrication properties which are highly advantageous in the field of metal forming by cold plastic deformation, and especially in stamping.
In fact, by virtue of such properties, during the deformation of a metal sheet by a tool, it is possible: to increase the lifetime of the tools, to obtain stamped metal sheets of better quality, especially where the surface quality is involved, to produce articles of complex shapes or to increase the depth of the stamped articles (such articles being difficult to produce, because the technological limit related to the sheet-tool interface is reached and it is no longer possible to modify the operating conditions of the stamping, namely the stamping speed, the shape of the blank and the blank-clamping pressure).
Despite everything, the use of an oil during the stamping is indispensable in order to avoid a seizure.
Tests have been conducted to test the nature of improvement in the friction coefficient of the organic coating, the component taken for comparison being an alkali metal salt and especially potassium phosphate K3PO4, which is known to improve the deformability of a metal sheet.
The tests show a decrease in the friction coefficient of the sheets coated with the organic compound and a retrogression of the technological limits resulting in seizure, these two results contributing to the improvement in the stamping performance such as, for example, the depth of the stamped article.
One of the fundamental characteristics of a metal sheet after a first treatment is that it can undergo a subsequent treatment. In particular, the application of a paint requires the prior preparation of the substrate which it is desired to paint and, more particularly, a metal sheet requires an initial so-called phosphating stage. This stage consists in coating the sheet with an additional microcrystalline film consisting, for example, of zinc, nickel or manganese phosphate a few micrometers in thickness, which is highly adherent to the substrate.
Tests performed in laboratory consisted in subjecting a metal sheet coated beforehand with the copolymer to a complete tricationic phosphating cycle and revealed a completely homogeneous microcrystalline film.
Thus, the treatment of the metal sheet as described in the present invention does not in any way impair the fitness of the sheet for phosphating.
It has been found, advantageously, that the copolymer also exhibits electrical resistance properties, its resistivity being higher than one megaohm meter.
In the class of organic macromolecular compounds which can be employed according to the invention there should also be mentioned the block copolymers made up of dimethylsiloxane and vinylpyridine and the block copolymers made up of dimethylsiloxane and acrylic esters.
For example, the solubility parameter of vinylpyridine is 9.5 (cal/cm3)1/2, making it suitable application according to the invention.
The results of the tests described below make it possible to demonstrate in a significant manner the properties of the metal sheets coated using the process of the invention.
Test 1
The copolymer employed for this test is that described in the example below, and will be coded X.
The test was performed on steel sheet test pieces 50 ×100 mm in size, to which a layer with a thickness of 0.015 μm of a solution of 1,1,1-trichloroethane containing a concentration of 1% (w/v) of dissolved copolymer was applied. The application is made by two methods, by dipping and by rotation. According to the first method the test piece is immersed in a bath containing the solution described above. According to the second method the test piece is rotated in a bath containing the same solution.
Other products, for comparison, which are corrosion inhibitors made up of amine groups and commercially available under the names RC305, NAC and MA19 (the products RC305 and MA19 are marketed by Croda Chemicals and NAC is marketed by Quaker) are dissolved in 1,1,1-trichloroethane in concentrations of 0.3 and 0.5% w/v.
They are then applied by spraying onto test pieces.
A test piece which has not undergone any treatment against corrosion is used as a control sample.
All the treated test pieces and the control are exposed to atmospheric corrosion in a storage hall which combines fairly severe conditions: the temperature is of the order of 30° C. and the relative humidity reaches 70%.
The various test pieces are observed for several days, taking into account the visual appearance of the corrosion as a function of time. The visual appearance of the corrosion is scored on a marking scale ranging from 1 to 5, the coefficient 1 being awarded to a test piece on which the first pinholes appear, the coefficient 5 corresponding to the end of the corrosion.
Table 1, which follows, summarises the change in the severity of corrosion with time.
TABLE 1
______________________________________
CORROSION
START CORROSION END
PRODUCT IN DAYS IN DAYS
______________________________________
Control 7 12
RC 305 22 33
NAC 18 25
MA 19 14 30
X applied by rotation
65 75
X applied by dipping
120 130
______________________________________
The results of the tests show us the superiority of the product X according to the invention over the corrosion inhibitors, since the latter display their limits after approximately 30 days, whereas the metal sheets treated with the product X resist corrosion for at least 60 days; after that, at about 65 days, corrosion is initiated and the process of degradation of the metal sheets sets in very rapidly.
Furthermore, the preferred method of application of the copolymer is dipping, as, so to speak, it doubles the protection period.
Test 2
The tests which follow make it possible to single out the influence of the product X according to the invention on the measurement of the friction coefficients of a metal sheet.
Test pieces were treated using the process of the invention, namely in that a layer of a solution of copolymer in 1,1,1-trichloroethane at concentrations of 0.25 and 1% (w/v) respectively were applied to the sheet by dipping.
Friction tests were performed with the aid of a conventional tribometer with parallel surfaces, also known as a plane-plane tribometer.
The oil chosen for the tests is the least lubricating one of the oils employed and is the oil marketed by Shell under the reference 2769E.
As shown by the curve in FIG. 1, attached, when a product which is known for its properties of improving the deformability of metal sheets is employed, such as potassium phosphate in 0.25% solution, the latter seizes at about 1600 daN, whereas the product according to the invention seizes up only at about 1800 daN.
On the curve in FIG. 2, attached, the above two products, which are compared, are in a concentration of 1% in solution and a seizure of the product containing potassium phosphate is found at about 1600 daN whereas at 2000 daN the product X does not yet seize up, the seizure limit being a function of the concentration of product employed.
In FIG. 2, at 1400 daN the product X has a friction coefficient of 0.08 in relation to that containing phosphate, which is 0.11.
Test 3
A metal sheet test piece to which a layer of a 0.3% w/v solution of copolymer in 1,1,1-trichloroethane has been applied by dipping, is subjected successively to a tricationic phosphating cycle:
degreasing
rinsing
fining down
phosphating
rinsing
drying.
Photographs taken with the electron microscope show a phosphate coating made up of uniform and fine crystals of zinc, manganese and nickel, whose distribution is uniform at the surface of the sheet, which is a sign of good phosphating.
What is claimed as new and desired to be secured by Letters Patent of the United States is:
1. A process for imparting protection against corrosion for a minimum period of two months to a metal surface and for decreasing the friction coefficient of said metal surface, comprising coating said metal surface with a layer of a solution comprising a solvent and a block copolymer made up of at least two blocks, the first block being based on a siloxane monomer and the second block consisting essentially of monomers selected from the group consisting of acrylic and vinyl monomers.
2. A process according to claim 1, wherein the siloxane monomer is dimethylsiloxane.
3. A process according to claim 1, wherein the first block consists essentially of a siloxane monomer and acrylic or vinyl monomers and the second block consists essentially of acrylic or vinyl monomers.
4. A process according to claim 1, wherein said acrylic monomers are selected from the group consisting of methyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate.
5. A process according to claim 3, wherein said acrylic monomers of the first block are selected from the group consisting of methyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate.
6. A process according to claim 1, wherein the block copolymer consists of (i) a first block consisting of 30-50 wt % methyl methacrylate, 0-20 wt % hydroxyethyl methacrylate and 40-60 wt % dimethylsiloxane monomers, and (ii) a second block consisting of 30-50 wt % methyl methacrylate, 30-50 wt % butyl methacrylate and 10-30 wt % hydroxyethyl methacrylate.
7. A process according to claim 1, wherein the copolymer consists of (i) a first block which consists of methyl methacrylate, hydroxyethyl methacrylate and dimethylsiloxane, whose proportions by weight in said block are 40, 10 and 50% respectiely, the block (i) representing 60% by weight of the copolymer, and (ii) a second block which consists of methyl methacrylate, butyl methacrylate and hydroxyethyl methacrylate, whose proportions by weight in the said second block are 40, 40 and 20% respectively, the block (ii) representing 40% by weight of the copolymer.
8. A process according to claim 1, wherein said solvent is selected from the group consisting of ketones, esters, chloroalkanes, and aromatic compounds.
9. A process according to claim 1, wherein said solvent is selected from the group consisting of acetone, methyl ethyl ketone and cyclohexanone.
10. A process according to claim 1, wherein said solvent is selected from the group consisting of ethyl acetate and butyl acetate.
11. A process according to claim 1, wherein said solvent is l,l,l-trichloroethane.
12. A process according to claim 1, wherein said solvent is selected from the group consisting of toluene and xylene.
13. A process according to claim 1, wherein the solution contains from 2 to 10 g/l of copolymer.
14. A process according to claim 1, wherein the solution is heated to a temperature of between 20 and 40° C. before being applied to the metal surface.
15. A process according to claim 1, wherein the coating of said metal surface with a layer of solution is performed by one of the following methods:by spraying with a gun, by dipping, by rotation, by coating with a brush or roller, by enamelling as a strip.
16. A process according to claim 1, wherein said layer is dried at a temperature of between 70 and 100° C. after coating the metal surface.
17. A coated metal surface obtained by the process according to claim 1, wherein said coating has a thickness of between 0.01 μm and 3 μm.
| 1992-06-04 | en | 1994-05-17 |
US-96681397-A | Method and apparatus for preventing formation of snowmen and removing lumps of coating in clinker coolers
ABSTRACT
A method and apparatus for preventing the accumulation of fines and the resulting formation of snowmen in a clinker cooler by applying short duration blasts of high pressure, high velocity air from openings in the cooler inlet grate. The cleaning air can be selectively supplied to a portion or portions of the cooler inlet grate. Monitoring may be provided to aid in the selective application of the cleaning air.
This application is a continuation of application Ser. No. 08/573,222, filed Dec. 15, 1995, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a method and apparatus for preventing the formation of snowmen within a clinker cooler. The invention relates more specifically to a method and apparatus which allow the monitoring and selective application of short duration blasts of high-pressure, high-velocity air through openings in the stepped supporting surface of a clinker cooler, jostling the clinker and thereby disrupting the accumulation of fines which grow to form snowmen, and dislodging any such accumulations in the clinker bed.
2. Description of Related Art
In the production of cement, raw materials are combusted to produce cement clinker, typically in a rotary kiln according to known methods. U.S. Pat. No. 5,437,721, to Kupper. et al., for example, describes one method of producing cement clinker from fine-grained cement raw materials.
Kiln temperatures of 1400° C. and above are common in the production of cement clinker. The temperature of the clinker as it is discharged from the kiln is typically approximately 1350° C. As the clinker exits the kiln, it must be cooled rapidly. Most commonly, the hot clinker is discharged from the kiln onto a grate constructed to facilitate the introduction of cooling air to cool the clinker. The clinker is exposed to cooling air while on the cooler inlet grate, and is then typically discharged to a conveyor which transports the clinker to a grinder or milling device.
A variety of cooling grates for cooling cement clinker have been developed and are known in the art. For example, U.S. Pat. No. 2,434,845 to Gaffney shows a clinker cooling chamber including a stepped grating onto which the hot clinker is discharged from the kiln. As the clinker moves downwardly, by gravity, along the grate, cooling air is introduced into the clinker pile through openings in the stepped surface.
Similarly, U.S. Pat. No. 4,732,561 to Eiring, et al. shows a cooling apparatus wherein hot material such as clinker, discharged from a kiln, is conveyed by gravity over a step-like series of air-permeable carrier elements. Cooling air is introduced to the material through the carrier elements, and may be delivered in pulses to individual carrier elements or groups of carrier elements.
The clinker typically discharged from a kiln is generally spherical and approximately one to three inches in diameter. Along with the clinker, "fines" are discharged from the kiln into the clinker cooler. These fines comprise smaller particulate matter and can cause a number of undesirable effects within the clinker cooler. For example, the fines can cling to the surfaces of adjoining pieces of clinker in the cooler and cause the clinker to clump together. This is referred to as agglomeration or caking. Also occasionally discharged from the kiln are large lumps of coating which have broken loose from the interior surface of the kiln. These large lumps interfere with effective heat transfer within the cooler and disrupt clinker flow through the cooler.
U.S. Pat. No. 4,870,913 to Schneider seeks to prevent caking in the clinker cooler by providing a grate cooler comprising stepped layers of grate plates, the forward facing surfaces of the grate plates having nozzle-shaped cooling air openings oriented to inhibit caking between the grate plates. Because the air supplied to its nozzle openings is drawn from the cooling air supply, Schneider is intended to prevent caking of clinker in localized areas. Schneider's air flow is insufficient to jar or shock the clinker itself, and is unable to dislodge fines which have already adhered to the clinker.
A more severe problem than that of caking of the clinker is the formation of "snowmen" in the clinker cooler. Snowmen are formed when fines fall from the kiln above, onto the top surfaces of large lumps of kiln coating on top of the clinker bed within the cooler. Snowmen also sometimes form on the top surfaces of the clinker, especially when the clinker cakes together. As layer after layer of the fines fuse onto the lump of kiln coating, snowmen "grow" upwardly into stalagmite-like structures. In effect, the lumps of kiln coating act as "seeds" for the formation of snowmen. Left unchecked, these snowmen may eventually grow to reach the mouth of the kiln, thereby blocking the discharge of clinker from the kiln.
To date, several attempts have been made to prevent the formation of snowmen. For example, U.S. Pat. No. 5,330,350 to Tegtmeier, et al. discloses a reciprocating grate cooler having a hydraulic mechanism for driving the cooler inlet grate in a reciprocating manner. It is also known to provide a rotating ram and thrust bar, such as that shown by U.S. Pat. No. 4,732,561 to Eiring, et al., which is mechanically driven to break-up any deposits or encrustations on the clinker.
These and other known methods and devices have been found less than entirely satisfactory to remove lumps of kiln coating from the cooler inlet, or to prevent the formation of snowmen. This is, in part, because such devices suffer the disadvantage that, by their nature, they inherently incorporate moving parts. Due to the weight of the clinker and its abrasive nature, these moving parts are highly susceptible to wear and breakage, especially at the high temperatures commonly encountered within the cooler. Moreover, the presence of fines from the kiln within the cooler environment can lead to the clogging and jamming of moving parts. Also, because the large lumps of kiln coating tend to float or ride on the surface of the clinker bed, reciprocating scrapers or thrust bars, which operate entirely beneath the surface of the clinker bed, are incapable of removing them from the cooler inlet.
It has also been proposed to direct pulses of high pressure air onto the clinker from openings in the cooler walls or in refractory walls within the cooler. In some instances, this has proven successful in shearing off the tops of snowmen in the immediate vicinity of the air openings. The lower portions of the snowmen, however, remain in place on the clinker bed and serve as seeds for the formation of new snowmen. Furthermore, because the air openings are located generally at the outer periphery of the cooler, the air pulses are unable to affect snowmen or other accumulations nearer to the center of the cooler. Also, except for air pulses from openings in the headwall at the back of the cooler, it is not possible for such an apparatus to direct air pulses in the direction of clinker flow. This limits the ability of such devices to move large lumps of kiln coating any significant distance from the headwall. This arrangement also suffers the disadvantage that, once the air openings are provided in the cooler walls, their position is fixed. As the depth of the clinker bed varies, the location of these openings may render them ineffective.
Thus, it can be seen that there exists a need for a method of preventing the formation of snowmen by removing lumps of kiln coating from the cooler inlet. A need further exists for a method of dislodging snowmen, once formed, during cooling. Likewise, a need exists for the provision of an apparatus capable of carrying out these methods, without the need for moving parts, and which is not affected by variations in the depth of the clinker bed.
It is to the provision of such a method and apparatus that the present invention is primarily directed.
SUMMARY OF THE INVENTION
Briefly described, in a preferred form, the present invention comprises a method for preventing the accumulation of fines forming snowmen, during the cooling of cement clinker. The method comprises the steps of feeding the hot clinker to a cooling grate, applying low-pressure cooling air to the clinker, and the improvement characterized by directing blasts of high-pressure cleaning air of a selected duration, from the cooler inlet grate into the clinker bed, generally horizontally in the direction of clinker flow, to shock or jar the clinker, thereby dislodging any incipient accumulations or agglomerations and conveying any large lumps of kiln coating away from the kiln inlet. The method can further include the monitoring of the clinker within the cooler and the selective application of cleaning air to chosen portions of the cooler inlet grate at selected blast intensities.
The present invention also comprises an apparatus for preventing not only caking, but the formation of snowmen during the cooling of cement clinker. In a preferred form, the apparatus of the present invention comprises a cooler inlet grate having a stepped surface for supporting the clinker, a low-pressure cooling air supply system for applying cooling air to the clinker, and additionally, a separate high-pressure cleaning air supply system for directing short duration blasts of high pressure cleaning air of selected intensity into the clinker pile. The apparatus can also include monitoring means and control means for the selective application of cleaning air to the clinker.
Accordingly, it is an object of the present invention to provide a method for preventing the accumulation of snowmen and removing large lumps of kiln coating from the cooler inlet during the cooling of cement clinker.
It is another object of the present invention to provide an apparatus for preventing the formation and accumulation of snowmen during the cooling of cement clinker, which apparatus eliminates or minimizes the necessity of moving parts in and around the clinker.
A further object of the present invention is to provide a method and apparatus for the cooling of cement clinker, whereby short duration blasts of high pressure air are applied to the clinker to jar or shock the clinker, and thereby prevent the creation of snowmen within the clinker cooler and dislodge snowmen once formed.
Still another object of the present invention is provide a method and apparatus for positively effecting flow of the static clinker bed by discharging bursts of high pressure cleaning air from the cooler inlet grate, generally horizontally and in the direction of clinker flow.
Yet another objective of the present invention is to provide a method and apparatus whereby short duration blasts of high pressure air may be selectively applied to a portion or portions of the clinker cooler.
Another object of the present invention is to provide a method and apparatus capable of selectively varying the intensity of the blasts of cleaning air applied to the clinker.
Still another object of the present invention is to provide a method and apparatus allowing monitoring of the clinker within the clinker cooler to permit the selective application of high pressure air to that portion of the cooler when and where the accumulation of snowmen is observed.
It is yet another object of the present invention to provide a method and apparatus for the cooling of cement clinker which is durable and reliable in operation, and simple and economical in manufacture, installation and repair.
These and other objects, features, and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures.
DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a side elevation, in partial cross section, showing a clinker cooler according to a preferred form of the present invention.
FIG. 2 is a top view of the cooler inlet grate and cleaning air supply portions of the clinker cooler shown in FIG. 1.
FIG. 3 shows, in greater detail, the cooler inlet grate of the clinker cooler of FIG. 1.
FIG. 4 shows the cleaning air supply to, and the cleaning air flow from a portion of the cooler inlet grate shown in FIG. 3.
FIG. 5 shows a detailed cross-sectional view of a grate plate, which may form a portion of the cooler inlet grate, according to a preferred embodiment of the invention.
DETAILED DESCRIPTION
Referring now in detail to the drawing figures, wherein like reference numerals represent like parts throughout the several views, FIG. 1 shows a clinker cooler 20 according to a preferred form of the invention. Clinker cooler 20 is arranged beneath kiln discharge 10, and receives hot clinker 12 and fines 14 from a kiln (unshown) at a cooler inlet portion 16. The clinker 12 and fines 14 which enter clinker cooler 20 are supported above a cooler inlet grate 22. The cooler inlet grate 22 slopes downwardly from high end 17 to low end 18 in the direction of arrow 19. The slope of cooler inlet grate 22 is preferably between 10 and 20 degrees downward from the horizontal, and most preferably 14 degrees from the horizontal.
Clinker 12 accumulates into a clinker bed (unshown) on the cooler inlet grate 22. The layer of clinker immediately above the cooler inlet grate 22 typically remains in place, thereby providing cooler inlet grate with a protective layer against the friction and heat of the clinker 12 from the kiln discharge 10. This layer is commonly referred to as the static clinker bed.
Cooler inlet grate 22 is shown in progressively greater detail by FIGS. 3 through 5. In one preferred form, cooler inlet grate 22 comprises a plurality of rows of removable grate plates 24. Grate plates 24 within each row abut or connect with one another. Grate plates of adjacent rows can be interconnected as shown in greater detail by FIG. 5. This grate plate arrangement is preferably a variation of similar design to that shown by U.S. Pat. No. 5,322,434 to Milewski et al, the teaching of which is incorporated herein by reference. It will be readily apparent to those of ordinary skill in the art, however, that the present invention is applicable to many other known cooler grating arrangements as well.
Grate plates 24 support the clinker as it accumulates, the clinker commonly having an angle of repose of approximately 30°-35°. The accumulated clinker above the static clinker bed travels downwardly along the cooler inlet grate 22, generally in the direction of arrow 19. Grate plates 24 are supported by grate plate supports 26, which are arranged in step like fashion adjacent one another. The grate plate supports 26, in turn, are supported by a support frame 50 and the adjacent structure 52 as necessary, depending on the specific installation.
FIGS. 4 and 5 show the separate cooling and cleaning air delivery systems of clinker cooler 20 in greater detail. Grate plate 24 comprises an upright grate panel 40 and a grate plate base 41 to form a generally L-shaped element. Grate plate 24 is preferably a casting, and should be of sufficient strength and wear resistance to support the clinker without undue deflection and resist abrasion from the clinker as it moves across the cooler inlet grate. The removable nature of the grate plates 24 facilitates easier replacement and repair of the cooler inlet grate 22. Upright grate panel 40 terminates in an upper lip 42 adapted to fit adjacent lower lip 44 of the adjoining grate plate's base 41 in an overlapping or interlocking fashion. Grate plate base 41 comprises at least one grate plate cooling air opening 34 to permit cooling air to pass therethrough. As shown in greater detail by U.S. Pat. No. 5,322,434, grate plate 24 is adapted to receive an aeration cap 36 over the grate plate cooling air opening 34. In this manner, an annular cooling air slot or gap 38 is formed between the upper surface of grate plate base 41 and the lower surface of aeration cap 36.
Cooling air 28 is supplied at low pressure from an unshown source into cooling air duct 30. "Low pressure," for purposes of the present invention, is defined as below approximately 2 psi. Cooling air duct 30 is provided with at least one cooling air duct opening 32 through which cooling air may pass. Cooling air duct opening 32 is located to align with grate plate cooling air opening 34 when grate plate 24 is installed on the grate plate support 26. In this manner, cooling air 28 is discharged from the cooling air duct 30, through cooling air duct opening 32 and the adjacent grate plate cooling air opening 34, through the annular cooling air slot or gap 38, and around aeration cap 36 to cool the clinker. The cooling air is preferably supplied at a pressure of between approximately 1.1 and 1.8 psi, a velocity of between approximately 60 and 130 ft/sec. and a flow rate of between approximately 200 and 350 a.c.f.m. (actual cubic feet per minute), per plate opening, generally depending upon the volume and nature of the clinker to be cooled and the temperature the clinker is received from the kiln, in order to sufficiently cool the clinker by the time it leaves the cooler.
As seen best in FIG. 4, the grate plate supports 26 are preferably hollow beams of square or rectangular cross-section. Grate plate support 26 can be the same structure utilized as cooling air duct 30, as shown in the figures. Alternatively, separate structures may be utilized, with cooling air duct 30 constructed of piping disposed within a structural framework acting as the grate plate support 26. Grate plate supports 26 are arranged in step-like fashion, and are supported above support frame 50. Each step-like grate plate support further comprises a tread 56 at its top, and a riser 58 forming the vertical face of the stair-like grate plate support 26. When grate plate 24 is installed, its upright grate panel 40 fits adjacent and in close proximity to riser 58, and the grate plate base 41 is adjacent and in close proximity to the tread 56.
In order to prevent the accumulation of fines, to remove any lumps of kiln coating from the cooler inlet, and to dislodge any snowmen which may form, the clinker cooler of the present invention further comprises a high pressure cleaning air system which will now be described in greater detail. "High pressure," for purposes of the present invention, is defined as above 50 psi. As shown by FIG. 2, one or more air cannons 60 supply cleaning air to the clinker cooler's cleaning air system. Air cannons 60 provide short duration (preferably between approximately 0.5-1.2 seconds, and most preferably approximately 0.7 seconds) blasts of high pressure, high velocity air to the cleaning air system. The "on-off" nature of the blasts of cleaning air supplied by the air cannons 60 of the present invention are capable of shocking or jarring the clinker, as opposed to the "pulsed" cooling air supplied by known coolers, which vary the pressure of cooling air applied to the clinker, but which are incapable of shocking or jarring the clinker. An example of a suitable air cannon is a Martin BB4-24-48.
Cleaning air from the air cannons 60 is fed through cleaning air supply lines 62. Cleaning air supply valves 64 may be provided in the cleaning air supply lines 62. Air cannons 60 are preferably remotely operable through pneumatic or electronic control means such as remote air cannon controller 66.
As shown best in FIGS. 3-5, the cleaning air from air cannons 60 feeds through cleaning air feed conduit 68 into the cleaning air plenum 70. Cleaning air plenum 70 is preferably constructed by attaching a length of angle-iron 72 to the interior surface of the riser portion 58 of the grate plate support 26 as shown in FIG. 5. The angle-iron cleaning air plenum is preferably attached to the grate plate support by a continuous weld, thereby providing an airtight seal. Cleaning air plenum orifices are provided through the riser 58 in spaced apart positions where cleaning air is to be discharged.
Slots 76 in the upright grate panel 40 of the grate plates 24 align with the cleaning air plenum orifices 74 to permit cleaning air to be discharged from cleaning air plenum 70 into the clinker pile in the direction of arrow 78. By aligning slots 76 such that the cleaning air is discharged in a generally horizontal direction, the energy of the cleaning air blast is substantially entirely transferred to the clinker pile. This promotes more effective dislodging of any accumulation of snowmen. Moreover, a horizontal orientation of slots 76 assists in propelling the static clinker bed along the cooler inlet grate 22. Preferably slots 76 are approximately three inches wide by one-half inch high, with two slots provided on each grate plate 24 which delivers cleaning air.
The cleaning air supply system described above should be capable of supplying cleaning air in short duration bursts at an elevated pressure of at least between approximately 50 and 100 psi, a velocity of at least between approximately 330 and 660 ft/sec., and a flow rate of at least between approximately 40 and 60 ft3 /sec. A variety of commercially-available air cannons are capable of adequately supplying cleaning air according to these parameters, as will be known to those of ordinary skill in the art. To provide air blasts meeting these criteria, it is necessary to provide a cleaning air supply which is independent from the cooling air supply and an independent cleaning air distribution system capable of operating at pressures of approximately 10 to 50 times that of the cooling air system. In this way, the pressures and velocities provided by the cleaning air through slots 76 are elevated significantly above the pressures and velocities of the cooling air provided to clinker through grate plate openings 34.
By selectively operating one or more of the air cannons 60, cleaning air can be supplied to selected sections or zones of the cooler inlet grate 22. Air cannon controller 66 allows the remote manipulation of the air cannons 60 for the selective application of the cleaning air. By providing separate cleaning air plenums on the right and left sides of the center line 69 of the cooler inlet grate 22, the cooler inlet grate can be further segregated so that cleaning air can be directed to selected zones of the cooler inlet grate 22. For example, in the configuration shown in FIG. 2, cleaning air can be selectively applied to any of eight zones (four left and four right of center line 69), corresponding to each air cannon 60. Alternatively, the cleaning air plenum 70 can be continuous from one side of the cooler inlet grate 22 to the other, or can be provided with removable air dams or valving enabling the segregation of the cleaning air plenum into any desired number of zones.
Although FIGS. 3 and 4 show every grate plate 24 provided with a slot 76, it will be understood that this is not necessary. As represented in FIG. 2 by the portions of the cooler inlet grate having an "X" shown thereon, slots 76 may be provided in only selected grate plates 24 as necessary to supply cleaning air blasts to dislodge any accumulation of fines within the cooler. It is desirable, however, to provide a sufficient number and distribution of grate plates 24 with cleaning air slots 76 to allow the application of cleaning air over substantially the entire width of the cooler inlet grate 22. The placement of these grate plates will necessarily vary, depending on factors such as the geometry and size of the cooler inlet grate 22.
By varying the number of grate plates 24 which are provided with cleaning air slots 76, the intensity of the cleaning air blasts may be selectively varied. For example, if all grate plates 24 are provided with cleaning air slots 76, the cleaning air from air cannons 60 will be distributed approximately equally over the width of cooler inlet grate 22. With this arrangement, the intensity of the blast of cleaning air supplied from any given cleaning air slot 76 will be minimized. If half of the grate plates 24 are supplied with cleaning air slots 76, the intensity of the cleaning air blast from any given slot will be approximately double the minimum intensity described above. On the other hand, if only one grate plate 24 is supplied with a cleaning air slot 76, the cleaning air blast intensity from that single slot will be maximized.
It is also possible to selectively vary the intensity of the blast of cleaning air discharged to the clinker by means of selective valving. For example, one or more air cannons could be used to supply cleaning air to a common manifold supplying more than one cleaning air supply line. By appropriately opening or closing selected cleaning air supply valves, blasts of cleaning air could be directed to one or more cleaning air feed conduits, fewer conduits resulting in a greater cleaning air blast intensity being provided.
To aid in the selective application of cleaning air to the clinker, monitoring means, such as an infrared camera 90 can be provided in the clinker cooler 20 as shown by FIG. 1. Alternatively, temperature monitoring, a standard closed-circuit video camera, or even a window or view-hole may be utilized as the monitoring means. By providing a remote monitor 92 for the infrared camera 90, an operator can monitor the clinker cooler from a remote location. If the development of snowmen is observed, the operator can selectively apply blasts of cleaning air to the zone of the cooler inlet grate where the accumulation is observed by means of the remote cleaning air valve controller 66. Alternatively, mechanical or electronic control means or a timer can be provided to sequentially or randomly apply bursts of cleaning air to the various zones of the cooler inlet grate 22.
In operation, the kiln discharge 10, including clinker 12 and fines 14, is deposited onto the cooler inlet grate 22 and travels downward along the grate, generally in the direction of arrow 19. As the clinker moves along the cooler inlet grate 22, it is cooled by low pressure cooling air 28 discharged into the clinker as described above. If remote monitoring is provided, an operator can generally observe the progress of the clinker to detect the formation of any snowmen. If any such formations are observed, the operator, through the use of remote air cannon controller 66, can selectively apply bursts of high pressure cleaning air to the appropriate zone of the cooler inlet grate 22. These bursts of cleaning air are discharged from openings in the riser portions of the stepped cooler inlet grate 22.
The cleaning air is discharged from the cooler inlet grate at grate level, generally horizontally and in the direction of clinker flow. The bursts of cleaning air are of sufficient intensity to shock or jostle the clinker, thereby disrupting the stability of the clinker bed and causing any snowmen which have formed to topple and tumble down the slope of the clinker bed, breaking up the snowman. The direction and point of discharge of the cleaning air also positively effect flow of the static clinker bed. Also, because the blasts of cleaning air are discharged at grate level, the air expands as it absorbs heat while traveling through the hot clinker bed, thereby increasing the intensity of the air blasts.
The blasts of cleaning air also propel any lumps of kiln coating entering the clinker cooler away from the cooler inlet in the direction of clinker flow, thereby eliminating the "seeds" which could potentially grow into snowmen. Moreover, these results are obtained without the necessity of moving parts in the vicinity of the clinker cooler.
While the invention has been disclosed in its preferred forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims.
What is claimed is:
1. An apparatus for cooling hot material including fines, said apparatus comprising:a. a cooler inlet grate for supporting said material and having cooling air openings and cleaning air openings separate from said cooling air openings; b. a low pressure cooling air supply for supplying cooling air to said cooling air openings; and c. a selectively operable high pressure cleaning air supply, separate from said low pressure cooling air supply for supplying cleaning air to at least one of said cleaning air openings separately from the cooling air at a pressure sufficiently high enough to dislodge accumulation of the fines on the hot material.
2. The apparatus of claim 1 wherein said cooler inlet grate comprises a stepped surface further comprising at least one tread portion and at least one riser portion.
3. The apparatus of claim 2 wherein said cooling air openings are provided in said at least one tread portion, and said cleaning air openings are provided in said at least one riser portion.
4. The apparatus of claim 3 wherein said cleaning air openings are aligned to direct said cleaning air outward from said at least one riser portion in a generally horizontal direction.
5. The apparatus of claim 3 wherein said cooler inlet grate further comprises a plurality of removable grate plates.
6. The apparatus of claim 1 wherein said high pressure cleaning air supply comprises at least one air cannon.
7. The apparatus of claim 6 wherein said at least one air cannon supplies said cleaning air to said cleaning air openings in blasts of less than 1 second in duration, at a pressure of between approximately 50 and 100 psi, at a velocity of between approximately 330 and 660 ft./sec., and at a flow rate of between approximately 40 and 60 ft3 /sec.
8. The apparatus of claim 6 wherein said cooler inlet grate is segregated into at least two zones and said high pressure cleaning air supply further comprises a number of cleaning air supply conduits, each of said conduits supplying cleaning air from said at least one air cannon to one of said zones.
9. An apparatus for cooling hot material including fines, said apparatus comprising:a. a cooler inlet grate segregated into at least two zones for supporting said material and having cooling air openings and cleaning air openings separate from said cooling air openings: b. a low pressure cooling air supply for supplying cooling air to said cooling air openings; and c. a high pressure cleaning air supply for supplying cleaning air to said cleaning air openings separately from the cooling air comprising at least one air cannon and a number cleaning air supply conduits, each of said conduits supplying cleaning air from said at least one air cannon to one of said zones, and wherein said at least one air cannon is remotely operable to supply said cleaning air to one or more of said zones.
10. The apparatus of claim 9 further comprising monitoring means for viewing said hot material and allowing a selective application of said cleaning air to one or more of said zones.
11. The apparatus of claim 8 further comprising a timing means for operating said at least one air cannon to supply said cleaning air to one or more of said zones.
12. The apparatus of claim 8 wherein said cleaning air is supplied in blasts having intensities which can be selectively varied by varying the number of said cleaning air openings.
13. A method for cooling hot material including fines in a cooler, said method comprising:a. providing a grate within said cooler, the grate being provided with a cooling air opening and a separate cleaning air opening; b. feeding said hot material onto the grate within said cooler; c. discharging cooling air into said cooler from a low pressure cooling air supply through the cooling air opening in the grate to cool said material; and d. applying cleaning air from a separate selectively operable high pressure cleaning air supply through the cleaning air opening in the grate to said material in blasts of less than 1.2 second in duration, at a pressure of at least 50 psi, and at least a velocity of 330 ft/sec sufficient to shock or jar the hot material and to thereby dislodge said fines from said material.
14. The method of claim 13 wherein said cleaning air is supplied in blasts of less than 1 second in duration, at a pressure of between approximately 50 and 100 psi, at a velocity of between approximately 330 and 660 ft./sec., and at a flow rate of between approximately 40 and 60 ft3 /sec.
15. The method of claim 14 wherein said cleaning air is directed outward from the grate in a generally horizontal direction.
16. The method of claim 13 further comprising applying said cleaning air to one or more zones of said grate.
17. A method for cooling hot material including fines in a cooler, said method comprising:a. feeding said hot material onto a grate within said cooler; b. discharging cooling air into said cooler from a low pressure cooling air supply to cool said material; c. applying cleaning air to one or more zones of said grate from a high pressure cleaning air supply through the grate to said material to dislodge said fines from said material; and d. monitoring said material within said cooler and selectively applying said cleaning air to said one or more zones of said grate.
18. The method of claim 17 further comprising the selective variation of the intensity at which said cleaning air is applied.
19. The method of claim 16 wherein said application of cleaning air to said one or more zones of said grate is controlled by a timing means.
20. An apparatus for preventing accumulation of fines within a cooler for cooling cement clinker, said apparatus comprising:a. means for monitoring said cooler to detect the location of any accumulation of fines within said cooler; b. a cleaning air supply system within said cooler for delivering blasts of cleaning air to the cooler; and c. means for segregating said cleaning air supply system into at least two zones and permitting the delivery of said blasts of cleaning air to only those zones where the accumulation of fines is observed.
21. The method of claim 13, further comprising isolating the cleaning air from the cooling air until the cleaning air is applied to the material.
22. An apparatus for cooling hot material including fines, said apparatus comprising:a. a stepped grate comprising at least one generally horizontal tread and at least one generally vertical riser said grate supporting the hot material and transporting a portion of the hot material in a first direction; b. a low-pressure air system for cooling the hot material, said low-pressure air system delivering cooling air at a first pressure to at least one opening, provided in said at least one generally horizontal tread of said grate; and c. a high-pressure air system for dislodging accumulations of the fines on the hot materials, said high-pressure air system delivering bursts of air at a second pressure through a high-pressure plenum to at least one opening provided in said at least one generally vertical riser of said -rate,wherein said high-pressure plenum prevents the bursts of air delivered by said high-pressure air system from mixing with the cooling air delivered by said low pressure air system until the bursts of air and the cooling air are introduced into the hot material.
23. The apparatus of claim 22, wherein said second pressure is at least 50 psi.
24. The apparatus of claim 22, wherein said high-pressure air system comprises at least one air cannon.
25. The apparatus of claim 24, wherein said stepped grate is segregated into at least two zones, and wherein said high-pressure air system comprises at least two high-pressure plenum segments, each zone of said grate being delivered bursts of air through an associated high-pressure plenum segment.
26. The apparatus of claim 25 further comprising monitoring means for observing said hot material and allowing a selective application of the bursts of air from one or more of said high-pressure plenum segments to one or more of said zones.
| 1997-11-10 | en | 1999-02-16 |
US-26405781-A | Throttle opener for carburetors
ABSTRACT
A throttle positioning device for prevent rapid closure of the throttle valve of an internal combustion engine under extreme decel conditions. The throttle control device includes a vacuum motor that is responsive to the pressure in the induction system at a point just slightly upstream of the throttle valve of the engine so that vacuum will be exerted on the vacuum motor when the throttle valve is substantially opened from its idle position and atmospheric pressure will be exerted when the throttle valve is closed toward its idle position. Various arrangements are provided for adjusting the rate of air flow between the vacuum motor and the intake passage in different directions.
BACKGROUND OF THE INVENTION
This invention relates to a throttle opener for carburetors, and more particularly to an improved device for controlling the movement of a throttle valve of an engine on decel.
When the throttle valve of a vehicle powered by an internal combustion engine is suddenly closed, a high vacuum is exerted in the induction system. This high vacuum acts upon the fuel discharge circuits and tends to draw an overly rich mixture into the intake system under such running conditions. To avoid these difficulties, it has been proposed to provide a throttle positioning device which will either prevent or retard the complete closure of the throttle valve under such conditions. Such devices normally hold the throttle valve from reaching its fully closed or idle position for a period of time after the throttle valve has been suddenly closed. The prior art type of throttle positioning devices have normally employed a vacuum motor that is responsive to the intake vacuum downstream of the throttle valve. Thus, when the throttle valve is suddenly closed, a high vacuum will be exerted in the intake system and the vacuum motor is actuated so as to prevent full closure of the throttle valve. Such arrangements have, however, certain disadvantages. For example, if the throttle valve closure is delayed for too long a period of time, there will be substantially no engine braking. Also, such delayed closure will cause the engine to race under certain conditions. For example, if the throttle is rapidly opened and closed when the vehicle is not being driven, the action of the throttle positioner will cause over-revving of the engine.
In order to preclude these problems, it has been proposed to employ a device that is responsive to either vehicle speed, transmission condition or a combination of these factors which will override the operation of the throttle positioner. Such devices further complicate the overall system, add to its cost, and increase the likelihood of malfunction.
It is, therefore, a principal object of this invention to provide a throttle valve positioner which is more sensitive to actual engine conditions.
It is another object of this invention to provide a throttle valve positioner which retards the rate of closure of the throttle valve under sudden decelerations but which does not unduly delay the closing of the throttle valve and also which will not hold the throttle valve open under conditions in which such action is unnecessary.
SUMMARY OF THE INVENTION
This invention is adapted to be embodied in the throttle control device for an internal combustion engine having an induction passage and a throttle valve in the induction passage. The control device comprises a operating member that is moveable between a normal position and an operative position and which is operatively connected to the throttle valve wherein the throttle valve may be positioned in a partially opened position when the operating member is in its operative position. A vacuum motor responsive to subatmospheric pressure is operatively connected to the operating member for moving the operating member from its normal position to its operative position when a subatmospheric pressure is exerted on the vacuum motor. Means communicate the vacuum motor with a point in the induction passage that is upstream of the idle position of the throttle valve.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic cross-sectional view taken through a single cylinder of an internal combustion engine embodying this invention.
FIG. 2 is a cross-sectional view of the engine shown in FIG. 1 showing in less schematic form the induction system.
FIG. 3 is a side elevational view showing the throttle positioner associated with the engine.
FIG. 4 is a schematic view of a control device that may be used in conjunction with the embodiment of FIGS. 1 through 3.
FIG. 5 is a schematic view of another form of control device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An internal combustion engine embodying a throttle positioner constructed in accordance with an embodiment of this invention is identified generally by the reference numeral 11. The engine 11, except for the throttle positioner and its operation, is conventional and for that reason it has been illustrated schematically and only those portions necessary to understand the invention have been described and illustrated.
The engine 11 includes a cylinder block 12 having cylinder bores 13 which slideably support pistons 14. The pistons 14 are connected by means of connecting rods 15 to a crankshaft (not shown) in a known manner. A cylinder head 16 is affixed to the cylinder block 12 and has a plurality of cavities 17 that cooperate with the cylinder bores 13 and pistons 14 to form the combustion chambers.
The cylinder head 16 is formed with intake passages 18 that serve each of the chambers 17 and exhaust passages 19 which, in a like manner, serve the chambers 17. Intake 21 and exhaust 22 valves control the communication between the intake passages 18 and exhaust passages 19 with the chambers 17 as is well known.
The engine 11 is provided with an induction system for serving the cylinder head intake passages 18. This induction system includes an air cleaner 23, a carburetor, indicated generally at 24, and an intake manifold, indicated generally at 25. The intake manifold 25 has a plenum chamber 26 that is in communication with the outlet end of the carburetor 24 and individual runners 27 that extend from the plenum chamber 26 to the individual cylinder head intake passages 18.
The carburetor 24 is of the two-barrel, stage type and includes a primary barrel 28 and a secondary barrel 29. A primary throttle valve 31 controls the flow through the primary barrel 28 and a secondary throttle valve 32 controls the flow through the secondary barrel 29. As is well known, the primary throttle valve 31 is appropriately connected to a throttle linkage for operator control of the speed of the engine 11. The secondary throttle valve 32 may be mechanically linked to the primary throttle valve 31 so as to be opened after a predetermined degree of the primary throttle valve 31. Alternatively, the secondary throttle valve 32 may be controlled by a vacuum motor or the like. Such throttle controls are well known in the art and form no part of this invention.
The primary barrel 28 is also provided with a choke valve 33 that is operated in any known manner, as by means of an automatic actuator, indicated generally by the reference numeral 34. A vacuum operated accelerating pump system, indicated generally by the reference numeral 35, is also provided for the primary barrel 28. This includes a discharge nozzle 36 and the associated components which are well known and, for that reason, will not be described in detail.
The construction of the engine 11 thus far described and the fuel system therefor is well known and, as has been previously noted, for that reason will not be described in any more detail.
The engine 11 is provided with a throttle positioning device, indicated generally by the reference numeral 37, for holding the primary throttle valve 31 in a partially opened position (as indicated by the dot-dash position in FIG. 2) under certain operating conditions, as will become apparent. The throttle positioning device 37 includes a vacuum motor comprised of an outer housing 38 which is divided by means of a diaphragm 39 into a vacuum chamber 41 and an atmospheric chamber 42. The atmospheric chamber 42 is vented in any suitable manner to the atmosphere, as by a vent passage 43. A coil compression spring 44 is positioned in the vacuum chamber 41 for normally urging the diaphragm 39 and components associated with it to a direction in which the primary throttle valve 31 can be maintained in its normal idle position.
A throttle operating member in the form of a rod 45 is affixed to the diaphragm 39 and extends through the atmospheric chamber 41 toward the body of the carburetor 24. The rod 45 is coupled to the throttle valve 31 in a manner best shown in FIG. 3, this connection being represented by the dot-dash line in FIG. 1.
A bellcrank 46 is pivotally supported on the carburetor body by means of a pivot pin 47. The rod 45 is operatively connected to one arm 48 of the bellcrank 46 in any known manner. A adjustable screw 49 is threaded into the other arm of the bellcrank 46 and is juxtaposed to a lever 51 that is affixed to the throttle valve shaft of the primary throttle valve 31. The lever 51 normally engages an adjustable screw 52 which determines the idle position of the primary throttle valve 31. A torsional spring 53 acts against the lever 51 to urge it into engagement with the screw 52. In this position the adjustable screw 49 is spaced from a tang 54 of the lever 51.
FIG. 3 illustrates the arrangement as it appears when the engine 11 is operating in a normal idle position and the throttle positioner 37 is not operative to adjust the positioning of the primary throttle valve 31. In this condition, the spring 44 urges the diaphragm 39 and rod 45 in such a direction that the bellcrank 46 is pivoted in a clockwise direction so that the screw 49 is spaced from the tang 54, as aforenoted. When conditions warrant repositioning of the throttle valve 31, a vacuum signal will be exerted in the chamber 41 in a manner to be described. When a predetermined vacuum is present in the chamber 41, the diaphragm 39 and rod 45 will be drawn downwardly. This will cause the bellcrank 46 to be pivoted in a counterclockwise direction so that the adjustable screw 49 is positioned to be engaged by the tang 54 and prevent the throttle valve 31 from moving to its normal idle position. Thus, the throttle valve 31 will be held in the dot-dash position as shown in FIG. 2. The exact degree of opening of the throttle valve 31 is controlled by adjustment of the screw 49 and adjustment of a stop 55 position within the diaphragm vacuum chamber 41.
In accordance with this invention, the vacuum signal for the actuator 37 is taken in the induction passage via a port 56 that is positioned closely adjacent the idle position of the throttle valve 31 and upstream of it. The port 56 is also preferably upstream of the partially opened position of the throttle valve 31 as it is controlled by the throttle positioner 37. The pressure signal from the port 56 is transmitted to the throttle positioner vacuum chamber 41 via a conduit 57, control device 58 and conduit 59. Ignoring, for the time being, the operation of the control device 58, it should be apparent that when the engine is operating at speeds above normal idle speeds that the throttle valve 31 will be opened sufficiently so that the port 56 is in effect downstream of it. Thus, the reduced pressure existent in the induction system will be transmitted through the port 56 to the vacuum chamber 41. Thus, the diaphragm 39 and rod 45 will be actuated so as to place the screw 49 in a position to be contacted by the tang 54 if the throttle valve 31 is suddenly closed. However, upon closure of the throttle valve 31, the port 56 will be upstream of the throttle valve 31 and sense atmospheric pressure. Thus, the pressure in the chamber 41 will be returned to atmospheric pressure and the diaphragm 39 and rod 45 will resume the position shown in FIG. 3 and the throttle 31 will be permitted to close. Thus, the device permits more accurate control of the throttle valve 31 and insures against its being held open for an unnecessarily long period of time and also against its being held open during times when such action is not necessary.
The control device 58 is arranged so as to control the rate of communication between the conduits 57 and 59 and, accordingly, the rate of transmission of pressure between the port 56 and the diaphragm vacuum chamber 41. In accordance with two illustrated embodiments of the invention, as shown in FIGS. 4 and 5, the control device 58 acts so as to provide different degrees of flow resistance in different directions. Specifically in these two embodiments there is a lesser degree of resistance of flow from the chamber 41 to the port 56 than in the opposite direction. As will become apparent, this delays the point at which the throttle positioner 37 is operative to hold the throttle valve 31 in an open position and return of the throttle valve 31 to its normal idle position will occur at a greater rate.
Referring first the the embodiment of FIG. 4, the control device 58 includes a pair of parallel passages 61 and 62 that interconnect the conduits 57 and 59. A fixed orifice 63 is provided in the conduit 61 and a fixed orifice 64 is provided in the conduit 62. The orifice 63 is smaller in effective area than the orifice 64. A check valve 65 in the conduit 61 is disposed so that the orifice 63 controls the communication of the flow from the diaphragm conduit 59 to the engine induction system conduit 57. An oppositely disposed check valve 66 is provided in the conduit 62 so that the orifice 64 controls the flow of air from the induction system conduit 57 to the diaphragm conduit 59.
The engine 11 is also provided with an auxiliary induction system for improving the performance at low engine speeds. The auxiliary induction system comprises an auxiliary intake passage 67 (FIGS. 1 and 2) which extends from an inlet 68 in a spacer 69 that is interposed between the intake manifold 25 and cylinder head 16. A control valve 71 is positioned in the spacer 69 for each cylinder head intake passage 18 and is effective, in a manner to be described, so as shunt the intake charge flow to the chamber 17 through the auxiliary induction system 67 under idle and low speed running. The auxiliary intake passage 67 has a discharge end 72 that is disposed closely adjacent each intake valve 18. The control valves 71 are coupled to the primary carburetor throttle valve 31 by means of a linkage system including a lost motion device, indicated schematically at 73. When the engine 11 is idling and the throttle valve 31 is in its idle position, the linkage operating the control valve 71 is such that they will be closed or substantially fully closed. The intake charge is thus shunted to the chamber 17 through the relatively small auxiliary intake passages 67 so that the charge will be delivered as a high velocity into the chamber 17. This high velocity insures good turbulence in the chambers and rapid flame propagation that has been found to significantly improve combustion efficienty at low speeds. As the primary throttle valve 31 is progressively opened, the lost motion device 73 will eventually cause the control valve 71 to open so that an increasing proportion of the charge will be delivered to the chambers through the main intake passages 27 and 18. The arrangement is such that the primary throttle valve 31 and control valves 71 will reach their fully opened position at approximately the same time.
Referring to the operation of the throttle positioning device 37 embodying the control unit 58 of the embodiment of FIG. 4, the figures show the arrangement in the idling condition. During idle, the port 56 will be positioned upstream of the idle position of the throttle valve 31 and atmospheric pressure will be transmitted to the vacuum chamber 41. The pressure in the chambers 41 and 42 will, therefore, be the same and the spring 44 will urge the diaphragm 39 and rod 45 to a position wherein the throttle positioning device 37 is not operative on the primary throttle valve 31, as has been previously described.
When the throttle 31 is opened sufficiently so that the port 56 is positioned on the downstream side of it and assuming intake manifold vacuum is high enough, the reduced pressure will be transmitted through the conduit 57 and opened check valve 65 and orifice 63 to the vacuum chamber 41. The orifice 63 is sized so that it will take at least ten seconds for the vacuum to build up in the chamber 41 to cause movement of the diaphragm 39 and rod 45 downwardly. After this time period has elapsed, the bellcrank 46 will have been rotated so that the adjustable screw 49 is positioned to be engaged by the tang 54 if the throttle valve 31 is suddenly released. Upon such sudden release of the throttle valve, the throttle valve 31 and its associated lever 51 will move rapidly toward their closed or idle positions. The tang 54 will, however, engage the screw 49 and the throttle valve 31 will be held in the dot-dash position as shown in FIG. 2. When this occurs, the port 56 will be positioned upstream of the throttle valve 31 and atmospheric pressure will again be exerted in the conduit 57. This atmospheric pressure will pass through the conduit 62 of the control device 57 through the now opened check valve 66 and orifice 64. The orifice 64 is sized so that the pressure in the chamber 41 will be returned to atmospheric at a faster rate than the vacuum was generated in this same chamber. In a preferred embodiment of the invention, the orifice 64 is sized so as to return the pressure to atmospheric in about three seconds. When this occurs, the spring 44 will again urge the diaphragm 39 to the position wherein the throttle valve 31 can move to its normal idle position.
By providing the delay in full closure of the throttle valve 31, it is insured that an excessively rich fuel-air mixture will not be drawn into the chamber 17 so as to cause unwanted exhaust gas emission and unnecessarily high fuel consumption. Also, since the control valves 71 will be fully closed during the decel condition, any charge introduced into the chamber 17 will flow through the auxiliary induction passages 67 so as to increase turbulence and improve efficiency during this running condition.
As has been noted, it is desireable to delay actuation of the throttle positioning device 37 so as to become effective for ten or more seconds. Another form of control device 58 for achieving the different rates of flow in shown in FIG. 5. In this embodiment, parallel conduits 81 and 82 interconnect the manifold conduit 57 with the diaphragm conduit 59. Fixed orifices 83 of the same flow resistance are positioned in each of the conduits 81 and 82. A check valve 84 is provided only in the conduit 81. The check valve is such that it will permit flow from the diaphragm conduit 59 to the manifold conduit 57 through the conduit 81 but will prevent flow in the reverse direction. Thus, when the port 56 is downstream of the throttle valve 31 due to a wide opening of this throttle valve, vacuum will be transmitted from the manifold conduit 57 to the diaphragm conduit 59 only through the control device conduit 82. The check valve 84 will prevent any flow through the conduit 81. On the other hand, under deceleration conditions when the throttle valve 31 is moved so that the port 56 is again exposed to atmospheric pressure, under this condition atmospheric air may bleed back to the diaphragm chamber 41 through both of the conduits 82 and 81 of the control device 58. Thus, atmospheric pressure is re-established more rapidly in the chamber 41 than vacuum was established in this chamber.
Various other arrangements may be provided for controlling the respective rates of communication between the induction system and the chamber 41. In some instances only a single orifice providing the same rates of communication in both directions may be employed. Various other types of control arrangements for achieving these relative flow rates will be readily apparent to those skilled in the art.
From the foregoing description it should be readily apparent that by providing the control signal for the throttle positioner 37 at a point which is just slightly upstream of the idle position of the throttle valve, it is possible to provide an arrangement wherein the throttle valve can be prevented from returning immediately to its idle position under extreme decel conditions. This insures against unnecessarily rich mixtures being drawn into the intake system which would adversely effect exhaust gas emissions as well as fuel economy. The arrangement, however, insures rapid closure of the throttle valve after a predetermined time delay so that smooth running can be insured and adequate engine braking provided without necessitating speed switches of the like. Furthermore, the use of the auxiliary induction system further improves operation both at idle and low speeds and under these decel conditions. The arrangement also insures against inadvertant operation of the throttle positioning device when the engine is being raced temporarily. It is also possible to insure against unnecessary operation of the throttle positioning device 37 during these engine racing conditions by making the resistance of the control device 58 sufficient to delay premature operation of this device.
It is to be understood that, in addition to the various embodiments and modifications disclosed, other modifications and variations may suggest themselves to those skilled in the art without department from the spirit and scope of the invention, as defined by the appended claims.
I claim:
1. A throttle control device for an internal combustion engine having an induction passage and a throttle valve in said induction passage, said control device comprising an operating member moveable between a normal position and an operative position, means operatively connecting said operating member to said throttle valve wherein said throttle valve may be positioned in a partially opened position when said operating member is in its operative position, a vacuum motor responsive to a sub-atmospheric pressure operatively connected to said operating member for moving said operating member from its normal position to its operative position when a sub-atmospheric pressure is exerted on said vacuum motor, and means for communicating said vacuum motor only with a point in said induction passage upstream of the idle position of said throttle valve for controlling said vacuum motor by the pressure at said point.
2. A throttle control device as set forth in claim 1 wherein the operative connection between the operating member and the throttle valve is such as to provide a variable stop for the closing movement of the throttle valve without interfering with the opening movement thereof.
3. A throttle control device as set forth in claim 1 wherein the means for communicating the vacuum motor with the induction passage includes means providing a restriction in the communication therebetween.
4. A throttle control device as set forth in claim 3 wherein a different degree of restriction is provided in the communication of the vacuum motor with the induction passage for flow from the induction passage to the vacuum motor than for flow from the vacuum motor to the induction passage.
5. A throttle control device as set forth in claim 4 wherein the different communication is provided by a control device having parallel flow paths interconnecting the vacuum motor with the induction passage, one of said flow paths being effective to control the flow from the vacuum motor to the induction passage and the other of said flow paths being effective to control the flow from the induction passage to the vacuum motor.
6. A throttle control device as set forth in claim 5 wherein the flow restrictions between the communication paths comprise fixed orifices and oppositely disposed check valves.
7. A throttle control device as set forth in claim 4 wherein a flow control device provides the variable communication between the induction passage and the vacuum motor, said flow control device comprising a pair of parallel flow paths therebetween and means for providing flow through one of said flow paths in one direction and both of said flow paths in the opposite direction.
8. A throttle control device as set forth in claims 1 or 3 wherein the means for providing communication between the vacuum motor and the induction passage comprises a port in the induction passage positioned upstream of the idle position of the throttle valve and downstream of the throttle valve when the throttle valve is opened substantially passed its idle position.
9. A throttle control device as set forth in claim 8 wherein the operative connection between the operating member and the throttle valve is such as to provide a variable stop for the closing movement of the throttle valve without interfering with the opening movement thereof.
| 1981-05-15 | en | 1984-02-14 |
US-94793197-A | Satellite communication service with non-congruent sub-beam coverage
ABSTRACT
A method for use in a satellite communications system (20) of a type that has at least one satellite (22) having forward and reverse beams each comprised of sub-beams for relaying user communications between a ground station (24) and user terminals (30). In a first embodiment forward and reverse antenna systems are separately optimized for their intended applications without regard for maintaining congruence between antenna beam sub-beams at the surface of the earth. In a second embodiment a method optimizes signal flow between the ground station and the user terminals and includes the steps of: (a) determining user terminal RF signal conditions within the sub-beams of at least one of the forward and reverse beams; and (b) in response to the determined RF signal conditions, re-allocating sub-beams of at least one of the forward and reverse beams such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth. The step of determining includes a step of maintaining a database that stores a map of the sub-beams. In one embodiment of this invention the steps of determining and maintaining are executed at the ground station, while in another embodiment the steps of determining and maintaining are executed on-board the satellite.
FIELD OF THE INVENTION
This invention relates generally to satellite communications systems and, in particular, to satellite communications systems that are operable with hand-held user terminals for providing communication links to existing telephone and/or network infrastructures.
BACKGROUND OF THE INVENTION
Satellite telephone systems are emerging as a new and important global business. These systems utilize many individual circuits routed through one satellite or a constellation of many satellites to provide communications for terrestrial terminals. One significant advantage of the satellite telephone system is that it provides ubiquitous coverage of large areas of the earth without requiring the construction of many small terrestrial cells.
In the past, satellites have employed antennas that produce antenna beams to provide coverage to areas occupied by users or subscribers. For full duplex communication systems, it has been the practice for the beam pattern of the region covered by the antenna for transmission to be identical to the beam pattern of the region covered by the antenna for reception; i.e., the beam pattern of the regions for transmission is congruent with the beam pattern of the region covered for reception.
It has also been the practice to fill desired satellite service regions with more than one beam when there has been insufficient allocated bandwidth (frequency range) to serve a required number of users with a required bandwidth, and to lower the power requirements of both the satellites and the earth stations. This approach relies on the re-use of the allocated bandwidth with spatial diversity. Spatial diversity is established by dividing the service region into sub-regions, and employing separate and unique smaller beams or sub-beams to serve each service sub-region. This technique enables frequency re-use through spatial diversity, wherein adjacent sub-beams operate at different frequencies, and wherein non-adjacent sub-beams may use the same frequency, thereby avoiding interference between the users located in the non-adjacent sub-beams.
In the past, the transmission sub-regions (or sub-beams) have been defined to be the same shape and size as the corresponding reception sub-regions (or sub-beams). This is typically done in order to simplify signal routing and the overall system architecture. FIG. 1 depicts an example of a multibeam antenna beam pattern that can be used for both reception by user terminals (downlink) and transmission from user terminals (uplink). That is, the downlink beam pattern and the uplink beam pattern are substantially identical, or congruent, at the surface of the earth. In FIG. 1 the service region (SR) is partitioned into 16 sub-regions, individual ones of which are serviced by one sub-beam (assuming no sub-beam overlap). The pattern is characterized by a central sub-beam 1, a ring of six inner sub-beams (2-7), and a ring of nine outer sub-beams (8-16). Phased arrays are one suitable antenna type for generating such beam patterns. Reference in this regard can be had to, by example, U.S. Pat. No. 5,422,647, issued Jun. 6, 1995, entitled "Mobile Communication Satellite Payload", by E. Hirshfield and C. A. Tsao; U.S. Pat. No. 5,283,587, issued Feb. 1, 1994, entitled "Active Transmit Phased Array Antenna", by E. Hirshfield; and to U.S. Pat. No. 5,504,493, issued Apr. 2, 1996, entitled "Active Transmit Phased Array Antenna with Amplitude Taper", by E. Hirshfield.
More particularly, in the past satellites used for duplex communications have (as best as could be designed) congruent antenna beam coverage areas for a given uplink and downlink. For example, if a satellite has a certain coverage area and that coverage area is covered by sixteen separate beams (sub-beams) for the uplink and downlink, the sixteen beam coverage areas for the uplink are the same coverage areas for the downlink (with boundary lines located within, for example, 30 miles of one another), as shown in FIG. 1.
That is, in the conventional implementations of satellites used for duplex communications, the antenna beam area of the service links was designed to be the same for the uplink and the downlink. This was done for simplicity in satellite antenna design, simplicity in ground operations, and, when using conventional parabolic antennas, the antenna design optimization could be the same for the uplink frequency and the downlink frequency.
The inventors have realized that the use of fixed congruent sub-beams for transmission and reception, as in FIG. 1, can in some instances result in inefficiencies and a loss of overall system flexibility.
OBJECTS AND ADVANTAGES OF THE INVENTION
It is a first object and advantage of the invention to provide a satellite communication system having sub-beam patterns that overcome the foregoing and other problems.
It is a further object and advantage of this invention to provide a satellite communication system wherein individual satellites each service a congruent uplink and downlink service region, but wherein the sub-regions (or sub-beams) are non-congruent.
It is a further object of this invention to provide a satellite communication system that employs non-congruent antenna beam coverage areas for the uplink and downlink, with the antenna beam coverage areas being separately optimized for each of the uplink and the downlink without consideration for the antenna beam coverage areas of the other.
It is one further object of this invention to provide a satellite communication system wherein individual satellites each service a congruent uplink and downlink service region, but wherein the sub-regions (or sub-beams) are non-congruent, and wherein the shapes of the sub-regions can be dynamically controlled, either from a ground station or the satellite, as a function of current or expected signal routing constraints, system loading, and other factors.
SUMMARY OF THE INVENTION
The foregoing and other problems are overcome and the objects of the invention are realized by methods and apparatus in accordance with embodiments of this invention.
The inventors have realized that user terminal service links do not require congruent antenna beam coverage areas because the gateway (in the case of a repeater satellite) or the satellite (in the case of a satellite that performs on-board signal processing) can determine which beam a given user is located in separately for the uplink and the downlink. With the advent of modern antenna designs (e.g., phased arrays, both passive and active), the optimization in antenna gain pattern for the downlink (transmitting) satellite antenna may not lead to the same antenna beam coverage areas as the antenna beam coverage areas that are optimized in antenna gain pattern for the uplink (receiving) satellite antenna. These different antenna beam coverage areas can be accommodated with knowledge of the patterns on the ground in the gateway or in the satellite.
As such, in accordance with this invention a communication satellite has a downlink transmit service antenna and an uplink receive service antenna, wherein the downlink transmit service antenna and the uplink receive service antenna are separately optimized for their intended functions without regard for maintaining congruency, at the ground, of the individual sub-beams or coverage areas of the two antennas.
Also disclosed is a method for use in a satellite communications system of a type that has at least one satellite having forward and reverse beams each comprised of sub-beams for relaying user communications between a ground station and user terminals. The method optimizes signal flow between the ground station and the user terminals and includes the steps of: (a) determining user terminal RF signal conditions within the sub-beams of at least one of the forward and reverse beams; and (b) in response to the determined RF signal conditions, re-allocating sub-beams of at least one of the forward and reverse beams such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth. The step of determining includes a step of maintaining a database that stores a map of the sub-beams. In one embodiment of this invention the steps of determining and maintaining are executed at the ground station, while in another embodiment the steps of determining and maintaining are executed on-board the satellite.
Also disclosed is a satellite communications system that is constructed so as to implement the foregoing method.
BRIEF DESCRIPTION OF THE DRAWINGS
The above set forth and other features of the invention are made more apparent in the ensuing Detailed Description of the Invention when read in conjunction with the attached Drawings, wherein:
FIG. 1 illustrates conventional uplink and downlink congruent sub-beam assignments as viewed from a satellite, looking at earth nadir;
FIG. 2 illustrates an exemplary uplink sub-beam assignment as viewed from a satellite, looking at earth nadir, which is non-congruent with a downlink sub-beam assignment of a type shown in FIG. 1, wherein
in FIGS. 1 and 2 the +X axis is a velocity vector of the spacecraft (sc) when operating in an orbit normal mode, the +Y axis is normal to the orbital plane in the direction defined by a right-handed coordinate system, with the +Z axis pointed at the center of the earth, and in FIG. 2 the degrees are given with respect to spacecraft nadir;
FIG. 3 is block diagram of an embodiment of a satellite communication system that is operated in accordance with this invention; and
FIG. 4 is a simplified block diagram of an exemplary satellite communications payload that is suitable for practicing this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 3, a block diagram is shown of an embodiment of a satellite communication system 20 that is operated in accordance with this invention. In a presently preferred embodiment of this invention the satellite system 20 is a low earth orbit (LEO) system comprised of a constellation of satellites 22, one or more gateways 24 each having a plurality of steerable antennas 23, a ground operations control center (GOCC) 26, and a satellite operations control center 28. Each of the antennas 23 can be pointed at a different satellite 22, it being assumed that there will typically be two or more satellites in view of the gateway 24 at any given time. A given user terminal 30 communicates with the gateway 24 via one or more of the satellites 22 and a corresponding one or more of the antennas 23. The gateway 24 includes a Public Land Mobile Network (PLMN)/Public Switched Telephone Network (PSTN) switch 24a for bidirectionally connecting the user terminal 30 to various public networks 24b, cellular networks 24c, and private networks 24d.
The following U.S. Patents teach various aspects of a LEO satellite constellation, and the associated communication system, which may be used in conjunction with the satellite system 10 shown in FIG. 1: U.S. Pat. No. 5,422,647, issued Jun. 6, 1995, entitled "Mobile Communication Satellite Payload", by E. Hirshfield and C. A. Tsao; U.S. Pat. No. 5,283,587, issued Feb. 1, 1994, entitled "Active Transmit Phased Array Antenna", by E. Hirshfield; U.S. Pat. No. 5,504,493, issued Apr. 2, 1996, entitled "Active Transmit Phased Array Antenna with Amplitude Taper", by E. Hirshfield; U.S. Pat. No. 5,552,798, issued Sep. 3, 1996, entitled "Antenna for Multipath Satellite Communication Links", by F. J. Dietrich and P. A. Monte; and U.S. Pat. Nos. 5,448,623, issued Sep. 5, 1995, and 5,526,404, issued Jun. 11, 1996, "Satellite Telecommunications System Using Network Coordinating Gateways Operative with a Terrestrial Communication System", by R. A. Wiedeman and P. A. Monte. The disclosures of these various U.S. Patents are incorporated by reference herein in their entireties.
In a presently preferred, but not limiting, embodiment of this invention, there are a total of 48 satellites 22 in, by example, a 1414 km Low Earth Orbit (LEO). The satellites are distributed in eight orbital planes with six equally-spaced satellites per plane (Walker constellation). The orbital planes are inclined at 52 degrees with respect to the equator and each satellite completes an orbit once every 114 minutes. This approach provides approximately full-earth coverage with, preferably, at least two satellites in view at any given time from a particular user location between about 70 degree south latitude and about 70 degree north latitude. As such, the user terminal 30 is enabled to communicate from nearly any point on the earth's surface to other points on the earth's surface via one or more of the gateways 24 (by way of the PLMN/PSTN switch 24a) and one or more of the satellites 22.
Reference in this regard may be had to the above-referenced U.S. Pat. No. 5,422,647, by E. Hirshfield and C. A. Tsao, entitled "Mobile Communications Satellite Payload", which discloses one type of communications satellite having linear amplifiers and phased array transmit and receive antennas. The described satellite payload is suitable for use with the teaching of this invention, as well as are other satellite transponder types.
User/gateway communications are accomplished via a spread spectrum (SS), code division multiple access (CDMA) technique. The presently preferred SS-CDMA technique is similar to the TIA/EIA Interim Standard, "Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System" TIA/EIA/IS-95, July 1993, although other spread spectrum and CDMA techniques and protocols can be employed. However, Time Division Multiple Access (TDMA) may also be used. Frequency Division Multiple Access (FDMA) can also be employed, as can combinations of these various access techniques.
The low earth orbits of the satellites 22 permit the low-powered fixed or mobile user terminals 30 to communicate via the satellites 22, each of which functions, in one embodiment of this invention, solely as a "bent pipe" repeater to receive a communications traffic signal (such as speech and/or data) from a user terminal 30 or from a gateway 24, to convert the received communications traffic signal to another frequency band, and to then re-transmit the converted signal. However, it should be realized that the teaching of this invention is not limited to "bent pipe" repeater satellites, and can function equally well with on-board processing and regenerative repeater types of satellites. There need be no direct communication link or links between the satellites 22, although such links may be provided if desired.
The user terminals 30 communicate via, by example, L-band RF links (uplink or return link) and S-band RF links (downlink or forward link) through return and forward (linear) satellite transponders, respectively. The return L-band RF links may operate within a frequency range of 1.61 GHz to 1.625 GHz, a bandwidth of 16.5 MHz, and are modulated with in accordance with the preferred spread spectrum technique in multiple 1.25 MHz segments. The forward S-band RF links may operate within a frequency range of 2.485 GHz to 2.5 GHz, a bandwidth of 16.5 MHz, and are also modulated in accordance with the spread spectrum technique in multiple 1.25 MHz segments.
The 16.5 MHz bandwidth of the forward link is partitioned into 13 frequency channels with, by example, up to 128 users being assigned per channel. A given frequency channel is assigned to one (or more) of the sub-beams, with any re-used frequency channels being assigned to non-adjacent sub-beams. The return link may have various bandwidths, and a given user terminal may or may not be assigned a different frequency channel than the frequency channel assigned on the forward link.
The gateway 24 communicates with the satellites 22 via a full duplex RF link comprised of a forward link (to the satellite 22) and a return link (from the satellite 22) that operates within a range of frequencies generally above 3 GHz and preferably in the C-band. The C-band RF links bi-directionally convey the communication feeder links, and also convey satellite commands to the satellites and telemetry information from the satellites. The forward feeder link may operate in the band of 5 GHz to 5.25 GHz, while the return feeder link may operate in the band of 6.875 GHz to 7.055 GHz.
The antenna beam from a LEO satellite can be analogized as a push broom, where a yaw axis of the satellite is the broom's "handle" and where the satellite's coverage area, that is, a region illuminated by the beam, is "pushed" over the earth's surface. The portion of the earth's surface that can be seen from the orbiting LEO satellite at any instant is its coverage footprint. The antenna beam may be all or some portion of the footprint. The coverage area has a size and shape which typically depends on the altitude of the orbit and the elevation angle to the satellite from the extremity of the coverage area footprint. The antenna beam does not necessarily need to be regular in shape, nor does it have to illuminate all of the coverage area. However, for the purposes of this discussion it is assumed that the coverage area is a circular area centered on a point on the earth directly below the satellite. The satellite beam is typically divided into the smaller sub-beams for communications efficiency.
Furthermore, for this discussion it is assumed that the antenna is fixed to the body of the satellite. However, this is not necessary, and the antenna can instead be gimbled and directed to point in some direction with respect to the satellite axes.
Having described a presently preferred, but not limiting, embodiment of a satellite communications system within which the teaching of this invention may be used to advantage, reference is now made to FIG. 2 for illustrating an exemplary antenna pattern of sub-beams in accordance with the teachings of this invention.
The use of this invention preserves the principle of congruent coverage for satellite communication taken as a whole, but establishes non-congruent sub-regions to enable optimization of the transmission sub-regions according to principles governing a most efficient transmission, and also optimization of the reception sub-regions according to principles governing most efficient reception. It is noted that the criteria in some systems are different for efficient transmission than for efficient reception.
By example, due to the difference in frequency between the L band uplink and the S band downlink to the user terminal 30, these links will typically experience different, and varying, amounts of attenuation and fading due to the presence of rain, foliage, and other such RF signal path impairments.
Further by example, differences in allowable amounts of transmitted power may exist between the uplink and the downlink. Also, the presence of RF noise sources, terrestrial RF links, and/or other satellite systems, that operate in frequency bands that overlap or that are co-frequency with the L band and S band frequencies, may introduce varying levels of interference in different frequency bands. These interference levels may change with time over the course of hours or days, and may furthermore shift among the set of frequency bands or channels that are individually assigned to individual ones of the sub-beams. By example, certain frequency bands may experience high levels of interference only during certain hours of the day, while at other times the levels of interference are negligible.
As such, it can be appreciated that congruence between the sub-beams of the uplink beam and the sub-beams of the downlink beam may be less than desirable.
This leads to antenna beam coverage areas that are non-congruent, as shown in FIG. 2 when compared to FIG. 1. There are different reasons that various optimizations can lead to non-congruent beams.
A first reason is, given that the transmit and receive frequencies are different and that the antennas can be the same size, the beam pattern of the antenna with the higher frequency can be shaped more sharply, with the same size aperture for both antennas, than the antenna with the lower frequency. This may lead to non-congruent beams when optimizing both the transmit and receive frequencies.
A second reason is that amplitude taper and phase control are preferably used to optimize antenna patterns. Amplitude taper and phase control can be used together or separately. When used together amplitude taper and phase control give more degrees of freedom in the antenna design and, therefore, lead to more well defined antenna patterns (i.e., a higher average gain over each beam). For some antennas, such as a phased array (whether used on a satellite or not), there may be thermal gradients across the antenna aperture which may distort the antenna beam patterns. The presence of such thermal gradients can impose amplitude taper constraints on the typically much higher power transmit (downlink) antenna. Thus, an optimization of antenna performance with amplitude taper constraints on the transmit antenna, and not on the receive antenna, may lead to non-congruent beams.
Also, when considering amplitude taper and phase control with a linear or semi-linear transmit requirement, it is desirable to drive all elements with the same power at the same instant. This linear requirement can constrain the transmit antenna to have only phase control and no amplitude taper. With only phase control on the transmit antenna and both phase and amplitude control on the receive antenna, the separate optimization of each antenna may lead to non-congruent beams.
Furthermore, the optimization of antenna beams typically implies high gain in the desired area of coverage and lower gain in the undesired area of coverage. This in turn leads to higher average gain, higher beam efficiency, low side lobes, and low beam overlap. Thus, if a sharper, more defined beam shape can be achieved on the receive antenna by use of amplitude and phase taper, but only phase taper on the transmit antenna, it is desirable to take advantage of the improved receive antenna even if the same cannot be achieved for the transmit antenna.
In accordance with the teachings of this invention there is provided an ability to separately change the shape of the beams, as well as the number of beams, on the uplink and the downlink. The variation in beam shape and/or number may be done statically (i.e., making the beam shapes and/or number permanent), or can be made to vary in accordance with a predetermined plan, or may be dynamically varied in response to changing conditions.
For example, the beams can be changed by changing the amplitude and phase of the elements of an antenna. The beams can also be changed by moving the lens of a lensed antenna.
In a given example, all of the various considerations discussed above may be present (i.e., same antenna size and different frequency, thermal constraints, and linear amplification constraints). When the average gain over each beam and the beam efficiency (e.g., a low beam overlap) are optimized, the uplink and downlink antennas are non-congruent, as when comparing FIG. 1 to FIG. 2. Given the constraints of a particular antenna implementation, the use of non-congruent beams in accordance with the teaching of this invention yields better optimized antenna performance to deliver higher traffic capacity.
Furthermore, in the presently preferred embodiment the gateway 24 is enabled to accurately determine the location of a given one of the user terminals 30 through the use of, by example, position location measurements. This is typically done when the user terminal 30 first requests service. Knowing the location of the user terminal 30, and also the locations, shapes and sizes of the various sub-beams of the uplink and downlink beams at any point in time (based on satellite ephemeris data and a knowledge of the transmit and receive antenna system characteristics), the gateway 24 can determine which sub-beams the user terminal is located in for both the uplink and the downlink, and can assign traffic channel frequencies accordingly.
In general, a satellite communications system can provide enhanced performance if there is high gain (sharper beams) directed towards higher traffic density areas, and lower gain (broader beams) directed at the low traffic density areas. These considerations are important for the embodiment using pre-planned changes and/or dynamic changes in the beam patterns and/or numbers. Given a certain user traffic density, an optimal beam pattern can be defined. The beam pattern will change over time as the traffic changes or as the satellite moves over the traffic areas. An optimum change in the beam pattern, or re-allocation of sub-beams, may thus be determined in advance based upon a historical traffic database, or may be changed dynamically, in real-time, as traffic demand changes.
It is also within the scope of the invention to operate in accordance with a predetermined sub-beam allocation plan, and to dynamically modify the predetermined plan as needed to accommodate changes in demand, the addition of new subscribers, and other events.
The satellite communications system will also provide enhanced performance if there is there is high gain directed towards areas where interference is high to provide a better quality of service for the users in areas experiencing high interference. The interference could be due to external systems (terrestrial or satellite) or due to signal attenuation (trees, buildings, etc.). Of course, if there is an area with high interference and little or no communications traffic, it is also desirable to have a minimum gain directed towards that area for the uplink antenna. For the case of a high interference area with few users, it may be most efficient to have high gain on the downlink antenna and low gain on the uplink antenna. This condition leads to the use of non-congruent beams in accordance with the teaching of this invention.
For example, desired beam patterns could be uploaded by command from a gateway 24 to indicate the locations of major cities. In response the satellite 22 provides higher gain beams directed towards the major cities, either because there is more signal attenuation present in the urban environment, or because the traffic is denser, or because of the presence of a terrestrial system which uses the same frequencies, leading to increased interference.
Furthermore, if the satellite 22 is in elliptical orbit (an orbit where the satellite altitude changes), in order to maintain a constant beam size at the earth's surface, the beam shape has to change (i.e., the beams shape must become sharper as the satellite altitude increases).
In any of the above cases, it may be most efficient to change the number of beams as well in order to obtain the highest possible directional beams(s) on areas with high traffic demand, or to decrease the amount of power used by beams which are on but not being used.
In accordance with an aspect of the teaching of this invention the gateway 24, or some other ground station connected to the gateway 24, includes a database 25 wherein maps are maintained of the coverage areas of each sub-beam of each satellite 22 that the gateway 24 is communicating through. Within each sub-beam are user terminals 30 that are communicating with the gateways 24. An indication of user terminal interference and general RF operating conditions is sensed by the gateway 24 from, by example, a power control request from the user terminal 30 that is transmitted on the L band return link and the associated C band return feeder link. In general, the gateway 24, using its closed loop user terminal power control equipment, responds by increasing (or decreasing) the power used by the satellite 22 to overcome the interference. Since the location of the user terminal (i.e., identity of the sub-beam) and the amount of power used by the user terminal 30 is known by the gateway 24, it is possible to quantize this information and store it in the database 25. Another indication of the RF conditions within a given sub-beam can be determined from a bit error rate required in the channel to achieve reliable bi-directional communications. For example, if the gateway 24 finds that it receives the user terminal transmission with a low bit, word or frame error rate, but that the user terminal 30 indicates through re-transmission requests that it is not reliably receiving the forward link transmission, it may be inferred that the forward link (S band) is more impaired than the reverse link (L band) for a given one of the sub-beams and its associated frequency channel. The reverse situation may also exist. The gateway 24 may also request that the user terminals periodically measure the power and/or signal quality of the forward link and report the results back to the gateway. It can be further appreciated that, even under ideal RF propagation and interference conditions, the user terminals 30 located in the outer sub-beams (e.g., 13, 14 and 15 of FIG. 1) may experience a different RF signal quality than the user terminals 30 located in the inner sub-beams (e.g., 1, 4, 5 of FIG. 1).
Having made a determination of the RF signal quality of each of the sub-beams of at least the reverse beam, and having stored this information in the database 25, the gateway 24 is enabled to modify or re-allocate the locations of the sub-beams so as to optimize the conditions for RF signal reception by the gateway 24 (and/or by the user terminals 30).
By example, and referring also to FIG. 2, there is illustrated an exemplary uplink (reverse) sub-beam assignment as viewed from the satellite 22, looking at earth nadir, which can be seen to be non-congruent with the downlink (forward) sub-beam assignment of a type shown in FIG. 1. In accordance with the teaching of this invention two beams may be considered to be congruent if each has a same number of sub-beams having sub-beam boundaries that are offset from one another, at the surface of the earth, within some predetermined threshold (e.g., 50 miles or less). Normally the beams are intended to be congruent, and any differences at the surface of the earth are due to imperfections and mismatches in the satellite transmit and receive antennas. Conversely, two beams are non-congruent if the sub-beam boundaries are intentionally made to differ from one another, and/or if different numbers of sub-beams are used, and/or if no attempt is made to preserve any overlap between like sub-beams.
If it is assumed that the forward link sub-beam distribution is as is shown in FIG. 1, then the sub-beams of the reverse link as shown in FIG. 2 are clearly not congruent with the sub-beams of the forward link. However, the overall beam (i.e., the region that bounds the totality of the forward and reverse sub-beams) may be congruent at the surface of the earth. That is, both beams may centered at approximately the same point on the earth's surface, and the beam perimeters may be substantially equal in size and shape.
In the illustrated example all of the user terminals 30 located at about the center of the beam pattern will find themselves in sub-beam 1 for both the forward and reverse links. However, those user terminals 30 that are located in the forward link sub-beams 7 and 8 (FIG. 1) will find that they have been assigned by the gateway 24 to one of reverse link sub-beams 1 or 2 (FIG. 2), depending on their distance from the center of the beam pattern.
The gateway 24 determines the distribution of the reverse link sub-beams in accordance with the above-mentioned pre-planned beam shape assignments, and/or from the information stored in the database 25, and in accordance with the goal of separately optimizing both the forward and the reverse link quality for the user terminals 30 within the service region or coverage area of the satellite 22, given the constraints imposed by differences in frequency, differences in thermal gradients across the satellite antennas, etc.
It can be appreciated that the sub-beam assignments for both the uplink and downlink can be changed by the gateway 24 as RF signal propagation conditions warrant. Such changes can be made as a function of, by example, system loading, an amount of external interference from terrestrial RF sources, an amount of external interference from other satellite communication systems, weather conditions within the service region, and other factors. The desired result is to employ the gateway 24 to maintain maps of the coverage areas of each antenna sub-beam, and to route user terminal signals as required to establish and maintain connectivity.
The control of the locations of the various sub-beams is achieved by the use of phased arrays on the satellite 22 for establishing the forward and reverse user links, and through the use of known types of beam steering techniques for the phased arrays.
Referring now to FIG. 4, there is illustrated an exemplary satellite payload providing non-congruent beam coverage. More particularly, the L-band receive feed 33 and the S-band transmit feed 32 couple the uplink and the downlink service links, respectively, to the terrestrial user terminals (fixed or mobile). Feeds 32 and 33 are each a phased array comprised of, by example, 91 elements (32a) and 61 elements (33a), respectively. The elements are packed into a generally hexagonal configuration, and use every one of the 91 or 61 elements for every one of the beams.
Directly coupled to the 61 elements 33a of the receive feed 33 are low noise amplifiers (LNAs) for receipt of the L-band uplink signals. Directly coupled to the 91 elements 32a of the transmit feed 32 are high power amplifiers (HPAs) for transmitting the S-band downlink signals. The HPAs are capable of transmitting with several different power levels. The LNAs and the HPAs are designed to operate in a linear region wherein the output signal is directly proportional to the input signal. Linear operation preserves the fidelity of the signals transmitted, and also provides the ability for every antenna element to carry multiple independent beams simultaneously.
As the satellite 22 passes over a group of user terminals, the access to the satellite 22 moves from beam to beam in a direction opposite to that of the satellite motion. Thus, the need for transmission power for the S-band downlink from the satellite 22 must also move from beam to beam in a corresponding manner. The communications payload shown in FIG. 4 provides for the available power to be assigned to a particular downlink beam that is illuminating the same ground area as the uplink beam in use. This occurs because the downlink HPAs are associated with each of the downlink feed elements 32a, and thus each element 32a participates in every beam. The power is therefore assigned on a demand basis, automatically in cooperation with the gateways, and without the need for command or logic control.
In greater detail, the phased array feeds 32 and 33 are formed by multiple beam forming networks 32b and 33b, respectively, which establish the direction that each beam points relative to the satellite 22. In the illustrated embodiment there are 32 active uplink and 32 active downlink beams, and thus 32 uplink beam former networks (BFNs) 33b and 32 downlink BFNs 32b.
In one exemplary embodiment of this invention 37 uplink beams are collected by the receive feed 33 from the user signals through the use of 37 uplink BFNs 33b. The number of beams is then reduced to 32 by selecting one from each particular set of five pairs in a 5 pole-10 throw (5P10T) electronic beam switch (EBS) 29. The 32 resultant uplink beams at the outputs of the receive feed elements 33a are divided by 61 power dividers 35, after amplification by the LNAs, into 32 paths that are fed to the BFNs 33b, thereby establishing the direction and shape of each uplink beam. The same is true of the downlink beams, wherein 37 inputs are combined in 91 power combiners and then amplified by the HPAs for transmission by the 91 elements 32a. Since the feed 32 has 37 beams, another 5 pole-10 throw (5P10T) electronic beam switch (EBS) 29 makes selections within five designated pairs of beams (at the periphery of the overall coverage pattern), so that only 32 beams are active at any time.
It should be noted that, for simplicity, the EBSs 29 are shown connected to one polarization only. However, any combination of polarizations can be used.
Transmission between the gateway 24 and the satellite 22 is via the C-band RF links. To accommodate this mode of operation, the L-band signals received by the 32 active beams are frequency division multiplexed (FDM) into two groups of 16 for transmission over the C-band of frequencies. This is accomplished by a plurality of amplifier mixers 34 which operate to up-convert the L-band signals to C-band signals. The frequencies of each of the FDM channels are established by local oscillators 36, in conjunction with the amplifier mixers and associated filters. Multiple channels are combined in individual ones of summing networks 38 and 40 and are provided to power amplifiers (SSPAs) 42 and 44, respectively. The outputs of power amplifiers 42 and 44 are applied to orthogonal channels for transmission to a gateway from antenna 46 (in a frequency band of about 6907 to 7066 MHz). The orthogonal channels are established by a polarizer 48.
Circularly polarized orthogonal signals received from the gateway 24 arrives through antenna 50 (in a frequency band of about 5050 to 5250 MHz), are separated by polarizer 52, amplified by LNAs 54 and 56, and are provided to power dividers 58 and 60, respectively. The outputs of the power dividers 58 and 60 are provided to a plurality of filters and amplifier mixers 62 which, in conjunction with local oscillators 64, down-convert the C-band gateway transmissions to establish the S-band return channels to the beam forming networks 26. Signals from the beam forming networks 32b are collected in the n-way (n=37 in the example) power summers 31 and are provided to the individual elements 32a of the transmit phased array antenna 32.
In the illustrated embodiment the receive phased array 33 may employ both amplitude taper and phase control, while the transmit phased array, due to the significantly higher power requirements, may employ only phase control.
Furthermore, the sizes of the two phased arrays are different, and the transmit phased array 32 is constructed with more elements than the receive phased array (i.e., 91 elements vs. 61 elements). Significantly, the terrestrial beam patterns are not congruent for the uplink and down link beams. That is, both antennas are optimized for their intended applications without regard for maintaining beam congruency.
It is noted that all of the frequencies, bandwidths and the like that are described herein are representative of but one particular system. Other frequencies and bands of frequencies may be used with no change in the principles being discussed. Furthermore, the teaching of this invention is not limited to only the disclosed numbers of satellites, elevation angles, altitudes and the like. Other than CDMA-type systems (for example, TDMA-type systems) can also benefit from the teaching of this invention. Also, and although described in the context of a low earth orbit satellite system, it should be appreciated that the teachings of this invention apply as well to medium earth orbit (MEO), as well as to geosynchronous orbit (GSO), satellite systems.
Furthermore, the teachings of this invention have been thus far described primarily in the context of relatively simple repeater satellites, and the maintenance of the database 25 by the gateway 24 (FIG. 3). It should be realized, however, that in a system that utilizes satellites capable of on-board signal processing-the satellite may determine the RF conditions within the various sub-beams, may maintain the database 25 on-board the satellite, and may itself re-allocate the sub-beams of the forward and/or reverse links, either autonomously or in cooperation with the gateway 24 and/or GOCC 26. In this type of system the on-board satellite processing thus maintains the maps of the sub-beam coverages and routes signals accordingly to maintain connectivity.
The teaching of this invention can also be employed to accommodate ground-based RF "hot spots" by re-allocating beams accordingly.
The teaching of this invention is especially advantageous for the case wherein multiple non-geosynchronous orbit satellites project multiple overlapping beams on the earth's surface, with each of the beams being comprised of a plurality of sub-beams, with the beams passing over the earth's surface in different directions. The teaching of this invention furthermore enables a high gain to be achieved, as desired, at the periphery of the beams.
Thus, while the invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that changes in form and details may be made therein without departing from the scope and spirit of the invention.
What is claimed is:
1. A satellite communications system of a type having at least one satellite that projects forward and reverse beams that move across the surface of the earth, each of said beams being comprised of sub-beams for relaying user communications between a ground station and user terminals, said system further comprising a data processor for determining user terminal RF signal conditions within said sub-beams of at least one of said forward and reverse beams, said data processor being responsive to said determined RF signal conditions for re-allocating sub-beams of at least one of said forward and reverse beams such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth.
2. A satellite communications system as set forth in claim 1, wherein said data processor is bidirectionally coupled to a database that stores a map of said sub-beams.
3. A satellite communications system as set forth in claim 2, wherein said data processor and said database are co-located with said ground station.
4. A satellite communications system as set forth in claim 2, wherein said data processor and said database are located on-board said at least one satellite.
5. In a satellite communications system of a type having at least one satellite having forward and reverse beams each comprised of sub-beams for relaying user communications between a ground station and user terminals, a method for optimizing signal flow between the ground station and the user terminals comprising the steps of:determining user terminal RF signal conditions within the sub-beams of at least one of the forward and reverse beams; and in response to the determined RF signal conditions, re-allocating sub-beams of at least one of the forward and reverse beams such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth.
6. A method as set forth in claim 5, wherein the step of determining includes a step of maintaining a database that stores a map of the sub-beams.
7. A method as set forth in claim 6, wherein the steps of determining and maintaining are executed at the ground station.
8. A method as set forth in claim 6, wherein the steps of determining and maintaining are executed on-board the at least one satellite.
9. A satellite communications system of a type having a plurality of satellites each having forward and reverse beams that move across the surface of the earth, each forward and reverse beam being comprised of sub-beams for relaying user communications between a ground station and user terminals located within the beams, said system further comprising a data processor for determining, for each of the plurality of satellites, user terminal RF signal conditions within said sub-beams of at least one of said forward and reverse beams, said data processor being responsive to said determined RF signal conditions for re-allocating sub-beams of at least one of said forward and reverse beams, for each of said plurality of satellites, such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth.
10. A satellite communications system as set forth in claim 9, wherein said data processor is bidirectionally coupled to a database that stores a map of said sub-beams.
11. A satellite communications system as set forth in claim 10, wherein said data processor and said database are co-located with said ground station.
12. A satellite communications system as set forth in claim 10, wherein said data processor and said database are located on-board said at least one satellite.
13. A satellite communications system of a type having at least one satellite having forward and reverse service beams that form a beam pattern at the surface of the earth, each of said forward and reverse service beams operating in respective and different frequency bands and being associated with a forward antenna system and a reverse antenna system, respectively, on-board said satellite, wherein said antenna systems are separately optimized for their intended applications without regard for maintaining congruence between antenna beam sub-beams at the surface of the earth, and where at least one of said antenna systems is operated to reallocate sub-beams in accordance with at least one of real-time or predicted variations in communications traffic loading or RF propagation conditions, said antenna system being operated such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth.
14. A satellite communications system as set forth in claim 13, wherein said forward and reverse antenna systems each comprise a phased array, wherein said phased array of said reverse antenna system uses both amplitude taper and phase control, and wherein said phased array of said forward antenna system uses phase control and not amplitude taper.
15. A satellite communication system as set forth in claim 13, and further comprising a data processor for determining user terminal RF signal conditions within said sub-beams of at least one of said forward and reverse service beams, said data processor being responsive to said determined RF signal conditions for re-allocating sub-beams of at least one of said forward and reverse beams such that the totality of the sub-beams of the forward beam are non-congruent with the totality of the sub-beams of the reverse beam, at the surface of the earth, while maintaining the forward beam substantially congruent with the reverse beam, at the surface of the earth.
16. A satellite communications system as set forth in claim 15, wherein said data processor is bidirectionally coupled to a database that stores a map of said sub-beams.
17. A satellite communications system as set forth in claim 16, wherein said data processor and said database are co-located with said ground station.
18. A satellite communications system as set forth in claim 16, wherein said data processor and said database are located on-board said at least one satellite.
19. A satellite communication system as set forth in claim 13, and further comprising a data processor for re-allocating sub-beams of at least one of said forward and reverse beams based on at least one of a predetermined plan or a dynamically varying plan.
20. A satellite communication system as set forth in claim 13, wherein said predicted variations are derived from a database that stores information reflecting past usage of said satellite communications system.
| 1997-10-09 | en | 2000-08-08 |
US-41573195-A | Orthotic joint
ABSTRACT
Disclosed is an orthotic joint for an orthotic knee, hip or other similar brace that would eliminate the use of sidebars and would automatically lock upon full extension. The locking mechanism could also be fixed in an unlocked position if desired. Instead of a lock, one of a series of barrels of different diameters could be used as stops. The diameter of the barrel would determine the degree of stop. The locking mechanism or barrel would be vacuum-formed into the knee section of a typical custom-made knee orthosis or knee ankle foot orthosis. A round disk with a range-of-motion cutout and a locking hole is positioned between the thigh and calf portions of the brace. In one embodiment, a plunger mounted through the locking mechanism would roll on a cutout in the disk until reaching the tapered hole and then be forced in by a spring to lock the joint. Barrels, instead of a plunger, could be used if a stop, instead of lock, is desired. The locking mechanism could be unlocked by pulling or turning the plunger. This is accomplisher rotating a machined male part relative to a machined female part.
BACKGROUND OF THE INVENTION
The present invention is related to an orthotic joint, and more particularly to an orthotic plastic joint with a lock or with multiple adjustable extension stops.
Many different types of orthotic knee joints exist. They all have some mechanical joint made to flex and extend with the anatomical knee joints.
Typically, knee joints incorporated into long term knee ankle foot braces (long leg brace) are made of steel with sidebars attached to thigh and calf cuffs. Individuals requiring long term braces generally obtain custom braces made from measurements and a casting of the affected limb. The braces are made by attaching sidebars to a steel joint that flexes and extends in the sagital plane. A drop lock is pushed over the mechanical knee joint to lock the knee joint in place when the leg is fully extended so the knee will not buckle. Steel sidebars are, however, very heavy, and such weight limits the mobility of the brace wearer.
Steel knee joints presently are contoured away from the knee so they will not hit against the leg and cause pressure sores. Sometimes condylar knee pads and straps are added to the knee joints to gain direct control of the knee for medial/lateral correction and stability.
Other orthotic joints are constructed in a similar manner and have many of the same drawbacks. The principles of the invention described below will have application to all such joints.
It is therefore a principal object of the present invention to provide an orthotic joint without sidebars which will automatically lock during full extension.
It is another object of the present invention to provide an orthotic joint without sidebars which has the ability to limit the range of motion of the knee.
Another object of the present invention is to provide an orthotic joint which is lighter and easier to use than existing orthotic joints.
Still another object of the present invention is to provide an orthotic joint that can be vacuum-formed on a positive mold with the attached limb section.
A still further object of the present invention is to provide an orthotic joint which enables the wearer to have greater medial/lateral control.
SUMMARY OF THE INVENTION
The orthotic joint of one embodiment of the present invention will be described as a knee joint and includes one circular disk and a locking mechanism. The disk has a slot cutout which defines the range-of-motion of the leg. A tapered hole is formed at the one end of the slotted cutout. A spring-loaded plunger glides in the range-of-motion cutout. A locking mechanism is attached to the thigh section after it is vacuum-formed. The thigh section is mounted adjacent the disk with the slot cutout. At full extension, a steel plunger would automatically lock into the hole on the slotted disk. It would unlock for sitting with a simple turn or pull. To keep unlocked, the locking mechanism could be rotated an additional distance. Generally, the person using such a brace would want the joint to automatically lock, but, the option to be able to lock in an unlocked mode is available and could prove important to some clients. For instance, a paraplegic that needed a locked knee initially, but, through extensive physical therapy, wanted to test the ability of his quadriceps to lock his knee without the automatic locking mechanism, would be able to do so.
In another embodiment of the present invention a stop mechanism is used instead of the locking mechanism. In this embodiment, a steel barrel of the correct diameter could be used. It would also be attached in the same general area of the thigh section as the automatic locking mechanism. Different range-of-motion stops of different diameters would be used depending on the desired degree of stop required.
These and other features and objects, will become apparent to those skilled in the art from the following detailed description which should be read in a light of the accompanying drawings in which corresponding reference numbers refer to corresponding parts throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an orthotic knee brace of the present invention.
FIG. 2 is an exploded view of the components of the orthotic brace shown in FIG. 1.
FIG. 3 is a top plan view of the locking mechanism of the present invention mounted on a portion of a leg brace.
FIG. 4 is a perspective view of a disk mounted between the brace sections shown in FIG. 2.
FIGS. 5(a)-5(c) are perspective views of barrels used in the slot of the disk shown in FIG. 4.
FIG. 6 is a perspective view of the disk shown in FIG. 4 with barrels mounted in a slot (although in practice only one barrel would be needed).
FIG. 7 is a perspective view of one embodiment of the spring-loaded locking mechanism of the present invention shown in FIG. 2.
FIG. 8 is a perspective view of the female receptor part of the spring-loaded mechanism shown in FIG. 7.
FIG. 9 is a perspective view of the moveable male part of the spring-loaded locking mechanism shown in FIG. 7.
FIG. 10 is a perspective view of the plunger incorporated in the locking mechanism shown in FIG. 7 shown in a compacted position.
FIG. 11 is an exploded view of the plunger shown in FIG. 10.
FIG. 12 is a top plan view of the stationary female part shown in FIG. 8.
FIG. 13 is a top plan view of the moveable male part shown in FIG. 9 mounted over the stationary female part shown in FIG. 12.
FIG. 14 is another perspective view of the stationary female part shown in FIG. 8.
FIG. 15 is another perspective view of the moveable male part shown in FIG. 9.
FIGS. 16 and 17 are representative views of the interaction of the displacement pins of the male part shown in FIG. 13 and the ramps on the stationary female part shown in FIG. 12.
FIG. 18 is a perspective view of an alternate embodiment of the locking mechanism of the present invention.
FIG. 19 is a perspective view of a hip orthosis utilizing the locking mechanism shown in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring FIGS. 1 and 2, one embodiment of an orthotic brace 10 of the present invention is shown. The brace 10 shown is a knee brace which includes a knee joint 12. While a knee brace will be described below the present invention could be incorporated in any orthotic joint such as the hip orthosis shown in FIG. 19.
An automatic locking mechanism 20, which can lock the knee joint 12 and thereby lock the calf section 16 relative to the thigh section 14, is mounted on one of the calf or thigh sections 16, 14. In the embodiment shown, it is mounted on the outer wall 22 of the thigh section 14. Locking mechanism 20 has a round stock spring loaded plunger 24 that glides on the range-of-motion cutout 26 in a disk 28 securely mounted (e.g. with screws or rivets) to calf section 14 between thigh and calf sections 14, 16. As thigh section 14 is rotated relative to disk 28, the plunger 24 will glide in cutout 26 until it plunges into the tapered hole 30 on the disk 28. The automatic locking is achieved through the force of the spring 32.
In one embodiment shown in FIGS. 7 and 10-11, the plunger 24 includes a top section 56 with threads 35 which screw into the male part 34, and a mid-shaft 58 which is screwed into a bottom section 60. A compression spring 62 is mounted around the mid-shaft 58. A second threaded shaft or encasement 65 is also mounted around mid-shaft 58 so that it glides up and down along mid-shaft 58. The outside diameter of the spring is the same as the outside diameter of the bottom section 60 of the plunger, slightly larger than the outside diameter of the top section 56 and less than the interior diameter of the shaft 65 so that when the plunger 24 is compressed the spring 62 fits within shaft 65. These dimensions ensure that the spring is secured on the mid-shaft 58 between the top of shaft 65 and the bottom section 60. The encasement 64 is threaded into female part 36. The encasement 64 has a tapered hole. The diameter of the tapered hole 66 at the end of the encasement is large enough to allow the top section 56 of the plunger 24 to fit through the hole. The plunger 24 is put under compression by the spring not being able to continue through the hole in the encasement and since the top section 56 of the plunger 24 is screwed to the male part 34 spring tension is increased. The thread 35 in the top section 56 allows for small adjustments for variances in plastic thickness on the vacuum form poles of the fabrication.
While the bottom section 60 of the plunger is unlocked and travelling within the range of motion disk 28 it is under compression until it is forced into the locking hole. At that point, the plunger is still under compression, but the compression is not as great because the plunger has extended approximately 3/16 inches into the locking hole. The travel length is equal to the height of the plateau 52 on the female part 36 which locks the knee joint in an unlocked position. The plunger bottom section 60 which passes into hole 30 can travel no further than the male displacement pins 42 travel because they are stopped at the surface of the female part 36.
As shown most clearly in FIGS. 7, 9 and 13, male part 34 also includes a set of three displacement pins 42 which extend from one surface of the male part 34. In preferred embodiment, these pins are spaced 120° apart around the male part 34. The purpose of the pins is to keep the male parts 34 separated from the female part 36 when the tension of the spring causes the two parts to come together.
When the plunger 24 is not in the tapered hole 30, the male 34 and female 36 parts are separated and the locking mechanism is unlocked. The spring 32 puts the moveable male part 34 under tension to be drawn close to female part 36. As shown in FIGS. 12 and 14, the female part 36 also includes three ramps 46 which are formed on a surface of the female part 36. These ramps are preferably spaced apart 120° from each other. In any event, the ramps 46 are spaced apart the same distance as the displacement pins 42 are spaced from each other. The ramps 46 should be located the same distance from the center hole of the female part 36 as each corresponding pin 42 is located from the center hole of the male part 34.
When locking mechanism 20 locks, the male 34 and female 36 parts come together and contact each other in three locations 120 degrees apart. To unlock the knee joint for sitting, the wearer of the brace either pulls or turns the moveable male part 34. Since the plunger 24 is threaded into the male part 34, the plunger 24 moves with the male part 34 and comes out of the tapered hole 30. Turning the male part 34 causes its set of displacement pins 42 to slide up the ramps 44 formed on the female stationary part 36 thereby causing the plunger 24 to come out of hole 30. Since the female part 36 is stationary, it is preferably attached to the outer disk portion of calf section 16 by any known fabricating means, and in one embodiment it is attached with three small screws 48 which are spaced apart by 120 degrees. These screw holes could also be placed on stationary female part 36 between ramps 46 if a smaller diameter, lower profile female part 36 is desired.
A slight turn of the male part 34 unlocks the knee joint for sitting. The act of pulling and turning the male part 34 and starting to flex the knee is enough to move the plunger 24 out of the tapered hole 30. Once the slight turn or pull is stopped, the plunger 24 is put back under pressure as the male displacement pins 40 slide closer to the female receptor site base 50. The nature of the spring's recoil properties wants to pull male part 34 back towards the female part 36 as shown in FIG. 17. The action of the spring's recoil properties puts the plunger 24 under tension ready to "pop" back into the tapered hole 30 upon leg extension.
To lock the locking mechanism 20 in an unlocked mode, the male part 34 would be turned an additional distance. This would cause the displacement pins 42 to slide further up the ramps 46 and drop down slightly to fix on a plateau 52 on the female part 36 that is half the height of female ramp 46 incline. The male part 34 is then fixed on plateau 52 which is high enough to raise the plunger 24 out of the tapered hole 30. A safety dowel 54 is positioned in a preferred embodiment against only one of the three ramps 46 to prevent overturning of the male part 34 when locking in an unlocked mode.
Since brace wearers either need to have their joint (knee, ankle, hip, etc.) locked or unlocked, the feature enabling locking in an unlocked position is an enhancement for testing clients with or without their joint locked. Once the position is decided, the plunger 24 could be put in the optimum position and kept there.
If locking is never desired, then the locking mechanism 20 can be replaced by a round barrel 58(a), 58(b), or 58(c) mounted on the brace to fit in the cutout 26. The round barrel 58(a), 58(b) or 58(c) would simply be used to limit the range of motion of the joint. The diameter of the barrel 58(a), 58(b), or 58(c) would determine where the joint was stopped when extended. Three barrels 58(a)-58(c) of different diameter are shown together in the range-of-motion cutout 26 for comparison. Only one barrel would be used at a time depending on the degree stop desired. The larger the diameter, the larger the degree of stop because the barrel edge 20 would hit the edge of the range-of-motion cutout 26 sooner when the leg extends.
The same disk 28 can be used with locking mechanism 20 or barrels 58(a)-58(c). The barrels are attached to the inner surface of the disk portion of thigh section 14. The stopping screw and barrel 58(a), 58(b) or 58(c) attaches in the same place as the locking mechanism 20. Either the stopping barrel 58(a), 58(b) or 58(c) or the locking mechanism 20 would be used, and they would not be used at the same time.
Turning now to FIG. 18, an alternate embodiment of the present invention is shown which utilizes the plunger shown in FIGS. 10 and 11 and a stationary female part 72 which is mounted to an orthotic joint in the same manner as female part 36. This locking mechanism is engaged simply by pulling on ring 74 to pull the plunger 24 out of engagement with hole 30 and cutout 26.
The joint described above is intended for use in any long-term orthotic joint candidates. The joint should be incorporated into a typical custom-made vacuum-formed brace such as the hip orthosis shown in FIG. 19. Because of its light weight, a brace incorporating this joint would not require the use of aluminum and/or steel sidebars or steel joints. As a result, the brace would be considerably lighter which would make it useful not only with the elderly but with children as well. Although in the preferred embodiment, the various components are manufactured through polypropylene vacuum-forming, the brace could also formed using composite resin which would make it a stronger brace.
Orthotic joints are also preferably marketed in kits and sold to orthotic practitioners who have the ability to vacuum-form their own orthoses. The kits would preferably contain a one-quarter inch thick plastic disk 28 approximately two and three-eighths inches in diameter. The one quarter inch thick disk 28 would have a range-of-motion cutout 26 which would be approximately one-eighth inch deep. The knee locking mechanism 20 would also be pre-assembled in the kit. If barrels 58(a)-58(c) were used instead of the locking mechanism 20, the one-quarter inch plastic disk 28 would also still be used. There also could be an adaptable extension lever that could be sold with the locked knee kit for the physically challenged that could not reach down to unlock the knee. This would be an extension fulcrum lever.
While the foregoing invention has been described with reference to its preferred embodiments, various alterations and modifications will become apparent to one skilled in the art. All such alterations and modifications are intended to fall within the scope of the appended claims.
What is claimed is:
1. An orthotic brace comprising:a first molded support member and a second molded support member, said first and second support members being shaped so that when mated at adjacent ends said first and second support members rotate about a common axis; a disk positioned between said mating portions of said adjacent ends of said first and second support members, said disk including an arc-shaped cutout on one surface of said disk, said cutout extending only partially through the depth of said disk; means mounted to one of said first and second support members for passing into said cutout to limit the range of motion of said first support member relative to said second support member.
2. The orthotic brace of claim 1 wherein said means mounted to one of said first and second support members is a locking mechanism comprising:a female part having an opening therethrough; a male part to which a spring-loaded plunger is connected, said spring-loaded plunger having one end with dimensions small enough to allow said one end to pass through said opening through said female part.
3. The orthotic brace of claim 2 further comprising means for keeping said male and female members separated from each other.
4. The orthotic brace of claim 3 wherein said means for keeping said male and female members separated from each other comprises displacement pins mounted on a surface of one of said male and female members.
5. The orthotic brace of claim 3 wherein said means for keeping said male and female members separated from each other comprises ramps extending from a surface of one of said male and female members.
6. The orthotic brace of claim 4 further comprising ramps extending from a surface of one of said male and female members.
7. The orthotic brace of claim 2 wherein said spring-loaded plunger is a compression spring plunger.
8. The orthotic brace of claim 2 wherein said spring-loaded plunger is a torque spring plunger.
9. The orthotic brace of claim 2 further comprising means for locking said locking mechanism in an unlocked position.
10. The orthotic brace of claim 9 wherein said means for locking said locking mechanism in an unlocked position comprises a second surface positioned above a surface of said male or female part to which it is attached.
11. The orthotic brace of claim 1 wherein said means to limit the range of motion has dimensions small enough to allow it to fit within said arc-shaped cutout.
12. The orthotic brace of claim 11 wherein said range of motion limiting means is a barrel mounted on one of said molded first and second support sections so that when said disk with said arc-shaped cutout is positioned adjacent said barrel said barrel fits within at least a portion of said arc-shaped cutout.
| 1995-04-03 | en | 1997-05-20 |
US-20323998-A | Distributed resistance leadwire harness assembly for physiological monitoring during magnetic resonance imaging
ABSTRACT
A leadwire harness system is used for recording an electrocardiogram (ECG) during magnetic resonance imaging (MRI). The system includes a set of leadwires each having a nichrome wire helically wound on a bundle of glass or other high strength fibers and surrounded by an insulating jacket to provide for uniformly distributing the high resistance within each leadwire so that the eddy currents generated by the rapidly changing magnetic field are greatly reduced. The set of leadwires are twisted within a surrounding tube of foam insulation. The reduction of the eddy currents dramatically reduces MRI image distortion as well as the potential for localized heating and skin burns under the ECG electrodes used with the harness system.
RELATED APPLICATION
This application claims the benefit of provisional patent appication Ser. No. 60/069,147, filed Dec. 9, 1997.
BACKGROUND OF THE INVENTION
Magnetic Resonance Imaging (MRI) is a relatively new technique used in medicine to investigate in great detail the condition of the human body. The patient is typically placed supine on a moveable horizontal table which is moved through rapidly changing and intense magnetic fields. Detailed information on the interior of the body can be obtained by computer analysis of the magnetic resonance produced by the rapidly changing magnetic fields. In many instances, the information obtained from MRI is more detailed than the information available from the use of X-Ray and at less risk to the patient. Because the patient undergoing MRI is sick for one reason or another and because the MRI experience is often traumatic, it is important that the physiological state of the patient be monitored.
The room in which the MRI is performed is highly shielded, with monitoring equipment placed in an adjacent room. The patient connections are typically fed through the shielded wall to the monitoring equipment. While the shielding isolates the monitoring equipment from the intense, rapidly changing magnetic fields generated by the MRI equipment, the leadwires which extend from the patient and through the shielded wall are subjected to this intense magnetic field. The rapidly changing magnetic fields induce high level noise signals into the physiological monitoring leads, and these noise signals can interfere with MRI image, as well as the physiological monitoring image, and this can cause localized heating and skin burns under the physiological monitoring electrodes.
U.S. Pat. No. 4,991,580 discloses a method to improve the quality of an Electrocardiogram (ECG) by reducing the high level noise signals induced into the cardiac monitoring leads. This is accomplished by employing special circuitry in the room with the ECG monitoring equipment in order to reduce the noise and amplify the ECG signal. However, this patent does not address the problem of skin heating or burns that also result from the eddy currents that produce this noise.
U.S. Pat. No. 5,445,162 discloses a method to reduce the amount of magnetic metal and associated Electroencephalogram (EEG) equipment outside of the bore of the MRI magnet and possibly outside of the MRI room. The intent is to reduce distortion of the MRI and also to obtain an EEG during Magnetic Resonance Imaging. The patent mentions the induction of significant current flow in electrodes and wires within the magnetic field and the possibility of these currents producing localized heating or burns under EEG electrodes connected to the patient's scalp. However, this patent does not attempt to resolve the possibility of burns under the monitoring electrodes. A similar phenomena occurs under ECG electrodes connected to the patient and located within the rapidly changing magnetic fields of the MRI system.
Van Genderingen et al (Radiology 1989) discloses a system of using carbon fiber electrodes and leads for obtaining an ECG during cardiac gating with MRI. The primary goal was to reduce the amount of distortion of the gradient magnetic field and the corresponding image distortion and artifact caused when metallic electrodes and leads are used. The electrical resistance of the carbon fiber leads was around 1,000 ohms. While this resistance reduces distortion, it is insufficient to prevent patient burns.
U.S. Pat. No. 4,951,672 discloses a leadwire designed specifically to monitor ECG signals during MRI and provide protection from unwanted heating under monitoring electrodes. The patent recognizes the need for the ECG leadwires to have a high resistance in order to reduce the possibility of heating under the electrodes, but the solution was to mold metal film resistors, of the 33k ohm to 10k ohm range, in the electrode connector of the wire. Since this produced a hot spot at the electrode connector, the patent discloses the inclusion of resistor modules along the length of the wire. However, the resistor modules result in producing many hot spots. The patent also mentions that the resistance could be distributed over the length of the leadwire. From the drawings, this must mean that if enough resistor modules are added along the length of the wire, the heat can be evenly spread, thereby reducing the possibility of burns. In actual practice, this proposed solution cannot work well. As the multiple of resistor modules increases, so does the number of hot spots, and the resistance is not uniformly distributed along the length of the wire.
Pat. No. 4,280,507 discloses a "Patient Cable with Distributed Resistance Protection in Conductors". In this patent, the concept of distributed resistance is employed. However, the protection this device provides is protection of the ECG monitor circuitry from the extreme electrical pulses that are present at the patient's ECG electrode sites when the patient is defibrillated while still connected to the ECG monitor via the ECG electrodes and cable/wires. The device is not designed to provide patient protection from heating or burns. Moreover, the use of carbon loaded polymers for a distributed resistance conductor, limits how high of resistance can be employed and how tight of a resistance tolerance that can be maintained.
SUMMARY OF THE INVENTION
The present invention is directed to a leadwire harness system for obtaining physiological patient information during an MRI process, and which dramatically reducing the possibility of patient burns under the physiological monitoring electrodes, while also reducing image distortion on the MRI unit.
The above identified problem is solved by the current invention by making the leadwire conductor itself the high resistance. By using a high resistance nichrome conductor which is helically wound around a fiber core, the exact resistance per foot of finished wire can be very tightly controlled by the number of turns of the conductor per linear foot of finished wire stock. As a result, the resistance is distributed evenly and uniformly from one end of the wire to the other, which results in even heating of the wire from one end to the other, with no spots of high concentrated heat. The wire is jacketed by a high temperature plastic layer, and a multiple of the wires form one assembly which is jacketed by a tube of high temperature foam so that the patient is not in contact with any hot wire.
The present invention overcomes problems not completely resolved in the prior art. By providing a uniformly distributed higher-than-normal resistance within the ECG leadwire system, the effect of eddy currents generated by the rapidly changing magnetic field of the MRI unit, is greatly reduced. The reduction of these eddy currents dramatically reduces the potential for MRI image distortion and the localized heating and skin burns under ECG electrodes used in conjunction with this system, especially if the electrodes are non-magnetic and essentially non-metallic.
The present invention makes use of a considerably higher resistance, for example, on the order of 2,500 to 10,000 ohms per foot. Thus, for a six foot cable, this resistance totals around 15,000 to 60,000 ohms. As the resistance in the individual leads (e.g. RA, RL, LA, LL) increases, it becomes increasingly important for these resistances to be closely matched. The difference in the individual lead resistances will cause problems with the common mode noise rejection of the ECG monitor, if it becomes excessive. This means that the tolerance or variation of the individual leadwire resistances must be well controlled. In one embodiment, the distributed resistance between any two of the leadwires varies less than 1%.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a leadwire harness system or assembly onstructed in accordance with the invention, and attached to a pad of medical electrodes;
FIG. 2 is a greatly enlarged fragmentary section of one of the conductors shown in FIG. 1;
FIG. 3 is a fragmentary perspective view of the non-conductive fibrous core and helically wound resistance wire shown in FIG. 2; and
FIG. 4 is an enlarged fragmentary section of the harness assembly, taken generally on the line 4--4 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment of the invention, a harness assembly 10 includes a set of four leadwires 12 each having a very fine nichrome conductor wire 13 with a diameter on the order of 0.0015 inch. Each wire 13 is helically wrapped or wound around a corresponding non-conductive fibrous core such as a glass fiber core 14 for support. Each core has a length of about six feet and provides both strength and flexibility which dramatically increases the tensile strength and flex life of the composite wire and core sub-assembly 15. The fiberglass core 14 also allows close control of the nichrome wrapped wire 13 which has a length of about 1440 inches for the six foot core. This produces a very uniformly distributed resistance along the length of the core 14. In one embodiment, the distributed resistance of each of the leadwires varies less than 5% along the length of the leadwire.
In one embodiment, each wire 13 has a resistance of 2,500 ohms per foot. However, the field strength of MRI units may eventually increase in order to shorten the MRI scan time. It is thus within the scope of the present invention to increase the resistance per foot in order to remain below the eddy current threshold for patient burns. This is readily accomplished by increasing the resistance per foot, for example, to 10,000 ohms per foot, if necessary. However, since higher resistance requires tighter tolerances in resistance, the illustrated embodiment is 2,500 ohms per foot.
To provide a high level of patient safety, pinch-type electrode connectors 16 are connected to the patient ends of the wires 13 and form part of the harness assembly 10. The connectors 16 are both non-magnetic and non-metallic. The harness assembly 10 is preferably used with medical electrodes 18 which are also non-magnetic and essentially non-metallic with one leadwire 12 for each electrode 18. Since the individual wires 13 can become hot to the touch during use (as high as 150 degrees Celsius for short durations), each wire 13 is insulated with a high temperature plastic layer 22 (FIG. 2), such as ETFE or other comparable engineering grade polymer. In addition, the group of four leadwires 12 for the harness system 10 is jacketed by a soft, highly flexible, high temperature silicone foam tubing 25 (FIG. 4).
The electrode connector ends of the leadwires 12 are very short and extend from the foam insulation. As a result, the patient cannot come into contact with any component that has an elevated temperature. A tubular rubber-like collar 26 (FIG. 4) surrounds each end portion of the tubing 25 and encloses a washer 27 and a plastic band or tie 28 which is clamped to the leadwires 12. Metal terminal pins or connectors 30 are attached to the inner ends of the leadwires 12, as shown in FIG. 1.
The group of leadwires 12 of the assembly 10, with the individual conductor wires 13 being helically wound around their respective cores 14, are twisted or helically wound around each other from end to end to provide, preferably, about nine complete turns within the foam insulation tube 25 which has a length of about six feet. This twisted arrangement of the leadwires 12 causes the eddy currents to somewhat cancel each other and further helps to reduce the distortion of the gradient magnetic field and the corresponding distortion of the MRI image.
While the form of leadwire harness assembly and the method of producing the assembly constitute a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of harness assembly and method, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.
The invention having thus been described, the following is claimed:
1. An improved leadwire system adapted for connecting a plurality of physiological monitoring electrodes on a living body to a physiological monitoring device and for minimizing the risk of burns under the monitoring electrodes and for reducing image distortion on a scanning device, said leadwire system comprising a plurality of leadwires each including a high resistance conductor helically wound around an electrically insulating fibrous core, a layer of high temperature thermal insulating material surrounding each said conductor and providing a generally uniformly distributed high resistance along the length of each leadwire, said plurality of leadwires having means for reducing gradiant noise on the monitoring device, a jacket of high temperature thermal insulating material surrounding said plurality of leadwires, each said leadwire having one end portion adapted to be connected to a corresponding monitoring electrode, and each said leadwire having an opposite end portion adapted to be connected to an input of the monitoring device.
2. A leadwire system as defined in claim 1 wherein each of said leadwires has a substantially uniformly distributed electrical resistance of at least 2500 ohms per foot.
3. A leadwire system as defined in claim 1 wherein said electrical conductor of each said leadwire is substantially non-magnetic.
4. A leadwire system as defined in claim 3 wherein said conductor of each said leadwire comprises a nickel-chrome alloy.
5. A leadwire system as defined in claim 1 wherein said insulating fibrous core of each said leadwire comprises a bundle of glass fibers.
6. A leadwire system as defined in claim 1 wherein said plurality of leadwires are twisted around each other as a group between opposite ends of said jacket to provide said means for reducing gradiant noise.
7. A leadwire system as defined in claim 1 wherein the distributed resistance of each of said leadwires varies less than 5% along the length of said leadwire.
8. A leadwire system as defined in claim 1 wherein the distributed resistance between any two of said leadwires varies less than 1%.
9. A leadwire system as defined in claim 1 wherein said one end portion of each said leadwire is connected a by non-magnetic and non-metallic connector.
10. A leadwire system as defined in claim 1 wherein said jacket of high temperature thermal insulating material comprises an extruded tube of flexible foam material.
11. A leadwire system as defined in claim 1 wherein each of said leadwires has a substantially uniformly distributed electrical resistance within a range of about 2500 to 10,000 ohms per foot.
12. A leadwire system as defined in claim 1 and including a non-magnetic and non-metallic spring biased pinch connector attached to said one end portion of each said leadwire.
13. An improved leadwire system adapted for connecting a plurality of physiological monitoring electrodes on a living body to a physiological monitoring device and for minimizing the risk of burns under the monitoring electrodes and for reducing image distortion on a scanning device, said leadwire system comprising a plurality of leadwires each including a high resistance conductor helically wound around an electrically insulating fibrous core, a layer of high temperature thermal insulating material s surrounding each said conductor and providing a generally uniformly distributed high resistance along the length of each leadwire, said plurality of leadwires being twisted as a group for reducing gradiant noise on the monitoring device, a tubular jacket of high temperature thermal insulating material surrounding said twisted group of leadwires, a first releasable connector secured to one end portion of each said leadwire for releasably connecting said leadwire to a corresponding monitoring electrode, and a second connector secured to an opposite end portion of each said leadwire for releasably connecting said leadwire to an input of the monitoring device.
14. A leadwire system as defined in claim 13 wherein each of said leadwires has a substantially uniformly distributed electrical resistance of at least 2500 ohms per foot.
15. A leadwire system as defined in claim 13 wherein said electrical conductor of each said leadwire is substantially non-magnetic.
16. A leadwire system as defined in claim 15 wherein said conductor of each said leadwire comprises a nickel-chrome alloy.
17. A leadwire system as defined in claim 13 wherein the distributed resistance of each of said leadwires varies less than 5% along the length of said leadwire.
18. A leadwire system as defined in claim 13 wherein the distributed resistance between any two of said leadwires varies less than 1%.
19. A leadwire system as defined in claim 13 wherein said jacket of high temperature thermal insulating material comprises an extruded tube of flexible foam material.
20. A leadwire system as defined in claim 13 wherein each of said leadwires has a substantially uniformly distributed electrical resistance within a range of about 2500 to 10,000 ohms per foot.
21. A leadwire system as defined in claim 13 wherein said first connector comprises a non-magnetic and non-metallic spring biased pinch connector.
22. A leadwire system as defined in claim 13 wherein said group of leadwires has about nine complete turns within about six feet of said tubular jacket.
| 1998-12-01 | en | 2000-02-29 |
US-1843098-A | Image forming apparatus
ABSTRACT
An image forming apparatus provided with a memory which stores predetermined data, receiver which receives data via a communications line, a first modifier which changes predetermined data based on data received by the receiver, a second modifier which changes predetermined data based on data input from an operation panel provided on the apparatus, wherein modification of predetermined data by the first modifier is allowed and modification of predetermined data by the second modifier is prohibited insofar as data can be transmitted via the communications line.
This application is based on application No. Hei 9-22535 filed in Japan, the content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus capable of receiving data through a communications line.
2. Description of the Related Art
Image forming apparatuses such as copiers and the like are widely used today.
Copiers are installed and used in various types of companies and offices as well as so-called convenience stores and the like.
Many companies and offices have multiple copiers, and even many franchise-related convenience stores have installed multiple copiers.
In the aforesaid situations, there are times when, for example, specific information must be collected from a plurality of copiers, or conversely information must be input to a plurality of copiers. More specifically, consider collecting and totaling at one location the copy number of a plurality of copiers, clearing the copy number counters of a plurality of copiers from one location, and managing from one location various maintenance information such as parts replacement and repair and the like for a plurality of copiers.
Each such copier is used independently without communications lines. Accordingly, such copiers are constructed so as to allow information input and output using an operation panel or the like. Even when copiers are linked to a communications line, there is the possibility that each copier contains information unique to that particular copier, such that even though information may be input and output via the communications line, such information is normally input and output using an operation means provided on each copier.
On the other hand, when managing as a group a plurality of copiers linked by a communications line, there is the possibility of generating input errors when data input from each copier is subjected to modification. Disadvantages arise when information containing input errors are data that may produce a large variance in result. Furthermore, data such as may generate skewing of sequential data between copiers as in clock data may be managed in one location to modify or revise data simultaneously in all copiers from the single location. Complex or troublesome data may also be managed in batches so as to be periodically revised in each copier, and in this instance also may be managed in one location to modify or revise data simultaneously in all copiers from the single location.
Therefore, the operational states and functional states and the like of a plurality of copiers can be managed in one location. Such copiers are provided functions to communicate with a predetermined location such as a management center or the like.
Copiers provided with communications functions are subject to the following disadvantages. Even copiers provided with communications functions are typically also provided with data input/output means so as to be capable of inputting and modifying data locally in the manner of conventional copiers. On the other hand, copiers provided with communications functions are constructed so as to be capable of inputting and modifying the same data from a predetermined location using the communications functions.
In copiers provided with communications functions, data can be modified using the specific data input means of each copier even though specific important data are input to each copier from a predetermined location as in the case of centralized management. As a result, disadvantages arise in that such dual input means hinder centralized management.
For example, specific data under centralized management such as date and time of tracking materials of document creation to be printed on copy sheets can be disadvantageously modified locally on each copier even though the data has been modified in a batch from the management center.
SUMMARY OF THE INVENTION
An object of the present invention is to eliminate the previously mentioned disadvantages.
A further object of the present invention is to provide an image forming apparatus that does not hinder batch management of copiers.
Another object of the present invention is to provide an image forming apparatus that restricts data input/output and data modification from an operation panel.
Still another object of the present invention is to provide an image forming apparatus that does not allow modification of data input via a communications line from the local copier under predetermined conditions.
These and other objects are attained by providing an image forming apparatus comprising a memory to store predetermined data, first and second modifier to modify predetermined data in the memory, and controller to permit modification of the predetermined data by the first modifier and prohibit modification of the predetermined data by the second modifier under predetermined conditions.
The aforesaid objects of the present invention are further attained by providing an image forming apparatus comprising a memory to store predetermined data, receiver to receive data through a communications line, first modifier to modify predetermined data based on data received by the receiver, second modifier to modify predetermined data based on data input from an operation panel provided on the apparatus, and controller to permit modification of predetermined data by the first modifier and prohibit modification of predetermined data by the second modifier under conditions allowing reception of data through the communications line.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will become apparent from the following description of the preferred embodiments thereof taken in conjunction with the accompanying drawings, in which:
FIG. 1 briefly shows the construction of a digital color copying apparatus of the present invention;
FIG. 2 is a plan view of an operation panel of the digital color copying apparatus;
FIG. 3 illustrates the date and time screen displayed on the operation panel;
FIG. 4 is a block diagram of the electrical circuits of the digital color copier;
FIG. 5 shows the copier group connected to central management centers via communications lines;
FIG. 6 is a flow chart of the main routine of the central processing unit (CPU); and
FIG. 7 is a flow chart of the data modification process routine.
In the following description, like parts are designated by like reference numbers throughout the several drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention are described hereinafter with reference to the accompanying drawings.
FIG. 1 shows the general construction of a digital color copier of the present invention. This digital color copier broadly comprises an image reading unit 100 to read documents, and copying unit 200 to reproduce the read image data.
Image reading unit 100 comprises a scanner 10, exposure lamp 12 to illuminate a document, rod lens array 13 to condense the reflected light from an illuminated document, and a sealed-type charge-coupled device (CCD) color image sensor 14 to convert condensed light to electrical signals. Scanner 10 is driven by a scanner motor 11 so as to move in the arrow direction (subscan direction) to scan a document placed on document platen 15 when reading a document. Image sensor 14 converts the reflected light from the document surface to electrical signals of three colors red (R), green (G), blue (B). The R, G, B electrical signals are converted to 8-bit gradient data by image signal processing unit 20, and subsequently stored in synchronizing buffer memory 30.
In copying unit 200, a printhead 31 generates laser diode drive signals by digital-to-analog (A/D) conversion of input gradient signals, and emits a laser beam based on the drive signal. The laser beam irradiates the surface of a rotatable photosensitive drum 41 via a reflecting mirror 37. The surface of photosensitive drum 41 is irradiated by eraser lamp and uniformly charged by charger 43 prior to the optical exposure of each formation of toner image cyan (C), magenta (M), yellow (Y), and black (Bk). When the surface of photosensitive drum 41 is subjected to optical exposure in the aforesaid condition, an electrostatic latent image of a document is formed on the surface of photosensitive drum 41. Thereafter, only one among the cyan (C), magenta (M), yellow (Y) black (Bk) toner developing devices 45a˜45d is selected to develop the electrostatic latent image formed on the surface of photosensitive drum 41. A copy sheet of a desired size is fed from one of three paper cassettes 50. The leading edge of a fed copy sheet is chucked by a chucking mechanism 52 on transfer drum 51, so as to be held on the drum 51 without dislocation during the image transfer. A developed toner image is transferred to the copy sheet wrapped around transfer drum 51 via a transfer charger 46.
The aforesaid transfer process is sequentially repeated for the four color cyan (C), magenta (M), yellow (Y), black (Bk). At this time, scanner 10 repeats the scanning operation synchronously with the operation of photosensitive drum 41 and transfer drum 51. Thereafter, the copy sheet is separated from the transfer drum 51 via the operation of a separation member 47, and passes through fixing device 48 which fuses the toner image to the sheet which is then ejected to a discharge tray 49.
FIG. 2 shows a plan view of operation panel 16. Operation panel 16 is provided with a display 161, print key 162 to start a copy operation, stop key 163 to stop a copy operation, ten-key pad 164 to set the copy number and the like, clear key 165 to clear numerical values set by the ten-key pad, panel reset key 166 to reset the panel, and time setting key 167 described later.
Display 161 is a touch-panel type liquid crystal display, which allows input and setting of the copy mode, copy number and the like by pressing the various setting and selection buttons displayed on the display panel as well as input of settings and the like via the ten-key pad 164.
Display 161 displays the copy mode, copy number and the like set by the user.
This copying apparatus is provided with q clock CL (refer to FIG. 4) described later. The current date and time in this copying apparatus can be displayed on display 161 via time setting key 167. In this display state, the date and time can be updated by operating the ten-key pad 164 as described later. This update is accepted only under conditions which are described later.
FIG. 3 shows an example of a screen displayed on display 161 via the operation of time setting key 167. In this example, the date and time displayed in the top level have been changed by input from the ten-key pad, and the date and time displayed in the bottom level show the current internal values. When the OK! button is pressed on the screen in this state, the modified date and time displayed in the top level is displayed in the internal date and time windows in the bottom level, and the current date and time is changed to the displayed values. Then, the date and time modification process ends when the Ex! button is pressed on the screen.
FIG. 4 is a block diagram of the electrical circuits of the image signal processing unit 20 and the like of a digital color copier. The RGB image data of a document read by CCD color image sensor 14 are subjected to analog-to-digital (A/D) conversion and shading correction in the preprocessing unit 141 within image signal processing unit 20, and thereafter subjected to predetermined gradient correction in γ-correction unit 142. Gradient-corrected data are temporarily stored in image memory 144 via memory control unit 143. Two-dimensional addresses including an x-coordinate (main scan direction) and y-coordinate (sub-scan direction) of a document are set in image memory 144, and the RGB image data and 8-bit attribute data are stored for each pixel.
Image data are read out to color conversion unit 145 with a timing matching the operation timing of each color in the image forming unit. In color conversion unit 145, the RGB image data read out from image memory 144 are converted to 8-bit gradient data of either cyan (C), magenta (M), yellow (Y), or black (Bk), and output. Color-converted data are then converted to analog signals in D/A conversion unit 146. Laser control unit 150 in printhead 31 generates laser drive signals based on the analog signals output from D/A conversion unit 146 so as to drive laser diode 151.
The information relating to various copying conditions set from operation panel 16 by a user is stored in control memory 148. Central processing unit (CPU) 160 reads the information stored in control memory 148, and executes control sequences for the read signal processing unit 20 and printhead 31 based on the read data. Other input controls during copy execution and communication controls with other CPUs are executed via input/output control integrated circuit (IC) 147. The operation panel 16 is also connected to CPU 160. Input/output control IC 147 is connected via communications lines such as telephone lines or the like to, for example, the computer of a central management facility CENT such as a copier management center in a company or office, management center which mainly manages a plurality of franchise stores (hereinafter referred to as "center") or the like.
FIG. 5 shows the connection state via communications lines. In FIG. 5, COPY1˜COPYn refer to the aforesaid plurality of digital color copiers. Copiers of specific groups of the aforesaid copiers are connected to center CENT (CENT1) via communications line L, and copiers of other groups are connected to center CENT (CENT2) via communications line L.
The clock CL is connected to CPU 160 shown in FIG. 4. The current date and time are displayed on display 161 via the operation of date/time setting key 167 by clock CL.
CPU 160 also controls the general operation of the copier. Each center CENT can transmit predetermined data suitable for central management (e.g., in this instance, currently correct date and time data, threshold data, and telephone numbers) to each copier.
Threshold data are used by the preventive maintenance counter and jam counter. That is, if the preventive maintenance counter value attains a threshold value, a parts replacement request is transmitted to the center. Similarly, when the jam counter value attains a threshold value, a maintenance request including parts replacement is transmitted to the center.
Telephone numbers are used by the supervisor to telephone the center.
The data updating process executed by CPU 160 shown in FIG. 4 is described below.
FIG. 6 is a flow chart showing the main routine of CPU 160. One subroutine of this main routine is the data updating process.
As shown in FIG. 6, CPU executes initialization when the program starts, and an internal timer is started (step S1 and S2). Thereafter, the data updating process, copy operation process, and other processes are sequentially executed (steps S3, S4, S5), and the end of the internal timer is awaited in step S6, whereupon the routine returns to step S2.
FIG. 7 is a flow chart of the data updating process. In the data updating process of step S3 of the main routine, first, a check is made to determine whether or not data have been input to the device (S31). If data have not been input, the subroutine returns to the main routine. When data have been input, a determination is made as to whether the input data are date and time data, threshold data, or telephone number data (S32˜S35). When the input data are none of the aforesaid data types, data are updated based on the input data (S37). When the reply to the query of steps S32˜S35 is YES, a determination is made as to whether or not the data have been input via the communications line (S36). If the data have been input via the communications line, the internal copier data are updated in accordance with the input data (S37).
On the other hand, if the data have not been input via the communications line, i.e., if the data have been input from operation panel 16 of the copier, the routine advances to step S38. In step S38 a check is made to determine whether or not the copier is able to communicate with the center. When the reply to the query of step S38 is NO, the internal copier data are updated in accordance with the input data. When the reply to the query of step S38 is YES, however, the routine returns without data updating.
That is, the internal data of the copier is updated even when the input data are date data, time data, threshold data, or telephone number data insofar as the copier cannot communicate with the center. Data are not updated when the input data have not been transmitted via the communications line and the copier is able to communicate with the center.
After data have been input via the communications line, changing the date and time data on the copier side via the operation panel 16 is prohibited insofar as the copier is connected to and able to communicate with the center CENT.
In this example, once a copier is connected to and able to communicate with the center CENT, updating of date and time data and the like via the operation panel 16 of the copier is prohibited even though date and time data have not once been received from the center CENT. Normally, when a copier is connected to the center via a communications line, date and time data and the like will be quickly transmitted from the center to the copier to update the date and time data in the copier.
When a copier cannot communicate with the center because either the copier or the center have not yet been connected to the communications line, it is permitted to update the date and time data and the like on the copier side.
The date and time data and the like are printed on copy sheets in the copy operation process (step S4) of the main routine.
In the aforesaid copier, accurate date and time data, threshold data, and telephone number data may be entered in the copier using the communications line from the center that manages the copier. This process eliminates the trouble of inputting and updating date and time data, threshold data, and telephone number date to the copier, and prevents data discrepancies among the copiers.
Furthermore, when correct date and time data have been input to the copier from the center, it is by design subsequently prohibited to update the same data on the copier side, which is safer than allowing the data to be updated or corrupted on the copier side.
Printing of date and time data and the like transmitted from the center on copy sheets prevents counterfeiting of currencies, stock certificates and other negotiable securities on the copier, and provides tracking material for securities crimes such as forgery of currency or stock certificates.
When a date and time data have not yet even once been received by the copier from the center even though the copier can communicate with the center, the same data can be updated on the copier side, and after the date and time data and the like have once been received by the copier from the center, the date and time data, threshold data, and telephone data cannot be updated on the copier side, and a process such as Have date and time data, threshold data, and telephone number data been received from the Center?! may be substituted for the process of step S38.
Although the aforesaid example has been described in terms of date and time data, threshold data, and telephone data as the specific data transmitted from the center to each copier, it is to be noted that other data (e.g., copy number, user name, department, maintenance information, maintenance record, various internal settings, priority sequence of internal settings, serial number of the copier and the like) may be used.
The copying apparatus of the present invention may be provided with a means to print predetermined data on copy sheets.
When the present invention is provided with the means to print data, examples of the predetermined data include current date and time data that can be used to prevent counterfeiting of currencies, stock certificates and other negotiable securities on the copier, and provide tracking material for securities crimes such as forgery of currency or stock certificates.
Copiers used to counterfeit currency and the like are typically full color copiers.
The present copying apparatus of the present invention uses a communications line from a specific location to input accurate predetermined data in each copier under the management of the specific location. As a result, the trouble of inputting and updating data to each copier is eliminated, and data discrepancies among copiers is prevented.
When predetermined data are input to each copier via a communications line, modifying the predetermined data using the data input means of the local copier is prohibited. Therefore, the present invention is by design safer in preventing data modification and data corruption on the copier side.
As described above, the present invention is a copying apparatus provided with a data input means to input predetermined data, and receives the predetermined data via a communications line to update the predetermined data based on the received data, and the copying apparatus is safer inasmuch as the data are input from a communications line and modification and corruption of the data is prevented on the copier side.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modification will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.
What is claimed is:
1. An image forming apparatus, comprising:a memory which stores predetermined data; first and second modification means for modifying the predetermined data in the memory; and control means for permitting modification of the predetermined data by said first modification means and for prohibiting modification of the predetermined data by said second modification means under a predetermined condition.
2. An image forming apparatus according to claim 1, further comprising:receiving means for receiving data through a communication line; and inputting means for inputting data.
3. An image forming apparatus according to claim 2, wherein said first modification means modifies the predetermined data based on data which is received by said receiving means, and said second modification means modifies the predetermined data based on data inputted said inputting means.
4. An image forming apparatus according to claim 3, wherein said inputting means is an operation panel furnished on the apparatus.
5. An image forming apparatus according to claim 3, wherein said predetermined condition is a condition which allows a communication through the communication line.
6. An image forming apparatus according to claim 3, wherein said predetermined condition is a condition after data have been modified by said first modification means.
7. An image forming apparatus according to claim 3, wherein said predetermined data is date data.
8. An image forming apparatus according to claim 3, wherein said predetermined data is time data.
9. An image forming apparatus according to claim 3, wherein said predetermined data is maintenance data which will be used for maintenance of the apparatus.
10. An image forming apparatus according to claim 3, wherein said predetermined data is telephone number.
11. An image forming apparatus according to claim 3, further comprising print means for forming an image of the data on a sheet.
12. An image forming system including an image forming apparatus and a managing apparatus, both of which are connected through a communication line, said system comprising:first modification means for modifying predetermined data stored in said image forming apparatus based on data sent from said managing apparatus; second modification means for modifying the predetermined data stored in said image forming apparatus based on data inputted from said image forming apparatus; and control means for permitting modification of the predetermined data by said first modification means and for prohibiting modification of the predetermined data by said second modification means under a predetermined condition.
13. An image forming system according to claim 12, wherein said second modification means includes an operation panel furnished on the image forming apparatus.
14. An image forming system according to claim 12, wherein said predetermined condition is a condition after the predetermined data have been modified by said first modification means.
15. An image forming system according to claim 12, wherein said predetermined data is date data.
16. An image forming system according to claim 12, wherein said predetermined data is time data.
17. An image forming system including an image forming apparatus and a managing apparatus, both of which are connected through a communication line, said system comprising:first modification means for modifying predetermined data stored in said image forming apparatus based on data sent from said managing apparatus; second modification means for modifying the predetermined data stored in said image forming apparatus based on data inputted by an operator at an operation panel on the image forming apparatus; and control means for permitting modification of the predetermined data by said first modification means and for prohibiting modification of the predetermined data by said second modification means under a predetermined condition.
18. The image forming system of claim 17 wherein said predetermined condition is the condition existing after the predetermined data have been modified by said first modification means.
19. The image forming system of claim 17 wherein the control means permits modification of the predetermined data by said second modification means when no predetermined data is stored in the image forming apparatus.
20. The image forming system of claim 17 wherein the control means permits modification of the predetermined data by said second modification means when the communication line between said image forming apparatus and said managing apparatus is nonfunctional.
| 1998-02-04 | en | 1999-08-17 |
US-87048978-A | Clamping arrangement for supporting raw castings during processing
ABSTRACT
A clamping arrangement to firmly clamp workpieces of variable shape to permit the workpieces to be processed on all peripheral sides includes a rotating platform and a clamping lever. The platform and the lever are separately mounted on the housing of the clamping arrangement. The lever is mounted on the housing by means of a column and a bearing part. The column is fixedly secured to the housing. The bearing part is rotatably and adjustably connected to the column to permit the bearing part to be located at various positions along the length of the column. The clamping lever is pivotably coupled to the bearing part and may be driven by fluid pressure operated cylinders between clamping and releasing positions. The clamping lever has two telescoping parts to permit the portion of the clamping lever which engages the workpiece to be radially adjustable with respect to the column. When the clamping lever is actuated, the workpiece is secured between a conical clamping peg at the free end of the clamping lever and supports on the rotating platform.
This invention relates to a device for clamping workpieces of variable shape so that the workpieces may be operated on different sides thereof without the workpiece being completely removed from the device.
BACKGROUND OF THE INVENTION
Known and conventional means for clamping workpieces for multilateral processing have involved the mounting of workpieces on the periphery of rotary work tables by means of clamping levers supported and attached to the rotary tables. The disadvantage in these devices is that no processing is possible or is greatly restricted on the side of the workpiece where the attachment or support of the clamping lever is located.
Other known clamping arrangements involve the use of magnetic work tables. Although magnetic work tables obviate the disadvantage noted above, they are only suitable for workpieces having flat gripping surfaces and may only be used when relatively small cutting forces are incurred in the processing of the raw casting.
BRIEF DESCRIPTION OF THE INVENTION
It is the object of this invention to provide an arrangement for clamping workpieces in such a manner that the workpieces may be processed by a tool on all sides of the workpiece's periphery without interfering with the movement of the tool and without removing the workpieces from the clamping arrangements, and capable of maintaining a firm gripping action to resist high cutting forces.
Another object of the present invention is to provide a clamping arrangement which may be easily and quickly adjusted to grip workpieces of varying shapes.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description of two preferred embodiments of the present invention.
Briefly described, the invention includes a clamping arrangement for supporting raw castings or other workpieces during processing comprising housing means adapted to be connected to a frame, a platform rotatably mounted on the housing means about a first vertical axis, a column secured to the housing means adjacent to, but outside, the periphery of the platform, the column extending along a second vertical axis, supporting means rotatably mounted on the column about the second vertical axis, and a clamping lever pivotably coupled to the supporting means to permit the lever to move toward the platform to clamp a workpiece therebetween and away from the platform to release a workpiece, the lever including a guiding means and a telescoping arm slidably mounted in the guiding means to permit the telescoping arm to move along a telescoping axis which is disposed radially with respect to the second vertical axis, the telescoping arm having means mounted thereon for engaging the workpiece.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the manner in which the foregoing and other objects are attained in accordance with the invention can be understood in detail, particularly advantageous embodiments thereof will be described with reference to the accompanying drawings, which form a part of the specification, and wherein:
FIG. 1 is a side view of a clamping arrangement in accordance with the present invention;
FIG. 2 is a top view of the clamping arrangement of FIG. 1;
FIG. 3 is an enlarged sectional side view of a portion of the clamping arrangement of FIG. 1;
FIG. 4 is a top view of FIG. 3;
FIG. 5 is a cross-sectional view of the clamping arrangement taken along lines V--V of FIG. 3;
FIG. 6 is an enlarged side cross-sectional view of an alternative embodiment of the clamping lever shown in FIG. 3;
FIG. 7 shows a cross-sectional view of the alternative embodiment taken along lines VII--VII of FIG. 6; and
FIG. 8 shows a cross-sectional view of the alternative embodiment of the gripping lever taken along lines VIII--VIII of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, the clamping arrangement comprises a frame and housing 8, a platform 2 rotatably mounted on the housing 8 about a vertical axis 3, a column 16 secured to the housing 8 adjacent to, but outside, the periphery of the rotatable platform 2, and a clamping device 18 connected to the column 16. A workpiece 15 is clamped between the clamping device 18 and the platform 2.
The platform 2 is attached to a rotary body 5. The body 5 is rotatably mounted to the housing 8 by means of sliding pieces 7 and peripheral groove 6. The peripheral groove 6 is formed in the rotary body 5. The sliding pieces 7 extend inwardly from the housing 8 and into the groove 6 of body 5 to provide a three-point bearing to support the body 5. One of the sliding pieces 7, as shown in FIG. 2, is connected to a hydraulic cylinder 9 which enables that sliding piece to be moved radially within the groove 6. When that sliding piece is in its retracted position, the rotary body 5 is able to rotate relative to the housing 8. When fluid pressure is applied to the hydraulic cylinder 9 and the sliding piece connected to the hydraulic cylinder 9 is forced radially inwardly to engage forcibly the sides of groove 6, the rotary body 5 will be clamped firmly in a fixed position relative to the housing 8. The rotating of the platform 2 is accomplished by means of a hydraulic motor 10 which is attached to the housing 8.
Two arms 11 are fixedly attached to the housing 8 and extend upwardly thereform. The ends of the arms 11 remote from the housing 8 are mounted rotatably in the bearings of two holding arms 12. The arms 11 may be rotated in the bearings about the horizontal axis 4 by a hydraulic motor 13. This arrangement permits the entire clamping structure on the housing to be rotated about the horizontal axis 4. The two holding arms 12 may be attached to a supporting frame (not shown).
Supports 14 are mounted on the platform 2 and are so located thereon so as to correspond with the pertinent support places of the workpiece 15. The pointed shape of the supports 14 ensures a secure engagement between the platform 2 and the workpiece 15.
Column 16 is attached to the housing so that it is adjacent to, but outside of, the periphery of the platform 2. Column 16 extends along a vertical axis 17 which is parallel to the axis 3 about which the platform rotates. Screws 19 secure the column 16 to the housing 8.
The clamping device 18 comprises a clamping lever 20 which is connected to the column 16 by a bearing part 21. The bearing part 21 is connected to the column 16 so that it may rotate about axis 17 and be selectively positioned at various locations along the length of the column 16. A holding mechanism 24 provided on the bearing part 21 secures the bearing part 21 to the column 16. Column 16 is formed with a plurality of annular grooves 25 disposed in parallel relationship to one another along the length of column 16. The holding mechanism 24 includes two sheet metal holder members 26 pivotably attached to the upper front side of the bearing part 21 by screws 27. Projections 28 formed on the inside edges of the holder members 26 are adapted to selectively engage any one of the annular grooves 25. A tension spring 29 is connected to adjacent ends of the holder members 26 to bias the projections toward each other into a groove-engaging position. Handle members 30 are attached to the holder members 26 on the ends thereof remote from the spring 29. The handle members 30 enable the holder members 26 to be pivoted about the screws 27 and against the bias of spring 29 to cause the projections to be removed from an annular groove 25 to permit the bearing part to be moved axially along the vertical length of column 16. When the bearing part is located on column 16 in its desired position, the handle members 30 are released so that the spring 29 forces the projections 28 into the annular groove 25 to hold the bearing part in position. In this manner, the height of the clamping device 18 above the platform 2 may be adjusted.
The clamping lever 20 is pivotably coupled to the bearing part 21. A bolt 31 is provided on the bearing part 21, as clearly shown in FIGS. 3 and 4. Adjacent each end of the bolt 31, a depression 32 is provided on a lower peripheral area of the bolt 31. A ball bearing 33 is located in each of the depressions 32. The balls 33 provide the bearing surface about which the clamping lever 20 pivots. The clamping lever 20 is provided with depressions 34 so that it may also receive the ball bearings 33. The bearing part and the clamping lever 20 are flexibly connected by tension springs 26. The tension springs 36 are suspended between the bolt 31 on the bearing part 21 and the bolt 35 on the clamping lever 20.
Two clamping cylinders 22 are mounted on the bearing part to actuate the clamping lever 20. The clamping lever 20 has a guide part 37 which extends about the bearing part 21. Portions of the clamping cylinders 22 are operably coupled to the guide part 37 to cause the clamping lever 20 to pivot in a clamping direction. On the side of the bearing part, opposite to the side on which the clamping cylinders 22 are located, a clearing cylinder 23 is mounted. A projection 42 extends downwardly from the clamping lever 20 adjacent the clearing cylinder 23. Upon actuation of the clearing cylinder 23, a portion of the clearing cylinder 23 pushes against the projection 42 to pivot forcibly the clamping lever in a releasing direction. The clamping cylinders 22 and the clearing cylinder 23 may be operated at different pressure levels to develop different forces to be applied against the workpiece 15.
A portion of the guide part 37 of the clamping lever 20 comprises a rigid hollow member which extends radially with respect to the axis 17. A telescoping arm 38 is mounted in the hollow member so that it may be shifted along telescoping axis 44. The telescoping arm comprises a bushing 39 fixed within the hollow member and a bar 40 axially slidable, but not twistable, relative to the bushing 39. As shown in FIG. 5, both the bushing 39 and the bar 40 have round guides 43 and flattened portions 45. Some of the flattened portions 45 are oriented in planes parallel to the plane in which the clamping lever 20 pivots. Other of the flattened portions 45 are oriented in planes perpendicular to the plane in which the clamping lever 20 pivots. The engagement of the flattened surfaces on the bushing 39 and the bar 40 prevent the bar 40 from rotating within the bushing 39 about the axis 44.
The transmission of the clamping force in the telescoping arm 38 between the bar 40 and the bushing 39 and between the bushing 39 and the guide part 37 is accomplished on surfaces at 45° relative to the plane in which the clamping lever pivots. This compensates for the lateral clearance between the bushing 39 and the bar 40 and between the bushing 39 and the guide part 37 and cushions the lateral machining forces experienced in processing a casting. The transmission of the forces between the clamping device 18 resp. the bearing part 21 and the column 16 is accomplished at 45° relative to the clamping plane due to the recesses 46 disposed in the bore of the bearing part 21 in direction of the clamping plane and perpendicularly thereto. This also serves to cushion the lateral machining forces developed during processing of a casting.
A clamping peg 41 extends downwardly from the free end of the clamping lever 20. The free end of the clamping peg 41 is preferably formed with a taper at an angle of 90° to provide a friction factor between the workpiece 15 and the peg 41 of 0.45 to 0.48. This permits the adhesive or frictional force required for high machining performance to be achieved with a relatively small clamping force. Since the clamping arrangement of this invention may be employed for the machanical trimming of raw castings by the removal of chips therefrom, the impressions developed in these workpieces by the clamping peg 41 are not objectionable. Such impressions would also develop as a result of a Brinell hardness test.
In operating the clamping arrangement of the instant invention, the first step is to adjust the clamping device 18 on the column 16 to a level corresponding to the workpiece 15. This is accomplished by operating the holding mechanism 24 into and out of engagement with the annular grooves 25 and by moving the bearing part 21 along the length of the column 16. The clamping device 18 is then moved to a lateral position relative to platform 2 as shown in FIG. 2. After the workpiece 15 is placed onto the supports 14 of the platform 2, the clamping device 18 is rotated manually to a position over the workpiece 15 and the clamping peg 14 is placed upon the workpiece in an area in which no processing is to take place. The point at which the peg 41 contacts the workpiece should be selected so as to be as concentric as possible relative to the supports 14. Since the clamping device 18 includes a telescoping arm 38, the clamping point may lie within an area outside the rotary axis 3 of the platform 2. Once the precise clamping point has been located, the two clamping cylinders 22 are actuated at a high pressure level to clamp the workpiece 15 against the platform 2 with a high clamping force. At this time, the processing of a first peripheral side may take place by the processing tool 47.
In order to process the remaining peripheral sides of the workpiece 15, the platform 2 with the workpiece 15 thereon must be rotated relative to the tool 47. The column 16 remains locally fixed. To permit rotation of the platform 2, the two clamping cylinders 22 are actuated at a low pressure level to produce a clamping force between the peg 41 and the workpiece 15 of such a magnitude that the peg 41 may join in the movement about the rotary axis 3. This permits the telescoping arm 38 to move radially with respect to the axis 17 of column 16 and the clamping lever 20 to rotate about the axis 17. After completion of the rotary movement to a desired position, the clamping lever 20 is again firmly pressed against the workpiece by the operation of the two clamping cylinders 22 at a high pressure level.
For processing the front side of the workpiece 15, the entire clamping arrangement may be rotated about the axis 4 through an angle of 90°. In this position it is also possible to process various surfaces of the workpiece lying in the area of the clamping lever 20 by rotating platform 2 in the manner discussed above to make these areas accessible to the processing tool 47. After the processing has been completed and the platform 2 is located in a horizontal position, the clearing cylinder 23 is acted upon with a low pressure to lift the clamping lever 20 from the workpiece 15. The workpiece 15 may then be removed after the clamping device 18 is rotated about axis 17 to a position in which it will not interfere with the removal of the workpiece 15.
FIGS. 6-8 illustrate an alternative embodiment for the construction of the telescoping arm 38. In this embodiment, the telescoping arm 38 is guided by rolling members 50. The clamping lever 20 includes a guide part 37a which embraces the bearing part 21 in the same manner as disclosed in connection with FIG. 3. The bar 40a is slidably mounted in the rigid hollow member of guide part 37a to permit the bar 40a to be shifted along axis 44 but not twisted about the axis 44. A clamping peg 41 is disposed on the free end of the bar 40a to engage a workpiece. Twisting of the bar 40a about the axis 44 is prevented by a peg 61 which is screwed into the bar 40a. The peg 61 is guided in a groove 62 formed in the guide part 37a. A holding piece 63 which is adjustably attached to the guide part 37a by screws 65 has a recess 64. The peg 61 extends into the recess 64. The recess 64 has plate springs disposed therein so as to be on opposite sides of the peg 61 extending into the recess 64. The plate springs 66 are guided by guide pegs 67 of a guide part 68 on the peg 61. The spring forces created on both sides of the peg 61 by the plate springs 66 resiliently position the bar 40a, and thereby the clamping peg 41, in a starting location in the middle of the extent of its sliding movement.
The rolling members 50 comprise balls 51 disposed at 45° angles relative to the plane in which the clamping lever 20 pivots. Two balls are provided in the telescoping arm on the side thereof adjacent to the peg 41 and above the telescoping axis 44. Two additional balls 51 are provided in the telescoping arm on the side thereof adjacent to the column 16 and below the telescoping axis 44. The balls 51 are mounted in elongated recesses 52 in the bar 40a and are held in the middle of the recesses 52 by springs 53. The recesses 52 have radial bores 54 in which pegs 55 are disposed to support the balls 51.
The bar 40a has a central bore 56 in which a flexible rod 57 is located. The rod 57 acts as a spring. The longitudinal axis 58 of the rod 57 is coextensive with the telescoping axis 44. The pegs 55 are supported on the thinner ends 59 of the flexible rod 57 to resiliently support the balls 51 in a radial direction relative to the telescoping axis 44. The balls 51 may also be resiliently supported in a radial direction relative to the axis 44 by means of plate or spiral springs disposed in the radial bores 54.
The bar 40a is provided with flat portions 45a on its periphery which extend parallel to the telescoping axis 44. Some of the flat portions 45a are located in planes parallel to the plane in which the clamping lever 20 pivots. Other of the portions 45a are located in planes perpendicular to the plane in which the clamping lever 20 pivots. The diameter of the bar 40a is slightly less than the internal diameter of the hollow member of the guide part 37a. When the bar 40a is located concentrically relative to the hollow member of guide part 37a, a uniform gap 60 is provided between the bar 40a and the guide part 37a. The balls 51 extend into the gap 60 to support the bar 40a.
The bar 40a is maintained in a concentric relationship with the hollow member of guide part 37a by the resiliently supported balls 51 even when the clamping cylinders 22 actuate the clamping lever 20 against a workpiece 15 with a low clamping force. Since the rod 57 will not flex or will flex only to a very slight degree when the clamping cylinders 22 are operated at a low pressure level, the telescoping arm may be shifted easily along the axis 44 only against the slight rolling friction of the balls 51, despite the fact that a clamping force is being applied to the clamping lever 20. In this manner, only a slight tilting force is developed on a workpiece 15 when the peg 41 is pressed against it eccentrically relative to the axis 3 during rotation of the platform 2, even if the workpiece 15 is relatively high. This slight tilting force is not sufficient to cause the workpiece to tilt on the platform 2.
When the clamping cylinders 22 are operated at a high pressure level, the rod 57 will flex. This causes the balls 51 to retract within the periphery of the bar 40a so that the periphery of the bar 40a comes into frictional engagement with the internal surface of the hollow member of guide part 37a. The frictional engagement of bar 40a and guide part 37a produces a jamming effect which is sufficiently great to prevent the shifting of the telescoping arm along the axis 44 during processing of the workpiece.
From the above description it is clear that a workpiece held in the clamping arrangement of this invention may be processed on all its peripheral sides and in large areas of its front side in a single clamping of the workpiece without the elements of the clamping arrangement significantly limiting the operational area of the work tool. This permits complete removal of the core and divisional burr ridges and of feeders or remains of chamfer in the case of raw castings in a single clamping without great expenditure. The secure manner in which the workpiece is held within the clamping arrangement of this invention permits the arrangement to withstand the high cutting forces which may incurred during processing of the casting. This enables the casting to be processed profitably.
While certain advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
What is claimed is:
1. A clamping arrangement for supporting raw castings or other workpieces during processing comprisinghousing means adapted to be connected to a frame; a platform rotatably mounted on said housing means about a first vertical axis; a column secured to said housing means adjacent to, but outside, the periphery of said platform, said column extending along a second vertical axis; supporting means rotatably mounted on said column about said second vertical axis; and a clamping lever pivotably coupled to said supporting means to permit said lever to move toward said platform to clamp a workpiece therebetween and away from said platform to release a workpiece, said lever including a guiding means and a telescoping arm slidably mounted in said guiding means to permit said telescoping arm to move along a telescoping axis which is disposed radially with respect to said second vertical axis, said telescoping arm having means mounted thereon for engaging the workpiece.
2. A clamping arrangement according to claim 1, wherein said column has a plurality of parallel annular grooves formed therein and spaced along its length, andsaid supporting means has holding means for releasably and selectively engaging each of said grooves to permit said supporting means to be adjustably mounted at various positions along the length of said column, whereby the distance between said clamping lever and said platform may be varied.
3. A clamping arrangement according to claim 1, further including at least one fluid pressure operated clamping cylinder operably coupled to said clamping lever for actuating same at different pressure levels, whereby said clamping lever may be forced against a workpiece with a relatively high pressure during processing and be forced against a workpiece with a relatively low pressure during rotation of said platform.
4. A clamping arrangement according to claim 3, further including a fluid pressure operated clearing cylinder operably coupled to said clampng lever so as to act counter to said clamping cylinder to force said clamping lever to move away from a workpiece placed on said platform.
5. A clamping arrangement according to claim 1, wherein said telescoping arm has guides which are parallel to said telescoping axis and are disposed between 30° and 60° relative to the plane defined by the pivotable movement of said clamping lever.
6. A clamping arrangement according to claim 5, wherein said telescoping arm guides are round and have at their periphery flattened portions which are parallel to said telescoping axis, some at said flattened portions disposed in planes parellel to the plane defined by the pivotable movement of said clamping lever and some of said flattened portions disposed in planes perpendicular to the plane defined by the pivotable movement of said clamping lever, whereby said telescoping arm does not twist within said guiding means.
7. A clamping arrangement according to claim 5, wherein said guides comprise rolling members and means for resiliently supporting said rolling members in said telescoping arm.
8. A clamping arrangement according to claim 7, wherein said means for resiliently supporting said rolling members extend said rolling members beyond the periphery of said telescoping arm to permit said rolling members to roll against said guiding means during movement of said telescoping arm along said telescoping axis when a low clamping force is applied to said clamping lever and retract said rolling members within the periphery of said telescoping arm to permit the periphery of said telescoping arm to engage frictionally the guiding means when a high clamping force is applied to said clamping lever to lock said telescoping arm in a single position along said telescoping axis.
9. A clamping arrangement according to claim 7 wherein said rolling members are balls which are disposed at a 45° angle relative to the plane defined by the pivotable movement of said clamping lever.
10. A clamping arrangement according to claim 9, wherein two balls are provided in said telescoping arm on the side thereof adjacent to said means for engaging a workpiece and above said telescoping axis, and two balls are provided on said telescoping arm on the side thereof adjacent to said column and below said telescoping axis.
11. A clamping arrangement according to claim 10, wherein said means for resiliently supporting said rolling members comprises a bending rod disposed in said telescoping arm, said rod biases and supports said balls in a radial direction relative to said telescoping axis.
12. A clamping arrangement according to claim 11, wherein said rod is located in said telescoping arm so that the longitudinal axis of said rod is coextensive with said telescoping axis.
13. A clamping arrangement according to claim 1, wherein said means for engaging a workpiece comprises a conical clamping peg.
14. A clamping arrangement according to claim 1, wherein said supporting means comprises a bearing part having two balls upon which said clamping lever is pivoted and tension springs connected at their respective ends to said bearing part and said clamping lever, whereby said bearing part is positively connected to said clamping lever.
15. A clamping arrangement according to claim 14, wherein said bearing part has contact surfaces adjacent to said column and disposed between 30° and 60° relative to the plane defined by the pivotable movement of said clamping lever.
| 1978-01-18 | en | 1979-04-17 |
US-2461570-A | Electroacoustic transducer with controlled beam pattern
ABSTRACT
A piezoelectric ceramic disc flexurally drives a thin vibratile diaphragm in its first overtone resonance mode. The center portion of the diaphragm has a displacement which is out of phase with respect to the displacement of the peripheral area of the diaphragm. A sound mask either precludes or selectively controls radiation from the center portion of the diaphragm.
1 States Patent 1 1 1111 3,849,679
Massa Nov. 19, 1974 ELECTROACOUSTIC TRANSDUCER WITH [56] References Cited CONTROLLED BEAM PATTERN UNITED STATES PATENTS Inventor: Frank Massa, Cehasset, Mass- 2,967,957 1/1961 Massa 310/94 3,268,855 8/1966 Hagey 3l0/8.2 X [73] Asslgnee' g Y' h 3,271,596 9/1966 31111116111611 1 1 340/10 0 mg 3,518,460 6/1970 Wood et al. 3l0/8.6 x Mass- 3,577,020 5/1971 Carlson 3l0/8.5 [22] Filed: Apr. 1, 1970 [211 Appl No: 24,615 Primary Exammer-Mark O. Budd Related US. Application Data [57] ABSTRACT [63] Continuation-impart of Ser. No. 10,748, Feb. 12,
1970, p 3,638,052 and a continuatiommpan A plezoelectric ceram1c dlSC flexurally dr1ves a thm of Ser No, 17,430, March 9, 1970, abandone vibratile diaphragm in its first overtone resonance mode. The center portion of the diaphragm has a dis- [52] 11.8. CI 310/8.2, 179/110 A, 310/8.5 pl m n h h is out of phase with respect to the [51] Int. Cl H04r 17/00 p acement of he p ripheral area of the diaphragm. [58] Field of Search 310/8, 82, 8,3, 85, 8,6, A sound mask either precludes or selectively controls 310/9.l, 9.4; 340/10; l79/110 R, 110 A, 110 C radiation from the center portion of the diaphragm.
2 Claims, 6 Drawing Figures PATENTL- TZSV 1 9197 3 INVENTOR.
FRANK MA SSA ELECTROACOUSTIC TRANSDUCER WITH CONTROLLED BEAM PATTERN This is a continuation-in-part of my eo-pending application Ser. No. 10,748, filed Feb. 12, 1970, entitled ELECTROACOUSTIC TRANSDUCERS OF THE BILAMINAAR FLEXURAL VIBRATING TYPE now US. Pat. No. 3,638,052, and co-pending application Ser. No. 17,430, filed Mar. 9, 1970, now abandoned entitled IMPROVEMENTS IN ELECTRO- ACOUSTIC TRANSDUCERS," both of these applications being assigned to the assignee of this invention.
This invention relates to electroacoustic transducers, and more particularly to transducers especially adapted for radiating sound in a controlled beam pattern.
One way to manufacture an electroacoustic transducer assembly is to place 'a transducer element at the open end of a rigid housing structure for transmitting sonic energy. The element may also act as a housing closure. Here, the transducer element includes a vibratile diaphragm driven by a piezoelectric disc, in a complex flexural mode of vibration.
More specifically, it is convenient to operate the vibrating diaphragm at its first overtone circular resonance mode, which occurs at approximately 3.9 times the fundamental resonance frequency. For this overtone mode of operation, the center and outer peripheral portions of the diaphragm have displacements in opposite phase. That is, the center moves up while the periphery moves down, and vice versa, with flexure occurring about an annular node. This selected complex mode of vibration may be used to obtain a relatively broad directional pattern. It is possible to use this vibration mode to transmit relatively high intensity levels of sound in regions which are removed from the normal axis of the diaphragm. This form of transmission secures a more uniform sound distribution over a relatively large area in front of the vibrating diaphragm.
A square, freely suspended bilaminar transducer element may be driven at its fundamental flexural resonant mode. The four corners of this element vibrate in phase with each other. However, the phase of the corner displacements is opposite to the phase of the center displacement. For this type of a transducer element, a sound opaque mask may be mounted in close proximity to the center portion of the vibrating plate. Thus, the center of the flexural plate is not able to radiate the out of phase vibrations into the medium receiving the sonic energy.
Accordingly, an object of this invention is to provide new and improved electroacoustic transducers with better performance characteristics.
Another object of this invention is to provide vibra tile diaphragms which produce concentrated beams of sound radiation at a specific operating frequency.
A further object of this invention is to provide inexpensive diaphragm assemblies which may also act as closures for the open ends of rigid housing structures.
Yet another object of this invention is to provide vibratile diaphragms which operate in desired overtone resonance modes, when driven at a specified frequency.
In keeping with one aspect of the invention, these and other objects are accomplished by providing a vibratile diaphragm driven by a piezoelectric transducer element, which is preferably a ceramic material. The
diaphragm vibrates in a specific overtone mode, selected to provide a beam-like pattern in a sound field. The energy distribution of this sound field is more concentrated in a beam extending outwardly from the transducer, along an axis normal to the surface of the vibratile diaphragm, than it would be concentrated if the same diaphragm were operating at its fundamental resonance mode.
These and other objects. features and advantages of the invention will become more apparent from a study of the following description when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a plan view of the top or diaphragm side of a transducer incorporating one embodiment of this invention;
FIG. 2 is a cross-sectional view of the transducer taken along the line 22 of FIG. 1;
FIG. 3 schematically illustrates the peak amplitude displacement of the diaphragm when it is driven at its first overtone, nodal circle, resonant frequency;
FIG. 4 is a schematic representation of an edgemounted diaphragm with a masking plate closely positioned near the center portion of the diaphragm;
FIG. 5 is another schematic representation, which is similar to the representation illustrated in FIG. 4; however, the masking plate is moved to a preferred distance away from the diaphragm surface; and
FIG. 6 is yet another schematic representation wherein the masking plate is undercut so that only the peripheral edge of the plate is in close proximity to the diaphragm surface.
In FIGS. 1 and 2, a section of cylindrical tubing 10 serves as a housing for the transducer assembly. A steplike annular recess 11 is machined into each end of the inner wall of the cylindrical tubing to provide a shoulder for supporting portions of the transducer assembly, and particularly a bilaminar vibratile assembly 12, 13.
A circular diaphragm 12 has a piezoelectric disc 13 attached to its center by means of a suitable rigid cement, such as epoxy. The relationship between the thicknesses and diameters of the ceramic disc 13, and the clamped diaphragm 12, are selected so that the first overtone concentric resonance mode of the bilaminar assembly, occurs at the desired frequency of operation. as illustrated in FIG. 3. Preferably, the optimum diameter for the piezoelectric disc 13 lies in a range extending from about one-fourth to one-half the diameter of the diaphragm 12. An alternate possibility is to use a ceramic disc 13 which covers the entire surface of the diaphragm 12. Before the diaphragm 12 is inserted into the open end of the housing structure 10, a waterproof cement may be applied to the periphery of the diaphragm. This waterproof sea] is formed between the edge of the diaphragm and the shoulder 11 of the housing surface.
To complete the assembly of the transducer, a sound masking plate structure 15 is positioned over the central part of the disc. This mask comprises a central circular disc portion held by three radial spoke-like members 17-19. A spacing washer 20 is located over the spokes, as illustrated in FIG. 2. Then, the outer edge of the housing wall is crimped over at 21. This crimp locks the outer periphery of the masking plate structure 15 to thereby complete the assembly and provide a closure for the transducer housing 10. The opposite and open end of the housing, is closed with a waterproof seal by a plate member 25 having an opening therein for giving passage to a cable 26. The cable 26 is sealed to the center opening in plate 25 by means of a rubber seal 27. The conductors in cable 26 are electrically connected to the ceramic disc by means of wires 28 and 29. Finally, the lower peripheral edge of housing is crimped at 30 to completely seal the transducer assembly.
FIGS. 4, 5, and 6 diagramatically illustrate various arrangments for constructing and spacing the sound masking plate in relation to the diaphragm 12. The term sound baffle is used herein as generically descriptive of the structure shown in FIGS. 4-6. The sound masking disc 5, of FIG. 2, is schematically represented by the disc 32 in FIG. 4. The vibratile diaphragm 12, of FIG. 2, is schematically represented by the diaphragm 33 in FIG. 4. The schematic arrangement of FIG. 4 places the sound masking disc 32 is very closely spaced proximity S1 to the diaphragm 33. Therefore, sound radiating from the center portion of the diaphragm is prevented from being transmitted to the driven medium.
When the spacing 81 between the diaphragm 33 and sound masking plate 32 is sufficiently small, there is a thin air film having a viscosity which causes an absorption of the sound radiated from the center portion of the diaphragm. Preferably, space S1 is less than onetenth the diameter of the masking plate. Hence, only the peripheralregion of the vibratile diaphragm is able to radiate sound outwardly into the medium. The diameter of the masking plate 32 should be made approximately equal to the nodal diameter D of the diaphragm 12 (FIG. 3). This nodal diameter D is somewhat less than one-half the diameter of the diaphragm. The exact nodal diameter D may be determined experimentally by observing a dust pattern on the vibrating diaphragm when it is driven at its desired overtone frequency.
FIG. 5 illustrates another embodiment of the invention for enabling the sound radiation from the center portion of the diaphragm to combine with and enhance the sound radiation from the peripheral portion of the diaphragm. This enhancement is achieved by adjusting the spacing S2 so that the annular area represented by spacing S2 multiplied by the periphery of the sound masking disc 37, is approximately equal to the area of the masking disc 37. A further requirement to be satistied in order to achieve the enhancement is that the average phase of the sound coming from the center region of the diaphragm is delayed by approximately onehalf wavelength. This delay condition is achieved if the radius R of the masking plate 37 lies in the region extending from approximately one-fourth wavelength to one-half wavelength of the frequency of operation. If the radius R is less than one-fourth wavelength, the phase of the sound radiated from the center portion of the diaphragm destructively interferes with the sound radiated from the outer portion of the diaphragm. This interference causes a reduction in total radiation. If the radius R is larger than one-half wavelength, destructive interference also takes place for the sound energy generated by the center portion of the diaphragm. Therefore, this energy does not reach the region lying beyond the periphery of the sound masking disc 37.
Yet another embodiment of the invention prevents radiation from the center portion of the diaphragm (FIG. 6). Here, the sound masking plate 43 has an undercut area forming a cavity 44. The peripheral edge surrounding the undercut area is then placed in close proximity to the diaphragm 45. By this design, there is an air chamber with a volume 44, terminated at a thin annular slit. As a result, there is a close spacing between the plate 43 and the diaphragm 45. This provides a low pass acoustic filter that prevents the transmission of the sound energy generated by the center portion of the diaphragm, provided that the cut-off frequency of the filter is made to lie below the frequency of the transducer operation.
The low frequency cut-off of the acoustic filter is easily controlled by a proper selection of the spacing between the masking plate periphery and the surface of the diaphragm 45. The principles required to make this selection are well known in the art of acoustic engineering. A wide range of operating frequencies and dimensions of structure may be chosen to satisfy any specific application requirement of a particular transducer design.
It may be possible or desirable under certain conditions to eliminate the sound masking plate 15 from the assembly in FIG. 2 and to operate the transducer at its first overtone resonance mode as illustrated in FIG. 3, without appreciable deterioration in the performance, provided that the diaphragm diameter does not exceed certain limits. If the clamped diameter of the diaphragm 12 leaves a free and unsupported diameter which does not exceed 3 wavelengths of sound in the transmitting medium less than I or 2 decibels of loss in sensitivity occurs because of the out of phase radiation at the center portion of the diaphragm. The beam pattern is not significantly deteriorated. Thus, the omission of the masking plate produces a satisfactory transducer at a minimum cost and with a negligible loss in performance.
Thus, it should now be apparent that the invention provides a way of controlling the beam pattern of an electroacoustic transducer. By way of example, spacing S1 (FIG. 4) provides one alternative for absorbing sonic energy and spacing S2 (FIG. 5) provides another alternative for enhancing sonic energy. In between these two alternatives, there are an infinite number of other alternatives. The other embodiments disclose still other alternatives. Thus, the term selective" is used in the appended claims to mean the state of being wherein one of the alternatives is selected by the nature of the structure.
While several specific embodiments have been shown and described, it will be understood that various modifications may be made without departing from the true spirit and scope of the invention. Therefore, the appended claims are intended to cover all equivalent constructions which fall within their true spirit and scope.
I claim:
1. An electroacoustic transducer comprising a tubular housing open on at least one end, vibratile diaphragm means having a center portion and an outer peripheral portion, means for sealing the periphery of said vibratile diaphragm to close the open end of said tubular housing and form a clamped vibratile disc, transducer means comprising a piezoelectric disc rigidly bonded to one side of said diaphragm, electrical conductor means attached to said piezoelectric disc for imparting electrical signals thereto, the center and peripheral portions vibrating in different modes which give rise to alternative sonic effects depending upon the degree of interaction between said modes of vibration, and sound baffle means for controlling the radiation of sound from the center portion of said diaphragm as compared with the radiation of sound from the outer peripheral portion of said diaphragm, said vibratile diaphragm operating at its overtone resonant frequency mode of operation, wherein said means for controlling the sound radiating from the center portion comprises a rigid sound masking disc positioned over the center portion of said vibratile diaphragm and spaced away from the radiation surface thereof, the diameter of said sound masking disc being less than one-half the diameter of the free and unsupported portion of said vibratile disc, and the spacing between said sound masking disc and said vibratile diaphragm being a linear distance approximately equal to a number derived by dividing the area of said masking disc by the periphery of said disc.
2. An electroacoustic transducer comprising a tubular housing open on at least one end, vibratile diaphragm means having a center portion and an outer peripheral portion, means for sealing the periphery of said vibratile diaphragm to close the open end of said tubular housing and form a clamped vibratile disc, transducer means comprising a piezoelectric disc rigidly bonded to one side of said diaphragm, electrical conductor means attached to said piezoelectric disc for imparting electrical signals thereto, the center and peripheral portions vibrating in different modes which give rise to alternative sonic effects depending upon the degree of interaction between said modes of vibration, and sound baffle means for controlling the radiation of sound from the center portion of said diaphragm as compared with the radiation of sound from the outer peripheral portion of said diaphragm, said vibratile diaphragm operating at its overtone resonant frequency mode of operation, wherein said means for controlling the sound radiating from the center portion comprises a rigid sound masking disc positioned over the center portion of said vibratile diaphragm and spaced away from the radiating surface thereof, the diameter of said sound masking disc being less than one-half the diameter of the free and unsupported portion of said vibratile disc, said masking disc having a recess forming a cavity at its center portion on the side of the mask which faces said diaphragm, characterized in that there is a close spacing between the peripheral surface of said undercut disc and the opposing surface of said vibratile diaphragm.
1. An electroacoustic transducer comprising a tubular housing open on at least one end, vibratile diaphragm means having a center portion and an outer peripheral portion, means for sealing the periphery of said vibratile diaphragm to close the open end of said tubular housing and form a clamped vibratile disc, transducer means comprising a piezoelectric disc rigidly bonded to one side of said diaphragm, electrical conductor means attached to said piezoelectric disc for imparting electrical signals thereto, the center and peripheral portions vibrating in different modes which give rise to alternative sonic effects depending upon the degree of interaction between said modes of vibration, and sound baffle means for controlling the radiation of sound from the center portion of said diaphragm as compared with the radiation of sound from the outer peripheral portion of said diaphragm, said vibratile diaphragm operating at its overtone resonant frequency mode of operation, wherein said means for controlling the sound radiating from the center portion comprises a rigid sound masking disc positioned over the center portion of said vibratile diaphragm and spaced away from the radiation surface thereof, the diameter of said sound masking disc being less than one-half the diameter of the free and unsupported portion of said vibratile disc, and the spacing between said sound masking disc and said vibratile diaphragm being a linear distance approximately equal to a number derived by dividing the area of said masking disc by the periphery of said disc.
2. An electroacoustic transducer comprising a tubular housing open on at least one end, vibratile diaphragm means having a center portion and an outer peripheral portion, means for sealing the periphery of said vibratile diaphragm to close the open end of said tubular housing and form a clamped vibratile disc, transducer means comprising a piezoelectric disc rigidly bonded to one side of said diaphragm, electrical conductor means atTached to said piezoelectric disc for imparting electrical signals thereto, the center and peripheral portions vibrating in different modes which give rise to alternative sonic effects depending upon the degree of interaction between said modes of vibration, and sound baffle means for controlling the radiation of sound from the center portion of said diaphragm as compared with the radiation of sound from the outer peripheral portion of said diaphragm, said vibratile diaphragm operating at its overtone resonant frequency mode of operation, wherein said means for controlling the sound radiating from the center portion comprises a rigid sound masking disc positioned over the center portion of said vibratile diaphragm and spaced away from the radiating surface thereof, the diameter of said sound masking disc being less than one-half the diameter of the free and unsupported portion of said vibratile disc, said masking disc having a recess forming a cavity at its center portion on the side of the mask which faces said diaphragm, characterized in that there is a close spacing between the peripheral surface of said undercut disc and the opposing surface of said vibratile diaphragm.
| 1970-04-01 | en | 1974-11-19 |
US-40205182-A | Compound curve-flat pattern process
ABSTRACT
Flat pattern equivalents for curved surfaces may be generated by developing a regular network of quadrilateral grid elements resembling a fish net which is mathematically smoothed onto the curved surface. Surface features such as boundaries and cutouts are mapped onto the network. The network is then transformed onto a flat mapping plane to form a grid in a manner analagous to smoothing a fish net mesh onto a flat surface. The surface features are then transformed to the flat surface grid.
Individual plies or parts are then cut based upon the flat patterns. The plies or parts will conform to the curved surface exactly.
A source code listing of a computer program labelled FISHNET is included as a microfiche appendix.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods for forming flat pattern equivalents for curved surfaces. It is particularly useful in accurately transforming originally flat deformable materials such as sheet metal, glass and woven cloth into precise compound curved surfaces.
2. Description of the Prior Art
The method of this invention is particularly useful but not limited to the fabrication of high strength resin-matrix composites which are formed into parts with complex curved shapes. The term "composite" refers to material made up of two or more separate components. Carbon fiber resin matrix composites are particularly useful because of their high strength-to-weight ratio and high resistance to crack growth. One method of making a carbon fiber resin matrix composite component is to impregnate the carbon fiber fabric with resin, partially cure the impregnated fabric to a "B" stage, bring the separate layers or plies of the fabric together in a suitable tool/mold, and then completely cure the laminate under suitable heat and pressure conditions.
On a flat, constant thickness component, cutting the laminate is a simple operation. However, for components with contours or compound curves, a flat pattern must be made for each ply or sets of plies. There are a number of methods to approximate the flat pattern equivalent for the compound curve shape; one of the most common is known as the "triangulated flat pattern" method. In this method the compound curve shape is first approximated as a ruled surface, and then triangulation is used to transform the points from a three dimensional to a two dimensional surface. Unfortunately, as the complexity of the compound surface increases, the fit of the flat pattern becomes increasingly dependent upon the skill, judgment and experience of the designer and the inaccuracy of the assumption of a ruled surface. When dealing with complex shapes, unless the skill level of the designer is quite high, commonly the flat pattern will not fit. Since a composite part is often made up of as many as 150 layers of fabric, the task of obtaining flat patterns is laborous and susceptible to errors. Indeed, some complex shapes are so intricate that they may not be flat patterned by any existing method. In such cases a full scale model of the surface must first be built, and sheets of Mylar plastic are then positioned upon the tool, and the edge of the part and features are marked on the sheets. The resulting flat patterns are still not precise since the Mylar plastic does not deform in the manner of a fabric. Clearly, with the increased use of resin-matrix composite structures, a more accurate method for producing flat patterns is needed.
SUMMARY OF THE INVENTION
This process for determining a flat pattern equivalent for a portion of a curved surface comprises: first forming two tooling lines upon the surface which intersect at a collation reference point; then forming a fish net-like grid upon the surface such that one of the grid intersections coincides with the collation reference point, and the grid lines extending outward from this intersection coincide with the tooling lines upon the surface; then marking the intersections of the perimeter of the relevant portion of the curved surface with the grid; then forming a flat mapping grid having a grid spacing equal to the grid spacing of the fish net-like grid; and, finally, determining the flat pattern equivalent for the portion of the compound curved surface by transforming the fish net-like grid containing the marked intersections onto the flat mapping grid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a mathematical diagram;
FIG. 2 is a series of geometric construction steps useful in this process;
FIG. 3 shows the fish net-like grid produced in one quadrant by the geometrical construction steps of FIG. 2;
FIG. 4 shows the flat pattern equivalent to the quadrant of FIG. 3;
FIG. 5 shows the starting conditions for a complex curved surface as it would be handled by another embodiment of this process;
FIG. 6 shows the complex surface of FIG. 5 with tooling lines added and with the corresponding mapping plane;
FIGS. 7, 8, 9 and 10 show various steps in the geometrical construction process which operate upon the complex curved surface;
FIG. 11 shows the generated grid intersections constructed upon the tooling lines on the curved surface;
FIG. 12 shows the flat pattern equivalent to the complex curved surface developed in the preceding figures;
FIG. 13 shows one embodiment of a process for applying flat patterns to a tooling mold.
FIG. 14 is a flow chart of the system software;
FIG. 15 is a diagram of the algorithm used in the FPPCD3 subroutine;
FIG. 16 is a diagram of the algorithm used in the FPPCD2 subroutine; and
FIG. 17 is a diagram of the algorithm used in the FPLOCP subroutine.
DETAILED DESCRIPTION OF THE INVENTION
As mentioned above, heretofore there has been no efficient and accurate method available for the production of flat pattern equivalents for compound curved surfaces. We have invented a method which accurately describes the behavior of a material undergoing compound deformation and which can be used to generate a flat pattern of the surface. The flat pattern will fit the curved surface exactly. Additionally, information will be generated by this method which will inform the designer of potential darts, folds and wrinkles in the material when applied to the curved surface. The flexibility of this process allows the designer to initiate the flat pattern generation process at any point on or off of the compound curved surface. A further advantage is that, unlike any other known method, this process generates information relative to positioning the flat pattern on the lay-up or forming tool, thereby facilitating the automation of the lay-up or forming process. Additionally, this process assures the designer that the flat pattern will be laid up in its proper orientation relative to the other plies in a composite structure. A perfect fit is of great importance in locations such as interior plies in composites where there can be no trimming after the part has been laid up and cured. In other materials the need for accuracy still holds, even though as much as 18 inches of material is allowed from the edge of the part for gripping the part for the forming process.
This method is based on a simulation of the actual behavior of a material undergoing the deformations associated with its conformation to a compound curved surface. Any type of feature, including cutouts and rivet patterns, can be developed on the flat pattern. The great accuracy of this method is also beneficial in terms of weight computations, material savings, and intermediate hand trimming operations.
One embodiment of this method defines "points" as being the points of intersection of the woof and warp of the cloth on the curved surface . For other, non cloth-like materials such as metal sheet or glass, the "woof" and "warp" directions are the neutral axes of the material. The "points" for such materials are arbitrarily chosen since there are no woof and warp yarns. However, this method can accurately model the deformation behavior of these materials. In order to simplify the mathematics and to reduce the number of calculations, an assumption is made that any distance between points is defined as the chordal distance between the points along the axis directions. The difference between the theoretical and actual tolerance of the part comes into play at this point. If the distance from point to point were measured along the curve, then the flat pattern would be exact. Since the points are computed along a straight line distance from point to point, the difference between the actual distance along the curve and the straight line distance is the error within that particular measurement. Summing the errors along an axis directon will result in the total error within the part. It can be shown that, even though the points are computed as chordal distances, the error is still very small. In other words, the total error in the part may be minimized by minimizing the length of the individual chords used in the calculations based on the curvature of the part.
An initial decision must be made as to the spacing between the points in the fish net-like grid. Again, the accuracy of the method may be related to the grid spacing. FIG. 1 shows a portion of a curved surface, s, having a radius of curvature, R, not shown, a chord of length, L, and a height, h. The relevant equations are: R=L2 /8h+h/2; θ=s/R; and total error =Rθ-2R sin θ/2. The total arc length (s) is 49.975647277 inches, the base chord length (L) is 48.0000 inches, and the radius of curvature (R) is 51.0000 inches. For the purposes of demonstration, three computations were made using a 1.00 inch, a 0.25 inch, and a 0.05 inch grid spacing (chord length). The total arc length (s) of the part is, again, 49.975647277 inches. The use of a 1.00 inch grid spacing (chord length) would require 47.999231047 chords with a total error of 0.00076895248. The use of a 0.25 inch spacing would require 199.90238896 chords with a total error of 0.00005003556 inches. The use of a 0.05 inch spacing would require 959.9999616 chords with a total error of 0.00000191999 inches. It should be noted that a part of dimensions 49.97 inches by 49.97 inches with one inch spacings would have 2,401 computed points (grid intersections on the surface); with 0.25 inch spacing, 39,601 computed points; and with 0.05 inch spacing, 998,001 computed points. Therefore, a compromise must be made between a very high degree of accuracy and an unreasonable amount of grid intersection points. The advantage of the 1.0 inch spacing is that it requires fewer computations. For the purposes of this discussion and example, a spacing of 0.35 inches will be used.
The remainder of this specification will be devoted to the discussion of two embodiments of this process. The first embodiment will be a rather simple approach which will serve mainly as an explanatory tool, although it could be utilized as a production process. The second embodiment is more complicated and is intended as a production process to be used in conjunction with a computer graphics system having a capability to mathematically handle a three dimensional curved surface.
Embodiment No. 1
First, a model of the surface for which a flat pattern is desired must be constructed or generated. Two lines are then drawn on this surface which intersect each other at a predetermined starting point. These lines represent the axis of the material and are designated the tooling lines. These lines are generally started with an angle of 90° between them because that is the condition of the material in its undeformed state. It should be noted that the lines do not have to be at right angles to each other as the angle would represent the axes of the material in a predeformed condition. That is, the material is deformed to some degree prior to its being positioned on the layup tool. This would primarily be applied to a woven material. FIG. 2 shows the sequence of steps by which the fish net-like grid of intersecting points is generated upon the curved surface. Step 1 of FIG. 2 shows the tooling lines m, n which intersect at right angles at the starting point 100. A circle is then constructed with its origin at point 100 having a radius equal to the desired spacing interval or chord length of 0.35 inches. In this discussion the grid will be developed one quadrant at a time. As such, the intersections of the circle 10 with the tooling lines m and n at points 11 and 12 are indicated. Two further circles 13 and 14 are then constructed having their origins at points 11 and 12 respectively. The intersections of these new circles with the tooling lines m and n are then marked as points 16 and 17 respectively, and the intersections with each other at point 15 are also marked. Similarly, in steps 3 and 4, further circles are constructed with their centers at points 15, 16 and 17 which form further intersection points with the m and n axis labelled 23 and 19 respectively. More and more grid intersection points within the quadrant are then constructed by this algorithm until a complete quadrant between the tooling lines is completed in the manner shown in FIG. 3. The object of these intersected circles is then to generate a network of points, on the surface of the part, which are all the same chordal distance away from each other. This figure also shows the perimeter 30 of the compound curve surface within the quadrant of interest. Once the grid intersection network has been completed within this quadrant, the transformation from this curved surface to the flat surface mapping plane shown in FIG. 4 will be commenced. The first point to be transformed onto the flat surface mapping plane is the intersection of the perimeter 30 with the m tooling line at point 31. It is important to note at this point that the grid intersections coincide consecutively along both the m and n tooling lines. Point 31 falls 0.1 inches past the tenth grid intersection point along the m axis and as such is (10) (0.35 inches)+0.1 inches=3.6 inches along the m tooling line. The flat pattern mapping grid shown in FIG. 4 is laid out with the grid spacing of 0.35 inches, the same spacing as was used on the curved surface in FIGS. 2 and 3. The transformed axes are shown as m' and n' with a translating starting point of 100'. Thus, the transformed point 31' will appear at 3.6 inches out along the m' axis on the flat pattern. In a similar manner, further intersections of the perimiter 30 with the curved surface grid shown in FIG. 3 will be similarly transferred onto the flat pattern mapping grid shown in FIG. 4 where the perimeter appears as the line 30'. FIG. 4, then, shows the flat pattern equivalent to the curved surface outline for this particular quadrant. The process would then be repeated for the remaining three quadrants until the total perimeter of the portion of the curved surface for which is desired a flat pattern has been completed.
Once this flat pattern equivalent for the part is generated in its undeformed condition, the woven material would be cut out and laid up on the layup tool. The starting point and axis lines which were developed on the surface are either optically projected or drawn on to the layup tool. The material has a collation reference point and axis lines marked upon it as well. If the material is cloth, then it is positioned on the layup tool such that the starting point and woof (or axes) and warp lines and the projected lines coincide.
If the flat pattern is cut out and the axis lines are positioned to correspond to the tooling lines on the surface, the flat pattern will fit the surface exactly. Another way to lay up a clothlike material is to line up one edge of the flat pattern at a time with the edge of the layup tool and then work the cloth into the tool. This is the way most layup work is done at present.
Embodiment No. 2
A more efficient way to utilize this compound curve flat pattern method is to employ a computer graphics system. For this particular embodiment, the system which was used in the development of the method was an Evans and Sutherland Picture System 2 (PS-2) display processor unit. The three-dimensional data describing the curved surface are received at the PS-2 from a Digital Equipment Corporation (DEC) 11/70 minicomputer which is cable connected to the display processor. Each 11/70 minicomputer can operate up to four PS-2 microprocessors (eight consoles). The DEC 11/70 communicates with a DEC 11/34 minicomputer that is located near and cable connected to a main frame IBM 370 computer. However, this method may be employed upon any existing computer graphics system of sufficient capability.
First, a mathematical description of the surface of the part being flat patterned must be obtained. Parametric cubic (PC) geometry is a mathematical technique for describing bounded three dimensional curves and surfaces in a form useful to engineering design and analysis. As an integral part of computer-aided design, PC geometry satisfies the need for speed, accuracy, economy, and manipulative flexibility required to solve complex engineering problems. For curves, each real space coordinate, X, Y, and Z, is expressed as a cubic polynomial function of an independent parameter, U. Thus, the X-coordinate of any point on a space curve may be expressed as: ##EQU1## for surfaces, each real space coordinate is expressed as a bicubic function of two independent parameters, U and W. Thus, the X coordinate of any point on a surface may be expressed as: ##EQU2## where a given set of coefficients, axi, ayi, azi, defines a unique, unambiguous curve in space, and a second given set of coefficients, axij, ayij, azij, defines a unique, unambiguous surface in space; and where the values of the parametric values U and W are limited to the interval between zero and 1, inclusive.
Parametric representation is used because it allows independent control of each real space coordinate by employing a common, independent parameter, (U for curves, U, W for surfaces). It follows the representation of bounded curves and surfaces through the axiomatic and explicit concept of domain. Nonparametric relationships between real space coordinates, for example, X=F (y) and Z=G (y), can be shown both to restrict allowable curve or surface behavior and to produce undefined results under certain transformations. A cubic polynomial function is used because it is the simplest form capable of describing a curve which may twist in space and which may also have a point of inflection. Higher degree functions could have been used, for example, a quintic polynomial, but these introduce cumbersome and unnecessary complexities. A bicubic polynomial function is used because it is the simplest form capable of describing a surface whose boundaries are curves of the type described above and whose interior shape is controlled by analogous functions defining surface normals at these boundaries. PC functions are easy to express in the form of matrices, making geometric operations and analysis relatively simple matrix manipulations. Further, the simplicity of PC matrix expressions also allows economical application of computers to the solution of complex geometric problems. Finally, the use of a single, common mathematical format for representing any curve or surface drastically reduces the number and complexity of subroutines required to process and analyse the geometric relationships.
The surface itself will be called for the purposes of this discussion the "parametric bicubic" end surface. The surface is directly related to the PC curve and can be called the bicubic surface or the PC surface. "Patch" is another term which can be conveniently used to denote this surface. Patch is generally more meaningful to describe a single bicubic surface when many bicubic surfaces must be continuously joined to represent a complex physical or phenomenological surface.
The surface may be defined as a curve bounded collection of points whose position coordinates in three dimensional space are continuously defined by two-parameter, single valued mathematical functions. Thus:
x=f(u, w)
y=g(u,w)
z=h (u,w).
For bicubic surfaces, each real space coordinate is expressed as a bicubic function of the independent parameters u and w as seen in the equations above which are used to generate the x, y, and z values (the dependent variables) for the coordinates in three dimension space. Any surface may be considered to consist of an infinite number of points. Similarly, there are an infinite number of pairs of u, w values. There is a unique pair of u, w values in parametric space corresponding to each point in three dimensional x, y, z- space. In other words, a bicubic surface in real space is assembled point wise from its components in parametric space.
It is important to note that the bicubic surface is bounded by four curves. Each boundary curve turns out to be the PC curve. Though any of these curves may be degenerate curves containing only a single point, each has a unique characteristic which results in its name; i.e., the u=0 curve, the u=1 curve, the w=0 curve, and the w=1 curve. The boundary curves rise at the constant, limiting values of the parametric variables. There are also four unique corner points (u=0, w=0; u=0, w=1; u=1, w=0; and u=1, w=1). Consequently, a bicubic surface is generated by successive ordered pairs of the parametric variables u and w. As with the PC curve, an identical surface can be generated with the sequence of u, w values inverted. The choices of which boundary curve to make the u=0 curve and which to make the w=0 curve is arbitrary unless there is some external or computational constraint dictating a preferred or necessary order. Either way, there are no theoretical constraints or biases, and there is no practical distinction between possible u, w orders insofar as the resulting sets of points in x, y, z-space.
First a mathematical description of the surface of the part being flat patterned must be obtained. A surface may be defined by a curve-bounded collection of points whose position coordinates in three dimensional space are continuously defined by two parameter single-valued mathematical functions.
x=f(u,w)
y=g(u,w)
z=h(u,w).
This mathematical surface information is then stored in some convenient form, such as a parametric bicubic patch.
To initiate the compound curved flat pattern process in this embodiment, three points are positioned on or off the surface. Point 100 is the starting point of the flat pattern and will be referred to as the collation reference point. This point will match the collation reference point on the completed flat pattern. Points 200 and 300 are chosen such that vectors to these points from point 100 indicate the directions of the axis of the material. The warp directon is chosen to coincide with a required orientation of that particular ply of a clothlike material.
If point 100 is located off of the surface, then an additional point 100A is projected down along a normal to the plane defined by point 100, 200 and 300 from point 100 and located on the surface. Similarly, if point 100 is located on the surface, an additional point 100A will be projected normal to the plane defined by points 100, 200 and 300 some convenient distance above it. In any event, the angle between the two vectors 100-200 and 100-300 should be 90° since this is the angle which the material will assume when it is cut as a flat sheet, although, as in embodiment no. 1, a 90° angle is not necessarily required.
Two cutting planes are now formed. A first cutting plane will intersect the three points 100A, 100 and 300. A second cutting plane will intersect the three points 100, 100A and 200. These cutting planes will then be extended to intersect the surface 500 as shown in FIG. 6. The intersection of these cutting planes upon the surface 500 will form the two tooling lines m and n which meet at the right angles at the starting point 100. Also shown in FIG. 6 is the corresponding flat pattern mapping plane with its axes m' and n' meeting orthogonally at point 100'. In these representations the perimeter of the compound curved surface is indicated as 510.
In a manner quite similar to that found in embodiment no. 1, using the intersection of the tooling lines m and n as a starting point or origin 100, a sphere 50 of radius 0.35 inch is constructed. The intersections of this spherical surface 50 with the tooling lines m and n produce four additional grid intersection points on the surface, here labelled 51, 52, 53 and 54. Then, as shown in FIG. 8, four additional spheres are constructed using these four points 51, 52, 53 and 54 as origins. The intersections of these adjacent spherical surfaces respectively 61, 62, 63 and 64 with each other and the compound curved surface 500 produce four additional grid intersection points on the surface as shown in FIG. 9 as points 71, 72, 73 and 74. As embodiment no. 1, the process or algorithm is repeated continuously (but always referenced to the tooling lines m and n) until the entire compound curved surface is covered with the constructed grid as indicated in FIG. 10. Here, as in embodiment no. 1, it is convenient to consider the problem one quadrant at a time. FIG. 11 shows the development of the grid intersections along the extended tooling lines even past the perimeter 510 of the compound surface 500 with their intersection marked as point 100.
Then, as in embodiment no. 1, the various intersections of the perimeter 510 of the curved surface 500 are marked as they intersect the curved surface grid and are then transformed onto the flat pattern mapping plane shown in FIG. 12 Additional features, not shown, such as cutouts and rivet holes, would also be provided for in the same manner. Once again the tooling lines m and n from the curved surface translate onto the mapping plane as m' and n'. Similarly, the origin on the curved surface 100 translates onto the mapping plane as starting point 100' and as each of the intersections of the perimeter of 510 of the curved surface 500 are marked on the curved surface grid and transformed onto the mapping plane, the flat pattern perimeter 510' is generated.
As each leg of a quadrant is developed, every developed curved surface grid point along a face of the quadrant is checked as to its position relative to the surface boundary 510. When all the developed points are located outside the surface boundary 510 within a given quadrant, then the appropriate quadrant face is considered as fully developed. The individual boundary points or intersections of the perimeter 510 with the curved surface grid are transformed onto the flat mapping plane whenever a developed grid intersection point crosses the perimeter of the part. Thus, when a developed grid intersection point does cross the perimeter, its location is known in terms of increments of the curved surface grid network spacing. The flat pattern mapping grid is then drawn witn the same grid spacing as for the curved surface grid
As a brief summary, a network of points is developed on a surface representing the part to be flat patterned. Each point is exactly the same chordal distance away from any adjacent point. Assuming that the lengths between the developed points do not bend or flex, the conformation of the cloth onto the curved surface is then caused by a "scissor action" of the lengths at the pivot points (the grid intersection points). This simulates the behavior of a woven fabric material and the atomic behavior of other materials. Darts, folds and wrinkles reveal themselves when the angle between the lengths reaches a sufficiently small angle. In fabric the lengths or threads have a finite thickness. Therefore, the angle formed between the lengths can only go down to about 45° before a cloth material will deform out of its original.
The method of this invention is versatile in terms of the shapes that it can handle. As was mentioned in the description of the prior art, differently shaped parts have required different methods to obtain a flat pattern in the past. With the method of this invention, any shape or size part can be flat patterned accurately. Addtionally, since this method shows the designer where a dart, fold or wrinkle will result in the material for a given orientation, the designer can choose a different collation point or orientation of the material which would move the dart or fold outside the edge of the part. Since the process is methodical and repetitive, it can be programmed into any existing computer system which has surface mathematics capability.
Once the flat pattern has been generated for a composite part, a fabric ply is cut out which is then applied to a lay-up tool. This process is shown in FIG. 13. The starting point 100 and tooling lines m and n are optically projected by suitable means 80 onto the lay-up tool 520. The flat patterned fabric 500' is then positioned on the lay-up tool 520 such that the starting point 100' and the tooling lines m' and n' which are marked on the fabric and the projected tooling lines m and n coincide. If the process is carried out correctly, the flat pattern will fit the curved surface exactly. Any internal features such as cutouts or rivet hole locations can be mapped accordingly by this process and exactly positioned on the lay up tool.
PROCESS SOFTWARE
The function of the software program is to develop flat patterns for textile-type (woven) and other deformable materials to be laid up or formed on compound-curved molds. The program uses certain operator-selected elements which describe a part and define the initial conditions of the material.
A brief discussion of flat patterns is in order to review the problems associated with obtaining them. In order to understand the significance of what the operator inputs to the program should be, it must be realized that there is not a single, unique flat pattern for any given part. A vast (theoretically infinite) number of flat patterns, all different, can be made that would fit the mold correctly. Several of the operator inputs should specify conditions which force a single, unique solution out of the many possible solutions.
The first parameter needed to arrive at a unique solution is the collation point on the surface, most easily explained by an analogy to the typical manual method of making flat patterns. The manual method involves cutting a piece of material more than large enough to cover the mold surface, laying it across the layup tool, and picking a point on the material to press against the surface of the layup tool. Now moving radially away from this point in all directons, the material is smoothed (wrinkle-free) against the surface until the entire mold surface is covered. At this point, the excess material beyond the edges of the part is trimmed off, and the trimmed material is removed from the tool and laid out flat in an undeformed condition. The material must be returned to its original condition if patterns are to be cut from undeformed material. Deformation of a material and flattening out is handled by the algorithm. This process results in a flat pattern which can be used as a template to cut additional pieces. If this process is repeated starting at a different point on the tool and smoothing the material from that point outward, a different flat pattern (but one that still fits) will result. This phenomenon may be clarified through an example. Most textile materials are woven with the warp (lengthwise) fibers crossing and the woof (crosswise) fibers at a 90 degree angle. When the material is laid up on a compound curved tool, the smoothing of the cloth against the tool forces the fibers to conform to the compound curvature by distortion of its weave; that is, the angle between its woof and warp fibers is forced to change locally in order to conform to the compound curvature of the tool. It should be noted that the starting point chosen represents a point where the cloth will remain in its original, undistorted condition, and that its location, therefore, affects the distribution of weave distortion across the entire mold surface. Although the assumption is made that the cloth will start out in a 90° angle between the woof and the Warp threads at the collating reference point, this may not always be the case. If the material is predeformed prior to placing it on the layup tool, then the angle between the woof and warp fibers at the collation reference point will not be 90°. This can be taken care of in the software package as will be discussed later. The assumption will be made hereinafter that, for practicality in the manufacturing process of the part, the cloth will be laid up as it comes from the bolt and not predeformed in any substantial or deliberate manner.
To illustrate the results that would be obtained by moving the starting point, the flat pattern of a section of a sphere will be used. Imagine cutting a sphere in half and then quartering the remaining hemisphere with two cuts perpendicular to the original equatorial slice. The surface of one of the octants shall represent the compound-curved surface to be flat patterned for this example.
If the layup of a clothlike material is started somewhere along the equatorial cut, deformation of the cloth weave will, by definition, be zero at that point; the woof and warp threads will cross at an as-manufactuted 90° angle. As the cloth is smoothed against the surface toward the remaining pole of the sphere, however, the weave will be forced into progressively greater deformation with maximum deformation occuring at the pole of the sphere. If the excess material around the edges is trimmed off and the cloth returned to its original 90° weave condition, maximum distortion of the originally planar cuts that created the flat pattern will occur in the area of maximum weave distortion of the laid-up cloth, i.e., at the pole. Conversely, minimum distortion of the trim cuts occur in areas of minimum weave distortion. In this particular example, the entire equatorial slice is covered with undistorted cloth and will, therefore, flat pattern as a straight line.
If the layup of cloth is started at the pole rather than at a point along the equator, the distribution of weave distortion will occur along the equator (the extreme ends) while the weave at the pole will be undeformed. This time the varying distortion along the equator will result in that trim slice not flat patterning to a straight line. Thus, we have two distinctly different flat patterns for the same part, both of which will fit correctly. Also, the starting orientation of the woof and warp of the fabric will determine the locations of deformations along the part's surface. The shape of a flat pattern will alter, even though the starting point may not have changed, just by changing the direction of the axes threads through the collation reference point.
The process software used in this embodiment comprises 19 subroutines which are listed below.
FPMAIN--the header routine for the Compound Curve Flat Pattern Software package.
FPMENU--prompts the user for information relating to the grid spacing and the minimum allowable deformation. The routine also analyses the pick information associated with the model to be flat patterned and collects information about the three points, surfaces, features to be developed, and the flat pattern plane.
FPMPFT--analyzes the picked features that are to be mapped on to a mapping plane.
FPSUMP--sets up a planar coordinate system (2D) onto which the flat pattern will be mapped.
FPSTUP--sets up the cutting planes on the surface which define the neutral axis.
FPSTRT--sets up the first four points along the axis from the starting point.
FPPLIM--determines within which quadrant features to be mapped fall.
FPCONT--the counter and logic which develops the grid on the surface.
FPPKPP--returns a new patch surface based on the patch which is worked at the time, and the border of that patch which was crossed.
FPPCD3--computes a point on a surface which completes a box, given three previously computed points.
FPPCD2--computes a point on a surface which is the same distance away from two previously computed points.
FPPCCK--determines if any picked features have crossed an Mface or an Nface of a developed box.
FPLOCP--checks the interior area of a developed box for any internal points which are to be mapped.
FPCKBD--checks a developed point for relative position based on the location of the point to the outside or inside of the patch presently being worked on.
FPGMAL--converts to a new patch geometry and algebra based on the new surface number input to the routine.
FPIPSC--intersects a space curve (arc) with a surface.
FPMAP--computes a feature point, which was based on its relative position to the woof and warp lines on the surface, on to the mapping plane.
FPDRBD--analyses the "mapped features" points and curve fits the results.
FPERR--error message routine which displays the correct error message based on an input parameter.
A flow chart of the software package is illustrated in FIG. 14.
The following is a simplified description of the logic involved in obtaining a pattern:
1. Determine the subdivision of the surface (patches) to be flat patterned.
a. The subdivisions will be called QUADRANTS.
b. The quadrants will be labelled 101, 102, 103 and 104 in a counter clockwise direction (FIG. 6).
c. The quadrants will share a common point called the collation reference point 100.
2. Label the axes of each quadrant as Mface (m) or Nface (n) as indicated in FIG. 6.
3. Do the following for all four quadrants:
Note: This description is for quadrant 101. It will also hold true for all other quadrants.
a. Obtain the Nface row.
b. Check the row for any crossings on its Nface and Mface.
(1) If a crossing occured, map the point of crossing.
c. Check the row for any internal features or points.
(1) If a feature is found, map the feature.
d. If there were no face crossings, switch directions and continue with the next row.
e. If there were face crossings, develop the direction of the crossing.
f. This process continues until all the features in a quadrant have been all mapped.
The following definitions are included for a better understanding of the subroutines which are explained in more detail below.
Collation Reference Point (100)
A point on or adjacent to the surface to be flat patterned, analogous to the location on the surface at which the initial contact of the cloth and the surface takes place. From that initial point of contact, the cloth is smoothed onto the surface.
The "collation reference point" is also the starting point 100' on the flat pattern. This is described under the section dealing with the mapping of points.
Quadrants (101, 102, 103, 104)
The quadrants are defined by the intersection of two planes and the surface. The planes are defined as the direction of the weave of the cloth on the surface. One plane defines the woof direction while the other plane defines the warp direction. Both directions originate at the collation reference point 100. It therefore follows that the two planes intersect at a line which pierces the surface at the collation reference point.
The intersection of the surface and the planes define the quadrants.
Point Storage
The array which is used to develop a face is dimensioned (1000,2,6) for each face. This provides two levels for a face and a total of 1000 points per the two levels, per quadrant. As a third level is developed, it overwrites the level 2 part of the array. When level four is developed, level three is moved up.
The dimension of 6 contains information about each developed point and is stored in the following order:
1. X Coordinate in 3-space,
2. Y Coordinate in 3-space,
3. Z Coordinate in 3-space,
4. U the u value of the point on the patch,
5. W the w value of the point on the patch, and
6. PATNO the number of the patch within which the point falls.
As the program starts, points are developed along the picked features. These are stored in an array in the form (5000,9). This provides the capacity for 5000 points (or features) to be mapped. The information is in the following order:
1. X Coordinate in 3-space,
2. Y Coordinate in 3-space,
3. Z Coordinate in 3-space,
4. U the u value of the point on the patch,
5. W the w value of the point on the patch,
6. PATNO which is the patch number on which the point falls,
7. QUADNO which is the quadrant number in which the point falls,
8. CURVNO which is the pick number of the curve picked to be mapped, and
9. UCURVE the u value of the point on the picked curve from which the point came.
As the points are found within the surface, the x, y and z values in the array are replaced with the x, y and z values of the point as computed for mapping on the mapping plane. The following paragraphs describe the individual subroutines.
FPMAIN
The subroutine FPMAIN is the entry point for the software package The routine basically calls the subroutines necessary to develop a flat pattern.
FPMENU
The subroutine FPMENU splits up the user-picked information, needed in a later subroutine, into separate arrays. The three starting points, the two intersection lines, the surface, and the features to be mapped are all sorted, and the addresses of their locations in computer memory are stored in the appropriate arrays.
Menus prompt the user for input as to the grid size and the minimum allowable angle of deformation.
FPMPFT
The subroutine FPMPFT first loops through the array of picked PC curves. At each curve, a minimum of 10 points are computed. The points are a constant u value apart from each other. The points are projected to the patches in an effort to find the patch within which each point falls. The points are also located in relation to the quadrant system which are defined by the woof and warp cutting planes. This information is all stored in the array labelled MAPPCT. The knowledge of the location of the points relative to the quadrants is important. By knowing the number of points which must be found in any particular quadrant, it is possible to use this information to determine if all the points for that particular quadrant have been found, thereby ending the need for further development of that quadrant. A quadrant is developed in this manner: The rows of points which are computed will develop along a direction of any curve which happens to cross either the Nface or the Mface of the row. The algorithm will chase the feature along its general direction in order to map it fully. By having a check in the logic of the points yet to be found (or found already), one can alleviate the problem of ending in an infinite loop or, just as detrimental, of ending before all the points are found. If no features have been reached, the routine continues developing points in that quadrant because it has not found all the points in the quadrant.
FPSUMP
The subroutine FPSUMP sets up the mapping plane. The mapping plane is a flat surface onto which the flat pattern is developed. The plane is defined using two intersection lines which were user defined. The lines are intersected and the point of intersection is stored. This point will be defined as the mapped collation reference point 100'. It is about this point that the flat pattern will be developed. The plane itself is defined by the following points: one end point from a first of the two intersection lines, one end point from the second of the two intersection lines, and the collation reference point which marks the point of intersection of the two lines.
FPSTUP
The subroutine FPSTUP sets up the cutting planes on the surface of the part to be flat patterned. The cutting planes are intersected with the surface to obtain two sets of curves which represent the woof and warp directions. The routine works as follows: Referring to FIG. 5, the collation reference point is labelled 100, the woof point direction is labelled 200, and the warp direction point is labelled 300. These points are user defined and the directions are based on a vector between points 200 and 100 and a second vector between points 300 and 100. The first line is the woof direction, and the second line is the warp direction. These two direction lines also define a plane which can be called either the working plane or plane A. Another plane is constructed which contains the woof direction line and which is perpendicular to plane A. This is the woof cutting plane. A further plane is constructed which contains the warp direction line and which is perpendicular to plane A. This is the warp cutting plane. The woof and warp cutting planes are intersected with the surface. These intersections on the surface are the woof and warp lines (or axis lines, lines n and m in FIG. 6, respectively).
FPSTRT
The subroutine FPSTRT computes the first points along the axis directions in each of the four quadrants. Using the collation reference point 100 as the starting point, the first partials with respect to u and w are obtained along each of the cutting plane directions. Traveling along the tangent vector to the starting point and in each of the cutting plane directions, a point is obtained which is a distance away from the starting point. The distance away is the grid spacing contained in the menu routine. Once each of the points is computed, the points are projected down to the surface. The new distance from the projected point to the starting point is checked and compared to the grid spacing. If the distance is different than the spacing, the point is adjusted until the distance is exactly the same as the grid spacing. Once the point is found, the coordinates of the point and the u and w of the points location on the patch are stored in a working array to be used later in the counter routine (FPCONT).
FPPLIM
The subroutine FPPLIM determines within which quadrant picked features fall. The routine uses the first starting direction vectors for defining the quadrants. The array (MAPPCT) contains the points, which were computed along the picked features, which will be checked. The routine loops through the array of points and creates a vector from each of the points to the collation reference point. This vector is checked relative to the direction vectors for determining within which area the vector falls. The quadrants are defined counter clockwise starting from the area in which the direction vectors both point. If there are no points (or features) in a quadrant, then the quadrant will not be developed.
FPCONT
The subroutine FPCONT is the main counter for the software package. The routine has a main loop which basically loops through the package for each of the four quadrants. Basically, the counter is split into two working sections, the Nface and the Mface sections. Each is identical and functions the same as the other with the exception of the method and order that the points are stored and retrieved. Once the routine starts a quadrant, a determination is made between which face is to be developed at which time. Beginning with the Mface section, the working patch information is set up within the patch where the points are presently located. FPPCD2 is called which obtains a new point along the axis (or woof/warp directions). Once the point is obtained, the point is input into FPCKBD which determines, based on the value of the u and w of the computed point, whether the point fell within the boundaries of the patch presently being worked. If the point falls outside the patch, then FPPKPP is called. The output of FPPKPP is a new patch and patch information. The point is then recomputed based on the new and correct patch data. The point is then stored in an array for further use later. The routine then calls FPPCD3 to obtain points within the fuadrant. Once a point is output from FPPCD3, the point is once again checked to make sure that it fell within the patch border. If the point is outside the patch, then a new patch is located, and the point is recomputed and stored. If a point falls off the patch and there is no new patch in the area, such as an edge of part, then the point will be computed based on the patch extension of the patch presently being worked. If a loop is encountered in a point which is claimed by neither the patch being worked nor the adjacent patch, then the adjacent four patches of the second patch are checked. This prevents a problem when the point computed falls outside the patch in a diagonal direction. Once the point is accepted and stored, FPPCCK is called to check for any crossings of a face of a developed box (by FPPCD3) and a curve (feature). The routine is called twice, once for each outward most edge. If a point or points are found, they are stored in the MAPPCT array, and they are also mapped by FPMAP. Once this has been done, a flag is set which determines which, if any, face was crossed by a feature. This will be used to determine which row will be computed next. If no edge was crossed, then a row in the opposite face is developed next. FPLOCP is then called to check if any points out of the MAPPCT array fall within the borders of the defined box. If they do, the point is marked in the array and mapped. The routine will loop back and forth until all the features in a quadrant are found and all the features of the surface are found and mapped.
FPPKPP
The subroutine FPPKPP outputs the new patch information based on which border of the old patch was crossed. Once a point has been known to cross a boundary, it is easy to find, based on the u and w of the point, which border of the patch was crossed. Once the border is known, a search is made to find patches which share the border. Once the new patch is found, the algebraic and geometric forms of the patch are easily obtained and output. If there were no other patches sharing the common border, then the original patch data is left unchanged.
FPPCD3
The subroutine FPPCD3 developes a box in a quadrant on the surface. The development of a box is one of the first steps in obtaining the grid on the surface. The term "box" is really only one section of the network grid or fish net. Actually, a box is any four link closed section of the fishnet grid. Starting with the collation reference point 100, one obtains points 51 and 52 along the axis lines (refer to FIG. 7) at a distance (grid spacing) away from the collation reference point (this will be explained later).
The following description is a simplified version of the process. All the sides of the box are the same length. First, using point 51, construct a sphere with its origin at 51 and having a radius of "Distance." Once having that sphere, a second sphere is constructed with a radius of "Distance" and its origin at 52 as in FIG. 8. The two spheres are then intersected. The intersection of the two spheres results in a circle which is perpendicular to the surface at the collation reference point. Once the circle is obtained, it is then intersected with the surface. This intersection would result in two points on the surface. In FIG. 9, the two points are labelled 100 and 71. Since we are interested in developing a box, clearly point 100 is at the same location as the collation reference point; therefore, the point that is needed to complete the box is point 71. One is left with four points which are on the surface, and all are the same distance apart from adjacent points.
The actual method of obtaining the points is described hereinafter with reference to FIG. 15. Create a vector (VEC 1) from 201 to 202 (two opposite points in the uncompleted box) and normalize the vector. Obtain the midpoint of 201 and 202 XMIDPT 210. Using VEC 1, create a plane normal to the VEC 1 direction which includes point 210. Create a vector VEC 2 from XMIDPT to point 203 (the remaining point of the uncompleted box) and normalize it. Obtain the length of the segment from XMIDPT to 203 (R). Now, adding the length R to XMIDPT in a VEC 2 direction, obtain point XP 211. Now assume that XMIDPT is at the center of a circle, and R is the radius, and XP is the first guess point. Now go to the routine (FPIPSC) which will intersect the space curve (circle) with the surface to obtain the remaining corner point of the developed box on the surface.
FPPCD2
This subroutine computes an axis point on the curved surface which is the chordal distance beyond the second of two previously computed axis points. Referring to FIG. 16, 219 and 220 develop an axis point, obtain a previous point 220 and develop a sphere of radius R about that point. Then the sphere is intersected with the axis curve. For the next successive axis point, a vector is created from point 20 to point 219 (VEC 3) and normalized. An additional point 221 is obtained by starting at point 20 and traveling along VEC 3 for a distance which was previously picked by the user as the grid space. This ends up being the input into the routine (FPIPSC) which intersects the constructed space curve (circle 250) and the surface (500) to yield the desired next axis point 230.
FPPCCK
This subroutine determines if any picked surface features have crossed an Mface or an Nface of a developed box. Each grid row is made up of four-sided equilateral polygons (boxes) which are arranged side by side. As each polygon is developed, the two sides which are formed by the new corner point and relative to the Nface and Mface are checked for crossings by selected surface features (the picked curves that are to be mapped).
Assume that a feature has crossed one of the faces of an individual grid element. There will normally be no true intersection of the face and the curved surface, since the face chord will not normally intersect the curved surface at the feature point. Therefore, the apparent intersection is obtained.
First a plane is identified which contains the end points of the face chord and is perpendicular to the surface at one of the end points. Then it is easy to project the feature point in the plane to the face chord for mapping onto the flat pattern map. All the curves are intersected with the constructed plane. When a point is found, it is checked for location within the limits of the two points which define the face. If the point falls within the points (of face), then the point is mapped.
FPLOCP
As each box is constructed, this subroutine checks for points located within the borders of the box. The four vertices of the box are labelled 301, 302, 303 and 304 as shown in FIG. 17. Vector 10 is defined from 301 to 303. Vector 20 is defined from 303 to 304. Vector 30 is defined from 304 to 302. Vector 40 is defined from 302 to 301. X is the point which is to be checked. First, it must be determined if the point is located within the borders of the box formed by the four points.
Obtain the normal vector to vectors 10 and 40 through point 301 and in a positive direction. By crossing this normal vector with each side's vector (V10, V20, V30, V40), four normal vectors are obtained in which all the vectors point to the "inside of the box" V10N, V20N, V30N, V40N. Using a vector called R1, from 303 to X, and R2 from 302 to X, employ the dot product to determine the location of the point. Dot R1 with V20N and V10N. If the two dot products are positive, then the point is on the inside of V10 and V20. Dot R2 with V40N and V30N and, if the dot products are positive, then the point is on the inside of V30 and V40. Once it is determined that the point is inside the box, the location of the point relative to point 301 within the box will be obtained.
Since the vectors which define the sides of the box are known, they can be used to determine the location of the point X relative to 301. First reverse the direction of V10 and translate it to originate at point X. Then intersect this transformed vector with V40 to obtain point 310, and, in a similar manner, obtain point 312. Using the ratio of the distance of point 310 to point 301 and the distance of 301 to 302, a ratio of the distance of point X from 301 in a V40 direction is found. The ratio of the distance point 312 from 301 compared to the distance 301-303 gives the relative distance of X along the V10 direction. This results in a relative location of point X to 301 in the local axis system defined by V10 and V40. The point can then be mapped.
FPCKBD
This subroutine checks the position of a point relative to a patch being currently computed. As was previously described, boxes are constructed to form rows of a face. Since the surface is made up of patches, and it is important to know which patch geometry to work with, a check must be made after each box is developed to see if the point just developed is in the geometry of the correct patch. If a point is developed using patch 1 geometry and the point falls outside the patch 1 border, it will fall on the extension of the patch 1, and it would be wrong. Therefore, the point must be redeveloped using the patch 2 Patch data.
FPGMAL
This subroutine converts the stored patch coefficients from the stored geometric form to the algebraic form of the patch. This routine is a mathematical procedure.
FPIPSC
This subroutine intersects a space curve (arc) with the surface. The input to this routine is in the form of the geometric form of the patch and a circle. The circle is converted to the form of a parametric curve. A function curve is developed from a guess u and w on the patch to the XP point on the curve. The distance between the points is checked and the derivatives of the point on the patch are obtained. A Newton-Rapson iteration moves the point on the patch in the direction of the point on the curve. When the points are exactly the same, then the u and w of the point are known. The u and w are evaluated by the blending functions of the patch and the X, Y and Z values are features which cross the faces of the row.
FPMAP
This subroutine transforms a feature point from the surface grid to the mapping plane. The mapping of a point is relatively easy. The mapping plane is defined by the intersection of two picked lines. The intersection of these two lines is the mapped collation reference point. The picked points on the surface determine the woof and warp directions on the surface, and the first line picked of the two mapping plane lines corresponds to the woof direction on the surface. As each point is found, either a crossing of a box face or an internal feature, its position is known by:
(1) quadrant location,
(2) row and column,
(3) the relative distance to a box corner point,
(4) length of a box side.
In the mapped condition Mface and Nface form a 90° angle. So, by knowing the length of the sides of a box and the number of boxes for each direction, the point can be mapped.
FPDRBD
This subroutine analyzes the mapped feature points and curve fits the results. Once all the points to be mapped are mapped, the array in which the points are stored is evaluated. The important information about the point is:
(1) the collation curve features to the individual mapped points; and
(2) the u values of the points along that curve.
First the array is looped through to find points from a common curve. These points are then sorted in order of the u values from 0 to 1. If a point has a value of less than 0 or greater than 1, it is dropped from the list. The points are then input into a curve fitting routine. The points that were picked as features, such as tooling holes or rivet pattern holes, clearly are not curve fit.
The need for an accurate flat pattern method is well known in a number of different industries. The automobile industry requires flat patterns for parts such as fenders, bumpers, roofs, etc. In the aircraft industry, the need for flat patterns is even greater. Components such as speed brakes, wing skins, fuselage components, and internal parts must be flat patterned. By utilizing this method, the requirement that the individual plies be laid up and trimmed by hand is eliminated, thus opening the way for new concepts in material handling and ultimately large cost savings in the fabrication of composite parts.
We claim:
1. A process for forming an article comprising bonded multiple plies of a woven material arrayed to form a compound curved surface, the process comprising:forming a unique flat pattern equivalent for the compound curved surface for each ply wherein the flat pattern and the compound curved surface each have common reference means; forming each ply to correspond to its flat pattern equivalent; laying up the plies upon a tool which duplicates the compound curved surface wherein the plies and the tool also have the common reference means such that each ply is referenced to the common reference means on the tool; and bonding the plies together to form the article wherein said step of forming a unique flate pattern equivalent for the compound curved surface comprises: forming two tooling lines upon a portion of the surface such that the lines intersect within the boundaries of the portion; forming a surface grid of quadrilateral elements with identifiable points at the vertices of the elements upon the surface such that each of the points is separated from an adjacent point by an identical chordal distance, one such point being coincident with the intersection of the tooling lines, and two groups of such points being formed at consecutive said identical chordal distances along the tooling lines; marking the intersections of selected surface features of the portion of the surface with the surface grid; forming a flat pattern grid having a grid of quadrilateral elements having a grid spacing equal to the chordal distance; and, determining a flat pattern equivalent for the portion of the compound curved surface by translating the compound curved surface grid containing the marked intersections onto the flat pattern grid.
2. The process of claim 1 wherein the tooling lines correspond to the woof and warp of the woven material.
3. The process of claim 1 wherein the flat pattern grid is an orthogonal grid.
4. The process of claim 1 wherein the common reference means comprise two tooling lines which intersect at a collation point.
5. The process of claim 1 wherein the woven material comprises carbon fiber cloth.
6. The process of claim 1 wherein the woven material comprises glass fiber cloth.
7. The process of claim 1 wherein the woven material comprises polyaramid fiber cloth.
8. The process of claim 1 wherein the woven material comprises boron fiber cloth.
9. A process for forming an article comprising at least one layer of an initially flat deformable material arrayed to form a compound curved surface, the process comprising:forming a unique flat pattern equivalent for the compound curved surface for said at least one layer wherein the flat pattern and the compound curved surface each have common reference means; forming said at least one layer to correspond to its flat pattern equivalent; laying up said at least one layer upon a tool which duplicates the compound curved surface wherein said at least one layer and the tool also have the common reference means such that said at least one layer is referenced to the common reference means on the tool; and, forcing said at least one layer onto the tool to form the article, wherein said step of forming a unique flat pattern equivalent for the compound curved surface comprises: forming two tooling lines upon a portion of the surface such that the lines intersect within the boundaries of the portion; forming a surface grid of quadrilateral elements with identifiable points at the vertices of the elements upon the surface such that each of the points is separated from an adjacent point by an identical chordal distance, one such point being coincident with the intersection of the tooling lines, and two groups of such points being formed at consecutive said identical chordal distances along the tooling lines; marking the intersections of selected surface features of the portion of the surface with the surface grid; forming a flat grid having a grid of quadrilateral elements having a grid spacing equal to the chordal distance; and, determining a flat pattern equivalent for the portion of the compound curved surface by translating the compound curved surface grid containing the marked intersections onto the flat grid.
10. The process of claim 9 wherein the tooling lines correspond to the neutral axis lines of the deformable material.
11. The process of claim 10 wherein the deformable material is selected from the group consisting of aluminum and aluminum alloy sheet, titanium and titanium alloy sheet, steel and steel alloy sheet, tin and tin alloy sheet, glass sheet, and hydrocarbon polymer plastic sheet.
| 1982-07-26 | en | 1985-08-13 |
US-22810494-A | Cord assembly and method for making
ABSTRACT
A cord assembly including an insulated electric cord containing a plurality of twisted pairs of insulated solid wire conductors and terminated by a plug having an inner part and an outer part. Terminal end portions of the conductors wrapped about an inner part and trapped between the inner and outer parts extend across an opening in the plug for direct releasable plugging connection with an inline array of insulation displacement contacts (IDCs) carried by a mating connector block mounted on a cross-connect panel. An assembly jig is used to position the conductor terminal end portions and supports the inner part while the terminal end portions are wrapped about the inner part.
BACKGROUND OF THE INVENTION
This invention relates in general to electrical cord assemblies and deals more particularly with an improved modular plug and cord assembly for telephonic and/or data signal transmission and a method for making such an assembly.
The cord assembly of the present invention is particularly adapted for use as a patch cord on a cross-connect panel, such as an AT&T 110 type panel. Such a cross-connect panel meets EIA/TIA Commercial Building Standards --"Category 5" requirements-and provides a convenient centralized location for networking the communications and data processing systems within a building and for interconnecting the systems with an outside telecommunication network. When problems of signal coupling (crosstalk) or intermittent contact (clicking) occur in such a cross-connect panel system these problems can usually be attributed to the patch cords used with the system.
A typical patch cord for a modern cross-connect panel system of the aforedescribed general type includes a flexible stranded wire cord with a patch plug attached to each end. The patch plug generally has a housing containing an inline array of flat contact blades adapted to be simultaneously pressed or plugged into and extracted from an equal number of mating insulation displacement contacts (IDCs) mounted on and projecting from the cross-connect panel. Typically the contact blades within the plug housing are connected to individual stranded wire conductors in the patch cord by IDC terminations.
While stranded wire patch cords afford the advantages of flexibility, for ease of cable buildup during panel board installation, and enhance high frequency transmission performance, due to increased pair twisting capability, these advantages do not adequately compensate for the basic incompatibility of IDC technology and stranded wire. Further, the initial concept of mass termination to enhance efficiency by cross-connecting an entire network (four pair), as opposed to terminating individual conductors, is seriously flawed by insertion of eight relatively large flat formed blade contacts at each end of the patch cord into associated IDC slots on a cross-connect panel.
U.S. Pat. No. 5,226,835 to Baker III, et al entitled Patch Plug For Cross-Connect Equipment, issued Jul. 13, 1993 and assigned to AT&T Bell Laboratories, Murray Hill, New Jersey, addresses the problem of near-end crosstalk associated with a patch plug of the aforedescribed type. The patch plug disclosed in the patent to Baker III et al includes a housing containing pairs of non-insulated flat blade contacts that cross-over and are spaced-apart from each other. The cross-over contacts add a controlled half-twist to each input wire pair for reduced crosstalk between conductor pairs within a patch plug and between adjacent patch plugs. However, the wire pairs are terminated at the flat blade contacts within the plug housing by conventional IDCs on the contacts. The further problems of IDC termination at the contacts and flat blade plugging at the cross-connect panel are not addressed by Baker III, et al.
It is the general aim of the present invention to provide an improved cord assembly which satisfies the requirements of Category 5 and which may be produced at a substantially lower cost than presently available cord assemblies. It is a further aim of the invention to provide an improved patch cord which wholly eliminates the requirements for contacts.
SUMMARY OF THE INVENTION
In accordance with the invention, an improved cord assembly for repeated plugging connection to and extraction from an inline array of insulation displacement connectors (IDCs) includes a cord assembly having a plurality of insulated solid wire conductors and a plug including a housing defining an exterior opening for receiving the insulation displacement connectors. The wire conductors have spaced apart bridging portions which extend across the exterior opening. A retaining means is provided for securing the bridging portions in predetermined positions relative to the housing and each other to cooperate in releasable plugging engagement within the insulation displacement connectors in response to insertion of the inline array of insulation displacement connectors into the exterior opening.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a cord assembly embodying the present invention.
FIG. 2 is a somewhat enlarged fragmentary sectional view through the cord assembly taken generally along the line 2--2 of FIG. 1.
FIG. 3 is an exploded prospective view of the plug shown in FIG. 1.
FIG. 4 is a perspective view of a typical cross-connect panel having two rows of attached connector blocks and shown with two cord assemblies attached thereto.
FIG. 5 is a somewhat enlarged perspective view of a typical connector block.
FIG. 6 is a front view of the plug inner part.
FIG. 7 is a top plan view of the plug inner part.
FIG. 8 is an end elevational view of the plug inner part.
FIG. 9 is a rear elevational view of the plug inner part.
FIG. 10 is a sectional view taken generally along the line 10--10 of FIG. 6.
FIG. 11 is a somewhat enlarged sectional view taken along the line 11--11 of FIG. 6.
FIG. 12 is a somewhat enlarged sectional view taken along the line 12--12 of FIG. 6.
FIG. 13 is a somewhat schematic enlarged fragmentary sectional view through an insulated wire conductor disposed in plugging engagement within an associated IDC.
FIG. 14 is an exploded perspective view illustrating another patch plug embodying the invention.
FIG. 15 is an exploded perspective view of a jig used in making a cord assembly in accordance with the present invention.
FIG. 16 is a perspective view illustrating a step in a method for making the cord assembly shown in FIG. 1.
FIG. 17 is similar to FIG. 16 and illustrates a further step in the method.
FIG. 18 is similar to FIG. 16 and illustrates still another step in the method.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT AND METHOD
Referring now to the drawings, a cord assembly embodying the present invention is shown in FIGS. 1 and 2 and indicated generally by the reference numeral 10. The illustrated cord assembly 10 is particularly adapted for use as a patch cord for a cross-connect panel of the type usually found in large office buildings and other commercial establishments for networking the communications and data processing systems within a building and interconnecting these systems with an outside telecommunications network. The patch cord assembly 10 is generally used to selectively simultaneously interconnect a plurality of individual wire conductors terminated at such a cross-connect panel and includes a patch plug indicated generally at 12 and a patch cord attached to the plug and designated generally by the numeral 14.
In FIG. 4 a typical wall mounted cross-connect panel of a type with which the patch cord assembly 10 is used is shown and indicated generally by the reference numeral 16. The illustrated panel 16 is an AT&T 110 cross-connect panel (110 AWI-100) and includes a frame 18 molded from dielectric plastic material. A plurality of rows of spaced apart first plugging elements 20, 20 and 22, 22 project from the frame. The end portions of individual wire conductors to be interconnected by patch cord assemblies at the cross-connect panel 16 are received in the spaces between the first plugging elements 20, 20 and 22, 22 and terminated by connector blocks indicated generally at 24, 24 which carry double ended IDC connectors and snap into lock-on engagement with the frame 18.
A typical connector block 24, shown in FIG. 5, has a dielectric body 25 and contains an in-line array of double ended connector elements 26, 26. Each connector element 26 has insulation displacement connectors (IDCs) at its opposite ends. The IDCs at the front ends of the connector elements 26, 26 project from the front or frame side of the connector block 24 and simultaneously terminate an inline array of individual wire conductors positioned in spaces between associated first plugging elements 20, 20 and 22, 22 on the frame 18 when the connector block 24 is pushed into snap-on locking engagement with the frame. The IDCs at the opposite or rear ends of the connector elements 26, 26 are exposed in spaces between second plugging elements 28, 28 and 29, 29 integrally formed on the rear end of the connector block body 25 and facilitate plugging connection with a patch plug 12 on an associated patch cord assembly 10.
A prior art patch cord assembly (not shown) for use with a cross-connect panel 16 usually includes a patch plug containing a plurality of plugging contacts which terminate the wire conductors of an associated patch cord attached to the patch plug and define flat contact blades for plugging insertion into the IDCs 26, 26 exposed between the second plugging elements 28, 28 and 29, 29 at the rear or plugging end of the cross-connect panel 16. The illustrated patch cord assembly 10 is particularly adapted for use as a retrofit patch cord assembly to replace a prior art patch cord assembly of the aforedescribed general type and wholly eliminates the need for separate plugging contacts generally employed in such prior art patch cord assemblies, as will be hereinafter evident.
Considering now the patch cord assembly 10 in further detail, the patch plug 12 may take various forms, but preferably, and as shown, it is molded from dielectric plastic material and has an inner part or body indicated generally at 30 and an outer part or shell designated generally by the numeral 32. The inner part is particularly adapted for plugging engagement with a plurality of second plugging elements 28, 28 and 29, 29 on an associated cross-connect panel to establish electrical connection with IDCs. The outer part 32 forms a housing for the inner part, is preferably formed by two substantially identical half sections 34, 34, as best shown in FIG. 3, and secures the patch cord 14 to the plug 12.
The inner part 30, as oriented in FIGS. 6-12, comprises a hollow generally rectangular body member 38 which has a top wall 40, a bottom wall 42, a rear wall 44 and an opening 46 at the forward end. A horizontally spaced apart series of vertically disposed and forwardly open notches 48, 48 are formed in the top wall 40 above the opening 46 as best shown in FIG. 7 and 12. The illustrated plug 12 is adapted to connect eight solid wire conductors to eight associated IDCs, therefore eight notches 48, 48 are provided. Another series of similar notches 50, 50 equal in number to the notches 48, 48 are formed in the bottom wall 42 below the frontal opening 46. Each notch 48 is vertically aligned with an associated notch 50 therebelow, as best shown in FIGS. 6 and 12. A plurality of vertically disposed and forwardly extending support walls 52, 52 cooperate with the top, bottom and rear walls 40, 42 and 44, respectively, and divide the hollow interior of the inner part 30 into a plurality of individual plugging element receptacles. Each support wall 52 has a forward end which terminates at an associated pair of upper and lower notches 48 and 50, as best shown in FIGS. 10 and 12, and defines a central horizontally disposed and forwardly open slot 56. The inner end of each slot 56 terminates at a forwardly facing abutment surface 58 defined by a rear portion of the dividing wall 52.
A series of forwardly and downwardly open recesses 60, 60 are formed in the top wall 40. Each recess 60 opens into an associated plugging element receptacle between a pair of adjacent dividing walls 52, 52 to provide clearance for first plugging elements 20, 20 and 22, 22. Similar but opposing recesses 62, 62 are formed in the bottom wall 42 for the same purpose and open into all but the central plugging element receptacle, as best shown in FIGS. 6 and 10. A boss 64 integrally formed on the bottom wall 42 projects into the central plugging element receptacle as shown in FIGS. 6 and 10, for a purpose which will be hereinafter further explained.
The patch cord 14 comprises a flexible insulated cable which has an outside insulation jacket 66 containing four pair of twisted insulated solid wire conductors C, C. The conductors of each pair are twisted about each other a plurality of times along the length of the cable. Terminal end portions of each pair of conductors C, C extend from and beyond the insulation jacket 66 and are untwisted or separated from each other along sufficient lengths to enable an end portion of each conductor C to be wrapped about an associated outer peripheral surface portion of the inner part 30, as shown in FIG. 2. The terminal end portion of a typical conductor C, shown in FIG. 2, has a first segment 68 which extends for some distance along the outer surface of the back wall 44, a second segment 70 which extends across the outer surface of the top wall 40, a third or bridging segment 72 which extends downwardly across the opening 46 and through an associated pair of upper and lower grooves 48 and 50, a fourth segment 74 which extends along the bottom wall 42, and a fifth segment 76 which extends upwardly along an associated portion of the rear wall 44 terminating on the rear wall, substantially as shown. It will be noted that a portion of the insulation on each third or contact defining segment 72 is displaced exposing a contact portion of each conductor C within the opening 46 and in alignment with an associated slot 56. The exposed or bare contact portion of the solid wire conductor C shown in FIG. 2 is indicated by the numeral 78.
The two half sections 34, 34 which comprise the outer part 32 cooperate in assembly to provide a clamshell-like housing for the inner part 30. Sufficient clearance is provided between the inner surfaces of the outer part 32 and the associated outer peripheral surfaces of inner part 30 to accommodate the terminal end portions of the various conductors C, C wrapped about the inner part. The outer part 32 and the inner part 30 cooperate in assembly to trap the terminal end portions of the various conductors C, C therebetween and retain the various associated segments which comprise these conductor end portions in predetermined positions within and relative to the patch plug 12.
The half sections 34, 34 are preferably bonded or welded together in assembly and define an annular collar 80 which surrounds an associated end portion of the outer insulation jacket 66. Projections 82, 82 on the inner surface of the annular collar 80, best shown in FIG. 2, incise and grip the cord or cable jacket 66 to provide strain relief for the patch cord 14. The half sections 34, 34 further cooperate in assembly to form a rearwardly projecting handle 84 on the plug 12.
When the patch plug 12 is plugged into engagement with an inline array of second plugging elements 28, 28 and 29, 29 on an associated cross-connect panel, such as the panel 16, as shown in FIG. 4 the abutment surfaces 58, 58 on the patch plug cooperate with the forward ends of the projecting second plugging elements 28, 28 and 29, 29 to limit insertion of the latter elements into the patch plug 12. The exposed or bare contact portions 78, 78 of the conductors C, C establish direct contact with IDCs 26, 26 located between associated second plugging elements 28, 28 and 29, 29 on the panel 16 thereby wholly eliminating the need for blade-like plugging contacts such as those employed in patch cord assemblies of the prior art.
Initial plugging engagement of the bridging portion 72 of each insulated conductor C into an associated IDC 26 causes some flattening of the contact surfaces on the wire conductor C as shown in FIG. 13. However, this flattening is advantageous because it increases the area of contact between each conductor C and its associated IDC 26. This flattening or deformation of the conductor in the region of contact does not appreciably increase with repeated plugging and unplugging of the patch cord assembly so that a high degree of contact integrity is maintained throughout the life of the patch cord assembly.
The patch plug 10 cannot be plugged onto the cross-connect panel 16 when one of the second plugging elements 28 is aligned with a central plug receptacle containing a boss 63. The boss 64 cooperates with each second plugging element 28 to provide interference and prevent improper plugging thereby assuring proper plugging polarity.
A patch cord made in accordance with the invention may be provided to accommodate any number of twisted wire pairs. In FIG. 4 there is shown another patch cord assembly indicated at 10b and including a cord 14a containing a single twisted wire pair.
In FIG. 14 there is shown an exploded perspective view of another patch plug 12a used in practicing the invention. The patch plug 12a is similar in most respects to the patch plug 12 previously described and parts of the plug 12a which correspond to previously described parts bear the same reference numeral and a letter a suffix. Specifically, the plug 12a differs from the plug 12 in the manner in which the outer parts 34a, 34a are assembled with the inner part 30a to partially encapsulate the inner part. The outer parts 34a, 34a are adapted for snap-together assembly with the inner part. Resilient locking elements 86, 86 carried by the inner part are received within associated apertures 88, 88 formed in the outer parts 34a, 34a when the plug parts are brought together in assembled relation to each other. A patch cord assembly which utilizes a patch plug of this type is particularly adapted for field assembly, thereby enabling a cord assembly to be produced in any desired length as may be required to satisfy a particular need encountered in the field.
Preparatory to making a patch plug assembly 10 a portion of the outer insulation jacket 66 is removed from a patch cord 14 to expose end portions of the twisted pairs of insulated wire conductors C, C contained within the cord. The terminal end portions of each twisted pair are untwisted and arranged in predetermined spaced part and generally parallel relation to each other. An assembly jig indicated generally at 90 for properly positioning the terminal end portions of the various individual conductors C, C is illustrated in FIG. 15. The jig 90 has a base 92 including a cavity 93 receiving a connector block body 25 which is secured to the base by a set screw 94. The jig 90 further includes a plurality of alignment pins 95, 95 which project from the base 92 and cooperate with the connector block body 25 to provide a means for aligning the individual terminal end portions in proper position relative to each other for wrap around assembly with an associated inner part 30.
After the terminal end portions of the conductors C, C have been positioned on the jig, as shown in FIG. 16, an inner part 30 is plugged onto the upwardly projecting plugging elements 28, 28 and 29, 29 on the jig 90 as shown in FIG. 17. Thus, the individual insulated wire conductors C, C are properly positioned relative to each other and to the inner part to extend across the opening 46 in the inner part 30. Each insulated conductor C is disposed within a pair of aligned notches 48 and 50 in the upper and lower walls of the inner part 30. While the inner part 30 remains in position on the jig 90 the terminal end portions of the wire conductors C, C are wrapped about the outer peripheral surfaces of the inner part, substantially as shown in FIG. 18. It will be noted that the twisted pairs which extend to the outboard ends of the inner part 30 extend in twisted condition for some distance along the outer surface of the rear wall 44 to positions of alignment with the outermost or outboard notches 48 and 50 in the inner part.
Thus, each individual wire conductor is wrapped about the inner part to extend along exterior surfaces of the rear wall, the bottom o wall and the top wall, substantially as shown. Upon completion of the conductor wrapping operation the sub-assembly comprising the patch cord 14 and the inner part 30 appear as shown in FIG. 18. The completed sub-assembly which comprises the inner part with the patch cord 14 wrapped therearound is then removed from the jig 90. The plug assembly is completed by assembling the outer parts 34, 34 on the sub-assembly as previously described.
I claim:
1. A cord assembly for releasable plugging connection to an inline array of insulation displacement connectors including at least two connectors, said cord assembly comprising a plug having a housing defining an exterior opening for receiving the insulation displacement connectors, a cord including a plurality of insulated solid wire conductors having spaced apart bridging portions extending across said exterior opening, reinforcing means on said housing for supporting said bridging portions, and retaining means for securing said bridging portions in predetermined positions relative to said housing and each other to cooperate in releasable plugging engagement within the insulation displacement connectors in response to insertion of the inline array of insulation displacement connectors into said opening.
2. A cord assembly as set forth in claim 1 wherein said housing has an inner part and an outer part and said outer part comprises said retaining means.
3. A cord assembly as set forth in claim 2 wherein said insulated solid wire conductors extend around associated outer surface portions of said inner part between said inner part and said outer part.
4. A cord assembly as set forth in claim 2 wherein said retaining means includes a plurality of notches in said housing receiving associated portions of said insulated solid wire conductors therein.
5. A cord assembly as set forth in claim 4 wherein said notches are disposed at opposite sides of said exterior opening.
6. At cord assembly as set forth in claim 2 wherein said outer part comprises a plurality of sections and said plug includes securing means for maintaining said sections in assembly with each other.
7. A cord assembly as set forth in claim 6 wherein said securing means comprises a bonding agent.
8. A cord assembly as set forth in claim 6 wherein said securing means comprises means for retaining said sections in snap-together assembly with each other.
9. A cord assembly as set forth in claim 1 wherein said reinforcing means comprises a plurality of webs disposed within said exterior opening generally adjacent said bridging portions.
10. A cord assembly as set forth in claim 1 wherein said plug includes a handle projecting from said housing.
11. A cord assembly as set forth in claim 10 wherein said housing has an inner part and an outer part and said handle comprises a portion of said outer part.
12. A cord assembly as set forth in claim 1 wherein said insulated solid wire conductors comprises at least one pair of insulated solid wire conductors twisted about each other a plurality of times along the length of said cord.
13. A cord assembly as set forth in claim 1 wherein the insulation on each of said bridging portions is displaced and an associated contact portion of each of said solid conductors is exposed within said exterior opening by said displaced insulation.
14. A method for making a plug and cord assembly for releasable plugging connection with an inline array of insulation displacement connectors comprising the steps of forming a plug body having an exterior opening for receiving the insulation displacement connectors, forming a plurality of reinforcing webs on said housing in predetermined spaced apart positions within said opening and in bridging relation to said opening providing an electrical cord having a plurality of insulated solid wire conductors, arranging terminal end portions of the conductors in predetermined spaced apart positions relative to each other, positioning the spaced apart terminal end portions adjacent the plug body with contact defining segments of the terminal end portions in bridging relation to the exterior opening and with each of the contact defining segments disposed in parallel alignment with and supported by an associated one of the reinforcing webs, wrapping the remaining segments of the terminal end portions about the plug body, and securing the remaining segments to the plug body.
15. A method for making a plug and cord assembly as set forth in claim 14 including the additional step of forming a plug housing for containing the plug body and the remaining segments of the terminal end portions and wherein the step of securing the remaining segments comprises assembling the plug housing with the plug body trapping the remaining segments between the plug body and the plug housing.
16. A method for making a plug and cord assembly as set forth in claim 15 wherein the plug housing is formed by a plurality of separate parts the step of assembling the plug housing further comprises joining the plug housing parts in snapped together assembly.
17. A method for making a plug and cord assembly as set forth in claim 15 wherein the plug housing is formed by a plurality of parts and the step of assembling further comprises ultrasonically welding the plug housing parts in assembly.
18. A method for making a plug and cord assembly as set forth in claim 15 wherein the plug housing is formed by a plurality of parts and the step of assembling further comprises adhesively bonding the plug housing parts in assembly.
19. A method for making a plug and cord assembly as set forth in claim 14 including the additional step of forming notches in the plug body at opposite sides of the exterior opening and wherein the step of positioning the terminal end portions comprises positioning the contact defining segments the notches before the step of assembling is performed.
| 1994-04-15 | en | 1996-03-05 |
US-41860273-A | Flow control valve
ABSTRACT
A flow control valve which consists of a valve housing including a valve body having a straight cross bore therethrough, a pair of end covers which seal the bored hole at the sides of the valve body and which also serve as a bearing means to rotatably support a rectangular valve plate rotatively positioned within the bored hole, the valve body having a first hole extending through the valve body from one exterior surface thereof to run out at the cross bore and a contoured hole of continuous profile extending from a surface of the valve body to run out at the cross bore, the included angle in the cross bore of the fluid flow path between these holes with the valve plate in full open position relative to these holes being less than 180*.
United States Patent m1 Bubniak l l FLOW CONTROL VALVE [75] Inventor: William C. Bubniak, Troy. Mich.
[731 Assignee: General Motors Corporation,
Detroit, Mich.
[221 Filed: Nov. 23, 1973 [21] Appl No.: 418,602
[52] U.S. Cl. 251/208; 251/305; 251/283 [51] Int. Cl. F1614 47/00; Fl6k 1/22 [58] Field of Search 251/283. 305, 208
[56] References Cited UNITED STATES PATENTS 1,841.568 H1932 Bradley l. 251/305 X 1174,547 10/1939 Bailey t i 251/305 X 2 624 54l l/l953 Ziehol'zi v .1 251/283 2,7591%)7 8/1956 Harzu 251/305 X 2862,685 12/l953 Lundherg 25l/3OS June 10, 1975 Primary ExaminerHenry T. Klinksiek Attorney, Agent, or Firm-Arthur N. Krein [57] ABSTRACT A flow control valve which consists of a valve housing including a valve body having a straight cross bore therethrough a pair of end covers which seal the bored hole at the sides of the valve body and which also serve as a bearing means to rotatably support a rectangular valve plate rotatively positioned within the bored hole. the valve body having a first hole extending through the valve body from one exterior surface thereof to run out at the cross bore and a contoured hole of continuous profile extending from a surface of the valve body to run out at the cross bore, the included angle in the cross bore of the fluid flow path between these holes with the valve plate in full open position relative to these holes being less than 180 4 Claims, 4 Drawing Figures PATENTEUJUH 10 m5 9 1 2 a I; J/ n i {I M "-1 a a 1 I w AZ 5Z Zl7 ,2 x a 4! AW 20 ///A X"'"T J r 1 GEOMETRIC FLOW AREA- m.
MODIF'ED CONVENTIONAL BUTTERFLY VALVE LOW CONTROL VALVE INTAKE MANIFOLD T VACUUM IN. HG.
CLOSED FLOW CONTROL VALVE This invention relates to a flow control valve and, in particular. to a butterfly type valve having a scheduled valve throat area opening.
In certain fluid flow applications as. for example. those associated with the engine of an automotive vehicle, it is necessary to control the flow of fluid as a func tion of certain engine operating conditions or operating parameters. Thus. in certain of these applications, it is necessary to use a flow control valve of a type whose flow characteristics and, therefore, its flow rate can be so regulated as to provide the necessary flow rates required for a particular engine operating condition or operating parameter.
Conventional butterfly valves, because they are simple and reliable. are commonly used in automotive vehicle engines as. for example. to control airflow in the induction passage of an engine. As is well known, the flow area of such a standard conventional butterfly valve is the area of the duct which houses the valve plate of such a valve minus the projected area of the valve plate. Regardless of the shape of the butterfly valve plate, whether it is round, square. or rectangular, and it is contained in a conforming duct. such a standard butterfly valve will have flow areas of a character istic shape. Some latitude can be obtained in modifying this characteristic shape by elongating the valve plate so that the valve closes at angles of less than 90 relative to the centerline of the duct. The degree of flexibility in varying the flow area by this latter defined means is, however, limited. Because of this limitation in a conventional butterfly valve. such a valve is impractical for use as a flow control valve in certain applications.
Shaped plug-type valves, which can be adapted to obtain flow area characteristics other than those obtained by the use of a standard butterfly valve. are also well known in the prior art. Although many design variations of shaped plugvalves are described in patents and in the literature, some basic principles apply to all valves in this category which are listed as follows:
a. The shape of a plug-valve, in combination with its position relative to an orifice, determines the flow area. Therefore, apart from shaping the plugvalve appropriately. it must be positioned accurately if the desired flow characteristic is to be achieved.
b. In its simplest form, plug-valves are not balanced against static pressure differences. Therefore, they can require relatively large operating forces. In some applications, a balance piston is used to minimize this problem.
c. The force versus displacement curve for such a plug-valve usually is non-linear. This in turn can affect the positioning accuracy of the valve when confronted with the use of a limited power actuator.
d. The greater the deviation from a linear flow characteristic for such a plug-valve, the greater the deviation from a uniformly tapered plug. With abrupt curvatures in the tapered plug, the flow area can shift from plane to plane rapidly to the point of compromising precise control of such a plug-valve.
In view of the above comments. it is apparent that, if the design requirements dictate the use of a valve having nonlinear flow area characteristics. a shaped plugvalvc may not be the optimum type valve for use in such application, especially if the valve is to be operated by a limited power source. for example, a realistically sized vacuum actuator.
It is, therefore. the principal object of this invention to provide an improved butterfly valve whereby a rectangular valve plate rotatable in a cross bore of a valve housing is used to uncover a flow area in the valve formed by a contoured hole of continuous profile extending from one surface of the valve housing to run out at the cross bore in the housing, the profile of the contoured hole being of any predetermined size and shape, as desired, to obtain the desired flow area characteristics.
Another object of this invention is to provide an improved butterfly type valve having a simple. practical arrangement for varying the flow area characteristics obtainable by such a valve.
Still another object of this invention is to provide an improved butterfly valve of a configuration to provide a unique solution to flow control applications that can not normally be resolved with conventional butterfly valve structures.
These and other objects of the invention are attained by means of flow control valve having a valve body with a straight-through bored hole in which a rectangular valve plate is rotatively positioned. Two end covers seal the bored hole at the sides of the valve body and also serve as bearings to support the rotatable valve plate. On one side of the body, there is a contoured hole of continuous profile which runs out at the housing bore, and a second hole which extends from a side of the valve body to run out at the cross bore. The valve plate is positioned so that one radial edge thereof moves relative to the contoured hole of continous profile from a closed position relative thereto to an open position relative to this contoured hole whereby a flow area is uncovered which is defined by a segment of the wall formed by the contoured hole in the housing and a radial edge of a valve plate. The scheduling of flow area to meet specific flow requirements is achieved by defining the shape of the contoured hole. The included angle in the cross bore in the valve body in the fluid flow path therein between the hole openings in the body with the valve plate positioned in a full open position relative to these holes being less than For a better understanding of the invention, as well as other objects and further features thereof, reference is bad to the following detailed description of the invention to be read in connection with the accompanying drawings, wherein:
FIG. 1 is a side elevational view of a flow control valve constructed in accordance with the invention showing an embodiment of the valve with a preferred profile for the contoured hole of continuous profile in the valve housing;
FIG. 2 is a sectional view taken along line 22 of FIG. 1;
FIG. 3 is a graph showing the relationship between the flow area and intake manifold for a conventional butterfly valve, :1 modified conventional butterfly valve and a flow control valve constructed in accordance with the invention with a discharge hole of a profile as shown in FIG. I; and,
FIG. 4 is a schematic sectional view, similar to FIG. 2, showing how the relationship between the inlet and discharge holes of the valve can be varied within prescribed limits.
Referring now to FIGS. 1 and 2, the flow control valve, generally designated 10, consists ofa valve housing including a valve body 12 having a straight-through bored hole therein to provide an inner peripheral wall 14. the bore being of a suitable internal diameter to rotat-ably receive a parallel sided valve plate 16, suitably mounted on a shaft 18, for rotation therewith. In the embodiment illustrated, the valve plate I6 is a rectangular, flat valve plate. A pair of side plates or covers 20, suitably secured to the valve body I2. seal the bored hole at opposite sides of the valve housing and also serve to rotatably support the shaft I8 as by having suitable apertures 22 therethrough rotatably receiving the ends of shaft I8 whereby this shaft is positioned for rotation about an axis corresponding to the axis of the bore in the valve body 12. The inner peripheral wall I4 and the inner surfaces of covers thus define a cylindrical cavity in the valve housing which includes the valve body 12 and covers 20.
As best seen in FIG. 2, the body 12 is provided with a hole or passage 24 extending from one surface of the housing to run out at the wall 14 of the cross bore,- this hole 24 being, in the embodiment illustrated, the inlet opeining or passage of the valve and is. for example. of a conventional circular cross section of a diameter suitable for the particular application in which this valve is to be used.
In accordance with the invention, the valve body 12 is also provided with a contoured hole of continuous profile extending from one surface of the valve body to run out at the wall 14 of the cross bore, this hole, in the embodiment illustrated. being the outlet opening or passage of the valve.
The profile of contoured hole 30 can be of any desired configuration to provide for a desired flow area to provide the desired flow characteristics for a given ap plication in which the flow control valve of the invention is to be used. In the embodiment of the contoured hole 30, as shown in FIG. I, the profile of the hole 30 has been scheduled to provide the desired flow characteristics whereby this flow control valve can be used in an engine exhaust gas recirculation system of the type disclosed in copending US. Pat. application Ser. No. 381,754 filed July 23. l973 in the name of Donald J. Pozniak entitled Exhaust Gas Recirculation System with High Rate Valve." assigned to the same assignee as that of the subject patent application. The contoured hole 30 is thus profiled to provide a flow rate area in square inches which is continuously varied in accordance with the intake manifold vacuum of the engine, as shown by the curve for the flow control valve in FIG. 3.
In the above'identified application of the subject flow control valve, the profile of contoured hole 30 is formed with a base edge 32, parallel to the pivotal axis of the valve plate, and with oppositely curved sides 34 and 34a which merge with gradually inclined edge portions 36 and 3641. respectively. The inclined edge portions 36 and 36: each merge with an edge 38 and 380, respectively. inclined at a steeper angle relative to the base edge 32 and the edges 36 and 36a, edges 38 and 38a then merging with edges 40 and 400, respectively, that are at right angle to the base edge 32, these two edges 40 and 40a being joined together by a curved top edge 42. For more details regarding the dimensional relationship of the various edges of the contoured hole 30 and the overall size thereof, as used in a particular application. reference is made to the above-identified patent application Ser. No. 323L754, and, accordingly, these dimensions are not described herein since they are not deemed necessary for an understanding of the invention.
As best seen in FIG. 2, the valve plate 16 is centered on the shaft 18 to provide a balanced butterfly valve arrangement whereby the valve plate may be pivoted with a minimum power force through a suitable power actuator, not shown, operatively connected to the valve actuator lever 44 fixed to the shaft 18. With this arrangement, the pressure of incoming fluid through hole 24 would act on the face 46 of the valve plate I6 equally on opposite sides of the pivotal axis of the valve plate. In a similar manner. any fluid pressure on the backside 48 ofthe valve plate [6 would also be equally balanced about opposite sides of this valve plate from its pivotal axis.
The width of the valve plate 16 is such that the radi' ally extending side edges thereof would have minimum sliding clearance relative to the interior surfaces of the end covers 20 to limit fluid flow therebetween while the radial outermost edges of the valve plate are similarly positioned relative to the inner peripheral surface of wall 14 formed by the bore in the valve body. One of these radial edges of the valve plate is defined as the flow control edge 50 while the other edge is defined as the sealing edge 52.
The rotative extent of travel of the valve plate 16 in a particular embodiment would be limited to a predetermined number of degrees, as desired. whereby the flow control edge 50 of this valve plate would be permitted to travel between a closed position and an open position relative to the contoured hole 30, these positions being shown schematically be the broken line positions of the valve plate 16 identified as positions A and B, respectively. in the embodiment shown in FIG. 2. At the same time the sealing edge 52 would only traverse over nonapertured portions of the wall 14 so as to prevent fluid flow around this edge of the valve. Accordingly. to permit such movement of the valve plate to effect proper control of fluid flow through the contoured hole 30, the angular extent C between the extreme outer edges of the hole 24 and of the contoured hole 30, in the fluid flow path in the bored opening of the valve body as defined by these openings in wall 14 and the face 46 of the valve plate, is thus less than as will become more apparent from the description of the embodiment of the flow control valve illustrated in FIG. 4, to be described.
Again referring to FIG. 2, the valve plate 16, in this embodiment, would rotate in a counterclockwise direction when moving from its closed position A to its fully opened position B relative to the contoured hole 30.
When the valve plate 16 is in a closed position A, no contoured hole 30 area is uncovered by the valve plate and thus fluid flow from the hole or passage 24 through the contoured hole 30 is prevented. As the valve plate 16 is rotated in a counterclockwise direction, to the position seen in FIG. 2, the control edge would uncover a portion of the contoured hole 30 to define a flow area therethrough. As seen in FIG. 1, a flow area is thus uncovered defined by a segment of the wall formed by the contoured hole 30 in the valve body 12 and the control edge 50 of the valve plate. It is apparent that the size of the uncovered area or flow area for a given valve plate angle and diameter of bore depends upon the average width of the opening. As the result of this, innumerable valve area-angle relationships can be obtained simply by incorporating the desired profile of the contoured hole in the valve body. More specifically. any desired positive or Zero slope flow area characteristic can be obtained by this means. Included as part of the overall flow area would be flow area as defined above of the contoured hole 30 and the leakage area around the valve and the flow are of a separate bypass. il' dc sired. these last two area being constant for a particular valve design. as is well known.
As previously mentioned. the scheduling ot'lluid flow area to meet a specific flow requirement for a particular application is achieved by defining the shape or profile of the contoured hole 30, as desired. This is a relatively simple procedure. since the controlling orifice area uncovered by the control edge of the valve plate is always in a plane parallel to the continuous cross section of the contoured hole 30. Thus. this mechanism. as described. for controlling the flow area is analagous to the method used in a simple sliding plate valve in which a flat plate with a hole therethrough is uncovered by a second flat plate. However. in the arrangement of the subject flow control valve. the valve plate 16 is essentially pressure balanced so that the power requirements for positioning the valve plate are minimized. which would not be the case with a simple sliding plate valve.
Referring now to FIG. 3. the upper curve shown in this figure defines the variation in geometric flow area required and obtained with the subject flow control valve for an exhaust gas recirculation control system as disclosed in the above-identified patent application Ser. No. 381.754. these flow area requirements being plotted as a function of intake manifold vacuum for an internal combustion engine.
The lower dotted line curve in this figure defines the flow area of a conventional butterfly valve also plotted as a function of intake manifold vacuum. this flow area being the area of the duct which houses the valve plate minus the projected area of the valve plate. By elongating the valve plate of a conventional butterfly valve so that the valve closes at angles of less than 90 relative to the centerline of the duct. the characteristic shape of the flow area ofthe conventional butterfly valve can be varied as shown by the shaded area in FIG. 3. From a comparison of the curve for a conventional butterfly valve and the shaded area of a modified conventional butterfly valve. as compared to the curve of the subject flow control valve. it is apparent that a conventional butterfly valve. as previously known. would not be acceptable for use in certain applications. such as the exhaust gas recirculation system disclosed in the above identified US. Pat. application Ser. No. 381,754.
In the embodiment of the flow control valve shown in FIGS. 1 and 2. the hole 24 and the contoured hole 30 are shown as positioned as substantially right angles to each other and extending from the bottom and a side ofthc valve body. However. it is to be realized that the position of these holes relative to the outer surfaces of the valve body can be chosen. as desired. it only being necessary that the radial extent in the bore of the valve body between the hole 24 and the contoured hole 30. through the wall 14. in the flow path portion between these holes as controlled by the valve plate. be less than I80". as previously described.
Thus. for example. in the embodiment illustrated in FIG. 4. where like numerals indicate like parts. the hole or passage 24 is curved within the valve body 12 so that this hole extends from one side of the valve body into til the bore therein forming wall 14. while the hole 30. which would be the contoured hole 30, of a suitable profile. extends from the opposite side of the valve body to extend into the bored hole therein. As can be seen in this figure. the angular extent between these holes is just sufficiently less than 180. whereby. as the valve plate I6 as it rotates from the closed position shown in solid line relative to the contoured hole to its open position shown in broken line. its sealing edge will always traverse a nonapertured portion of the inner peripheral wall I4 in the valve body formed by the bore therein.
It is to be realized that although the contoured hole 30. shown as the discharge passage from the valve body, flow through which is controlled by the vahe plate I6, it may be used as the inlet passage for the valve and. of course. then the hole or passage 24 would serve as the outlet passage.
In addition. since it is apparent that the subject flow control valve would be connected to suitable intake and discharge ducts. in communication with the passage 24 and contoured hole 30. respectively. with reference to FIGS. I and 2. the description of the contoured hole 30 as being of continuous profile merely defines the critical profile portion of the contoured hole closely adjacent to the wall 40. Thus. for example. with reference to FIG. 2, the flow path downstream of a line tangential to the arc of the wall 14 and at right angle to the contoured wall of the contoured hole 30 could be enlarged and need not be contoured. However. for ease and accuracy in manufacturing. it is preferable to make the contoured hole 30 ofcontinuous profile from a surface of the valve body to the wall 14 defined by the through bore in the valve body 12.
From the above description. it is apparent that while the subject flow control valve is essentially a butterfly valve, it is a valve in which the flow area can be scheduled, as desired. to meet the flow requirements of a given application.
What is claimed is:
I. A flow control valve including a valve body having a circular cross bore therethrough. side covers secured to opposite sides of said valve body to enclose said cross bore. a contoured hole of continuous profile ex tending from one surface of said valve body to run out at said cross bore, said contoured hole in cross section being ofa predetermined scheduled area configuration. a hole extending from a surface of said valve body to run out at said cross bore. a shaft journalled in said side covers and extending through said cross bore concentrically therewith. a rectangular valve plate fixed to said shaft for rotation in said cross bore about the axis of rotation of said shaft for movement between a closed pt sition and a full open position relative to said contoured hole. the included angle in the cross bore between said contoured hole and said hole when said valve plate is in said full open position being less than I", said valve plate when in an open position defining with said contoured hole a flow area. the size of which increases at a predetermined fixed rate relative to the rotativc angle of said valve plate as determined by the predetermined scheduled area configuration of said contoured hole.
2. A flow control valve including housing means haw ing an enclosed cylindrical cavity therein ofa predetermined axial length defined by an annular inner peripheral wall and oposed side walls in said housing means.
a first hole extending from an outer surface of said housing means through said inner peripheral wall, a second hole, contoured and of continuous profile, extending from an outer surface of said housing means through said inner peripheral wall, the cross section of said second hole defining a predetermined scheduled area, a shaft rotatably journalled in said housing means to extend through said cylindrical cavity concentric therewith, a flat valve plate of a length and width corresponding to the diameter and length of said cylindrical cavity fixed to said shaft for rotation in said cylindrical cavity about the axis of rotation of said shaft whereby one radial edge of said valve plate is moved between a closed position and a full open position relative to said second hole, the angular spacing between the intersection of said first hole and said second hole with said inner peripheral wall being such that, as said valve plate is rotated between said closed position and said open position, the opposite radial edge of said valve plate will always be in sealing relationship to non-apertured portions of said inner peripheral wall.
3. A flow control valve including housing means having an enclosed cylindrical cavity therein of a predetermined diameter and ofa predetermined axial length defined by an annular inner peripheral wall and opposed side walls in said housing means, a first hole extending from an outer surface of said housing means to run out at said inner peripheral wall, a contoured hole of continuous profile and of a predetermined scheduled area in cross section extending from an outer surface of said housing means to run out at said inner peripheral wall, a shaft rotatably journalled in said housing means and extending coaxially through said cylindrical cavity, a valve plate within said cylindrical cavity fixed to said shaft for rotation therewith about the axis of rotation of said shaft whereby one radial edge of said valve plate is moved between a closed position and a full open position relative to said contoured hole, said valve plate being of a length and width complementary to the di ameter and length of said cylindrical cavity, both said first hole and said contoured hole extending through said inner peripheral wall on less than one-half of the circumferential length of said inner peripheral wall on the flow side of said valve plate whereby as said one radial edge of said valve plate traverses over said contoured hole as said valve plate is moved from said closed position to said full open position, the opposite radial edge of said valve plate will traverse over only nonaperture portions of said inner peripheral wall, said predetermined scheduled area in cross section of said contoured hole being as desired, whereby. as said one radial edge of said valve plate traverses over said contoured hole as said valve plate is moved toward said full open position. a flow area is provided, the size of which increases at a predetermined rate, as desired. relative to the opening angular movement of said valve platev 4. A flow control valve including a valve body having a straight-through annular bored hole therein, side cov ers fixed to opposite sides of said valve body to seal said bored hole at said sides of said valve body, a shaft extending coaxially through said bored hole and rotatably journalled in said side covers, a valve plate rotatably positioned in said bored hole and fixed to said shaft for rotation about the axis of rotation of said shaft, an inlet passage in said valve body which runs out at said bored hole, a contoured outlet passage of continuous profile in said valve body which runs out at said bored hole, the cross section of said contoured outlet passage being of a predetermined scheduled area profile, the included run out angle of said inlet passage and said contoured outlet passage into said bored hole being less than one hundred eighty degrees, said valve plate being rotatable in said bored hole whereby a radial edge of said valve plate is moved between a closed position relative to said contoured outlet passage to a full open position relative to said contoured outlet passage, the flow area from said valve body as said radial edge is moved be tween said closed position to said full open position being defined by a segment of the wall in said valve body formed by said contoured outlet passage therein and said radial edge of said valve plate, said flow area being in a plane parallel to the continuous cross section of said contoured outlet passage with a predetermined scheduled flow area for each incremental angular movement of said valve plate.
1. A flow control valve including a valve body having a circular cross bore therethrough, side covers secured to opposite sides of said valve body to enclose said cross bore, a contoured hole of continuous profile extending from one surface of said valve body to run out at said cross bore, said contoured hole in cross section being of a predetermined scheduled area configuration, a hole extending from a surface of said valve body to run out at said cross bore, a shaft journalled in said side covers and extending through said cross bore concentrically therewith, a rectangular valve plate fixed to said shaft for rotation in said cross bore about the axis of rotation of said shaft for movement between a closed position and a full open position relative to said contoured hole, the included angle in the cross bore between said contoured hole and said hole when said valve plate is in said full open position being less than 180*, said valve plate when in an open position defining with said contoured hole a flow area, the size of which increases at a predetermined fixed rate relative to the rotative angle of said valve plate as determined by the predetermined scheduled area configuration of said contoured hole.
2. A flow control valve including housing means having an enclosed cylindrical cavity therein of a predetermined axial length defined by an annular inner peripheral wall and oposed side walls in said housing means, a first hole extending from an outer surface of said housing means through said inner peripheral wall, a second hole, contoured and of continuous profile, extending from an outer surface of said housing means through said inner peripheral wall, the cross section of said second hole defining a predetermined scheduled area, a shaft rotatably journalled in said housing means to extend through said cylindrical cavity concentric therewith, a flat valve plate of a length and width corresponding to the diameter and length of said cylindrical cavity fixed to said shaft for rotation in said cylindrical cavity about the axis of rotation of said shaft whereby one radial edge of said valve plate is moved between a closed position and a full open position relative to said second hole, the angular spacing between the intersection of said first hole and said second hole with said inner peripheral wall being such that, as said valve plate is rotated between said closed position and said open position, the opposite radial edge of said valve plate will always be in sealing relationship to non-apertured portions of said inner peripheral wall.
3. A flow control valve including housing means having an enclosed cylindrical cavity therein of a perdetermined diameter and of a predetermined axial length defined by an annular inner peripheral wall and opposed side walls in said housing means, a first hole extending from an outer surface of said housing means to run out at said inner peripheral wall, a contoured hole of continuous profile and of a predetermined scheduled area in cross section extending from an outer surface of said housing means to run out at said inner peripheral wall, a shaft rotatably journalled in said housing means and extending coaxially through said cylindrical cavity, a valve plate within said cylindrical cavity fixed to said shaft for rotation therewith about the axis of rotation of said shaft whereby one radial edge of said valve plate is moved between a closed position and a full open position relative to said contoured hole, said valve plate being of a length and width complementary to the diameter and length of said cylindrical cavity, both said first hole and said contoured hole extending through said inner peripheral wall on less than one-half of the circumferential length of said inner peripheral wall on the flow side of said valve plate whereby as said one radial edge of said valve plate traverses over said contoured hole as said valve plate is moved from said closed position to said full open position, the opposite radial edge of said valve plate will traverse over only non-aperture portions of said inner peripheral wall, said predetermined scheduled area in cross section of said contoured hole being as desired, whereby, as said one radial edge of said valve plate traverses over said contoured hole as said valve plate is moved toward said full open position, a flow area is provided, the size of which increases at a predetermined rate, as desired, relative to the opening angular movement of said valve plate.
4. A flow control valve including a valve body having a straight-through annular bored hole therein, side covers fixed to opposite sides of said valve body to seal said bored hole at said sides of said valve body, a shaft extending coaxially through said bored hole and rotatably journalled in said side covers, a valve plate rotatably positioned in said bored hole and fixed to said shaft for rotation about the axis of rotation of said shaft, an inlet passage in said valve body which runs out at said bored hole, a contoured outlet passage of continuous profile in said valve body which runs out at said bored hole, the cross section of said contoured outlet passage being of a predetermined scheduled area profile, the included run out angle of said inlet passage and said contoured outlet passage into said bored hole being less than one hundred eighty degrees, said valve plate being rotatable in said bored hole whereby a radial edge of said valve plate is moved between a closed position relative to said contoured outlet passage to a full open position relative to said contoured outlet passage, the flow area from said valve body as said radial edge is moved between said closed position to said full open position being defined by a segment of the wall in said valve body formed by said contoured outlet passage therein and said radial edge of said valve plate, said flow area being in a plane parallel to the continuous cross section of said contoured outlet passage with a predetermined scheduled flow area for each incremental angular movement of said valve plate.
| 1973-11-23 | en | 1975-06-10 |
US-42925973-A | Capacitive weighted acoustic surface wave filter
ABSTRACT
A new technique for weighting acoustic surface wave filter interdigital transducers in which transducer pads are first deposited on a substrate, a dielectric layer deposited thereover and interdigital fingers deposited atop the dielectric layer with the fingers having a variable and selectable area where they overlap the dielectric to thereby effectively vary the amount of capacitive coupling of each finger and resulting in an acoustic wave which is uniform across its beam width.
United States Patent [191 Rosenfeld CAPACITIVE WEIGHTED ACOUSTIC SURFACE WAVE FILTER [75] Inventor: Ronald C. Rosenfeld, Richardson,
Tex.
[73] Assignee: Texas Instruments, Incorporated,
Dallas, Tex.
[22] Filed: Dec. 28, 1973 21 Appl. No.: 429,259
[52] US. Cl 333/72; 310/9.8; 333/30 R [51] Int. Cl. H03H 9/02; HO3l-l 9/06; H03 9/32; H01L 41/10 [58] Field of Search 333/30 R, 70 T, 72; 310/8, 310/8.l, 9.7, 9.8
[56] References Cited UNITED STATES PATENTS 6/1971 Adler et a1 333/72 X [451 Sept. 9, 1975 3,688,223 8/1972 Pratt ct al., 333/72 Primary Examiner lames W. Lawrence Assistant Examiner-Marvin Nussbaum Attorney, Agent, or Firm-Haro1d Levine; James T. Comfort; William E. Hiller [5 7 ABSTRACT 6 Claims, 9 Drawing Figures F/GSQ CAPACITIVE WEIGI-ITED ACOUSTIC SURFACE WAVE FILTER BACKGROUND OF THE INVENTION This invention relates to acoustic surface wave devices in general and more particularly to an improved method of weighting an acoustic surface wave filter. Surface wave acoustic devices are gaining wide-spread use as filters, delay lines and the like. In particular, in frequency ranges between mhz and 1 ghz, devices which are compact and provide numerous advantages over inductive-capacitive type filters and tuned electromagnetic waveguides are possible This results directly from the fact that acoustic waves travel at a much slower speed than electromagnetic waves and thus, the size ofa structure can be correspondingly smaller in the orderof 10".
When used in filtering applications these devices generally comprise a piezoelectric substrate on which are deposited two spaced transducers. The most common type of transducer used is what is known as the interdigital transducer wherein a plurality offingers extend from a transducer pad on each side of the substrate and have overlapping portions. Electric fields created between the overlapping fingers of the transducer excite the piezoelectric material to generate the surface waves. In order to obtain the proper filter response, weighting of the interdigital fingers is necessary. The manner of designing such filters is described in a paper published in the IEEE Transactions on Microwave Theories and Techniques entitled Impulse Model Design of Acoustic Surface Wave Filters" by C. S. Hartmann, D. T. Bell, Jr., and R. C. Rosenfeld, Vol. MTF-2l No. 4, April, 1973, pp. 162l75. In the design method described therein, the impulse response is used with the desired frequency response converted into a time response through the use of Fourier transforms and the weighting then done in accordance with the time response obtained. The most common method of obtaining weighting is through the use of variable overlap in which the overlap pattern essentially follows the type of response required. A transducer of this nature results in a surface wave which has a constant amplitude but a non-uniform beam width. The wave is transmitted through the piezoelectric material to a second transducer which will have voltages induced therein in accordance with the "transmitted wave.
Ideally, it is desirable to have half of the filtering done by each of the two transducers. In practice, however, such is not possible unless a multi-strip coupler is placed between the two transducers. An'arrangement such as this is shown in the above identified article. When using such couplers, the two transducers must be off-set and the device becomes larger and suffers from greater losses.
Although transducers weighted in this manner operate fairly well, they do suffer from a number of disadvantages. The uneven overlap in such filters results in diffraction effects which can severely degrade the response of certain high performance filters. This diffraction is an effect in which the wave fronts from the smaller overlapping pairs tend to not move in a planar beam but, tend to have a beam which becomes circular which, when it intersects the other transducers, will resultin a distorted output, i.e., the waves become like the waves emanating from a point source and could be analogized to the ripples formed when a stone is thrown in the water. With large overlap, such does not occur and the wave is more likely to have a straight front avoiding such distortion effects. In addition, the electric fields between the fingers extend beyond the fingers creating undesirable effects. If all fingers are of the same overlap, these effects may be easily corrected. However, unequal overlap results in varying fields at the ends, also known as fringing fields. In addition, analysis of variable overlap fingers, also known apodized fingers, requires that each transducer must be channeled and each channel analyzed separately. Also, as noted above, in order for both the input and output transducers to be weighted, multi-strip couplers must be used. Because of the number of electrodes involved, these multi-strip couplers cannot be used in a practical device which is constructed on a low coupling substrate such as quartz.
Another type of weighting is known as the finger removal technique, in which sets of fingers are removed to come up with an average which is equal to the desired response. All fingers in this type of device are of the same length but groups of fingers are selectively removed to obtain the desired response. Although such weighting overcomes some of the problems noted above, it creates other problems, particularly in that smooth weighting is difficult to obtain.
Thus, it can be seen that there is a need for an improved weighting technique which avoids the disadvantages of these different types of prior art weighting techniques to obtain a better filter.
SUMMARY OF THE INVENTION The present invention provides a new weighting technique. Rather than weighting by means of variable overlap or by selective finger removal, the present invention uses fingers having equal overlap and obtains weighting through a variable capacitive coupling to each of the individual fingers. Two transducer pads are first deposited on a piezoelectric substrate, over which is placed a dielectric layer. The fingers are then deposited with the portion of the finger overlapping the dielectric and thus, forming the weighting capacitor or pad which gives the desired weighting. The result is a surface wave having a uniform beam width but having variable amplitude. That is, the amount of energy picked up by the receiving transducer will be a function of the product of the amplitude of the surface wave and its beam width. The prior art devices control beam width to obtain the desired response while maintaining constant amplitude. In the present invention on the other hand, beam width is kept constant while the amplitude is varied through the use of capacitive coupling. The result of this weighting technique is that both input and output transducers may be weighted with no diffi culty since the beam width is uniform. In addition, since all finger overlaps are equal, the above mentioned diffraction effectsv are substantially eliminated as are the fringing effects. The insertion loss associated with apodized fingers is eliminated and analysis of the filter is simplified since the capacitively weighted filter does not need to be channeled and each channel analyzed separately as in the apodized filter. In comparison to the finger removal technique, much smoother weighting can be obtained.
In the preferred embodiment, extra fabrication steps are required in that a transducer pad and a dielectric layer must be deposited before the deposit of the finger whereas in the prior art device, only one step of depositing the fingers and pad was required. However, these steps are all well known steps commonly used in the manufacture of semiconductor devices, and the extra effort involved is minimal. For example. the sametechniques which are used for producing thin film tantalum oxide and anodized tantalum capacitors in microcircuits can be used in the present invention. In addition, a second embodiment in which the capacitors are formed in a single step is also shown. The filters made according to the present invention have a somewhat increased electrical Q. However, it has been shown that this increase is not significant as long as the capacitance of the largest weighting capacitor is much larger than the capacitance of an individual finger in the transducer, i.e., the capacitance between two opposite fingers. The capacitor introduces asmall amount of phase shift which, in some cases, must be compensated for. In filters using quartz as a..substrate,such phase shift has been found to be negligible and the phase shift in a substrate of LiNbO almost negligible. Although the possibility of capacitor shorting due topin holes is a possibility, the yield for thin film capacitors is presently of the ,order of 99% for capacitors on a two inch slice and thus, the required capacitors can be reliably produced. The capacitance will, of course, depend to some degree on the thickness of the dielectric. However, the present state of the art in manufacturing capacitors of this nature indicates that control within is possible on a production line, which accuracy is sufficient for the present device.
A further alternate embodiment of theinvention contemplates the replacement of the dielectric layer with resistive material. In this embodiment, the filter Q is not increased. The useof resistance coupling however, will result in additional loss, which may in some applications be tolerable. Furthermore, an inductor may be placed in series with each finger using available techniques and will result in a further advantage in that an external inductor may not be needed for, matching the transducer. However, in most cases, this would not be practical because of fabrication and size problems.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view partially in schematic form illustrating a prior art apodized filter. t
FIG. 2 is a waveform diagram illustrating the amplitude of the wave of the filter of FIG.- 1.
FIG. 3 is aplan view of a filter according to the pres-, ent invention. I i
FIG. 4 illustrates the wave'as sociated with the filter of FIG. 3.
FIGS. 5a, b and c are plan views illustrating the steps followed in making the transducers on the filter of FIG.
FIG. 6 is aschematic diagram of the equivalent circuit of a single finger pair of the filter of FIG. 3.
FIG. 7 is a plan view of an alternate embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. I illustrates atypical prior art filter arrangement such as those described in the above referenced paper. As shown on FIG. 1, transducers are deposited on each end of a substrate 11. Thus, there is shown an intcrdigital transducer 13 connected to a source 15 at one end and-an interdigital transducer 17 connected to a load 19 at the other end. Each of the transducers includes a pair of transducer pads 21 from which extend a plurality of overlapping interdigital fingers 23. The transducer 13 has its interdigital fingers apodized or weighted by overlapping as is apparent from the FIG- URE. The voltages induced on opposite fingers, for example, fingers 25 and 27, will result in an electric field therebetween which will excite the piezoelectric material to induce acoustic surface waves therein. The electric field will have fringes such as that indicated as 29 on the FIGURE i.e., the electric field will extend from the ends of the fingers over to the next finger. This effect will vary much more in a filterweighted in this manner than in the transducer 17 at the other end, wherein equal overlap is present. Also shown on FIG. 1 is a representation 31 of the type of wave produced by the transducer 13. The wave essentially takes the shape of the transducer overlap pattern. Those pairs which have small overlap result in wave fronts which have aytendency to be subject to diffraction effects as is illustrated by the wave front 33. Since the pair overlap from which it was generated begins to approach a point source, this wave front tends to radiate equally in alldirections rather than in a straight line as does the wave frontindicated as 35. t
The amplitude of the wave will be constant as indicated by FIG. 2 which represents a cross-sectional elevation view looking at the wave 31 along the lines II- -II. As noted above,'to properly pick up a wave such as wave 31, the interdigital transducer 17 must have fingers of equal length and thus, without the use of other measures such as multi-strip couplers, weighting of both transducers is not possible in this arrangement.-
FIG. 3 illustrates thetransducer of the present invention and the type of wave formed thereby, with similar parts given identical reference numerals to FIG. 1. In this embodiment, the transducers 13 and 17 on substrate 11,.each have fingers of constant'Overlap but which are capacitively weighted as will be described below. The result is a wave indicated by 41 which has a constant beam width. Because of the constant beam width, weighting of both transducers is possible. In ad dition, the fringing problems and the diffraction effect associated with thewave front 33 above are not pres ent. As long as the distance between transducers is not too large with respect to the beam width, diffraction will not be significant. In this regard, the width of overlap indicated as w on FIG. 3, which is also the beam width, should be made to be many wavelengths long in 'wellknown fashion. In a transducer of this nature. the
finger spacing will be equal to the wavelength to be reproduced in well-known fashion i.e., the wavelength A corresponding to the center frequency of the filter. The substrate should be at least 10 X A thick and the distance d between transducers approximately equal to twice the thickness. Below the center portion of the substrate a short circuit plate 43 may be deposited in conventional fashion to reduce cross-talk.
FIG. 4 illustrates the type of wave generated by the arrangement of the present invention. Unlike the wave of FIG. 2 which is of constant amplitude, the wave is of variable amplitude with the amplitude following the desired response pattern just as the beam width did in the prior art embodiment. The result at the output transducer is approximately equivalent since the resulting energy will be a function of-the product of beam width and amplitude.
FIGS. 50. b. and c illustrate the process used in making a transducer according to the present invention. A substrate which may. for example. be quartz or LiNbO will be prepared in conventional fashion. Upon the substrate is deposited a pair of transducer pads 51 and 52. These may be deposited in any well-known manner such as by evaporation or sputtering. Over the major portion of the deposited transducer pads 51 and 52. is deposited a dielectric material using \\elll-:no.wn tech niques such as those used in producing thin film capaci tors. These dielectric layers indicated as 53 will cover all except the edges 54 and 55 which will allow space for external leads to be connected to the transducer pads. In the final step, over the pads and dielectric, are deposited fingers 57, each of equal length as they extend out from the edge of the dielectric end pads but each having a selected size 'ontheir end portion indicated by the reference numeral 59. This end portion 59 will result in a capacitor being formed between itself and its respective transducer pad which has a Weighting capacitance which is expressedby: I
where e is the permittivity of the dielectric and l the thickness of the dielectric and .4 the area of the end portion 59.
In selecting the capacitor sizes. techniques similar to that described in the above referenced paper are used with weighting done as a function of the impulse response of the filter. Thus. rather than varying overlap. the weighting is done through varying the capacitor which couples the finger to the source. The capacitor results in a voltage drop which reduces the voltage between adjacent fingers and thereby reduces the driving strength of the electric field provided thereby. Thus, the magnitude of the finger weighting is controlled by its capacitance which is in turn a function directly of the area of the portion 59 since each of the other parameters in the capacitance equation remain constant.
FIG. 6 illustrates an equivalent circuit of a weighted finger. This model assumes a weak coupling approximation in that the performance of an individual finger does not depend on the number or location of other fingers. As illustrated on FIG. 6, C is the weighting capacitor which can be varied from finger to finger with C. and R, representing the series equivalent capacitance and radiation resistance of the finger and V the source voltage. The amplitude of the acoustic surface wave is proportional to the voltage V, which is given by the following equation:
The phase of the \oltagc V. is represented by:
It has been shown that the phase shift caused by the weighting capacitor is negligible on quartz and almost negligible on LiNbO;,. Also. although the weighting ca pacitor increases the filters electrical Q, this increase has been found not to be significant as long as the capacitance of the largest weighting capacitor the capacitor formed by the end 61 on FIG. 50, is much larger than the capacitance of an individual finger or more correctly, the capacitance between two fingers such as that between the fingers 63 and 65. Note that this will almost always be the case since the crosssectional area of the fingers facing each other will be relatively small.-
FIG. 7 illustrates an alternate embodiment of the invention which permits depositing the capacitively weighted fingers all at once. In this arrangement, the pads 51 and 52 are horizontally separated from the fingers 57 rather than vertically separated as in the embodiment of FIG. 5. Thus, in depositing the arrangement. a mask is used which separates the fingers 57 from the pads 52, with indentations being formed in the pads and spacing between the indentations and fingers used to provide the desired capacitance. Capacitance here is dependent on the dimensions of the indentations and the width indicated by l on FIG. 7. However, the calculation is more complex than the parallel-plate calculation used above. Because of the small capacitance per unit length between the finger and indentation, relatively large distances will possibly be required thereby materially increasing the size of this arrangement and possibly making its use less desirable than the embodiments of FIG. 5 even though that embodiment requires additional processing steps.
In other embodiments, it is also possible for the cou pling between the pads 51 and 52 and the fingers 57 of FIG. 5 to be resistive or inductive. In each case. conventional techniques may be used to interpose either a resistor or inductor between the pads and the respective fingers with the impedence thereof selected according to the required weighting.
In some cases it may prove advantageous to short some of the fingers to the bonding pads instead of coupling them to the pads through weighting capacitors. Alternatively, it may also be advantageous to leave some of the fingers floating, that is, neither coupled to the pad through weighting capacitors nor shorted to the pad. Shorting a finger to the pad, may in some cases decrease the value required for the largest weighting capacitor which makes fabrication easier. Floating a finger is an alternative to fabricating an extremely small weighting capacitor. This also makes fabrication easier. Also the weighting technique can be used in conjunction with other weighting techniques. That is. capacitive weighting could be used in the same transducers with overlap weighting or finger withdrawal mentioned above. or with other weighting techniques not previously mentioned such as phase weighting where the weighting is accomplished by varying the spacing between the elcctrodes. These and other modifications may be made without departing from the spirit of the invention which is intended to be limited solely b the appended claims.
\Vhat is claimed is:
I. An acoustic surface wave filter including at least one weighted transducer comprising:
substrate means including at least one surface of piezoelectric material,
an interdigital acoustic surface wave transducer disposed on said at least one surface of piexoeleetric material, said transducer including 7 I i first and second transducer pads disposed on said piezoelectric surface in aligned spaced apart relationship, v i a first plurality of fingers disposed on said piezoelectric surface and operably associated with said first transducer pad, I a second plurality of fingers disposed on said piezoelectric surface and operably associated with said second transducer pad, said second plurality of fingers being parallel to and interdigitated with said first plurality of fingers so as to have overlapping finger portions, I i l means defining respective capacitive relationships coupling the individual fingers included in said first v I plurality of fingers to said first transducer'pad, v
means defining respective capacitive relationships coupling the individual fingers included in said sec ond plurality of fingers to said second transducer pad,' and g i I said capacitive relationship-defining means being selectcd to provide a predetermined weighting to the interdigitated first and secondpluralities of fingers for obtaining a desired impulse response.
2. An acoustic surface wave filter as set forth in claim 1, wher'ein'said overlapping finger port ions of said first and second pluralities'of fingers are of equal lengths.
3 An acoustic surface wave filter as set forth in claim 2, wherein said first and second transducer pads con -.tain indentations into which corresponding fingers extend with the fingers being spaced from the indentation-defining transducer pad portions such that the opposing edges of the fingers and the indentation-defining transducer pad portions form capacitors comprising said capacitive relationship-defining means.
4. An acoustic surface wave filter as set forth in claim 2, wherein said capacitive relationship-defining means comprises respective layers of dielectric material disposed over each of said first and second transducer pads, a portion of each finger in said first and second pluralities of fingers overlying a portion of the dielectric layer associated with its respective transducer pad to form capacitors, and the size of the portion of each finger overlying the respective dielectric layer being determinative of the capacitive coupling of that finger to the-transducer pad corresponding thereto.
5. An acoustic surface wave filter as set forth in claim 4, whereinthe'sizes ofthe portionsof said fingers over lying the respective said dielectric layer are varied to obtain a desired impulse response.
6. An acoustic surface wave filter as set forth in claim 5, further including a second' interdigital acoustic surface wave transducer disposed on said at least one piezoelectric surface of said substrate means, said second
1. An acoustic surface wave filter including at least one weighted transducer comprising: substrate means including at least one surface of piezoelectric material, an interdigital acoustic surface wave transducer disposed on said at least one surface of piezoelectric material, said transducer including first and second transducer pads disposed on said piezoelectric surface in aligned spaced apart relationship, a first plurality of fingers disposed on said piezoelectric surface and operably associated with said first transducer pad, a second plurality of fingers disposed on said piezoelectric surface and operably associated with said second transducer pad, said second plurality of fingers being parallel to and interdigitated with said first plurality of fingers so as to have overlapping finger portions, means defining respective capacitive relationships coupling the individual fingers included in said first plurality of fingers to said first transducer pad, means defining respective capacitive relationships coupling the individual fingers included in said second plurality of fingers to said second transducer pad, and said capacitive relationship-defining means being selected to provide a predetermined weighting to the interdigitated first and second pluralities of fingers for obtaining a desired impulse response.
2. An acoustic surface wave filter as set forth in claim 1, wherein said overlapping finger portions of said first and second pluralities of fingers are of equal lengths.
3. An acoustic surface wave filter as set forth in claim 2, wherein said first and second transducer pads contain indentations into which corresponding fingers extend with the fingers being spaced from the indentation-defining transducer pad portions such that the opposing edges of the fingers and the indentation-defining transducer pad portions form capacitors comprising said capacitive relationship-defining means.
4. An acoustic surface wave filter as set forth in claim 2, wherein said capacitive relationship-defining means comprises respective layers of dielectric material disposed over each of said first and second transducer pads, a portion of each finger in said first and second pluralities of fingers overlying a portion of the dielectric layer associated with its respective transducer pad to form capacitors, and the size of the portion of each finger overlying the respective dielectric layer being determinative oF the capacitive coupling of that finger to the transducer pad corresponding thereto.
5. An acoustic surface wave filter as set forth in claim 4, wherein the sizes of the portions of said fingers overlying the respective said dielectric layer are varied to obtain a desired impulse response.
6. An acoustic surface wave filter as set forth in claim 5, further including a second interdigital acoustic surface wave transducer disposed on said at least one piezoelectric surface of said substrate means, said second transducer also being weighted in the manner of the first transducer, and the total predetermined weighting for the acoustic surface wave filter being divided between said first and second transducers.
| 1973-12-28 | en | 1975-09-09 |
US-78134877-A | Integrated message accounting system
ABSTRACT
An integrated message accounting system for use in a telephone system operating in time frames each consisting of a plurality of time slots. The system includes line groups each having a number of primary and secondary input and output portions for receiving input data signals and transmitting output data signals where one or the other of the primary and secondary portions is activated for receiving and transmitting the input and output signals. The system also includes a second number of time slot interchangers for connecting the active input portions to the active output portions where one of the interchangers is activated for connecting the input portions to the output portions. The system also includes a system controller for activating the primary or secondary portions and one of the interchangers.
CROSS REFERENCE TO RELATED APPLICATIONS
1. A TIME SLOT INTERCHANGER, Ser. No. 762,811, filed Jan. 26, 1977, now U.S. Pat. No. 4,071,703, issued Jan. 31, 1978, invented by Craig Schaffter and assigned to the same assignee of the present invention.
2. DATA PULSE REGISTER/SENDER FOR A TDM SWITCHING SYSTEM, Ser. No. 762,801, filed Jan. 26, 1977, invented by Johannes A. R. Moed and assigned to the same assignee of the present invention.
3. MULTIFREQUENCY SENDER/RECEIVER IN A MULTITIME SLOT DIGITAL DATA STREAM, Ser. No. 762,809, filed Jan. 26, 1978, invented by Bradley A. Helliwell and James R. Baichtal, and assigned to the same assignee of the present invention.
4. A DOUBLE REDUNDANT PROCESSOR, Ser. No. 781,437, filed Mar. 25, 1977, invented by John C. McDonald and James R. Baichtal, and assigned to the same assignee of the present invention.
5. SERVICE GENERATOR CHECKING APPARATUS, Ser. No. 762,808, filed Jan. 26, 1977, now U.S. Pat. No. 4,071,704, issued Jan. 31, 1978, invented by Johannes A. R. Moed, and assigned to the same assignee of the present invention.
6. PATH TEST APPARATUS AND METHOD, Ser. No. 762,934, filed Jan. 26, 1977, invented by James R. Baichtal and assigned to the same assignee of the present invention.
7. SERVICE GENERATOR FOR GENERATING A PLURALITY OF TONES, Ser. No. 762,810, filed Jan. 26, 1977, now U.S. Pat. No. 4,110,562, issued Aug. 29, 1978, invented by Johannes A. R. Moed and assigned to the same assignee of the present invention.
BACKGROUND OF THE INVENTION
The present invention relates to an integrated message accounting system for use in a telephone system operating in time frames each consisting of a plurality of time slots.
The use of pulse code modulated (PCM) digital signals in a telephone system enable a multiplicity of conversations to be translated over a two wire digitally multiplexed line commonly known as a T1 trunk line. A T1 trunk line is multiplexed with other T1 lines to form what is known as a line group. The multiplexed PCM data from the line group is then applied to a time slot interchanger for switching the data from one time slot of a line group to a time slot of another line group.
A message accounting system is employed for recording information resulting from toll, long distance and other types of telephone service. Such equipment requires the ability of the system to continuously process telephone calls in progress without disruption to service.
While the use of redundancy is well known for improving the reliability of any data transmission and storage system, redundancy techniques have not been previously employed in major subsystems of an integrated message accounting system to prevent a single point failure which could cause the system to go down.
There is a need for redundancy techniques in an integrated message accounting system where faulty subsystems could be switched automatically off-line to provide minimum interruption to service.
With the advent of microprocessors and electronic solid state design, it is desirable for major subsystems in an integrated message accounting system to utilize microprocessors thereby permitting the subsystems in the message accounting system to operate as independent entities.
In accordance with the above background, there is a need for an improved integrated message accounting system utilizing redundancy techniques and electronic solid state design for use in a telephone system utilizing PCM techniques.
SUMMARY OF THE INVENTION
The present invention relates to an integrated message accounting system operating in a multi-time frame format where each frame includes a plurality of time slots and each of the time frames include a framing bit for identifying each frame of the multi frame format. The system operates to switch data samples between a time slot on one communication line and a time slot on another communication line where the data samples occur as serial bits in the time slots at a predetermined rate.
The system includes line group means having a number of primary and secondary redundant input portions for receiving input data signals where one or the other of the primary and secondary input portions is activated for receiving the input signals.
The line group also includes a number of primary and secondary redundant output portions equal to the number of input portions for transmitting output signals where one or the other of the primary and secondary output portions is activated for transmitting the output signals.
The system also includes a second number of time slot interchangers for connecting the active input portions to the active output portions where one of the interchangers is activated for connecting the input portions to the output portions such that the input signals become output signals.
The system also includes a system controller for activating the primary or secondary portions and one of the interchangers.
In accordance with the above summary, the present invention achieves the objective of providing an improved integrated message accounting system for use in a telephone system operating in time frames each consisting of a plurality of time slots.
Additional objects and features of the invention will appear from the following description in which the preferred embodiments of the invention have been set forth in detail in conjunction with the drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an integrated message accounting system in accordance with the present invention.
FIG. 2 is a representation of the time slot frame structure employed within a multiframe format.
FIG. 3 shows the frame bit code utilized by the integrated message accounting system of FIG. 1.
FIG. 4 shows the system time slot organization of the integrated message accounting system.
FIG. 5 shows a block diagram of a T1 input portion of the I/O interface of FIG. 1 which is a portion of the FIG. 1 system.
FIG. 6 shows a block diagram of a T1 output portion of the I/O interface of FIG. 1 which forms part of the FIG. 1 system.
FIG. 7 shows a block diagram of a digital switch which forms part of the FIG. 1 system.
FIG. 8 is a timing diagram for the system master clock of FIG. 1.
FIG. 9 shows a block diagram for the time slot interchanger, which forms a part of the FIG. 1 system.
FIGS. 10-12 show an exemplary flow chart for describing the operation of the processor which forms a part of FIG. 9.
FIG. 13 shows an exemplary flow chart for describing the operation of the reframe control circuit which forms a portion of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the integrated message accounting system (IMAS) is seen in block diagram form. The IMAS can be used at class 4P toll points to process 1+ toll calls originating in class 5 offices, local calls, and other similar uses. It may be used as a LAMA (Local Automatic Message Accounting) system or as a CAMA (Centralized Automatic Message Accounting) system.
The basic functions of the IMAS are to provide recording of calls on magnetic tape, alternate routing for originating traffic, ONI operation, traffic monitoring reports, tandem routing for completing traffic, and WATS service (wide area telephone service). The subsystems of FIG. 1 utilize integrated circuitry forming modular hardware, thus providing electronic solid state reliability and long equipment life.
In FIG. 1, the span terminating equipment (STE) 86 is well-known equipment which functions to transmit, receive, terminate, monitor status of, or loop back the PCM bit streams of T1 lines used as digital trunks in connection with the IMAS.
The VB3 voice bank 87 is well-known equipment which provides time division multiplexing-demultiplexing, PCM encoding-decoding and terminal failure group alarm functions between 24 telephone circuits (VF and signaling) and a 1.544 MB/S bipolar pulse stream in D3 format. As seen in FIG. 1, VB3 87 provides appropriate interfacing with tributary offices, toll network, WATS service, recorded announcements, local first selectors, and Operator Number Identification (ONI) positions. The pulse stream is applied to a T1 input/output interface in the IMAS digital switch. Individual trunks (channel units) are chosen and configured appropriately for each application.
In FIG. 2, the PCM data format in the STE and VB3 equipment is compatible with the American Telephone and Telegraph Company's D3 channel bank, the operation of which is well known. With a sampling frequency of 8,000 Hz for encoding PCM data, one timing frame equals 125 microseconds with 24 time slots per frame per T1 line. Each channel of information is in the form of 8 bit channel words. A framing bit is added every 24 channels to form and define a frame. Each frame of 125 microseconds equals one frame bit plus the 24 time slots of 8 bits each and therefore there are 193 bits per frame for a D3 channel bank.
In FIG. 3, the frame bit occurs once at the start of each frame. It contains a framing code that takes 12 frames to repeat.
In each time slot there is an 8 bit speech code to digitally represent a quantized value of a particular portion of an analog signal. Once each six frames the eighth bit of each time slot carries a signaling bit to indicate on-hook or off-hook status of that particular channel or time slot.
In PCM systems like that of FIG. 1, quantizing a message signal by certain discrete levels or steps inherently introduces an initial error in the amplitude of the samples, giving rise to quantization noise. Quantization noise can be reduced by the use of nonuniform spacing of levels, to provide smaller steps for weaker signals and coarser quantization near the peak of large signals. The μ-255 companding law utilizes this concept of encoding PCM data in which the coding magnitude range is divided into 8 segments, and 16 levels are equally spaced within each of the 8 segments. From one segment to the next higher, the level spacing (step size) increases by a factor of 2. In the 8 bit code word representing any sample, the first bit gives the sign, the next 3 bits describe which of the 8 segments contain the sample, and the last 4 bits specify the nearest of the 16 possible levels within the segment.
In FIG. 1, the unit 20 is either a STE 86 or a VB3 87 unit as previously described. Data from STE/VB3 unit 20 is applied to both the primary and secondary interfaces of a line group 10. For example, data is input to T1 I/O primary interface 11 and the secondary I/O interface 15 via buses 34, 35, and 34, 36, respectively. Data is output from T1 I/O interfaces 11, 15 to STE/VB3 unit 20 via buses 41, 40 and 42, 40, respectively.
As seen in FIG. 1, primary and secondary interface redundancy is employed in all major subsystems in the IMAS to prevent a single point failure which could cause the system to go down. Faulty subsystems are automaticaly switched off line to provide minimum interruption to service.
A line group 10 interfaces any T1 line pair such as lines 34 and 40 with four Time slot Interchangers (TSI) 21 designated TSI φ-3. A primary T1 I/O Interface also interfaces the optional primary multifrequency sender (MFS) 13 and receiver (MFR) 14 with the TSI 21. A primary T1 I/O interface such as interface 11 accepts bipolar PCM data from a T1 line (34, 40) carrying information in D3 format (standard D3 decode transfer characteristic). A secondary (redundant) T1 I/O Interface such as Interface 15 also interfaces any T1 line pair such as lines 34, 40 with the TSI 21. Interface 15 also interfaces the secondary MFS 17 and MFR 14 with TSI 21.
Incoming data from a unit 20 is stored and synchronized by the I/O Interface such as interface 11 to the IMAS system frame. Data is converted by each I/O interface to 9 bit parallel (includes parity bit) and sent to the time slot interchanger (TSI) 21. Carrier group alarm (CGA) detection (B2=0) and signal bit recovery (Bit 8 of 6th and 12th frames) is also accomplished. Error signals and signal bits are sent to the primary signal processor (SP) 72 or secondary SP 75 for further analysis.
It is possible to operate 16 of these T1 I/O interfaces for each primary and secondary subsystem per line group. Each I/O interface accommodates one T1 line or one VB3 voice bank. Up to four line groups per system may be used. Further discussions of the various primary and secondary subsystems will be limited to the primary subsystem, although it will be understood that the discussion would apply with equal effect to the secondary subsystem.
A line group organizes the voice frequency data from 16 T1 lines or 15 T1 lines and the MFS onto a 384 time slot data bus to the TSI's (TSIφ-TSI3).
Referring to FIG. 4, one frame is equivalent to 125 microseconds or 193 bits. The frames recur at the 8 KHz sampling frequency. There are 24 D3 channel numbers as indicated by N, and there are a total of 384 time slots of 324 nanoseconds each, with an additional two time slots for the frame bit. FIG. 4 shows how time slots are organized with respect to the incoming frame. The first 16 time slots are constructed of data from channel one of the 16 incoming frames. The next 16 times are from channel 2 and so on. Each T1 I/O interface is allocated to one of 16 time slots for each D3 channel. 16 T1 lines are each input to the respective T1 line I/O interface and multiplexed to time slots 0-15. P indicates the particular line group interface accessed during a channel number. For example, during channel number one, P1 would indicate primary I/O interface 11 and secondary I/O interface 15 of FIG. 1 is accessed. P15 would indicate primary I/O interface 12 and secondary I/O interface 16 are accessed. P16 would indicate primary multifrequency sender 13 and secondary sender 17 of FIG. 1 are accessed. If the line group did not employ a multifrequency sender and receiver, P16 would indicate accessing another I/O interface. During channel 24, P16 would indicate the primary MF receiver 14 and secondary MF receiver 18 are accessed. The D of FIG. 4 indicates the decimal time slot for the line group from 0-385. D3 channels 1-8 are assigned to the MF sender. D3 channels 17-24 are assigned to the MF receiver and D3 channels 9-16 are assigned to either MFS or MFR, dependent upon traffic conditions.
In FIG 1, the IMAS digital switch comprises line groups 0-3 and TSI 0-3.
Referring to FIG. 1, the TSI 0-3 switch channel time slot data from any of the four line groups to any other channel time slot of any other of the four line groups. For example, data from line group 0 could be sent via bus 26-1 to TSI 0 and switched out bus 28-4 to line group 3. The TSI's receive channel time slot data (8 bits plus parity). When it is available from the line group data bus, the TSI's hold it until the proper time for output in the next frame and transmit the data to the line group data for output. The TSI contains control and data memory for all time slots. The TSI's communicate with both the primary and secondary system controllers (SC) 50, 64 via bus 57, 63. Further details of the digital switch are described in the above-referenced application entitled "Time Slot Interchanger".
In FIG. 1, the primary and secondary service generators (SG) 22, 23 provide capability to connect one of several standard tones in PCM format to any of the channel time slots. These tones include 1,000 Hz, 120 IPM busy, 60 IPM busy, dial tone, ring back tone and internal tones for the IMAS. The primary and secondary SC 22, 23 receive control signals from the respective system controller (SC) 50, 64. Further details of the service generator are described in the above referenced application entitled "Service Generator For Generating A Plurality Of Tones".
The primary and secondary signal processors (SP) 72, 75 monitor all the input channels of the IMAS for changes of state and dial digits. Each time a channel is seized or released, or a digit is dialed, a message is sent to the respective SC 50, 64 via buses 74, 77, containing the channel number and the event. All the information needed to determine the changes of state or dial digits is time division multiplexed over several leads originating from the line group.
The SP 72, 75 also have the capability to seize or release channels or dial digits on these channels. Frames 6 and 12 are signaling frames. During these frames, the least significant bit of the 8 bit PCM byte is replaced with a signaling bit. Frame 6 is used for an A signaling bit and frame 12 is used for a B signaling bit. The signal processor uses the A signaling bit for seizure, release and dial digit detection. The B signaling bit is used for state change detection only. Further details of the signal processor are described in the abovereferenced application entitled "Register/Sender".
In FIG. 1, the primary and secondary system Master Clock 79, 78 is a conventional device for generating all basic clock signals used by the IMAS. The clock generates 4 clock signals MCLKφ-MCLK3 all of which are 3.088 MHz square waves, but each one is phase shifted by 270 ns nominal. The purpose of this phase shifting is to allow for propagation delay of data as it is routed through the different subsystems contained in the IMAS.
Referring to FIG. 8, the basic frequency of the system master clock is a crystal generated 18.528 MHz. The basic frequency of the system master clock is divided down to the 3.088 MHz square wave.
Master frame pulses FSφ-FS3 generate a 648 ns pulse every 125 us and are used to mark the start of a new frame. FSφ-FS3 are primarily used by subsystems to synchronize their address generators.
The master frame bit signal FBφ-FB3 generates a repeating pattern of serial bits. The pattern repeats every 12 frames and the bits can be decoded to identify each of the 12 frames as seen in FIG. 3.
Again referring to FIG. 1, in addition to the clock signals of FIG. 8 originating from the master clock, an "Active" signal originates from the system controller 50, 64 of FIG. 1 to inform some of the IMAS subsystems that they are on line.
Should a single point failure occur somewhere in the primary system, the primary system controller 50 will inactivate the on-line system by inactivating the "Active" signal. The off-line system will go on-line by the secondary system controller 64 activating the secondary master clock 78, thereby switching the secondary (redundant) system on-line to process data.
In FIG. 1 the operator number identification subsystem (ONI 80) provides a control interface between the IMAS and ONI operator positions for serving lines not equipped with automatic number identification (ANI) or for calls experiencing ANI failure.
The MF senders (MFS) 13, 17 generate and output MF tone pairs onto the line group data bus 26-1, 44-1 for switching through the time slot interchangers 21 to an outgoing path such as 28-4, 46-4. The MFS 13, 17 communicate directly with system controllers 50, 64 via buses 37, 47, respectively. The MF receivers (MFR) 14, 18 detect MF tones in PCM digital input form and send them to the SC 50, 64 via buses 38, 48, respectively.
The MFS and MFR jointly share one group of 24 D3 time slots and associated control facilities. A minimum of 8 time slots and a maximum of 16 time slots for each sender such as MFS 13 and each receiver such as MFR 14 are available to traffic at any time subject to a total maximum of 24 time slots. Systems with more than one line group may be equipped with the above capacity per line group as required by traffic.
The operation of the MF sender will be described briefly. When a calling party has dialed a called party, the SC choses an outgoing trunk group and an idle outgoing trunk is selected. The digital switch consisting of the line group and TSI paths is set up and path tested between the selected MFS channel and the selected outgoing trunk and the MF sender is commanded by the SC to outpulse onto the TSI Bus.
Referring to FIG. 4, the 24 channel times of a D3 frame are used by the MFS as follows: the first 16 channel times are reserved for outputting tone bursts on MFS channel numbers 1 through 16, respectively. The last 8 are reserved for processing commands from the SC. Depending upon traffic conditions, the SC can assign DC channel numbers 9-16 to any combination of the MF Sender and MF Receiver.
The multifrequency pulsing (MF) system consists of transmitting and receiving equipment for transferring valid number information over telephone trunks by various combinations of two, and only two, of five frequencies in the voice band. Each combination of two frequencies represents a digit. The digits are digitally encoded into PCM code for transmission along a T1 line for switching through a digital switch. MF receivers detect the digits and transfer the digital information to control equipment which establishes connection through the switches. MF pulsing is also used to transmit calling number information in CAMA-ANI (centralized automatic message accounting--automatic number identification) operation. In this case, the calling number is MF pulsed forward in PCM digital format from the originating office to the CAMA office following the forwarding of a called number whether the called number is transmitted in MF or dial pulsing.
Referring now to FIG. 2, the 24 channel times of a D3 frame are used as follows for the MF receiver: the first 3 channel times are ignored except for parity checking. The last 16 are used as multifrequency receiver (MFR) channel numbers 1 through 16, respectively. In the timing figure, the MFR channel members are allotted to time slots 143, 159, 175, . . . 351, 367, 383. Time slots 143, 159, 175, 191, 207, 223, 239 and 255 are shared between the MFS and the MFR. The system controller (SC) has the option of assigning any one of the middle 8 channel times of the D3 frame (time slots 143, 159, . . . 255) to the MFS or MFR (but not both). Therefore, the maximum number of senders and receivers that can be used at any one time ranges from 8 senders and 16 receivers to 16 senders and 8 receivers. The particular combination of MFS and MFR during the D3 frame would be dependent upon traffic conditions.
The operation of the MFR will now be briefly described, assuming a calling party has initiated a 1+ DDD call in which the SC initiates calling number identification by activating the CAMA-ANI subsystem. The SC assigns the MFR to a time slot in the D3 frame corresponding to the time slot occupied by the 1+ originating trunk. The calling number information in CAMA-ANI pulsing format will consist of a KP signal (MF frequencies 1100+1700) which is a preparatory signal for digits; an information digit "I" meaning the automatic identification of the calling number has been done in the originating office; the 7 digit calling number in MF format; and the ST signal (MF signals at 1500+1700 Hz), signifying end of the pulsing sequence. Further details of the MF sender and receiver are described in the above-identified application entitled "Multifrequency Sender/Receiver in a Multitime Slot Digital Data Stream".
The primary and secondary system controllers (SC) 50, 64 are Intel 8080A stored program microprocessors surrounded by a number of peripheral devices and inferfaced to each subsystem. For further details of interconnections between the Intel microprocessor and associated peripheral devices, see the Intel 8080 Systems Users Manual.
The System Controllers 50, 64 provide the following functions:
(1) call processing including routing, ANI (Automatic Number Identification), ONI, recorded announcement control and creation of billing records;
(2) SC self test; and
(3) system test and maintenance data outputs for accumulation of traffic monitoring data and generation of traffic monitoring reports. The secondary (redundant) SC 64 is updated continuously so that it can assume control of the system with a minimum disruption to service should primary SC 50 experience a failure.
To enable the secondary system controller to come on line and start processing calls should the primary system controller experience a failure, portions of the memory containing the states of all calls in progress are periodically copied into the memory of the secondary system controller through direct memory access techniques which are well known in the art. Also, hard copies of messages that are displayed on the CRT are output via the teletype by the secondary system controller.
When the secondary system controller is on line and processing calls, the call records are stored in its cartridge until the primary system is back on line for the reason that the secondary system controller is not equipped with a MTR. At that time, the call records are read from the cartridge into the secondary system controller, transferred to the primary controller and dumped onto tape in the MTR.
Each system controller is equipped with 64 K bits of memory addressable by a 16 bit address bus. Further details of the operation of the Intel 8080 microprocessor are described in the Intel 8080 System User's Manual.
The panel interface is equipped with display light emitting dials and control switches to take the place normal front panel in a computer, allowing some manual control of the operation and selectively displaying the data or address.
The alarm monitor monitors all alarm signals from the primary system controller as well as active and alarm lines of the other system controller, and in addition supplies a 10 MS interrupt to the central processing unit.
The peripheral devices connected to the System Controllers 50, 64 are as follows:
The CRT 51 which is used for:
a. Primary system information display (e.g., traffic, alarms, maintenance program results)
b. Keyboard entry of system control commands and data (e.g., translation table data, trunk-type assignments, test trunk control, and system diagnostic control)
The CRT 51 is the primary system interface to office personnel.
Printer 67: provides printed output records of traffic, alarms, maintenance diagnostics and other system data. In the event of CRT 51 maintenance of failure, the printer may be used as a substitute input-output device.
MTR 52--The magnetic tape recorder is the primary system billing recording device. The MTR 52 records can be read by a similar industry standard MTR in an EDP data center.
MTC 53--A magnetic tape cartridge recorder is associated with each SC, primary and secondary. The MTCs are used to load standard programs and office data from tape cartridges. Additionally, the secondary MTC is used as a backup recording device when the MTR is not in service.
RTC 54, 65--The Real-Time Clock generates the stable time bases for timing all programs in each SC 50, 64.
COI 55, 56, 68, 69--Control Office Interfaces are used to interface signals in and out of the CO (e.g., Dynamic Overload Control Signals--DOC).
Office Connection Panel 71--the OCP contains terminal blocks for connection of the system to office alarms, DOC and other office signals as required.
Status and Alarm Panel 70--the SAP provides basic system status and alarm display and allows limited, direct control of essential functions. It communicates with the SC via COIs.
Test Trunk Panel 88--the TTP provides jackfields and access to voice and signaling of two 4-wire trunks assigned as system test trunks. Pushbutton switches on the panel allow for talking, dialing and testing on each trunk, for patching together the two test trunks and for momentary monitoring of a call in progress.
ANI Adapter 83 (optional)--provides interface facilities between standard local identifiers and the IMAS SC and VB3 trunks.
An example of a call processing overview of the IMAS will be given to provide a better understanding of the operation of the present invention. The overview will be given in conjunction with FIG. 1 and assumes that the primary portion of the IMAS is on-line. The secondary portion of the IMAS is off-line but would automatically be switched on-line should the primary portion experience a failure. Therefore, the description of the call processing overview as it applies to the primary portion of the IMAS will apply with equal effect to the secondary portion.
Call Overview
Referring to FIG. 1, a subscriber in a tributary office 90 goes off hook, receives a dial tone from the local office and dials "1" to initiate a 1+ direct distance dialing (DDD) call. This causes a 1+ toll connecting trunk 92 to the IMAS to be seized (go off hook) at the tributary office 90. The seizure is passed into the IMAS through STE/VB3 unit 20 as a change of state of a signaling bit on a T1 line such as 34, 40 entering a T1 I/O interface such as interface 11. The seizure is recognized by the signal processor 72 which passes the change in trunk state to the system controller (SC) 50. The Controller 50 begins a process of building up a Call Processing Record. As the subscriber dials a called number, the signal processor (SP) 72 detects each dialed digit and forwards it to the SC 50 for storage in memory.
At the appropriate time, the Controller 50 signals the tributary office 90 via the SP 72 to initiate calling number identification. The tributary identifier in the tributary office 90 is activated, the SC 50 connects an MF receiver (by assigning the MFR 14 to a time slot corresponding to the time slot occupied by the 1+ originating trunk 92) and the Calling number information is passed to the MFR 14. The MFR 14 forwards each digit received to the SC 50 where this information is assembled in memory with called number and other information necessary to form a complete record for eventual use as a billing record.
With called number information in the memory of the SC 50, the controller 50 proceeds to perform a translation (3 digits or 6 digits are required). An outgoing trunk group connected to Toll Network 91 is chosen and an idle outgoing trunk such as trunk 93 is selected. The digital switch (consisting of line group 10 and time slot interchanger 21 paths) is set up and path tested for path continuity. The MF sender 13 is commanded by the SC 50 to out pulse an MF tone. Alternatively, dial pulse sending (DP) is also possible using the SP 72.
The SP 72 monitors the state of the outgoing trunk 93 after outpulsing and initiates call timing in the SC 50 at answer supervision by using the real time clock 54 associated with the SC 50. The SP 72 continues to monitor the state of the outgoing trunk signaling until the call is terminated. At this point, the SP 72 informs the SC 50 that the subscriber associated with the tributary office 90 went back on hook. The SC 50 then assembles a billing record in its output memory buffer area. When a block of 16 billing records is present in the buffer area, it is written on the output magnetic tape recorder (MTR) 52.
The information contained in a call record is: the date; connecting time; elapsed time in minutes and seconds; originating number; terminating number; type code; class code; information code; time and charge code; trouble code; CPFR code; incoming trunk ID; outgoing trunk ID; and toll center number.
Referring to FIG. 5, the input portion of the T1 I/O interface 11 of FIG. 1 accepts serial bipolar PCM data from a T1 line 35 carrying information in D3 format. Each time slot of incoming data comprises 8 bits of PCM sampled data so that there are 192 bits for 24 channels per T1 line plus one framing bit. Incoming data is stored and synchronized to the IMAS system frame. Serial data is converted to 9 bit parallel (8 bits data plus parity bit) and sent to the time slot interchanger (TSI). Carrier group alarm (CGA) detection (Bit 2=0) and signal bit recovery (Bit 8 of 6th and 12th frames) is also accomplished. Error signals and signal bits are sent to the signal processor for further analysis.
It is possible to operate 16 of these interfaces per line group. Each interface accommodates one T1 line or VB3 voice bank. Up to 4 line groups per system may be used.
Incoming PCM data on Bus 35 from the unit 20 is converted to normal TTL levels by a conventional Unipolar Converter 102 and gated through the conventional Data Select 131 on Bus 103 by an Active signal applied to the line group in response to the Master Clock 78 under control of the system controller 50 of FIG. 1.
Although the data into interface 11 is from a T1 line, the system could be modified to receive data from a satellite, remote terminal, or teletype.
The Master Clock 78 provides the necessary timing signals to the Input Timing Generator (ITG) 129 via bus 60. The ITG 129 includes conventional counters and logic to distribute common miscellaneous timing functions to the various subsystems of the I/O Input Interface of FIG. 5. The conventional Clock Recovery circuit 110 receives the PCM data and reconstitutes a clock signal to provide a clocking edge that lags the data bit by one quarter period of the square wave period. Data is loaded from Data Select 104 into a holding buffer in the Elastic Store 106, a 256 bit store, via bus 105 until the next available write window from the Read/Write Control (RWC) 120. The Read/Write Control 120, a typical selector circuit to insure there is no interference between read and write times, then gates the Write Address Counter 118 through a conventional Address Select Circuit 129 to the Elastic Store 106 and writes the data bit at this address location on a 256×1 bit RAM. The Write Address Counter 118 is 8 bits wide (to address 192 bits of data per T1 line) and free running at 1.544 MHz. Since the system clock has a basic frequency of 3.088 MHz, it will have 2 rising edges per incoming data bit; thus there are two available write windows per incoming bit to assure that each bit will be written in the Elastic Store 106 regardless of the phase or jitter of the recovered incoming clock with respect to the master clock timing of the ITG 129.
When the line group is not active, data from the output interface of FIG. 6 is looped around through Data Select 104 of FIG. 5 via Bus 199. This allows off line checking of a line group to be sure that it is ready for service, the details of which are more fully described in the above-identified application entitled "Service Generator Checking Apparatus And Method".
The Reframe Control Circuit 144 controls the state of the Read Address Counter 154, and clocks the appropriate data bit from the Elastic Store 106 into the Serial To Parallel Converter 136 via Bus 132. Converter 136 is a conventional shift register. When the 8 bit word (D3 format) of a T1 channel is present in the Serial To Parallel Converter 136, it is clocked into the Output Buffer 140 via 8-Bit Bus 138 by the ITG 129 along with a parity bit from Parity Generator 134 computed at the input to the Serial To Parallel Converter 136. ITG 129 then sequentially connects this output buffer 140 in its turn with 15 other input interface circuits of the FIG. 5 type to the TSI bus 26-1 through Line Driver 143 and bus 24-1 to the TSI of FIG. 7. TSI bus 26-1 is a conventional three-state bus that is accessed by the other fifteen T1 input interfaces in their turn to form 384 (16×24 D3 channels) time slots. The 16 input interface circuits each with their 24 T1 channels (D3 format) form the 384 (16×24) channels per line group.
Once per frame, the Reframe Control 144 compares the frame bit at the appropriate position in the Serial To Parallel Converter 136 with its own frame code generator. If two or more errors in four frames occur, a reframe mode is initiated. Reframing is accomplished by adjusting the delay through the Elastic Store 106. A frame error signal appears on bus 147 for transmission to SP 72 of FIG. 1 via bus 73-1.
The Reframe Control 144 includes a comparator, four frame counter and processor, which includes a PROM and data selector. A group of data bits in the vicinity of the system frame bit time is inspected for potential frame bits. Each bit position is checked until it either produces the correct framing sequence for ten frames or one error in a potential sequence is detected. When the entire group has been checked and no frame code sequence has been found, the Read Address Counter 154 is advanced to select the next group of bits. This process continues until the above mentioned framing sequence is found. The "found" bit position is synchronized with the system frame bit position by delaying the Read Address Counter 154 and a framed condition is reestablished.
An exemplary flow chart for describing the operation of the processor contained within the reframe control is shown in FIG. 13. The processor of reframe control 144 will execute the following steps for finding the framing bit for the line group.
In FIGS. 3 and 4, the frame bit position shown occurs once at the start of each frame. It contains a framing code that takes 12 frames to repeat.
Referring to FIG. 13, steps 0, 1, 2, 3 and 5 are executed in a sequence when the reframe control 144 is in a framed condition. The read address counter 154 and converter 136 of FIG. 5 are continuously being clocked once per incoming bit. Thus the read address counter 154 keeps pace with the write address counter 118.
The processor will wait at step 0 until IFC (input frame control) decision sends it to step 1. IFC is a typical signal from the ITG 129 of FIG. 5, which occurs one D3 time slot after the frame bit. If IFC is no, the processor returns to step 0. If IFC is yes, the processor proceeds to step 1.
At step 1, the frame code generator/comparator (internal to the reframe control 144) is clocked to keep its internal frame bit up to date. In addition, the Address Counter 154 and Converter 136 of FIG. 5 are incremented as in step 0.
At this point the incoming frame bit FB is compared with the internal frame bit. Assuming the four frame counter is at frame 0, if no code error is detected (CE=OF) the processor will continue to step 2 and clock the address counter 154 and converter 136 of FIG. 5.
From step 2, the processor goes to step 3 if the four frame counter is at frame zero in its count where the four frame counter is kept reset and a reframe flag is lowered. Lowering the reframe flag will apply the appropriate flag state to the most significant bit of the four frame counter when being loaded.
The processor returns then to step 0 and repeats the cycle.
In step 1, if the frame code generator does detect a code error, at frame zero or no code error at frames 1, 2, or 3 (CE=OF is a yes condition), the processor branches to step 5 where the four frame counter is incremented to the next state. The cycle repeats until the four frame counter returns to 0 or another code error occurs. A second error in four frames causes the reframe mode to be entered at step 12 via step 2.
At step 12, the reframe flag is raised when the four frame counter is reset. Raising the reframe flag applies the appropriate reframe flag stage to the most significant bit (MSB) of the four frame counter when being loaded. Also, the read address counter 154 of FIG. 5 is advanced 8 counts with respect to the write address. For 3 consecutive frames, the 8 bits in this frame position are loaded into converter 136. This is accomplished in steps 13, 14 and 9 and is controlled by decision IRL (input reframe load) and the four frame counter of reframe control 144. IRL is another timing signal from ITG 129 of FIG. 5.
When the four frame counter returns to frame 0, the processor branches from the load loop to state 15. At this point the 4th set of 8 bits together with the three previous sets of 8 bits form 8 4-bit words that are clocked into the frame code generator and inspected one at a time for any of the twelve codes shown in FIG. 3. If one is found, the code compare (CC) indicates that a potential frame code sequence has been found and the processor goes to step 6. If no valid code is found the processor branches to step 6 after the 8th word has been inspected.
Referring to FIG. 13, at step 6, the processor checks CC to see if it has terminated the search mode. If not the processor jumps back to step 12 to repeat the process for the next 8 bits in the frame. If CC is a yes, then the sync mode is entered at step 7.
In steps 7 and 8, the four frame counter is set to zero to prepare for the check mode, and the position of the found code is synchronized to the system frame bit position by decision IAS (input address sync), a timing signal from ITG 129 of FIG. 5.
Steps 10, 11 and 4 are the check mode in which the processor inspects the FB position in the normal manner for 3 more frames, after rechecking the found bit. Decision CE (code error) indicates that the incoming frame bit is not equal to the frame code generator bit. If CE is yes, it will cause the processor to jump back to step 12 to repeat the process. Otherwise the four frame counter returns to 0 and the processor branches to step 5. Three more FB positions are checked for errors with a single error causing a return to step 12 via step 2.
After 10 consecutive FB positions containing no errors have occurred, the processor restores a framed condition at step 3.
In FIG. 5, signal bits are written into the Signal Bit Store 150, a 32×4 bit RAM, during frames 6 and 12, as determined by the internal frame code generator of the Reframe Control 144 from the appropriate output of the Serial To Parallel Converter 136. Since the Reframe Control 144 synchronizes the incoming frame bit to the nearest system frame bit position, the incoming frame number bears no relation to the current system frame number. Therefore, signal bits from the Signal Bit Store 150 are allowed to stay on line for 12 consecutive frames to be sure they are valid during the system signaling frames.
During normal operation, the second bit position (next to the most significant bit) in all 24 words is inspected by conventional Detector 148. If all 24 bits are zero, then a B2=0 signal appears on bus 149 which is sent to SP 72 of FIG. 1 via BUS 73-1.
The B2=0 means that all 24 bit 2 positions in one frame (D3 format) are 0. This is a carrier group alarm (CGA) sent by the associated D3 equipment. The framing error has priority over the B2=0 error.
Signal bits, B2=0 error signals, and framing errors are applied to the SP bus 73-1 and sent to the SP in the same manner as data sent to the TSI. These signals are processed and relayed to the System Controller to give trunk status information.
Path tests are performed to insure that the particular path is or is not set up through the TSI. The Path Test Generator (PTG 156) receives a command from the SP via bus 73-2 to invert the parity bit of the channel under test. The parity is inverted at line driver 143. Parity checking of all output interfaces discloses the results of the path test. Further details of the path test are described in the above-identified application entitled "Path Test Apparatus and Method".
Referring to FIG. 6, the output interface accepts data from the TSI and Signal Processor (SP) in parallel form. It is converted to a serial format and then to bipolar PCM to be applied to the T1 line. During signaling frames, signal bits from SP are inserted at the appropriate place in the parallel word. The signaling frames in the IMAS are frames 6 and 12 with the 8th bit of each channel time slot allocated for a signal bit to indicate on-hook or off-hook status. Also, a zero suppression circuit maintains at least a 1 out of 16 pulse density on the T1 line. The zero suppress circuit monitors all 8 bits being applied to the parallel to serial converter. If all 8 bits are 0, Bit 7 is forced to a one. This insures that no more than 15 consecutive zeros will appear in a T1 stream, a condition necessary to keep clock recovery circuits alive. A parity check is made of all data. Parity errors are sent to the signal processor for analysis.
It is possible to operate 16 of these interfaces per line group. Each interface accommodates 1 T1 line or VB3 voice bank. Up to four line groups per system may be used.
Referring to FIG. 6, the output portion of the I/O Interface 11 of FIG. 1 is shown in more detail. Data from the TSI is applied to the conventional Input Buffer 167 via Line Receiver 165 and buses 28-1, 30-1.
The Output Timing Generator (OTG) 196 loads Input Buffer 167 whenever an outgoing PCM word appears on the bus 30-1. The OTG 196 is similar to the ITG 129 of FIG. 5. When 16 words have been loaded (1 word in each buffer for up to 16 interfaces), the conventional Parallel To Serial Converter 171 in all of the interfaces is loaded with this data. The serial data immediately starts shifting out on the T1 line 41 via the Bipolar Converter 179 and the T1 Line Driver 181. The Active signal from Master Clock 78 of FIG. 1 controls a pair of relays that connect the T1 Line Driver to the T1 line. The primary and secondary interfaces are connected in parallel at the T1 line. Therefore the off-line driver is disconnected by the relays.
During system frames 6 and 12, signal bits are inserted at Bit 8 via the Signal Select 175, which is similar to data select 104 of FIG. 5. In FIG. 6, signal bits are received from the signal processor via bus 73-3, 192 and line Receiver 191, and are loaded with parity in the same manner as data from the TSI. Bus 73-3 corresponds to Bus 73 of FIG. 1.
In FIG. 6, the Zero Suppress circuit 174 is a comparator circuit that monitors all 8 bits being applied to the Parallel To Serial converter 171. If bits 1-6 and 8 are 0, Bit 7 is forced to a 1. This insures that no more than 15 consecutive zeros will appear in a T1 stream, a condition necessary to keep clock recovery circuits alive.
The conventional Parity Checker 184 is preset to its start state at the beginning of each serial word. The preset state is determined by monitoring data parity, signal parity if frames 6 or 12, and the Zero Suppress circuit 174. The Parity Checker 184 computes parity on the serial word as it is applied to the input of the T1 Line Driver 181. The proper parity error condition exists at the end of the serial word and is loaded into the Parity Muxer 186 along with the 15 other parity error conditions. The Parity Muxer 186 sends the 384 channels of parity error data per frame to the Signal Processor 72 of FIG. 1 via Line Driver 188 and buses 187, 73-2. Bus 73-2 corresponds to Bus 73 of FIG. 1.
In FIG. 6, the frame bit is always applied to the serial input of the Converter 171. The OTG 196 only allows the frame bit to shift through to the output at the appropriate frame bit time.
When a line group is off line, the Active signal will select data from the Bipolar Converter 179 instead of data from the Unipolar Converter of the T1 input interface of FIG. 5. This allows a loop around test to be performed by the Service Generator (SG) 22 of FIG. 1. The T1 input interface frames up on the serial T1 stream from the output section allowing TSI output bus data to be looped around to the TSI input bus.
Referring to FIG. 7, the timed division multiplexed PCM digital switch network configuration used in the IMAS is shown. The digital switch comprises line groups 0-3 and TSI 0-3 of FIG. 1. Network paths have been derived by multiplexing together sixteen 24-channel T1 lines in a line group to form 16×24 or 384 time division channels or time slots. In a full size IMAS there are 4 line groups 10 for a total of 1536 terminations or channels. Each line group has primary and secondary redundancy as previously described, but not shown here. The channels appear sequentially on the horizontal input paths 26-1 to 26-4 of the network and are switched to the desired outgoing paths 28-1 to 28-4 by the time slot interchanger TSI φ-3, associated with the vertical paths 208-1 to 214-4 of the network.
As an example, assume a call is in progress from LG0 to LG1 through TSI 0. In operation, under control of the System Controller 50, an originating channel sample from one of the T1 lines is multiplexed out on a horizontal path such as path 26-1 as one of 384 time slots for the group. The data is switched to a vertical path such as 210-1 to TSI 0. The TSI 0 transfers the sample to its memory, where it is held until the terminating channel time slot in the next frame appears, whereupon the sample is transferred back on path 208-1 and switched to a path such as 28-2 to the line group LG1 and the T1 line on the terminating channel.
Since each line group can be connected to 16 T1 lines each with 24 channels, and has a channel repetition time of 125 us, the line group must output to the TSI 16×24 channels every 125 us or 1 channel every 324 ns. Each channel on the T1 line contains 8 data bits; thus each output channel from the line group must have 8 data bits. If transmission were kept serial like the T1 line input, the data rate would be 8 bits/324 ns or 40.5 ns/bit or 24.7 Mb/s. To solve this high rate problem, the line group, as previously described, converts the serial T1 data to a parallel data bus, adding a parity bit to form 9 bits. The actual data transmission rate is the same but now 9 bits are transmitted at one time and the bus transmission rate becomes 3.088 MHz or one 9-bit sample every 324 ns.
The TSI has the capability of switching channel time slot data from any one of four line groups to any other channel time slot of any of the four line groups. The line groups are redundant, thus a full system with 1536 terminations has 8 line groups and 8 data buses (4 primary and secondary). Only 1/2 of the line groups in the fully redundant system are on-line processing call traffic at any one time. The other half of the line groups are off-line and are occupied with self-testing to insure availability for switching on-line should the active line group experience a failure. In a full system of 8 line groups, each TSI connects to the 8 line groups (4 each for primary and secondary) through 8 separate data buses and 8 cross point switches.
Referring to FIG. 9, a Time Slot Interchanger (TSI) 21 of FIG. 1 is shown in more detail, for a redundant system with a total of 2 line groups, each line group having a primary and secondary interface. 18-bit data buses 301-304 each replace the pair of 9-bit buses 26, 28 and 44, 46 of FIG. 1. Buses 301-304 transmit PCM data between the line groups and the TSI. Buses 301-304 would also connect to Service Generators 22, 23 of FIG. 1.
Data Sample Memory 313 is connected to data buses 301-304 through a three-state data bus 311 (such as National Semiconductor Corporation's Tri-State Bus Drivers and Receivers) and cross point switches (CPS) 306-309. Each cross point switch includes differential line drivers and receivers and three-state data buses 311 and 312. Similarly, Data Sample Memory 314 is connected to data buses 306-309 through another three-state data bus 312 and CPS 306-309. Thus, the TSI cross point switches are used as an interface and switch to connect the TSI with the PCM data Buses 301-304 coming from the line groups. In each TSI, up to 8 cross point switches are used to interface to the maximum 4 primary and 4 secondary data buses from the line groups.
Data from bus 301 is input only to CPS 306 for switching to either data bus 311 or 312 and thereby input to DSM 313 or 314, respectively.
Controls for activating the CPS 306-309 are located on the Cross Point Control And System Clock (CPC) 316. The information necessary to control which cross point switch is to be active at any one time comes from the Control Memory 326. The CPC 316 includes a conventional decoder to decode the information from the Control Memory 326 and synchronizes it with the proper master clock edge necessary to activate via buses 319-322 the input and output cross points on the cross point switch that was decoded. The CPC 316 also provides a master clock interface for timing in the TSI. The signals MCLK1 and FS1 from the Master Clock circuit of FIG. 1 via bus 60 are the only clock signals necessary for the TSI.
The PCM data storage is provided by memories 361, 366. Each memory is a 9 bit×512 word memory of which 386 are used, and also contains an address multiplexer 353, 354, which are controlled by an odd-even frame signal 355 from the time slot address counter (TSC) 332. The multiplexer is used to select addressing from either the Control Memory 326 or the TSC 332. When one data sample memory is addressed by the TSC 332. When one data sample memory is addressed by the TSC 332, the other memory is addressed by the Control Memory 326. The addressing alternates between Control Memory 326 and TSC 332 during successive even and odd frames.
Each DSM 313, 314 also contains an input buffer 360, 365 and output buffer 362, 367. Buffers 360, 365, 362 and 367 are 1×9 bit latches. The input buffers 360, 365 insures the PCM input data is presented to the memory chips 361, 366 for a full channel time slot of 324 ns. PCM data stored in the memories 361, 366 is output to an output buffer 362, 367 for one channel time slot storage which insures that data is presented to a cross point such as CP 306 and thereby to the time slot bus 301.
The TSC 332 provides three functions in the TSI. First, it contains a 9-bit binary counter which provides a time slot address for the Control Memory 326 and DSM 313, 314. The master clock signal from the CPC 316 via bus 324 is used to advance the counter in binary sequence from 0-385, where each number is a channel number. Each time the counter is reset to 0, the Even/Odd Frame signal on Bus 355 changes to the opposite state. Frame synchronization is used to keep the counter synchronized with the rest of the IMAS. The second function of TSC 332 is to provide load, drop and read control synchronization for the Control Memory 326. Channel information stored in the From (F) and To (T) register 337 is compared with the address counter and ANDed with control signals from the TSI-CPU 348 to generate write and read commands for the Control Memory 326. For its last function the TSC 332 includes status registers and address latches (not shown) for storing the address and type of parity error from the DSM 313, 314 and the Control Memory 326 via bus 334. This information is sent to the System Controller upon request through the System Interface 341.
The Control Memory 326 is used to store all information necessary to set up a path or paths through the switch. It is used to control the CPS 306-309 and to address DSM 313, 314 to relate the "From" channel time slot to the "To" channel time slot.
The Control Memory 326 is a 17×512 memory, of which 386 bits are used, which is constantly read and the outputs are used by DSM 313, 314 and CPC 316 via buses 329, 330, respectively to control time slot switching. Information stored in the memory is obtained from the System Controller 50, 64 of FIG. 1. The Control Memory 326 is divided into two parts, the first of which is used only to control the "From" channel time slot cross points. The remainder of the memory is used to control the "To" channel cross points and the addresses of the DSM 313, 314. The Control Memory 326 includes two parity bits. During one frame, the "From" information will control the connections of CPS 306-309 to Bus 311 by the Even/Odd signal on Bus 355. During the next frame, the "From" information will control the connections of CPS 306-309 to Bus 312. The "To" information will operate similarly, except that the connections are reversed.
The System Interface 341 and the F and T Register 337 work together to load, drop, or read a path in the TSI. The System Interface 341 has communication in both directions to both the primary and secondary System Controller 50, 64 via buses 57, 63 through a conventional Universal Asynchronous Receiver/Transmitter (UART). The input information from a System Controller is received by the Interface 341 and sent to the CPU 348 for command decoding, then to the F and T Register 337 for temporary path channel storage. The System Interface 341 is used to interface the TSI with both System Controllers 50, 64.
The System Interface 341 also provides a holding register for reading the Control Memory 326 via 17-bit bus 342. Information to the System Controller 50, 64 from the status register in the TSC 332, command information from the CPU 348 and path read data from the memory output registers in the System Interface 341 are sent to the UART on a three-state bus 335 for transmission back to the SC.
Commands and data from the system controller enter the interface 341 in serial form of an 11 bit byte, 8 data bits, 1 parity, start and stop bit which is converted to a parallel byte by the UART and output to CPU 348 via bus 349.
Data to be sent to the system controller is sent in a serial 11-bit byte as that received by UART. The receive data rate is 31.25 K baud. The transmit data rate is 3.906 K baud. Serial data is sent out via a differential line driver to either system controller. The selection of which system controller can communicate with the TSI is determined by the Active signal from the on-line system controller which is received by a differential line receiver and is used to enable communication with the active System Controller and to enable cross point control 316 via bus 343.
The F and T Register 337 is used for temporary storage of all path information necessary to load the Control Memory 326. The TSI gets path information in byte serial format from the System Controller. All bytes must be in the TSI before loading takes place. The F and T Register 337 is used to accumulate these bytes and to connect the proper bits from these bytes to the TSC 332 and the Control Memory 326 via Buses 339, 338. Input data to the TSI from the System Controller enters the F and T Register 337. The "From" and "To" refers to the way a path is set up in the TSI and is always "From" a channel "To" another channel, without regard to which channel may be originating and which may be terminating. The F and T Register 337 contains two 12-bit registers which hold the "From" channel number and the "To" channel number when they are being loaded into the Channel Memory 326. Eleven bits in each register identify the channel time slot (9 bits) and line group (2 bits). The twelfth bit is for parity.
All communications controlled between the TSI and System Controller and all internal loading, dumping or reading control is sequenced by the TSI CPU 348. The CPU 348 is a small stored-program, 256 step microprogram processor whose program is contained in two 4×256 PROMs.
The CPU 348 can check input instructions from the System Controller, check hardware flags from circuits in the TSI and do program branching according to the condition of the instructions and flags.
The operation of the processor 348 will be explained in conjunction with FIGS. 10 and 11, which show an exemplary flow chart for the operation of the TSI processor, and with FIG. 9.
In FIGS. 10 and 11, the processor will commence at state A, assuming that an initial up sequence has been completed.
At step A, the processor will loop until a character is received and entered in a command register in the SC Interface 341. The processor will continue to determine whether any UART errors are detected in the system interface. If yes, the processor will go to step B as shown in FIG. 11. to output an UART error message and reset the UART, returning to step A. If there are no UART errors, the processor will determine if there are any command errors. If yes, the processor goes to step C in FIG. 11 and outputs a command error message and resets the UART.
If there are no command errors, the processor will continue to determine if there is a status request command or loop back command. If either is a yes, the processor goes to steps D or E in FIG. 11. Step D outputs the contents of the status register of TSC 332 of FIG. 9. Step E will output a received character.
The subprogram 1 (SPRG 1) is shown in FIG. 11 in which the processor will loop and increment an index register until either a character is received or the index equals 4096. If the index increment to 4096 the processor will proceed to step F which will output a UART time out message and reset the UART.
If the character is received, the processor will then load registers F1, F2, T1 and T2. Registers F1 and F2 form the F portion of register 337 and registers T1 and T2 form the T portion of register 337 of FIG. 9.
In FIG. 12, if a load command is received, the processor will determine through step H if either path set up by the system controller is busy. That is to say, the processor will determine whether the F data and T data paths requested by the system controller are availalbe. As seen in step H, if the F data path is busy, the processor will go to step K to output the busy 1 flag set message. Similarly, if the T data is busy, the processor will go to step L to ouput a busy 2 flag set message.
Step H gives the time slot interchanger the capability of determining path availability in the TSI by this routine without the requirement of a memory map in the system controller.
In FIG. 10, if the processor receives a dump command, it will go to step I. In step I, the processor will proceed through the routine and output a dump complete message and return to Step A. If there is no read command, the processor goes to Step C and outputs a command error message and returns to Step A.
The Processor will continue through the Step A outputting memory registers 1-4, reset the UART and return to Step A.
Because the time slot interchanger is maintaining the status of the calls in progress, the system controllers 50,64 can "relearn" what the status of the call is should both controllers experience a failure. Thus, accurate accounting records can be maintained as no calls are lost.
Referring now to FIG. 9, an example of a call progressing through the time slot interchanger will be given, assuming that the system is operating with two primary and two secondary line groups and that the primary line groups are on line. Each TSI in the network has the capability of switching the send and receive PCM data from any of the 384 time slots to any other time slot. Since the TSI is a folded duplex switch, it switches both the send and receive data at the same time and any matrix path is two way and equivalent to a four wire switch. It will be assumed for purposes of explanation that the System Controller has instructed the TSI to set up a call path connected from line group one, channel 3 (1-3) to line group two, channel 4 (2-4).
Assuming an even frame number for the call path progress, DSM 313 contains PCM data from line group two, channel 4 (2-4) at address 3 while DSM 314 contains PCM data from line group one, channel 3 (1-3) at address 3. The Control Memory 326 includes a CMF 327 and CMT 328 portions which control which cross point switch CPS 306 or 308 closes at which time slot, thereby providing the space division switching between the two line groups. The CMF 327 ("From" channel cross point control) and CMT 328 ("To" cross point control) provides the path store in the TSI and are loaded by the System Controller. The "From" and "To" refers to the way a path is set up in the TSI, and is always "From" a channel "To" another channel without regard to which channel may be originating and which may be terminating. When the CMF 327 portion of the CONTROL MEMORY 326 is addressed at address 3, the data at that location will close cross point 306. For simplicity, the designation CP1 will indicate CPS 306.
When the CMT 328 is addressed at 4, data at that location will close cross point 308 and the rest of the CMT 328 contains the information necessary for time division switching and is used to address DSM 313, 314. In this example, the data at address location 4 of CMT 328 is an address used to index DSM 313, 314 at location 3. The designation CP2 at location 4 indicates cross point switch 308.
When the TSC 332 counts to 3, the CMF 327 is addressed at 3 and closes cross point CP1 for the Bus 311. The DSM 313 is also addressed at 3 by the TSC 332 and the old line group two, channel 4 (2-4) PCM data is sent to line group one, channel 3, and the PCM data from line group one, channel 3, replaces it at the same time. No action occurs at this time (time slot 3) on the CMT 328 or DSM 314 unless there were other paths set up in the TSI.
The TSC 332 next advances to 4, which addresses both the CMT 328 at address location 4. The CMT 328 closes cross point CP2 on the Bus 312 and addresses DSM 314 at address 3.
The old 1-3 PCM data in DSM 314 is then sent to line group two, channel 4, and new PCM data from line group two, channel 4 replaces it. No other action occurs in the CMF 327 or DSM 313. The TSC 332 will now continue counting until it reaches its maximum count (the end of the frame--386) and goes back to 1. Connections in the TSI are then changed for an odd frame by the even/odd frame signal on bus 355.
During time slots 1 and 2 of the odd frame, no action occurs. When the TSC 332 counts to 3, it addresses CMF 327, which closes cross point CP1 on Bus 312, and the DSM 314 now addressed by the TSC 332 sends its old 2-4 PCM data to line group one, channel 3, and loads new 1-3 PCM data from line group one, channel 3. No other action occurs at this time (time slot 3).
When the TSC 332 reaches count 4, the CMT 328 closes cross point CP2 on the Bus 311. The DSM 313 now addressed by the CMT 328 at location 3 sends its old 1-3 data to line group two, channel 4, and loads new 2-4 PCM data. The TSC 332 will now count through a full frame (386 time slots) and change the connections back to an even frame. Thus one full cycle of two frames has occurred and the data in the DSM 313 and DSM 314 will be from the same line group and channel as that shown in the FIG. 9. This process continues in this manner for each path set up in the TSI.
An exemplary flow chart for the system controllers is shown below in Chart I.
CHART I
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State
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φ IDLE
1 EXAM CLASS MARK
2 RCVG 1rst CLD DIGIT
3 RCVG 2, 3rd CLD DIG.
4 INITIAL XLATION
5 STATE CHG/DIG INPUT
6 OG. SIGNAL CK ROUTINES
7 RCVG CLD DIG RT
10 HAVE CLD DIG EXP
11 ST.CHG/DIG IN-INTERCHG CODE T.O
20 SATT ANI-SELECT MFR
21 S.U.P. MFR-ORIG TRK
22 PTST MFR-ORIG TRK
23 SATT ANI START SIG.
ABST SENDS OFF HOOK→ORIG TK
24 HAVE MFR, SEND ON HOOK
25 AWAITING AE ANI DUAL TONES
26 RCVG AE ANI DIG
27 ANI FINISHED
DROP PATH-TRK-MFR
30 AWAITING PTST RET.
31 PATH & MFR DRPO. RCVG CLD DIG
60 ONI
61 CHECK FOR IDLE ONI TRK
62 SET UP PATH INC TRK-OGT
63 AWAITING PTST INC-OGT
64 SEND MESSAGE TO ONI
65 AWAIT W.P. REPLY & ONI HANDSHAKE
66 RECEIVING ONI DIGITS
67 AWAITING ONO RET AFTER
SENDING SNDR MESSAGE
70 HAVE ONI DIG-DRP PATH
71 AWAIT PTST-SP REPLY
73 ONI ATB-SEND RBT
74 AWAITING IDLE ONI TRK
77 IF AE TRIBANI TRK SEND OFF HOOK
100 ROUTE TRANSLATION
101 CHECK SCREENING TABLE
102 CHECK PRIMARY TRK CRP
105 FIND IDLE O.G.T.
106 SEIZE OUTGOING TRK
SEND OFF HOOK TO OGT
114 SET UP OUTPULSING
120 SELECT MF SENDER
121 SET UP PATH MFS-OGT
122 PATH TEST MFS-OGT
124 AWAITING THE BEG NG OF WINK
125 AWAIT END OF WINK/DELAY DIAL
126 AWAITING STOP DIAL
127 AWAIT. END OF OUTPLSG DELAY
130 OUTPULSE KP.
131 OUTPULSING DIGITS
132 AWAIT. MFS TO SEND DIG.
133 AWAIT. MFS TO SEND "ST"
134 AWAIT. 100 MS "ST" TO-DRP PATH
135 SET UP PATH INC-OGT
136 AWAITING PTST INC-OGT
200 CK IF ALREADY HAVE ANS. SUPV
201 AWAITING ANSWER SPV
202 AWAIT. END OF CHARGE DELAY
203 CALL IS IN PROGRESS
210 AWAITING CPD TIME OUT
220 SET UP TIME DURATION
FOR BILLING RECORD
221 AWAITING FOR SPO ONHK
THEN SET UP BILLING REC
222 AWAITING BILLING REC. PROCESS
230 TEST TRUNKS FIRST DIG. = 1
231 AWAIT. FOR 3RD DIG. LINK THRU ABST
232 TTRK 109 ACCEPT 3 MORE DIGITS
PERMIT TTK CODE TO SNBR
233 102 1HZ WI 9-10SEC OFF HK
234 WAITING FOR ON HK/TIME OUT
235 OUTPUTTING ONHK TOINC.
TURN OFF TONE
236 WAITING FOR ON HOOK
237 TEST TRK 100
240 IDLE ON INC. WAIT FOR ON HOOK
241 CALL INWARD TO T.TRK 1
242 103-ON/OFF HOOKS
243 103 A&B BITS SENT
260 TRK IDLE
261 AWAITING MFR, SET UP PATH
262 AWAITING DIGITS
263 DISABLE MFR
265 TRK SENT IDLE
266 DROP PATH, MFR
267 AWAITING IDLE
300 SET UP ANNOUNCEMENT TRUNK
301 WAITING FOR ONHK ONINC
PATH SETUP INC-ANN. TRK
340 PATH DID NOT DROP
342 STAND BY IDLE
343 STANDBY/CALL IN PROGRESS
344 STANDBY/CALL IN PROGRESS
FINISHED W/OGT
345 S.P. RETS WHEN DONE
346 PATH SET UP VERIFICATION COMPLETE
347 IDLE-AWAITING CTS ENTRY
350 BEGIN IDLE SEQUENCE
351 AWAITING PATH TEST DONE
352 AWAITING SP. TO SEND
ON HOOK TO OGT
353 AWAITING S.P. TO SEND
ON HOOK TO INC.
354 STATUS REQUEST ONINC TK
357 PHONY STATE FOR FE/B2 ERROR
360 REORDER SEQUENCE
361 AWAITING PTST DONE
362 AWAITING S.P. TO SEND
ON HOOK TO OGT
363 AWAITING USGO RET
364 AWAITING STATUS REQUEST
365 RECORDING ONINC TRK
AWAITING IDLE
366 AWAITING IDLING OF S.G.
______________________________________
The operation of the exemplary flow chart of the system controller will be described below.
Referring to the flow chart, State 0 is an idle state.
The system controller will go to State 1 and examine the class marking. If a digit is received too soon, the controller will go to State 360. If the called number is in MF format, the controller goes to State 20. If the called digit is dial pulse, the controller continues to State 2. If the party went on-hook at State 1, the controller goes to State 350.
If the party went on-hook at State 2, the controller goes to State 350. If an invalid digit is received or the first digit is 0, the controller goes to State 360. If the first digit is one, the controller goes to State 230. If no digits have been received within 30 seconds, the controller will go to State 360. If the first digit received is not a 0 or 1, the controller goes to State 3.
In State 3, the system will receive the second and third called digits. As before, if on-hook occurs the controller goes to State 350. If an invalid digit or interdigital time out occurs, the controller will go to State 360. If the controller receives three valid digits, it goes to State 4.
At State 4, the valid three digits will be translated. The three digits will identify a geopraphical area of the numbering plan area (NPA) used in present switching systems.
In State 5, if the 3 digits received are a vacant code, the processor goes to State 300. If valid digits are received and the system utilizes a Strowger Automatic Toll Ticketer (SATT ANI), the controller goes to State 23. If an interdigital time out occurs, the controller goes to State 360. If not an automatic electric (AE) tributary ANI, the controller goes to State 6.
In State 6, if the number of digits received are the number of digits expected, the controller goes to State 10. If a time out occurs before all digits are received the controller goes to State 360. If more digits are to be received, the controller goes to State 7.
At State 7, the controller waits until all digits are received or the caller has hung up. If all digits expected are received, the system controller goes to State 10.
In State 10, if there is an interdigital time out the controller goes to State 360. If there is not an interchangeable code, the system controller goes to State 77. If it is an interchangeable 7 or 10 digit code, the controller goes to State 11.
In State 11, if no more digits are received and there are 7 digits, the controller goes to State 10. If more digits are received, the controller returns to State 6.
As previously described, if the system controller determines there is a SATT ANI start signal, the controller goes to State 23. An off-hook is sent to the originating trunk to signal that the system is ready for ANI (automatic number identification). The system controller will instruct the signal processor routing to output a message. If the transmit by the signal processor has an error, the system controller will go to State 360. If the transmit is successful, the system controller has initiated a wink. The SC will go to State 20. Further details of the operation of the signal processor are described in the above-referenced application entitled "Register/Sender".
In State 20, the controller will select an MF receiver to identify the SATT ANI digits. Further details of the operation of the MF receiver are described in the above referenced application entitled "Multifrequency Sender/Receiver In A Multi-Time Slot Digital Data Stream".
In State 21, a path between the MFR of the system and the originating trunk is set up. If the path set up is good, the controller continues to State 22. If not, the system controller will go to State 360. The path is set up from the originating trunk through the Time Slot Interchanger to the MFR. Further details of the operation of the Time Slot Interchanger are described in the above referenced application entitled "Time Slot Interchanger".
In State 22, a path test is initiated between the MFR and originating trunk. If the path test is busy or done, go to State 24. If an invalid digit or the path test is unsuccessful, the system goes to State 360. Further details of the operation of the path test are described in the above referenced application entitled "Path Test Apparatus and Method".
In State 24, the controller has an MF receiver (MFR) assigned and now sends an on-hook signal to finish the wink. As before, if there is an invalid digit or the transmission is wrong, the controller goes to State 360. If the transmission is correct, the MFR is ready to receive signals and the system goes to State 25.
In State 25, the controller is awaiting AE ANI dual tones to identify the number of the calling party.
The controller will proceed to State 26 to receive the AE ANI digits.
Proceeding to State 27, when ANI is finished, the path between the incoming trunk and the MR receiver is dropped. If the path does not drop, the controller goes to State 340.
In States 30 and 31, the MFR and path is dropped. The controller goes to State 11.
In State 77, the controller will send an off-hook to the incoming trunk. If the signal processor output reply is valid, and system goes to State 100.
At State 100, the system goes through a route translation.
In State 101, the controller checks whether the call with proceed through the digital switch. For example, local calls cannot be switched through a toll system. For a vacant code the controller goes to State 360. For local ANI, the controller goes to State 13. If ANI failure has occurred, the controller goes to State 60 for operator number identification (ONI). States 60-74 are a routine for the controller to determine by operator number identification (ONI) the calling number. In state 60, the controller will go to State 73 if all ONI trunks are busy and send a ringback tone, then return to state 61 when a trunk is available. Upon successful completion of ONI, the controller will go to State 102. The generation of the various tones utilized by the IMAS are described in the above referenced application entitled "Service Generator For Generating A Plurality Of Tones".
In State 102, the controller will look for the primary outgoing trunk group. If all trunks are busy and there is no alternate route, the controller goes to State 360. If the hard to reach numbers (HR) are at their maximum count the controller goes to State 300. Otherwise, the controller has an idle trunk and goes to State 105.
In State 105 the system searches for an outgoing trunk. If a trunk is found, the system goes to State 106.
In State 106 the outgoing trunk group is seized by sending an off-hook from the signal processor. The controller will go to State 114.
In State 114, the controller will set up in outpulsing either dial pulse or multifrequency. If multifrequency outpulsing the controller goes to State 120.
In State 120, the controller selects an MF sender and a path is set up between the MF sender selected and the outgoing trunk. Further details of the operation of the MF sender are described in the above referenced application entitled "Multifrequency Sender/Receiver In A Multi-Time Slot Digital Data Stream".
In State 122, a path test is initiated between the selected MF sender and outgoing trunk.
States 124-127 will await the end of either a wink or delay dial, techniques which are known in the art.
In State 130, the controller will outpulse the KP signal, which is the start of the MF tones.
In State 131, the controller outpulses the digits. In State 132, the system awaits the MF sender to send the digits. In State 133, the MF system sends the ST signal.
In State 200, the controller is waiting for answer supervision.
In State 203, a call is in progress and the controller will go to State 220 if the incoming trunk goes on-hook and to State 210 if the outgoing trunk goes on-hook. If an excessive conversation in excess of 5 hours is detected, the controller goes to State 220.
In State 210, the controller is awaiting the called party time out and will go to State 302 if the outgoing trunk goes back off-hook. If the called party disconnects the controller goes to State 220.
In State 220, the controller will set up the time duration for billing purposes and send an on-hook to the outgoing trunk.
In State 221 the controller is awaiting the signal processor output on-hook signal, then will begin setting up a billing record.
In State 230, the controller has received a first digit equal to one and proceeds to State 231 if the second digit is a 0.
In State 231 the system is waiting for the third digit. If the third is a 9, the controller goes to State 232. If the digit is a 2, the controller goes to State 233, if the digit is a 0 the controller goes to State 237. If the third digit is a 1, the controller goes to State 241. If the third digit is a 3 through 8, the controller goes to State 360.
In State 240, the controller is in an idle state on the incoming trunk waiting for an on-hook.
In State 260, the controller is in a trunk idle state and States 260-267 are an outgoing trunk loop used for testing.
In State 300-301 the controller is awaiting on-hook for the incoming trunk and a path is set up for the incoming announcement trunk.
In State 340, the controller is in a condition where the path did not drop and will go to State 360.
In State 342 the controller is in a stand-by idle routing which ignores the day and rate changes on incoming and outgoing trunks.
In State 343 the controller is in a stand-by and call in progress routine in which an off-hook is sent to the outgoing trunk.
State 350 is an idle sequence in which an on-hook is sent to the outgoing trunk and to the incoming trunk via states 352,353.
State 360 is a reorder sequence in which the controller will go to State 350 if the incoming trunk goes on-hook. If an outgoing trunk is assigned, an on-hook is sent via State 362.
In States 361 and 362 the controller is awaiting the signal processor to send an on-hook to the outgoing trunk.
In State 363 the system is waiting for the service generator to send a reorder on the incoming trunk.
In State 364 the system is awaiting a status request.
In States 365 and 366 the system is awaiting the idling of the service generator.
It should be noted that the various subsystems in the IMAS operate asynchronously of each other. The particular subsystems rely on their own processors to operate properly, thereby insuring that each subsystem is an independent entity in the IMAS.
What is claimed is:
1. An integrated message accounting system operating in a multiframe format, each frame having a plurality of time slots, where each of said time frames include a framing bit for identifying each frame in said format, said system operating to switch data samples between a time slot on one communication line and a time slot on another communication line, where the samples occur as serial bits in said time slots at a predetermined rate, comprising:line group means including a number of primary and secondary input portions for receiving input data signals where one or the other of said primary and secondary input portions is activated for receiving said input signals, and a number of primary and secondary output portions for transmitting output signals where one or the other of said primary and secondary portions is activated for transmitting said output signals, a second number of time slot interchangers for connecting said active input portions to said active output portions where one of said interchangers is activated for connecting said input portions to said output portions whereby said input signals become output signals, system controller means for activating said primary or secondary portions and one of said interchangers, said input portions including elastic store means for storing said data samples, clock recovery means connected to receive said data samples for providing a clocking edge lacking the data bit for each of said samples, read/write control means, address select means responsive to said read/write control means for selecting location in said elastic store means into which said data bit is to be written, write address counter means and read address counter means connected to said address select means for specifying the address at which data is to be written into or read from said elastic store means, serial to parallel converter means connected to said elastic store means for converting said serial data samples to parallel samples, reframe control means connected to said read address counter for clocking said data samples from said elastic store to said converter means, and output buffer means for connecting said parallel samples to one of said time slot interchangers specified by said system controller means.
2. A system as in claim 1 wherein said system controller means includea primary system controller for activating said primary portions of said line group means and one of said time slot interchangers, and a second system controller for activating said secondary portions of said line group means and one of said time slot interchangers, where one of said primary or secondary system controllers is in an active state and said other is in a stand-by state.
3. A system as in claim 1 further including primary service generator means connected to said primary portions and secondary service generator means connected to secondary portions for connecting selected tone signals in time slots specified by said system controller means.
4. A system as in claim 1 further including primary signal processor means connected to said primary portions and secondary signal processor means connected to said secondary portions, said signal processor means responsive to said system controller means for detecting changes of state of supervisory signals where the supervisory signals occur as signaling bits during a signaling frame of a multiframe format.
5. A system in claim 1 wherein said line group means further include primary multifrequency sender means connected to said primary portions and secondary multifrequency sender means, connected to said secondary portions, said sender means responsive to said system controller means for sending multifrequency signals in selected time slots specified by said system controller means.
6. A system as in claim 1 wherein said line group means further include primary multifrequency receiver means connected to said primary portions and secondary multifrequency receiver means for detecting in specified time slots the presence of multifrequency tone signals.
7. A system as in claim 1 further including primary master clock means for activating said primary portions and said time slot interchangers and secondary master clock means for activating said secondary line group means and said time slot interchangers, said master clock means responsive to an active signal from said system controller means.
8. A system as in claim 7 wherein said master clock means includes means for generating a framing bit code identifying each of said frames in a multiframe formal thereby forming system frame bits.
9. A system as in claim 8 where said input portions include data selector means activated by said system controller means for receiving said data samples.
10. A system as in claim 7 wherein said master clock means generate clock signals to said line group means where the rate of said clock signals is twice the rate of said data samples.
11. A system as in claim 1 wherein said system controller means include real time clock means for timing the duration of a call between a calling and called party.
12. A system as in claim 1 further including signal processor means for monitoring the state of an outgoing trunk signal whereby said signal processor means signals said system controller means upon termination of said call.
13. A system as in claim 12 further including elastic store means for storing said data signals, read/write control means for reading and writing said data signals into said elastic store means, said read/write control means responsive to said master clock signals thereby providing two rising clocking edges per incoming data bit thereby providing two write windows per incoming bit.
14. A system as in claim 1 wherein said system controller means include means for receiving automatic number identification data.
15. A system as in claim 14 wherein said system controller means include means for receiving operator number identification data.
16. A system as in claim 1 wherein said time slot interchangers include processor means for controlling the operation of said interchanger.
17. A system as in claim 16 wherein said processor means include means for determining availability of a path in said interchangers without requirement of a memory map in said system controller means.
18. A system as in claim 17 wherein said system controller means include means for storing a called record for a telephone call.
19. An integrated message accounting system operating in a multiframe format, each frame having a plurality of time slots where each of said time frames includes a framing bit for identifying each frame in said format, said system operating to switch data samples between a time slot and one communication line and a time slot on another communication line, where the samples occur as serial bits in said time slot at a predetermined rate, comprising:line group means includinga number of primary and secondary input portions for receiving input data signals where one or the other of said primary or secondary input portions is activated for receiving said input signals, and a number of primary and secondary output portions for transmitting output signals where one or the other of said primary and secondary portions is activated for transmitting said output signals, a second number of time slot interchangers for connecting said active input portions to said active output portions where one of said interchangers is activated for connecting said input portions to said output portions whereby said input signals become output signals, system controller means for activating said primary or secondary portions in one of said interchangers, said input portions including data selector means activated by said system controller means for receiving said data samples, elastic store means for storing said data samples, clock recovery means connected to receive said data samples for providing a clocking edge lagging the data bit for each of said samples, read/write control means, address select means responsive to said read/write control means for selecting the location in said elastic store means into which said data bit is to be written, write address counter means and read address counter means connected to said address select means for specifying the address at which data is to be written into or read from said elastic store means, serial to parallel converter means connected to said elastic store means for converting said serial data samples to parallel samples, reframe control means connected to said read address counter for clocking said data samples from said elastic store to said converter means, and output buffer means for connecting said parallel samples to one of said time slot interchangers specified by said system controller means.
20. A system in claim 19 wherein said reframe control means includes processor means for comparing once per frame said framing bit in each of said frames with said framing bit code whereby said reframe control means synchronizes said frame bit to the nearest system frame bit.
21. A system as in claim 20 further including signal bit store means connected to receive signal bits frame said converter means under control of said reframe control means where said signal bits occur during a signaling frame of a multiframe format.
22. A system as in claim 20 wherein said output portions include line receiver means for receiving said input signals from one of said interchangers, input buffer means for storing said samples, parallel to serial converter means for converting said parallel samples to serial samples, and line converter means for connecting said serial samples to said communication line.
23. A system as in claim 22 wherein said output portions include line receiver means connected to said signal processor means for receiving signal bits from said signal processor means, input buffer means for storing said signal bits, and signal select means for connecting signaling bits from said input buffer means into said converter means.
24. A digital switching system operating in a multiframe format having a number of time frames each consisting of a plurality of time slots, said system operating to switch data samples between time slots, where said samples occur as serial bits in said time slots, comprising:line group means includinga number of primary and secondary input portions for receiving input data signals where one or the other of said primary and secondary input portions is activated for receiving said input signals, a number of primary and secondary output portions for transmitting output signals where one or the other of said primary and said second portions is activated for transmitting said output signals, means for connecting said input portion to said output portion whereby said input signals become output signals, and system controller means for activating said primary or secondary portions, said input portions further including elastic store means for storing said data samples, clock recovery means connected to receive said data samples for providing a clocking edge lagging the data bit for each of said samples, read/write control means, address select means responsive to said read/write control means for selecting the location in said elastic store means into which said data bit is to be written, write address counter means and read address counter means connected to said address select means for specifying the address at which data is to be written into or read from said elastic store means, serial to parallel converter means connected to said elastic store means for converting said serial data samples to parallel samples, reframe control means connected to said read address counter for clocking said data samples from said elastic store to said converter means, and output buffer means for connecting said parallel samples to one of said time slot interchangers specified by said system controller means.
25. An integrated message accounting system operating in time frames each having a plurality of time slots, said system operating to switch data samples between a time slot on one communication line and a time slot on another communication line, where the samples occur as serial bits in said time slots, comprising:line group means includinga number of primary and secondary input portions for receiving input data signals where one or the other of said primary and secondary input portions is activated for receiving said input signals, a number of primary and secondary output portions equal to said input portions for transmitting output signals where one or the other of said primary and secondary output portions is activated for transmitting said output signals, time slot interchanger means for connecting said nput portion to system controller means for activating said primary or secondary portions, said input portions further including elastic store means for storing said data samples, clock recovery means connected to receive said data samples for providing a clocking edge lagging the data bit for each of said samples, read/write control means, address select means responsive to said read/write control means for selecting the location in said elastic store means into which said data bit is to be written, write address counter means and read address counter means connected to said address select means for specifying the address at which data is to be written into or read from said elastic store means, serial to parallel converter means connected to said elastic store means for converting said serial data samples to parallel samples, reframe control means connected to said read address counter means for clocking said data samples from said elastic store to said converter means, and output buffer means for connecting said parallel samples to one of said time slot interchangers specified by said system controller means.
26. An integrated message accounting system operating in time frames each having a plurality of time slots where each of said time frames includes a framing bit for identifying each frame in a multiframe format, said system operating to switch data samples between a time slot on one communication line and a time slot on another communication line, where the samples occur as serial bits in said time slots on said lines, comprising:line group means includinga number of primary and secondary input portions for receiving input data signals where one or the other of said primary and secondary portions is activated for receiving said signals, a number of primary and secondary output portions equal to said input portions for transmitting output signals where one or the other of said primary and secondary output portions is activated for transmitting said output signals, time slot interchanger means for connecting said input portion to said output portion whereby said input signals become output signals, system controller means for activating said primary or secondary portions, master clock means for activating said primary or secondary line group means and said time slot interchangers, said master clock means including means for generating a clock signal equal to twice the data rate of said data samples and means for generating a frame bit signal identifying each of the frames of said multiframe format, said input portions including data selector means activated by said system controller means for receiving said data samples, elastic store means for storing said samples, clock recovery means connected to receive said data samples for providing a clocking edge lagging the data bit for each of said samples, read/write control means, address select means responsive to said read/write control means for selecting the location in said elastic store means into which said data bit is to be written, write address counter means and read address counter means connected to said address select means for specifying the address at which said data bit is to be written into or read from said elastic means, serial to parallel converter means connected to said elastic store means for converting said serial data samples to parallel data samples, reframe control means connected to said read address counter for clocking said data samples from said elastic store to said converter means, output buffer means for connecting said parallel samples to one of said time slot interchangers specified by said system controller means, said reframe control means including processor means for comparing once per frame said frame bit with said master clock frame bit whereby said reframe control means synchronizes the incoming frame bit to the nearest clock frame bit.
27. In a telephone system operating in a multitime frame format, each frame having a plurality of time slots, said system operating to switch data samples between said time slots where the samples occur as serial data bits at a predetermined rate, line group apparatus comprising:data selector means for receiving input data samples, elastic store means for storing said data samples, clock recovery means connected to receive said data samples for providing a clocking edge lagging the data bit for each of said samples, read/write control means, address select means responsive to said read/write control means for selecting the location in said elastic store means into which said data bit is to be written, counter means connected to said address select means for specifying the address at which data is to be written into or read from said elastic store means, serial to parallel converter means connected to said elastic store means for converting said serial data samples to parallel samples, and reframe control means connected to said counter means for clocking said data samples from said elastic store means to said converter means.
28. An integrated message accounting system operating in a multiple frame format, each frame having a plurality of time slots, said system operating to switch data samples between time slots on a plurality of multitime slot input and output digital data buses, comprising:line group means includinga number of primary and secondary input portions for receiving input data samples on said input buses where one or the other of said primary or secondary input portions is activated for receiving said input samples, a number of primary and secondary output portions for transmitting output data samples on said output buses where one or the other of said primary or secondary output portions is activated for transmitting said output data samples, a second number of time slot interchangers for connecting said active input portions to said active output portions where one of said interchangers is activated for connecting said input portions to said output portions whereby said input samples become output samples, system controller means for activating said primary or secondary portions in one of said interchangers wherein said system controller means includea primary system controller for activating said primary portions of said line group means and one of said time slot interchangers, and a second system controller for activating said secondary portions of said line group means and one of said time slot interchangers, where one of said primary or secondary system controllers is in an active state and said other controller is in a standby state, primary service generator means connected to said primary portions and second service generator means connected to said secondary portions for connecting selected service tone signals to selected time slots specified by said system controller means, primary signal processor means connected to said primary portions and secondary signal processor means connected to said secondary portions, said signal processor means responsive to said system controller means for detecting changes of state of supervisory signals for each of said time slots where said supervisory signals occur as signaling bits during a signaling frame of said multiframe format, and for sending supervisory signals in specified ones of said time slots, primary multifrequency sender means connected to said primary portions and secondary multifrequency sender means connected to said secondary portions, said sender means responsive to said system controller means for sending multifrequency signals in selected time slots specified by said system controller means, primary multifrequency receiver means connected to said primary portions and secondary multifrequency receiver means connected to said secondary portions for detecting the presence of multifrequency tone signals in time slots specified by said system controller means.
| 1977-03-25 | en | 1979-10-23 |
US-90680792-A | Fusion adhesive
ABSTRACT
The present invention relates to polyurethane fusion adhesives that are hardened by the action of moisture and which contain at least one reaction product from a component that contains NCO groups and an essentially linear hydroxypolyester, hydroxypolyether, and/or hydroxypolyetherester component. In addition, the present invention relates to a procedure for manufacturing a material that is permeable to water only in vapor form, this being in the form of a fiber material, in particular in the form of a web, which is joined to a polyurethane film, in which the fiber material is coated with a polyurethane material and subsequently the polyurethane material is hardened to form a water-vapor permeable film. The present invention also relates to a material that is permeable to water only in vapor form and which is in the form of a fiber material, in particular in the form of a web, that is bonded to a polyurethane film. According to the present invention, a fusion adhesive with a segmented hydroxypolyester or an hydroxypolyether or an hydroxypolyetherester component is used for this purpose as polyurethane material. The fusion adhesive according to the present invention can be applied directly or by a transfer technique to the fiber material and is hardened in only one step, by the action of moisture, to form a water-vapor permeable, but otherwise high quality water-proof membrane film.
The present invention relates to fusion adhesive containing at least one reaction product of a component that contains NCO groups, and at least one essentially linear hydroxypolyester component. In addition, the present invention relates to a process for producing a material that is permeable only to water in vapour form, this material being, in particular in the form of a web, the fibre material being bonded on it surface with a polyurethane foil, in which the fibre material is coated with the polyurethane material, the polyurethane material subsequently being hardened to form a foil that is water-vapour permeable. The present invention also relates to a material that is permeable only to water in vapour form and is in the form of a web-like fibre material that is bonded on its surface to a polyurethane foil.
Materials that permit the passage of water in vapour form but not in liquid form have been produced for a considerable time and are extremely important for the manufacture of weather-proof clothing, as well as for tarpaulins, in the construction industry, and for many other applications in which the water-vapour permeability is desirable.
Such materials can be produced on the basis of fibre materials, which can be either knitted or random-laid materials such as fleeces. Such fibre materials are not only water-vapour permeable per se: they are also water permeable. Up to the present, the desired degree of hygro-stability has been achieved mainly in that a foil that is only water-vapour permeable and which is of synthetic material has been joined to the fibre material. The examples of these known materials are, for example, the GORETEX laminates.
U.S. Pat. No. 3,953,566 describes a textile material to which a porous water-vapour permeable polytetrafluorethylene film has been laminated by using an adhesive.
From DE-OS 38 36 434, it is known that a web of water-vapour permeable foil can be laminated thermally onto textiles by using a spray-on fusion adhesive. According to DE-OS 38 15 720, in place of this, it is possible to laminate a polyurethane film that is preformed from solution or dispersion onto textiles thermally (by welding) from a reversal paper.
However, in many respects it is disadvantageous to join premanufactured foils to fibre materials. It requires a number of costly processing steps to join foil and fibre materials. The use of an adhesive to join foil and fibre material entails the disadvantage that this frequently makes the product stiffer. In addition, the adhesive that is used can clog and thus block, the film structure that is essential to achieve water-vapour permeability. Welding a polyurethane film directly onto the fibre material, as described in DE-OS 38 15 720, requires the costly pre-formation of the foil from either solution or dispersion, and, for this reason, it is extremely difficult to do from the technical standpoint.
A first step towards overcoming these problems is described in EP-A2-0 287 736, according to which a water-vapour permeable and water absorbing coating of a special polyurethane oligomer that has been derivatized with acrylate is produced. This oligomer, together with a pre-formed PTFE matrix film, is rolled onto the fibre material and then hardened in two subsequent hardening stages (irradiation hardening and subsequent moisture hardening) and joined to the fibre material.
However, this procedure is still very costly and does not constitute a solution to the problems of the prior art. As was formerly the case, a pre-formed PTFE film has to be used; the simultaneous application of liquid polyurethane material and preformed teflon-matrix film, as well as the two subsequent hardening stages, make the procedure very costly.
DE-OS 39 22 028 proposes that material of this type be manufactured in that a layer of adhesive material is applied to a web-like fibre material and joined to the surface of the fibre material by gluing. The adhesive material should be water-vapour permeable but not water-proof, and should, for example, be formed from a fusion adhesive. The application contains no details as to the type of fusion adhesive that is to be used in this process.
A very large number of various types of fusion adhesives are known from the prior art. Usually, these contain a polymer material that essentially determines the cohesion properties of the adhesive, in a mixture with resins or the like that render it adhesive and which are essentially decisive for the adhesion properties. Conventional plastifying components are added to this. All three of these principle components can be of the most varied kinds.
According to the applicant's knowledge, however, it is not possible to form a membrane-like film that is water-vapour permeable and equal to the demands placed on the finished material by a particular application on a fibre layer by using any of the fusion adhesives described in the prior art, let alone those that are commercially available.
For this reason, it is an important task of the present invention to describe fusion adhesives that are suitable for producing a water-vapour permeable, membrane-like film on a fibre material in situ, so that the foil component of the material does not have to be pre-formed, the properties of the finished material with respect to water-vapour permeability, water-proof properties, service life, stiffness, etc., being approximately equal to the materials known from the prior art.
It is a further task of the present invention to describe a procedure for the inexpensive and problem-free manufacture of water-vapour permeable materials of this kind and to describe materials that can be manufactured accordingly. The features set out in the independent claims provide a solution to this problem; advantageous developments are defined in the sub-claims.
The fusion adhesives according to the present invention are, in principle, polyurethane fusion adhesives.
DE-OS 38 27 224 discloses similar fusion adhesives for bonding metal, glass, wood, ceramic, leather, plastics, and the like.
These known fusion adhesives consist either wholly or in part of conversion products of components that contain NCO groups, namely, polyfunctional isocyanates (polyisocyanates) and partially crystalline hydroxypolyesters with contents of exclusively aliphatic dicarboxylic acids, of the general formula ##STR1## wherein x+y=12 to 26 and, optionally y=8 to 12 or x=6 to 18 and z=3 to 50. The ratio of the reaction of OH:NCO is 1:1.2 to 1:3.0, and preferably 1:1.5 to 1:2.5.
These known fusion adhesives are intended to achieve a particularly short bonding time in that the partially crystalline polyesters contain decanic diacid, dodecanic diacid, or tetradecanic diacid, with dodecanic diacid being greatly preferred.
It is preferred that the diol component of the polyesters consist of aliphatic C6 -C12 diols, and, in the case of long-chain dicarboxylic acids, of C2 or C4 diols as well. In addition to these diols, etherdiols can also be contained, preferably those based on ethyleneglycol or butanediol-1,4, which however is not preferred. In no case should the proportion of such ether diols be greater than 50 mol-% of the diol component. According to the embodiments, this does not involve segmenting chain components of the polyester, but components of the monomer mixture that regulate the bonding behaviour.
DE-OS 38 27 224 contains no details about the properties of a film-like formed and hardened fusion adhesive according to their teachings, and in particular nothing of their porosity, to say nothing of the water-vapour permeability of such a film. Similarly, DE-OS 38 27 224 contains no indication of the use of the fusion adhesive that they describe to produce water-vapour permeable materials that are, however, water-proof.
The fusion adhesives found in the prior art are not suitable as such for the purposes of the present invention.
An important advantage of the present invention is the fact that the fusion adhesive according to the present invention can be applied directly (as well as by a transfer procedure) to a fibre material and processed in situ, in only one hardening stage (namely by the effects of moisture, without being irradiated), to form a membrane-like film that is water-vapour permeable but which, at the same time, displays a considerable degree of hygro-stability. This makes the manufacture of materials according to the present invention extremely simple. For example, the fusion adhesive according to the present invention can be applied by means of a sheet die to a textile or fleece web when in the molten state, or to a transfer medium (and from this, preferably immediately thereafter, onto the fibre material); after this has been done, the desired membrane film is produced by the simple effect of moisture. Penetration of the fusion adhesive into the fibre material, and the weight per unit area of the foil that is formed (usually approximately 20 g/m2) can be controlled by a suitable choice of the processing conditions. This very thin membrane-type film does not detract from the properties of the fibre material even though it is bonded to it very strongly. The thinness of the foil, as well as its very low inherent stiffness, contributes to this. Nevertheless, the foil displays hygro-stability, measured according to DIN 53886, up to test pressures of more than 0.7 bar or 7 m static water column.
Fusion adhesives according to the present invention, in which the component(s) that contain(s) the NCO groups can be caused to react with at least two different components that contain OH groups, namely on the one hand, with an hydroxypolyester and, on the other hand, with an hydroxypolyether, have, according to the applicant's knowledge, no parallel in the prior art. In these reaction products, two urethane functionalities are each connected either by a polyester chain or by a polyether chain, when the sequence of the polymer components in the molecular chain of the reaction product can be statistical. In one variation, the polyester chain can be segmented by inserted polyether groups.
In the other fusion adhesives according to the present invention in each instance two urethane functionalities are connected by polyester units which, in their turn, are segmented by inserted polyether groups. In the extreme case, the polyester groups can be replaced completely by polyether groups, i.e., the fusion adhesive then contains a reaction product of a component that contains NCO groups with an essentially linear hydroxypolyether component.
The essential modification of this fusion adhesive according to the present invention compared to the prior art according to DE-OS 38 27 224 lies in the segmentation of the diol component by the incorporation of polyether groups. It is particularly preferred that the polyester components be modified to form diol molecules by condensing in polyethyleneglycol with weight average molecular weights in the range of a few thousand (in the usual manner by fusion condensation in a vacuum).
The particularly preferred polyester components are derived from copolyesters that are characterized as follows: they are built up from aliphatic and from aromatic dicarboxylic acids and diols having a chain length of C2 to C20. The OH-number of the polyester group lies between 10 and 50, preferably between 10 and 40; its glass transition temperature is between 0° and -50° C. According to the present invention, these polyesters are modified in that a polyether, preferably polyethyleneglycol with a weight average molecular weight of >1,000, preferably >3,000, is condensed in at a quantity of >10, and preferably >20%-mass.
It is preferred that a polyester obtained on the basis of the product Dynacoll® 7210 obtainable from Huls AG, which has been modified with 30%-mass PEG 3000 is used.
The copolyester that has been so modified--segmented--can then be caused to react with polyisocyanates, preferably diisocyanates such as, for example, MDI, to form a reactive fusion adhesive. This isocyanate is, for example, obtainable from Bayer AG under the name "Desmodur 44 M"®. The reaction is effected at a ratio of OH:NCO=1.0:1.6 to 1.0:2.6, and preferably 1.0:1.8 to 1.0:2.4.
In order to adjust the mechanical properties of the hardened product, in particular its tensile strength as well as its impermeability to water, up to 30 parts (relative to 100 parts of the segmented copolyester according to the present invention) of a non-segmented copolyester with a higher glass transition temperature, for example 0° to 50° C., and preferably Tg +20° to +40° C. can be added during the reaction with the isocyanate. A preferred example for this is the product Dynacoll® 7140 that can be obtained from Huls AG.
According to the present invention, fusion adhesives are manufactured according to the customary process, when the reaction of the hydroxypolyester components according to the present invention and any additional commercially available hydroxypolyester components with the polyisocyanate can be effected simultaneously. In contrast to this, it may be advantageous to react the particular hydroxypolyester separately with the polyisocyanate and then mix the fusion adhesive from the PU components so obtained.
Even though the above-described hydroxycopolyesters are especially preferred according to the present invention, the fusion adhesives according to the present invention can also contain other hydroxypolyesters, hydroxypolyether esters, or hydroxypolyethers, e.g., polycaprolactone, polycarbonates, or polytetrahydrofuran.
A fusion adhesive according to the present invention may be a reaction product of a dihydroxy functional polyester component which contains a segmenting dihydroxy functional polyether component that has a weight average molecular weight of between 100 and no more than 10,000, preferably between 2,000 and 6,000 and in particular of approximately 3,000. The segmenting dihydroxy functional polyether content may suitably be 10%-wt or more, preferably 20 to 95 %-wt, and in particular approximately 30%-wt, relative to the total diol constituent of the dihydroxy functional polyester component.
Optionally the diol component of the fusion adhesive may further contain a dihydroxy functional polyether component having a weight average molecular weight between 100 and 10,000, preferably between 2,000 and 6,000.
The dihydroxy functional polyester component may contain a linear aliphatic dicarboxylic acid residue, preferably a residue of a C2 to a C14 dicarboxylic acid and in particular of adipic acid.
The dihydroxy functional polyester component may alternatively be a copolyester that is built up from aliphatic and aromatic dicarboxylic acids and diols having a chain length of C2 to C20 and preferably an OH number between 10 and 50, in particular between 20 and 40, and a glass transition temperature between 0° and -50° C.
As a further alternative, the dihydroxy functional polyester component may have a content of an aromatic dicarboxylic acid, preferably of terephthalic acid and/or phthalic acid or isophthalic acid. In one embodiment, the dihydroxy functional polyester component contains approximately equal parts by weight of aliphatic and aromatic dicarboxylic acid. In this embodiment, the aromatic dicarboxylic acid constituent of the dihydroxy functional polyester component may consist of approximately equal parts by weight of terephthalic acid and phthalic acid.
The fusion adhesive of the present invention may further contain an amorphous, dihydroxy functional polyester component which is formed from isophthalic acid and at least one lower aliphatic diol or polyol, in particular ethylene glycol, hexanediol, and/or neopentylglycol.
An exemplary fusion adhesive according to the present invention may contain, relative to the total weight, between 50 and 70 %-wt of the dihydroxy functional polyester component that has approximately 30%-wt relative to the total diol, of a segmenting dihydroxy functional polyether component having a weight average molecular weight of approximately 3,000; a linear dihydroxy functional polyester that contains no dihydroxy functional polyether component; and approximately 10%-wt diisocyanate. Alternately, the fusion adhesive may contain, relative to the total weight, between 60 and 65%-wt of a dihydroxy functional polyester formed from a diol and a diacid in which the diol comprises polyethyleneglycol; between 25 and 30%-wt of a dihydroxy functional polyester in which the diol does not comprise polyethylene glycol; between 5 and 15 %-wt of diphenylmethane-4,4' diisocyanate; and may optionally contain anti-oxidants and other usual additives. A still further embodiment of the fusion adhesive of the present invention may contain relative to the total weight, between 20 and 90%-wt of a dihydroxy functional polyether; between 0 and 70%-wt of a linear dihydroxy functional polyester that contains no polyether; between 0 and 70%-wt of a dihydroxy functional polyester that contains polyether; and approximately 10%-wt diisocyanate.
It is advantageous that aliphatic polyisocyanates such as, for example, isophoronediisocyanate, tetramethylxylyldiisocyanate, hydrated MDI and hexanediisocyanate can be used instead of diphenylmethane-4,4'-diisocyanate (MDI).
It is preferred that the fusion adhesives according to the present invention contain the derivatized hydroxypolyester component according to the present invention (or hydroxypolyetherester or hydroxypolyether component) as well as a commercially available non-derivatized hydroxypolyester component at a ratio of approximately 2:1. Usual additives of anti-oxidants, fillers (for example, flame retardants), pigments, and the like can also be incorporated. There are no restrictions with regard to the fibre materials that can be combined with the fusion adhesives according to the present invention, neither are there any restrictions with regard to the number of layers or coatings that can be joined to each other and foil that can be formed from fusion adhesive.
Application of the molten fusion adhesive to the fibre material or the transfer medium is preferably effected by using a sheet die, for example, the MA 25 sheet die application valve from Macon Klebetechnik, Erkrath. This permits absolutely even coating across the whole of the application width at a constant application rate, even with fusion adhesive of varied viscosity, and, simultaneously, minimal application weights. No counter-pressure roller is required during application and this makes the manufacture of the materials according to the present invention significantly simpler. At the same time, profiled applications are also possible by using different dosing rates across the application width.
The present invention will be described in greater detail below on the basis of the embodiments described. It is understood that these embodiments only illustrate the work that is done according to the present invention and are not to be understood as being restrictive.
EXAMPLE 1
The hydroxycopolyester component of a fusion adhesive according to the present invention was manufactured in that a mixture of 70%-mass ethyleneglycol and 30%-mass polyethyleneglycol with a weight average molecular weight of 3,000 was subjected to fusion condensation in a vacuum with adipic acid, terephthalic acid, and ortho-phthalic acid (in a weight proportion of approximately 2:1:1).
EXAMPLE 2
In order to manufacture a fusion adhesive according to the present invention, 280 g (63.3%-wt) of the modified copolyester described in Example 1 was heated to 120° C. with 120 g (27.1%-wt) of commercially available amorphous copolyester with Tg =+40° C. (Dynacoll® 7140), and then evacuated for 30 minutes at this temperature. The vacuum was below 1 Torr. Subsequently, 42 g (9.5%-wt) diphenylmethane-4,4'-diisocyanate (Desmodur® 44 MS) was added to it. Subsequently, 0.2 g Irganox® 1010 (an anti-oxidant) was added.
The mixture was heated for 60 minutes at 120° to 130° C. and homogenized. The fusion adhesive so obtained was then allowed to cool.
EXAMPLE 2a
In order to produce a fusion adhesive according to the present invention, 75 g (37.5%-wt) of Dynacoll 7130, a commercially available copolyester, 25 g (12.5%-wt) of Dynacoll 7210, a commercially available copolyester, and 23 g (11.5%-wt) of Dynacoll 7381, a commercially available copolyester, were heated to 120° C. and together with 51 g (25.5%-wt) of a polyethyleneglycol with a molecular weight of 3,000 were evacuated for 45 minutes at this temperature. The vacuum was below 1 Torr. Then, 25 g (12.5%-wt) of diphenylmethane-4,4'-diisocyanate (Desmodur 44 MS) were added. Subsequently, 1 g (0.5%-wt) of Irganox 1010 (an anti-oxidant) was added.
EXAMPLE 3
The fusion adhesive as described in Example 2 was applied at a weight per unit volume of 38 g/m2 to silicon paper using a sheet die application valve MA 25 (Macon Klebetechnik), and then immediately applied to a fleece fibre web, when it was subsequently hardened by the action of moisture.
EXAMPLE 4
The water-vapour permeability as measured by DIN 53333 was determined using a sample of the material described in Example 3, when, in a deviation from the standard, work was carried out with static air.
The water-vapour permeability was determined to be 99 g/m2.d.
EXAMPLE 5
The water-proof qualities were determined according to DIN 53886 in a water pressure test, using a further sample of the material as described in Example 3. To this end, a seam checker (PFAFF) was used.
According to this standard, the material according to the present invention was water-proof up to a pressure of 0.7 bar (7 m static water column).
The foregoing shows that the present invention permits particularly simple and economical manufacture of water-vapour permeable but otherwise water-proof materials using a simple application stage and a similarly simple hardening stage, and results in materials with outstanding permeability and water-proof qualities.
We claim:
1. Fusion adhesive containing at least one polyurethane consisting essentially of the reaction product ofa component that contains NCO groups and a diol component comprising at lust one linear dihydroxy functional polyester, characterized in thatthe dihydroxy functional polyester is formed from a diacid constituent and a diol constituent, the diol constituent comprising a dihydroxy polyether that has a weight average molecular weight of at least 1000, thereby providing polyether segmenting of said polyester, and wherein the ratio of OH:NCO in said isocyanate functional polyurethane is between 1.0:1.6 and 1.0:2.6.
2. Fusion adhesive as defined in claim 1, characterized in that the dihydroxy polyether content of the diol constituent of the dihydroxy functional polyester is 10%-wt or more relative to the total diol constituent of the dihydroxy functional polyester.
3. Fusion adhesive as defined in claim 2, wherein the dihydroxy polyether content is 20 to 95%-wt relative to the total diol constituent of the dihydroxy functional polyester.
4. Fusion adhesive as defined in claim 3, wherein the dihydroxy polyether content is approximately 30%-wt relative to the total diol constituent of the dihydroxy functional polyester.
5. Fusion adhesive as defined in claim 1 wherein the polyether constituent of the dihydroxyfunctional polyester has a weight average molecular weight of approximately 3000.
6. Fusion adhesive as defined in claim 1, wherein said diol component includes at least two different components that contain OH groups, of which one is said dihydroxy functional polyester and in which the other is a polyether diol, wherein said dihydroxy functional polyester is segmented by polyether units with a weight average molecular weight of at least approximately 1000.
7. Fusion adhesive as defined in claim 6 characterized in that the dihydroxy functional polyester is segmented by polyether units with a weight average molecular weight of approximately 3000.
8. Fusion adhesive as defined in claim 6 wherein the polyether diol of the diol component of said :reaction product has a weight average molecular weight less than 10,000.
9. Fusion adhesive as defined in claim 8 wherein the polyether diol of the diol component of the reaction product has a weight average molecular weight between 2,000 and 6,000.
10. Fusion adhesive as defined in claim 1 characterized in that the diacid constituent of the dihydroxy functional polyester comprises a linear aliphatic dicarboxylic acid.
11. Fusion adhesive as defined in claim 10 wherein the linear aliphatic dicarboxylic acid is a C2 to C14 dicarboxylic acid.
12. Fusion adhesive as defined in claim 11 wherein the C2 to C14 dicarboxylic acid is adipic acid.
13. Fusion adhesive as defined in claim 1 characterized in that the dihydroxy functional polyester includes a copolyester that is formed from aliphatic and aromatic dicarboxylic acids and diols having a chain length of C2 to C20, the copolyester having an OH number between 10 and 50 and a glass transition temperature between 0° and -50° C.
14. Fusion adhesive as defined in claim 13 wherein the OH number of the copolyester is between 20 and 40.
15. Fusion adhesive as defined in claim 1 characterized in that the dihydroxy functional polyester component has a content of an aromatic dicarboxylic acid.
16. Fusion adhesive as defined in claim 15, characterized in that the diacid constituent of the dihydroxy functional polyester contains approximately equal parts by weight of aliphatic and aromatic dicarboxylic acid.
17. Fusion adhesive as defined in claim 16, characterized in that the aromatic dicarboxylic acid of the diacid constituent of the dihydroxy functional polyester component consists of approximately equal parts by weight of terephthalic acid and phthalic acid.
18. Fusion adhesive as defined in claim 15 wherein the aromatic dicarboxylic acid is a member of the group consisting of terephthalic acid, phthalic acid, isophthalic acid and mixtures thereof.
19. Fusion adhesive as defined in claim 1 further comprising an amorphous dihydroxy functional polyester component which is formed from isophthalic acid and at least one aliphatic diol having a carbon chain length of C6 or less.
20. Fusion adhesive as defined in claim 19 wherein the amorphous dihydroxy functional polyester component is formed from isophthalic acid and at least one aliphatic diol selected from the group consisting of ethyleneglycol, hexanediol, neopentylglycol and mixtures thereof.
21. Fusion adhesive as defined in claim 1 characterized in that the component that contains the NCO groups is a diisocyanate.
22. Fusion adhesive as defined in claim 21 wherein the component that contains the NCO groups is diphenylmethane-4,4'-diisocyanate.
23. Fusion adhesive as defined in claim 21 wherein the component that contains the NCO groups is an aliphatic diisocyanate.
24. Fusion adhesive as defined in claim 1 wherein the reaction product contains, relative to the total weight,a) between 50 and 70%-wt of the dihydroxy functional polyester, said polyester being a first polyester and having approximately 30%-wt relative to the total diol constituent thereof, of a segmenting dihydroxy polyether having a weight average molecular weight of approximately 3,000; b) a second linear dihydroxy functional polyester that contains no dihydroxy polyether constituent; and c) approximately 10%-wt diisocyanate.
25. Fusion adhesive as defined in claim 1, containing, relative to the total weight,a) between 60 and 65%-wt of a dihydroxy functional polyester formed from a diol and a diacid in which the diol comprises a polyethyleneglycol; b) between 25 and 30%-wt of a dihydroxy functional polyester in which the diol does not comprise a polyethyleneglycol; and c) between 5 and 15%-wt of diphenylmethane-4,4' diisocyanate.
26. The fusion adhesive of claim 25 further including an anti-oxidant.
27. Fusion adhesive as defined in claim 1 wherein the reaction product contains, relative to the total weight,a) between 20 and 90%-wt of a dihydroxy polyether; b) between 0 and 70%-wt of a linear dihydroxy functional polyester that contains no polyether; c) no more than 70%-wt of said dihydroxy functional polyester that contains polyether; d) approximately 10%-wt diisocyanate.
28. The fusion adhesive of claim 1 wherein the component that contains NCO groups is an aliphatic diisocyanate selected from the group consisting of isophoronediisocyanate, tetramethylxylyldiisocyanate, hydrated diphenylmethane-4,4' diisocyanate, hexanediisocyanate and mixtures thereof.
29. The fusion adhesive of claim 1 wherein the ratio of OH:NCO is between 1.0:1.8 and 1.0:2.4.
30. Fusion adhesive as defined in claim 1 wherein said dihydroxy polyether constituent is polyethyleneglycol.
31. Fusion adhesive as defined in claim 1, characterized in that the fusion adhesive can be hardened by the action of moisture, without being irradiated.
| 1992-06-30 | en | 1996-04-16 |
US-4733498-A | Automated data storage library media handling with a plurality of pickers having multiple grippers
ABSTRACT
Disclosed are an automated data storage library having a plurality of pickers with multiple grippers and a method for operating the library to respond to received input commands which require an exchange of media at a point of exchange (e.g., at a storage slot or read/write station), by first determining whether the source and destination locations for the media to be exchanged are on opposite sides of the point of exchange. Next, if the source and destination locations for the media to be exchanged are on opposite sides of the point of exchange, the exchange is decomposed into separate moves, and each of the separate moves is assigned to a different one of the pickers. The assignment may additionally comprise ordering the sequence of the separate moves so that the fetch of a medium from the point of exchange precedes the delivery of another medium to the point of exchange, and the picker selected to fetch the medium from the point of exchange is the picker having an available gripper which is closest to the destination location.
TECHNICAL FIELD
This invention relates to automated data storage libraries for storing media in a plurality of storage slots, and, more particularly, to automated data storage libraries having a plurality of pickers for independently accessing the plurality of storage slots.
BACKGROUND OF THE INVENTION
In an automated data storage library, numerous storage slots, or cells, arrayed within the library are used to hold data storage media, such as magnetic tape cartridges or cassettes, or optical disk cartridges. (The term "media" used herein refers to any portable housing structure containing any type of data storage media.) The storage slots are typically arranged in planar or cylindrical arrays of rows and columns. A picker, furnished with one or more grippers, is a robotic device which moves along a guideway in a horizontal motion, or about a pivot in a rotary motion, and moves vertically to access the various storage slots with the gripper, and transports selected data storage media amongst the storage slots and one or more read/write stations. Libraries also typically contain input/output stations or ports through which an operator may pass data storage media to be added to the storage array and through which the picker may pass data storage media to be removed from the data storage array. The operation of the picker is typically under the direct control of a library manager, which is a data processing controller typically situated in a library or in an external host controlling the library. The library controller is interconnected with one or more host computer systems, such as a mainframe or network computer, which issues commands to the library. The read/write stations may be interconnected with the host(s) and, after a data storage medium is delivered to the station, typically search for, and read selected data from or write data to the selected data storage medium under the control of a host.
Commands received by the library manager from the host(s) are often queued to permit the receipt of additional commands during the execution of the previous command so that the processing speed of the system is increased. Two grippers may be provided on a picker to further increase the speed of the system. An example of a library having queuing and a two gripper picker is illustrated in co-assigned U.S. Pat. No. 5,646,918, Dimitri et al., issued Jul. 8, 1997. Additionally, two pickers may be provided and may be operated simultaneously to increase the speed of the system. An example of a library having queuing and two pickers is illustrated in U.S. Pat. No. 5,513,156, Hanaoka et al., issued Apr. 30, 1996.
It is desirable that an automated data storage library operate at high efficiency, minimizing the picker motion. Thus, a two gripper picker may, as described in the '918 patent, conduct an "exchange" of media at a read/write station or at a storage slot, using one of the grippers to fetch a cartridge or cassette from a read/write station (or storage slot) and the other to deliver another cartridge or cassette to the read/write station (or storage slot). The "exchange" in the '918 patent comprises a combination of individual cartridge moves directed by commands received from the host(s). The combined commands involve, for example, a move of one cartridge from a storage slot to a read/write station and a move of another cartridge from the same read/write station to a different storage slot.
While an exchange of media may lead to greater efficiency in many cases where a single picker with dual grippers is employed, a library having two or more pickers may be unable to employ the technique. For example, the dual pickers in the '156 patent may be restricted in movement, so that it may not be possible for one picker to conduct an exchange where one of the cartridges is to be moved from or to an area where the other picker is located. Copending patent application Ser. No. 09/015272, Dimitri et al., filed Jan. 29, 1998, "Automated Data Storage Library Dual Picker Interference Avoidance," allows two pickers to conduct moves, including exchanges by one of the pickers, while avoiding interference between the pickers. In many instances, it is not efficient to attempt an exchange where two or more pickers are involved, even though interference may be avoided, for example, if one picker must be moved out of the way and idled so that another picker may conduct an exchange.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide efficient exchanges of data storage media in automated data storage libraries having two or more pickers.
Disclosed are an automated data storage library having two or more pickers with multiple grippers, a method, a computer program product and an article of manufacture embodying program code for operating the library to respond to received input commands which require an exchange of data storage media, by first determining whether the source and destination locations for the media to be exchanged are on opposite sides of the point of exchange thereof. Next, if the source and destination locations for the media to be exchanged are on opposite sides of the point of exchange thereof, decomposing the exchange into separate moves, and assigning each of the separate moves to a different one of the pickers.
The assignment additionally comprises ordering the sequence of the separate moves so that the fetching of a medium from the point of exchange precedes the delivery of a medium to the point of exchange.
The selection of the pickers to conduct the moves additionally comprises selecting the one of the pickers having an available gripper which is closest to the destination location to fetch the medium from the point of exchange.
An advantage of the present invention is that two independently operated pickers are involved in the exchange and can therefore save otherwise wasted movements of one picker to accommodate the exchange as conducted by another picker.
For a fuller understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an automated data storage library with two dual-gripper pickers in accordance with the present invention;
FIG. 2 is a perspective illustration of the automated data storage library of FIG. 1;
FIG. 3 is an enlarged perspective view of a portion of a dual-gripper picker of FIG. 2;
FIGS. 4A and 4B are illustrations of one type of data storage media which may be stored in the automated data storage library of FIGS. 1 and 2;
FIGS. 5 and 6 are diagrammatic representations of the automated data storage library of FIGS. 1 and 2;
FIG. 7 is a table depicting the identification of the status of the automated data storage library of FIGS. 5 and 6; and
FIGS. 8 through 16 are schematic representations of various scenarios illustrating the operation of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, an automated data storage library 10 and library controller 11 are illustrated in block diagram form. The library is shown connected to two host data processing systems 12 and 13 over busses 15 and 16. For example, the hosts may comprise AS/400 or RISC SYSTEM 6000 data processors supplied by IBM. The busses 15 and 16 may comprise any suitable bus communication path or paths between the host data processing systems 12 and 13 and the automated data storage library 10 and Into controller 11. One example comprises the small computer systems interface (SCSI) which is defined by various standards and is well known in the industry.
The library controller 11 comprises a computer processor having, or supplied with, computer readable program code which causes the controller to operate the library. An example of a suitable computer processor is a PS-2 computer processor supplied by IBM. The computer readable program code may be stored in memory or storage of the computer processor or may be supplied to the computer processor by means of an article of manufacture, such as a CD-ROM.
The library 10 stores a plurality of data storage media in storage slots 18 on both inside walls. Two pickers 21 and 22 (shown enlarged in FIG. 3) are each provided with a dual-gripper assembly 23 having first and second grippers 24 and 25. (Although the description herein is directed toward a dual-gripper picker, the invention is not limited thereby, but is applicable to pickers with more than two grippers). The pickers 21 and 22 ride along a common guideway 26, which may comprise one or more tracks, to remove and replace data storage media from and to the storage slots 18.
The pickers 21 and 22 operate under the control of controller 11, which may have an operator terminal 30, to fetch the data storage media from storage slots 18 and supply them to any of read/write stations, or data storage drives 31-36. The controller 11 may be situated at the library or may be in an external host processor. In the illustrated embodiment, host processor 12 is directly connected to drives 31, 32 and 35, and host processor 13 is directly connected to drives 33, 34 and 36. This allows maximum data transfer rates between drives and associated hosts. The SCSI busses 15 and 16 also allow alternate pathing from the hosts to the other drives. The host processors issue commands to the drives to search for, and to read and/or write data on the data storage media, and supply or receive the data with respect to the associated drive.
The controller operates the pickers to move in the "X" direction along the common guideway 26, and to raise or lower the gripper assembly 23 in the "Y" direction, so that a gripper 24 or 25 may move in the "Z" direction to fetch or to deliver a data storage medium to a data storage drive or storage slot.
An example of one type of media, a typical tape cassette 41, is illustrated in FIGS. 4A and 4B. The typical cassette has two reels 42 and 43 on which is wound a tape 44. A cover 45 protects the tape while the cassette is being stored and transported, and the read/write data storage (tape) drive 31-36 of FIG. 1 opens the cover 45 during loading to gain access to the tape for reading and/or writing thereon.
A bar code 47 may be provided on an edge of the cassette for identification of the cassette by a bar code reader (not shown) mounted on the pickers 21 and 22 of FIG. 1.
Referring to FIGS. 1, 4A and 4B, when the tape cassette 41 is fetched and transported to a read/write tape drive 31-36, the tape 44 is positioned at the "beginning of tape", or BOT. The host will typically command the operation of the tape drive to search for particular data to read or a particular location on the tape at which to write, and read or write data at that location. BOT is the location on the tape where the "volume serial number" (VOLSER) for the cassette is recorded, along with other control information for this volume. This data is used to verify the correct tape is being accessed, and to determine the block size and blocking factor used for this volume. BOT may be located at one end of the tape so that the tape is wound primarily on one of the reels of the cassette for storage. Alternatively, the BOT may be located at a midpoint of the tape so that the seek distance to a desired location is likely to be shorter.
The typical read/write tape drive 31-36 will reel the tape 44 while searching for the desired data to read or the desired location at which to begin writing. Upon locating the desired data or location, the tape drive will conduct the read and/or write operation. Upon completion of reading and/or writing, the tape 44 will most likely be displaced a considerable distance from the BOT, and the tape must be rewound from it's position at the completion of reading and/or writing to the BOT. A rewind command from a library manager would normally operate the read/write tape drive control to rewind the tape to BOT.
The tape cassette 41 may then be returned to the original storage slot, or, more likely, will be exchanged for the next media fetched by the picker 21 or 22.
Two basic commands of the controller 11 are "move" and "exchange". As defined in the '918 patent, a "move" command is the movement of one data storage medium from one (source) location and the delivery of that data storage medium to another (destination) location; and an "exchange" command is the removal of one data storage medium from one location, delivery of the data storage medium to second location already having a data storage medium, exchanging the one medium for the other, and delivery of the removed data storage medium to a third location.
In accordance with the '918 patent (which has only one picker), to conduct an exchange, both grippers of the picker must initially be empty. One of the grippers then grips a first cartridge, while the second gripper is empty. The picker travels to the location of the exchange, which is the location of a second cartridge. The picker fetches the second cartridge with the second gripper, inserts the first cartridge into the location with the first gripper, then transports the second cartridge to a new location.
As described above, while an exchange of media may lead to greater efficiency in many cases where a single picker with dual grippers is employed, a library having two or more pickers may restrict the area of the movement of the pickers to avoid interference, so that it may not be possible for one picker to conduct an exchange where one of the cartridges is to be moved from or to an area where the other picker is located. In many instances, it is not efficient to attempt an exchange where two or more pickers are involved, even though interference may be avoided, for example, if one picker must be moved out of the way, for example, to a garage area, so that another picker may conduct an exchange.
An example of an automated data storage library is the IBM 3494 Data Storage Library, which stores magnetic tape cartridges, the IBM 3575 Data Storage Library, which stores magnetic tape cassettes 41, the IBM 3995 Data Storage Library, which stores optical disk cartridges, or the IBM 3850 Mass Storage Subsystem, with dual pickers.
FIGS. 5 and 6 illustrate, respectively, top and front views of one embodiment of a library in accordance with the present invention. The library incorporates the elements of library 10 of FIG. 2, as will be explained. The storage slots 18 are arranged in rows and columns. In the illustrated arrangement, the storage slots are arranged in planar fashion on either side of the pickers 21 and 22. As an alternative, the storage slots may be arranged in a cylindrical fashion on either side of the pickers, and the pickers may rotate about a common pivot point at the center of the cylinders.
There are separate garages 57 and 58 on each side of the library, one for each picker. Input/output stations 59 may be provided for allowing insertion of data storage media from outside the library. Additionally, special slots (not shown) may be provided, preferably in the garage areas for storage of special purpose media, such as cleaning cartridges. The garage can be used as storage for a picker (e.g., as it is repaired or updated).
Groupings of read/write stations (data storage drives) 60 and 70 are not located within garage regions, but with the storage slots since the other picker cannot reach into the garage region. The drives of FIG. 1, for example, are preferably intermingled among the groupings of drives, so that some of the primary drives for each host are on each side of the library.
The library controller 11 includes a table illustrated in FIG. 7 which correlates each of the data storage media in the library with its storage slot location 80, the X-Y location in the library of each drive 81, the X-Y location of the current position of each picker 82, and each of the data storage media in the input/output slots with its slot location 83. This table is updated each time a data storage media is fetched and each time a data storage media is stored, and each time a picker is moved. Thus, the library controller is able to identify the storage slot of the data storage media from the received command, determine the location of any media in a drive, and the current position of the pickers. This information is used in conjunction with job queue contents to schedule picker moves.
The library controller 11 arranges each of the commands in a queue and recognizes where the pickers are located, where the source and destination for the data storage media identified in the commands are located, and manages the queue to select appropriate jobs from the queue in the most efficient order, or delaying certain jobs to allow execution of other jobs in the most efficient way.
In accordance with the present invention, sets of jobs which result in the requirement for exchanges of media at a location, called the "point of exchange" location, are examined by the controller 11 to determine whether the source location for the medium to be delivered to the point of exchange, and the destination location for the medium to be fetched and removed from the point of exchange, are on opposite sides of the point of exchange thereof.
If the source and destination locations for the media to be exchanged are on the same side of the point of exchange, an exchange is conducted utilizing a single picker, as described in the '918 patent.
If the source and destination locations for the media to be exchanged are on opposite sides of the point of exchange thereof, the controller 11, in accordance with the present invention, decomposes the exchange into separate moves, and assigns each of the separate moves to a different one of the pickers (if the pickers have available grippers and are not already occupied with another job).
The assignment of moves additionally comprises ordering the sequence of the separate moves so that the fetching of a medium from the point of exchange precedes the delivery of a medium to the point of exchange.
The selection of pickers to conduct the separate moves additionally comprises selecting the one of the pickers having an available gripper which is closest to the destination location to fetch the medium from the point of exchange.
An advantage of the present invention is that two independently operated pickers are involved in the exchange and can therefore save otherwise wasted movements of one picker to accommodate the exchange as conducted by another picker.
An "exchange" (or swap) of media, as described above with respect to the '918 patent, is defined as the removal and transport away of one data storage medium from a specific location (point of exchange) to a destination, and insertion of another data storage medium from a source location to the same specific location (point of exchange) all in a continuous sequence of moves. In accordance with the present invention, an exchange may additionally comprise a series of overlapping moves.
For example, in accordance with the present invention, upon the source location and the destination location being determined to be on opposite sides of the location of the point of exchange, and if two pickers have at least one available gripper, then the exchange is decomposed into separate moves. In one move, the first picker moves to the point of exchange (drive or storage slot), fetches the first data storage medium from the point of exchange and transports the first data storage medium to the destination (storage slot or drive), and delivers the first data storage medium. Simultaneously, in the second move the second picker is moved to the source location (storage slot or drive) and fetches the second data storage medium. The second picker then transports the second data storage medium to the point of exchange and delivers the second data storage medium, thus effecting an efficient exchange of media at the point of exchange.
FIGS. 8 through 16 illustrate exemplary scenarios for jobs which include at least one exchange of media and wherein at least one exchange of media is of the type having the source and destination locations on opposite sides of the point of exchange thereof. The scenarios relate to the arrangement of the library as represented in FIGS. 5 and 6. The point of exchange may be a data storage drive (in group 60 or in group 70), may be a storage slot 18, or may be a storage slot in an input/output station 59. FIG. 8 represents a best response time scenario; FIGS. 9 and 10 represent best throughput scenarios; FIG. 11 represents a best response time scenario; FIG. 12 represents a best throughput scenario; FIG. 13 represents a best throughput and best response time scenario; and FIGS. 14-16 represent best throughput scenarios. Of course, the arrangement of FIGS. 5 and 6 is exemplary only, and libraries implementing the present invention may be of any arrangement employing two pickers.
Referring to FIGS. 8-16, data storage media (cartridges) are referenced by letters, e.g., "A", "B", etc.; each read/write station (drive) comprises a rectangle, e.g., drive 71; and each storage slot comprises an oval, e.g., storage slot 91. The designation of two cartridges in a drive or storage slot, e.g., cartridges A and B in drive 71 in FIG. 8, represents an exchange of cartridges, and the drive or storage slot having the designation of two cartridges, e.g., drive 71 in FIG. 8 is a point of exchange.
The two pickers are respectively designated "P1" and "P2", and may comprises pickers 21 and 22 in FIG. 5. Drives 71-76 may be in group 70, and drives 61-65 may be in group 60 in FIG. 5. Storage slots 96-97 are to the right of drives in group 70, storage slots 100-103 are to the left of drives in group 60, and storage slots 91-94 are between drives in group 60 and the drives in group 70. The arrows represent the direction of movement of the pickers.
Referring now to FIG. 8, the assumptions are that there is one exchange command (at drive 71) in the queue, and that the target cartridge B source slot 91 in the exchange is on the opposite side of drive 71 from the destination slot 96 for cartridge A in the exchange. If, instead, storage slots 91 and 96 were on the same side of drive 71, only one picker would be used to conduct the exchange. Another assumption is that each picker initially has at least one free gripper.
The controller first utilizes the table of FIG. 7 to determine the X-Y locations of the source slot 91, of the destination slot 96, and of the drive 71 to determine whether the source location 91 for the medium B to be delivered to the point of exchange 71, and the destination location 96 for the medium A to be fetched and removed from the point of exchange, are on opposite sides of the point of exchange. Next (this can also be first), the controller determines whether each of the pickers has an available gripper. If both determinations are affirmative, the controller decomposes the exchange into two separate moves 121 and 122. Since cartridge A must be removed from drive 71 before cartridge B is inserted into the drive, the controller preferably orders the sequence of the separate moves so that the move involving the fetch of cartridge A from the point of exchange 71 precedes the move involving the delivery of cartridge B to the point of exchange.
The separate moves are then assigned by the controller to different ones of the pickers. Since picker P2 is on the common guideway to the side of picker P1 in the same direction as is slot 96 (with respect to drive 71), the controller selects picker P2 for move 121, and selects picker P1 for move 122.
The controller then operates picker P2 to fetch cartridge A from drive 71 and operates picker P1 to fetch cartridge B from source slot 91. Picker P2 moves cartridge A to destination slot 96 and its gripper delivers the cartridge to slot 96. Picker P1 moves cartridge B from source slot 91 to drive 71, inserting cartridge B in the drive. Thus, cartridge B has been inserted into the drive and thereby exchanged for cartridge A.
Since both pickers P1 and P2 have been operating simultaneously and in accordance with the present invention, the response time is quicker than if a single picker had made both moves. Additionally, since the moves occupy both sides of the library from the drive 71, if only one picker had been used, the other picker would have had to have been moved out of the way, which may have been an inefficient use of the pickers.
The scenario of FIG. 9 illustrates two exchanges, and requires the use of both grippers on each picker. The assumptions are that there are two exchange commands (at drives 71 and 72) in the queue, that the target cartridge C source slot 91 in the exchange is on the opposite side of drive 71 from the destination slot 96 for cartridge A in the exchange, and that the target cartridge D source slot 92 in the exchange is on the opposite side of drive 72 from the destination slot 97 for cartridge B in the exchange. Another assumption is that each picker initially has two free grippers.
The controller first utilizes the table of FIG. 7 to determine the X-Y locations of the source slots 91 and 92, of the destination slots 96 and 97, and of the drives 71 and 72 to determine (A) whether the source location 91 for the medium C to be delivered to the point of exchange 71, and the destination location 96 for the medium A to be fetched from the point of exchange, are on opposite sides of the point of exchange, and (B) whether the source location 92 for the medium D to be delivered to the point of exchange 72, and the destination location 97 for the medium B to be fetched from the point of exchange, are on opposite sides of the point of exchange. The controller also determines whether each of the pickers initially has two available grippers.
If the determinations are affirmative, the controller decomposes each exchange into two separate moves to be assigned to separate pickers, then combining each set of separate moves for each picker into one set of moves 123, 124 and 125 for one picker, and into another set of moves 126, 127 and 128 for the other picker.
The separate moves are then assigned by the controller to different ones of the pickers. Since picker P2 is on the common guideway to the side of picker P1 in the same direction as are slots 96 and 97 (with respect to drives 71 and 72), the controller selects picker P2 for moves 123-125, and selects picker P1 for moves 126-128.
The controller then operates picker P2 to fetch cartridge A from drive 71 in one gripper and operates picker P1 to fetch cartridge C from source slot 91 with one gripper. Picker P2 moves to drive 72 to fetch cartridge B from drive 72 with the other gripper and then moves cartridge A to destination slot 96 to deliver the cartridge, and moves to destination slot 97 and its other gripper delivers cartridge B to slot 97. Picker P1 moves to slot 92 to fetch cartridge D from source slot 92 in its other gripper, and moves to drive 71, inserting cartridge C in the drive. Thus, cartridge C has been inserted into drive 71 and thereby completes the exchange for cartridge A. Picker P1 also moves to drive 72, inserting cartridge D in the drive. Thus, cartridge D has been inserted into drive 72 and thereby completes the exchange for cartridge B.
Since both pickers P1 and P2 have been operating simultaneously and in accordance with the present invention, the response time is quicker than if a single picker had made all of the moves, and far quicker than if each exchange had been conducted by a different picker. Specifically, since the moves occupy both sides of the library from the drives 71 and 72, if only one picker had been used for one exchange, and only the other picker had been used for the other exchange, the picker not used in the first exchange would have had to have been moved out of the way until the exchange was completed, and then the picker not used in the second exchange would have had to have been moved out of the way, which may have been an inefficient use of the pickers. This scenario provides the best throughput. It is not the best response time since two cartridges are fetched before a delivery is made to a drive.
Alternately, picker P1 could pick up cartridge D first and cartridge C second and picker P2 could deliver cartridge B first and A second, depending on the physical source locations of cartridges and D, or the physical destination locations of cartridges A and B. For example, if cartridge D was further from the drive than cartridge C, it would be more efficient to fetch cartridge D first. Similarly, if the physical destination location of cartridge B was closer to the drive than that of cartridge A, it would be more efficient to deliver cartridge B first. Thus, the controller may order the commands in the queue to select the moves in the most efficient order.
FIG. 10 illustrates a combination of an exchange and a move to a slot. The exchange comprises the insertion of cartridge C in drive 71, replacing cartridge A which is moved to slot 96. Thus, with the controller determining that destination slot 96 is on the opposite side of drive 71 (the point of exchange) from source slot 91, and with picker P1 having at least one gripper available and picker P2 having two grippers available, the controller selects picker P2 to fetch cartridge A from drive 71, moving on path 130 to drive 72 and fetch cartridge B. Then picker P2 moves on path 131 to deliver cartridge A to slot 96 and on path 132 to deliver cartridge B to slot 97. In another move, the controller selects picker P1 to fetch cartridge C and move on path 133 to deliver the cartridge to drive 71, exchanging the cartridge for cartridge A.
FIG. 11 illustrates a similar scenario to that of FIG. 8, but with the point of exchange being a storage slot 91 rather than a drive. The controller first utilizes the table of FIG. 7 to determine the X-Y locations of the source drive 71, of the destination drive 61, and of the slot 91, the point of exchange, to determine that the source location 71 for the medium B to be delivered to the point of exchange 91, and the destination location 61 for the medium A to be fetched from the point of exchange, are on opposite sides of the point of exchange. Assuming the controller determines that each of the pickers initially has an available gripper, the controller decomposes the exchange into two separate moves 135 and 136. Since cartridge A must be removed from slot 91 before cartridge B is inserted into the drive, the controller orders the sequence of the separate moves so that the move involving the fetching of cartridge A from the point of exchange 91 precedes the move involving the delivery of cartridge B to the point of exchange.
The separate moves are then assigned by the controller to different ones of the pickers. Since picker P2 is on the side of picker P1 in the same direction as is drive 71 (with respect to slot 91), the controller selects picker P2 for move 136, and selects picker P1 for move 135.
The controller then operates picker P1 to fetch cartridge A from slot 91 and operates picker P2 to fetch cartridge B from source drive 71. Picker P1 moves cartridge A to destination drive 61 and picker P2 moves cartridge B from source drive 71 to slot 91. Thus, cartridge B has been inserted into the drive and thereby exchanged for cartridge A.
The scenario of FIG. 12 is similar to that of FIG. 9, but with the exchanges at slots 91 and 92, instead of at drives. The controller determines that (for the two exchange commands at slots 91 and 92) the target cartridge A source drive 72 in the first exchange is on the opposite side of slot 91 from the destination drive 62 for cartridge C in the first exchange, and that the target cartridge B source drive 71 in the second exchange is on the opposite side of slot 92 from the destination drive 61 for cartridge D in the second exchange. The controller also determines that each picker initially has two free grippers.
Then, the controller decomposes each exchange into two separate moves to be assigned to separate pickers, then combining each set of separate moves for each picker into one set of moves 140, 141 and 142 for one picker, and into another set of moves 143, 144 and 145 for the other picker.
The separate moves are then assigned by the controller to different ones of the pickers. Since picker P1 is on the common guideway to the side of picker P2 in the same direction as are drives 61 and 62 (with respect to slots 91 and 92), the controller selects picker P1 for moves 140-142, and selects picker P2 for moves 143-145.
The controller then operates picker P1 to fetch cartridge C from slot 91 in one gripper and operates picker P2 to fetch cartridge A from source drive 72 with one gripper. Picker P1 moves to slot 92 to fetch cartridge D from slot 92 with the other gripper and then moves cartridge C to destination drive 62 and delivers the cartridge, and moves to destination drive 61 and its other gripper delivers cartridge D to drive 61. Picker P2 moves from drive 72 to drive 71 to fetch cartridge B from source drive 71 in its other gripper, and moves to slot 91, inserting cartridge A in the slot. Thus, cartridge A has been inserted into slot 91 and thereby exchanged for cartridge C. Picker P2 also moves to slot 92, inserting cartridge B in the slot. Thus, cartridge B has been inserted into slot 92 and thereby exchanged for cartridge D.
The scenario of FIG. 13 is similar to that of FIG. 10 and illustrates a combination of an exchange and a move. The exchange comprises the insertion of cartridge C in slot 91, replacing cartridge A which is moved to drive 72. Thus, with the controller determining that destination drive 72 is on the opposite side of slot 91 (the point of exchange) from source drive 61, and with picker P2 having two grippers available and picker P1 having one gripper available, the controller selects picker P2 to fetch cartridge A from slot 91 with one gripper, moving on path 146 to slot 92 and fetch cartridge B with its other gripper. Then picker P2 moves on path 147 to deliver cartridge A to drive 72 and on path 148 to deliver cartridge B to drive 71. In another move, the controller selects picker P1 to fetch cartridge C and move on path 149 to deliver the cartridge to slot 91, exchanging the cartridge for cartridge A.
FIG. 14 is intended to illustrate 5 exchanges, in conjunction with the teaching of the '918 patent. For the purpose of illustration, all of the exchanges are at drives 61-65. Briefly, the source and destination slots for cartridges A and B are on the same side of the drive 61, so that the exchange with drive 61 at the point of exchange employs the technique of the '918 patent; the source and destination slots for cartridges C, and the source and destination slots for cartridge D are on opposite sides of the point of exchange (drive 62), so that the exchange is conducted in accordance with the present invention. Similarly, the exchange of cartridge E for cartridge F involves source and destination slots on the same side of drive 63, and the exchange of cartridge I for cartridge J involves source and destination slots on the same side of drive 65, respectively, employing the technique of the '918 patent; and the exchanges of cartridges G and H involve a destination and a source on opposite sides of point of exchange drive 64, so that the exchange is conducted in accordance in accordance with the present invention.
Thus, the controller selects picker P2 to fetch cartridge A from slot 91, move on path 150 to drive 61 and exchange cartridge A for cartridge B, move on path 151 to drive 62 and fetch cartridge C, thereby having both grippers occupied, as a step in a separate exchange in accordance with the present invention. Another move is on path 152 to deliver cartridge B to slot 92 and cartridge C to slot 93. The controller selects picker P1 to fetch cartridge D from slot 100 in one gripper, move on path 154 to slot 101 to fetch cartridge E in the other gripper, and move on path 155 to deliver cartridge D to drive 62, completing the exchange at point of exchange 62 in accordance with the invention. Picker P1 next moves on path 156 and exchanges cartridge E for cartridge F in drive 63.
With cartridge F in one gripper, and the other gripper empty, picker P1 moves on path 157 and fetches cartridge G to begin the exchange at drive 64. Picker P1 then moves on path 158 to deliver cartridge F to slot 102 and on path 159 to deliver cartridge G to slot 103.
Next, the controller selects picker P2, whose grippers are now both empty, to first fetch cartridge H from slot 94 in one gripper, move on path 160 to fetch cartridge I from slot 95, and move on path 161 to deliver cartridge H to drive 64, completing the exchange at drive 64 in accordance with the present invention.
Picker P2 then moves on path 162 to drive 65 and exchanges cartridge I for cartridge J at drive 65, and moves on path 163 to slot 96 and delivers cartridge J.
FIG. 15 illustrates three exchanges with slots in the middle, only one of which (at slot 92) is an exchange in accordance with the present invention.
Thus, the controller selects picker P2 to fetch cartridge A from drive 71 and move on path 170 to slot 91, exchanging cartridge A for cartridge B. Picker P2 then moves on path 171 to fetch cartridge C, as the first step in the exchange at slot 92 in accordance with the invention. The picker then moves on path 172 to deliver cartridge B to drive 72, and on path 173 to deliver cartridge C to drive 73.
The controller selects picker P1 to fetch cartridge D at drive 61 and move on path 174 to fetch cartridge E at drive 62, moving on path 175 to deliver cartridge D to slot 92, thereby completing the exchange at slot 92 in accordance with the present invention.
Picker P1 then moves on path 176 to exchange cartridge E for cartridge F at slot 93, moving on path 177 to fetch cartridge G from slot 94, then on path 178 to deliver cartridge F to drive 63 and on path 179 to deliver cartridge G to drive 64.
FIG. 16 illustrates exchanges in accordance with the present invention at both a drive 71 and a slot 91.
The assumptions are that there are two exchange commands (to be conducted at drive 71 and slot 91) in the queue, that the target cartridge C source slot 101 in the exchange is on the opposite side of drive 71 from the destination slot 96 for cartridge B in the exchange, and that the target cartridge D source drive 61 in the second exchange is on the opposite side of slot 91 from the destination drive 76 for cartridge A. Another assumption is that each picker initially has two free grippers.
The controller first utilizes the table of FIG. 7 to determine the X-Y locations of the source slot 101 and drive 61, of the destination slot 96 and drive 76, and of the drive 71 and slot 91 to determine (A) whether the source location 101 for the medium C to be delivered to the point of exchange 71, and the destination location 96 for the medium B to be fetched from the point of exchange, are on opposite sides of the point of exchange, and (B) whether the source location 61 for the medium D to be delivered to the point of exchange 91, and the destination location 76 for the medium A to be fetched from the point of exchange, are on opposite sides of the point of exchange. The controller also determines whether each of the pickers has two available grippers.
If the determinations are affirmative, the controller decomposes each exchange into two separate moves to be assigned to separate pickers, then combines each set of separate moves for each picker into one set of moves 180, 181 and 182 for one picker, and into another set of moves 185, 186 and 187 for the other picker.
The separate moves are then assigned by the controller to different ones of the pickers. Since picker P2 is on the common guideway to the side of picker P1 in the same direction as are slot 96 and drive 76 (with respect to drive 71 and slot 91), the controller selects picker P2 for moves 180-182, and selects picker P1 for moves 185-187.
The controller then operates picker P2 to fetch cartridge A from slot 91 in one gripper, and move on path 180 to fetch cartridge B from drive 71 with the other gripper. Picker P2 moves on path 181 to drive 76 to deliver cartridge A to drive 76 and move cartridge B to destination slot 96 to deliver the cartridge. The fetching of cartridges A and B each comprises the first step in an exchange in accordance with the present invention. Picker P1 first fetches cartridge C from slot 101 and moves on path 185 to drive 61 to fetch cartridge D from source drive 61 in its other gripper. Then picker P1 moves to drive 71 along path 186, inserting cartridge C in drive 71. Thus, cartridge C has been inserted into drive 71 and thereby exchanged for cartridge B. Picker P1 also moves on path 187 to slot 91, delivering cartridge D. Thus, cartridge D has been inserted into slot 91 and thereby exchanged for cartridge B.
Since both pickers P1 and P2 have been operating simultaneously and in accordance with the present invention, and, since the moves occupy both sides of the library from the drive 71 and slot 91, the exchanges are conducted much quicker than if only one picker had been used for one exchange, and only the other picker had been used for the other exchange. In that case, the picker not used in the first exchange would have had to have been moved out of the way, and then the picker not used in the second exchange would have had to have been moved out of the way, which may have been an inefficient use of the pickers as compared to the operation of the pickers in accordance with the present invention.
While the preferred embodiments of the present invention have been illustrated in detail; it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims.
We claim:
1. A method for operating an automated data storage library, said library having a plurality of media storage slots for storing data storage media, a plurality of read/write stations, at least one of said read/write stations positioned between at least ones of said plurality of media storage slots, at least two pickers arranged on a common guideway alongside said media storage slots and said read/write stations, each said picker having at least one gripper for fetching and delivering media at said media storage slots and said read/write stations, said library receiving input commands for jobs to move media amongst said media storage slots and said read/write stations, including input commands resulting in the requirement for an exchange of media at point of exchange locations in said library, said point of exchange locations including ones of said read/write stations or ones of said media storage slots, said method comprising the steps of:in response to said received said input commands requiring an exchange, determining whether the source location for the medium to be delivered to the point of exchange, and the destination location for the medium to be fetched from said point of exchange, are on opposite sides of said point of exchange thereof; if said determining step determines that the source and destination locations for said media to be exchanged are on opposite sides of said point of exchange thereof, decomposing said exchange into separate moves; and assigning said separate moves to different ones of said pickers.
2. The method of claim 1, wherein said determining step additionally comprises determining whether each of two of said pickers has at least one available gripper.
3. The method of claim 2, wherein said assigning step additionally comprises ordering the sequence of said separate moves so that the fetch of a medium from said point of exchange precedes the delivery of a medium to said point of exchange.
4. The method of claim 2, wherein said step of assigning said moves additionally comprises selecting the one of said pickers having an available gripper which is closest to said destination location to fetch said medium from said point of exchange.
5. The method of claim 1, wherein each of said pickers additionally has at least two grippers, and wherein if said determining step determines that the source and destination locations for said media to be exchanged are on the same side of said point of exchange thereof, maintaining said exchange as combined moves without decomposition, and wherein said assignment step additionally comprises assigning said combined exchange moves to only one of said pickers.
6. An automated data storage library, comprising:a plurality of media storage slots for storing data storage media; a plurality of read/write stations, at least one of said read/write stations positioned between at least ones of said plurality of media storage slots; at least two pickers arranged on a common guideway alongside said media storage slots and said read/write stations, each said picker having at least one gripper for fetching and delivering media at said media storage slots and said read/write stations; an input for receiving input commands for jobs to move media amongst said media storage slots and said read/write stations, including input commands resulting in the requirement for the exchange of media at point of exchange locations in said library, said point of exchange locations including ones of said read/write stations or ones of said media storage slots; and a controller for responding to said received input commands, determining whether, in an exchange, the source location for the medium to be delivered to the point of exchange, and the destination location for the medium to be fetched from said point of exchange, are on opposite sides of said point of exchange thereof; and if said determination is that the source and destination locations for said media to be exchanged are on opposite sides of said point of exchange thereof, decomposing said exchange into separate moves; and assigning said separate moves to different ones of said pickers.
7. The automated data storage library of claim 6, wherein said controller additionally determines whether each of two of said pickers has at least one available gripper, and only if said gripper determination is that each of two of said pickers has at least one available gripper, said controller decomposes said exchange.
8. The automated data storage library of claim 7, wherein said controller additionally orders the sequence of said assigned separate moves so that the fetch of a medium from said point of exchange precedes the delivery of a medium to said point of exchange.
9. The automated data storage library of claim 7, wherein said controller additionally assigns the one of said moves for fetching said medium from said point of exchange to the one of said pickers having an available gripper which is closest to said destination location.
10. The automated data storage library of claim 6, wherein if said controller determination is that the source and destination locations for said media to be exchanged are on the same side of said point of exchange thereof, said controller additionally maintains said exchange as combined moves without decomposition, and wherein said controller additionally assigns said combined exchange moves to only one of said pickers.
11. A computer program product usable with a programmable computer processor having computer readable program code embodied therein for operating said programmable computer processor for operating an automated data storage library, said library having a plurality of media storage slots for storing data storage media, a plurality of read/write stations, at least one of said read/write stations positioned between at least ones of said plurality of media storage slots, at least two pickers arranged on a common guideway alongside said media storage slots and said read/write stations, each said picker having at least one gripper for fetching and delivering media at said media storage slots and said read/write stations, said library receiving input commands for jobs to move media amongst said media storage slots and said read/write stations, including input commands resulting in the requirement for an exchange of media at point of exchange locations in said library, said point of exchange locations including ones of said read/write stations or ones of said media storage slots, comprising:computer readable program code which causes a computer processor to respond to said received said input commands requiring an exchange, by determining whether the source location for the medium to be delivered to the point of exchange, and the destination location for the medium to be fetched from said point of exchange, are on opposite sides of the point of exchange thereof; computer readable program code which causes a computer processor to respond to said determination determining that the source and destination locations for said media to be exchanged are on opposite sides of said point of exchange thereof, by decomposing said exchange into separate moves; and computer readable program code which causes a computer processor to assign each of said separate moves to a different one of said pickers.
12. The computer program product of claim 11, wherein said computer readable program code which causes a computer processor to make said determination, additionally causes said computer processor to determine whether each of two of said pickers has at least one available gripper, and only upon said additional determination indicating that each of two of said pickers has at least one available gripper, then causes said computer processor to decompose said exchange.
13. The computer program product of claim 12, wherein said computer readable program code which causes a computer processor to assign said separate moves additionally causes said computer processor to order the sequence of said separate moves so that the fetch of a medium from said point of exchange precedes the delivery of a medium to said point of exchange.
14. The computer program product of claim 12, wherein said computer readable program code which causes a computer processor to assign said separate moves additionally causes said computer processor to select the one of said pickers having an available gripper which is closest to said destination location to fetch said medium from said point of exchange.
15. The computer program product of claim 12, wherein said computer readable program code which causes a computer processor to determine whether the source and destination locations for said media to be exchanged are on opposite sides of said point of exchange thereof, additionally causes said computer processor to, upon said determination is that the source and destination locations for said media to be exchanged are on the same side of said point of exchange thereof, maintaining said exchange as combined moves without decomposition, and additionally causes said computer processor to assign said exchange moves to only one of said pickers.
16. An article of manufacture comprising a computer readable medium having computer readable program code embodied therein for operating a programmable computer processor for operating an automated data storage library, said library having a plurality of media storage slots for storing data storage media, a plurality of read/write stations, at least one of said read/write stations positioned between at least ones of said plurality of media storage slots, at least two pickers arranged on a common guideway alongside said media storage slots and said read/write stations, each said picker having at least one gripper for fetching and delivering media at said media storage slots and said read/write stations, said library receiving input commands for jobs to move media amongst said media storage slots and said read/write stations, including input commands resulting in the requirement for an exchange of media at point of exchange locations in said library, said point of exchange locations including ones of said read/write stations or ones of said media storage slots, comprising:computer readable program code which causes a computer processor to respond to said received said input commands requiring an exchange, by determining whether the source location for the medium to be delivered to the point of exchange, and the destination location for the medium to be fetched from said point of exchange, are on opposite sides of the point of exchange thereof; computer readable program code which causes a computer processor to respond to said determination determining that the source and destination locations for said media to be exchanged are on opposite sides of said point of exchange thereof, by decomposing said exchange into separate moves; and computer readable program code which causes a computer processor to assign each of said separate moves to a different one of said pickers.
17. The article of manufacture of claim 16, wherein said computer readable program code which causes a computer processor to make said determination, additionally causes said computer processor to determine whether each of two of said pickers has at least one available gripper, and only upon said additional determination indicating that each of two of said pickers has at least one available gripper, then causes said computer processor to decompose said exchange.
18. The article of manufacture of claim 17, wherein said computer readable program code which causes a computer processor to assign said separate moves additionally causes said computer processor to order the sequence of said separate moves so that the fetch of a medium from said point of exchange precedes the delivery of a medium to said point of exchange.
19. The article of manufacture of claim 17, wherein said computer readable program code which causes a computer processor to assign said separate moves additionally causes said computer processor to select the one of said pickers having an available gripper which is closest to said destination location to fetch said medium from said point of exchange.
20. The article of manufacture of claim 16, wherein said computer readable program code which causes a computer processor to determine whether the source and destination locations for said media to be exchanged are on opposite sides of said point of exchange thereof, additionally causes said computer processor to, upon said determination is that the source and destination locations for said media to be exchanged are on the same side of said point of exchange thereof, maintaining said exchange as combined moves without decomposition, and additionally causes said computer processor to assign said combined exchange moves to only one of said pickers.
| 1998-03-25 | en | 1999-09-21 |
US-7533798-A | Hand-held LCD fish finder
ABSTRACT
A hand-held LCD game machine is used as a hand-held LCD fish finder, in addition to its original game functions. Instead of a typical ROM game cassette, another device, which includes a cassette portion, a main body, and a float sensor having an ultrasonic transmitter, is inserted into the LCD game machine, so that the topography of the water bottom and the fish in water are displayed on a LCD panel by means of a program ROM having a memory to display the same based on an echo signal issued and received through the ultrasonic transmitter.
RELATED INVENTION
This application claims the priority of Japanese Utility Model Application No. 9-4592 (filed on May 16, 1997) which is expressly incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
In the prior art, a fish finder equipped with an ultrasonic transmitter has been well known. The prior art transmitter issues an acoustic wave into water and receives a counter echo which shows the existence of fish in the water.
On the other hand, a hand-held LCD (Liquid Crystal Display) game machine has been also very popular. This machine is operated with both thumbs of a player after a cartridge with its memory cell having a memory of a program data is inserted into the machine.
The prior fish finder in general is large in size and heavy in weight. Its operation is very complicated in use and also the finder is an expensive apparatus. These situations make it difficult for lovers of fishing to prepare a fish finder by themselves.
Accordingly, it has been for a long time desired by them that a new fish finder in light weight, inexpensive in price, and with easier operation shall be realized.
The hand-held LCD game machine is actually sold in a very competitive price, and its operation is far easier than that of the normal fish finder for everyone. Thus, everyone is becoming familiar with this kind of the machine and is willing to operate the same by himself.
SUMMARY OF THE INVENTION
This invention has an object to provide a hand-held LCD fish finder, wherein a function to indicate topography of a water bottom and an existence of fish in the water on its LCD display portion is established in addition to normal game functions.
In order to attain this object, the present invention has adopted the following constructions.
The fish finder developed by this invention is equipped with a fitting device for fish finding instead of a game cassette cartridge having a memory cell of program data for the game development. The fish finder fitting device is also equipped with a fish float wherein an ultrasonic transmitter is built in. In other words, the fish finder fitting device is composed of the memory cell having a memory of the program data with a function to find fish in the water. When an echo signal is received from the transmitter, the LCD display portion indicates the topography of the water bottom and fish thereof.
The invention, at the same time, provides that in this hand-held LCD fish finder, the fitting device having an ultrasonic transmitter, the fish float as a sensor and a cable which is covered with foamed plastic for floating over the water are all tightly connected to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a normal hand-held LCD game machine.
FIG. 2 is a block and circuit diagram of FIG. 1
FIG. 3 is a perspective view of a hand-held LCD fish finder developed this invention.
FIG. 4 is a wiring diagram for a cassette as shown in FIG. 3.
FIG. 5 is a wiring block diagram for a fish float sensor connected with a fitting device as shown in FIG. 3.
FIG. 6 is a flow chart explaining a program to indicate a topography of water bottoms and existence of fishes operated by the present fish finder developed by this invention.
FIG. 7 is a flow chart explaining another program to indicate a topography of water bottoms and existence of fishes operated by the present fish finder developed by this invention.
FIG. 8 is a flow chart explaining the other program to indicate a topography of water bottoms and existence of fishes operated by the present fish finder developed by this invention.
FIG. 9 is a flow chart explaining an additional program to indicate a topography of water bottoms and existence of fishes operated by the present fish finder developed by this invention.
FIG. 10 is an example of the display indicated on a LCD panel portion developed by the present embodiment.
DESCRIPTIONS OF THE PREFERRED EMBODIMENT
The preferred embodiment is now explained with the offered drawings.
According to FIG. 1, the numeral 1 is a hand-held LCD game machine. On the front surface, a LCD panel (2) is prepared to show the development of a game. When the game is operated by hand, a cruciform key (3) controls the shifting direction of a character and a set of movement keys (4a and 4b) instructs various movements for the character. A start switch (5a) and a select switch (5b) are also arranged. This portion equipped with these keys and switches is called as an operating portion. Further in this position, a speaker (6) is also formed to issue sound effects. On the back side, an inserting hole, although it is not shown on the drawing, is established thereof to receive a cassette (7). The casette (7) has a memory cell having a recorded memory of game program data. On both sides, a luminance controller (8) for the display panel (2) and a volume controller (9) are formed. The volume controller can be seen clearly at FIG. 2. A power supply and a power supply switch are omitted.
With reference to FIG. 2, the numeral 10 is a CPU which controls a program data recorded in the cassette (7), a game development on the LCD panel (2) and a sound effect. The CPU (10) has a built-in CPU core (12) which performs arithmetic unit treatment to output its results after receiving various signals. With this CPU core (12) a control line is connected via a timer (13), an address bus (1) and a datum bus (15), and a 32-pin model pin connector (16). A work RAM (17) are also connected via the address bus (14) and the datum bus (15). An operating portion (11) is connected with the core (12) via a port (18). A built-in ROM (20) to be accessed by a memory change signal through a bank change circuit (19) and a built-in RAM (21) are connected with the core (12). A LCD controller (24) is connected with the core (12) via a DMA controller (22) and via a line buffer (23). A clock oscillator (25) is further connected with the core (12) and plural sound circuits (26, 27, 28 and 29) and a wave table RAM (30) are also connected therewith, where different sound signals output by the oscillator (2) are recognized by the sound circuits (26, 27, 28 and 29) and such output sound signals are now decided by the wave table RAM (30). The LCD controller (24) is connected with the LCD panel (2) by a LCD common driver (33) and a LCD segment driver (34) via a drive signal buffer (31), while this controller (24) is also connected with a display RAM (36) which includes a character RAM and V(Video)-RAM through a control line, an address bus and a datum bus via a LCD display RAM interface (35). A luminance controller (8) is connected with the LCD panel (2) by the LCD common driver (33) and the LCD segment driver (34) via a LCD buffer amplifier (37). The sound circuits (26, 27, 28 and 29) and the wave table RAM (30) are connected with a sound controlling circuit (38) which treats with the sound signal, and the sound controlling circuit (38) is connected with the speaker (8), the volume controller (9) and a head phone jack (40) respectively via a sound amplifier (39).
When the cassette (7) is inserted into the game machine (1), an outer ROM within the casette (7) and the CPU core (12) output an indicating datum of the game program data on the LCD controller (24) via the line buffer (23) under the control of the DMA controller (22). When the indicating datum is output by the CPU core (12), the address for the character RAM and the V-RAM is designated in the display RAM (36), a character signal from the character RAM and a object signal from the V-RAM are output, and then these signals are changed into the LCD drive signals by the LCD controller (24). The LCD signals are conveyed to the LCD common driver (33) and the LCD segment driver (34), and then by order of these two drivers (33 and 34), a display image with a display data offered from the CPU core is now shown on the LCD panel (2). This image is now adjusted by the luminance controller (8) via the LCD buffer amplifier (37).
On the other hand, the sound effects are output through the speaker (6) or the head phone jack (40) after the sound signals are formed in the sound circuits (26, 27, 28 and 29) from the clock oscillator (25) and the sound is decided by the wave table RAM (30) and the sound is then treated properly by the sound control circuit (38) and also it is increased by the sound amplifier (39).
With reference to FIG. 3, FIG. 4 and FIG. 5, the numeral 41 is a fitting device which comprises a fitting portion composed of a cassette portion (42) and a main body (43), and which also comprises a cable (45) connecting a fish float sensor (44) and the main body (43), and thus this fitting device (41) works as a fish finder in this hand-held LCD game machine. This cable (45) is covered with foamed plastic material, so that the cable (45) may float on the water. As preferable material for this cable cover, urethane cover with outer diameter of 4.0 mm and with two shield cores of 0.7 mm diameter inserted therein is adopted. The cassette portion (42) is exactly in the same shape and form as the normal cassette which is inserted into the hand-held LCD game machine (1), and the portion (42) is equipped with a 32-pins edge connector (46) which should be connected with the 32-pins connector (16) and a program ROM (47) which has a memory program to display the topography of the water bottoms and fishes on the LCD panel (2) of the game machine (1) after receiving an echo of a signal issued by the float sensor (42). An IC controller (48) is also built in the portion (42), and the IC controller (48) controls the echo signal and the program ROM (47) as well as outputs a timing signal (a). In order to stabilize the echo signal to be input into the cassette portion (42), an input signal stabilizing circuit (49) is also prepared. On the other hand, in order to oscillate an ultrasonic acoustic wave and to receive the echo signal, an ultrasonic transmitter (50) is built in the fish float sensor (44).
In the main body (43), an oscillator circuit (51) which generates the ultrasonic wave after receipt of the timing signal (a) from the IC controller (48), a receiving circuit (52) which receives the echo issued by the ultrasonic transmitter (50) and changes it into the echo signal, and a signal-comparative circuit (53) which allots the marks of "H", "M" and "L" for the received echo signal at the signal receiving circuit (52) and which outputs those marks to the input signal stabilizing circuit (49) are established.
When the cassette portion (42) of the fitting device (41) is inserted into the game machine (1), the fish float sensor is placed onto the water, and the power switch of the game machine (1) is turned on, and the cruciform key (3) is operated to select the fish finding mode, and finally the start switch (5a) is pushed on. The "fishes finding program" stored in the program ROM (47) displays the topography of the water bottom and fish.
With reference to FIG. 6, the fish finding program is composed of four treatments. The first is a scanning treatment with which data obtained by the ultrasonic transmitter (50) are stored into the work RAM (17). The second is a change treatment with which the data of the work RAM (17) are changed into dots by the CPU core (12). The third is a transferring treatment with which the changed data are transferred into the display RAM (36), while the fourth is a display treatment with which the data are displayed on the LCD panel (2).
When these treatments are performed, as shown in FIG. 7, through an interrupt sub-routine, between the above treatments, the water bottom is obtained and an input treatment is performed after receiving various operative signals from the operating portion (11).
In this subroutine, a depth setting treatment is performed in the method that the cruciform key (3) is operated to register a cursor with "Depth" of the display in finding mode shown on the LCD panel (2) and at the same time the select switch (5b) is pushed on, and then the movement keys (4a and 4b) are properly operated to set up the required distance. Then the set point of the required depth can be obtained, and this required distance is read in the memory as one line. This treatment to set up the depth can be seen in FIG. 10, where on the display the setting depth 30 meter deep is shown clearly.
In an automatic setting treatment, when the cursor is registered with an automatic position and the select switch (5b) is pushed on, an automatic selection for the depth can be performed from plural depth grades which are predetermined based on the values supplied by a sonar.
In an enlargement treatment, when the cursor is registered with an enlargement position and the select switch (5b) is pushed on, the half distance from the bottom is displayed on the LCD panel in the enlarged manner.
In a menu shift treatment, when the cursor is registered with a menu shift position and the select switch (5b) is pushed on, the display of the LCD panel (2) is changed into another mode to be selected such as dictionary mode to distinguish the kind of fishes or normal game mode. The decision of these different modes may be operated by the movement keys (4a and 4b) accordingly.
In a fish mark treatment, when the cursor is registered with a fish mark position and the select key (5b) is pushed on, the selection display shows how to display the fish by dots or by fish marks, and then the movement keys (4a and 4b) are operated how to select this display of the obtained fish.
In a speed treatment, when the cursor is registered with a speed position and the select key (5b) is pushed on, the selection speed shows how to select the speed showing the display to scroll toward the left, and then the movement keys (4a and 4b) are operated to obtain the required speed where the display scrolls toward the left by one line unit.
According to FIG. 8, with regard to the scanning treatment, a step (S1) forbids the interruption of the subroutine, and a step (S2) promotes to read in the depth distance into the work RAM (17), while a step (S3) outputs the timing signal (a) to the oscillator circuit (51) from the control IC (48). The oscillator circuit (51) after receipt of the timing signal (a) offers an ultrasonic acoustic wave and also receives a returned echo into the receiving circuit, and then the echo is classified into three signals (H, M and L) or without signal by the signal-comparative circuit (53) and finally it is stored into the work RAM (17) via the input signal stabilizing circuit (49). Continuously, a step (S4) judges whether the work RAM (17) scans the data for one line unit, and when this scanning is confirmed, a step (S5) permits the interruption of the subroutine performance. The mark "Y" means "Yes", while the mark "N" means "No", and when the mark "N" appears, the procedure returns to the previous step.
Now, with reference to FIG. 9, with regard to the change treatment, under the control of the CPU core (12), by a step (S6) each datum of H, M, L, or without signal corresponding to the depth of one line unit stored in the work RAM (17) is now picked up, and by a step (S7) the datum is changed into dots to be displayed on the LCD panel. Namely, by this step (S7), H datum is changed into dark dots, M datum into light dots, while L datum is changed into colorless dots by a step (S9) and the non-signal is also changed into colorless dots by a step (S10) respectively. By a step (S11) this treatment is performed at one line unit.
With regard to the transferring treatment, the indicated dots data are transferred into the V-RAM in the display RAM (36), and as explained for the display treatment aforesaid, the indicated dots data output by the CPU core designate the address of the character RAM in the display RAM (36) and also the address of the V-RAM, and then a character signal from the character RAM and an object signal from V-RAM are output. These signals are changed into the drive signals by the LCD controller (24), and the LCD drive signals are offered to the LCD common driver (33) and the LCD segment driver (34) via the LCD drive signal buffer (31), and thus by these two drivers (33 and 34) the topography of the water bottom and fish in accordance with the indicated data for one line unit are displayed on the LCD panel (2).
In this way, the scanning treatment is again performed after one line unit is scrolled away.
In the present invention, in stead of the cassette (7) to be inserted into the hand-held LCD game machine (1), the cassette portion (42) which is exactly as the same type and shape of the cassette (7) and is also built in the ROM having a memory cell of the fish finder is now inserted, so that the topography of the water bottom and fish are displayed on the LCD panel (2) based on the echo signals of the ultrasonic transmitter (50). In this constitution, fishing can be enjoyed with feeling of playing the game under the simple operation, and at the same time, the present fish finder is very small and in light weight suitable for carrying, so that this machine can be used at any place with ease.
When the fishing float sensor (44) is placed on the water, the cable (45) which connects the main body (43) with the sensor (44) floats on the water.
As explained so far, this invention can provide the hand-held LCD fish finder which can be installed with the normal hand-held LCD game machine, and therefore it is not necessary to purchase an expensive fish finder for lovers of fishing.
At the same time, the user of this machine can enjoy both the normal games function as the original purpose and the fish finder function in a easy-portable way.
It is further understood by those skilled in the art that the foregoing description is a preferred embodiment of the disclosed matter and that various changes and modifications may be made in the invention without departing from the spirit and scope thereof.
What is claimed is:
1. A LCD fish finder comprising in combination:a hand-held LCD game machine which receives game cassette cartridges, which is equipped with a memory cell of program data inserted, and which develops a game on a LCD display panel, and which has a cassette connector; a fitting device adapted to be inserted into said cassette connector; a fish float equipped with an ultrasonic transmitter; the fitting device comprising a fitting portion composed of a cassette portion and a main body; a memory cell is built in the fitting portion; and the memory cell having a program to display topography of water bottom and fish in water on the LCD panel based on a sonar signal issued by the ultrasonic transmitter and transferred to the fitting portion.
2. An LCD fish finder according to claim 1, wherein the fitting portion and a fish float equipped with an ultrasonic transmitter are connected by a cable which is covered with foamed plastic for floating over water.
3. An LCD fish finder according to claim 1, wherein said fish finder is hand held.
| 1998-05-11 | en | 1999-07-20 |
US-34680894-A | Detection of deviations in monitored patterns
ABSTRACT
A system and method for detecting significant deviations in a pattern in near real time by making forecasts about the pattern and determining if the actual pattern is within a threshold of the forecast. The preferred embodiment is a method for detecting recording errors in a telephone network that provides services to a plurality of customers, the method comprising: recording information output by the telephone network relating to a service that was provided to the customers in a first time period; forecasting, based on the recorded information, information that will be output by the network in a second time period that has not yet occurred; recording information output by the telephone network relating to the provision of the service to the customers in the second time period; and comparing the result of the forecasting step with the information recorded during the second time period to generate a deviation.
FIELD OF THE INVENTION
This invention relates to the monitoring of a pattern to detect significant deviations from a previously made forecast of the pattern. In the preferred embodiment, the invention relates to the monitoring of call detail recording in a telephone network and, more specifically, to a system for detecting recording failures in near real time.
BACKGROUND OF THE INVENTION
Telephone systems must record details of telephone activity in order to appropriately bill customers for the services provided. Errors in call detail recording (or "CDR") can result in significant revenue loss to the telephone service provider. Such errors can be caused by call provisioning errors, errors in the transmission of billing information between telephone systems, errors in billing number screening databases, and hardware and software errors.
CDR errors are usually discovered in down-stream billing systems long after they have occurred. Earlier detection can lead to correction of the problem and minimization of the revenue loss.
SUMMARY OF THE INVENTION
The disadvantages of the prior art have been overcome by the present invention which provides, in its preferred embodiment, a system and method for detecting recording errors in a telephone network in near real time by making forecasts about recording information and determining if the actual recording information is within a threshold of the forecast.
In one embodiment, the invention features a method for detecting recording errors in a telephone network that provides services to a plurality of customers, the method comprising: recording information output by the telephone network relating to the provision of a service to the customers in a first time period; forecasting, based on the recorded information, the expected content of information that will be output by the network for a second time period that has not yet occurred; recording information output by the telephone network relating to the provision of the service to the customers in the second time period; and comparing the result of the forecasting step with the information recorded during the second time period to generate a deviation.
In preferred embodiments, the method further comprises the steps of: forecasting, based on the information recorded during the second time period, the expected, content of information that will be output by the network for a third time period that has not yet occurred; recording information output by the network relating to the provision of the service to the customers in the third time period; and comparing the result of the step of forecasting associated with the third time period with the information recorded during the third time period to generate a deviation.
The preferred method generates an alarm if the deviation is greater than a predetermined threshold, and the steps are carried out for a plurality of services provided by the network. An alarm is automatically generated each time a generated deviation for any of the services is greater than a threshold.
The first time period can correspond to a preceding time period and the second time period can correspond to a future time period, with all of the steps being iteratively repeated to continuously generate deviations corresponding to a comparison of data recently output by the network and a forecast for the recently output data.
The step of generating an alarm can be suspended for data output by the network during a holiday period due to the irregularities usually experienced during holidays.
The step of forecasting can include the steps of generating a model to fit the information recorded in the first time period and using the model to generate a forecast of data that will be recorded in the second time period. A quality measurement can periodically be made of the model to determine whether a new forecasting model should be generated.
The method of the invention can be applied to each of a number of services being provided by the telephone network. The method can further comprise the step of generating a timeseries for each service provided by the network, each timeseries comprising data relating to the provision of a service to the customers as a function of time.
The step of forecasting can further comprise the steps of generating a model to fit each of the timeseries and using each model to generate a forecast for each timeseries to predict values for each timeseries during a future time period. The step of generating a model preferably comprises identifying a number of potential model forms for the timeseries, ordering the potential model forms according to the likelihood that each will fit the timeseries, and iteratively fitting each of the potential model forms to find a model form that satisfactorily fits the timeseries.
The step of using each model to generate a forecast for each timeseries includes the steps of identifying, in each timeseries, data that differs from forecast data by greater than a threshold and replacing the identified data in each timeseries.
A default model can be generated for each timeseries, the default model being chosen as the model for the timeseries if none of the potential model forms fit the timeseries. The potential model forms for each timeseries are selected from a stored library of model forms associated with each timeseries.
Two timeseries are generated for each service provided by the network, including: (1) a volume timeseries identifying the number of times each service is provided by the network as a function of time; and (2) a ratio timeseries identifying the ratio of the number of times the network connects a call corresponding to each service over a given time period to the number of times the network disconnects a call corresponding to each service over the given period of time, as a function of time.
In another aspect, the invention features a method for detecting recording errors in a telephone network that provides services to a plurality of customers, the method comprising: (a) recording information output by the telephone network relating to the provision of a service to the customers in a first time period; (b) generating a model to fit the information recorded in the first time period; (c) using the model to generate a forecast of information to be output by the telephone network in a future time period; (d) recording, during the occurrence of the future time period, information output by the telephone network relating to the provision of the service to the customers; (e) comparing the forecast generated in step c with the information recorded in step d to generate a deviation; and (f) repeating steps c-e to continuously generate deviations between information output by the network and forecast information.
In preferred embodiments, the method of the invention further comprises the steps of: (g) periodically making a quality measurement of the model; (h) determining, based on the quality measurement, whether a new forecasting model should be generated; and (i) if the result of step h indicates that a new forecasting model should be generated, then performing the additional steps of (j) generating a new forecasting model to fit information recorded in a predetermined prior time period; and (k) substituting the new forecasting model for the model being used for forecasting in the repeated implementation of steps c-e. Step k is preferably carried out while maintaining the continuous generation of deviations as specified in step f.
In yet another aspect, the invention features a method for detecting deviations between a monitored pattern and a forecast for the pattern, the method comprising: (a) recording the pattern during a first time period; (b) generating a model to fit the pattern recorded in the first time period; (c) using the model to generate a forecast of the pattern in a future time period; (d) recording the pattern during the occurrence of the future time period; (e) comparing the forecast generated in step c with the pattern recorded in step d to generate a deviation; (f) repeating steps c-e to continuously generate deviations between the pattern and a forecast of the pattern; (g) periodically making a quality measurement of the model; (h) determining, based on the quality measurement, whether a new forecasting model should be generated; and, if so, performing the additional steps of: (i) generating a new forecasting model to fit information recorded in a predetermined prior time period; and (j) substituting the new forecasting model for the model being used for forecasting in the repeated implementation of steps c-e. Once again, step j is preferably carried out while continuously generating deviations as specified in step f.
In still another aspect, the invention features a method for detecting deviations between a plurality of monitored patterns and a forecast for each pattern, the method comprising: (a) generating a timeseries for each monitored pattern, each timeseries comprising data relating to the value of the pattern as a function of time; (b) selecting a model to fit each timeseries, the selection for each timeseries comprising the steps of: (1) identifying a number of potential model forms for the timeseries; and (2) iteratively fitting each of the potential model forms to find a model that satisfactorily fits the timeseries; (c) using the model to generate a forecast of each timeseries in a future time period; (d) recording each timeseries during the occurrence of the future time period; (e) comparing each forecast generated in step c with the timeseries recorded in step d to generate a deviation; and (f) repeating steps c-e to continuously generate deviations between the pattern and a forecast of the pattern.
The invention provides a significant improvement in the monitoring of call detail records in a telephone network since the monitoring can be done in near real time, can be applied simultaneously to a large amount of data output by the network in a fully automated way, and can self-adapt to changes in the data. The near real time detection of recording errors using the invention can cause early detection of telephone recording errors and a resulting significant savings of revenue.
Furthermore, the pattern monitoring techniques of the invention find application in fields other than telephone networks, such as, e.g., executive decision support systems, fraud detection in various fields, and the analysis of demographic pattern changes. Other advantages and applications of the invention will be apparent to those skilled in the art from the following detailed description of a preferred embodiment of the invention, as applied to a telephone network.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system according to one embodiment of the invention.
FIGS. 2A through 2D are graphs of "volume timeseries" (explained below) for various services provided by an AT&T 4ESS™ switch.
FIGS. 3A through 3D are graphs of "ratio timeseries" (explained below) for various services provided by an AT&T 4ESS™ switch.
FIG. 4 is a flow chart of the overall method for predicting recording errors according to one embodiment of the invention.
FIG. 5 is a flowchart illustrating the steps carried out for one portion of the flow chart shown in FIG. 3.
FIG. 6 is a chart illustrating an example of a timeseries for a service on an AT&T switch along with forecast and threshold data.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention is a system for CDR Monitoring (or "CDRM") in near real time to detect errors significantly sooner than in traditional down stream analysis. One embodiment of the present invention will be described in the environment of monitoring of call detail recording associated with AT&T 4ESS™ and 5ESS™ switches. The electronic switching system of the 4ESS™ design is described in greater detail in a series of articles published in the Bell System Technical Journal (BSTJ), September 1977, Vol. 56, No. 7 at pages 1017 et seq., incorporated herein by reference. The electronic switching system of the 5ESS™ design is extensively described in a series of articles in the AT&T Technical Journal, Vol. 64, No. 6, part 2, July/August 1985, at pages 1305-1564, also incorporated herein by reference.
FIG. 1 shows a telephone switch 10 (such as a 4ESS™ or 5ESS™) having a number of inputs 12 and a number of outputs 14. Inputs 12 and outputs 14 are, for example, calls being routed by switch 10, as will be well known in the art. Switch 10 provides a number of services to the customers of the telephone network to which switch 10 belongs, and information concerning the provided services is output at outputs 16, 18. Outputs 16, 18 are received by CDRM system 20, which functions to monitor these outputs and detect errors in the information as is described further below. CDRM system 20 can include a general purpose digital processor and suitable memory, as will be apparent to those of skill in this art.
There are a number of different types of services offered on the AT&T 4ESS™ switch which can be monitored by the present invention. An automated message accounting record (or "AMA") is formed for each monitored call. AMA records are similar to CDRs. Examples of the information on the 4ESS™ used by the present invention include the following:
(1) "PBEAV"--Direct Voice Interface and Equal Access Signaling Voice. These are 1+ calls made from subscriber stations that are billed for the call. They include regular long distance calls from home.
(2) "DSDC"--Direct Service Dialing Capability. These are the 1(800)+ calls where the called station is billed for the call. (Sometimes called the "INWATS" calls.)
(3) "BSDN"--Basic software Defined Network calls. These are calls that are switched over "virtual" private networks. Billing to the calling subscriber includes a monthly charge plus a charge for aggregates of calls to various area codes specified in the customer's service order. Individual calls switch only to the specified area codes.
(4) MEG--MEGACOM service is similar to "OUTWATS" service. Subscriber PBX's have direct links to the 4ESS™, bypassing the local exchange (i.e., local telephone carrier). The AT&T switch knows who to bill by knowing the nature of the incoming trunk. Calls switch anywhere based on the dialed digits.
(5) DISK4E--Total number of AMA records written to disk. This count does not represent a service, but rather a total count for a switch.
Considering the 5ESS™ switch, some of the monitored information is:
(1) "AMAC5E"--This is a count of all calls in the 5ESS™ for which an AMA record must be formed. (Similar to DISK4E on the 4ESS™ switches);
(2) "TOANSW"--Answered toll calls that were not assisted by an operator;
(3) "TOOP"--Answered calls that were assisted by an operator;
(4) "TOUNANS"--Unanswered calls for which an AMA record was formed;
(5) "TOSPEC"--Answered special calls; and
(6) "TOOTH"--Answered "other" calls.
The data relating to CDR on the 4ESS™ switch is organized in two ways. First, "MLSS" (Machine Load and Services Summary) provides hourly counts of CDR by switch and by type of service. The MLSS counts each call at the moment of its connection, i.e., when a connection is established between the caller and the callee. Depending on the type of service and on the switch generic, these counts may or may not include unanswered calls. Second, "Tracers" (Tracer record counts) are provided by the 4ESS™, and counts each call at the time of its disconnection (aggregated on an hourly basis).
Using the MLSS and Tracers data, CDRM has two main data types that it monitors:
Volumes--For each switch and service the volumes are in fact the sum of Full Charge, Partial Charge and Lost/Discarded records, as provided by the tracer records.
Ratios--These are obtained hourly by dividing the MLSS count by the tracer count, corresponding to each switch/service type.
Monitoring the volumes enables the detection of recording errors resulting from errors in suppliers' billing information, errors in network elements that feed into a switch, etc. Monitoring of the ratios allows the detection of recording errors due to intra-switch failures, database and provisioning errors, etc. Since ratios serve as a comparison between two separate recording elements in the network, it is more likely that deviations detected in their expected pattern are directly linked to actual recording failures.
FIG. 2 shows examples of volume timeseries for various services on one 4ESS™, while FIG. 3 shows examples of ratio timeseries. Specifically, FIG. 2A shows a timeseries for the BSDN service, FIG, 2B for the DSDC service, FIG. 2C for the MEG service and FIG. 2D for the PBEAV service. FIGS. 3A-D similarly represent volumes for the BSDN, DSDC, MEG and PBEAV services, respectively.
In each of the timeseries shown in FIGS. 2 and 3, a period of 4 weeks is depicted. The weekends and the 2 daily peak hours are easily noted on the volume timeseries. The period chosen contains no holidays. The regularity of the pattern is apparent for the BSDN, DSDC and PBEAV series, while the MEG data is much more variable. One reason for that is the relatively low volume counts for the MEG service--it is usually the large number of volume contributors that results in a regular pattern.
For the BSDN and DSDC services (FIGS. 3A and 3B, respectively) the ratios fluctuate around a mean value of ˜1. This is to be expected since, over time, the number of calls connected should equal the number of calls disconnected. (Recall that the ratios are the number of connected calls divided by the number of disconnected calls.) The large spikes on those plots could be attributed to problems in recording, but they could also represent points of missing data which was here replaced using a start-up mechanism. (Details on missing data replacement and anomaly cleanup are presented below.)
The value of a ratio exceeds 1 when the number of calls that are being connected exceeds the number of calls being disconnected, as in the case, for example, during the starting business hours of each day. The ratio drops below 1 in the converse situation, when the number of disconnected calls outweighs the number of the calls being connected, as happens, for example, during the late afternoon hours for those business oriented services. In the 4E17 generic (introduced in all 4E switches during 1993), the PBEAV and MEG MLSS counts include unanswered calls, whereas the tracer counts don't. This explains the fact that the mean value for the corresponding ratios is around 1.3, and the more "noisy" pattern.
All ratios are preferably monitored on a hourly basis, as are also most of the volumes. When the hourly volume counts are low and thus subject to large statistical variations, daily monitoring of the volumes can be implemented. The decision on the frequency of monitoring, however, need not necessarily be applied globally for any particular service, but rather should depend on the volume counts. To improve the statistical quality of the monitoring, a service can be monitored hourly on some switches, and daily on others. A criterion to determine the appropriate frequency should consider the ratio p of the standard deviation of forecast errors to the busy-hour volume count. (Discussed further below.) For example, if p>10%, the critical alarms raised by the current volume monitoring algorithm won't be generated before a 100% drop in volume is present. In some cases, a variable may be monitored on both an hourly and a daily basis (or yet another level of aggregation). Larger deviations are detected in real-time, through the hourly monitoring. Smaller deviations, and sometimes even very small deviations (no more than 0.1%) can be detected at the end of the day (or at the end of the aggregation period).
The overall algorithm used by the present invention is illustrated in FIG. 4, and includes three stages: (1) a model fitting stage; (2) a forecasting and alarming stage; and (3) a model monitoring stage. The model fitting stage begins with obtaining a timeseries for fitting, containing at least 3 weeks of data, and preferably 4 weeks of data. If the timeseries is a ratio, a cleaning step then follows. After cleaning, a model is fit to the timeseries using the well known "Box-Jenkins" method. The Box-Jenkins method is documented in, for example. G. E. P. Box and G. M. Jenkins, "Time Series Analysis and Control", Revised Edition, Prentice Hall, 1976, and S. Makridakis, S. C. Wheelwritght, V. E. McGee, "Forecasting: Methods and Applications", John Wiley & Sons, 1983 each of which is incorporated herein by reference. For volumes, the timeseries is cleaned after model fitting, and then the various forecasting timeseries are initialized in preparation for stage 2.
After stage one is completed, the system moves into the forecasting and alarming stage. In this stage, the timeseries being monitored is compared to a forecast for that timeseries that is generated based on the model created in stage one. Alarm thresholds are also generated and, if the result of the comparison shows that the current timeseries differs from the forecast by more than the threshold, then an alarm is generated. The alarm will alert an operator to the potential recording error, which can then be investigated.
The specific steps for stage two, as shown in FIG. 4, include computation of forecasts and alarm thresholds, application of "outlier," step, and holiday treatment (if necessary), updating of the forecasting timeseries, and the comparison step for alarm generation if appropriate. In stage 3, the quality of a forecasting model is tested and a determination is made if a "refit" is needed, and if so, the system returns to stage one to create new models. If no refit is needed, the system returns to the beginning of stage two.
Details of data cleaning and initialization (stage one) as well as forecast computing, outlier treatment, alarm generation and refitting (stage two) are provided below.
Considering first the model generation of stage one, the Box-Jenkins method is preferred because it provides a systematic approach to fit Auto Regressive Integrated Moving Average ("ARIMA") models to timeseries. It is accurate, can accommodate seasonality and trends in the data, provides diagnostics to verify model validity and measures of forecast uncertainty, as well the theoretical means to ensure stability of the model. The method can be easily adjusted to various degrees of error level, through proper choice of data granularity, and when used in its multi-variate version enables correlating recording events across services or across switches.
Another important merit of Box-Jenkins is its computational simplicity: each forecast is obtained as a simple linear combination of a handful of historical values of the related timeseries. Combined with very modest storage and data access needs per forecast, this quality makes it especially suited for the very-large-scale and near-real-time monitoring challenge that CDRM poses.
In the traditional Box-Jenkins method, fitting an ARIMA model to a timeseries is an iterative process, that loops several times through the following 3 steps, until a satisfactory fit is found:
1. Determination of model form, or what terms will be used. This determination is primarily based on the examination of the autocorrelation function ("ACF") of the timeseries. One or more differencing steps may be required, depending on the existence of trends and periodicities in the timeseries. This step requires the judgment of one experienced in the Box-Jenkins method.
2. Estimation of model parameters. Usually this step involves some form of the standard statistical MLE (maximum likelihood estimate) optimization routine.
3. Diagnose the model for adequacy. The portmanteau lack of fit test is used.
FIG. 5. illustrates how the traditional 3-step method is adapted to simultaneously fit a large number of timeseries with similar periodicities, without the repeated reliance on a human expert, as would be required by the traditional method. This adaptation is useful in light of the repeated need of model refitting due to changes in the timeseries patterns.
The algorithm of FIG. 5 also includes two stages, (1) form selection; and (2) model selection. In stage one, a number (N) of candidate model forms are selected by an expert, using the Box-Jenkins method, and are then ordered according to the likelihood of fitting. An ordered list of forms is customized for each service type separately. A general notation for two-seasonal ARIMA models is given by:
(p, d, q)(P1, D1, Q1)s1 (P2, D2, Q2)s2.
This notation is well known in the art and is explained, for example, on page 428 of the Makridakis et al. reference cited above. In this notation, the two forms most frequently used in those lists, and also most likely to be used in a model, are represented by (0, 0, 1)(0, 0, 1)24 (0, 1, 1)168 and (0, 0, 1)(0, 1, 1)24 (0, 1, 1)168.
A default model is also chosen. This model uses the top priority form in the corresponding form list, along with parameters that are calculated as average values for the corresponding service and form.
Once the forms are selected and ordered, the system moves into stage two, where the models are generated by iteratively fitting the forms in the appropriate list to a given timeseries, by estimating their parameters. If no adequate and stable model is generated in this process, the appropriate default model is selected and used for forecasting.
Thus, once a model is fit to a timeseries using this algorithm, it is used to produce forecasts, on an hourly or daily basis, and, ultimately, alarms to warn of possible recording errors.
It is important to remove from the timeseries used for forecasting data "outliers" that might affect future forecasts. (Details about outlier detection and replacement are provided below.) For that purpose CDRM maintains an outlier-clean timeseries in addition to an actual timeseries.
Along with each model, CDRM's model fitting procedure provides an initial value σ0 for the standard deviation of the forecast error. σ0 is produced by applying a newly fit model to the same data to which it was fit. σ0 is used as a starter to generate alarm thresholds, as explained below.
Each combination of switch/service/type of data that the system monitors is referred to as a variable. For each variable, the timeseries that the CDRM algorithms maintain include: "xt " which is the actual value of variable x at time t (If data is missing before the initial model fitting stage, xt is replaced, as described further below); "wt " which is equal to xt with outliers and missing data replaced on an ongoing basis; "ft ", the forecast for time t; "εt ", equal to wt -ft, the forecast error at time t (i.e., the forecast value at time t minus the actual value of the variable with outliers replaced); "σt ", the approximate standard deviation of the forecast error at time t; "bt "-[(xt -ft)/σt-1 ], the normalized deviation level, before outlier treatment and "rt "-(σt /σ0) used to determine "refits" as explained more fully below.
A typical forecast for an hourly model in CDRM is given by ##EQU1## where a, b and α are parameters specific to the model.
Once the forecast has been determined using the Box-Jenkins technique, the alarm thresholds must be determined. Alarm thresholds in CDRM are determined by two factors:
1. σt --this is the current value of the sample standard deviation of the forecast error.
2. βmn,βmj,βcr --these constants correspond to 3 levels of alarm thresholds: minor, major and critical. They are factors that multiply σt-1 to determine the width of the alarm threshold at time t.
To approximate σt the following formula is used: ##EQU2## In the above formula n is set to 672 for hourly models and to 28 for the daily ones.
At each point in time t (hourly or daily), the CDRM algorithm examines the quantity ##EQU3## and based on the examination alarms are generated as follows:
______________________________________
minor alarm: if |b.sub.t | > βmn
major alarm: if |b.sub.t | > βmj
critical alarm: if |b.sub.t | > βcr
______________________________________
The values of βmn,βmj, and βcr can be controlled by the user, and can be adjusted separately for each type of data and type of service. This adjustment enables the user to control the number of alarms they want to be generated, and thus is one of the main parameters that allows flexibility to the user. The preferred default settings for the example described herein are given in Table 1:
TABLE 1
______________________________________
Default Settings for β.sub.i
type of data
β.sub.mn β.sub.mj
β.sub.cr
______________________________________
Hourly 5 7.5 10
Daily 3 5 7
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FIG. 6 shows an example of a timeseries (a ratio on a 4ESS™) and its associated forecasts and alarm thresholds. The solid line is the actual ratio, the dotted line is the forecast, and the two dashed lines represent the minor thresholds. For this example, an alarm would have been generated towards the right side of the graph, when the actual ratio exceeded the alarm threshold.
We refer to the quantities βmn σt-1, βmj σt-1, βcr σt-1, as the minor, major, and critical threshold widths, respectively, i.e., the width of the minor, major, and critical alarm confidence interval. A quantity which is helpful in expressing the relative widths of the alarm thresholds is ##EQU4##
Using (3), βmn Pt, βmj Pt, and βcr Pt, provide the relative widths of the minor, major and critical alarm thresholds, respectively.
CDRM algorithms can be tailored to detect smaller errors in recording by adjusting the data granularity. For the daily ratios, the simple model:
x.sub.t =μ+ε.sub.t, where μ=mean(x.sub.t)
is sufficient to model the alarm thresholds. This model does not involve any computational effort for model fitting (as it does not involve any parameters) and only a trivial effort for forecasting: the forecast is always equal to the mean, and in its computation the mean can be computed over the past N values (in our example, N=28). (For generic 4E16 the mean is very close to 1 for all daily ratio variables). In this case (i.e., considering the daily ratios), σ is simply the standard deviation of the daily timeseries itself, and ##EQU5##
Data pre-processing routines that are used before the forecasting algorithm is turned on are next described. CDRM uses the data in the timeseries it monitors in two major ways: (1) for model fitting or refitting; and (2) for generating forecasts, thresholds and alarms. For both purposes, it is desirable to have data that is free of outliers and does not have holes in it. Outliers in a timeseries which is used to create a model can disrupt the model fitting process by either causing it to fail or by producing an inadequate model. The use of a poorly fitting model, in turn, reduces the sensitivity of monitoring, inflates the alarm thresholds, and may interfere with the failure detection capability of CDRM. When present in a forecasting timeseries, outliers may corrupt the forecasts, causing false alarms to be generated. Both problems can be solved once the monitoring algorithm is turned on, as described below.
Missing data is not an uncommon problem, in particular when the MLSS data is considered. Before the monitoring algorithms are turned on, the missing values are replaced based on periodicity assumptions on the data. If most values of the timeseries xt are available in the range 1≦t≦T (covering a period of at least 3 weeks), a missing xt.sbsb.o can be simply replaced by
x.sub.t.sbsb.o =x.sub.t.sbsb.k =x.sub.t.sbsb.o.sub.-168k, where k is smallest integer such that 1≦t.sub.o -168k≦T, assuming x.sub.t.sbsb.o.sub.-168k is available. (4)
Alternatively, xt.sbsb.o can be an average of several such xt.sbsb.k. Another alternative is to use some higher order interpolating formula.
This simple replacement is satisfactory for volume monitoring purposes, provided not too many values are missing. Too many such replacements may artificially boost the autocorrelation function of the fitting timeseries, interfering with the model quality. In that case it is best to delay the initial fitting until the missing data problem is alleviated.
The replacement policy from (4), or the like, can however, be inadequate for ratios, since the quotient of a replaced MLSS value to an existing tracer value may create a large deviation. Data cleanup procedures described next solve this problem. Another method to replace missing data after the monitoring has begun is described later on.
Two separate "data cleaning" procedures can be used, one for ratios and the other for volumes. The different characteristics of volumes and ratios, as well as the different nature of the data anomalies present in them, suggest different cleanup routines for the two data types are appropriate.
Ratios for the services monitored on the 4E55 switches fluctuate around a mean of ˜1 for BSDN and DSDC services, and a mean of ˜1.3 for the PBEAV and MEG services in the 4E17 generic. When no major anomalies are present, the standard deviations and the ranges of these timeseries are small relative to their means. Typical anomalies are few in number and have a negligible effect on the mean, while dramatically affecting the standard deviation and the range. The following ratio cleanup procedure is designed to remove these few anomalies with only a minimal effect on the remainder of the timeseries:
x=ratio timeseries to be cleaned
M=mean (x)
S=standard deviation (x)
R=range (x)
count=0
while ##EQU6## identify the set J={j:|xj -M|>4S} for (jεJ)
Replace xj by the average of xj-168 and xj+168 (wrap around ends of timeseries if needed)
Update M,S,R
count=count+1
C1 and C2 are preferably set to 7 and 3, respectively.
Volume anomalies are often less prominent than the ratio anomalies, have a relatively smaller effect on the timeseries statistics, and may not be as easy to detect using such statistics unless they occur during busy hours. For all those reasons, with the exception of very significant anomalies, timeseries that contain them may still successfully pass the model fitting stage. However, if an anomaly is present, false alarms are likely to be generated once the forecasting stage begins, since the anomalous data is now believed to be normal. The volume cleaning procedure shown below provides some protection against this problem.
1. Partition the timeseries used for fitting into 168 sub-series, one sub-series for each hour of the week.
2. In each sub-series replace the max and min value by the mean of remaining values.
3. Re-assemble the timeseries.
This procedure is helpful in preventing the generation of false alarms, and is only applied once--after the initial fitting. It is not needed once forecasting begins, since then the outlier treatment will remove anomalies from the wt timeseries. It is also undesirable to apply it before fitting as its effect on the autocorrelation function of the timeseries can disrupt the fitting procedure.
A refitting of an existing model to the timeseries it models is occasionally needed. Refits are primarily needed because of changes in traffic pattern. These can cause a mismatch between a model and the timeseries it models. Such a mismatch is often evident in a significant or a persisting change in the forecast errors, and a corresponding change in σt as given in (3). There are two main reasons for such a change. Namely, either the timeseries variability increases, or the timeseries variability decreases.
Such changes have undesirable effects on the alarming thresholds, which are determined by σt. In the first case, the thresholds increase, the monitoring sensitivity decreases, and the probability of subtle recording failures not being detected increases. In the second case, the decrease in σt indicates that whatever noise was present during the model fitting period is now stabilizing, and therefore a better fitting model, and tighter alarm thresholds, may be achieved through refitting.
To detect changes in σt the following timeseries is monitored: ##EQU7##
A refit of the model is triggered if rt significantly deviates from 1 for a prolonged period of time. The refitting criteria used in the preferred embodiment is as follows.
Let ##EQU8## Perform a refit at time t if 1. t is not within 28 days since last "step detection" (discussed below);
2. t is not within 14 days of last refit;
3and if:
For Hourly Timeseries
i. rt, rt-1, . . . ,rt-118 >1.25 and rt-119 ≧1.3, or
ii. rt, rt-1, . . . ,rt-70 >1.35 and rt-71 ≧1.4, or
iii. rt, rt-1, . . . ,rt-22 >1.45 and rt-23 ≧1.5
or
i. rt, rt-1, . . . ,rt-118 <0.75 and rt-119 ≦0.7, or
ii. rt, rt-1, . . . ,rt-70 <0.65 and rt-71 ≦0.6, or
iii. rt, rt-1, . . . ,rt-22 <0.55 and rt-23 ≦0.5
For Daily Timeseries
i. rt, rt-1, . . . ,rt-3 >1.35 and rt-4 ≧1.4, or
ii. rt, rt-1 >1.45 and rt-2 ≧1.5
or
i. rt, rt-1, . . . ,rt-3 <0.65 and rt-4 ≦0.6, or
ii. rt, rt-1 <0.55 and rt-2 ≦0.5
Refitting can also be triggered if a default model is in use, as described above. The default model is used after none of the forms in the appropriate form list prove successful through the model fitting process. Although an infrequent event, when it does happen it is often when the variability of the fitting timeseries is large, and patterns either aren't very clear, or they may vary within the timeseries used for fitting. Because of this, a refit is forced of a default model after 4 weeks of its use, assuming that data will be more stable then.
To avoid undesirable effects on the overall system's performance, the fitting/refitting process can be done off line, on a separate system. The process of refitting is preferably completely automated, and no human intervention is needed after the initial fitting. However, human intervention and control are allowed by the CDRM system.
Following each fitting, be it an initial fitting or refitting, several start-up stages are present. First, the "start up period" is the initial period during which forecasting cannot take place, because insufficient data had been accumulated. The length of this period is determined by the model form, and corresponds to the "look-back" period used by the model to generate its forecast. For the general 2-season ARIMA form, the duration of the start-up period T1 is given by
T.sub.1 =max {p+d+S.sub.1 (P.sub.1 +D.sub.1)+S.sub.2 (P.sub.2 +D.sub.2), q+S.sub.1 Q.sub.1 +S.sub.2 Q.sub.2 } (5)
In the hourly models that CDRM uses, T1 ≦193 for the hourly models, and T1 ≦8 for the daily models.
The second start up stage is the "warm-up period." In models that contain an MA component, values of historical εt are used. Before forecasting is active these forecast error values are set to 0. The first 2-3 weeks of forecasting after each refitting are therefore a transient period until the εt stabilize at their steady state values. The wt timeseries, which depends on the εt, must also be created.
This state of affairs could potentially cause two sorts of undesirable delays. First, following an initial fit, for which data corresponding to 4 weeks needs to be collected, a period of an additional 3-4 weeks would be needed before a new variable could be effectively monitored in the system. Second, following each refit, monitoring would have to be disrupted for about 3-4 weeks. In the CDRM algorithms these delays are eliminated allowing shorter variable introduction periods and, more importantly, continuous monitoring. This is accomplished as follows:
1. Once a model is fit to a timeseries, it is then applied to the same timeseries to produce forecasts (in the case of initial volume fitting--the timeseries is cleaned-up of anomalies before computing the forecasts).
2. The forecast-errors timeseries εt and the forecasting timeseries wt are populated, through the cleanup procedures and comparisons of actual and forecast values.
3. σ0 is calculated based on the εt.
4. The look-back period T1 is calculated.
5. The output of the fitting process includes, besides the new model and ε0, also εt and wt timeseries of length T1, whose end point coincides with the end-point of the fitting timeseries.
6. The forecasting program is able, once a refit request is issued, to "freeze" in time until the refit is completed, at which time forecasting resumes at the point of freeze.
For most of the time CDRM's monitored timeseries exhibit a quite regular seasonal pattern, allowing very accurate forecasts, and, depending on data type and service, often quite tight alarm thresholds. Nevertheless, events may happen that disrupt this regularity, and which do not necessarily represent recording errors. Examples of such events are many:
national holidays, local holidays,
trunk rehoming, switch generic changes,
seasonal changes in demand, e.g., college opening/closing
commercial promotions, fare wars,
storms, earthquakes, other natural disasters
missing data.
Even when they do represent recording errors, after having produced the appropriate alarm, we need to "shield" the timeseries from the residual effects of such disruptions. These residual effects may adversely affect the algorithms by introducing false alarms in the future and/or impairing the refitting process, should one be triggered, by producing an inferior model and inflated σ0.
It is the first of these effects that is of most concern. If the system allows anomalous data, or outliers, to be included in the wt and σt timeseries, which are the timeseries used to calculate the subsequent forecasts, abnormal forecasts may be generated, therefore triggering false alarms.
The CDRM's treatment of outliers, missing data, and step changes which are not known to the system apriori, as well as the treatment of holidays are explained next.
To prevent the undesired impact of outliers on the monitoring algorithm's outputs we need to: (i) Select a criterion for outlier detection; and (ii) decide on an outlier replacement policy.
The outlier detection criterion is based on the degree of deviation of the actual data from the forecast produced by the algorithm: A value xt is identified as an outlier if ##EQU9## βout in (6) is set to 7.
The setting of βout is somewhat arbitrary, and is based on experimentation with the data. It is probably one of the more important areas where field experience and feedback can be useful. A refinement of this criterion could allow βout to be a function of the model form, and maybe other parameters.
Once a value xt is judged to be an outlier, it receives the "outlier treatment", unless such treatment is inhibited. The preferred outlier treatment is as follows:
If |x.sub.t -f.sub.t |>β.sub.out σ.sub.t-1, then:
1. Generate an appropriate alarm.
2. Generate rnorm as a random variate from a unit normal distribution.
3. While rnorm>3 continue generating rnorm;
4. Set εt as rnorm. σt-1
5. Set ωt as ft +εt.
As part of the treatment we introduce a random forecast error generated from a normal distribution with the appropriate standard deviation. The simple alternative to that would be just setting εt to 0. However, if a prolonged outlying event is present, the resulting ωt timeseries would be overly correlated, and unfit for refitting.
Holidays, and periods that surround them, affect about 70 days per year. (This number does not include local holidays). In most cases the actual volume counts during a holiday largely deviate from their forecasts, yet rarely do they represent a recording failure.
Continued monitoring throughout the holiday periods is difficult. A given holiday may have varying effects from switch to switch and from year to year. CDRM deals with holidays as follows.
Global holiday periods have been identified and are stored in tables that are updated once a year. There are basically 2 types of global holidays. First are holidays that are observed on a fixed day of the week (Columbus Day, Presidents Day, Thanksgiving, Mother's day, Easter, Memorial day, Labor day, etc.). These holidays have a more predictable effect in terms of the periods they affect, although the magnitude of this effect varies from switch to switch and from one service type to the other. A major holiday observed on Monday, for example, would often affect volume counts starting the previous Thursday, with the effect lasting until the following Wednesday.
The second type of holidays are those observed on a fixed date of the year. These have a less predictable pattern. Fourth-of-July will have a different effect if it falls in the middle of the week than when it falls on or close to a weekend. The proximity and significance of the Christmas and New-Years holidays create a pattern of their own, that depends on the day of the week they occur. Studying their effect for a few years is therefore needed before their effect can be readily predicted.
Alarms are preferably suppressed during holiday periods. To avoid disrupting the timeseries window used for further forecasting, regular outlier treatment is applied to the εt and wt timeseries during a holiday period, as described above. The update of σt is also suspended during a holiday period.
The various holidays have a much less pronounced effect on the ratios, and no special holiday treatment need be applied there.
The monitored timeseries often experience changes in pattern. Whenever the maximal or the average values in the timeseries experience a significant change in value, the pattern change is considered a "step." Since such a change may be of a more permanent nature, it is often undesirable to apply the outlier treatment in these cases. As the data arrives to the system on an hourly (or daily) basis, the system uses the following criterion to determine that a step change has occurred.
A step situation is present if the percentage P of outliers among any consecutive W values of the monitored timeseries Xt exceeds a threshold T.
T is set to 25-30%, and W is set to 72 hours for a ratio timeseries and to 120 hours for a volume timeseries.
Whenever a step situation is detected in a monitored timeseries, the following procedure is applied:
1. The outlier treatment is suspended for T1 time units.
2. All automatically triggered refitting requests are ignored for T2 time units.
Step 1 allows for the forecasts to adjust to the new level of the timeseries, and step 2 prevents the performing of refits until at least 4 weeks of data at the new level have accumulated. T1 is determined by formula (5), and T2 is set to 672 for hourly models and to 28 for daily models.
Sometimes one or more entries xt are missing from a monitored timeseries. These values need to be backfilled in the corresponding wt timeseries, to allow the continuous functioning of the monitoring algorithm. This is done using the existing value of the forecast ft, as follows (with some similarities to the outlier treatment described above):
1. Generate rnorm as a random variate from a unit normal distribution;
2. While rnorm>3 continue generation rnorm;
3. Set εt as rnorm.σ0 ;
4. Set wt as ft +εt.
The preceding discussion of the invention is for illustrative purposes only and it should be understood that many modifications may be made as will readily be apparent to those skilled in this art.
I claim:
1. A method for detecting recording errors in a telephone network that provides services to a plurality of customers, said method comprising:recording information output by said telephone network relating to the provision of a service to said customers in a first time period; forecasting, based on said recorded information, an expected content of information that will be output by said network for a second time period that has not yet occurred; recording information output by said telephone network relating to the provision of said service to said customers in said second time period; and comparing the result of said forecasting step with the information recorded during said second time period to generate a deviation.
2. The method of claim 1 further comprising the steps of:forecasting, based on said information recorded during said second time period, the expected content of information that will be output by said network for a third time period that has not yet occurred; recording information output by said telephone network relating to the provision of said service to said customers in said third time period; and comparing the result of said step of forecasting associated with said third time period with the information recorded during said third time period to generate a deviation.
3. The method of claim 1 further comprising the step of generating an alarm if said deviation is greater than a predetermined threshold.
4. The method of claim 1 wherein said steps are carried out for a plurality of services provided by said network, and an alarm is automatically generated each time a generated deviation is greater than a threshold.
5. The method of claim 1 wherein said first time period corresponds to a preceding time period and said second time period corresponds to a future time period, and wherein all of said steps are iteratively repeated to continuously generate deviations corresponding to a comparison of data recently output by said network and a forecast for said recently output data.
6. The method of claim 5 further comprising the step of generating an alarm if a generated deviation is greater than a predetermined threshold.
7. The method of claim 6 wherein said step of generating an alarm is suspended for data output by said network during a holiday period.
8. The method of claim 1 wherein said step of forecasting comprises the steps of:generating a model to fit said information recorded in said first time period; using said model to generate a forecast of data that will be recorded in said second time period.
9. The method of claim 8 further comprising the steps of periodically making a quality measurement of said model and determining, based on said quality measurement, whether a new forecasting model should be generated.
10. The method of claim 1 wherein each of said recording steps records information relating to the provision of each of a number of services to said customers.
11. The method of claim 10, further comprising the step of generating a timeseries for each service provided by said network, each said timeseries comprising data relating to the provision of a said service to said customers as a function of time.
12. The method of claim 11, wherein said step of forecasting further comprises the steps of:generating a model to fit each of said timeseries; using each said model to generate a forecast for each said timeseries to predict values for each said timeseries during a future time period.
13. The method of claim 12 wherein, for each said timeseries, said step of generating a model comprises:identifying a number of potential model forms for said timeseries; ordering said potential model forms according to the likelihood that each will fit said timeseries; and iteratively fitting each of said potential model forms to find a model that satisfactorily fits said timeseries.
14. The method of claim 12 wherein before said step of using each said model to generate a forecast for each said timeseries, said method comprises the steps of:identifying, in each said timeseries, data that differs from forecast data by greater than a threshold; and replacing said identified data in each said timeseries.
15. The method of claim 13 wherein said step of generating a model further comprises generating a default model for each said timeseries, said default model being chosen as the model for a said timeseries if none of said potential model forms fit said timeseries.
16. The method of claim 13 wherein, for each said timeseries, said potential model forms are fitted from a stored library of model forms associated with each said timeseries.
17. The method of claim 11 wherein two timeseries are generated for each said service, including: (1) a volume timeseries identifying the number of times each said service is provided by said network as a function of time; and (2) a ratio timeseries identifying the ratio of the number of times said network connects a call corresponding to each said service over a given period of time to the number of times said network disconnects a call corresponding to each said service over said given period of time, as a function of time.
18. A method for detecting recording errors in a telephone network that provides services to a plurality of customers, said method comprising:(a) recording information output by said telephone network relating to the provision of a service to said customers in a first time period; (b) generating a model to fit said information recorded in said first time period; (c) using said model to generate a forecast of information to be output by said network for a future time period; (d) recording, during the occurrence of said future time period, information output by said telephone network relating to the provision of said service to said customers; (e) comparing the forecast generated in step (c) with the information recorded in step (d) to generate a deviation; and (f) repeating steps (c)-(e) to continuously generate deviations between information output by said network and forecast information.
19. The method of claim 18 further comprising the steps of:(g) periodically making a quality measurement of said model; (h) determining, based on said quality measurement, whether a new forecasting model should be generated; and (i) if the result of step (h) indicates that a new forecasting model should be generated: (j) generating a new forecasting model to fit information recorded in a predetermined prior time period; and (k) substituting said new forecasting model for the model being used for forecasting in the repeated implementation of steps (c)-(e).
20. The method of claim 19 wherein step (k) is carried out while maintaining the continuous generation of deviations as specified in step (f).
21. A method for detecting deviations between a monitored pattern and a forecast for said pattern, said method comprising:(a) recording said pattern during a first time period; (b) generating a model to fit said pattern recorded in said first time period; (c) using said model to generate a forecast of said pattern in a future time period; (d) recording said pattern during the occurrence of said future time period; (e) comparing the forecast generated in step (c) with the pattern recorded in step (d) to generate a deviation; (f) repeating steps (c)-(e) to continuously generate deviations between said pattern and a forecast of said pattern; (g) periodically making a quality measurement of said model; (h) determining, based on said quality measurement, whether a new forecasting model should be generated; and, if so: (i) generating a new forecasting model to fit information recorded in a predetermined prior time period; and (j) substituting said new forecasting model for the model being used for forecasting in the repeated implementation of steps (c)-(e).
22. The method of claim 21 wherein step (j) is carried out while continuously generating deviations as specified in step (f).
23. The method of claim 21 further comprising the step of generating an alarm if said any of said generated deviations is greater than a predetermined threshold.
24. The method of claim 21 wherein said steps are carried out simultaneously for a number of patterns.
25. The method of claim 24 further comprising the step of generating a timeseries for each monitored pattern, each said timeseries comprising data relating to the value of said pattern as a function of time.
26. The method of claim 25, wherein said step of forecasting further comprises the steps of:generating a model to fit each of said timeseries; using each said model to generate a forecast for each said timeseries to predict values for each said timeseries during a future time period.
27. The method of claim 26 wherein, for each said timeseries, said step of generating a model comprises:identifying a number of potential model forms for said timeseries; ordering said potential model forms according to the likelihood that each will fit said timeseries; and iteratively fitting each of said potential model forms to find a model that satisfactorily fits said timeseries.
28. The method of claim 26 wherein before said step of using each said model to generate a forecast for each said timeseries, said method comprises the steps of:identifying, in each said timeseries, data that differs from forecast data by greater than a threshold; and replacing said identified data in each said timeseries.
29. The method of claim 28 wherein said step of generating a model further comprises generating a default model for each said timeseries, said default model being chosen as the model for a said timeseries if none of said potential models fit said timeseries.
30. The method of claim 27 wherein, for each said timeseries, said potential model forms are selected from a stored library of model forms associated with each said timeseries.
31. A method for detecting deviations between a plurality of monitored patterns and a forecast for each said pattern, said method comprising:(a) generating a timeseries for each monitored pattern, each said timeseries comprising data relating to the value of said pattern as a function of time; (b) selecting a model to fit each said timeseries, said selection for each timeseries comprising the steps of:(1) identifying a number of potential model forms for said timeseries; (2) iteratively fitting each of said potential model forms to find a model that satisfactorily fits said timeseries; (c) using said model to generate a forecast of each said timeseries in a future time period; (d) recording each said timeseries during the occurrence of said future time period; (e) comparing each forecast generated in step (c) with the timeseries recorded in step (d) to generate a deviation; and (f) repeating steps (c)-(e) to continuously generate deviations between said pattern and a forecast of said pattern.
32. The method of claim 31 wherein after step (a) and before step (c) said method comprises the additional steps of:identifying, in each said timeseries, data that differs from forecast data by greater than a threshold; and replacing said identified data in each said timeseries.
33. The method of claim 31 wherein step (b) further comprises generating a default model for each said timeseries, said default model being chosen as the model for a said timeseries if none of said potential model forms fit said timeseries.
34. The method of claim 31 wherein, for each said timeseries, said potential model forms are selected from a stored library of model forms associated with each said timeseries.
35. A system for detecting recording errors in a telephone network that provides services to a plurality of customers, said system comprising:means for recording information output by said telephone network relating to the provision of a service to said customers in a first time period; means for forecasting, based on said recorded information, an expected content of information that will be output by said network for a second time period that has not yet occurred; means for recording information output by said telephone network relating to the provision of said service to said customers in said second time period; and means for comparing the result of said forecasting step with the information recorded during said second time period to generate a deviation.
| 1994-11-30 | en | 1997-08-19 |
US-9789879-A | Process for the detoxification of waste water containing phenol, phenol derivative or phenol and formaldehyde
ABSTRACT
Waste water containing phenol, phenol derivatives or phenol plus formaldehyde is purified by treating the waste water with hydrogen peroxide and either iron, copper or the complex salt sodium iron (III) ethylenediamine tetraacetate.
This is a division of application Ser. No. 862,760 filed Dec. 20, 1977.
BACKGROUND OF THE INVENTION
Phenol containing waste water of different concentrations occur in the synthesis of phenol, in coke oven plants and gas making plants, in lignite carbonization and, not of least importance, in the production of phenolformaldehyde resins (phenoplasts).
The removal of toxic phenol without residue and also the removal of the likewise toxic formaldehyde from waste waters of the above-mentioned branches of industry, particularly for a subsequent biological clarification of such waste water is now as ever a very important problem which until now has not been able to be solved satisfactorily within a large range of concentration.
In the mentioned phenoplasts for example in the so-called "reaction waters" which according to the condensation process can react either alkaline or acid, there can be present a content of volatile phenol in the range of 1,700 to 15,000 mg/l and of free formaldehyde between 1,200 and 8,100 mg/l (F. Meinck, H. Stoff, H. Kohlschutter, "Industrie-Abwasser," 4th edition, Gustav Fischer-Verlag, Stuttgart, 1968 page 619).
There are already a large number of processes for the purification of phenol containing waste water which, however, are not universally usable over a large range of concentrations.
At high phenol concentrations, for example, for the purpose of recovery of phenol, a steam distillation can be suitable. Besides, there is a series of extraction processes in which an extraction of the phenol is undertaken with the help of, for example, benzene, toluene or tricresyl phosphate. Attendant on this process is the disadvantage that certain residual parts of the extraction agent enter the waste water; besides, the so-called "Degree of Washing" of the various processes is different so that it is not possible to remove the phenol without residue.
A total removal of phenol can be produced by evaporation of the waste water and burning of the residue. However, this process requires a high expenditure of energy.
At low phenol concentrations it is possible to remove a sufficient amount of phenol also with help of special activated carbon, but the effect depends on the amount of carbon, type and granulation as well as the process (duration of the action, pH and temperature of the waste water).
According to the composition and concentration of the phenol containing waste water the effect of the adsorption is very different and at average and high concentrations too expensive, e.g., from 1,000 ppm and higher.
A further adsorption process consists of the use of specific synthetic resins, e.g., polymethacrylates or polyvinyl benzenes. Thus, the phenol content in a phenol containing waste water can be reduced from 6,700 ppm to about 0.1 ppm (Albright U.S. Pat. No. 3,663,467 and Gustafson U.S. Pat. No. 3,531,463).
However, this type of adsorption process cannot be used in phenol-formaldehyde containing waste waters of the synthetic resin industry because in the thus treated waste water just as before the toxic formaldehyde remains behind.
Sporadically the phenol rich waste water can also be treated biologically according to the "Nocardia Process". Pure cultures such as orgabisms closely related to actinomyces are colonized in trickling filters or activated sludge plants.
In favorable cases a purification effect of 99% can be produced so that even with biological breakdown there always remains a certain residual amount.
The effect depends on the remaining conditions, thus the flora is severely injured by a too great amount of phenol or by other waste water poisons and eventually even destroyed.
The process therefore produces no guarantee for waste water detoxification.
Besides, for adopting such a special biological turf or activated sludge there must be added N and P containing nutrient salts (Gesundh. Ing. Vol. 81 (1960) pages 205 et seq.). This procedure requires the relatively expensive operation of a special biological clarification plant.
A well known process is the oxidation of phenol by means of chlorine dioxide. Chlorine dioxide is obtained either through the action of acids on chlorites, preferably sodium chlorite, or also by reaction of chlorine with sodium chlorite in, e.g., sulfuric acid medium.
However, in the last process there is the danger of chlorination of the phenol to the still more toxic chlorophenols. Besides, the oxidation does not go one hundred percent. This is true even for the development of chlorine dioxide by the action of acids on chlorites. Here also a substantial oxidation can be produced. However, our experiments of this type show, as can be seen from gas chromatographic analysis of this type of treated waste water, that after the oxidation there was always still present a greatly varying residual content of phenol in order of between more than 10 to above 100 ppm. Besides, there occurs in the gas chromatogram foreign peaks which have not been previously identified, from which it can be assumed that it is a matter of intermediate oxidation products (quinones, hydroquinones or eventually even chlorinated products) (see also H. Thielemann, Gesundh. Ing. Vol. 92 (1971) No. 10 page 297).
Also, there should not be disregarded the corrosion problems which occur in the strong acidification of the waste water.
According to data in the literature (Klossowski, Jerzy, Gaz, Woda Tech. Sanit. (1968) Vol. 42 pages 197-200) phenol and its derivatives are decomposed only in an amount of 83% by gaseous chlorine dioxide which is developed from sofium chlorite and sulfuric acid.
The oxidation of phenol by chlorine dioxide in the acid or neutral range should lead to p-benzoquinone as the end product of the phenol oxidation, while in alkaline medium by a high excess of chlorine dioxide (5 mg C102 to 1 mg phenol) there is formed a mixture of organic acids, chiefly maleic and oxalic acids (Chemical Abstracts, Vol. 79, 23266m).
In Russian Patent 141,814 there is described the purification of waste waters of phenol-formaldehyde resin production wherein formaldehyde is removed by treatment of the water with quicklime at room temperature or at 98° C. and phenol is removed by oxidation either electrochemically or with MnO2. This process is relatively expensive. By quicklime is meant calcium hydroxide.
In another process the waste water purification from phenol, methanol and formaldehyde is undertaken by means of a so-called "Liquid Phase Oxidation" (I. S. Stepanyan, I. A. Vinokur, G. M. Padaryan, khim. prom (1972) Vol. 6 pages 30-31 or Int. Chem. Eng. Vol. 12 (1972) No. 4 pages 649-651). In this process, the waste water is nozzled into an electrically heated reactor by means of air under 40 bar pressure and at 200° C. However, test data have only given a degree of oxidation around 95% for phenol, 77% for methanol and 93% for formaldehyde.
In another series of experiments, the degree of oxidation is only 80% for the named substances. The process is industrially very expensive. There remains a residual amount of the toxic acting materials.
In German OS No. 2,404,264 there is described a process for the preliminary purification of waste water from phenol, formaldehyde and their reaction products after which there is added to the waste water soluble aminoplast resin precondensates or their aqueous solutions. The reaction mixture is held at the boiling temperature in the alkaline range for 2 to 8 hours, subsequently neutralized and the precipitated reaction product separated.
As can be seen from the examples with this process there can merely be produced a preliminary purification of such waste water; a complete removal of phenol and formaldehyde is impossible.
It has also been proposed to treat phenol and phenol-formaldehyde containing waste water with alkali or alkaline earth metal chlorites in the presence of specific amounts of formaldehyde (Junkermann and Hafner application Ser. No. 857,356 filed Dec. 2, 1977 U.S. Pat. No. 4,157,300, and entitled "Process for the Purification of Phenol and Phenol-Formaldehyde Containing Waste Water" corresponding to German patent application No. P 26 57 192.6). By this process there is obtained a complete elimination of phenol and formaldehyde but the treated waste water is made salty with the alkali or alkaline earth chlorite. The thus treated waste water can then in a given case still be post treated with activated carbon.
Furthermore, it is known to remove phenol from waste waters with hydrogen peroxide, i.e., in the presence of ferric chloride. The pH of the waste water in this case which before the treatment is 2.5 to 3.5 is adjusted after the treatment to 10. After clarification of the suspension with appropriate agents the waste water still contains 0.3 ppm phenol (Japanese patent application 118 8902/72--Publication Number 77449/74).
A further process for the detoxification of phenolformaldehyde containing waste water likewise uses hydrogen peroxide, i.e., in an amount which is more than 1.5 times the COD (Chemical Oxygen Demand) of the waste water, as well as ferrous sulfate. The pH of the waste water upon the addition of the hydrogen peroxide and the ferrous salt is lowered to 3 to 4 (Japanese patent application No. 44906/72--Publication Number 6763/74).
Both last named processes refer to lower phenol and formaldehyde contents up to 100 ppm.
To guarantee complete oxidation at higher phenol contents in the waste water, the amount of iron salt must be increased correspondingly which leads to salt loading that cannot be tolerated.
Besides after the last named process there still remains a residual formaldehyde content of at least 50 ppm.
Also the named processes do not effect detoxification on waste waters which contain phenol derivatives, i.e., substituted phenols, such as brenzcatechol, resorcinol, pyrogallol, cresols, chlorophenol and hydroquinone.
An object of the invention is to completely eliminate phenol, phenol derivatives (substituted phenols) or phenol plus formaldehyde from waste waters, even present at higher concentrations without the occurrence of a salt loading.
As higher concentrations is meant contents of phenol or phenol derivatives of at up to a maximum of 0.5% and formaldehyde contents of up to 5% since at higher concentrations the process is not so economical.
SUMMARY OF THE INVENTION
In one aspect of the invention it has now been found that phenol, phenol derivative (substituted phenol), or phenol plus formaldehyde containing waste water can be completely freed from these compounds by addition of hydrogen peroxide without causing salination (loading with salt) if the waste water is treated with hydrogen peroxide in the presence of metallic iron or copper.
The named metals can be introduced into the waste water container as sheets, wires or granulates; in the case of iron, which is especially preferred, the metal can even be present as the material of the reactor, e.g., as iron reaction or waste water tanks or even as iron stirrers. Because of the expense copper is not generally used in the form of the reaction or waste water tank or as the stirrer.
It has proven most favorable that there be used per cubic meter of waste water an iron surface of 1 to 20 square meters.
As iron there can be used the industrial types such as pig iron, cast iron, steel, see Ullmann, Enzyklopadie der Technischen Chemie (1975), Vol. 10, page 312.
As copper there can be used commercial types, see, for example, Ullmann (1960) Vol. 11, pages 205-206.
In contrast to the prior art process with hydrogen peroxide and iron salts the present process is independent of pH. Thus, it can be carried out with neutral, acid or alkaline waste water without doing anything additional.
The starting up of the detoxification is dependent on the one hand on the height of the concentration of the phenol or phenol derivative or the phenol-formaldehyde concentration and on the other hand the available metal surface per cubic meter of waste water, see Examples 1 and 2 in this connection.
Should the detoxification not commence so quickly, it has proven favorable to accomplish this to add very small amounts of activators to start the reaction. As activators there can be used halides, e.g., chlorides or bromides, sulfates, nitrates, or even organic salts such as the formates of alkali or alkaline earth metals such as sodium, potassium, calcium or barium or even the corresponding salts of zinc, aluminum, nickel or manganese. Sodium chloride is very suitable. Other salts included potassium chloride, calcium chloride, barium chloride, barium bromide, potassium bromide, sodium bromide, sodium sulfate, potassium sulfate, calcium nitrate, barium nitrate, sodium nitrate, potassium nitrate, sodium formate, calcium formate, potassium formate, zinc chloride, zinc sulfate, aluminum chloride, aluminum sulfate, aluminum nitrate, nickel nitrate, manganese sulfate.
The activators should be used in amounts of 0.1 to 0.2 weight percent, based on the hydrogen peroxide added. It is possible to add them already dissolved in the hydrogen peroxide or to add them in solid form directly into the waste water.
There are also suitable as activators, likewise in the named amounts, highly dispersed silicas insoluble in the water.
Hydrogen peroxide is added in amounts of 7.5 to 8 moles per mole of phenol or substituted phenol. In the presence of formaldehyde it is necessary to add a further 2 moles of hydrogen peroxide per mole of formaldehyde.
The detoxification is carried out preferably at room temperature (about 20° C.) or at the temperature at which the waste water accumulates.
Generally, the waste water which is to be detoxified can be added as such for the process. Only at phenol concentrations above 5,000 ppm it is recommended, if there is desired a purification according to the process of the invention, to dilute the waste water to a phenol value below 5,000 ppm so that the reaction does not proceed too violently.
The quantitative determination of phenol and in certain cases derivatives is carried out gas chromatographically under the following conditions.
Gas chromatograph Perkin-Elmer F 7 with FID. Temperature of the column 180° C.; injection block 230° C.; flow about 24 ml/min; column 1 meter Poropak P, No. 85, amount of sample 1 μl/min; paper advance 0.5 cm/min.
The analysis of the formaldehyde was carried out colorimetrically with the help of the very sensitive condensation reaction between formaldehyde, acetyl acetone and ammonia or ammonium acetate to form the yellow-colored diacetyl dihydrolutidine (T. Nash, Nature (London) Vol. 150 (1952), page 976).
As the simplest and most elegant procedure there has been found that there should be used hydrogen peroxide solutions which contain dissolved therein 0.05 to a maximum of 0.1 weight % of NaCl. It goes without saying that sodium chloride can also be added in solid form to the waste water to be treated.
In general one then proceeds in such manner that to the waste waters which contain the phenol, phenol derivative or phenol and formaldehyde there is added with stirring the corresponding amount of hydrogen peroxide with about 0.1% activator, preferably sodium chloride, whereby inside a few minutes after the end of the addition the oxidation begins at room temperature. It is recognizable by the dark coloration of the waste water, the development of carbon dioxide, the increase in temperature and the reduction of the pH to a value of between 2 and 1.
After the end of the entire reaction, which generally lasts 30 to 60 minutes and is recognizable by the slackening of the development of gas as well as the constant temperature or the cooling which occurs, the acid reacting waste water is then neutralized. Hereby the small amount of iron ions present simultaneously precipitate out.
For neutralization there are suited all known alkali and alkaline earth metal hydroxides, e.g., sodium hydroxide, potassium hydroxide, strontium hydroxide or barium hydroxide but preferably there is employed calcium hydroxide in the form of milk of lime.
After removal of the iron hydroxide precipitate, and in certain cases, alkaline earth metal hydroxide precipitate, the practically almost colorless detoxified waste water is led to the biological clarification plant.
Only after addition of the hydrogen peroxide there is dissolved from the metal surface a violet, also partially brownish colored haze with which the oxidation is apparently catalytically accelerated.
Thus there is not necessary a minimum concentration of iron salts, as is the case of the above-mentioned Japanese patent applications in which the amount of iron salts must be adjusted in each case according to the phenol concentration in order that a complete elimination of the phenol occurs, but the least possible concentration of iron ions is established automatically, independent of the phenol concentration present in each case.
The above-mentioned process of the invention is not as favorable with alkaline reacting waste waters (as with acid or neutral reacting waste waters) since the oxidation reaction is strongly retarded in alkaline medium. For the complete elimination of phenol and formaldehyde for the most part it takes several hours in contrast to the reaction in acid and neutral medium in which the oxidation process is completed within 30 to 60 minutes.
Of course, the process can be accelerated by addition of mineral acids, e.g., sulfuric acid, hydrochloric acid or phosphoric acid to the alkaline waste waters but thereby there results an undesired salt formation in the waste water.
It has now been found as another aspect of the invention that alkaline reacting waste water which contains phenol, phenol derivatives (substituted phenols) and phenol plus formaldehyde) also can be relatively quickly detoxified with hydrogen peroxide if there is added to the waste water to be treated 0.5 to 2 g/l of waste water of the complex salt sodium iron (III) ethylenediamine tetraacetate trihydrate (emperical formula C10 H12 N2 O8 FeNa . 3H2 O). Of course, there can also be used the same salt in an equivalent amount without the water of crystallization.
It goes without saying that the just mentioned complex salt can also be added as an aqueous solution to the waste water to be treated.
The amount of hydrogen peroxide per mole of phenol or phenol derivative which is employed to oxidize the phenol or phenol derivative is the same as in the other aspect of the invention, e.g., 8 moles of hydrogen peroxide. With the simultaneous presence of formaldehyde an additional 2 moles of hydrogen peroxide are needed per mole of formaldehyde.
Independent of the phenol and formaldehyde content in the water there is sufficient per liter of waste water 1 to a maximum of 2 grams of the complex salt sodium iron (III) ethylenediamine tetraacetate trihydrate. The pH of the waste water should be at least 8.
Neutral or acid waste waters can also be treated according to the invention if they are previously adjusted to a pH of at least 8, e.g., with alkali liquor (aqueous sodium hydroxide), but not higher than a pH of 12.
Generally, one proceeds in such a manner that there is first added to the alkaline reacting waste water to be treated the complex salt used according to the invention and subsequently the necessary amount of hydrogen peroxide solution corresponding to the concentration of phenol, phenol derivative and formaldehyde.
A few minutes, namely, generally after about 5-15 minutes after addition of the hydrogen peroxide the oxidation reaction begins which is noticed by the dark coloration of the waste water, increase in temperature, development of carbon dioxide and reduction of the pH.
At the end of the reaction which lasts about 30 minutes the pH is at most 2.
As pointed out above in connection with the first aspect of the invention to neutralize the acid, dark colored waste water there are suited all known alkali or alkaline earth metal hydroxides but preferably there is used calcium hydroxide in the form of milk of lime.
In the neutralization of the waste water resulting from the process of the invention there takes place lightening and deposition of the alkaline earth metal hydroxide precipitate which contains small amounts of iron hydroxide.
The analysis of phenol and formaldehyde, i.e., both of acid as well as neutralized waste water samples shows that after the use of the process of the invention neither phenol, phenol derivatives nor formaldehyde is present. Their elimination is thus complete.
In the process of the invention there can be eliminated in addition to phenol per se other phenols such as alkylated phenols, e.g., o-cresol, p-cresol, m-cresol, t-butyl phenol, polyhydric phenols, e.g., hydroquinone, resorcinol, pyrocatechol and pyrogallol, halogenated phenols, e.g., chlorophenol.
The following examples further explain the process of the invention. Examples 1-15 are directed to the first form of the invention and examples 16-18 are directed to the second form of the invention.
Thereby there are used both artificially produced waste waters with contents of phenol, phenol derivatives and phenol plus formaldehyde between 100 and 5,000 ppm and even up to 10,000 ppm as well as waste waters of the phenol-resin industry.
The process can comprise, consist essentially of or consist of the steps set forth and the materials employed can comprise, consist essentially of or consist of those set forth.
Unless other wise indicated all parts and percentages are by weight.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLE 1
To 7 waste water samples having phenol contents of 0.5% whose pH values were between 4 and 6, there were added per liter in each case 0.4 ml of a 10% solution of the following salts:
NaCl, calcium formate, MnCl2, MnSO4, CuSO4,
AlCl3, NiSO4.
After addition of the salt solutions there were added to the waste water samples in each case under stirring 140-150 ml of a 10% hydrogen peroxide solution. There were hung in the samples iron sheets of the same total surface area (8 square meters per cubic meter of waste water). The iron sheet used was structured steel St 37.
A short time after addition of the hydrogen peroxide solutions the oxidation reaction began, recognized by the solutions becoming dark, the increase in temperature to 50° to 60° C., the development of carbon dioxide and the reduction of the pH.
Within 40 to a maximum of 50 minutes the oxidation was complete, the temperature fell back slowly, the pH of the waste water samples was between 1.6 and 1.9.
By the addition of milk of lime (30%) the samples were neutralized whereupon there took place the precipitation.
After removal of the time precipitate which contained small amounts of iron hydroxide the supernatent clear waste water was analyzed as set forth above (gas chromatographically).
The analysis showed a complete elimination of phenol.
EXAMPLE 2
An alkaline reacting waste water having a pH of 8.7 and 0.5% of phenol was treated with 4 ml of 10% aqueous sodium chloride solution based on 1 liter of waste water, subsequently there were added with stirring 140 ml of 10% aqueous hydrogen peroxide solution (per liter of waste water). There were hung in the waste water the same iron sheet as in Example 1.
The oxidation reaction started after 30-40 minutes but was finished after a maximum of 60 minutes whereupon the same course in regard to coloration, temperature increase, carbon dioxide development and pH reduction was observed. After the end of the reaction the strongly acid reacting waste water having a pH of 1 was neutralized and worked up as in Example 1.
Here also the phenol was completely removed.
EXAMPLE 3
A waste water sample containing 0.5% phenol and 0.5% formaldehyde having a pH of 5.6 was treated with 253 ml of 10% aqueous hydrogen peroxide solution based on 1 liter of waste water. There were previously dissolved in the hydrogen peroxide solution 0.1% NaCl. In the waste water sample there was located the iron sheet of Example 1.
Immediately after addition of the hydrogen peroxide solution provided with sodium chloride the oxidation reaction began with stirring, it was recognized by the characteristics already mentioned in connection with the previous examples. After a duration of about 30 minutes whereby the temperature increased to 55° C. and the pH sank to 1.5 the reaction was finished. After addition of milk of lime the treated waste water was again neutralized, after removal of the precipitate, the supernatent water was of a yellowish coloration.
The presence of formaldehyde accelerated the completion of the reaction. The analysis showed that both phenol and formaldehyde were completely eliminated.
EXAMPLE 4
A waste water sample which containing 0.5% phenol and the same amount of formaldehyde and whose pH value was 5.3 was treated with 255 ml of 10% (aqueous) hydrogen peroxide, based on 1 liter of waste water.
In the hydrogen peroxide solution there was dissolved 0.1% NaCl. A copper sheet was placed in the waste water. The copper metal was 99.9% pure; per cubic meter of waste water there were used 15 square meters of copper sheeting.
After addition of hydrogen peroxide, there was a long time until the reaction began, recognizable by the dark coloration of the alkali. The reaction was delayed in comparison to the reactions in the presence of metallic iron, the pH value lowered more slowly, the temperature increase was likewise delayed.
Only after several hours was the reaction ended which otherwise was analogous to the examples described in the earlier examples in regard to coloration, lowering of pH, increased temperature.
The neutralization was carried out in the manner already stated. The yellow-colored waste water which formed above the deposited precipitated no longer showed any phenol and formaldehyde.
EXAMPLE 5
A waste water sample having 0.5% phenol was treated with a 10% hydrogen peroxide solution (amount of additive 140 ml per liter of waste water) in the presence of iron and copper sheets. The sheets corresponded to those in Examples 1 and 4. The initial pH of the waste water was 4.5, the reaction was strongly retarded at room temperature, first upon slight heating to 40° C. could the oxidation be brought to conclusion under the above-described conditions within 70-80 minutes. The analysis showed that neutralized waste waste was free from phenol.
EXAMPLE 6
A waste water sample containing 0.5% phenol and having a pH of 6.3 was treated with 5 grams of highly dispersed silica. In the waste water sample there was hung an iron sheet in accordance with Example 1, whereupon under stirring the amount of hydrogen peroxide corresponding to the phenol concentration was added. There was used a 10% aqueous hydrogen peroxide solution in an amount of 140 ml per liter of waste water.
After about 60 minutes the reaction began with increase in temperature and strong reduction in pH and was finished within a further 2 hours. The pH was 1.8. After the treatment with milk of lime the supernatent waste water was colorless and clear, phenol could no longer be detected.
EXAMPLE 7
A great number of waste water samples with different phenol and formaldehyde contents between 100 and 5,000 ppm were oxidatively treated in the presence of metal iron according to Example 1 using 35 weight % peroxide solution and NaCl as in the previous examples.
In part the sodium chloride was dissolved in the peroxide solution, in part the sodium chloride was partially dissolved also in the waste water, wherein per liter of waste water there were used 200 mg of sodium chloride.
In the following table there are set forth the different concentrations of phenol and formaldehyde and the amounts of 35% hydrogen peroxide and sodium chloride are also set forth.
TABLE TO EXAMPLE 7
______________________________________
Elimination of Phenol and Formaldehyde from Waste Waters.
Necessary Amounts of 35% by Weight Hydrogen Peroxide Solution
per Liter of Waste Water in the Presence of Metallic Iron
Concentration of the Waste
Water of 35 Weight % H.sub.2 O.sub.2
Phenol Formaldehyde Solution NaCl
% % ml mg
______________________________________
0.5 0 36.5.sup.(1) --
0.1 0 7.5.sup.(1) --
0.01 0 1.5.sup.(1) --
0.5 1.0 96.5 200
0.5 0.75 81.5 200
0.5 0.5 66.5.sup.(1) --
0.5 0.25 51.5 200
0.2 0.4 38.6 200
0.2 0.3 32.6 200
0.2 0.1 20.5 200
0.1 0.1 13.5.sup.(1) --
0.05 0.1 9.7 200
0.05 0.075 8.2 200
0.05 0.025 5.2 200
0.01 0.01 2.7.sup.(1) --
______________________________________
.sup.(1) Hydrogen peroxide solution containing 0.1% NaCl.
In all cases there could be produced within a short time of between 30 to a maximum of 60 minutes a complete detoxification of the waste water samples, indeed with the higher phenol content quicker than at lower.
EXAMPLE 8
There were treated with stirring in a ferrous reaction container having a capacity of 20 liters made of V 2 A steel waste water samples having phenol contents of 100 and 1,000 ppm as well as samples having phenol and formaldehyde contents of 100 to 1,000 ppm with 35% aqueous hydrogen peroxide solution. Before addition of the hydrogen peroxide solution per liter of waste water there were dissolved in wach case 200 mg of sodium chloride. The amounts of 35 weight % peroxide solutions corresponding to the phenol or phenol and formaldehyde concentrations are taken from the Table to Example 7.
In all charges the course of the oxidation reaction was according to the same pattern as in the previous examples.
After less than 60 minutes the oxidation was ended, the pH of the treated waste water samples was 2.5.
After correspondingly working up the waste water samples the analyses showed that they were free from both phenol and formaldehyde.
EXAMPLE 9
The analysis of a plant waste water from the production of phenol resin (acid condensation with formaldehyde novolak type) showed a phenol content of 4.5% and a formaldehyde content of altogether 5.8%.
The formaldehyde in the predominant part was in bound form, only a portion of 0.06% thereof was free formaldehyde. The pH value of the plant waste water was 3.
Besides phenol and formaldehyde the waste water still contained other organic constituents, inter alia residual organic solvent.
In order to make possible a corresponding detoxification of this waste water from phenol and formaldehyde it was necessary to dilute the waste water at least ten-fold in working with peroxide because otherwise the oxidation reaction would proceed too strongly and uncontrollably.
In a correspondingly large reaction container whose entire inside was provided with sheet iron. 46 liters of the original waste water were diluted with 410 liters of water. There were dissolved 100 grams of sodium chloride in this diluted waste water and subsequently there were added with stirring an amount of 35 weight % aqueous hydrogen peroxide solution totaling 34.5 liters. This amount of hydrogen peroxide is somewhat above the amount required for oxidizing the phenol and formaldehyde because it was found from corresponding laboratory experiments that there also had to be oxidized other organic constituents.
In order that the reaction did not occur too violently the hydrogen peroxide solution was added portionwise, that is, in each case in amounts of 5 to 10 liters.
According to this process the waste water can be completely detoxified within 1 to 2 hours. The temperature increased to 75° C. during the treatment, the pH, which was 6.8 after the dilution of the original waste water, fell to 1.9. After addition of the first portion of hydrogen peroxide because of the strong development of CO2 there first commenced observable foaming which slacked toward the end of the reaction.
After the oxidation reaction the product was neutralized by addition of 30% milk of lime whereby both lime and ferric hydroxide precipitated.
The supernatant foam free waste water which was clear and lighter could then be discharged.
The analysis showed that the waste water was completely free from phenol and formaldehyde.
EXAMPLE 10
A waste water sample containing 1,000 ppm of phenol, a second waste water sample containing 1,000 ppm of phenol and 1,000 ppm of formaldehyde were treated with the necessary amount of 10% aqueous hydrogen peroxide for the oxidation of phenol or phenol plus formaldehyde in the presence of metallic sheet iron, in accordance with Example 1. There was dissolved in the hydrogen peroxide solution 0.1% sodium chloride.
The oxidation proceeded in the manner already described in the previous examples. After the end of the reaction the samples were, as in the other examples, neutralized and the clear, light colored waste water decanted off. Corresponding samples were again analyzed, the analytic results showed that neither phenol nor formaldehyde was still present.
Besides the analyses there were carried out both on the starting samples and also on the samples treated with hydrogen peroxide the chemical and biochemical oxygen demand, besides toxicity measurements as well as a fish test and the determination of carbon.
There were determined on the starting samples which still contained phenol and formaldehyde COD, on the treated waste water samples the COD, the BOD5, the toxicity, the fish toxicity and the TOC value.
The toxicity was measured in the sapromat, the fish toxicity with guppies. The COD value is ascertained according to Standard Methods or according to the methods provided in the rules for discharge of waste water.
The determination of the carbon took place with a Beckmann "Total Organic Carbon Analyzer".
The following table shows the results.
______________________________________
Waste Water
with Phenol and
Waste Water with
Formaldehyde
1000 ppm Phenol
per 1000 ppm
Sample 1
Sample 2 Sample 3 Sample 2
treated
untreated
treated untreated
______________________________________
COD (mg O.sub.2 /l)
140 2400 300 3400
BOD.sub.5 (mg/l) of 1:1
diluted sample
33 -- 34 --
Toxicity
checking in %
(at 500 ml sample in
1000 ml mixture)
4 -- 15 --
TC (mg/l) 84 -- 160 --
TOC (mg/l) 50 -- 158 --
TAC (mg/l) 34 -- 2 --
Fish test:
Fish survived 48 hours
333 ml -- 333 ml --
sample sample
in 1000 in 1000
ml ml
mixture mixture
______________________________________
In the table TC is "total carbon", TOC is "total organic carbon", and TAC is "total inorganic carbon".
As can be seen the COD can be lowered considerably. Also, the BOD5 value is within the acceptable range. The results of the fish test are interesting according to which the added fish survived 48 hours at a mixing ratio of the treated waste water sample of 333 ml in 1000 ml.
EXAMPLE 11
Variation of the Iron Surface
(The type of iron used corresponded to that in Example 1).
Waste water samples containing 5,000 ppm, 1,000 ppm and 100 ppm of phenol were treated in the presence of metallic iron with the amount of 10% aqueous hydrogen peroxide solution required for the oxidation of the phenol.
There was dissolved 0.1% of sodium chloride in the hydrogen peroxide solution. The iron surface wetted by the waste water was varied. These iron surfaces were present as sheets as in Example 1.
The following table gives information as to the results:
Elimination of phenol from waste waters with the help of hydrogen peroxide and metallic iron.
Use of a 10% aqueous hydrogen peroxide solution containing 0.1% NaCl.
Influence of the metallic surface area on the reaction rate.
______________________________________
Phenol Content
Iron Surface Area
Reaction Reaction
of the Waste
in m.sup.2 per 1 m.sup.3
Began Duration
Water Waste Water After Min Min
______________________________________
0.5 16 5-6 17
12 5-6 21
7.5 8-10 35
3.5 20-22 75
0.1 15 10-12 43
11 10-12 47
7 13-14 70
3.5 15 110
0.01 15 25-30 65
11 40-45 100
7 55-60 120
3.5 120 220
______________________________________
From the table it can be seen that lowering the iron surface area lengthened the reaction time. It goes without saying that the reaction rate also depends on the phenol concentration.
EXAMPLE 12
Waste waters some with 5,000 ppm phenol+5,000 ppm formaledehyde, with 1,000 ppm phenol+1,000 ppm formaldehyde as well as with 100 ppm phenol+100 ppm formaldehyde were, as in Example 11, treated in the presence of metallic iron with the required amount of 10% aqueous hydrogen peroxide for oxidation of the phenol and formaldehyde.
There was dissolved in the hydrogen peroxide solution 0.1% of sodium chloride.
As in Example 11 there was also varied the iron surface area based on the amount of waste water to be treated.
The following table gives information as to the results. It also follows therefrom that with lowering of the iron surface area the time of reaction is increased:
Elimination of phenol and formaldehyde from waste waters with the help of hydrogen peroxide and metallic iron.
Use of 10% aqueous hydrogen peroxide solution containing 0.1% NaCl.
Influence of metal surface area on the reaction rate.
______________________________________
Iron
Surface
Phenol Formaldehyde
Area in m.sup.2
Reaction
Reaction
Content
Content per 1 m.sup.3
Began Duration
% % Waste Water
After Min.
Min
______________________________________
0.5 0.5 18 4-5 17
13 8-9 27
8.5 8-9 33
4.4 10-11 52
0.1 0.1 16 8-9 41
11.5 8-9 52
7.5 9-10 63
3.6 13-14 105
0.01 0.01 15 13-15 70
11 25-30 110
7 25-30 120-125
3.5 30-35 175-180
______________________________________
EXAMPLE 13
There were treated waste water samples containing 1,000 ppm brenzcatechol, resorcinol, pyrogallol, o- and p-cresol with 35% aqueous hydrogen peroxide solution which in each case had 0.1% of sodium chloride dissolved therein. There were used per mole of the named phenol derivatives 8 moles of hydrogen peroxide and the iron sheets corresponding to those of Example 1.
The oxidation reactions proceeded at normal temperature wherein the reaction started after about 5 minutes. The duration of the reaction with brenzcatechol and resorcinol was 45 minutes in each case, with o- and p-cresol it was about 70 minutes, with pyrogallol it was over 90 minutes.
After this time the waste water samples were free from the named phenol derivatives.
EXAMPLE 14
A further waste water sample containing 1,000 ppm of o-chlorophenol was likewise treated with 35% aqueous hydrogen peroxide solution in which 0.1% of sodium chloride was dissolved in the presence of metallic iron in accordance with Example 1.
Here also the course of the reaction was analogous to that of the other phenol derivatives; after about 1 hour the oxidation reaction was finished and the treated waste water was free from o-chlorophenol.
EXAMPLE 15
A waste water sample containing 0.5% of hydroquinone was treated with 10% aqueous hydrogen peroxide containing 0.1% sodium chloride dissolved therein in the presence of metallic iron in accordance with Example 1.
Per mole of hydroquinone there were used 8 or 10 moles of hydrogen peroxide.
The reaction proceeded under the already mentioned conditions; after about 45 minutes the oxidation was ended and the treated waste water sample was free from hydroquinone.
EXAMPLE 16
Alkaline reacting waste water having pH values between 8 and phenol contents of 100, 1,000 and 5,000 ppm were treated with sodium iron (III) ethylenediamine tetraacetate trihydrate with stirring. The amounts of complex salt, based on a liter of waster water, were between 1 and 2 grams. After solution of the complex salt the necessary amounts of 10% aqueous hydrogen peroxide solution for the phenol content were added with stirring. At 100 ppm there were used 2.8 ml of 10% hydrogen peroxide solution per liter of waste water, at 1,000 ppm of phenol 27.4 ml of 10% hydrogen peroxide per liter of waste water and at 5,000 ppm of phenol 137 ml of 10% hydrogen peroxide solution per liter of waste water.
The same series of experiments were carried out with 35% aqueous hydrogen peroxide solution wherein correspondingly there were used per liter of waste water 1.5 ml of 35% hydrogen peroxide solution for 100 ppm phenol; 7.2 ml of 35% hydrogen peroxide solution for 1,000 ppm phenol and 36.2 ml of 35% hydrogen peroxide solution for 5,000 ppm of phenol.
The reaction was initiated within a few minutes, recognized by the waste water becoming dark, the increase in temperature and reduction in pH as well as development of CO2.
After 30 minutes the oxidation was ended; the acid reacting waste water samples were neutralized by the addition of milk of lime and the clear waste water above the settled precipitate analyzed. The analysis showed that the samples were free from phenol.
EXAMPLE 17
Waste water samples which had pH values between 8 and 9, which besides phenol still contained formaldehyde, namely, in each case 100 ppm phenol plus 100 ppm formaldehyde, 1,000 ppm phenol plus 1,000 ppm formaldehyde and 5,000 ppm phenol and 5,000 ppm formaldehyde were treated with sodium iron (III) ethylenediamine tetraacetate trihydrate with stirring wherein again there were dissolved 1-2 grams of complex salt in the samples per liter of waste water.
Subsequently the addition of 35 weight % aqueous hydrogen peroxide solution took place wherein the following amoutns were used.
For the waste water with 100 ppm phenol plus 100 ppm formaldehyde 2.7 ml of 35% hydrogen peroxide solution per liter of waste water; for waste water samples with 1,000 ppm phenol plus 1,000 ppm formaldehyde 13.4 ml of 35 weight % hydrogen perocide solution based on 1 liter of waste water; for waste water samples with 5,000 ppm phenol + 5,000 ppm formaldehyde 66.4 ml of 35% hydrogen peroxide solution per liter of waste water.
After addition of hydrogen peroxide solution the oxidation reaction proceeded according to the process described in Example 16.
Within 30 minutes the oxidation reaction was ended. The acid reacting waste water samples, pH about 2, were neutralized with milk of lime, after settling of the precipitate the light, clear waste water was again analyzed. The analysis showed that all of the samples were completely free from phenol and in several cases only traces of formaldehyde of 10 ppm were present.
EXAMPLE 18
The analysis of an industrial waste water resulting from the alkaline condensation of phenol and formaldehyde (resole resin) showed a phenol content of 0.15% and a formaldehyde content of 0.04%.
The formaldehyde was present in bound form. The pH of the waste water was 8.9. In this waste water there was also still contained amines and ammonia.
A large amount, namely, 400 liters of this industrial waste water was treated under stirring with 400 grams of an aqueous solution of the complex salt of Example 16 (concentration 1 grams/liter of waste water). After solution of the complex salt there were added to the waste water in two portions 6.3 liters of 35 weight % aqueous hydrogen peroxide solution. The first portion was two thirds of the total amount used, the second portion the remainder of the amount. After addition of the first portion the temperature increased. After about 15-20 minutes the oxidation reaction was clearly visible, recognized by reduction of the pH and the at first weaker development of CO2 which subsequently increased. The temperature increased up to 35° C. After addition of the residual amount of hydrogen peroxide the temperature still increased somewhat, the pH fell to about 3.
After about 1 hour the oxidation reaction was ended, whereupon the waste water was colored brown.
Subsequently, it was neutralized by the addition of milk of lime whereupon there was observed a lightening of the waste water. After settling of the lime precipitate which contained small amounts of ferric hydroxide the clear waste water could be analyzed.
The analysis showed that it was completely free of phenol and there were still present only traces of formaldehyde in the order of magnitude of 10 ppm.
It may be noted that 0.5 to 2 grams of sodium iron (III) ethylenediamine tetraacetate trihydrate (C10 H12 N2 O8 FeNa.3H2 O) is equivalent to about 0.44 to 1.84 grams of the anhydrous complex having the formula C10 H12 N2 O8 FeNa.
What is claimed is:
1. A process of purifying waste water containing (1) phenol in the absence of formaldehyde, (2) a substituted phenol or (3) phenol+formaldehyde comprising treating the waste water with hydrogen peroxide in the presence of either (a) metallic iron under acid conditions and an activator which is a salt of an alkali metal, a salt of an alkaline earth metal, a zinc salt, an aluminum salt, a nickel salt or a manganese salt or is insoluble silica or (b) metallic copper and an activator which is a salt of an alkali metal, a salt of an alkaline earth metal, a zinc salt, an aluminum salt, or a manganese salt or is insoluble silica, said activator being present in an amount of 0.1 to 0.2% based on the hydrogen peroxide.
2. A process according to claim 1 wherein the waste water contains phenol, an alkyl phenol, a polyhydric phenol, a halogenated phenol or phenol+formaldehyde.
3. A process according to claim 2 wherein the waste water contains phenol, cresol, chlorophenol, resorcinol, pyrocatechol, pyrogallol, hydroquinone or phenol+formaldehyde.
4. A process according to claim 1 wherein the waste water contains phenol.
5. A process according to claim 1 wherein the waste water contains phenol+formaldehyde.
6. A process according to claim 1 wherein the metal is present in the form of a sheet, wire or granulate.
7. A process according to claim 1 wherein the purification is carried out in a ferrous metal containers.
8. A process according to claim 1 wherein the purification is carried out with stirring using a ferrous metal stirrer.
9. A process according to claim 1 wherein there are employed 7.5 to 8 moles of hydrogen peroxide per mole of phenol or substituted phenol with the proviso that when formaldehyde is also present in the waste water there are employed an additional 2 moles of hydrogen peroxide per mole of formaldehyde.
10. The process of claim 9 wherein the metal is iron and per cubic meter of waste water there is an iron surface area of about 1 to 20 square meters.
11. The process of claim 10 wherein the activator is sodium chloride or silica.
12. A process according to claim 11 wherein the activator is silica.
13. The process of claim 11 wherein the activator is sodium chloride.
14. A process according to claim 13 wherein the waste water contains phenol in an amount of about 0.01 to 0.5% and the iron surface area is about 7.5 to 16 square meters per cubic meter of waste water.
15. A process according to claim 14 wherein the waste water contains phenol in an amount of about 0.1 to 0.5% and the iron surface area is about 11 to 16 square meters per cubic meter of waste water.
16. The process of claim 13 wherein the waste water contains phenol in an amount of 0.01 to 0.5% and formaldehyde in an amount of 0.01 to 0.5% and the iron surface area is about 7.5 to 18 square meters per cubic meter of waste water.
17. A process according to claim 1 wherein the activator is sodium chloride or silica.
18. A process according to claim 17 wherein the activator is sodium chloride.
19. A process according to claim 1 wherein the activator is a salt of an alkali metal or a salt of an alkaline earth metal.
20. A process according to claim 1 wherein per cubic meter of waste water there is an iron or copper surface area of 1 to 20 square meters.
21. A process according to claim 1 wherein the metal is iron in the form of V 2 A steel.
22. A process according to claim 1 wherein after the purificatiion the acid reacting waste water is neutralized.
23. A process according to claim 1 wherein there is present metallic iron.
24. A process according to claim 1 wherein the activator is a salt of an alkaline earth metal.
25. A process according to claim 1 wherein the activator is silica.
| 1979-11-27 | en | 1983-01-25 |
US-89079297-A | Robotic furniture texturing
ABSTRACT
A programmable furniture texturing robotic system includes a programmable multiaxis robot fixed to a support frame and a table fixed to a support frame such that they form an integrated unit and the programmable multiaxis robot has a furniture texturing tool unit attached to the end of the robot arm. The furniture texturing tool unit is attachable to and detachable from the arm of the robot and is either a furniture chattering tool unit or a furniture distressing multitool turret. The furniture chattering tool unit has a circular saw blade which produces surface chatter marks when it is dragged across the surface of a furniture part. The furniture distressing tool unit has a plurality of furniture distressing tools, each of which produce a plurality of furniture distress marks including simulated wood rot, worm holes, hatchet marks, rock marks, wood split marks, crooked vein lines, and cigarette burn marks.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to robotic furniture texturing, and more particularly to an apparatus and method of producing a plurality of furniture parts with substantially the same texture markings and to the plurality of furniture parts which have substantially the same texture marks.
2. Description of Related Art
Hand-crafted furniture has a desirable aesthetic appeal with many consumers. Similarly, many consumers find furniture which has picked up characteristic distress marks over time to be very desirable. Modern manufacturing methods produce furniture which does not have the aesthetically appealing surface texture markings such as those produced by hand-crafted methods or by distressing over periods of time.
This has led to manually texturing the surfaces of newly manufactured furniture to give the furniture the appearance of being hand-crafted and/or to impart the desirable appearance of being aged. The manual methods of texturing furniture have many disadvantages. It is time consuming and expensive to texture furniture manually. Furthermore, it is difficult to attain consistent and controllable results. Consequently, the manual methods of texturing furniture have the additional disadvantage of not consistently producing texturing effects which are aesthetically appealing.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a furniture texturing system which produces consistent, controllable and repeatable surface texture features to furniture.
It is another object of this invention to provide a furniture texturing system which produces seemingly random yet aesthetically pleasing patterns of distress marks on various surfaces of pieces of furniture in a consistent, controllable and repeatable manner.
It is another object of this invention to provide a furniture texturing system which produces aesthetically pleasing chattering surface texture features in a consistent, controllable and repeatable manner.
It is another object of this invention to provide a furniture texturing system in which a large variation of furniture surface texture features can be produced with a minimal amount of retooling of manufacturing equipment.
It is another object of this invention to provide furniture texturing tools to be used in a furniture texturing apparatus which produces consistent, controllable and repeatable furniture surface texture features which are aesthetically pleasing.
It is another object of this invention to provide a method of producing aesthetically pleasing surface texture features to furniture in a consistent, controllable and repeatable manner.
It is still another object of this invention to provide a plurality of furniture parts which have substantially the same aesthetically pleasing, consistent, controllable and repeatable surface texture features.
Still another object of this invention is to provide furniture parts with consistent and controllable surface chattering texture marks.
The above and related objects of this invention are realized by providing a programmable furniture texturing robotic system which can be programmed to produce aesthetically pleasing furniture surface textures in a consistent, controllable and repeatable manner. The preferred embodiment of this invention has a programmable robot with a furniture texturing tool unit attached to a tool end of the robot arm. It is desirable for the furniture texturing tool unit to be able to produce a large variety of furniture surface-texture features to minimize the requirement of having to change the furniture texturing tool unit. The furniture texturing robot of this invention has a large number of degrees of freedom and high precision for positioning furniture texturing tools of the furniture texturing tool unit at desired locations. In addition, the furniture texturing robot is capable of moving the furniture texturing tools across the furniture surface in substantially the desired motion.
In a preferred embodiment of this invention, there are two types of furniture texturing tool units. One furniture texturing tool unit is a furniture chattering tool unit which produces a plurality of furniture chattering effects. The other furniture texturing tool unit is a furniture distressing tool unit. Although the preferred embodiment has separate tool units for furniture chattering and furniture distressing, alternative embodiments include furniture texturing tool units which produce both furniture chattering and furniture distressing effects.
The furniture chattering type of surface texturing is produced with a circular saw blade which is dragged across a surface region of the furniture part. As the circular saw blade is dragged across a surface region of the furniture part, it produces crescent shaped undulations which are first shallow, increase to a maximum depth, and then abruptly return to approximately the original surface or shallow depth. These undulations can be produced to be substantially periodic over selectable small or large regions of the surface of a furniture part, or can be made to be a periodic or random. The controllability of the robot combined with the furniture chattering tool unit of the preferred embodiment, or a combined tool unit of an alternative embodiment, permit the user to produce furniture chatter patterns which cannot reasonably be produced by hand or by other prior art methods.
The furniture distressing tool unit has a plurality of furniture distressing tools. Each of the furniture distressing tools can produce a plurality of furniture distress marks. The robot is programmed such that a large variety of furniture distress marks are produced without the need to change the furniture distressing tool unit. In an alternative embodiment, the furniture distressing tool unit includes a furniture chattering tool.
In the preferred embodiment, the furniture distressing tool unit has four different furniture distressing tools. A distressing router tool is used to produce a plurality of furniture distress marks which includes simulated crooked vein lines, uneven plank cuts and cigarette burn marks. A descalar distressing tool produces a plurality of furniture distress marks which include marks which simulate worm hole marks and rot marks. A distressing rock tool produces a plurality of indentations in the surface of the furniture which simulate rock marks. The hatchet distressing tool produces a plurality of furniture distress marks which include distress marks which simulate hatchet marks and wood split marks. The wood split marks are typically along the edge of a furniture part.
The method of texturing surfaces of furniture according to this invention includes putting a piece of wood, such as a furniture part, onto the table of the programmable furniture texturing robotic system such that it can be held while the user programs the furniture texturing robot to produce a sequence of furniture texture features. Once the user has programmed the robot to perform a sequence of furniture texturing operations which result in aesthetically pleasing furniture texturing features, the program can be used repeatedly to produce substantially the same furniture texture features on a plurality of similar furniture parts. Additional programs can be developed such that a plurality of such programs are available for use at any given time.
Finally, this invention includes furniture in which a plurality of items of furniture have surface texture features which are aesthetically pleasing and give the appearance of being unique. However, a plurality of items of furniture have surface texture features which are substantially the same even though they have the desirable appearance of being unique. This invention also includes furniture parts which have chattering-type surface textures which cannot reasonably be produced by previously known methods and devices.
BRIEF DESCRIPTION OF THE DRAWINGS
The file of this patent contains at least one color photograph. Copies of this patent with color photographs will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.
FIG. 1 is a side view of the programmable furniture texturing robotic system of the present invention.
FIG. 2A is a top view of the programmable furniture texturing robotic system of the present invention.
FIG. 2B is a front elevation view of the programmable furniture texturing robotic system of the present invention which also illustrates protective shielding.
FIG. 3 is a view of the furniture distressing tool unit according to a preferred embodiment of the invention.
FIG. 4A is a view of a router bracket according to a preferred embodiment of the invention.
FIG. 4B is a view of an alternative embodiment of a router bracket for an embodiment of the invention.
FIG. 5A is a front view of a compound furniture distressing tool attachment bracket according to a preferred embodiment of the invention.
FIG. 5B is a side view of a compound furniture distressing tool attachment bracket according to a preferred embodiment of the invention.
FIG. 6 is a side view of a furniture distressing tool unit according to a preferred embodiment of the invention with the scalar distressing tool and router distressing tool removed to provide a clearer view of the rock distressing tool and hatchet distressing tool.
FIG. 7A is a front view of a hatchet holder according to a preferred embodiment of the invention.
FIG. 7B is a side view of a hatchet holder according to a preferred embodiment of the invention.
FIG. 8A is a front view of a distressing hatchet according to a preferred embodiment of the invention.
FIG. 8B is a side view of a distressing hatchet according to a preferred embodiment of the invention.
FIG. 9A is a top view of a rock spacer according to a preferred embodiment of the invention.
FIG. 9B is a front view of a rock spacer according to a preferred embodiment of the invention.
FIG. 10A is a top view of a distressing rock according to a preferred embodiment of the invention.
FIG. 10B is a side view of a distressing rock according to a preferred embodiment of the invention.
FIG. 11 is a side view of a descalar bracket according to a preferred embodiment of the invention.
FIG. 12 is a side view of a furniture chattering tool unit according to a preferred embodiment of the invention.
FIG. 13 is a front view of a furniture chattering tool unit according to a preferred embodiment of the invention as one would view from the direction of motion of the furniture chattering tool unit.
FIG. 14 is a router bit according to a preferred embodiment of the invention illustrating the production of one type of furniture distress mark.
FIG. 15 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including uneven cut lines.
FIG. 16 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including uneven cut lines across the center of the figure.
FIG. 17 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including uneven cut lines across the center of the figure.
FIG. 18 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including uneven cut lines across the center of the figure.
FIG. 19 is a view of a router bit according to a preferred embodiment of the invention illustrating the production of furniture distress marks which simulate cigarette burn marks.
FIG. 20 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including simulated cigarette burn marks.
FIG. 21 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including simulated hatchet distress marks.
FIG. 22 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including simulated hatchet distress marks.
FIG. 23 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including wormhole distress marks.
FIG. 24 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including wormhole distress marks.
FIG. 25 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including simulated wood rot distress marks.
FIG. 26 shows a surface of a furniture part with surface texturing produced according to a preferred embodiment of the invention including simulated wood rot distress marks.
FIG. 27 shows an example of furniture part with surface texturing produced a preferred embodiment of the invention.
FIG. 28 shows an example of a furniture chatter marks according to a preferred embodiment of the invention.
FIG. 29 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 30 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 31 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 32 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 33 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 34 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 35 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 36 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 37 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 38 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 39 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 40 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
FIG. 41 shows an example of furniture chatter marks according to a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The programmable furniture texturing robotic system of the present invention is designated generally by the reference numeral 50 in FIG. 1. The programmable furniture texturing robotic system 50 includes a furniture texturing robot 51 which includes a programmable multiaxis robot 52 having a tool arm 54. The tool arm 54 has a tool end 56. A suitable programmable multiaxis robot is a MOTOMAN K120 six-axis robot commercially available from Sphearhead Automated Systems Inc. having a YASNAC MRC controller and a robot tolerance of±0.1 mm. The MOTOMAN robot comes with dual 32 bit RISC processors that allow for smooth path motion, speed, accuracy and a 120 kg payload capacity. The MOTOMAN robot comes equipped with a teaching, editing and programming pendant with one touch programming execution. However, other robots may be selected without departing from the scope or spirit of the invention.
The programmable multiaxis robot 52 is attached to a support frame 58. A table 60 is attached to the support frame 58 such that the programmable multiaxis robot 52, support frame 58, and table 60 form an integrated unit to maintain proper alignment of the tool end 56 of the arm 54 of the programmable multiaxis robot 52. Preferably, the table 60 is a vacuum table which holds the furniture part in position while the programmable multiaxis robot produces texture markings on the furniture part. Vacuum tables for holding both flat and curved furniture parts in place are known in the art of furniture manufacturing for uses other than a programmable furniture texturing robotic system.
The programmable furniture texturing robotic system 50 has a furniture texturing tool unit 62 fixedly attached to the tool end 56 of the tool arm 54. Preferably, the furniture texturing tool unit 62 is fixedly attached to an attachment plate 64 at the tool end 56 of the tool arm 54. The attachment plate 64 is rotatable about an axis 65 substantially perpendicular to the attachment plate 64. Preferably, the attachment plate 64 can be rotated by substantially 360° about the axis 65.
The programmable multiaxis robot has a counter weight 66 attached at a distance from the tool end 56 of the tool arm 54 to substantially cancel a primary component of torque on the tool arm 54 generated by the furniture texturing tool unit 62. One skilled in the art would recognize that a robot other than a MOTOMAN K120 six-axis robot may require a counterweight and mounting configuration different from that of the preferred embodiment.
A top view of the programmable furniture texturing robotic system for a preferred embodiment is illustrated in FIG. 2A. This preferred embodiment has two tables 60, and a work cell 68. The work cell 68 preferably has a frame 69 made from 8 in×6 in rectangular steel tubing. In the example of FIG. 2A, the work cell 68 is 25 ft 2 in×17 ft 3 in. The work cell 68 is further enclosed by safety glass such as LEXAN guarding 70, which can best be seen illustrated in FIG. 2B. In the example of FIG. 2A, a YASNAC controller 72 and vacuum pump 74 are disposed proximate to the work cell 68. An air supply of 80 psi dried is suitable in this example.
The preferred embodiment of this invention has two furniture texturing tool units 62 (FIG. 1). The user selects one of the two furniture texturing tool units 62 and attaches it to the attachment plate 64 of the programmable multiaxis robot 52. The specific furniture texturing tool unit 62 illustrated in FIG. 1 is an embodiment of a furniture distressing tool unit which is different from the preferred embodiment. Other alternative embodiments are within the scope and spirit of the invention, e.g., a furniture texturing tool unit 62 may include both furniture distressing and furniture chattering tools. FIG. 3 shows a preferred embodiment of the furniture distressing tool unit 76. The furniture distressing tool unit 76 has a multitool turret 78 which has a tool end attachment region 80. Preferably, the tool end attachment region 80 has a multitool attachment plate 82 attached at one face to the multitool turret 78 and at an opposing face to the attachment plate 64. A suitable material for the multitool attachment plate 82 and the multitool turret 78 is aluminum. The multitool turret 78 has a plurality of furniture distressing tool attachment regions, such as 84, 86, and 88. A greater or lesser number of furniture distressing tool attachment regions may be selected without departing from the spirit or scope of the invention. Tools other than furniture distressing tools, such as furniture chattering tools, may be attached at the furniture distressing attachment regions.
In the preferred embodiment, the furniture distressing tool unit 76 includes a plurality of furniture distressing tools attached to the multitool turret 78. A suitable material for the multitool turret is aluminum. In the preferred embodiment, a first furniture distressing tool is a router distressing tool 90. The distressing router 90 has a router bit 92 which is selectable according to the desired texturing effect. The distressing router 90 has an end plate 94 and a router mounting packet 96 to attach router 98 to the multitool turret 78. A suitable router 98 is available from Porter Cable (Model 6902). The router bracket 96 is preferably constructed from aluminum such that it defines a circular hole therethrough for accommodating the router 98, as one may view more clearly in FIG. 4A. A saw cut gap 100 and mechanical fastener 102 permit the bracket to be clamped tightly around a selected circumferential region of the router 98. Alternatively, a bracket 104 may be used instead of bracket 96 (see FIG. 4B).
The furniture distressing tool unit 76 (FIG. 3) includes a compound distressing tool unit 106 which has a plurality of furniture distressing tools. The compound furniture distressing tool unit 106 has a compound furniture distressing tool attachment bracket 108 which preferably attaches to a furniture distressing tool attachment region 86 by mechanical fasteners. One can view the compound furniture distressing tool attachment bracket 108 in FIGS. 5A and 5B. A plurality of furniture distressing tools are attached to the compound furniture distressing tool attachment bracket 108 (see FIG. 3). In the preferred embodiment, a descalar distressing tool 110, a rock distressing tool 112 and a hatchet distressing tool 114 are attached to the compound furniture distressing tool attachment bracket 108. The hatchet distressing tool 114 is immediately behind the rock distressing tool 112 in FIG. 3. The hatchet distressing tool 114 and rock distressing tool 112 are more clearly visible from a side view illustrated in FIG. 6.
The hatchet distressing tool 114 has an expansion component 116 attached to compound furniture distressing tool attachment bracket 108 by hatchet attachment bracket 118 mechanically fastened to the compound furniture distressing tool attachment brackets 108. Preferably, the expansion component is an air cylinder selected from conventionally known air cylinders and is attached to a variable pressure air supply unit in a conventional manner (not shown). A suitable commercially available air cylinder is a NUMATICS ACTUATOR S2FM-02A1D-CAA2. Similarly, in a conventional manner, a slidable member 120 such as a piston is attached to a hatchet holder 122. The hatchet holder 122 is attached to the distressing hatchet 124'. (One may view the hatchet holder 122 more clearly in FIGS. 7A and 7B and a preferred embodiment of the distressing hatchet 124 in FIGS. 8A and 8B.) A suitable material for the distressing hatchets 124 and 124' is tool steel. A first angle 123 of approximately 90° and a second angle 125 of approximately 20° was found to be suitable for the distressing hatchet 124' .
In the preferred embodiment, the operating elements of the rock distressing tool 112 are similar in construction to the hatchet distressing tool 114 (FIG. 6). The rock distressing tool has an expansion component 127 which is preferably, for example, one or more conventional pneumatic air cylinders. The expansion component 127 is attached to a variable pressure air source (not shown). The expansion component 127 is preferably attached to the compound furniture distressing tool attachment bracket 108 by the air cylinder brackets 126 with mechanical fasteners. The rock distressing tool has a slidable member 128 which is part of a conventional air cylinder. The distressing rock element 130 is itself attached to a rock spacer 132, which in turn is attached to the slidable member 128. The distressing rock element 130 includes a distressing face 134, perhaps best seen in FIGS. 3, 6 and 10B, that has a plurality of rock-like shapes including convex and concave surface regions as well as sharp and rounded areas to replicate actual rock-like effects on the article of furniture.
The plurality of rock-like shapes are selectable in accordance with the desired furniture distressing effect. The rock spacer 132 is also illustrated in FIGS. 9A and 9B. A suitable material for the rock spacer 132 is aluminum. FIGS. 10A and 10B show an enlarged view of the distressing rock element 130. A suitable material for the distressing rock element 130 is steel.
As one may see illustrated in FIG. 3, the descalar distressing tool 110 has a descalar bracket 136 attached to the compound furniture distressing tool attachment bracket 108, preferably by mechanical fasteners. The descalar distressing tool 110 includes a descalar 138, similar to a conventional descalar, but modified such that it has two descalar pins 140 rather than a large number of descalar pins as in a conventional descalar used in the metal industry for removing burs from metal parts. In addition, the modified descalar pins 140 are sharpened. The descalar pins 140 are typically attached at an attachment end 142 of the descalar 138. Descalars are also known as jet chisels. A suitable commercially available descalar is the jet chissel by Nittokohkico Ltd. (Model JT-20). The descalar 138 has conventional pistons which move the descalar pins 140 in a back-and-forth motion along the longitudinal direction of the descalar 138. The motion of the descalar pins 140 typically have an amplitude of about, for example, 0.2 to 0.5 inches but greater or lesser movement is contemplated. The attachment end 142 of the descalar 138 is typically circular as viewed end-on and the descalar pins 140 are typically attached off center. The attachment end 142 typically rotates about a center axis of the circular attachment end 142 in operation so that pins 140 can move inwardly, outwardly, and/or rotate or incorporate a plurality of these motions, as well as a variety of angular positions relative to the furniture surface.
FIG. 11 illustrates a more detailed view of the descalar bracket 136. The descalar bracket 136 has a tube 144 which is preferably aluminum. Brackets 146 and 148 are preferably attached to aluminum tube 144 by mechanical fasteners. Bracket 150 is preferably attached to aluminum tube 144 by welding. An angle 151 of approximately 30° is suitable for the bracket 150. Aluminum is a suitable material for brackets 146, 148 and 150. The bracket 150 attaches to the compound furniture distressing tool attachment bracket 108, preferably by mechanical fasteners (FIG. 3). As one can see illustrated in FIG. 3, the descalar distressing tool 110 also has a descalar spacer 152.
Although the preferred embodiment of the furniture distressing tool unit 76 has four furniture distressing tools, the furniture distressing tool unit 76 is not limited to that exact number. A greater or lesser number of distressing tools is within the scope and spirit of the invention.
The second furniture texturing tool unit of the preferred embodiment is a furniture chattering tool unit 154 illustrated in FIGS. 12 and 13. The furniture chattering tool unit 154 has a support frame 156 with an attachment region 158 to attach and detach the furniture chattering tool unit 154 to the attachment plate 64 of the programmable multiaxis robot 52 (see FIG. 1 for an illustration of the attachment plate 64). The support frame 156 has an upper frame portion 160 and a lower frame portion 162. Preferably, as one may best view in FIG. 13, a pair of Gibb plates 164 are attached to lower frame portion 162 by mechanical fasteners and slidably attached to upper frame portion 160 by bearings 166. (See FIG. 12 for an illustration of the bearings 166 on one of the two Gibb plates 164. The bearings 166 on the other Gibb plate 164 are not shown.) A motor 168 is disposed within the support frame and in contact with a bottom surface 170 of the lower support frame 162. The motor 168 is preferably an air operated motor and is selectable from conventional motors. A model 8AM-NRV-76 6ZC-94 commercially available from Gaft Manufacturing Corp. is suitable.
The motor 168 has a drive shaft 172 which extends in a direction from the attachment end 158 of the support frame 156 to a furniture part end 174 of the furniture chattering tool unit 154.
In the preferred embodiment, a plurality of compression springs 176 are disposed between a top surface 178 of the motor 168 and an inner surface 180 of the upper frame portion 160 such that the compression springs 176 exert a force tending to increase the distance between the motor 168 and the inner surface 180 of the upper frame portion 160 when the compression springs 176 are in a compressed state. A gas shock 182 is attached at one lateral side of the support frame 156 such that one end is attached to the upper frame portion 160 and the other end is attached to the lower frame portion 162. Similarly, another gas shock 184 is attached at the opposite lateral side of the support frame 156 such that one end is attached to the upper frame portion 160 and the other end is attached to the lower frame portion 162. The upper frame portion 160 has a cross support member 186. The lower support frame portion 162 has a cross support member 188. A suitable material for the cross support members 186 and 188 is steel. A support member 190 is slidably attached between the cross support member 186 of the upper frame portion 160 to the cross support member 188 of the lower frame portion 162. An expansion spring 192 has one end attached to the cross support member 186 of the upper frame portion 160 and the other end attached to the cross support member 188 of the lower frame portion 162. The furniture chattering tool unit 154 has a saw blade 194 attached substantially perpendicularly to the drive shaft 172 and substantially at its center point.
The furniture chattering tool unit 154 also has an adjustable roller bearing unit 196 fixed to the a bottom surface 198 of the support frame 156. The roller bearing unit 196 extends substantially parallel to the drive shaft 172 of the motor 168 and has a roller bearing 200 at a furniture part end 174 of the furniture chattering tool unit 154. A plate 202 is fixedly attached between the saw blade 194 and the drive shaft 172 such that it is substantially parallel to the saw blade 194.
In operating the programmable furniture texturing robotic system 50 according to the present invention, one first selects a furniture texturing tool unit 62 from a plurality of possible types of furniture texturing tool units. In the preferred embodiment, one selects either a furniture distressing tool unit 76 or a furniture chattering tool unit 154 and attaches it to the attachment plate 64 of the tool end 56 of the tool arm 54 of the programmable multiaxis robot 52. Although the preferred embodiment has two different furniture texturing tool units 62, a lesser number or a greater number of tool units 62 are within the scope and spirit of the invention. Also, an alternative embodiment may include both furniture distressing and chattering tools on the same furniture texturing tool unit.
The user then fixes a wood part, such as a furniture part 204, to table 60 (see FIG. 3). Preferably, the table 60 is a vacuum table adapted from vacuum tables known in the art for furniture manufacturing. For flat parts, a pod 206 is placed on the vacuum table and the flat part is placed on the pod 206. For furniture parts with curved surfaces, and irregular shapes, a mold (not shown) is placed on top of the vacuum table. The mold may define openings to provide a surface with a pressure lower than atmospheric pressure such that the curved or irregular furniture part is held to the surface due to the vacuum. Alternatively, or in combination thereof, the curved or irregular furniture part may be clamped or otherwise fastened to the mold.
The user then programs the programmable furniture texturing robot 51 to perform a predetermined sequence of furniture texturing operations. The MOTOMAN K120 robot is suitable since it has a teach mode and a teaching input device in which the user uses the teaching input device to program all of the robot's motions. The user positions the desired furniture texturing tool at a desired point in contact with, or proximate to, the surface point of the furniture part 204. The configuration of the furniture texturing robot 51 is recorded as a step in the program. The user then selects another point of the surface of the furniture part 204 such that the desired furniture texturing tool is in contact with, or approximate to, the selected point. The MOTOMAN K120 robot also permits linear and circular interpolation between selected points. The user repeats this process such that the desired furniture texturing marks are produced at the desired locations on the surface of the furniture part.
After the user completes the program of all of the robot motions, preferably in a teaching mode of a programmable multiaxis robot 52, the program is ready to be used in production runs to produce the selected furniture texturing marks on a plurality of furniture parts. In a production run, a furniture part is secured to a table 60. It is suitable to secure the furniture part in the production run in the same way as described above for securing a wood part, or a furniture part, to a table 60 for programming the furniture texturing robot 51. The programmable multiaxis robot 52 of the preferred embodiment is then run through the predetermined sequence of furniture texturing operations which the user programmed during the programming step. The furniture texturing robot 51 will thereby substantially produce the predetermined furniture texturing marks on the surface of the furniture part.
After the furniture texturing robot 51 has completed the predetermined sequence of furniture texturing operations, the user removes the furniture part 204 from the table 60. The user then disposes another furniture part 204 on the table 60 in substantially the same manner as described above. The programmable multiaxis robot 52 is then run through the predetermined sequence of furniture texturing operations, thus producing a second furniture part with substantially the same furniture texturing marks as in the first mentioned furniture part. This process is then repeated to produce a desired number of furniture parts with substantially the same texture marks.
The programmable furniture texturing robotic system 50 is not limited to a single table 60. In the preferred embodiment, the programmable furniture texturing robotic system 50 has two substantially identical tables 60. This permits a user, either manually or with a suitable apparatus, to remove the textured furniture part and to replace it with an untextured part while the furniture texturing robot 51 runs through the predetermined sequence of furniture texturing operations on a furniture part on the other table 60.
In order to produce distress marks on a furniture part, the user selects a furniture distressing tool unit. In a preferred embodiment of the invention, the furniture distressing tool unit 76 is selected to produce furniture distress marks. Each of the plurality of furniture distressing tools of the furniture distressing tool unit 76 produce a plurality of furniture distress marks.
FIG. 3 illustrates a furniture distressing router 90 proximate to a flat furniture part 204. The flat furniture part 204 is disposed on a pod plate 206 which, in turn, is disposed on the top surface of the table 60. In this case, the table 60 is a vacuum table with a top aluminum vacuum plate 208.
FIG. 14 illustrates a router bit 92 in contact with the furniture part 204 such that a longitudinal axis 210 of the distressing router 90 forms an angle 212 with the surface of the furniture part 204. For the particular router bit 92 depicted in FIG. 14, an angle 212 of approximately 30° is suitable. An angle 213 of approximate 75° is suitable for the cutting edge. The user selects a second point on the surface of the furniture part 204 with a depth of penetration of the bit 92 into the surface of the wood part 204 similar to or the same as that depicted in FIG. 14 and selects a linear interpolation between the two points to produce a substantially straight line such as that shown as a horizontal dark line in FIG. 15. In addition, uneven vein lines, or cut lines, can be produced in a similar manner by selecting different penetration depths of the bit 92 into the surface of the furniture part 204 at the different selected points, or selecting nonlinear interpolation between the points, selecting a plurality of points with nonuniform depths of penetration of the bit 92 into the furniture part 204 or which are not precisely along a single line, or some combination of these or other factors. FIG. 16 shows an example of an uneven cut line across the center of the figure. This type of distress mark simulates markings which would be produced in hand-crafted furniture. FIGS. 17 and 18 show additional examples of uneven cut or vein lines. The depth of the cut lines is selectable for the router bit 92, and other router bits may be selected. A typical depth of such a cut may be between 1 and 4 mm.
FIG. 19 illustrates an example in which the router bit 92 is brought into contact with the furniture part 204 at a different angle 214 compared to the first mentioned angle 212. For the router bit 92, an angle 214 of approximately 60° is suitable. The user may program the robot to come into contact with the furniture part 204 as illustrated in FIG. 19 in order to simulate cigarette burn marks. In this case, the router produces an indentation in the surface of the furniture part 204 which is approximately 3-7 cm long such that the center of the indentation is deeper than the edges. Such a simulated cigarette burn mark is illustrated in the upper left hand corner of FIG. 20. Although the above description of the use of the distressing router 90 refers to producing simulated uneven vein lines, uneven plank cut lines or cigarette burn marks, it is not limited to producing only those types of distress marks.
The distressing hatchet 114, illustrated in FIG. 3, is used to produce a plurality of furniture distress marks. In order to produce distress marks which simulate a hatchet mark, the furniture texturing robot 51 is positioned such that the hatchet is above, or proximate to, a point on the furniture part 204. The distance of the hatchet above the furniture part 204 is selected such that an impulse from the expansion component 116 forces the piston 120 (FIG. 6) and the hatchet blade 124 into the surface of the furniture part 204 to the desired depth. The user, during the programming step, can select the desired angle between the distressing hatchet 124 and the furniture part 204. Typical simulated hatchet distress marks in which the distressing hatchet 124 impacts the surface of the furniture part 204 at nearly orthogonal angles are shown in FIGS. 17, 21 and 22.
The user may also program the furniture texturing robot 51 such that the distressing hatchet 114 produces simulated wood split marks. In this case, the expansion component 116 does not provide an impulse to the distressing hatchet 124. Instead, the blade of the distressing hatchet 124 is brought into contact with the surface of the furniture part 204. Typically, a corner of the hatchet blade is brought into contact with the surface of the furniture part 204. The user then programs the robot such that the hatchet is drawn across the surface of the furniture part 204 substantially in a straight line motion which is substantially parallel to the surface of the furniture part 204. Examples of such distress marks are the two shorter distress lines shown in FIG. 18. Although the specification describes the use of the hatchet distressing tool 114 to simulate hatchet marks or wood split marks, the invention is not limited to producing only those types of simulated furniture distress marks with the hatchet distressing tool 114.
The user can program the rock distressing tool 112 to produce a plurality of the furniture distress marks. The surface 134 of the distressing rock 130 has a plurality of concave and convex regions. This results in portions which protrude relative to other portions of the surface. These protrusions are selectable in a great variety of forms since they can be used to simulate distress marks produced by rocks, and actual rocks have a great variety of surface features. The user positions the furniture texturing robot 51 such that a desired portion of the distressing rock 130 surface 134 is proximate to, and above, a region of the furniture part 204 in which the user desires to produce a simulated rock distress mark. The furniture texturing robot 51 is programmed such that the expansion component 127 delivers an impulse to the rock 130 by means of the piston 128 and rock spacer 132, so as to thrust the surface 134 of the distressing rock 130 into the surface of the furniture part 204. The height of the rock distressing tool 112 is selected so as to produce a desired depth of penetration of the rock surface 134 into the surface of the furniture part 204. Typical penetration depths are 1-4 mm. The user can further select various angles of orientation of the rock distressing tool 112 relative to the surface of the furniture part 204 to produce different rock distress marks. Consequently, a single distressing rock 130 with a plurality of concave and convex surface regions 134 can produce a plurality of simulated rock distress marks. The lower left hand corner of FIG. 21 shows an example of a rock distress mark. The center of FIG. 22 shows another example of a rock distress mark. Although the specification describes programming the furniture texturing robot 51 such that it produces a plurality of simulated rock distress marks with the rock distressing tool 112, the invention is not limited to only simulating rock distress marks with the rock distressing tool 112.
The user can program the furniture texturing robot 51 to produce a plurality of furniture distress marks with the descalar distressing tool 110 (see FIG. 3). To produce distress marks which simulate worm hole marks, the user positions the furniture texturing robot 51 such that the descalar pins 140 are oriented such that their longitudinal axis is substantially orthogonal to a surface region of the furniture part 204. The user programs the furniture texturing robot 51 such that the descalar pins 140 are thrust into the surface of the furniture part 204 by the descalar piston. The user programs the furniture texturing robot 51 such that the descalar pins 140 move quickly into proximity with the surface of the furniture part 204 and then out of proximity of the furniture part 204. This process is repeated at predetermined rarefied locations, so as to simulate a random pattern of rarefied and approximately circular wormhole distress marks. This sequence results in the descalar appearing to hop randomly about the surface of the furniture part 204. FIG. 16 shows an example of such wormhole furniture distress marks in the upper right hand corner. FIG. 23 shows another example of wormhole distress marks along with other types of distress marks. A typical wormhole distress mark is approximately a millimeter deep and approximately circular in shape. The user may also program the robot such that the descalar pins 140 come into contact with the surface of the furniture part 204 at angles less than 90° so as to produce oblong or elliptical shaped wormhole marks.
The user may also program the furniture texturing robot 51 to produce simulated wood rot marks with the descalar distressing tool 110. In this case, the user programs the furniture texturing robot 51 such that the descalar pins 144 come into contact with the furniture part 204 in a highly concentrated region and typically at very shallow angles of the longitudinal axis of the descalar pins relative to the surface of the furniture part 204. The upper edge of FIG. 24 illustrates the simulated wood rot furniture distress marks. FIG. 24 includes other types of distress marks such as a random pattern of wormhole marks and an uneven cut mark across the bottom. FIGS. 21, 25 and 26 provide further examples of simulated wood rot distress marks produced according to this invention. Although the specification describes simulating wormhole distress marks and wood rot distress marks using the descalar distressing tool 110, it is not limited to producing only these types of distress marks with the descalar distressing tool.
The user selects the furniture chattering tool unit 154, illustrated in FIGS. 12 and 13, and attaches it to the attachment plate 64 of the programmable multiaxis robot 52, if the user desires to program the furniture texturing robot 51 to produce chattering texture marks according to the preferred embodiment. The user adjusts the roller bearing unit 196 such that the roller bearing 200 comes into contact with the surface of the furniture part 204 after the saw blade 194 has penetrated the surface of the furniture part 204 to a desired depth. The user then programs the robot such that the saw blade 194 has a desired angle of incidence with the surface of the furniture part 204. Selecting different angles of incidence or depths of cutting, provide different chattering effects. The user programs the robot to drag the furniture chattering tool unit 154 across a predetermined region of the surface of the furniture part 204. The user may select to program the furniture texturing robot 51 to produce a substantially uniform chattering pattern across the surface of the furniture part 204, or may vary the chattering path, saw blade angle and depth of cutting at different regions of the surface of the furniture part 204. The maximum depth of a chatter mark relative to the adjacent minimum depth is typically one to a few millimeters. The user may program the furniture texturing robot 51 to produce predetermined furniture chattering marks which appear to be random and others which cannot reasonably be produced by known methods.
In a case in which the surface of the furniture part 204 is a curved surface, the user must exercise a great amount of care in programming the furniture texturing robot 51 such that the saw blade 194 makes the desired angle of contact with each desired point of the curved surface of the furniture part 204. FIGS. 27-41 show a variety of furniture chattering marks which one may produce with the furniture texturing robotic system of this invention. However, this invention is not limited to producing only the predetermined chattering marks shown in the examples of FIGS. 27-41.
One skilled in the art would recognize that the programmable furniture texturing robotic system of this invention is not limited to only the specific robot described, the specific furniture texturing units described in detail, and the specific table. The invention is not limited to the two furniture texturing tool units described in detail nor to the specific tools, methods of texturing furniture, nor only the specific examples of textured furniture of the preferred embodiments.
Although the invention has been described with reference to specific embodiments, one should realize that these embodiments are illustrative of the application of the principles of the invention. One skilled in the art should recognize that modifications and rearrangements of the above illustrated preferred embodiments may be made without departing from the spirit and scope of the invention.
We claim:
1. A programmable furniture texturing robotic system, comprising:a programmable multiaxis robot having a tool arm and a tool end of said tool arm; and a furniture texturing tool unit attached to said tool end including at least one furniture texturing tool, wherein said furniture texturing tool unit is selected from the group consisting of a furniture distressing tool unit and a furniture chattering tool unit.
2. A programmable furniture texturing robotic system according to claim 1, further comprising:a vacuum table constructed and arranged to hold said furniture part while said at least one furniture texturing tool produces texture markings on said furniture part.
3. A programmable furniture texturing robotic system, comprising:a programmable multiaxis robot having a tool arm and a tool end of said tool arm; and a furniture texturing tool unit attached to said tool end including at least one furniture texturing tool, wherein said furniture tool unit is a furniture distressing tool unit which includes:a multitool turret having a tool arm attachment region, said multitool turret is attachable to and detachable from said tool end, and has a plurality of furniture distressing tool attachment regions, and said at least one furniture texturing tool is a first furniture distressing tool attached to said multitool turret at a first furniture distressing tool attachment region of said plurality of furniture distressing tool attachment regions.
4. A programmable furniture texturing robotic system according to claim 3, wherein said furniture distressing tool unit includesa compound furniture distressing tool attachment bracket attached to said multitool turret at a second furniture tool attachment region of said plurality of furniture distressing tool attachment regions, wherein said compound furniture distressing tool bracket has a plurality of compound bracket furniture distressing tool attachment regions.
5. A programmable furniture texturing robotic system according to claim 4, wherein said furniture distressing tool unit includessecond, third, and fourth furniture distressing tools attached to first, second and third compound bracket furniture distressing tool attachment regions of said plurality of compound bracket furniture distressing tool attachment regions, wherein said first furniture distressing tool is a router distressing tool having a selectable router bit to selectively produce a first plurality of furniture distress marks, said second furniture distressing tool is a descalar distressing tool including a descalar and having first and second descalar pins pivotally attached to said descalar to selectively produce a second plurality of furniture distress marks, said third furniture distressing tool is a rock distressing tool having a distressing rock with a plurality of convex and concave surface regions and is attached to a first slidable member which is in contact with a first expansion component such that an impulse applied by said first expansion component to said first slidable member thrusts said distressing rock into a furniture part to selectively produce a third plurality of furniture distress marks, and said fourth furniture distressing tool is a hatchet distressing tool having a distressing hatchet attached to a second slidable member which is in contact with a second expansion component such that an impulse applied by said second expansion component to said second slidable member thrusts said distressing hatchet into said furniture part to selectively produce a fourth plurality of furniture distress marks.
6. A programmable furniture texturing robotic system, comprising:a programmable multiaxis robot having a tool arm and a tool end of said tool arm; and a furniture texturing tool unit attached to said tool end of said tool arm including at least one furniture texturing tool, wherein said furniture texturing tool unit is a furniture chattering tool unit which includes:a support frame having an attachment region which is attachable to and detachable from said tool end, a motor attached to said support frame such that a drive shaft of said motor has a longitudinal axis that extends in a direction from an attachment end of said support frame to a furniture part end of said support frame, and a chattering saw blade fixed to said drive shaft substantially at a center point of said saw blade and substantially orthogonal to said longitudinal axis of said drive shaft, wherein said saw blade rotates as said drive shaft rotates.
7. A programmable furniture texturing robotic system, comprising:a programmable multiaxis robot having a tool arm and a tool end of said tool arm; and a furniture texturing tool unit attached to said tool end including at least one furniture texturing tool, a vacuum table constructed and arranged to hold said furniture part while said at least one furniture texturing tool produces texture markings on said furniture part; and a support frame, wherein said vacuum table and said programmable multiaxis robot are mounted to said support frame to form an integrated unit to maintain proper alignment of said tool end relative to said furniture part.
8. A programmable furniture texturing robotic system according to claim 7, wherein said programmable multiaxis robot includes a counterweight disposed at an end of said tool arm which is disposed a distance from said tool end of said tool arm to substantially cancel a primary component of torque on said tool arm generated by said furniture texturing tool unit.
9. A method of texturing furniture comprising the steps of:selecting a furniture texturing tool unit from a plurality of different furniture texturing tool units; attaching said furniture texturing tool unit selected in said selecting step to a tool end of an arm of a programmable furniture texturing robot; programming a programmable furniture texturing robot to perform a predetermined sequence of furniture texturing operations; disposing a furniture part proximate to said programmable furniture texturing robot; and running said programmable furniture texturing robot through said predetermined sequence of furniture texturing operations thereby substantially producing said predetermined furniture texture marks on a surface of a furniture part, wherein a furniture part is disposed proximate to said programmable furniture texturing robot as part of said programming.
10. A method of texturing furniture according to claim 9, further comprising the steps of:repeating said disposing step and said running step, respectively, a plurality of times after the first said disposing step and the first said running step thereby substantially producing said predetermined furniture texture marks on a surface of each of a plurality furniture parts.
11. A plurality of furniture parts produced in accordance with the method of claim 10,wherein each furniture part within said plurality of furniture parts has texture markings that are substantially identical.
12. A plurality of furniture parts produced in accordance with the method of claim 10,wherein each furniture part within said plurality of furniture parts has furniture distressing marks that include at least one of a wormhole, wood rot, hatchet, rock, or cigarette burn.
13. A plurality of furniture parts according to claim 12,wherein said furniture distressing marks produced in each of said plurality of furniture parts are substantially identical to the remaining ones of said plurality of furniture parts.
14. A method of texturing furniture according to claim 9, whereinsaid step of selecting a furniture texturing tool unit consists of selecting a furniture distressing tool unit, and said programming step includes programming to perform a predetermined sequence of furniture distressing operations thereby substantially producing predetermined furniture distress marks on a surface of a furniture part.
15. A method of texturing furniture according to claim 14,wherein said predetermined sequence is repeated to produce furniture distressing marks which are substantially identical to the first mentioned furniture distress marks.
16. A method of texturing furniture according to claim 14,wherein said predetermined sequence is repeated to produce furniture distressing marks which are different from the first mentioned furniture distress marks.
17. A method of texturing furniture according to claim 9, wherein said step of selecting a furniture texturing tool unit consists of selecting a chattering tool unit, andsaid programming step includes programming to perform a predetermined sequence of chattering operations thereby substantially producing predetermined furniture chatter marks on a surface of a furniture part.
18. A plurality of furniture parts produced in accordance with the method of claim 17,wherein each furniture part within said plurality of furniture parts has chattering marks produced therein that are substantially identical.
19. A method of texturing furniture comprising the steps of:selecting a furniture texturing tool unit from the group consisting of a furniture distressing tool unit and a furniture chattering tool unit; attaching said furniture texturing tool unit selected in said selecting step to a tool end of an arm of a programmable furniture texturing robot; programming a programmable furniture texturing robot to perform a predetermined sequence of furniture texturing operations; disposing a furniture part proximate to said programmable furniture texturing robot; and running said programmable furniture texturing robot through said predetermined sequence of furniture texturing operations thereby substantially producing said predetermined furniture texture marks on a surface of a furniture part.
| 1997-07-11 | en | 1999-11-16 |
US-38214582-A | Cleaning of balls
ABSTRACT
A golf ball cleaning device comprises a cylindrical casing 1 lined with a helical strip of bristles 8. A cleaning pad 7 is provided in the casing base and a removable cap 11 at the top allows a ball to be inserted for cleaning.
BACKGROUND OF THE INVENTION
This invention relates to the cleaning of balls, particularly golf balls. In order that a golf ball rolls true it has long been a recognized requirement that the ball should be clean and it is the object of the present invention to provide a simple device which enables a golf ball to be cleaned without the use of rags and without dirtying the hands of the user.
SUMMARY OF THE INVENTION
In accordance with the present invention a golf ball cleaning device comprises a tubular casing openable at one end to provide access, resiliently flexible cleaning elements extending radially inwardly into the casing and defining a passage of a diameter suitable for entry of the ball to be cleaned and, preferably a dispensing pad capable of holding cleaning liquid at at least one end of the passage.
The arrangement is that in use the ball is inserted into the passage and the casing closed and shaken. The ball moves longitudinally within the casing flexing the cleaning elements thereby cleaning the surface of the ball; abutment of the ball against the pad provides release of cleaning liquid to enhance the cleaning operation.
The resiliently flexible elements can conveniently be a helical extending strip of bristles. A helical mounting strip which fits inside the tubular casing holds the bristles.
BRIEF DESCRIPTION OF THE DRAWINGS
A particular embodiment of the invention will now be described by way of example and with reference to the accompanying drawings wherein:
FIG. 1 is a side view of the device;
FIG. 2 is a section on the line II--II of FIG. 1 with the lid removed; and
FIG. 3 is a side view, partly in section of the cap.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device illustrated is formed of plastics and comprises a cylindrical casing 1 closed at the lower end to provide a base 2. The open end has an outwardly extending rim 3 from the upper part of which extend four inclined ramps 4 of a bayonet connection. A shallow radially inwardly extending rib 5 is positioned around the upper part of the rim and an annular shoulder 6 is provided below the rib 5. A disc shaped pad 7 of liquid-absorbent, for example foam, material fits the base of the container and a helically disposed strip of bristles 8 extends continuously from the pad 7 to seat on the shoulders 6 and be retained by a washer 9 retained under the rib 5. The bristles are held in a channel member 10 formed into the helix with the bristles 8 extending radially inwardly as shown in FIG. 2, the channel member 10 forms a helical mounting strip which fits inside casing 1.
A cleaning passage is thus defined within the free ends of the bristles 8 having a diameter similar to a golf ball schematically indicated at A in FIG. 2.
The device is completed by a detachably engaged cap 11 having a frusto-conical head 12 with triangular ribs 13 to facilitate turning. A cleaning pad 14 of disc shape is located in the upper part of the cap. The cap 11 has a dependent rim 15 to fit over rim 3 of the casing 1, the inner surface of rim 15 having inclined projections 16 of the bayonet connection.
In use the cap is removed and the ball is inserted into the cleaning passage, the pads 7 and 14 having previously been moistened conveniently with water. The device is then shaken and rubbing action of the ball against the bristles 8 cleans the ball. The cap is then removed and the clean ball is ready for use.
I claim:
1. A golf ball cleaning device comprising:a closed, tubular casing openable at one end to provide access; a helical mounting strip fitting inside and at the inside of the tubular casing; a helically disposed continuous strip of bristles mounted on the helical mounting strip; the bristles extending inwardly from said strip and defining a passage of a diameter appropriate for cleaning engagement with the ball; and a dispensing pad capable of holding cleaning liquid at at least one end of the casing.
2. A golf ball cleaning device comprising:a closed tubular casing openable at one end to provide access; a helical mounting strip fitting inside and at the inside of the tubular casing; a helically disposed continuous strip of bristles mounted on the helical mounting strip; the bristles extending inwardly from said strip and defining a passage of a diameter appropriate for cleaning engagement with the ball; and a removable cap over the one openable end of the casing, the cap being lined with a dispensing pad capable of holding cleaning liquid.
3. A golf ball cleaning device comprising:a closed, tubular casing openable at one end to provide access; a helical mounting strip fitting inside and at the inside of the tubular casing; and a helically disposed continuous strip of bristles mounted on the helical mounting strip; the bristles extending inwardly from said strip and defining a passage of a diameter appropriate for cleaning engagement with the ball.
4. A device as in claim 3 in which the helical mounting strip is a channel shaped member for holding the bristles, the channel shaped member being formed into a helix with the bristles extending radially inward.
| 1982-05-26 | en | 1984-10-02 |
US-3716162D-A | Tamper-proof closure arrangement
ABSTRACT
A tamper-proof seal that is located between a container and a cap received on a threaded open end of the container. The tamperproof seal consists of a flange integral with the container wall adjacent the open end and defining an upwardly opening recess that has a reduced mouth at the upper end. The flange is divided into a fixed portion and a flexible, frangible portion. The cap has an enlarged bead on the lower end thereof that has a dimension greater than the dimension of the mouth to cause outward deflection of the frangible portion when the cap is threaded onto the container and the enlarged bead and frangible portion cooperate to define interlocking elements when the cap is placed in sealing engagement with respect to the open end of the container.
Botkin States Patent 1 [54] TAMPER-PROOF CLOSURE ARRANGEMENT [76] Inventor: Albert L. Botkin, 3018 W; Hood Avenue, Chicago, 111. 60645 22 Filed: Sept. 20, 1971 [21] Appl.No.: 182,073
[ 5 6 References Cited UNITED STATES PATENTS 4/1937 Ahlquist .12 1 5/42 12/1965 Fields ..2l5/7 Primary Examiner-George T. Hall Attorney-MacDressler et a1.
[ 1 Feb. 13,1973
[57] ABSTRACT A tamper-proof seal that is located between a container and a cap received on a threaded open end of the container. The tamper-proof seal consists of a flange integral with the container wall adjacent the open end and defining an upwardly opening recess that has a reduced mouth at the upper end. The flange is divided into a fixed portion and a flexible, frangible portion. The cap has an enlarged bead on the lower end thereof that has a dimension greater than the dimension of the mouth to cause outward deflection of the frangible portion when the cap is threaded onto the container and the enlarged bead and frangible portion cooperate to define interlocking elements when the cap is placed in sealing engagement with respect to the open end of the container.
10 Claims, 4 Drawing Figures PATENTEUFEB 13 I975 lllllllll 1 TAMPER-PROOF CLOSURE ARRANGEMENT BACKGROUND OF THE INVENTION The use of tamper-proof seals between containers and caps has become increasingly prevalent in numerous industries in recent years because of the substantial losses that have been incurred while products are being displayed for sale. Examples of such devices areshown in Hogg U.S. Pat. No. 1,908,245; Merolle U.S. Pat. No. 2,062,271; and Cheeley U.S. Pat. No.
Devices of the character disclosed in the above patents, while partially solving the problem of unauthorized removal of the caps on containers, have several serious drawbacks. Tamper-proof seals of this type require a modification of the container and the cap as well as a separate element to provide an interlock between the container and cap. For example, the
three patents referred to above, all require a separate band of metal or other material that is applied over enlarged cooperating flanges on the container and the cap to provide the tamper-proof seal. Such an arrangement is not only expensive in the initial manufacture of the seals of the above type is that the containers and caps can be reused by applying a new tamper-proof band. In
many areas, such as the milk industry, sanitation requirements dictate that the container be designed so as to be truly non-refillable. With devices of the above type, the containers can readily be reused any number of times.
While efforts have been directed towards the-design of truly non-refillable containers with a tamper-proof seal, as evidenced by. U.S. Pat. Nos. 3,088,6l7; 3,224,6l6; and 3,504,818, such devices have not found any degree of commercial success because of the manufacturing and assembly problems and/or number of parts that are required.
SUMMARY OF THE INVENTION The present invention contemplates a tamper-proof seal between a container and a closure that requires only a modification of the container so that a conventional commercially available cap can be utilized with the container and the container can be filled and the closure applied thereto by well known filling and closure operations.
The container modification consists of a flange that is molded integral with. the plastic container and has an outwardly directed first portion, an upwardly directed second portion and an inwardly directed third portion adjacent the upper end of the second portion to define an upwardly opening recess having a reduced mouth at its open end. The inwardly directed third portion or wall has an interlocking element defined by a downwardly directed lip that cooperates with an interlocking element in the form of an enlarged bead on the bottom end of the cap so that tamper-proof seal is created as the cap is threaded into sealing engagement with the open end of the container. The upwardly directed second portion of the flange has a weakened section that provides a franglible connection between the first and third portions of the flange.
With this arrangement, the cap can be inserted onto the container with a conventional type of closure machinery and the tamper-proof seal will automatically be provided between the cap and container.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF DRAWINGS FIG. I is a fragmentary plan view of a container and cap in the assembled condition;
FIG. 2 is a fragmentary plan view of the container and cap shown in FIG. 1;
FIG. 3 is a vertical section through the cap and the upper end of the container; and
FIG. 4 is a section similar to FIG. 3 showing the cap as it is being assembled onto the container.
DETAILED DESCRIPTION While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.
FIG. 3 of the drawings shows a portion of a container 10 having an open upper end 12 with an external thread 14 on the periphery of the container adjacent the open end that receives a cap 16. The cap or closure 16 has a circular portion 18 with a sealing member 20 secured therein and a depending skirt 22 that has a cooperating thread 24 defined therein.
According to the present invention, the tamperproof seal 30 is formed integral with the container 10 and cooperates with the closure or cap 16 to automatically interlock the container and cap as the cap is threaded into a sealing engagement with the open end 12 of the container. Furthermore, the cap may be of a conventional, commercially available type that can be assembled onto the container utilizing conventional assemblytechniques. The tamper-proof seal 30 consists of a flange 31 that has a first outwardly directed substantially fixed portion 32 that is integral with the wall of the container and a second upwardly directed portion 34 with an integral inwardly directed third portion 36 along the upper end of the second portion; The first, second and third portions of the flange cooperate to define an upwardly opening recess 38 that is adapted to receive the lower end of the skirt 22 of the cap 16. In addition, the inwardly directed third portion 36 of the flange is of reduced cross-section on the 'free end thereof to define a downwardly directed lip 40 that terminates adjacent the periphery of the container to define a reduced area opening or mouth for the recess and an undercut portion or groove 41 in the third portion or wall.
The second portion has a weakened area 42 that defines a frangible connection between the first and third portions of the flange. The weakened area 42 also provides a flexing connection between the first and third portions of the flange but has sufficient rigidity to maintain the portions in a predetermined position when no external forcesare applied thereto. This is accomplished by circumferentially spaced openings 44 that divide the vertical portion or leg 34 into a plurality of spaced segments 46 that are of reduced thickness at 48 to define the point of fracture for the segments.
As was indicated above, the cap 16 is of a conventional, commercially available type that is normally formed of metal and has the free end of the skirt 22 curled outwardly to eliminate any sharp edges. This outwardly directed curl or bead S is utilized as one interlocking element that cooperates with the inwardly directed lip 40 to produce interlocking means between the container and the cap as the cap is threaded on the container. As more clearly shown in FIG. 3, the bead or enlarged portion 50 on the lower end of the cap has a transverse dimension which is greater than the mouth or opening for the recess 38 that is defined by the inwardly directed lip 40. With this arrangement, the threading of the cap on the container after a filling operation will cause the enlarged portion or curl 50 to be forced into the mouth. Since the mouth or opening on the upper end of the recess is of a dimension substantially less than the transverse dimension of the enlarged portion, the threading action or axial movement of the cap relative to the opening will cause an outward deflection of the free end portion of the flange to the position shown in FIG. 4. Continued rotation of the cap relative to the container will locate the enlarged bead 50 below the inwardly directed lip and when the cap is in sealing engagement with respect to the open end 12 of the container 10, the elastic memory of the plastic flange will return the second and third portions of the flange to their initial position shown in FIG. 3. An inspection of FIG. 3 reveals that in this position the inwardly and downwardly directed lip 40 is positioned above the enlarged bead and the bead is received in the groove 41 and cooperates therewith to prevent removal of the cap without destroying the frangible seal.
When the purchaser desires to remove the cap, the tab 60 integral with the third portion 36 of the flange is utilized for severing the frangible connection incorporated into the flange. Thereafter, it is impossible to reposition the frangible portion onto the remainder of the container which insures that the container will not be reused.
To insure that the bead or enlarged portion 50 enters the recess 38 with a minimum of force applied thereto, it is also desirable to have cooperating camming surfaces on the wall or third portion 36 and the bead 50.
These surfaces are identified as arcuate surfaces 62 and 64.
It is to be noted that the arcuate surface 64 is shaped to produce an expansion of the opening or mouth for recess 38 as the cap is screwed into position on the container. in contrast, lip 40 is shaped to prevent expansion of the opening or mouth when the cap is unscrewed or moved upwardly and thus rupture of the seal is required to remove thecap.
While the invention has been described in connection with a threaded cap, the invention is equally applicable to non-threaded cap such as a press-fit or pushon cap. Also, the manner of weakening the vertical portion 34 could readily be in the form of a continuous thinned area in the vertical portion or leg rather than the segmented arrangement produced by the openings 44. The material for the container may be any flexible plastic but polyethylene is preferred.
The tamper-proof seal provides a simple and inexpensive expedient for sealing the cap to the closure and gives an indication of whether the cap has been removed since the filling operation has taken place. All of this is accomplished with only a small additional amount of plastic material and a redesign of the plastic container without the need for separate additional elements. Also, the container having the tamper-proof seal can be used on existing filling lines for non-tamperproof containers without modification of the filling line.
lclaim:
1. in a container having an open upper end; tamperproof means integral with the periphery of said container below said open end and defining a recess open toward said upper end, said tamper-proof means having a frangible portion; and a cap received on the open end of said container to seal said open upper end, said cap and tamper-proof means having interlocking elements that engage each other when said cap is placed in sealing engagement with said open upper end to prevent removal of said cap without separating said frangible portion from said container.
2. The combination as defined in claim 1, in which said frangible portion has an upwardly and outwardly directed camming surface along the upper portion to guide the interlocking element on said cap into said recess.
3. The combination as defined in claim 1, in which said interlocking elements include an inwardly directed wall adjacent the upper end of said frangible portion defining a reduced area opening for said recess and an enlarged portion on the lower end of said cap having a dimension greater than the dimension of said opening, said frangible portion being temporarily deflected during threading of said cap onto said container to allow said enlarged portion to be received into said recess below said wall.
4. The combination as defined in claim 3, further including cooperating camming surfaces on said wall and said enlarged portion to cause outward deflection of said frangible portion when said cap is threaded on said container.
5. in combination with a plastic container having an open end with an externally threaded portion adjacent the open end and a cap having a cooperating thread defined on a depending portion; a tamper-proof seal between said container and cap including a flange integral with the periphery of said container below said threaded portion, said flange having a first outwardly directed fixed portion, a second upwardly directed frangible portion and a third inwardly directed portion on the upper end of said second portion, said portions cooperating to define an upwardly open recess having a reduced mouth in the open end thereof; and an enlarged bead on said cap and having a dimension greater than the dimension of said mouth so as to cause said inwardly directed third portion to be temporarily deflected outwardly upon threading of said cap into sealing engagement with the open end of said container and position said bead below said inwardly directed portion.
6. The combination as defined in claim 5, in which said bead and said inwardly directed portion have cooperating camming surfaces to produce said outward deflection during threading of said cap onto said container.
7. The combination as defined in claim 6, in which said second portion includes a plurality of spaced segments interconnectingsaid first and third portions of said flange.
8. The combination as defined in claim 5, in which .said inwardly directed third portion has an undercut groove adjacent the free end for receiving a portion of directed portion and an inwardly directed portion on the upper end that cooperate to define a recess having a reduced mouth along the periphery of said container adjacent said open end, said flange being deflectable to enlarge said mouth when a cap is received on said container and cooperating therewith to prevent removal of the cap without separating said frangible portion.
10. A container as defined in claim 9, in which said inwardly directed portion has a downwardly directed lip that has an arcuate camming surface on the upper surface thereof and a groove on the lower surface thereof.
1. In a container having an open upper end; tamper-proof means integral with the periphery of said container below said open end and defining a recess open toward said upper end, said tamperproof means having a frangible portion; and a cap received on the open end of said container to seal said open upper end, said cap and tamper-proof means having interlocking elements that engage each other when said cap is placed in sealing engagement with said open upper end to prevent removAl of said cap without separating said frangible portion from said container.
1. In a container having an open upper end; tamper-proof means integral with the periphery of said container below said open end and defining a recess open toward said upper end, said tamper-proof means having a frangible portion; and a cap received on the open end of said container to seal said open upper end, said cap and tamper-proof means having interlocking elements that engage each other when said cap is placed in sealing engagement with said open upper end to prevent removAl of said cap without separating said frangible portion from said container.
2. The combination as defined in claim 1, in which said frangible portion has an upwardly and outwardly directed camming surface along the upper portion to guide the interlocking element on said cap into said recess.
3. The combination as defined in claim 1, in which said interlocking elements include an inwardly directed wall adjacent the upper end of said frangible portion defining a reduced area opening for said recess and an enlarged portion on the lower end of said cap having a dimension greater than the dimension of said opening, said frangible portion being temporarily deflected during threading of said cap onto said container to allow said enlarged portion to be received into said recess below said wall.
4. The combination as defined in claim 3, further including cooperating camming surfaces on said wall and said enlarged portion to cause outward deflection of said frangible portion when said cap is threaded on said container.
5. In combination with a plastic container having an open end with an externally threaded portion adjacent the open end and a cap having a cooperating thread defined on a depending portion; a tamper-proof seal between said container and cap including a flange integral with the periphery of said container below said threaded portion, said flange having a first outwardly directed fixed portion, a second upwardly directed frangible portion and a third inwardly directed portion on the upper end of said second portion, said portions cooperating to define an upwardly open recess having a reduced mouth in the open end thereof; and an enlarged bead on said cap and having a dimension greater than the dimension of said mouth so as to cause said inwardly directed third portion to be temporarily deflected outwardly upon threading of said cap into sealing engagement with the open end of said container and position said bead below said inwardly directed portion.
6. The combination as defined in claim 5, in which said bead and said inwardly directed portion have cooperating camming surfaces to produce said outward deflection during threading of said cap onto said container.
7. The combination as defined in claim 6, in which said second portion includes a plurality of spaced segments interconnecting said first and third portions of said flange.
8. The combination as defined in claim 5, in which said inwardly directed third portion has an undercut groove adjacent the free end for receiving a portion of said bead.
9. A container having an upper open end adapted to receive a cap on a periphery thereof to seal the end, and including an integral flange on the periphery of said container adjacent said open end, said flange having an outwardly directed portion, a frangible upwardly directed portion and an inwardly directed portion on the upper end that cooperate to define a recess having a reduced mouth along the periphery of said container adjacent said open end, said flange being deflectable to enlarge said mouth when a cap is received on said container and cooperating therewith to prevent removal of the cap without separating said frangible portion.
| 1971-09-20 | en | 1973-02-13 |
US-52579174-A | Sensing arm water fill shut off for ice maker
ABSTRACT
A control for shutting off an automatic ice maker in a refrigeration apparatus, such as a refrigerator-freezer. The ice maker apparatus is driven by an electric motor which is permitted to run continuously and thereby provide additional timing functions for other controls in the refrigeration apparatus. The ice maker mechanism is caused to be inoperative for purposes of providing ice bodies such as when the level of collected ice bodies in a storage bin reaches a preselected full level. The ice maker mechanism is made inoperative for providing ice by preventing delivery of water to the ice maker freezing mold. One end of a bin level sensing arm acting on and biased by a switch spring contact is utilized to prevent electrical conduction through the spring contact when a full level is detected by another end of the sensing arm.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a refrigeration apparatus and in particular to apparatus for automatically making ice bodies in an apparatus such as a refrigerator-freezer.
2. Description of the Prior Art
In controlling conventional automatic ice body maker devices, bin level switches have been utilized to deactivate the device when the bin reaches a preselected full level. One such device is disclosed in U.S. Pat. No. 3,675,437 wherein a bin level switch is operated in response to the weight of ice bodies in the bin to disconnect power from the water fill solenoid valve when the bin reaches the full level. The same patent further describes a sensing arm mechanism for water fill solenoid shut off arranged to sweep through the collecting bin by means of a cooperating spring biased carrier and timing cam. Another ice maker mechanism is shown in U.S. Pat. No. 3,217,506 wherein a bin lever is coupled to a switch contact to deactivate the entire mechanism whenever a full bin level is detected. Both of the above described devices require special biasing springs for the bin levers and also require separate and complicated timing means for the water fill solenoid.
SUMMARY OF THE INVENTION
The present invention comprehends an improved control mechanism for controlling the water fill to the ice making mold. In the present invention the ice body maker mechanism is permitted to be driven continuously through its normal cycle except that under certain conditions delivery of water for forming ice bodies in the freezing mold is prevented. A switch means is provided for electrically completing a circuit for the water delivery means. The switch means includes a spring means which biases the switch contacts and a bin level sensing arm. The spring means comprises two conducting leaf springs, each carrying a switch contact. The springs bias the contacts against a contoured cam surface having an electrically conductive portion for periodically electrically completing a circuit to connect the water delivery means to a source of power. A sensing arm is provided having a first end in association with the collecting bin and a second end biased by one of the leaf springs. The second end has a projection in contact with one of the springs and is operable in response to the first end detecting a full level in the bin to prevent at least one of the contacts from contacting the cam surface.
Other features and advantages of the invention will be apparent from the following description taken in connection with and accompanying the drawings wherein:
FIG. 1 is a fragmentary perspective view of a refrigeration apparatus incorporating the invention;
FIG. 2 is an isometric view of an ice body maker embodying the invention;
FIG. 3 is a fragmentary vertical section thereof taken substantially along the line 3--3 of FIG, 4;
FIG. 4 is a front elevation thereof with portions removed to facilitate illustration of the control mechanism;
FIG. 5 is a fragmentary transverse section taken substantially along the line 5--5 of FIG. 4;
FIG. 6 is a schematic electrical wiring diagram illustrating the control for the ice body maker;
FIG. 7 is a fragmentary isometric view of a switch mechanism embodying the invention; and
FIG. 8 is a fragmentary enlarged front elevation of a portion of a mechanism of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the exemplary embodiment of the invention as disclosed in the drawing, a refrigeration apparatus generally designated 1 is shown to comprise a freezer section 2 and a fresh food storage section 3. The apparatus further includes a compressor 4, a condenser 5, a capillary 6 and evaporator 7. Located within freezer section 2 an ice maker generally designated 10 is shown to comprise a mold 11 defining a plurality of cavities 12 adapted to receive water to be frozen into a plurality of ice bodies. Mold 11 is mounted for rotation about a horizontal axis whereby the ice bodies may be formed with a mold cavity opened upwardly and may be discharged from the mold by turning the mold to an inverted position with the cavities opening downwardly subsequent to a suitable freeing of the ice bodies from the walls of the mold such as by twisting the mold. Rotation of the mold is effected by an electric drive motor 14 forming a part of a control mechanism generally designated 15 mounted in a suitable housing 16. The mold may be partially received within an enclosure wall 17 projecting forwardly from housing 16 as shown in FIG. 2. A receptacle 18 is slidably carried on suitable brackets 19 to be disposed subjacent the mold to receive the discharged ice bodies in the harvesting operation as shown in FIG. 3. Mechanism 15 includes a sensing arm 20 adapted to swing an end 20a through the upper portion of a space 21 within collecting bin 18 thereby to sense the level of ice bodies collected in the bin. When the sensing arms senses a full condition, the condition at which a level of ice bodies is at least at a preselected full level, it causes a discontinuation of the ice body forming process, thereby providing a suitable control of mechanism 15. The present invention comprehends an improved mechanism for effecting this discontinuation.
More specifically, as shown in FIG. 3, motor 14 is provided with an output shaft 23 turning a pinion gear 24. Pinion gear 24 drives a pair of gears, main drive gear 25 and spur gear 26. Spur gear 26 is made for rotation on a stub shaft 27 received in a front wall 28. Main drive gear 25 is rotatably mounted on a tubular shaft 29. Shaft 29 includes a forward projection 30 connected to one end of mold 11 whereby rotation of tubular shaft 29 effects the desired rotation of mold 11 into the cyclic ice maker operation discussed above. The opposite end of the mold 11 may be rotatably mounted by means of a stub shaft 31 pivoted in a front portion 32 of the enclosure wall 17.
As best seen in FIG. 5, spur gear 26 includes a rearwardly opening recess 33 and drive gear 25 includes an opening 34 which becomes aligned with recess 33 at periodic intervals as the result of the different rates of rotation of gears 25 and 26.
Carried on shaft 29 is a tubular housing 35 extending parallel to the axis of the shaft 29 and arranged to be aligned with opening 34 at one point in the relative rotation of the drive gear 25 on shaft 29. A pin 36 is slidably mounted in housing 35 to have a nose portion 37 enter into opening 34 when the opening is aligned. Pin 36 carries a rearward extension 38 received in an opening 39 in a rear wall 40 of mechanism 15. A coil spring 41 extending between pin 36 and rear wall 35a of housing 35 biases the pin forwardly against the drive gear.
Nose portion 37 of pin 36 is frustoconical and is urged outwardly from opening 34 by a coacting portion 42 of gear 25 whenever the movement of the pin into the opening is limited by the engagement of nose portion 37 with the face of spur gear 26. The resultant movement of rearward extension 38 of pin 36 is not sufficient to remove it from the opening 39 in rear wall 40. Thus, under these conditions, no motion of shaft 29 is effected by the rotation of gear 25 as pin 36 merely moves in and out of opening 34.
However, when the condition occurs wherein spur gear recess 33 becomes aligned with the opening 34, nose portion 37 of pin 36 may enter fully into opening 34 so that the extension 38 of pin 36 is biased outwardly from opening 39 thereby freeing the tubular housing 35 and the shaft 29 for rotation with gear 25.
Nose portion 37 of pin 36 moves outwardly from recess 33 to the circumferential edge of spur gear 26 permitting the pin to move in an annular path in locked association with gear 25 and opening 34 for one complete revolution of gear 25. On completion of the revolution, nose portion 37 of pin 36 reenters the recess in spur gear 26 and is cammed outwardly thereby to restore extension 38 through opening 39 in rear wall 40 once again locking shaft 29 against rotation with gear 25. A more detailed description of this functioning is presented in U.S. Patent No. 3,382,682 issued to E. H. Frohbieter on May 14, 1968 for "Method For Harvesting Ice Bodies And Apparatus For The Same".
As shown in the wiring diagram of FIG. 6, the refrigeration apparatus includes a conventional compressor motor 78 for effecting suitable refrigeration to form the ice bodies in mold 11. The compressor motor is controlled by a conventional cabinet thermostat 79. Further, timer and ice maker drive motor 14 is caused to run continuously and thereby is available to control the periodic energization of a suitable defrost heater 77 for automatically defrosting the refrigeration apparatus.
The control 15 is operated by the motor 14 and normally functions to harvest successive batches of ice bodies from the mold 11 by repeated cycling of the ice body mechanism. However, when the ice bodies in bin 18 reach the preselected full level as sensed by arm, 20 the discontinuation of the ice body forming process is caused by preventing energization of a solenoid valve 75 to starve the ice maker of water.
In the present structure, as shown in FIG. 6, the control circuit is fed from suitable supply leads L1 and L2. The circuit includes a defrost control switch 22 having a pair of defrost switches, defrost switch 22 and defrost time control switch 22a. Switch 22 comprises a single pole double throw switch having a moving contact 60a connected to power supply lead L1, a fixed contact 60b connected to cabinet thermostat switch 79 and a fixed contact 60c connected to bin level switch 63 and timer motor 14. Defrost time control switch 22a comprises a single pole double throw switch having its moving contact 61a connected through a normally closed defrost bimetal switch 62 to power supply lead L1. A first fixed contact 61b is connected to fixed contact 60c of switch 22, and a second fixed contact 61c connected to the defrost heater 77. The other side of each of compressor motor 78, water valve solenoid 75, timer motor 14, and defrost heater 77 are connected to power supply lead L2. Defrost control switch 22 may be operated by a gear mechanism, not shown, like that disclosed in FIG. 4 of U.S. Pat. No. 3,714,794 issued to W. J. Linstromberg et al and assigned to the assignee of this application.
When the timer motor 14 times a preselected period of time a defrost operation is initiated by throwing of switch arms 60a and 61a of defrost control switches 22 and 22a from the position of FIG. 5 into contact with fixed contacts 60c and 61c respectively. Thus, operation of the compressor is prevented at this time and energization of the defrost heater 77 is effected through switch 22a and normally closed switch 62. In the event that the temperature sensed by switch 62 does not reach a preselected high temperature during a defrost period, motor 14 causes switch arms 60a and 61a to be thrown back to the position of FIG. 6 terminating the defrost heating cycle and re-establishing the circuit for further ice body formation and harvesting cycles. While the switch arm 60a is thrown to fixed contact 60c the timer motor remains energized therethrough and water fill solenoid valve 75 may be energized by the closing of switch 63. Thus, timer motor 14 may be utilized as a continuous timer motor to control switches 22 and 22a to effect the automatic defrosting cycle even though the circuit through switch 63 may be open to prevent the operation of water filled solenoid 75 and further forming of ice bodies.
Referring now to FIGS. 4, 7 and 8 the operation and construction of the sensing arm 20 and the bin level switch 63 is explained. Switch 63 comprises two spring arms 63a and 63b having respectively switch contacts 64a and 64b. Spring arms 63a and 63b are carried on insulating support 67 mounted on wall 28 by suitable fasteners 68. Contact 64a is electrically connected through spring arm 63a and lead 66a to contact 60c of switch 22. Contact 64b is electrically connected through spring arm 63b and lead 66b to solenoid valve 75. The sensing arm 20 includes an upper portion 45 and is pivotally mounted on front wall 28 by a pin 44. Portion 45 of sensing arm 20 has a projection 46 which bears against spring arm 63a so as to bias portion 45 against the cam surface 47 carried by shaft 29. Cam surface 47 includes a recessed portion 48 which permits spring arm 63a to bias the lower end 20a of the sensing arm 20 downwardly into the bin while the remaining portion of cam surface 47 being circular is arranged to urge the sensing arm end 20a in a counterclockwise direction sufficiently to raise the sensing arm above the preselected full level during the remainder of the rotation of the shaft 29. Cam surface 47 further includes an electrically conducting section 65 such that once during each cycle of rotation of shaft 29 sensing arm 20 senses the level of ice bodies in the bin and in the event that the level is below the preselected level, sensing arm end 45 under the bias of spring arm 63a will follow cam surface 48 and thereby allow contact 64a to contact conductive portion 65 together with contact 64b to operate water solenoid valve 75 through the electrically conductive portion 65. However, in the event that the level of ice bodies collected in bin 18 is at least at the preselected full level, spring arm 63a is prevented by the action of sensing arm end 20a against the ice bodies from biasing the sensing arm portion 45 sufficiently in a clockwise direction to allow switch contact 64a to contact portion 65 and thereby to electrically conduct through portion 65 with contact 64b as shown in dotted lines in FIG. 8. Although the mold 11 and control mechanism 15 continue operation as though ice bodies are being formed in the mold, water solenoid valve 75 is not operated and no ice bodies are formed until such time as the bin level is again below the preselected full level. Thus, ice body formation is prevented by the absence of water addition to the mold and the ice maker "dry" cycles during this full bin condition.
The electrically conductive portion 65 of cam surface 47 combined with switch contacts 64a and 64b provides an accurate water filled timing which requires no adjustment as has been heretofore found in prior art devices. As shown in FIG. 7, the conductive portion 65 is T-shaped and positioned on cam surface 47 parallel to the axis of rotation of shaft 29. Portion 65a is wider than portion 65b such that contact 64a always contacts the conductive surface before and after switch contact 64b. Thus, the width of the conductive material 65b and the speed at which the surface 47 and accordingly shaft 29 is turned establish the time that the water solenoid valve 65 is energized. Accurate timing is therefore provided by the width of the conductive material at 65b which can be held to close tolerance in production.
Thus, the continuous operation of the timing motor 14 is effected to allow the refrigeration apparatus to operate through its normal defrost cycle and to drive the ice body making mechanism through its normal cycle. The bin level sensing arm is biased by the switch contact spring arm to control the admission of water to the mold as a function of the level of the ice bodies in the bin. Thus, a simply constructed, accurate, water-filled timing mechanism and ice body level bin sensing is provided.
The foregoing disclosure of the specific embodiment is illustrative of the broad inventive concepts comprehended by the invention.
Having described the invention, the embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. Refrigeration apparatus comprising:cooling means; ice making means for automatically making ice bodies including a mold, water delivery means for delivering water to the mold for cooling thereof by said cooling means to form ice bodies in said mold, drive motor means; harvesting means driven by said motor for cyclically harvesting the ice bodies from said mold including a collecting bin for removably storing the harvested ice bodies; and shut off means preventing operation of said water delivery means whenever the level of ice bodies in said collecting bin is at a preselected full level thereof to permit continued operation of the ice making means by said drive motor while preventing forming of ice bodies thereby, said shut off means including, a switch means having a plurality of switch contacts for electrically completing a circuit for said water delivery means, said switch means having a spring means for biasing said contacts for making said electrical connection, and a bin level sensing arm, said arm having a first end in association with said bin for detecting said preselected full level and a second end biased by said spring means and operable in response to detection of said preselected full condition by said first end to prevent said contacts from completing said circuit.
2. The refrigeration apparatus of claim 1 wherein said harvesting means includes a rotatable cam having a contoured cam surface, and an electrically conducting portion, and said spring means comprises two electrically conducting leaf springs, each of said springs carrying one of said plurality of contacts, said springs biasing said contacts against said cam surface for periodic contact with said electrically conducting portion upon rotation of said cam.
3. The refrigeration apparatus of claim 2 wherein said second end of said sensing arm includes a projection contacting at least one of said leaf springs, said projection operable in response to said first end of said arm detecting said full level to prevent one of said contacts from contacting said cam surface.
4. The refrigeration apparatus of claim 2 wherein said second end of said sensing arm has a projection contacting one of said leaf springs, said second end is biased by said leaf spring against said contoured cam surface on said rotatable cam, said cam surface having a recessed portion adjacent said electrically conducting portion of said cam surface, said recessed cam portion positioning said projection to allow said contact on leaf spring to complete said circuit.
5. The refrigeration apparatus of claim 2 wherein said electrically conducting portion comprises a T-shaped conductive band transverse to the direction of rotation of said cam surface, and wherein one of said leaf spring contacts is positioned to pass over the stem portion of said T-shaped band and the other of said leaf spring contacts is positioned to pass over the top portion of said T-shaped band.
6. Refrigeration apparatus comprising:cooling means; ice making means for automatically making ice bodies including a mold, water delivery means for delivering water to the mold for cooling thereof by said cooling means to form ice bodies in said mold, drive motor means; harvesting means including a rotatable cam surface driven by said motor for cyclically harvesting the ice bodies from said mold including a collecting bin for removably storing the harvested ice bodies; switch means having a plurality of contacts for electrically completing a circuit for said water delivery means, said switch means including a spring means for biasing said contacts against said cam surface, said cam surface having an electrically conductive portion for periodically connecting said contacts, and a bin level sensing arm biased by said spring means and operable in response to the level of ice bodies in said collecting bin reaching a predetermined full level to prevent at least one of said contacts from contacting said cam surface.
7. The refrigeration apparatus of claim 6 wherein said spring means comprises two electrically conducting leaf springs, each of said springs carrying one of said plurality of contacts and said sensing arm includes a first end in association with said bin and a second end, said second end having a projection contacting at least one of said leaf springs, said leaf spring biasing said projection and thereby said second end to cause said first end to detect said full level of ice bodies in said bin upon rotation of said cam.
8. The refrigeration apparatus of claim 7 wherein said one of said leaf springs biases said second end against said contoured cam surface, said cam surface includes a recessed portion and a conductive portion, said recessed portion being adjacent said conductive portion of said cam surface, and said recessed portion positions said projection to allow said contact on said leaf spring to complete said circuit upon rotation of said cam.
9. The refrigeration apparatus of claim 6 wherein said spring means comprises two leaf springs each carrying one of said contacts and said electrically conducting portion comprises a T-shaped band transverse to the direction of rotation of said cam surface, one of said leaf spring contacts positioned to pass over the top portion of said T-shape and the other of said leaf spring contacts positioned to pass over the stem portion of said T-shape.
| 1974-11-21 | en | 1976-06-22 |
US-4379679-A | Surgical foreceps
ABSTRACT
Surgical forceps comprising cross members having a pair of gripping arms pivotally connected to a pair of clamping arms comprising a pair of end members directed away from the axis of the gripping arms and terminating with a pair of slightly curved mating jaws having aligned notches disposed on their outer surfaces to accommodate a needle for sutures. The pair of mated jaws are disposed in a plane substantially perpendicular to the plane containing the pair of end members.
This application is a continuation-in-part application of Ser. No. 831,221 filed Sept. 7, 1877, now abandoned which in turn is a continuation-in-part of Ser. No. 706,847 filed July 19, 1976, now abandoned.
FIELD OF THE INVENTION
This invention relates to a surgical forceps and specifically to a manual vaginotomy clamp for use in surgical operations and specifically abdominal hysterectomy to more effectively separate and extirpate the uterus from the vagina.
BACKGROUND OF THE INVENTION
In the surgical procedure known as abdominal hysterectomy, the uterus is extirpated from the vagina at the junction of the two elements. This entails the partial clamping of the junction of the uterus and the vagina and then the excising of the uterus in a simple cutting operation or performing a plurality of cutting steps until the uterus is completely severed. Usually these operations involve inexact severing of the uterus which leaves a ragged edge, i.e., redundant tissue on the vaginal cuff. Despite the use of conventional clamps affixed on the edges of the vagina, the vaginal cuff is quite vascular and generally results in moderately profuse bleeding from the ragged edges, especially at the lateral angles of the vagina. The combination of the ragged edges of the vaginal cuff and tendency towards bleeding can result in the direct contamination of the vaginal cuff with vaginal bacterial flora, thus possibly resulting in the following major post-operative problems:
1. The infection and abscess of the vaginal cuff, and
2. Hemorrhage from the vaginal cuff usually within eight to fourteen days after the surgical operation.
Another drawback with using conventional type clamping means is that the inexact severing of the uterus could result in the removal of too little or too much of the vaginal edges anteriorly or posteriorly. This possibly could occur due to slipping of portions of the vaginal cuff (tissue) from the conventional type surgical forceps being employed.
U.S. Pat. No. 2,887,111 discloses a surgical forceps having uneven jaws so that one of the jaws extends with a projection which possesses an eye as in a sewing needle through which an appropriate thread may be passed for the tieing or binding of veins or the like.
U.S. Pat. No. 2,842,132 discloses a surgical clamp having relatively thin jaw sections with teeth therein for gripping a relatively small blood vessel longitudinally thereof. The jaw sections of the surgical clamp have interlocking fixation means to prevent scissoring or shifting of the jaw sections relative to each other while applying clamping pressure to the jaw sections for bringing the walls of a portion of a blood vessel into contact with each other.
U.S. Pat. No. 1,852,542 discloses a scissor-type surgical clamp having a mortise joint between the crossing portions of the clamp and having means for adjusting the clamp to tighten or loosen the connection between the crossed portions so that true alignment between the jaws or working points of the instrument may be effectively maintained.
French Pat No. 378,427 discloses a scissor-type surgical clamp having affixed to pivoted means a pair of extended curved members disposed in a plane containing a pair of gripping members extending in the opposite direction from the securing means. The curved members have spaced-apart edge slots which can be used to accommodate a needle for sutures.
In an article titled "New Forceps For Retropubic Prostatectomy" appearing in the Journal of Urology, 107:626, April 1972, a forceps is disclosed in which one of its extended jaws has four keyholes to receive sutures.
It is an object of the present invention to provide forceps for use in surgical operations which has hemostastosis means and appropriately spaced-apart grooves or notches for accommodating a needle for sutures.
Another object of the present invention is to provide surgical forceps having extended jaws which substantially conform to the anatomical curve of the cervix.
Another object of the present invention is to provide surgical forceps having a pair of extended jaws adapted to provide a crushing action so as to instantly provide hemostasis through the entire width of the body organ contained within the jaws.
Another object of the present invention is to provide surgical forceps that can be used in place of a plurality of conventional clamps presently being employed in certain surgical operations, such as abdominal hysterectomy.
Another object of the present invention is to provide surgical forceps that will expedite and shorten the surgical time required for abdominal hysterectomy.
Another object of the present invention is to provide surgical forceps which comprise few and simple parts and which will be easy to manipulate for use in surgical operations.
Another object of the present invention is that in cancer surgery two of the forceps can be employed with the first being used to effectively seal off the uterus cavity from possibly bleeding of the cancer cells into the vagina and abdominal cavity and the second being used to lift and remove the extirpated cancer-containing uterus out of the abdominal cavity.
The foregoing and additional objects will become more fully apparent from the following description and the accompanying drawings.
SUMMARY OF THE INVENTION
The invention relates to a surgical forceps comprising a pair of cross members having securing means for pivotally securing the members to one another, said cross members having a first set of arms extending in a first direction from the securing means and a second set of arms secured to said first set of arms and extending in an opposite direction from said securing means, said first set of arms adapted with gripping means for pivoting said first set of arms and said second set of arms about the securing means; the second set of arms having a pair of end members substantially disposed in a plane containing the first set of arms and directed away from the longitudinal axis of the first set of arms, and the extremity of the end members terminating with a set of mating jaws disposed in a plane substantially perpendicular to the plane containing the securing means, said set of jaws comprising a first jaw having spaced-apart notches disposed in its outer lengthwise edge and a second jaw having a like number of notches disposed in its outer lengthwise edge such that when the jaws are in a closed mated position, the notches are in alignment.
The pair of end members of the second set of arms could have an arcuate configuration; be composed of straight segments sequentially inclined so as to provide a somewhat overall curved configuration; be composed of a first straight segment terminating in a curved or arcuate segment; be composed of a straight segment in alignment with the longitudinal axis of the first set of arms and a second straight segment disposed at an angle other than 0° with the longitudinal axis of the first set of arms. The longitudinal axis of the end segment of the end members should form an angle of between about 90° and 150°, preferably between about 110° and 130°, and most preferably about 120° with the longitudinal axis of the first set of arms. This will insure that the first set of arms containing the gripping means will not unnecessarily obstruct the line of view of the physician to the body organ clamped between the jaws and also permit the physician to effectively maneuver the forceps during the operation so as to facilitate the clamping and extirpation of the vaginal cuff.
Preferably, the inner surface of the first jaw should have a lengthwise groove, the inner surface of the second jaw should have a lengthwise projection and said projection should be shaped to mate with and seat within the groove in the inner surface of the first jaw in a tongue and groove manner. The projection and groove can have any polygonal configuration as long as the projection mates with and seats within the groove. This tongue and groove arrangement will provide a lengthwise crushing action on the body organ contained within the jaws and thereby effect hemostasis through the entire length of the organ within said jaws and also prevent slipping of the organ from the forceps.
In addition, the mating surfaces of the jaws of the surgical forceps could be serrated, i.e., a formation resembling the toothed edge of a saw and disposed such that when the forceps are in the closed position, the toothed edge surface of one jaw will mate within the toothed edge surface of the other jaw. The serration can be extended substantially across the width of the jaws or extended lengthwise of the jaws. Thus when the forceps are pivoted toward the closed position, the serrated surfaces will help to provide an additional crushing action on the body organ contained therebetween which will further effect hemostasis through the entire width of the organ within the jaws and also prevent slipping of the organ from the forceps.
The extended jaws may be appropriately curved to conform to the anatomical curve of the cervix so that when the forceps are used, an almost instant hemostasis can be provided through the entire width and length of the vaginal cuff with a simple crushing action imparted through a closing of the forceps while simultaneously preventing slipping of the vaginal cuff from the forceps.
The outer lengthwise edge of each of the jaws has notches, e.g., expanded U-shaped, that are sufficiently spaced apart so that sutures can be placed in a body organ held between the jaws. When the surgical forceps are for use in abdominal hysterectomy operations, the center point of the notches which are disposed on the outer curved edge of the jaws, i.e., the edge facing away from the gripping means, can be spaced apart between about 3/8 and about 3/4 inch, preferably about 9/16 inch. For abdominal hysterectomy applications, three spaced-apart notches will generally be sufficient for effective suturing of the vagina. The areas of the outer side surface of the jaws disposed adjacent to and substantially perpendicular to each of the notches could be burnished or dull finished, or slightly indented, so as to highlight the location of the notches and thereby aid the surgeon in finding the suture notches during an operation.
The present invention will become apparent from the following description thereof when considered together with the accompanying drawings which are set forth as being exemplary of embodiments of the present invention and are not intended, in any way, to be limitative thereof and wherein:
FIG. 1 is a front view of the surgical forceps of this invention.
FIG. 2 is a side view of the surgical forceps as shown in FIG. 1.
FIG. 3 is an enlarged front view of the mating jaws of the surgical forceps as shown in FIG. 2 from line 3--3.
FIG. 3a is another embodiment of an enlarged front view of the mating jaws for use in the surgical forceps of this invention.
FIG. 4 is an inner side view of one of the jaws of the surgical forceps as shown in FIG. 1 through line 4--4.
FIG. 5 is an inner side view of the other jaws of the surgical forceps as shown in FIG. 1 through line 5--5.
Referring in detail to FIGS. 1 and 2, there is shown surgical forceps 1 comprising a pair of cross members 2, 4 pivoted to one another by pivotal connection 7 such as with a box or mortise type joint. Each of the cross members 2, 4 comprise arms 6 and 8, respectively, extending from the pivotal connection means 7 in one direction and arms 10 and 12, respectively, extending from the pivotal connection means 7 in an opposite direction. Arms 6 and 8 terminate with looped handle portions 14 and 16, respectively, for receiving a user's fingers for pivoting arms 6 and 8 about pivotal connection 7. As shown in FIGS. 1 and 2, the pivotal connection 7 is located at the rearward portion of arms 6 and 8 so as to substantially be in the plane therewith. As stated above, arms 6 and 8 have looped handle portions 14 and 16, respectively, so that the user can operate the forceps in a conventional manner, and as in all instruments of this type, the arms possess catches 18 and 20, respectively, forming a broach for maintaining the corceps in a closed position after crushing a part of an organ between jaws 22 and 24 as discussed hereinafter.
A first pair of straight segments 26, 28 of arms 10 and 12 extend from pivotal connection 7 and then culminate in a second pair of segments 30, 32. The angle formed between the longitudinal axis 33 of the first set of arms and the longitudinal axis 35 of the segments 30, 32 forms an angle α which is shown to be about 120°. As stated above, angle α could vary, for example, from between about 90° to 150°, preferably between about 110° and 130° and most preferably about 120°. The extremity of segments 30, 32 terminate with slightly curved or arcuate mating jaws 24 and 22, respectively, which lie in a plane 37 substantially perpendicular to the plane 41 containing pivotal connection 7 as shown by FIGS. 1 and 2. Plane 37 is defined as the plane containing the longitudinal axis that bisects the side area 52 disposed adjacent to and substantially perpendicular to the center outer edge notch 48 as shown in FIG. 2. If an even number of notches are employed, then the plane 37 would be defined as a plane containing a line that contains the center point of the two side areas disposed adjacent to and substantially perpendicular to the two center outer edge notches. The jaws 22 and 24 are shown curved to the anatomical curve of the cervix.
As shown in FIGS. 3 and 5, jaw 24 has a lengthwise or longitudinal groove 34 and as shown in FIGS. 3 and 4, jaw 22 has a lengthwise or longitudinal projection 36. As shown in FIG. 3, the longitudinal projection 36 of jaw 22 is designed to mate within the longitudinal groove 34 of jaw 24. The top surface of projection 36 has serrations 43. As stated above, this arrangement will provide a crushing action on the body organ contained within the jaws 22, 24 and thereby effect hemostasis through the entire length of the organ within said jaws while also preventing slipping of the organ.
As shown in FIGS. 4 and 5, the mating jaws 22, 24 have widthwise serrations 38 and 40, respectively. Thus when the arms 6 and 8 are pivoted to the closed position, the jaws 22 and 24 are brought into a mating position which will be sufficient to widthwise crush and thereby provide an almost instant hemostasis through the width of the body organ clamped therebetween while simultaneously preventing slipping of the organ through the forceps.
FIG. 3a shows an enlarged front view of another embodiment of mating jaws 21 and 23 for use in this invention. Specifically, the only difference between the jaws 21 and 23 of this view and the jaws 22 and 24 of FIG. 3 is that the projection 46 on jaw 23 has a truncated pyramidal shape while projection 36 on jaw 22 has a rectangular shape. Thus in accordance with this invention, the projection could have any polygonal configuration. The only requirement is that the groove in the mating jaw be shaped in a similar manner so that the projection can seat and mate within the groove.
As shown in FIGS. 1 and 2, the outer edges 42 and 44 of jaws 22 and 24, respectively, have three spaced-apart notches 47, 48 and 49. In the closed position, notches 47, 48 and 49 in jaw 22 will be in alignment with notches 47, 48 and 49 in jaw 24 so as to provide slots to accommodate a needle for suturing a body organ confined and secured between the jaws. As shown in FIGS. 1 and 2, the user, such as a surgeon, can grasp the forceps by the looped members and by conventional pivoting can open and close the jaws of the forceps. By having the jaws of the forceps oriented approximately 90° to the gripping arm members and having the second pair of segments 30 and 32 disposed at an angle between about 90° to 150°, most preferably 120°, from the first pair of segments 26 and 28, the user can squeeze a body organ between the jaws thereby exposing the squeezed area without having the gripping arm obscuring or blocking the view and access to said squeezed area. To aid the surgeon locating the suture notches 47, 48 and 49, the areas designated 50, 52 and 54, respectively, adjacent the notches are shown slightly indented. The length of each of the areas 50, 52 and 54 is approximately equal to the length of the respective notches 47, 48 and 49 as shown in FIG. 2.
When using the surgical forceps of this invention in an abdominal hysterectomy operation, the forceps clamp the uterus at its cervical end and squeeze it down so as to force the lower aspect of the uterus (hereinafter referred to as cervix) cephalad or upwards. Three sutures are then placed through the notches in the jaws of the forceps to secure the vaginal cuff. The cervis uteri can then be excised in one step without leaving redundant or uneven vaginal edges at the vaginal junction. The surgical forceps of this invention serve to provide excellent hemostasis by its crushing action of the vaginal cuff secured between the jaws of the forceps and also provide a seal against vaginal contamination as it effectively closes off the entire vagina. The use of the surgical forceps as a single clamp during the operation will not obscure the area of the uterus being excised. The surgical forceps of this invention can effectively shorten the time of excising the cervis uteri from the vagina from 15 to 30 minutes. This reduction in operating time can materially benefit the patient by shortening anesthetic time which can be most important in the marginally healthy patient who requires abdominal hysterectomy.
It is to be understood that other modifications and changes to to the preferred embodiment of the invention herein shown and described can also be made without departing from the spirit and scope of the invention.
What is claimed is:
1. A surgical forceps comprising a pair of cross members having securing means for pivotally securing the members to one another, said cross members having a first set of arms extending in a first direction from the securing means and a second set of arms secured to said first set of arms and extending in an opposite direction from said securing means, said first set of arms adapted with gripping means for pivoting said first set of arms and said second set of arms about the securing means; the second set of arms comprising a pair of end members substantially disposed in a plane containing the first set of arms and directed away from the longitudinal axis of the first set of arms, and the extremity of the end members terminating with a set of mating jaws disposed in a plane substantially perpendicular to the plane containing the securing means, said set of jaws comprising a first jaw having spaced-apart notches disposed in its outer lengthwise edge and a second jaw having a like number of notches disposed in its outer lengthwise edge such that when the jaws are in a closed mated position, the notches are in abutting alignment.
2. The surgical forceps of claim 1 wherein one of the jaws has a longitudinal groove in its inner surface and the other jaw has a longitudinal projection on its inner surface, said groove and said projection being designed such that when the jaws are in the mated closed position, the projection will mate with and seat within the groove.
3. The surgical forceps of claim 2 wherein the projection and groove has a polygonal configuration.
4. The surgical forceps of claim 2 wherein the projection and groove have a substantially rectangular shaped configuration.
5. The surgical forceps of claim 4 wherein the inner surface of the projection is serrated.
6. The surgical forceps of claim 1 wherein the longitudinal axis of the first set of arms forms an angle of between about 90° and 150° with the longitudinal axis of the end members.
7. The surgical forceps of claim 6 wherein the angle is between about 110° and 130°.
8. The surgical forceps of claim 7 wherein the angle is about 120°.
9. The surgical forceps of claim 1 wherein the second set of arms comprises a first pair of segments substantially in axial alignment with the first set of arms and extending with a second pair of segments directed away from the longitudinal axis of the first set of arms.
10. The surgical forceps of claim 9 wherein the longitudinal axis of the first set of arms forms an angle of between about 90° and about 150° with the longitudinal axis of the second pair of segments.
11. The surgical forceps of claim 10 wherein the angle is between about 110° and 130°.
12. The surgical forceps of claim 11 wherein the angle is about 120°.
13. The surgical forceps of claim 1 wherein the jaws are arcuately shaped.
14. The surgical forceps of claim 1 wherein the inner surface of each jaw is serrated.
15. The surfical forceps of claim 14 wherein the serrations are oriented widthwise on the inner surface of each jaw.
16. The surgical forceps of claim 1 wherein the outer edge of the extending jaws has three spaced-apart notches.
17. The surgical forceps of claim 16 wherein the center point of each notch is spaced apart from the center point of an adjacent notch by between about 3/8 and about 3/4 inch.
| 1979-05-30 | en | 1980-10-07 |
US-62509275-A | Solar energized steam generator system
ABSTRACT
A solar energized steam generator includes a flux collector or projection lens for collecting and concentrating solar energy, and a reflector funnel for enhancing and concentrating the solar energy still further. The lower end of the funnel is connected by means of a conduit to an insulated vault, made of, for example, rock, gravel, stone, sand, or the like, whereby the heated air is conducted directly to the vault so as to heat the same to extremely high temperatures. An air duct, operatively connected to the vault, is disposed in heat exchange relationship with a steam generator and is also fluidically connected to the reflector funnel through a fluid duct or conduit, a fan or blower being disposed within the duct or conduit for recirculating the air throughout the system. The blower may be a two-speed blower so as to operate at high speed during time periods wherein solar energy is being received by the lens and funnel amplifier, and at low speed during those time periods when such energy is not being received, and in order to maximize the interception and collection of the radiated solar energy, the lens is mounted upon an altazimuth system which continuously varies the disposition of the lens relative to the sun in order to continuously properly align the lens therewith throughout the solar day, as well as adjusts the position of the lens so as to compensate for the alteration of the relative disposition between the sun and earth throughout the solar year.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to steam generators, and more particularly to a stream generator which is powered or energized by means of solar energy or radiation.
2. Description of the Prior Art
The utilization of solar energy for domestic and industrial applications has heretofore been proffered, by interested scientists and engineers, as a practicable solution to current energy problems, and with ever-increasing demands being placed upon the conventional, non-replaceable fossil fuels, such as for example, coal, natural and synthetic gases, petroleum products, and the like, and in light of the realistically predicted and potential shortages thereof, the importance and necessity of practical apparatus, capable of effectively utilizing solar energy, the supply of which is virtually inexhaustible, takes on new dimensions.
The utilization of solar energy, however, presents problems which are especially peculiar, as a result of the intermittent, unreliable, and variable nature of the solar cycle, and consequently, solar energized or powered systems must effectively accommodate, and compensate for, such eccentricities. In addition, in order to render such solar energized systems publicly acceptable whereby such systems will in fact be widely employed as an effective means of reducing the demand and use of conventional fuels and sources of power, it is necessary that such systems be simple, efficient, inexpensive to construct, maintain, and operate, and exhibit long service lives.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a new and improved solar energized power system.
Another object of the present invention is to provide a new and improved steam generator system.
Still another object of the present invention is to provide a new and improved solar energized steam generator system which is extremely simple and inexpensive to construct, maintain, and operate.
Yet another object of the present invention is to provide a new and improved solar energized steam generator system, which, due to its simple construction, exhibits a long and reliable service life.
Still yet another object of the present invention is to provide a new and improved solar energized steam generator system which can readily compensate for the intermittent, unreliable, and variable nature of the solar cycle.
A further object of the present invention is to provide a new and improved solar energized steam generator system which, as a result of means embodied within the system for readily compensating for the intermittent, unreliable, and variable nature of the solar cycle, exhibits a high degree of efficiency.
The foregoing and other objectives are achieved in accordance with the present invention through the provision of a solar energized steam generator system which includes a flux collector or projection lens for collecting and concentrating the solar energy, and a reflector funnel for enhancing and concentrating the solar energy still further. The lower end of the funnel is connected by means of a conduit to an insulated vault, which may be made of, for example, rock, gravel, sand, stone, or the like, whereby the heated air is conducted directly to the vault so as to heat the same to extremely high temperatures. An air duct, operatively connected to the vault, is disposed in heat exchange relationship with a steam generator and is also fluidically connected to the reflector funnel through means of another fluid duct or conduit, a fan or blower being disposed within such duct or conduit for recirculating the air throughout the system. The blower may be a two-speed blower so as to operate at high speed during the time periods solar energy is being received by the lens and funnel amplifier, and at low speed during those time periods when such energy is not being received, and in order to maximize the interception and collection of the radiated solar energy, the lens is mounted upon an altazimuth system which continuously varies the disposition of the lens relative to the sun in order to continuously properly align the lens therewith, as well as adjusts the position of the lens so as to compensate for the alteration of the relative disposition between the sun and earth throughout the solar year.
BRIEF DESCRIPTION OF THE DRAWINGS
Varies other objects, features, and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the several views, and wherein:
FIG. 1 is a schematic view of a solar energized steam generator system constructed in accordance with the present invention and showing its cooperative parts;
FIG. 2 is a view similar to that of FIG. 1, showing however another embodiment of a solar energized steam generator system; and
FIG. 3 is a partial perspective view, partly broken away, of the funnel portion of the apparatus showing its detailed construction.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
Referring now to the drawings, and more particularly in FIG. 1 thereof, a first embodiment of a solar energized steam generator system, constructed in accordance with the present invention and generally indicated by the reference character 10, is adapted to be disposed within a domestic residence or other edifice 12 and is seen to include a flux collector or projection lens 14 disposed above a funnel-shaped upper portion 16 of a vertically oriented, tubular conduit 18, the top of funnel portion 16 being closed by means of a glass dome 21, which may be made, for example, of Pyrex. The lower end of the tubular conduit 18 is fluidically connected interiorly of the lower portion of a vault 22, through means of a port or opening 23, which is disposed within a lower portion of the edifice 12, lens 14 and the upper portion of conduit 18 being of course disposed exteriorly of edifice 12 so as to in fact be subjected to the solar radiation.
The vault 22 is disposed within suitable insulation, not shown, whereby the vault material, which may be, for example, suitable rock, gravel, sand, stone, firebrick, or the like, will serve to increase and retain the heat capacity of the vault. The lens 14 is of course provided for concentrating the rays of the sun into funnel 16, and as will be explained hereinafter in greater detail, the rays, further concentrated by funnel 16, cause the air within the system to be heated to high temperatures whereupon the same being conducted to the vault 22, the vault material will in turn be heated to extremely high temperatures, the vault material, of the type noted heretofore, being particularly heat absorptive and durable.
An air duct or conduit 24, having a port or opening 25 at one end thereof for fluidically connecting the duct 24 with the interior portion of vault 22 in a manner similar to the connection between amplifier portion 18 and vault 22, is disposed about vault 22 and is further provided with another port or opening 26, at the other end thereof, which has operatively associated therewith one end of another substantially vertically oriented fluid conduit 28, the other end of conduit 28 being integrally joined, in an air-tight manner, to funnel portion 16 of the conduit 18.
An enclosed fan or blower 30 is disposed within conduit 28 at a position adjacent funnel portion 16 and in this manner, air is continuously circulated within the closed system comprising conduit 18, vault 22, air duct 24, and conduit 28.
As noted more particularly within FIG. 3, the upper portion of conduit 28 is directly connected to an annular ring or tube 17 integrally formed within the upper portion of funnel 16 and the ring or tube 17 is in turn provided with a plurality of downwardly directed air jets 19 disposed equidistantly around the circumference thereof. In addition, a screen 27 is secured within the bottom of funnel 16 and suitable porous material 29, such as, for example, sand, gravel, coarse asbestos fibers, or the like, is supported upon the screen so as to reflect the solar beams, the screen also being made of high heat-resistant material. In this manner, the downwardly directed jets of air are directed upon the screen 27 and reflective material 29 and are immediately effectively pre-heated thereby, the air still being able to enter conduit 18 as the screen 27 and its supported material 29 is of course porous.
Disposed above air duct 24, and in heat exchange relation therewith, is a steam boiler or generator 32 which is of course provided with a water infeed or supply conduit 34 and a steam exhaust conduit 36, a pressure gauge 38 also being operatively associated with generator 32, and it is noted that the length of generator 32 substantially corresponds to that of duct 24 in order to maximize the heat exchange time period.
In operation, air is continuously circulated within the closed system by means of fan or blower 30, and as the air enters funnel portion 16 and tubular conduit 18 the air exits from the jets 19 and is heated to extremely high temperature as a result of the interaction with screen 27 and material 29 as well as the concentration of solar energy by means of lens 14. As a result of such heating of the air, and the conveyance of such heated air to the vault material, the temperature of the vault is raised to extremely high levels.
As the air passes through the vault 22, its temperature is increased still further, as a result of the continuous heating of the vault material directly by means of the heated air from conduit 18, as well as by the heat accumulated and stored within vault 22 as determined by the heat capacity thereof which is dependent upon the type of material employed with the vault as well as the construction of the same, and as such air is conducted through air duct 24, the same experiences a heat exchange process with steam generator 32 whereby the water, entering generator 32 through means of the conduit 34 and circulating therethrough, is converted to steam which is exhausted through conduit 36. The air entering conduit 28 from duct 24, through means of port 26, having been cooled somewhat as a result of the aforenoted heat exchange process having occured within generator 32, is recirculated, by means of fan 30, so as to again enter funnel portion 16 and tubular conduit 18 whereby reheating of the air is performed by means of the lens 14 and reflector funnel 16.
It is to be noted that as the port 23, fluidically interconnecting the tubular conduit 18 with the interior portion of vault 22, is provided within the lower portion of vault 22, at one end thereof, while port 25, fluidically interconnecting the air duct 24 with the interior portion of vault 22, is provided within the upper portion of vault 22 at the opposite end thereof relative to the end within which the port 23 is provided, substantially the entire volume of the vault 22 is effectively uniformly heated by means of the heated air flow induced therethrough by means of fan or blower 30 as well as by the natural tendency of the heated air to rise within the vault 22 after its entry thereinto through means of the port 23.
In addition, the flow path and consequent heating of the heated air through vault 22 is maximized as a result of the dispositions of ports 23 and 25 therewithin, and in like manner, the relative disposition of ports 25 and 26 within air duct 24 serves to similarly maximize and uniformize the heat exhange process between duct 24 and steam generator 32, such structure of course serving to maximize the efficiency of the system. It is also to be noted that while only one lens and reflector unit has been disclosed in connection with the vault 22, it is apparent that a plurality of such units may be appropriately connected to a single vault in order to saturate the vault with sufficient heat as determined by its heat capacity.
In order to increase the efficiency of the system still further, the fan or blower 30 should be a variable speed blower, such as for example, a two-speed blower, and the same is disposed within an electrical circuit, along with the funnel portion 16, within which a heat sensitive or light-sensitive photoelectric switch 40, operatively connected to or mounted upon funnel portion 16, is also disposed. In this manner, switch 40 is able to detect those operative periods when a predetermined amount of solar radiation energy is in fact fully and directly impinging upon reflector 16 whereby the switch will actuate fan or blower 30 so as to operate the same at high speed and thereby maximize the steam generator output of the system, while if the switch 40 does not detect such a predetermined amount of intense solar radiation, such as for example, during cloudy or overcast weather conditions, or during nighttime hours, the switch will in turn actuate fan or blower 30 so as to operate at low speed whereby only a minimum amount of heat, supplied from vault 22 will be recirculated throughout the system, such quantity of heat nevertheless being sufficient to maintain boiling of the water within steam generator 32 and thereby obtain a minimum quantity of steam generated therefrom.
Still yet further, in order to compensate for the variable relative movement between the sun and the earth throughout the solar day, as well as the altered relative position between the sun and the earth throughout the solar year, the projection lens 14 is mounted upon or within an altazimuth motor system 42 which continuously rotates the lens 14 throughout the day in order to properly align the same with the sun and thereby maximize the solar energy intercepted and collected by means of the lens 14. In addition, the motor system 42 is further selectively adjustable so as to compensate for the change in the relative azimuth between the sun and earth as a result of the passage of time throughout the solar year.
Referring now to FIG. 2, a second embodiment of the present invention is disclosed wherein, in lieu of the generator system being disposed within an orifice 12, the entire system, except of course for lens 14, reflector 16, and the upper portion of conduit 18, is disposed underground, the depth of which vault 22 is deposited within the earth and beneath the earth's surface 44 being variably selected to be within the range of 8-50 feet. It will also be noted that air duct 24 completely encases the steam boiler or generator 32 and that the duct 24 and generator 32 are physically disposed and spaced above vault 22.
Thus, it may be seen that the present invention has important advantages over the known prior are solar systems in that the solar energy is collected and concentrated and heated air is conducted directly to the insulated vault so as to thereby heat the same to extremely high temperatures, the air being conducted through the reflector and tubular conduit by means of the blower or fan. In addition, the same heated air is conducted through the vault in such a manner as to uniformly heat the same as well as be heated still further thereby, and such air is then utilized to heat water within a steam generator, the air subsequently being recirculated back to the optical reflector so as to be preliminarily reheated thereby. In this manner, a single fluid is utilized within the system for providing heat to the vault material as well as for heating the water within the steam generator.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood therefore that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
What is claimed as new and desired to be secured by Letters Patent of the United States is:
1. A solar energized steam generator system, comprising:solar energy collecting and concentrating means for collecting and concentrating solar energy; optical reflector means operatively connected to said collecting and concentrating means for receiving said collected and concentrated solar energy and for concentrating said solar energy still further. insulated vault means operatively connected to said reflector means for directly receiving heated air from said reflector means so as to be directly heated thereby; air conduit means interposed between said vault and said reflector means for conducting air from said vault back to said reflector means; blower means disposed within said air conduit means for recirculating said air through said reflector, said vault, and said air conduit means, said air being heated within said reflector means and said vault; and steam generator means operatively connected to said air conduit means in a heat exchange relationship for receiving said heat from said heated air in order to generate steam from water supplied to said steam generator means through water infeed means.
2. A solar energized steam generator system as set forth in claim 1, wherein:said solar energy collecting and concentrating means is a projection lens.
3. A solar energized steam generator system as set forth in claim 2, further comprising:altazimuth motor means for selectively adjusting and continuously varying the disposition of said projection lens with respect to the sun as the position of the sun, relative to the earth, is varied throughout the solar day and solar year.
4. A solar energized steam generator system as set forth in claim 1, wherein:said reflector means is connected to the lower portion of said vault means and within one end thereof so as to permit said heat to rise within said vault and thereby distribute said heat throughout said vault.
5. A solar energized steam generator system as set forth in claim 4, wherein:said air conduit means is connected to the upper portion of said vault means and at the end thereof opposite said one end of said vault means within which said reflector means is connected, whereby the flow path of said heated air through said vault is maximized so as to uniformly distribute said heat within said vault and to maximize the heat imparted to said heated air as the same traverses said vault flow path.
6. A solar energized steam generator system as set forth in claim 1, wherein:said air conduit means comprises an air duct fluidically connected to said vault and an air conduit fluidically connected to said air duct at one end thereof and to said reflector means at the other end thereof; the length of said air duct substantially corresponding to that of said steam generator; and the fluidic connections of said air duct between said vault and said air conduit being disposed within opposite ends of said air duct, whereby the heat exchange process between said air duct and said steam generator is maximized and uniformed.
7. A solar energized steam generator system, as set forth in claim 6, wherein:said air duct completely encases said steam generator means.
8. A solar energized steam generator as set forth in claim 1, wherein:said vault is made of rock, stone, sand, gravel, firebrick, or the like.
9. A solar energized steam generator system, as set forth in claim 1, wherein:said blower means is a variable speed blower.
10. A solar energized steam generator system as set forth in claim 9, further comprising:a heat or light sensitive switch means operatively connected to said reflector means and said blower means for detecting the heat or light impringing upon said reflector means and for actuating said blower means to operate at a high rate of speed when a predetermined amount of solar energy is detected as impinging upon said reflector means and for actuating said blower means to operate at a low rate of speed when less than said predetermined amount of solar energy is detected.
11. A solar energized steam generator system as set forth in claim 1, wherein:said vault and said steam generator means are disposed underground.
12. A solar energized steam generator system, as set forth in claim 1, wherein:said vault and said generator means are disposed within an edifice.
13. A solar energized steam generator system, as set forth in claim 1, wherein said reflector means comprises:a funnel; a screen disposed within the bottom of said funnel and supporting solar ray reflective material; and air jet means for directing air, being recirculated by said blower means, onto said screen and reflective material.
14. A solar energized steam generator system as set forth in claim 13, wherein said air jet means comprises:a tubular ring integrally formed within the upper portion of said funnel; and a plurality of air jet openings disposed equidistantly about the circumference of said ring.
| 1975-10-23 | en | 1976-11-23 |
US-16259688-A | 4-chlorooxazole derivatives and processes for their preparation and use
ABSTRACT
The invention relates to 4-chlorooxazole derivatives of the general formula I ##STR1## which carry an unsaturated group in the 2- or 5-position, e.g., the --CH═CH-- or --CH═CH--CH═CH-- group.
In the formula
R 1 is phenyl, which is optionally substituted in one or more positions by (C 1 -C 4 )-alkoxy or di-(C 1 -C 4 )-alkylamino radicals and
R 2 is phenyl, phenyloxazolyl, pyridyl, julolidin-9-yl, N-(C 1 -C 4 -alkyl)-carbazol-3-yl, coumarin-6-yl, or stilben-4-yl, which are optionally substituted in one or more positions by (C 1 -C 4 )-alkyl, (C 1-C 4 )-alkoxy, halogen-(C 1 -C 4 )-alioxy, hydroxy, halogen, di-(C 1 -C 4 )-alkylamino, or dibenzylamino radicals.
The compounds are used as photoconductive substances.
BACKGROUND OF THE INVENTION
The present invention relates to new 4-chlorooxazole derivatives, processes for their preparation and their use.
European Pat. No. 0 010 652 discloses 4-chlorooxazole derivatives and the preparation and use thereof in photoconductive layers and as optical brighteners. The compounds are prepared by condensing an acyl cyanide with an aldehyde in the presence of hydrogen cloride. However, 4-chlorooxazole derivatives carrying unsaturated groups in the 2- or 5-position cannot be prepared according to this known method since, in the condensation reaction, there is also an addition of hydrogen chloride at the double bond.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide 4-chlorooxazole derivatives having unsaturated groups at the 2- or 5-position in substantially pure form.
It is a further object of the present invention to provide 4-chlorooxazole derivatives without addition at the unsaturated groups.
It is yet another object of the present invention to provide 4-chlorooxazole derivatives without hydrogen chloride addition at the unsaturated groups.
It is a further object of the present invention to provide processes for obtaining 4-chlorooxazole derivatives having unsaturated groups at the 2- or 5-position in substantially pure form.
In accordance with these and other objects, the present invention provides 4-chlorooxazole derivatives of the general formula I in substantially pure form wherein
A is a single bond or the --CH═CH-- group,
B is a single bond, the --CH═CH-- or --CH═CH--CH═CH-- group and is a single bond, in the case of A representing the --CH═CH-- group,
R1 is phenyl, which is optionally substituted in one or more positions by (C1 -C4)-alkoxy or di-(C1 -C4)-alkylamino radicals, and
R2 is phenyl, phenyloxazolyl, pyridyl, julolidin-9-yl, N-(C1 -C4 -alkyl)-carbazol-3-yl, coumarin-6-yl or stilben-4-yl, which are optionally substituted in one or more positions by (C1 -C4)-alkyl, (C1 -C4)-alkoxy, halogen-(C1 -C4)-alkoxy, hydroxy, halogen, di-(C1 -C4)-alkylamino or dibenzylamino radicals.
The preferred compounds of the general formula I are those, in which
A is a single bond,
B is the --CH═CH-- group,
R1 is phenyl, which is substituted by (C1 -C4)-alkoxy radicals, and
R2 is phenyl or N-(C1 -C4 -alkyl)-carbazol-3-yl, which are substituted by (C1 -C4)-alkoxy, halogen, hydroxy and/or di-(C1 -C4)-alkylamino radicals.
Particularly suitable compounds of the general formula I are those, in which
A is a single bond,
B is the --CH═CH-- group,
R1 is methoxyphenyl, and
R2 is p-ethoxyphenyl, p-dimethylaminophenyl, p-diethylaminophenyl, o-chloro-p-dimethylaminophenyl, o-hydroxy-p-diethylaminophenyl or N-ethylcarbazol-3-yl.
The invention also provides processes for the preparation of the 4-chlorooxazole derivatives of the present invention, corresponding to the general formula I. In the processes according to the present invention the unsaturated structural elements A or B, resp., carrying the respective substituents R1 and R2 and a corresponding 4-chlorooxazole compound are condensed in the presence of a base and the 4-chlorooxazole derivative is isolated from the reaction mixture and dried.
The process may comprise the steps of condensing a compound of general formula II ##STR2## wherein
A is a single bond, and
R1 is defined as above with a compound of general formula III ##STR3## wherein R2 is defined as above in an inert organic solvent in the presence of a base, at a temperature in the range from about 20° C. to 80° C., to form a compound of general formula I, in which A is a single bond and B is the --CH═CH-- group; and separating said compound of formula I from said reactants.
Alternatively the process may comprise the steps of condensing a compound of general formula IV ##STR4## wherein
B is a single bond, and
R2 is defined as above with a compound of the general formula V ##STR5## wherein
R1 is defined as above in an inert solvent in the presence of a base, at a temperature in the range from about 0° C. to 40° C., to form a compound, in which A is the --CH═CH-- group and B is a single bond; and separating said compound of general formula I from said reactants.
Another process which may be used comprises the steps of condensing a phosphonium salt corresponding to general formula VI ##STR6## wherein
A is a single bond, and
R1 is defined as above with an aldehyde corresponding to the general formula VII
X--R.sub.2 (VII),
wherein
R2 is defined as above, and
X stands for --CHO or --CH═CH--CHO,
in an inert organic solvent in the presence of a base, at about room temperature, to form a compound, in which A is a single bond and B is the --CH═CH-- or the --CH═CH--CH═CH-- group; and separating said compound of general formula I from said reactants.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In one process for the preparation of a compound corresponding to the general formula I, a compound of the formula II ##STR7## in which A and R1 have the indicated meanings, is condensed with a compound of the formula III ##STR8## in which R2 has the indicated meaning, in an inert organic solvent in the presence of a base, at a temperature in the range from about 20° C. to 80° C., to form a compound in which A is a single bond and B is the --CH═CH--group. The compound so produced is separated, dried and optionally purified by reprecipitation (Process A). It is preferred to perform the condensation reaction at a temperature in the range from about 40° C. to 60° C. and to use dimethyl formamide as the solvent and potassium hydroxide as the base.
In another process for the preparation of a compound corresponding to the general formula I, a compound of the formula IV ##STR9## in which B and R2 have the indicated meanings, is condensed with a compound of the formula V ##STR10## in which R1 has the indicated meaning, in an inert solvent in the presence of a base, at a temperature in the range from about 0° C. and 40° C., to form a compound, in which A is the --CH═CH-- group and B is a single bond. The compound so produced is separated and optionally purified by reprecipitation. It is preferred to perform the condensation reaction at a temperature in the range from about 20° C. to 30° C. (Process B).
A compound corresponding to the general formula I can also successfully be prepared with the aid of a process in which a phosphonium salt corresponding to the formula VI ##STR11## in which A and R1 have the indicated meanings, is condensed with an aldehyde corresponding to the formula VII
X--R.sub.2 (VII)
in which R2 has the indicated meaning and X stands for --CHO or --CH═CH--CHO, in an inert organic solvent in the presence of a base at room temperature to form a compound in which A is a single bond and B is the --CH═CH-- group or the --CH═CH--CH═CH-- group. The compound so produced is separated from the reaction mixture, dried and optionally purified by reprecipitation (Process C). The preferred solvent used comprises dimethyl sulfoxide and the preferred base comprises dimethylsulfinyl sodium.
The combination is effected by condensing 2-methyl-4-chlorooxazoles of the formula II (Process A) or 5-methyl-4-chlorooxazoles of the formula IV (Process B) with appropriate derivatives of aldehydes (III or V, respectively), according to a method for methyl heterocycles described by I. J. Fletcher, A. E. Sigrist in "Adv. Heterocyclic Chem.", A. R. Katritzky, A. J. Dowlton, eds., Academia Press, New York, 1978, Vol. 23, p.171.
It is also advantageous to condense aldehydes VII with triphenylphosphonium compounds of the 4-chlorooxazole VI, under conditions which are customarily used within the scope of Witting reactions ("Neuere Methoden der Organischen Chemie" ["Recent Methods of Organic Chemistry"], W. Foerst, ed., Verlag Chemie Weinheim, 1967, volume V, p.1) (Process C). ##STR12##
The 4-chlorooxazoles II and IV which are required as the starting materials are readily obtainable according to methods known from the literature, as described in European Pat. No. 0 010 652, for example, by hydrogen chloride-catalyzed compensation of substituted benzoyl cyanides with acetaldehyde (in the case of II) or by an analogous reaction of acetyl cyanide (pyruvonitrile) with aldehydes (in the case of IV).
The compounds VI are obtainable by methods known from the literature (Houben-Weyl, "Methoden der Orgarischen Chemie" ["Methods of Organic Chemistry"], Vol. V, 1b, page 383, E. Mueller, ed., G. Thieme Verlag, 1972), from the corresponding bromomethyl oxazoles which, in turn, are readily available, for example, by brominating compounds II or IV.
The compounds of the general formula I are particularly advantageously used as photoconductive substances, for example, in electrophotographic recording materials, comprised of a conductive support and a layer arrangement which has an insulating action in the dark, but is rendered conductive under exposure to light. The layer arrangement may comprise one or more layers. In the case of a single layer, at least one photoconductive substance is dispersed or dissolved in at least one binder and, for example, vapor-deposited directly onto a conductive support. A multi-layer arrangement comprises at least one charge-carrier-generating layer and at least one charge-transporting layer.
Charge images on electrophotographic layers are produced in an exposure step following charging. On exposure, electric charge is first generated and then transported through the layer up to the layer surface, where it neutralizes the charge there present. In the process, photoreceptors in which charge generation and charge transport are effected by the same chemical substance are distinguished from others, in which charge generation is achieved by adding a second substance, i.e., the sensitizer. It is thus possible to practice the electrophotographic process even with light of a wavelength which is not absorbed by the photoconductive substance.
To obtain a homogeneous sensitization the organic dyes listed in Schultz' Dye Tables (7th edition, Volume 1, 1931) are used. These include, for example, triarylmethane dyes, such as Brilliant Green (No. 760, page 314), Victoria Blue B (No. 822, page 347), Methyl Violet (No. 783, page 327), Crystal Violet (No. 785, page 329), Acid Violet 6B (No. 381, page 351); xanthene dyes, i.e., rhodamines, such as Rhodamine B (No. 864, page 365), Rhodamine 6G (No. 866, page 366), Rhodamine G Extra (No. 865, page 366), Sulforhodamine B (No. 863, page 364) and Fast Acid Eosin G (No. 870, page 368), and phthaleins, such as, Eosin S (No. 883, page 375), Eosin A (No 881, page 374), Erythrosin (No. 866, page 376), Phloxin (No. 890, page 378), Bengal Rose (No. 889, page 378), and Fluorescein (No. 880, page 373); thiazine dyes, such as Methylene Blue (No. 1038, page 449); acridine dyes, such as Acridine Yellow (No. 901, page 383, Acridine Orange (No. 908, page 387), and Tryiaflavin (No. 906, page 386); quinoline dyes, such as Pinacyanol (No. 924, page 396) and Cryptocyanine (No. 927, page 397); quinone dyes and ketone dyes, such as Alizarin (No. 1141, page 449), Alizarin Red S (No. 1145, page 502) and Quinalizarin (No. 1148, page 504). Suitable dyes are also cyanine dyes (polymethine dyes), such as Astrazone Yellow 3 G (Color Index [C.I.] No. 48 055) and 5 G (C.I. 48 065), Basic Yellow 52 115 (C.I. 48 060), Astrazone Yellow GRL, Astrazone Orange G C.I 48 040) and R (C. I. 48 035) and Astrazone Orange 3R (not yet classified). Pyrylium salts, thiapyrylium salts and benzopyrylium salts can also be used. It is also possible to use mixtures of sensitizing dyes.
Dispersed dyes or pigments can also be used comprising metal-containing or metal-free phthalocyanine pigments, e.g., copper phthalocyanine, perinone, thioindigo, polycyclic quinone, quinacridone, perylene, anthraquinone, dioxazine, azo, bisazo, trisazo and cyanine pigments or benzo(thio)-xanthene derivatives and mixtures thereof.
Particularly preferred are phthalocyanine pigments, such as the various copper phthalocyanine modifications (α,β,ε), bis- and trisazo pigments, perylene-3,4,9,10-tetracarboxylic acid anhydride and its imide derivatives or (iso)violanthrones. They can be present in an amount of up to 30%, based on the total weight of the photoconductive layer. The preferred quantities of pigment used are in the range from 0.1% to 10%.
The highly insulating binders used in the charge carrier-generating layer and in the charge transport layer may be identical or different. Binders which are suitable from the point of view of flexibility, film-forming properties and adhesion, comprise natural and synthetic resins which, in the preparation of the layers, incipiently dissolve or swell in customary solvents or solvent mixtures. Resins of this kind include polyester resins, which comprise copolyesters of isophthalic acid and terephthalic acid with glycols. Silicone resins have also proved suitable. Polycarbonate resins can advantageously be used. In the production of printing plates and printed circuits preference is given to binders which are soluble in aqueous or alcoholic solvent systems with an addition of acid or alkali, if appropriate. Aromatic or aliphatic, easily flammable solvents are excluded for physiological and safety reasons. Suitable resin binders therefore comprise high-molecular weight substances carrying groups which render them alkali-soluble. These groups include, for example, acid anhydride, carboxyl, carboxylic acid amide, phenol, sulfonic acid, sulfonamide, or sulfonimide groups. Resin binders with high acid numbers are preferably used. Copolymers containing anhydride groups can successfully be employed since, due to the absence of free acid groups, they have a low dark conductivity and are, nevertheless, readily soluble in alkali. Copolymers of styrene and maleic anhydride, sulfonyl urethanes according to German Offenlegungsschrift No. 32 10 577 and copolymers of acrylic and methacrylic acid have proved particularly suitable.
The layers contain customary additives comprising substances which are added to the coating solutions and thus improve the surface texture and flexibility of the layers. The additives may include, for example, plasticizers, such as triphenyl phosphate, and levelling agents, such as silicone oils.
Suitable electrically conductive layer supports are comprised of materials having adequate electrically conducting properties, such as those conventionally used for this purpose. The layer support may be in the form of a flexible web or a plate. In a preferred embodiment the layer support is suited for the production of printing plates and printed circuits and comprises, for example, an aluminum, zinc, magnesium, copper, iron, nickel or multi-metal plate. It is also possible to use metallized supports, for example, vacuum-metallized plastic films, such as polyester films vacuum-metallized with aluminum or copper-clad polyimide films and plates.
Surface-finished layer supports of aluminum have proved particularly suitable. Surface finishing comprises a mechanical or electrochemical graining treatment, optionally followed by anodization and treatment with polyvinyl phosphonic acid, according to German Offenlegungsschrift No. 16 21 478, corresponding to U.S. Pat. No. 4,153,461.
In general, an insulating intermediate layer can be present on the layer support, for example, a thermally, anodically or chemically produced metal oxide layer, such as an aluminum oxide layer. This barrier layer serves to reduce or prevent charge-carrier injection in the dark, from the electrically conductive layer support into the charge carrier-generating layer. The barrier layer also favorably influences adhesion of the following layers to the layer support. Organic barrier layers can comprise various natural or synthetic resin binders which adhere well to a metal or aluminum surface and are not incipiently dissolved or even detached in the subsequent application of the further layers. The organic barrier layer has a thickness of about 1 μm, and a metal oxide layer has a thickness in the range from 10 to 104 nm.
For example, in the production of printed circuits, as conventionally used in electronics, the photoconductive layer may initially be applied to an intermediate support, from which it is subsequently transferred to the layer support, in the form of a so-called dry resist. The dry resist may, e.g., be transferred by lamination. Plastic films, such as polyester films, especially polyethylene terephthalate films, have proved particularly suitable for use as intermediate supports.
The coatings are applied in the customary manner, for example, by doctor knife or spray coating. Preference is given to flow-coater application. The layers are, for example, dried in drying channels, the different drying stages being determined by the temperatures in the individual zones, by the travelling speed of the material and by the prevailing rate of air flow.
Below, the syntheses of the compounds corresponding to the general formula I, in accordance with the respective processes A, B or C are explained in detail by means of general working instructions; the compounds I prepared are compiled in Table 1.
TABLE 1
__________________________________________________________________________
##STR13## I
Pro-
No.
A R.sub.1 B R.sub.2 M.P.
cessgree.C.]
__________________________________________________________________________
I a
Single Bond
##STR14## CHCH
##STR15## 128-129
A
b " " "
##STR16## 124-125
A
c " " "
##STR17## 188-189
C
d " " "
##STR18## 175-176
C
e " " CHCHCHCH
##STR19## 99-100
C
f " " "
##STR20## 142-143
C
g "
##STR21## CHCH
##STR22## 106-107
C
h " " "
##STR23## 124-125
C
i " " "
##STR24## 76-77 C
j " " "
##STR25## 91-92 C
k " " "
##STR26## 67-68 C
l " " "
##STR27## 159-160
A
m " " "
##STR28## 130-131
C
n " " "
##STR29## 104-105
C
o " " "
##STR30## 171-172
A
p " " "
##STR31## 107-108
C
q " " "
##STR32## 143-144
C
r " " "
##STR33## 166-169
C
s " " "
##STR34## 210-211
C
t " " "
##STR35## 92-95 C
u " " "
##STR36## 134-135
C
v " " "
##STR37## 137-139
C
w " " "
##STR38## 175-176
C
x " " "
##STR39## 211-212
C
y " " "
##STR40## 193-194
C
z " " CHCHCHCH
##STR41## 158-160
C
aa "
##STR42## CHCH
##STR43## 138-139
C
ab " " "
##STR44## 205-207
C
ac "
##STR45## "
##STR46## 138-139
A
ad " " "
##STR47## 154-155
A
ae " " "
##STR48## 178-180
B
af CHCH
##STR49## Single Bond
##STR50## 164-165
B
ag " " "
##STR51## 195-196
B
__________________________________________________________________________
Process A--General Instruction
160 mmols of potassium hydroxide powder are added to a solution of 40 mmols of 2-methyl-4-chlorooxazole II and 50 mmols of N-(4-chlorophenyl)-R2 (-)azcmethine III in 100 ml of dimethyl formamide. Within 30 minutes the reaction mixture is heated to 60° C. and is kept at this temperature for 2 hours. After cooling to 20° C., 400 ml of methanol are added, followed by cooling to -10° C. The solid substance is then separated and recrystallized from methylglycol.
Elementary Analysis for 1-[4-chloro-5-(4-methoxy)phenyl-oxazol-2-yl]-2-(4-dimethylamino)-phenylethene, i.e, general formula I, wherein:
R1 =4-methoxyphenyl
A=single bond
B=--CH═CH--
R2 =4-dimethylaminophenyl:
C20 H19 ClN2 O2 : calculated: C 67.7, H 5.4, Cl 10.0, N 7.9. found: C 67.8, H 5.3, Cl 10.3, N 7.9.
Process B--General Instruction
A solution of 17 mmols of 5 methyl-4-chlorooxazole IV, 21 mmols of N-(4-chlorophenyl)-R1 -azomethine V and 68 mmols of potassium hydroxide powder in 40 ml of dimethyl formamide is stirred for 2 hours at 20° C. After adding 160 ml of methanol, the reaction mixture is cooled to -10° C. and the solid substance is separated and recrystallized from methylglycol.
Elementary Analysis for 1-[4-chloro-2-(4-dimethylamino)phenyl-oxazol-5-yl]-2-(4-dimethylamino)phenyl-ethene, i.e., general formula, I wherein:
R1 =4-dimethylaminophenyl
A=--CH═CH--
B=single bond
R2 =4-dimethylaminophenyl:
C21 H22 ClN3 O: calculated: C 68.6, H 6.0, Cl 9.6, N 11.4. found: C 68.4, H 6.1, Cl 9.7, N 11.4.
Process C--General Instruction
60 mmols of sodium hydride (80% suspension) and 100 ml of dimethyl sulfoxide are reacted, finally by heating to 75° C. 60 mmols of finely powdered triphenyl phosphonium salt VI are added to the cooled solution, and after the salt has dissolved, stirring is continued for 50 minutes at 25° C. 60 mmols of aldehyde VII are then added dropwise, and the mixture is stirred for 2 hours at 25° C. and for 3 hours at 75° C. The solid substance obtained after hydrolysis with 500 ml of ice water is recrystallized from methylglycol.
Elementary Analysis for 1-[4-chloro-5-phenyl-oxazol-2-yl]-2-[4-chloro-5-(4-methoxy)-phenyl-oxazol-2-yl]-ethene, i.e., general formula I, wherein:
R1 =phenyl
A=Single bond
B=--CH═CH--
R2 =4-chloro-5-(4-methoxy)-phenyl-oxazol-2-yl:
C21 H14 Cl2 N2 O3: calculated: C 61.0, H 3.4, Cl 17.2, N 6.8.found: C 60.8, H 3.5, Cl 17.6, N 6.6.
According to the instruction given in European Pat. No. 0 010 652, a solution of 100 mmols of 4-methoxy-benzoyl cyanide and 100 mmols of cinnamaldehyde in 50 ml of tetrahydrofuran is saturated with hydrogen chloride at 0° C. After the mixture has been allowed to stand for 10 hours at 0° C. it is poured onto 200 g of ice, extracted with dichloromethane and the extract obtained is washed and dried. By means of column chromatography on silica gel with elution by dichloromethane, a chlorooxazole-containing fraction can be separated as the main constituent.
According to analysis by gas chromatography, the unsaturated condensation product, corresponding to compound Ig in Table 2 prepared by another route, is only present in an amount of 19.4%.
The main constituent comprises compounds containing a 1,2-substituted chlorethyl unit, which together amount to 68.1%, as determined by 1 H-NMR analysis.
Separation of this mixture by means of chromatography, distillation or crystallization proves impractical.
EXAMPLES OF APPLICATION
Different coating formulations were used to test the electrophotographic properties of the compounds of this invention, corresponding to the general formula I.
Coating Formulation 1:
15.0 g of Hostaperm Orange GR (Pigment Orange 43, C.I. 71.105) were added to a solution of 10 g of polybutylmethacrylate (®Plexigum P 676, manufacturers Roehm GmbH) in 200 g of tetrahydrofuran and dispersed by milling in a ball mill for 2 hours. After adding 32 g of polymethylmethacrylate (®Plexigum M 345 in 340 g of tetrahydrofuran, the layer was applied to a polyethylene terephthalate film vacuum-metallized with aluminum at a layer weight of 6 g/m2 and was dried. The dried layer was then treated with a 5% solution of the compounds of the invention in tetrahydrofuran and again dried.
Coating Formulation 2:
5 g of the compounds according to the invention, 5 g of a copolymer of a maleic acid half-ester and styrene, decomposition point 200° C. to 240° C., and 0.05 g of Rhodamine B were dissolved in 90 g of tetrahydrofuran and applied to a grained and anodized aluminum support for offset printing plates in such a way that a dry layer weight of 6 g/m2 resulted.
Coating Formulation 3:
A polyethylene terephthalate film vacuum-metallized with aluminum was first coated by sublimation with a charge-carrier generating layer of N,N'-dimethylperylene-3,4,9,10-tetracarboxylic acid diimide to give a layer weight of 200 mg/m2. This layer was coated with a solution comprising 50 parts by weight of the substances according to the invention and 50 parts by weight of a polyester (®Dynapol L 206, manufacturers Dynamit Nobel), such that this charge transport layer had a layer weight of 10.5 g/m2.
The results of electrophotographic investigations carried out on the layers prepared according to the examples are compiled in the following Table 2. In the table E1/2, E1/4 and E1/8 refer to the exposure energies in μJ/cm2, which must be applied at a light intensity of 3 μW/cm2 to produce a discharge from the original charge Uo to 0.5 Uo, 0.25 Uo and 0.125 Uo, respectively. The samples according to coating formulation 1 were measured at 485 nm and the samples according to coating formulations 2 and 3 were measured in white light (halogen-tungsten lamp, heat-absorption glass filter at 650 nm). Ue denotes the residual charge which remains on the layer after exposure for 10 seconds.
Comparison Examples:
For comparison, investigations were also carried out on the coating formulations using compounds IX (German Pat. No. 10 58 836) and VIII (European Pat. No. 0 010 652). Coating formulation 1 was, for comparison, also used without post-treatment with a photoconductor-containing solution. ##STR52##
TABLE 2
______________________________________
Compound
Formul. U.sub.o U.sub.e
E.sub.1/2
E.sub.1/4
E.sub.1/8
______________________________________
Iac 1 -406 -63 16.4 25
Iad 1 -462 -47 11 14 32
Ie 1 -430 -67 21.6 70
If 1 -39 -15 70.6
Ih 1 -770 -39 6.1 8 13
Ii 1 -857 -47 5.7 7 10
In 1 -734 -31 5.9 8 11
Ir 1 -857 -23 3.7 4.7 6.1
Is 1 -647 -23 3.6 5.2 8.2
Iw 1 -632 -47 9 23 67
Iy 1 -193 -51 59.5
Iz 1 -308 -59 27.5 96
without 1 -746 -319 75
VIII 1 -525 -75 20.4 62
IX 1 -620 -7 5.7 7 10
Iac 2 -268 -31 20.7 51
Iad 2 -165 -15 19.7 50 99
Iaf 2 -529 -177 70.4
Ie 2 -481 -240 146
If 2 -493 -51 16.9 47 126
Ig 2 -623 -470
Ih 2 -596 -55 12 25 47
Ij 2 -722 -481
Il 2 -169 -3 19.1 41 65
Io 2 -292 -3 10.7 27 49
Ip 2 -730 -94 11.7 28
Iw 2 -647 -7 7.9 18 36
Iz 2 -406 -165 101
VIII 2 -398 -11 10.6 30 62
IX 2 -426 -7 8 20 39
Ik 3 -647 -181 4.7
Im 3 -556 0 1.7 3.2 5
It 3 -339 0 2.3 4.8 7.5
IX 3 -205 -7 4.9 10.1 18.4
______________________________________
What is claimed is:
1. A recording material comprising: a support;at least one photoconductive layer on the support comprising a 4-chlorooxazole compound of general formula I: ##STR53## wherein: A is a single bond or the --CH═CH-- group,B is a single bond, the --CH═CH-- or --CH═CH--CH═CH-- group and is a single bond, in the case of A representing the --CH═CH-- group, R1 is phenyl, which is optionally substituted in one or more positions by (C1 -C4)-alkoxy or di-(C1 -C4)-alkylamino radicals, and R2 is phenyl, phenyloxazolyl, pyridyl, julolidin-9-yl, N-(C1 -C4 -alkyl) carbazol-3-yl, coumarin-6-yl or stilbene-4-yl, which are optionally substituted in one or more positions by (C1 -C4)-alkyl, (C1 -C4)-alkoxy, halogen-(C1 -C4)-alkoxy, hydroxy, halogen, di-(C1 -C4)-alkylamino or dibenzylamino radicals.
2. A recording material as claimed in claim 1, comprising a compound of general formula I whereinA is a single bond, B is the --CH═CH-- group, R1 is phenyl, which is substituted by (C1 -C4)-alkoxy radicals, and R2 is phenyl or N-(C1 -C4 -alkyl)-carbazol-3-yl, which are substituted by (C1 -C4)-alkoxy, halogen, hydroxy and/or di-(C1 -C4)-alkylamino radicals.
3. A recording material as claimed in claim 1, comprising a compound of general formula I whereinA is a single bond, B is the --CH═CH-- group, R1 is methoxyphenyl, and R2 is p-ethoxyphenyl, p-dimethylaminophenyl, p-diethylaminophenyl, o-chloro-p-dimethylaminophenyl, o-hydroxy-p-diethylamino-phenyl or N-ethylcarbazol-3-yl.
4. A recording material as claimed in claim 2, comprising a compound of general formula I whereinA is a single bond, B is the --CH═CH-- group, R1 is mathoxyphenyl, and R2 is p-ethoxyphenyl, p-dimethylaminophenyl, p-diethylaminophenyl, o-chloro-p-dimethylaminophenyl, o-hydroxy-p-diethylamino-phenyl or N-ethylcarbazol-3-yl.
5. A recording material as claimed in claim 1, comprising:a support; a charge-generating layer comprising at least one photoconductive layer on the support comprising a 4-chlorooxazole compound of general formula I; and a charge-transporting layer comprising at least one photoconductive layer on the support comprising a 4-chlorooxazole compound of general fomrula I.
6. A recording material as claimed in claim 5, wherein the charge generating layer additionally comprises a sensitizer.
7. A recording material as claimed in claim 1, additionally comprising a metal oxide insulating intermediate layer between the support and the photoconductive layer.
| 1988-03-01 | en | 1990-01-09 |
US-50396983-A | Differential lock control system responsive to steering and/or braking action to unlock differential
ABSTRACT
A farm tractor includes differentials interposed in the front and rear axles of an agricultural vehicle. The differentials include hydraulically-operated locks each controlled by a solenoid-operated valve. The solenoid valves are controlled by a control circuit which includes a latching relay, a normally open manual switch operable only to close the relay and lock the differential and a pair of series-connected, normally closed switches which are operable only to unlock the differential in response to vehicle steering or braking operation.
BACKGROND OF THE INVENTION
This invention relates to a control system which controls the locking and unlocking of a differential gear mechanism. It is well known to provide vehicles, such as farm tractors, with differentials which can be selectively locked or unlocked. In a simple form, differential lock control systems are in use wherein a solenoid-operated differential lock control valve is controlled by a single, manually-operated floor switch. However, with such a system, the vehicle operator must continuously depress the floor switch in order to keep the differential locked. It is also well known that it is desirable to have the differential automatically unlocked under certain conditions, such as when steering the vehicle or when applying the brakes in anticipation of or in order to facilitate vehicle turning. One patent that teaches a control system for unlocking a differential in response to steering of the vehicle in U.S. Pat. No. 2,874,740. This patent further teaches unlocking and locking the differential in response to operation of an ignition switch and in response to brake application. To accomplish these results, a differential lock mechanism is controlled by a plurality of series-connected switches. One disadvantage of such a circuit is that after the differential has been unlocked, as a result of a braking or steering operation, the differential will automatically be re-locked when these operations are terminated without the operator making a conscious decision to re-lock the differential. A further disadvantage is that the circuit includes a manual switch which can be toggled to both unlock and lock the differential. Another differential control circuit is described in U.S. Pat. No. 4,347,760. This circuit includes (in part) a flip-flop and a manual floor switch. However, successive application of this floor switch will alternately lock and unlock the differential. Thus, with this dual function floor switch, there is the possibility that the operator can toggle these manual switches with the intention of unlocking the differential, wherein such a toggling would actually lock the differential and vice-versa.
Additional differential control circuits are described in U.S. Pat. No. 3,732,752. However, one embodiment described therein also includes such a dual-function manual switch. The other embodiment includes a latching relay and a momentary contact switch operable only to lock the differential. However, this last embodiment apparently has no direct manual controlled means for unlocking the differential, nor is there provided any means for unlatching the relay after it is latched, thus making the momentary contact switch useless after its first operation and thus, causing a permanent power drain on the vehicle electrical system.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a differential lock control system with one set of operator-controlled devices which are operable only to lock the differential and with another set of operator-controlled devices which are operable only to unlock the differential.
Another object of the present invention is to provide a differential lock control system wherein the differential is automatically unlocked in response to steering or braking.
These and other objects are achieved by the present invention which includes differentials interposed in the front and rear axles of an agricultural vehicle. The differentials include hydraulically-operated locks, each controlled by a solenoid-operated valve. The solenoid valves are controlled by a control circuit which includes a latching relay, a normally open manual switch operable only to close the relay and lock the differential and a pair of series-connected, normally closed switches which are operable only to unlock the differential in response to vehicle steering or braking operation.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a schematic diagram of a differential lock control system constructed according to the present invention.
DETAILED DESCRIPTION
The power train of a four-wheel drive vehicle includes front and rear axle conventional differential mechanisms 10 and 12 (interposed in the front and rear axles) with conventional, hydraulically-operated locking mechanisms 14 and 16, such as described in U.S. Pat. No. 3,292,720. Fluid communication between the locks 14 and 16 and pump 18 and a reservoir 20 is controlled by a conventional solenoid-operated 2-way, 2-position valve 22 with solenoid 24.
The control circuit 30 includes a potential source or battery 32, a series-connected pair of normally closed switches 34 and 36, a normally open momentary contact switch 38 and a conventional latching relay 40. Switches 34 and 36 are coupled between the battery 32 and a first terminal 42 of the relay 40. The second relay terminal 44 is coupled to the solenoid of valve 22, to one side of normally open switch 38 and to the third or coil or latch terminal 46 of relay 40. A switch 48 bridges terminals 42 and 44 and is operated by the relay coil 50.
If the vehicle (not shown) is of the articulated variety, then switch 34 will preferably be operatively coupled to the vehicle hinge (not shown) so that switch 34 opens whenever the vehicle articulates at least a certain amount, such as 10 degrees. The particular design of such an angle-sensitive switch is believed to be evident to one with ordinary skill in the art. For example, the switch mechanism shown in FIG. 3 of U.S. Pat. No. 2,874,790 could be easily adapted for use with the hinge of an articulated vehicle.
For a non-articulated vehicle, the switch 34 would preferably be operatively coupled to the vehicle steering system 50 so that switch 34 opens whenever a predetermined steering operation is performed, such as at least a 10 degree turn of the steering wheel. This could be accomplished with an appropriately shaped cam which turns with the steering wheel and a follower coupled to the switch 34. Alternatively, a steering-operated switch mechanism, such as described in U.S. Pat. No. 2,874,790 could be used.
Switch 36 is preferably operatively coupled to the vehicle brake system so that switch 36 opens whenever the vehicle brakes are applied. Such a brake-operated switch is well known and is also described in U.S. Pat. No. 2,874,740. Switch 38 is also preferably mounted in the vehicle operator's compartment so as to be easily accessible to the vehicle operator.
MODE OF OPERATION
To lock up or engage the lock mechanisms 14 and 16 of differentials 10 and 12 (assuming relay 40 is initially open), the operator momentarily closes switch 38. This simultaneously energizes the solenoid of valve 22 and engages locks 14 and 16 while also energizing coil 50 of relay 40 which closes the switch 48. The coil 50 is now also energized via switches 34, 36 and 48, so that when switch 38 is released and opened, the coil 50 remains energized and switch 48 is latched in the closed position and the differential locks 14 and 16 remain engaged. At this point, further and successive operations of switch 38 have no effect since the solenoid 24 is energized independent of switch 38 via switches 34, 36 and 48.
Now, a hinge movement or steering operation, or a brake application will open either of switches 34 or 36 and thus, de-energize solenoid 24. This also de-energizes coil 50 which opens switch 48. Switch 48 will remain open so that reclosings or further and successive operations of switches 34 and 36 will no re-engage the differential locks 14 and 16. Thus, switch 38 is operable only to engage but not disengage the differential locks 14 and 16, while switches 34 and 36 are operable only to disengage, but not to engage or re-engage the differential locks 14 and 16. In this manner, once switches 34 or 36 have been opened, the differential locks 14 and 16 can be re-engaged only if the operator intentionally closes switch 38.
While the invention has been described in conjunction with a specific embodiment, is to be understood than many alternatives, modifications and variations will be apparent to those skilled in the art in light of the aforegoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.
I claim:
1. A locking differential control system for a vehicle having first and second axle shafts driven through a differential and locking means for selectively locking and unlocking the differential in response to locking and unlocking signals applied to an input thereof, the control system comprising:a potential source; a latching relay having a coil connected between a latch terminal and a grounded terminal and having first and second switch coupled terminals, the latch terminal and one of the switch coupled terminals being connected directly to the input of the locking means, switch means for selectively connecting and disconnecting the first and second terminals with and from each other, the coil opening and closing the switch means in response to signals applied to the latch terminal; a normally open momentary contact operator-actuated switch coupled on one side to the latch terminal and to the input of the locking means and on its other side to the potential source to initially energize said coil and to activate said relay to position said differential in a locked position; and first and second series-connected, normally closed switches coupled between the potential source and the other of the first and second switch-coupled relay terminals to retain the coil in an energized condition when both said first and second series-connected switches are closed; means for opening the first normally closed switch in response to a predetermined vehicle steering operation; and means for opening the second normally closed switch in response to a vehicle brake application whereby said coil is deenergized to deactivate said relay to unlock said differential whenever either of said first and second series-connected switches are opened concurrent with said normally open momentary contact switch being open, and the control system generating the locking signal when the potential source is communicated with the input of the locking means and generating the unlocking signal when the potential source is disconnected from the input of the locking means.
| 1983-06-13 | en | 1986-02-18 |
US-86305286-A | Fume control in strand casting of free machining steel
ABSTRACT
Lead or bismuth fumes emitted from steel during a strand casting operation are confined, collected and removed.
BACKGROUND OF THE INVENTION
The present invention relates generally to fume control in steel making operations and more particularly to fume control in the strand casting of steel to which fume-emitting ingredients are added.
Examples of fume-emitting alloying ingredients are lead and bismuth which are added to molten steel to improve the machinability properties of the solidified steel product.
In the strand casting of steel, molten steel is introduced from a ladle into a tundish from where the molten steel is directed into a casting mold where at least an outer shell of solidified steel is formed.
The fume-emitting ingredients may be added to the molten steel in the ladle, or they may be added to the stream of molten steel flowing from the ladle to the tundish. Aside from the ladle, fumes may be emitted from the molten stream between the ladle and the tundish and from th molten steel in the tundish.
In the strand casting process, the partially solidified steel moves downstream from the casting mold into a spray chamber in which the steel is sprayed with water to cool the steel and further solidify it. The solidified steel then moves into a run-out chamber located at the downstream end of the spray chamber. Relatively clean gases, devoid of fumes from the fume-emitting gases, are generated in the spray chamber and in the run-out chamber.
After the run-out chamber, the solidified steel strand moves to a torch-cutting station located immediately downstream of the run-out chamber where the strand is cut into pieces. Torch-cutting of the strand generates fumes from the fume-emitting ingredients in the solidified steel strand. These fumes must be prevented from escaping into the work place environment surrounding the strand casting equipment because the fumes can pose a health hazard. In the case of lead, the law restricts the quantity of lead bearing material which may be present in the work place environment as dust or fumes to no more than 50 micrograms per cubic meter.
The fumes emitted from the molten steel, or from the strand during the torch-cutting step, are at least initially in the form of lead or bismuth vapors which may then react with the atmosphere to form oxides of lead or bismuth. In accordance with the present invention, it matters not whether the fumes from the fume-emitting ingredients are in the form of metallic vapors or the oxides thereof. Both forms are equally undesirable.
Gases carrying fumes collected from steel making operations are normally passed through a bag house which removes the fumes from the carrying gases which are then exhausted to the atmosphere minus the fumes.
At the torch-cutting station, water sprays are used to wash scale and dross resulting from the torch-cutting step into a flume located beneath the steel strands at the torch-cutting station. Fumes generated during the torch-cutting step are removed from the torch-cutting locale by exhaust ducts. Because of the water sprays employed at the torch-cutting station, the gases exhausted from this location are wet and cool. It is undesirable to process wet, cool gases through a bag house because the moisture in such gases can precipitate in the bag house and interfere with the ability of the bag house to perform its fume-removing function.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus for severely restricting the amount of toxic fume which can escape from the strand casting operation into the surrounding work place environment.
The stream of molten steel is enclosed in a shroud as it passes between the ladle and the tundish. The tundish is covered and has an opening through which the molten steel may enter the tundish. A movable exhaust hood is positioned between the ladle and the tundish with an exhaust inlet located immediately adjacent the opening in the tundish. Baffles are provided to confine any fumes emitted through the opening in the tundish to the vicinity of the exhaust inlet.
After the tundish has been emptied of essentially all the steel that can be drained therefrom, it continues to emit some toxic fumes as it cools because of a residue of molten steel remaining in the tundish or sticking to the walls thereof. In accordance with the present invention, the tundish is moved from a casting to a non-casting position, together with its associated exhaust hood, and the fumes which continue to be emitted from the tundish while the latter is in its non-casting position, are collected through its associated exhaust hood.
The exhaust gases collected from the tundish while it is in its casting position, during the casting operation, before the tundish is emptied, are relatively hot and dry compared to the gases collected at the torch-cutting station. In accordance with the present invention, the hot, dry gase from the tundish are mixed with the cool, wet gases from the torch-cutting station, at a location upstream of the bag house, to raise the temperature of the gases collected at the torch-cutting location to a temperature above the dew point thereof to prevent precipitation within the bag house of moisture from the gases.
There is a substantial delay between the time the molten steel from the ladle first enters the tundish and the time the strand is first subjected to the torch-cutting operation. This delay period can be one hour, for example. The hot, dry gases generated at the tundish during this delay period are circulated through the bag house to preheat the bag house prior to the introduction therein of exhaust gases collected at the torch-cutting station. Preheating the bag house assists in preventing the precipitation therein of moisture in the gases collected at the torch-cutting station.
After the tundish has been essentially emptied, the temperature of the exhaust gases collected therefrom is substantially lower than the temperature of the exhaust gases collected from the tundish while it contained substantial amounts of molten steel. As a result, the gases collected from the tundish at this stage may not be hot enough to prevent precipitation in the bag house of moisture from gases collected at the torch-cutting station, when the latter are mixed with the gases from the tundish.
The present invention compensates for this heat deficiency by utilizing the clean gases generated at the run-out chamber located immediately upstream of the torch-cutting station. These gases, consisting essentially of hot air, are relatively hot and dry compared to the gases generated at the torch-cutting station. By mixing the hot, dry gases from the run-out chamber with the cool, wet gases from the torch-cutting station, precipitation of moisture in the bag house is prevented. The location of the run-out chamber, where the relatively hot, dry gases are generated, is sufficiently close to the torch-cutting station so that the hot, dry gases retain sufficient heat at the time they are mixed with the gases from the torch-cutting station to maintain the temperature of the mixed gases above the dew point thereof when the mixed gases enter the bag house. Moreover, because the gases from the run-out chamber are relatively dry, the percentage of water in the mixed gases is substantially less than the percentage of water in the gases from the torch-cutting station.
Large droplets of moisture, initially carried by the cool, wet gases collected from the torch-cutting station, are removed by passing these gases through a cyclone separator located upstream of the location where the gases from the torch-cutting station are mixed with gases from other locations in the strand casting operation. The fumes which are controlled in accordance with the present invention may be either metallic vapors or oxides of the fume-emitting ingredients, or both.
Othe features and advantages are inherent in the method and apparatus claimed and disclosed or will become apparent to those skilled in the art from the following detailed description in conjunction with the accompanying diagrammatic drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of a strand casting operation;
FIG. 2 is a perspective of an embodiment of apparatus in accordance with the present invention;
FIG. 3 is a fragmentary, vertical sectional view illustrating a portion of the strand casting equipment illustrated schematically in FIG. 1;
FIG. 4 is a fragmentary perspective of a portion of one embodiment of apparatus in accordance with the present invention; and
FIG. 5 is a fragmentary, vertical sectional view of a bag house bag in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a strand casting operation wherein molten steel from a ladle 10 is introduced through a shroud 11 into a tundish 12 from which the molten steel passes through tundish nozzles 13 into a casting mold 14 wherein the steel is at least partially solidified. The steel then moves along an arcuate path through a spray chamber 15 of conventional construction employing conventional water spray nozzles to cool the steel as it moves along the arcuate path. Located at the downstream end of spray chamber 15, and separate and discrete therefrom, is a run-out chamber 16 from which emerges a solid steel strand 17 which passes over rollers 18 to a torch-cutting station comprising a cutting table 19 having an open top and associated with a torch-cutting device 20 of conventional construction which moves back and forth along a path at 21 to cut strand 17 into a multiplicity of pieces, e.g. steel billets. Conventional water sprays (not shown), normally associated with such a torch-cutting device, are employed at the torch-cutting station.
FIG. 3 shows tundish 12 located in a casting position directly below ladle 10. Tundish 12 comprises a top cover 24 having an opening 25. Extending from the bottom of ladle 10 toward tundish opening 25 is a conduit 26 for directing molten steel from ladle 10 through tundish opening 25. Enclosing conduit 26 is a tubular, outer shroud 27 extending from the bottom of ladle 10 through opening 25 in the top 24 of tundish 12. Shroud 27 encloses both conduit 26 and the stream of molten steel directed by the latter into tundish 12 and helps protect the stream of molten steel from the atmosphere outside the stream of molten steel.
Fume-emitting ingredients, such as lead or bismuth, are introduced into the stream of molten steel through a tube 28 extending at a downward angle through the wall of tubular shroud 27. Another tube 29 communicates with the interior of shroud 27 for introducing a pressure-regulating gas into the interior of shroud 27. The apparatus illustrated in FIG. 3 is described in greater detail in U.S. application Ser. No. 731,077 filed May 6, 1985, now U.S. Pat. No. 4,602,949 and the disclosure thereof is incorporated herein by reference.
The introduction of fume-emitting ingredients into the molten steel entering tundish 24 generates fumes at tundish 24 and in shroud 27. These fumes can escape through that part of tundish opening 25 not occupied by the cross section of shroud 27. These fumes are prevented from polluting the work place environment by apparatus illustrated in FIGS. 1, 2 and 4. To collect the fumes generated in the tundish and the shroud, an exhaust hood 32 is located between ladle 10 and tundish 12 (FIG. 1). Exhaust hood 32 has an inlet 33 which is located adjacent top opening 25 of tundish cover 24 (FIG. 4). Exhaust inlet 33 has an arcuate shape conforming to the shape of that part of tundish top opening 25 where exhaust inlet 33 is located. As shown in FIG. 4, tundish top opening 25 has an irregular shape to accommodate tilting of shroud 11 to facilitate the positioning of the shroud in opening 25.
Extending from exhaust conduit 32, on opposite sides of inlet 33, are a pair of baffles 34, 35 which are normally located adjacent tundish opening 25 when exhaust inlet 33 is similarly located. Baffles 34, 35 extend between the bottom of ladle 10 and tundish top cover 24. Baffles 34, 35 perform the function of substantially confining toxic fumes from tundish 12 and shroud 11 to the vicinity of exhaust inlet 33.
Baffles 34, 35 are mounted on hood 32, at 36 and 37 respectively (FIG. 4), for pivotal movement of the baffles, relative to hood 32, toward and away from each other. This facilitates positioning of the baffles to perform their intended function. As shown in FIG. 4, baffle 34 comprises a bottom portion 38 for covering at least part of top opening 25 on tundish 12. Extending upwardly from bottom portion 38 is a wall portion 39.
Referring to FIG. 2, exhaust conduit 32 is connected to one end of a piston rod 42 reciprocable within an air actuated cylinder 43 for moving exhaust conduit 32 relative to tundish opening 25, back and forth along a horizontal path, between an extended, operative position adjacent opening 25 and a retracted, displaced position relatively remote from opening 25.
Exhaust hood 32 has an outlet end 44 communicating with the inlet end 45 of a coupling 46 when exhaust hood 32 is in its operative position. Coupling 46 has an outlet end 47 for communicating with another coupling 48 in turn communicating with a conduit 49.
Tundish 12 is part of an assembly also comprising exhaust hood 32, piston rod 42 and cylinder 43, and coupling 45, as well as supporting framework (not shown). This assembly is mounted on a car having wheels 52, 52 for moving the assembly from a casting position (solid lines in FIG. 2) to a non-casting position (dash-dot lines in FIG. 2).
For a time after it has been drained of all the molten steel which can be withdrawn therefrom, the tundish continues to emit toxic fumes. At this stage, the tundish must be moved from the casting position, where fume collection is available, to the non-casting position so that other parts of the strand casting equipment can be readied for the next cast.
The tundish is often preheated at the non-casting position, before the start of the strand casting operation. When a tundish has been previously used for the strand casting of molten steel containing fume-emitting ingredients, there is a residue in the refractory lining of the tundish which, during preheating, will vaporize and emit fumes.
The present invention provides for the capture of toxic fumes emitted from the tundish when the latter is in the non-casting position. Referring to FIG. 2, exhaust hood 32 is normally retracted to its displaced position (dash-dot lines above cylinder 43) when the tundish and associated equipment are moved from the casting to the non-casting position. Hood 32 is moved back to its operative position, wherein inlet 33 is adjacent opening 25 in tundish 12, when the assembly is at the non-casting position so as to capture fumes escaping through opening 25. Located in tundish top 24, on opposite sides of opening 25, and spaced from opening 25, are a pair of exhaust vents 53, 54 each covered by a respective plate 55, 56 when the tundish is in its casting position (solid lines in FIG. 2). However, when the tundish is in its non-casting position (dash-dot lines in FIG. 2), the cover plates, 55, 56 are removed from over exhaust vents 53, 54, and fumes escaping through these vent openings are exhausted through additional hoods 57, 58 located at the non-casting position.
Exhaust hoods 32, 57 and 58 are all employed to exhaust fumes from tundish 12 when the latter is in its non-casting position, either during a preheating operation or after a casting operation while the tundish continues to emit toxic fumes.
Exhaust hoods 57, 58 each communicate with a respective branch conduit 60, 61 each communicating with a main conduit 62 communicating with a coupling 63 in turn communicating with a connecting conduit 64 which communicates with conduit 49. Conduit 49 is employed to remove fumes generated at the tundish when the latter is in its casting position (solid lines in FIG. 2).
Exhaust hood 32 typically has a cross sectional area sufficient to provide a 7,000 ft./min. (2134 m/min.) capture velocity in the vicinity of tundish opening 25 when the tundish is in the casting position. This will maintain the toxic fumes in the work place environment surrounding tundish opening 25 below the required maximum of 50 micrograms per cubic meter. The rest of the exhaust system downstream of hood 32 also has a capacity sufficient to maintain these conditions.
Referring to FIGS. 1 and 2, located below the torch-cutting station at table 19 is a flume 66 for collecting the dross and scale which falls from slab 17 through the open top of table 19 during the torch-cutting step. Flume 66 also collects water which falls from above as a result of the water sprays (not shown) which accompany the torch-cutting step. Flume 66 has a pair of opposite sides 99,100 on each of which is located a plurality of exhaust outlets 67, 67 communicating with an exhaust manifold 68 communicating with a conduit 69. Fumes generated by the torch-cutting step are drawn into flume 66 and exhausted therefrom through exhaust outlets 67, 67.
Flume 66 has a bottom 70 which slopes downwardly in a downstream direction. This causes the water which drops into flume 66 to flow in the downstream direction, creating a downstream current, to wash downstream the scale and dross which falls into flume 66. The current in flume 66 also causes some of the fumes drawn into flume 66 to be carried towards the downstream end 74 of flume 66, and at least part of these fumes avoid removal through exhaust outlets 67, 67. To prevent these fumes from escaping into the work place environment surrounding downstream flume end 74, an exhaust hood 72 is provided immediately downstream of, and above, the downstream end 71 of table 19 (FIG. 2). Exhaust hood 72 communicates with a conduit 73 in turn communicating with conduit 69 which, as noted above, also connects to exhaust manifolds 68, 68. Exhaust hood 72 will also collect any fumes generated by a sample cut-off device (not shown) normally located adjacent downstream end 71 of table 19.
In summary, exhaust outlets 67, 67 collect gases at a location directly below the torch-cutting station, and exhaust hood 72 collects gases at the downstream end of the torch-cutting station, a location immediately downstream of the furthest downstream position to which torch-cutting device 20 moves as it performs the torch-cutting step. As shown in FIG. 2, exhaust hood 72 is located above exhaust outlets 67, 67.
Gases collected at exhaust hood 72 and exhaust outlets 67, 67 are conducted by conduit 69 to a cyclone separator 75 wherein large droplets of moisture are separated from the gases which then exit through the top of separator 75 into a conduit 76.
The gases entering conduit 69 contain moisture as a result of the water sprays employed at the torch-cutting station. Accordingly, the gases in conduit 69 are relatively cool and wet compared to the gases exhausted from the tundish into conduit 49. The gases exiting from cyclone separator 75 through conduit 76, although stripped of large droplets of water, are still relatively wet and cool. These gases are conveyed through a conduit 77 to a bag house 78 for removing from the gases the toxic ingredients therein, e.g. oxides of lead and bismuth.
It is undesirable that gases entering a bag house have a temperature below the dew point of the gases because this causes moisture in the gases to precipitate in the bag house thereby interfering with the ability of the bag house to perform its intended function. More particularly, in a bag house, dirty gases are drawn through the walls of vertically extending fabric bags, from the outside to the inside of the bags. As the gases pass through the fabric walls of the bags, they are cleaned of dust particles which accumulate on the outside of the bag walls. The cleaned gases entering the inside of the bags are conducted further downstream and eventually exhausted to the atmosphere. Periodically, when the dust accumulating on the outside of the bag walls gets too thick, the bags are shaken to dislodge the dust. This is necessary because an overly thick dust layer will impede the passage of gas through the bag. If the gases have a temperature below the dew point thereof, moisture in the gases will precipitate on the outside of the bag walls, causing the dust particles which accumulate there to cake, and this interferes with the dislodgement of the dust particles from the bag walls. On the other hand, if the temperature of the gases are above the dew point thereof, the moisture is in the form of a vapor and it will pass through the bag walls with the cleaned gases.
Raising the temperature of the cool, wet gases from the torch-cutting station to a temperature above the dew point thereof is accomplished by mixing these gases with the relatively hot, dry gases exhausted from the tundish. Mixing of the gases also produces an H2 O percentage therein substantially less than the H2 O percentage in the gases from the torch-cutting station just before mixing. The increase in gas temperature and the decrease in H2 O percentage, compared to the corresponding conditions in the gases from the torch-cutting station, both contribute to reducing the likelihood of H2 O precipitation in the bag house.
Mixing of the gases begins at a junction 80 where conduit 76, containing the relatively wet, cool gases from the torch-cutting station, joins conduit 49 containing the relatively hot, dry gases from the tundish. Conduits 76 and 49 join at junction 80 to form conduit 77. Junction 80, is upstream of bag house 78.
There is a substantial delay period between the beginning of the molten steel introducing step at tundish 12 and the beginning of the torch-cutting step at table 19. During this delay period, the hot, dry gases generated at tundish 12 are directed through conduits 49 and 77 into bag house 78 to preheat the bag house before any fumes from a torch-cutting step are directed into the bag house. This reduces the precipitation of moisture in the bag house when the gases from the torch-cutting station are eventually directed therethrough. More particularly, the gases used to preheat bag house 78 during the delay period are hotter than the mixed gases which will enter the bag house after the delay period. Accordingly, at least at the beginning of the time when the mixed gases enter the bag house, the bag house is at a substantially greater temperature than the entering gases. Eventually, of course, the temperature of the bag house will drop and approach that of the mixed gases entering the bag house, but the temperature of the bag house will not drop below the dew point of the entering mixed gases, which are maintained at a temperature above the dew point thereof.
During the delay period, a damper 81 in conduit 76 is closed to prevent cool gases from being drawn into conduit 77 at junction 80. During this period, no fumes are being generated at the torch-cutting station because that station is inoperative.
Just as the introduction of molten steel into the tundish proceeds for a substantial period before the beginning of the torch-cutting step, so also the torch-cutting step proceeds for a substantial period after the conclusion of the introduction of molten steel into the tundish. Thus there will continue to be a substantial generation of cold, wet fumes at the torch-cutting station during a time when there is a substantial diminution, if not a total cessation, in the generation at the tundish of hot, dry gases which can be mixed with the cool, wet gases at junction 80. To prevent the gases entering bag house 78 from dropping below the dew point thereof, the wet, cool gases entering conduit 77 from conduit 76 are mixed with hot, dry gases from another source.
More particularly, as slab 17 passes through run-out chamber 16, the slab is still relatively hot. The slab is not subjected to spray cooling in run-out chamber 16, so that the air within run-out chamber 16 is heated by slab 17, and that air is neither cooled nor moistened by water sprays. Thus, the gases within run-out chamber 16 are relatively hot and dry compared to the gases exhausted from the torch-cutting station.
The hot, dry gases in run-out chamber 16 are withdrawn through an exhaust outlet at 83 communicating with a conduit 84 in turn communicating with a connecting conduit 85 communicating with another conduit 87 which joins conduit 49 at a junction 88.
As previously noted, run-out chamber 16 is located at the downstream end of spray chamber 15 and is immediately upstream of the torch-cutting station. Run-out chamber 16 is sufficiently close to the torch-cutting station so that the hot, dry gases withdrawn from run-out chamber 16 retain sufficient heat at the time they reach junction 80, where they are mixed with the cold, wet gases from the torch-cutting station, to maintain the temperature of the mixed gases above the dew point thereof when the mixed gases enter bag house 78.
Connecting conduit 85 contains a damper 89, and conduit 84 contains a damper 90 located downstream of the junction 91 between conduit 84 and connecting conduit 85. Damper 89 is opened and damper 90 is closed when the hot, dry gases from run out chamber 16 are to be mixed with the cool, wet gases from the torch-cutting station. Damper 89 is closed and damper 90 is opened when the gases from run-off chamber 16 are not to be mixed with the gases from the torch-cutting station. In that instance, the gases flowing through conduit 84 bypass bag house 78.
Clean gases from bag house 78 flow into an exhaust conduit 93 which communicates with a pair of inlet conduits 94, 94 each leading into a respective blower 95, each having an outlet conduit 96, communicating with a conduit 97 in turn communicating with a stack 98.
Referring now to FIG. 5, bag house 78 contains a plurality of bag-type filters each comprising a fabric sock 101 having an open top 104 and a closed bottom 105, and into which the gas passes from the outside forming a film of dust on the sock which acts as a filtering medium. Bag house exhaust outlet 93 (FIG. 2) is in communication with the open top 104 on each sock. Each sock 101 is supported at the top 104 in a conventional manner (not shown). When the film of dust becomes too thick, the exit end of the sock may be closed at 104 thereby shutting off the gas flow, and the sock may be shaken or vibrated to drop the excess dust into a collecting hopper at the bottom of the socks. Alternatively, the socks may be "pulsed" by directing an air blast down through the open top 104 of each sock, e.g. by reversing blowers 95, 95.
As noted above, if the temperature of the gas entering the bag house drops below its dew point, moisture will precipitate on the fabric wall of the sock, thereby forming a caked deposit of dust on the sock which would be extremely difficult if not impossible to dislodge. In a preferred embodiment of the present invention, illustrated in FIG. 5, this problem is avoided by lining the outside of each sock 101 with a layer or membrane 102 of polytetrafluoroethylene (e.g. Teflon). In effect, the sock has an inner layer 103 of fabric, and an outer layer or membrane 102. This has tw advantages. The membrane has pores which are so small that it does a much more efficient job than the fabric of excluding dust particles from passing into the interior of the sock. In addition, membrane 102 is much smoother than the fabric so that, even if moisture does precipitate and cause caking on the membrane, the caked material will not stick thereto but will slide off the membrane when the sock is pulsed.
Th foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modification will be obvious to those skilled in the art.
I claim:
1. In the strand casting of steel wherein undesirable fumes are generated, a method for preventing said fumes from polluting the work-place environment, said method comprising the steps of:introducing a stream of molten steel from a ladle into a tundish located in a casting position below the ladle; providing said tundish with a cover having an opening; directing said molten steel through a conduit extending from the bottom of the ladle toward said opening in the covered tundish; enclosing said conduit within a tubular outer shroud extending from said ladle bottom through said opening in the covered tundish; adding fume-emitting ingredients to said stream of molten steel in said outer shroud; locating, between said ladle and said tundish, an exhaust hood having an inlet; locating said inlet adjacent said top opening of the covered tundish; collecting fumes generated in said tundish and said shroud at said exhaust hood through said inlet; locating, adjacent said top opening, baffles extending between the bottom of the ladle and the top of the covered tundish; and substantially confining said fumes to the vicinity of said exhaust inlet with said baffles.
2. A method as recited in claim 1 wherein said tundish continues to emit said fumes after the completion of the strand casting operation, said method comprising:moving both the tundish and said exhaust hood from said casting position to a non-casting position; and collecting fumes, emitted by said tundish at the non-casting position, with said exhaust hood.
3. A method as recited in claim 2 wherein said tundish has at least one exhaust vent in the tundish top at a location spaced from said top opening in the tundish, and said method comprises:exhausting fumes from said tundish through an additional hood located over said exhaust vent.
4. A method as recited in claim 1 wherein said tundish is preheated before said strand casting operation and emits said fumes during the preheating due to a residue of fume-generating material remaining in the tundish from a previous strand casting operation, said method comprising:conducting said preheating at a non-casting position displaced from said casting position; moving said tundish between said casting and non-casting positions together with said exhaust hood; and collecting fumes, emitted by said tundish during said preheating, with said exhaust hood.
5. A method as recited in claim 4 wherein said tundish has at least one exhaust vent in the tundish top at a location spaced from said top opening in the tundish, and said method comprises:exhausting fumes from said tundish through an additional hood located over said exhaust vent.
6. In the strand casting of steel wherein undesirable fumes are generated, a method for preventing said fumes from polluting the work-place environment, said method comprising the steps of:introducing a stream of molten steel from a ladle into a tundish located in a casting position below the ladle; collecting fumes generated in said tundish, said fumes being relatively hot and dry; casting said molten steel into a strand at a location below the tundish; torch cutting said strand; generating fumes at said torch cutting step which are relatively cool and wet compared to the hot, dry fumes generated at said tundish; there being a substantial delay period between the beginning of said molten steel introducing step at the tundish and said torch cutting step; collecting gases containing said fumes from the torch cutting step and directing said gases through a bag house to clean the gases; and directing gases containing the hot, dry fumes generated at said tundish through said bag house during said delay period to preheat the bag house before the fumes from the torch cutting step are directed into the bag house, thereby to reduce the precipitation of moisture in the bag house when the fumes from the torch cutting step are directed therethrough.
7. A method as recited in claim 6 and comprising:mixing said relatively hot, dry fumes from the tundish with said relatively cool, wet fumes from the torch cutting step, at a location upstream of said bag house, during the period when fumes are generated at both the tundish and the torch cutting location.
8. In the strand casting of steel wherein undesirable fumes are generated, a method for preventing said fumes from polluting the work-place environment, said method comprising the steps of:introducing a stream of molten steel from a ladle into a tundish located in a casting position below the ladle; casting said molten steel into a strand at a location below the tundish; spray cooling said strand downstream of the tundish; torch cutting the strand downstream of said spray cooling step; generating fumes at said torch cutting step which are relatively wet and cool; and collecting gases containing said fumes from the torch cutting step and directing said gases through a bag house to clean the gases; said gases being collected at a first collecting location directly below the location where said torch cutting step is performed and at a second collecting location immediately downstream of the location where said torch cutting step is performed and above said first collecting location.
9. In the strand casting of steel wherein undesirable fumes are generated, a method for preventing said fumes from polluting the work-place environment, said method comprising the steps of:introducing a stream of molten steel from a ladle into a tundish located in a casting position below the ladle; casting said molten steel into a strand at a location below the tundish; spray cooling said strand downstream of the tundish; torch cutting the strand downstream of said spray cooling step; generating fumes at said torch cutting step which are relatively wet and cool; generating gases, immediately downstream of said spray-cooling step and upstream of said torch cutting step, which are relatively hot and dry; collecting gases containing said fumes from the torch cutting step and directing said gases through a bag house to clean the gases; collecting the relatively hot, dry gases generated immediately downstream of the spray cooling step; and mixing said relatively hot, dry gases generated downstream of said spray cooling step with said relatively cool, wet fumes from the torch cutting step, at a location upstream of said bag house.
10. A method as recited in claim 9 and comprising:subjecting said gases from said torch cutting step to a cyclone separating step, before said mixing step, to remove relatively large droplets of moisture from said gases.
11. A method as recited in claim 9 wherein:the location where said relatively hot, dry gases are generated is sufficiently close to the location of said torch cutting step so that said hot, dry gases retain sufficient heat at the time of said mixing step to maintain the temperature of the mixed gases above the dew point thereof when the mixed gases enter the bag house.
12. In the strand casting of steel wherein undesirable fumes are generated, a method for preventing said fumes from polluting the work-place environment, said method comprising the steps of:introducing a stream of molten steel from a ladle into a tundish located in a casting position below the ladle; collecting fumes generated in said tundish, said fumes being relatively hot and dry; casting said molten steel into a strand at a location below the tundish; torch cutting said strand; generating fumes during said torch cutting which are relatively cool and wet compared to the hot, dry fumes generated at said tundish; collecting gases containing said fumes from the torch cutting step and directing said gases through a bag house to clean the gases; and mixing said relatively hot, dry fumes from the tundish with said relatively cool, wet fumes from the torch cutting step at a location upstream of said bag house, during the period when fumes are generated at both the tundish and the torch cut-off location.
13. A method as recited in claim 12 and comprising:providing said tundish with a cover having an opening; directing said molten steel into said covered tundish through a conduit extending from the bottom of the ladle toward said opening in the covered tundish; enclosing said conduit within a tubular outer shroud extending from said ladle bottom through said opening in the covered tundish; adding fume-emitting ingredients to said stream of molten steel in said outer shroud; locating, between said ladle and said tundish, an exhaust hood having an inlet; locating said inlet adjacent said top opening of the covered tundish; collecting fumes generated in said tundish and said shroud at said exhaust hood through said inlet; locating, adjacent said top opening, baffles extending between the bottom of the ladle and the top of the covered tundish; and substantially confining said fumes to the vicinity of said exhaust inlet with said baffles.
14. A method as recited in claim 12 and comprising:spray cooling said strand downstream of the tundish and upstream of the torch cutting step; generating gases, immediately downstream of said spray-cooling step and upstream of said torch cutting step, which are relatively hot and dry; collecting the relatively hot, dry gases generated immediately downstream of the spray cooling step; and mixing said relatively hot, dry gases generated downstream of said spray cooling step with said relatively cool, wet fumes from the torch cutting step, at a location upstream of said bag house.
15. A method as recited in claim 14 wherein:there is a substantial delay period between the beginning of said molten steel introducing step at the tundish and said torch cutting step; said method comprising directing gases containing the hot, dry fumes generated at said tundish through said bag house during said delay period to preheat the bag house before the fumes from the torch cutting step are directed into the bag house, thereby to reduce the precipitation of moisture in the bag house when the fumes from the torch cutting step are directed therethrough.
16. A method as recited in claim 14 and comprising:subjecting said gases from said torch cutting step to a cyclone separating step, before any of said mixing steps, to remove relatively large droplets of moisture from said gases.
17. A method as recited in claim 14 wherein:the location where said relatively hot, dry gases are generated is sufficiently close to the location of said torch cutting step so that said hot, dry gases retain sufficient heat at the time of said mixing step to maintain the temperature of the mixed gases above the dew point thereof when the mixed gases enter the bag house.
18. In the strand casting of steel wherein undesirable fumes are generated, a method for preventing said fumes from polluting the work-place environment, said method comprising the steps of:introducing a stream of molten steel from a ladle into a tundish located in a casting position below the ladle; casting said molten steel into a strand at a location below the tundish; spray cooling said strand downstream of the tundish; torch cutting the strand downstream of said spray cooling step; generating fumes at said torch cutting step which are relatively wet and cool; collecting gases containing said fumes from the torch cutting step and directing said gases through a bag house having bags to clean the gases; accumulating dust from said gases on the outside of the bags in said bag house; and preventing the moisture in said wet, cool fumes from interfering with the removal of accumulated dust from the outside of said bags, by providing the outside of said bags with a membrane composed of polytetrafluoroethylene.
19. In a metallurgical process which generates gases containing dust and moisture, a method for cleaning said gases, said method comprising the steps of:directing said gases through a bag house having bags; accumulating dust from said gases on the outside of the bags in said bag house; and preventing the moisture in said gases from interfering with the removal of accumulated dust from the outside of said bags, by providing the outside of the bags with a membrane composed of polytetrafluoroethylene.
20. An apparatus for strand casting steel, wherein undesirable fumes are generated, and for preventing said fumes from polluting the work-place environment, said apparatus comprising:a ladle for containing molten steel; a covered tundish having a top opening and located in a casting position below the ladle; a conduit extending from the bottom of the ladle toward said opening in the top of the covered tundish; said conduit comprising means for directing a stream of molten steel from said ladle to said tundish; a tubular outer shroud enclosing said conduit and extending from said ladle bottom through said opening in the covered tundish; means for adding fume-emitting ingredients to said stream of molten steel in said outer shroud; an exhaust hood located between said ladle and said tundish and having an exhaust inlet located adjacent said top opening of the covered tundish; said exhaust hood comprising means for collecting fumes generated in said tundish and said shroud; and baffles located adjacent said top opening and extending between the bottom of the ladle and the top of the covered tundish; said baffles comprising means for substantially confining said fumes to the vicinity of said exhaust inlet.
21. An apparatus as recited in claim 20 and comprising:means for moving said exhaust hood relative to said tundish opening, back and forth along a horizontal path, between an operative position adjacent said opening and a displaced position remote from said opening.
22. An apparatus as recited in claim 20 and comprising:means for moving both the tundish and said exhaust hood from said casting position to a non-casting position; said exhaust hood comprising means for collecting fumes emitted by said tundish at the non-casting position.
23. An apparatus as recited in claim 22 wherein:said tundish has at least one exhaust vent in the tundish top at a location spaced from said top opening in the tundish; said apparatus comprising an additional hood and means for locating said additional hood over said exhaust vent to exhaust fumes from said tundish through the additional hood.
24. An apparatus as recited in claim 22 and comprising:means for moving said exhaust hood relative to said tundish opening, back and forth along a horizontal path, between an operative position adjacent said opening and a displaced position remote from said opening.
25. An apparatus as recited in claim 20 and comprising:means mounting said baffles on said exhaust hood for pivotal movement of the baffles, relative to the exhaust hood, toward and away from each other.
26. An apparatus as recited in claim 25 wherein at least one of said baffles comprises:a bottom portion for covering at least part of said top opening in the tundish; and wall means extending upwardly from said bottom portion.
27. An apparatus for strand casting steel, wherein undesirable fumes are generated, and for preventing said fumes from polluting the work-place environment, said apparatus comprising:a ladle; a tundish comprising means for receiving a stream of molten steel from said ladle; means for collecting fumes generated in said tundish; means for casting said molten steel into a strand at a location below said tundish; means located downstream of said casting means, for torch cutting said strand and for generating fumes which are relatively cool and wet compared to the fumes generated at said tundish; means for providing a substantial delay period between the initial reception of said molten steel at the tundish and the time said strand first reaches said torch cutting means; a bag house; means for collecting gases containing said fumes generated at the torch cutting means and for directing said gases through said bag house to clean the gases; and means for directing gases containing the fumes generated at said tundish through said bag house during said delay period to preheat the bag house before the fumes generated at said torch cutting means are directed into the bag house.
28. An apparatus as recited in claim 27 and comprising:means for mixing said fumes from the tundish with said relatively cool, wet fumes from the torch cutting means, at a location upstream of said bag house.
29. An apparatus as recited in claim 28 and comprising:a cover on said tundish; an opening in said cover; a conduit extending from the bottom of the ladle toward said opening in said cover; a tubular outer shroud enclosing said conduit and extending from said ladle bottom through said opening in the covered tundish; means for adding fume-emitting ingredients to said stream of molten steel in said outer shroud; an exhaust hood located between said ladle and said tundish and having an exhaust inlet located adjacent said top opening of the covered tundish; said exhaust hood comprising means for collecting said fumes generated in said tundish and said shroud; and baffles located adjacent said top opening and extending between the bottom of the ladle and the top of the covered tundish; said baffles comprising means for substantially confining said fumes to the vicinity of said exhaust inlet.
30. Apparatus for strand casting steel, wherein undesirable fumes are generated, and for preventing said fumes from polluting the work-place environment, said apparatus comprising:a ladle; a tundish comprising means for receiving a stream of molten steel from said ladle; means for casting said molten steel into a strand at a location below said tundish; means for spray cooling said strand downstream of the tundish; means for torch cutting the strand downstream of the spray cooling means and for generating fumes which are relatively wet and cool; a bag house; means for collecting gases containing said fumes generated at the torch cutting means and for directing said gases through said bag house to clean the gases; said gas collecting means comprising means for collecting gases at a first location directly below said torch cutting means and means for collecting gases at a second location immediately downstream of said torch cutting means and above said first collecting location.
31. Apparatus for strand casting steel, wherein undesirable fumes are generated, and for preventing said fumes from polluting the work-place environment, said apparatus comprising:a ladle; a tundish comprising means for receiving a stream of molten steel from said ladle; means for casting said molten steel into a strand at a location below said tundish; means for spray cooling said strand downstream of the tundish; means for torch cutting the strand downstream of the spray cooling means and for generating fumes which are relatively wet and cool; means for generating relatively hot, dry gases immediately downstream of said spray-cooling means and upstream of said torch cutting means; a bag house; means for collecting gases containing said fumes generated at the torch cutting means and for directing said gases through said bag house to clean the gases; means for collecting the relatively hot, dry gases generated immediately downstream of the spray cooling means; and means for mixing said relatively hot, dry gases generated downstream of said spray cooling means with said relatively cool, wet fumes from the torch cutting means, at a location upstream of said bag house.
32. An apparatus as recited in claim 31 and comprising:cyclone separating means located upstream of said mixing means; and means for directing said gases collected at said torch cutting means into said cyclone separating means, to remove relatively large droplets of moisture from said gases.
33. An apparatus as recited in claim 31 wherein:the location of said means for generating said relatively hot, dry gases is sufficiently close to the location of said torch cutting means so that said hot, dry gases retain sufficient heat at the time they reach said mixing location to maintain the temperature of the mixed gases above the dew point thereof when the mixed gases enter the bag house.
34. An apparatus for strand casting steel, wherein undesirable fumes are generated, and for preventing said fumes from polluting the work-place environment, said apparatus comprising:a ladle; a tundish comprising means for receiving a stream of molten steel from said ladle; means for collecting fumes generated in said tundish; means for casting said molten steel into a strand at a location below the tundish; means located downstream of said casting means for torch cutting said strand and for generating fumes which are relatively cool and wet compared to the fumes generated at said tundish; a bag house; means for collecting gases containing said fumes generated at the torch cutting means and for directing said gases through said bag house to clean the gases; and means for mixing said fumes from the tundish with said relatively cool, wet fumes from the torch cutting means, at a location upstream of said bag house.
35. An apparatus as recited in claim 34 and comprising:means for providing a substantial delay period between the initial reception of said molten steel at the tundish and the time said strand first reaches said torch cutting means; and means for directing gases containing the fumes generated at said tundish through said bag house during said delay period to preheat the bag house before the fumes at said torch cutting means are directed into the bag house.
36. An apparatus as recited in claim 34 and comprising:cyclone separating means located upstream of said mixing means; and means for directing said gases from said torch cutting means into said cyclone separating means, to remove relatively large droplets of moisture from said gases.
37. An apparatus as recited in claim 34 and comprising:means for spray cooling said strand downstream of the tundish and upstream of the torch cutting means; means for generating relatively hot, dry gases immediately downstream of said spray-cooling means and upstream of said torch cutting means; means for collecting the relatively hot, dry gases generated immediately downstream of the spray cooling means; and means for mixing said relatively hot, dry gases generated downstream of said spray cooling means with said relatively cool, wet fumes from the torch cutting means, at a location upstream of said bag house.
38. An apparatus as recited in claim 37 wherein:the location of said means for generating said relatively hot, dry gases is sufficiently close to the location of said torch cutting means so that said hot, dry gases retain sufficient heat at the time they reach said mixing location to maintain the temperature of the mixed gases above the dew point thereof when the mixed gases enter the bag house.
| 1986-05-14 | en | 1988-02-16 |
US-36825164-A | Cutting-off machine for transverse cutting of tubes
Dec. 6, 1966 P. MORSBACH ETAL 3,289,506
CUTTING-OFF MACHINE FOR TRANSVERSE CUTTING OF TUBES Filed May 18, 1964 NM mm K MN. wN N m .l lllllil h mvE United States Patent 3,289,586 CUTTING-OFF MACHKNE FOR TRANSVERSE QUTTING 0F TUBES Paul Morshaeh, Bahnhofstr. 3, Angermund, Germany, and Klaus Leben, Hirsehstr. l9, Oberhausen-Sterkrade, Germany Filed May 18, 1964, Ser. No. 368,251 Claims priority, applicatiognlgsermany, May 18, 1963, 3 Claims. (Cl. 8253.1)
The invention relates to a cutting-otf machine adapted for transverse cutting of tubes during the rotation of the tubes and during the axial movement, comprising a frame encircling the tube and moving with it in the same direction. This frame is also equipped with the cutting tool. In the operation of machines of this type it is necessary that after having cut-oif the tube same should remain in its relative position in relation to the end of the tube so as to avoid any damages to the cutting tool and, if necessary, to retract same just before the cut-off portion of the tube might be able to start a motion of its own. Especially in those cases when simultaneously with the cutting operation welding edges at the tube ends must be prepared, an exact centering and unchangeable relative position is required so as to avoid any damages to the welding edge after the cutting operation.
The solution of this problem according to the invention comprises a frame movably arranged in axial direction of the tube by means of rollers running on rails. Furthermore, the frame is equipped with two roller beds having a rectangular position in relation to the tube axis and carrying circular plates which by means of pistons and piston rods actuated by hydraulic pressure cylinders radially arranged and fastened to the plates are intended for pressing claws on the tube on both sides of the intended cutting line.
The two plates can be connected together rigidly, however, there is also a mechanical connection or coupling possible in furnishing the plates with the same toothed wheel rim being in action with corresponding pinion gears arranged on the same shaft driven by a motor. The rotation of the motor must be adjusted ac cording to the number of revolutions of the tube.
Since machines of this type are intended for the production of spiral tubes of various diameters the frame must be adapted to be lowered or to be raised with regard to the feature that not the level of the tube axis but the level of the lower limiting line must be maintained. This can be accomplished in such a manner that the frame is arranged on a travelling carriage running parallel to the axis by means of inclined supports. The lower ends of these inclined supports are connected to nuts having screw threads for running in opposite directions on sliding-ways and which nuts can be actuated by means of a spindle driven by a motor. However, more advantageous is a measure whereby the rails of the carriage are fastened to supports which in relation to their level can be adjusted "ice FIG. 2 represents a vertical cross-section taken rectangularly to the tube axis.
With reference to the drawing the tube 1 is concentrically seized by the cutting off machine 2 comprising a carriage 3 running on rails 5 by means of rollers 4. The rails 5 are parallel to the tube axis. This carriage carries the frame 6 consisting essentially of two U-shaped bent rings 7 and 8 being open on their inner side. The center planes of these rings are rectangular to the tube axis. Both rings are connected by cross bars 9 thus embodying a rigid frame 6 which can be rigidly connected to the carriage 3. In the drawing is shown an embodiment of the invention according to which the frame 6 is arranged concentrically in relation to the tube by means of devices which will be described later.
In the rings 7 and 8 there are rollers 10 pivotally arranged the axis of which represent the generating curves of a regular cylinder. These rollers support circular plates 11, 11 which are held in their rectangular position in relation to the tube axis by means of guide rollers 12, 13, 14, and 15 which are attached to the rings 7 and 8. To the plates 11 and 11 in radial direction there are fastened hydraulical cylinders 16, 17, the pistons or piston rods (18, 19) of which carry by means of pivotally arranged connections 20, 21, the rod type holding devices 22, 23 pressing the claws 24, 25, or 26, 2 7, respectively, to the tube 1.
The measures described alone would be sufficient to hold the tube 1 and the tube portion 28 after the cutting operation in an isoaxle position and rotation considering, however, that the torque must be taken over by the frame 2. For its relief it can be used itself for the drive. For this purpose each of the circular plates 11, 12, is equipped with the same toothed wheel rim 3t 31, being in contact with the corresponding pinion gears 32, 33, arranged on the common shaft 34. This shaft 34 rests in bearings 35, 36, fastened to the cross bar 9. This shaft is driven over a reduction gear 37 by a motor 38 the speed of which is adjusted accord ing to the rotations of the tube 1.
For the separation of the tube portion 28 a cutting device of known type can be used comprising a slide rest (carriage) 39 running on one or two cross bars 9 with the possibility of locking it. It carries a motor 40 driving over a reduction gear the cutting tool repre sented for example by an autogenous cutting device, or roller shears 41, or a disk type milling cutter, or a circular saw. Furthermore, to this slide rest can be attached the tools required for the machining of the welding edge which can be driven by the same motor.
The arrangement described ensures the fixed position of the tube portion 28 in relation to the tube 1, even after the cutting operation. Only after this has been finished the holding devices 22, 23 can be raised whereupon the tube portion 28 rests free on the roller table for being taken off. After the tube 1 has been moved forward far enough the cutting-off machine 2 can be moved parallel to the axis for adjusting it for the cutting cycle following next in the described manner.
In its horizontal transverse direction the cutting device is unchangeably aligned and adjusted in relation to the tube axis whilst in its vertical direction it can be adjusted by means of an auxiliary device in a corresponding manner. According to the drawing the frame 2 is supported on the carriage 3 by means of doublearmed levers 42. The upper ends of the levers 42 are pivotally connected with the frame 2 by means of bolts 43 whilst the middle eyes are connected by means of bolts 44 with the sliding shoe which is movably arranged on the carriage 3. The lower ends are bifurcated and embrace, pivotally arranged in the same manner, the screw nuts 45 having thread in opposite directions. In these screw nuts 45 is arranged the spindle 46 having thread in opposite directions which can be actuated either by means of a socket pin or driven by a motor. As on each side of the carriage 3 such a lifting device must be operated it follows from the drawing that each of the spindles is equipped with a Worm Wheel 48 which are driven simultaneously by a worm 47. The worm gear is self-locking, for that reason a special safety device is not necessary.
Instead of the lifting device there can be arranged screw spindles or any hydraulic devices 49 to change the level of the rails 5 of the carriage 3 in relation to the base plate 50. It is clear that in such cases the rails must be connected as a frame and conducted in vertical direction.
What is claimed is:
1. Apparatus for transverse cutting off of a longitudinally advancing tube comprising:
(A) a frame encircling the path of such tube and being axially advanceable therewith;
(B) a plurality of tube engaging claws encircling the path of such tube, pairs of said claws rigidly connected to each other so as ato cradle a longitudinal portion of such tube;
(C) a pair of motor driven circular plates supported in roller bearings rotatably supported in said frame, together with hydraulic means interposed between said circular plates and said tube engaging claws;
(D) a cutting device with cutting member supported in said frame so that its cutting member engages such tube between said pairs of tube engaging claws; (E) articulated knees vertically adjusting said frame 5 with respect to a base upon which it is supported,
so as to maintain leveling of said frame and such tube, while adjusting the height of said cutting device.
2. Apparatus for transverse cutting 01f of a longitudinally advancing tube as in claim 1,
said articulated knees being pivoted to said 'frame at one end and at their other end being pivoted to a sliding shoe engaging a threaded bolt adjusting mechanism supported upon said base.
1 3. An apparatus for transverse cutting oil of a longitudinally advancing tube, as in claim 2, said frame being supported upon a wheeled shoe advanceable longitudinally upon rails whose level may be adjusted vertically.
References Cited by the Examiner UNITED STATES PATENTS 3,029,674 4/1962 Southwell 8253.l X 3,043,576 7/1962 Diener 8253.1 X 3,211,059 10/1965 Linsinger 8253.1 X
FOREIGN PATENTS 116,430 7/1961 Russia.
ANDREW R. JUHASZ, Primary Examiner.
HARRISON L. HINSON, Examiner.
1. APPARATUS FOR TRANSVERSE CUTTING OFF OF A LONGITUDINALLY ADVANCING TUBE COMPRISING: (A) A FRAME ENCIRCLING THE PATH OF SUCH TUBE AND BEING AXIALLY ADVANCEABLE THEREWITH; (B) A PALURALITY OF TUBE ENGAGING CLAWS ENCIRCLING THE PATH OF SUCH TUBE, PAIRS OF SAID CLAWS RIGIDLY CONNECTED TO EACH OTHER SO AS TO CRADLE A LONGITUDINAL PORTION OF SUCH TUBE; (C) A PAIR OF MOTOR DRIVEN CIRCULAR PLATE SUPPORTED IN ROLLER BEARINGS ROTATABLY SUPPORTED IN SAID FRAME, TOGETHER WITH HYDRAULIC MEANS INTERPOSED BETWEEN SAID CIRCULAR PLATES AND SAID TUBE ENGAGING CLAWS; (D) A CUTTING DEVICE WITH CUTTING MEMBER SUPPORTED IN SAID FRAME SO THAT ITS CUTTING MEMBER ENGAGES SUCH TUBE BETWEEN SAID PAIRS OF TUBE ENGAGING CLAWS; (E) ARTICULATED KNEES VERTICALLY ADJUSTING SAID FRAME WITH RESPECT TO A BASE UPON WHICH IT IS SUPPORTED, SO AS TO MAINTAIN LEVELING OF SAID FRAME AND SUCH TUBE, WHILE ADJUSTING THE HEIGHT OF SAID CUTTING DEVICE.
| 1964-05-18 | en | 1966-12-06 |
US-18584188-A | Method of making braided rug construction
ABSTRACT
A braided rug method and construction is based on securing by stitching a relatively small auxiliary strand over the junction of large stitched together strands of braid. By selection of auxiliary strand color, alternating the side of the rug on which the auxiliary strand appears or by employing auxiliary strands on both sides of the rug new appearances in braided rug color, texture and appearance are achieved.
REFERENCE TO RELATED APPLICATION
This is a division of U.S. application Ser. No. 07/048,885 filed May 12, 1987, now U.S. Pat. No. 4,764,407.
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates broadly to rugs but more specifically to methods and constructions related to rugs commonly referred to as braided rugs.
2. Background Art
The type of floor rug typically referred to in the trade as a braided rug is made in some selected round, oval, elliptical, rectangular or other shape by coiling a strand of braid in the shape desired starting from the inside then working out. The strands are typically held together by a zig-zag type lock stitch and the braid may be in various solid or variegated colors to meet the desires of the consumers. The strand typically referred to as the braid may actually be in the form of a platted or braided strand and may include a filler within the braid to increase the bulk or body of the strand. The strands may also be substantially round in cross-section or may be of an oval or substantially flat construction.
Variety in appearance or color has generally been obtained by varying the nature of the strand of braid used to form the rug. With increasing consumer demand for braided rugs, there is thus an increasing consumer demand for more variety in texture, color and appearance. Thus, the present invention has for its primary object the provision of a new braided rug construction and method of making a braided rug to provide choices of color, appearance and texture not heretofore achieved in the braided rug art. Other objects will appear as the description proceeds.
DISCLOSURE OF THE INVENTION
The braided rug method and construction of the invention is based on adding and stitching in a relatively small yarn, cord, braid, roving, plastic molded strand or the like in the valley or "V" between but on the outer surface of adjoining strands of the substantially larger braid used to form the rug. This auxiliary small strand is secured to the adjacent larger strands by the same thread employed to hold the larger strands togther. By choosing contrasting colors or textures for the auxiliary small strand in contrast to the larger strand used to form the rug there is achieved a wide choice in both color, texture and appearance of the braided rug.
DESCRIPTION OF DRAWINGS
FIG. 1 is a plan view of a braided rug made according to the invention.
FIG. 2 is an enlarged plan view of a typical section of the rug of FIG. 1.
FIG. 3 is a cross-section view illustrating the relation of the relatively small auxiliary strand to the larger rug braid strand when the auxiliary strand is placed on only one side of the rug with the braid strand being of circular cross-section.
FIG. 4 illustrates a pair of auxiliary strands placed on opposite sides of the rug.
FIG. 5 illustrates a single auxiliary strand alternating from one side of the rug to the other throughout the construction.
FIG. 6 illustrates the auxiliary strand applied to a relatively flat tape-like braid.
BEST MODE FOR CARRYING OUT THE INVENTION
Making reference initally to FIGS. 1-3 and the first embodiment of the invention, the braided rug 10 of the invention is made up by coiling a conventional strand of braid 12 and laying in along the junction of and adjacent adjoining strands of the coiled braid 12 a relatively small auxiliary strand 14 in the nature of a relatively small yarn, cord, braid or the like. The size of the relatively small auxiliary strand 14 is selected such that it tends to lay in the valley or "V" between the adjacent larger braid strands 12 as best seen in FIG. 3. A zig-zag type lock stitch thread 15 conventional to the trade is employed with the top thread of the stitch effectively overlying and locking in the auxiliary strand 14 to the larger strands of braid 12.
What is particularly unique about the method and construction of the invention is the fact that the relatively small auxiliary strand 14 can be of a contrasting color or texture relative to the color or texture of the relatively large braid 12. Thus as somewhat schematically illustrated in FIG. 1 the center area of the rug 10 may employ a red auxiliary strand 14, the next adjoining area a green auxiliary strand 14 and the outer area a red auxiliary strand 14. An interesting and attractive color pattern is thus achieved that contrasts with whatever color is presented by the larger braid 12.
In an alternative second embodiment of FIG. 4, auxiliary strands 14 are placed on both sides of the rug and occupy the opposed valleys inherent between adjacent braid strands 12 illustrated as being of substantially circular cross-section. Thus, if the auxiliary strands 14 are red on one side as depicted and yellow on the opposite side, the user of the rug can obtain a substantially different appearance by simply turning the rug over. In this second embodiment it has been found that one auxiliary strand can be captured by the bobbin thread and the other auxiliary strand captured by the needle thread.
In a third embodiment illustrated in FIG. 5, the auxiliary strand 14 alternates between being on one side of the rug and the other thus adding to variety in appearance and color.
While it is presently believed that the method and construction of the invention will find its widest application to braided rugs formed of braid of substantially circular cross-section, it has also been found as depicted in FIG. 6 in a fourth embodiment that the method and construction of the invention lends itself to a braided rug formed of relatively large, flat tape-like braid 16 with a smaller layed-in auxiliary strand 18. The term "braid" as used herein is thus intended to refer to the conventional types of strands used for the conventional so-called braid rug whether technically braided, platted or otherwise.
The fabrication of the rug 10 of the invention is started in conventional manner by coiling the conventional braid 12 from inside out and utilizing a zig-zag lock stitch. The needle and bobbin threads can be of suitable size, type or color. In one embodiment, the needle yarn was a monofilament, transparent, nylon thread and the bobbin thread was a grey, spun, "Dacron" thread. When the assembly fabrication is started the added small yarn, cord, braid or the like employed as the auxiliary strand 14 is laid in the valley or "V" between but outside of the junction of the adjacent larger braids 12. It has been found that the smaller auxiliary strand 12 seeks to position itself in the valley between the larger strands of braid 12. When starting to sew, the auxiliary strand 14 is initially anchored by a few stitches to the larger braid strand 12 so that the auxiliary strand 14 is pulled under the machine presser foot evenly and at the same time as the larger braid strand 12. The length and width of the stitch are determined according to the specific characteristics of rug being made.
What has thus been achieved is a dramatic increase in the choice of color, texture and appearance for the braided type rug. While an oval shape has been depicted in FIG. 1, it will of course be appreciated that braided rugs may be made in round, rectangular, square or other shapes of the users choice. While the exact dimensions of the braid 12 and the auxiliary strand 14 may vary, in one embodiment the braid 12 had a filling within the braid and was approximately one half inch in diameter whereas the auxiliary strand 14 was a small braided cord approximately one eighth inch in diameter. By varying the color of the auxiliary strand 14 in different areas of the rug 10, an extremely interesting color and texture effect was achieved.
What is claimed is:
1. The method of making a braid type rug, comprising:(a) starting with one end of a strand of braid at the center of the rug, coiling the braid to form a rug of selected size and shape; (b) starting with one end of a first auxiliary strand substantially smaller in size than said braid and secured by stitches to said one end of the braid, coiling said auxiliary strand such that said auxiliary strand in relation to said braid lies outside but immediately adjacent the junction of and between and parallel to adjacent strands of said braid and exposed to view; and (c) stitching said braid and auxiliary strand together to retain said braid and auxiliary strand in said relation throughout the portion of the rug in which said auxiliary strand is employed.
2. The method of claim 1 wherein the color of said auxiliary strand is selected so as to change in various portions of said rug.
3. The method of claim 1 wherein said auxiliary strand alternates between being on one side and the other of said rug.
4. The method of claim 1 including a second auxiliary strand similarly placed and stitched as said first auxiliary strand but on an opposite side of said rug.
5. The method of claim 4 wherein said first and second auxiliary strands are selected to be of different color.
6. The method of claim 1 wherein said braid is selected to be of substantially circular cross-section.
7. The method of claim 1 wherein said braid is selected to be of substantially flat, tape-like cross-section.
| 1988-04-25 | en | 1989-02-07 |
US-28619672-A | Aluminide coating removal method
ABSTRACT
An improved method for removing an aluminide coating from an article includes a sequential treatment of an aqueous mixed acid solution of nitric and phosphoric acids, an alkaline permanganate aqueous solution and then the mixed acid solution repeated. In one form in which the article has been exposed to air and products of fuel combustion at elevated temperatures, the method combines a mechanical pretreatment with the chemical stripping operation. An optional final mechanical removal of residue can be included. The mechanical pretreatment includes the use of angular metallic particles, such as steel, which are soluble in a subsequently applied solution, such as the mixed acids.
United States Patent Grisik et al.
[ ALUMINIDE COATING REMOVAL METHOD [75] Inventors: John J. Grisik, Cincinnati, Ohio;
Ellis J. Airola, Ipswich, Mass.
[73] Assignee: General Electric Company,
Cincinnati, Ohio [22] Filed: Sept. 5, 1972 [21] Appl. No.: 286,196
[52] US. Cl 134/3, 134/7, 134/26, 1.34/28, 134/41, 134/42, 156/22, 252/79.2, 252/79.5, 252/103, 252/142 [51] Int. Cl. 1308b 3/08, C23g l/02, C23g 1/14 [58] Field of Search 134/3, 27, 28, 41, 26, 134/42, 7; 204/1415; 252/79.2, 101, 103, 142
[56] References Cited UNITED STATES PATENTS 3,000,829 9/1961 Arden 252/103 3,085,917 4/1963 Netzler et al. 134/27 3,216,857 11/1965 Duvall 134/3 3,457,107 7/1969 Mickelson et al. 134/28 Sept. 3, 1974 3,607,398 9/1971 Lucas 252/142 X 3,622,391 11/1971 Baldi 134/3 Primary Examiner-Joseph Scovronek Assistant Examiner-Barry I. Hollander Attorney, Agent, or Firm-Derek P. Lawrence [5 7] ABSTRACT An improved method for removing an aluminide coating from an article includes a sequential treatment of an aqueous mixed acid solution of nitric and phosphoric acids, an alkaline permanganate aqueous solution and then the mixed acid solution repeated. In one form in which the article has been exposed to air and products of fuel combustion at elevated temperatures, the method combines a mechanical pretreatment with the chemical stripping operation. An optional final mechanical removal of residue can be included. The mechanical pretreatment includes the use of angular metallic particles, such as steel, which are soluble in a subsequently applied solution, such as the mixed acids.
6 Claims, No Drawings BACKGROUND OF THE INVENTION This invention relates to the removal of coatings from metallic surfaces and, more particularly, to an improved method for removing from a metallic surface an aluminide coating, in one particular form, one which has been subjected to high temperature operating conditions. The invention herein described was made in the course of or under a contract, or a subcontract thereunder, with the US. Department of the Air Force.
The quest for more efficient gas turbine engines has led to the wide spread use of increasingly intricate and expensive air cooled components in hot sections of the engine. The cost of such components has increased as a result of the more sophisticated design as well as the advanced alloys employed. Consequently a corresponding increase in service life is required to maintain the cost per operating hour at an acceptable level. To a great degree the extension of the service life has been accomplished, and it is not uncommon for such components to have an expected life time of at least about 10,000 hours. In order to achieve the expected life time, it is necessary to provide environmental protection for those components operating at high temperatures in air and in the presence of corrosive products and products of fuel combustion.
At present, the most common, reliable and least expensive method of providing the necessary protection is through the use of an aluminide diffusion coating. While the coating provides adequate protection, it is normally life-limited to the range of up to about 5000 hours. Therefore, the necessity arises to renew the protection provided by the coating several times during the life of the part. The removal of the coating is made more difficult since the coating has been designed and developed to resist attack. A significant problem, therefore, is one of removing the coating without affecting the structural material of the article.
SUMMARY OF THE INVENTION A principal object of the present invention is to provide an improved method for removing all types of aluminide coatings while maintaining the integrity of and avoiding intergranular attack on the coated article.
Another object is to provide, for use with articles having cooling passages, such an improved method which avoids cooling hole blockage and dimensional changes.
These and other objects and advantages will be more clearly understood from the following detailed description and examples which are intended to be typical and representative of rather than limiting on the scope of the present invention.
Briefly, the method of the present invention, in one form, comprises subjecting the coating to an aqueous mixed acid solution consisting essentially of greater than 25 percent to less than 75 percent by volume nitric acid of about 70 weight percent HNOa and greater than 25 percent to less than 75 percent by volume phosphoric acid of about 85 weight percent H PO After rinsing the mixed acid solution from the coating, it is subjected to an alkaline permanganate solution consisting essentially of, by weight, about 8 ll percent sodium hydroxide, about 8 11 percent anhydrous sodium carbonate, about 4 6 percent potassium permanganate, with the balance water and incidental impurities. The alkaline permanganate solution is then rinsed from the coating and the coating is again subjected to the mixed acid solution.
The method of the present invention, in a form in which it is used for removing an aluminide coating from an article which has been exposed to air and products of fuel combustion at elevated temperatures, provides a mechanical pretreatment involving abrading the coating to a surface finish of no greater than about rms (root mean square) with angular particles, preferably metallic, which are soluble in a subsequently applied liquid. In another form, after sequential treatment with the aqueous solutions and after rinsing, the surface on which the coating existed is mechanically treated to remove any chemical residue.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention provides an improved balance between speed and safety for stripping aluminide coatings from a variety of high temperature operating superalloys including those based on nickel as well as those based on cobalt. Through the alternate use of acid solutions and alkaline solutions, the process avoids termination of aluminide coating removal due to passivation yet avoids detrimental attack on the base material which was coated.
The method of the present invention is useful in removing aluminide coatings which have been exposed to elevated temperature operating conditions in air and in the presence of products of combustion. Such coatings are particularly difiicult to remove because of an oxide layer which is created under such operating conditions.
In the evaluation of the present invention. a variety of known and development solutions were tested. Commercial alkaline nickel strippers, for example containing ammonium salts, were initially effective in attacking the nickel. However, after a short time the attack stopped due to passivation. Other products including mixtures of organic and inorganic compounds, which included alkaline sodium cyanide mixtures, were tested. The alkali attacked the aluminum while the cyanide constituents attacked the nickel. Passivation did not occur since both the aluminum and, in the case of the nickel base alloy, the nickel are attacked concurrently. However, the method provided little or no stripping action on articles which had an oxide layer or layers due to operating exposure. Other solutions containing combinations of nitric and hydrofluoric acids were evaluated in connection with mixtures including sodium cyanide. Although the combination worked reasonably well, there is a serious safety problem using acid and cyanide salts in the same operation, because of the danger of forming the poisonous hydrogen cyanide gas, and possible intergranular attack of the base alloy. In general, stripping of articles which had been oxidized in air in the presence of products of fuel combustion for periods of 100 hours or more using known solutions resulted in very sluggish or incomplete aluminide coating removal, particularly in the stripping of aluminides from cobalt base alloys.
In the practice of the method of the present invention, two principal aqueous chemical solutions are provided. The first is an aqueous mixed acid solution of mixed nitric and phosphoric acid. The amounts of acids included are equivalent to those which consist essentially of greater than 25 to less than 75, and preferably 45 55, volume percent nitric acid of about 70 weight percent HNO and greater than 25 to less than 75, and preferably 45 55, volume percent phosphoric acid of about 85 weight percent H PO The second solution is an alkaline permanganate solution consisting essen tially of, by weight, about 8 ll percent sodium hydroxide, about 8 11 percent anhydrous sodium carbonate, about 4 6 percent potassium permanganate, with the balance water and incidental impurities.
. In an initial evaluation of the present invention, a series of tests were conducted using the above identified type of mixed acid solution to establish the interrelationship between its components. The specimens tested were of a nickel base superalloy of a type described in US. Pat. No. 3,027,254 issued Mar. 27, 1962 and sometimes referred to as SEL alloy. The coating was an aluminide which had been applied by a pack diffusion method and which had been aged for 2 hours in hydrogen at about lO0C. Typical of such tests are those summarized in the following table.
tion in a jet engine, for example, at least about 100 hours, to remove all of the coating. This was due to the presence of oxides and products of fuel combustion on or in the coating surface. For example, a nickel base superalloy in the form of a turbine blade and including an aluminide coating applied through a pack diffusion method was evaluated for coating removal after the turbine blade had been used in a jet engine. The blade was immersed in the 1:1 HNO /H PO mixed acid solution at 80C for 2 hours after which it was rinsed and immersed in the alkaline permanganate solution consisting essentially of, by weight, 10.9 percent sodium hydroxide, 10.9 percent anhydrous sodium carbonate, 5.5 percent potassium permanganate with the balance essentially water and incidental impurities at a temperature of 80C for 1 hour. After rinsing, it was again immersed in the above identified mixed acid solution for 2 hours. After rinsing it was mechanically abraded with a number 1250 grit silicon dioxide, suspended in water, to remove a chemical residue or smut which remained on the surface. Examination of the article surface after treatment showed such surface to be particularly rough in the ar ea on which heavy oxides had been generated shown by the data of the table, the test of example 2 within the range of the amount of mixed acid solution used in the practice of the method of the present invention provided removal of all of the coating, including the diffusion zone, from specimens which had not been exposed to conditions of elevated temperature operation in air or products of fuel combustion as would be experienced in a jet engine.
The test of example 2 was repeated on specimens of other nickel base superalloys such as those described in US. Pat. Nos. 3,155,501 issued Nov. 3, 1964, 3,642,469 issued Feb. 15, 1972 and 3,615,376 issued Oct. 26, 1971. The specimens were coated with different types of diffusion applied aluminides. However, the hydrogen pretreatment which is less desirable, both from the standpoint of high temperature requirements and lack of ability to reduce alumina, was eliminated even though hydrogen can be effective in chemically converting or reducing sulfidation reaction products from engine run components. The results showed that exposure to the mixed acid solution alone for up to about 2 hours at about 80C did not remove all of the coating. However, subsequent exposure for about onehalf hour in the alkaline permanganate solution at about 80C, followed by an additional exposure to the mixed acid solution at about 80C, with water rinses in between, removed the coatings cleanly from these specimens. The specimens were in the form of turbine blades which asLasatb smwnin aasas aa s additional steps were required after appreciable operaduring jet engine operation and disclosed that the diffusion zone remained in such rough oxided area. However, when the same method was repeated on an identical article from the same engine but with a pretreatment prior to application of the first mixed acid solution, all of the coating including the diffusion zone was removed. The pretreatment, which is in accordance with one form of the method of the present invention, is to first abrade the coating to a surface finish of no greater than rms. Greater than 100 rms provides a surface which results in subsequent imperfect coating. In this example, the same grit suspended in water was used to abrade or blast the coating surface prior to treatment with the aqueous solutions.
Thus, the present invention, in one form, provides an improved method for removing an aluminide coating from an article surface including a pretreatment involving abrading the coating surface to a certain surface finish, treating the article with a particular combination of aqueous solutions and then, optionally, abrading the treated surface to remove any chemical smut or residue. The above comparative test procedures, with and without pretreatment including grit blast, in this example with a grit of number 220, applied to different areas of the same blade, produced the same results: the coating was removed from those surfaces of the article which had been pretreated with a grit blast but was not completely removed from those areas on which no grit blast pretreatment had been applied. On such areas, 'there were remains in spots both of the difiusion zone as well as some of the originally applied coating.
An additional problem which exists in the removal of aluminide coatings is that frequently such coatings are applied to such articles as jet engine turbine blades including relatively small cooling holes or passages. In such instances, use in the above described pretreatment steps of a grit, which is not soluble in the subsequently applied liquid, can penetrate, remain in and cause blockage of such holes or passageways. The present invention, in one form, contemplates use in the pretreatment of a grit of metallic particles soluble in the subsequently applied aqueous solutions of either the mixed acid or alkaline permanganate or both. For example, during evaluation of this aspect of the present invention, various angular iron and angular steel grits were evaluated both from the standpoint of their ability to pretreat or abrade the coated surface to be stripped as well as their solubility in the subsequently applied aqueous solutions during practice of the present invention. In general, it was found that iron and steel are completely soluble in the mixed acid solution and are not as hard as alumina abrasives which can have a detrimental effect on the article. One material tested was a chilled iron grit 325 mesh having a hardness in the range of about 50 56 R In other tests, dry, angular steel abrasive in the range of 25 120 grit was used. Because steel is single phase compared with the two phase structure in cast iron, it was found that the steel was more readily soluble in the subsequently applied mixed acids solution. An added benefit from the use of such materials as angular iron abrasives is that, in addition to operating on a coating, they have a tendency to polish the substrate material.
What is claimed is:
1. In an improved method for removing an aluminide coating from an article based on an element selected from the group consisting of Co and Ni, the steps of:
providing an aqueous mixed acid solution consisting essentially of an aqueous solution of HNO in an amount greater than 25 to less than 75 volume percent nitric acid of about 70 weight percent HNO and an aqueous solution of mm, in an amount greater than 25 to less than 75 volume percent phosphoric acid of about 85 weight percent H PO providing an alkaline permanganate solution consisting essentially of, by weight, about 8 ll percent sodium hydroxide, about 8 l 1 percent anhydrous sodium carbonate, about 4 6 percent potassium permanganate, with the balance water and incidental impurities;
subjecting the coating to the mixed acid solution at a temperature of about 160 180F for about A 2 hours;
rinsing the mixed acid solution from the coating;
subjecting the coating to the alkaline permanganate solution at a temperature of about 145 175F for about A 2 hours;
rinsing the alkaline permanganate solution from the 6 coating; subjecting the coating to the mixed acids solution at a temperature of about 160 180F for about /4 2 hours; and then rinsing the mixed acid solution from the coating.
2. The method of claim 1 in which:
the aqueous solution of HNO; is in an amount equal to 45 55 volume percent of the nitric acid.
3. In an improved method for removing an aluminide coating from an article based on an element selected from the group consisting of Co and Ni, the coating including products resulting from elevated temperature exposure to air and fuel combustion, the steps of:
mechanically abrading the coating with angular particles to a surface finish of no more than 100 rms; providing an aqueous mixed acid solution consisting essentially of an aqueous solution of HNO in an amount greater than 25 to less than 75 volume percent nitric acid of about weight percent HNO and an aqueous solution of l-l PO in an amount greater than 25 to less than volume percent phosphoric acid of about weight percent H PO providing an alkaline permanganate solution consisting essentially of, by weight, about 8 l 1 percent sodium hydroxide, about 8 l 1 percent anhydrous sodium carbonate, about 4 6 percent potassium permanganate, with the balance water and incidental impurities;
subjecting the coating to the mixed acid solution at a temperature of about 160 l80F for about /4 2 hours;
rinsing the mixed acid solution from the coating;
subjecting the coating to the alkaline permanganate solution at a temperature of about l75F for about 2 hours;
rinsing the alkaline permanganate solution from the coating;
subjecting the coating to the mixed acids solution at a temperature of about F for about A 2 hours; and then rinsing the mixed acid solution from the coating.
4. The method of claim 3 in which the particles are of a metallic material soluble in at least one liquid to which the coating subsequently is subjected.
5. The method of claim 4 in which the material of the particles is selected from the group consisting of iron and iron base alloys.
6. The method of claim 3 including the additional subsequent step of mechanically removing chemical residue from the article.
2. The method of claim 1 in which: the aqueous solution of HNO3 is in an amount equal to 45 - 55 volume percent of the nitric acid.
3. In an improved method for removing an aluminide coating from an article based on an element selected from the group consisting of Co and Ni, the coating including products resulting from elevated temperature exposure to air and fuel combustion, the steps of: mechanically abrading the coating with angular particles to a surface finish of no more than 100 rms; providing an aqueous mixed acid solution consisting essentially of an aqueous solution of HNO3 in an amount greater than 25 to less than 75 volume percent nitric acid of about 70 weight percent HNO3 and an aqueous solution of H3PO4 in an amount greater than 25 to less than 75 volume percent phosphoric acid of about 85 weight percent H3PO4; providing an alkaline permanganate solution consisting essentially of, by weight, about 8 - 11 percent sodium hydroxide, about 8 - 11 percent anhydrous sodium carbonate, about 4 - 6 percent potassium permanganate, with the balance water and incidental impurities; subjecting the coating to the mixed acid solution at a temperature of about 160* - 180*F for about 1/4 - 2 hours; rinsing the mixed acid solution from the coating; subjecting the coating to the alkaline permanganate solution at a temperature of about 145* - 175*F for about 1/2 - 2 hours; rinsing the alkaline permanganate solution from the coating; subjecting the coating to the mixed acids solution at a temperature of about 160* - 180*F for about 1/4 - 2 hours; and then rinsing The mixed acid solution from the coating.
4. The method of claim 3 in which the particles are of a metallic material soluble in at least one liquid to which the coating subsequently is subjected.
5. The method of claim 4 in which the material of the particles is selected from the group consisting of iron and iron base alloys.
6. The method of claim 3 including the additional subsequent step of mechanically removing chemical residue from the article.
| 1972-09-05 | en | 1974-09-03 |
US-3881398-A | Wingtip vortex impeller device for reducing drag and vortex cancellation
ABSTRACT
The present invention is a wingtip vortex device installed at the wingtips of an aircraft for induced drag reduction and vortex cancellation. Also, the wingtip vortex device is self-contained and is powered by the wingtip vortex. The wingtip vortex device comprises a shaft coupled between the wing and a spinner. The spinner is a streamlined body of revolution with a number of radial fins. The wingtip vortex of the aircraft induces spinner whirl, which is opposite to that of the wingtip vortex. As a result, the spinner-induced whirl produces an upwash superimposed on the downwash of the vortex. Thus, the total downwash, and hence the induced drag, are reduced.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to vortex cancellation for aircraft in general, and in particular to a wingtip vortex device for induced drag reduction and vortex cancellation at the wingtip of aircraft.
2. Related Art
Current wingtip vortex devices operate on the principle of self-cancellation of counter-rotating vortices generated in tandem. Typical vortex devices employ a propeller or related rotary device mounted at wingtips to produce vortex cancellation. Many studies of anti-swirl-producing propellers have been performed and documented.
Typically, a propeller is installed ahead of or behind the wingtip chord where, as a byproduct of thrust generation, the propeller-generates swirl, while also weakening the wingtip vortex, to thereby reduce induced drag. However, since current propellers are designed to produce thrust efficiently, they are only marginally effective in producing counter-swirl. Such a deficiency was pointed out by Alexander Lippisch as reported by Snyder and Zumwalt in "Effects of Wingtip-Mounted Propellers on Wing Lift and Induced Drag," Journal of Aircraft, Vol. 6, No. 5, September-October 1969.
As a result, an impeller was disclosed as a more effective alternative. An impeller consists of an oval-oblong-shaped body having a multitude of slender fins on its periphery. The impeller can efficiently produce swirling flow. Snyder and Zumwalt achieved a 64-percent induced drag reduction with an impeller as described.
Nevertheless, although the impeller disclosed by Snyder and Zumwalt is quite efficient in producing swirling flow, it generates little or no thrust. Also, Snyder and Zumwalt do not provide information on the power needed to drive the impeller. Thus, a process which requires mechanical power (presumably from the propulsion system) to reduce drag has little technical merit.
Therefore, what is needed is a device that limits or eliminates wingtip vortices by utilizing a "free" power source, such as the rotational energy of the wingtip vortex itself, to drive the device. What is also desired is a device that utilizes the power extracted from a wingtip vortex to generate a counter-swirling flow.
Whatever the merits of the above mentioned systems and methods, they do not achieve the benefits of the present invention.
SUMMARY OF THE INVENTION
To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention is a wingtip vortex device for induced drag reduction and vortex cancellation.
The wingtip vortex device of the present invention is an aerodynamic drag reduction system installed at the wingtips of an aircraft. Also, the wingtip vortex device is self-contained and is powered by the wingtip vortex. Consequently, induced drag is reduced without requiring an external power source such as the aircraft propulsion system.
The wingtip vortex device comprises a shaft coupled between the wing and a spinner. The spinner is a streamlined body of revolution with a number of radial fins. The wingtip vortex of the aircraft induces spinner whirl, which is opposite to that of the wingtip vortex. As a result, the spinner-induced whirl produces an upwash superimposed on the downwash of the vortex. Thus, the total downwash, and hence the induced drag, are reduced.
A feature of the present invention is embodied in a spinner device that limits or eliminates wingtip vortices by utilizing the rotational energy of the wingtip vortex itself. Yet another feature of the present invention is embodied in a device that utilizes the power extracted from a wingtip vortex to generate a counter-swirling flow.
An advantage of the present invention is that drag can be reduced without the need for an external power source. Another advantage of the present invention is that vortices can be limited or eliminated. Yet another advantage of the present invention is that it reduces the necessary distance between aircraft to allow more take-off and landings.
The foregoing and still further features and advantages of the present invention as well as a more complete understanding thereof will be made apparent from a study of the following detailed description of the invention in connection with the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
FIG. 1 is a perspective view illustrating a wingtip generating a vortex;
FIG. 2 is a perspective view of a wingtip vortex device system of the present invention; and
FIG. 3 is a rear view of the wingtip vortex device of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
Introduction:
FIG. 1 is a perspective view illustrating a wingtip creating a vortex. During take-off, landing, and flight of an aircraft, the aircraft's wing 10, as it travels through the air, creates a vortex 20 (a vortex is a high-velocity, helically rotating air mass) at the aircraft's wingtip 30. Since the vortex is a high-velocity rotating air mass, numerous problems can occur during flight, take-off, and landing of the aircraft.
Principally, during flight of the aircraft, the vortex creates undesirable drag on the wing 10. To overcome that drag, more thrust is required from the engines, and the related increase in fuel usage limits the distance the aircraft can fly.
Furthermore, the vortex creates air traffic problems during takeoff and landing. Because the vortices are high-velocity rotating airstreams, a wingtip vortex of one aircraft can greatly disturb the airmass through which a following aircraft may pass. This vortex interference can lead to the loss of control of the following aircraft and thereby cause an accident. Consequently, aircraft are spaced great distances apart from each other during takeoff and landing so that there is sufficient time for the wingtip vortices to decay before they encounter another aircraft. This creates substantial delays and air traffic control problems. The vortex cancellation device of the present invention solves this problem by greatly reducing or eliminating wingtip vortices. Thus, with the present invention, the distance between aircraft during take-off and landing can be reduced to allow more take-offs and landing.
Structure:
FIG. 2 illustrates a wingtip vortex device system of the present invention. The wingtip vortex device 40 of the present invention is a self-contained system installed at the wingtips 30 of an aircraft for reducing aerodynamic drag. The wingtip vortex device 40 is driven by the whirl of the wingtip vortex 20, and in the process the vortex 20 is weakened, thereby reducing aerodynamic drag. As such, an external power source, such as the aircraft propulsion system, is not required to power the vortex device 40.
Referring to FIG. 3 along with FIG. 2, FIG. 3 is a rear view of the wingtip vortex device of FIG. 2. The wingtip vortex device 40 is comprised of a shaft attached to the wing and a spinner 52. The spinner 52 is a streamlined body of revolution with a number of radial fins 54. The spinner's axis 58 is parallel to the axis 60 of the wingtip vortex 20. The spinner 52 is positioned inboard of the wingtip vortex 20 such that the outboard area 62 of each fin 54 extends into the inboard flowfield 64 of the wingtip vortex 20.
The fins or blades 54 of the spinner 52 are positioned to operate on the rotational flow components of the wingtip vortex to avoid a drag-producing deceleration of the axial flow components. The blades 54 are preferably in a streamwise orientation with little or no incidence relative to the free-stream flow vector. The blades'tips are preferably curved slightly backwards with respect to the rotation so that they point more nearly into the tangential flow vector of the vortex.
The shaft 50 of the spinner extends forward into the wing structure 10. The shaft 50 is preferably deflectable in pitch about its wing support so that the spinner axis 58 is kept parallel to the vortex axis 60 as the angle of attack changes. If desired, the shaft 50 of the spinner can be coupled to an internal generator 66 (such as a generator driver for driving aircraft subsystems) to extract power from the wingtip vortex 20 by the spinner 52. In the alternative, an internal gear device 64 can be coupled between the shaft 50 and the internal generator 66. However, it should be noted that such arrangements would be at the expense of the downwash reduction.
Operation:
Referring to FIG. 2, the spinner 52 is in direct contact with the wingtip vortex 20 and rotates in an opposite direction as the wingtip vortex 20. The wingtip vortex 20 weakens as it drives the spinner 52. Like meshing gears, the wingtip vortex 20 rotates the spinner 52 in opposite direction to that of the wingtip vortex 20 itself. The torque transmitted from the wingtip vortex 20 to the spinner 52 decreases the wingtip vortex circulation and, hence, reduces downwash and induced drag. The rotating spinner 52 of the wingtip vortex device 40 produces a counter-whirling airstream. This induced whirl further weakens the wingtip vortex when the two opposing whirls counteract each other farther downstream.
On the inboard side of the spinner 52, the upward motion of the induced whirl opposes the downwash of the wing. Thus, the downwash is reduced by the two-fold action of the weakened wingtip vortex and the opposing flow generated by the induced spinner whirl inboard of the device.
The vortex device 40 reduces downwash behind an aircraft for decreasing induced drag. Downwash is caused by the circulation of the wingtip vortices 20. As such, a reduction of wingtip vortex 20 circulation will cause a reduction of the induced drag.
The spinner 52 is solely propelled by the wingtip vortex 20, and thus, an external power source, such as the aircraft propulsion system, is not required to power the vortex device 40.
Since the blades'tips are curved in the direction slightly backward with respect to the rotation, they point more nearly into the tangential flow vector of the vortex. Thus, meshing of the spinner 52 and wingtip vortex 20 occurs under favorable conditions. For example, the fin tips, having the highest tangential velocity, extend into the vortex center where its tangential velocities are highest.
It is important to note that, although the spinner 52 generates drag on its own (unrelated to its rotary action), the induced-drag reduction outweighs the device's drag, especially at maneuvering flight conditions where induced drag is a multiple of the zero lift drag.
Almost any existing and future aircraft, including sailplanes and gliders, can utilize the wingtip vortex device of the present invention. If high total system efficiencies can be achieved, the design of aircraft utilizing the wingtip vortex device of the present invention could be materially affected. For instance, wing span would become less important as it would loose much of its induced drag determinacy. Shorter-span wings generate stronger tip vortices providing the vortex devices with a higher amount of vortex energy for conversion.
The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.
What is claimed is:
1. An aerodynamic drag reduction and vortex cancellation system for an aircraft wingtip characterized by a wingtip vortex induced adjacent thereto, the wingtip vortex generally defined by inboard and outboard vortex flowfields, the system comprising:a propeller disposed adjacent the wingtip in fluid communication with the wingtip vortex, the propeller being generally defined by inboard and outboard propeller areas, the outboard propeller area extending into the inboard vortex flowfield, the propeller being sized and configured to rotate in an opposing rotational direction from that of the wingtip vortex in response to exposure to the inboard vortex flowfield for mitigating the wingtip vortex and reducing aerodynamic drag.
2. The aerodynaic drag reduction and vortex cancellation system of claim 1 further comprises a shaft, the propeller extends from the shaft.
3. The aerodynamic drag reduction and vortex cancellation system of claim 1 wherein the wingtip vortex is generally defined by a vortex axis of rotation and the propeller is generally defined by a propeller axis of rotation, the propeller axis of rotation is disposed generally parallel to the vortex axis of rotation.
4. The aerodynamic drag reduction and vortex cancellation system of claim 3 wherein the propeller having a plurality of fins, the propeller axis and the vortex axis are positioned at least the length of one of the fins apart.
5. The aerodynamic drag reduction and vortex cancellation system of claim 1 wherein the propeller has a propeller axis of rotation, the angular orientation of the propeller axis of rotation is adjustable.
6. The aerodynamic drag reduction and vortex cancellation system of claim 2, further comprising an intermediate gear device coupled between said shaft and a power generator.
7. The aerodynamic drag reduction and vortex cancellation system of claim 6, wherein said intermediate gear device is a bevel set of gears.
8. The aerodynamic drag reduction and vortex cancellation system of claim 7, wherein said bevel set comprises a first bevel gear meshing with a second bevel gear.
9. The aerodynamic drag reduction and vortex cancellation system of claim 8, wherein said first bevel gear is connected to said shaft, said second bevel gear is attached to said power generator.
10. The aerodynamic drag reduction and vortex cancellation system of claim 9, wherein said power generator is driven solely by said shaft and does not require an additional power source.
11. The aerodynamic drag reduction and vortex cancellation system of claim 2, wherein said shaft is coupled to a power generator.
12. An aerodynamic drag reduction and vortex cancellation system comprising:an aircraft wing having an aircraft wingtip characterized wingtip vortex induced adjacent thereto, the wingtip vortex generally defined by inboard and outboard vortex flowfields; and a propeller disposed adjacent the wingtip in fluid communication with the wingtip vortex, the propeller being generally defined by inboard and outboard propeller areas, the outboard propeller area extending into the inboard vortex flowfield, the propeller being sized and configured to rotate in an opposing rotational direction from that of the wingtip vortex in response to exposure to the inboard vortex flowfield for mitigating the wingtip vortex and reducing aerodynamic drag.
13. A method of reducing aerodynamic drag reduction and canceling vortex forces adjacent an aircraft wingtip characterized by a wingtip vortex induced adjacent thereto, the wingtip vortex generally defined by inboard and outboard vortex flowfields, the method comprising the steps of:(a) locating a propeller adjacent the wingtip in fluid communication with the wingtip vortex, the propeller being generally defined by inboard and outboard propeller areas, (b) extending the outboard propeller area into the inboard vortex flowfield, the propeller being sized and configured to rotate in an opposing rotational direction from that of the wingtip vortex in response to exposure to the inboard vortex flowfield for mitigating the wingtip vortex and reducing aerodynamic drag.
14. The method of reducing aerodynamic drag reduction and canceling vortex forces of claim 13 further comprises the step of attaching a power generation device in mechanical communication with the propeller for extracting power from the wingtip vortex.
15. The method of reducing aerodynamic drag reduction and canceling vortex forces of claim 14 wherein the propeller has an axis of rotation, the method further comprises the step of adjusting the angular orientation of the axis of rotation of the propeller.
| 1998-03-11 | en | 1999-07-06 |
US-61678975-A | Circuit for combining pulse trains
ABSTRACT
An electric circuit with a plurality of inputs, each input receiving a train of pulses. Each pulse of each train sets a latch of cross-coupled logic gates to an output of logic 1. A clock generating regular voltage pulses is connected in parallel to the latches so as to reset the output of each gate to logic 0 in series with each other. The plurality of outputs from the latches is passed through a common gate to form the output train of pulses as an addition of the plural inputs.
BACKGROUND OF THE INVENTION
1. Field
This invention adds quantitative signals from a plurality of sources. More specifically the signals from each source are stored separately and released in sequence from the plurality of storage points by signals from a third source.
2. Prior Art
By some standards, the need to provide a single point of addition for a number of quantity indications is esoteric. However, there is such need.
We recognize there are many ways to approach the problem. However, where the primary element directly interfacing with the quantitative variable generates a train of voltage pulses, a particular system for processing the pulses is required. Where there is a plurality of pulse trains to be combined into a single train, provision for storing each train must be made. A release of each train, for the combination, must be provided so the pulses of each train may be meshed, added, for the single point of manifestation.
All of the storing, releasing and addition functions must be performed. The prior art which I have studied does not carry out these functions with logic gate latches released by a voltage pulse generator clock.
SUMMARY OF THE INVENTION
The invention processes a multiple of signal trains into a single train which is a total of the quantity represented by the trains. The invention is embodied in an electric circuit which receives the trains in the form of a series of voltage pulses. The circuit is divided in sections, each section receiving a pulse train. Each pulse of the train is applied to a latch of cross coupled logic gates. The latch output is carried to logic 1 by each pulse and returned to logic 0 by a clock pulse. The return to logic 0 generates in the output of the circuit a voltage pulse and in sequence with pulses from other sections.
Other objects, advantages and features of the invention will be apparent to those skilled in the art from the written specifications, claims and drawings, i.e., the disclosure.
The drawing is a diagrammatic circuit embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The circuit disclosed in the drawing receives signals on a quantitative basis. The number of signals equals the amount of whatever material generated the signals. The more common example is fluid flow. As the fluid passes a position, it generates a signal for each increment of fluid which passes the position.
The circuit embodying the invention will receive the signal in the form of surges of voltage. The primary element directly responding to the flowing fluid will generate a pulse of voltage for each flowing fluid increment. These voltage pulses will be fed into the circuit at more than one position. The circuit is so arranged as to add the pulses from the positions and flow them from the circuit in one train. An accumulation does not form a part of the invention, but it can receive the pulse train and display it as a total flow of two or more fluid streams.
The plural number of inputs are received by separate input sections of the circuit. The pulses to each section may be received sequentially or at the same time.
Within each circuit section, the pulses received are stored in latches. A generated train of pulses is then applied to the sections to serially transfer the stored pulses from the latches. The generator of the pulse train which triggers the latches will be termed here a "clock."
The embodying circuit is built around the so-called logic circuits. Those skilled in the art have used both the NAND gate and NOR gate. It is simply a matter of design which is selected for the present circuit. The circuit will be disclosed with the use of the NAND gate which was convenient when the invention was first reduced to practice.
Each section of the circuit includes a couple of NAND gates connected as cross coupled latches. The signal, as a voltage pulse, is inverted to set the output of the latch to logic 1. The clock pulse feed will reset the latch output to logic 0 which, on the output gate of the circuit appears as a voltage pulse. Each section of the circuit sequentially has any logic 1 latch output lowered by a clock pulse to appear at the output gate. Accumulated, the pulses from the output gate may be registered as a total of all inputs to the circuit sections.
In the drawing, the circuit is disclosed with only two sections A and B and a voltage generator, or clock.
SECTION A
Input lead 1 to section A is connected to the input of inverter A1. Actually, a NAND gate with inputs connected will function as an inverter. In any event, inverter A1 receives a positive input pulse of voltage and converts it to an output voltage pulse which is in the opposite direction of the input. It is a matter of magnitudes. An increase in input voltage is inverted to a decrease in output voltage. Lead 2 places the inverted input on the section A latch.
The section A latch comprises NAND gates A2 and A3, connected as disclosed. The inverted pulse signal applied to one of the two input leads of the latch causes the output of A2 to go to logic 1. Logic 0 is applied by lead 2 and logic 1 is applied to lead 3 through A2 of the latch. Logic 1 remains on lead 3 until returned to logic 0 by a clock pulse. It is this shift from logic 1 to logic 0 on lead 3 that generates the output of this section of the circuit.
Keep in mind that the logic 1 on lead 3 is applied to one input of A3, the other NAND gate of the latch. The second input to A3 is also at logic 1, making the output of A3 to go to logic 0. The logic 0 output of A3 on the input of A2 latches in the logic 1 as an output of A2. Then, nothing happens until a clock pulse changes the logic 1 on the second input to A3. This logic 1 on lead 4 to A3 is sustained by inverter A5. The input to A5 is normally at logic 0. It is disclosed as connected to ground. Therefore, the output to lead 4 is logic 1.
Note that lead 5 to inverter A5 has a capacitor 6. Therefore, each change in input to capacitor 6 from logic 0 to logic 1 will cause a quick change in the output of inverter A5 to logic 0. This simple change will shift the logic 1 of lead 3 to logic 0. Only this shift from logic 1 to logic 0 on lead 3 generates an output voltage pulse from the circuit. How does the clock voltage output function to transfer the change from logic 1 to logic 0 of the latch to the output as a voltage pulse?
THE CLOCK
The clock circuit is a stable, cyclic source of voltage pulses. The change in forming the leading and trailing edges of each clock pulse gives the desired result.
Each clock pulse is applied to both section A and section B in parallel. However, the pulse to one section is inverted. Specifically, A4 is shown connected to invert the clock pulse to section A.
Remember, only the change on capacitors at the entrances of each section from low to high values will lower the lead 4 signal to transfer the pulse latched on lead 3. As the clock pulse is inverted, as between the sections A and B, the readout from the section latches will alternate, the resulting pulses fed sequentially to the circuit output gate A6.
LATCH OUTPUT CIRCUIT
Each input to A6 is provided a positive voltage, or logic 1, from a divider circuit comprised of resistances 7 and 8. This divider circuit is tied to lead 3 through capacitor 9. Therefore, as the latch output shifts from logic 1 to logic 0, the voltage on lead 10 changes downward, to be inverted by A6 to a positive output voltage pulse on lead 11.
Sections A and B alternate in supplying signals to output lead 11. They alternate because the triggering clock pulses are inverted into one of the sections. If a logic 1 is found on a latch output it is transferred to lead 11 by the clock pulse edge which shifts the logic 0 of lead 5 to logic 1. But the clock pulse inversion dictates this shift to occur alternately, as between sections.
CONCLUSION
The circuit is built around pairs of logic gate circuits. Each pair of gates is connected to each other as a cross-coupled latch. The input of a voltage pulse sets the output to logic level 1. The pulse is "stored" on the latch. The pulse is released by the edge of a pulse generated by a "clock."
Each of section A and section B has its own latch, independently receiving its input pulses in a train. Each section receives each pulse to set its latch.
Next, a generator of a pulse train supplies its output to the sections and their latches in parallel. The edges of these clock pulses resets the latches of the sections. In the pair of sections disclosed, the clock output to one of the sections is inverted so that the latches will be reset alternately, in sequence.
The change in latch output is applied to a resistance divider circuit which generates a voltage output when the latch output is reset. This voltage pulse generation, from the plurality of sections, is formed into a single pulse train through a final logic gate.
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.
The invention, having been described, what is claimed is:
1. A circuit arranged to respond to a plurality of voltage pulse trains and generate a single voltage pulse train which is an addition of the plurality of trains, including;a first circuit section connected to a first of the input pulse trains, including,a. a pair of logic gate circuits connected as a cross coupled latch and connected to receive the pulses of the input to the section and generate an output logic 1, b. a connection between the output of an independent, stable source of voltage pulses and the cross coupled latch through which a first of the edges of the pulses shifts the latch output to logic 0. c. and a resistance divider circuit means capacitively connected to said latch and responding to only the shift in the latch output to logic 0 to generate a voltage pulse in the output of the circuit; and a second circuit section connected to a second of the input pulse trains which generates a voltage pulse in the output of the circuit with the second of the edges of the pulses of the stable source of voltage pulses, whereby the differential source pulses generates a pulse train output of the circuit from the plurality of input pulse trains.
2. A circuit connected to a plurality of voltage pulse trains, including;a section for receiving each pulse train, each section including;a. a pair of logic gate circuits connected to form a cross-coupled latch and receiving the pulse train to the section as one of two inputs, b. a resistance divider circuit means capacitively connected to the output of the latch so as to generate an output voltage pulse as the latch output shifts in a predetermined direction, c. and a source of independent stable, cyclic voltage pulses connected to the latch as the other of the two inputs, a selected edge of each pulse shifting the latch output in the predetermined direction; whereby the output voltage pulses from the circuit means of each section is sequentially formed into an output of the circuit as a single pulse train.
3. The circuit of claim 2 in which the pair of logic gate circuits are NAND gates which receive each pulse to their section for generation of an output logic 1 and the circuit means generates its output voltage pulse as the logic 1 output is shifted to logic 0.
| 1975-09-25 | en | 1977-01-04 |
US-42392282-A | Wide dynamic range ultrasound echo receiver
ABSTRACT
The wide dynamic range ultrasound receiver utilizes a multi-stage logarithmic amplifier in order to logarithmically amplify a returned echo signal. The output of the returned echo signal from the logarithmic amplifier is simply added to a saw-tooth wave Time Gain Control (TGC) signal. Thus, the wide dynamic range of the returned echo signals is simply converted into a video display.
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasound echo receiver of the type which is used in medical diagnostic devices.
Ultrasound is used in medical diagnostic equipment in order to perform non-invasive examinations of organs within a patient3 s body. Typically, an ultrasound pulse is transmitted into the patient3 s body, and an echo, representative of the location of a reflecting surface, is returned to the transducer. In view of the fact that the strength of reflected signals falls off exponentially as the distance between the ultrasound transducer and the reflecting surface increases, it is necessary to amplify the echo which is received from the reflecting surface within the diagnostic equipment.
Heretofore, a time-variable gain control (TGC) was used to regulate the RF gain of the ultrasound echos. TGC was used, because echos which are returned from surfaces farther from a transducer are weaker, and therefore require greater gain, than echos which are returned from surfaces closer to the transducer
Problems with the prior art methods of regulating RF gain relate to the fact that it is difficult to eliminate the TGC control voltage from the resulting echo signal, the fact that there is relatively low response speed of RF gain changes to TGC signal changes, and the fact that it is complicated to control RF gain. Typical ultrasound diagnostic receivers use a cathode ray tube (CRT) to display images corresponding to the cross-section of the organs being scanned. The gray scale on a CRT monitor typically has a range of about 40 dB. That 40 dB range is used to represent the strength of received echos having a signal range which extends over approximately 110 dB.
In view of the problems with controlling RF gain in the receiver circuit, it would be desirable to have a circuit which is capable of controlling the gain of the input video signal to the CRT.
SUMMARY OF THE INVENTION
The present invention is a receiver for ultrasound medical diagnostic equipment which includes a series of fixed gain RF amplifiers, together with a logarithmic amplifier, preferably a monolithic, logarithmic amplifier. In the preferred embodiment, the logarithmic amplifier has four 30 dB log stages. The gain in each stage is such that output of each stage is proportional to the logarithm of the input voltage over the 30 dB input voltage range. The four stages are interconnected to obtain an input voltage range which is consistent with the return signal strength in the echo receiver, i.e. approximately 110 dB.
A receiver package having three RF amplifiers which are connected in series, will, accordingly, have four input voltages (corresponding to the input voltage of each of the three RF amplifiers and the output voltage of the final RF amplifier) to input into the four stages of the logarithmic amplifier.
The output of the logarithmic amplifier is further amplified and detected, and that output signal is used to provide an input video signal to the ultrasound unit's CRT display.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a block diagram of a portion of an ultrasound echo receiver which includes the present invention;
FIG. 2 is a block diagram of another portion of an ultrasound echo receiver including the present invention;
FIG. 3 is a graph of the type of signal which is received by the ultrasound echo receiver of the present invention;
FIG. 4 is a graph of the TGC signal used in the present invention;
FIG. 5 is a graph of the composite TGC signal of FIG. 4 combined with the return signal of FIG. 3 to provide the composite video signal; and
FIG. 6 is a detailed schematic diagram of the portion of the receiver illustrated in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring generally to FIG. 1, a block diagram of a portion of an ultrasound echo receiver 10 is shown. The receiver 10 includes an ultrasound pulser 12, used to generate pulses of ultrasound energy, typically in the 1-10 MHz range. The pulser 10 sends pulses of ultrasonic energy to an ultrasound transducer (not shown) of the type typically used in medical diagnostic equipment. The ultrasound transducer may be a mechanical sector scanner, or it may be a transducer which uses either phased array or linear array technology. Pulses from the ultrasound pulser 12 are sent through diodes 14 into a transmit-receive switch 16. When the energy level into the transmit-receive switch 16 exceeds a predetermined value, the transmit-receive switch 16 opens, and the ultrasound energy from the pulser 12 goes into the ultrasound transducer. At all other times, the transmit-receive switch 16 is closed, and the ultrasound energy from the transducer is the input voltage to the receiver 10.
In addition to the transmit-receive switch 16, there are connected, in series, an RF pre-amplifier 18 and two RF amplifiers 20, 22. The input signal to the RF pre-amplifier 18, the input signals to the RF amplifiers 20, 22, and the output signal from the RF amplifier 22 are input signals to a multistage logarithmic amplifier 24, such as a Texas Instruments TL441C monolithic logarithmic amplifier.
The output signal from the logorithmic amplifier 24 is further amplified by an amplifier 26, and the output signal from the amplifier 26 is sent through a video detector 28 to a buffer amplifier 30.
The output signal from the buffer amplifier 30, shown in FIG. 3, is essentially equal to the logarithm of the input signal from the transducer, i.e., the input to the RF amplifier 18. With reference to FIG. 2, that signal is on a first line 32.
A time gain control (TGC) signal on a second line 34 is added in an adder 36 to the log video signal which comes out of the receiver 10. The TGC signal has the form shown in FIG. 4. At the time the transmission occurs, a delay generator 38, set by a variable resistor 40, together with a slope generator 42, also set by a variable resistor 44, have combined outputs which are further combined at a summation point with the output of a variable resistor 46 which acts as the near gain control. These controls 40, 42, 46 establish the base gain of the overall receiver 10. The voltages are passed through a first operational amplifier 48 and diode 50 to point A. Similarly, voltages corresponding to a far field are sent through a second operational amplifier 52, i.e. the far field amplifier 52, through a second diode 54 to point A. The TGC waveform is limited so that it cannot go beyond the far field voltage, VFF, as shown in FIG. 4.
Referring to FIG. 4, the TGC voltage drops rapidly from the far field voltage, VFF, down to the near field voltage, VNF and then slopes back up to the far field voltage, VFF, in the form of a saw-tooth wave.
The TGC signal of FIG. 4 is added to the log video signal coming out of the buffer amplifier 30 of the receiver 10 (shown in FIG. 3). At the end of the delay period during which the TGC signal is held at the near field level, VNF, the TGC slope is generated by the slope generator 42 whose slope can be varied using the slope control resistor 44. At the time the pulse is transmitted by the transducer, the delay generator 38 is started. At the end of the delay period, during which the TGC signal is held at the far field level VNF, the TGC slope is generated by the slope generator 42 whose slope can be varied using the slope control resistor 44. That is combined with the voltage from the near gain resistor 46 to set the base gain of the overall receiver.
With reference to FIG. 2, there are two signals going into point A. The voltage that comes from the far field amplifier 54 is established to negative limits and cannot go any lower than that. The TGC voltage drops to that lower limit. It starts out at the higher level set by the near gain control 46 and then it ramps back up to far field voltage. The slope that it uses is set by the slope control 44.
Addition of the log video signal on line 32 with the TGC voltage on line 34 results in the composite video signal, shown in FIG. 5. The composite video is amplified, filtered, attenuated, and applied to an Analog-to-Digital Converter. Digitized video is displayed on the CRT. Only that portion of the composite video signal which falls within the Analog-to-Digital window will be displayed. The linear addition of the TGC voltage to the log video signal effectively reduces the gain of the receiver when strong signals from nearby reflectors are received and increases the gain of the receiver when weak signals from distant reflectors are received, so that at all distances only the strongest 40 dB segment of the echos are displayed.
Referring now to FIG. 6, a detailed schematic diagram of the receiver circuit 10 is shown. The transmit-receive switch 16 (as shown in FIG. 1) is implemented by diodes CR1, CR2, CR3, CR4, and CR6. The RF pre-amplifier 18 is implemented by transistors Q1 and Q3 and associated components which are used for signal coupling. The RF amplifiers 20, 22 are comprised of a pair of substantially identical stages. The first stage is made up of transistors Q5, Q6, Q7, and Q8, together with associated resistors. Similarly, the second RF amplifier 20 is comprised of transistors Q9, Q10, Q11, Q12, and associated resistors.
The output of the RF preamplifier is passed through transistor Q5 which operates in the emitter follower mode, i.e. as a unity gain amplifier, into the monolithic logarithmic amplifier U1 via resistor R17. Similarly, the output of RF amplifier 20 is passed through resistor R33 into the monolithic logarithmic amplifier U1, and the output of RF amplifier 22 is passed into the logarithmic amplifier U1 via transistor Q12 operating in the emitter follower mode. The post amplifier 26 is comprised substantially of transistors Q13 and Q14 and their associated components.
In view of the detail shown in the schematic diagram of FIG. 6, and the fact that the operation of the circuit has heretofore been described with reference to FIG. 1, no additional description of the components or operation is required.
I claim:
1. A wide dynamic range ultrasound echo receiver comprising:(a) a first linear amplifier having an input and an output: (b) a multi-stage logarithmic amplifier having a first input associated with a first stage and at least one subsequent input associated with at least a second stage, said multi-stage logarithmic amplifier having a single output, whereby each stage has a gain such that the output of said stage is proportional to the logarithm of the input voltage to said stage and the output of said multi-stage logarithmic amplifier corresponds to the sum of the logarithms of the input voltages to the various stages; (c) means for introducing a voltage signal representative of a received ultrasound echo into the input of said first linear amplifier and into said first input associated with said first stage of said multi-stage logarithmic amplifier; (d) means for introducing the output of said first linear amplifier into said subsequent input of said second stage of said multi-stage logarithmic amplifier; and (e) means for generating and adding a sawtooth voltage signal to the output signal of said multi-stage logarithmic amplifier, whereby the composite signal thus formed will be representative of the subject matter being scanned by said received ultrasound echo.
2. The wide dynamic range ultrasound echo receiver of claim 1, further comprising video means coupled to the output of the multi-stage logarithmic amplifier for detecting a video signal from said composite output signal.
3. The wide dynamic range ultrasound echo receiver of claim 2 further comprising at least a second linear amplifier having an input and an output, the output of said first linear amplifier being the input to said second linear amplifier and said subsequent input into the second stage of said multistage logarithmic amplifier, the output of said second linear amplifier serving as said subsequent input to a third stage of said multistage logarithmic amplifier.
4. The wide dynamic range ultrasound echo receiver of claim 2 further comprising at least a third linear amplifier having an input and an output, the output of said second linear amplifier being the input to said third linear amplifier and being yet another said subsequent input to the third stage of said multistage logarithmic amplifier, the output of said third linear amplifier serving as yet another said subsequent input to a third stage of said multistage logarithmic amplifier.
| 1982-09-27 | en | 1984-06-19 |
US-31695772-A | Friction element composition
ABSTRACT
1. A FRICTION ELEMENT COMPOSITION COMPRISING A FRICTION IMPARTING AGENT, AN INORGANIC FILLER AND A BINDER COMPOSITION COMPRISING A NON-HYDROXYALKYLATED HYDROXY AROMATIC HYDROCARBON ALDEHYDE RESOLE CONTAINING SUBSTANTIALLY NO ETHERIFIED AROMATIC HYDROXYL GROUPS AND AN HYDROXYALKYL HYDROXY AROMATIC HYDROCARBON ALDEHYDE RESOLE CONTAINING LESS THAN ABOUT 0.5 PERCENT OF THE AROMATIC HYDROXYL ORIGINALLY PRESENT IN THE HYDROXYL AROMATIC HYDROCARBON ALDEHYDE CONDENSATE.
United States Patent 3,850,874 FRICTION ELEMENT COMPOSITION Frank S. Grazen, Melvin L. Buike and Frank M. Bryzinsky, New York, N.Y., assignors to Hooker Chemicals & Plastic Corporation N0 Drawing. Application Oct. 12, 1971, Ser. No. 188,596, now Patent No. 3,767,612, which is a continuation of abandoned application Ser. No. 872,737, Oct. 30, 1969, Divided and this application Dec. 20, 1972, Ser. No.
Int. Cl. C08g 37/18, 51/10 US. Cl. 260-38 9 Claims ABSTRACT OF THE DISCLOSURE A friction binder for a friction element composition, especially useful where cashew nut shell oil and/ or vegetable oils have been used in a phenolic resin composition, may be prepared by blending a non-oxyalkylated resole with resin selected from the group consisting of an oxyalkylated resole, alkylated resole, an oxyalkylated novolac, an alkylated novolac, and mixture thereof. The friction element composition is prepared by adding to this binder asbestos fiber and friction imparting materials, and curing the resultant material.
This is a division of co-pending application Ser. No. 188,596, filed Oct. 12, 1971, now US. Pat. 3,767,612, issued Oct. 23, 1973; which is a continuation of application Ser. No. 872,737, filed Oct. 30, 1969, now abandoned.
This invention relates to a resinous material as a binder for friction elements and more particularly to those elements which are suitable for use in brakes of automotive vehicles, clutch facing, machine brakes and many other industrial applications. It is especially useful where cashew nut shell oil polymerizates or vegetable oil-modified phenolic resin compositions have been used in the past.
Phenol aldehyde, or hydroxy aromatic-aldehyde condensation products having methylol side or end groups are known in the art as resoles. They are formed from condensing a phenol with an excess of aldehyde and with an alkaline catalyst, also known as one-stage resins and are of the thermosetting type. Except when oxyalkylated, they are self setting. That is, upon the application of heat there results the formation of a resite, which is an infusible three-dimensional polymer.
Phenol aldehyde novolac resins, on the other hand, are phenol-ended chain polymers. They are formed by the reaction of an aldehyde with an excess of phenol in the presence of an acid catalyst and/or heat. They are thermoplastic, permanently soluble and fusible. However, upon the addition of a curing agent, they can be cured into an insoluble, infusible resin. Thus, novolac resins are known as two-stage resins.
Phenol aldehyde condensation products have been used as binders for abrasive materials. However, to our knowledge, the novel phenol aldehyde products of this invention have not been used as binders.
As used herein friction particle is intended to mean having the properties of substantially no softening at elevated temperatures and will not flow together or cohere with other particles, as a friction binder would, or fuse with like friction particles. It is insoluble, having an acetone extraction of less than 35 percent and often less than percent; it is infusible, i.e., has gone beyond the B stage, to the C stage. It will not melt at 700 degrees Fahrenheit. A friction particle is held in place with a friction binder.
As used herein, a friction binder has the properties of fiowability, and has adhesive and cohesive bonding action and thereby binds together the asbestos and other 3,850,874 Patented Nov. 26, 1974 additives (including a friction particle) necessary for building a brake lining or other similar article of manufacture. The binder, as supplied to the industry, will melt as a dry powder or is a liquid resin, and can be either an A stage or B stage resin. The binder becomes a C stage resin after it is combined with the other ingredients and cured.
The composition of the binder, friction particle and other additives, is heated to between 300-400 degrees Fahrenheit and pressed at between 500200() pounds per square inch in order to form a brake lining composition, or clutch facing or other braking device.
It has now been found that a composition of matter useful as a friction binder can be prepared by blending hydroxy aromatic hydrocarbon-aldehyde resole with a resin selected from the group consisting of an oxyalkylated hydroxy aromatic hydrocarbon-aldehyde resole, an alkylated hydroxy aromatic hydrocarbon-aldehyde resole, an alkylated hydroxy aromatic hydrocarbon-aldehyde, an oxyalkylated hydroxy aromatic hydrocarbon-aldehyde novolac and mixtures thereof. The first said resole can be alkylated but not oxyalkylated. Among the preferred embodiments of this invention are the following:
1. The blended product of between about 5 and about 40 percent by weight of an oxyalkylated resole with be tween about and about 60 percent by weight of one or more of (a) one or more non-oxyalkylated, non-alkylated resoles,
(b) a non-oxyalkylated, alkylated resole,
(c) a mixture of a non-oxyalkylated resole and a nonoxyalkylated, non-alkylated resole,
(d) a mixture of a non-oxyalkylated, non-alkylated resole and a non-oxyalkylated alkylated novolac, and (e) a mixture of a non-oxyalkylated, non-alkylated novolac and a non-oxyalkylated, non-alkylated resole.
2. The blended product of between about 95 and about 60 percent by weight of a non-oxyalkylated, non-alkylated resole with between about 5 and about 40 percent by weight of one or more of (a) an oxyalkylated novolac, and (b) a non-oxyalkylated, alkylated resole.
3. The blended product of between about 5 and about 40 percent by weight of an oxyalkylated novolac with between about 95 and about 60 percent by weight of one or more of (a) two or more non-oxyalkylated, non-alkylated resoles,
(b) an alkylated resole,
(c) a mixture of an alkylated resole and a non-oxyalkylated, non-alkylated resole,
(d) a mixture of a non-oxyalkylated, non-alkylated resole and a non-oxyalkylated alkylated novolac, and (e) a mixture of a non-oxyalkylated, non-alkylated resole and a non-oxyalkylated, non-alkylated novolac.
4. The blended product of between about 5 and about 95 percent by weight of a solid, B-stage, non-oxyalkylated, alkylated resole, with between about 95 and about 5 percent by weight of a liquid, A-stage non-oxyalkylated, alkylated resole.
In general, an oxyalkylated hydroxy aromatic material, whether it i a novolac or a resole, will not react with a novolac by itself. The methylol groups on a resole are believed to be needed to react with the polyol groups of the oxyalkylated materials.
The friction binder is formed by blending the resole with the novolac, or other resole. Usually, the resole and oxyalkylated resole or oxyalkylated novolac are both liquids, so blending is easily achieved. However, when one 3 is a solid, it is powdered and mixed with the liquid. When both are solids, both are dry blended such as by ball milling together. Then they are mechanically blended, such as by being passed through a hammer mill equipped with a quarter mesh screen.
Normally, the materials are not reacted together. However, in some cases, it may be desirable to partially react the blended mixture to increase its viscosity. The temperature chosen should be within the limits of relatively easy reaction control and will normally be from about 150 to 210 degrees Fahrenheit. The resultant material is normally in the A stage of polymerization. However, in some cases, the oxyalkylated resole or oxyalkylated novolac in combination with a resole and a novolac is reacted and carried to a B stage condition. This reacted B stage blend can be used by itself or in combination with a formaldehyde donor, such as hexamethylenetetramine, as a binder. The blend is suitable for use as a friction composition constituent and as a binder for brake lining fillers.
Examples of phenols which can be used in preparing a phenol aldehyde resole or novolac for use in practicing the invention include ortho-, para-directing hydroxy or amine aromatic compounds having 6 to 24 carbon atoms such as phenol itself (C H OH), naphthol, anthranol and substituted derivatives thereof where the substituents on the aromatic compound are independently selected from H, Cl, Br, F.NH and (a) alkyl groups or radicals of 1 to carbon atoms, preferably of 1 to 30 carbon atoms, and their various isomeric forms and substituted on the aromatic nucleus in the orthoor para-position;
(b) cycloalkyl groups of 5 to 12 carbon atoms such as cyclohexyl, cyclopentyl, methylcyclohexyl, butylcyclohexyl, and the like;
(c) alkyl, aryl and cycloalkyl ketonic groups wherein the hydrocarbon portion is as defined above in (a) and (b);
(d) alkyl, aryl and cycloalkyl carboxylic groups wherein the hydrocarbon part is defined as above in (a) and (e) aryl groups of 6 to 24 carbon atoms such as phenyl,
naphthyl, anthryl, and the like;
(f) aryl substituted alkyl wherein the aryl is phenyl which may contain lower alkyl and/or hydroxy substituents so that the resulting hydroxy aromatic is, for example, a bisphenol; and
(g) mixtures of the aforesaid hydroxy aromatics.
Suitable substituted phenols include the following: para-phenyl phenol, para-benzyl phenol, para-beta-naphthyl phenol, cetyl phenol, para-curnyl-phenol, para-tertbutyl phenol, sec-butyl phenol, para-tert-amyl phenol, para-tert-hexyl phenol, para-alpha-naphthyl phenol, parahydroxyacetophenone, para-hydroxybenzophenone, paraisooctyl phenol, para-tert-octyl phenol, para-cyclohexyl phenol, para-d-limonene phenol, para-l-limonene phenol, a phenol alkylated with oleic acid, such as phenol alkylated with oleic acid, para-decyl phenol, para-dodecyl phenol, para-tert-decyl phenol, butyl naphthol, amyl anthranol, para-nonyl phenol, para-methyl phenol, bisphenols such as para,para'-isopropylidene diphenol, para, para'-methylene diphenol, as well as the corresponding ortho-derivatives of the previously mentioned compounds such as ortho-butyl phenol and ortho-nonyl phenol as well as mixtures thereof, and aniline.
Mixtures of various hydroxy aromatic compounds mentioned herein also may be used.
Included among the phenolic reactants which may be used are those known as the cresylic acids and these often comprise a heterogeneous mixture of having two reacting hydrogen positions on each of them; that is, compounds unsubstituted in the orthoand para-positions of the molecule, to compounds that only have one functional position, and hence, relatively unreactive. These compounds may include the following: 3,5-xyleno1,
m-cresol, 3,4-xylenol, 2,5-xylenol, 2,3-xylenol, phenol, pcresol, ortho-cresol, 2,4-xylenol and 2,6-xylenol. Cresylic acids or tar acids are generally applied to phenol and its homologs which may include cresols xylenols, trimethyl phenols, ethyl phenols, and higher boiling materials such as dihydroxy phenols, polycyclophenols and the like. They are often obtained by a low-temperature trimerization of coal, lignite, and the like, or a conventional high-temperature coke oven tar, or the liquid product of petroleum cracking both thermo and catalytic, shell oil, coal hydric hydrogenation products, and the like.
Polyhydroxy aromatic reactants, such as resorcinol, may also be used.
Particularly useful in this invention are mixtures of aniline and phenol to react with an aldehyde or ketone to produce either a novolac or a resole, depending on the other conditions described above.
Also useful in the invention are mixtures of urea and phenol to react with the aldehyde or ketone to produce either a novolac or a resole depending on the other conditions described above.
Among the aldehydes which may be used within the scope of this invention to produce either the resole or the novolac, are formaldehyde or any of its variations, such as 37 percent formalin concentration or para-aldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde, isopentaldehyde, and the like. The aldehyde should have not more than 8 carbon atoms and should not detrimentally affect the resinification or oxyalkylation of the resin. Preferred aldehydes are those having from 1 to 4 carbon atoms, such as formaldehyde, which may be in aqueous solution (37 percent), or in any of its low polymeric forms such as paraform or trioxane. Other aldehydes include para-aldehydes, furfural, Z-ethyl-hexanal, ethylbutyraldehyde, heptaldehyde and glyoxal, benzaldehyde and crotonaldehyde.
Novolacs To prepare a novolac, the proportion of aldehyde to be condensed with the hydroxy aromatic compound may be varied in order to obtain different molecular weights, and the viscosity of the finished resin may be controlled by the mole weight of the novolac; preferably the proportion of aldehyde employed is from 0.5 to 1.0 per mole of the hydroxy aromatic compound.
Among the substituted phenols which may be used to prepare the novolacs for this invention are those substituted with long-chain ethylenically unsaturated hydrocarbons, such as the linseed-type oils. However, it is within the scope of this invention to employ any animal and/or vegetable oil which achieves the objects of this invention based on the similarity in properties with the long-chain hydrocarbon oils. Such oils would be positioned on the phenol in the orthoor para-positions, and preferably in the para-position. Many of them are similar in properties to linseed oil having non-conjugated unsaturation of at least 50 iodine number, and have sufiicient compatibility with the novolac after it is polymerized. Safflower oil is typical of these oils. It may be in the form of a glycerol ester of the fatty acids wherein the fatty acids are of a composition comprising more than 40 percent by weight of linolenic acid. The remaining percentages of fatty acid can be any saturated or ethylenically unsaturated fatty acid having 12 to 22 carbon atoms and more preferably oleic and linolenic acid so that the fatty esters have an iodine number of at least 50. The iodine value (iodine number) is a measure of unsaturation, and is defined as the number of grams of iodine required per grams of unsaturated material to obtain the saturated material. In addition to the preferred glycerol ester, other polyhydric alcohols can be reacted with the described fatty acids to produce a low acid number ester of a polyol having 2 or more hydroxyl groups. Typical polyols include ethylene glycol, diethylene glycol, pentaerythritol, dipentaerythritol, sorbitol and the other polyhydric alcohols.
The acid catalyst to be used when preparing the novolacs to be used in this invention may be chosen from oxalic acid, sulfuric acid, hydrochloric acid and other strong acids used in the art for preparing novolacs. In addition, wetting agents of the anionic type, such as so- Idium alkylaryl sulfonates, are also useful as secondary catalysts in preparing novolacs.
The two-stage resins are curable by reaction with hexamethylene tetramine to form dibenzyl and tribenzyl amines, as well as hexatriphenol. One may also use ammonium hydroxide, which reacts with the formaldehyde to form hexamethylene tetramine. Other amines may also be used, such as ethylene diamine or ethylene triamine, or methylamines, etc. These can be used to react with formaldehyde to form a composition similar to hexamethylene tetramine. The resulting compound would be an aldehyde donor.
The phenol aldehyde novolac type resin is prepared by charging the desired phenol and aldehyde raw materials and catalysts to a raction vessel. The reaction begins at about 100 degrees centigrade and proceeds under temperatures up to about 200 degrees centigrade, at any pressure up to about 100 lbs/square inch gauge for about one and one-half hours, or until the desired degree of polymerization has taken place. Thereafter, the catalyst is neutralized where necessary, and the excess reactant, water, and other materials are taken off by dehydration and the molten resin is discharged from the vessel. It has been found that a novolac which has not been neutralized and is stable will cure more rapidly with a resole than a novolac which has been neutralized.
From the foregoing, it is apparent that many hydroxy aromatic compounds may be used in practicing the present invention to provide a novolac which can be then reacted with an hydroxy aromatic aldehyde resole to form t the friction particle of this invention, provided the aromatic hydroxyl group is reactive and the hydroxy aromatic compound is capable of reacting with an aldehyde or a mixture of aldehydes to produce a novolac condensate. Pure, refined phenols may be used, but this is not necessary. For instance, phenols may be alkylated and then may be reacted in crude form with an aldehyde. In such crude form, the phenols may contain some polyalkylated, as well as non-alkylated, phenols.
The process for alkylation of a phenol is well-known in the art. First, dehydration (of water) is carried out with vacuum at elevated temperatures, for instance, between about 100 and about 150 degrees centigrade under a vacuum of between about 20 and about 30 inches of mercury. Then, the dehydrated phenolic material is acidified to a pH of between about 1 and about 5 with H 804 or in some cases BF Following this, a terpene or vegetable oil is added and the reaction mixture heated to between about 80 and about 140 degrees centigrade at atmospheric pressure. The molar ratio of reactants is between I about 0.1 mole of terpene or vegetable oil per mole of phenol to about 2.5 mole of terpene or vegetable oil per mole of phenol. When tung oil is employed as a vegetable oil in the alkylation, use of BF to acidify would cause gelation, so it is not used, but H 80 can be used.
The proportion of aldehyde to be condensed with the hydroxy aromatic compound to form a precondensate may be varied to prepare novolacs of different molecular weights. Viscosity of the finished precondensate may be controlled by the mole weight of the novolac. Preferably, the proportion of aldehyde employed varies from about 0.5 to 1.0 mole per mole of phenol when a monoor difunctional phenol is used. In instances where a trifunctional phenol is used, i.e. unsubstituted in the orthoand para-positions, a preferred upper limit of the aldehyde may be about 0.70 mole of aldehyde per mole of phenol so as to minimize the formation of insoluble, infusible condensates. It is preferred that the aldehyde and phenol be condensed using an acid catalyst to shorten the time 6 required for complete condensation of the reactants. Suitable acid catalysts include sulfuric acid, hydrochloric acid, and oxalic acid. These catalysts are generally employed in the amount of 0.1 to about 5 percent by weight of phenol to be condensed.
Where a mixed aldehyde, phenol-aldehyde precondensate is to be prepared, it is formulated by charging the desired phenol and aldehyde raw materials and catalysts to a reaction vessel. The reaction proceeds under temperatures from about 25 to about 150 degrees centigrade at a pressure from about ambient up to about 100 pounds per square inch gauge pressure for a period of time from about 5 minutes to about 5 hours, a suitable time being about one and one-half hours, or until the desired degree of condensation has taken place. The phenol is first reacted with the longer-chain aldehyde to form a phenollonger chain aldehyde precondensate, followed by a second-step reaction of the phenol-longer chain aldehyde precondensate with formaldehyde to form a thermosettable phenol aldehyde precondensate material. In the second step, the reactants are refluxed at atmospheric pressure, although higher reflux temperatures up to about 150 degrees centigrade can be used by employing elevated pressure. The formaldehyde can be added all at once in the second step, or added gradually. If the formaldehyde is added all at once, then a temperature range between about and about degrees centigrade is used at the beginning of the second-step reaction, until the exothermic reaction subsides, and then the temperature is increased slowly to between about and about degrees centigrade and held until further exothermic reaction subsides, and then the reaction mixture is heated to reflux temperature which is about degrees Centigrade at atmospheric pressure. If elevated pressure is used, then the reflux temperature can be increased to as high as about degrees centigrade. If the formaldehyde is added gradually in the second step, then a temperature range between about 95 and about 140 degrees centigrade can be used. The catalyst is then neutralized and the excess reactant, water and other materials are taken 00?.
While the precondensate is still at an elevated temperature, from about 25 degrees to about degrees centigrade, but below the boiling point of the resultant solution or suspension, with about 100 degrees centigrade being very suitable, it may be reduced in viscosity by addition of suitable solvent. The amount of solvent may vary from about 10 to 70 percent of the precondensate by weight and a suitable ratio of precondensate to solvent is about 10 parts of precondensate to 9 parts of solvent. The controlling factor is the resulting viscosity of the precondensate prepared, rather than the actual volume of solvent charged. Among the solvents which may be used for this purpose are ethanol, methanol, toluene, xylene, ketones, such as acetone, and methyethyl ketone, and mixtures of aromatic and aliphatic hydrocarbons, such as mixtures of benzene and mineral spirits, or benzene and acetone.
Oxyalkylation Oxyalkylated resins are prepared which preferably contain substantially no free reactive hydroxy aromatic groups, for example, less than about 0.5 percent of the aromatic hydroxyl present originally in the hydroxy aromatic or hydroxy aromatic aldehyde condensate. To remove the aromatic hydroxys, the hydroxy aromatic aldehyde resin can be reacted with a compound which etherifies the aromatic hydroxyl groups so that almost all of the aromatic hydroxy groups present in each hydroxy aromatic aldehyde condensate unit are so reacted.
The preferred method of hydroxyalkylation is by reaction with compounds containing a mono-oxirane ring. Such compounds include ethylene oxide, propylene oxide, butylene oxide, styrene oxide and cyclohexene oxide, glycidol and epichlorohydrin. Many other monoepoxides can be used, but the alkylene oxides containing not more than 6 carbons are generally preferred. Additional useful compounds are phenyl glycidyl ether and related compounds prepared from the reaction of epichlorohydrin and monofunctional alkylated and halogenated phenols such as pentachlorophenyl glycidyl ether.
Catalystst for the reaction of the oxirane ring compounds and phenolic hydroxyl groups may be alkali or alkaline earth hydroxides, primary amines, secondary amines, tertiary amines or basic alkali salts. These include sodium, potassium, lithium, calcium and barium hydroxides, amines such as methyl, dimethyl, diethyl, trimethyl, triethyl, tripropyl, dimentyl benzyl, dimethyl hydroxyethyl, dimethyl-Z-hydroxypropyl and the like, and salts of strong bases and weak acids such as sodium acetate and benzoate.
The reaction may be carried out at temperatures of about room temperature to 250 degrees centigrade, and preferably in the absence of solvents, although solvents may be used to reduce viscosity when desired. When oxyalkylating resoles, the reaction should be carried out at lower temperatures than when oxyalkylating novolacs, because there is a possibility that reaction of the methylol groups with other methylol groups gives methylene linkages, formaldehyde and gelation. When oxylalkylating a novolac, temperatures between room temperature and about 200 degrees centigrade can be used. When oxylating a resole, temperatures between room temperature and about 100 degrees centigrade may be used.
The aromatic hydroxyl of the novolacs may also be hydroxyalkylated by reacting alkylene halohydrins with the aromatic hydroxyl using equivalent amounts of an alkali metal hydroxide to bring about the reaction. Suitable alkylene halohydrins are ethylene chloroand bromohydrins, propylene chloroand bromohydrins, 2,3-butylene chloroand bromohydrins, and glyceryl chloroand bromohydrins.
Another method for hydroxyalkylating novolacs is reaction with alkylene carbonates such as ethylene carbonate and propylene carbonate, using a catalyst such as potassium carbonate.
At least one mole of alkylene oxide or other etherifying or esterifying agent is required per mole of aromatic hydroxyl. However, resins prepared by reaction with up to 7 moles of alkylene oxides per mole of phenolic hydroxyl have been found to be useful.
Resoles The liquid one-stage resin (resole) which forms a part of this invention may be formed by reacting an hydroxy aromatic compound with an excess of formaldehyde in alkali such as sodium hydroxide dissolved in water. The reaction mixture is gradually heated to reflux and held at reflux until less than about 1 percent of free formaldehyde remains. This provides a preferred reaction product which has less than 2 percent of the formaldehyde un reacted, although this is not critical in this process. Less than 2 percent free CH O is desirable. The reaction mixture is then cooled and the catalyst neutralized with some acid such as glacial acetic acid and the pH is adjusted to roughly 6 to 7.5. The reaction mixture may be then further reacted with hexamethylene tetramine or some other aldehyde donor, i.e., curing agent. The resin is then dehydrated to between about 50 to 95 percent solids, and preferably between about 81 to 85 percent solids.
The alkaline catalyst used in preparing the resoles to be used in this invention may be any of those known in the art; for instance, sodium hydroxide and calcium hydroxide. In general, the alkali metal hydroxides and the alkaline earth metal hydroxides and ammonium hydroxide and the amines such as triethanol amines may be used.
Following the intercondensation reaction to form a resole, a stoichiometric quantity of a strong acid such as sulfuric acid, hydrochloric acid, phosphoric acid or oxalic acid, or the like, is added to the reaction mixture in order 8 to neutralize the alkaline condensation catalyst. Sulfuric acid is conveniently employed to neutralize a sodium hydroxide catalyst. The alkaline catalyst may also be neutralized by dilution through repeated washing, however, it is preferred to use an acid. The final resin should have a pH between about 5.5 and 7.5 for good stability.
The hydroxy aromatic compound employed in a resole can be alkylated, if desired, with alkyl groups containing 1 to 12 carbon atoms, or with unsaturated groups, including the long-chain unsaturated vegetable or animal oils, to form alkylated hydroxy aromatic compounds that when reacted with an aldehyde form heat reactive resoles. These include alkylene groups of 2 to 36 carbon atoms, fatty acids, polyethers, alkyl ethers, polyesters and polyols and mixtures of these.
Among the high molecular weight or polymeric materials containing aliphatic carbon-to-carbon unsaturation, there are included such naturally occurring materials as unsaturated vegetable, fish or animal oils such as linseed, soya, tung, sesame, sunflower, cotton seed, herring, menhaden, and sardine oils, etc., or chemically modified naturally occurring materials such as allyl ethers of starch, cellulose, or acrylate esters thereof, etc., synthetic drying oils, polymers obtained by polyetherification of such unsaturated compounds such as maleic, fumaric, itaconic, aconitic, chloromaleic, dimerized fatty acids, anhydrides or acids from allyl glycerol, methallyl glycerol ether, glycerol monoacrylate, butene diol, pentene diol, or polymers obtained by polyetherification of the unsaturated polyols. Other oils include castor oil, tall oil, oiticia oil, safflower oil, and the like, oleic and linolenic acids. These fatty acids have from 12 to 22 carbon atoms. They are often in combination as a glycerol ester or in combination with other polyhydric alcohols or polyols such as ethylene glycol, diethylene glycol, pentaerylthritol, dipentaerythritol, sorbitol, and the like polyhydric alcohols.
The blending of the resole with other components in accordance with this invention can be in various proportions depending upon the ultimate properties desired in the friction binder to be produced, but will generally be in the range of about to about 95 weight percent of the non-oxyalkylated resole based on the total weight of resin components.
It is to be understood that the oxyalkylated resole or oxyalkylated novolac described herein will not be a friction binder alone unless blended with a non-oxyalkylated, non-alkylated resole resin or with a non-oxyalkylated alkylated resole resin. The oxyalkylated resole product is a liquid and will not cure. The preferred compositions of the invention contain at least one of an oxyalkylated resole and an oxyalkylated novolac in combination with the non-oxyalkylated resole.
The friction binder of this invention may be used alone or with other friction binder materials known in the art.
A typical frictional element contains about 30 to weight percent asbestos fiber, up to 40 weight percent other inorganic filler and abrasives, about 5 to 15 weight percent organic filler and about 15 to about 30 weight percent binder, including the binder of this invention; all percents are by Weight of total composition. Asbestos fiber, abrasive materials and filler materials are charged into a mixer followed by the addition of the binder. The components are kneaded until the fiber, abrasives, and any fillers are thoroughly wetted and a uniform mass is obtained. The mass is discharged from the mixer, rolled out into sheets or extruded or pressure molded and dried, after which it is ready for further processing into friction elements. When the blend is in a B stage condition of polymerization, and powdered, it is mixed with the asbestos and other additives, pressed together in a hot molding operation at approximately 1000 p.s.i. at a mold temperature from about 300350 degrees Fahrenheit and then cured.
The abrasives, that is, the friction imparting agents and fillers employed within the scope of this invention include,
but are not limited to brass chips, metal shavings and filings, silica, talc, wood flour, chalk, clay, mica, fiber glass, felt, carbon black, graphite metal nitrides and oxides, ground cashew nut shell oil polymerizate, and the friction particle disclosed in Ser. No. 872,753 filed Oct. 30, 1969, now Pat. No. 3,658,751. These abrasives and fillers can be used to achieve the particular amount of bulk and coefiicient of friction desired. The above listed materials have a particle size such that they will pass through a US. Standard Sieve (1940) Number 3 which has a sieve opening of 6.3 millimeters. Preferably, the particle size of these materials will range from passing through a Number 4 sieve, sieve opening size 4.76 millimeters, and yet be retained on a Number 100 sieve, sieve opening size 0.140 millimeter.
The following Examples are given to further illustrate the invention. Unless otherwise indicated, all parts are by weight and temperatures in degrees centigrade.
EXAMPLE 1 Part A (The Resole) A reaction vessel is charged with 100 parts of phenol, 120 parts of formalin (37 percent formaldehyde) and 2 parts of flake caustic dissolved in 4 parts of water. This reaction mixture is heated gradually to 60 degrees centigrade and held at 60 degrees centigrade until there is less than 3 percent free formaldehyde and cooled to 30 degrees centigrade, after which 5 .5 parts of lactic acid diluted with 5.5 parts of water is added which neutralizes this composition to a pH of 5.5-6.5. After the pH range is achieved, the resin is dehydrated to 59-63 percent solids and cooled to room temperature. The resultant product is a low viscosity liquid, and is identified in Table II as resin Rd.
Part B (The Oxyalkylated Novolac) The oxyalkylated novolac can also be referred to as a polyol of a novolac which is oxyethylated, using from about one mole to about 7 moles of ethylene oxide to 1 mole of phenol, depending on the properties desired. For this Example, a resin was used with a ratio of 2 moles of ethylene oxide to one mole of phenol.
A typical modified phenol-aldehyde condensation product is prepared by introducing 3,000 parts phenol, 13 parts of oxalic acid catalyst and 6 parts of a wetting agent of Nacconol (sodium alkylaryl sulfonate) into a jacketed reactor and heating to 100 degrees centigrade. (The anionic wetting agents of alkylaryl sulfonate type are preferred.) Then 1,110 parts of a 37 percent aqueous formaldehyde solution are added to the reactor at a rate that the heat of reaction provides a vigorous reflux. Refluxing is continued for 2 hours after the completion of the formalin addition. The reactor contents are dehydrated at 180 degrees centigrade and then dephenolated at 200 degrees centigrade at 50 millimeters vacuum. Approximately 2,030 parts of phenol-aldehyde condensate are produced. Then 7.2 parts of sodium hydroxide are introduced to the reactor. Ethylene oxide is then added to the reactor as either a vapor or a liquid. The reactor temperature is maintained at 190 degrees centigrade for the initial 2 hours and is then permitted to increase to the range of 200 to 220 degrees centigrade until the addition of 878 parts of ethylene oxide is complete. The resulting condensation product had a hydroxyl number of 370, and a Gardner viscosity at 50 degrees centigrade of about 2,000 seconds, and is identified as resin Nc in Table III.
A novel friction binder of the invention was made by blending 60 parts of Part A with 40 parts of Part B. The friction binder was used in formulating a mixture comprising 80 parts of dry mix, and 0.6 part water as follows. The dry mix was composed of 62.5 parts by weight of asbestos shorts, Quebec Standard Asbestos Grade 7K, 12.5 parts by weight of Cardolite friction particles, and 25 parts of barytes abrasive filler. The moisture content of the dry mix was held low between 0.75 and 1.0 percent to avoid any possibility of blistering of the element during cure.
The dry mix was charged to an internal mixer equipped with a Sigma-type blade. The dry materials were mixed and blended for 5 minutes. Then 20 parts of the abovedescribed friction binder were added and mixed for 1 hour until the mass was uniform. The dough-like mix was then discharged from the mixer and charged to an extruder. The extruder was equipped with a 2 inch by 4 inch rectangular die and had an applied ram pressure of to 300 pounds per square inch. The dough-like mix was then extruded in a shape which was satisfactory for brake linings. The extruded linings were oven dried for 16 hours at degrees Fahrenheit. The linings were then cut to proper length, reheated for 2 to 3 minutes at about 325 degrees Fahrenheit, bent or arched to the desired curvature and placed into forms (i.e., molds) for curing. These linings were then cured for 8 hours at about 350 degrees Fahrenheit. The cured linings after cooling were expanded to the proper size for mounting into brake shoes. The re. sulting friction elements were found to be satisfactory for use on automobile brakes.
EXAMPLE 2 70 parts of Part A and 30 parts of Part B of Example 1 were blended. The resulting friction binder was then made up into a brake lining by adding sufficient amounts of the resin blend to give 20 parts of solid resin after curing, 50 parts asbestos fibers, 10 parts Cardolite friction particle, and 20 parts barytes abrasive filler. The resulting mix was extruded to form a drum-type brake lining, which was then dried for 16 hours at 120 degrees Fahrenheit and cured for 8 hours at 350 degrees Fahrenheit. The cured brake lining was tested an found to have a Rockwell hardness of 33M at room temperature which is satisfactory in commercial practice. The lining was heated at 500 degrees Fahrenheit for 15 minutes and had retained a Rockwell hardness of 43L, indicating that the composition retained strength and hardness at elevated temperature.
EXAMPLES 3 to 15 The procedure of Example 2 was repeated to produce additional drum-type brakes linings using various proportions of resoles and novolacs for which the formulations are shown in Tables II and III. In. Table I are shown the proportions of the indicated resins used to make the resin binders, the Rockwell hardnesses of the cured brake linings as prepared and after heating at 500 degrees Fahrenheit for 15 minutes.
TABLE I Rockwell hardness of brake lining xy- After alkylation 15 min- As preutes at TAELE IL-RESOLE RESIN FORMULATIONS Resin- Raw material a b e d Ammoniaeal liquor Para-teritary oetyl phenol Caustic soda Oxalic acid Para-tcritary butyl phenol Sulfuric d Phosphoric acid. Propylene oxide Triethylamine Lactic acid 1 In Resole Rc-the phenol, formaldehyde, and 2.5 parts of triethylamino were first reacted. This product was then oxypropylatcd with the remaining specified ingredients.
TABLE III.NOVOLAC RESIN FORMULATIONS Raw material a b o Phenol 58. 45 Formaldehyde (37.2%)...
Para-tertiary octyl phenol Sodium alkylaryl sultonate Oxalic acid Water Ammoniacal liquor Butyl acid phosphat Caustic soda Ethylene oxide Maleic anhydride EXAMPLE 16 3000 parts of asbestos fiber, 750 parts barytes abrasive filler, 250 parts of Cardolite friction particle and 1000 parts of the resin binder of Example 2 were mixed in a sigma blade mixer to produce a granular mixture. The resulting mixture was charged into a mold and cold pressed at 1000-3000 pounds per square inch to form a disc brake pad. The molded pad was stripped from the mold and cured in a circulating air oven by raising the temperature gradually from room temperature to 350 degrees Fahrenheit over a period of 8 hours, followed by holding the temperature at 350 degrees Fahrenheit for 8 hours.
EXAMPLE 17 The procedure of Example 15 was repeated except that the friction particle was prepared in accordance with Example 2 of copending application Ser. No. 872,753, filed on even date herewith now Pat. No. 3,658,751.
Various changes and modifications can be made in the products of this invention without departing from the spirit and scope thereof. The various embodiments of the invention disclosed herein serve to further illustrate the invention but are not intended to limit it.
We claim:
1. A friction element composition comprising a friction imparting abrasive agent, an inorganic filler and a binder composition comprising a non-hydroxyalkylated hydroxy aromatic hydrocarbon aldehyde resole containing substantially no etherified aromatic hydroxyl groups and 60 an hydroxyalkylated hydroxy aromatic hydrocarbon aldehyde resOle containing less than about 0.5 percent of the aromatic hydroxyl originally present in the hydroxy aromatic hydrocarbon aldehyde condensate.
2. The composition of Claim 1 wherein the first said resole is the condensation product of phenol and formaldehyde in an alkaline medium.
3. The composition of Claim 1 wherein the hydroxyalkylated resole is the hydroxyalkylated product of a phenol with an aldehyde in alkaline medium.
4. The composition of Claim 1 comprising from about 5 to about 40 percent by weight of an hydroxyalkylated resole with from about 95 to about percent by weight of oiie or more of a non-hydroxyalkylated, non-alkylated reso e.
5. The composition of Claim 1 comprising from about 5 to about 40 percent by weight of an hydroxyalkylated resole with from about to about 60 percent by weight of a non-hydroxyalkylated, alkylated resole.
6. The composition of Claim 1 comprising from about 5 to about 40 percent by weight of an hydroxyalkylated resole with from about 95 to about 60 percent by weight of a mixture of a non-hydroxyalkylated alkylated resole and a non-hydroxyalkylated, non-alkylated resole.
7. The composition of Claim 1 comprising from about 5 to about 40 percent by weight of an hydroxyalkylated resole with from about 95 to about 60 percent by weight of a mixture of a non-hydroxyalkylated, non-alkylated resole and a non-hydroxyalkylated, alkylated novolac.
8. The composition of Claim 1 comprising from about 5 to about 40 percent by weight of an hydroxyalkylated resole with from about 95 to about 60 percent by weight of a mixture non-hydroxyalkylated, non-alkylated novolac and a non-hydroxyalkylated, non-alkylated, resole.
9. A friction element composition comprising about 30 to about 60 weight percent asbestos fiber, up to about 55 weight percent other fillers and friction imparting abrasive agents and about 15 to about 30 weight percent of a binder composition comprising a non-hydroxyalkylated hydroxyaromatic hydrocarbon aldehyde resole containing substantially no etherified aromatic hydroxy groups and an hydroxalkylated hydroxy aromatic hydrocarbon-aldehyde resole containing less than about 0.5 percent of the. aromatic hydroxyl originally present in the hydroxy aromatic hydrocarbon aldehyde condensate.
References Cited UNITED STATES PATENTS 2,894,931 7/ 1959 Somerville et al 260-838 3,455,868 7/1969 DAlessandro 260-838 3,647,722 3/1972 Albertson et al. 260-838 3,658,751 4/1972 Grazen et a1. 260-838 2,625,530 1/1953 Doelling et al. 260-838 2,626,942 1/ 1953 De Groote 260-838 2,971,936 2/1961 Dubien et al. 260-838 3,177,090 4/1965 Bayes et al. 260-838 3,767,612 10/1973 Grazen et a1. 260-838 IOHN C. BLEUTGE, Primary Examiner U.S. Cl. X.R.
260-19 R, 19 A, 39 R, 39 SB, 51.5, 838, 840, Dig. 39
1. A FRICTION ELEMENT COMPOSITION COMPRISING A FRICTION IMPARTING AGENT, AN INORGANIC FILLER AND A BINDER COMPOSITION COMPRISING A NON-HYDROXYALKYLATED HYDROXY AROMATIC HYDROCARBON ALDEHYDE RESOLE CONTAINING SUBSTANTIALLY NO ETHERIFIED AROMATIC HYDROXYL GROUPS AND AN HYDROXYALKYL HYDROXY AROMATIC HYDROCARBON ALDEHYDE RESOLE CONTAINING LESS THAN ABOUT 0.5 PERCENT OF THE AROMATIC HYDROXYL ORIGINALLY PRESENT IN THE HYDROXYL AROMATIC HYDROCARBON ALDEHYDE CONDENSATE.
| 1972-12-20 | en | 1974-11-26 |
US-51853183-A | Construction for alerting health-care professionals
ABSTRACT
An improved health-care professional alert system is disclosed. The system is compatible with existing health-care professional call systems having a patient operable call unit; a cord connecting the unit to a receptacle; a detector determining when the patient call unit is disconnected from the receptacle; and an activator that operates an alarm signal upon detection of a patient-unit disconnect. The invention comprises an insert mateable with the existing receptacle, the insert being connected by a cord to a patient's body or gown. In the preferred embodiment, the cord is connected to a patient's body by a spring operated clip.
BACKGROUND OF THE INVENTION
This invention relates to an improved construction for alerting health-care professionals, such as nurses, orderlies and the like, in the event of undesirable movement by a patient in a hospital or other health-care facility. More specifically, the invention relates to an improved construction for alerting health-care professionals that can be activated upon a patient's undesirable movement and without a conscious choice by the patient to so activate. Additionally, the invention relates to an improved construction and method for alerting health-care professionals that is compatible with existing call systems.
Hospitals, nursing homes, and other health-care facilities conventionally have communication systems designed to allow patients to call nurses, orderlies or other health-care professionals. Traditionally, such call systems include an electronic communication system having a patient-operable signal device located at each patient's bed or treatment location. Such patient-operable signalers often consist of a button or switch unit connected by a message transmitting cord to a wall receptacle. The wall receptacle is usually connected to an information switching system, so that operation by the patient of the button or switch unit activates a signal within the information switching system, which thereafter operates an alarm that may be perceived or observed by a health-care professional at a remote location. Such health-care professional call systems are constructed in a variety of different configurations, and are generally well known to persons skilled in the art.
Existing health-care professional call systems have a significant drawback: activation of the system requires a conscious decision by the patient to call the health-care professional, because the patient must push the button or throw the switch. Consequently, patients who are confused, have a nocturnal disorientation, require assistance in moving where there is evidence they will not ask for help, are under the influence of narcotics or sedatives, or are subject to temporary or permanent disorientation, are often unable to activate the call system. Moreover, conventional call systems cannot be activated by sleeping patients. In many instances, such patients undergo undesirable movement, as, for example, when attempting to sit upright or get out of bed, or when they are attached to some medical treatment apparatus, and thereby aggravate their condition. Further, disoriented patients, or patients unable to walk without the assistance of crutches or some other device, may often in the initial moments of waking believe themselves to be at home and in familiar surroundings. Such patients will occasionally attempt to get out of bed, or move in some other undesirable manner, while not realizing that they are suffering from a partially or wholly disabling injury. The patient's attempt at movement can result in new injuries or aggravation of old injuries if a health-care professional is not alerted immediately to assist the movement.
Conventionally, confused and disoriented patients of the kind described above have been protected by subjecting them to an increased frequency of surveillance by health-care professionals or by relying on the patient's ability to activate the existing call system after the disorientation has ceased. In some instances, health-care professionals are alerted by other patients in the vicinity. Alternatively, sophisticated devices have been attached to the patient to monitor various aspects of a patient's physiology and movement, such as heart rate, blood pressure, and other functions, so that when an undesirable variation in those function occurs, the devices automatically produce a signal or sound an alarm summoning a health-care professional. Such systems are normally expensive, cumbersome, and require elaborate supervision and maintenance. Sophisticated monitoring systems are therefore primarily used on patient's for whom such elaborate measures are required, such as patients undergoing intensive care.
It is therefore desirable that some relatively inexpensive and simple construction be developed for signaling health-care professionals upon any undesirable motion of a confused, disoriented, or sedated patient. Ideally, such a construction and method would operate through interaction with existing health-care professional call systems, so that extensive modification and installation of an elaborate new electronic communication systems will not be necessary. Moreover, it is desirable that such a system be constructed in a manner providing patients the option to activate the health-care professional alert system on their own conscious choice, without relying on undesirable movements.
Conventional health-care professional call systems are normally automatically activated when the button or switch unit is disconnected from the electronic signaling system. The connection between the cord and the wall receptacle normally consists of a plug at the end of the cord mateable with a receptacle mounted into a wall. The electronic signaling system includes a detector that determines when the plug has been removed from the receptacle, and upon such an occurrence activates the call signaler. Such systems are normally present in health-care professional alert systems that are "wired in" to the walls and physical structures of the health-care facility. Of course, "wired in" facilities are not necessary, and receptacles for call unit cords, and the entire system, may be attached to or rest on any structure, such as the patient's bed or surrounding furniture.
SUMMARY OF THE INVENTION
The present invention comprises an improved health-care professional alert system compatible with existing call systems having (a) a patient operable call unit, (b) a cord connecting that unit to a receptacle, (c) a detector which determines when the patient call unit is disconnect from the receptacle, and (d) an activator that operates an alarm signal upon detection of a patient unit disconnect. In the principal embodiment, the present invention includes an insert mateable with the existing receptacle, such insert connected by a cord to a means for attaching the cord to a patient's body or gown. In the preferred embodiment, the means for attaching the cord to a patient's body comprises a clip, such as an alligator clip or other spring-operated clip, which may be attached to the patient's gown. The length of cord attaching the clip to the insert may be adjusted by tying a loose knot in the cord, so that undesirable movement, such as a patient sitting up or attempting to get out of bed, pulls the insert from the receptacle. The disconnection resulting from removal of the insert from the receptacle is thereupon detected and results in activation of a health-care professional call signal. In the preferred embodiment, operation of the alert system simultaneously calls the health-care professionals and illuminates the lights in the patient's room to provide an opportunity for the patient to gain additional orientation.
Thus, it is an object of the present invention to provide a health-care professional call system having an improved means for alerting health-care professionals upon undesirable movement by a patient.
It is a further object of this invention to provide a health-care professional alert system that is operable upon undesirable movement of a patient without a conscious decision by the patient to activate the system.
A further object of this invention is a health-care professional alert system meeting the objects described above and simultaneously being compatible with existing health-care professional alert systems.
Still another object of the present invention is to provide a health-care professional alert system that is simple, easy to operate, and is independent of electrical power failures or constant maintenance of complex machinery.
Yet another object of this invention is to provide a health-care professional alert system meeting the objects described above and still capable of being operated by a conscience decision on the part of the patient.
These and other objects, advantages, and features of the invention will be set forth in greater detail in the description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description which follows, reference will be made to the drawings comprised of the following figures, wherein like numerals refer to like elements in the various drawings:
FIG. 1 is a perspective view of the health-care professional alert system in operation connected to a patient for whom some movements are undesirable;
FIG. 2 is perspective view of a principal embodiment of the invention, showing an insert, a clip, and a cord connecting the insert to the clip;
FIG. 3 is a side view of the preferred embodiment of the insert;
FIG. 4 is a perspective view of an alternative embodiments of the means for connecting the insert and cord to a patient for whom some movement is undesirable;
FIG. 5 is a perspective view of a second alternative embodiment of the means for connecting the insert and cord to a patient;
FIG. 6 is a combined perspective drawing and block diagram showing the basic elements of a full health-care professional alert system operable in accordance with the disclosure in this invention; and
FIG. 7 is a perspective drawing of the alternative embodiment of the means for attaching the insert and cord shown in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, a general illustration of the preferred embodiment is shown. As illustrated in FIG. 2, the invention generally comprises a construction 10. A patient 12, normally restricted to a bed 14, is shown with the construction 10 is operation. In the preferred embodiment, the construction 10 comprises an insert 16, a clip 18, and a cord 20 connecting the insert 16 and clip 18. As illustrated in FIG. 6, the insert 16 is inserted into a compatible receptacle 22. The receptacle 22 in the preferred embodiment is normally used for insert of the cord connecting a patient-operated call unit (not shown) in a conventional health-care professional call system. Also as shown in FIG. 6, the invention includes a detector 24, an activator 26, and a signal device 28 shown in FIG. 6 as a light bulb. The detector, activator, and signal device may all be permanently mounted in a wall 30 as shown in FIG. 1. Alternatively, the detector 24, activator 26, and signal device 28 may all be placed in a remote location in a manner well-known in the art or may be mounted along with the receptacle 22 on some other permanent structure in the patient's room, such as the bed 14.
FIG. 3 illustrates some of the details of the preferred embodiment of the invention. In preferred form, the insert 16 comprises a plurality of coaxial cylinders 32 with each cylinder of different diameter and stacked upon the other coaxial cylinders in order of progressively reducing diameter. The end 34 of the insert 16 having the largest diameter is connected to the cord 20 with a permanent fixture 36. The large end 34 has a larger diameter rim 38 for ease of removal of the insert 16 from the receptacle 22. The smaller diameter end 40 of the insert 16 is the portion first inserted into the receptacle 22. To ease that insertion, the smaller diameter end 40 has a rounded surface 42.
The connection between each of the coaxial cylinders 32 creates a plurality of right angle annular shelves 44, which upon insertion of the insert 16 into the receptacle 22 are mateable with the interior of the receptacle 22. The coaxial cylinders 32 consist of a variety of sizes so that insert 16 has a plurality of different shelves 44, and the insert 16 may be placed within a variety of different size and different shaped receptacle 22. Hence, a single insert 16 may be compatible with a variety of different conventional health-care professional call system receptacles.
In the preferred embodiment, a spring-operated clip 18 is used for attaching the insert and cord to a patient. As shown in FIG. 1, the clip 18 is preferably attached to a portion of the patient's gown 46. The clip 18 may be constructed in a variety of different configurations and need not have the precise features shown in the illustrations. For example, the spring (not shown) used in clip 18 may be either a conventional wound spring, or may be a leaf spring utilizing a portion of the clip's frame. Referring to FIGS. 4 and 5, the means for attaching the insert 16 and cord 20 to the patient 12 need not be a clip. A clamp 48 as shown in FIG. 4 may also be used and connected to the patient around a wrist or other appendage. Such clamps may be adjustable in size, as shown by the buckle 50 in clamp 48. Alternatively, the clamp 48 may be attached to support instruments, such as an IV unit 49. Moreover, as illustrated in FIG. 5, the means for attaching the insert 16 and the cord 20 to the patient can consist merely of loops 52 of the cord 20 configured in a slip connection 54. Operation of the health-care professional alert system utilizing the embodiment shown in FIG. 5 is illustrated in FIG. 7. Generally, such a slip connection requires a permanent connection 56 of one end 58 of the cord 20 to an inner portion 60 of the same cord 20.
Alternatively, the cord 20 may be tied to some portion of the patient 12 or the patient's gown 46. The various embodiments illustrated in FIGS. 2, 4, and 5 for the means for connecting the insert 16 and the cord 20 to the patient 12 illustrate only some of the variety of ways in which the invention may be practiced.
In operation, the cord 20 is rarely of the exact length required for removal of the insert 16 from the receptacle 22 during undesirable motion of the patient 12. Accordingly, the cord 20 must be adjusted in length upon attachment of the cord 20 to the patient 12. Such an adjustment preferably consists of a knot 62 loosely tied in the cord 20 which allows temporary modification of the length of the cord 20 for each particular patient 12. Operation of the construction 10 and practice of the method of this invention begins with removal of the existing patient-operated call unit cord (not shown) from the receptacle 22. The clip 18 is then attached to the patient 12 or the patient's gown 46, and the knot 62 is tied into the cord 20 to adjust the cord's length.
Alternatively, the cord 20 may be attached to some other object or appendage of the patient 12 regarding which any undesirable movement should be detected.
Referring to FIGS. 1 and 6, movement by the patient 12, as for example results during an attempt to sit up or stand, stretchs cord 20 and pulls insert 16 from receptacle 22. The absence of either a plug or insert from receptacle 22 is detected by detector 24, which signals the activator 26. An alert device, such as lamp 28 is then operated by activator 26. Detector 24 and activator 26 may be comprised of a variety of different well-known constructions, either electrical, mechanical, or electro-mechanical.
In the preferred embodiment, detector 24 comprises a mechanical switch (not shown) within receptacle 22, such as is well-known in the art, which produces an electrical signal to activator 26 when the switch is operated by removing insert 16 from receptacle 22. Activator 26 preferably comprises any of the well-known electrical means for operating an electrical signaling device upon receipt of an electrical signal. In the preferred embodiment, the electrical signaling device is a lamp 28 within the room of the patient 12, as well as a signal light and tone received at a remote location by a health-care professional.
Operation of the health-care professional alert system may also be effected through a conscious decision by the patient, even though the button or switch call unit has been disconnected and replaced with the above-described construction. Should a patient desire to summon a nurse or other health-care professional, the patient 12 need merely grasp the cord 20, and pull the cord 20 with sufficient force to dislodge the insert 16 from the receptacle 22. As described above, removal of the insert 16 will result in activation of the alarm and lights 28.
While the preferred embodiments of the present invention have been set forth in the above-detailed description, the preferred embodiment is only an example of the invention. Other modifications may be used without departing from the scope of the present invention, and the invention is limited by the following claims and their equivalents.
What is claimed is:
1. An improved construction for operating a health-care professional alert system upon undesirable movement by a patient, the health-care professional alert system being of the kind having a signaling device that can be activated by a patient and capable of producing a signal detectable by health-care professionals, the signaling device having a patient-operable switch unit connected by a message transmitting cable to a wall-mounted receptacle and constructed such that removal of the patient-operable switch unit activates the signal, the construction comprising, in combination:an insert mateable with the wall-mounted receptacle, the insert having an insertion end and an exposed end, the insert further comprising a plurality of stacked concentric cylinders, each cylinder being of progressively lesser diameter toward the insertion end, the insert being attached to the cord at the largest diameter cylinder, with the insertion of each cylinder to each adjoining cylinder defining an annular shelf mateable with portions of the interior of the receptacle, and the insert further being compatible with a plurality of receptacles that were each originally sized to receive different diameter inserts; a segment of cord attached at one end of the exposed end of the insert; and means for attaching the remaining end of the cord segment to a patient comprising a spring operated clip attached to the cord segment opposite the insert; whereby undesirable movement of the patient's body pulls on the cord and results in the detachment of the insert from the receptacle, so that the signaling device activates the signal and alerts a health-care professional that undesirable movement is occuring.
2. A construction as claimed in claim 1, wherein the signal comprises a visual signal detectable at a remote location and activation of an illumination source in the patient's room that allows the patient to see.
| 1983-07-29 | en | 1986-03-18 |
US-5197660-A | Air free packaging
May 7, 1963 F. E. FAUTH ETAL 3,088,831
AIR FREE PACKAGING Filed Aug. 25, 1960 2 Sheets-Sheet 1 "l 6 e3 24/ .912540544 {11 u W Ham? May 7, 1963 F. E. FAUTH ETAL AIR FREE PACKAGING 2 Sheets-Sheet 2 Filed Aug. 25, 1960 ares Uite
The present invention relates to methods and apparatus for packaging iiowable products and, more particularly, a method and apparatus for packaging a flowable product susceptible to foaming to prevent overflow of the product aud/or to displace air from the head space above the product in the container with an inert gas.
In the packaging of carbonated beverages such as beer or soft drinks, it has been realized almost universally that the elimination of air from the head space improves the product .as flavor is maintained and oxidation is reduced or eliminated. In recent years, the packaging of products other than beer and carbonated soft drinks have been improved by displacing head space of air with an inert gas such as carbon dioxide or nitrogen. Examples of such air free packaging have extended into the uid food packaging of fruit juices, soups, mayonnaise, and other iiowable products.
Difficulties have been encountered in the air free packaging of iiuid foods in that the foam induced by either releasing gas within the product or injecting gas into the product produced spillage over the lip of the container resulting in loss of product, variation in filling height, and detraction from the standpoint of package appearance. For example, in the lling of containers with a carbonated soft drink, the release of CO2 from the carbon dioxide gas liquid is not necessarily uniform or stable and, therefore, the control of foam has been diflicult. The instability and non-uniformity of foam can be due to package variation such as when bottles are used and their wall thickness varies or to product gas retention variation due to filling characteristics of the filling machine and its Valves, or the like. Generally speaking, a carbonated beverage is usually less stable as the volume of carbon dioxide is increased and thus different foaming producing properties result. Because of the high sugar content in soft drinks, overflow of foam results in stickiness on the outside of the container and dust collects if the container is not thoroughly rinsed. Also foaming often results in product loss which results in Variable filling height and detracts from package appearance.
While the method and apparatus of the present invention is primarily intended for use with carbonated beverages such as soft drinks and beer, it may also be extended to use in fluid food packaging where a foaming condition may occur from filling the container or where a foaming condition is induced to increase the life of the product being packaged. In the first instance, a beverage such as milk may be flowed into a container in such a manner that foaming results with possible spillage, and the method and apparatus of the present invention can be used to control the rise of such foam to prevent spillage. In the latter instance, fluid food products may be packaged and then inert gas may be jetted into the product to drive out head space air, the inert gas resulting in foaming of the product. In this instance, the apparatus and method of the present invention may be utilized to control the height of foaming to prevent spillage and provide a substantially air free package.
Accordingly, an object of the present invention is to provide an apparatus and method for controlling the height to which foam will rise in a partially filled container.
Another object of the present invention is to provide an apparatus and method for the air free packaging of a container and the elimination of the loss of contents by spillage of foam over the lip of a container.
A further object of the present invention is to provide .an improved method and apparatus whereby foaming of the product within the container is controlled regardless of the variance of thickness of the container walls and regardless of the variance of the foaming properties of the product filled into the container.
A still further object of the present invention is to provide an improved method and apparatus for controlling foaming so that the container can be free of air when a closure is applied thereto.
Heretofore, attempts have been made to exclude air from the head space of the container by tapping the c0ntainer, jetting an inert gas into the container, or the like. The degree of tapping or the amount of gas jetted into the container have not been completely successful in preventing uncontrollable foaming. Supplementing tapping and jetting, efforts have been made to break the foam by use of flame or by injecting inert gas above the foam into the head space after the foam has been induced. Such methods have not been satisfactory because they create a flow of current into the head space bringing some air back into the same.
Ancillary to the preceding objects, it is a further object of the present invention to provide a method and apparatus which will cause the foam to dissipate as it approaches the lip of .a container, such dissipation being accomplished without the induction of flow currents or the like.
Another object of the present invention is to provide an apparatus and method wherein gas enclosing lm rising from the surface of a product is dissipated without the loss of gas or the product.
These and other objects and advantages of the present invention will appear more fully in the following specification, claims and drawings in which:
FIGURE 1 is a schematic plan view of apparatus for `accomplishing the method of the present invention;
FIGURE 2 is a fragmentary side elevational view of the schematic illustration of FIGURE 1, portions of the filling machine and the capping apparatus being omitted for purposes of clarity;
FIGURE 3 is an enlarged sectional View through a bottle partially lled and illustrating the control of the foaming height by lthe method of the present invention;
FIGURE 4 is a schematic plan view similar 'no FIG- URE 1 but illustrating apparatus for filling and closing cans `and accomplishing the method of the .present invention;
FIGURE 5 is a fragmentary side elevational View of the schematic illustration of FIGURE 4, portions of the `apparatus being broken away for purposes of clarity;
FIGURE 6 is an enlarged fragmentary sectional view through a partially filled can and illustrating the control of foaming height by the method of the present invention.
Referring now to the drawings wherein like character and reference numerals represent like or similar parts, and in particular to FIGURES l and 2, the filling machine there 4illustrated is of lthe well known type comprising a stationary table 10 having an inner edge 12 of arcuate form and a rotating .table 14 lhaving its forward periphery positioned closely adjacent the arcuate edge 12 of the stationary table in the usual manner. The rotating filling table 14 is provided adjacent its periphery with la plurality of bottle supporting platforms 16, each having a filling head 18 positioned thereabove and supported on a rotating reservoir '20. The stationary table 10 includes conveyor transfer rneans 22 for delivering Ibottles to an infeed transfer dial 24 which positions the bottles on the platforms 16 as they pass thereby. The bottles are elevated Iby the platforms 16 into sealing engagement with the filling heads 18 and then the bottles are filled as the rotating table -14 rotates 'in the direction of the arrow A along with the reservoir 20.
After the bottles are iilled, the platforms 16 lower the bottles to the elevation of the stationary table and they a-re transferred therefrom by means 4of an outfeed transfer dial 26 to the usual capping mechanism 28. From the capping mechanism 28, the bottles rnove on the usual straight line conveyor 30 to suitable casing mechanism (not shown).
The filling machine heretofore briey described may be of the type disclosed in detail 4in the United States Patent No. 2,202,033, issued May 28, 1940, to Robert I. Stewart and Wiltie I. Gl-adfelter. 'Ihe filling cycle of such a filling machine includes placing the bottle to be filled under a counterpressure, filling of the bottle with carbonated liquid such Ias beer or soft drinks, Iand then removal tof the bottle from the filling head fo-r capping. In the case of soft drinks, a snifting stage is usually accompli-shed after the filling stage yin order that the pressure in the head space of the bottle may be controllably released to atmosphere just prior to breaking the seal of the bottle away from the: filling head.
After the bottle has been filled and prior to its being transferred tothe capping mechanism 28, it has been the usual practice to tap `or agitate the bottle so that the carbonated contents of the beverage in the bottle are agitated. This results in the gas normally entrapped in the beverage to be libera-ted and rise to the surface forming foam thereon. The foam rises in the head space of the bottle so as to idrive any air therein out of the bottle, it being the purpose to till the head space with the inert carbon dioxide gas. As schematically shown in FIGURE 1, la bottle tapper designated at 32 is provided on the stationary table `10 in yan yarea adjacent the outfeed dial 26. The tapper 32 is provided with an arm 34 extending into the path 4of the containers ltraveling With .the dial 26, the arm being such that it hits each of the containers as they pass thereby causing the contents therein to be agitated. The tapping mechanism 32 may be lof the type disclosed in the prior United States Patent No. 2,329,304 issued September 14, 1943, to Robert I. Stewart.
Instead of using a tapping mechanism 32 toy agitate the carbonated beverage in the bottles, a jetter mechanism (not shown) may be installed in a known manner on the stationary worktable y10 inbetween the filling machine and the capping mechanism 28. Such a jetter mechanism is shown in the prior United States Patent No. 2,204,832, issued June 18, 1940', to Robert I. Stewart, the mechanism being capable of supplying la jet of inert gas imnrediately -below the surface of the beverage in the container. The jet of inert 4gas causes agitation of the beverage and, consequently, liberation of gas entrapped in the beverage so a-s to form foam in the head space of the container which will displace any air therein.
Positioned above the outfeed transfer dial 26 is a transducer member 40 which is capable of converting electrical energy into high frequency sound waves such as ultrasonic sound Waves or other energy vibrations with a' proper pattern This could be characterized by resonance of sound waves or other energy vibrations into nodules of a desired pattern. Th etransducer member `40 is' arranged immediately after the tapping mechanism 32 so that open containers, after they have been agitated, pass immediately therebeneath. Sound waves or vibrations are directed or focused vertically downwardly into the open mounth of the container, the sound waves or other energy vibrations being of a suliiciently high frequency and pattern so as to be capable of bursting the membranes lof bubbles of foam rising in the container as the foam approaches the lip of the container. The product carried with the Vfoam and forming the lm or membrane of the lbubbles will drop back into the container so that none of the product is lost and all of the containers being 'filled will have the Same quantity of product therein. Immediately after the containers pass from beneath the transducer member 40, they are transferred to the capping mechanism 28 where a cap is applied before there is any loss of gas from the head space of the container. By utilizing high frequency energy vibrations created by the transducer member `40, the break down of bubbles of foam in the head space of the container may be accomplished without disturbing the gas released by the breakdown and, consequently, the -air which has been previously physically displaced by the foam cannot re-enter the head space in the container and the container may be sealed free of air.
While the invention has been described with respect to the lling of containers with a carbonated beverage such as beer or other soft drinks, it will be recognized that other uid food products are susceptible to foaming during the filling operation. After the filling operation of such fluid food products has 'been completed, the foam oftentimes continues to rise in the container and spill over the lip of the container. By utilizing the transducer member 40 positioned above the open container iilled with a foaming fluid food product prior to the container being delivered to the closing mechanism, the control of the height of the foaming may be accomplished so that there is no spillage of product over the lip of the container. Like- Wise, the method of the present invention contemplates injecting an inert gas into the head space of a container iilled with a non-carbonated product. The injection of inert gas into the non-carbonated fluid product oftentimes causes the product to foam especially if the product is of a character susceptible to foaming. In this instance, the method of controlling the foaming height while maintaining the inert gas in the head space of the container is accomplished by directing or focusing the high frequency energy vibrations axially of and toward the open mouth of the container just prior to the container being received in a closing mechanism.
Referring now to FIGURE 3 of the drawings, it will be noted that a bottle B is shown With a carbonated bever-age E iilled to the level L. Carbon dioxide `gas bubbles F are shown rising in the beverage E to the surface of the same where foam F rises and approaches the lip C of the container. High frequency waves represented by the arrow W directed vertically downwardly into the open mouth of the bottle B are shown dissipating or bursting the bubbles of foam iF and the droplets D of beverage released by the dissipation of the foam fall by gravity back into the bottle.
FIGURES 4 and 5 represent a modified form of apparatus for accomplishing the method of the present invention. The filling machine shown in FIGURES 4 and 5 is of the type for filling cans with carbonated beverage such as beer or soft drinks. The cans are arranged to be fed on a straight line infeed conveyor mechanism 22' to an infeed transfer dial 24 where they are positioned and transferred on platforms 16'. In the embodiment shown, rotating filling table 14 rotates in an opposite direction to the lling machine shown in FIGURE 1 and as it rotates, the platform 1-6 -lift the cans into engagement with filling heads 18 where the stages of filling, such as counter-pressure, filling and venting, and/or snifting, vare accomplished.
After the cans have been filled, they are transferred onto a takeoff conveyor mechanism 50 which is adapted to move the cans to the conventional can-seaming machine represented lby the numeral 52. A tapping mechanism 32 having its tapping arm 34 positioned in the path of containers traveling on the conveyor mechanism 50 is adapted to agitate each of the cans so that gas will be released from the beverage therein to displace air in the head space of the cans. The tapping mechanism 32 may be suitably supported on a stationary table 10. Positioned intermediate of the tapping mechanism 32 and the can-seaming mechanism 521 is a transducer member 40 for converting electrical energy into high frequency energy vibrations such as ultrasonic waves. ,'Ihe transducer member 40' is arranged above the conveyor mechanism 50' so that each of the open cans must pass therebeneath and the wave vibrations emitted from the transducer member lare directed or focused vertically downwardly into the open mouth of the cans. As the foam rises in the head space of the can, the high frequency wave vibrations will dissipate the foam by bursting the bubbles as the foam approaches the lip of the can. As soon as the can passes from beneath the transducer member 40', it is received by the can-seaming machine which applies -a can end to the can body to close the can without the admission of air to the head space thereof.
FIGURE 6 illustrates a can B passing beneath the transducer member 40. As the foam F created from the bubbles F rises in the head space of the can B toward the lip C', the downwardly directed high frequency waves W' cause dissipation of the foam and the droplets D of product returned to the interior of the can.
Transducer members 40 or 40 may be intermittently or continuously operated as containers such as bottles B or cans B pass therebeneath.
It is thus seen that the objects and advantages of this invention have been fully and effectively accomplished by the method and apparatus described hereinbefore. However, the foregoing specific embodiments of the apparatus as well as the method are subject to some changes without departing from the principles of the invention involved. For this reason, the terminology used in this specification is for the purpose of description and not limitation, the scope of the invention being defined in the appended claims.
We claim:
1. The method of packaging an edible fluid product susceptible to foaming in a container comprising the steps of: lling the container with the product to a level where a head space remains in :the container; allowing foam to rise in the head space of the container toward the lip of the same; subjecting an area immediately adjacent the containers lip while the container is open and prior to closing with energy vibrations of suicient frequency to cause bursting of bubbles of foam as the foam approaches the lip of the container; and then closing the container.
2. The method of packaging an edible uid product susceptible to foaming in a container comprising the steps of: filling the container with the product to a level where a head space remains in the container; allowing foam to rise in the head space of the container; directing nodules of resonance of energy vibrations of sufiicient frequency to cause bursting of bubbles of foam as the foam approaches the lip of the container, the energy vibrations being directed toward and axially of the container while the container is open and prior to closing; and then closing the container.
3. The method of packaging an edible fluid product susceptible to -foaming in a container comprising the steps of: lling the container with the product to a level where a head space remains in the container; inducing a foam of bubbles in the product by introducing a jet of inert gas immediately below the surface of the product in said container and allowing the foam to rise in the head space of the container; directing ultrasonic wave vibrations at the rising bubbles of foam while the container is open and causing the bubbles to burst as they approach the lip of the open container with the product of the bubbles returning to the interior of the container; and then closing the container with the head space of the same lled with lthe inert gas released from the bursting bubbles of the foam and the foam remaining on the surface of the product.
4. The method of claim 3 wherein the ultrasonic wave vibration is directed toward and axially of the container.
5. 'Ihe method of packaging an edible liquid in a container comprising the steps of: filling the container with the liquid to a level where a head space remains in the container and the surface of the liquid has bubbles of foam rising therefrom toward the lip of the container; bursting the bubbles of foam rising from the surface of the liquid as they approach the lip of the container while the container is open and prior to closing by directing ultrasonic wave vibrations toward the lip ofthe container; and then closing the container.
6. The method of packaging an edible liquid in a con-V tainer comprising the steps of filling the container with the liquid to a level where a head space remains in the container and the surface of the liquid has bubbles of foam rising therefrom toward the lip of the container directing an ultrasonic wave vibration toward the lip and axially of the container while the container is open and prior to closing to cause bursting of the bubbles of foam as they approach the lip of the container, and then closing the container.
7. The method of packaging a carbonated beverage in a container comprising the steps of: filling the container with the carbonated beverage to a level where a head space remains in the container; allowing gas to be released from the beverage in the filled container so as to form bubbles of foam `on the surface of the liquid, the foam rising toward the lip of the container, directing sound waves toward the lip of the container while :the container is open and prior to closing at a suflicient frequency to cause bursting of the bubbles of foam as the foam approaches the lip of the container; and then closing the container with the gas released from the bubbles trapped in the head space of the container.
8. 'Ihe method of packaging a carbonated beverage in a container comprising the steps of: filling the container with the carbonated beverage to a level where a head space remains in the container; agitating the beverage in the container to cause gas to be released therefrom so as to induce bubbles of foam on the surface of the container rising toward Ithe lip of the container; directing ultrasonic wave vibrations axially of and toward the lip of the container while the container is open and prior to closing to cause bursting of the bubbles of foam as the foam approaches the lip of the container; and then closing the container with the gas release from the bubbles trapped in the head space of the container.
9. In combination: means to partially iill a container with a beverage containing carbon dioxide; means for applying a closure to the container; means for transferring the container while open to atmosphere from said filling means Ito said closure applying means, and transducer means positioned between said filling means and said closure applying means for directing high frequency waves at a partially filled container to thereby burst gas filled bubbles being liberated by the beverage in the container.
l0. The combination of claim 9 wherein said transducer means is arranged above said transfer means and wherein high frequency waves from said transducer means are directed axially of and toward an open container passing therebeneath.
ll. In combination: means to partially lill a container with a beverage containing carbon dioxide, means for applying a closure to the container; means for transferring the container from said lling means to said closure applying means while open to atmosphere; means arranged between said filling means and said closure applying means for inducing libera-tion of gas from the beverage of a partially filled container on said transfer means; and transducer means arranged to direct high frequency waves at a partially lled container to thereby burst gas iilled bubbles liberated by the beverage in the container as gas filled bubbles approach the lip of the container.
l2. The combination of claim ll wherein said transducer means is arranged above said transfer means and wherein waves from said transducer means are directed axially of and toward an open container passing therebeneath.
13. The combination of claim 11 wherein said transducer means is arranged between said gas liberating means and said closure applying means whereby waves from said 'transducer means are directed toward a lip of an open container afterinitiial inducement of liberating of gas in the beverage therein.
14. In combination: means to partially ll a container with an edible fluid product susceptible to foaming; means for applying a closure to the container; means for transferring fthe container from said lliing means to said closure applying means while open to atmosphere; and transducer means positioned above said transfer means and between said lling means and said closure applying means for directing high frequency waves at a partially illed container to thereby burst foam bubbles as the same approaches the lip of the container.
References Cited in the le of this patent UNITED STATES PATENTS
1. THE METHOD OF PACKAGING AN EDIBLE FLUID PRODUCT SUSCEPTIBLE TO FOAMING IN A CONTAINER COMPRISING THE STEPS OF: FILLING CONTAINER WITH THE PRODUCT TO A LEVEL WHERE A HEAD SPACE REMAINS IN THE CONTAINER; ALLOWING FOAM TO RISE IN THE HEAD SPACE OF THE CONTAINER TOWARD THE LIP OF THE SAME; SUBJECTING AN AREA IMMEDIATELY ADJACENT THE CONTAINER''S LIP WHILE THE CONTAINER IS OPEN AND PRIOR TO CLOSING WITH ENERGY VIBRATIONS OF SUFFICIENT FREQUENCY TO CAUSE BURSTING OF BUBBLES OF FOAM AS THE FOAM APPROACHES THE LIP OF THE CONTAINER; AND THEN CLOSING THE CONTAINER.
| 1960-08-25 | en | 1963-05-07 |
US-14011961-A | Cryogenic coupling device
April 16, 1963 N. H. MEYERS EIAL 3,086,130
CRYOGENIC COUPLING DEVICE Filed Sept. 22, 1961 2 Sheets-Sheet 1 P fifi ,110 I 1 5 FIG. 1A 105 106- L \33 Am SUPERCONDUCTOR GROUND PLATE INVENTORS NORMAN H. MEYERS NATHANIEL ROCHESTER EUGENE S. SCHLIG MLW AGENT I IIIlIlIIIIIl'lIIIIII/I April 1963 N. H. MEYERS ETAL CRYOGENIC COUPLING DEVICE Filed Sept. 22, 1961 2 Sheets-Sheet 2 201 202 205 L I I fly l fi 204 A, 0m A SUBSTRATES 206 I 224 I [207 SUBSTRATES SECTION LENGTH United States Patent Ofitice 3,086,130 Patented Apr. 16, 1963 3,086,130 CRYOGENIC CGUPLKNG DEVICE Norman H. Meyers, Chappaqua, Nathaniel Rochester,
Mount Kisco, and Eugene S. Schlig, Ossining, N.Y., assignors to International Business Machines Corporation, New York, N.Y., a corporation or New York Filed Sept. 22, 1961, Ser. No. 140,119 7 Claims. ((11. 3tl7-88.5)
This invention relates to cryotronic circuitry and more particularly to a device for coupling between cryotronic circuits which are located on different substrates.
Because of fabrication difiiculties, cryotronic circuits are generally deposited on relatively small substrates. These substrates do hold a substantial amount of circuitry; however, in many instances, for example in computing systems, in order to provide the desired amount of circuitry several substrates must be used. The present in vention is directed at providing a device for coupling between cryotronic circuits which are located on diiterent substrates.
Copending application Serial No. 132,961 by R. L. Garwin entitled Transformer, filed on August 21, 1961, shows a device for coupling between cryotronic circuitry which is located on diiferent substrates by using inductive or transforming coupling. The device which is the subiect of the present invention (though somewhat similar in appearance to the device disclosed in the above application) operates on an entirely diiierent principle than the device disclosed in the above application. The present invention does not use inductive or transformer coupling.
Cryotro-ns which consist of a gate which has superconductive and resistive states, and a control conductor which is positioned so that the magnetic field generated by current in the control conductor can make the gate resistive are well known. Cryotronic circuitry (i.e., circuitry which includes cryotrons) is generally deposited on substrates by vacuum deposition techniques. It is known that if cryotronic circuitry is fabricated with a superconducting plane between the cryotronic circuitry and the substrate on which it is deposited the only region wherein the magnetic field generated by current in a circuit path is appreciably strong is the region between the particular circuit path and the superconducting ground plane. Furthermore, if a superconducting plane is positioned between the circuitry and the substrate an image current flows in the superconducting ground plane beneath each circuit path. Each image current is equal in magnitude and opposite in direction to the current which produced the image current. Cryotronic circuits which have a superconducting ground plane near the circuitry have a relatively low inductance and hence they can opcrate at high speed. Examples of this type of circuitry are found in copending application Serial No. 625,512, filed November 30, 1956 in behalf of R. L. Garwin, and application Serial No. 824,120, filed June 30, 1959' in behalf of l. J. Lcntz, and US. Patent 2,966,647, filed April 29, 1959 in behalf of J. J. Lentz, all of which have been assigned to the assignee of the subject invention.
Coupling between cryoelcctric circuitry which is located on two different substrates can be effected by merely placing the control conductor for a cryotron on the bottom of a first substrate and the gate for the same cryotron on the top of a second substrate, neither circuitry having a superconducting plane between it and the substrate on which it is located. By bringing the control conductor into close proximity with the gate and passing suflicient current through the control conductor the mag netic field generated by the current in the control conductor causes the gate to become resistive. It has, however, been found that such an arrangement necessitates the use of an unduly large amount of current in the control conductor. Furthermore, the inductance of such circuitry is large and hence it cannot operate at high speeds.
The amount of current needed in the control conductor is slightly reduced if a first superconducting plane is placed between the first substrate and the cryotronic circuitry which includes the control conductor, and a second superconducting plane is placed between the second substrate and the cryotronic circuitry which includes the gate conductor. Such a coupling device requires a substantial amount of current in the control conductor in order to switch the gate; however, the inductance of the cryotronic circuitry which includes the control conductor and the inductance of the cryotronic circuitry which in cludes the gate conductor is low and, hence these circuits can operate at high speeds.
The amount of current needed in the control conductor in order to switch the gate conductor is substantially reduced if one superconducting ground plane is located between the second substrate and the cryotronic circuitry which includes the gate conductor and no superconducting ground plane is located between the first substrate and the cryotronic circuitry which includes the control conductor. The absence of a superconducting ground plane between the first substrate and the cryotronic circuitry which includes the control conductor increases the inductance of the cryotronic circuitry which includes the control conductor and severely limits the speed of such circuitry.
One feature of the present invention is directed at providing a device for coupling between low inductance cryotronic circuitry which is located on one substrate and other low inductance cryotronic circuitry which is located on a second substrate and in which a small amount of current in the control conductor causes the gate to become resistive.
In the coupling device of the present invention cryotronic circuitry which includes a cryotron gate i located on the bottom surface of a first substrate and a first superconducting ground plane is located between the first substrate and the cryotronic circuitry which includes the cryotron gate. Cryotronic circuitry which includes a control conductor is located on the top of a second substrate and a second superconducting ground plane is located between the second substrate and the cryotronic circuitry which includes a control conductor. The two substrates are positioned so that the control conductor is near the gate. At the point Where the control conductor is near the gate, an aperture is cut in the superconductor ground plane which is located beneath the control conductor (i.e., in the second superconducting ground plane).
In the device of the present invention the region wherein the magnetic field generated by current in the control conductor is appreciably strong is confined to the area between the control conductor and the second superconducting ground plane everywhere except at the point where the aperture is cut in the second superconducting ground plane. At the point where the aperture is cut in the second superconducting ground plane the region of strong magnetic field generated by current in the control conductor extends above the control conductor into the area where the gate and the first superconducting ground planes are located.
For reasons which will be explained in detail later the aperture in the second superconducting ground plane causes an image current of substantial magnitude to flow above the gate in the first superconducting plane. The magnitude of this image current is equal to the current in the control conductor.
The resultant magnetic field generated by the current in the control conductor and by the image current in the first superconducting ground plane cause the gate to become resistive. The current in the control conductor and its image in the first superconducting ground plane effectively form a current loop around the gate. In this manner a relatively small amount of current in the control conductor causes the gate to become resistive. Furthermore, both the cryotronic circuitry which includes the control conductor and the cryotronic circuitry which includes the gate conductor can operate at high speed since each has a superconducting ground plane located between it and the substrate on which it is deposited.
in accordance with another feature of the invention, the invention can be used to couple between a transmission line and cryotronic circuitry which is located on a plurality of different substrates. The coupling between the transmission line and the cryotronic circuitry can be accomplished without introducing reflections into the transmission line within a certain frequency range.
It is an object of the present invention to provide a device for coupling between cryotronic circuitry which is located on different substrates.
A further object of the present invention is to provide a simple, reliable, inexpensive device for coupling between cryotronic circuitry which is located on di ferent substrates.
A further object of the present invention is to provide a cryotronic device which couples directly from a control line which is located on one substrate to a cryotron gate which is located on a second substrate.
A further object of the present invention is to provide a cryotronic device whereby a small current in a control line on one plane can cause a gate located on another plane to become resistive.
Another object of the present invention is to provide a device consistent with the above objects which operates at a high speed.
Still another object of the present invention is to provide a device whereby the same line can be used as the control line for a plurality of cryotron gates which are located on a plurality of different substrates.
It is another object of the present invention to provide a device for coupling between a transmission line and cryotron gates located on a plurality of different substrates.
It is yet another object of the present invention to provide a device for coupling between a transmission line and cryotronic circuitry which is located on a plurality of different substrates.
It is a still further object of the present invention to provide a device for coupling between a transmission line and crytronic circuitry which is located on a plurality of dilferent substrates without introducing reflections into the transmission line within a useful band of frequencies.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings.
In the drawings:
FIGURE lA is an overall diagram of the first embodiment of the invention with the various components in their assembled positions.
FlGURE 1B shows the substrates shown in FTGURE 1A separated so that the circuitry on the substrates can be seen.
FIGURE 1C is an exploded perspective view of the first embodiment of the invention.
FIGURE 2A is an overall view of the second embodiment of the invention.
FIGURE 2B is an exploded perspective view of the transmission line shown in FIGURE 2A.
FIGURE 2C is a cross section View taken at the junction of one pair of substrates shown in FIGURE 2A.
In order to completely explain the various facets of the invention two difiierent embodiments of the invention are shown and described herein. The first embodiment is shown in FIGURES 1A, 1B and 1C and the second embodiment is shown in FIGURES 2A, 2B and 2C.
The following uniform numbering scheme is used in the specification in order to facilitate reference between the specifications and the drawings. All of the reference numerals used are three digit numerals and all of the reference numerals on FIGURES 1A, 1B and 1C have a l in the hundreds digital position, and all of the reference numerals in FIGURES 2A, 2B and 20 have a 2 in the hundreds digital position. Hence, the reference numeral designating any component specifies the embodiment of which the component is a 1 art.
The first embodiment of the invention which includes two substrates and 1% is shown in assembled form in FIGURE 1A. Cryotronic circuitry is located on the underneath surface of substrate res and this circuitry is coupled to other cryotronic circuitry which is located on the top surface of substrate The substrates 195 and 1% are shown separated in FTGURE ll and Cryotronic circuitry m7 and which is respectively located on the top of substrate and on the bottom of substrate 16-5 can be seen.
The cryotronic circuitry M37 includes a cryotron control conductor M9 and the cryotronic circuit 168 includes a cryotron gate lid. When the device is assembled as shown in FiGUl-KE 1A the cryotron control it is located directly beneath and at a right angle to the cryotron gate lit. The first embodiment of the invention is shown in exploded perspective fashion in FIGURE lC.
As can be seen from FIGURE 1C the cryotrouic circuitry 187 and N8 is not deposited directly on substrates res and id A superconducting ground plane is first deposited on the substrates and then the circuitry is dcposited on the ground planes. A superconducting ground plane 11?. is located between circuitry lit-'3 and substrate 1% and superconducting ground plane is located between circuitry llfl'l' and substrate Ell-5. A hole or aperture 1119 is cut in the superconducting ground plane 113 below the control conductor Naturally, the cryotronic circuitry 167 and 168 is respectively separated from the superconducting ground planes H3 and 112 and the circuitry lid? is separated from the circuitry by suitable insulating material. For the sake of clarity of illustration and since the use of such material is well known in the art, it is not shown in the drawings nofurther described herein.
The particular cryotronic circuitry which is located on substrate 165 and which is connected to the control 169 is not relevant to the present invention. It is merely represented in the figures by the superconducting paths and 128. Likewise the particular cryotronic circuitry which is located on substrate 1&6 and which is connected to gate 116 is not relevant to the present invention. It is represented in the drawings by superconducting paths T116 and 127. Cryotronic circuitry which includes gates and control lines is well known in the art.
When the device is assembled as shown in FIGURE 1A, the superconducting circuitry ill-7 is brought into proximity with the superconducting circuitry 168, the gate lid being located directly above the control conductor res and the aperture 119. The distance between cryotronic circuitry 107 and the superconducting plane 113 and the distance between cryotronic circuitry 10:; and superconducting plane 112 is fixed by the thickness of the insulation (not shown) which is located between the circuitry and the respective planes. Cryotronic circuitry ill? is also separated from cryotron circuitry 198 by a layer of insulating material (not shown). However, the distance between Cryotronic circuitry 107 and Cryotronic circuitry 108 is not only established by the thickness of the layer of insulating material which separates the circuits, but it is also established by the mechanical positioning of substrates M5 and 106.
The distance between cryotronic circuitry 107 and cryotronic circuitry 108 will generally be slightly more than the distance between the circuitry 107 and 108 and the respective superconducting planes 112 and 113.
The purpose of the present invention is to couple between the cryotronic circuitry 107 which is located on top of substrate 105 and cryotronic circuitry 108 which is located on the bottom of substrate 106. Current signals are applied to the control 109 through circuit 107. These signals cause gate 110 to become resistive. The increase in resistance of gate 110 is used to control cryotronic circuitry which is connected to gate 110 by current paths 116 and 127 in the usual manner Well known in the cryotronic art.
Certain of the currents which flow in certain of the components is shown in FIGURE with arrows. A solid arrow indicates that the particular current indicated by the arrow flows on the .top surface of the particular part on which the arrow is located and a dotted arrow indicates that the current indicated by the arrow flows on the bottom surface of the particular part on which the arrow is located.
As is well known in the cryotronic art, the current in the superconducting wire attempts to flow in a section of the wire which is as close as possible to a current equal in magnitude and opposite in direction to the current flowing in the wire. The current which is equal in magnitude and opposite in direction to the current flowing in the wire is referred to as an image of the current flowing in the wire. ()ne explanation of why the current in a superconducting wire attempts to flow as close as possible to its image current is that the current in the wire attempts to adopt a path whereby the volume of the flux between the current in the wire and the image is a minimum, and hence, so that the stored energy is a minimum.
It is also known that current in a superconducting wire generates a stronger magnetic field in the region between the current in the wire and the image of this current than in any other region. Considering the fact that it is the magnetic field generated by current in the control line that causes the gate of a cryotron to change state, it is clear that in Order to operate a cryotron with a small amount of current in the control line the gate should be positioned between the control line and the image of the current which flows in the control line.
If a superconducting wire is located between two superconducting planes there is current in the two faces of the wire closest to the planes and there is an image current in each of the planes. The relative magnitude of the currents in the two faces of the wire and the relative magnitude of the two image currents depends upon the spacing of each of the superconducting planes from the wire. The magnitude of the various currents also depends on the size of the superconducting planes; however, since the size of the wire is usually very small compared to the size of the planes the planes can usually be considered to be infinitely large.
In the portions of cryotronic circuitry 107 which are not located over aperture 119 (e.g., in superconducting paths 115 and 128) some portion of the current flows on the bottom side of circuit .107 and an image of this portion of the current flows in the top surface of superconducting plane 113. The remaining portion of the current in circuit 107 flows on the top surface of circuit 107 and an image of this portion of the current flows in the bottom surface of superconducting plane 112. The relative portions of the current which flow on the top and bottom faces of circuit 107 and the relative magnitude of the image currents in planes 112 and 113 depends upon the spacing of circuit 107 from planes 112 and 1 13. Since (as previously described) circuitry 107 is closer to plane 113 the greater portion of the current in circuit 107 flows on the bottom surface of the circuitry 107 and the image current in plane 113 due to current in the bottom surface of circuitry 107 is greater than the image current in plane 112 due to current in the top surface of circuitry 107. However, as will now be described the above explanation does not apply to the portion of circuitry 107 which is located above aperture 119. That is, the above explanation does not apply to the current in control 109.
By cutting aperture 119 in superconducting ground plane 113 the current which normally flows on the bottom side of circuit 107 is altered in the area of the aperture (as shown by the arrows in FIGURE 1C). The current which flows on the top side of circuit 107 and its image current in superconducting ground plane 112 remains substantially unaltered (for clarity of illustration this current is not shown by arrows in FIGURE 1C). Instead of flowing on the bottom of control conductor 109 (i.e., control conductor 109 is the portion of circuit 107 which is located over aperture 119) and having an image in superconducting ground plane 113, the current normally flowing on the bottom of circuit 107 goes around the sides of circuit 107 and flows in the top of control conductor 109 and an image of this current is induced in the bottom face of superconducting ground plane 112 (i.e., in the face of superconducting plane 112 which is closest to the control conductor 109).
It should he noted that in addition to the current which normally flows on the bottom of circuitry 107 and which moves to the top of control 109' over the aperture 119 and which induces the image shown by the arrows in the face of superconducting ground plane 112 there is current which normally flows in the top surface of circut-ry 107 merely due to the presence of superconducting ground plane 112 and irrespective of whether aperture 119 is present. No arrows are shown in FIGURE 1C to indicate the current which normally flows in the top of circuitry 107 nor are any arrows shown in FIGURE 1C to indicate the image of this current which flows in superconducting ground plane 112.
The current which normally flows on the top surface of control 109 plus the current which is forced to the top surface of control 109 by the aperture 119 together constitute the total of the current passing through control 109 and the image current directly above control 109 in superconducting .graund plane 112 has a magnitude equal to the total current passing through control 109.
The current on the top of control 109 and its image on the bottom of plane 112; effectively form a loop around the gate 110. The gate 110 is therefore located in a region which is between all of the current in control 109 and an image of all of the current in control 109. Because of this the gate can be switched to the resistive state by a relatively small amount of current in the control 109 and in cryotronic circuitry 107.
It should be noted that there is also current in circuit 108 and that an image of a portion of the current in circuit 108 flows directly above circuit 108 in superconducting ground plane 112 and an image of the remaining portions of the current in circuit 108 flows directly beneath circuit 108 in plane 113. The current in circuit 108 and its image in superconducting planes 112 and 113 is not shown in FIGURE 1C since it has no direct bearing on the present invention.
It should be particularly noted that there is no inductive coupling between the cryotronic circuit 107 and the cryotronic circuitry 108. The device of the present invention does not depend for its operation upon inductive coupling or transformer action. Instead the present invention utilizes the magnetic field generated by the current in control conductor 109 to switch the gate 110 from the supercon ducting state to the resistive state. This is an entirely different phenomenon from coupling by induction or by transformer action.
The gate conductor 110 and the control 109 need not be perpendicular as shown in FIGURE 1. In-line cryotrons in which the control conductor and the gate oonductor are parallel are well known in the art. For example,
spas-nae see application Serial No. 112,373, filed by Brennemann and Meyers on May 24, 1961, entitled Superconductive Storage Circuits. Similarly, in the present device the gate conductor and the control conductor may be parallel. If the gate and the control are parallel there will be some inductive coupling between the circuit which includes the control conductor and the circuit which includes the gate conductor; however, the device of the present invention does not depend for its operation upon this inductive coupling.
In the embodiment shown herein the aperture 119 is round; however, a round aperture is not essential to the operation of the device and the aperture may be square or any other convenient shape. The only requirement is that the aperture must be sufiiciently large to encompass a substantial portion of the area beneath the gate conductor.
The cryotronic circuitry 107 and W9 is not herein shown as connected to the respective superconducting planes 112 and 113 on which the circuitry is respectively deposited. However, as is well known in the art, the superconducting planes I12 and 113 may respectively be used as the return path for the current in circuits M3 and int. Connecting circuits 107 and 198 to the ground planes on which they are deposited would not alter the previously described current paths except in the vicinity where the connection is made. It is herein assumed that such a connection is made a substantial distance from the device of the present invention.
The specific materials from which the gate conductors, the control conductors, the other circuitry, the ground planes, and the substrates are made is not described in detail herein since the fabrication of these elements is Well known in the art. Furthermore, the circuitry of the present invention requires temperatures near the absolute zero for its operation. Refrigeration devices to produce such temperatures are also well known in the art and no description thereof is given herein.
Second Embodiment The second embodiment of the invention is shown in FIGURES 2A, 2B and 2C. The overall operation of the second embodiment of the invention is best understood with reference to FIGURE 2A. There are a plurality of pairs of substrates (only three pairs are shown in FIG- URE 2A). The first pair of stubstrates consists of substrates 232 and 203, the second pair of substrates consists of substrates 2M and 2% and the third pair of substrates consists of substrates 2% and 207. Substrates 202, 294 and 2% have cryotronic circuitry on their lower surfaces and substrates 293, 205 and 207 have cryotronic circuitry on their top surfaces. A transmission line 201 fits between each pair of substrates and as will be explained later, the transmission line is electrically coupled to the circuitry which is on each of the substrates.
The details of the transmission line are shown in FIG- URES 2B and 2C. The transmission line consists of two strips of superconducting material, 215' and 21s separated by a strip of dielectric material 218. The dielectric material 218 may be mylar tape. The transmission line 2M has four sections, 221, 223, 225, and 227 where the superconducting strips 215 and 216 are superimposed and three sections 222, 224 and 226 where the superconducting strips 215 and 216 are separated. As can be seen from FIGURE 2A, the sections of the transmisison line 201 where the superconducting strips 215 and 216 are separated are the sections of the transmission line 2% which fit between abutting substrates. For example, section 222 fits between substrates 202 and 2%.
FIGURE is an enlarged cross section View taken along line ZC-ZC in FIGURE 2A. The details of substrates 2% and 267 and the details of the circuitry on the substrates as shown in FIGURE 2C is representative of the substrates and the circuitry on each pair of abutting substrates shown in FIGURE 2A.
As shown in FIGURE 2 substrate 2% has a superconducting ground plane 235 covering its underneath surface and substrate 267 has a superconducting ground plane 235 covering its top surface. Superconducting ground planes 235 and 236 respectively have cryotronic circuitry 237 and 23? on their surfaces. The cryotronic circuits 237 and 239 respectively include cryotron gates 233 and 240. The cryotronic circuitry 237 and 238 is respectively separated from superconducting planes 235 and 236 by two layers of insulation 245 and 246. Superconducting plane 236 and insulating layer 246 have an aperture 2 32 beneath cryotron gate 238 and superconducting plane 235 and insulating layer 245 have an aperture 243 above cryotron gate 240. No particular configuration of circuitry is shown on substrates 266 and 2d? since the particular circuits which are on the substrates is irrelevant to the present invention. The present invention provides a device for coupling to any particular circuitry which is on the substrates (an example of circuitry which may be on the various substrates is given later). The invention merely requires that cryotron gates 238 and 2 3-0 be included in the circuitry.
The transmission line 2% is between substrate 206 and its associated substrate 297. The superconducting strip 215 is positioned directly beneath the cryotron gate 238 but separated from actual contact by a thin insulating layer (not shown) and superconducting strip 216 is positioned directly above the cryotron gate 249 but also insulated from direct contact by a thin insulating layer (not shown). Superconducting strip 215 acts as a control conductor for the cryotron gate 238 and superconducting strip 215 acts as a control conductor for the cryotron gate 24-h. The aperture 242 which is located below cryotron gate and the aperture 243 which is located above cryotron gate 24% function in the same manner as the aperture 119 in superconducting ground plane 113 shown in FIGURE 1. That is, aperture 242 causes a large image current to flow in the superconducting ground plane 235 and aperture 24-3 causes a large image current to flow in the superconducting ground plane 236. The resultant magnetic field generated by current in superconducting strip 215 and its image current which flows in superconducting ground plane 235 is incident on both faces of cryotron gate 238 and the resultant magnetic field generated by the current in superconducting strip 16 and by its image current in superconducting ground plane 236 is incident upon both faces of cryotron gate 249. The manner in which the image currents are generated and the function which the image currents perform is similar to the generation and functioning of the image current generated in superconducting ground plane 112 which was previously explained with reference to the first embodiment. Hence, no further explanation of the image currents which flow in the superconducting ground planes is given herein.
A current pulse applied to the beginning of transmission line Ztlll propagates through the sections 221' to 227 of the transmission line 23' As the pulse passes through section 222 a cryotron gate on each of the substrates 202 and 293 is activated, when the pulse passes through section 224, a cryotron gate on each of the substrates 2G4- and 26:5 is activated, and when the pulse passes through section 2213 a cryotron gate on each of the substrates 206 and 2:37 (i.e., cryotron gates 238 and 246) is activated.
The inductance L and the capacitance c of sections 222, 224 and 226 of the transmission line 201 where the strips of superconducting material 215 and 216 are separated is different from the inductance l and the capacitance C of the sections 221, 223, 225 and 227 where the strips of superconducting material 215 and 216 are superimposed. It should be noted that the section length of the line is defined as the length of a section of the line where the strips 2355 and 216 are separated plus the length of a section of the line Where the strips 215 and 2316 are superimposed. (See FIGURE 23.) If the section length is short in relation to the quarter wave length of desired or needed frequency components of the signal which is introduced into the transmission line the impedance of the transmission line will appear to be uniform or smooth and the desired frequency components of the signal introduced into the line will not be reflected at each place where the impedance changes. Stated differently, although the inductance and capacitance of a transmission line varies along its length, the transmission line appears to be a smooth transmissions line (i.e., a transmission line wherein the inductance and capacitance per unit length is constant) if the quarter wave length of the highest frequency component of interest in the signal applied to the transmission line is much longer than the section length of the line. At frequencies at which the transmission line appears to be smooth the impedance of the line appears to be approximately L+l C+c Considering the fact that the dimensions of cryotronic circuitry are in general very small, the substrates 202 to 207 can be positioned close enough together that the section length of the transmission line 201 is such that the transmission line 201 appears to be a uniform transmission line at a substantially high frequency.
The substrates 202 to 207 are positioned by using techniques well known in the cryotronic art. Each pair of substrates is positioned one half centimeter distant from the adjacent pair of substrates and the pairs of substrates are positioned with an overlap of one half centimeter. The section length of the transmission line is approximately one centimeter. At a frequency of cycles per second (one kilomegacycle) a quarter wave length is about four centimeters long and even at this very high frequency a quarter wave length is still about four times the section length of the transmission line. The transmission line 201 therefore appears smooth over the band of frequencies which extends from direct current up to one kilomegacycle. Hence, it can be seen that using the device of the present invention signals of extremely high frequency can be coupled to the cryotronic circuitry location on a plurality of different substrates without any unnecessary loss of power due to reflections in the transmission line which carries signals to the circuitry on the various substrates. Naturally, the dimensions given herein are merely given as one example of an embodiment of the invention and they could be changed without departing from the spirit of the invention.
An example of the type of system wherein the second embodiment of the invention may be used is a bit organized memory system. For example, the memory might store a plurality of six 'bit words, the first bit for each word would be stored in cryotronic circuitry on substrate 202, the second bit of each word would be stored in cryotronic circuitry on substrate 203, the third bit of each word would be stored in cryotronic circuitry on substrate 204, the fourth bit of each word would be stored in cryotronic circuitry on substrate 205, the fifth bit of each word would be stored in cryotronic circuitry on substrate 206, and the sixth bit of each word would be stored in cryotronic circuitry on substrate 257. Each Word in the memory would have associated therewith a transmission line such as transmission line 201, and each transmission line would control one cryotron gate on each substrate as does transmission line 201. The cryotron gates on the various planes which are activated by a particular transmission line would be efiective to cause read out of the bits of information in the word associated with the particular transmission line. Thus, there would be one transmission line for each word in the memory, and activation of each transmission line would cause readout from one bit of information on each of the planes 202 to 207, thus reading an entire word from the memory.
While the invention has been particularly shown and 10 described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
What is claimed is:
1. A coupling device for superconducting circuitry comprising first and second substrates,
a first superconducting ground plane on the underside of said first substrate,
a second superconducting ground plane on the top side of said second substrate,
a cryotron gate beneath said first superconducting ground plane (i.e., between the first superconducting ground plane and the second superconducting ground plane),
a control conductor above said second superconducting ground plane (i.e., between the second superconducting ground plane and said cryotron gate), said control conductor being juxtaposed to said cryotron gate,
said second superconducting ground plane having an aperture therein beneath the place where said cryotron gate is juxtaposed to said control conductor,
whereby current in said control conductor generates an image current above said gate in said first superconducting ground plane, said image current being equal in magnitude and opposite in direction to the total current in said control conductor, the total current in said control conductor and said image current eife'ctively forming a loop about said gate conductor whereby a relatively small amount of current in said control conductor causes said gate conductor to become resistive.
2. A cryotronic coupling device comprising,
cryotron gate positioned over a first superconducting ground plane on the bottom of a first substrate and and a control conductor deposited over a second superconducting ground plane on the top of a second substrate (the elements thereby being positioned in the following order: 1, first substrate, 2, first superconducting ground plane, 3, cryotro gate, 4, control conductor, 5, second superconducting ground plane, 6, second substrate),
said control conductor being positioned to cross said gate,
said second superconducting ground plane having an aperture at the point where the control conductor crosses the gate conductor.
whereby current in said control conductor generates an image current in said first superconducting ground plane substantially equal in magnitude to the total current in said control conductor, said gate being positioned between the control conductor and said image current.
3. A cryotron gating device comprising,
a first superconducting ground plane,
a cryotron gate below said first superconducting ground plane,
a control conductor below said cryotron gate, said control conductor being juxtaposed to said cryotron gate,
a second superconducting ground plane located below said control conductor,
said second ground plane having an aperture therein at the point where said control conductor is juxtaposed to said gate conductor,
whereby current in said control conductor generates an image current above said gate in said first superconducting ground plane, said image current being equal in magnitude and opposite in direction to the total current in said control conductor, the total current in said control conductor and said image current eifectively forming a loop about said gate conductor whereby a relatively small amount of current in said ll control conductor causes said gate conductor to be come resistive.
4. In a device for coupling between cryotronic circuitry located below a first substrate and cryotronic circuitry located above a second substrate,
the cryotronic circuitry on said first substrate including a cryotron gate positioned below a first superconducting ground plane,
the cryotronic circuitry on said second substrate including a cryotron control conductor positioned above a second superconducting ground plane, said control conductor being juxtaposed to said cryotron gate,
the improvement comprising;
an aperture in said second superconducting ground plane at the place where said control conductor is juxtaposed to said gate conductor whereby an image current is generated in said first superconducting ground plane by current in said control conductor, said image current having a magnitude equal substantially to the total current in said control conductor.
5. A device for coupling to cryotronic circuitry,
a plurality of pairs of substrates each pair having a first and a second substrate, each first substrate overlapping the associated second substrate for some portion of its area,
each first substrate having a superconducting ground plane located on the undersurface thereof and a cryotron gate located beneath said superconducting ground plane,
each second substrate having a superconducting ground plane positioned on its top surface and a cryotron gate located on top of said last mentioned superconducting ground plane;
said cryotron gates being located in the area where the respective pairs of planes overlaps, each cryotron gate thereby having a first superconducting ground plane on the same substrate as it is located and a second superconducting ground plane on the opposite substrate,
a cryotronic tranmission line comprising a dielectric tape having first and second surfaces, and two strips of superconducting material respectively deposited on said first and second surfaces,
said transmission line passing between the area where each pair of substrates overlap;
said strips of superconducting material being superimposed except at the place where said transmission line passes between each pair of substrates, at the place where said transmission line passes between each pair of substrates said superconducting strips being separated, one of said superconducting strips being juxtaposed to the cryotron gate which is on each substrate of the respective pair of substrates,
said superconducting strips being juxtaposed to the respective gates and forming control conductors for the respective cryotron gates,
the superconducting plane opposite each cryotron gate having an aperture therein at the place where the strip of superconducting material is juxtaposed to the gate,
whereby current in said transmission line causes an image current in the first superconducting plane associated with each gate, said image current having a magnitude substantially equal to the total current in said transmission line, and
whereby a relatively small amount of current in said transmission line can change the state of all of said gates.
6. A cryotronic device comprising the combination of,
a transmission line which includes a strip of dielectric material, a first strip of superconducting material on top of said strip of dielectric material and a second strip of superconducting material on the bottom of said strip of dielectric material,
said strips of superconducting material having periodically superimposed sections interspersed by sections where the two superconducting strips are separated,
one pair of superconducting planes for each section of said transmission line where said first and second superconducting strips are separated, the superconducting planes in each pair of superconducting planes being disposed on the top and bottom of the associated section of the transmission line,
a plurality of cryotron gates, a first cryotron gate between the first strip of superconducting material of said transmission line and the top superconducting plane in each section where the strips of superconducting material are separated and a second cryotron gate between the second strip of superconducting material of said transmission line and the bottom superconducting plane in each section where the strips of superconducting material are separated,
each top superconducting plane having an aperture therein above each second cryotron gate and each bottom superconducting plane having an aperture therein below each first cryotron gate,
whereby current in the first strip of superconducting material produces an image current in the top superconducting plane above each first cryotron gate, and whereby current in the second strip of superconducting material produces an image current in the bottom superconducting plane below each second cryotron gate,
said image currents having a magnitude substantially equal to the total magnitude of the current in said transmission line, whereby a relatively small current in said transmission line changes the state of said gates.
7. A cryotronic device comprising the combination of,
a transmission line which includes a strip of dielectric material, a first strip of superconducting material on top of said strip of dielectric material and a second strip of superconducting material on the bottom of said strip of dielectric material,
said strips of superconducting material having periodically superimposed sections interspersed by sections where the two superconducting strips are separated, each superimposed section being one half centimeter long and each section where the strips are separated being one half centimeter long, the superimposed sec tions of said transmission line having an inductance of land a capacitance of C and the separated sections having an inductance of L and a capacitance of 0.
one pair of superconducting planes for each section of said transmission line where said first and second superconducting strips are separated, the superconducting planes in each pair of superconducting planes overlapping by one half centimeter the overlapping section of each pair being disposed on the top and bottom of the associated section of the transmission line,
a plurality of cryotron gates, a first cryotron gate between the first strip of superconducting material of said transmission line and the top superconducting plane in each section where the strips of superconducting material are separated and a second cryotron gate between the second strip of superconducting material of said transmission line and the bottom superconducting plane in each section where the strip of superconducting material are separated,
each top superconducting plane having an aperture therein above each second cryotron gate and each bottom superconducting plane having an aperture therein below each first cryotron gate,
whereby current in the first strip of superconducting material produces an image current in the top superconducting plane above each first cryotron gate, whereby current in the second strip of superconducting material produces a second image current in the 3,086,180 13 14 bottom superconducting plane below each second said transmission line appearing to be a smooth line cryotron gate, with an impedance of said image currents having a magnitude substantially if +Z equal to the total magnitude of the current in said transmission line, whereby a relatively small current 5 in said transmission line changes the state of said to Signal frequencles less than one kllomegacycle' gates, No references cited.
6. A CRYOTRONIC DEVICE COMPRISING THE COMBINATION OF, A TRANSMISSION LINE WHICH INCLUDES A STRIP OF DIELECTRIC MATERIAL, A FIRST STRIP OF SUPERCONDUCTING MATERIAL ON TOP OF SAID STRIP OF DIELECTRIC MATERIAL AND A SECOND STRIP OF SUPERCONDUCTING MATERIAL ON THE BOTTOM OF SAID STRIP OF DIELECTRIC MATERIAL, SAID STRIPS OF SUPERCONDUCTING MATERIAL HAVING PERIODICALLY SUPERIMPOSED SECTIONS INTERSPERSED BY SECTIONS WHERE THE TWO SUPERCONDUCTING STRIPS ARE SEPARATED, ONE PAIR OF SUPERCONDUCTING PLANES FOR EACH SECTION OF SAID TRANSMISSION LINE WHERE SAID FIRST AND SECOND SUPERCONDUCTING STRIPS ARE SEPARATED, THE SUPERCONDUCTING PLANES IN EACH PAIR OF SUPERCONDUCTING PLANES BEING DISPOSED ON THE TOP AND BOTTOM OF THE ASSOCIATED SECTION OF THE TRANSMISSION LINE, A PLURALITY OF CRYOTRON GATES, A FIRST CRYOTRON GATE BETWEEN THE FIRST STRIP OF SUPERCONDUCTING MATERIAL OF SAID TRANSMISSION LINE AND THE TOP SUPERCONDUCTING PLANE IN EACH SECTION WHERE THE STRIPS OF SUPERCONDUCTING MATERIAL ARE SEPARATED AND A SECOND CRYOTRON GATE BETWEEN THE SECOND STRIP OF SUPERCONDUCTING
| 1961-09-22 | en | 1963-04-16 |
US-95152897-A | Apparatus for attaching a vehicle steering wheel
ABSTRACT
An apparatus includes a vehicle steering wheel (10) for attachment to a vehicle steering column (12). The steering wheel (10) is rotatable and has a hub (130) for non-rotatable attachment to an end (162) of the steering column (12) so that the steering column rotates about an axis (B) upon rotation of the steering wheel. The hub (130) has a first surface (138) defining a first passage (140) for receiving the end (162) of the steering column (12) and a second surface (152) defining a second passage (150) extending transverse to the first passage and partially intersecting the first passage. A hollow cylindrical member (200) blocks axial movement of the hub (130) relative to the steering column (12). The hollow cylindrical member (200) is radially contractible for insertion into the second passage (150) and is radially expandable into contact with the second surface (152) and the steering column (12).
FIELD OF THE INVENTION
The present invention relates to an apparatus for attaching a vehicle steering wheel to a vehicle steering column.
BACKGROUND OF THE INVENTION
A vehicle steering wheel is typically attached to a vehicle steering column by a splined connection. The splined connection non-rotatably attaches the steering wheel to the steering column and transmits torque from the steering wheel to the steering column. The steering wheel is also typically attached to the steering column to prevent relative axial movement between the steering wheel and the steering column. Usually, a nut is screwed onto a threaded extension located on the end of the steering column. The nut is normally accessed through the center of the steering wheel.
Certain steering wheel configurations, however, particularly those with an integrated (or non-removable) air bag cover, prevent access to the top of the steering column through the center of the steering wheel.
SUMMARY OF THE INVENTION
The present invention comprises a vehicle steering wheel for attachment to a vehicle steering column. The steering wheel is rotatable. The steering wheel has a hub for non-rotatable attachment to an end of the steering column so that the steering column rotates about an axis upon rotation of the steering wheel. The hub has first surface means for defining a first passage for receiving the end of the steering column and second surface means for defining a second passage extending transverse to the first passage and partially intersecting the first passage. Means is provided for blocking axial movement of the hub relative to the steering column. The means comprises a hollow cylindrical member which is radially contractible for insertion into the second passage and is radially expandable into contact with the second surface means and the steering column and blocks axial movement of the hub relative to the steering column.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon reading the following description of the invention with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic view, partly in section, of a steering wheel assembly and a steering column constructed in accordance with the present invention;
FIG. 2 is a plan view taken along line 2--2 in FIG. 1 and illustrating the parts assembled;
FIG. 3 is a sectional view taken approximately along line 3--3 of FIG. 1; and
FIGS. 4-6 are three different perspective views showing a part of the invention in three different conditions.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a vehicle steering wheel assembly 10 and a vehicle steering column 12 constructed in accordance with the present invention. The steering wheel assembly 10 includes a die cast armature 20 having an outer rim 22 and an inner rim 24 connected by a plurality of radially extending spokes (not shown). The inner rim 24 has three threaded openings 26, one of which is visible in FIG. 1, which are equally spaced about the inner rim.
An integral (or non-removable) cover 30 is molded about the armature 20. In particular, the cover 30 covers the outer rim 22, the inner rim 24 and the spokes. The cover 30 has a continuous outer surface 32 which extends uninterruptedly over a central area of the steering wheel assembly 10. An inner surface 34 of the cover 30 has a side wall portion 36 and an end wall portion 38. The inner surface 34 defines a cavity 40 in the central area of the cover 30. A tear seam 42 extends across the end wall portion 38 of the inner surface 34 of the cover 30. In accordance with the preferred embodiment of the invention, the cover 30 is made of a homogeneous urethane material.
It is contemplated that the cover 30 could alternatively be made of several cover portions rather than the integral cover shown. For example, an alternate cover could include a first cover portion covering the outer rim 22 and spokes and a second cover portion covering the inner rim 24 and the central area of the steering wheel assembly 10.
The steering wheel assembly 10 includes a reaction plate 50. The reaction plate 50 partially encloses the cavity 40 in the cover 30. The reaction plate 50 is a metal ring centered on an axis A. The reaction plate 50 has axially extending inner and outer surfaces 52 and 54, respectively. The inner surface 52 defines a central opening 56 in the reaction plate 50. The reaction plate 50 includes first and second radially extending side surfaces 58 and 60, respectively, which are parallel to one another. A first series of circumferentially spaced apertures 62 in the reaction plate 50 are located adjacent the outer surface 54. The first series of apertures 62 are spaced and located identically to the plurality of threaded openings 26 in the inner rim 24 of the steering wheel armature 20. A second series of circumferentially spaced apertures 64 in the reaction plate 50 are located adjacent the inner surface 52.
The steering wheel assembly 10 includes an inflatable air bag 70 and an actuatable inflator 80 for, when actuated, inflating the air bag. The inflator 80 is circular in cross-section and has a cylindrical outer surface 82. The diameter of the cylindrical outer surface 82 of the inflator 80 is slightly smaller than the diameter of the central opening 56 in the reaction plate 50. A portion of the inflator 80 extends through the central opening 56 in the reaction plate 50 and into the cavity 40 in the cover 30.
The inflator 80 has an annular mounting flange 84 and radially extending first and second end surfaces 86 and 88, respectively. The mounting flange 84 has first and second side surfaces 90 and 92, respectively, which are parallel to the first and second end surfaces 86 and 88, respectively. The first side surface 90 of the mounting flange 84 abuts the second side surface 60 of the reaction plate 50. The mounting flange 84 includes a plurality of openings 94 which are circumferentially spaced so as to align with the second series of apertures 64 in the reaction plate 50.
The air bag 70 is located in the cavity 40 in the cover 30 between the inner surface 34 of the cover and the portion of the inflator 80 extending into the cavity. The air bag 70 includes an annular metal retaining ring 72 sewn into the air bag material for securing the air bag to the reaction plate 50. The retaining ring 72 has a plurality of circumferentially spaced openings 74 which align with the second series of apertures 64 in the reaction plate 50. Fasteners (not shown) extend through the aligned openings 94 in the inflator flange 84, through the apertures 64 in the reaction plate 50, and through the openings 74 in the retaining ring 72 to secure the air bag 70 and the inflator 80 in the steering wheel assembly 10.
The steering wheel assembly 10 further includes a support plate 100. The support plate 100 is a generally T-shaped part, as is shown in FIG. 2, and is preferably made of cast magnesium. The support plate 100 comprises three leg portions 102 which extend radially and axially from a generally rectangular base portion 104. Each leg portion 102 includes a foot portion 106 located at the terminal end of the leg portion. The foot portions 106 are axially offset from the base portion 104. Each foot portion 106 has an opening 108 which aligns with a respective one of the three threaded openings 26 in the inner rim 24 of the armature 20. Bolts 110 (FIG. 1) extend through the openings 108 in the foot portions 106 of the support plate 100 and into the threaded openings 26 in the armature inner rim 24 to secure the support plate to the steering wheel assembly 10.
The support plate 100 includes an axially ally extending surface 120 which defines a central passage 122 (FIG. 1) through the base portion 104 of the support plate. The passage 122 is centered on an axis B. An annular radially inwardly extending ridge 124 extend from the axially extending surface 120 into the passage 122.
A metal hub 130 is partially located in the passage 122 in the base portion 104 of the support plate 100. The hub 130 is annular and is centered on the axis B. The hub 130 is preferably cast into the support plate 100 and is thus fixed to the support plate. The annular ridge 124 of the support plate 100 extends into the body of the hub 130 to attach the hub non-rotatably to the support plate during casting. Alternatively, it should be understood that the hub 130 could be formed integrally with the support plate 100 as a one-piece cast part.
The hub 130 has first and second end portions 132 and 134, respectively (FIG. 3). The first end portion 132 is disposed within the passage 122 in the support plate 100. The second end portion 134 extends axially beyond the base portion 104 of the support plate 100 and includes a radially extending end surface 136.
An axially extending surface 138 defines a central passage 140 through the hub 130 which extends from the first end portion 132 to the second end portion 134. The passage 140 is centered on the axis B. The surface 138 has a first section 142 adjacent the first end portion 132 of the hub 130 and a second section 144 adjacent the second end portion 134 of the hub. The first section 142 of the surface 138 is splined and the second section 144 of the surface 138 is smooth and tapered.
The base portion 104 of the support plate 100 further includes a transversely extending aperture 150 (FIGS. 2 and 3) defined by a transversely extending surface 152 which extends through the base portion 104 of the support plate and through the hub 130 attached to the support plate. The aperture 150 is centered on an axis C which is offset from the axis B. A portion of the transversely extending aperture 150 intersects the axially extending central passage 140 in the hub 130.
The steering column 12 is a cylindrical shaft member centered on the axis B, which is the axis of rotation for the steering column. As shown in FIG. 3, the steering column 12 includes a main portion 160 and an upper end portion 162. The upper end portion 162 has a radially inwardly extending first surface 164, an axially extending second surface 166, and an axially extending third surface 168. The second surface 166 intersects the first surface 164 and has a tapered contour similar to the tapered second section 144 of the surface 138 in the passage 140 in the hub 130.
The third surface 168 in the upper end portion 162 of the steering column 12 extends between the second surface 166 and a chamfer 170 on a radially extending upper end surface 172 of the steering column. The third surface 168 has splines which mesh with the splined surface in the first section 142 of the surface 138 in the hub 130. An arcuate recess 180 (FIG. 1) is located in the third surface 168 of the upper end portion 162 of the steering column 12. The recess 180 is defined by a surface 182 which has a radius of curvature centered on the axis C. The surface 182 extends transverse to the axis B.
A spring pin (or roll pin) 200 secures the steering wheel assembly 10 against axial movement relative to the steering column 12. The spring pin 200 is a hollow cylindrical member which is preferably made of metal, but could be made of another material, such as a hard plastic. The spring pin 200 is centered on the axis C and includes parallel, cylindrical inner and outer surfaces 202 and 204, respectively (FIG. 4). The diameter of the outer surface 204 of the spring pin 200 is normally slightly larger than the diameter of the transversely extending aperture 150 in the base portion 104 of the support plate 100.
The spring pin 200 further includes an axially extending slot 206 which extends throughout the entire length of the pin. The slot 206 in the spring pin 200 provides the pin with the ability to contract radially and then expand. This feature can be seen in the three conditions for the spring pin 200 shown in FIGS. 4-6. FIG. 5 illustrates the spring pin 200 in a radially expanded normal condition. This is the condition of the spring pin 200 in a free state. In the condition of FIG. 5, the slot 206 in the spring pin 200 has a first circumferential width W1.
FIG. 6 shows the spring pin 200 in a radially contracted condition. The spring pin 200 is squeezed in order to place it in this condition. In the condition of FIG. 6, the slot 206 in the spring pin 200 has a second circumferential width W2 which is less than the width W1.
FIG. 4 illustrates the spring pin 200 in a condition which is intermediate the expanded condition of FIG. 5 and the contracted position of FIG. 6. This is approximately the condition of the spring pin 200 when the pin has been inserted into the transversely extending aperture 150 in the support plate 100. In the condition of FIG. 4, the slot 206 in the spring pin 200 has a third circumferential width W3 which is less than the width W1 but greater than the width W2.
To attach the steering wheel assembly 100 to the steering column 12, the hub 130 in the support plate 130 of the steering wheel assembly is placed over the steering column such that the upper end portion 162 of the steering column is received in the passage 140 in the hub. The splined section 142 of the surface 138 in the passage 140 meshes with the splined surface 168 of the steering column 12. The steering wheel assembly 10 is oriented so that the recess 180 in the splined surface 168 of the steering column 12 aligns with the transversely extending aperture 150 in the support plate 100 and attached hub 130.
As the steering wheel assembly 10 is pushed onto the wheel column 12, the tapered surfaces 144 and 166 seat against one another and the end surface 136 of the hub 130 comes into contact with the radially extending first surface 164 of the upper end portion 162 of the steering column 12 (FIG. 1). The recess 180 in the steering column 12 and the transversely extending aperture 150 in the support plate 100 now extend co-linearly along the axis C.
The spring pin 200 is radially contracted from its free condition (FIG. 5) to its second condition (FIG. 6). The spring pin 200 is then inserted into the transversely extendingly aperture 150 in the support plate 100. When inside the aperture 150, the pin 200 is released so that it expands radially to its third condition (FIGS. 3 and 4). The outer surface 204 of the spring pin 200 engages the surface 152 defining the aperture 150 and the surface 182 defining the semi-circular recess 180 in the steering column 12. The spring pin 200 exerts a radially outwardly directed biasing force against the surfaces 152 and 182.
Once installed as described above, the engagement of the spring pin 200 and the surfaces 152 and 182 of the aperture 150 and the recess 180, respectively, prevents axial movement of the steering wheel assembly 10 relative to the steering column 12.
To remove the steering wheel assembly 10 from the steering column 12, the spring pin 200 is removed from its position in the aperture 150 in the support plate 100. This is accomplished by forcing a portion of the spring pin 200 out of the aperture 150 and then manually contracting the pin to its second position (FIG. 6) so that it can be completely pulled from the aperture.
From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.
Having described the invention, I claim:
1. A vehicle steering wheel assembly comprising:a vehicle steering wheel attached to a vehicle steering column, said steering wheel being rotatable about an axis, said steering wheel including a support plate with an opening centered on said axis, said steering wheel having a hub partially disposed in said opening in said support plate, said hub for non-rotatable attachment to an end of the steering column so that said steering column rotates about said axis upon rotation of said steering wheel, said hub having first surface means for defining a first passage for receiving the end of the steering column and second surface means for defining a second passage extending transverse to said first passage and partially intersecting said first passage; and means for blocking axial movement of said hub relative to the steering column, said means comprising a hollow cylindrical member which is radially contractible for insertion into said second passage and is radially expandable into contact with said second surface means and the steering column, said means for blocking axial movement of said hub being located in said support plate of said steering wheel and being partially disposed in said opening through said support plate.
2. A vehicle steering wheel assembly as defined in claim 1 wherein said steering wheel has a rim portion extending from said support plate, said vehicle steering wheel assembly further comprising an inflatable air bag and an air bag inflator supported by said support plate.
3. A vehicle steering wheel assembly as defined in claim 2 wherein said hollow cylindrical member is located below said air bag and said air bag inflator.
4. A vehicle steering wheel assembly as defined in claim 1 wherein said hollow cylindrical member has a slot which extends axially throughout the entire length of said hollow cylindrical member, said slot having a circumferential width which decreases when said cylindrical member radially contracts and increases when said cylindrical member radially expands.
5. A vehicle steering wheel assembly as defined in claim 4 wherein said slot has a first circumferential width prior to insertion of said hollow cylindrical member into said second passage, a second circumferential width during insertion into said second passage, and a third circumferential width when in said passage and blocking axial movement of said hub relative to the steering column, said third width being of a dimension intermediate said first and second widths.
6. A vehicle steering wheel assembly as defined in claim 1 wherein the steering column has splines and said hub has splines which intermesh with the splines on the steering column to provide said non-rotatable attachment of said hub to said steering column.
7. A vehicle steering wheel assembly as defined in claim 1 wherein the steering column has an arcuate recess extending transverse to said axis, said hollow cylindrical member being radially expandable into said arcuate recess.
| 1997-10-16 | en | 1999-12-28 |
US-40528382-A | Ground detection arrangement for an A.C. generator
ABSTRACT
The present invention relates to a ground detection arrangement for an A.C. generator in which positive and negative D.C. voltages are alternately applied to the neutral point of an armature winding so as to detect voltages proportional to ground currents corresponding to the respective D.C. voltages, and the average of the sum of the absolute values of both the detected voltages is compared with a reference value thereby to detect the existence of grounding, whereby the existence of the grounding can be detected without being affected by the grounding position of a field winding.
BACKGROUND OF THE INVENTION
This invention relates to a ground detection arrangement for an A.C. generator.
FIG. 1 illustrates an example of a conventional arrangement of the type of the present invention.
In FIG. 1, numeral 1 denotes a brushless A.C. generator, numeral 2 an armature winding, numeral 3 a three-phase full-wave rectifier, numeral 4 a field winding and numeral 5 an insulation resistance detector. The insulation resistance detector 5 includes both a D.C. voltage source (voltage E) 8 and current relay 9 for the direct current introduced across a brush 6 and a slip ring 7 in between the neutral point C of armature winding 2 and the ground A. If the ground resistance (insulation resistance) Rs is reduced to cause a current exceeding the critical reference value, the current relay 9 is actuated. Numeral 10 denotes a protection resistor.
In such a conventional device, however, the current value Isp in case of the grounding occurring on the side of positive pole in field winding 4 and the current value Isn in the case of the grounding occurring on the side of the negative pole N are different from each other as follow: ##EQU1## where: Ef =Voltage of field winding
Ri =Resistance value of the protection resistor
Therefore, conventional devices do not allow for correct detection of the existence of grounding in the field winding 4.
SUMMARY OF THE INVENTION
The present invention has been introduced in order to eliminate the disadvantage described above, and has for its object to provide a ground detection arrangement for an A.C. generator in which positive and negative D.C. voltages are alternately applied to the neutral point of an armature winding so as to detect voltages proportional to ground currents corresponding to the respective D.C. voltages, and the average of the sum of the absolute values of both the detected voltages is compared with a predetermined reference value thereby detecting the existence of grounding in the field winding, whereby the existence of the grounding can be detected without being affected by the grounding position of the field winding.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a ground detection arrangement for an A.C. generator in a prior art; and
FIG. 2 is a circuit diagram of a ground detection arrangement for an A.C. generator according to the present invention.
FIG. 3 is a flow diagram to explain the steps followed in determining the grounding and the values of insulation resistance (if so equipped).
In the drawings, the same symbols indicate the same or corresponding parts.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 2, D.C. sources 11 and 12 are connected to the neutral point C of an armature winding 2 through the contacts 13a and 13b of a change-over switch 13, respectively. A detection resistor 14 is inserted between both the D.C. sources 11, 12 and the ground A. Numerals 15 and 16 indicate protective resistors having a high resistance Ri. A detected voltage Ed developing across the detection resistor 14 is applied to an analog input type arithmetic controller 18 through a voltage amplifier 17. The arithmetic controller 18 executes the below-mentioned calculation, compares the calculated result with a reference value and transmits an alarm signal to an alarm device 19. It also provides a control signal for changing-over the contacts 13a and 13b of the change-over switch 13 at regular time intervals.
The arithmetic controller 18 calculates the average value Ed of the sum between the absolute value of the detected voltage Ed+ developing across the detector resistor 14 upon the application of the voltage +E of the D.C. source 11 to the neutral point C of the armature winding 2 and the absolute value of the detected voltage Ed- developing across the detection resistor 14 upon the application of the voltage -E of the D.C. source 12. When the average value Ed is found smaller than the reference value by the comparison, the alarm signal is transmitted.
Since, as stated before, the ground current at the grounding of the field winding 4 differs depending upon the ground point, also the detected voltage which is the product between the ground current and the resistance value Rd of the detecting resistor 14 changes depending upon the ground point. In contrast, the average value Ed becomes as follows and has the influence of the voltage Ef of the field winding: ##EQU2## Since Ri and Rd are constants, Ed varies in accordance with the change of the ground resistance Rs. Accordingly, wherever the ground point lies, the alarm signal is transmitted when the substantial grounding has occurred and the ground resistance Rs has been decreased to a dangerous level.
In the above, there has been described the case where the average value Ed of the sum of the absolute values of the detected voltages is compared with the predetermined value (voltage). However, it is also possible to calculate the value of the ground resistance Rs from the average value Ed of the sum of the absolute values according to the following equation and to transmit the alarm signal when the resistance Rs has become lower than a predetermined reference value (resistance): ##EQU3##
As set forth above, according to this invention, positive and negative D.C. voltages which are alternately switched and applied across the neutral point of an armature winding and the ground, ground currents are converted into and detected as voltages by a detection resistance, and the average value of the sum of the absolute values of the detected voltages at the application of the respective positive and negative D.C. voltages is calculated and then compared with a reference value by means of an arithmetic controller to detect the existence of grounding in the field winding. Hence, influence due to different ground positions of the field winding can be eliminated, so that the existence of the substantial grounding can be detected more accurately than in the prior art.
In summary, referring to the flow diagram of FIG. 3, Ed+ and Ed- are detected as the voltages across the resistor Rd and are alternatively fed into the amplifier 17 which serves as a combiner at a frequency which is controlled by the controller. The combiner feeds the combined (mixed) voltages to the controller. (Values of Rd, Ri and E are stored in the controller if Rs is to be calculated). The controller calculates the average of the sum of the absolute voltage values 1/2(|Ed+ |+|Ed- |) and Rs using equation (4) based on the calculated average and the stored values Rd, Ri and E. An alarm is actuated if the average of the sum of the absolute voltage values is less than a predetermined reference value or when Rs is less than a predetermined reference value.
What is claimed is:
1. A ground detection arrangement for an A.C. generator comprising:a high resistance element (Ri) connected to a neutral point of an armature winding of an A.C. generator; a D.C. voltage source of positive and negative D.C. voltages applied alternately to the neutral point of said armature winding through said high resistance element (Ri); a detecting resistor connected between said D.C. voltage source and the ground of the circuit arrangement; and an arithmetic controller including means for calculating an average voltage value of a sum of absolute values of D.C. voltage values of positive and negative polarities developed across said detecting resistor and for comparing the average voltage value with a reference voltage value, thereby to detect existence of grounding in the field winding of the A.C. generator.
2. A ground detection arrangement for an A.C. generator as defined in claim 1, wherein said arithmetic controller transmits the alarm signal when the average voltage value of the absolute values has become greater than a predetermined reference value.
3. A ground detection arrangement for an A.C. generator as defined in claim 1, wherein said arithmetic controller transmits the alarm signal when an value of a ground resistance calculated by the controller, based on the average voltage value of the absolute values has become smaller than a predetermined reference value.
| 1982-08-04 | en | 1985-09-17 |
US-35650499-A | Electrical socket device with overheating and overcurrent protection
ABSTRACT
An electrical socket device includes a base member formed with an open top side for access to a mounting chamber. Two conductive prong engaging members are mounted on the base member inside the mounting chamber, and are formed with prong engaging portions. One of the prong engaging members is further formed with a first fuse contact. A conductive fuse contacting member is mounted on the base member inside the mounting chamber, and has a second fuse contact aligned with and spaced apart from the first fuse contact. A thermal fuse has first and second fuse terminals held removably by the fuse contacts. A cover member is mounted on the base member to cover the top side of the base member, and includes a plug engaging portion formed with prong inserting slots aligned with the prong engaging portions, and a fuse locating portion formed with an access opening for exposing the fuse contacts. A cover plate is mounted removably on the cover member to cover the access opening, and has the thermal fuse retained removably thereon such that mounting of the cover plate on the cover member will result in engagement of the thermal fuse with the fuse contacts.
FIELD OF THE INVENTION
The invention relates to a socket device, more particularly to an electrical socket device with overheating and overcurrent protection.
BACKGROUND OF THE INVENTION
Referring to FIG. 1, a conventional electrical socket device is shown to include a base member 1 made from an insulator material, a pair of conductive prong engaging members 2, an electrical cable 3, and a cover member 4 also made from an insulator material.
As illustrated, the base member 1 is formed with a mounting chamber 1a, and an open top side for access to the mounting chamber 1a. The conductive prong engaging members 2 are mounted on the base member 1 inside the mounting chamber 1a. The conductive prong engaging members 2 are formed with three pairs of prong engaging portions 2a, each pair of which is adapted to engage a pair of prongs of an appliance plug (not shown). The electrical cable 3 has two insulator conductors 3a, 3b connected electrically and respectively to the prong engaging members 2 at one end, and terminated by a device plug 3c at the other end. The cover member 4 is mounted removably on the base member 1 to cover the top side of the base member 1, and is formed with three pairs of prong inserting holes 4a that are aligned with the prong engaging portions 2a, respectively.
Some of the disadvantages of the aforesaid conventional electrical socket device are as follows:
(a) When three plugs of three electrical appliances are inserted into the prong engaging portions 2a via the prong inserting holes 4a in the cover member 4, a relatively large amount of current will flow through the prong engaging members 2, which after long term use, will result in overheating and can lead to the outbreak of a fire.
(b) Since there is no safety device installed in the conventional electrical socket device, the user is exposed to constant danger as long as the electrical socket device is use.
SUMMARY OF THE INVENTION
The main object of this invention is to provide an electrical socket device with overheating and overcurrent protection.
Accordingly, an electrical socket device of the present invention includes a base member, a pair of conductive prong engaging members, a conductive fuse contacting member, a thermal fuse, a cover member, and a cover plate. The base member is made from an insulator material, and is formed with a mounting chamber, and an open top side for access to the mounting chamber. The conductive prong engaging members are mounted on the base member inside the mounting chamber. The prong engaging members are formed with at least one pair of prong engaging portions that are adapted to engage a pair of prongs of an appliance plug. One of the prong engaging members is further formed with a first fuse contact. The conductive fuse contacting member is mounted on the base member inside the mounting chamber, and is formed with a second fuse contact. The second fuse contact is aligned with and is spaced apart from the first fuse contact. The thermal fuse extends between and has first and second fuse terminals held removably and respectively by the first and second fuse contacts. The cover member is made from an insulator material, and is mounted on the base member to cover the top side of the base member. The cover member includes a plug engaging portion formed with at least one pair of prong inserting slots aligned with a respective pair of the prong engaging portions, and a fuse locating portion formed with an access opening for exposing the first and second fuse contacts. The cover plate is mounted removably on the cover member to cover the access opening, and has one side with the thermal fuse retained removably thereon such that mounting of the cover plate on the cover member will result in engagement of the thermal fuse with the first and second fuse contacts, and such that removal of the cover plate from the cover member will result in corresponding removal of the thermal fuse from the first and second fuse contacts.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiment of this invention, with reference to the accompanying drawings, in which:
FIG. 1 is an exploded view of a conventional electrical socket device;
FIG. 2 is a perspective view of a preferred embodiment of an electrical socket device of the present invention;
FIG. 3 is an exploded view of the preferred embodiment;
FIG. 4 is a fragmentary sectional view of the preferred embodiment; and
FIG. 5 is a partial view of the preferred embodiment, illustrating how installation of thermal fuses is conducted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 2, 3 and 4, the electrical socket device of a preferred embodiment of the present invention is shown to comprise a base member 10, a pair of conductive prong engaging members 20, a pair of elongated conductive fuse contacting members 40, two thermal fuses 50, a cover member 30, a cover plate 33 and an electrical cable 200.
As illustrated, the base member 10 is elongated in shape and is made from an insulator material. The base member 10 is formed with a mounting chamber 100, and an open top side 101 for access to the mounting chamber 100.
The conductive prong engaging members 20 are mounted on the base member 10 inside the mounting chamber 100 in a parallel manner so as to extend in a longitudinal direction of the base member 10. The prong engaging members 20 are formed with three pairs of prong engaging portions 21, each pair of which is adapted to engage a pair of prongs 70 of an appliance plug. Each of the prong engaging members 20 is further formed with a first fuse contact 22 on one end.
The conductive fuse contacting members 40 are mounted on the base member 10 inside the mounting chamber 100. Each of the fuse contacting members 40 is formed with a second fuse contact 42 that is aligned with and that is spaced apart from the respective one of the first fuse contacts 22 at a distance along the longitudinal direction.
Each of the thermal fuses 50 extends between and has first and second fuse terminals 51,52 held removably and respectively by an aligned pair of the first and second fuse contacts 22, 42.
The cover member 30 is made from an insulator material, and is mounted on the base member 10 to cover the top side 101 of the base member 10. The cover member 30 includes a plug engaging portion 301 that is formed with three pairs of prong inserting slots 31 aligned with a respective one of the pairs of the prong engaging portions 21, and a fuse locating portion 302 that is formed with an access opening 32 for exposing the first and second fuse contacts 22,42 (see FIG. 5).
The cover plate 33, also made from an insulator material, is mounted removably on the cover member 30 by means of a screw fastener 34 to cover the access opening 32. The cover plate 33 has a bottom side with the thermal fuses 50 retained removably thereon such that mounting of the cover plate 33 on the cover member 30 will result in engagement of the thermal fuses 50 with the first and second fuse contacts 22, 42, and such that removal of the cover plate 33 from the cover member 30 will result in corresponding removal of the thermal fuses 50 from the first and second fuse contacts 22,42.
In the preferred embodiment, the bottom side of the cover plate 33 has two fuse holding sleeves 331 mounted thereon. Each of the thermal fuses 50 has an intermediate portion 53 disposed between the first and second fuse terminals 51,52 and retained by a respective one of the fuse holding sleeves 331 on the cover plate 33. Each of the first and second fuse contacts 22, 42 is a resilient contact which defines a fuse holding groove 221, 421 with a groove access that opens upwardly for holding removably the respective one of the first and second fuse terminals 51,52. Preferably, the groove access of each of the first and second fuse contacts 22, 42 has a width slightly smaller that a diameter of the respective one of the first and second fuse terminals 51,52 such that the latter will be held firmly in the fuse holding grooves 221, 421 when the cover plate 33 is mounted on the cover member 30.
The cover member 30 is further formed with an indicator window 35. An indicator lamp 60 is mounted on the base member 10 and is connected electrically across the conductive prong engaging members 20. The lamp 60 is registered with the indicator window 35 so as to be visible from an exterior of the cover member 30, when electrical current flows through the prong engaging members 20, the indicator lamp 60 will be activated.
The electrical cable 200 has two insulated conductors 202, 203 connected electrically and respectively to the prong engaging members 20 at one end via the thermal fuses 50, and terminated by a device plug 201 at the other end.
In the event of excessive electrical current, which exceeds the rated load of the thermal fuses 50, flows into the electrical socket device of the present invention, the thermal fuses 50 will fuse and subsequently break the current flow to the prong engaging members 20, thereby preventing damage to the electrical appliances that are connected to the electrical socket device. By removing the cover plate 33 from the cover member 30, the thermal fuses 50 can be easily removed from the first and second fuse contacts 22, 42 to facilitate replacement of the same.
With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.
What is claimed is:
1. An electrical socket device, comprising:a base member made from an insulator material and formed with a mounting chamber, and an open top side for access to said mounting chamber; a pair of conductive prong engaging members mounted on said base member inside said mounting chamber, said prong engaging members being formed with at least one pair of prong engaging portions adapted to engage a pair of prongs of an appliance plug, one of said prong engaging members being further formed with a first fuse contact; a conductive fuse contacting member mounted on said base member inside said mounting chamber, said fuse contacting member being formed with a second fuse contact that is aligned with and that is spaced apart from said first fuse contact; a thermal fuse extending between and having first and second fuse terminals held removably and respectively by said first and second fuse contacts; a cover member made from an insulator material and mounted on said base member to cover said top side of said base member, said cover member including a plug engaging portion formed with at least one pair of prong inserting slots aligned with a respective pair of said prong engaging portions, and a fuse locating portion formed with an access opening for exposing said first and second fuse contacts; and a cover plate mounted removably on said cover member to cover said access opening, said cover plate, having one side with said thermal fuse retained removably thereon such that mounting of said cover plate on said cover member will result in engagement of said thermal fuse with said first and second fuse contacts, and such that removal of said cover plate from said cover member will result in corresponding removal of said thermal fuse from said first and second fuse contacts, wherein said cover member is formed with an indicator window, said electrical socket device further comprising an indicator lamp mounted on said base member and connected electrically across said prong engaging members, and registered with said indicator window.
2. An electrical socket device, comprising:a base member made from an insulator material and formed with a mounting chamber, and an open top side for access to said mounting chamber; a pair of conductive prong engaging members mounted on said base member inside said mounting chamber, said prong engaging members being formed with at least one pair of prong engaging portions adapted to engage a pair of prongs of an appliance plug, one of said prong engaging members being further formed with a first fuse contact; a conductive fuse contacting member mounted on said base member inside said mounting chamber, said fuse contacting member being formed with a second fuse contact that is aligned with and that is spaced apart from said first fuse contact; a thermal fuse extending between and having first and second fuse terminals held removably and respectively by said first and second fuse contacts; a cover member made from an insulator material and mounted on said base member to cover said top side of said base member, said cover member including a plug engaging portion formed with at least one pair of prong inserting slots aligned with a respective pair of said prong engaging portions, and a fuse locating portion formed with an access opening for exposing said first and second fuse contacts; a cover plate mounted removably on said cover member to cover said access opening, said cover plate, having one side with said thermal fuse retained removably thereon such that mounting of said cover plate on said cover member will result in engagement of said thermal fuse with said first and second fuse contacts, and such that removal of said cover plate from said cover member will result in corresponding removal of said thermal fuse from said first and second fuse contacts; and a screw fastener for mounting removably said cover plate on said cover member.
3. An electrical socket device, comprising:base member made from an insulator material and formed with a mounting chamber, and an open top side for access to said mounting chamber; a pair of conductive prong engaging members mounted on said base member inside said mounting chamber, said prong engaging members being formed with at least one pair of prong engaging portions adapted to engage a pair of prongs of an appliance plugs, one of said prong engaging members being further formed with a first fuse contact; a conductive fuse contacting member mounted on said base member inside said mounting chamber, said fuse contacting member being formed with a second fuse contact that is aligned with and that is spaced apart from said first fuse contact; a thermal fuse extending between and having first and second fuse terminals held removably and respectively by said first and second fuse contacts; a cover member made from an insulator material and mounted on said base member to cover said top side of said base member, said cover member including a plug engaging portion formed with at least one pair of prong inserting slots aligned with a respective pair of said prong engaging portions and a fuse locating portion formed with an access opening for exposing said first and second fuse contacts; a cover plate mounted removably on said cover member to cover said access opening, said cover plate, having one side with said thermal fuse retained removably thereon such that mounting of said cover plate on said cover member will result in engagement of said thermal fuse with said first and second fuse contacts, and such that removal of said cover plate from said cover member will result in corresponding removal of said thermal fuse from said first and second fuse contacts; and an electrical cable having two insulated conductors connected electrically and respectively to said prong engaging members at one end, and terminated by a device plug at the other end.
4. The electrical socket device as defined in claim 3, wherein said thermal fuse connects said electrical cable in series with said one of said prong engaging members.
5. An electrical socket device, comprising:a base member made from an insulator material and formed with a mounting chamber, and an open top side for access to said mounting chamber; a pair of conductive prong engaging members mounted on said base member inside said mounting chamber, said prong engaging members being formed with at least one pair of prong engaging portions adapted to engage a pair of prongs of an appliance plug, one of said prong engaging members being further formed with a first fuse contact; a conductive fuse contacting member mounted on said base member inside said mounting chamber, said fuse contacting member being formed with a second fuse contact that is aligned with and that is spaced apart from said first fuse contact; a thermal fuse extending between and having first and second fuse terminals held removably and respectively by said first and second fuse contacts; a cover member made from an insulator material and mounted on said base member to cover said top side of said base member, said cover member including a plug engaging portion formed with at least one pair of prong inserting slots aligned with a respective pair of said prong engaging portions, and a fuse locating portion formed with an access opening for exposing said first and second fuse contacts; and a cover plate mounted removably on said cover member to cover said access opening, said cover plate, having one side with said thermal fuse retained removably thereon such that mounting of said cover plate on said cover member will result in engagement of said thermal fuse with said first and second fuse contacts, and such that removal of said cover plate from said cover member will result in corresponding removal of said thermal fuse from said first and second fuse contacts, wherein said base member is elongated, said prong engaging members are elongated and extend parallel to each other in a longitudinal direction of said base member, said first fuse contact is formed on one end of said one of said prong engaging members, and said second fuse contact is spaced apart from said first fuse contact in the longitudinal direction.
| 1999-07-19 | en | 2000-10-17 |
US-69383796-A | Process for preparation of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers
ABSTRACT
A process for preparation of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers comprises the steps of:
(i) reacting a 4-equivalent 5-pyrazolone magenta coupler and a diaryldisulfide compound in the presence of 1,8-diazabicyclo-[5,4,0]-undecen-7-ene and an organic solvent to obtain a reaction product between 4-arylthio-5-pyrazolone magenta coupler and 1,8-diazabicyclo-[5,4,0]-undecen-7-ene, and
(ii) converting the reaction product with an inorganic acid into the 4-arylthio-5-pyrazolone magenta coupler.
The reaction product between the 4-arylthio-5-pyrazolone magenta coupler and the 1,8-diazabicyclo-[5,4,0]-undecen-7-ene is easily formed in high yield and purity. This reaction product, which is insoluble in the reaction solvent, can be easily isolated from the reaction mixture and converted by acidification into the 2-equivalent 4-arylthio-5-pyrazolone magenta coupler in high yield and purity.
FIELD OF THE INVENTION
The present invention relates to a process for preparation of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers. More particularly, the present invention relates to a process for preparation of 2-equivalent 1-phenyl-3-anilino-4-phenylthio-5-pyrazolone magenta couplers.
BACKGROUND OF THE INVENTION
It is known that color images may be obtained from imagewise exposed silver halide photographic elements by development with a primary aromatic amine color developing agent in the presence of a color coupler. The oxidized color developing agent formed in the areas of silver halide development couples with the coupler to form a dye. The coupler is normally incorporated in the sensitive photographic element.
It is also known that 5-pyrazolones in which the 4-position of the pyrazolone ring is free, that is having only hydrogen substituents (4-equivalent magenta couplers), can be used as magenta couplers in color photographic elements to provide magenta dye images having useful properties. Examples of such couplers are the 4-equivalents 3-anilino-5-pyrazolone couplers described in, for example, U.S. Pat. Nos. 3,519,429, 3,907,571, 3,928,044, 3,935,015 and 4,199,361. However, 4-equivalent 5-pyrazolone couplers have a number of disadvantages, as they require four equivalents of silver to produce each molecule of dye, are sensitive to certain chemical vapors, for example formaldehyde, and have poor dye light and dye dark stability. These drawbacks can be overcome by using so-called 2-equivalent 5-pyrazolone magenta couplers in which a substituent is introduced into the coupling position (4-position) of the coupler and eliminated as a leaving group (coupling-off group or splitting-off groups) during the color development process, thus requiring only two equivalent of silver in order to produce each molecule of dye.
Among coupling-off groups known in this connection are the arylthio groups described, for example, in U.S. Pat. Nos. 3,227,554, 3,701,783, 3,935,015, 4,351,897, 4,413,054, 4,556,630, 4,584,266, 4,740,438, 4,853,319, 4,876,182, 4,900,657, 4,929,540, 4,942,116, 5,250,407, 5,262,292, and 5,256,528; WO 88/04795, 92/18902, and 93/02393; EP 341,204, and GB 1,494,777.
Methods for preparing 2-equivalent 4-arylthio-5-pyrazolone magenta couplers are described in, for example, U.S. Pat. Nos. 3,227,554, 3,701,783 and Research Disclosure 13806 (1975). The method disclosed in U.S. Pat. Nos. 3,227,554 and 3,701,783 comprises converting an arylmercaptan into the corresponding arylsulfenyl halide and reacting the arylsulfenyl halide with a 4-equivalent 5-pyrazolone magenta coupler to introduce the arylthio group into the active coupling position of the coupler. Research Disclosure 13808 describes a method which comprises adding bromine to a solution of the 4-equivalent 5-pyrazolone coupler and arylmercaptan. The methods disclosed in U.S. Pat. Nos. 3,277,554 and 3,701,783 and in Research Disclosure 1308 have been further modified by using a diaryldisulfide instead of arylmercaptan, chlorine instead of bromine or presence of a base, as disclosed in, for example, U.S. Pat. Nos. 4,351,897, 4,853,319, 4,900,657, 4,929,540, 4,942,116, and 4,876,182, EP 341,204, GB 1,494,777, and WO 92/18902. In spite of the large number of methods disclosed in the prior art, these methods of synthesizing 2-equivalent 4-arylthio-5-pyrazolone magenta couplers have disadvantages as later will be shown by Comparative Examples, and there is still the need for more convenient, efficient and expeditious methods.
U.S. Pat. No. 4,032,346 discloses a method for preparing 2-equivalent couplers comprising at the active coupling position a group of formula --S--C(═Z)--B wherein Z represents an oxygen or sulfur atom and B represents a substituent group. The method comprises reacting a 4-equivalent coupler and a disulfide of formula B--C(═Z)--S--S--C(═Z)--B in the presence of an alkali catalyst and a solvent.
U.S. Pat. No. 4,293,691 discloses a method for preparing 2-equivalent couplers comprising at the active coupling position an alkylthio group. The method comprises reacting a 4-equivalent coupler A--H, wherein A is a yellow, magenta or cyan coupler residue, with an asymmetrical disulfide of formula ##STR1## wherein R is an alkyl, a cyclic alkyl or alkenyl group, or an aralkyl group, and R1 and R2 are substituent groups, in the presence of a base and a solvent to obtain a 2-equivalent coupler of formula A--S--R.
The methods disclosed in U.S. Pat. Nos. 4,032,346 and 4,293,691 are not useful for the synthesis of 2-equivalent 4-arylthio-5-pyrazolones, as will later be shown by Comparative Examples.
The present invention provides an improved process for preparation of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers which overcome drawbacks of prior art processes and provides a simple reaction mechanism.
SUMMARY OF THE INVENTION
A process for preparation of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers comprises the steps of:
(i) reacting a 4-equivalent 5-pyrazolone magenta coupler and a diaryldisulfide compound in the presence of 1,8-diazabicyclo-[5,4,0]-undecen-7-ene and an organic solvent to obtain a reaction product between 4-arylthio-5-pyrazolone magenta coupler and 1,8-diazabicyclo-[5,4,0]-undecen-7-ene, and
(ii) converting the reaction product with an inorganic acid into the 4-arylthio-5-pyrazolone magenta coupler.
It has been found in the process of the present invention that a reaction product is easily formed in high yield and purity between the 4-arylthio-5-pyrazolone magenta coupler and the 1,8-diazabicyclo-[5,4,0]-undecen-7-ene. This reaction product, which is insoluble in the reaction solvent, can be easily isolated from the reaction mixture and converted by acidification into the 2-equivalent 4-arylthio-5-pyrazolone magenta coupler in high yield and purity.
DETAILED DESCRIPTION OF THE INVENTION
The 4-equivalent 5-pyrazolone magenta couplers for use in the process of the present invention may be represented by the formula (I) ##STR2## wherein R1 represents an anilino group, an acylamino group or a ureido group, and R2 represents a phenyl group. In more details, R1 represents an anilino group such as, for example, phenylamino, o-chlorophenylamino, 2-4-dichlorophenylamino, 2,4-di-chloro-5-methoxyphenylamino, 2-chloro-5-tetradecanamidophenylamino, 2-chloro-5-[α-(2,4-di-t-amylphenoxy)-butyramido]-phenylamino, 2-chloro-5-[(3-octadecenyl)-succinimido]-phenylamino, 2-chloro-5-{α-[(3-t-butyl-4-hydroxy)-phenoxy]-tetradecan-amido}-phenylamino, an acylamino group such as, for example, acetylamino, butyramido, α-[(3-pentadecylphenoxy)butyramido]benzamido, n-tetradecanamido, α-(2,4-di-t-amylphenoxy)-butyramido, 3-[α-(2,4-di-t-amylphenoxy)butyramido]-benzamido, benzamido and 3-acetylamidobenzamido, or a ureido group such as, for example, phenylureido, methylureido, and 3-[α-(2,4-di-t-amyl-phenoxy)-butyr-amido]phenylureido, and R2 represents a phenyl group such as, for example, 2,4,6-trichlorophenyl, 2,4-dichloro-6-methylphenyl,2,6-dichloro-4-methoxyphenyl, and 4-[α-(2,4-di-t-amylphenoxy)-butyramido]-phenyl.
Preferred 4-equivalent 5-pyrazolone magenta couplers for use in the process of the present invention are represented by the formula (II) ##STR3## wherein a represents an integer from 1 to 5,
R4 represents hydrogen, alkyl, alkoxy, halogen, aryl, aryloxy, acylamino, sulfonamido, sulfamoyl, carbamoyl, arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylureido, arylureido, nitro, cyano, hydroxyl or carboxy group,
R3 is halogen atom, alkyl or aryl group,
X is a direct group or a linking group,
Ball is a ballasting group of such size and configuration as to render a group to which it is attached non-diffusible in photographic coatings (e.g., gelatin), and when a is 2 or more, R4 groups may be the same or different.
In the above formula, examples of R4 include hydrogen; alkyl group, including straight or branched chain alkyl group, such as alkyl group containing 1 to 8 carbon atoms, for example methyl, trifluoromethyl, ethyl, butyl, and octyl; alkoxy group, such as an alkoxy group having 1 to 8 carbon atoms, for example methoxy, ethoxy, propoxy, 2-methoxyethoxy, and 2-ethylhexyloxy; halogen, such as chlorine, bromine, and fluorine; aryl group, such as phenyl, naphthyl, and 4-tolyl; aryloxy group, such as phenoxy, p-methoxyphenoxy, p-methylphenoxy, naphthyloxy, and tolyloxy; acylamino group, such as acetamido, benzamido, butyramido, and t-butylcarbonamido; sulfonamido group, such as methylsulfonamido, benzenesulfonamido, and p-toluylsulfonamido; sulfamoyl group, such as N-methylsulfamoyl, N,N-diethylsulfamoyl, and N,N-di-methylsulfamoyl; carbamoyl group, such as N-methyl-carbamoyl, and N,N-dimethylcarbamoyl; arylsulfonyl, such as tolylsulfonyl; aryloxy-carbonyl group, such as phenoxycarbonyl; alkoxycarbonyl group, such as alkoxy-carbonyl group containing 2 to 10 carbon atoms, for example methoxycarbonyl, ethoxycarbonyl, and benzyloxycarbonyl; alkoxysulfonyl group, such as alkoxysulfonyl group containing 2 to 10 carbon atoms, for example methoxysulfonyl, octyloxysulfonyl, and 2-ethylhexylsulfonyl; aryloxysulfonyl group, such as phenoxy-sulfonyl; alkylureido group, such as N-methylureido, N,N-dimethylureido, and N,N-dibutylureido; arylureido group, such as phenylureido; nitro, cyano, hydroxyl and carboxy group.
Examples of R3 include halogen, such as chlorine, bromine, and fluorine; alkyl group, including straight or branched chain alkyl group, such as alkyl group containing 1 to 8 carbon atoms, for example methyl, trifluoromethyl, ethyl, butyl, and octyl; aryl group, such as phenyl, naphthyl, and 4-tolyl.
"Ball" is a ballasting group, i.e., an organic group of such size and configuration as to render a compound to which it is attached non-diffusible from the layer in which the compound is coated in a photographic element. Said ballasting group includes, for example, an organic hydrophobic residue having 8 to 32 carbon atoms bonded to the coupler either directly or through a divalent linking group X, such as an alkylene, imino, ether, thioether, carbonamido, sulfonamido, ureido, ester, imido, carbamoyl, and sulfamoyl group. Specific examples of suitable ballasting groups include alkyl groups (linear, branched, or cyclic), alkenyl groups, alkoxy groups, alkylaryl groups, alkylaryloxy groups, acylamidoalkyl groups, alkoxyalkyl groups, alkoxyaryl groups, alkyl groups substituted with an aryl group or a heterocyclic group, aryl groups substituted with an aryloxyalkoxycarbonyl group, and residues containing both an alkenyl or alkenyl long-chain aliphatic group and a carboxy or sulfo water-soluble group, as described, for example, in U.S. Pat. Nos. 3,337,344, 3,418,129, 3,892,572, 4,138,258, and 4,451,559, and in GB 1,494,777.
When the term "group" or "residue" is used in this invention to describe a chemical compound or substituent, the described chemical material includes the basic group or residue and that group or residue with conventional substitution. Where the term "moiety" is used to describe a chemical compound or substituent, only the unsubstituted chemical material is intended to be included. For example, "alkyl group" includes not only such alkyl moiety as methyl, ethyl, butyl, octyl, stearyl, etc., but also moieties bearing substituent groups such as halogen cyano, hydroxyl, nitro, amino, carboxylate, etc. On the other hand, "alkyl moiety" includes only methyl, ethyl, stearyl, cyclohexyl, etc.
According to the step (i) of the process of the present invention, a 4-equivalent 5-pyrazolone magenta coupler is reacted with a diaryldisulfide compound. Diaryldisulfide compounds may be represented by the formula (III) ##STR4## wherein R5 represents a hydrogen atom, alkyl group, including straight or branched chain alkyl group, such as alkyl group containing 1 to 8 carbon atoms, for example methyl, trifluoromethyl, ethyl, butyl, and octyl; alkoxy group, such as an alkoxy group having 1 to 8 carbon atoms, for example methoxy, ethoxy, propoxy, 2-methoxyethoxy, and 2-ethylhexyloxy; halogen, such as chlorine, bromine, and fluorine; aryl group, such as phenyl, naphthyl, and 4-tolyl; aryloxy group, such as phenoxy, p-methoxyphenoxy, p-methylphenoxy, naphthyloxy, and tolyloxy; acylamino group, such as acetamido, benzamido, butyramido, and t-butylcarbonamido; sulfonamido group, such as methylsulfonamido, benzenesulfonamido, and p-toluylsulfonamido; sulfamoyl group, such as N-methylsulfamoyl, N,N-diethylsulfamoyl, and N,N-di-methylsulfamoyl; carbamoyl group, such as N-methylcarbamoyl, and N,N-dimethylcarbamoyl; arylsulfonyl, such as tolylsulfonyl; aryloxycarbonyl group, such as phenoxycarbonyl; alkoxycarbonyl group, such as alkoxycarbonyl group containing 2 to 10 carbon atoms, for example methoxycarbonyl, ethoxycarbonyl, and benzyloxycarbonyl; alkoxysulfonyl group, such as alkoxysulfonyl group containing 2 to 10 carbon atoms, for example methoxysulfonyl, octyloxysulfonyl, and 2-ethylhexylsulfonyl; aryloxysulfonyl group, such as phenoxysulfonyl; alkylureido group, such as N-methylureido, N,N-dimethylureido, and N,N-dibutylureido; arylureido group, such as phenylureido; nitro, cyano, hydroxyl and carboxy group, b represents an integer from 1 to 5, and when m represents 2 or more, each R5 may be the same or different.
Preferred diaryldisulfide compounds are represented by the formula (IV) ##STR5## wherein R5 represents a hydrogen atom or a substitute as defined for formula (III) above, c represents an integer from 1 to 4, Ball represents a ballasting group such as defined for formula (II) above, and when c represents 2 or more, each R6 may be the same or different.
The reaction of diaryldisulfide compounds and 4-equivalent 5-pyrazolone magenta couplers of step (i) is carried out in the presence of 1,8-diazabicyclo-[5,4,0]-undecen-2-ene of formula ##STR6## and an organic solvent. The solvents useful in step (i) are those organic liquids in which the reactants and the 1,8-diazabicyclo-[5,4,0]-undecen-2-ene are highly soluble over a wide range of temperatures, and in which, on the contrary, the adducts between formed 2-equivalent 4-arylthio-5-pryrazolone magenta couplers and 1,8-diazabicyclo-[5,4,0]-undecen-2-ene are not soluble. Representative organic liquids which are useful in this invention include ethylacetate, dimethylformamide, acetone and mixtures thereof. The reaction is completed in a short time (less than one hour) at low reaction temperatures (e.g., 40° to 70° C.). Typically, the organic solvent is the major component by volume of the reaction mixture, such as, for example, 80 to 90 percent by volume. Optionally, an additional effective amount of solvent may be added during the reaction to maintain the reaction mixture in a readily stirrable condition. At end of the reaction, the mixture is cooled at room temperature and the reaction product is recovered from the remaining mixture by filtration or centrifugation. A suitable molar ratio of the diarydisulfides to the 4-equivalent 5-pyrazolone magenta couplers is 1:1 and a suitable molar ratio of 1,8-diazabicyclo-[5,4,0]-undecen-2-ene to the 4-equivalent 5-pyrazolone magenta couplers is 2:1.
The reaction product between the 2-equivalent 4-arylthio-5-pyrazolone magenta coupler and 1,8-diazabicyclo-[5,4,0]-undecen-2-ene is a salt between a base (i.e., 1,8-diazabicyclo-[5,4,0]-undecen-2-ene) and the magenta coupler, and its structure has been confirmed by NMR and elemental analysis. It is believed that one proton is transferred by the magenta coupler to the base, with the resulting negative charge being delocalized on the coupler molecule.
As a subsequent step (ii) in the process of the present invention, the reaction product between 2-equivalent 4-arylthio-5-pryrazolone magenta couplers and 1,8-diazabicyclo-[5,4,0]-undecen-2-ene is converted with an inorganic acid into the 2-equivalent 4-arylthio-5-pyrazolone magenta coupler. A suitable conversion procedure comprises dissoving the reaction product in an organic solvent in which the reaction product is soluble, pouring the solution into an aqueous solution of an inorganic acid, such as hydrochloric acid, recovering the precipitated 2-equivalent 4-arylthio-5-pyrazolone magenta coupler by filtration or centrifugation and, if desired, subjecting to washing and crystallization from an organic solvent before drying. Suitable solvents for dissolving the reaction product include aliphatic alcohols having 1 to 4 carbon atoms, such as methanol and ethanol, taken alone or in combination with lower amounts, such as 20 to 30% by volume, of dimethylformamide.
According to the process of the present invention, 2-equivalent 5-pyrazolone magenta couplers having a 4-arythio group can be easily prepared in high yield and purity through the intermediate reaction product between 2-equivalent 4-arylthio-5-pyrazolone magenta couplers and 1,8-diazabicyclo-[5,4,0]-undecen-2-ene which is isolated in high yield and purity from the step (i), without the need of conventional extraction, drying, concentration and crystallization techniques of the prior art methods.
2-Equivalent 4-arylthio-5-pyrazolone magenta couplers which can be synthetized with the process of the present invention may be represented by the formula (V) ##STR7## wherein R1, R2, R5 and b are as defined for formulas (I) and (III).
Preferred 2-equivalent 4-arylthio-5-pyrazolone magenta couplers which can be synthetized with the process of the present invention may be represented by the formula (VI) ##STR8## wherein R3, R4, X, Ball, a and c are as defined for formulas (II) and (IV).
Illustrative examples of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers represented by formula (v) are as follows. ##STR9##
Other illustrative couplers include: ##STR10## wherein Q represents a coupling-off group according to the invention.
Illustrative coupling-off groups Q are as follows: ##STR11##
The invention is further illustrated by the following examples, but the process of this invention is not limited to these examples.
EXAMPLE 1
Preparation of 1-(2,4,6-trichlorophenyl)-3-(2-chloro-5-tetradecanamido)-4-{[2-(2,4-di-t-amylphenoxy)-butylcarbamoyl]-phenylthio}-5-pyrazolone (Coupler V-1)
45 g of 2.2'-dithiodibenzoic acid were added to 64.33 ml of thionyl chloride. Under stirring, the solution was refluxed for 3 hours and, after evaporation of half the total volume of the solvent, 120 ml of dry heptane were added. A pale yellow-brown solid was collected by filtration and dried overnight under vacuum to obtain 2,2'-dithiodibenzoyl chloride in 80% yield. The structure was confirmed by NMR and the purity by acid/base titration.
42 g of 2,2'-dithiodibenzoyl chloride were suspended in 250 ml acetone and added dropwise with 74 g of 2,4-di-tert.-amylphenoxybutylamine dissolved in 500 ml of acetone. The temperature of the solution was raised to 40 ° C. Then, 36 g of triethylamine were added dropwise. The suspension was poured in 2,000 ml of water, the precipitate was filtered, washed with ethanol and crystallized from ethanol. The yield was 75% of the intermediate compound having the formula: ##STR12## whose structure was confirmed by NMR and elemental analysis:
Found: % C=73.29% H=8.60% N=3.56% S=7.75
Required: % C=73.59% H=8.69% N=3.18% S=7.28
70 g of the intermediate compound above and 48.8 g of the 4-equivalent magenta coupler of formula ##STR13## were added to 592 g of ethylacetate under stirring and the mixture was warmed to 40° C. to obtain a solution. Then, 24 g of 1,8-diazabicyclo-[5,4,0]-undecen-2-ene were added. After 15 minutes, a white solid precipitated. The suspension was heated at 60° C. and then cooled at room temperature. The solid reaction product was collected by filtration, washed with ethylacetate and dryed. The yield was 86 g (90% by weight). The molar ratio of disulfide B to magenta coupler A and 1,8-diazabicyclo-[5,4,0]-undecen-2-ene was 1:1:2. The structure of the reaction product in the form of a salt between coupler V-1 and 1,8-diazabicyclo-[5,4,0]-undecen-2-ene was confirmed by NMR and elemental analysis:
C65 H89 Cl4 N7 O4 S
Found: % C=64.60 % H=7.50 % N=8.11 % S=2.60
Required: % C=64.72 % H=7.44 % N=8.13 % S=2.66
86 g of the intermediate reaction product above were added to 257 ml of a 80% by volume methanol and 29% by volume dimethylformamide solution. A solution was obtained at room temperature. About 2 g of Celite™ absorbent were added to the solution. Then, the solution was filtered and poured into 2.5 liters of water brought at pH 1 with concentrated hydrochloric acid cooled at 10°-15° C. The white solid obtained was collected by filtration, washed with water until neutrality and dried. The yield of coupler V-1 was 90% by weight. The structure was confirmed by NMR and the purity was confirmed by acid/base titration resulting 99%. The results of the elemental analysis were:
Found: % C=63.76 % H=7.09 % N=6.84 % S=2.67
Required: % C=63.81 % H=6.98 % N=6.64 % S=3.04
The same process was carried out using other bases, such as 1,1,3,3-tetramethylguanidine, sodium acetate and 1,4-diazabicyclo-[2,2,2]-octane, but the reaction did not appreciably occur.
COMPARATIVE EXAMPLE 1
A solution of 7.52 g of bromine in 50 ml of dimethylformamide was added dropwise to a solution of 35.02 g of the magenta coupler A and 26.43 g of diaryldisulfide compound B in 210 ml of dimethylformamide under stirring. Stirring was continued for 5 hours at 60° C., then at room temperature overnight. The mixture was poured in ice water. The crude product was collected and dried. It was not possible to isolate a pure product by crystallization, but only by chromatography on silica gel (ethylacetate/methylene chloride) on a small scale with a yield of 75%. The molar ratio of the disulfide B to the magenta coupler A and bromine was 1:1.9:1.6.
COMPARATIVE EXAMPLE 2
Sulfuryl chloride (0.63 g) in methylene chloride (7.5 ml) was added dropwise and under stirring to diaryldisulfide compound B (4.13 g) in methylene chloride (25 ml). After stirring for three hours at room temperature, magenta coupler A (5.57 g) in dimethylformamide (25 ml) and triethylamine (1.3 ml) were added to the methylene chloride solution above. The mixture was stirred at room temperature for 48 hours. At this stage, unreacted compounds were still found in appreciable amounts on a thin layer chromatography. The molar ratio of disulfide compound B to magenta coupler A and triethylamine was 1:1.9:2.
The same negative results were obtained using other bases, such as 1,1,3,3-teramethylguanidine and 1,8-diazabicyclo-[5,4,0]-undecen-2-ene, and other solvents, such as toluene and ethylacetate.
We claim:
1. A process for preparation of 2-equivalent 4-arylthio-5-pyrazolone magenta couplers which comprises the steps of:(i) reacting a 4-equivalent 5-pyrazolone magenta coupler and a diaryldisulfide compound in the presence of 1,8-diazabicyclo-[5,4,0]-undecen-7-ene and an organic solvent to obtain a reaction product between 4-arylthio-5-pyrazolone magenta coupler and 1,8-diazabicyclo-[5,4,0]-undecen-7-ene, and (ii) converting the reaction product with an inorganic acid into the 4-arylthio-5-pyrazolone magenta coupler.
2. The process of claim 1, wherein the 4-equivalent 5-pryrazolone magenta coupler is represented by the formula ##STR14## wherein R1 represents an anilino group, an acylamino group or a ureido group, and R2 represents a phenyl group.
3. The process of claim 1, wherein the 4-equivalent 5-pyrazolone magenta coupler is represented by the formula ##STR15## wherein a represents an integer from 1 to 5,R4 represents hydrogen, alkyl, alkoxy, halogen, aryl, aryloxy, acylamino, sulfonamido, sulfamoyl, carbamoyl, arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylureido, arylureido, nitro, cyano, hydroxyl or carboxy group, R3 is halogen atom, alkyl or aryl group, X is a direct group or a linking group, Ball is a ballasting group of such size and configuration as to render a compound to which it is attached non-diffusible in photographic coatings, and when a is 2 or more, R4 groups may be the same or different.
4. The process of claim 1, wherein the diaryldisulfide compound is represented by the formula ##STR16## wherein R5 represents hydrogen, alkyl, alkoxy, halogen, aryl, aryloxy, acylamino, sulfonamido, sulfamoyl, carbamoyl, arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylureido, arylureido, nitro, cyano, hydroxyl or carboxy group, b represents an integer from 1 to 5, and when b represents 2 or more, each R5 may be the same or different.
5. The process of claim 1, wherein the diaryldisulfide compound is represented by the formula ##STR17## wherein R5 represents hydrogen, alkyl, alkoxy, halogen, aryl, aryloxy, acylamino, sulfonamido, sulfamoyl, carbamoyl, arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylureido, arylureido, nitro, cyano, hydroxyl or carboxy group, c represents an integer from 1 to 4, Ball represents a ballasting group, and when c represents 2 or more, each R6 may be the same or different.
6. The process of claim 1, wherein the 4-arylthio-5-pyrazolone magenta coupler is represented by the formula ##STR18## wherein R1 represents an anilino group, an acylamino group or a ureido group, R2 represents a phenyl group, R5 represents hydrogen, alkyl, alkoxy, halogen, aryl, aryloxy, acylamino, sulfonamido, sulfamoyl, carbamoyl, arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylureido, arylureido, nitro, cyano, hydroxyl or carboxy group, b represents an integer from 1 to 5, and when b represents 2 or more, each R5 may be the same or different.
7. The process of claim 1, wherein the 4-arylthio-5-pyrazolone magenta coupler is represented by the formula ##STR19## wherein a represents an integer from 1 to 5,R4 represents hydrogen, alkyl, alkoxy, halogen, aryl, aryloxy, acylamino, sulfonamido, sulfamoyl, carbamoyl, arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylureido, arylureido, nitro, cyano, hydroxyl or carboxy group, R3 is halogen atom, alkyl or aryl group, X is a direct group or a linking group, Ball is a ballasting group of such size and configuration as to render a compound to which it is attached non-diffusible in photographic coatings, R5 represents hydrogen, alkyl, alkoxy, halogen, aryl, aryloxy, acylamino, sulfonamido, sulfamoyl, carbamoyl, arylsulfonyl, aryloxycarbonyl, alkoxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylureido, arylureido, nitro, cyano, hydroxyl or carboxy group, c represents an integer from 1 to 4, andwhen a and c each represents 2 or more, each R4 and R5 may be the same or different.
| 1996-08-01 | en | 1997-07-08 |
US-39820895-A | Upstream transmission using multiple transmission tags and downstream acknowledgements in conditional access packets
ABSTRACT
Upstream transmissions in a two-way communications network are effected from subscriber terminals in upstream packets having one of a plurality of different separately acknowledgeable acknowledgment tags. Downstream acknowledgments of upstream messages are contained in CA packets multiplexed with product packets to form a transport bitstream. The transport bitstream is applied to a digital conditional access module (DCAM) in the terminal which is controlled by the conditional access data bits of the CA packets. The DCAM includes a status register for storing the acknowledgment bits of the CA packets, which bits are coupled by a microprocessor for controlling the upstream transmitter.
BACKGROUND OF THE INVENTION
The present invention relates generally to two-way communication networks of the type used in cable television systems and particularly concerns techniques for providing downstream acknowledgments of subscriber upstream messages.
Cable television systems utilize a central provider of program information which services a large number of end users generally referred to as subscribers. The central provider portion of the cable television system, usually called the "headend", provides a plurality of program information as well as other information to the subscribers via a multiple branch distribution network which may define several tiers of distribution facilities.
In addition to actual programming information, the cable television system is required to carry additional management and operating data, such as conditional access data, provided by the headend to the large number of end users or subscribers. Communication from the headend to the subscribers is generally referred to as "downstream" communication. In some cable television systems referred to as one-way, all information and data is transferred downstream. In other cable television systems referred to as two-way systems, communication is also provided from the various subscribers throughout the network to the headend in what is referred to as "upstream" communication.
Upstream communication in a cable television system is normally provided using an out-of-band carrier, usually between five and thirty megahertz, which is modulated with upstream data at the subscriber decoder and transmitted to the headend. Examples of subscriber originated upstream messages may include program purchasing requests, opinion poll responses, and subscriber terminal status information. Some of these messages, e.g. program requests, may require downstream acknowledgment and authorization while others, e.g. terminal status information, may be initiated in response to an appropriate downstream command.
Upstream communications are typically effected using either a contention protocol as disclosed in U.S. Pat. Nos. 4,528,663 and 4,553,161 wherein the subscriber's contend for access to the upstream channel or by providing each subscriber with guaranteed access to a respective relatively small portion of the upstream spectrum. Depending on the type and quantity of usage, one protocol may be more advantageous than the other, or a mixture of both may provide the most effective performance. In either case, upstream messages are transmitted in respective time slots which may be assigned to individual subscribers on a reserved basis to guarantee access to the upstream channel or which multiple subscribers may use on a contention basis. Acknowledgment by the central facility of successfully received upstream subscriber messages is normally effected using dedicated downstream acknowledgment messages. Such acknowledgment messages may, for example, be multiplexed as auxiliary data packets in a downstream transport bitstream and separated therefrom in the subscriber's terminal on the basis of their unique header identification code. This approach is wasteful of downstream overhead and is therefore not considered desirable. This approach suffers the further disadvantage that the downstream acknowledgment messages are substantially displaced in time from the downstream messages providing subscriber authorization of a requested program or service since the two are transmitted in separate downstream packets.
It is therefore a basic object of the present invention to provide an improved two-way data transmission system for a subscription service such as a two-way cable television network.
It is a more specific object of the invention to provide a two-way data transmission system which provides downstream acknowledgment of upstream subscriber messages using a minimum amount of overhead.
It is a further object of the invention to provide a two-way data transmission system in which disjunctive downstream responses to upstream messages are minimized.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements and in which:
FIG. 1 sets forth a general block diagram of a cable television subscriber decoder constructed in accordance with the present invention;
FIG. 2 sets forth a block diagram of the upstream transmitter of the present invention upstream data transmission system;
FIG. 3 illustrates the format of an upstream transmission packet in accordance with the invention;
FIG. 4 sets forth a block diagram of the DCAM shown in FIG. 1;
FIGS. 5A-5C illustrate the format of different CA packets according to the invention;
FIG. 6 illustrates the PID and countdown registers of the DCAM of FIG. 4;
FIG. 7 sets forth a block diagram of the cable system headend of the upstream data transmission system of the invention;
FIG. 8 is a table illustrating a model used by the network controller of FIG. 7 for controlling the operation of the upstream data transmission system of the invention, and
FIG. 9 is a block diagram of the modulator of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 sets forth a block diagram of a cable television subscriber terminal constructed in accordance with the present invention and generally referenced by numeral 10. Subscriber terminal 10 includes a tuner 12 for receiving transmitted downstream signals from a cable television distribution system 11 or other suitable transmission medium. The output of tuner 12 is coupled to an intermediate frequency filter 13, typically a SAW filter, and therefrom to the input of an intermediate frequency amplifier and demodulator circuit 14. The output of demodulator 14 is coupled to an analog to digital converter 15, the output of which is applied to the input of a digital data recovery and error correction circuit 16.
The output of digital circuit 16 comprises an MPEG transport bitstream including a series of MPEG product and conditional access (CA) packets. Each such packet includes an unencrypted 4-byte header comprising a 13-bit packet identifier (PID) identifying the contents of the packet followed by 184-bytes of encrypted payload. A product packet may comprise a compressed video packet, a compressed audio packet or a packet containing auxiliary data. Each such packet is identified by its own unique PID, with a PID having a value of one (00..01) be reserved for CA packets. Depending on the degree of compression employed and on the maximum bit-rate provided by the transmission system, the transport bitstream derived from a tuned 6 MHz television channel may represent one or more television programs, the components (e.g. video and audio) of each television program being identified by their own respective PID's.
The MPEG transport bitstream developed at the output of circuit 16 is coupled to a digital condition access module (DCAM) 17 which is responsive to CA packets multiplexed in the transport bitstream for selectively authorizing and deauthorizing subscriber terminal 10 for various television programs and other services. DCAM 17 is also operative for decrypting the payloads of product packets having PID's corresponding to a program selected for viewing by the subscriber and for which the subscriber has appropriate authorization. The output of DCAM 17 is coupled to an MPEG transport demultiplexer 18 which couples the decrypted video packets to a video decompression circuit 19 and the decrypted audio packets to an audio decompression circuit 30. Video decompression circuit 19 may include a random access memory 20 coupled thereto. The decompressed video signal developed at the output of video decompression circuit 19 is applied to a D/A converter 21 which is coupled to a suitable video display. Correspondingly, the decompressed audio signal developed at the output of audio decompression circuit 30 is applied to a D/A converter 31 which is coupled to a suitable audio system.
Subscriber terminal 10 further includes a microprocessor 40 having a channel selection output 41 for controlling tuner 12, an input for receiving an interrupt signal from DCAM 17 and a bidirectional data coupling to demodulator 14, digital circuit 16, DCAM 17 and demultiplexor 18. Microprocessor 40 is responsive to signals from a user control interface 44 operable by a subscriber for selecting a program for viewing. Subscriber terminal 10 further includes an upstream transmitter 50, the structure of which is set forth below in FIG. 2 in greater detail. Upstream transmitter 50 includes an input 51 coupled to output 43 of microprocessor 40 and has an output 55 coupled to cable 11 for providing upstream transmissions over the cable distribution system. Upstream transmitter 50 further includes a symbol clock input 52 coupled to digital circuit 16, a frame sync signal input 53 also coupled to digital circuit 16, and a superframe synchronization signal input 54 coupled to demultiplexor 18.
In operation, a plurality of broadcast signals are coupled by cable 11 to the input of tuner 12 which in response to a channel selection signal supplied by microprocessor 40 couples a selected signal to intermediate frequency filter 13. The output of filter 13 is demodulated by intermediate frequency amplifier and demodulator circuit 14. Demodulator 14 may be constructed in accordance with conventional fabrication techniques and may, for example, include a synchronous demodulator. The essential function of demodulator 14 is to recover the baseband analog signal modulated upon the carrier selected by tuner 12. While different transmitting signal formats and methods may be utilized in communicating data through a cable television system, the example shown in FIG. 1 utilizes a digital vestigial sideband system in which N-level symbols having a symbol rate of approximately 10.76 megahertz are transmitted and received together with a data frame sync signal having a frequency of approximately 41.2 kilohertz resulting in data frames of approximately 24.3 milliseconds in duration. The demodulated baseband analog signal at the output of demodulator 14 comprises successive N-level symbols equally spaced by the period of the symbol clock signal. The analog to digital conversion performed by converter 15 is clocked at the symbol clock frequency to accurately recover the amplitudes of each symbol in the form of a multibit value. The output of converter 15 is processed by digital circuit 16 to recover the frame sync signal in synchronism with the received frame and to generate the symbol clock signal for operating converter 15. The output data signal of digital circuit 16 comprises the recovered digital MPEG transport bitstream comprising CA packets and product packets representing one or more television programs. This transport bitstream is further selectively processed by DCAM 17 and thereafter demultiplexed in demultiplex circuit 18 to provide input video and audio signals to decompression circuits 19 and 30 respectively. Circuits 19 and 30 perform conventional video and audio decompression operations upon the applied video and audio data to produce decompressed video and audio signals which are converted to corresponding analog signals within digital to analog converters 21 and 31. The analog signals thus provided are applied to the video display and audio system (not shown) respectively.
The structure of upstream transmitter 44 is set forth below in FIG. 2 in greater detail. Upstream transmitter 50 is coupled to cable 11 for upstream transmission and operates in response to a symbol clock input at input 52 from digital circuit 16 together with a frame sync signal input at input 53 also received from digital circuit 16. Upstream transmitter 50 further responds to a superframe sync signal at input 54 which is provided by transport and demultiplexor 18 and to a programmable width signal which is coupled from output 43 of microprocessor 40 to input 51 of upstream transmitter 50. Upstream transmitter 50 utilizes the width signal, the superframe sync signal, the symbol clock and the frame sync signal to properly time upstream communication applied to cable 11 from subscriber terminal 10 by generating a plurality of message transmission time slots each of which may be uniquely assigned to a respective subscriber or which may be used as a contention time slot. The width and timing location of the time slots for subscriber terminal 10, as well as all other subscriber terminals on the cable television system, is programmably controllable by headend manipulation of the width and superframe sync signals applied to the subscriber terminals. Thus, the time slots for each subscriber terminal are programmably controlled from the headend to accommodate dynamic changes within the cable television system, including establishing the time slots as contention or reserved and controlling the width and number of the slots.
As will be described in greater detail hereinafter, both the upstream carrier signal and the generated time slots are synchronized with the symbol clock. This allows the use of a plurality of upstream carrier signals at different frequencies which are all locked to the symbol clock which makes the most efficient use of the available upstream bandwidth. Thus, with each carrier signal locked to a common reference, different subscriber terminals may readily transmit at different upstream carrier frequencies.
In addition, because the symbol clock is used in creating the subscriber time slots, the proper relative timing between time slots at each subscriber terminal is assured. That is to say, all time slots are synchronized to the common reference of the symbol clock.
Referring to FIG. 2 in more detail, upstream transmitter 50 includes a slot width down counter 60 having a load input 61, a clock input 62, an output 63 and a preset input 51. A slot counter 65 includes a clear input 66, a clock input 67, a clock enable input 68 and an output 69. A frame counter 80 includes a clock enable input 81, a clock input 82, a clear input 83 and an output 84. Symbol clock input 52 (corresponding to the downstream symbol rate) is coupled to clock input 62 of counter 60, clock enable input 67 of counter 65 and clock input 82 of counter 80. Superframe sync input 54 is coupled to clear input 83 of counter 80. Frame sync input 53 (corresponding to the downstream data frame sync signal) is coupled to load input 61 of counter 60, clear input 66 of counter 65 and clock enable input 81 of frame counter 80. Output 63 of counter 60 is coupled to clock enable input 68 of slot counter 65.
Microprocessor 40 includes output 43 coupled to preset input 51 of counter 60. Microprocessor 40 further includes a tuning voltage output 56, a q signal output 59, a data output 57 and a status signal coupling 58. A comparator 85 includes an input 86 coupled to output 69 of counter 65, an input 87 coupled to output 84 of frame counter 80, an input 89, and an output 88. A timing and control circuit 100 includes an input 101 coupled to output 88 of comparator 85, an output 102, and a transmission clock signal input 103. Timing and control circuit 100 further includes a data input 105 coupled to data output 57 of microprocessor 40 and an input 106 coupled to status line input 58 of microprocessor 40. Timing and control circuit 100 also includes a data output 111 and an address output 110 coupled to inputs 131 and 132 of a memory 130. Timing and control circuit 100 further includes a data output 109 and an address output 108 coupled to inputs 136 and 137 respectively of a second memory 135. A multiplex circuit 140 includes an input 141 coupled to output 107 of circuit 100, inputs 142 and 143 coupled to outputs 133 and 138 of memories 130 and 135 respectively, and an output 144. A slot register 115 includes an output 116 coupled to input 89 of comparator 85, an enable input 117 coupled to output 102 of circuit 100, and an input 118 coupled to output 144 of multiplex 140. A time multiplex circuit 125 includes an input 126 and an output 127. A transmission modulator 120 includes a transmission clock output 121 coupled to input 103 of circuit 100 and a transmission enable input 122 coupled to output 104 of timing and control circuit 100. Transmission modulator 120 further includes a transmission data input 124 coupled to output 127 of multiplex circuit 125 and an output 123 coupled to cable 11 (seen in FIG. 1).
In operation, processor 40 provides a programmable slot width number to preset input 51 of down counter 60. Down counter 60 responds to the next frame sync signal applied to load input 61 to set down counter 60 to the programmable slot width number. Thereafter, down counter 60 responds to symbol clock signals at input 62 to count downwardly from the slot width number and produces an output signal at output 63 each time a zero count is obtained. Thereafter, slot width down counter 60 recycles producing a plurality of successive output signals at output 63 each of which corresponds to the time interval in which counter 60 counts downwardly from the programmable slot width number. The succession of outputs from slot width counter 60 is applied to clock enable input 68 of counter 65 which is cleared each time a frame sync signal is applied to clear input 66. Counter 65 responds to the applied clock signals to produce an output count at output 69 synchronously with the symbol clock which corresponds to the sequentially established time slots created by slot width counter 60. Thus, the output of slot counter 65 at output 69 provides a time slot identifying number which is applied to input 86 of comparator 85. Frame counter 80 receives frame sync signals at clock enable input 81 to produce an output count at output 84 synchronously with the symbol clock which corresponds to the number of frame sync intervals which have occurred following the most recent superframe sync signal. The output count of frame counter 80 is coupled to input 87 of comparator 85.
Thus, the output of counter 65 comprises a succession of eight-bit slot identifying numbers occurring within each data frame sync interval. Correspondingly, the output of frame counter 80 comprises an eight-bit running count identifying each successive frame which has occurred following the previous superframe sync signal. As a result, the combination of eight-bit output counts of counters 65 and 80 when combined form a 16-bit number which identifies a plurality of periodically recurring time slots coextensive with one or more data frames of the received vestigial sideband signal. Each time slot therefore is uniquely identified by the combined number formed by the outputs of counters 65 and 80 in which the output of counter 65 forms the eight least significant bits of the number while the output of counter 80 forms the eight most significant bits of the time slot identifying number. This combined number is utilized by comparator 85 to provide sequential identification of each time slot within each superframe as the vestigial sideband signal is received.
Each subscriber terminal within the network may be assigned a unique time slot or a contention time slot for upstream data transmission. Such assignments are made by downloading one or more time slot numbers to microprocessor 40 via transport demultiplexer 18, which time slot numbers can be used by the subscriber terminal for upstream transmissions as described in further detail hereinafter. A uniquely assigned time slot (sometimes referred to as a reserved time slot) can, of course, only be used by the respective subscriber terminal and thereby guarantees access to the network. On the other hand, all subscriber terminals may attempt upstream transmissions during contention time slots, a successful transmission resulting in the receipt of an "Acknowledge" signal (ACK) by the terminal. In the case of an unsuccessful transmission, the message is normally retransmitted in a subsequent contention slot defined by a so-called "back-off" algorithm which may also be downloaded in microprocessor 40 by the network.
Upstream transmitter 50 initiates upstream data transmission by initially transferring a sixteen-bit time slot identifying number (which may represent either a reserved or contention time slot) to memory 130 through timing and control circuit 100. In transferring the sixteen-bit time slot identifying number to memory 130, the eight least significant bits and eight most significant bits are preferably loaded into different memory location to be accessed separately. The remaining memory locations within memory 130 are filled with a data packet (described in further detail hereinafter) to be transmitted upstream (which is also transferred to the memory through timing and control circuit 100). Thereafter, the eight most significant bits which correspond to the frame identifying portion of the time slot identifying number are coupled from memory 130 by multiplexor 140 to slot register 115. Comparator 85 generates an internal match signal when the eight most significant bits of the time slot identifying number at input 89 match the eight most significant bits from counter 80. In response thereto, the eight least significant bits comprising the time slot identifying number from memory 130 are coupled through multiplexor 140 to slot register 115. Thereafter, slot register 115 applies the eight least significant bits to input 89 of comparator 85. Comparator 85 performs a comparison of the eight least significant bits of the time slot identifying number at input 89 to the current eight least significant bits at input 86 and produces an output signal at output 88 when a match occurs. In response to the match signal, timing and control circuit 100 then causes the stored data packet within memory 130 to be outputted to multiplexor 140 and thereafter to time multiplexor 125. Multiplexor 125 converts the data packet to a serial data stream which is applied to modulator 120 forming the transmission data. Concurrently, timing and control circuit 100 enables transmission modulator 120 causing the serial bit stream transmission of the data packet upon cable 11 (seen in FIG. 1) during the respective time slot.
To further enhance the effectiveness of upstream transmitter 50, a second memory 135 identical to memory 130 and coupled to data and address outputs 109 and 108 respectively is also coupled to multiplex circuit 140. The purpose of providing memory 135 is to utilize an alternating memory access for timing and control circuit 100 in which one memory may be loaded with data while the other is outputting data to transmit upstream. This improves the effectiveness and throughput capability of the present invention system.
The configuration of an exemplary data packet is illustrated in FIG. 3. As shown in the Figure, the upstream data packet comprises a 3-byte Message Synch code followed by a 2-byte Message Type code. The remainder of the packet comprises the upstream message payload and a 2-byte CRC. The message payload typically comprises a subscriber identification number and the identification of a particular requested service, such as a particular impulse-pay-per-view (IPPV) television program. The Message Type code identifies the type of message provided in the message payload and further comprises an Acknowledgment (ACK) tag which, in the preferred embodiment of the invention, can take either one of two values referred to as odd ACK and even ACK. In a more general sense, the ACK tag can take any number N of different values with due consideration taken of the overall packet size and upstream network traffic. The purpose of the ACK tags is to allow for the transmission of multiple data packets each of which is separately acknowledgeable by the central facility. Thus, for example, in a system using N=16 ACK tags, 16 data packets may be transmitted in succession each with its own unique ACK tag and each being separately acknowledged by the central facility. As soon as an acknowledgment is received over the downstream path, the associated ACK tag may be reused by microprocessor 40 to transmit another packet. The use of ACK tags as described above increases the upstream message rate of a given subscriber terminal 10. If upstream message traffic becomes excessive, the central facility may initiate a downstream message to microprocessor 40 (delivered via demultiplexer 18) to reduce the number of ACK tags being used (e.g. from 16 to 8 to 4, etc.) to accommodate the increase in upstream traffic.
As mentioned previously, in a preferred embodiment of the invention 2 ACK tags referred to as odd and even are used. The ACK tag in the Message Type code (see FIG. 3) would therefore identify the packet as requiring either odd acknowledgment (odd ACK tag) or even acknowledgment (even ACK tag). Two packets may therefore be transmitted one after the other, one with an even ACK tag and the other with an odd ACK tag. Receipt by terminal 10 of an even acknowledgment from the central facility indicates successful reception of the upstream packet with the even ACK tag and receipt of an odd acknowledgment indicates successful reception of the upstream packet with the odd ACK tag. Odd and even acknowledgments (or more if an ACK tag having a value greater than 2 is used) are received by terminal 10 according to an important aspect of the invention in a CA packet addressed to the terminal, and in particular to DCAM 17 of the terminal.
The structure of DCAM 17 is shown in greater detail in FIG. 4. DCAM 17 preferably comprises an ASIC which implements the conditional access and decryption functions of subscriber terminal 10. As shown in FIG. 4, the transport bitstream from digital circuit 16 is supplied to a payload crypto device 250, whose output is coupled to transport demultiplexer 18 and also supplies a CA packet interceptor 252. The transport bitstream is also supplied through a PID filter 253 to a payload countdown circuit 254 which includes an output coupled to the Enable input of payload crypto device 250. The output of CA packet interceptor 252 is supplied to an embedded CPU 256 over a bus 258. Bus 258 also couples CPU 256 to payload countdown circuit 254, a RAM 260, a ROM 262, a one-time-programmable memory (OTPM) 264, a key source generator 266, a CA crypto device 268 and a status register 270. Communications between CPU 256 and processor 40 (see FIG. 1) are effected over lines 45 and 47.
The operation of DCAM 17 is controlled by CA packets (PID=1) coupled by CA packet interceptor 252 to CPU 256. There are a number of different types of CA packets (identified by the first 3-bits of the packet payload) including CA initialization packets, CA configuration load packets and CA PID authorization packets. The CA initialization packets (see FIG. 5A) are used to initialize various keys used in DCAM 17, to initialize the subscriber authorization levels of a bit map (e.g. 256 bits) and an authorization list stored in RAM 260 and to supply a series of communication status bits used to control the operation of upstream transmitter 50 as will be described in further detail hereinafter. In particular, each subscriber DCAM 17 includes a unique 4-byte public serial number (S/N), a common load and a private (master) load all stored in OTPM 264. The common and private (master) loads are combined with selected bytes of ROM 262, which includes a stored program for controlling the operation of CPU 256, for providing respective common and private (master) keys. Each subscriber DCAM further includes active CA and payload key sources and received CA and payload key sources provided by key source generator 266. Each CA initialization packet includes the public S/N of one or more subscriber terminals together with the associated active and received CA and payload key sources, communication bits and authorization levels. The received public S/N, which is encrypted with the network common key, is decrypted by payload crypto device 250 in response to the common key derived from OTPM 264. The decrypted public S/N is supplied to CPU 256 which determines whether it matches the public S/N stored in OTPM 264. If a match exists, CPU 256 fetches the received active and received CA key sources for storage in key source generator 266. These key sources are encrypted first with the private key corresponding to the packet public S/N and then with the network common key. They are therefore decrypted first by payload crypto device 250 using the common key from OTPM 264 and then by the CA crypto device 268 using the private key from OTPM 264. The active CA key source now provided by key source generator 266 is used to build a decryption table used by CA crypto device 268 to decrypt further CA encrypted data bytes. Such further data bytes include the active and received payload key sources which after decryption are stored in key source generator 266, the communication status bits which after decryption are stored in status register 270, and authorization levels which after decryption are stored in the bit map and authorization list of RAM 260.
The CA configuration load packet is illustrated in FIG. 5B. It is similar in format to the CA initialization packet and is used to provide new CA and payload key sources for key source generator 266. The packet is also used to refresh the authorization bit map stored in RAM 260. As shown in FIG. 5B, the packet type and public S/N are encrypted using the active payload key source previously downloaded in a CA initialization packet and are therefore decrypted by payload crypto device 250 in response to the corresponding decryption table. If CPU 256 establishes that the decrypted public S/N matches the public S/N stored in OTPM 264, the received payload and CA key sources are decrypted by CA crypto device 268. These key sources will become the active key sources if they differ from the current active key sources and result in rebuilt decryption tables for payload and CA crypto devices 250 and 268.
Processing of the CA initialization and configuration load packets therefore results in DCAM 20 having been individually addressed to download various decrypted critical operating parameters (i.e. decryption keys and authorization levels). In particular, the CA key source is downloaded after it is decrypted using the private key of DCAM 17, the downloaded CA key source being used in turn to provide for downloading of the payload key source. Moreover, a would-be pirate can neither artificially create nor selectively filter subsequent CA packets since the packet payload, including CA packet type, of each such CA packet is encrypted using the payload and CA key sources. As will be explained in further detail, the inability to either create illegitimate CA packets or selectively filter de-authorizing packets prevents a would-be pirate from compromising system security.
The format of a CA PID authorization packet is illustrated in FIG. 5C. This packet, which is globally addressed using a public S/N=1, is the most frequently transmitted CA packet. The packet comprises a type code and a public S/N=1, both encrypted using the active payload key source and both decrypted by payload crypto device 250. The packet further comprises one or more PID's, each with an associated authorization level and countdown register level, all encrypted using the active CA key source and therefore decrypted by CA crypto device 268. As will be explained in further detail hereinafter, each active PID within a given 6 MHz channel must be transmitted and received by DCAM 17 in a CA PID authorization packet at a predetermined minimum rate in order to maintain payload crypto device 250 operable for decrypting payloads of product packets with corresponding PID's. Therefore, if the CA bitstream to DCAM 17 is interrupted, payload crypto device 250 will become inhibited and thereby cease decrypting product packets.
More specifically, assume a subscriber elects to view a particular television program contained within a tuned 6 MHz television channel. The selected program has an authorization level "A" and is comprised of packets having PID's 317, 318, and 319. PID 317 may, for example, identify compressed video packets, PID 318 compressed audio packets and PID 319 auxiliary data packets. Upon selecting the program (using user control interface 46), external processor 40 causes CPU 256 to determine whether the subscriber is authorized to view the program. That is, CPU 256 checks RAM 260 to determine if authorization level "A" is found in the stored authorization bit map or authorization list. Assuming authorization level "A" is found in RAM 260, the three PID's 317, 318 and 319 of the selected program are transferred over bus 258 for storage in respective PID registers 272a, 272b and 272c (see FIG. 6) of payload countdown circuit 254. At the same time, respective associated countdown registers 274a, 274b,, and 274c of countdown circuit 254 are set to selected values.
Payload crypto device 250 is operative for decrypting product packets only if the PID of the respective packet is stored in one of the ten PID registers 272a-272j of countdown circuit 254 (the packet PID's are supplied to countdown circuit 254 by PID filter 253) and the contents of the corresponding countdown register does not equal zero. Therefore, payload crypto device 250 begins decrypting payloads of product packets having PID's 317, 318 and 319 and couples the decrypted packet payloads (together with all unencrypted packets) to transport demultiplexer 18 for further processing. Moreover, each time a product packet having a PID stored in a PID register 272a-272c is received by countdown circuit 254, the associated PID countdown register 274a-274c of countdown circuit 254 is decremented by a factor of unity. If any one of the countdown registers reaches a value of zero, countdown circuits 254 inhibits payload crypto device from decrypting any further packets having the corresponding PID. For example, if countdown register 274a, which is associated with PID register 272a storing PID 317, reaches a zero count, countdown circuit 254 will inhibit payload crypto device 250 from encrypting any further product packets having PID 317.
However, under normal operating conditions CA PID authorizations packets are transmitted and received at a rate sufficient to prevent anyone of the countdown registers 274a-274c from reaching a zero count. In particular, after verification by CPU 256 that the authorization level of a received CA PID authorization packet matches a subscriber authorization level in RAM 260 and that its PID matches a PID stored in one of the PID registers 272a-272j, the associated countdown register 274a-274j is set to the countdown register level value of the received CA PID authorization packet. The countdown register level preferably comprises one byte allowing the countdown register to be set to any one of 256 different values. It will thus be seen that by operating the network such that appropriate CA PID authorization packets (i.e. having selected PID/authorization level pairs) are transmitted and received before a given countdown register reaches a zero value, payload crypto device 250 will remain operative for decrypting product packets having the corresponding PID's. Authorization level matches may be established by searching the authorization list and bit map of RAM 260 in response to each received CA PID authorization packet. Alternatively, the authorization list and bit map may be searched only once in response to the viewer's program request. The corresponding authorization level, assuming that a match exists, is then stored in a reserved portion of RAM 260 associated with the PID's stored in PID registers 272a-272j and is checked for a match with each received CA PID authorization packet. The latter approach is, of course, less CPU intensive since a search of RAM 260 is not effected in response to each received CA PID authorization packet.
As a further option, the operation of DCAM 17 can be enhanced such that countdown registers 274a-274j are each also decremented in response to the receipt of any CA packet (PID=1). This will in effect clear (i.e. set to zero) all countdown registers 274a-274j having corresponding PID registers 272a-272j storing inactive PID's.
Referring back to FIG. 4, the communication status bits stored in status register 270 (derived from a received CA initialization packet) represent central facility acknowledgments of upstream packets transmitted by terminal 10. In particular, one communication status bit is provided for each ACK tag used by upstream transmitter 50 to signal acknowledgment of a message transmitted using the respective ACK tag. In the case of the preferred embodiment which uses odd and even ACK tags for upstream transmission packets, two communication bits are provided--one for each ACK tag. Acknowledgment of an upstream packet is provided by setting the respective communication status bit to "1" in the downstream CA initialization packet and then storing the received bit in status register 270. CPU 256 subsequently generates an interrupt to microprocessor 40 and transfers all stored communication status bits in one contiguous group from status register 270 to the microprocessor, after which the register is cleared. The transferred status communication bits thereby provide an indication to microprocessor 40 that the respective previously transmitted packet(s) have been successfully received at the central facility. Absent such indication, microprocessor 40 will initiate retransmission of the packet (using either an odd or even ACK tag) in accordance with a suitable backoff algorithm until an acknowledgment is received from the central facility in the form of an appropriately set communication bit as previously described.
In addition to the foregoing, one of the communication bits of the downstream CA packet is preferably designated as an Interrogate Command (IC) bit. The IC bit is transferred in parallel with the other communication bits (representing upstream packet acknowledgments) from status register 270 of DCAM 17 to processor 40. In response to the IC bit, processor 40 applies a predetermined message to upstream transmitter 50 for transmission back to the central facility. The predetermined message includes the S/N of the terminal and may also reflect various operating parameters, e.g. power level, of the upstream transmitter and is therefore useful in diagnosing problems effecting upstream transmissions.
As mentioned previously, upstream packets are transmitted in respective time slots which may be assigned for use in a reserved mode wherein a given time slot is reserved only for usage by a particular terminal or in a contention mode wherein all terminals may attempt to use the time slot to gain access to the network, all under supervision of the central facility. In particular, referring to FIG. 7, upstream packets from subscriber terminal 10 are received over cable 11 by a receiver 300 and supplied to a network controller 302. Controller 302 generates data and CA packets for downstream transmission, the CA packets being intercepted by DCAM 17 as previously described and the data packets being supplied to microprocessor 40 by transport demux 18. The output of network controller 302 is combined with video and audio data in an inserter/modulator 304 and transmitted in the downstream direction in the format previously described.
Network controller 302 provides various data for downstream transmission including the superframe signal and data defining the modalities of the upstream transmission time slots. The table of FIG. 7 illustrates a simplified strategy which may be used by network controller 302 in defining network time slot modality. Four parameters are considered in the table; upstream transmission power, the nature of the slot (i.e. reserved or contention), the number of ACK tags to be employed and the nature of the back-off algorithm used for contention slots. In a preferred embodiment of the invention, the transmission medium comprises a hybrid-fiber-coaxial (HFC) transmission network so that instantaneous transmission power must be limited to prevent laser clipping.
Referring in more detail to FIG. 8, assuming a relatively small population of subscriber terminals, i.e. less than Po, and relatively low upstream traffic, i.e. less than To, the most effective upstream transmission scenario is represented by block 400, in which each system subscriber is assigned one or more unique reserved time slots for upstream transmission at a maximum allowable energy level. Also, a maximum number N of ACK tags are assigned for use in transmitting upstream packets. Network controller 302 may establish this scenario by providing data for downstream transmission including slot width and superframe signals for establishing an adequate number of upstream transmission time slots (at least one per subscriber terminal) together with data assigning at least one unique time slot for usage by each respective terminal. The same scenario may be used with increased upstream traffic as represented by blocks 402 and 404 since each terminal has its own reserved upstream transmission time slots. In this regard, network controller 302 may determine the extent of upstream traffic as a function of the number of successfully received upstream messages over a given period of time.
As the population of subscriber terminals increases, for example greater than Po but less then P1, it becomes impractical to assign a unique time slot to each terminal. Thus, if upstream traffic is relatively low, as represented by block 406, 75% of the time slots may be assigned for use on a reserved basis while the remaining 25% are designated for contention use. This time slot mix may be achieved, for example, by assigning each terminal the same number of reserved and contention time slots or by skewing the number of reserved slots in favor of terminals having a history of extensive interactive use of the upstream channel. Also, in connection with the contention time slots, data is provided by network controller 302 for downloading a minimum retransmission backoff algorithm and limiting transmission power to 75% of maximum allowable energy. As the upstream traffic increases as represented by block 408 (more than To but less than T1) the time slot mix is changed to 50% reserved and 50% contention. Also, the transmission back-off algorithm for the contention slots is increased to a selected medium value and the transmission power is reduced to 50% of maximum allowable energy. With further increases in upstream traffic as represented by block 410 (more than T1 but less than T2), the transmission mix is further adjusted to provide 25% reserved and 75% contention time slots, with the latter using an increased retransmission back-off algorithm value and 25% maximum allowable energy.
Further increases in subscriber terminal population as represented by blocks 412-416 (more than P1) makes the use of any reserved slots impractical so that all upstream transmission time slots are used in a contention mode. As illustrated in the table, the retransmission back-off increases and the transmission power decreases with increasing upstream traffic.
It will be appreciated that the table of FIG. 7 represents a highly simplified model of the manner in which upstream transmission modes may be varied as a function of terminal population and upstream traffic and that many much more sophisticated models are possible. In addition, various other factors may be considered in defining the model such as the type of service requested. For example, it would be much more advantageous to assign a reserved slot to a terminal for use in playing an interactive game than for ordering a pay-per-view movie.
FIG. 9 sets forth a block diagram of transmission modulator 120 of FIG. 2 in greater detail. As is seen in FIG. 2, transmission modulator 120 operates to modulate a selected carrier with the upstream data for transmission during a selected time slot to the cable system headend via the system network. The timing of upstream data transmission is controlled by the upstream transmitter shown in FIG. 2 in accordance with the above-described time slot allotment leaving the function of transmission carrier modulation to transmission modulator 120. Thus, transmission modulator 120 utilizes a discrete time oscillator 530 together with a phase lock loop 540 to provide a carrier signal at a selected frequency which is locked to a network reference such as the network symbol clock signal. A modulator 565 receives the generated carrier signal together with the to-be-transmitted data and produces the modulated carrier used for upstream communication.
More specifically, transmission modulator 120 includes discrete time oscillator 530 having a voltage controlled oscillator 500 having a tuning voltage input 501 coupled to output 56 of microprocessor 40 (seen in FIG. 2). Discrete time oscillator 530 further includes a latch circuit 510 having a clock input 511 coupled to output 502 of oscillator 500, a Q output 513 and a D input 512. A summer 505 includes an input 506, an input 507 coupled to output 59 of microprocessor 40, seen in FIG. 2, an input 508 coupled to the Q output 513 of latch 510, and an output 509. Output 509 of summer 505 is coupled to an input 516 of a sine wave lookup table 515. In addition, output 509 is further coupled to the D input 512 of latch 510. Sine lookup table 515 includes an output 517 coupled to an input 519 of a comparator type slicing circuit 518.
Transmission modulator 120 further includes a phase lock loop 540 having a phase detector 542 having inputs 543 and 544 and an output 545. A frequency dividing circuit 541 is coupled between output 520 of slicer 518 and input 543 of phase detector 542. A second frequency dividing network 551 is coupled to input 544 of phase detector 542. Output 545 of phase detector 542 is coupled to an input 548 of a latch circuit 547 via a low pass filter 546. Latch 547 includes a clock input 549 coupled to the input of frequency dividing network 551 and an output 550 coupled to input 506 of summer 505. Transmission modulator 120 includes a clock signal input 121 coupled to the input of frequency divider network 551 and which comprises the symbol clock from input 52 seen in FIG. 2.
As mentioned above, transmission modulator 120 includes an input 124 which receives the serial bit stream of data for upstream transmission. Transmission modulator 120 further includes a signal constellation coding circuit 560 which may for example comprise a conventional byphase shift key coding circuit which appropriately codes the serial bit data steam of upstream transmission data and applies it to an input 557 of a low pass filter 555. Filter 555 includes a clock signal input 556 coupled to symbol clock input 121. Output 558 of low pass filter 555 is coupled to input 562 of modulator 565. Modulator 565 includes an input 561 coupled to output 517 of sine wave lookup table 515 and an output 563. A channel filter 564 couples output 563 to an input 567 of a variable attenuator 566. Attenuator 566, which is controlled by a signal from microprocessor 40 to establish the upstream transmission energy, includes an output 568 coupled to cable 11 (seen in FIG. 1).
In operation, microprocessor 40 (seen in FIG. 2) produces initial values of the tuning voltage and value "q" for application to input 501 of oscillator 500 and to input 507 of summing network 505. These initial values of tuning voltage and input signal "q" to summing network 505 are programmable values selected to generate an output carrier having one of a plurality of frequencies within the upstream communication bandwidth of the system. Typically, such upstream communications are modulated upon carriers having frequencies within a range of 5-30 Megahertz. Oscillator 500 is a voltage controlled oscillator producing an output signal having a frequency determined by the tuning voltage input. Thus, the output signal of oscillator 500 is applied to the clock input of latch 510 having a Q output applied to one input of summing network 505. With the value q input to summing network 505 established by microprocessor 40 (seen in FIG. 2), an output combined signal is applied to sine wave lookup table 515. For purposes of speed and efficiency, only a predetermined number of the most significant bits within the output data of summer 505 are required for input to sine wave lookup table 515. Sine wave lookup table 515 responds to the input data at input 516 to produce a stream of digital values which are converted by slicer 518 to an output square wave or clock signal at the frequency of the sine wave produced by the values of lookup table 515. The output square wave signal from slicer 518 is applied to a divide by M frequency divider 541 which forms one input to phase detector 542.
Concurrently, the input symbol clock signal received at input 121 is frequency divided within divider 551 using a divide by N frequency division and applied to the remaining input of phase detector 542. The combination of frequency dividers 541 and 551 together with phase detector 542 is used to provide a carrier frequency for upstream communication which is locked to a network reference signal which is common to all subscriber terminals. Thus, as each transmission modulator within the cable television system uses carrier frequencies for upstream data communication which are all locked to a common network reference, the available bandwidth of upstream frequencies will be used with maximum efficiency. In the example shown in FIG. 8, the common network reference selected is that of the symbol clock signal. Thus, it is anticipated that other transmission modulators similar to transmission modulator 120 within the host cable television system will utilize different upstream carrier frequencies each locked to the common network reference provided by the symbol clock signal.
Accordingly, the values of M and N selected for frequency dividers 541 and 551 are selected to satisfy the expression fc=fs2M /2N in which fc is the frequency of the upstream transmission carrier and fs is the frequency of the symbol clock reference signal. Phase detector 542 provides a frequency and phase comparison of the frequency divided input signals at inputs 543 and 544 and produces an output error signal representing the phase and frequency difference between the divided carrier signal and the divided symbol clock signal. This error signal is filtered by low pass filter 546 and applied to data input 548 of latch 547. Latch 547 is clocked by the symbol clock signal. The output signal of latch 547 representing the phase and frequency error signal is applied to input 506 of summing network 505. The application of the output error signal of latch 547 to input 506 of summing network 505 closes the control loop for discrete time oscillator 530 and phase lock loop 540 which operates to frequency and phase lock the carrier signal produced by discrete time oscillator 530 to the symbol clock signal.
Thus, in the event the frequency of carrier signal is less than its desired value, a positive error signal will be developed at the output of latch 547. In response, the output of summer 505 will increase at a more rapid rate thereby increasing the carrier frequency output signal of lookup table 515. Conversely, in the event the frequency of the carrier signal produced by discrete time oscillator 530 is greater than its desired value, a negative error signal will be produced at the output of latch 550 which in turn will decrease the rate of signal increase at the output of summer 505 thereby decreasing the frequency of carrier signal at the output of lookup table 515. When the carrier signal and symbol clock signal are properly phase and frequency locked, the value of error signal at the output of latch 550 will be zero.
The carrier frequency signal produced by discrete time oscillator 530 is applied to one input of modulator 565. The transmission data is properly coded by coding circuit 560 and filtered by filter 555 for application to the remaining input of modulator 565. The output of modulator 565 comprises a carrier having the carrier frequency produced by discrete time oscillator 530 modulated with the properly coded transmission data. Channel filter 564 filters the undesired modulation components from the modulated carrier signal and applies the desired modulated carrier to cable 11 (seen in FIG. 1) through programmable attenuator 566 for upstream communication.
It should be noted that the frequency of the carrier signal is controlled by programmable values of tuning voltage as well as frequency divider values M and N. Thus, the carrier frequency of transmission modulator 120 is readily established or changed using the programmable values providing substantial flexibility for the present invention upstream data transmission system.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. For example, the disclosed upstream transmission system can also be used in a network where the downstream signals are of an analog nature, or a hybrid network where some of the downstream signals are analog and some are digital. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.
That which is claimed is:
1. In a two-way communications network, a method of acknowledging an upstream data message transmitted from a subscriber terminal to a central facility comprising the steps of:multiplexing a plurality of product and conditional access data packets to form a transport bitstream, said conditional access packets comprising a plurality of conditional access data bits and one or more upstream data message acknowledgment status bits; transmitting said transport bitstream in a downstream direction from said central facility to said terminal; and controlling a conditional access module and an upstream data transmission module in said terminal in response to said conditional access data bits and said upstream data message acknowledgment status bits respectively of said transmitted conditional access packets.
2. The method of claim 1 including applying said transmitted transport bit stream to said conditional access module, controlling said conditional access module in response to the conditional access data bits of the conditional access packets applied thereto, coupling said upstream data message acknowledgment status bits of said applied conditional access packets to said upstream data transmitter and controlling said upstream data transmitter in response to the acknowledgment status bits coupled thereto.
3. The method of claim 2 wherein said conditional access packets have a unique packet identification code and including intercepting said conditional access packets in said conditional access module in response to said unique packet identification code.
4. The method of claim 3 including controlling said conditional access module for authorizing a subscriber requested service and controlling said upstream transmission module in response to respective conditional access data bits and acknowledgment status data bits contained in the same conditional access packet.
5. In a two-way communications network, a method of sending an upstream data message from a subscriber terminal to a central facility comprising the steps of:defining a plurality of acknowledgment tags each having a different assigned value; composing said data message including an acknowledgment tag having a value selected from said plurality of assigned values, transmitting said data message in an upstream direction from said terminal to said central facility; multiplexing a plurality of product and conditional access data packets to form a transport bitstream, said conditional access packets comprising a plurality of conditional access data bits and one or more acknowledgment status bits representing the successful receipt at said central facility of said data message including the acknowledgment tag having said selected value; and transmitting said transport bitstream in a downstream direction from said central facility to said terminal and controlling a conditional access module and an upstream data transmission module in said terminal in response to said conditional access data bits and said acknowledgment status bits respectively of said transmitted conditional access packets.
6. The method of claim 5 wherein said defining step comprises defining two acknowledgment tags each having a different value.
7. The method of claim 5 including transmitting a downstream message from said central facility to said terminal for controlling the number of said plurality of acknowledgment tags which can be used in said composing step.
8. The method of claim 5 including applying said transmitted transport bit stream to said conditional access module, controlling said conditional access module in response to the conditional access data bits of the conditional access packets applied thereto, coupling said acknowledgment status bits of said applied conditional access packets to said upstream data transmitter and controlling said upstream data transmitter in response to the acknowledgment status bits coupled thereto.
9. The method of claim 8 wherein said conditional access packets have a unique packet identification code and including intercepting said conditional access packets in said conditional access module in response to said unique packet identification code.
10. The method of claim 9 including storing said acknowledgment status bits in a register in said conditional access module and transferring said stored bits as a group to said upstream data transmitter.
11. The method of claim 10 including controlling said conditional access module for authorizing a subscriber requested service and controlling said upstream transmission module in response to respective conditional access data bits and at least one acknowledgment status bit contained in the same conditional access packet.
12. The method of claim 10 wherein at least one of said acknowledgment status bits comprises an interrogate command bit, and including transmitting a predetermined upstream data message in response to said interrogate command bit.
13. A subscription decoder comprising:means for composing an upstream data message; means for transmitting said upstream data message to a central facility; a conditional access module; and means for receiving a stream of multiplexed downstream conditional access and product packets, said conditional access packets including a plurality of conditional access bits for controlling access of said conditional access module to said received product packets and at least one communication status bit representing acknowledgment by said central facility of successful receipt of said upstream data message.
14. The decoder of claim 13 wherein said conditional access module comprises a register for storing said at least one communication status bit and means for transferring said stored bit from said register to said composing means.
15. The decoder of claim 13 wherein said composing means comprises means for appending an acknowledgment tag to said upstream data message, said tag having a value selected from a plurality of different acknowledgment tag values and said received conditional access packets comprising a plurality of said communication status bits each corresponding to a respective one of said acknowledgment tag values and each representing acknowledgment by said central facility of successful receipt of an upstream data message including an acknowledgment tag having said corresponding value.
16. The decoder of claim 13 wherein said conditional access packets comprise a plurality of said communication status bits and wherein said conditional access module comprises a status register for storing said plurality of communication status bits and means for transferring said stored bits as a group from said status register to said composing means.
17. The decoder of claim 16 wherein said plurality of communication status bits further include an interrogate command bit, said composing means composing an upstream data message denoting the identity of said decoder in response to transfer of said interrogate command bit from said status register to said composing means.
| 1995-03-02 | en | 1996-05-14 |
US-75955391-A | Discrete phase shift mask writing
ABSTRACT
A method and apparatus for photolithographically fabricating features on a very large scale integrated circuit wafer by use of a phase shift mask defining discrete regions. This overcomes the problems of intensity nulls at the junction of regions formed by portions of the mask having opposite phase. The mask includes a transition region defining three phases which are assigned to pixels in the transition region, such that the phase assignment of the pixels is synthesized from an algorithm taking into account optical resolution and depth of focus. Each pixel is assigned one of three discrete phases, which thereby creates a transition region simulating a ramp between the two regions of opposite phases, such that intensity variation of the optical image corresponding to the transition region is minimized.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to phase shift masks as used in photolithography for fabrication of very large scale integrated circuits. More specifically, this invention relates to a method for forming transition regions between adjacent phase shift mask regions which are of different phase to create a smooth transition between the two phases after optical exposure and hence a transition region in a feature of the integrated circuit with no artifacts due to phase shift intensity nulls.
2. Description of the Prior Art
Phase shifting mask technology for optical lithography is well known. If light from a coherent or partially coherent source is divided by a mask into two or more beams that are superimposed, the intensity in the region of super position varies from point to point between maxima, which exceed the sum of the intensities in the beam, and minima, which may be zero. This phenomenon is called interference. Phase shifting can influence the location and intensity of the interference maxima and minima by adjustment of pattern design and deliberate phase change of the light beams. This results in imaging of higher spatial frequency objects, enhancement of edge contrast, larger exposure latitude, and/or improved depth of focus. Phase shifting is typically accomplished by introducing an extra patterned layer (or layers) of transmissive material on the mask. It is alternatively implemented by etching the mask substrate to various thicknesses so as to effectively provide at least one extra layer. As light propagates through the substrate and through the extra layer, the wave length of the light is reduced from that in the ambient air by the refractive indices of the substrate and the extra layer, respectively.
The optical path difference between the two beams through the extra material layer and without it, is (n-1)a where n is the refractive index of the extra layer and a is the thickness of the extra layer. The phase difference is then proportional to the optical path difference divided by the wave length (in vacuum) of the transmitted light. Usually a phase shift of π (180°) is desirable, i.e., one-half the wave length The added layer is usually considered to be the phase shifter. Further details of various means for implementing of phase shifting are in "Phase Shifting and Other Challenges in Optical Mask Technology," 10th Bay Area Chrome Users Symposium, 1990, by Burn J. Lin, dated Sep. 26, 1990.
Thus, phase shifting is implemented so that the waves transmitted through two adjacent apertures in a photolithography mask are 180° out of phase with one another, whereby destructive interference minimizes the intensity between the images formed by the two apertures. Any optical system will project the images of such a phase shifting transmission object with better resolution and higher contrast than a corresponding transmission object without phase shifts. This improvement in resolution and contrast is highly advantageous in fine line optical lithography, as is typical of fabrication of very large scale integrated circuits.
One problem encountered with use of phase shift masks occurs when two adjacent regions of the mask which abut one another are of different phases. The presence of a transition region between two adjacent regions of an opposite-type phase is typically encountered for instance when a "T" junction is needed or at an "elbow" in which the two arms of the elbow are of different phase, or whenever two linear structures abut one another. For instance, as shown in top view in FIG. 1(a), a mask includes region A of phase 0° and region B of phase 180°, where regions A and B are intended to print on a wafer two adjacent structures which together define a single feature, such as a semiconductor region The areas 10, 12 on either side of regions A and B are the unexposed opaque portions of the mask which are covered with a material such as chrome. Note that FIG. 1(a) is a computer generated optical simulation for a projection lithography system using the Hopkins model of partial coherence called "SPLAT" (a well known system from the University of California, Berkeley) as are FIGS. 1(b) and the associated FIGS. 2 to 3. The printed line width of the feature in FIGS. 1 through 3 is 0.35 μm.
The mask shown in FIG. 1(a) (as is understood from optics) forms an intensity null in the image formed on the wafer at the junction between regions A and B as shown in FIG. 1(b). This undesirable intensity null 16 is shown in the inverted areal image intensity (dotted lines) in FIG. 1(b) where instead of the feature line defined by regions A and B being a straight clearly defined line there is instead bridging, i.e., unexposed portions (dotted line) 16 at the transition region. In a typical application this means that a semiconductor region defined by regions A and B might include a highly undesirable discontinuity.
A number of techniques have been proposed to solve this problem. One solution is use of the mask as shown in FIG. 2(a) which includes region A which is 0° phase, region B which is 180° phase, and also intermediate region C which is 90° phase.
It is to be understood that in the phase shifting mask context, typically a 0° phase means that there is no phase shifter layer present over that region. A 180° phase indicates that there is a full thickness of transparent material (phase shifter layer) over that region of the mask. For example the full thickness is about 3600 Å which is one-half of the wavelength divided by (n-1), where n is the index of refraction of the phase shifter (here 1.5) for 365 nm light used to print the mask pattern onto a wafer. A 90° phase indicates that the thickness of the phase shifter layer over that portion of the mask is one-half of the full thickness, i.e., approximately 1800 Å in this example. It is to be understood that the various thicknesses of the phase shift layer are achieved by conventional masking and etching steps of the mask. The phase shifting layer material may be a resist such as PMMA or SOG (spun-on-glass). In another version, the actual mask substrate material (such as quartz) is conventionally masked, exposed by E-beam equipment, then etched to define subregions of various thicknesses, each thickness defining one phase.
The mask shown in FIG. 2(a) (in simulation) when used for integrated circuit fabrication prints the feature on the wafer as shown (also simulated) in FIG. 2(b). The image intensity is again shown by the white lines in FIG. 2(b). In FIG. 2(b) there are still significant intensity nulls 22, 24 at the two junctions defined between regions A and C and between C and B of FIG. 2(a). Again, this is undesirable because it is a degraded image and hence may produce a faulty semiconductor device (i.e., reduced fabrication yield).
Note however that there is a distinct improvement (in terms of the lessening of the intensity nulls) of FIG. 2(b) over that of FIG. 1(b). Thus it is clear that introducing one additional phase, i.e., having the three phases 0°, 90° and 180°, provides some improvement although this is probably insufficient for very small line width integrated circuits. It is to be appreciated that phase shifting is most useful for small line width integrated circuits, such as those having feature sizes well below 1 micrometer.
FIG. 2(c) is an exposure defocus diagram of the image shown in FIG. 2(b), showing the exposure defocus contours for a given critical dimension (such as the line width). The vertical axis of FIG. 2(c) is an arbitrary scale of exposure intensity; the horizontal axis shows defocus distance in μm. The shaded area is where lithography is acceptable, i.e., the critical dimension is maintained within +10% tolerance. The exposure contours are taken along horizontal lines (labelled a and b) through the line feature of FIG. 2(b). The exposure latitude as defined by the shaded areas is fairly narrow even at 0 μm defocus distance, and falls off sharply at higher defocus distances
A known improvement over the FIG. 2(a) mask is to introduce an additional phase so as to have four phases forming a transition region As shown in FIG. 3(a), here a mask includes region A having a 0° phase, region B having a 180° phase, region D having a 60° phase, and region E having a 120° phase. This provision of four phases provides a smoother transition between the 0° region A and the 180° phase region B in the resulting image and as shown in simulation in FIG. 3(b), will form a feature on the wafer with reduced intensity nulls 28, 30, 32, i.e., closer to a continuous line. However, simulation indicates that even the four phase FIG. 3(b) version exhibits to a certain extent the undesirable intensity nulls 28, 30, 32. FIG. 3(c) shows an exposure defocus diagram for the image of FIG. 3(b). Note that the gray area is significantly broader at both 0 μm and at higher defocus distances than was the correspondence diagram of FIG. 2(c), but still is quite narrow at the higher defocus distances. Here, the exposure contours are taken along four arbitrarily located horizontal lines (a, b, c, d) of the image of FIG. 3(b).
This suggests that five or more phases are needed for excellent resolution at for instance 0.35 μm feature sizes. FIG. 4 shows an exposure defocus diagram for 15 phases (the corresponding mask and image simulations are not shown). While 15 phases provides a broad exposure latitude at 0 μm defocus distance, the latitude (gray area) still narrows significantly at 2 μm defocus distance. Thus even a very large number of phases still results in a less than optimum image using the prior art technique.
However, the solution to this problem as provided by the four phase mask of FIG. 3(a) (or a mask with for instance five phases) has the significant disadvantage that such multiple phase regions substantially increase the cost and complexity of mask making This is because exposing additional phase shifter layers using the usual electron beam mask lithography system complicates mask production, because transfer of the desired pattern to the phase shift medium in the mask increases mask fabrication complexity and time. The increase in complexity requiring extra process steps significantly reduces yield of the masks and hence increases cost.
The mask shown in top view in FIG. 3(a) is shown in a cross-sectional side view in FIG. 5 with the mask formed on a quartz substrate 40. Three thicknesses of phase shifters B, E, D are formed on the substrate. The greatest thickness is in region B which is the 180° phase shift. Regions D and E are comparatively thinner, proportional to the amount of the phase shift. In region A where there is 0° phase shift, no phase shifter material is present. Thus the transition region is a step-type ramp as seen in cross-section. As discussed above, this structure while it approaches the goal of a properly printing transition region, has the significant disadvantage of being relatively difficult and complex to form on the mask and also requires additional processing steps to form up to five phases.
Also relating to phase shifting, U.S. Pat. No. 4,902,899 issued Feb. 20, 1990 to Burn J. Lin et al. is directed to a lithographic process having improved image quality that employs a mask including a plurality of opaque elements or transparent elements smaller than the resolution of the lithography. At column 5, beginning at line 11 Lin et al. disclose use of pixels in a phase shifting mask where different pixels define regions of varying thicknesses, for phase shifting masks. However this document does not disclose any implementation of the described method. Also, this document is not directed to the problem of the junction between two abutting regions of different phase, i.e., the undesirable existence therein of intensity nulls.
SUMMARY OF THE INVENTION
In accordance with the invention, a phase shift mask for lithography includes a transition region between two regions of opposite phase, where the transition region simulates the effect of a ramp in the phase shifter material by using small subregions each of which is one of three phases, in one embodiment This advantageously provides a transition region having only three phases, which has the advantages in terms of resolution and depth of focus of a prior art transition region using four or more phases. The three phases are assigned to pixels (subregions of arbitrary size and shape) in the transition region, whereby the phase assignment of each pixel is assigned by an algorithm which takes into account optical resolution and depth of focus of the fabrication process.
The minimum number of phases required is three, if two of the phases are 0° and 180°, since these two phases would merely reverse the sign of the electric field. An additional degree of freedom is gained by using a phase with a non-zero complex (orthogonal) component such as a 90° phase. Then summation of electric field contributions from the pixels with various phase arrangements lead to a result with a different overall phase at the image (i.e., printed on the resist layer on the wafer). The assignment algorithm determines the assignments of the phases to individual pixels and provides various pixel arrangements to simulate the effects of phases other than the actual pixel phase assignments. Thus a continuous transition, i.e., a ramp, is emulated by suitable assignment of phases. The pixel size (diameter) is approximately 1/5th the wave length of the intended incident light divided by the numerical aperture of the lithography system (but may be of smaller size).
This method minimizes critical dimension variation in the exposure dose, comparable to the critical dimension variation achievable with phase shift techniques in non-transition regions. The transition region is as high quality using three phases, i.e., has as few intensity nulls, as is a transition region generated using the conventional technology using four phases or more.
In one embodiment, a transition region between the 0° phase region and the 180° phase region includes a number of rows of pixels, each row having a particular combination of pixels of various phases so as to smoothly transition from the 0° phase to the 180° phase.
In another embodiment, the transition region of the mask between two regions of opposite phase includes an arbitrary number (such as approximately five) intermediate regions in the phase shifting material. Each intermediate region includes several subregions where each subregion (a pixel in one embodiment) is of a particular phase and the subregions in each intermediate region are selected so as to provide a gradual transition from the phases which are to be joined by the transition region. Thus for instance the first intermediate region adjacent the 0° region is chiefly of subregions of 0° phase with some subregions of 90° phase. The next adjacent intermediate region is approximately half 0° phase subregions and half 90° phase subregions. The next intermediate region is all 90° phase. The next intermediate region is half 90° and half 180° phase subregions. The next intermediate region is mostly 180° phase subregions with some 90° phase subregions. The final intermediate region is all 180° phase subregions. The subregions may be pixels as exposed by the mask making imaging system.
Thus with both embodiments, a transition is created from the 0° phase region to the 180° phase region such that intensity variation in the optical image corresponding to the intermediate transition region is minimized, and/or sensitivity to the edge contrast of the optical image is minimized, and/or resolution is improved, and/or focus sensitivity is minimized in the transition region. The synthesized transition region pattern, i.e., the selection of the various pixels, achieves this result using a combination of a pattern manipulation algorithm and optimization techniques.
In other embodiments, the number of phases n used may be four or more; in each case, the depth of focus (defocus distance) and exposure latitude (intensity variation) are superior to that provided by prior art phase shift masks having the same number n of phases.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a), 1(b), 2(a), 2(b), 2(c), 3(a), 3(b), 3(c), 4, and 5 show prior art phase shifting masks and the resulting wafer images.
FIGS. 6(a), 6(b), 7(a), and 7(b) show phase shifting masks in accordance with the invention and the resulting wafer images.
FIG. 8 shows another phase shifting mask in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 6(a) shows in simulation a top view of a portion of a phase shifting mask in accordance with the invention. The structure of FIG. 6(a) corresponds to that of FIG. 2(a); however, in FIG. 6(a), instead of there being three distinct phase regions, i.e., 0°, 90°, and 180°, the transition region 50 is a mosaic of rows and columns of pixels of three phases: 0° (the all white pixels), 90° (the darker pixels), and 180° (the shaded pixels). The transition region joins two end regions A, B which are respectively of 0° and 180° phase. Those portions (rows of pixels) of the transition region 50 nearest the 0° phase region A are chiefly 0° phase pixels. Some of the pixels in these rows are of 90° phase. At the center of the transition region 50, in three of the rows all of the pixels are of 90° phase. Progressing from the 0° phase region A to the center of the transition region, an approximately linearly increasing proportion of pixels in each row are of 90° phase. Then moving upwards in the drawing towards the 180° phase region B, the transition region 50 is a combination in each row of 90° phase pixels and 180° phase pixels, with the proportion of the 180° phase pixels in each row approximately linearly increasing moving upwards towards the 180° phase region B. The rows of the transition region immediately adjacent to the 180° phase region B are mostly 180° phase pixels.
The transition region 50 is 12 pixels wide, i.e., each row of pixels has 12 pixels, defining 12 columns. Each pixel conventionally is defined by four circular electron beam spots arranged quadrilaterally to define a square.
As shown, the transition region 50 between the 0° and 180° phase regions A, B is wider by two pixels (20% of the width of region 50) than are the 0° and 180° phase regions A, B. This extra width minimizes deviation of the image from the nominal mask pattern.
To further define the algorithm by which the pixels are assigned a particular phase, in FIG. 6(a), the bottom-most row of pixels in the transition region 50 has 12 pixels, of which 10 are 0° phase and 2 are 90° phase. The next two rows (moving upwards) each have 8 pixels of 0° phase and 4 pixels of 90° phase. The next three rows moving upwards each have 6 pixels of 0° phase and 6 pixels of 90° phase. The next three rows (center of region 50) are all 90° phase pixels. The pixels in the upper portion of region 50 are approximately a mirror image (about the horizontal axis of region 50) of those in the lower portion in terms of the numbers of pixels of each phase in each row, except that 180° phase pixels are substituted for the 0° phase pixels used in the lower portion of region 50. In each row of region 50 the arrangement (order) of pixels is random but symmetric about the vertical axis of region 50.
The length of the transition region 50 (the distance from region A to region B) is in the range of 0.6 * λ/na to 2.0 * λ/na.
It is to be understood that as described above, in the context of mask making "phase" refers only to the local thickness of the phase shifting layer, with 0° phase meaning no phase shifting layer, 180° meaning a phase shifting layer having a thickness of one-half the wavelength of the imaging light used for printing, and 90° referring to a thickness of one quarter of the wavelength of the imaging light.
The mask shown in simulation FIG. 6(a) when used to fabricate (image) a feature on a wafer provides a feature having the exposure characteristics shown (in simulation) in the exposure defocus diagram of FIG. 6(b). The imaged feature (not shown) exhibits only minimal intensity nulls, and advantageously as shown in FIG. 6(b) has a relatively broad exposure latitude (shaded area) even at large defocus distances. Thus the resolution provided by the mask of FIG. 6(a) is comparable to that provided by the prior art mask of FIG. 3(a). Advantageously, however, this is accomplished by use of only three phases rather than four phases as in the prior art of FIG. 3(a).
FIG. 7(a) shows another mask similar to that of FIG. 6(a); the difference is that in FIG. 7(a), the pixels are organized so that pixels of like phase are arranged to the extent possible in columns. FIG. 7(b) shows that the mask of FIG. 7(a) yields similar exposure defocus lithography results (i.e., as good an image) as does the mask of FIG. 6(a). Thus the arrangement of pixels on each row of the transition region 50 on a microscopic basis does not affect the quality of the resulting image. Desirably, however, again in FIG. 7(a) each pixel row is symmetric about the vertical axis of region 50 in terms of pixel phase assignments.
FIG. 8 shows another embodiment of a mask in accordance with the invention. The transition region 62 connects the 0° phase region A with the 180° phase region B. Near the center of transition region 62 is a relatively narrow region 66 of 90° phase. Intermediate between the 90° phase region 66 and the 0° phase region A are two regions 68, 70 the lower one 68 of which is a combination of 0° phase subregions 74 (also referred to as pixels) and 90° phase subregions 76. The next intermediate region 70 moving upwards in the figure is also such a combination but with the 90° phase subregions 76 being a larger proportion of the area of region 70. Immediately above the all 90° phase region 66 is another intermediate region 80 which is chiefly 90° phase subregions 66 with some 180° phase subregions 84. The next intermediate region 88 moving upwards in the figure is chiefly 180° phase subregions 84. With some 90° phase subregions 66. The next region is the all 180° phase region B.
In FIG. 8 the subregions (pixels) 66, 74, etc. are elongated rectangles. The mask of FIG. 8 differs from that of FIG. 6(a) in that in FIG. 8, (1) the pixels are elongated rectangles (not squares); (2) there are (arbitrarily) only 6 rows 68, 70, 66, 80, 88 of pixels; (3) in each row of pixels (except for region 66), the two types of pixels alternate, rather than the more random arrangement as in FIG. 6(a); and (4) in FIG. 8, the size of the pixels (length and width) differs from row to row.
Simulation results indicate that the actual microscopic pixel arrangement (in terms of rows or columns) in accordance with the invention is not critical in terms of the performance of the feature printed using such a mask. In other words, it is the macroscopic qualities of the pixel arrangements as described above which is both novel over the prior art and also provides the desired advantage.
The width of each subregion in FIG. 8 is about 0.2*λ/na, where λ is the wavelength of the light used to print the wafer from the mask, and na is the numerical aperture of the printing imaging system. The pixel rectangles of FIG. 8 and squares of FIG. 6(a) and 7(a) are arbitrary shapes; the subregions (pixels) may be any geometric figure capable of close packing, i.e., hexagons, squares, rectangles, etc.
Fabrication and use for imaging wafers of the masks of FIGS. 6(a), 7(a) and 8 is as follows. Beginning with a conventional quartz mask substrate, a layer of chrome is conventionally applied to a principal surface thereof. The chrome layer is then conventionally masked and etched to define the non-opaque portions (apertures) of the mask. Then a resist layer of conventional E-beam (electron beam) resist such as PBS is applied to the exposed (non-chromed) portions of the substrate. This may be a negative or positive resist. Then using conventional E-beam mask writing equipment, the E-beam scans the surface of the resist in a first pass, writing (exposing) the mask pattern conventionally, and particularly exposing at a particular dose those pixels in the transition regions which are the 0° phase pixels. The other pixels in the transition regions are not exposed on this first pass.
Then a second exposing pass is made on the mask, exposing at a different dose (typically one half the first pass dose) the 90° phase pixels in the transition region. It is to be understood that these two passes are also used for purposes of writing other features on the mask.
Then the exposed resist is conventionally developed and the underlying substrate is conventionally etched, forming areas of localized thickness in the phase shifter layer on the substrate surface corresponding to the degree of exposure. Note that the 180° phase pixels need not be exposed since they represent the maximum thickness of phase shifter material.
Alternatively, the pixels of all phases may be written in one pass by changing dosage between pixels.
Alternatively, the step of developing and etching may immediately follow each of the two exposing steps.
After the substrate is etched and all remaining resist is stripped, other processing of the mask is conventional.
The mask is then used conventionally to photolithographically form patterns (print features) on wafers. The actual use of the phase shifting mask is wholly conventional and compatible with existing wafer fabrication processes, except that resolution (or other corresponding optical factors such as depth of focus) is improved.
It is to be understood that the above description is illustrative and not limiting. For instance, one may use four phases (or more) rather than three phases. In the case where four phases are used, these phases might be 0°, 60°, 120°, and 180°. Thus a first row of the transition region would be all 0° phase pixels adjacent the 0° phase end region, and pixel assignments would transition over several pixel rows to an all 60° phase pixel row. The next portion of the transition region would then transition in terms of pixel assignments over several rows to an all 120° phase pixel row, and the final portion transition over several rows to an all 180° phase pixel row adjacent the 180° phase end region.
The above description of the use of three phases emphasizes the advantage of the invention in using three phases over the prior art use of four phases to achieve similar results. In another embodiment, additional rows of pixels (i.e., smaller size pixels) would improve the image resolution. Also, the invention is applicable to masks for use in lithography at all optical wavelengths, and also ultra violet, infra red, and other wavelengths.
I claim:
1. A phase shift mask for lithography for defining transition region between a first and a second region of respectively two different first and second phases, the mask also defining at least a third phase, and the transition region comprising:at least one intermediate portion being composed of the third phase; a first portion between the first region and the intermediate portion being composed of a plurality of subregions of the first phase and subregions of the third phase, the density of the first phase in the first portion increasing from the intermediate portion toward the first region; and a second portion between the second region and the intermediate portion being composed of a plurality of subregions of the second phase and subregions of the third phase, the density of the second phase in the second portion increasing from the middle portion toward the second portion.
2. The mask of claim 1 wherein each subregion is rectangular.
3. The mask of claim 1 wherein the third phase includes a complex optical component relative to the first two phases.
4. The mask of claim 1 wherein each subregion is formed of at least one pixel.
5. The mask of claim 1 wherein the width of each subregion is equal to approximately 1/5th of the wave length of incident light for the photolithography divided by the numeric aperture of an imaging system used for the lithography.
6. The mask of claim 1 wherein the subregions are of close packing shape.
7. The mask of claim 1 wherein the first phase is defined by the presence of a phase shifter layer and the second phase is defined by the absence of a phase shifter layer on a substrate of the mask.
8. The mask of claim 4, wherein the pixels are arranged in rows and columns, the columns being arranged along an axis defined by a length of the transition region, and the pixels in each row are arranged in terms of phase assignment symmetrically about a centerline of the transition region.
9. The mask of claim 8, wherein the phase assignment of pixels in each row is an approximately linear function of a distance of the row from either the first region or the second region.
10. The mask of claim 1, wherein the transition region differs in width by about 20% from the width of the first region.
11. A method of lithographically forming features on a substrate using the mask of claim 1 and comprising the steps of:providing the mask of claim 1; lithographically defining features on the substrate by passing radiation through the mask onto a substrate having a sensitive layer on its surface; and forming the defined features in the substrate.
12. A method of lithographically forming features on a substrate using a mask and comprising the steps of:providing the mask for defining at least one transition regions between two regions of differing phase, said transition region comprising pixels of at least one third phase, and pixels of the two differing phases to simulate a ramp between the two regions; lithographically defining features on a sensitive layer formed on a surface of the substrate by passing radiation through the mask onto the layer; and etching the defines features into the surface.
13. A method as in claim 12, wherein said transition region comprises at least one intermediate portion being composed of a third phase;a first portion between the region of one differing phase and the intermediate portion being composed of a plurality of subregions of the pixels of the one differing phase and subregions of the pixels of the third phase, the density of the one differing phase in the first portion increasing from the intermediate portion toward the region of the one differing phase; and a second portion between the region of the other differing phase and the intermediate portion being composed of a plurality of subregions of the pixels of the other differing phase and subregions of the pixels of the third phase, the density of the other differing phase in the second portion increasing from the intermediate portion toward the region of the other differing phase.
14. A method of making a phase shift mask comprising the step of:providing a substrate; forming a resist layer on the substrate; exposing the resist layer for defining a first and second region of opposite first and second phases and for defining a plurality of pixels on the resist layer defining a transition region between the first and second regions, said pixels comprising pixels of at least one third phase and pixels of the first phase and second phase, the transition region including at least one intermediate portion being composed of the pixels of the third phase, a first portion between the first region and the intermediate portion being composed of the pixels of the first and third phases, the density of the pixels of the first phase in the first portion increasing from the intermediate portion toward the first region, and a second portion between the second region and the intermediate portion being composed of the pixels of the second and third phases, the density of the pixels of the second phase in the second portion increasing from the intermediate portion toward the second region; and developing the resist layer.
| 1991-09-12 | en | 1993-09-21 |
US-25417088-A | Lock deadbolt protector
ABSTRACT
Mortise lock has a guardbolt which, when depressed, moves a hooked lever inside the lock housing from a first position in which it blocks operation of the deadbolt operator, to a second position in which it clears the deadbolt operator and permits it to operate. This protects against extension of the deadbolt unless the door is closed.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a mortise lock. More specifically, this invention relates to a mortise lock having means preventing the throwing of the deadbolt until a guardbolt is first depressed.
2. Description of the Related Art Including Information Disclosed Under §§1.97-1.99
The prior art is, of course, replete with examples of mortise locks generally comprising a rectangular housing adapted to fit into an opening in the end of the door at waist level, and generally containing a latch and a separate deadbolt and operating means for both of them. The operating means for the latch is generally in the form of a rotatable cam which is driven by a handle. For the deadbolt the operating means is usually a turnbolt on the inside of the door and a key cylinder from the outside of the door.
It has been common to use such mortise locks in the doors of guest rooms in hotels and the like with the latch bolt automatically locking when the door is closed so that the door may be opened from the hallway, only by a key operating the lock cylinder. Mortise locks to such guest rooms have also included a deadbolt operated by a turnbolt from inside the guest room.
A problem has been experienced in the past in that the guest room maid in a hotel in making up the room has abused the deadbolt. As is conventional, the linen supply for the guest rooms is brought to the hallway outside a room on a wheeled supply cart, and it is from such a cart that the maid services the room. In servicing the room the maid will strip the beds of their soiled sheets and carry them out through the door. Although the maid has a key for the room, in order to avoid having to use the key to gain readmittance to the guest room, the maid will before leaving the room simply throw the deadbolt by turning the turnbolt and then let the door close on her way out. Because the deadbolt is extended, it will engage the door frame, keeping the door from closing and therefore unlatched. Later, loaded with fresh linens, the maid will merely push the door open to get back into the room.
The above-described way of operating, while saving the maid energy and time, has been hard on both the deadbolt and the door frame, because hotel doors, generally being heavy, have relatively heavy-duty closers which will drive the door toward closed position, causing a severe impact of the deadbolt on the frame.
In the past, when because of the damage caused the maid is confronted and criticized for throwing the deadbolt, she has often proclaimed her innocence, saying that it was accidental. As a result, attempts have been made in the past to make it more difficult to throw the deadbolt with the door open. An example of such an attempt is found in the U.S. Pat. Re. No. 26,677 (copy enclosed) from a patent which issued on Aug. 22, 1967 to F. J. Russell et al. In this mortise-type lock an auxiliary bolt is provided having an inward horizontal arm which carries on it a blocking element which, unless the auxiliary latch is depressed, blocks the downward movement of a special linkage pivoted to the crank arm of the deadbolt operator. The mechanism of the resissue patent has been improved upon by providing a simpler and more easily operatable structure.
SUMMARY OF THE INVENTION
Under the present invention the mortise lock is provided with a special guardbolt. Inside the mortise housing a lever is mounted, pivoted intermediate its ends. One end is accessible to the inner end of the guardbolt while the other end is formed with a hook. The adjacent deadbolt operator carries, spaced from its axis, a transverse pin. The lever may take one of two positions: the first position with the hook engaging the pin and blocking the extension of the deadbolt, and the second position clearing the pin. The lever is shiftable from the first to second position by depressing the guardbolt.
As a result, with the door closed and the strike depressing the guardbolt, the hook clears the pin and the deadbolt is throwable in the conventional manner by the guest. With the door open and the guard-bolt extended, the lever is in its first position with the hook blocking the operation of the deadbolt. Thus, if a maid intends to throw the deadbolt with the door open, she would have to first manually depress the guardbolt. As a consequence, it is much more difficult for her to plead that the objectionable setting of the deadbolt was "accidental".
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the invention will be apparent from the following specification and drawings, all of which disclose a non-limiting embodiment of the invention. In the drawings:
FIG. 1 is a simplified view of a mortise lock embodying the invention showing the lever in the first position; and
FIG. 2 is similar to FIG. 1 but shows the lever in the second position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A mortise lock embodying the invention is generally designated 10 in FIG. 1. As shown with its cover removed, the lock includes a rectangular housing 12 having an apertured face plate 14 with its ends extending beyond the ends of the housing to be mounted against the end of the door as is conventional.
Extending through the aperture in the face plate 14 are the deadbolt 16, the latchbolt 18 and the guardbolt 20. Inside the housing the latchbolt 18 has a rearward reciprocable latch shaft 22 having a pull-back plate 24 on its inner end. A pair of projections 26 in the wall of the housing supports the latch shaft 22 in proper alignment. The shaft is enlarged as at 28 adjacent the latch 18, and an axial spring 30 is disposed intermediate the projections 26 and the enlargement 28 to bias the latch outward.
The spindle of the door handle (not shown) is square in shape and engages a square-shaped opening 32 in a pull-back 34 mounted for rotation between the side walls of the housing. The pull-back is formed with projections 34a which work against the latchbolt-operating lever 36, pivoted as at 38 in the housing. A nose 40 on the latchbolt lever 36 engages the plate 24 when the pull-back is operated to retract the latchbolt, as is conventional. By using the latch-operating lever 36 the "throw" of the pull-back 34 is increased so that for limited turning of the latch handle (not shown) the latchbolt 18 is completely retracted.
The deadbolt operator 42 is mounted on a hub 44 journaled in aligned openings in the side walls of the housing 12. The hub is formed with a square opening 46 to receive the square spindle of a turnbolt (not shown). The operator 42 is provided with an arm 48 which carries on its distal end a cam follower 50. The deadbolt 16 has attached to its inner end a drive plate 52 having an elongated cam slot 54 disposed on an incline therein. The drive plate 52 has a pair of legs 55 which for support of the drive plate straddle the hub 44 of the operator in the conventional arrangement. When the turnbolt (not shown) is turned, it rotates the operator 42 so that the follower 50, moving downward, slides along the cam slot 54, propelling the deadbolt 16 outward. In the retraction of the deadbolt the turnbolt is turned in the opposite direction and the arm 48 raises, causing the follower 50 to move upward in the cam slot 54, once again retracting the deadbolt.
Spaced from the hub 44 and secured to the operator 42 is a plurality of pins 56 and 56a. The pins extend between the operator plate shown and an identically shaped plate parallel and behind it. A hairpin-shaped spring 58 has one arm disposed against the side wall of the housing and loops over a screw boss 60 in the upper corner of the housing. The other arm of the spring 58 is formed with an inward deflection 62 which serves, when the deadbot is retracted, to press downward on the lower pin 56a to hold the operator in retracted position.
Above the deadbolt operating mechanism in the case 12 there is room for the conventional key-operated cylinder (not shown) having an operating lever which will engage the deadbolt operator so that the deadbolt may be operated from outside the door with a key.
Turning now to the focus of the invention, a lever 70 is disposed in the housing and pivoted intermediate its ends on a pin 72 rigidly supported between the side walls of the housing. At the inner end of the lever is a hook 74, and at the other end is a working surface 76. The lever 70 is capable of taking two positions. In its first position the lever has its hook 74 engaging around the pin 56a, blocking the counterclockwise rotation of the operator 42 (FIG. 1). In its second position (FIG. 2) the lever has its hook well clear of the pin 56a. An axial spring 76 surrounding the pin 72 biases the lever 70 towards the first position.
Completing the assembly is a plate 80 mounted on the inner end of the guardbolt 20. The plate carries an upward nib 82, and a wire spring 84 has one end engaging a projection 26, loops about a pin 86 formed in the back wall of the housing, and a second arm which applies outward pressure against the pin 82 on the plate 80, the arm 84a being well beneath the lever of the working surface 76 on the lever.
Extending perpendicular to the plate 80 is a fin 87 which, when the guardbolt 20 is pressed inward against the force of spring 84, engages the working surface 76 to move the lever 70 into second position, freeing the operator 42 to throw the deadbolt out. It should be clear that the guardbolt 20 can be depressed either manually or by engaging a strike on the frame of the door when the door is closed. Either of the ways of depressing the guardbolt results in the liberation of the pin 56a from the hook 74.
It will be clear to those skilled in the art that the present invention greatly simplifies and makes more reliable than disclosures in the art the blocking of operation of a mortise lock deadbolt until the guardbolt is forced inward.
While the invention has been disclosed in only one form, it should be clear it is not so limited but is capable of many variations and modifications within the scope of the following claim language and equivalents thereof which define the invention.
What is claimed is:
1. A mortise lock comprisinga. a box-like housing having an apertured face plate adapted to be mounted in the end surface of a door b. an outwardly biased latchbolt protruding through the face plate c. an operator for said latchbolt d. a deadbolt mounted in the housing for reciprocation through the face plate e. an operator for the deadbolt comprising:(1) a drive body mounted in the housing for rotation about an axis perpendicular to the door, the body having pins on its periphery and parallel to its axis, the deadbolt operator being connected to the body at its axis, (2) a link connecting one of the pins to the end of the deadbolt, f. a guardbolt mounted in the housing for reciprocation through the face place g. deadbolt blocking means comprising:(1) an outwardly biased auxiliary latchbolt normally extending through the end plate, (2) a lever pivoted intermediate its ends in the housing and having a hook on one end adapted when the lever is in a first position to hook around one of the pins in the body to block the operator from turning, and in a second position to clear said pin to permit turning of the operator, part of the lever being accessible to the inner end of the guardbolt,whereby when the guardbolt is moved inward as by engagement with a door strike or by manual manipulation it moves the lever from first to second position.
2. A mortise lock as claimed in claim 1 wherein the body comprises a pair of spaced aligned end plates having the pins extending between the end plates.
| 1988-10-06 | en | 1989-10-03 |
US-89611086-A | Monoacrylates of trihydric phenols and method for producing same
ABSTRACT
Compounds of the general formula I ##STR1## in which R is a hydrogen or halogen atom, a cyanide or an alkyl group having 1-4 carbon atoms and
R 1 is a hydrogen or halogen atom, nitro, alkyl, alkoxy, aryl, aryloxy, acyl or alkoxycarbonyl group,
are prepared by esterifying two adjacent OH groups to give the cyclic carbonate, esterifying the free OH group with (meth)acrylic acid and selectively hydrolyzing the carbonate. The compounds are free of polyunsaturated impurities and can be used for preparing purely linear polymers.
BACKGROUND OF THE INVENTION
The invention relates to polymerizable esters of acrylic or methacrylic acid with polyhydric phenols and to a process for their preparation.
Monoacrylates and monomethacrylates of dihydric phenols are described in German Offenlegungsschrift No. 1,933,657 and No. 2,659,809. They are prepared by reacting dihydric phenols with for example acryloyl or methacryloyl chloride. The resulting reaction mixtures, in addition to unreacted starting compounds, contain monoacylated and diacylated phenols which can only be separated with difficulty and with yield losses. The isolated monoesters generally still contain the indicated impurities and are obtained in yields which, as a whole, are significantly below 50%, based on the starting materials. The impurities due to compounds having more than one polymerizable ester group in the molecule can lead to considerable difficulties in the further processing of the compounds to polymers, since they give rise to branched and, possibly, cross-linked polymers which have completely different solubility and viscosity properties than linear polymers.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide monoacrylates and monomethacrylates of trihydric phenols in a pure form.
It is another object of the invention to provide a process whereby these compounds are obtainable in a pure form and high yield.
These objects are achieved by a compound of the general formula I ##STR2## in which
R is a hydrogen or halogen atom, a cyanide or an alkyl group having 1-4 carbon atoms and
R1 is a hydrogen or halogen atom, a nitro, alkyl, alkoxy, aryl, aryloxy, acyl or alkoxycarbonyl group.
The objects of the invention are further achieved by a process for preparing compounds of the above formula I, which comprises the steps of reacting a compound of the formula II ##STR3## in which R1 has the above-mentioned meaning, with a compound of the formula III ##STR4## in which X denotes a halogen atom, an alkoxy or aryloxy group, to give a compound of the formula IV ##STR5## reacting the resulting compound of the formula IV with a compound of the formula V ##STR6## in which
Y is a halogen atom, a hydroxyl group, an alkoxy group or a radical of the formula ##STR7##
R has the above-mentioned meaning, to give a compound of the formula VI ##STR8## and hydrolyzing the resulting compound of the formula VI to a compound of the formula I.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
When in the above formula I R is an alkyl group, it preferably has 1 or 2 carbon atoms, particular preference being given to compounds with R=H or methyl.
When R1 is a halogen atom, it can preferably be a fluorine, chlorine or bromine atom, in particular a chlorine atom. When R1 is an alkyl or alkoxy group, it preferably has 1 to 6, in particular 1 to 3, carbon atoms; preferred acyl and alkoxycarbonyl groups have 2 to 15, in particular 2 to 10, carbon atoms. Aryl and aryloxy groups R1 generally have 6 to 10 carbon atoms. The radical CH2 ═C(R)--COO can be in the 3- or 4-position relative to the two phenolic hydroxyl groups, particular preference being given to the 3-position. R1 can likewise be in the 3- or 4-position.
Examples of compounds of the formula II are hydroxyhydroquinone, 5-ethylpyrogallol, pyrogallol, methyl gallate, ethyl gallate, propyl gallate, octyl gallate and dodecyl gallate. Compounds of the formula II can also be easily converted by customary halogenating and nitrating methods to the corresponding monosubstituted, disubstituted or trisubstituted chlorine, bromine, iodine and nitro derivatives.
Representatives of compounds of the formula III are phosgene, diethyl carbonate or diphenyl carbonate. When diphenyl carbonate is used, no solvent is necessary. Heating to from about 200°-300° C. gives rise to the formation of 2 moles of phenol which distill off under these reaction conditions. The purification of the cyclic carbonates of the formula IV which remain behind is effected initially through vacuum distillation and then in general through recrystallization.
In the case of using phosgene, an apolar solvent, for example toluene or xylene, is preferably used. Phosgene is customarily passed in with ice-cooling in the presence of 2 moles of a base such as pyridine, dimethylaniline or triethylamine. After the customary working-up with acid and water it is likewise possible to obtain compounds of the formula IV by removing the solvent, and to purify them by recrystallization.
Compounds of II and III are usually reacted with each other in a molar ratio of from about 0.8:1.2 to about 1.2:0.8, preferably from about 0.9:1.1 to about 1.1:0.9. When compounds of the formula II are reacted with carbonic acid derivatives of the formula III in a different molar ratio, the yields decrease, since if, in the case of using less than the stated amount of carbonic acid derivative, still unreacted starting material is present while in the case of using more than the stated amount of carbonic acid derivative, the free hydroxyl group on reaction products of the formula IV further reacts with the excess reagent to give intermolecular or intramolecular byproducts.
Preferred compounds of the formula V are acryloyl chloride, methacryloyl chloride or methacrylic anhydride. Further representatives are for example acrylic acid, methacrylic acid, 2-ethylacrylic acid and 2-butylacrylic acid and also their methyl and ethyl esters.
The esterification of compound IV must be carried out in such the way that the carbonate grouping is preserved as a protective group. This is achieved for example by reacting acryloyl or methacryloyl chloride in aprotic solvents such as chlorohydrocarbons, for example methylene chloride, chloroform, carbon tetrachloride, or aromatic hydrocarbons, for example toluene or xylene, in the presence of bases such as triethylamine. It is also advantageously possible to use the less costly methacrylic anhydride in place of methacryloyl chloride. This can be done in the presence of bases or even in the presence of acids, for example concentrated sulfuric acid. In the case of using acrylic acid and methacrylic acid or their methyl or ethyl esters, it is also possible to effect direct esterification or transesterifications under the acid or neutral conditions.
The reaction products of the formula VI prepared in this way are in general crystalline and can easily be purified by recrystallization. They are then preferably hydrolyzed in water within the temperature range of 50°-100° C. In the course of the hydrolysis, the two hydroxyl groups protected as cyclic carbonate are set free.
The elimination of the carbonate protective group must be effected in such a way that the unsaturated ester grouping is preserved. This is achieved in a preferred variant in a neutral aqueous medium. In this context, it has been found to be advantageous to regulate the amount of water used for hydrolysis in such a way that a clear solution forms when hot and, after cooling down, the compounds of the formula I crystallize out completely. Using this process they are obtained with an overall yield of at least 50%. The process described can be applied to any trihydroxyaromatic which has two alpha-position hydroxyl groups.
To prepare polymers, the new monomers can be either homopolymerized or even copolymerized with other ethylenically unsaturated monomers, in the conventional manner by means of heat, radiation and catalysts, for example peroxides or azo compounds.
The processing of the compounds according to the invention into polymers and their use as binders in light-sensitive mixtures is described in copending, concurrently filed U.S. patent application No. 896,250; the contents of which are hereby incorporated by reference.
The following preparative examples illustrate the invention.
EXAMPLE 1
Preparation of 1,2-dihydroxy-3-methacryloyloxybenzene
In a flask with a distillation attachment, 504 g of pyrogallol and 816 g of diphenyl carbonate are thoroughly mixed and gradually heated to 250° C. After complete removal of the resulting phenol by distillation, the residue is distilled in vacuo and recrystallized from toluene. This gives 490 g of 1-hydroxy-2,3-carbonyldioxybenzene (81% of theory).
The product is then dissolved in a mixture of 25 ml of concentrated sulfuric acid in 2.5 l of toluene. This solution has added to it at room temperature 496 g of methacrylic anhydride in the course of 2 hours, and the mixture is stirred at room temperature for 12 hours and is then washed repeatedly with water. The organic phase is freed from the solvent. The remaining residue becomes crystalline after addition of diisopropyl ether. The crystalline precipitate is filtered off with suction and washed with the diisopropylether, leaving 475 g of 1-methacryloyloxy-2,3-carbonyldioxybenzene (67% of theory).
This product is stirred at 65° C. in 3 l of water for 2 hours. CO2 evolves to leave a clear solution. After cooling down, the resulting crystals are filtered off with suction and recrystallized from toluene. This gives 385 g of analytically pure 1,2-dihydroxy-3-methacryloyloxybenzene (92% of theory) having a melting point of 100°-102° C.
The total yield, based on pyrogallol, is 50% of theory.
EXAMPLE 2
Preparation of 1,2-dihydroxy-3-acryloyloxybenzene
Into a mixture of 125 g of pyrogallol in 400 g of toluene and 150 g of pyridine are passed with ice-cooling 99 g of phosgene. Twelve hours of stirring at room temperature is followed by heating at 100° C. for one hour. After cooling down, the reaction mixture is acidified and washed with water. The solvent is removed. The residue is recrystallized from toluene. This gives 123 g of 1-hydroxy-2,3-carbonyldioxybenzene (81% of theory).
This product is dissolved in a mixture of 81 g of triethylamine and 0.7 l of toluene. To this solution are added with ice-cooling in the course of 3 hours, 73 g of acryloyl chloride, and the mixture is stirred at room temperature for 12 hours. The organic phase is first washed with water then freed from solvent. The remaining residue is recrystallized from diisopropyl ether. This gives 130 g of 1-acryloyloxy-2,3-carbonyldioxybenzene (78% of theory).
This product is stirred at 65° C. in 0.8 l of water for 1.5 hours. CO2 evolves to leave a clear solution. The crystals precipitated on cooling down are filtered off with suction and dried. This gives 94 g of 1,2-dihydroxy-3-acryloyloxybenzene (83% of theory) having a melting point of 92°-95° C.
The total yield, based on pyrogallol, is 52% of theory.
EXAMPLE 3
Preparation of ethyl 3,4-dihydroxy-5-methacryloyloxybenzoate.
In a flask with a distillation attachment, 198 g of ethyl gallate and 204 g of diphenyl carbonate are thoroughly mixed and gradually heated to 250° C. After complete removal of the resulting phenol by distillation, the residue is distilled in vacuo and recrystallized from ethyl acetate. This gives 183 g of ethyl 3-hydroxy-4,5-carbonyldioxy-benzoate (82% of theory).
This product is dissolved in a mixture of 82 g of triethylamine in 800 ml of toluene. To this solution are added in the course of 3 hours with ice-cooling, 86 g of methacryloyl chloride, and the mixture is stirred at room temperature for 12 hours. The organic phase is first washed with water and then freed from solvent. The remaining residue is recrystallized from diisopropyl ether. This gives 191 g of ethyl 3-methacryloyloxy-4,5-carbonyldioxybenzoate (80% of theory).
This product is stirred at 65° C. in 1.2 l of water for 5 hours until a clear solution is formed. After cooling down, the precipitated crystals are filtered off with suction and recrystallized from toluene. This gives 146 g of ethyl 3,4-dihydroxy-5-methacryloyloxybenzoate (84% of theory) having a melting point of 106°-108° C.
The total yield, based on ethyl gallate, is 55% of theory.
EXAMPLE 4
1,2-dihydroxy-4-methacryloyloxybenzene having a melting point of 112°-114° C. is prepared analogously to Examples 1-3.
What is claimed is:
1. A compound consisting essentially of a monoester of the formula I in a pure form ##STR9## wherein R is hydrogen or halogen, a cyano group or an alkyl group having from 1 to 4 carbon atoms;R1 is hydrogen or halogen, a nitro, alkyl, alkoxy, carbocyclic aryl having from 6 to 10 carbon atoms, carbocyclic aryloxy having from 6 to 10 carbon atoms, acyl having from 2 to 15 carbon atoms or alkoxycarbonyl having from 2 to 15 carbon atoms group; and R1 and the radical CH2 ═CR--COO-- are in the 3 and 4 positions relative to the two hydroxyls.
2. A compound as claimed in claim 1, wherein said acyl comprises from 2 to 10 carbon atoms.
3. A compound as claimed in claim 1, wherein said alkoxycarbonyl comprises from 2 to 10 carbon atoms.
4. A compound as claimed in claim 1, wherein said compound further comprises at least one additional ring substituent comprising a chloro, bromo, iodo or nitro substituent.
5. A monoester of trihydric phenol of formula I in a pure form ##STR10## wherein R is hydrogen or halogen, a cyano group or an alkyl group having from 1 to 4 carbon atoms;R1 is hydrogen or halogen, a nitro, alkyl, alkoxy, carbocyclic aryl having from 6 to 10 carbon atoms, carbocyclic aryloxy having from 6 to 10 carbon atoms, acyl having from 2 to 15 carbon atoms or alkoxycarbonyl having from 2 to 15 carbon atoms group; and R1 and the radical CH2 ═CR--COO-- are in the 3 and 4 positions relative to the two hydroxyls, produced by: reacting a compound of the formula II ##STR11## with a compound of the formula III ##STR12## wherein X is halogen or an alkoxy or aryloxy group, to give a compound of the formula IV ##STR13## reacting the resulting compound of the formula IV with a compound of the formula V ##STR14## wherein Y is halogen, a hydroxyl group, an alkoxy group or a radical of the formula ##STR15## to give a compound of the formula VI ##STR16## and hydrolyzing the resulting compound of the formula VI to a compound of the formula I.
6. A product produced by the method as defined by claim 5, wherein said compound of the formula II further comprises at least one additional ring substituent comprising a chloro, bromo, iodo or nitro substituent.
7. A compound as claimed in claim 1, wherein the radical CH2 ═CR--COO-- is in the 3-position relative to the two hydroxyls.
| 1986-08-13 | en | 1988-04-19 |
US-3632028D-A | Hanger for articles of clothing or the like
ABSTRACT
A hanger for trousers, slacks, skirts or like articles of clothing wherein two plastic arms are movable in parallelism with each other between article-engaging and article-releasing positions. Each arm has an elongated slot which receives the stem of a guide pin provided on the other arm. An elastic band or a helical spring is connected to the pins and biases the arms to their article-engaging positions. A deformable suspending member is separably connected to coupling elements provided at the upper sides of the arms and enables the user to suspend the hanger on a nail or the like. The suspending member may carry a hook to permit suspension of the hanger on a rod.
United States Patent Kurt Fussel Afferde, Germany Feb. 13, 1970 Jan. 4, 1972 Sinram & Wendt Hameln -Afl'erde, Germany Feb. 25, 1969 Germany lnventor App]. No. Filed Patented Assignee Priority References Cited UNITED STATES PATENTS 2/ 1920 Barclay Primary Examiner-Jordan Franklin Assistant ExaminerGeorge H. Krizmanich Attorney-Michael S. Striker ABSTRACT: A hanger for trousers, slacks, skirts or like articles of clothing wherein two plastic arms are movable in parallelism with each other between article-engaging and articlereleasing positions. Each arm has an elongated slot which receives the stem of a guide pin provided on the other arm. An elastic band or a helical spring is connected to the pins and biases the arms to their article-engaging positions. A deformable suspending member is separably connected to coupling elements provided at the upper sides of the arms and enables the user to suspend the hanger on a nail or the like. The suspending member may carry a hook to permit suspension of the hanger on a rod.
HANGER FOR ARTICLES OF CLOTHING OR THE LIKE BACKGROUND OF THE INVENTION The present invention relates to improvements in hangers for articles of clothing or the like, particularly to hangers which can be used to suspend trousers, slacks, skirts or like articles of clothing, wherein two relatively movable parts can be introduced into an opening of the article to thereupon engage from within the waistband or the cuff and to maintain the thus engaged part under at least some tension.
It is already known to provide a hanger for slacks or skirts with a pair of arms which are movable relative to each other and are biased to their article-engaging positions by a helical spring which is outwardly adjacent to the arms. As a rule. the arms are provided with projections each of which is attached to one end convolution of the spring. A drawback of such hangers is that the metallic spring can come into contact with the articles of clothing so that the articles are likely to be soiled if the spring becomes rusty when the hanger is used in moist climates. Moreover, the spring is rather large and thus contributes to the bulk of the hanger; this is undesirable when the hanger is intended to be taken along on trips and must be stored in a small area when not in use. Furthermore, since the spring is located externally of the arms, it is likely to be damaged by a clumsy user. Finally, the mounting of the spring also presents certain problems.
SUMMARY OF THE INVENTION An object of the invention is to provide a simple, compact and versatile hanger for articles of clothing or the like.
Another object of the invention is to provide an improved hanger of the type wherein two relatively movable article-engaging arms are connected to each other by resilient means and to construct the hanger in such a way that the resilient means is held out of contact with articles of clothing and is therefore less likely to soil the clothing or to be damaged during storage.
A further object of the invention is to provide a collapsible or contractable clothes hanger which can be manipulated by one hand and which can be used for proper suspension of a variety of articles of clothing, particularly skirts and trousers.
An additional object of the invention is to provide a hanger wherein the biasing means for the relatively movable parts can be readily removed, inspected or replaced.
Still another object of the invention is to provide a hanger which can be used to suspend articles of clothing on nails, hooks or rods and which can support garments without slippage.
The hanger of my invention comprises a pair of arms which are movable lengthwise in substantial parallelism with each other between article-engaging and article-releasing positions and are provided with elongated slots and guide pins each extending into and slidable in the slot of the other arm to guide the arms during movement between the two positions, and biasing means for urging the arms-to their article-engaging positions. Such biasing means includes a springy element (e.g., an elastic band of finite length, an endless elastic band or a helical spring) which is connected to the guide pins. At least one of the arms defines a chamber which accommodates the springy element to further reduce the likelihood of contact between such element and the suspended article.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved hanger itself, however, both as to its construction and the mode of utilizing the same, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of a clothes hanger which embodies one form of the invention and whose arms are shown in fully extended positions;
FIG. 2 is an end elevational view of the hanger as seen in the direction of arrows from the line IIII of FIG. 1;
FIG. 3 is an enlarged transverse vertical sectional view as seen in the direction of arrows from the line IIl-III of FIG. 1;
FIG. 4 is an enlarged fragmentary horizontal sectional view as seen in the direction of arrows from the line IVIV of F 10. 1;
FIG. 5 is a similar fragmentary horizontal sectional view of a second hanger;
FIG. 6 is a similar fragmentary horizontal sectional view of a third hanger;
FIG. 7 is a fragmentary side elevational view of a fourth hanger; and
FIG. 8 is an end elevational view of a detail as seen in the direction of arrows from the line VIII-VIII of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 to 4, there is shown a garment hanger 10 which comprises two elongated mirror symmetrical arms 11, 12 which are respectively provided with elongated slots 14, 15 and guide pins 17, 18. As best shown in FIG. 4, each of the guide pins 17, 18 comprises an end portion or head 17a, 18a which is preferably round and whose diameter exceeds the width of the respective slot 14, 15 and a stem 17b, 18b which is integral with the respective arm 11, 12 and extends through the slot 15, 14 of the other arm. The inner side surfaces 20, 21 of the arms 11, 12 abut against and are slidable along each other so that the hanger 10 is held against buckling by such side surfaces and the heads 17, 18a to permit controlled movements of arms 11, 12 between their fully extended (article-engaging) positions (shown in FIG. 4 wherein each of the stems 17a, 18a is received in the inner end portion of the respective slot) and fully collapsed (article-releasing) positions in which the heads 17a, 18a respectively register with the enlarged outer end portions 53, 54 of the slots 15, 14. The end portions 53, 54 are large enough to permit passage of the heads 17a, 18a and to thus permit rapid assembly or dismantling of the hanger 10.
The intermediate positions of the arms ll, 12 are also article-engaging positions if the size of the cufis on a pair of slacks (or the size of the waistband on a skirt) is such that the cuffs do not permit movement of arms 11, 12 to their fully extended positions.
An intermediate portion of each of the arms I l l2 defines a substantially trough-shaped chamber 25, 26 (best shown in FIGS. 3 and 4). These chambers are in at least partial registry with each other in each position of the arms (i.e., the open side of the chamber 25 always overlies at least a portion of the open side of the chamber 26) and the registering portions of the chambers 25, 26 are disposed between the guide pins 17, 18. The chambers 25, 26 accommodate a biasing means including a springy element 50 which operates between the stems 17b, 18b of the guide pins and tends to move the guide pins toward each other, i.e., to move the arms 11, 12 to their fully extended positions shown in FIG. 4. In the embodiment of FIGS. 1 to 4, the springy element 50is an endless band of natural or synthetic rubber which is simply trained over the stems 17b, 18b and whose length is selected in such a way that it is at least slightly stressed in fully extended positions of the arms. The band 50 is placed around the stems 17b, 18b before the arms are assembled, i.e., before the heads 17a, are respectively caused to pass through the enlarged end portions 53, 54 of the slots 15, 14. The band 50 thereupon automatically moves the guide pins 17, 18 toward the positions shown in FIG. 4. When the arms 11, 12 are assembled, the band 50 extends at an angle from the chamber 25 into the chamber 26 as shown in FIG. 4. In this way, the band is held away from contact with suspended articles of clothing and is less likely to be damaged when the hanger 10 is not in use. The band 50 never leaves the chambers 25, 26 but portions thereof can be observed through the slots 14, 15 if the anns 11, 12 are moved away from their fully extended positions. Thus, and referring to FIG. 1, portions of the band 50 will be seen through those portions of the slots 14, 15 which will be located between the guide pins 17, 18. The slots 14, 15 are provided in those portions of the arms 1 I, 12 which define the chambers 25, 26.
The outer ends of the arms 11, 12 carry downwardly extending forked article-engaging portions 30, 31 (see FIGS. 1 and 2) each having two preferably parallel prongs 33, 34 whose outer faces are knurled, serrated or otherwise roughened, as at 35, 36, to prevent slippage of suspended articles. It is clear that one of the prongs 33, 34 can be omitted, for example, if the hanger is used to engage from within the waistband of a skirt or the waistband of a pair of slacks. The distance between the profiled faces 35, 36 on the portion 30 and the profiled faces on the portion 31 in fully extended positions of the anns 11, 12 determines the number of uses to which the hanger can be put. If the maximum distance is about 10 inches, the hanger will be used mainly for engagement with the cuffs of legs on trousers or the like. If the maximum distance is greater, the hanger can be used to engage from within the waistbands of slacks or skirts. Since each of the portions 30, 31 comprises two prongs 33, 34, one prong of each of these portions can be introduced into the open lower end of one leg of a pair of slacks so that the hanger can properly engage and stretch both legs.
The upper sides of the arms 11 12 are respectively provided with upwardly extending hook-shaped projections 37, 38 which can be engaged by two fingers (e.g., with the thumb and middle finger) of a single hand to facilitate movement of arms 11, 12 to their retracted or article-releasing positions while the other hand manipulates the legs of a pair of slacks which are to be suspended on the end portions 30, 31.
Furthermore, the arms l1, 12 are provided with female coupling portions 40, 41 which are preferably (but not necessarily) integral with the projections 37, 38 and serve to permit attachment of the end portions 42, 43 of a deformable suspending member 47 carrying in its central portion a bearing eye 48 for a tumable hook 49. The end portions 42, 43 comprise pairs of spaced flanges connected by transversely extending shafts 44, 45 which can be separably engaged with the female coupling portions 40, 41, preferably by snap action. The major part of the suspending member 47 is a rod of transparent or opaque synthetic plastic material which is deformable and can be at least slightly elastic to enhance the action of the springy band 50, i.e., to assist the latter in biasing the arms 11, 12 to their fully extended positions. When the projections 37, 38 are moved by hand toward each other to stress the band 50, the rod of the suspending member 47 buckles and moves the hook 49 upwardly and away from the arms.
All components of the hanger 10 preferably consist of lightweight synthetic plastic material which can be washed in water and which can be furnished in one or more colors.
FIG. 5 illustrates a portion of a second hanger whose arms 11, 12 are identical with the arms of the hanger 10. However, the springy band 50 is replaced with a helical spring 55 of steel or other suitable metallic material. The end convolutions 56, 57 of the spring 55 are suitably deformed to form hooks or eyelets which are coupled to the stems of the adjacent guide pins. Since the spring 55 is fully accommodated in the chambers 25,26 of the arms 11, 12, it cannot contact the suspended articles of clothing so that the hanger can be used in climates where the spring is likely to become corroded on prolonged contact with moist air. Also, the spring 55 need not be made of high-quality metallic material because it is invariably held away from contact with suspended articles.
Referring to FIG. 6, there is shown a portion of a hanger 60 having arms 61, 62 which are not mirror symmetrical to each other. The arm 61 is substantially flat and a portion thereof constitutes a cover for the open side of a chamber 73 which is defined by a portion of the arm 62. The guide pins of the arms 61, 62 are respectively shown at 63, 64; the stems of these pins have diametral slots 65, 66 for the end portions of an elastic band 69 of finite length. The outer ends of the band 69 are provided with knots or other enlargements, as at 70, 71, to prevent separation from the respective stems. Of course, the
band 69 can be replaced with an endless band which is flattened and whose ends are thereupon caused to pass through the slots 65, 66 to receive rivets, short studs or the like which prevent withdrawal from the respective slots. The entire band 69 is fully accommodated in the chamber 73 in each position of the arms 61, 62. It is further clear that the band 69 can be replaced with a helical spring or with an endless band which is mounted on the stems of guide pins 63, 64 in the same way as shown for the band 50 of FIG. 4. The hanger 10 of FIGS. 1-4 is preferred at this time because its arms 11, 12 can be produced in a single mold.
An important advantage of such mounting of the springy elements 50, 55, 69 that they are disposed between the arms and are received in the chamber or chambers defined by one or both arms is that the overall dimensions of the hanger can be reduced well below the dimensions of hangers with externally mounted springy elements, and also that such elements cannot contact the suspended articles of clothing. The force with which the arms are biased toward their fully extended positions depends on the dimensions and other characteristics of the respective springy element and, if desired, such force can be changed by the user who can readily replace the endless band 50 of FIG. 4 with a stronger or weaker band or the helical spring 55 of FIG. 5 with a stronger or weaker spring. An advantage of bands 50, 69 is that they can be produced at a minimal cost. The spring 55 of FIG. 5 is normally capable of furnishing a stronger force.
It is also within the purview of my invention to mount the springy element, particularly the band 50 or 69, externally of the anns, for example, at the outer side of the arm 61 shown in FIG. 5. The guide pin 163 is then provided with an extension which projects beyond the outer side of the arm 61 and the guide pin 64 is made longer so that the band 50 or 69 can be attached to the pin 64 and to the extension of pin 63 at the outer side of the arm 61. However, the hangers shown in FIGS. 1 to 6 are preferred at this time because the springy elements are properly protected and are held out of contact with the suspended articles. Also, the illustrated constructions are more compact.
FIGS. 7 and 8 illustrate a portion of a further hanger having two arms one of which is shown at and comprises a coupling portion or eye 82 having a hole 83 for one end portion 85 of a flexible suspending member 84, e.g., a cord, a piece of wire, a length of cable or the like. The end portion 85 is looped and secured at 85a to prevent detachment from the coupling portion 82. In this embodiment of my invenh'on, the coupling portion 82 is remote from the projection 81 which corresponds to one of the projections 37, 38 shown in FIG. 1. The other end portion 87 of the suspending member 84 is similar to the end portion 42 or 43 shown in FIG. 1', it comprises two substantially parallel disk-shaped flanges 88, 89 (FIG. 8) connected by a shaft 90 which can enter a notch of the coupling portion on the other arm of the hanger substantially in the same way as shown for the end portion for the end portion 42 or 43 and coupling portion 40 or 41 of FIG. I. The suspending member 84 of FIG. 7 can be used to facilitate suspension of the hanger on a hook, nail, bolt or a like pro jeetion. Of course, the central portion of the suspending member 84 may also carry a hook, such as the hook 49 of FIG. 1. It is further clear that the suspending member 47 or 84 can be replaced with a rigid member one end of which is fixed to one of the arms and the other end of which is slidably guided in or on the other arm of the hanger. Moreover, the end portion 87 shown in FIGS. 7 and 8 can be omitted if the other end of the suspending member 84 is also provided with a loop 85 which is secured to an eye on the other arm of the hanger.
An advantage of the flanger 88, 89 shown in FIG. 8 is that they can flank the complementary coupling portion of the adjacent arm (such as the coupling portion 40 or 41 of FIG) and thus stabilize the connection between the arm and the suspending member. This is more important when the suspending member is relatively stiff. The cord 84 is collapsible, on purpose, i.e., it is made of readily deformable material so that it occupies little room in storage and is capable of being properly suspended on a hook, nail or the like. Thus, the suspending member 84 is normally not intended to assist the springy element to move the arms of the hanger to their fully extended positions. The hanger which embodies the features shown in FIGS. 7 and 8 is particularly suited for use by tourists or other persons who must store their belongings in a suitcase or the like. The coupling portions are preferably located in the general planes of the respective arms to further enhance the compactness of the hanger.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
1. A hanger for articles of clothing or the like comprising a pair of arms movable lengthwise in substantial parallelism with each other between article-engaging and article-releasing positions, each of said arms having an elongated slot extending in longitudinal direction of the arm and having at the outer end thereof a width greater than the remainder of said slot, and a guide pine integral with respective arm, each of said guide pins having a stem extending through the slot of the other arm and being slidably guided therein and an outer end portion of a dimension greater than the width of the remainder of the slot of the other arm but smaller than that of the end portion thereof so that the pin of one arm may be introduced into and removed from the slot in the other arm when the pin of one arm is aligned with said outer end portion of the slot in the other arm; biasing means for urging said arms to said article-engaging position and including a springy element having portions attached to said pins; an elongated deformable suspension member attached at opposite ends thereof to said arms; cooperating coupling means on at least one arm and on one of said ends of said suspension member for releasably coupling said one end to said one arm; and a hook attached to said suspension member intermediate the ends of the latter.
2. A hanger as defined in claim 1 wherein said springy element consists of rubber.
3. A hanger as defined in claim 2, wherein said springy element is a band.
4. A hanger as defined in claim 2, wherein said springy element is an endless band.
5. A hanger as defined in claim 1, wherein said springy element is a helical spring.
6. A hanger as defined in claim 1, wherein said springy element is disposed between said arms.
7. A hanger as defined in claim 6, wherein one of said arms include a chamber formed therein which accommodates said springy element.
8. A hanger as defined in claim 6, wherein said arms together define chamber means which accommodates said springy element.
9. A hanger as defined in claim 1, wherein at least one of said arms includes a first portion which includes an open-sided chamber formed therein and the other of said arms includes a second portion overlying the open side of said chamber, said springy element being accommodated in said chamber and said slots being provided in said portions of the respective arms.
10. A hanger as defined in claim 1, wherein each of said arms comprises a projection and wherein said projections are engageable by the fingers of one hand to facilitate movement of said arms to said article-releasing positions against the opposition of said springy element.
11. A hanger as defined in claim 10, wherein said arms have upper sides and said projections extend upwardly from said up er sides thereof. I
2. A hanger as defined in claim 1, said coupling means being provided on each of said arms and said deformable suspending member having end portions attached to said coupling means.
13. A hanger as defined in claim 12, wherein each of said arms further comprises a projection which is integral with the respective coupling means, said projections being engageable by the fingers of one hand to facilitate movement of said arms to said article-releasing positions against the opposition of said springy element.
14. A hanger as defined in claim 12, wherein said suspending member is a cord.
15. A hanger as defined in claim 12, wherein said suspending member comprises a rod consisting of synthetic plastic material.
16. A hanger as defined in claim 12, further comprising a hook connected to said suspending member.
1. A hanger for articles of clothing or the like comprising a pair of arms movable lengthwise in substantial parallelism with each other between article-engaging and article-releasing positions, each of said arms having an elongated slot extending in longitudinal direction of the arm and having at the outer end thereof a width greater than the remainder of said slot, and a guide pine integral with respective arm, each of said guide pins having a stem extending through the slot of the other arm and being slidably guided therein and an outer end portion of a dimension greater than the width of the rEmainder of the slot of the other arm but smaller than that of the end portion thereof so that the pin of one arm may be introduced into and removed from the slot in the other arm when the pin of one arm is aligned with said outer end portion of the slot in the other arm; biasing means for urging said arms to said article-engaging position and including a springy element having portions attached to said pins; an elongated deformable suspension member attached at opposite ends thereof to said arms; cooperating coupling means on at least one arm and on one of said ends of said suspension member for releasably coupling said one end to said one arm; and a hook attached to said suspension member intermediate the ends of the latter.
2. A hanger as defined in claim 1 wherein said springy element consists of rubber.
3. A hanger as defined in claim 2, wherein said springy element is a band.
4. A hanger as defined in claim 2, wherein said springy element is an endless band.
5. A hanger as defined in claim 1, wherein said springy element is a helical spring.
6. A hanger as defined in claim 1, wherein said springy element is disposed between said arms.
7. A hanger as defined in claim 6, wherein one of said arms include a chamber formed therein which accommodates said springy element.
8. A hanger as defined in claim 6, wherein said arms together define chamber means which accommodates said springy element.
9. A hanger as defined in claim 1, wherein at least one of said arms includes a first portion which includes an open-sided chamber formed therein and the other of said arms includes a second portion overlying the open side of said chamber, said springy element being accommodated in said chamber and said slots being provided in said portions of the respective arms.
10. A hanger as defined in claim 1, wherein each of said arms comprises a projection and wherein said projections are engageable by the fingers of one hand to facilitate movement of said arms to said article-releasing positions against the opposition of said springy element.
11. A hanger as defined in claim 10, wherein said arms have upper sides and said projections extend upwardly from said upper sides thereof.
12. A hanger as defined in claim 1, said coupling means being provided on each of said arms and said deformable suspending member having end portions attached to said coupling means.
13. A hanger as defined in claim 12, wherein each of said arms further comprises a projection which is integral with the respective coupling means, said projections being engageable by the fingers of one hand to facilitate movement of said arms to said article-releasing positions against the opposition of said springy element.
14. A hanger as defined in claim 12, wherein said suspending member is a cord.
15. A hanger as defined in claim 12, wherein said suspending member comprises a rod consisting of synthetic plastic material.
16. A hanger as defined in claim 12, further comprising a hook connected to said suspending member.
| 1970-02-13 | en | 1972-01-04 |
US-18372188-A | Polyimide resins
ABSTRACT
A method for the preparation of a polyimide containing reversible crosslinks comprising the step of curing a monomer having the formula ##STR1## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms under conditions conducive to the formation of a polyimide and thereby forming a polyimide having the formula ##STR2## R and R' are as defined above and n is an integer from 10 to 100. The polyimide may be converted to a soluble polymer by cleaving the disulfide bond in the presence of a solvent and a reducing agent. The reduced polymer may be reformed into the polymer in an oxidation step or into a modified polyimide in other reaction steps. Copolymerization processes are also disclosed.
The invention described herein was made with the support of the Federal Government and the Federal Government has certain rights in the invention.
FIELD OF THE INVENTION
The invention relates broadly to polyimide resins. More specifically, the invention relates to thermosetting polyimides containing disulfide bonds. The insoluble, infusible polymers can be converted to soluble and therefore recoverable polyimide materials without degradation by methods of the invention and can thereafter be reformed, modified to improve their properties, and cured to form new polymers. The invention relates to methods for homopolymerizing and copolymerizing disulfide-containing bismaleimides, to the polymer and copolymer structures obtained, to methods for preparing condensation polyimides from disulfide-containing aromatic diamines with dianhydrides of tetracarboxylic acids or their derivatives, to methods for converting such polymers to soluble forms, to methods for reforming the insoluble polymers, to methods for modifying the soluble form of the thermoset polymers, and to the products themselves.
BACKGROUND OF THE INVENTION
Bismaleimide polymers are a recently developed class of polymeric materials that have grown in importance as high strength materials that can perform at high temperatures. Polyimides prepared from bismaleimides are distinguished from other polyimides by their ease of processing, a function of their fully imidized form.
Bismaleimides are prepared by the condensation reaction of a diamine, e.g., methylenedianiline, with maleic anhydride and subsequent imide formation (cyclization). The condensation product tends to be crystalline and has a high melting point. While eutectic blends of different bismaleimides may be used to reduce the melting point of the polyimides formed from them, generally coreactants may be used to make bismaleimides processible, and to obtain the desired properties in the cured resins.
Bismaleimides are reactive because of the double bond on each end of the molecule. They can therefore react with themselves or with other compounds containing functional groups. Coreactants typically improve bismaleimide strength and toughness, and the ease of processing. When amines or other nucleophiles are used to co-cure a bismaleimide, the copolymer is less brittle than the homopolymer.
Bismaleimides are typically cured at temperatures of from 200° C. to 350° C. for 1 to 4 hours. Curing may be followed by a postcure step at about 350° C. for 4 hours, to fully develop their properties. The glass transition temperatures of the polymers usually exceed 300° C. The polymers may be used at temperatures exceeding 350° C.
The monomers from which the bismaleimide polymers are obtained are those, for example, taught in U.S Pat. No. 3,297, 713 to Ladd. That patent discloses the preparation of symmetrical dithiobis (N-phenylmaleimides).
U.S Pat. No. 4,323,662 to Oba et al. discloses a broad range of bismaleimide-containing polymers and methods for forming those polymers.
While polyimide resins have been prepared by prior art methods and have demonstrated satisfactory properties for their intended uses, attempts to reuse the resins have not been successful. The cured polymers are generally insoluble, infusible, and not in any sense recoverable or modifiable. The art has heretofore failed to provide any method for reversibly crosslinking polyimide resins. Practically speaking, commercial polyimide resins cannot be recovered and the constituents thereof cannot be reused in new or modified resin structures.
OBJECTS OF THE INVENTION
It is the primary object of this invention to provide methods for the preparation of polyimides containing reversible chemical bonds in the structure.
It is another primary objective of this invention to provide polyimide resins having reversible crosslinks such that the polyimides can be efficiently solubilized and the oligomeric and polymeric constituents thereof recovered.
It is a related purpose of this invention to provide thermoset polyimide resins which are recoverable through solubilization, and which have satisfactory physical and chemical properties in comparison with nonrecoverable known polyimide structures.
It is still a further object of this invention to provide methods for solubilizing the polyimides, to prepare the soluble form thereof, and to provide methods for reforming the solubilized material into a crosslinked material.
It is still a further and related object of this invention to provide methods for solubilizing polyimides and then modifying the solubilized form to prepare novel modified polymers of desirable properties.
SUMMARY OF THE INVENTION
These and other objects of the invention are achieved in methods for the preparation of polyimides containing reversible crosslinks which comprise the step of curing a monomer having the formula ##STR3## wherein R and R' may be the same or different and each is H or lower alkyl having 1 to 5 carbon atoms under conditions conducive to the formation of a polyimide and thereby forming the polyimide having the formula ##STR4## wherein R and R' are as defined above and n is an integer from 10 to 100. The invention also provides methods for polymerizing comonomers with the bismaleimides to form copolyimides.
The polyimides and copolyimides can be solubilized by cleaving the disulfide bond in the polyimide or copolyimide by reducing the polyimide in the presence of a solvent and a reducing agent and thereby producing a new soluble polymer. The soluble polymer may, in turn, be reformed into a new insoluble polyimide by oxidation or by reaction with polyfunctional reagents.
The invention affords heretofore unachievable flexibility in the reuse of insoluble, infusible polyimide structures in that these structures can be solubilized and then reformed, or, alternatively, the solubilized form can be modified by reaction with, e.g., bifunctional alkylating agents, to form different classes of polyimides.
The invention also relates to methods for the preparation of polyimides containing reversible crosslinks which comprise the step of curing a monomer having the formula ##STR5## wherein R and R' may be the same or different and each is H or lower alkyl having 1 to 5 carbon atoms with a comonomer compound or derivative of such compound having the formula ##STR6## wherein Ar is a tetravalent aromatic radical under conditions conducive to the formation of a polyimide and thereby forming a polyimide having the formula ##STR7## wherein R and R' are as defined above and n is an integer from 10 to 100.
The invention also relates to the polyimides thus formed, to methods for solubilizing such polyimides, reforming them by oxidation, and modifying them, as well as to the soluble forms prepared during these steps.
The invention also relates to the preparation of polyimides containing reversible bonds by condensing the bismaleimide monomers described above with dienes in a polymerization step, and to the solubilization, reformation, and modification steps as briefly described above.
The invention also includes methods for forming disulfide-containing polyimides by Michael addition reactions in which the disulfide-containing bismaleimides (I) are reacted with Michael addition comonomers, and to the copolyimides, methods for reduction, oxidation, and modification as described.
The invention also is directed to methods for the preparation of polyimides having reversible bonds by reacting disulfide-containing bismaleimides, e.g., formula I, with aromatic or aliphatic dihydrazides.
The invention permits heretofore unobtained level of flexibility in adapting polyimides for different uses and applications. For example, siloxane-modified polyimides which have recently been developed as coatings in microelectronic applications and as high temperature adhesives can be prepared according to the invention. The siloxane-modified disulfide-containing polyimides can be removed from the device or product containing them by the solubilization reactions described. Where coatings are made of siloxane-modified polyimides, the substrate materials can be reprocessed for repair of costly devices without entailing major processing steps.
In general, the polyimides of the invention can be reused and the relatively costly materials in the polyimide structures can be reapplied several times for different purposes. This recycle capability has major economic consequences.
The ability to modify the soluble form of the polymer lends still further flexibility to the use of polyimides.
In still a further embodiment of the invention, inherently photosensitive polyimides can be obtained from ortho-alkyl substituted disulfide-containing monomers.
DETAILED DESCRIPTION OF THE INVENTION
The invention is in a method for the preparation of polyimide polymers containing reversible disulfide crosslinks and comprises the step of curing a monomer having the formula ##STR8## wherein R and R' may be the same or different, and each is H or lower alkyl having 1 to 5 carbon atoms under conditions conducive to the formation of a polyimide and thereby forming a polyimide homopolymer having the formula ##STR9## wherein R and R' are as defined above, and n is an integer from 10 to 100. Typically, the curing is carried out at 200° C. to 350° C. Among the preferred polyimides formed according to the invention are those wherein R and R' are both H. Other preferred polyimides are those wherein R and R' are --CH3, --C2 H5, and --C3 H7, and are each ortho to the nitrogen atom.
The polyimides may be converted to a soluble polymeric form by cleaving the disulfide bond in the polyimide by reducing it in the presence of a solvent, typically an inert ethereal solvent such as diglyme, dioxane, triglyme, or tetrahydrofuran, and a reducing agent, typically selected from the group consisting of tributylphosphine, sodium borohydride, triphenylphosphine, and alkali metal hydrides and thereby producing a soluble polymer having the formula ##STR10##
The soluble form may be reformed into a polyimide having the formula II by oxidizing the soluble polymer to reform the polyimide. The oxidizing agent is typically selected from the group consisting of iodine, air, and hydrogen peroxide.
It is envisioned that it may be of significant value to solubilize the polyimides of the invention and thereafter reform them in order to recover or reprocess the resins. Alternatively, the soluble polymer, i.e., formula III, can be modified by reacting it with a bifunctional alkylating agent selected from the group consisting of aliphatic or aromatic dihalides, -diepoxides, and aromatic bismaleimides. Among the preferred bifunctional alkylating agents are dibromobutane and xylylene dibromides.
The invention also relates to methods for the preparation of polyimide copolymers containing reversible bonds which comprise the step of curing a monomer having the formula I, wherein R and R' may be the same or different and each is H or lower alkyl having 1 to 5 carbon atoms together with a comonomer of the formula ##STR11## or a comonomer of the formula ##STR12## wherein X is a divalent alipahtic, aromatic, or alkyl aromatic radical of 6 to 25 carbon atoms under conditions conducive to the formation of a copolyimide having the formula ##STR13## The copolyimides having formulae V-A and V-B may be solubilized by cleaving the disulfide bonds therein by reducing the copolyimides in the presence of a solvent and a reducing agent and thereby producing a soluble polymer having the formula ##STR14## The methods for reducing the copolymers are substantially the same as described above for the bismaleimide homopolymers.
The solubilized polymer may be reformed by oxidation, as described above for the homopolymer, or the solubilized polymer may be modified as described above by reaction with a bifunctional alkylating agent as described above with respect to the copolymers.
The invention is also in methods for the preparation of disulfide-containing, recoverable condensation polyimides by reacting diamines, e.g., symmetrical, aromatic diamines of the formula ##STR15## in condensation reactions with comonomers having the formula ##STR16## wherein Ar is a tetravalent aromatic radical under conditions conducive to the formation of a polyimide and thereby forming a polyimide having the formula ##STR17## wherein R and R' are as defined and n is an integer from 10 to 100. The cocondensation comonomer may advantageously be a dianhydride of tetracarboxylic acid, or an appropriate derivative thereof. The curing step is typically carried out at 150° to 350° C. after formation of the polyamic acid to obtain a fully imidized condensation polyimide. Solubilization, reformation, and modification steps may be carried out as described above.
The useful polyimides having reversible crosslinks can also be obtained by reacting bismaleimides having formula I together with dienes through intermolecular Diels Alder polymerization reactions, as shown, for example, in U.S. Pat. No. 4,656,235 for siloxane-containing bisfurans. Bismaleimides having formula I are reacted with stoichiometric amounts of a diene having the formula ##STR18## wherein Y is an aliphatic or aralkyl hydrocarbon radical of 3 to 10 carbon atoms (e.g., p-xylelene) or ##STR19## A is a divalent alkyl or aryl radical having 3 to 6 carbon atoms, and m is an integer from 1 to 10, under conditions conducive to the formation of a polyimide and thereby forming a polyimide having the formula ##STR20##
The reduction, reformation, and modification steps are as described above.
Useful disulfide-containing polyimides may also be obtained to meet specific requirements by Michael-type addition reactions of bismaleimides of formula I with compounds of the formula
HX--Q--XH
wherein Q is an alkyl, aryl, or aralykyl radical having 6 to carbon atoms, or ##STR21## where A is a divalent alkyl or aryl radical having 3 to 6 carbon atoms and m is an integer from 1 to 10 and X is --N, --O, or --S, under conditions conducive to the formation of a polyimide and thereby forming a polyimide having the formula ##STR22## A preferred compound of the formula HX--Q--XH is bisphenol A having the formula ##STR23## The resulting poly(imido-ethers) may have particularly desirable properties for thermally stable engineering resins.
Still further Michael addition reactions may be used to prepare novel disulfide-containing polyimides from known and available bismaleimides by reacting the latter with disulfide-containing dihydrazides. The dihydrazides may be aliphatic or aromatic and have the formula
H.sub.2 NHNCO--X--CONHNH.sub.2
wherein X is a divalent aliphatic, aromatic, or alkyl aromatic radical of 6 to 25 carbon atoms. The polyimides may be solubilized, reformed, or modified according to methods described above.
The disulfide-containing polyimides of the invention may be designed for multiple uses and applications. For example, siloxane-modified polyimides have been recently developed as coatings for microelectronic components and as high temperature adhesives. Siloxane-modified disulfide-containing polyimides of the invention could be removed from such microelectronic components by reduction reactions and efficient processes. This may facilitate the reprocessing and repair of costly electronic devices. In still other polymer systems, e.g., composites and laminates, where polyimides are used, application of the invention may permit solubilization and recovery of valuable and costly materials in efficient processes. The recoverable polyimides of the invention are of primary importance in the effort to solve the problems of recycling polymeric materials and particularly thermosets.
The invention also provides great flexibility in modifying the polyimides after they are solubilized. The soluble polymers may be crosslinked anew by oxidation of the thiol groups formed. By reacting the thiol groups with compounds selected for specific structural reasons, it is possible to obtain valuable new polyimide structures. For example, reactive polyfunctional compounds for forming stable covalent bonds, e.g., dihalides, bismaleimides, etc., may be employed and other components may be used to produce specific functional groups. Modifiers for increasing the solubility, plasticization, compatibility and other functions of the solubilized recured resin may also be used.
In an important embodiment, the invention is valuable for the production of inherently photosensitive polyimides, for example, those obtained from ortho-alkyl substituted monomers of formula VII. Such compounds have the formula ##STR24## wherein R and R' are alkyl groups such as methyl, ethyl, and isopropyl. The compounds of formula VII-A are reacted with benzophenone tetracarboxylic dianhydride (BTDA) or other compounds containing an aromatic keto group to form photosensitive polyimides having the formula ##STR25##
Photosensitive polyimides may also be obtained by reacting ortho-alkyl substituted bismaleimides of formula I, i.e., compounds having the formula ##STR26## with a comonomer in which an aromatic keto group is present.
An important advantage of the invention is the ability to produce a highly desirable class of photosensitive polyimides, namely, positive working polyimide photoresists. These may be prepared by reaction of the reduced thiol-containing polyimide with dihalo-aromatic hydrocarbon (e.g., diiodobenzene, dibromobenzene, 4-iodophenylether, 4-bromophenyl ether) to yield phenylene sulfide moieties which can subsequently be converted to triaryl sulfonium salt groups. Polyimides of this structure can undergo photoinduced main chain cleavage using UV irradiation and are candidates for positive working, high temperature photoresist materials.
An example of such a reaction is shown below where equation (1) schematically represents the reduction of a disulfide-containing segment in a polyimide prepared from dithiodianiline by condensation with a tetracarboxylic acid dianhydride or from the bismaleimide of dithiodianiline (DTDA) by thermal curing.
The reduced, soluble, mercaptan-containing polymer produced by reaction (1) can be converted to the aryl sulfide-containing polymer shown as the product of equation (2), where the mercapto groups are reacted with a dihalobenzene (XC6 H4 X), by known procedures. The photochemical reaction of dihalobenzene in liquid ammonia is a preferred method because it does not require elevated temperature or severe conditions, and it has been shown to yield disubstitution products in high yield (J. F. Bunnett and X. Creary, J. Org. Chem. 39, 3173; 3611 (1974)). The aryl sulfide-containing polyimide obtained by the reaction shown in equation (2) can be converted to the triarylsulfonium salt by arylation, for example with diphenyliodonium hexafluorophosphate or with diphenyliodonium hexafluoroarsenate as shown in equation (3). The desired level of arylation of the sulfur-containing polyimide may be attained by adjusting the stoichiometry (J. V. Crivello et al., Journal of Polymer Science (Chemistry edition) 25:3293 (1987)), and the optimal photoresponse of the arylated polymer can then be determined. ##STR27## Equation (1): Reduction Equation (2): Thioether formation ##STR28## Equation (3): Triphenylsulfonium salt
[(C.sub.6 H.sub.5).sub.2 I.sup.30 AsF.sub.6.sup.- Cu(OB.sub.z).sub.2 ]
(Ref.--J. V. Crivello et al., J. Polymer Sci (Chemistry) 25:3293-3309 (1987).
EXAMPLES
Materials and Methods
Dithiodianiline (DTDA) and methylene dianiline (MDA) were recrystallized from methanol/water. Methylene dianiline bismaleimide (MDABM), tri n-butyl phosphine (Bu3 P), triethylamine (TEA), diglyme, dry N, N-dimethyl acetamide (DMAc), dry N, N-dimethyl formamide (DMF)--all (Aldrich)--were used as received. Benzophenone tetracarboxylic acid dianhydride (BTDA)--Aldrich--was recrystallized from acetic anhydride.
The following abbreviations are used throughout the discussion.
DTDA 4,4'-dithiodianiline
DTDABM 4,4'-dithiodianiline bismaleimide
MDA methylene dianiline
MDABM methylene dianiline bismaleimide
BTDA 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride
DMF N,N-dimethyl formamide
DMAc N,N-dimethyl acetamide
THF tetrahydrofuran
DSC differential scanning calorimetry
TGA thermogravimetric analysis
GPC gel permeation chromatography
EXAMPLE I
Cure, Reduction, and Reoxidation of Homopolymer from Dithiodianiline Bismaleimide (DTDABM)
Synthesis of 4,4'-dithiodianiline (DTDA) bismaleimide
3.355 g of DTDA was dissolved in 10 ml dry dimethylacetamide (DMAc) and added under nitrogen, via a dropping funnel, to 2.649 g of maleic anhydride dissolved in 10 ml dry DMAc, with constant stirring. The solution was stirred for 2 hrs. and poured into water. The yellow precipitate was filtered and dried in a vacuum oven to give 6.002 g (99.9%) of crude amic acid.
To 4.287 g of the amic acid was added 1 g fused sodium acetate and 10 ml acetic anhydride. The solution was stirred under nitrogen in an oil bath kept at 85°±3° C. for 4 hrs. The solution was then cooled and poured into water. The bright yellow solid was filtered, washed with dilute sodium bicarbonate, water, and methanol, and dried to give 3.885 g (98.6%) of crude product. Recrystallization from benzene/methanol afforded 3.420 kg (86.8%) of the bismaleimide.
Curing of 4,4'-dithiodianiline (DTDA) bismaleimide
A cure temperature of 240° C. (as determined from DSC) was used. About 2 grams of the bismaleimide (I) was dissolved in minimal DMAc in a Teflon beaker. The beaker was then placed in a vacuum oven at 100° C. to remove the solvent. Once the solvent was removed, the temperature of the oven was raised to 240° C. and kept at this temperature for 4 hrs. The dark red resin (II) was cooled and ground (with liquid N2) to 600 μ size particles (TD =352° C.) : Tg (DSC) 334° C.
Reduction of bismaleimide resin (II)
1.300 g of the resin was transferred to a 50 ml round bottomed flask. 30 ml of diglyme, 10 ml of tributyl phosphine, and 4 drops of water (obtained from 15 ml H2 O containing 2 drops conc. HCl) were then added. The solution was refluxed under nitrogen for 4 hrs. About half the diglyme was then distilled off. The solution remaining was cooled and poured into methanol. The solution was allowed to stand overnight. The methanol was decanted. To the solid left at the bottom, a few drops of water were added to further aggregate the solid, which was then filtered and dried to give 0.812 g of a pink solid. The reduced product is shown schematically in Formula II. It was soluble in organic solvents, demonstrating cleavage of the crosslinked structure.
Reoxidation of soluble polymer
About 0.5 g of the reduced product Formula III was dissolved in 5 ml DMAc. To this solution was added a 10% iodine solution in DMAc, with constant stirring, until a precipitate started forming. The solution was then heated to 60° C., and addition of the iodine solution was continued drop by drop until no more precipitate was visually observed. 10 ml additional DMAc was added to the mixture which was stirred at 60° C. for 1 hr. The solid was filtered, washed with methanol, and dried at 100° C. in a vacuum oven.
TD =372° C. (N2, 20° C./min.)
Tg =329.5° C.
The thermal response of homopolymers prepared from compound I under different conditions of curing is shown in Table 1. The polyimide obtained with a 300° C./N2 /4 hours cure profile gave a 13° C. rise in the onset of decomposition and no difference in the Tg as compared to the 240° C./vac/4 hours cure profile. Curing at 350° C. resulted in higher onset of decomposition temperature and high residue content at 700° C. (Table 2). Reoxidation of reduced polymer from the 300° C.-cured polyimide gave a product with decomposition and glass transition temperatures similar to those of the 240° C.-cured resin (Table 2).
EXAMPLE II
Cure, Reduction and Reoxidation of DTDABM-Methylene Dianiline Bismaleimide (MDABM) at 1:1 Ratio (Copolymer)
Copolymerization
The copolyimide from DTDABM and MDABM in a 1:1 molar ratio was synthesized by weighing appropriate amounts into a teflon beaker and adding minimal DMAc to obtain a clear solution. Two such samples were made. The solvent was removed by placing the beakers in a vacuum oven at 100° C. overnight. One sample was cured at 300° C. for 4 hours in nitrogen, and the second sample was cured at 350° C. for 4 hours in nitrogen. As in the case of hompolymers, curing at 350° C. gave a high residue at 700° C. (Table 2) possibly indicating side reactions during cure. Further reactions described below were carried out on the 300° C.-cured copolyimide (Tg 347.8 by DSC).
Reduction
To 0.5 grams of the copolymer resin in a 35 ml round bottomed flash was added 15 ml DMAc, 4 ml Bu3 P and 3 drops of water (obtained from a stock solution of 15 ml H2 O containing 2 drops conc. HCl). The reaction mixture was refluxed under nitrogen for 48 hours. A small amount of resin was still insoluble. The solution was filtered. The residue was dried and weighed (0.1455 g) giving 29.1% unreduced resin. The filtrate was poured into water and the solid obtained was filtered, dried and weighed (0.3535 g) giving 70.7% reduced, soluble polymer. Thermal properties and --SH content are given in Table 2.
The equimolar ratio of the two bismaleimide monomers does not necessarily yield an ideal alternating copolyimide, and thus MDA/BM blocks devoid of disulfide bonds may not be reduced and remain insoluble.
Reoxidation
0.1 g of the reduced soluble polymer was dissolved in 5 ml DMAc. A 10% iodine solution in DMAc was added dropwise until the color of the iodine persisted. About 10 more drops of the iodine solution was added. The solution was warmed to 60° C. for 15 minutes and allowed to stand at room temperature for 24 hours. The mixture was poured into water and the precipitate filtered and dried. Thermal properties are given in Table 2.
The TD and Tg of the reoxidized copolymer did not reach those of the parent resin as was the case for reoxidized homopolymer from dithiodianiline bismaleimide.
EXAMPLE III
Synthesis, Reduction and Reoxidation of Michael-Addition Type Polyimides
Synthesis of polymer from DTDA/BM and MDA
The procedure of Crivello (J. P. Crivello, Journal of Polymer Science (Chemistry Ed.), 11:1185-1200 (1973)) was followed. To 2.0423 g (5 mmol) of DTDA/BM and 0.9913 g (5 mmol) MDA in a 100 ml round bottomed flash with a magnetic stirrer, was added 15 ml freshly distilled m-cresol and 0.2 ml glacial acetic acid. The flask was immersed in an oil bath at 105°±3° C. and fitted with a reflux condenser. The solution was stirred under nitrogen for 68 hours. The viscosity of the reaction mixture visually increased. The solution was cooled and poured into excess methanol with continuous stirring giving a fibrous polymer. The mixture was filtered and the precipitate washed with methanol. The solid was transferred to a 250 ml beaker and warmed with 50 ml ethanol at 60° C. for 15 minutes. The solution was filtered hot and the precipitate washed with ethanol. The solid was dried, yielding 3.008 g (99%) of greenish-brown polymer. Thermal properties are given in Table 2.
Reduction
To 0.3 g of the polyimide was added 15 ml diglyme, 5 drops diluted HCl (from a stock solution of 15 ml H2 O containing 2 drops conc. HCl) and 2 ml Bu3 P. The solution was refluxed under nitrogen for 2 hours, cooled and poured into water. The yellow solid was filtered and dried to give 0.2782 g reduced polymer. Thermal properties and thiol content are given in Table 2. Thiol content was determined by the method of Bald (E. Bald: Talanta 27:281 (1980)).
Reoxidation
0.2 g of the soluble polymer was dissolved in 5 ml DMAc. A 10% iodine solution in DMAc was added dropwise until the color of the iodine persisted. The solution was warmed to 60° C. and stirred for 15 minutes, then cooled and let stand at room temperature for 24 hours. The solution was poured into excess water and the solid filtered and dried. Thermal properties are given in Table 2.
EXAMPLE IV
Synthesis, Reduction and Reoxidation of Michael-Addition Type Polyimides
Synthesis of polymer from DTDA and MDABM
The procedure for the DTDABM/MDA polymer was followed using 1.2418 g DTDA and 1.7918 g MDABM to give 2.891 (95.3%) of polymer, thermal properties of which are given in Table 2.
Reduction
The procedure was similar to that for the DTDABM/MDA polymer using 0.3 grams of the polymer and a reduction time of 1 hour to give 0.24 g of reduced polymer. Thermal properties and thiol content are given in Table 2.
Reoxidation
The procedure as for the DTDABM/MDA was followed. Table 2, gives thermal properties of the reoxidized polymer.
Decomposition and glass transition temperatures for the addition polyimides (Table 2) were in expected ranges. The polymers were fairly soluble in diglyme. Reduction of the polymers was relatively fast, but reoxidation gave polymers of poor thermal stability--especially in the case of the DTDA/MDABM polymer.
EXAMPLE V
Synthesis, Reduction and Reoxidation of DTDA/BTDA Condensation Polyimide
Synthesis of polymer from DTDA and BTDA
To 2.4837 g. (0.01 mol) DTDA in a 100 ml round bottomed flash was added 20 ml dry DMAc. Once the diamine had dissolved, 3.2223 g (0.01 mol) BTDA was added to the solution. The reaction mixture was stirred under nitrogen for 6 hours, then poured into excess methanol. The solid polyamic acid was filtered and dried in a vacuum oven overnight at 60° C. The bright yellow solid was ground in a blender to 600 micron size particles and cured at 250° C. in vacuum for 5 hours to given an orange colored polyimide. Thermal properties are given in Table 2.
Reduction
To 0.5 g of the polymer was added 3 ml Bu3 P, 15 ml diglyme and 5 drops dil. HCl (from a stock solution of 15 ml H2 O containing 2 drops conc. HCl). The reaction mixture was refluxed under nitrogen for 30 hours until the polymer completely dissolved. The solution was cooled and poured into water. The water was carefully decanted from the orange viscous liquid. The product was washed once more with water, decanting the water, and the viscous liquid was dried under high vacuum for 24 hours at room temperature to give 0.4877 g of the reduced polymer.
Reoxidation
To 0.2 g of the reduced polymer in 5 ml DMAc was added dropwise at 10% iodine solution in DMAc until the iodine color persisted. The solution was warmed to 60° C. for 15 minutes, cooled, and let stand at room temperature for 24 hours. The insoluble precipitate was filtered and dried to give 0.168 g of reoxidized polymer, the thermal properties of which are given in Table 2.
Reduction to complete solubility of the condensation polymer of DTDA and BTDA was possible after 30 hours. The reduced polymer was a viscous liquid. Reoxidation of this liquid gave an insoluble polymer. The onset of decomposition temperature of the reoxidized material (TD =242° C.) was significantly lower than that of the original polyimide (TD =533° C.), as was the glass transition temperature (Tg =178.5° C. reoxidized polymer; Tg =240.2° C.--original polyimide).
TABLE 1
__________________________________________________________________________
THERMAL PROPERTIES OF CURED BISMALEIMIDE RESINS
FROM DTDA/BM AND MDA/BM
CURING 20° C./Min.
DSC (N.sub.2)
CONDITIONS
TGA (N.sub.2)
% Residue
10° C./min.
BISMALEIMIDE
(°C./hrs.)
T.sub.D °C.
at 700° C.
Tg.sup.c
__________________________________________________________________________
DTDA/BM (240/4) vac
345.4 46.6 334
DTDA/BM (300/4) N.sub.2
358.7 42.2 334.1
DTDA/BM (350/4) N.sub.2
547.7 77.5 --
DTDABM/MDABM
(300/4) N.sub.2
425.7 45.9 347.8
(1:1)
DTDABM/MDABM
(350/4) N.sub.2
592.5 81.7 --
(1:1)
__________________________________________________________________________
TABLE 2
__________________________________________________________________________
FULLY CURED POLYMER
REDUCTION
CURING
SH REOXIDATION
CONDITIONS
T.sub.D
T.sub.g
REDUCTION*
T.sub.D
T.sub.D
CONTENT
OXIDATION
T.sub.D
T.sub.g
(°C./hrs.)
°C..sup.a
°C..sup.a
(solvent/hrs.)
°C..sup.a
°C..sup.b
(meq/gm)
CONDITION
°C..sup.a
°C.
__________________________________________________________________________
DTDABM (250/4) vac.
352.4
334
(diglyme/4)
185.9
144.7
3.65 I.sub.2 /DMF
372
329.5
DTDABM' (300/4) N.sub.2
358.7
334.1
(diglyme/4)
182.6
177.5
2.42 I.sub.2 /DMF
373.6
329.5
DTDABM/MDABM
(300/4) N.sub.2
425.7
347.8
(DMAc/48)
291.8
197.8
1.04 I.sub.2 /DMF
242.7
139.0
(1:1) 24 hrs.
DTDABM/MDA (100-110/3)
328.2
266.5
(diglyme/2)
260.8
106.7
1.68 I.sub.2 /DMAc
242.2
146.6
(1:1) m-cresol, AcOH 24 hrs.
DTDA/MDABM (100-110/3)
304.3
246.7
(diglyme/1)
265.1
106.9
1.19 I.sub.2 /DMAc
155.8
128.1
(1:1) n-cresol, AcOh 24 hrs.
DTDA/BTDA (250/5) vac.,
533.9
240.2
(diglyme/30)
-- -- 1.39 I.sub.2 /DMAc
232
178.5
(1:1) amic acid 24 hrs.
__________________________________________________________________________
.sup.a TGA (N.sub.2); 20° C./min.
.sup.b DSC (N.sub.2); 10° C./min.
.sup.c Not reduced to complete solubility
*Bu.sub.3 P/solvent/reflux hrs.
What is claimed is:
1. A method for the conversion to a soluble polymer of a polyimide having the formula ##STR29## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms and n is an integer from 10 to 100, comprising the step of cleaving the disulfide bond in said polyimide by reducing said polyimide in the presence of a solvent and a reducing agent and thereby producing a soluble polymer having the formula ##STR30##
2. A method as recited in claim 1 wherein said reducing agent is selected from the group consisting of tributyl phosphine, triphenyl phosphine, sodium borohydride, and an alkali metal hydride.
3. A method for reforming a polyimide having the formula ##STR31## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms and n is an integer from 10 to 100, from a polymer having the formula ##STR32## comprising the steps of reforming the disulfide bonds by oxidizing the said polymer to reform the said polyimide.
4. A method as recited in claim 2 wherein the oxidizing agent is selected from the group consisting of iodine, air and hydrogen peroxide.
5. A method for reprocessing a polyimide having the formula ##STR33## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms and n is an integer from 10 to 100, and thereafter reforming the said polyimide, comprising the steps of:(a) cleaving the disulfide bonds in said polyimide by reducing said polyimide in the presence of a solvent and a reducing agent and thereby forming a soluble polymer having the formula ##STR34## and (b) reforming the disulfide bonds by oxidizing the cleaved mixture formed in step (a) to reform the said polyimide.
6. A method as recited in claim 5 wherein the reducing agent is selected from the group consisting of tributyl phosphine, triphenyl phosphine, sodium borohydride, and an alkali metal hydride and the oxidizing agent is selected from the group consisting of iodine, air and hydrogen peroxide.
7. A soluble polyimide having the formula ##STR35## 'wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms and n is an integer from 10-100.
8. A soluble polyimide as recited in claim 7 wherein R and R' are H.
9. A method for the conversion to a soluble polymer of a polyimide having the formula ##STR36## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms, n is an integer from 10 to 100, Y is an aliphatic or aralkyl hydrocarbon radical of 3 to 10 carbon atoms or ##STR37## A is a divalent alkyl or aryl radical having 3 to 6 carbon atoms, and m is an integer from 3 to 6, comprising the step of cleaving the disulfide bonds in said copolyimide by reducing said copolyimide in the presence of a solvent and a reducing agent and thereby producing a soluble polymer having the formula ##STR38##
10. A method for reforming a polyimide having the formula ##STR39## wherein R and R1 may be the same or different and each is H or lower alkyl having 1-5 carbon atoms, n is an integer from 10 to 100, Y is an aliphatic or aralkyl hydrocarbon radical of 3 to 10 carbon atoms or ##STR40## A is a divalent alkyl or aryl radical having 3 to 6 carbon atoms, and m is an integer from 3 to 6 from a soluble polymer having the formula ##STR41## comprising the step of reforming the disulfide bonds by oxidizing the said polymer to reform the said polyimide.
11. A method for solubilizing a copolyimide having the formula ##STR42## R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms, n is an integer from 10 to 100, and Y is an aliphatic or aralkyl hydrocarbon radical of 3 to 10 carbon atoms or ##STR43## A is a divalent alkyl or aryl radical having 3 to 6 carbon atoms, and m is an integer from 1 to 10, and thereafter reforming the said polyimide, comprising the steps of(a) cleaving the disulfide bonds in said polyimide by reducing said polyimide in the presence of a solvent and a reducing agent and thereby forming a soluble polymer having the formula ##STR44## and (b) reforming the disulfide bonds by oxidizing the cleaved mixture formed in step (a) to reform said polyimide.
12. A soluble copolyimide having the formula ##STR45## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms, and Y is an aliphatic or aralkyl hydrocarbon radical of 3 to 10 carbon atoms or ##STR46## a is a divalent aryl or alkyl radical having 3 to 6 carbon atoms and n is an integer from 10-100, and m is an integer from 1 to 10.
| 1988-04-20 | en | 1993-11-09 |
US-37258282-A | Registration system for a photocopier
ABSTRACT
The document registration system disclosed is incorporated in a full-frame illumination and imaging system for a photocopier capable of copying at magnification ranging from 1.0× through 0.647×. The registration system combines a non-linear movement of the projection lens in conjunction with the vertical translation of a document platen to maintain proper lens position and document corner registration throughout the magnification range.
The present invention relates to a corner registration system for a full-frame, flash exposure copier and, more particularly, to a drive system which translates a projection lens along a non-linear path during magnification changes so as to maintain proper lens position and document image registration at the image plane.
As demands for faster copying and duplicating have increased, conventional machines which scan documents in incremental fashion to provide a flowing image on a xerographic drum have proved inadequate. New high speed techniques have evolved which utilize flash exposure of an entire document (full-frame exposure) and the arangement of a moving photoconductor in a flat condition at the instant of exposure.
It is desirable for these flash systems that images of documents to be copied be projected onto the same effective image area of the photoconductor regardless of the size of the document or the magnification at which the document image is projected. The present invention is utilized in a system wherein a reference mark is established on the document platen surface so that the same corner of a document, of whatever size, is placed along the reference mark. For magnification changes, a fixed focus wide angle lens is moved with reference to a photoreceptor and the document platen is simultaneously translated to provide proper object-to-image conjugate length. To insure the projection of the images onto the desired image portion of the photoconductor, the projection lens is mounted on a lens carriage to which is imparted linear vertical and non-linear horizontal components of motion. The lens path is in a generally transverse direction and along a path which maintains proper lens position for the particular magnification while aligning the document corner set at the platen reference mark with a desired reference corner on the photoconductor surface.
More particularly, the present invention is directed to a compact, full-frame, corner registered flash illumination and imaging optical system for a photocopier comprising:
a movable platen member for supporting original documents to be copied;
an enclosed housing having a diffuse, highly reflective interior surface, said housing containing therein a wide angle projection lens located below said platen, and flash illumination means for substantially uniformly illuminating the underside of said platen;
means for changing the magnification of said optical system and including a first means for vertically translating said platen member and a second means for translating said projection lens with reference to an imaging plane, said second means including:
a lens carriage assembly having said projected lens mounted thereon;
means for providing a vertical linear component of motion to said carriage assembly;
means for providing a horizontal component of motion to said carriage assembly; and
means for modifying said horizontal component to produce a degree of non-linearity in said horizontal component whereby the sum of said vertical and horizontal components of motion is a non-linear path which causes the lens carriage and hence the projection lens to maintain correct magnification and document registration of the image projected to the imaging plane at any point along said non-linear path.
A better understanding of the present invention can be had with reference to the following description in conjunction with the accompanying drawings wherein:
FIG. 1 is a perspective view of a full-frame illumination and imaging system in a 1× magnification mode.
FIG. 2 is a top view of the assembly of FIG. 1.
FIG. 3 is a left side view of the assembly of FIG. 1.
FIG. 4 is a rear view of the assembly of FIG. 1.
FIG. 5 is a perspective view of the illumination and imaging assembly in a 0.647× magnification mode.
DESCRIPTION
General
Referring now to FIGS. 1 and 2, there is shown a preferred embodiment of a document illumination and imaging system 2 which incorporates the document registration system of the present invention. The system generally comprises a light housing 4 the top surface of which is defined by a transparent platen 6 upon which a document (not shown) is placed. Within housing 4 is a flash lamp 8 connected to a power source (not shown). Wide angle lens 10 is movably mounted within floor 12 of the housing. Drive motor 14 drives main pulley 16 which provides motion to four platen elevation cams 18 through a pulley/cable arrangement described in greater detail below. In a reduction mode of operation, platen 6 is vertically displaced upward while lens 10 is simultaneously translated along a short, non-linear path towards photoreceptor belt 20, a portion of which is shown in FIG. 1.
During a copying mode, lamp 8 is pulsed and the underside of platen 6 is uniformly illuminated. The document image passes through lens 10 shown in the 1× position with the top of the lens approximately flush with housing floor 12. The projected light image discharges the previously charged surface of belt 20 whereby there remains on the surface a latent electrostatic image 22. Assuming the document being copied has an 81/2×11" dimension, the exposed image area will be 81/2×11". The document is corner registered at a platen registration guide mark 24. This registration corner is projected onto belt 20 at point 24A. Belt 20 moves in the indication direction to bring an unexposed portion of the belt into the exposure position. (An exemplary photoreceptor belt for use in the present system is disclosed in U.S. Pat. No. 4,265,990).
It will be appreciated that the document exposure system, as disclosed above, forms part of a series of subsystems which are combined within a signel housing to form the multi-magnification document copying machine. The other machine functions; e.g. charging of the photoreceptor, image development, transfer of developed image, and cleaning of the photoreceptor are well known in the art and hence are not set forth herein.
Light Housing
Referring to FIGS. 1 and 2, housing 4 comprises lower left, right, back and front walls 26, 28, 30 and 32 respectively. Lens 10 is seated in an aperture 34 formed in housing floor 12. The lens is mounted in a lens carriage assembly 40 which has a top surface 42, a portion of which is visible in FIG. 1. When lens 10 is in the 1× position shown, surface 42, and lens 10, are approximately flush with the surface of housing floor 12. Surface 42 has a slot-like aperture 44 formed thereon. Lens 10 is secured within an aperture formed in lens mounting plate 46. Plate 46 is maintained in a sliding, light-tight relationship with the bottom of surface 42. The operation of the various components of the lens carriage assembly are described in greater detail below. These components have been introduced at this point only insofar as they effectively form part of the light housing.
Continuing with the description of the light housing, platen 6 defines the top of the housing. Platen registration guide mark 24 serves to locate a document corner position. Both surfaces of the platen may be coated with an anti-reflective material so as to prevent any platen-derived specular reflection from entering the lens. In a normal copying mode, a platen cover, pivotably attached to the side of the housing, will be lowered to form a nearly light-tight cover over the document. If the platen cover is left open, the operator is protected from flash light by the provision of appropriately shaped translucent blocking elements above and to the sides of the lamp 8. For ease of description, the platen cover and blockers are not shown.
The platen is mounted within aperture 48 formed within aperture frame member 50. Frame member 50 is an integral unit having side walls 52, 54, 56, and 58. Each side wall has a cam follower member 59, each associated with its respective platen elevation cam 18. These side walls are interior to side walls 26, 28, 30 and 32, respectively and effectively comprise extensions of these walls as the platen is translated in a vertical direction, as will be described below. In the 1× position, the visible portion of the side walls 52, 54, 56, 58 form approximately 1/2 of the total interior wall surface.
All the interior surfaces of housing 4 are coated with high (90% minimum) reflectivity material such as celanese polyester thermal setting paint No. 741-13. All interior surfaces including the side walls, floor and all visible portions of lens carriage 40 are coated thusly, thereby making these surfaces diffusely reflective to light impinging therein. When lamp 8 is pulsed and caused to flash, light is directed against these coated surfaces, undergoing one or more reflections and irradiating the underside of the platen with a generally uniform level of illumination. The bottom surface of the platen cover and the white portions of the document also effectively form part of the housing since some light is reflected from their surfaces.
From the above description, housing 4 is seen to function as a highly efficient light integrating cavity which provides a uniform illumination level along the bottom of the document plane. The total cavity gain can be controlled, to some extent by tailoring the reflectivity of the area directly behind the lamp. For example, small strips of a thermally stable material, of variable width and absorptivity can be fastened to the housing wall.
Platen Drive
Referring to FIGS. 1-4, the platen 6 is driven in a vertical direction via reversible drive motor 14 operating under the control of a machine logic control circuit. A first shaft 60 is driven by motor 14 in response to signals from controller 62 (FIG. 3). Controller 62 contains the logic and memory circuits to continually track the instant position of the lens and platen and to provide signals to the motor to drive shaft 60 in a direction and for a duration determined by the specific magnification setting. An exemplary controller circuit for accomplishing this function is disclosed in U.S. Pat. No. 4,316,668.
Shaft 60 drives main drive pulley 16 to which is attached drive cable 66 (FIG. 3). The other end of cable 66 is entrained via idler pulley 67 upon a second take-up pulley 68 which is fixedly attached to shaft 70 and rotates therewith. Shaft 70 has a counter-torsion spring 72 (FIG. 2) attached at one end thereof to provide a tensioning force to drive cable 66. Fixedly attached to each end of drive shafts 60 and 70 are the platen elevation cams 18. In moving from a 1× to a reduction position, pulleys 16 and 68 rotate in opposite directions (as shown in FIG. 3), the cams 18 rotate in opposite directions to provide an upward force to the platen frame member 50 and hence to platen 6, via the cam followers 59. An initial adjustment is made at pulley 68 to orient the cams in the same position. Cam follower arms 59a provide adjustment for overall conjugate changed and platen leveling. As the frame member 50 moves upward, it slides past a mylar seal separating side walls 52, 54, 56, 58 from the abutting lower side walls of the light housing.
The cams in FIG. 1, are shown fully seated in the 1× position with the distance between the center of cam followers 59 and the center of shafts 60, 70 being at a minimum. When a reduction mode is enabled, the cam rotates in the direction shown and the center-to-center distance increases in a non-linear fashion which is directly related to the upward translation of the platen frame member and, hence, of the platen. At the extreme cam position, corresponding to a 0.647× reduction (FIG. 5) the platen will have moved upward to its maximum position. On return to higher magnification ratios, the rotation of the cam is reversed and the weight of the platen ensures an even platen descent following, again, the cam 18 surface.
Lens and Lens Drive Mechanism
In a preferred embodiment lens 10 is an f/10, fixed focus, wide angle lens (≈35°). Over a 1.0 to 0.647× magnification range, the effective ƒ number varies from 20 to 16.47 and semi-field angle from 35.8 to 34.5 respectively. In FIG. 1, the lens was shown in the 1× position and, as briefly described, the lens was mounted in a mounting plate 46 which, in turn, formed part of a lens carriage assembly 40. FIGS. 4 and 5 show the lens in a 0.647× reduction position with FIG. 5 showing a portion of the housing broken away to more clearly show the lens carriage assembly. Referring to FIGS. 4 and 5, lens carriage assembly 40 has a top surface 42 and a generally triangular surface 84. Surface 84 has a generally rectangular slot 86 at the upper end thereof and raised boring surfaces 87A, 87B. Carriage 40 consists further of an elliptical-shaped plate 46 which generally conforms to the shape of aperture 44 (FIG. 2) but of larger dimensions. Plate 46 is slidably mounted on guide rods 90, 92 by means of sleeve bearing 94 and anti-rotation member 96. As previously described, lens 10 is seated within plate 46. The plate, and hence the mounted lens, are thus adapted for horizontal movement along guide rods 90, 92, the plate maintaining a light-tight contact with the underside of surface 42. This horizontal motion is one of two components imparted to the lens which, combined together, provide the required lens motion through a continuous magnification range.
A second, vertical component of motion is imparted to lens carriage 40 and hence to lens 10 by utilizing a portion of the previously described pulley/cable arrangement used to provide platen translation. As shown in FIGS. 4 and 5 carriage 40 is slidably mounted on vertical guide rod 104 which projects downward perpendicularly from housing floor 12 and extends through the apertures in raised surfaces 87A, 87B. Vertical movement is provided to carriage 40 by vertical drive cable 110. Cable 110 is entrained about capstan 112 mounted upon main drive shaft 60. Cable 110 is also entrained about pulleys 114 and 116 and is connected to anchor point 120 located approximately in the center of the raised portion of boring surface 87B. The initial length of cable 110, and hence of lens 10, can be adjusted by means of adjustment screw 122.
With a system magnification change from 1× (FIG. 1) to 0.647× (FIG. 5), the platen is elevated as described above. With the rotation of shaft 60, cable 110 is played out and the weight of carriage 40 causes its descent along rod 104. With a return towards the 1× position, shaft 60 rotates in the opposite direction, winding cable 110 about capstan 112 and providing the force to raise the carriage. A rotational motion of the lens carriage about rod 104 is prevented by a second guide rod 123 shown in FIG. 3.
Relative Illumination Filter
In order to ensure a uniform exposure at photoreceptor belt 20, a relative illumination filter 124 is fixedly mounted below lens 10. The center of the filter is aligned with the center of the lens and the XY plane of the filter is perpendicular to the center line. The filter comprises a circular glass plate having most of its surface covered by a circular coating of varying density with a transparent ring along its outer edge. The density of the coating is maximum in the center of the plate and decreases with increasing radial distance from the center. The filter is designed to compensate for the well known phenomenon of cos4 falloff of light through the lens as well as lens exit pupil distortion which increases with increasing field angles. An exemplary filter is disclosed in U.S. Pat. No. 4,298,275, assigned to the same assignee as the present invention.
An occluder plate (not shown) is also mounted below the filter to crop the image at belt 20 so that the image assumes the general outline shown in FIG. 1 and to reduce excessive stray light.
Lens Registration
The two lens motions described in the preceding section provide a non-linear path of travel for the lens which is enabled by means of a registration cam arrangement shown in FIGS. 4 and 5. This arrangement comprises registration cam bracket 134, lens cam plate 136 and lens cam follower 138.
Registration cam mounting bracket 134 is bolted to the underside of housing floor 12 in a generally perpendicular orientation. Formed within bracket 134 is a generally rectangular shaped slot 140. Mounted to the inner surface of bracket 134 by screws 142, 144 is lens cam plate 136. Plate 136 has, extending along its length, a generally rectangular shaped slot 146 which has a dogleg 148 at the upper end thereof. The surface 150 of the rectangular-shaped portion of slot 146 is non-linear with a slight upward curvature at the upper end and a gradual flattening out at the lower end. Surface 150 has been formed to provide the corrective motion to the aforementioned lens registration path to enable registration to be maintained through a continuous magnification range.
The lens horizontal position is adjusted at initial assembly by first obtaining the desired image registration point at 1× magnification by axially moving plates 134 and 136. Lens 10 is then translated to the 0.647× position; pivoting the cam plate 136 about pivot screw 142 until the registration point coincides and then tightening screws 142, 144. The geometry of the cam is such that the 1× position does not change.
Plate 46 has a cam follower 138 mounted thereon. The cam follower extends through cam follower slot 86 and projects into cam plate slot 146 so as to ride along cam surface 150. The lens translational path is thus seen to combine the vertical component of motion provided by the pulley/cable arrangement and the horizontal component of motion as constrained by the shape of cam plate slot 146.
Operation In 1× and Reduction
An operational cycle will now be described wherein a document is copied at a 1× magnification and then at a 0.647× magnification. Referring to FIG. 1, a document is placed so that its corner is registered at registration mark 24. The operator will push the appropriate print button applying power to lamp 8. The lamp provides a flash of light which undergoes multiple reflections from all interior surfaces of housing 4 to provide a nominally uniform level of illumination of the document. Sufficient light is reflected from the document and passes through lens 10 onto photoreceptor belt 20 to form a latent document image area 22 of the same dimensions as the document. Belt 20 continues to move, advancing the next unexposed area.
To enable a 0.647× reduction mode, the lens must move toward the photoreceptor and the object and image conjugates must be adjusted for the particular magnification. The objects are accomplished by moving platen frame member 50 to its maximum extended position by means of the cable/pulley/cam mechanism described above and by moving lens carriage 40 along the full length of the non-linear path defined by surface 150.
Upon selection of the 0.647× reduction mode, platen frame member begins to be translated upwards by the rotation of corner cams 59. Simultaneously, cable 110 is played out from capstan 112 allowing the weight of lens carriage 40 to cause its descent along vertical guide rod 104. Lens cam follower and lens 10 initially drop the short vertical distance bounded by dogleg 148. The bottom of this dogleg corresponds to a 0.98× magnification and ensures that any information which may have extended up to the document edge will be projected onto the imaging area of the belt with no loss of information.
Platen frame member 50 continues to be driven upwards exposing additional surfaces of previously covered lower side walls 26, 28, 30, 32. Cam follower 138 (FIG. 5) moving with a horizontal component of motion along cam follower slot 86 now enters the diagonally extending portion of slot 146 and the lens acquires an additional, horizontal, registration adjusted component of motion. As shown in FIG. 3, as the top surface 42 of lens carriage 40 drops away from the housing floor 12, a flexible pleated circular wall 152 is shown attached to floor 12 and surface 42. The wall expands in a downward direction and serves to maintain an optical seal during full vertical translation of the lens. The inner surface of this wall is coated with a diffusely reflective material.
The lens continues its descent along the path defined by cam follower slot 86 and surface 150, and for the time determined by controller circuit 62, until it reaches the position shown in FIGS. 4 and 5. Platen frame member 50 will also reach the fully extended position shown in FIG. 5.
If the next magnification value selected is greater than 0.647×, lens carriage 40 will be moved upward by means of cable 110 causing reverse motion of the lens along surface 150 (path 130). Platen frame member will be lowered as cams 59 reverse their rotation.
The imaging system described above discloses a preferred mechanism for maintaining document registration through a continuous magnification range in a flash imaging system. It is understood that further variations within the provisions of the invention can be made and the following claims are intended to cover all such variations falling within the scope of the invention.
What is claimed is:
1. In a full-frame, corner registered flash illumination and imaging optical system for a photocopier, the combination of:a movable platen member for supporting original documents to be copied; an enclosed illumination housing positioned beneath said platen member and containing flash illumination means for substantially uniformly illuminating the underside of said platen, said housing further containing a movably mounted, relative illumination compensated projection lens, for projecting document images onto a photosensitive image plane; means for changing the magnification of said optical system and including a first means for vertically translating said platen member and a second means for translating said projection lens along a non-linear path, said second means including: a lens carriage assembly having said projection lens mounted thereon; means for providing a vertical linear component of motion to said carriage assembly; means for providing a horizontal non-linear component of motion to said carriage assembly said means including a horizontally movable upper plate assembly forming part of the lens carriage assembly in which said projection lens is mounted, said plate assembly having a single cam follower element projecting therefrom, which cooperates with a single cam member to define a non-linear path of travel for said lens, whereby the sum of said vertical and horizontal components of motion define a non-linear path at any point along which the lens carriage and hence the projection lens are in the required position to project corner-registered images at the selected magnification onto the imaging plane.
2. The optical system of claim 1 wherein said cam member position is pivotably adjustable.
| 1982-04-28 | en | 1985-03-19 |
US-18068194-A | Mop with removable interchangeable work pads
ABSTRACT
A mop having a head attached to a handle and a rectangular work pad removably attached to a rectangular flat surface of the head by fabric hook fasteners. The hook fasteners are located in recessed areas of the corners so that the hooks extend downwardly slightly below the lower surface of the head so that the work pad is substantially parallel and juxtaposed with the lower surface of the head throughout contact therebetween.
RELATED PATENT APPLICATIONS
This patent application is a continuation-in-part application of U.S. patent application Ser. No. 08/086,042 filed by Teddy Garcia on Jul. 6, 1993, now abandoned.
BACKGROUND OF THE INVENTION
Hand mops have been used for generations to dust, clean and polish floors, walls, ceilings and other surfaces. In earlier days mops had heads of fabric, yarns, sponges, or other soft absorbent materials permanently affixed to the end of a rod-like handle. Cleaning, wringing, and other renewal operations on the head were somewhat awkward with an elongated handle attached to the head. In more recent times there have been marketed mops with removable heads, frequently made of synthetic sponge material, but such heads are not always preferred for some cleaning operations. Fleeces, toweling, and felts are preferred for waxing, polishing, and the like. There has also appeared on the market the VELCRO fabric fastener in which fabric hooks and fabric loops, when pressed into each other, provide an excellent means of fastening one article to another and yet be easily releasable. The mop of this invention provides a mop with any of several work pads that can be interchangeably fastened to the mop head.
It is an object of this invention to provide a novel mop with releasably attachable work pads. It is another object of this invention to provide a novel mop with flat work pads attachable by means of a VELCRO fabric fastener employing fabric hooks and fabric loops. Still other objects will become apparent from the more detailed description below.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a mop having a removable flat work pad, the mop having a flat rectangular support plate with a top surface and a bottom surface, the top surface being attached to an elongated handle by a universal joint means, and the bottom surface being planar and having four corners with a portion in each corner recessed upwardly from the bottom surface and having in each recessed portion a pad of fabric hooks. The work pad is a three layered soft, compressible cushion having an upper non-woven fabric layer fastenable to the fabric hook pads, a central layer of a synthetic foam material, and a lower layer of a selected sheet material adapted for use in mopping operations.
In specific and preferred embodiments of the invention, the lower layer of the work pad may contain abrasive materials, may be a type of toweling, may be a fleece, may be a chamois skin, or the like. The recessed portions on the bottom surface of the mop head should be sized to receive pads of fabric hooks with the hook ends projecting slightly downward beyond the bottom surface. The work pads preferably are larger than the support plate of the mop head so as to extend laterally outward beyond the perimeter of the support plate.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a front elevational view of the mop in accord with this invention;
FIG. 2 is a side elevational view of FIG. 1;
FIG. 3 is a top plan view of FIG. 1;
FIG. 4 is a bottom plan view of FIG. 1;
FIG. 5 is a top plan view of a work pad employed with the mop of this invention;
FIG. 6 is a front elevational view of FIG. 5;
FIG. 7 is a bottom plan view of FIG. 5;
FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 5, showing a terry cloth lower surface;
FIG. 9 is a partial cross-sectional view similar to FIG. 8, depicting a second embodiment of the work pad wherein the lower layer is a fleece material; and
FIG. 10 is a partial cross-sectional view similar to FIGS. 8 and 9, showing a third embodiment of the work pad wherein the lower layer is an abrasive material.
DETAILED DESCRIPTION OF THE INVENTION
The details and embodiments of this invention are best understood by reference to the attached drawings.
The mop of this invention includes three elements; namely, the mop head 20, the mop handle 21, and the work pad 31. The mop head 20 and the mop handle 21 may be made of any rigid materials, such as wood, metal, plastic, or combinations of these basic materials. Plastic is preferred since in can be molded into a finished piece and thereby may be less expensive to manufacture. Handle 21 is an elongated rod of sufficient length for the job to be done, e.g., 4-6 feet for a floor mop and 6-10 feet for a wall or ceiling mop. Mop head 20 includes a flat support plate 22 having top surface 23 and a bottom surface 24. Top surface 22 has a central hub 41 from which radiate vertical reinforcement ribs 26 to eliminate flexibility of plate 22. Plate 22 is rectangular in the attached drawings and ribs 26 extend from hub 41 to the four corners of plate 22. Hub 41 and the lower end of handle 21 are joined via a universal joint means 25. In this instance the means includes an upper pivot pin or shaft 29 and a lower pivot pin or shaft 30. Pivots 29 and 30 are positioned at right angles to each other so as to permit handle 21 to be pivoted to almost any position while support plate 22 is kept in one position. Any other universal joint structure may be used to join handle 21 to support plate 22.
Bottom surface 24 of support plate 22 is a flat planar surface against which work pad 31 (FIGS. 5-10) is fastened to perform whatever operation (e.g. washing, dusting, polishing, scrubbing, etc.) is to be undertaken by using the mop this invention. Work pad 31 is a flat cushion or compressible pad, and when fastened to bottom surface 24, the result is a flat-faced mop, rather than a bundle of strands or yarns, which provides a much better implement to work on a flat surface, such as a floor, wall, or ceiling. At each of the four corners of bottom surface 24 there is a shallow recessed portion 27 which is adapted to receive a pad 28 of fabric hooks of the type employed in a Velcro fabric fastener. The depth of the recessed portion is enough to permit about half of the thickness of pad 28 to be above the level of bottom surface 24, leaving only the hook ends of the pad 28 to be below the level of bottom surface 24, i.e., just enough to fasten themselves to the upper layer 32 of work pad 31. Pads 28 are preferably attached to recessed portions 27 by an adhesive which firmly affixes the backing fabric of pads 28 to the material from which mop head 20 is made. The total area of four pads 28 must be enough to fasten work pad 31 firmly to mop head 20. Any larger area of pads 28 is certainly operable, but generally is a waste of money. The proportion of the area of four pads 28 to the total area of bottom surface should be about 15-40%, preferably 20-30%. An actual preferred example of such proportions is for bottom surface to be 6.5×11 inches in size, while pads 28 are 2×2 inches in size. These sizes produce a proportion of about 22.4% of the total area of bottom surface being the area of four fabric hook pads 28.
Work pad 31 is a thin cushion (about 1/4 to 3/4 inch thick) which overlays bottom surface 24, and preferably extends a short distance beyond the perimeter of bottom surface 24, in all directions. For a bottom surface measuring 6.5×11 inches, work pad 31 preferably should measure about 8×12.5 inches, or an overlap of about 0.75 inch on each side. Smaller or larger bottom surfaces 24 might employ correspondingly smaller or larger overlaps, although an overlap of about 0.5-1.0 inch will be suitable for most sizes of mop heads 20.
Work pad 31 is composed of three layers fastened together, preferably by stitching around the perimeter. Upper layer 32 is made of a sheet material that is fastenable to the hooks of pads 28 on mop head 20. Layer 32 may be fabric loops such as used in Velcro fabric fasteners, or other material which will fasten to fabric hooks. Preferably, upper layer 32 is a non-woven fabric or a felt which has not been processed with a hard finish, but which retains a fibrous surface sufficient to be fastened to fabric hooks. Many soft felts or soft non-woven materials are available on the market today with such properties, and may be natural or synthetic materials. Central layer 33 is a microporous foam of synthetic plastic material e.g., polyolefin, polyamide, polyvinyl, or the like. Lower layer 34 is a sheet of any selected fabric that has utility in mopping operations. For washing operations, lower layer 34 may be a terry cloth toweling, a woven fibrous material, a non-woven fibrous material, a spongy material, or the like. For dusting and polishing operations lower layer 34 may be a fleece, a shaggy fabric, or a terry cloth toweling including a multiplicity of long fibers, as identified by numeral 39 in FIG. 10. For scrubbing operations lower layer 34 may be an abrasive sheet material, a spongy material, or a shaggy fabric, as identified by numeral 38 in FIG. 9. For certain operations lower layer may be a chamois skin, or other leather-like material. In other words, lower layer 34 may be any selected material appropriate for the mopping operation.
The three layers 32, 33, and 34 of work pad 31 are joined together around the outside perimeter in any convenient manner, e.g., by adhesive bonding, stitching, or the like. Shown in the drawings is a rolled edge 35 held in place by stitching 36 around the perimeter. The central layer 33 may be laminated to upper layer 32 with the lower layer 34, or 38 or 39 being stitched to the laminated central and upper layers 33, 32. Work pad 31 is washable so that it may be washed by hand or otherwise.
Other shapes and sizes of mop head 20 and work pad 31 may be employed, such as round, elliptical, triangular, or the like, although rectangular is preferred.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.
What is claimed as new and what it is desired to secure by Letters Patent of the United States is:
I claim:
1. A mop comprising an elongated handle and a flat rectangular support plate having a perimeter and a top surface and a bottom surface, a universal joint means connecting said handle to said top surface, said bottom surface being planar and having four corners, each corner only containing a thin pad of fabric hooks with the remainder of said bottom surface being clear of any fabric hooks, a removable work pad being flexible and having a rectangular perimeter and extending outwardly beyond said perimeter of said support plate, said work pad having an upper planar layer of a non-woven fabric fastenable to said pads of fabric hooks, a central planar layer of a foamed synthetic plastic material, and a lower planar layer of a selected sheet material adapted to be used in a mopping operation, said corners of said bottom surface of said support plate, having square shallow depressions therein, said pads of fabric hooks being square and positioned in and filling respective said shallow depressions in said bottom surface of said support plate, said depressions being of a depth to permit said pads to extend generally half their thickness above said bottom surface of said support plate and to dispose said upper planar layer of said work pad flat against said bottom surface of said support plate and said pads of fabric hooks, and to dispose said lower layer of said work pad to be substantially planar when said upper layer is attached to said plate.
2. The mop of claim 1 wherein said central layer and said upper layer are laminated and said lower layer is stitched to said central and upper layers around said perimeter of said work pad, and forming a work pad about 1/4 to 3/4 inch thick.
3. The mop of claim 2 wherein said lower layer of said work pad is terry cloth.
4. The mop of claim 2 wherein said lower layer of said work pad is abrasive.
5. The mop of claim 2 wherein said lower layer of said work pad has a shaggy texture.
6. A mop with a plurality of interchangeable work pads comprising an elongated handle having opposite ends, a flat rectangular support plate having a perimeter and a top surface and a bottom surface, universal joint means for connecting one of said ends of said handle to said top surface, said bottom surface being planar and having four rectangular corner areas, a thin rectangular sheet member of fabric hooks disposed in each said corner areas with its hooks exposed adjacent said bottom surface, each said work pad being flexible and rectangular and extending outwardly of said perimeter of said support plate, said work pad having an upper planar layer being composed of a non-woven fabric fastenable to said sheet members of fabric hooks, a central planar layer of a foamed synthetic plastic material laminated to said upper layer, and a lower planar layer of a selected sheet material carried by said upper and central layers, said work pad being stitched around its perimeter to join together said lower planar layer to said laminated upper and central planar layers, said corner areas of said support plate being recessed upwardly to form shallow depressions, said sheet members of fabric hooks being positioned in said shallow depressions of said corner areas of said support plate with their hooks extending slightly below said bottom surface, said depressions being of a depth to permit said planar upper layer of said work pad to remain substantially planar when said upper layer is attached by said sheet members of fabric hooks to said support plate and said lower planar layer of said work pad being parallel therewith.
7. The mop of claim 6 wherein said lower layer of one said work pad is terry cloth.
8. The mop of claim 6 wherein said lower layer of one said work pad is abrasive.
9. The mop of claim 6 wherein said lower layer of one said work pad includes a multiplicity of long fibers used for dusting.
10. The mop of claim 6 wherein said lower layer of one said work pad is terry cloth, said lower layer of a second said work pad is abrasive and said lower layer of a third said work pad includes a multiplicity of long fibers used for dusting.
| 1994-01-13 | en | 1995-05-30 |
US-85261292-A | Method and apparatus for producing silicon single crystal
ABSTRACT
A method of producing a Czochralski-grown silicon single crystal stably and efficiently with high production yield comprises the steps of setting pulling conditions such that at least a portion of a growing silicon single crystal having a temperature in excess of 1150° C. is spaced upwardly from a surface of silicon melt by a distance greater than 280 mm; and pulling the growing silicon single crystal upward while maintaining the pulling conditions. The silicon single crystal produced by this method has an excellent oxide film dielectric breakdown strength. An apparatus for carrying out the method is also disclosed.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of and an apparatus for producing a silicon single crystal having an excellent dielectric breakdown strength of the silicon oxide film formed thereon.
2. Description of the Prior Art
It is well known in the art that a silicon single crystal grown by a pulling method commonly called the Czochralski (CZ) method is produced by an apparatus which comprises a main chamber having a side wall and a top wall disposed on an upper end of the side wall and having an open central portion extending upwardly so as to form a neck portion at an upper end of the main chamber, a quartz crucible disposed in the main chamber with a heater and a thermal shield disposed between the quartz crucible and the side wall of the main chamber, and a gate valve, a pull chamber and a crystal pulling mechanism that are disposed above the neck of the main chamber for pulling a growing silicon single crystal from a silicon melt retained in the quartz crucible. It is also known that single crystal wafers (CZ wafers) prepared from the Czochralski-grown silicon single crystal have an oxide film dielectric breakdown strength which is much smaller than that of single crystal wafers (FZ wafers) prepared from a silicon single crystal grown by the float-zone (FZ) method and wafers (epitaxial wafers) with a silicon film grown by epitaxy on a single crystal substrate prepared by the CZ method. However, due to various advantageous features, the CZ wafers are widely used as a material for fabricating electronic devices. In recent years, with an increase in degree of integration of MOS devices, a demand for a MOS device having a highly reliable gate oxide film had increased. Since the reliability of the gate oxide film is influenced very much by the oxide film dielectric breakdown strength, there is a great need for a CZ wafer having an excellent oxide film dielectric breakdown strength.
To meet the foregoing demand, an attempt has been proposed, as disclosed in Japanese Patent Laid-open Publication No. 2-267195. According to the disclosed prior attempt, a CZ wafer having an excellent oxide film dielectric breakdown strength can be produced by controlling the pulling rate (i.e., the crystal growth rate) of a silicon single crystal below 0.8 mm/min.
The prior attempt is, however, not fully satisfactory because the silicon single crystals produced at the pulling rate 0.8 mm/min may have an insufficient oxide film dielectric breakdown strength. In addition, such a low pulling rate which is smaller than the conventional pulling rate of about 1.2 mm/min brings about a substantial reduction in productivity and a substantial increase in manufacturing cost of the silicon single crystal.
SUMMARY OF THE INVENTION
With the foregoing drawbacks of the prior art in view, it is an object of this invention to provide a method by which a Czochralski-grown silicon single crystal having an excellent silicon oxide film dielectric breakdown strength can be produced stably at a high production yield and which is able to improve the productivity of the silicon single crystal.
Another object of the present invention is to provides an apparatus for carrying out the method.
According to the present invention, there is provided a method of producing a silicon single crystal grown by Czochralski method, which comprises the steps of: setting pulling conditions such that at least a portion of a growing silicon single crystal having a temperature in excess of 1150° C. is spaced upwardly from a surface of silicon melt by a distance greater than 280 mm; and pulling the growing silicon single crystal upward while maintaining the pulling conditions.
When the portion of the growing silicon single crystal having a temperature above 1150° C. has a length smaller than 280 mm, the grown silicon single crystal has an insufficient silicon oxide film dielectric breakdown strength.
It is preferable that in combination with the control of thermal conditions of the growing silicon single crystal, the pulling rate is set in the range of 0.8-2 mm/min. This combination increases the oxide film dielectric breakdown strength and productivity of the silicon single crystal. A pulling rate (i.e., a crystal growth rate) less than 0.8 mm/min lowers the productivity of the silicon single crystal. Conversely, a pulling rate greater than 2 mm/min may affect the oxide film dielectric breakdown strength.
The method of this invention is carried out by an apparatus of the type including: a main chamber having a side wall and an upper wall disposed on an upper end of the side wall, the upper wall having an open central portion extending upwardly so as to form a neck portion at an upper end of the main chamber; a quartz crucible disposed in the main chamber, with a heater and a thermal shield disposed between the quartz crucible and the side wall of the main chamber in the order named; and a gate valve, a pull chamber and a crystal lift mechanism that are disposed above the neck portion of the main chamber in the order named for pulling a growing silicon single crystal upward from a silicon melt retained in the quartz crucible, wherein the improvement comprises: a heat insulator disposed in the main chamber for keeping the temperature of an upper part of a hot zone defined by and between an upper portion of the side wall and the upper wall.
More specifically, the heat insulator extends between a lower end of the neck portion of the main chamber and an upper end of the thermal shield. From the viewpoint of the heat insulating efficiency, a heat insulator having a dome-like shape is preferable. The heat insulator preferably has a composite structure composed of a graphite and a heat-insulating material. The graphite constitutes an inner lining of the heat-insulating material.
The heat insulator may be replaced by a second heater which is disposed above the first-mentioned heater for heating the growing silicon single crystal.
Furthermore, in combination with the heat insulator disposed in the upper part of the hot zone, or alternatively with the second heater, a purge tube depending from a lower end of the neck may be provided for increasing the temperature gradient of only a portion of the growing silicon single crystal located near the silicon melt surface. With the purge tube thus provided, the pulling rate can be increased by 20-50%.
The above and other objects, features and advantages of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which preferred structural embodiments incorporating the principles of the present invention are shown by way of illustrative examples.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatical fragmentary front elevational view showing the internal construction of an apparatus for producing a Czochralski-grown silicon single crystal according to a first embodiment of this invention;
FIG. 2 is a view similar to FIG. 1, but showing the internal construction of an apparatus according to a second embodiment of this invention;
FIG. 3 is a view similar to FIG. 1, but showing the internal construction of an apparatus according to a third embodiment of this invention;
FIG. 4 is a graph showing the relationship between the distance from a silicon melt surface and the temperature of a silicon single crystal;
FIG. 5 is a graph showing the relationship between the crystal growth rate and the wave mark density;
FIG. 6 is a graph showing the relationship between the wave mark density and the percent non-defective of oxide film having a dielectric breakdown strength in excess of 8 MV/cm;
FIG. 7 is a graph showing the relationship between the crystal growth rate and the percent non-defective of oxide film having a dielectric breakdown strength in excess of 8 MV/cm; and
FIG. 8 is a graph showing the relationship between the heat treatment temperature and the wave mark density,
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to certain preferred embodiments illustrated in the accompanying drawings.
Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, FIG. 1 shows an apparatus 2 for producing a silicon single crystal grown by Czochralski (CZ) method according to a first embodiment of this invention.
The apparatus 2 includes a main chamber 6 having a reduced diameter portion or neck 4 at its upper end. The main chamber 6 has an annular side wall 6a and an upper wall 6b disposed on an upper end of the side wall 6a. The upper wall 6b has an open central portion extending upwardly to form the neck portion 4 of the main chamber 6. A pull chamber (not shown) is disposed above the main chamber 6 with a gate valve 8 disposed therebetween. Disposed above the pull chamber is a crystal pulling mechanism (not shown) for pulling a growing silicon crystal 28. The pull chamber and the crystal pulling mechanism are known in the art and, hence, description and illustration thereof can be omitted.
The main chamber 6 receives therein a quartz crucible 12 rotatably supported by a vertical support shaft 10. The quartz crucible 12 contains a melt 14 of polycrystalline silicon. The quartz crucible 12 is heated by a heater 16 disposed around the quartz crucible 12. The heater 16 surrounded by a thermal shield 18 extending along an inside surface of the side wall 6a of the main chamber 6. The top wall 6b of the main chamber 6 is provided with a view port 22 for enabling observation of the interior of the main chamber 6. The main chamber 6 as a whole has a water jacket structure to prevent undue temperature rise.
A pulling means comprising a pull shaft 24 extends vertically downward from the crystal lift mechanism through the pull chamber into the main chamber 6. A seed crystal 26 is attached to a forward end of the pull shaft 24. The pull shaft 24 is vertically movable to dip the seed crystal 26 into the silicon melt 14 and then gradually pull the seed crystal 26 upwardly from the silicon melt 14 while rotating the seed crystal 26, so that a silicon single crystal 28 grown by the CZ method is produced. The pull shaft 24 may be replaced by a flexible pulling means such as a pull wire.
Reference character H designates a hot zone extending above the silicon melt 14 in the quartz crucible 12. The hot zone H is surrounded by an upper portion of the side wall 6a and the upper wall 6b of the main chamber 6. The main chamber 6 has an exhaust hole E connected with a vacuum pump (not shown). The exhaust hole E is used for exhausting an inert gas filled in the main chamber 6 and controlling the pressure of the inert gas.
The apparatus 2 further includes a heat insulator 30 for keeping the temperature of an upper part of the hot zone H. The heat insulator 30 has a composite structure composed of a graphite 32 and a heat-insulating material 34 such as a carbon fiber heat-insulator sold under the trade name "KURECA" manufactured by Kureha Chemical Industry Co., Ltd. The graphite 32 constitutes an inner lining of the heat-insulating material 34. The heat insulator 30 has a dome-like shape and extends between a lower end of the neck portion 4 and an upper end or an upper end extension 18a of the thermal shield plate 18 to interconnect the neck portion 4 and the thermal shield plate 18. The heat insulator 30 has a view hole 36 aligned with the view port 22 for the purpose of observing the interior of the main chamber 6.
The shape of the heat insulator 30 is not limited to the dome-like shape. The heat insulator 30 may be formed in a cup-like shape composed of a vertical portion extending along the inside surface of the side wall 6a, and a horizontal portion lying over an inside surface of the top wall 6b.
The dome-like heat insulator 30, serving as means for keeping the temperature of the upper part of the hot zone H, may be replaced by a second heater 38 for heating the growing silicon single crystal 28, as shown in FIG. 2. The second heater 38 is disposed above the heater 16 (main heater) for heating the quartz crucible 12.
It is preferable that the apparatus further includes a purge tube 40 (FIG. 3) which may be provided in combination with the dome-like heat insulator 30 shown in FIG. 1, or alternatively in combination with the second heater 38 shown in FIG. 2. As indicated by the phantom lines shown in FIG. 3, the purge tube 40 depends from a lower end of the neck portion 4 so as to cover a portion of the growing silicon single crystal 28 located adjacent to the melt surface for increasing the temperature gradient only of this portion of the growing silicon single crystal 28. With the purge tube 40 thus provided, the pulling rate can be increased by 20-50%, without affecting the oxide film dielectric breakdown strength.
The invention will be further described by way of the following examples which should be construed as illustrative rather than restrictive.
Comparative Example
A silicon single crystal grown by Czochralski (CZ) method was pulled under the following conditions by using a conventional CZ equipment. During the pulling process, the silicon single crystal was removed from a furnace. After a platinum-rhodium platinum thermocouple was embedded in the removed silicon single crystal, the temperature distribution of a portion of the silicon single crystal extending upwardly from the silicon melt surface was measured. The results obtained are shown in FIG. 3. As indicated by the broken line (Prior Art) shown in FIG. 3, a portion of the growing silicon single crystal having a temperature ranging from 1150° to 1420° C. (i.e., the melting point of silicon) had a length (equal to the distance from the melt surface) not greater than 280 mm. Using the same CZ equipment, the pulling rate (crystal growth rate) was changed within the range of 0.4-1.6 mm/min to form various samples of silicon single crystal. The samples were processed into silicon wafers by effected the same machining processes and chemical polishing as done in the fabrication of commercial silicon wafers of 600-700 μm thick.
The silicon wafers were inspected to determine the defect density and the oxide film dielectric breakdown strength in conjunction with the crystal growth rate (pulling rate). The results obtained are shown in FIGS. 5-7.
For inspecting the defect density, each wafer was etched for 30 min by a preferential etching method [2 g: K2 Cr2 O7, 30 mL: H2 O, 100 mL: HF, Secco'd Aragona, : J. Electrochem. Soc., 119, 948 (1972)]. Using an optical microscope, defects appearing on the etched wafer as wave patterns or marks were counted by visual inspection.
For evaluating the oxide film dielectric breakdown strength, 100 pieces of devices were fabricated in each silicon wafer. Each of the devices had a polysilicon gate having an area of 8 mm2, and a 250 Å oxide layer formed by oxidation at 900° C. for 100 min in dry oxygen atmosphere. A dielectric breakdown test was made for each device and a device whose oxide layer having a dielectric breakdown strength greater than 8 MV/cm was evaluated as a non-defective device. Then, a percentage of the non-defective devices was given as representing the oxide film dielectric breakdown strength.
The relation between the crystal growth rate and the density of wave marks counted as specified above with respect to the silicon wafers according to the Comparative Example is shown in FIG. 5. As evidenced from the distribution of circles (Prior Art) shown in FIG. 5, the wave mark density is 20 pieces/cm2 when the pulling rate is as low as 0.4 mm/min. On the other hand, at the pulling rate exceeding 1 mm/min, the wave mark density is increased to more than 1000 pieces/cm2.
The relation between the wave mark density and the percent non-defective of oxide film dielectric breakdown strength taken with respect to the silicon wafers of the Comparative Example is shown in FIG. 6. The distribution of circles (Prior Art) shown in FIG. 6 indicates that those silicon wafers having a high wave mark density such as 1000 pieces/cm2 have a percent non-defective of oxide film dielectric breakdown strength nearly equal to 40%. The silicon wafers having a wave mark density of about 200 pieces/cm2 have a percent non-defective of oxide film dielectric breakdown strength approximately equal to 80%.
The relation between the crystal growth rate and the percent non-defective of oxide film dielectric breakdown strength of the silicon wafers according to the Comparative Example is shown in FIG. 7. As appears clear from the distribution of circles (Prior Art) shown in FIG. 7, the percent non-defective of oxide film dielectric breakdown strength is 80% when the crystal growth rate is relatively low such as 0.4 mm/min. At a crystal growth rate exceeding 0.8 mm/min, the percent non-defective of oxide film dielectric breakdown strength is reduced to about 50%. This means that in the case of the conventional CZ method, a low crystal growth rate is an essential condition in order to produce a silicon single crystal having an excellent oxide film dielectric breakdown strength. The low crystal growth rate, however, results in a considerable reduction in productivity of the silicon single crystal and hence is not practically useful.
Experiment
The Comparative Example described above suggests that a reduction in defect density of the silicon single crystal brings about a substantial improvement in oxide film dielectric breakdown strength of the silicon wafers.
An experiment was made to determine the relation between the wave mark density and the heat treatment temperature when silicon wafers of about 1000 pieces/cm2 in wave mark density were subjected to a heat treatment. As shown in FIG. 9, a heat treatment effected at 1100° C. for 2 hours provides only a negligible reduction in wave mark density (defect density). As against this, sharp reductions in wave mark density are attainable when the heat treatment is effected at temperatures above 1150° for 2 hours.
These experimental results have led the present inventors to an inventive idea that a grown silicon single crystal having a longer thermal history in the temperature range above 1150° C. has a considerably reduced amount of defects and an excellent oxide film dielectric breakdown strength.
Inventive Example
A silicon single crystal grown by the CZ method was produced under the same conditions as the Comparative Example with the exception that the conventional CZ equipment was replaced by the apparatus of the present invention described above. A measurement was made in the same manner as the Comparative Example for determining the temperature distribution of a portion of the silicon single crystal disposed above the melt surface. The results obtained are shown in FIG. 4. As is apparent from the phantom line (Present Invention) shown in FIG. 4, a portion of the silicon single crystal in the temperature range of from 1150° to 1420° C. (i.e., the melting point of silicon) had a length of 385 mm. Using the same CZ apparatus, two samples of silicon single crystal were pulled at different rates 0.9 mm/min and 1.2 mm/min, respectively. These samples were processed into 600-700 μm thickness silicon wafers by effecting the same machining processes and chemical polishing as done in the Comparative Example and also in the fabrication of commercial silicon wafers.
The defect density and oxide film dielectric breakdown strength of the fabricated silicon wafers were inspected in conjunction with the crystal growth rate (pulling rate). The results obtained are shown in FIGS. 5 through 7.
As indicated by triangles (Present Invention) shown in FIG. 5, the wave mark density observed at the crystal growth rate of 1.2 mm/min is 100 pieces/cm2 which is smaller by one digit than the wave mark density of Comparative Example (Prior Art). An additional reduction in wave mark density (20 pieces/cm2) is obtained when the crystal growth rate is 0.9 mm/min.
Two triangles shown in FIG. 6 indicate that the silicon wafers according to the Inventive Example have a wave mark density smaller than 100 pieces/cm2 and a percent non-defective of oxide film dielectric breakdown strength equal to 80%.
As shown in FIG. 7, the percent non-defective of oxide film dielectric breakdown strength of the Inventive Example (Present Invention) is not smaller than 80% irrespective of the crystal growth rate. A comparison made with respect to the same crystal growth rate 1.2 mm/min indicates that the Inventive Example (having a longer thermal history in the temperature range above 1150°) has an oxide film dielectric breakdown strength which is twice as large as that of the Comparative Example (having a shorter thermal history in the temperature range above 1150° C.).
As is obvious from the foregoing description, according to the method of this invention, a silicon single crystal having an excellent oxide film dielectric breakdown strength can be produced stably with high yield and high productivity.
obviously, various modifications and variations of the present invention are possible in the light of the above teaching. It is therefore to be understood 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 producing a silicon single crystal grown by Czochralski method, said apparatus comprising:a main chamber having a side wall and an upper wall disposed on an upper end of said side wall, said upper wall having an open central portion extending upwardly so as to form a neck portion at an upper end of said main chamber; a quartz crucible disposed in said main chamber, with a heater and a thermal shield disposed between said quartz crucible and said side wall of said main chamber; a heat insulator having a dome-like shape, extending between a lower end of said neck portion and an upper end of said thermal shield, and disposed in said main chamber for keeping the temperature of an upper part of a hot zone defined by and between an upper portion of said side wall and said upper wall, said heat insulator comprising a composite structure composed of a graphite and a heat-insulating material, said graphite forming an inner lining of said heat-insulating material; and a gate valve, a pull chamber and a crystal lift mechanism disposed above said neck portion of said main chamber for pulling a growing silicon single crystal upward from a silicon melt retained in said quartz crucible.
| 1992-03-17 | en | 1993-09-28 |
US-74634558-A | Process for the preparation of fluosulfonates
United States Patent Ofiice 3,083,220 Patented Mar. 26, 1963 3,083,220 PRQCESS FOR THE PREPARATIQN F FLUOSULEONATES William Lee Edens, New Castle, Del., assiguor to E. L du Pont de Nemours and Company, Wilmington, Del.,
a corporation of Delaware No Drawing. Filed July 3, 1958, Ser. No. 746,345 5 Claims. (Cl. 260-456) wherein R is a member of the class consisting of fluorine, perfiuoroalkyl groups and omega-hydroperfiuoroalkyl groups. The novel fiuosulfonates are prepared by the reaction of concentrated sulfuric acid with a fluorinated olefin having the formula RCF CF where R is as indicated above, at temperatures of 300 to 400 C., or by the reaction of fiuosulfonic acid with the periluorinated or substantially perfiuorinated olefin at temperatures of 100 to 400 C.
In contrast to completely halogenated ethylene containing more than one halogen-type such as difiuorodichloroethylene and trichlorofluoroethylene which do not form the fluosulfonates, it was found that perfluoroolefins and substantially periluorinated olefins react to form the fluosulfonates of the present invention and, surprisingly so, it was found that these compounds could be prepared by reaction of sulfuric acid with the olefin in addition to the preparation by reaction with iluosulfonic acid.
The preparation is carried out by combining the reactants and heating the mixture at elevated temperatures. No catalysts or solvents are necessary. The quantities of the reagents may be greatly varied and are in no way critical to the formation of the fluosulfonates. In general, it is preferred to react substantially equimolar quantities of the acid with the olefin. The reaction is carried out at a temperature of 300 C. to 400 C. and preferably at 350 C., when sulfuric acid is employed and at a temperature of 100 C. to 400 C., and preferably at a temperature of 150 0, when fiuosulfonic acid is employed. In general, the reaction is carried out at autog enous pressures, although higher or lower pressures may be employed if desirable.
The olefins which may be employed in the present invention are perfiuoroolefins and omega-hydroperfluoroolefins. Representative examples of these olefins suitable in the formation of the fiuosulfonates of the present invention include tetrafluoroethylene, and perfiuoroalkyl and omega hydroperfluoroalkyl substituted perfiuoroethylenes in which the alkyl groups are unsubstituted and straight chain, and contain up to 18 carbon atoms, such as perfluoropropene, perfluorobutene-l, perfiuorohexene-l, perfluoroheptene-l, perfiuorooctene-l, omegahydroperfluoroheptene-l, omegahydroperfiuorodecene-1, perfiuorododecene, perfiuoropentadecene, etc.
The process of the present invention is further illustrated by the following examples:
Example I Hexafluoropropene (150 g.) and 96% concentrated sulfuric acid (25 ml.) were charged into a platinum lined 320 ml. autoclave. The mixture was agitated for one hour at 350 C. under autogenous pressure. The light amber product was discharged, washed twice with water, dried over calcium sulfate and distilled through a 30 inch platinum spinning band column. There was obtained 37.6 g. (32%) of a clear colorless liquid product identified as p-hydroperfluoropropyl fluosulfonate having a boiling point of to 76 C., a refractive index of N =1.2865.
Analysis-Calculated for C HF O S: C, 14.4; H, 0.4; F, 53.2; S, 12.8; mol. wt. 250. Found: C, 15.5; H, 0.6; F, 52.8; S, 13.6; mol. wt. 248.
Example II Hexafluoropropene (50 g.) and fiuosulfonic acid {25 g.) were charged into a platinum lined 320 ml. autociave. The mixture was agitated for 3 hours at 150 C. under autogenous pressure. The dark amber product was poured onto ice, washed twice with water and distilled. There was obtained 11.3 g. (18%) of B-hydroperfiuoropropyl fluosulfonates boiling at 75-76 C.
Example 111 Into an evacuated 320 ml. platinum lined autoclave was charged 36 ml. of fluosulfonic acid and 70 g. of tetrafluoroethylene. The reactor was agitated for 3 hours under autogenous pressure at 200 C. The reaction products were collected in an acetone-Dry-Ice bath and. distilled. In addition to unreacted monomer there was obtained sulfur dioxide and tetrafluoroethylene dimer. The distillation heel was dropped into water and the insoluble layer resulting was separated and distilled. On distillation there was obtained 0.9 g. of B-hydroperfluoroethyl fluosulfonate having a boiling point at 56-57 C. The structure of the compound was further verified by infrared and nuclear magnetic resonance analysis.
Example I V Into a 320 ml. platinum lined autoclave was charged 11 g. of fluosulfonic acid and 20 g. of omega-hydroperfluorobutene. The reactor was agitated for 8 hours at 150 C. under autogenous pressure. Distillation of the reaction product resulted in isolation of 2.1 g. of 2,4-dihydroperfiuorobutyl fiuosulfonate, having a boiling point at 119 C.
Example V Into a 320 ml. platinum lined autoclave was charged 70 g. of perfluoroheptene-l and 15 g. of fluosulfonic acid. The reaction mixture was agitated for three hours at 150 C. under autogenous pressure. The resulting product was washed with water, sodium bicarbonate solution and again with water. The product was then filtered through anhydrous MgSO and dried over CaSO On distillation there was recovered 25 g. of unreacted olefin and 2.2 g. of ,B-hydroperfiuoroheptyl fluosulfonate having a boiling point of 53.5 to 54.5 C. at a pressure of 18 mm. Hg.
Example VI Into a 6" x platinum tube was charged 4.3 g. of omega-hydroperfiuoroctene-1 and 1.5 g. of iiuosulfonic acid. The tube was agitated for 3 hours at 200 C. under autogenous pressure. Distillation of the reaction product resulted in recovery of 2.8 g. of the olefin and isolation of 1.5 g. of 2,8-dihydroperfluorooctyl fiuosulfonate having a boiling point at to 81 C. at a pressure of 8 mm. Hg. The structure of the compounds was confirmed by infrared and nuclear magnetic resonance analysis.
Example VII Into a 320 ml. platinum lined autoclave was charged 200 ml. of fi-hydroperfluoropropyl fluosulfonate and 2 g.
of tert.-butyl peroxide. The autoclave was heated to 140 C. and pressured with 400 psi. of tetrafluoroethylene. The reaction vessel was agitated for 63 minutes at this pressure and at a temperature varying from 140 to 180 C. The reaction product was filtered and 104 g. of polytetrafiuoroethylene was isolated.
The formation of the fluosulfonates of the present invention is independent of the chain length of the fluoroalkyl radical attached to the perfluorovinyl group of the olefin and proceeds equally well with a low molecular weight fiuoroolefin as with a higher molecular weight fiuoroolefin. In general olefins having from 2 to 20 carbon atoms are employed in the formation of the novel fluosulfonate compounds of the present invention.
The fiuoroalkyl fluosulfonates of the present invention are to be distinguished from the fiuoroalkane sulfonates from which they differ in structure and properties. The fluoroalkyl groups in the fiuosulfonates are bonded to the sulfur atoms through an oxygen atom, whereas in the iluoroalkane sulfonates the fluoroalkyl group is bonded to the sulfur atom. The fluoroalkane sulfonates, furthermore, hydrolyze to fluoroalkane sulfonic acid, whereas the fluoroalkyl fiuosulfonates hydrolyze to a carboxylic acid.
The perfiuoroalkyl fluosulfonates prepared by the process of the present invention are highly valuable chemical intermediates. Thus the tluosulfonates may be employed to prepare highly fluorinated acids by base hydrolysis. The resulting Z-hydroperfluoroalkyl acids are useful as dispersing agents and may also be dehydrofiuorinated to give rise to perfitioro-a,fi-unsaturated carboxylic acids which may be employed as polymerization monomers. The perfiuoroalkyl fiuosulfonates of the present invention are furthermore useful as solvents and non-aqueous polymerization media for perfluorinated olefins, as shown by Example VII.
I claim:
1. A process for the preparation of substantially fluorinated alkyl fluosulfonates which comprises reacting an acid selected from the class consisting of sulfuric acid and fluosulfonic acid at a temperature of to 400 C., when the acid is fluosulfonic acid and 200 C. to 400 C. when the acid is sulfuric acid, with a substantially fiuorinated olefin having the formula Where R is a member of the class consisting of fluorine, perfluoroalkyl group and omega-hydroperfiuoroalkyl groups, said alkyl group being unsubstituted and straight chain and containing up to 18 carbon atoms.
2. A process for the preparation of substantially fiuorinated alkyl fiuosulfonates which comprises reacting sulfuric acid at a temperature of 200 to 400 C. with a substantially fiuorinated olefin having the formula substantially References Cited in the file of this patent UNITED STATES PATENTS 2,570,917 Calfee Oct. 9, 1951 2,628,972 Calfee et al Feb. 17, 1953 2,878,156 Davis Mar. 17, 1959
1. A PROCESS FOR THE PREPARATION OF SUBSTANTIALLY FLUORINATED ALKYL FLUOSULFONATES WHICH COMPRISES REACTING AN ACID SELECTED FROM THE CLASS CONSISTING OF SULFURIC ACID AND FLUOSULFONIC ACID AT A TEMPERATURE OF 100 TO 400*C., WHEN THE ACID IS FLUOSULFONIC ACID AND 200*C. TO 400*C. WHEN THE ACID IS SULFURIC ACID, WITH A SUBSTANTIALLY FLUORINATED OLEFIN HAVING THE FORMULA
| 1958-07-03 | en | 1963-03-26 |
US-6669887-A | Diamond-coated tungsten carbide-base sintered hard alloy material for insert of a cutting tool
ABSTRACT
A diamond-coated tungsten carbide-base sintered hard alloy material for inserts of cutting tools, which has greatly improved bond strength or degree of bonding of the diamond coating layer to the matrix and therefore is capable of exhibiting excellent cutting performance over a long period of time.
The sintered hard alloy material comprises:
(1) a matrix of a sintered hard alloy consisting essentially of 1-4 percent by weight cobalt, and the balance of tungsten carbide and inevitable impurities, the tungsten carbide having a coarse grain structure having an average grain size of 2-10 microns; and
(2) a diamond coating layer formed over surfaces of the matrix by forming an etching layer over the matrix surfaces and then forming the diamond coating layer over the matrix surfaces via the etching layer by a low pressure vapor-phase synthesization method.
If required, the matrix may further contain CO1-CO8 (ISO) free carbon.
BACKGROUND OF THE INVENTION
This invention relates to a diamond-coated tungsten carbide-base sintered hard alloy material for inserts of cutting tools, and more particularly to a cutting tool insert material of this kind which has greatly improved bond strength or degree of bonding of the diamond coating layer to the tungsten carbide matrix and is therefore capable of exhibiting excellent cutting performance over a long period of time.
In recent years, in development of inserts of cutting tools or the like there have been carried out many studies of the formation of diamond coating layers over surfaces of matrices formed of various materials. Conventional typical methods of forming diamond coating layers over surfaces of matrices include low pressure vapor-phase synthesization methods known as CVD Method (chemical vapor deposition method) which utilizes thermal decomposition of a gas such as CH4, PVD Method (physical vapor deposition method), etc.
However, diamond coating layers formed by these low pressure vapor-phase synthesization methods generally have low bond strength, i.e. a low degree of bonding to the matrices, and therefore it has so far been impossible to utilize sintered hard alloys having such diamond coating layers as inserts of cutting tools which are subjected to high load from the work materials.
SUMMARY OF THE INVENTION
It is therefore the object of the invention to provide a diamond-coated tungsten carbide-base sintered hard alloy material for inserts of cutting tools, which has greatly improved bond strength or degree of bonding of the diamond coating layer to the matrix and therefore is capable of exhibiting excellent cutting performance over a long period of time.
According to a first embodiment of the invention, there is provided a sintered hard alloy material for an insert of a cutting tool, comprising:
(1) a matrix of a sintered hard alloy consisting essentially of 1-4 percent by weight cobalt, and the balance of tungsten carbide and inevitable impurities, the tungsten carbide having a coarse grain structure having an average grain size of 2-10 microns; and
(2) a diamond coating layer formed over surfaces of the matrix by forming an etching layer over the matrix surfaces and then forming the diamond coating layer over the matrix surfaces via the etching layer by a low pressure vapor-phase synthesization method.
According to a second embodiment of the invention, there is provided a sintered hard alloy material for an insert of a cutting tool, comprising:
(1) a matrix of a sintered hard alloy consisting essentially of 1-4 percent by weight cobalt, C01-C08 (ISO) free carbon, and the balance of tungsten carbide and inevitable impurities, the tungsten carbide having a coarse grain structure having an average grain size of 2-10 microns; and
(2) a diamond coating layer formed over surfaces of the matrix by forming an etching layer over the matrix surfaces and then forming the diamond coating layer over the matrix surfaces via the etching layer by a low pressure vapor-phase synthesization method.
DETAILED DESCRIPTION
The present applicants have made studies in order to obtain a tungsten carbide-base sintered hard alloy on which can be formed a diamond coating layer having high bond strength or high degree of bonding to the matrix, and which can therefore be used as a cutting tool insert. As a result, the present applicants have reached the following findings:
(a) If a low pressure vapor-phase synthesization method is applied to the surfaces of a matrix of a tungsten carbide-base sintered hard alloy, nuclei of diamond are formed only on grains of tungsten carbide (hereinafter abbreviated as "WC") on the matrix surfaces, but part of the diamond can be graphitized on grains of cobalt (Co);
(b) Therefore, it is desirable that the content of Co as a combined phase-forming component in the matrix should be as small as possible. However, if the Co content is too small or less than 1 percent by weight, it will result in reduced strength of the alloy. Therefore, if the Co content is within a range from 1 to 4 percent by weight, the diamond coating layer of the resulting alloy material can have high bond strength and accordingly the alloy material can have sufficient strength for use as a cutting tool;
(c) If WC in the WC-base sintered hard alloy has a coarse grain structure having an average grain size of 2-10 microns, the speed at which the diamond coating layer is formed increases and also the bond strength of the resulting diamond coating layer increases;
(d) If a small amount, preferably C01-C08 (ISO=International Standardization Organization) more preferably C01-C04, free carbon having a fine grain size, is evenly dispersed throughout the matrix of the WC-base sintered hard alloy, the diamond cannot easily be graphitized and the resulting diamond coating layer cannot easily be exfoliated from the matrix;
(e) Further, if the surfaces of the matrix of the WC-base sintered hard alloy are etched to remove Co as the combined phase-forming component therefrom and form an etching layer which is free of Co, preferably having a mean layer thickness of 0.1-1 micron, and then the diamond layer is formed over the matrix surfaces via the etching layer, the bond strength or degree of bonding of the diamond coating layer to the matrix further increases.
The present invention is based upon the above findings (a) to (e).
Diamond-coated WC-base sintered hard alloy materials for inserts of cutting tools (hereinafter abbreviated as "coated cutting inserts") according to the invention have the aforestated chemical compositions and structures.
In coated cutting inserts according to the invention, the Co content is limited within a range from 1 to 4 percent by weight. That is, if the Co content is less than 1 percent by weight, the matrix cannot have sufficient strength required for use as a cutting tool insert. However, if the Co content exceeds 4 percent by weight, the speed of formation of the diamond coating layer decreases, and also part of the diamond can become graphitized, making it impossible to secure desired excellent wear resistance and bond strength. In the coated cutting inserts according to the invention, WC having a coarse grain llze is employed which has an average grain size of 2-10 microns. That is, if the average grain size is less than 2 microns, the speed of formation of the diamond coating layer can greatly decrease and also the bond strength can become degraded. On the other hand, in actuality it is difficult to manufacture a WC-base sintered hard alloy by using WC having an average grain size exceeding 10 microns. Therefore, the average grain size of WC has been limited within a range from 2 to 10 microns, and preferably within a range from 2 to 5 microns.
The etching layer is formed by dipping the matrix in an aqueous solution of a strong acid of concentration of from 1 to 10 percent selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid, for a period of time within a range from 1 to 30 minutes.
Examples of the coated cutting inserts according to the invention will now be described in detail.
EXAMPLE I
As starting powders, various WC powders having respective predetermined average grain sizes falling within a range from 2 to 10 microns, and Co powder having an average grain size of 1.2 microns were prepared. These starting powders were blended into respective predetermined compositions. Thereafter, in conventional ordinary manners, each of the blended powders was mixed, the mixed powder was compacted, and the green compact was sintered at a temperature within a range from 1430° to 1500° C. The sintered compacts were subjected to grinding to obtain throwaway inserts as WC-base sintered hard alloy matrices having a shape according to SPP 432 of CIS (Cemented Carbide Tool Industrial Standard) and compositions, average grain sizes of WC, and values of Rockwell hardness (A scale), which are shown in Table 1. These throwaway inserts were subjected to etching under conditions shown in Table 1 to form an etching layer over the surfaces of each throwaway insert. Then, the throwaway inserts each had their surfaces coated with diamond under the following conditions by CVD Method:
Reaction Vessel: Quartz tube with a diameter of 120 mm;
Filament: Metal W;
Matrix Temperature: 700° C.;
Atmosphere: CH+H2 under 10 torr;
Ratio of Reaction
Gas Components: CH4 /H2 =0.005;
Reaction Time: 3-6 hours.
Thus, coated cutting inserts Nos. 1-7 according to the present invention and comparative coated cutting inserts Nos. 1-3 were prepared which have mean layer thicknesses shown in Table 1.
The comparative coated cutting inserts Nos. 1-3 each have one or more of powder composition of the matrix and average grain size of WC falling outside the scope of the present invention.
TABLE 1
MEAN MEAN LAYER MATRIX LAYER THICK- EXFOLI- WEAR AVERAGE
THICK- NESS OF ATION WEAR AMOUNT COMPOSITION GRAIN ETCHING CONDITIONS
NESS OF DIAMOND OF DEPOSI- STATE OF WC + SIZE HARD- DIPPING ETCHING
COATING DIAMOND TION OF CUTTING Co IMPURI- OF WC NESS ETCHING TIME
LAYER LAYER COATING OF WORK CUTTING EDGE SPECIMEN (WT %) TIES (μm)
(H.sub.R
A) REAGENT (MIN.) (μm) (μm) LAYER MATERIAL EDGE (μm)
COATED CUTTING INSERTS ACCORDING TO PRESENT INVENTION 1 1.5 bal. 3.7
90.5 5% 5 0.2 3.6 NIL NIL NORMALLY 0.05 NITRIC WORN 2 2.5 "
3.2 90.4 ACID 15 0.4 3.7 " " NORMALLY 0.06 WORN 3 3.0 " 2.3
91.0 5 0.2 3.0 " " NORMALLY 0.06 WORN 4 3.0 " 4.7 90.1 30
0.5 3.4 " " NORMALLY 0.06 WORN 5 3.0 " 6.5 89.7 5% 10 0.15
3.5 " " NORMALLY 0.05 HYDRO- WORN 6 3.0 " 8.8 89.2 CHLORIC 15
0.2 3.8 " " NORMALLY 0.07 ACID WORN 7 4.0 " 6.0 89.9 3% SUL- 5
0.1 3.5 " " NORMALLY 0.06 FURIC ACID WORN COMPARATIVE COATED
CUTTING INSERTS 1 0.8* " 3.5 90.6 5% 5 0.2 3.0 PRESENT PRESENT CHIPPED
AFTER NITRIC 3 MIN. 2 3.5 " 1.2* 91.0 ACID 15 0.4 3.0
PRESENT " ABNORMALLY 0.48 AT CHIPPED WORN DUE PORTION
TO CHIPPING 3 5.2* " 4.0 89.1 5 0.2 3.2 PRESENT " HEAVILY 0.50
WORN AND RECESSED
*falls outside the range of the present invention
The coated cutting inserts Nos. 1-7 according to the invention and the comparative coated cutting inserts Nos. 1-3 were subjected to a cutting test by the use of a milling cutter under the following conditions:
Work Material: Al-18 wt% Si Alloy;
Cutter Diameter: Double Positive Type with a diameter of 160 mm;
Cutting Speed: 520 m per minute;
Feed rate: 0.18 mm per rev.;
Depth of Cut: 1.5 mm;
Cutting Time: 80 minutes.
After cutting under the above conditions, the state of exfoliation of the diamond coating layer of the coated cutting insert, the state of deposition of the work material on the coated cutting insert and the state of wear of the cutting edge, as well as the wear amount of the coated cutting insert were examined, results of which are shown in Table 1.
It will be learned from Table 1 that all of the coating cutting inserts Nos. 1-7 according to the present invention are almost free of exfoliation of the diamond coating layer from the matrix as well as deposition of the work material on the coated cutting insert, show normal states of wear of the cutting edge, and exhibit excellent wear resistance, by virtue of their high speed of formation of the diamond coating layer and very high bond strength or degree of bonding of the diamond coating layer to the matrix. On the other hand, the comparative coated cutting inserts Nos. 1-3, all of which have one or more of the matrix powder composition and average grain size of WC falling outside the range of the present invention show unsatisfactory results in respect of all of the work material and state of wear of the cutting edge, as well as the wear amount of the cutting edge and further exhibit unsatifactory wear resistance, owing to their low speed of formation of the diamond coating layer and inferior bond strength.
EXAMPLE II
As starting powders, various WC powders having respective predetermined average grain sizes falling within a range from 2 to 10 microns, Co powder having an average grain size of 1.2 microns, and carbon black having a fine grain size were prepared. These starting powders were blended into respective predetermined compositions. Thereafter, mixing, compacting, sintering and grinding were carried out under the same conditions as in Example I to obtain throwaway inserts as WC-base sintered hard alloy matrices having a shape according to SPP 422 of CIS and compositions, average grain sizes of WC, and values of Rockwell hardness (A scale), which are shown in Table 2. The free carbon or carbon black contents are shown in a unit according to CIS Standard. These throwaway inserts were subjected to etching under conditions shown in Table 2 to form an etching layer over the surfaces of each throaway insert. Then, the throwaway inserts each had their surfaces coated with diamond by CVD Method under the same coating conditions as in Example I. Thus, coated cutting inserts Nos. 8-14 and comparative coated cutting inserts Nos. 4- 6 were prepared which have mean layer thicknesses shown in Table 2.
TABLE 2
MEAN MEAN LAYER MATRIX ETCHING LAYER THICK- EXFOLI- WEAR
AVERAGE CONDITIONS THICK- NESS OF ATION WEAR AMOUNT COMPOSITION GRAIN D
IP- NESS OF DIAMOND OF DEPOSI- STATE OF WC + SIZE HARD- PING ETCHING C
OATING DIAMOND TION OF CUTTING Co FREE IMPURI- OF WC NESS ETCHING TIME
LAYER LAYER COATING OF WORK CUTTING EDGE SPECIMEN (WT %) CARBON TIES
(μm) (H.sub.R A) REAGENT (MIN.) (μm) (μm) LAYER MATERIAL EDGE
(μm)
COATED CUTTING INSERTS ACCORDING TO PRESENT INVENTION 8 1.3 C08 bal.
3.8 90.4 5% 5 0.20 3.6 NIL NIL NORMALLY 0.03 NITRIC WORN 9
2.6 C08 " 3.3 90.3 ACID 15 0.40 3.7 " " NORMALLY 0.07 WORN
10 3.0 C04 " 2.2 91.1 5 0.20 3.3 " " NORMALLY 0.07 WORN 11
3.0 C06 " 4.7 90.1 30 0.60 3.5 " " NORMALLY 0.04 WORN 12
3.0 C04 " 6.6 89.7 5% 10 0.18 3.8 " " NORMALLY 0.05 HYDRO-
WORN 13 3.0 C04 " 9.0 89.0 CHLORIC 15 0.30 3.9 " " NORMALLY 0.05
ACID WORN 14 3.9 C02 " 5.3 89.4 3% SUL- 5 0.15 3.3 " " NORMALLY
0.06 FURIC ACID WORN COMPARATIVE COATED CUTTING INSERTS 4
0.7* C02 " 4.0 90.5 5% 5 0.20 2.8 " PRESENT CHIPPED AFTER NITRIC
7 MIN. 5 5.0 C06 " 1.7* 91.3 ACID 15 0.40 2.9 " " ABNORMALLY 0.50
WORN DUE TO CHIPPING 6 5.4* --* " 4.4 89.9 5
0.20 2.8 " " HEAVILY 0.52 WORN AND RECESSED
*falls outside the range of the present invention
The comparative coated cutting inserts Nos. 4-6 each have one or more of powder composition of the matrix and average grain size of WC falling outside the range of the present invention.
The coated cutting inserts Nos. 8-14 according to the invention and the comparative coated cutting inserts Nos. 4-6 were subjected to a cutting test by the use of a milling cutter under the following conditions:
Work Material: Al-16 wt% Si Alloy;
Cutter Diameter: Double Positive Type with a diameter of 160 mm;
Cutting Speed: 570 m per minute;
Feed rate: 0.19 mm per rev.;
Depth of Cut: 1 mm;
Cutting Time: 70 minutes.
After cutting under the box conditions, the state of exfoliation of the diamond-coated layer of the coated cutting insert, the state of deposition of the work material on the coated cutting insert and the state of wear of the cutting edge, as well as the wear amount of the cutting edge were examined, results of which are shown in Table 2.
It will be learned from Table 2 that all of the coated cutting inserts Nos. 8-14 according to the present invention are superior to the comparative coated cutting inserts Nos. 4-6 in respect of all of the state of exfoliation of the diamond-coated layer of the coated cutting insert, the state of deposition of the work material on the coated cutting insert and the state of wear of the cutting edge, as well as the wear resistance.
What is claimed is:
1. A sintered hard alloy material for an insert of a cutting tool, comprising:(1) a matrix of a sintered hard alloy consisting essentially of 1-4 percent by weight cobalt, and the balance of tungsten carbide and inevitable impurities, the tungsten carbide having a coarse grain structure having an average grain size of 2-10 microns; and (2) a diamond coating layer formed over surfaces of the matrix by forming an etching layer over the matrix surfaces and then forming the diamond coating layer over the matrix surfaces via the etching layer by a low pressure vapor-phase synthesization method.
2. A sintered hard alloy material as claimed in claim 1, wherein said etching layer has a mean layer thickness of 0.1-1 micron.
3. A sintered hard alloy material as claimed in claim 1, wherein said etching layer is formed by dipping the matrix in an aqueous solution of a strong acid of concentration of 1-10 percent selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid, for a period of time within a range from 1 to 30 minutes.
4. A sintered hard alloy material for an insert of a cutting tool, comprising:(1) a matrix of a sintered hard alloy consisting essentially of 1-4 percent by weight cobalt, CO1-CO8 free carbon, and the balance of tungsten carbide and inevitable impurities, the tungsten carbide having a coarse grain structure having an average grain size of 2-10 microns; and (2) a diamond coating layer formed over surfaces of the matrix by forming an etching layer over the matrix surfaces and then forming the diamond coating layer over the matrix surfaces via the etching layer by a low pressure vapor-phase synthesization method.
5. A sintered hard alloy material as claimed in claim 4, wherein said etching layer has a mean layer thickness of 0.1-1 micron.
6. A sintered hard alloy material as claimed in claim 4, wherein said etching layer is formed by dipping the matrix in an aqueous solution of a strong acid of concentration of 1-10 percent selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid, for a period of time within a range from 1 to 30 minutes.
| 1987-06-24 | en | 1988-03-15 |
US-2744479-A | Epoxy imide compositions
ABSTRACT
A composition useful for making circuit boards which is the reaction product of (a) an epoxy resin or an epoxy novolac resin and optionally, a brominated epoxy resin and (b) a bismaleimide; wherein the product of (a) and (b) is subsequently reacting with a curing agent such as a diamine of the formula H2N-R1-NH2 where R1 is an aromatic, aliphatic or cycloaliphatic group. The composition is used to impregnate a fibrous substrate of fiberglass, high temperature polyamides or graphite fibers which is laminated to a copper sheet; the resulting laminate is used to form a circuit boards that have good electrical and physical properties.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of Ser. No. 848,638 filed Nov. 4, 1977, now abandoned.
BACKGROUND OF THE INVENTION
This invention is related to a composition that is useful for making circuit boards.
Circuit boards are widely used in the electrical industry for radio, television, appliances, industrial and electrical equipment. In general, circuit boards are made by impregnating a woven fiberglass sheet with a resin and laminating copper sheet to one or both sides of the resin impregnated fiberglass sheet; then an electrical circuit is etched into the copper to form the circuit board. Electrical connections are usually soldered to the board when the board is utilized.
Polyimide resins have been used to impregnate these fiberglass sheets and form excellent quality circuit boards which have resistance to high temperatures, low thermal expansion and good electrical properties, such as a high level of resistivity. However, these boards are of a relatively high cost in comparison to circuit boards made from an epoxy resin impregnated fiberglass sheets. Circuit boards of epoxy resin impregnated fiberglass sheets are not resistant to high temperatures and have poorer electrical properties and a higher level of thermal expansion in comparison to circuit boards of polyimide resin impregnated fiberglass sheets.
There is a need for a composition that has a cost that is comparable to epoxy resins but that will form a circuit board having physical and electrical properties close to polyimide circuit boards but substantially better than epoxy resin circuit boards. The novel composition of this invention will form circuit boards that have such properties.
SUMMARY OF THE INVENTION
The composition comprises 20-80% by weight of a reaction product and 20-80% of a nonamide solvent for the reaction product having a dispersion solubility parameter of 7.2-10.5, a polar solubility parameter of 3-9.5 and a hydrogen bonding solubility parameter of 0-5.5; wherein the reaction product consists essentially of
(a) an epoxy resin of the formula ##STR1## wherein R is an alkylene group of 1-4 carbon atoms, n is a positive integer and the resin has an epoxide equivalent of about 150-1000; or an epoxy novolac resin of the formula ##STR2## where n is a positive integer and the resin has an epoxide equivalent of about 150-300; and optionally, a brominated epoxy resin having the above epoxy resin formula except each aromatic group contains 2-4 bromine atoms that are substituted for hydrogen atoms of the aromatic group can be used with the above epoxy resin or epoxy novolac resin,
(b) a bismaleimide of the formula ##STR3## wherein (a) and (b) are reacted at 115°-135° C. for about 0.5-2 hours and subsequently contacting the product of (a) and (b) with
(d) a curing agent such as a diamine of the formula H2 N--R1 --N H2 to form the reaction product, where R1 of the bismaleimide and diamine is an aromatic, aliphatic or cycloaliphatic group and wherein the molar ratio of bismaleimide to diamine is less than 1.
DESCRIPTION OF THE INVENTION
The composition contains about 20-80% by weight of the reaction product and 20-80% by weight of a nonamide solvent or a blend of nonamide solvents for the reaction product. For most uses of the composition, the composition contains about 50-70% by weight of the reaction product.
The combination of epoxy resin or epoxy novolac resin and the optional brominated epoxy resin comprises about 10-96% by weight of the reaction product. The bismaleimide comprises about 2-60% by weight of the reaction product and the curing agent comprises about 2-30% by weight of the reaction product.
A process for forming the reaction product comprises the following steps:
(1) the epoxy resin or epoxy novolac resin and the optional brominated epoxy resin are reacted with the bismaleimide at about 115°-135° C. for about 0.5-2 hours to form a product soluble in nonamide solvents; preferred reaction conditions are 115°-125° C. for about 0.75-1.25 hours.
(2) a curing agent, such as a diamine is added to the product of Step (1).
The reaction product may be diluted with an appropriate nonamide solvent. These nonamide solvents have dispersion solubility parameter of 7.2-10.5, a polar solubility parameter of 3-9.5 and a hydrogen bonding solubility parameter of 0-5.5. These solubility parameters are measured at 25° C. A discussion of solubility parameters is in The Encyclopedia of Chemical Technology, Supplement Vol., 2nd Edition (1971), pages 889-910, which is hereby incorporated by reference. Typically useful solvents are as follows:
______________________________________
Hydrogen
Dispersion Bonding
Sol. Polar Sol. Sol.
Solvent Parameter Parameter Parameter
______________________________________
Acetone 7.6 5.1 3.4
methylethyl 7.8 4.4 2.5
ketone
cyclohexanone
8.7 3.1 2.5
diethyl ketone
7.7 3.7 2.3
methylisobutyl
7.5 3.0 2.0
ketone
methylisoamyl
7.8 2.8 2.0
ketone
methylene 8.9 3.1 3.0
dichloride
nitrobenzene
9.8 4.2 2.0
acetonitrile
7.5 8.8 3.0
proprionitrile
7.5 7.0 2.7
dichloroethane
8.1 4.0 0.2
ethylformate
7.6 4.1 4.1
2,4-pentanedione
7.8 3.9 2.8
______________________________________
Mixtures of the above solvents can be used and mixtures of the above solvents with other solvents that are not within the above solubility parameters can be used provided that the resulting mixture is within the above solubility parameters. Typically useful mixtures are cyclohexanol/methylethyl ketone, acetonitrile/methylisobutyl carbinol, diisobutyl keytone/propionitrile, cyclohexane/acetonitrile, proprionitrile/toluene or xylene, acetonitrile/aliphatic hydrocarbon solvent and the like.
One preferred epoxy resin used to form the reaction product which forms a good quality circuit board has the formula ##STR4## wherein n is a positive integer sufficient to provide a viscosity of 16,000-25,000 centipoises measured at 25° C. and has an epoxide equivalent of about 180-300.
Epoxide equivalent means the grams of resin that contain one-gram equivalent of epoxide.
One preferred epoxy novolac resin has the aforementioned formula for an epoxy novolac resin where n is a positive integer sufficiently large to provide a viscosity of about 1400-2000 centipoises measured at 25° C. and has an epoxide equivalent of about 170-180.
The brominated epoxy resin has the same formula as the above epoxy resin except each aromatic group contains 2-4 bromine atoms that are substituted for hydrogen atoms of the aromatic group. Preferably, the brominated epoxy resin has the formula. ##STR5## wherein n is a positive integer sufficient to provide a viscosity of about 250-4,000 centipoises measured at 25° C. and has an epoxide equivalent of about 300-800.
One particularly preferred brominated epoxy resin having the above formula has an epoxide equivalent of about 305-355 and contains about 44-48% by weight bromine.
Another preferred brominated epoxy resin having the above formula has an epoxide equivalent of about 460 and contains about 47-51% by weight bromine.
The bismaleimide used to form the reaction product is of the formula ##STR6## where R1 is an aromatic, aliphatic, or a cycloaliphatic group.
Preferably a bismaleimide is used in which R1 is an alkylene group having 1-6 carbon atoms, phenylene, cyclohexylene, ##STR7## where R2 is an alkylene group having 1-4 carbon atoms, SO2 or O.
Examples of typical bismaleimides are as follows:
N,N'-ethylene-bis-maleimide
N,N'-butylene-bis-maleimide
N,N'-hexamethylene-bis-maleimide
N,N'-phenylene-bis-maleimide
N,N'-4,4'-diphenyl methane-bis-maleimide
N,N'-4,4'-diphenyl ether-bis-maleimide
N,N'-4,4'-diphenyl sulfone-bis-maleimide
N,N'-4,4'-dicyclohexyl methane-bis-maleimide
N,N'-xylylene-bis-maleimide
N,N'-diphenyl cyclohexane-bis-maleimide and the like.
The curing agent used to form the reaction product can be a diamine of the formula H2 N--R1 --NH2 where R1 is an aromatic, aliphatic or a cycloaliphatic group, an amide, a primary, secondary or tertiary monoamine, such as N,N'-dimethyl amino benzaldehyde or benzyl dimethyl amine, diethanol amine, triethanolamine, diethyl amino propylamine; polyamines, melamines, Lewis acids, such as boron trifluoride, boron trifluoride monoethyl amine and the like.
Preferably, diamines are used as curing agents in which R1 is an alkylene group that has 1-6 carbon atoms, phenylene, cyclohexylene, ##STR8## where R2 is an alkylene group having 1-4 carbon atoms, SO2 or O.
Examples of typically useful diamines are as follows:
ethylene diamine,
propylene diamine,
tetramethylene diamine,
pentamethylene diamine,
hexamethylene diamine,
2-ethylhexylene diamine,
nonamethylene diamine,
decamethylene diamine,
2,11-diamino-dodecane and the like;
meta-phenylene diamine,
para-phenylene diamine,
2,2'-naphthalene diamine,
4,4'-biphenylene diamine,
methylene dianiline-(4,4'-diaminodiphenyl methane),
ethylene dianiline-(4,4'-diaminodiphenyl ethane),
propylene dianiline-(4,4'-diaminodiphenyl propane), and the like;
oxydianiline-(4,4'-diaminodiphenylether), ketodianiline,
4,4'-diamino-diphenyl sulfide,
3,3'-diamino diphenyl sulfide,
4,4'-diamino diphenyl sulfone
3,3'-diamino-diphenyl sulfone,
bis-(para-amino-cyclohexyl)methane,
bis(para-amino-cyclohexyl)ethane,
bis-(para-amino-cyclohexyl)propane,
bis-(para-amino-cyclohexyl)sulfide,
bis-(para-amino-cyclohexyl)sulfone,
bis-(para-amino-cyclohexyl)ether,
bis-(para-amino-cyclohexyl)diethyl silane,
bis-(para-amino-cyclohexyl)diphenyl silane,
bis-(para-amino-cyclohexyl)ethyl phosphine oxide,
bis-(para-amino-cyclohexyl)phenyl phosphine oxide,
bis-(para-amino-cyclohexyl)N-phenyl amine,
bis-(para-amino-cyclohexyl)N-methyl amine,
hexafluoroisopropylidene-bis-(4-phenyl amine),
4,4'-diamino-diphenyl methane,
4,4'-diamino-diphenyl ethane,
4,4'-diamino-diphenyl propane
4,4'-diamino-diphenyl butane,
2,6-diamino-pyridine,
bis-(4-amino-phenyl)diethyl silane,
bis-(4-amino-phenyl)diphenyl silane,
bis-(4-amino-phenyl)ethyl phosphine oxide,
bis-(4-amino-phenyl)phenyl phosphine oxide,
bis-(4-amino-phenyl)-N-phenylamine,
bis-(4-amino-phenyl)-N-methylamine,
3,3'dimethyl-4,4'-diamino-biphenyl,
3,3'dimethoxy-benzidine,
2,4-bis(b-amino-t-butyl)toluene,
bis-(para-b-amino-t-butyl-phenyl)ether,
para-bis-(2-methyl-4-amino-phenyl)benzene,
para-bis-(1,1-dimethyl-5-amino-pentyl)benzene,
m-xylylene diamine,
p-xylylene diamine,
1,2-bis-(3-amino-propoxy)ethane
2,2-dimethyl propylene diamine,
3-methoxy-hexamethylene diamine,
2,5-dimethylheptamethylene diamine,
5-methylnonamethylene diamine,
1,4diamino-cyclohexane,
1,2-diamino-octadecane,
2,5-diamino-1,3,4-oxadiazole,
Preferred diamines are the above diamino diphenyl sulfones which form a high quality reaction product that has good electrical and physical properties.
The molar ratio of bismaleimide to diamine used in the reaction product is less than 1 and preferably is about 0.6-0.8. The most preferred ratio is 0.7 which forms a reaction product with good electrical and physical properties.
The following reaction products are preferred since these products are used for circuit boards that have good electrical and physical properties:
(1) a reaction product of about 30-60% by weight of the aforementioned epoxy resin, 10-30% by weight of the aforementioned brominated epoxy resin, 10-30% by weight of a bismaleimide and 10-30% by weight of a diamine;
(2) a reaction product of about 40% by weight of the aforementioned preferred epoxy resin, 20% by weight of the aforementioned preferred brominated epoxy resin, 20% by weight N,N'-4,4'-diphenyl methane bismaleimide and, 20% by weight of diamino diphenyl sulfone;
(3) a reaction product of about 15-35% by weight of the aforementioned brominated epoxy resin, 40-60% by weight of the aforementioned epoxy novolac resin, 15-35% by weight of a bismaleimide and 15-35% by weight of a diamine;
(4) a reaction product of about 20% by weight of the aforementioned preferred brominated epoxy resin; 40% by weight of the aforementioned preferred epoxy novolac resin, 20% by weight of N,N'-4,4'-diphenyl methane bismaleimide and 20% by weight of diamino diphenyl sulfone.
The reaction product is used in making bases for circuit boards. In preparing these bases, a fibrous substrate is coated and impregnated with the reaction product using conventional coating equipment and then the resulting impregnated substrate is cured at about 50° to 200° C. for about 1 to 30 minutes to form a rigid sheet. A sheet of copper or another conductive material is then laminated to the rigid sheet using the following laminating conditions: 50 to 1000 pounds per square inch, 50° to 300° C. for 30 to 300 minutes.
A circuit can then be etched into the conductive layer using conventional techniques to form a circuit board.
The reaction product can be used to coat and/or impregnate fibrous substrates, in particular high temperature resistant substrates, such as substrates of fiberglass, high temperature polyamides, graphite, and the like.
The following examples illustrate the invention. All parts and percentages are on a weight basis unless otherwise indicated.
EXAMPLE 1
The following constituents are charges into a reaction vessel equipped with a stirrer, a heating unit and a reflux condenser:
__________________________________________________________________________
Parts by
__________________________________________________________________________
Weight
Portion 1
Epoxy resin (having the formula 40
##STR9##
where n is a positive integer sufficiently large to provide a viscosity
of 16,000-25,000
centipoises measured at 25° C. and has an epoxide equivalent* of
about 192-203)
Brominated epoxy resin (having the above formula except the resin
contains 44- 48% 20
by weight bromine and bromine atoms are substituted for hydrogen atoms of
the
aromatic groups and the resin has an epoxide equivalent* of 305-355)
Portion 2
Bismaleimide (having the formula 20
##STR10##
Portion 3
Diamino diphenyl sulfone 20
Methyl ethyl ketone 53
Total 153
__________________________________________________________________________
*Epoxide Equivalentgrams of resin containing onegram equivalent of
epoxide.
Portion 1 is added to the vessel and heated to a temperature of 125° C. Portion 2 is then slowly added to the vessel while maintaining the temperature at 125° C. When Portion 2 is added, the temperature is increased to 130° C. and held at this temperature for 1 hour and cooled to 100° C. Portion 3 is premixed and then slowly added to the vessel while maintaining a temperature of 100° C. The resulting resin solution is cooled to 70° C. and held at this temperature for 30 minutes and then filtered.
About 0.5 parts by weight of boron fluoride monoethyl amine complex dissolved in methyl ethyl ketone per 100 parts by weight of resin solids are added to the above prepared resin solution. The resulting resin solution is then coated onto a fiberglass fabric using a conventional coating tower.
The following fiberglass fabrics are coated in the tower:
108 glass fabric--1.5 ounces per square yard
116 glass fabric--3.5 ounces per square yard
7628 glass fabric--5.8 ounces per square yard.
The coating tower is operated at a speed of about 5-7 yards per minute and a heater temperature of about 120°-135° C. is used. About 1.5 ounces of resin per square yard of fabric is applied to both sides of the fabric providing a resin impregnated and coated glass fabric.
A copper sheet is then laminated to the top and bottom of each of the resin impregnated and coated glass fabric by placing the copper sheets and the resin impregnated glass fabric in a press for about 60 minutes at 400 pounds per square inch and at a temperature of about 175° C. The resulting laminates are formed into circuit boards using conventional techniques.
The expansion of each of the circuit boards from 25° C. to 250° C. is measured. Each of the boards expanded only about 3.0% under these conditions.
EXAMPLE 2
The following constituents are charged into a reaction vessel equipped as in Example 1:
______________________________________
Parts by Weight
Composition A
______________________________________
Portion 1
Epoxy novolac resin (having the formula
50
##STR11##
where n is a positive integer sufficiently
large to provide a viscosity of 1400-
2000 centipoises measured at 25° C.
and the resin has an epoxide equivalent
weight of 172-179)
Brominated Epoxy 25
Resin (described in Example 1)
Portion 2
Bismaleimide (described in Example 1)
25
Portion 3
Diamino diphenyl sulfone 25
Methyl ethyl ketone 165
Total 290
______________________________________
Portions 1, 2 and 3 are added and reacted using the identical conditions and procedures as used in Example 1 to form a resin solution. Boron fluoride mono methyl amine in the same amount as used in Example 1 is added to the resin solution.
The glass fabrics described in Example 1 are coated in a conventional coating tower with the above resin solution using the same coating speed and temperature conditions and the same amount of resin is applied to the fabric. A copper sheet is then laminated to the top and bottom of each of the resin impregnated and coated glass fabrics using the same time, temperature and pressure conditions used in Example 1. The resulting laminates are used for circuit boards.
The expansion of each of these circuit boards from 25° C. to 250° C. is measured. Each of the boards expanded about 3.0% under these conditions.
EXAMPLE 3
The following constituents are charges into a reaction vessel equipped with a stirrer, a heating unit and a reflux condenser:
__________________________________________________________________________
Parts by
__________________________________________________________________________
Weight
Portion 1
Epoxy resin (having the formula 40
##STR12##
where n is a positive integer sufficiently large to provide a viscosity
of 16,000-25,000
centipoises measured at 25° C. and has an epoxide equivalent* of
about 192-203)
Brominated epoxy resin (having the above formula except the resin
contains 47-51% by weight 20
bromine and bromine atoms are substituted for hydrogen atoms of the
aromatic groups and the resin has an epoxide equivalent* of 460)
Portion 2
Bismaleimide (having the formula 20
##STR13##
Portion 3
Diamino diphenyl sulfone 20
Methyl ethyl ketone 53
Total 153
__________________________________________________________________________
*Epoxide Equivalentgrams of resin containing onegram equivalent of
epoxide.
Portion 1 is added to the vessel and heated to a temperature of 115° C. Portion 2 is then slowly added to the vessel while maintaining the temperature at about 115°-125° C. After Portion 2 is added, the temperature is held at 115°-125° C. for 1 hour and then the methylethyl ketone is added and the solution is cooled to 60°-70° C. The diaminodiphenyl sulfone is added and the temperature is held at about 60°-70° C. for about 1 hour and then the solution is cooled to the ambient temperature and then filtered.
About 0.5 parts by weight of boron fluoride monoethyl amine complex dissolved in methylethyl ketone per 100 parts by weight of resin solids are added to the above prepared resin solution. The resulting resin solution is then coated onto a fiberglass fabric using a conventional coating tower.
The following fiberglass fabrics are coated in the tower:
108 glass fabric-1.5 ounces per square yard
116 glass fabric-3.5 ounces per square yard
7628 glass fabric-5.8 ounces per square yard.
The coating tower is operated at a speed of about 5-7 yards per minute and a heater temperature of about 120°-135° C. is used. About 1.5 ounces of resin per square yard of fabric is applied to both sides of the fabric providing a resin impregnated and coated glass fabric.
A copper sheet is then laminated to the top and bottom of each of the resin impregnated and coated glass fabric by placing the copper sheets and the resin impregnated glass fabric in a press for about 60 minutes at 400 pounds per square inch and at a temperature of about 175° C. The resulting laminates are formed into circuit boards using conventional techniques.
The expansion of each of the circuit boards from 25° C. to 250° C. is measured. Each of the boards expanded only about 3.0% under these conditions.
EXAMPLE 4
Example 2 is duplicated using the identical constituents in the same amounts except the following procedure is used to make the resin solution:
Portion 1 is added to the vessel and heated to a temperature of 115° C. Portion 2 is then slowly added to the vessel while maintaining the temperature at about 115°-125° C. After Portion 2 is added, the temperature is held at 115°-125° C. for 1 hour and then the methylethyl ketone is added and the solution is cooled to 60°-70° C. The diaminodiphenyl sulfone is added and the temperature is held at about 60°-70° C. for about 1 hour and then the solution is cooled to the ambient temperature and then filtered. Boron fluoride mono methyl amine in the same amount as used in Example 1 is added to the resin solution.
The glass fabrics described in Example 1 are coated in a conventional coating tower with the above resin solution using the same coating speed and temperature conditions and the same amount of resin is applied to the fabric. A copper sheet is then laminated to the top and bottom of each of the resin impregnated and coated glass fabrics using the same time, temperature and pressure conditions used in Example 1. The resulting laminates are used for circuit boards.
The expansion of each of these circuit boards from 25° C. to 250° C. is measured. Each of the boards expanded about 3.0% under these conditions.
I claim:
1. A composition comprising 20-80% by weight of a reaction product and 20-80% of a nonamide solvent for the reaction product having a dispersion solubility parameter of 7.2-10.5, a polar solubility parameter of 3-9.5 and a hydrogen bonding solubility parameter of 0-5.5; wherein the reaction product consists essentially of(a) an epoxy resin of the formula ##STR14## wherein R is an alkylene group of 1-4 carbon atoms, n is a positive integer; and the resin having an epoxide equivalent of about 150-1000; and (b) a bismaleimide of the formula ##STR15## where R1 is an aromatic, aliphatic or cycloaliphatic group and wherein (a) and (b) are reacted at 115°-135° C. for about 0.5-2 hours and subsequently contacting the product of (a) and (b) with (c) a diamine of the formula ##STR16## wherein the molar ratio of bismaleimide to diamine is about 0.6 to 0.8.
2. The composition of claim 1 in which R1 is an alkylene group having 1-6 carbon atoms, phenylene, cyclohexylene, ##STR17## where R2 is an alkylene group having 1-4 carbon atoms, SO2 or O.
3. The composition of claim 2 in which R is ##STR18##
4. The composition of claim 3 in which R1 is an aromatic group.
5. The composition of claim 4 in which R1 is ##STR19##
6. A process for forming the reaction product of claim 1 which comprises the following steps.(1) contacting the epoxy resin with the bismaleimide at about 115°-135° C. for about 0.5-2 hours to form a product and (2) adding the diamine to the product of Step 1.
7. A composition comprising 20-80% by weight of a reaction product and 20-80% of a nonamide solvent for the reaction product having a dispersion solubility parameter of 7.2-10, a polar solubility parameter 3-9.5 and a hydrogen bonding solubility parameter of 0-5.5; wherein the reaction product consists essentially of(a) an epoxy novolac resin of the formula ##STR20## where n is a positive integer and the resin has an epoxide equivalent of about 150-300 (b) a bismaleimide of the formula ##STR21## where R1 is an aromatic, aliphatic or cycloaliphatic group and wherein (a) and (b) are reacted at about 115°-135° C. for about 0.5-2 hours and subsequently reacting the product of (a) and (b) with (c) a diamine of the formula ##STR22## wherein the molar ratio of bismaleimide to diamine is about 0.6 to 0.8.
8. The composition of claim 7 in which R1 is an alkylene group having 1-6 carbon atoms, phenylene, cyclohexylene, ##STR23## where R2 is an alkylene groups having 1-4 carbon atoms, SO2 or O.
9. The composition of claim 8 in which R1 is an aromatic group.
10. The composition of claim 9 in which R1 is ##STR24##
11. A process for forming the reaction product of claim 7 which comprises the following steps(1) contacting the epoxy novolac resin with the bismaleimide at about 115°-135° for about 0.5-2 hours to form a product and (2) adding the diamine to the product of Step (1).
| 1979-04-05 | en | 1981-09-08 |
US-47425790-A | Apparatus for distributing sample liquid
ABSTRACT
An apparatus for distributing sample liquids from source test tubes into destination test tubes. It has distribution tips and air-supply devices for supplying air to the tips at a low rate. The tips are lowered into the source tubes, while air is flowing from the devices and through the tips. The moment the tips reach the surface levels of the liquids contained in the source tubes, the air pressure changes. When this change is detected, the tips start sucking the liquids from the source tubes. An apparatus similar to the above-mentioned one. It has distribution units each having a tip, a lever having a slit, and pins projecting from the units and inserted in the slit. The lever is rotated, changing the interval between the distribution units to the interval between the source or the destination tubes held in a rack. A similar apparatus which has distribution tips and a tray. The tray is kept away from below the tips while the sample liquids are being sucked into the tips from the source tubes or being distributed from the tips into the destination tubes, and is placed below the tips while the tips are being moved. A similar apparatus which has distribution units each having a tip, and a jig having cut-outs. The jig holds tips in the cut-outs as the distribution units are moved upward from the jig, whereby the tip are detached from the units.
This is a continuation of application Ser. No. 07/187,737, filed Apr. 29, 1988, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for distributing sample liquid, such as sampled blood, from a test tube into a plurality of other tubes, so that the distributed portions of the sample liquid are subjected to different items of analysis.
2. Description of the Related Art
In order to analyze sample liquid, such as blood, thereby to determine whether or not germs are contained in the liquid, and what kinds of germs they are, if contained in the liquid, it is necessary to distribute the sample liquid into a plurality of test tubes, to sort the test tubes containing the distributed portions of the liquid into groups in accordance with items of analysis, and to supply these test tubes, thus sorted, to various analyzers for performing the items of analysis on the sample liquid. Analyzers have been developed, and greatly improved analyzers have been put to practical use. The blood analyzer is a good example. Nonetheless, the distribution of a liquid sample is performed solely by human labor, as is seen in the hospitals and the research institutes. No automatic apparatus for distributing a sample liquid into a plurality of test tubes or the like have been developed.
There are problems with the distribution of a sample liquid carried out by human labor. First, the sample liquid may spill, wetting the hands of the persons engaged in the distribution of the liquid, or staining the floor. Secondly, the test tube from which the sample liquid is being distributed, or the test tubes into which the liquid is being distributed may be dropped, by mistake, onto the floor, inevitably staining the floor. Thirdly, the sample-distribution by means of manual labor requires a long time and is error-prone. Because of these problems, it is difficult to keep the sample-distribution room sufficiently clean and sanitary, or to accomplish a sufficiently high work efficiency.
The inventors hereof studied the possibility of developing an apparatus which has distribution tips, vacuum means for supplying a sample liquid into the tips from a test tube, transport means for moving the tips containing the liquid to other test tubes, and sample-distributing means for distributing the portions of the sample liquid from the tips into the test tubes. They found that such an apparatus cannot be practically employed unless it satisfies the following requirements:
(1) Each distribution tip must be set in a test tube at such an appropriate level that the sample liquid can be supplied into the tip from the test tube, without using a complex sensor (e.g., a photosensor) for detecting the surface level of the liquid in the tube or a complex control device for moving the tip to the desired level in accordance with the signal output by the sensor and representing the surface level of the liquid.
(2) The distribution tips must be arranged quickly and precisely at the same intervals as the test tubes which are held in a rack and into which the sample liquid will be distributed. This is because various kinds of racks are used, each having holes for holding test tubes at regular intervals specific to the rack.
(3) Measures must be taken to prevent the sample liquid from dribbling into the test tubes other than the desired ones while the distribution tips are being moved from the source tubes to the destination tubes, due to the vibration or the like applied to the distribution tips during the transportation.
(4) Means must be used to replace the distribution tips with new and clean ones, smoothly and quickly, every time a sample liquid has been distributed from the tips into test tubes.
SUMMARY OF THE INVENTION
It is accordingly the first object of the present invention to provide an apparatus which can automatically distribute a sample liquid from distribution tips into test tubes, without dropping the liquid onto the floor, and which can set each distribution tip in the test tube at an appropriate level, without using a complex sensor, such as a photosensor, thereby accomplishing a sufficiently efficient sample-distribution.
The second object of the invention is to provide an apparatus which can automatically distribute a sample liquid from distribution tips into test tubes, and can quickly arrange the distribution tips at the same intervals as the test tubes.
The third object of this invention is to provide an apparatus which can automatically distribute a sample liquid from distribution tips into test tubes, and can prevent the sample liquid from dribbling from the tips into test tubes other than the destination ones while the tips are being moved from the source tubes to the destination tubes, due to the vibration or the like applied to the tips during the transportation.
The fourth object of the present invention is to provide an apparatus which can automatically distribute a sample liquid from distribution tips into test tubes, and can automatically replace the distribution tips with new and clean ones, quickly and smoothly.
To achieve the first object of the invention, there is provided an apparatus comprising distribution tips, vacuum means for supplying a sample liquid from a source test tube into the distribution tips, transport means for moving the tips containing the sample liquid to destination tubes, and sample-distributing means for distributing the portions of the sample liquid from the tips into the destination tubes. The distribution tips are connected to air pipes. The air pipes are connected to changeover valves, respectively. Each changeover valve has two air-inlet ports. The first air-inlet port is connected to a pressure detector, which in turn is coupled to an air supply device. The second air-inlet port is connected to an air cylinder containing a piston. The pressure detector generates an electric signal upon detecting a change in the pressure of the air being supplied from the air supply device, and supplies this signal to the changeover valve. In response to the signal, the valve connects the air pipe to the air supply device or the piston/cylinder device. When the pipe is connected to the air supply device, the sample liquid can be sucked from the source tube into distribution tip by moving the piston in a first direction, or supplied from the tip into the destination tube by moving the piston in a second direction opposite to the first direction.
In operation, the air supply device is started, air is supplied from the distribution tip at a low rate. The tip is gradually lowered into the source tube. When the tip reaches the surface of the sample liquid contained in the tube, the air pressure of the air being supplied from the air supply device changes, whereby the pressure detector generates a signal. In response to this signal, the changeover valve connects the air pipe to the air cylinder. The piston of the air cylinder is moved in the first direction, whereby a portion of the liquid is sucked up into the distributing tip and retained therein. Then, the distribution tip is moved from the source tube to the destination tube. The piston is moved in the second direction, whereby the liquid is distributed from the tip into the destination tube. Thus, no sensors are required to detect surface level of the liquid in the source tube to set the tip at an appropriate position within the source tube.
To attain the second object of the invention, there is provided an apparatus which comprises distribution tips, vacuum means for supplying a sample liquid from a source test tube into the distribution tips, transport means for moving the tips containing the sample liquid to destination tubes, and sample-distributing means for distributing the portions of the sample liquid from the tips into the destination tubes. The apparatus further comprises a sample-distributing section having distribution units. Each of the distribution units has a tip holder for holding the distribution tip. Pins protrude from the tip holders holding the distribution tips, or from the members supporting the tip holders. The tip holders are therefore, set apart at regular intervals, and the pins are, also, set apart at regular intervals. These pins are inserted in the slit cut in a slanting lever. The lever is fixed at one end and can be rotated by drive means such as a pulse motor.
In operation, when the lever is rotated in either direction by the drive means, the intervals between the pins are changed. Hence, the regular intervals among the distribution tips are also changed. In this way, the distribution tips can be set at the same regular intervals as the destination test tubes, whereby portions of the sample liquid are simultaneously distributed into these test tubes.
To achieve the third object of the invention, there is provided an apparatus which comprises distribution tips, vacuum means for supplying a sample liquid from a source test tube into the distribution tips, transport means for moving the tips containing the sample liquid to destination tubes, and sample-distributing means for distributing the portions of the sample liquid from the tips into the destination tubes. The apparatus further comprises a sample-distributing section having distribution units and a plurality of cups. Each distribution unit has a tip holder for holding the distribution tip. The cups are positioned below distribution tips held by the holders, while the tips are being moved from the source tubes to the destination tubes, and vice versa, and are moved by drive means and remain away from the tips while the sample liquid is being sucked up into, or supplied from, the distribution tips. Thus, the liquid, if dribbling from the tips during the transport of the tips, falls into the cups, not into test tubes other than the destination tubes.
To accomplish the fourth object of the invention, there is provided an apparatus which comprises distribution tips, vacuum means for supplying a sample liquid from a source test tube into the distribution tips, transport means for moving the tips containing the liquid to destination tubes, and sample-distributing means for distributing the portions of the sample liquid from the tips into the destination tubes. The apparatus further comprises a jig and a sample-distributing section having distribution units. Each distribution unit has a tip holder and a plug attached to the holder. The plug has an O-ring mounted on it, and can be removably fitted in the proximal end of the distribution tip held by the holder. The jig is a rectangular plate having a semicircular notches cut in one side. The notches have a radius such that the plugs can be inserted into them, but the proximal ends of the tips cannot be inserted into them. The jig can be moved relative to the distribution tips, in both the vertical direction and the horizontal direction. In operation, when the jig or the tips are moved vertically and horizontally, the distribution tips are easily attached to, for detached from, the distribution units.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of an apparatus according to the present invention;
FIG. 2 is a side view of the apparatus illustrated in FIG. 1;
FIG. 3 is a schematic representation of the sample-distributing section incorporated in the apparatus shown in FIGS. 1 and 2;
FIG. 4 is a perspective view of the sample-distributing section of the apparatus, as is viewed from the back;
FIG. 5 is a perspective view of the distributing section, as is viewed from the front;
FIG. 6 is a side view of one of the distribution units included in the sample-distributing section; and
FIG. 7 is a perspective view of the mechanism used in the apparatus, for attaching distributing tips to, and detaching them from, the sample-distributing unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show an apparatus according to the present invention, which can automatically distribute a sample liquid from a source test tube into a plurality of destination test tubes. As is illustrated in these figures, the apparatus comprises housing 1, movable bed 2 mounted on housing 1, a sample-distributing section attached to bed 2 and including five distribution tips 3, L-shaped post 4 having a vertical portion protruding upward from housing 1 and a horizontal portion extending from the vertical portion, and console panel 5 attached to the free end of L-shaped post 4. Housing 1 contains a control system including a sequencer. Bed 2 can be moved in the direction of arrow X and also in the direction of arrow Y, as is illustrated in FIGS. 1 and 2.
The apparatus further comprises a sample-distribution section having five identical distribution units. FIG. 3 schematically shows the sample-distributing section. A blood sample is contained in source test tube 10, with serum 12 separated from cells 13 by separation agent 11. Each distribution tip 3 can be moved up and down by a drive mechanism (not shown), so that its distal end can be inserted into source tube 10. The proximal end of tip 3 is coupled to one end of air pipe 20 in airtight fashion. The other end of pipe 20 is connected to changeover valve 21 having two air-inlet ports 21a and 21b. First port 21a is connected by pipe 22 to air supply device 23 comprising compressed air source 23a and pressure regulator 23b. Second port 21b is connected by pipe 25 to piston/cylinder device 26. Pressure detector 24 is coupled to pipe 22, for detecting changes in the pressure of the air flowing through pipe 22. Upon detecting a change in the air pressure, detector 24 generates and supplies a signal to changeover valve 21. In response to this signal, valve 21 connects pipe 20 to pipe 25. As long as valve 21 connects pipes 20 and 25, serum 10 can be sucked from tube 10 into tip 3 and remain therein when the piston is moved in the direction of arrow A, and can be distributed from tip 10 into a destination test tube (not shown) when the piston is moved in the direction of arrow B. Pressure switch 27 is connected to pipe 20, for checking tip 3 for an abnormal condition, such as clogging.
The operation of the sample-distributing section will now be explained. First, air supply device 23 is turned on, whereby air is supplied at a low rate to tip 3 through pressure detector 24, and changeover valve 21. Hence, the air is continuously supplied from distribution tip 3 through the distal end thereof. In this condition, tip 3 is gradually lowered into source tube 10. The moment the distal end of tip 3 reaches serum 12, the air stream meets resistance, and the pressure of air flowing through pipes 20 and 22 rises. Pressure detector 24 detects this pressure rise, and generates and supplies a signal to changeover valve 21. In response to this signal, valve 21 disconnects pipe 20 from first port 21a and connects pipe 20 to second port 21b, thus connecting pipe 20 to pipe 25. Then, the piston of piston/cylinder device 26 is moved in the direction of arrow A. As a result, serum 12 is sucked into distribution tip 3. Simultaneously, pressure switch 27 determines whether tip 3 is clogged or not. When a predetermined amount of serum 12 has been introduced into tip 3, the piston is stopped, and this amount of serum is retained in tip 3.
The amount of serum 12 contained in source tube 10 has been calculated based on the surface level of separation agent 11, the surface level of serum 12, and the inner diameter of tube 10. Distribution tip 3 is lowered in accordance with the calculated amount of serum 12, so as to prevent its distal end from reaching separation agent 11.
Thereafter, movable bed 2 is moved toward the place where destination test tubes are located, until distribution tips 3 are positioned immediately above the destination tubes, respectively. Then, each tip 3 is lowered until its distal end enters the destination tube. The piston of piston/cylinder device 26 is moved in the direction of arrow B, whereby serum 12 is supplied from tip 3 into the destination tube. Thus, serum 12 is distributed from source tube 10 into the destination tube. Thereafter, tip 3 is replaced with a new one, so that another sample liquid is distributed from a source test tube into a destination test tube. The serum can be distributed from tip 3 into a plurality of test tubes.
FIG. 4 is a perspective view of the sample distributing section, as is viewed from the back. As is shown in this figure, the section comprises two vertical plates 30a and 30b located in a face-to-face relation, and five distribution units 31 to 35 interposed between plates 30a and 30b. Of these units, units 31 and 35 are fastened to plates 30a and 30b, respectively. The remaining units 32, 33, and 34 can slide on guide rails (not shown) which extend between plates 30a and 30b. Distribution units 31 to 35 each have a distribution tip 3 (not shown). Unit 31 is fastened to plate 30a, and unit 35 is secured to plate 30b. Rectangular plates 41 to 44 are fastened to the backs of units 31 to 34, respectively. These plates 41 to 44 extend horizontally and parallel to one another, and are staggered in the vertical direction. They have pins 51 to 55 protruding from their free ends. Pins 51 to 54 are arranged in a line inclined to the direction in which units 32, 34, and 34 can slide on the rails. Pins 51 to 54 are inserted in slit 61 cut in lever 60. Lever 60 is supported, at one end, by pivot 62 protruding from the back of distribution unit 35, and can thus rotate around pivot 62.
As is shown in FIG. 4, the sample-distributing section further comprises motor support 70 extending horizontally from the upper end of plate 30b toward plate 30a and having a rectangular portion projecting upward from the free end. Pulse motor 71 is fixed on support 70. Shaft 72 of pulse motor 71 is fastened to threaded rod 73 is fastened to shaft 72 of pulse motor 71. Rod 72 extends through the hole cut in the rectangular portion of support 70 and set in screw engagement with the screw hole cut in the upper end portion of plate 30a. Hence, When pulse motor 71 is driven in one direction, plate 30a and, thus, distribution unit 31 are moved away from plate 30b, whereby lever 60 rotates counterclockwise (FIG. 4), moving units 42, 43, and 44 such that the interval among units 41 to 45 increases. Conversely, when motor 71 is driven in the other direction, plate 30a and, thus, unit 31 are moved toward plate 30b, whereby lever 60 rotates clockwise (FIG. 4), thereby moving units 42, 43, and 44 such that the interval among units 41 to 45 decreases.
When the interval between tips 3 attached to units 31 to 35 is shorter than the interval at which test tubes are arranged from which sample liquids must be sucked up into tips 3, or into which they must be distributed from tips 3, it must be increased match to the interval of the tubes. To increase the interval between tips 3, pulse motor 71 is driven in the forward direction. Threaded rod 73 is rotated, thus moving plate 30a and distribution unit 31 in the direction of the arrow shown in FIG. 4. As a result, lever 60 rotates counterclockwise around pivot 62, thus moving distribution units 32, 33, and 34 such that the interval between units 31 to 35 increases to the interval of the test tubes.
When the interval between tips 3 is longer than the interval at which the test tubes are arranged, it must be decreased to match the interval of the tubes. To decrease the interval between tips 3, pulse motor 71 is driven in the reverse direction. Threaded rod 73 is rotated, thus moving plate 30a and distribution unit 31 in the direction opposite to the direction represented by the arrow. Here, lever 60 rotates clockwise around pivot 62, thus moving distribution units 32, 33, and 34 such that the interval between units 31 to 35 decreases to the interval of the test tubes.
Therefore, the sample-distributing section 30 can be used to distribute from source test tubes held in the holes of a rack, which are arranged at any intervals, into destination test tubes held in the holes of a rack, which are arranged at the same or different intervals.
FIG. 5 is a perspective view of distributing section 30, as viewed from the front. FIG. 6 is a side view of one of the distribution units included in the section 30. As is evident from FIGS. 5 and 6, each of distribution units 31 to 35 has distribution tip 3. Section 30 is attached to movable bed 2, and can move in the directions of arrows X and Y (FIGS. 1 and 2), along with movable bed 2. Sample-distributing section 30 has tray mechanism 80 comprising tray 81, two paralleled rods 82, and drive cylinder 83. Rods 82 connect tray 81 to drive cylinder 83.
When tips 3 are placed above source tubes to suck up serum 12 therefrom or above the destination tubes to distribute the serum thereinto, drive cylinder 83 pulls rods 82 in the direction of arrow C (FIG. 5), thus moving tray 81 from the position below tips 3. Tray 81 is no longer located between tips 3 and the source or destination tubes, and serum 12 can be sucked from the source tubes into tips 3, or distributed from tips 3 into the destination tubes. After serum 12 has been sucked into tips 3, or distributed into the destination tubes, drive cylinder 83 pushes rods 82 in the direction of arrow D (FIG. 5), thus moving tray 81 to the position below tips 3. Thus, tray 81 remains below tips 5 while tips 3 are being moved from the source tubes to the destination tubes, or vice versa. If the serum dribbles from tips 3, it falls onto tray 81, not into test tubes other than the destination tubes.
FIG. 7 is a perspective view of mechanism 90 for attaching distributing tips to, and detaching them from, the distributing units of sample-distributing section 30. This mechanism 90 comprises support plates 91 (only one shown), boxes 92 (only one shown) fastened to plates 91, and plugs 93 (only one shown) suspended from boxes 92. Air pipes 20 are connected to the upper ends of boxes 92. Plugs 93 are made of, for example, hard rubber and shaped such that they can be inserted into the proximal ends of tips 3. They have through holes and are connected by air pipes to boxes 92. The through holes of plugs 93 thus communicate with air pipes 20. A coil spring 94 is interposed between each box 92 and each plug 93, and is mounted on the pipe connecting the plug to the box. O-ring 95 is mounted on the outer periphery of each plug 93, for accomplishing a sufficiently airtight connection between plug 93 and tip 3.
Mechanism 90 further comprises jig 100 fastened to housing 1. Jig 100 is a rectangular plate having five semicircular cut-outs 101 to 105 made in one longer side. Cut-outs 101 to 105 have such a radius that plugs 93 can be inserted into them, but the proximal ends of tips 3 cannot be inserted into them. Jig 100 can be moved relative to the distribution tips, in both the vertical direction and the horizontal direction, by means of a drive mechanism (not shown).
Mechanism 90 operates in the following manner to attach tips 3 to, and detach them from, the distributing units of sample-distributing section 30. To attach tips 3 to distribution units 31 to 35 of section 30, the drive mechanism (not shown) is operated, thus moving sample-distributing section 30 such that plugs 93 are placed above tips 3 held in a rack (not shown). Then, the drive mechanism is operated, lowering section 30 this time, so that plugs 93 are inserted into the proximal ends of tips 3. Since coil springs 94 exert a constant force on plugs 93, plugs 93 are inserted into the proximal ends of tips smoothly and stably. Further, O-rings 95 mounted on plugs 93 are in complete contact with the inner peripheries of tips 3, a sufficiently airtight connection between tips 3 and plugs 39 is accomplished. The drive mechanism (not shown) then moves section 30 upward, thus lifting tips 3, now coupled to units 31 to 35, from the rack. To detach tips from distribution units 31 to 35, the drive mechanism is operated, thus moving section 30 such that tips 3 are moved in the direction of the arrow indicated by the one-dot, one-dash line. As units 31 to 35 are moved upward at semicircular cut-outs 101 to 105 of jig 100, plugs 93, whose diameters are smaller than the radii of the cut-outs, are lifted through the cut-outs, but tips 3, whose proximal ends have diameters greater than the radii of the cut-outs, cannot be lifted. As units 31 to 35 are further moved upward, plugs 93 are pulled out of the proximal ends of tips 3, and tips 3 eventually fall. Therefore, mechanism 90 automatically and smoothly replaces the used tips with new ones.
The present invention is not limited to the embodiment described above. It can also apply to apparatuses for automatically distributing sample liquids other than serum.
What is claimed is:
1. An apparatus for distributing sample liquids contained in a plurality of source test tubes into a plurality of destination test tubes, comprising:a plurality of distribution units having a plurality of plugs each provided with an O-ring for air-tight sealing at an outer periphery thereof, and being formed of a cylindrical body including a through-hole at a center portion thereof; a plurality of distribution tips fitted to said plugs, said tips being arranged so that a distal end portion of each of said tips can be inserted into and taken out of the corresponding one of said source test tubes, and a proximal opening portion thereof is detachably fitted with the corresponding one of said plugs of said distribution units; adjusting means for varying and setting the interval between any two of said plurality of distribution units, which are next to each other, so that the interval between said distribution tips coincides with each of the intervals between said source test tubes and/or said destination test tubes; a plurality of air-operated systems provided for said distribution units, and having a function of sucking and holding the sample liquids contained in said source test tubes, and a function of discharging the sample liquids held in said distribution tips into said destination test tubes; a mechanism for moving all of said distribution units simultaneously so that said distribution tips, which are holding the sample liquids sucked in by said air-operated systems, are transferred from a first position where said source test tubes are disposed to a second position where said destination test tubes are disposed; catching means for catching liquid leaking from said distribution tips while the distribution tips are transported by said moving mechanism, said catching means having a tray driven so that it is always located beneath all of said distribution tips while transporting the tips; and automatic replacing means for replacing said distribution tips, in which after the sample liquids held in said distribution tips are discharged by said air-operated systems into said destination test tubes, said distribution tips are removed from said plugs by hitching the proximal opening end of each of said distribution tips on a semicircular-shaped notch formed on a plate member for removing said tips, so as to mount new distribution tips on said plugs; each of said plurality of air-operated systems comprising: an air pipe having openings at both ends, one of which is connected to the corresponding one of said plugs of said distribution tips; a changeover valve having a common air-inlet port connected to the other end of said air pipe, and first and second air-inlet ports, one of which is selected to be connected to said common air-inlet port; an air-supplying device connected to said first air-inlet port of said changeover valve, for supplying a small amount of air to be discharged from said distal end of the corresponding one of said distribution tips thereto; a pressure detector for detecting a change of the pressure of the air being supplied from said air-supplying device and generating a signal upon detecting the change of the air pressure; a changeover means for switching said changeover valve from said first air-inlet port to said second air-inlet port in response to the signal generated from said pressure detector; and an air piston/cylinder device connected to said second air-inlet port of said changeover valve, for sucking and holding the liquid contained in the corresponding one of said source test tubes in the corresponding one of said distribution tips, and for discharging the liquid held in said corresponding one of said distribution tips into the corresponding one of said destination test tubes.
2. An apparatus for distributing sample liquids according to claim 1, wherein the tray for catching the liquid beneath said distribution tips is slidably movable in a horizontal direction by a driving piston/cylinder device.
3. An apparatus for distributing sample liquids according to claim 1, wherein means are provided for adjusting a suction force established by said air piston/cylinder device to retain the liquids contained in said distribution tips.
| 1990-02-06 | en | 1991-05-07 |
US-3558074D-A | Tension control for unwinding a web supply reel
ABSTRACT
A device for automatically maintaining a predetermined tension of a web which is being unwound from a reel includes an unwind shaft which is rotatable, for example, in conjunction with a drawoff roller for pulling the web off the reel. The unwind shaft is connected to a rotating hydraulic device such as a pump having a discharge which is influenced by a regulating device. The discharge of the pump is led to a volume or quantity control device which is directly or indirectly connected to the drawoff roller. The fluid pressure in the conduit between the pump and the volume or quantity control is exerted on one side of the regulating device. The fluid pressure produced by an additional pump and controlled by an adjustable valve is exerted on the other side of the regulating device. The differences between said pressures effects the adjustment of the discharge volume of the pump. With such an arrangement, the pressures acting upon the regulating device determine the web tension of the material being unwound.
United States Patent [72] Inventor Franz Held 3,043,535 7/1962 Chittenden 242/75.53 [21 1 A pl No g g g Germany Primary Examiner-Nathan L. Mintz P [2 Filed Nov. 1968 Attorney McGlew and Toren [4S] Patented Jan. 26, 1971 Asslgnee Maschmenfabnk Goehel ABSTRACT: A device for automatically maintaining a Darmsmdt, Germany predetermined tension of a web which is being unwound from 1967 a reel includes an unwind shaft which is rotatable, for exam- Germany ple, in conjunction with a drawoff roller for pulling the web off [31 1 P1574397 the reel. The unwind shaft is connected to a rotating hydraulic device such as a pump having a discharge which is influenced [54] TENSION CONTROL FOR UNWINDING A WEB by a regulating device. The discharge ot' the pump is led to a SUPPLY REEL volume or quantity control device which is directly or indirectl connected to the drawoff roller. The fluid ressure in 6 Claims 1 Drawing Fig. y p
the conduit between the pump and the volume or quantity US. Cl 242/75-53 control is exerted on one ide of the regulating device, The 77/00 fluid pressure produced by an additional pump and controlled of Search an adjustable valve is exerted on the other side of the regulating device. The differences between said pressures effects [56] References (med the adjustment of the discharge volume of the pump. With UNITED STATES PATENTS such an arrangement, the pressures acting upon the regulating 2,181,049 11/1939 Douglas 242/75.53X device determine the web tension of the material being un- 2,l90,529 2/ 1940 Bretschneider 242/75.53X wound.
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PATENTEU JAN26I97| 3558074 INVICNI'OR. FRAN p A Trap/vex;
TENSION CONTROL FOR UNWINDING A WEB SUPPLY REEL SUMMARY OF THE INVENTION This invention relates in general to the construction of devices for controlling the unwinding ofa web, for example, in a paper converting machine or printing press and the like, and in particular, to a new and useful device for maintaining a predetermined tension of a web during its unwinding from a reel supply.
Brakes are used for automatically adjusting the tension of a web which is being fed off from a reel supply since the diameter of the reel decreases and speed tends to increase during the unwinding. It is known to employ fluid pumps as such brakes, which are connected to the unwind shaft. Such fluid pumps operate against an adjustable valve for the fluid which is conveyed by them. For example, it is known to provide a pump which has a conveying capacity per revolution which is adjusted e.g. by displacement of its housing. The housing is acted upon by an adjustable pressure and by the hydraulic pressure which results from the adjustment of a discharge valve for the fluid which is conveyed. Such a brake system is based upon a known principle, that is, that the web tension at a constant web speed and constant brake efficiency remains constant and therefore the efficiency of the pump must remain constant independently of the number of revolutions of the unwind shaft. This requirement is satisfied if the quantity conveyed within a certain time and the fluid pressure against which the pump operates remain constant. In a known device, this is achieved by the adjustability of the quantity conveyed by the pump per revolution. This condition will be true, however, only if the web speed remains constant. As soon as the web speed changes, the fluid pressure between the pump and the valve changes also, and thus causes an adjustment of the quantity conveyed per unit of time. This, in turn, results in a faulty increase or decrease of the web tension.
Because changes in speed cannot be avoided, the changes in web tension will result in either a looping or tying of the portion of the web which will accumulate in a short period of time during overfeed, or there will be an increase in tension within a short time which will result in the tearing of the web. Intolerable changes in tension are incurred during the starting and running out periods of the apparatus and during such times it is necessary to completely relinquish automatic adjustment of the tension and as far as possible the tension must be manually set and continuously readjusted.
The disadvantages and drawbacks of the known devices are eliminated in accordance with the invention by an arrangement in which the changes in the speed of the web will not influence the automatic adjustment of the web tension. This is achieved by connecting the unwind shaft to a pump which works against a volume or quantity control. The control adjusts the fluid which is flowing from said pump to a fluid volume which is proportionate to the speed of the web. With such an arrangement there will be a fluid pressure between the pump and the volume control which is used for the adjustment of quantity to be conveyed per revolution by the pump. An adjustable hydraulic or mechanical pressure acting against said pressure determines the web tension.
In accordance with one embodiment of the invention, there is a known control element which is set or adjusted by the web driving through a tachogenerator which adjusts the volume control electrically in accordance with the existing speed of the web. However, a hydraulic motor may also be used as a volume or quantity control, such a member being coupled either directly or through a gear with a roller which rotates at a speed of a web. Such a roller may be a supporting roller in a roll slitting or winding machine. In addition, it may also be a conveying roller by means of which the web is driven or a friction or dummy roll which is only pressed against the web. By using a hydraulic motor as a volume control in accordance with the invention, there is the added advantage that such a motor has a driving effect on the web. In this manner an essential part of the brake efficiency can be regained and transformed into a driving power for the web. Thus the total driving power for the machine is decreased. In addition, the disadvantageous warming up of the brake means is reduced.
The arrangement is an improvement over the known arrangements for merely connecting an unwind shaft to a fluid pump because the adjustment is carried out automatically and need not be affected manually from the start to the completion of a winding process.
Accordingly, it is an object of the invention to provide an improved device for regulating the tension ofa web of material which is drawn off from a reel supply by a rotatable draw off roller which is driven by a separate drive motor and which includes hydraulic braking means which may be adjusted in order to provide a desired web tension and which will be automatically adjustable in accordance with the web speed.
A further object of the invention is to provide a paper unwinding device for unwinding paper from a reel using a motor driven draw off roller which includes a hydraulic pump connected to the unwind shaft and discharging to a hydraulic motor connected directly or indirectly to said draw off roller, and including pressure regulating means responsive to the pressure in the conduit between the said hydraulic pump and the hydraulic motor and to the pressure in the conduit between the valve for regulating the tension of the web and the regulating means itself.
A further object of the invention is to provide a device for regulating the tension of the web which is being drawn off from a reel which is simple in design, rugged in construction and economical to manufacture.
The various features ofnovelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING The only FIG. of the drawing is a partial top plan view and partially schematic view of a device for maintaining a predetermined tension of the web in a winding machine constructed in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A continuous strip of material or web 1 is drawn off from a reel supply or roll 3 by a draw off or conveyor roller 2. The conveyor roller 2 is driven by an electrical or hydraulic motor 4 and may, for example, form one supporting roller of a double supporting roller system for the rewinding roll (the opposite roller and the rewinding roll not being indicated). The roll 3 is carried on an unwind shaft 5 which is connected through a coupling 30 to fluid flow producing means preferably in the form of a hydraulic pump 6 the output of which being adjustable. The pump 6 sucks in a liquid, preferably oil, through a suction conduit 7 from a container 8. The pump 6 conveys the liquid through the conduit 9 to the hydraulic motor-pump 10. The motor-pump I0 is connected through the coupling 32 to the draw off shaft 11 carrying the conveyor roller 2. The liquid flowing out of the motor-pump I0 is discharged into a conduit 12 and into a container 13 which for the purposes of completing the circuit is advantageously connected back to the container 8 either directly or through a cooling device (not shown).
In accordance with the invention regulating means are provided controlling the discharge of the pump 6 and thus the pressure conditions in the conduit 9 and which includes a regulating cylinder 15 in which a control piston 14 the rod of which adjusts the discharge of the pump is slidable. The upper cylinder space in the cylinder is connected with the conduit 9 through conduit 16 and 17. The lower cylinder space on the other side of the piston 14 is connected through a conduit 18 to a flow direction valve 19 and through a pressure regulating or pressure reduction valve 20. The pressure reduction valve 20 is connected through conduit 21 and 22 to the auxiliary pump 23, A control valve 24 is located between conduit 22 and suction line 7 and it may be regulated to permit operation of the auxiliary or additional pump 23 to pressurize the suction line 7 and to drive the pump 6 as a motor and thus the roll 3, if required. The additional pump 23 is driven by an electri cal or hydraulic motor 25.
The operation of the device is as follows:
Prior to commencing the winding the auxiliary pump 23 is driven from its motor 25 in order to fill the conduits 21 and 18 and the lower cylinder space in cylinder 15 with the fluid and thus to cause the piston 14 to reach its uppermost position at which the pump conveys its largest volume per revolution. Simultaneously, the desired tension of the web is set at the pressure reduction valve 20.
After starting the motor 4, the web 1 is drawn off the reel 3 rotating shaft 5 and driving the pump 6. The pump 6 discharges into the conduit 9 to the motor-pump 10 which rotates because of its connection with the draw off shaft 11 and which will discharge a volume of fluid corresponding to its number of revolutions per unit of time into the discharge conduit 12. Due to the operation of the pump 6 and the motor pump 10 a very specific pressure will exist in the conduit 9 and this pressure will act on the upper surface of the piston 14 through the conduits 17 and 16 and can be read off by the manometer 26. On the opposite side of the piston 14 the fluid pressure in the lower cylinder space may be adjusted by adjusting the reduction valve 20 to a desired operating pressure as indicated by the manometer 27. If the pressures at the manometers 26 and 27 are different, a displacement or adjustment of the piston 14 will occur which causes a corresponding adjustment of the conveying volume of the pump 6 per revolution until an equilibrium is reached, that is, until the pressure in the conduit 9 is proportionate to the pressure set at the pressure reduction valve 20 which corresponds to a specific tension of the web 1.
Since the diameter of the roll 3 will decrease due to the unwinding and thus the number of revolutions of the roll 3 per unit of time and the shaft 5 will increase there will be a corresponding increase of the rotation of the pump 6 provided that the speed of the web remains constant. This results in an increased conveying volume of the pump 6. Since, however, the motor-pump 10 will run at the same speed provided that the speed remains constant it will not take up any more fluid than previously. Consequently, the pressure in the conduit 9 will be increased and this will disturb the equilibrium on both sides of the piston 14 and the piston will be displaced to adjust the volume of discharge by the pump 6. This will continue until equilibrium has been restored and the increased pressure in the conduit 9 has dropped off. This process is continuously repeated until the reel supply 3 has been completely unwound. in this process the setting or adjustment of the pressure reduction valve 20 is decisive for the tension which will be maintained on the web, that is, the tension of the web will be changed only if the pressure reduction valve is intentionally adjusted or reset.
in the event that the speed of the web 1 should change during the unwinding operation then the running speed of the pump 6 and the motor-pump 10 will also be increased or reduced correspondingly. if there is an increase in speed, the pump 6 conveys more pressure fluid per unit of time and similarly the motor-pump 10 will absorb more fluid per unit of time and both in proportion to each other. This means that the pressure in the conduit 9 will not be increased but remain the same so that no displacement or readjustment of the piston 14 will take place. Consequently, the brake torque of the web and the tension of the web will be maintained. The brake efficiency must be increased proportionally to the increase in speed and this is accomplished by the faster running of the pump 6.
If, however, the speed of the web is reduced the conditions are reversed. The pump 6 as well as the motor-pump 10 will run more slowly. Within a time unit the pump 6 will therefore convey less fluid. However, the motor-pump 10 would also take up a correspondingly lower amount of fluid so that the pressure in the conduit 9 and thus the tension of the web will be maintained.
The above conditions are maintained during starting and stopping of the machine. This offers the advantage that the tension of the web may be brought to the desired degree right from the start of the winding process and may be maintained at that level during the winding process. This eliminates the need for manual control and thus will be the reason for elimination of relatively large quantities of waste in its operation.
valve 24 is operated and the pump 23 driven from the motor 25 to convey fluid through the pump 6 which then operates as a motor. The number of revolutions of the drive may be adjusted by influencing the conveying volume of the pump 6. This may be achieved because the piston 14 is not only adjustable by a fluid pressure in cylinder 15 but may also be manually adjusted if desired.
In some instances, it is also desirable that the roll 3 be un windable in two directions. In such an event a pump 6 must be constructed such that, depending upon its adjustment, a conveyin g of fluid into the conduit 9 may be affected in both rotational directions of the pump. Adjustment of the volume conveyed per revolution by means of the piston 14 or by similar operating means is such that no conveying of liquid will take place in the neutral or center position of the piston. [f the pump rotates clockwise, the operating means for the regulation of the discharge must be brought from the center position to one direction, whereas said operating means must be brought into the opposite direction, if the pump rotates anticlockwise. In this case, however, it is additionally necessary to exchange the feed or the discharge line of the two cylinder spaces on each side of the piston 14 and this is done by displacing the valve 19 into its second position so that the conduit 17 is connected with the conduit 18 and the conduit 16 is connected to the pressure reduction valve 20.
lclaim:
l. A device for unwinding web material comprising a rotatable unwind shaft upon which a reel of material is adapted to be positioned and rotated during unwinding, a drawoff shaft spaced from said unwind shaft and having roller means for engaging the web material and for drawing it off the reel, a hydraulic motor connected to said drawoff shaft, a pump connected to said unwind shaft, a fluid flow conduit connected between said pump and said motor, and regulating means connected to said fluid flow conduit and affected by the pressure in said conduit for regulating the discharge of said pump to produce a desired tension of the web being drawn off.
2. A device, according to claim 1, wherein said regulating means comprises a regulating cylinder, a piston slidable in said cylinder and having one side exposed to the fluid flow in said conduit, additional fluid flow producing means connected to the opposite side of said piston.
3. A device, according to claim 2, wherein said additional fluid flow producing means comprises an additional fluid flow pump, independent means for driving said additional fluid flow pump, and a pressure regulating valve controlling the discharge of said fluid flow pump into said regulating cylinder on the opposite side of said piston.
4. A device for unwinding a web of material such as paper, synthetic material and fabric, from a reel while automatically maintaining a predetermined tension of the web being unwound, comprising a rotatable drawoff roller for drawing the web from the reel, an unwind shaft carrying said reel, a pumpmotor connected to said drawoff roller for rotation therewith, a pump connected to and rotated by said unwind shaft and providing a fluid flow to said pump-motor, a series fluid connection between said pump and said pump motor permitting movement of the fluid flow from said pump to said pump molf the roll 3 is not to be braked but is to be driven then the I tor, and flow regulating means connected to said series fluid connection and to said pump and being responsive to variations of the pressure in said series connection to regulate the output of said pump and the fluid discharge thereby into said pump-motor to vary the rotational speed of said pump motor and the speed of said drawoff roller.
5. A device, according to claim 4, wherein said regulating means includes a fluid cylinder and a piston slideable in said cylinder, said cylinder being exposed on one side of said piston to the pressure existing between said pump and said cylinder,
1. A device for unwinding web material comprising a rotatable unwind shaft upon which a reel of material is adapted to be positioned and rotated during unwinding, a drawoff shaft spaced from said unwind shaft and having roller means for engaging the web material and for drawing it off the reel, a hydraulic motor connected to said drawoff shaft, a pump connected to said unwind shaft, a fluid flow conduit connected between said pump and said motor, and regulating means connected to said fluid flow conduit and affected by the pressure in said conduit for regulating the discharge of said pump to produce a desired tension of the web being drawn off.
2. A device, according to claim 1, wherein said regulating means comprises a regulating cylinder, a piston slidable in said cylinder and having one side exposed to the fluid flow in said conduit, additional fluid flow producing means connected to the opposite side of said piston.
3. A device, according to claim 2, wherein said additional fluid flow producing means comprises an additional fluid flow pump, independent means for driving said additional fluid flow pump, and a pressure regulating valve controlling the discharge of said fluid flow pump into said regulating cylinder on the opposite side of said piston.
4. A device for unwinding a web of material such as paper, synthetic material and fabric, from a reel while automatically maintaining a predetermined tension of the web being unwound, comprising a rotatable drawoff roller for drawing the web from the reel, an unwind shaft carrying said reel, a pump-motor connected to said drawoff roller for rotation therewith, a pump connected to and rotated by said unwind shaft and providing a fluid flow to said pump-motor, a series fluid connection between said pump and said pump motor permitting movement of the fluid flow from said pump to said pump motor, and flow regulating means connected to said series fluid connection and to said pump and being responsive to variations of the pressure in said series connection to regulate the output of said pump and the fluid discharge thereby into said pump-motor to vary the rotational speed of said pump motor and the speed of said drawoff roller.
5. A device, according to claim 4, wherein said regulating means includes a fluid cylinder and a piston slideable in said cylinder, said cylinder being exposed on one side of said piston to the pressure existing between said pump and said cylinder, and a mechanical pressure adjustment valve connected to said cylinder on the opposite side of said piston and connected to said series connection.
6. A device, according to claim 4, said series connection including a liquid reservoir, said pump being connected to said reservoir for discharging liquid from said reservoir into the connection between said pump and said pump motor, said pump motor being adapted to discharge back into said reservoir means.
| 1968-11-13 | en | 1971-01-26 |
US-80618391-A | Process and apparatus for direct determination of low density lipoprotein
ABSTRACT
Low density lipoprotein are directly determined in body fluids by selectively precipitating very low density lipoprotein, forming clusters with low density lipoproteins, selectively consuming the high density lipoproteins, and resolubilizing the low density lipoproteins for direct determination thereof. The clusters are formed by treating the fluid sample with a mixture of a polyanionic compound, a divalent metal, and a nucleating agent.
FIELD OF THE INVENTION
The present invention relates to a process for the direct determination of low density lipoprotein in body fluids. More specifically, the present invention relates to a process and apparatus for determination of low density lipoprotein by selectively precipitating low density lipoprotein from a sample, providing enzymes which selectively consume the high density lipoprotein, and then resolubilizing the low density fraction and determining this fraction enzymatically.
BACKGROUND OF THE INVENTION
Lipoproteins are complex particles consisting of protein and lipid which are found in the circulatory system. One of their functions is to carry water-insoluble substances such as cholesterol and cholesterol esters for eventual cellular utilization. While all cells require cholesterol for growth, excess accumulation of cholesterol by cells is known to lead to certain diseases, including atherosclerosis.
It is known that the amount of total serum cholesterol can be correlated with the incidence of atherosclerosis. However, there are a variety of classes of lipoproteins in serum which can be classified by their density. These classes include very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL). All of these lipoprotein classes contain varying amounts of cholesterol, and a total serum cholesterol determination is a complex average of the amount that each lipoprotein class contributes to the total lipoprotein population of the serum.
It has long been suspected that specific lipoprotein classes were more closely associated than other lipoprotein classes with the progression of heart disease, including atherosclerosis. In fact, more recent studies have implicated LDL as the class of lipoproteins responsible for the accumulation of cholesterol in cells, whereas HDL has been shown to be important in the removal of excess cholesterol from cells. Additionally, the correlation of atherosclerosis and the levels of LDL cholesterol is much higher than a similar correlation between atherosclerosis and total serum cholesterol levels. Conversely, there appears to be a negative correlation of atherosclerosis and HDL cholesterol levels.
Despite the desirability of isolating LDL cholesterol levels in blood plasma from other soluble cholesterols, a technique suitable for use in clinical laboratories has not heretofore existed. One method which has been suggested relies upon the interaction of heparin in the presence of calcium to precipitate both LDL and VLDL, cf. Bursterin et. al., Adv. Lipid Res. 11: 67 (1973). To separate the LDL and VLDL fractions, ultracentrifugation techniques, which are time consuming and expensive, must be used.
Another method for determining LDL is calculation by the Friedewald Formula, as disclosed in Friedewald et al., Clin. Chem. 18: 499-502 (1972). In this method, LDL is estimated by the total cholesterol, HDL, and triglyceride contents of the sample. This method requires multiple assays, and is not accurate for samples containing high levels of triglycerides.
Ultracentrifugation, to separate the lipoproteins solely on the basis of their density, requires special equipment and long processing time. Electrophoretic separation also requires special equipment and long processing times.
A variety of precipitation methods have been used, which depend upon the use of polyanions and divalent cations. Okabe Xth Int. Cong. of Clin. Chem., Mexico (1978); Genzyme Diagnostics, Cambridge, Mass. LDL cholesterol precipitation reagent package insert. Other precipitation methods use polymers, as shown in U.S. Pat. No. 4,474,898 and U.S. Pat. No. 4,647,280; or lectin, as disclosed in U.S. Pat. No. 4,126,416. Kerscher et al., in U.S. Pat. No. 4,746,605, teach that VLDL and HDL can be precipitated by HDL antibodies with polyanions and divalent cations. However, the amount of antibodies required with this method is too expensive for routine use.
When LDL is precipitated with polyanions such as dextran sulfate and divalent cations such as magnesium, the precipitate redissolves if one tries to selectively convert the cholesterol in the supernatant by an enzymatic assay which requires the presence of surfactants. Moreover, LDL in the presence of the enzyme cholesterol esterase and cholesterol oxidase, is hydrolyzed thereby.
Consequently, there is a need for a simple procedure or device for the determination of LDL lipoprotein accurately.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the aforementioned deficiencies in the prior art.
It is another object of the present invention to provide a simple method for the determination of LDL.
It is a further object of the present invention to provide an apparatus for determination of LDL.
According to the present invention, LDL can be precipitated with a mixture of large polyanions and divalent cations in the presence of a small amount of nucleating particles. These particles may range in size from about 0.1 to about 200 microns, and may be either mixed with the polyanionic compound or the polyanionic compound may be immobilized thereon.
An LDL precipitate is formed in the presence of the nucleating particles and polyanionic molecule, which precipitate is not hydrolyzed at a noticeable rate by the enzyme cholesterol esterase in the presence of surfactants. The nucleating agents aid in the formation of large clusters of LDL precipitates, and also help to stabilize the clusters against the effect of surfactants and cholesterol esterase.
Both of the above phenomena were surprising because LDL precipitate normally dissolves quickly in the presence of surfactants such as sodium cholate, and cholesterol esterase usually hydrolyzes any cholesterol esters in lipoproteins rapidly in the presence of suitable surfactants. However, the presence of sufficient small particles to provide nucleating agents for clusters of LDL stabilized the clusters against the effect both of surfactants and of cholesterol esterase.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a direct LDL measurement device according to the present invention.
FIG. 2 is a side view of another direct LDL measurement device according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the device according to the present invention is shown at 10. A fluid sample is introduced to the device 10 at 20, and red blood cells are trapped in layer 11. Plasma then enters layer 12, where all of the VLDL is trapped as a precipitate in layer 12. Plasma containing all of the HDL and LDL then enters zone 13. A particle enhanced LDL precipitation reagent 21 in zone 13 causes the LDL to precipitate in large clusters 22 in less than 60 seconds. The enzymes cholesterol esterase (CE) and cholesterol oxidase (CO), together with the surfactants deposited in zone 13, react with the HDL to produce hydrogen peroxide. Surprisingly, the particle enhanced LDL precipitate 22 does not dissolve and does not react with the cholesterol enzymes, so that only the HDL reacts with the cholesterol enzymes, and the hydrogen peroxide generated thereby is consumed by endogenous catalase in less than ten minutes.
Zone 14 is a thin sucrose coating and is designed to dissolve in less than ten minutes. Zone 15 contains dried hydroxylamine (HA), which is a catalase inhibitor, and protease, which reacts with the protein moiety of LDL. When zone 14 is dissolved, both the hydroxylamine and the protease are mixed with the contents of zone 13, where the catalase is inhibited by hydroxylamine and the LDL clusters are then dissolved by the action of protease. The re-dissolved LDL then reacts with cholesterol oxidase and cholesterol esterase, generating hydrogen peroxide which flows through a timing barrier 17 into the measurement zone 16 on the device. The length of the color bar developed in the measurement zone is proportional to the concentration of the LDL in the whole blood sample.
More specifically, during the first ten minutes, the reactions in zone 13 are as follows: ##STR1##
During the next five minutes, the reactions in layer 13 are as follows: ##STR2##
The device of the present invention can be used with a different enzyme system, as shown in FIG. 2. In FIG. 2, whole blood is introduced into the device 40 at 30, the top of layer 31. Red blood cells are trapped in zone 31, and plasma enters zone 32. A VLDL precipitation reagent in zone 32 traps all VLDL, and plasma containing HDL and LDL enters zone 33. A particle enhanced LDL precipitation reagent 38 in zone 33 causes LDL to precipitate in large clusters 38 in less than 60 seconds. In addition, zone 33 is buffered to about pH 9, and contains cholesterol esterase, cholesterol oxidase, cholesterol dehydrogenase (CDH), protease, NAD, surfactants and cation exchange resins. HDL in the plasma reacts with cholesterol esterase, cholesterol dehydrogenase and NAPD to produce NAPDH, while the LDL precipitate remains unaffected. The pH in zone 33 drops with time because of the cation exchange resins which become bedded inside this zone. Additionally, as the pH falls from 9.0 to 7.0, the cholesterol dehydrogenase becomes inactivated, while the cholesterol oxidase and protease become activated. The LDL precipitate is then dissolved by the protease, and cholesterol esterase and cholesterol oxidase react with LDL to generate hydrogen peroxide. The hydrogen peroxide so generated flows through the timing barrier 37 into measurement zone 36. The length of the color bar developed in the measurement zone is proportional to the concentration of the LDL in the whole blood sample.
Of course, it will be appreciated that the devices specifically disclosed herein for use in assaying for low density lipoprotein are not the only devices in which the system for assaying for low density lipoprotein can be used. The system can be used with any suitable device which provides a means for trapping the VLDL precipitate and for forming clusters of LDL which can be separated from HDL for analysis.
Alternatively, instead of sequentially precipitating VLDL and LDL, a specific LDL precipitating reagent with added nucleating particles can be used. In this case, the HDL and VLDL in the supernatant react with the cholesterol enzymes first, and LDL reacts after the HA and protease are released.
The polyanions that can be used for forming the LDL clusters can be any suitable polyanions for use in clinical assays and which do not interfere with subsequent enzymatic or other assays for LDL. Among the polyanions that can be used are dextran sulfate, heparin, phosphotungstic acid, and polyvinyl sulfate. The dextran sulfate can be high molecular (i.e., molecular weight of from 5×104 to 2×106) or short-chained (molecular weight of from 5000 to 50,000). The preferred concentration ranges of the polyanions in the reaction mixture are from about 0.1 to about 8 g/liter in the case of high molecular weight dextran sulfate, from about 1 to about 15 g/liter in the case of short-chained dextran sulfate and heparin, from about 0.2 to about 5 g/liter in the case of polyvinyl sulfate, and from about 0.3 to about 6 g/liter in the case of phosphotungstic acid.
The polyvinyl sulfate is a polymer derived from polyvinyl alcohol, of which polymer at least 20% of the vinyl alcohol groups are sulfated. The molecular weight of the polyvinyl alcohol is not critical as long as it can be crosslinked. This is generally the case at a molecular weight of about 5000 or higher. Very favorable results can be obtained at molecular weights in the range of 10,000 to 150,000 or more.
For best results, at least 50% of the vinyl groups are sulfated. Optimum results are obtained wherein at least about 65% of the vinyl alcohol groups are sulfated. Sulfation of the polyvinyl alcohol is preferably carried out using a reaction product of sulfur trioxide or chlorsulfonic acid and a Lewis base. Particularly suitable is the addition product of pyridine to sulfur trioxide. The sulfation reaction is preferably carried out in dimethyl formamide or formamide at a temperature of between 60° and 110° C. The polyvinyl alcohol may be crosslinked before or after sulfation and the crosslinking may be effected either chemically or physically.
The divalent cations that can be used in the system of the present invention include calcium, magnesium and manganese. These cations can be added in the form of a salt such as a chloride salt. The concentration of the divalent metal ions to be added is preferably from about 10 to about 250 mMole/liter in the reaction mixture. Furthermore, the reaction mixture preferably contains sodium chloride in a concentration of from 0.1 to 1 mole/liter. A conventional buffer can be used to buffer in a pH range of from about 6.5 to about 8.5, such as MES (morpholino ethane sulfonic acid), triethanolamine, MOPS (morpholino propane sulfonic acid) or Tris buffer.
Once the LDL fraction has been separated from the other components in the sample, conventional methods of analysis can be used for the LDL determination. The LDL determination can, for example, take place by saponification with alcoholic potassium hydroxide solution and chemical determination according to Liebermann-Burchard. However, it is preferred to use an enzymatic determination using cholesterol oxidase and a cholesterol ester-splitting enzyme or enzyme system, such as cholesterol esterase. In the case of the use of cholesterol esterase, the determinations can be based upon the amount of oxygen consumed, the amount of cholestenon formed, or the amount of hydrogen peroxide formed using conventional methods for this purpose. Since the determination of bound cholesterol is well known, there is no need to describe it in detail.
The particles that can be used as nucleating agents for forming the LDL clusters can be any particles that do not interfere with the subsequent assay for LDL. For example, chromium dioxide, stainless steel, silicon dioxide, glass, methyl methacrylate particles, and the like can all be used. The particle size is generally between about 0.5 and 100 microns.
The nucleating agents can be added in with a mixture of the polyanionic compound and the divalent metal. Alternatively, the nucleating agents can be coated with the polyanionic compound or various compounds and added along with the divalent metal to the fluid sample.
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and therefore such adaptations and modifications are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation.
What is claimed is:
1. A process for direct determination of low density lipoprotein in a fluid sample comprising:selectively precipitating very low density lipoprotein from the fluid sample;adding a polyanionic compound, a salt of a divalent metal and a nucleating agent to the fluid sample to form clusters of low density lipoprotein; adding an enzyme selected from the group consisting of cholesterol oxidase, cholesterol esterase, and mixtures thereof to consume high density lipoprotein selectively from the fluid sample; contacting said sample with a protease for resolubilizing the low density lipoprotein; and contacting said fluid sample with reagents for determining the amount of low density lipoprotein in the sample.
2. The process according to claim 1 wherein said polyanionic component is selected from the group consisting of dextran sulfate, heparin, phosphotungstic acid, and polyvinyl sulfate.
3. The process according to claim 1 wherein said divalent cations are selected from the group consisting of calcium, manganese and magnesium.
4. The process according to claim 1 wherein said nucleating agents are selected from the group consisting of stainless steel particles, silicon dioxide particles, and polymethyl methacrylate particles.
5. The process according to claim 4 wherein said nucleating agents have a particle size ranging from about 0.1 to 200 microns.
6. The process according to claim 1 wherein said low density lipoprotein is determined enzymatically.
7. A process for direct determination in a measurement device of low density lipoprotein in a fluid sample comprising:providing a measurement device having first and second zones; introducing said sample into a first zone of said device wherein said sample contacts a mixture of a polyanionic compound, a salt of a divalent metal, and a nucleating agent to form clusters of low density lipoprotein; introducing said sample into a second zone of said device wherein said sample contacts an enzyme selected from the group consisting of cholesterol oxidase, cholesterol esterase, and mixtures thereof and to consume high density lipoprotein and very low density lipoprotein selectively from the fluid sample; contacting said sample with a protease to resolubilize low density lipoprotein; and determining the amount of low density lipoprotein in the sample.
8. The process according to claim 7 wherein said polyanionic component is selected from the group consisting of dextran sulfate, heparin, phosphotungstic acid, and polyvinyl sulfate.
9. The process according to claim 7 wherein said divalent cations are selected from the group consisting of calcium, manganese and magnesium.
10. The process according to claim 7 wherein said nucleating agents are selected from the group consisting of stainless steel particles, silicon dioxide particles, and polymethyl methacrylate particles.
11. The process according to claim 7 wherein said low density lipoprotein is determined enzymatically.
12. The process according to claim 7 wherein said nucleating agents have a particle size ranging from about 0.1 to 200 microns.
| 1991-12-13 | en | 1994-02-15 |
US-32631994-A | Connector for high density electronic assemblies
ABSTRACT
An electrical connector includes a housing and a plurality of terminals secured within the housing for mounting a mating connector or an electronic module or the like having a plurality of electronic leads disposed thereon to a printed substrate. A first contact beam is cantilevered from a base portion and has a distal end, while a second contact beam is similarly cantilevered from a base portion and also has a distal end wherein a gap is formed between the distal ends of the contact beams. The leads of the mating connectors or the like are inserted into the gap for contacting engagement with the contact beams. A gap adjustment integrally connected to the base portion provides for simple adjustment of the size of the gap between the contact beams.
This is a division, of application Ser. No. 08/169,586, filed Dec. 17, 1993, now U.S. Pat. No. 5,409,406, issued Apr. 25, 1995.
FIELD OF THE INVENTION
This invention relates to a connector having a plurality of terminals for connecting a mating connector or the like to a circuit board. More particularly, this invention relates to a connector having a plurality of terminals wherein each terminal comprises two resilient contact beams having free distal ends which are separated by a gap for receiving a lead of a mating connector or the like and wherein a gap adjustment provides for simple adjustment of the size of the gap.
BACKGROUND OF THE INVENTION
Miniature and portable electronic devices are among the fastest growing segments of the electronics industry. Among these devices are cellular phones operating with a ground cell network, satellite communication net terminals, laser and infrared measurement instruments, and work-stations including combinations of personal computers, facsimile machines with voice telecommunication terminals and notebook computers.
An important trend in the electronics industry has been the increasing utilization of integrated circuits as individual components due to their relatively inexpensive cost, miniature size, and electrical dependability. Today it is common for hundreds of complex integrated circuits to be treated as discrete components by the design engineer, with such integrated circuits being appropriately packaged and electrically connected to their associated printed circuit boards.
Many of the current electronic designs contain a variety of components such as, flexible, rigid, and semi-rigid printed circuit boards, hybrid circuits and large silicon integrated circuits. These components must be mounted together by electrical connectors having a plurality of terminal contacts which provide for inexpensive latching and containment of the electronic components.
Connectors having tuning fork type dual beam contact terminals wherein a gap is provided between the contact terminals are known for providing a mounting connection between an electronics package and a printed circuit board or the like. Leads of the electronics package are inserted into the gap for making contact with one or both of the contact terminals such that the electronics package is electrically interconnected with the printed circuit board. However, in order to manufacture these types of terminal having an extremely small gap size, the punching device which forms the gap from the terminal material during a stamping operation must also be extremely small. However, due to the forces exerted on the punching devices during a stamping operation, small punch devices are prone to breaking under the influence of such forces.
Therefore, there is a need for a low cost, high density connector having a plurality of terminal contacts which can be simply manufactured, allows for simple and effective regulation of insertion forces, has the strength necessary for providing a reliable connection between an electronic module or the like and a printed circuit board and which can be simply adjusted to provide a varying gap size between terminal contacts. The present invention provides an electrical connector which satisfies this need.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide an improved connector for a high-density electronic module, mating connector or the like that is inexpensive and simple in construction.
An electrical connector in accordance with the present invention comprises a housing and a plurality of terminals secured in the housing for connecting a mating connector or the like to a printed substrate. Each of the terminals has a first and second base portion. The first base portion has a first contact beam cantilevered therefrom, with the first contact beam having a first distal end. Similarly, the second base portion has a second contact beam cantilevered therefrom, with the second contact beam having a second distal end, and wherein a gap is formed between the first and second distal ends. The first and second contact beams are for receiving an electrical lead inserted in the gap such that the electrical lead contacts at least one of the distal ends for establishing electrical connection between the lead and the printed substrate and for providing reliable mounting of the mating connector on the printed substrate. A gap adjustment is integrally connected between the first and second base portions for adjusting the size of the gap.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a connector in accordance with the present invention.
FIG. 2 is a perspective view of a connector terminal in accordance with the present invention.
FIG. 3 is a perspective view of a second embodiment of a connector terminal in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to FIG. 1, an improved connector 10 is constructed and arranged to be attached to a motherboard or substrate 12 that has contacts 14, preferably comprising copper, thereon. Contacts 14 can be pads of solder disposed on substrate 12 in a known manner or plated through holes. Substrate 12 can be a printed circuit board or the like having electronic circuitry printed thereon for carrying out specific functions in a known manner. Connector 10 is adapted to receive an electronic male connector 16 that is of the type that has a plurality of leads 18 positioned on an underside thereof. Leads 18 can be, for example, contact pins that are bent downwardly orthogonally to the plane of the male connector 16 as shown in FIG. 1. However, the present invention is not intended to be limited in this manner and connector 10 can be adapted to receive a variety of electronic modules or the like, as set forth in further detail below, such as a thin card-type electronic module having a plurality of flat contact pad leads positioned on an underside thereof and adjacent to one or more edges of the electronic module.
Connector 10 includes a housing 20 preferably fabricated from a non-conductive, non-metallic material, such as hard plastic. A plurality of connector terminals 22 are positioned in and securely mounted in housing 20. Terminals 22 preferably comprise a material having a high electrical conductivity and high elastic modulus, such as phosphorous bronze or beryllium bronze, and can be formed by any known manufacturing method, such as stamping or etching.
As shown in FIG. 2, a terminal 22 includes base portions 24, 26. A resilient first contact beam 28 is cantilevered from base portion 24 and has a distal end 30. Similarly, a resilient second contact beam 32 is cantilevered from base portion 26 and has a distal end 34. The longitudinal plane of terminal 22 is herein defined as that plane in which contact beams 28, 32 are cantilevered from their respective base portions 24, 26. A gap 36 is formed between the distal ends 30, 34 of the contact beams 28, 32 and the contact beams receive lead 18 inserted in the gap 36, as shown in FIG. 1, such that the electrical lead 18 contacts at least one of the distal ends 30, 34 for establishing electrical connection between the lead and the printed substrate 12. As shown in the embodiment of FIG. 2, distal ends 30, 34 can be bent at an angle to the longitudinal plane of the terminal. In a preferred embodiment, distal ends 30, 34 are bent orthogonally to the longitudinal plane of the terminal. In this embodiment, the leads of a mating connector or the like are inserted substantially perpendicular to the longitudinal plane of the terminal.
The terminal embodiment shown in FIG. 2 can be surface mounted to the contact pads of a printed circuit board or the like wherein base portions 24, 26 are solderably connected to the contact pads in a known manner. However, the present invention is not intended to be limited in this manner and various other types of terminal mounting techniques are within the scope of the invention. For example, the terminal embodiment shown in FIG. 3 includes an attachment tail 39 which can be mounted in a plated through hole in the printed substrate in a known manner for connecting the terminal to a contact pad on the circuit board.
As discussed above, where a particular application requires that connector 10 is connected to an edge card type connector having a plurality of leads on one of the sides thereof, the edge of the card is disposed in the gaps of the adjacent terminals such that the leads contact the distal end of one of the contact beams of the connector terminal.
Gap adjustment 40 is disposed between and integrally joins base portions 24, 26. Gap adjustment 40 can be adjusted to provide a desired size for the gap 36 between the distal ends of the contact beams. In the embodiment shown in FIG. 2, gap adjustment 40 has a curved profile which projects a predetermined depth outside of the longitudinal plane of the terminal. This profile and depth correspond to a particular gap size.
Thus, a terminal 22 is manufactured by forming a quantity of terminal material, preferably by stamping, into a desired terminal profile, such as that shown in FIGS. 2 and 3.
In order to adjust the gap size, the depth or the profile, or both, of the gap adjustment 40 is altered to obtain the desired gap size. The gap adjustment can be altered by displacing the gap adjustment material to change the depth at which the gap adjustment extends outside of the longitudinal plane of the terminal and/or by displacing the gap adjustment material to change the profile of the gap adjustment while maintaining a specified depth. It is preferable to form the shape of the gap adjustment for a desired gap size such that the base portions 24, 26 remain aligned in parallel in the longitudinal plane of the terminal.
Thus, a connector in accordance with the present invention provides low cost, low-profile connector terminals which can be densely packed together and which provide a reliable latching mechanism for securing a mating connector or the like into electrical connection with a printed substrate. The connector terminals can be simply modified to receive variable size leads of a mating connector or the like.
Although particular embodiments of the present invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art. Consequently, it is intended that the claims be intended to cover such modifications and equivalents.
What is claimed is:
1. A method of manufacturing a connector terminal, comprising:providing a quantity of terminal material; forming said quantity of terminal material into:a first base portion having a first contact beam cantilevered therefrom, said first contact beam having a first distal end; a second base portion having a second contact beam cantilevered therefrom, said second contact beam having a second distal end, wherein a gap is formed between said first and second distal ends, wherein said first and second base portions lie substantially in a common plane; an intermediate portion disposed between and integral with said first and second base portions; and displacing an amount of said terminal material at said intermediate portion to adjust the size of said gap, wherein the terminal material displaced is bowed out of said plane.
2. The method according to claim 1 wherein said forming step is carried out in a stamping operation.
3. The method according to claim 2, wherein said displacing step is carried out in a stamping operation.
4. The method according to claim 1, wherein said terminal material is substantially planar.
| 1994-10-20 | en | 1996-03-26 |
US-3595269D-A | Drain valve for humidifier
ABSTRACT
A combined drain and overflow valve assembly adapted for upright mounting in the water reservoir of a humidifier comprises a hollow casing having a lateral inlet port and a hollow core rotatably mounted in the casing. The core has a longitudinal passage open at both upper and lower ends for overflow discharge, and is formed with a small diameter drain port and a larger diameter flush port both intersecting that passage and adapted respectively to register with said inlet in different rotative positions of the core.
United States Patent Inventor Richard J. Yeagle llartland, Mich.
Appl. No. 837,624
Filed June 30, 1969 Patented July 27, 1971 Assignee Skuttle Mfg. Co.
Milford. Mich.
DRAIN VALVE FOR HUMIDIFIER 9 Claims, 7 Drawing Figs.
11.8. C1 137/577, 126/113,261/92,4/206 Int. Cl F241 3/14 Field ol'Search... 137/1,577,
[56] References Cited UNlTED STATES PATENTS 2,266,043 12/1941 Hutchins 4/206 3,266,481 8/1966 Wentling et a1 126/113 3,456,927 7/1969 Martin etal. 126/113 X 3.491453 2/1970 Yurdin 261/97 Primary Examiner-William R. Cline Att0rneyStrauch, Nolan, Neale, Nies and Kurz ABSTRACT: A combined drain and overflow valve assembly adapted for upright mounting in the water reservoir of a humidifier comprises a hollow casing having a lateral inlet port and a hollow core rotatably mounted in the casing. The core has a longitudinal passage open at both upper and lower ends for overflow discharge, and is formed with a small diameter drain port and a larger diameter flush port both intersecting that passage and adapted respectively to register with said inlet in different rotative positions of the core.
PATENTEflJuLzmn 3,595,269 SHEET1UF2 IN V L'N TOR.
RICHARD J. YEA 6L E A TTORA/EYS DRAIN VALVE FOR HUMIDIFIER BACKGROUND AND HISTORY OF INVENTION This invention relates to humidifier assemblies of the type wherein a slowly rotating drum rotates with its lower sector immersed in a body of water to pick up water which is then evaporated therefrom into air to be humidified, usually the hot air supply in a central heating system.
Humidifiers of this type currently provide on the drum on annulus or so-called pad of open pore foamed polyurethane as the vehicle for picking up the water and providing large area contact with the dry heated air to be humidified. While this material is water resistant in that it does not absorb or react chemically with water or the various impurities such as alkalies and'the like in the usual public water supply, problems are being encountered'in that after a period of operation solid material derived from the water collects in the pad pores and passages clogging them, and in time rendering the pad incapable of picking up water or permitting passage of air through it. The padshave to be periodically replaced or cleaned but usually the loss of efficiency is gradual and the humidifier may be practically ineffective for long periods without such being detected.
Water in the usual city and other public supply has long been known to contain carbonates, sulfates, chlorine com pounds and many other impurities, depending on the locality and the purification treatments. These impurities are known to precipitate or crystallize to form solids deposits particularly when the water is heated. i
The water body in the humidifier is automatically maintained at a constant level by a float operated valve or the like, which intermittently operates to introduce fresh water into the body. The water in the body usually becomes hot because the humidifier is usually mounted at the warm air discharge conduit of the furnace, and heat is obtained both by conduction through the housing and from the warm air.
The water picked up by the drum pad contains the impurities but only water is evaporated therefrom into the air stream. As a result solids precipitated, crystallized, or otherwise deposited out of the water during evaporation remain on the rotating drum and are carried back into the body of water where, because of their relatively low attraction to the drum surfaces, most of the solids deposit into suspension in the water body. In time the solids concentration in the body increases toward saturation, and as the concentration increases more and more solids are picked up each time by the drum and gradually the drum pad becomes choked by the accumulated solids retained thereon and therein.
Attempts to solve the problem have included periodic introduction of tablets that chemically attack the solids, but even where this is helpful it depends upon the judgement and attention of the householder, so that in general it is not an entirely satisfactory solution.
Inthe present invention, solids concentration in the body of water is limited and held below safe values by continuously draining at a predetermined rate a very small amount of the water out of the water body into a waste outlet, preferably the rate of drain being sufficient to maintain the concentration of solids in the water body at a value that does not exceed the mineral content of the supply water, and this novel method and a special valve for accomplishing it constitute important objects of the invention. The invention also contemplates an improved humidifier drain control valve assembly which can be adjusted between the predetermined rate small flow drain position to a "more open position where it permits rapid thorough flushing of the tray or other container for the body of water at desired intervals, this being particularly useful when the solids accumulate beyond safe limits or periodic maintenance. The valve assembly of the invention is also preferably constructed to serve as an overflow valve whether the valve assembly is closed or in drain or flush positions, this being a safety measure to take care of improper operation of the float valve. The foregoing features of the valve assembly contribute to provide important objects of the invention.
Further objects will appear in conjunction with the attached claims and the accompanying drawings wherein:
FIG. 1 is a side elevation mainly in section showing a rotary drum humidifier incorporating the invention according to a preferred embodiment:
FIG. 2 is a section substantially on line 2-2 of FIG. 1 showing mounting of the valve assembly on the tray bottom;
FIG. 3 is an enlarged side elevation showing the valve as sembly, and showing in section its attachment to the tray bottom;
FIG. 4 is essentially a vertical section through the valve assembly of FIG. 3, showing detail of the valve casing and core;
FIG. 5 is a top plan view of the valve assembly;
FIG. 6 is a bottom plan view of the valve assembly; and FIG. 7 is a side elevation, partially broken away and sectioned, showing the valve core.
PREFERRED EMBODIMENTS FIG. 1 illustrates a rotary drum-type humidifier wherein the drum 11 comprises an annulus 12 of nonabsorbent water pickup material such as open pore polyurethane foam mounted on a skeleton frame 13 secured to a generally horizontal shaft 14 that has one end supported in a bearing device 15 on a sidewall 16 of a stationary sheet metal housing 17.
The other end of shaft 14 is suitably rotatably mounted on the opposite sidewall 18 0f the housing and is connected to a motor and gear reduction unit 19 externally mounted on that wall.
Supported on the bottom wall 21 within the housing is a tray 22 which is preferably an integral molded plastic unit resistant to corrosion by water. Normally tray 22 contains a body of water 23 in which the lower peripheral sector of annulus 12 is immersed. The level of water in the tray is automatically maintained by a valve assembly 24 controlled by a float 25, the normal water level being indicated at 26.
In operation drive unit 19 slowly rotates drum 11, at about 1 revolution per minute, the lower sector of annulus l2 picking up water from body 23 and the upper part of annulus 12 being traversed by air to be humidified.
The foregoing humidifier drum and drive structure and operation in general are essentially as disclosed in Stiles US. Pat. No. 3,408,880, and the float-operated valve may be that disclosed in Powers US. Pat. No. 3,099,286.
In the invention the tray bottom wall 27 is formed with a noncircular aperture 28, which may be circular except for opposed parallel flat sides 29 and 31. Mounted upright at aperture 28 is a two part combination overflow and drain valve assembly 32.
Referring to FIGS. 2 and 3, valve assembly 32 comprises as one part a casing 33 having at its lower end an enlarged radial flange 34 and a threaded boss 35. Boss 35 has flat sides 36 and 37, and is sized to nonrotatably fit tray aperture 28. As shown in FIG. 3, the threaded boss 35 extends through aperture 28 to mount a nut 40. A resilient gasket 30 surrounds the casing between flange 34 and the tray bottom, so that when nut 40 is drawn tight the casing 33 is nonrotatably secured fluidtight in upright position within the tray.
Valve casing 33, as shown in FIG. 6, has a cylindrical through bore 38 of uniform diameter, and bore 38 is intersected by a lateral intake port 39 at the upper side of flange 34. At its upper end casing 33 is formed with a lateral projection 41 preferably aligned vertically with the center of port 39 and a flat side 36 of the boss. Casing 33 is preferably a single unit molded of solid water resistant vinyl plastic material.
The other part of valve assembly 32 is a core 42 of similar plastic material rotatably mounted in casing bore 38. Core 42 has its cylindrical lower end 43 sized to be frictionally snug and substantially watertight but rotatable between definite angular positions within bore 38, and it is relieved at 44 to reduce the turning friction. The upper end of core 42 is an enlarged head 45 having a flat underside 46 adapted to seat on the corresponding flat upper end 47 of casing 33.
Core 42 is provided with a uniform diameter through bore 48 open at top and bottom. Bore 48 is intersected near its lower end by a large diameter lateral flush port 49, and at a circumferentially displaced location, preferably about 90 with a relatively small lateral drain port 51.
Ports 49 and 51 are disposed with their centers in slightly displaced planes, and when core 42 is pushed down into casing bore 38 to seat its head on the upper casing end 47 such locates the centers of ports 39 and 49 in substantially the same transverse plane. Port 51 is slightly below this center plane but it opens fully into port 49 when the two are aligned.
As shown in FIG. 3, the diameter of flush port 49 may be only slightly smaller than that of inlet port 39. In a working embodiment, port 39 is about one-quarter inch in diameter and port 49 about three-sixteenth inch in diameter. Port 51 on the other hand may be only about one-sixteenth inch in diameter. Passage 48 is about seven thirty-second inch in diameter.
The upper surface of core head 45, see FIG. 5, carries three index marks, namely 0, 1 and 2 as shown. When the valve core 42 is turned to this FIG. position, index 1 lines up with the index projection 41 to indicate that flush port 49 is aligned with intake port 39. When index 2 is turned to line up with index 41, this indicates drain port 51 in alignment with intake port 39. When index 0 is lined up with index 41, this indicates that intake port 39 is closed and that the valve assembly is open only at the top for overflow relief. Preferably head 45 is flat-sided for turning.
Referring to FIG. 1, the bottom housing wall is apertured at 52 below the valve assembly open lower end and has secured thereto a depending spout 53 the lower end of which may be coupled to a flexible drain conduit 54.
During normal operation the parts are disposed as shown in FIG. 1, with valve assembly 32 adjusted to the drain position where the index 2 aligns with projection 41 and drain port 51 is open to intake port 39. It will be noted that intake port 39 is located as low as practically possible within the body of water in the tray so that draining takes place from the region of greatest concentration of solids in the water. Also the upper end of valve assembly 32 is above the normal water level 26, so that there is normally no overflow.
Thus water continuously drains out of body 23 at a constant rate determined by the size of port 51, and this is continuously effective to reduce the solids concentration in the water body, particularly since it may be noted that the drained water is replaced periodically by fresh supply water due to float valve action. In normal operation the furnace discharges hot air only intermittently in response to the usual thermostat calling for heat, but the humidistat usually keeps motor 19 activated to rotate the drum during periods beyond the actual evaporation periods. During these extended periods the pad is moving through water that is being cleared of solids faster than during the evaporation periods, and this results in an increased automatic pad cleaning action as solids are loosened from the pad and deposited in the water body during these extended periods.
In a practical embodiment the port 51 is about one-sixteenth inch in diameter, providing a drain rate of about onehalf gallon per hour, and this has been found to maintain the solids content in water body 23 at an average value not greater than the mineral content of the usual supply water entering valve 24 under all conditions of operation ofthe humidifier.
Instead of the continuous drain provided when the index is at setting 2 of FIG. 5, it may be preferred to maintain the valve assembly normally closed and periodically flush out the tray when solids concentrations increase. For this the valve core is turned from a closed position wherein index 0 is aligned with projection 41 until index 1 is aligned with projection 41, thereby aligning the flush port 49 with the inlet port 39 and greatly increasing the drain rate through the intake port. With valve 32 in the index 1 position and the water supply shutoff the tray may be drained for servicing.
The drain rate may be even further varied by rotating the core to different positions of overlap of the flush and inlet ports, to provide a continuous drain rate in normal operation where abnormal solids concentrations are encountered.
In all positions of the valve core, passage 48 is available to act as an overflow whenever the water level rises above the top of head 45. In practice bore 48 should be large enough to pass water at the maximum rate of inflow through the float controlled valve 24.
The invention therefore provides a system and novel valving structure wherein solids concentration levels in the humidifier water reservoir are held to a safe maximum, and this results in more efficient humidifier operation over longer periods without requiring special maintenance. Replacement of humidifier pads is greatly reduced. The valve assembly may be adjusted to the various settings without dismantling the humidifier, and similarly the tray may be flushed out periodically without removing it from the humidifier.
It has been found that making the valve assembly 32 in two parts each on integral member made ofa vinyl resin material is an extremely beneficial part of the invention. Vinyl is very pliable, so that is is possible to build more interference fit relationship into the parts for increasing the seal between them, while permitting the designated positions. Moreover vinyl has certain natural lubricating qualities, perhaps enhanced by the water in which the valve assembly is located.
lclaim:
1. In a humidifier assembly of the type having means defining a reservoir containing a body of water from which water is extracted continually for evaporation into an associated warm airstream or the like and wherein the water level of said body is continually replenished automatically during normal operation, means for controlling the solids content of said body of water comprising valve means for continuously draining water from said body at a predetermined rate, said valve means comprising a valve casing secured to said reservoir and formed with a lateral inlet and a movable flow control member in said casing having a drain flow passage and a lateral drain port opening to said passage and adapted to register with said inlet, said flow control member also having a lateral flush port open to said passage and adapted to register with said inlet.
2. In the humidifier assembly defined in claim 1, said flow control member being a rotatable element internally formed with said passage and provided with said drain and flush ports in circumferentially spaced relation.
3. In the humidifier assembly defined in claim 2, cooperating index means on said valve casing and control member for indicating which port is registered with said inlet.
4. In the humidifier assembly defined in claim 2, said valve casing being secured upright in said reservoir and said control member passage having an open upper end disposed above the normal water level in said reservoir for emergency overflow.
5. In the humidifier assembly defined in claim 2, said casing being a hollow element secured at its lower end in fluidtight assembly in an aperture at the bottom of said reservoir, and said rotatable control element being hollow and slidably and rotatably disposed in an internal bore in said casing whereby said control element may be readily removed for cleaning, said rotatable element having means for limiting axial sliding thereofinto said casing.
6. A combined drain and overflow valve assembly adapted for upright mounting in the water reservoir of a humidifier, comprising a hollow casing having a lateral inlet port, and having means below said inlet port for securing the casing within an aperture in the bottom of said reservoir, and a hollow flow control element rotatably mounted in said casing and having an internal drain passage open at both upper and lower ends of said element and a lateral drain port intersecting said passage and adapted to register with said inlet in a rotative position of said control element, there being a larger lateral flush port in said control element intersecting said passage and adapted to register with said inlet in another rotative position ofsaid control element.
7. The valve assembly defined in claim 6, including cooperating index means on the control element and casing for indicating whether the drain or flush ports are registered with the casing inlet.
8. The valve assembly defined in claim 7, wherein said valve assembly is a two part unit consisting essentially of molded vinyl plastic water-resistant casing and control member parts.
9. In a humidifier assembly, means providing a reservoir for containing a body of water, means for continually extracting water from said body for evaporation into an associated warm airstream, an inlet having a valve for supplying water to said reservoir, means responsive to the water level in said reservoir connected to control said inlet valve to automatically maintain a predetermined normal water level in the reservoir, means for controlling the solids content of said body of water comprising valve means for draining water out of said body at a predetermined rate, said drain valve means comprising an upright hollow open ended valve casing secured over an outlet opening in said reservoir and a hollow open ended valve element rotatably mounted in said casing with its upper end disposed above said normal water level so that the open upper end of said element is exposed for overflow relief should excess water be supplied to said reservoir, and means providing lateral openings in the lower ends of said casing and valve element adapted to be aligned in a position of rotation of said valve element for continually draining water out of said reservoir at a predetermined rate, the interior of said hollow valve element providing an overflow relief passage large enough to pass water at the maximum rate of inflow through said inlet valve.
1. In a humidifier assembly of the type having means defining a reservoir containing a body of water from which water is extracted continually for evaporation into an associated warm airstream or the like and wherein the water level of said body is continually replenished automatically during normal operation, means for controlling the solids content of said body of water comprising valve means for continuously draining water from said body at a predetermined rate, said valve means comprising a valve casing secured to said reservoir and formed with a lateral inlet and a movable flow control member in said casing having a drain flow passage and a lateral drain port opening to said passage and adapted to register with said inlet, said flow control member also having a lateral flush port open to said passage and adapted to register with said inlet.
2. In the humidifier assembly defined in claim 1, said flow control member being a Rotatable element internally formed with said passage and provided with said drain and flush ports in circumferentially spaced relation.
3. In the humidifier assembly defined in claim 2, cooperating index means on said valve casing and control member for indicating which port is registered with said inlet.
4. In the humidifier assembly defined in claim 2, said valve casing being secured upright in said reservoir and said control member passage having an open upper end disposed above the normal water level in said reservoir for emergency overflow.
5. In the humidifier assembly defined in claim 2, said casing being a hollow element secured at its lower end in fluidtight assembly in an aperture at the bottom of said reservoir, and said rotatable control element being hollow and slidably and rotatably disposed in an internal bore in said casing whereby said control element may be readily removed for cleaning, said rotatable element having means for limiting axial sliding thereof into said casing.
6. A combined drain and overflow valve assembly adapted for upright mounting in the water reservoir of a humidifier, comprising a hollow casing having a lateral inlet port, and having means below said inlet port for securing the casing within an aperture in the bottom of said reservoir, and a hollow flow control element rotatably mounted in said casing and having an internal drain passage open at both upper and lower ends of said element and a lateral drain port intersecting said passage and adapted to register with said inlet in a rotative position of said control element, there being a larger lateral flush port in said control element intersecting said passage and adapted to register with said inlet in another rotative position of said control element.
7. The valve assembly defined in claim 6, including cooperating index means on the control element and casing for indicating whether the drain or flush ports are registered with the casing inlet.
8. The valve assembly defined in claim 7, wherein said valve assembly is a two part unit consisting essentially of molded vinyl plastic water-resistant casing and control member parts.
9. In a humidifier assembly, means providing a reservoir for containing a body of water, means for continually extracting water from said body for evaporation into an associated warm airstream, an inlet having a valve for supplying water to said reservoir, means responsive to the water level in said reservoir connected to control said inlet valve to automatically maintain a predetermined normal water level in the reservoir, means for controlling the solids content of said body of water comprising valve means for draining water out of said body at a predetermined rate, said drain valve means comprising an upright hollow open ended valve casing secured over an outlet opening in said reservoir and a hollow open ended valve element rotatably mounted in said casing with its upper end disposed above said normal water level so that the open upper end of said element is exposed for overflow relief should excess water be supplied to said reservoir, and means providing lateral openings in the lower ends of said casing and valve element adapted to be aligned in a position of rotation of said valve element for continually draining water out of said reservoir at a predetermined rate, the interior of said hollow valve element providing an overflow relief passage large enough to pass water at the maximum rate of inflow through said inlet valve.
| 1969-06-30 | en | 1971-07-27 |
US-63350090-A | Hand-held data capture system with interchangeable modules
ABSTRACT
A portable, hand-held data collection terminal unit is of modular structure including among other modules a display screen module, a keyboard module and a base module, each of which may be chosen from a plurality of modules available for assembly into the terminal unit. Consequently, a wide combination of terminal units may be assembled from a comparatively limited number of modular choices, such that the cost of assembly of a terminal unit with specific functions may be minimized. A particular selected module is a scanning module including a pivotable scanning head to permit a user to adjust the scanning head to a convenient position for operating the scanning module without sacrifice of visual access to a display screen of the display screen module. The display screen module may be selected from modules of standard width equal to the width of the terminal unit, of extended width extending when assembled to a selected keyboard module beyond either or both lateral edges of the terminal unit. The selected display screen module may include one of different sized screens, function keys and alphabetical keys.
CROSS REFERENCE TO RELATED APPLICATIONS (Claiming Benefit Under 35 U.S.C. 120)
This is a continuation-in-part of Ser. No. 626,711, Dec. 12, 1990, abandoned, which is a continuation-in-part application of U.S. application for patent by Keith Cargin, Jr. et al., Ser. No. 07/364,594, filed Jun. 7, 1989, U.S. application for patent by Arvin D. Danielson, et al., now abandoned, U.S. Ser. No. 07/364,902, filed Jun. 8, 1989, now abandoned, and PCT application PCT/US90/03282, filed Jun. 7, 1990.
INCORPORATION BY REFERENCE
The descriptive matter of the above-referred to PCT application PCT/US90/03282, filed Jun. 7, 1990, including forty-six pages of specification and nineteen sheets of drawings including FIGS. 1 through 37, is incorporated herein by reference in its entirety, and is made part of this application.
BACKGROUND OF THE INVENTION
This invention relates generally to data collection systems, and more particularly to such systems wherein a hand-held unit may be operated to collect data, to selectively process, and to communicate collected data within such systems by various automated or manual operations. A typical automated process which may be included in such operations relates to collecting data by scanning bar code data with a laser scanning device. Subsequently, the collected data or information may be processed such as by becoming included in a data base. In another operation, it may be desired to communicate the information to another unit within a respective data collection system.
Various investigatory efforts in this area have shown that some functional applications of the data collection systems may require certain features on such hand-held units which may not at all be required in other functional applications. Going toward specialization of the units for specific tasks, the cost of operating the data collection systems tends to become more and more prohibitive as systems become configured to accommodate various specific applications. On the other hand, when data entry units are mass produced for general applications, efficiency in the application is jeopardized and compromise on various features results in less than the most efficient data handling procedures. It is consequently desirable to provide a data collection system in which hand-held units are equipped with features relating to particular needs without having a prohibitively high price tag.
SUMMARY OF THE INVENTION
The PCT application Ser. No. 90/0382, filed Jun. 7, 1990, assigned to and owned by the assignee of the present application, the descriptive matter of which is incorporated herein by reference in its entirety, refers to a modular hand-held unit and discloses a manner of attaching one functional module to another.
In accordance with the present invention, a selected one of a plurality of special purpose functional modules may be attached to another module of one of a selected second functional configurations to configure a plurality of different modules of different specific functional features. Thus, according to one aspect of the invention, with a reasonable number of functional modules a great number of differently configured modules may be provided.
A hand-held data collection terminal unit includes an elongate housing having a lower portion supportable in the hand of a user and an upper portion facing such user when the terminal is in a typical use position. The upper portion includes a keyboard and a display screen. In accordance with the invention, the hand-held terminal comprises a plurality of modules in which a base module extends longitudinally and includes inner and outer end caps of the terminal. The inner end cap is disposed on the end of the terminal which typically points toward a user when the terminal is in use, the outer end cap being disposed on opposite end of the terminal. A keyboard module is defined as an intermediate module disposed adjacent the base module and between the end caps. A display screen module is further disposed adjacent the intermediate module and adjacent the outer end cap of the base module.
According to a more particular aspect of the invention, the display screen module extends from the outer end cap of the base module longitudinally toward an end intermediate of the inner and outer end caps, such that a portion of the keyboard module remains exposed and features an array of manual input keys arranged in an area between the display screen module and the inner end cap.
According to another aspect of the invention, a data collection terminal unit includes a base module, a keyboard module disposed adjacent the base module and substantially of the same length and width as the base module. A display screen module is disposed adjacent the keyboard module and is disposed over at least one key arrangement of the keyboard unit. The display screen module is slidably arranged to be selectively slidable outward away from a user and from such at least one key arrangement to expose such keys for user access when the terminal unit is being placed into use.
According to yet another aspect of the invention, it is desired to protect the modular hand-held units from damage when the units are accidentally dropped. Resilient end caps and a layered resilient interface extending peripherally beyond substantial module portions impart shock absorbing qualities to the modular hand-held units.
According to a further aspect of the invention, a scanner module is attached as an end cap module to an outer end of a modular hand-held terminal unit. The scanner module includes a scanner head which is rotatable about a longitudinal axis of the modular hand-held terminal unit and selectively adjustable to one of a plurality of user positions in which the scanner may conveniently be used to collect data from, for example, bar code labels while a display screen on a display screen module remains in view of the user of the terminal unit.
In further describing the various features and advantages of the invention and of particular hand-held terminal units including and embodying features of the invention, the following spacial relations are being followed. Directional indications refer to a normal position of use of a hand-held data collection terminal. In such position the user would hold the terminal or terminal unit such that a display screen faces "up" into the direction of view of the user. Similarly, a keyboard would normally face up to be visible and manually accessible to a user. Correspondingly, the upper face of a data collection terminal unit is also referred to as a frontal side or face. The opposite side or portion of the unit is referred to as the rear or bottom portion of the unit and the direction in which the rear portion faces is the "lower, bottom or down" direction, or term of similar import. Also of interest are the descriptors at opposite ends of a longitudinal axis through a terminal unit. With the keyboard and display screen facing up, the longitudinal end of the terminal unit typically facing away from the user will be referred to and denoted as an "outer" end, while an opposite end of the unit directed toward the user when the unit is in a general position as described, is referred to as an "inner" end. These references should be kept in mind when reading the following detailed description.
Various other features and advantages of the data collection terminal in accordance with the invention will become apparent from the following detailed description, which may be best understood when read with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a frontal view of a modular data collection terminal unit having a display screen module which is enlarged to one side of a generally elongate shape of the terminal unit;
FIG. 2 is a side view of the data collection terminal unit shown in FIG. 1;
FIG. 3 is an outer end view of the data collection terminal unit shown in FIG. 1;
FIG. 4 is a frontal view of an alternate embodiment of a data collection terminal unit such as shown in FIG. 1, the alternate embodiment showing additional features including an RF communications capability, as indicated by an attenna extending laterally of the longitudinal body of the data collection terminal unit;
FIG. 5 is a side view of the data collection terminal unit shown in FIG. 4;
FIG. 6 is a frontal view of yet another embodiment of a data collection terminal unit in accordance with the invention, the terminal unit showing a display screen which extends laterally beyond the basic longitudinal shape of the terminal unit;
FIG. 7 is a frontal view of a data collection terminal unit similar to the terminal unit shown in FIG. 1, except that a display screen module is shown which is confined to the generally longitudinal shape of the data collection terminal unit;
FIG. 8 is a frontal view of another embodiment of a data collection terminal unit in which the display screen module of the terminal unit in FIG. 7 has been replaced by an elongate display screen module in which function or control keys have been eliminated to afford room for added display area of the display screen;
FIG. 9 is a frontal view of a data collection terminal unit showing a first keyboard array adjacent an inner end of the terminal unit and a display screen module adjacent an outer end of the terminal unit;
FIG. 10 is a frontal view of the data collection terminal unit shown in FIG. 9, in which the display screen module has been extended outwardly away from the user to uncover a second keyboard array which is in the non-extended position of the display screen module disposed beneath such module;
FIG. 11 is a schematic representation of various modules and elements of the terminal unit showing a basic manner of assembling selected ones of the various modules to each other;
FIG. 12 is a somewhat simplified view of a data collection terminal unit in which a scanner module is mounted to an outer end of the terminal unit, the scanner module including a scanner head which is mounted to rotate about a longitudinal axis of the data collection terminal unit;
FIG. 13 is a side view of a scanner module, such as in FIG. 12, shown with the scanner head in a typical, laterally disposed rest position;
FIG. 14 is a side view of an alternate embodiment of a scanner unit, the scanner unit being fixedly attached to an outer end of the terminal unit and having a viewing direction at an angle with respect to the longitudinal axis of the data collection terminal;
FIG. 15 is an end view of a display screen module of the type shown in FIG. 6, the end view showing an attachment surface of the display screen module;
FIG. 16 is a frontal view of the display screen module of FIG. 15 in combination with a handle and power supply module;
FIG. 17 is a side view of the display screen and handle and power supply modules of FIG. 16;
FIG. 18 is a frontal view of a data collection terminal unit showing an alternate embodiment of a keyboard module in combination with a display screen;
FIG. 19 is side view of the data collection terminal unit shown in FIG. 18;
FIG. 20 is yet another embodiment of the data collection terminal unit shown in FIGS. 18 and 19, showing a screen display confined to the width of the keyboard module of the data collection terminal unit; and
FIG. 21 is an alternate frontal view of the data collection terminal unit shown in FIG. 20, showing a pivotally mounted screen display in an open position, revealing a second screen display and a second keyboard.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the various illustrations in sequence, a data collection terminal unit which is designated generally in FIG. 1 by the numeral 10, is shown as undergoing various changes and modifications as selected different modules may be substituted for other modules and functions and capabilities of the data collection terminal unit 10 are correspondingly altered.
In reference to FIG. 1, there is shown a frontal view of the data collection terminal unit 10. In furtherance of advantages and objects of the invention, the data collection terminal unit 10 is a modular unit in that a plurality of modules become attached to each other to form the terminal unit 10. A general shape of the terminal unit 10 is an elongate rectangular shape as can be ascertained from the drawing. The terminal unit has an inner end 11 which typically is closest to a person using the terminal unit 10 when the terminal unit is in a typical hand-held operating position in which a user exposes a keyboard and a display screen toward the line of sight. Opposite the inner end 11 an outer end 12 of the data collection terminal unit is directed away from a user when the terminal unit 10 is hand-held in a typical use position. The general shape of the terminal unit is that of an elongated rectangle, such that a hypothetical longitudinal centerline or central axis indicated at 14 can be envisioned to extend in the longitudinal inward-outward direction of the terminal unit 10. The frontal view shows a display screen module 16 which is enlarged to one side of the terminal unit 10. A lateral extension 18 of the display screen module is in the preferred embodiment shown to extend toward the right hand side of the central axis 14 beyond the generally elongate rectangular shape of the terminal unit 10. The direction may be one of convenience to a user. The lateral extension, whether toward the left or right of the longitudinal axis 14 extends the line width of the viewing area of a display screen 19 of the module 16. Such extension 18 is desired to permit an alphanumeric instruction to be contained within a single character line of display, for example. The display screen module 16 further may include a main power switch 20, in that in various configurations of the terminal unit 10 a display screen module or its equivalent would be included. Below the display screen module 16, and inwardly disposed, lies a keyboard module 21. The keyboard module 21 includes a particular keyboard 22 which may typically include an arrangement 23 of numerical keys 24. The numerical keys 24 are desirably supplemented by a cluster of cursor keys 25 and by selected function keys 26. The display screen module 16 may also include a cluster of further function switches 27. It should be understood that the modules 16 and 21 are mechanically attached to and part of the terminal unit 10 and are further electrically interconnected, such as may conveniently be achieved by typical flat cables and respective connectors, not shown. It is therefore convenient to provide cursor movement keys, such as the keys 25 as part of the keyboard, in that it is typically intended for the terminal unit 10 to feature a display screen module.
Further in accordance with the invention, the terminal unit 10, the unit being typically hand-held, is subject to accidentally being dropped. To protect the terminal unit 10 from damages when dropped an established height, resilient end caps 28 and 29 cover the inner end outer ends 11 and 12, respectively. In addition, it has been found desirable to protect lateral ends of the display screen module 16 similarly with resilient strips 31 and 32.
FIG. 2 is a side view of the data collection terminal unit 10. The side view of the terminal unit 10 further illustrates the modular construction of the terminal unit 10. A base module 34 desirably includes a central handgrip portion 35 and may further include a resilient strap 36, such that a user may insert the hand between the handgrip portion 35 and the resilient strap. A battery compartment 38 is shown at the lower, inner end of the base module 34. In that the terminal unit is a hand-held unit, an internally disposed electrical power source such as a battery module 39 is virtually required for desired operation of the terminal unit. In one configuration, the battery compartment comprises an opening into which the battery module 39 is inserted. The external shape of the battery module conforms to the shape of the base module to form part of it. The battery module 39 is desirably replaceable in a field exchange operation and may be removed by sliding the module 39 in the direction of the arrow 40. To secure the battery module within the base module 34, a locking mechanism which may be opened and closed by a coin, for example, is found to facilitate such replacement. A peripheral resilient strip or spacer 41 preferably overlies the base module 34 and functions as a shock absorber when the terminal unit 10 is accidentally dropped on its side surfaces. Adjacent the outer end of the handgrip portion 35 is disposed a function key 43. The function key 43 may be a data entry initiation key or a scanner operation control key when the terminal unit is equipped with a scanner module. It should be noted, that the function key 43 is disposed for persons holding the terminal unit in their right hand, such that the index finger of the user's right hand may be used to operate the key 43. The base unit may be furnished with a similar key 43, not shown, on the opposite side of the base module 34 to allow a person holding the unit with the left hand to operate such key. The respective keys would be electrically coupled to function in parallel, such that the desired function can be initiated from either side of the terminal unit 10. Disposed between the resilient end caps 28 and 29 and adjacent the resilient spacer 41 is the keyboard module 21. The keyboard module 21 functions consequently as a mounting base for the display screen module 16. A recess or step 46 in the upward facing surface 47 of the keyboard module 21 seats the display screen module 16. The display screen module 16 is preferably attached by typical screw type fasteners through the keyboard module 21. The keyboard module 21 in turn may be fastened in a similar manner from the bottom surface of the base module 34. In accordance with the invention, the keyboard module 21 further comprises a recess 48 for receiving one of a number of differently configured versions of the keyboard 22. The selected keyboard 22 is also attached through the body of the keyboard module 21 with respective fasteners, such as screws, for example.
FIG. 3 is an outer end view of the data collection terminal unit 10. The need for the referred to resilient protective strip 32 may be realized in viewing lateral extending portion 18 of the display screen module 16.
FIG. 4 is a frontal view of a data collection terminal unit 50 which is an alternate embodiment of the terminal unit 10. In particular, the terminal unit 50 comprises a display screen module 51 including an arrangement 52 of alphabetical keys 53. The display screen module 51 further includes an arrangement of function keys 54 disposed vertically along a display screen 55. To accommodate the key arrangement 52, the display screen module 51 is also laterally extended as the display screen module 16. Consequently, lateral resilient strips 56 and 57 are preferred to increase the drop resistance of the terminal unit 50 as previously discussed with respect to the terminal unit 10. Because of the area occupied by the keys 52 and the function keys 54, the display screen is does not extend beyond the lateral sides of the generally elongate shape other than the extended display screen display module 51. The terminal unit 50 further shows an outwardly extending antenna 58 as part of and evidencing a radio frequency communication system 59 being part of the terminal unit 50. As described with respect to the terminal unit 10, the terminal unit 50 also includes the resilient end caps 28 and 29. A keyboard 61 may be functionally different than the previously described keyboard 22, though it may be fitted into the aforementioned recess 48 of the keyboard module 21. In particular, the keyboard 61 shows a main power switch 62, rather than having such switch associated with the display screen module 51. As can be ascertained from the terminal unit 50, modules such as the keyboard module 21 may be interchangeably used with one of a number of display screen modules, such as the modules 16 and 51.
FIG. 5 is a side view of the data collection terminal unit 50. A base module 63 may in outer dimensions be the same as the base module 34 described with respect to FIG. 2. One difference may be noted in the configuration of a battery module 64 with respect to the configuration of the battery module 39. The battery module 64 shows less external surface and is inserted for a substantial portion into the base module 63. The central handgrip portion 35 of the base module is in essence identical in both base modules. Another notable difference relates to a laterally disposed outer function key 66 which preferably may include more than one function, such as an enter function and scan function. The function key may be operated to enter data and to operate a scanning module when such a scanning module is provided. To operate the enter function, an inner end 67 of the function key 66 is depressed. To operate the scanning function an outer end 68 may be depressed. The respective, inner and outer locations are assigned because of a preferred addition of a scanner module in lieu of the outer end cap 29. As described with respect to the function key 48, the function key may be provided on either or both sides of the respective base modules. When the function keys are not provided, they may be deleted and replaced by a plug (not shown) which would be installed in lieu of the function switch. Also to be observed is the one for one replacement of the display screen module 51 for the previously described display screen module 16 into the keyboard module 21.
FIG. 6 is a frontal view of yet another terminal unit 70, having a uniquely wide screen 71 disposed in a display screen module 72. The display screen module 72 is mounted in the manner described with respect to the display screen module 16 to the keyboard module 21. The display screen module 72 extends to both sides with respect to the central axis 14 of the terminal unit 70 beyond the width of the base module 34 or 66 and the keyboard module 21. The size of the display screen 71 permits only a limited number of function keys 73 which are preferably disposed adjacent the outer edge of the keyboard 22. The display screen module 72 may also include a power switch 74 when such a function is not part of the keyboard module 21 and its respective keyboard 22. It should be realized, however, that without diminishing the width of the display screen 71, the number of display lines thereon may be diminished to include on another display screen module an alphabetical keyboard.
FIGS. 7 and 8 show terminal units 75 and 76, respectively. Both terminal units show display screen modules 77 and 78, respectively, in which respective display screens 79 and 81 are contained within the lateral bounds of the keyboard module 21. The display screen module 77 includes function keys 82, arranged in an earlier referred to arrangement. In contrast, the display screen module 78 does not include the function keys 82 but is instead in the direction between the inner and outer ends 11 and 12 of the terminal unit 76, hence in the vertical direction of the display screen enlarged. Thus, FIGS. 7 and 8 show further embodiments of the terminal unit than can be provided with only minor modifications in the assembly of the respective units.
FIG. 9 is a frontal view of a data collection terminal unit 85 which features a variation of the described keyboard and display screen modules. The terminal unit 85 includes a display screen module 86 and a key board module 87. As in the previously described terminal units, the keyboard module 87 extends substantially between the inner and outer ends 11 and 12 of the terminal unit 85. A first keyboard 88 is mounted into an innermost end of the keyboard module 87. However, the display screen module 86 is outwardly slidably mounted to slide from an innermost position as shown in FIG. 9 to an outermost position shown in FIG. 10. Sliding motion is supported by rails 91 and 92 disposed along opposite sides of the terminal unit 85. In the outermost position of the display screen module 86, a second keyboard 94 is uncovered, in that the second keyboard is located directly adjacent the innermost position of the display screen module 86. The second keyboard 94 may be received by the keyboard module 87 in a recess similar to the keyboard 88. The first and second keyboards may be of different heights between inner and outer ends, or the keyboards may be configured to be of equal height. In such a configuration the keyboard module may be provided with proper recesses which are of the same size. In the described embodiment, the first keyboard has a greater vertical height than the second keyboard, and respectively differently sized cavities for receiving the first and second keyboards 88 and 94 are provided. The differences in size may prevent an inadvertent switching of the respective keyboards 88 and 94 during assembly of the terminal unit 85.
FIG. 11 is a schematic representation of various modules and elements of the described terminal units showing a basic manner of assembling selected ones of the various modules to each other. In particular, the base module 34 is shown adjacent the battery module 39. The two modules may be combined initially or at a later time in that it is contemplated to facilitate the replacement of the battery module 39 without further disassembly of the respective terminal unit . The resilient spacer 41 is preferably a rubber compound which may be of a hardness to absorb a typical fall of the unit. The spacer 41 is assembled between the base module 34 and the keyboard module 21 or a similar keyboard module. A selected keyboard and display screen module is assembled to the selected keyboard module prior to its assembly to the base module 34 or its selected equivalent base module. The outer end cap 29 may be removed or initially deleted from the assembly and a CCD type scanner module 96 or a laser scanner type module 97 may be attached to the outer end 12 of the terminal unit. FIG. 11 shows such scanner modules 96 and 97 in phantom lines as alternative additions to the respective terminal unit. In maintaining the shock absorbing characteristics of the assembled terminal unit, such as terminal unit 10, if a scanner module, such as shown at 96 or 97, is included at the outer end 12 of the terminal unit 10, the scanner modules are desirably furnished with an resilient end cap 98 or 99, respectively.
FIG. 12 is a simplified view onto an outer end 12 of a data collection terminal unit 101 in which a scanner module 102 is mounted to the outer end. The scanner module 102 is shown in a rest mode in which the scanner is less likely to be operated. The scanner module 102 has a scanning head 103 including an optical opening 104 through which scanned data are acquired. In the typically inactive position of the scanner module 102, any scanning would be done with the optical opening pointing toward one side of the terminal unit 101. In such position a user is not able to direct the scanning operation straight ahead while at the same time viewing a display screen 105 on the upper face of the terminal unit 101. To overcome the limitation, the scanning head 103 is rotatably or pivotably attached to the scanner module 102 to pivot about the longitudinal central axis 14 through the terminal unit 101. Preferably, the scanning head 103 may be moved to a number of intermediate positions between the lateral positions in which the optical opening 104 points to either side of the terminal unit 101. A particular number of positions, such at fifteen degrees increments may be preferred. Thus, between opposite extreme lateral positions, the scanning head may be pivoted through an angle of at least 180 degrees. An alternate, angularly disposed orientation of the scanning head 103 is shown in phantom lines as an example of the pivotable movement of the scanning head 103. The pivotable movement in either direction from the alternate position shown is indicated by an arrow 106.
FIG. 13 shows a side view of the data collection terminal unit 101. The scanner module 102 may be attached to the outer end of the data terminal unit by removing the end cap 29 and attaching in its place a mounting base 108 of the scanner module 102. Internal data communications connections which are not shown, would include a typical data bus coupled to the microprocessor control of the data collection terminal unit 101 to permit the scanner module 102 to be operated as an integral element of the data collection terminal unit 101. The position in which the scanning head 103 is shown, is a typical rest position for the scanner module, in which the scanner would be least likely to be operated.
FIG. 14 is a side view of an alternate embodiment of a scanner module 110. Contrary to the scanner module 102, the scanner module 110 is not pivotally attached by the base 108. Instead, a fixed scanner head 111 is shown, in which the direction of scanning may preferably at an angle in a range about 45 from the longitudinal axis of the data collection terminal unit 101 is preferred. To increase the shock absorbency of the scanner module outer surface, a window portion 112 of the scanner head 111 is protected at its outer rim with preferred rubber cushoning, a shock damper having been found supportive of preventing breakage of the data collection terminal unit 101 and particularly of the scanner head 101. The scanner module 110 further comprises an inward extension 113 adjacent a lower surface 114 of the data collection terminal unit 101. A threaded fastener 115 may be used to fasten the extension 113 to the underside 114 of the data collection terminal unit 101. It should be recognized that other modifications and changes may be made with respect to the laser scanner heads attached to the outer end of the data collection terminal unit in furtherance of the objects of the invention.
FIG. 15 is an end view of a display screen module 120 of the type of display screen module 72 shown in FIG. 6. The end view shows an upwards directed display screen surface 121, also showing in profile a plurality of keys 123 which may be a combination of alphanumeric keys and function keys for implementing functions of the display screen module 120. Also shown as an edge view or in profile is a sculptured lower surface 126 of the display screen module 120. Preferably, a central portion 127 of the lower surface 126 is a flat surface portion of substantially the same width as an interface surface of the respective keyboard module to which the display screen module typically mounts.
FIG. 16 shows a frontal view of the display screen module 120. An outer end 128 of the display screen module 120 may feature an antenna, such as the antenna 58 of the transceiver unit 59 shown in FIG. 4, for example. Adjacent an inward facing edge 131 of the display screen module 120 may be located an array of the plurality of keys 123 which may be alphanumeric, of numeric and a combination of function keys arranged in one or more rows as illustrated. Outwards adjacent the keys 123 there is a display screen 134 capable of displaying multiple rows and columns of graphic symbols or of alphanumeric information or data. A handgrip module or handle module 135 is shown as extending toward the left hand side of the display module 120 with respect to the inner edge 131 as a base line. The handle module 135 includes a grip portion 136 which also functions as a battery compartment. A strap 137 may overlie the grip portion 136, such that a user may slip a hand between the grip portion 136 and the strap 137. The strap 137 preferably includes two strap halves which may be attached to each other at various lengthwise displaced distances by typical hook and loop fastening materials for adjustment.
FIG. 17 is a side view of the display screen module 120 and handle module 135. A battery module 138 is disposed within the hand grip portion 135. An upper lip 140 of the grip portion 136 overlies the upper surface 121 of the display screen module 120. The upper lip 140 preferably engages a retainer ridge 141 disposed on the upper surface. An identical retainer ridge 141 may be disposed on the other side of the display screen module 120, such that the handle module 135 becomes reversible and may be attached to one side as shown, or to the other side of the display screen module, depending on the preference of the user. The handle module 135 has an elongate support portion 143 which extends along the lower surface 126 of the display screen module 120 and is preferably mounted to the central portion 127 of the lower surface 126. Electrical contact between the handle module 135 and the display screen module 120 may preferably be made across an interface 144 at the central portion 127. A plurality of spaced electrical contacts 145, disposed substantially in the plane of the interface 144 establish electrical and communication contact between the handle module 135 and the respective display screen module 120. A recess 146 in the support portion 143 is part of the grip portion. Adjacent the recess 146, oppositely spaced, parallel guide tracks 147 provide for the handle module to be slidably inserted into and to become electrically coupled to an external power supply and battery charger unit (not shown). A plurality of electrical power and communication contacts 148 establish contact for electrical power and signal communication with such a power supply and battery charger unit. A transceiver module 149 may be disposed within the support portion 143 for communication between an external data device (not shown) and the display screen module 120, such that data from the external data device may be displayed to be accessible to a user of the combination of the display screen 120 and the handle module 135. The described combination consequently refers to an alternate use of the display screen module 120 in addition to the previously described use of such a display screen module in combination with a keyboard assembly, as, for example, with respect to the data collection terminal unit 70.
FIG. 18 is a frontal view of a data collection terminal unit 150 showing a keyboard module 151. The keyboard module 151 differs from a previously described keyboard module 87, for example, in that a display screen module 153 is pivotally attached to an outer end 154 of the keyboard module 151. The display screen module 153 accordingly necessarily requires a hinged attachment to a respective module, such as the keyboard module 151. A hinge 156 includes display screen hinge members 157 and complementary hinge discs 158 of the keyboard module 150. A hinged attachment of the display screen module 153 to the keyboard module 151 shows an interleaved disposition of the disc-like, spaced hinge members 157 with the complementary hinge discs 158 of the keyboard module 151. The respective hinge members 157 and hinge discs 158 may include laterally disposed electrical contact members disposed on respectively facing surfaces thereof to couple electrical power and data communication from the keyboard module 151 to the display screen module 153. It is contemplated that the display screen module be pivoted from a first, closed position to a preferred open position selected from a range of possible positions, such as may be suitable and most convenient to a user. The keyboard module 151 may include a keyboard, such as the keyboard 88 described with respect to FIG. 10, for example. Keyboards which differ in their configuration from the configuration of the keyboard 88 but which are identical in electrical contacts and interface arrangements and in physical dimensions may be inserted in lieu of the keyboard 88. The display screen module 153 has a first display screen 161 disposed in an outer surface 162 thereof. The size of the display screen 161 is one of choice, but may preferably be chosen to accommodate a typical numerical data display, hence be of a size substantially less than one which might occupy a major portion of the outer surface 162 of the display screen module 153. Similarly to the embodiment described in reference to FIG. 4, the data collection terminal unit 150 may include a transceiver unit 59 as indicated by the antenna 58.
FIG. 19 is a side view of the data collection terminal unit 150. The terminal unit 150 includes a typical base module 165, similar to the base module 34 described with respect to FIG. 2 hereof. The base module 165 is shown as including the handgrip portion 35 and the strap 36. Resilient, shock absorbing ends caps 28 and 29 are desirably attached to the respective inner and outer ends 11 and 12 of the data collection terminal unit 150. The display screen module 153 is shown in the first or closed position. The closed position is considered also the normal position in which the module 153 is disposed essentially against an outward disposed portion 167 of the keyboard module 151. The display screen module 153 may however be pivoted into an upward or open position within a range of open positions, substantially as indicated by the alternate position of the display screen module 153 shown in phantom lines. As the display screen module is pivoted to such upward position, a second display screen 19 disposed on the normally hidden underside 168 becomes visually accessible to a user. The display screen 19 is preferably recessed within an outer rim 169 of the display screen module 153. In the downward pivoted position the display screen module 153 may cover an auxiliary or second keyboard 171. The additional keys 172 of the second keyboard 171 may add alphabetical keys and function keys to be accessed by the user. In achieving the advantages sought by the present invention, both the first and the second keyboards 88 and 121 are removably mounted to the keyboard module 151 and may be exchanged for keyboards of identical lateral extent and having different key arrangements on a front surface thereof. Thus, the keyboard 171 may be exchanged for another keyboard having keys for different data or control input to the respective data collection terminal unit. Also, depending on the type of operation contemplated by the user of the data collection terminal unit 150, the user may employ the unit with the display screen module 153 in a downward position with the first keyboard 88 being the sole keyboard available for data entry and the first display screen 161 providing a corresponding visual indication of data made available to the user. In the alternative, the user may pivot the display screen module into an upward pivoted position, giving access to a second display screen 19 which is in comparison to the first display screen 161 larger in active area and capable of displaying a greater amount of information. The second keyboard 171 to which the user has gained access simultaneously with the access to the relatively larger display screen 19 desirably provides the capability of alphabetical data information. Electrical provisions in the hinge 156 may include position controlled contacts 174 which selectively activate the display screen 161 or the display screen 19 in response to an opening or closing of the display screen module 153 in the manner described. The display screen module 153 differs from the previously described display screen modules in that the display screen module 153 is hingedly attached to the respective keyboard module 151. In this manner, the display screen module 153 is a sub-module of the keyboard module 151. However, it is also contemplated that the display screen module 153 may be interchanged with other display screen modules having similar spaced hinge members 157 to be compatible with the hinge discs 158 of the keyboard module 151.
FIG. 20 is a frontal view of such alternate embodiment, showing a data collection terminal unit 175 which includes the described keyboard module 151. To the outer end 154 of the keyboard module 151 a display screen module 176 has been pivotally attached in lieu of the already described display screen module 153. In clear contrast to the display screen module 153, the display module 176 is laterally confined substantially to the overall width of the keyboard module 151 of the data collection terminal unit 175. The attachment of the display screen module 176 to the keyboard module 151 is identical to the attachment of the display screen module 153 at the hinge 156 as previously described. In the closed position of the display screen module 176, the first or outer display screen 161 may preferably be identical to the first display screen of the display screen module 153 in that in the closed position of the display screen module 176 only the first keyboard, preferably the numerical keyboard 88 is accessible to the user, and the size and display area of the display screen 161 is adapted to a desired display format commensurate with data input from the first keyboard, such as the keyboard 88.
FIG. 21 is an alternate frontal view of the data collection terminal unit 175, showing the display screen module 176 in an upward pivoted position. The pivoted position reveals the second keyboard 171 of the keyboard module 151 and makes a second display screen 178 of the display screen module 176 accessible to the user. Consequently, as shown in FIG. 21, the user may now manually enter data by manipulating any of the keys which make up the keyboards 88 and 171. The combination of the substantially numerical keyboard 88 and the substantially alphabetical keyboard 171 results in a complete alphanumerical keyboard. As described, pivoting the display screen module 176 from a closed position, as shown in FIG. 20, to the open position of FIG. 21 would be effective in one embodiment to switch displayed information from the first display screen 161 to the second display screen 178.
Various changes and modifications in the structure of the described embodiment are possible without departing from the spirit and scope of the invention as set forth in the claims.
What is claimed is:
1. A modular hand-held data collection terminal unit comprising:a base module selected as a preferred one of a plurality of base modules; a keyboard module selected as a preferred one of a plurality of functionally different keyboard modules and including differently configured keys available for assembly into said terminal unit; a display screen module attached to one end of the selected keyboard, said display screen module being selectable from either a first display screen module type or a second display screen module type, said first and second display screen module types being interchangeable with the selected keyboard module, said first display screen module type being as wide as the width of the selected base module, said second display screen module type being wider than the width of the selected base module of the terminal unit and extending beyond at least one side of the lateral confines of the selected base module of said terminal unit when said second display type is connected to the selected keyboard, said base module being assembled with the selected keyboard module including a display screen module of said second display screen module type.
2. The terminal unit according to claim 1, wherein the terminal unit comprises shock absorbing means mounted externally of the terminal unit, said shock absorbing means comprising resilient end caps mounted to opposite ends of the terminal unit.
3. The terminal unit according to claim 1, wherein the terminal unit further comprises a radio frequency communications module.
4. The terminal unit according to claim 1, wherein the terminal unit further comprises a scanning module.
5. The terminal unit according to claim 4, wherein the scanning module is attached to an outer end of the terminal unit.
6. The terminal unit according to claim 5, wherein the scanning module includes a pivotable scanning head, the head being pivotable through at least 180 degrees between two opposite end positions.
7. The terminal unit according to claim 6, wherein the scanning head may be indexed to a plurality of discrete, predetermined positions intermediate the two opposite end positions.
8. The terminal unit according to claim 1, wherein the keyboard of the selected keyboard module comprises a keyboard selected from a plurality of keyboards available for assembly to the keyboard module.
9. The terminal unit according to claim 8, wherein the terminal unit comprises externally disposed shock absorbing means for protecting the terminal unit from sudden impact.
10. The terminal unit according to claim 8, wherein the selected display screen module comprises a display screen, function keys and an arrangement of alphabetical keys, and wherein the selected keyboard module comprises a keyboard including a power switch.
11. The terminal unit according to claim 10, wherein the keyboard further comprises an arrangement of numerical keys and a cluster of cursor keys.
12. The terminal unit according to claim 8, wherein the selected base module and the selected keyboard module are assembled with an interposed resilient shock absorbing means for minimizing impact forces directed against the terminal unit during a fall of the terminal unit.
13. The terminal unit according to claim 8, wherein the terminal unit further comprises a scanning module.
14. The terminal unit according to claim 13, wherein the scanning module is attached to an outer end of the terminal unit.
15. The terminal unit according to claim 14, wherein the scanning module includes a pivotable scanning head for pivoting through an angle of at least 180 degrees.
16. The terminal unit according to claim 15, wherein the terminal unit includes at least one laterally disposed function switch operatable to activate and deactivate the scanning operation of the scanning module.
17. The terminal unit according to claim 1, wherein the display screen module is slidably mounted to the keyboard module to slidably move between a retracted and an extended position, wherein the keyboard module includes a first key arrangement accessible with the display screen module being in either of the positions and a second key arrangement disposed below and covered by the display screen module when the display screen module is in the retracted position and accessible to a user when the display screen module is in the extended position.
18. The terminal unit according to claim 1, wherein the display screen module is pivotally attached to an outer end of the keyboard module for pivotal movement between a first closed position and a range of second, open positions, the keyboard module including first and second keyboards, the first keyboard being accessible when the display screen module is pivoted to a first, closed position, the display screen module having first and second display screens, the first display screen being outward facing and visually accessible when the display screen module is in the closed position, the second display screen being visually accessible when the display screen module is pivoted into the open position.
19. The terminal unit according to claim 18, wherein the display screen module, upon being in the closed position is disposed against the second keyboard and covers the second keyboard from access.
20. The terminal unit according to claim 18, wherein the first and second keyboards are selectively replaceable by a keyboard from a group of keyboards of different key arrangements and capable of communicating different functions to the terminal unit.
21. In a modular hand-held data collection terminal system a combination of modules comprising:at least one set of interchangeable display screen modules, a plurality of interchangeable keyboard modules, and at least one base module; each of the keyboard modules being selectively attachable to the base module, and a selected one of the display screen modules of a preselected set removably attached to a selected one of the plurality of interchangeable keyboard modules; the selected display screen module being removable from the keyboard module and attachable to a handgrip module, the selected display screen module having a width which is greater than the width of the base module to which the selected display screen module is removably attached.
22. The data collection terminal system according to claim 21, wherein the handgrip module comprises a handgrip portion, a battery compartment, a battery module disposed within the battery compartment, interface means for electrically and communicatively coupling the handgrip module to the selected display screen module, and means for electrically and communicatively coupling the handgrip module to a power supply module.
| 1990-12-26 | en | 1993-04-13 |
US-12572187-A | Treatment with dialkoxy pyridopyrimidines
ABSTRACT
Potent antiproliferative activity in combination with low inhibition of histamine N-methyltransferase has been found in a class of 2,4-diamino-6-(2,5-dialkoxybenzyl)-5-methylpyrido[2,3-d]pyrimidines.
PRIOR APPICATIONS
This application is a continuation of U.S. Ser. No. 024,678, filed Mar. 11, 1987 (now abandoned); which is a continuation of U.S. Ser. No. 590,547, filed Mar. 19, 1984 (now U.S. Pat. No. 4,661,490); which is a continuation of U.S. Ser. No. 384,147, filed June 1, 1982 (now abandoned); which is a division of U.S. Ser. No. 228,164, filed Jan. 23, 1981 (now U.S. Pat. No. 4,372,164); which is a continuation of U.S. Ser. No. 159,243, filed June 13, 1980 (now abandoned).
The present invention relates to 2,4-diaminopyrido(2,3-d)pyrimidines, to pharmaceutical formulations comprising such compounds and to their use in medicine.
U.K. patent No. 1 084 103 discloses 2,4-diaminopyrido(2,3-d)pyrimidines of the general formula (I): ##STR1## in which R1 is an alkyl group and R2 is an unsubstituted benzyl group or a benzyl group substituted by one or more halogen atoms, alkyl or alkoxy groups.
The compounds of formula (I) were described as having high in vitro and in vivo activity against bacteria or bacteria infections in experimental animals.
Subsequently it has been found that the compounds of formula (I) specifically disclosed in U.K. 1 084 103 show some inhibitory activity against mammalian dihydrofolate reductase (DHFR), and the activity was sufficient to render them potentially useful in the treatment of conditions where inhibition of mammalian DHFR is desirable. It has further been found that many of these compounds are potent inhibitors of histamine N-methyltransferase (HMT) an enzyme involved in the metabolism of histamine. In this manner they often cause an undesirable accumulation of histamine in organs and tissues. The effects of histamine as well known and any possibility of a further utility for these compounds was substantially diminished by their strong inhibition of HMT.
Further investigation showed that a number of other compounds of formula (I) also possess DHFR inhibitory activity but that these, too, were also potent inhibitors of HMT. Others, which had acceptably low levels of inhibition of HMT were found to have insufficient activity as inhibitors of DHFR.
It has now been surprisingly found that 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyrido[2,3-d]pyrimidine, which is within the scope of formula (I) but not specifically disclosed in U.K. 1 084 103, is not only a very potent inhibitor of mammalian DHFR, but also has acceptably low inhibitory activity against HMT. This compound is represented by the formula (II) below and is useful in the treatment of proliferative diseases, such as psoriasis basal and squamous cell carbinomas of the skin, and various forms of cancer including leukemias, lymphomas, sarcomas and solid tumors.
The invention herein accordingly sets forth in antiproliferative properties of the compound of formula (II): ##STR2## wherein R and R' are lower (C1 -C6) alkyl and pharmaceutically acceptable acid addition salts thereof. Preferably mono-basic salts are provided. Preferably R and R' are methyl.
The compounds of formula (II) are their use in the treatment of infections caused by Streptococcus pyogenes and Streptococcus facalis were discovered earlier by another whose rights are assignable to Burroughs Wellcome Co.
The antiproliferative activity of the compound of formula (II) resides in the free base and thus the nature of the acid participating in the acid addition salts is of minor importance. Such acid addition salts include, for example, those derived from hydrochloric acid, hydroiodic acid, sulphuric acid, phosphoric acid, acetic acid, p-toluenesulfonic acid, methanesulfonic acid, maleic acid, lactic acid, citric acid, tartartic acid, succinic acid, oxalic acid, p-chlorobenzenesulphonic acid, isethinic acid, glucuronic acid, pahtothenic acid and lactobionic acid.
The compound of formula (II) may be prepared by any method known in the art for the preparation of compounds of analogous structure.
In particular the compound of formula (II) may be prepared by the reductive cleavage of the corresponding 7-substituted compounds of the formula (III): ##STR3## wherein R and R' are as defined above and R3 is a leaving group capable of being removed by hydrogenolysis. Such groups include for example a mercapto or a halgeno (e.g. chloro) group.
Where the compound (III) R3 is SH the dethiation may for instance be conveniently effected by reaction with a reducing agent, for example Raney nickel or Raney cobalt or by catalytic hydrogenation utilizing hydrogen in the presence of a catalyst such as palladium on charcoal.
The compound of formula (III) wherein R3 is a mercapto group may be prepared from the corresponding 7-chloro compound (III) [R3 ═Cl], by reaction with a hydrosulfide as described in U.K. patent No. 913 710 or by treatment of the corresponding 7-hydroxy compound with phosphorus pentasulfide.
In the case where R3 is a halogen atom in the compound of formula (III) the compound of formula (II) may for instance be conveniently obtained by e.g. catalytic hydrogenation.
The compound of formula (II) may also be prepared by reacting 2,4,6-triaminopyrimidine (IV) with a compound of formula (V): ##STR4## wherein A is selected from ##STR5## R and R' are as defined above; and R4 is a leaving group such, for example, as a tertiary amino, alkoxy, alkylthio, halogeno, sulphonate or tosylate group.
The compounds of formula (II) may additionally be prepared by the conversion to amino groups, by methods known in themselves in pyrimidine chemistry, of the hydroxy and/or mercapto group(s) in the compound of formula (VI): ##STR6## in which Y and Z are the same or different and are OH, SH or NH2 provided that at least one of Y and Z is OH or SH.
Compounds of formula (VI) may be prepared by metods known in the art for the preparation of such compounds. In addition, those in which Y is OH or SH may be obtained for example by reaction of urea, guanidine or thiourea with a suitable compound of formula (VII): ##STR7## in which R and R' are as defined above and R5 is --CO2 H, CO2 H, CO2 Alkyl, CONH2 or CN and R6 is NH2, Cl or Br.
While it is possible for a compound of formula (II) or an acid addition salt thereof (hereinafter referred to as the "active compounds") to be administered as the raw chemical it is preferably presented in the form of a pharmaceutical formulation.
The invention therefore further provides a pharmaceutical formulation comprising the active compound together with a pharmaceutically acceptable carrier therefore. The carrier must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.
The invention additionally provides a method for the preparation of a pharmaceutical formulation comprising bringing into association an active compound and pharmaceutically acceptable carrier therefor.
Topical application is particularly suitable when the active compounds are for use in the treatment of proliferative skin diseases.
The term "topical" as applied herein relates to the use of the active ingredient incorporated in a suitable pharmaceutical carrier, and applied at the site of the disease for the exertion of local action.
Pharmaceutical formulations suitable for topical administration may be presented in anhydrous forms such as ointments, lotions, pastes, jellies, sprays, aerosols, and bath oils. The term ointment includes formulations (including creams) having oleaginous, absorption, water-soluble and emulsion type bases, for example petrolatum, lanolin, polyethylene glycols and mixtures thereof.
Topical formulations may contain a concentration of the active ingredient of from about 0.05 to about 2% w/w, preferably about 0.1 to about 1% w/w, most preferably about 0.2 to about 0.5% w/w.
Other pharmaceutical formulations include those suitable for oral, rectal, and parenteral administration although of those oral is preferred. The formulations may, where appropriate, be conveniently presented in discrete dosage units and may be prepared by any of the methods well known in the art of pharmacy. A convenient unit dose formulation contains the active compound in amount of from about 50 mg to about 1 g, preferably about 100 mg to about 500 mg, most preferably about 200 mg, to be taken once or several times daily.
All methods for the preparation of such formulations include the step of bringing into association the active compound with liquid carriers or finely divided solid carriers or both and then, if necessary shaping the product into the desired formulation.
Pharmaceutical formulations suitable for oral administration wherein the carrier is a solid are most preferably presented as unit dose formulations such as blouses, capsules, cachets or tablets each containing a predetermined amount of the active compound. A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active compound in a free-flowing form such as a powder or granules optionally mixed with a binder, lubricant, inert diluent, lubricating, surface active or dispensing agent. Molded tablets may be made by moulding an inert liquid diluent. Tablets may be optionally coated and, if uncoated, may be optionally scored. Capsules may be prepared by filling the active compound ingredients, into the capsule cases and then sealing them in the usual manner. Cachet are analogous to capsules wherein the active ingredient together with any accessory ingredient(s) are sealed in a rice paper envelope.
Pharmaceutical formulations suitable for oral administration wherein the carrier is a liquid may be presented as a solution or a suspension in an aqueous liquid, or as an oil-in-water or water-in-oil liquid emulsion.
Pharmaceutical formulations suitable for rectal administration wherein the carrier is a solid are most preferably presented as unit dose suppositories. Suitable carriers include cocoa butter and other material commonly used in the art, the suppositories may be conveniently formed by admixture of the active compound with the softened or melted carrier(s) followed by chilling and shaping in moulds.
Pharmaceutical formulations suitable for parenteral administration include sterile solutions or suspensions of the active compound in aqueous or oleaginous vehicles. Such preparations are conveniently presented in unit dose or multi-dose containers which are sealed after introduction of the formulation until required for use.
It should be understood that in addition to the aforementioned carrier ingredients the pharmaceutical formulations described above may include, as appropriate, one or more additional carrier ingredients such as diluents, buffers, flavouring agents, binders, surface active agents, thickeners, lubricants, preservatives (including anti-oxidants) and the like, and substances included for the purpose of rendering the formulation isotonic with the blood of the intended recipient.
As has been described above the compounds of the present invention are useful for the treatment of proliferative diseases. The inventon thus further provides a method for the treatment of a proliferative disease in mammals including humans which comprises the administration of an effective, non-toxic amount of compound of formula (II) or an acid addition salt thereof, once or several times a day orally, or applied topically.
The amount of compound of formula (II) required for therapeutic effect as an antiproliferative agent will of course vary not only with the particular salt used but also with the route of administration. In general, a suitable dose for the treatment of mammals (including humans) will lie in the range of from about 0.1 to about 100 mg per kilogram bodyweight (mg/kg) per day, preferably in the range from of about 2.0 to about 50 mg/kg, more preferably in the range of about 0.5 to about 20 mg/kg, not preferably in the range of about 1 to about 10 mg/kg.
Toxic manifestations attributable to the active compound are typically those associated with folate depletion, such as bone marrow depression, megaloblastic changes, and gastrointenstinal ulceration. Calcium leucovorin (calcium salt of 5-formyl-5,6,7,8-tetrahydrofolic acid) may be administered to effect reversal of these toxic manifestations or to prevent their occurrence. The administration of calcium leucovorin may be effected concurrently with treatment or at any stage therof whenever toxic symptoms appear.
Thus, the heamatological activity of the active compound can be prevented or reduced by the simultaneous administration of leucovorin. Consequently, tissue levels of the active compound may be safely raised by increasing the dose of the compound together with a simultaneous administration of leucovorin.
The following Examples, which illustrate the invention, should in no way be construed as constituting a limitation thereof.
EXAMPLE 1
2,4-Diamino-5-methyl-6-(2,5-dimethoxybenzyl)-pyrido[2,3-]pyrimidine
A mixture of 2,5-dimethoxybenzaldehyde (100 g), ethyl acetoacetate (84.5 g) and anhydrous benzene (200 ml), piperidine (6 ml) andd acetic acid (12 ml) was heated at reflux for 3 hours in an apparatus fitted with a Dean-Stark trap to collect the azeotropically distilled water. The reaction mixture was cooled, benzene (300 ml) added, and the solution was washed successively with water (100 ml), cold 0.1N hydrochloric acid (200 ml), 5% aqueous sodium bicarbonate (200 ml) and dilute acetic acid (100 ml) and dried over anhydrous magnesium sulfate. The solvent was then removed under reduced pressure and the residual oil distilled, b.p. 169°-170° C./0.3 mm Hg. The product, ethyl α-(2,5-dimethoxybenzylidene)acetoacetate, solidified on standing (104 g, m.p. 68°-69° C.) and was recrystallized from ethanol-pentane (m.p. 72°-73° C.). A portion (38 g) of the product was reduced catalytically in the presence of palladium on charcoal catalyst (Pd/C) in ethyl acetate (150 ml). The product, after removal of solvent, was purified by distillation under reduced pressure to give ethyl α-(2,5-dimethoxybenzyl)acetoacetate, b.p. 146°-148° C./0.3 mm Hg.
A mixture of ethyl α-(2,5-dimethoxybenzyl)acetoacetate (21.2 g), 2,4,6-triaminopyrimidine (10 g) and diphenyl ether (100 ml) was heated at 190°-230° C. for 15 hours in an apparatus fitted with a Dean-Stark trap and water-ethanol (4 ml) was collected. Methanol (200 ml) and ethanol (50 ml) were added to the cooled reaction mixture. The resulting solid was collected by filtration and treated with boiling water (1 l) to give 2,4-dianimo-5-methyl-6-(2,5-dimethoxybenzyl)-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidine (17 g), m.p. 325°-326° C.
2,4-Diamino-5-methyl-6-(2,5-dimethoxybenzyl)-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidine (8 g) was chlorinated by treatment with Vilsmeier reagent prepared by slowly adding thionyl chloride (28.6 ml) in dry chloroform (25 ml) to a solution of dimethylformamide (17.5 ml) in chloroform (100 ml) at 0°-5° C.
The cold mixture of the pyridopyrimidine and Vilsmeier reagent was stirred, gradually allowed to reach ambient temperature and then heated at a reflux for 3 hours. It was then treated with ethanolic base (80 ml) maintaining the temperature at 25°-30° C. with cooling. The brown product formed was isolated, treated further with aqueous ammonia and then recrytallized from ethanol to give 2,4-diamino-5-methyl-6-(2,5-dimethoxybenzyl)-7-chloro-pyrido[2,3-d]pyrimidine, m.p. 193°-196° (dec.).
The chloro compound (0.3 g) was dissolved in ethanol (200 ml) containing potassium hydroxide (0.2 g). Palladium on charcoal catalyst (0.2 g) was added and hydrogenation commenced. Reduction was complete after 48 hours and yielded 2,4-diamino-5-methyl-6-(2,5-dimethoxybenzyl)pyrido[2,3-d]pyrimidine, m.p. 252°-254° C.
EXAMPLE 2
Inhibition of Mammalian Dihydrofolate Reductase (DHFR) by 2,4-Diamino-5-methyl-6-benzylpyrido(2,3-d)pyrimidines
The inhibitory effect of the test compounds against DHFR partially purified from rat liver was determined. The results are given in Table 1 below. An IC50 of 5×10-8 M or less is considered significant potency, an IC50 of 1×10-8 M or less being particularly significant potency.
TABLE 1
______________________________________
TEST COMPOUND
##STR8##
R.sup.1
R.sup.2 IC.sub.50 × 10.sup.-8 M
______________________________________
CH.sub.3
##STR9## 4
CH.sub.3
##STR10## 1.6
CH.sub.3
##STR11## 2.7
CH.sub.3
##STR12## 5.0
CH.sub.3
##STR13## 5.3
CH.sub.3
##STR14## 9
##STR15## 25
CH.sub.3
##STR16## 0.15
______________________________________
EXAMPLE 3
Inhbition of Histamine N-Methyltransferase (HMT) by 2,4-Diamino-5-methyl-6-benzylpyrido(2,3-d)pyrimidines
The effect of the test compounds used in Example 3 against HMT was determined. The results are given in Table 2. An inhibition of less than 20% was considered acceptable and the lack of any effect on this enzyme is most desirable since any interference with histamine metabolism should be minimized.
TABLE 2
______________________________________
TEST COMPOUND
##STR17## % Inhibition of HMT
R.sup.1
R.sup.2 at 10.sup.-5 M
______________________________________
CH.sub.3
##STR18## 51
CH.sub.3
##STR19## 59
CH.sub.3
##STR20## 18
CH.sub.3
##STR21## 20
CH.sub.3
##STR22## 55
##STR23## 48
CH.sub.3
##STR24## 11
______________________________________
EXAMPLE 4
Antitumor Effect of 2,4-Diamino-6-(2,5-dimethoxybenzyl)-5-methylpyrido(2,3-d)pyrimidine Against a Solid Tumor (Carcinoma)
Solid Walker 256 tumors were implanted subcutaneously into three groups of rats. On the third day after implantation with the tumors, drug treatment was commenced and continued for 5 successive days. One group of rats was treated with 2,4-diamino-6-(2,5-dimethoxyphenyl)-5-methylpyrido[2,3-d]pyrimidine at a dose of 25 mg/kg q.i.d., a second group was treated with the same compound at 15 mg/kg b.i.d.; the third group was left untreated as controls. After 17 days the treated groups of rats showed mean tumor volumes of 29% and 10% respectively of the untreated group.
In a second study tumors were implanted subcutaneously and drug treatment delayed until 10 days after implantation. Drug treatment consisted of 30 mg/kg q.i.d. on days 10-13 and 50 mg/kg on days 20, 24 and 28 after tumor implantation. Mean tumor volumes were measured during the course of this study. Tumor volumes in animals which received no treatment increased rapidly whereas those in animals which receive drug treatment showed a decrease in mean tumor volume during the period of observation. Twenty-three days after tumor implantation the T/C was 0.03.
EXAMPLE 5
Antileukemic Effect of 2,4-Diamino-6-(2,5-dimethoxybenzyl)-5-methylpyrido(2,3-d)pyrimidine
Leukemia P388 cells were inoculated intraperitoneally in CDF, Charles River female mice, each animal receiving 106 cells. On the second day after implantation with the leukemia cells, drug treatment was commenced and continued twice daily for three days. Four groups of mice were treated with 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyrido(2,3-d)pyrimidine at doses of 22, 33.5, 50 and 75 mg/kg of body weight and a fifth group was left untreated as a control. All of the untreated mice died from the leukemia between the 10th and 12th day with a median survival of 11 days. All of the treated mice survived for periods longer than the untreated animals with a % increase in life span of 145%, 159% 140% and 154% for the drug treated grous receiving 22, 33.5, 50 and 75 mg/kg doses, respectively. This is a highly significant effect and there was no evidence of drug-related toxicity.
Within the same experiment, two closely related compounds were tested for antileukemic activity at the same dosage levels of 22, 33.5, 50 and 75 mg/kg, respectively, and the same schedule of treatment. The corresponding pyridopyrimidine with a 6-(4-methoxybenzyl) substituent was inactive at all doses and the 6-(2-chlorobenzyl) compound had only marginal or slight activity. Thus, the 6-(2,5-dimethoxybenzyl) compound has substantially greater antileukemic activity than these compounds of similar structure.
EXAMPLE 6
Water Soluble Ointments
______________________________________
Amount (g)
______________________________________
2,4-Diamino-5-methyl-6-(2,5-
0.5
dimethoxybenzyl)pyrido[2,3-d]pyrimidine
Polyethylene glycol 300 20.0
Polyethylene glycol 1500
79.5
Total 100.0
______________________________________
EXAMPLE 7
Skin Cream
______________________________________
Amount (g)
______________________________________
2,4-Diamino-5-methyl-6-(2,5-)
0.5
dimethoxybenzyl)pyrido[2,3-d]pyrimidine
Glyceryl monostearate 20.0
Methylparaben 0.3
Petrolatum, light liquid
4.0
Propylene glycol 5.0
Span 60 2.0
Tween 61 4.0
Water 64.2
Total 100.0
______________________________________
EXAMPLE 8
Injectable
______________________________________
Amount
______________________________________
2,4-Diamino-5-methyl-6-(2,5-
qs to 5 mg/ml
dimethoxybenzyl)pyrido[2,3-d]pyrimidine
Propylene glycol 40 ml
Ethanol 11 ml
Water 49 ml
______________________________________
EXAMPLE 9
Injectable
______________________________________
Amount
______________________________________
2,4-Diamino-5-methyl-6-(2,5-
qs to 5 mg/ml
dimethoxybenzyl)pyrido[2,3-d]pyrimidine
Propylene glycol 40 ml
5% Dextrose solution 60 ml
______________________________________
We claim:
1. The method of decreasing the volumn of a carcinoma in a human suffering from said carcinoma comprising administering to said human an effective carcinoma-volumn decreasing amount of the compound 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyridopyrimidine or a pharmaceutically acceptable salt thereof.
2. The method of treating carcinoma in a human suffering from a carcinoma comprising the administration to said human of an effective anticarcinoma treatment amount of 2,4-diamino-6-(2,5-dimethoxybenyl)-5-methylpyridopyrimidine or a pharmaceutically acceptable salt thereof.
3. The method of treatoing sarcoma in a human suffering from a sarcoma which comprises administering to said human an effective antisarcoma amount of 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyridopyrimidine or a pharmaceutically acceptable salt thereof.
4. The method of treating lymphoma in a human suffering from a lymphoma which comprises administering to said human an effective anti-lymphoma amount of 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyridopyrimidine or a pharmaceutically acceptable salt thereof.
5. The method of treating leukemia in a human suffering from leukemia which comprises administering to said human an effective antileukemia amount of 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyridopyrimidine or a pharmaceucically acceptable salt thereof.
| 1987-11-30 | en | 1990-01-30 |
US-17590562-A | Method for the manufacture of novelty yarn
Nov. 5, 1963 K. M. MOLELLAN 3,109,279
METHOD FOR THE MANUFACTURE OF NOVELTYYARN Filed Feb. 27, 1962 2 Sheets-Sheet 1 INVENTOR. KENNETH M. MQLE LLAN BY FIG. 2 JZW/ 7 A TTIORNE Y Nov. 5, 1963 M. M LELLAN 3,109,279
v METHOD FOR THE MANUFACTURE OF NOVELTY YARN Filed Feb. 27, 1962 2 Sheets-Sheet 2 INVENTOR. F 6 KENNETH M. MQLELLAN Jaw A2 ATTORNE United States Patent M 3,109,279 NETHOD FOR THE MANUFACTURE GF NOVELTY YARN Kenneth M. Mcllellan, Cleveland, Ohio, assignor to Midlafngigoss Corporation, Cleveland, Ohio, a corporation 0 0 Filed Feb. 27, 1962, Ser. No. 175,905 4 Claims. (Cl. 57-157) This invention relates to novelty yarns of the thick and thin type simulating shantung yarn and to a method of making such yarn. More particularly, the invention relates to the manufacture of such a yarn by a method applicable to apparatus for the continuous spinning of artificial multifilament yarn.
Since the advent of artificial yarn spinning by continuous methods, various improvements have been proposed for altering such spinning to effect physical deformities or exterior changes along the length of a yarn to thus imitate yarn constructions made from natural fibers or by various developed processes creating different kinds of physical characteristics designed for various textile end purposes. Continuously spun physically altered yarns, generally, are deformed in a regularly occurring manner which regularity becomes monotonous and which in cloth form will yield a regular pattern, although different from unaltered yarn.
lit would be advantageous to provide for a novelty yarn where the thick and thin portions were irregularly spaced along its length and where the thick portions also vary in size. Such a construction more closely simulates shantung yarn than even the normally spun thick and thin yarns by conventional methods. The yarn and the method of its construction, to be more specifically described hereinafter, difiers from conventional methods in that it yields thickened portions of a high bulk spaced at random intervals along a continuing length of yarn formed directly from a multifilament artificial yarn while being continuously spun and advantageously on a continuous spinning apparatus. Yarn having enlarged portions along a generally constant diameter can be produced with such desirable chracteristics on a continuous process apparatus. Such production avoids many subsequent separate handling steps and the need of special further required equipment; thus, also, making it more economical to produce.
More specifically, the thick and thin portions of multifilament yarn of this invention are formed as such yarn is being withdrawn from a continuously advancing helix, the yarn turns emerging from the helix being separated at intervals and the filaments forming the yarn at such times spread so as to make a web which upon rotation is converted to different uneven yarn of random thickened and thinned portions of various lengths and occurring at various intervals along its length. Such a yarn for certain uses can be strengthened if of low denier for subsequent handling in the various apparatuses used for making various types of fabrics, either by weaving or knitting, and processes and modifications thereof. Additional strength to low denier novel yarn is advantageously provided by enwrapment by another compatible yarn of continuously uniform diameter and of such size that is designed not to affect the imparted novel exterior characteristics; or a yarn to further such unusualness can be added.
Thick and thin bulk yarn made by drawing from a helix has been described in US. Patent No. 2,854,814. The present method and the product of this invention, however, are an improvement thereover in that slubs or thickened portions are interspersed rather than being continuous and will now be more fully described in the fol- 3,169,279 Patented Nov. 5, 19 63 lowing specification taken with the accompanying drawing; where FIGURE 1 represents the discharge end improvement to a thread storing, thread advancing device adapted to form irregularly spaced Webs or skeins in the running length of a continuous filament yarn.
FIGURE, 2 partly in side section, indicates the mounting of the discharge end improvement on a reel enabling the formation of the spaced webs or skeins;
FIGURE 3 is a representation of a yarn helix being moved over a thread storing, thread advancing device in a plurality of turns;
FIGURE 4 represents, in partial section taken across lines 4-4 of FIGURE 3, the separation of filaments to form a Web or skein;
FIGURE 5 represents, in side elevation, an abbreviated form of a continuous spinning apparatus capable of being utilized in making the yarn of this invention; and
FIGURES 6 and 7 represent details of the yarn and of its appearance in a fabric, respectively.
Referring to the drawing the applicant advantageously uses an interdigitating thread advancing reel with an add ed improvement, a conical device 10 having a mounting hub 11 adapted to fit into its fore-end. The type reel preferred is the thread storing, thread advancing reel of FIGURE 2 and more specifically that shown and described in the Knebusch Patent 2,210,914. As described in this patent the reel is adapted to store and advance yarn in a helix of many turns of thread lengthwise over its periphery. Normally, yarn approaching the end of the reel periphery is manually taken oif and led to another simjlar device positioned adjacent it and so on or (I to a final collecting device. It is proposed by this invention through the use of a temporary yarn storing improvement to the reel to more effectively utilize the helix form feed of yarn turns as it discharges them over the free end of the reel of FIGURE 2. The improvement 10 to the reel enables a better control of the yarn turn discharge over the reel end which results in an improved formulation at spaced but different intervals of a yarn webbing or skeining than previously, enabling the handling of a finer denier yarn readily yielding suddenly fiuifed or thickened extended sections giving an unusual and an improved textile product.
The section 10 on the reel 17 of FIGURE 2 has a brief cylindrical surface 14 for temporary turn storage, then a tapered serrated section 15, the taper being in a downwardly slanting direction and being part of the conical section 13. The device 10 is secured to the reel by means of bolts or studs 23 passing through holes 12 provided therefor. The reel 17 itself is formed of two reel members rotating on, offset and askew axes, each having a periphery of spaced bar members and the two being assembled in an interdigitating manner.
A continuously spun yarn 27, as shown in FIGURE 3, is stored in a plurality of turns in the form of a helix continuously advancing towards the reel discharge end. When the reel end is approached, the yarn turns are forced to slip oif the reel members 18, 19 onto the temporary storing section 14 of the device 10 and, in turn, are further forced by the turns behind them towards the tapered and serrated area 15. As the yarn turns are slidably forced onto the tapered discharge area 15 the filaments forming the yarn tend to separate and divide out to form a Web or skein. Meanwhile portions of the thread turns slip off intact or without being separated, the original being reformed into a different yarn having randomly positioned bulky and thin sections. The discharge of the yarn as a Web actually occurs at intervals rather than continuously as would appear from the drawing, the webbing or skeining is followed by a discharge of a substantial portion of a yarn turn of about normal denier. The random skeining and yarn turn sloughing off thus provide for an unusual appearing yarn product.
This webbing or skeining process is more specifically shown in FIGURE 4 of the drawing wherein the yarn 27 is advanced in turns which are discharged or let off the thread advancing reel members 18, 19 onto the fiat surface 14 of the device where the filaments start their separation from the yarn body. The division or separation of the filaments is enhanced by a wet treatment as they slide over the initial cylindrical area and the inclined portion 15 of the device 10 in the form of alternate webs or skeins of the filaments and straight lengths being reformed into thick (bulky) sections of yarn followed by normal diameter lengths continuously discharged by the reel. The reformed yarn 32 may be subsequently subjected to other desired processing stages prior to its collection. The yarn 32, however, in and of itself is not stretched so as not to destroy its unusual physical appearance. If it is of small diameter, such as of about 100 denier and strength is a requirement it is then enwrapped by another the enwrapment being spaced to prevent loss of appearance. Advantageously, the bulked yarn is enwrapped with a compatible reinforcing yarn, and in a con tinuous manner. This procedure will produce a novelty yarn having, generally, any required strength called for by subsequent operations yet retaining its unusualness.
A continuous method for making the complete improved novelty yarn is shown in FIGURE 5. The method will be described in connection with the spinning of a viscose rayon yarn although it is not considered as being limited thereto. The viscose yarn 27 is extruded through a spinneret 39 positioned in an acid bat-h con tained in trough and being part of the viscose solution conducting mass tube 38. The yarn 27 is directed onto a reel 40 positioned above the coagulating bath then advanced thereover until a desired number of turns have been established, and then it is passed onto and over subsequent reels 43, 45, etc. Various processing treatments 41, 44, 46 can be applied for regeneration, washing, bleaching, oiling, etc., designed to produce a yarn having required final characteristics. Since the manufacture of viscose rayon is an established art, the various a-ftertreatments will not be described in this application. The yarn 27 is then drawn off out of the helix on the final reel over its front end, in the manner hereinbefore described, to produce a nonuniformly bulked shantung appearing thread.
For additional strength purposes or a further modified appearance, a second yarn is wrapped about the reformed yarn. This step is effected by directing the reformed yarn 32 over a forwarding guide roller 47, through the core of the yarn containing and rotating spool 48 from which the wrapping yarn 50 is withdrawn. The spool 48 is rotated by an endless belt 49 at a speed giving the desired frequency of enwrapment of the novelty yarn 32-. The combined final yarn strand is then submitted to a drying process if wet because of a treatment on reel 51. The drying reel 51 may be heated by steam or hot gases circulated therethrough. The final combined yarn is then led off the thread advancing, drying reel 51 and over a guide 52 onto a storage device 53 driven by surface contact with cylinder 54.
The combined yarn has the appearance of flufied thick sections and thin interval yarn enwrapped with a con- The final combined yarn can then readily be utilized in a weaving or knitting operation since it is provided with sufficient strength to overcome the abrupt handling of a fabric forming apparatus. A sample of such a fabric is shown in FIGURE 7. It can be readily seen that the slubs of such a yarn being of various thicknesses and of various lengths when woven into a fabric providing for an unusual and a pleasing final design. Where the denier is substantial and no harsh subsequent handling need be anticipated, the further wrapping can be omitted. Also, the added yarn obviously can be of different color, denier, or kind depending upon final desired characteristics. It can be a thermoplastic yarn having desirable shrinkage characteristics to therethrough form and emphasize greater fullness of the final fabric; or it can be a thermosetting kind where its partial plasticization binds it to the different thick and thin yarn of viscose;
What is claimed is:
1. The method of manufacture of a novelty yarn having random thick and thin portions comprising, a source of multifilament yarn, storing and advancing said yarn in a plurality of turns as a helix, withdrawing turns out of the forward end of said helix and separating them out at random intervals into filamentary form so as to make a Web, and collecting said reformed yarn strand.
2. The method of manufacture of a novelty yam'having random thick and thin portions comprising, a source of multifilament yarn, storing and advancing said yarn in a plurality of turns as a helix, withdrawing turns out of said helix and separating them out at random intervals into filamentary form so as to make a web and simultaneously also partly sloughing off complete yarn lengths, and collecting said reformed yarn strand.
3. The method of manufacture of a novelty yarn having random thick and thin portions comprising, a source of multifilament yarn, storing said yarn in a plurality of turns and advancing it in the form of a rotating helix, withdrawing said yarn turns from the forwarding end of said helix, during the withdrawing separating said turns at random intervals into filamentary form so as to make a web of them, enwrapping said resultant yarn with another of substantially constant denier, and collecting said combined yarn strand.
4. The method of manufacture of a novelty yarn hay ing random thick and thin portions comprising, a source of continuously spun multifilament yarn, storing said yarn in a plurality of turns and advancing it in the form of a rotating helix, withdrawing said yarn turns from said helix, during withdrawal and at random intervals separating said turns into a filamentary web and simultaneously also partly sloughing 01f said turns, enwrapping said resultant yarn with another of substantially constant denier, and collecting said combined yarn strand.
References Cited in the file of this patent UNITED STATES PATENTS 2,278,888 Lewis Apr. 7, 1942 2,854,814 Burkholder Oct. 7, 1958 2,890,567 Taylor et al. June 16, 1959 2,894,802 Braunlioh July 14, 1959 3,071,917 Fisher Jan. 8, 1963
1. THE METHOD OF MANUFACTURE OF A NOVELTY YARN HAVING RANDOM THICK AND THIN PORTIONS COMPRISING, A SOURCE OF MULTIFILAMENT YARN, STORING AND ADVANCING SAID YARN IN A PLURALITY OF TURNS AS A HELIX, WITHDRAWING TURNS OUT OF THE FORWARD END OF SAID HELIX AND SEPARATING THEM OUT AT RANDOM INTERVALS INTO FILAMENTARY FORM SO AS TO MAKE A WEB, AND COLLECTING SAID REFORMED YARN STRAND.
| 1962-02-27 | en | 1963-11-05 |
US-26101194-A | Process for preparing low density ethylene copolymers
ABSTRACT
Low density ethylene copolymers are obtainable by adding an aromatic hydrocarbon solution of a catalyst system, containing, as active components, metallocene complexes of metals of subgroups IV and V of the Periodic Table and oligomeric alumina compounds, to a mixture containing ethylene, comonomers and aliphatic hydrocarbons.
This application is a continuation of application Ser. No. 07/981,487, filed on Nov. 25, 1992, now abandoned.
The present invention relates to low density ethylene copolymers obtainable by adding an aromatic hydrocarbon solution of a catalyst system containing, as active components, metallocene complexes of metals of subgroups IV and V of the Periodic Table and oligomeric alumina compounds to a mixture containing ethylene, comonomers and aliphatic or alicyclic hydrocarbons.
The present invention furthermore relates to processes for the preparation of such ethylene copolymers, their use for the production of fibers, films and moldings, and the fibers, films and moldings obtainable and consisting of the ethylene copolymers.
Many material properties of ethylene copolymers are determined not only by the molecular weight and the type of comonomers but in particular by the molecular weight distribution and comonomer distribution. These include, for example, the fracture mechanics of such materials and the sticking of polyethylene films due to low molecular weight polymer fractions having a high comonomer content.
Conventional Ziegler-Natta catalysts based on carrier-supported titanium, zirconium or vanadium compounds have the disadvantage that such low molecular weight, comohomer-rich polymer chains form in the copolymerization of ethylene with C3 -C10 alk-1-enes. The distribution of the comonomers is inhomogeneous and dependent on the chain length, as described in EP-A 70 220. Owing to the preferential incorporation of the comohomers in the short chains, in the preparation of low density polyethylene large amounts of comohomer are required in order to ensure the incorporation of a sufficient amount thereof in the higher molecular weight product fraction.
It is true that metallocene catalyst systems can be used to produce ethylene copolymers which have a more uniform comonomer distribution, as described in WO 88/04672, but said copolymers also have a narrow molecular weight distribution, which in turn leads to poorer processibility.
It is an object of the present invention to provide low density ethylene copolymers which do not have the stated disadvantages and at the same time exhibit a good morphology.
We have found that this object is achieved by the low density ethylene copolymers defined at the outset. We have also found processes for the preparation of such ethylene copolymers, their use for the production of fibers, films and moldings and the fibers, films and moldings obtainable and consisting of the ethylene copolymers.
The aromatic hydrocarbon solutions of catalyst systems used for the preparation of the novel ethylene copolymers contain, among the active components, metallocene complexes of metals of subgroups IV and V of the Periodic Table, in particular of titania, of zirconium, of hafnium, of vanadium, of niobium or of tantalum. Preferably used complexes are those in which the metal atom is bonded via π-bonds to unsaturated cyclic hydrocarbon radicals, for example cyclopentadienyl, fluorenyl or indenyl. Furthermore, in the preferably used complexes, the metal atom may also be bonded to further ligands, in particular to fluorine, chlorine, bromine or iodine or C1 -C10 -alkyl, for example methyl, ethyl, propyl or butyl.
Particularly suitable metallocene complexes are 30 of the general formula I ##STR1## where M is titanium, zirconium, hafnium, vanadium, niobium or tantalum,
X is fluorine, chlorine, bromine, iodine, hydrogen, C1 -C10 -alkyl, C6 -C15 -aryl or -OR6,
R6 is C1 -C10 -alkyl, C6 -C15 -aryl, alkylaryl, arylalkyl, fluoroalkyl or fluoroaryl, where each alkyl radical is of 1 to 10 carbon atoms and each aryl radical is of 6 to 20 carbon atoms,
R1 to R5 are each hydrogen, C1-C 10 -alkyl, 5-membered to 7-membered cycloalkyl, which in turn may carry C1 -C6 -alkyl as substituent, C6 -C15 -aryl or arylalkyl, where two adjacent radicals together may furthermore form a cyclic group of 4 to 15 carbon atoms, or Si(R7)3,
R7 is C1 -C10 -alkyl, C6 -C15 -aryl or C3 -C10 -cycloalkyl,
Z is X or ##STR2## R8 to R12 are each hydrogen, C1 -C10 -alkyl, 5-membered to 7-membered cycloalkyl, which in turn may carry C1 -C10 -alkyl as a substituent, C6 -C15 -aryl or arylalkyl, where two adjacent radicals together may furthermore form a cyclic group of 4 to 15 carbon atoms, or Si (R13)3, R13 is C1 -C10 -alkyl, C6 -C15 -aryl or C3 -C10 -cycloalkyl, or R4 and Z together form a group -[Y(R14)2 ]n -E-, Y is silicon, germanium, tin or carbon, R14 is C1 -C10 -alkyl, C3 -c10 -cycloalkyl or C6 -C10 -aryl, n is 1, 2, 3 or 4, ##STR3## A is -O-, -S-, ##STR4## R15 is C1 -c10 -alkyl, C6 -C15 -aryl, C3 -C10 -cycloalkyl, alkylaryl or Si(R16)3 and R16 is C1 -C10 -alkyl, C16 -C15 -aryl, C3 -C10 -cycloalkyl or alkylaryl.
Among the metallocene compounds of the general formula I ##STR5## are preferred.
Thus, it is not just the bis(η-cyclopentadienyl)metal complexes which are understood under the term metallocenes.
Particularly preferred compounds of formula Ia are those in which M is titanim, zirconim or hafnium, X is chlorine and R1 to R5 are each hydrogen or C1 -C4 -alkyl.
Preferred compounds of the formula Ib are those in which M is zirconim or hafnium, X is chlorine, C1 -C4 -alkyl or phenyl, R1 to R5 are each hydrogen, C1 -C4 -alkyl or Si(R7)3 and R8 to R12 are each hydrogen, C1 -C4 -alkyl or Si(R13)3.
Particularly suitable compounds of the formula Ib are those in which the cyclopentadienyl radicals are identical, the unsubstituted cyclopentadienyl radicals are preferred.
Examples of particularly suitable compounds includes bis(cyclopentadienyl)-zirconium dichloride, bis(pentamethylcyclopentadienyl)-zirconium dichloride, bis(cyclopentadienyl)-diphenylzirconium, bis(methylcyclopentadienyl)-zirconium dichloride, bis(ethylcyclopentadienyl)-zirconium dichloride, bis(n-butylcyclopentadienyl)-zirconium dichloride and bis(trimethylsilylcyclopentadienyl)-zirconiumdichloride and the corresponding dimethylzirconium compounds.
Particularly preferred compounds of the formula Ic are those in which R1 and R8 are identical and are each hydrogen or C1 -C10 -alkyl, R5 and R12 are identical and are each hydrogen, methyl, ethyl, isopropyl or tert-butyl, R3 and R10 are each C1 -C4 -alkyl, R2 and R9 are each hydrogen or two adjacent radicals R2 and R3 or R9 and R10 together form a cyclic group of 4 to 12 carbon atoms, R14 is C1 -C8 -alkyl, M is zirconium or hafnium, Y is silicon, germanium, tin or carbon and X is chlorine.
Examples of particularly suitable complexes include: dimethylsilanediylbis(cyclopentadienyl)-zirconium dichloride, dimethylsilanediylbis(indenyl)-zirconium dichloride, dimethylsilanediylbis(tetrahydroindenyl)-zirconium dichloride, ethylenebis(cyclopentadienyl)-zirconium dichloride, ethylenebis(indenyl)-zirconium dichloride, ethylenebis(tetrahydroindenyl)-zirconium dichloride, dimethylethylene-9 -fluorenylcyclopentadienyl zirconium dichloride, dimethylsilanediylbis(3-tert-butyl-5-methylcyclopentadienyl) -zirconium dichloride, dimethyls ilanediylbis(3-tert-butyl-5-ethylcyclopentadienyl) -zirconium dichloride, dimethyls ilanediylbis(3-tert-butyl-5-methylcyclopentadienyl) -dimethylzirconium, dimethylsilanediylbis(2-methylindenyl)-zirconium dichloride, dimethylsilanediylbis(2-isopropylindenyl)-zirconium dichloride, dimethylsilanediylbis(2-tert-butylindenyl)-zirconium dichloride, diethylsilanediylbis(2-methylindenyl)-zirconium dibromide, dimethylsilanediylbis(2-methyl-5-methylcyclopentadienyl)zirconium dichloride, dimethyls ilanediylbis(2-ethyl-5-isopropylcyclopentadienyl) -zirconium dichloride, dimethylsilanediylbis(2-methylindenyl)-zirconium dichloride, dimethylsilanediylbis(2 -methylbenzindenyl)-zirconium dichloride and dimethylsilanediylbis(2-methylindenyl)-hafnium dichloride.
Examples of particularly preferred compounds of the general formula Id are those in which M is zirconium or hafnium, X is chlorine or C1 -C10 -alkyl, Y is silicon or carbon when n is 1 or is carbon when n is 2, R14 is C1 -C8 -alkyl, C5 -c6 -cycloalkyl or C6 -C10 -aryl, A is -O-, -S- or >NR15 and R1 to R3 and R5 are each hydrogen, C1 -C10 -alkyl, C3 -C10 -cycloalkyl, C6 -C15 -aryl or Si(R7)3, or two adjacent radicals form a cyclic group of 4 to 12 carbon atoms.
The synthesis of such complexes can be carried out by conventional methods, the reaction of the correspondingly substituted, cyclic hydrocarbon anions with halides of titanium, zirconium, hafnium, vanadium, niobium or tantalum being preferred. Examples of corresponding preparation processes are described in, inter alia, Journal of Organometallic Chemistry, 369 (1989), 359-370.
The metallocene complexes may also be in cationic form, as described in EP-A 277 003 and EP-A 277 004. μ-Oxobis(chlorobiscyclopentadienyl)zirconiummay also be used as a metallocene complex.
In addition to the metallocene complexes, the catalyst systems used for the preparation of the novel ethylene copolymers also contain oligomeric alumina compounds. For example, open-chain or cyclic alumoxane compounds of the general formula II or III ##STR6## where R17 is C1 -C4 -alkyl, preferably methyl or ethyl, and m is an integer from 5 to 30, preferably from 10 to 25, are suitable.
The preparation of these oligomeric alumoxane compounds is usually carried out by reacting a solution of trialkylaluminumwith water and is described in, inter alia, EP-A 284 708 and US-A 4 794 096.
As a rule, the oligomeric alumoxane compounds obtained are present in the form of mixtures of both linear and cyclic chain molecules of different lengths, so that m should be regarded as an average value. The alumoxane compounds may also be present as a mixture with other metal alkyls, preferably with alkylaluminums.
It has proven advantageous to use the complex of metals of subgroups IV and V of the Periodic Table and the oligomeric alumoxane compound in amounts such that the atomic ratio of aluminum from the oligomeric alumoxane compound to the transition metal from the complex of metals of subgroups IV and V of the Periodic Table is from 10:1 to 106 :1, in particular from 10:1 to 104:1.
Conventional aromatic hydrocarbons, preferably of 6 to 20 carbon atoms, in particular xylenes and toluene, and mixtures thereof, are used as solvents for these catalyst systems.
The aromatic hydrocarbon solutions of these catalyst systems are then added to a mixture containing ethylene, comonomers and aliphatic or alicyclic hydrocarbons. The catalyst system may be added all at once, a little at a time or continuously to the polymerization mixture.
Preferred comonomers are C3 -C10 -alk-1-enes and cyclic alkenes which have no hydrocarbon radicals as substituents at the double bond, in particular propene, but-1-ene, pent-1-ene, hex-1-ene and cyclopentene. These comonomers can be used individually or as mixtures.
Suitable aliphatic or alicyclic hydrocarbons are those in which the catalyst systems are usually soluble to an extent of less than 5 g/1 under the reaction conditions. C4 -C15 -Alkanes, in particular isobutane, n-hexane and nheptane, have proven preferable, as well as C5 -C15 -cycloalkanes, in particular cyclopentane and cyclohexane, and highly substituted alkenes, ie. alkenes having at least one substituent at the double bond which is not terminal, for example 2,3-dimethylbut-2-ene and 1-methylcyclohexene, and diesel oil, liquid paraffin and gasoline. However, C4 -C5 -alkanes are particularly preferred. Mixtures of different aliphatic or alicyclic hydrocarbons may also be used.
The amount of comohomers is usually from 1 to 25% by weight, preferably from 3 to 15, % by weight, based on ethylene.
These copolymers can be prepared, either batchwise or preferably continuously, in the conventional reactors used for the polymerization of alkenes. Suitable reactors include continuously operated stirred kettles, and a plurality of stirred kettles connected in series may also be used.
The polymerization conditions as such are not critical, pressures of from i to 1,000 bar and temperatures of from -50° to +300° C. usually being employed.
In a preferred embodiment, the comonomers and aliphatic hydrocarbons are initially taken under an inert gas atmosphere, the solution is heated to 50°-100° C. and the pressure is brought to 1-100 bar with ethylene. The catalyst system is injected, preferably under superatmospheric pressure by means of an inert gas, into this mixture while stirring.
The ethylene copolymers are obtained as granular polymers which can be readily isolated by the conventional methods, such as evaporation of the aliphatic hydrocarbons.
The density of the resulting products is in general from 0.890 to 0.945, preferably from 0.910 to 0.930, g/cm3.
The novel ethylene copolymers have a good morphology, a uniform comonomer distribution and an advantageous molecular weight distribution, with the result that they can be readily processed.
The novel low density ethylene copolymers are suitable for the production of fibers, films and moldings.
EXAMPLES
Preparation of low density ethylene/hex-1-ene copolymers
EXAMPLES 1 TO 3
500 ml of heptane and various amounts of hex-1-ene were initially taken in a 11 autoclave. The solution was heated to 60° C. and the pressure was brought to 15 bar with ethylene. 10 ml of a toluene solution which contained 1.6 mg (5.5·10-6 mol) of bis(cyclopentadienyl)zirconiumdichloride and 1 g (19·10-3 mol Al) of methylalumoxane was injected into this mixture while stirring under superatmospheric pressure by means of an inert gas. Reaction for 30 minutes gave a granular ethylene/hex-1-ene copolymer which was suspended in heptane. No wall deposits occurred during the polymerization. 80% of the copolymer had a particle size of from 250 to 500 μm.
The amounts of hex-1-ene used, the yields, the activity of the catalyst systems and the properties of the ethylene/hex-1-ene copolymers are summarized in the Table.
The viscosities η were determined according to DIN 53,733, the density d was determined for pressed sheets according to ASTM D-792, the weight average molecular weight Mw and the number average molecular weight Mn were determined by gel permeation chromatography, the melting point Tm was determined by defined cooling of the melt (20° C./min) and reheating, the hex-1-ene content was determined by means of 13 C-NMR and the bulk density was determined according to DIN 53,468.
TABLE
__________________________________________________________________________
Activity
Hex-1-ene
Yield
[kg of copolymer/
η
d M.sub.w T.sub.m
Hex-1-ene
Bulk density
Example
[ml] [g] mol of Zr]
[dl/g]
[g/cm.sup.3 ]
[g/mol]
M.sub.w :M.sub.n
[°C.]
[% by wt.]
[g/l]
__________________________________________________________________________
1 30 87.1 15,840 2.41
0.930
250,000
4.45
120.1
3.3 210
2 50 92.0 16,730 2.21
0.920
169,000
4.32
116.5
5.1 198
3 70 98.5 17,910 1.90
0.916
145,000
4.75
111.9
6.8 225
__________________________________________________________________________
We claim:
1. A process for preparing a low density ethylene copolymer which comprises: adding an aromatic hydrocarbon solution of a catalyst system containing, as active components, metallocene complexes of metals of subgroups IV and V of the Periodic Table and oligomeric alumoxane compounds to a mixture containing ethylene, C3 -C10 -alk-1-enes and aliphatic or alicyclic hydrocarbons.
| 1994-06-14 | en | 1995-09-26 |
US-29583463-A | Process for textile decorating and textile webs decorated thereby
United States Patent 3,322,562 PROCESS FOR TEXTILE DECORATING AND TEXTHLE WEBS DECORATED THEREBY Charles A. Kurnins, Chappaqua, N.Y., V. Lindsay Chase,
Butler, N.J., Jerome Fine, Oceanside, N.Y., and Ernest Messrner, Fair Lawn, NJ, assignors to Inter-chemical Corporation, New York, N.Y., a corporation of ()hio No Drawing. Filed July 17, 1963, Ser. No. 295,834
12 Claims. (Cl. 117-62.2)
This invention relates to textile decorating with resin bonded pigment colors and to textile webs decorated by this process.
In our co-pending application, Ser. No. 295,813 filed July 17, 1963, it was disclosed, that after treatment of a deep-shade anionic padding or printing with minor amounts of a certain type of cationic polymeric material improves color value and imparts good Wash and scrubfastness. It also gives excellent migration control without impairing desirable hand in padding processes. The application of the system to textile printing has the advantage of improved color value, good fastness, and it also considerably improves the runability of low-crock systems. Runability refers to the length of continuous processing possible before it becomes necessary to stop the run to clean up the system.
It was found that considerable adjustment was required to achieve the required stability in the liquor used for after treatment. By the process of the instant invention, however, this diificulty has now been overcome. The special cationic binder is put in the pad liquor or printing paste, the latter being adjusted to a pH of 89. Preferably an aqueous solution of the special cationic binder, for instance a 25% solution, is adjusted to a pH of 8-9 before it is added to the pad liquor or printing paste, which also should be at a pH of 8-9. The padded or printed material is then after-treated with an aqueous solution of a suitable acid to bring the padded or printed composition to a pH of about. 6. Without these pH adjustments, addition of the cationic binder to the pad liquor or printing paste is impractical because fluocculation gets out of control. Also, in padding processes the bath is soon depleted of the cationic agent when cotton or other fabrics substantive to cationic materials are decorated.
In the process of this invention the cationic agent is no longer substantive to cotton and the danger of undesirable flocculation is eliminated. When the acidic after-treatment solution is applied, bringing the pH of the compositions down to about 6, the cationic agent is reactivated. Subsequently the fabric is dried. The textile web thus decorated has the excellent properties of webs decorated by the process of after treatment with a liquor containing the cationic agent, that is, the process described in our co-pending application, Ser. No. 295,813 filed July 17, 1963. As in that disclosure, the process of the instant invention also may include latexes and polysiloxanes in the after-treatment liquors, which may be applied by padding or spraying. By applying a latex in the after treatment the advantage is obtained of reducing the amount of binder in the printing paste or padding to a small amount, for instance to only 10% of the conventional quantity. The after treatment then applies more binder as a topcoating, giving adequate protection to the colorants, but reducing the total binder required to much less than that of conventional processes. The latexes used should, of course, be compatible with the acid present in the liquor, used for after treatment. The polysiloxanes found to be preferable are those of the type having methyl groups or methyl groups plus hydrogen atoms attached to the silicon in the typical repeating units of the polymer chain. Such materials are represented by the commercial products DC-36 emulsion and Silofi 22 for example.
3,322,552 Patented May 30, 1967 "Ice It is surprising that the polysiloxanes improve the dry crock resistance but not the wet crock resistance. The reproducibility, however, is bettered for both wet crock and dry crock. This phenomenon is quite different from the behavior of acrylics, for instance. The polysiloxanes are incompatible and heat resistant and their action here is believed to be due to their apparent migration to the top of coated textiles. Other materials will do part of the job performed by the polysiloxane but none can be used as completely satisfactory substitutes for it. Such other materials are for example microcrystalline wax and finelydivided polyethylene of molecular weight around 18,000.
EXAMPLE 1 A typical anionic padding formulation is:
Parts by weight dry basis Phthalocyamine blue 1.00 Sodium lauryl sulfate 0.80 Polyacrylic acid 0.45 Special binder Z 0.84 Hexamethyl ether of hexamethylolmelamine 1.50 Cationic agent (special binder) X 0.40
WaterTo make 100.00
The pH was adjusted to 8-9, cationic agent X having been added as a 25% aqueous solution at pH 8-9. This composition was then padded on x 80 count cotton to give 0.8% pigment on the weight of fabric, the wet pickup having been 80%. The padded fabric was oversprayed with the following composition having a pH of 3:
Parts by weight dry basis Special binder Z 7.0 Polydimethyl siloxane 1.5
Water-To make 100.0
The wet pickup of the overspray was 25 on the weight of the fabric. Spraying was carried out with Binks spray guns model 21A, 63 PB air nozzles, and 63A liquid nozzles at 7 inches from the web, one nozzle on each side. After drying the material had the excellent properties described above.
A similar overspray or overpadding composition may be applied to a printed fabric, the amount of binder being suitably adjusted with respect to the amount of pigment present The process may be applied to an all aqueous printing system or to an oil-in-water or water-inoil system. Typical formulations for these three types follow.
EXAMPLE 2 All-aqueous printing paste Color concentrate: Parts by weight Water-To make 100.0
These were combined in the conventional way and to the paste was added the special cationic agent X from a 25% aqueous solution at a pH of 8-9. The quantity of X added amounted to 40% of the weight of pigment.
A fabric was then printed with the paste and oversprayed with a composition similar to that used in Example 1.
3 EXAMPLE 3 Water-in-oil printing paste Color concentrate: Parts by weight Pigment 13.0 Dry melamine formaldehyde resin 6.5 Ethyl cellulose 0.5 Water 6.0 Organic solvent (Solvesso 150, turpentine,
pine oil) 74.0
An emulsion was made of the ingredients.
Clear: Parts by weight Alkyd resin 1.25 Varsol 31.25 Ammonium sulfate 0.30 Water 67.00
An emulsion was made of these ingredients. Cationic agent X was added to the print paste and overspray applied as in Example 2.
EXAMPLE 4 Oil-in-water printing paste Color concentrate: Parts by weight Pigment 16.0 Sodium lauryl sulfate 6.4 Methyl cellulose 0.3 NH O-H (26%) 0.6 Special binder and pigment disperant Y (dry basis) 0.8 Melamine formaldehyde resin 1.4 Varsol 3.7
Water-To make 100.0
The ingredients are emulsified.
Clear: Parts by weight Alkyd melamine formaldehyde resin 0. 26 Methyl cellulose 0.32 Sodium lauryl sulfate 0.22 Varsol" 49.6 Water 49.6
The ingredients were emulsified.
Cationic agent X was added as in Example 1 and the subsequent procedure was similar.
The cationic thermosetting polymeric materials preferred for carrying out the process of this invention comprise water-soluble reaction products of epichlorohydrin and a polyamide derived from a polyalkylene polyamine having two primary amine groups and at least one secondary amine group and a dicarboxylic acid selected from the group consisting of diglycollic .acid and C to C saturated aliphatic dicarboxylic acids. The polyamide referred to is a water-soluble, long chain polyamide, containing secondary amine groups, the mole ratio of polyal kylene polyamine to dicarboxylic acid being from about 0. 8 to 1 to about 1.4 to 1. The reaction of the polyamide with epichlorohydrin is carried out in aqueous solution in a mole ratio of from about 0.5 to about 1 epichlorohydrin to about 1.8 to 1 secondary amine groups of the polyamide to form an aqueous solution of a water-soluble, thermosetting cationic resin. Such mate= rials are described in U.S. Patent No. 2,926,154.
PREPARATION OF CA'IIONIC AGENTS (A) A polyamide was made by adding 290 g. of adipic acid to 319 -g. of triethylenetetramine and heating the resulting solution 1 /2 hours at 185-200" C. The batch was then allowed to cool to 140 C. while under vacuum supplied by a water pump. 430 g. of water were added at this point, giving a polyamide solution having 49.8% solids, a pH of 10.8, and an acid number of 3.2.
A solution consisting of 225 g. water and 63 g. of the above polyamide solution was heated to 50 C. and 25 g. of epichlorohydrin added dropwise over a period of 3 minutes. The solution was then heated to 60-70 C.
until the viscosity was E (Gardner). 225 g. of water were added, the batch was cooled to 25 C., and the pH adjusted to 5.0 with 11 ml. of 10% HCl. The product had a solids content of 8.4% and a Gardner viscosity of C, and constituted the previously mentioned special binder X."
(B) Similarly epichlorohydrin was reacted with a polyamide made from 2.8 moles diethylenetriamine and 2.0 moles adipic acid.
(C) A polyamide was also prepared by reacting 1.25 moles of triethylenetetramine with 1 mole of succinic acid. The product was reacted with epichlorohydrin.
(D) 1.98 moles of diethylenetriamine and 0.24 mole of ethylenediam-ine were reacted with 1.98 moles of adipic acid in g. water. The resulting polyamide was treated with epichlorohydrin as in the preceding examples.
(E) 2.2 moles of tetraethylenepentamine were reacted with 1.81 moles of adipic acid and the resulting polyamide was also reacted with epichlorohydrin.
The specific details of these and similar preparations may be found in U.S. Patent No. 2,926,154, previously referred to. The epichlorohydrin is added in sufiicient amount to convert all secondary amine groups to tertiary amine groups or quaternary ammonium groups including cyclic structures. More than this or even less may be used to help regulate the rate of reaction. The various polyamines and acids suitable are also described in the patent.
SPECIAL BINDER AND PIGMENT DISPERSANT Y parts of isopropanol were heated to reflux (82 C.). Then over a period of 1 hour was added a mixture of 28.2 parts acrylamide, 130.0 parts ethyl acrylate, 20.0 parts lauryl acrylate, 10.0 parts methacrylic acid, 75.0 parts isopropanol, 1.5 parts benzoyl peroxide, and 0.8 part of tertiary-dodecyl mercaptan, the reflux temperature of 8283 C. being maintained. Refiuxing was continued 2 hours more. 1.5 parts benzoyl peroxide were added. The batch was refluxed another hour, cooled, and the solvent vacuum distilled off at room temperature at 4.5 mm. of mercury. A solution of 64 parts of 37% formalin in 300 parts of water and 41 parts of 29% aqueous ammonium hydroxide was added to the resin and the mixture brought slowly up to 70 C. It was heated 4 hours more at 70-72" C. Solids content was 30.9%.
Other proportions may be used, for instance 60-70 parts of ethyl acrylate, 5-20 parts lauryl methac-rylate, 5-20 parts methacrylic acid, and 10 20 parts acrylamide. Instead of acrylamide, N-methylolacrylamide, N,N diallyl melamine, or similar compositions with similar properties would also be suitable. Instead of Y, Carboset 531 may be used.
SPECIAL BINDER Z This is a copolymer of 85 parts of 2 ethylhexyl acrylate, 13 parts acrylonitrile, and 2 parts of itaconic acid in latex form with a nonionic emulsifier such as Triton X305, parts being parts by weight.
-DX-840-73 is a high molecular weight copolymer of ethylene and maleic anhydride that is partly crosslinked and has a viscosity of 40,000 c.p.s. at 25 C. as a 1% solution in dimethyl formamide. Such compounds are described in U.S. Patent No. 2,921,928.
Solvesso is a liquid hydrocarbon solvent, predominantly aromatic in character, having a boiling range of 367421 F. and a kauri-butanol value of 90.
Varsol is a liquid hydrocarbon solvent, predominantly aliphatic in character, having a boiling range of 322- 386" F. and a k-auri-butanol value of 38.
What is claimed is:
'1. A process for decorating textiles consisting essentially of (1) applying to a textile web an anionic, pigment-containing, textile-coloring composition at a pH of about 8-9 containing a polymeric material containing carboxyl groups to which has been added a minor amount of a cationic, water-soluble thermosetting polymeric material made by reacting a polyalkylene polyamine having two primary amine groups and at least one secondary amine group with a dicarboxylic acid selected from the group consisting of diglycollic acid and C to C saturated aliphatic dicarboxylic acids to form a water-soluble long chain polyamide containing secondary amine groups, the mole ratio of polyalkylene polyamine to dicarboxylic acid being from about 0.8 to 1 to about 1.4 to 1, and then reacting the polyamide in aqueous solution with epichlorohydrin in a mole rat o of from about 0.5 to 1 mole of epichlorohydrin to about 1.8 to 1 mole of secondary amine groups of said polyamide to form an aqueous solution of a water-soluble cationic thermosetting resin which resin is reactive with said polymeric material containing carboxyl groups, (2) applying to the so-treated textile web an aqueous solution of an acid suitable for acidifying the applied liquors to a pH of about 6, and (3) subsequently drying the treated textile Web.
2. The process described in claim 1 in which the aqueous solution of an acid, used in step (2), also contains a substantial amount of at least one compatible latex in addition to the acid.
3. The process described in claim 1, in which the aqueous solution of an acid, used in step (2), also contains a minor amount of a polysiloxane, selected from the group consisting of polysiloxanes having (a) methyl groups and (b) methyl groups and hydrogen atoms attached to the silicone in the repeating units of the polymer chain.
4. The process described in claim 3, in which the material used in step (2) also contains a substantial amount of at least one compatible latex in addition to the acid.
5. A process as described in claim 1, in which the minor amount of said cationic thermosetting polymeric material is added to the textile-coloring composition as an aqueous solution which has been adjusted to a pH of 89 before being added thereto.
6. A process as described in claim 2, in which the minor amount of said cationic thermosetting polymeric material is added to the textile-coloring composition as an aqueous solution which has been adjusted to a pH of 89 before being added thereto.
7. A process as described in claim 3, in which the minor amount of said cationic thermosetting polymeric material is added to the textile-coloring composition as an aqueous solution which has been adjusted to a pH of 89 before being added thereto.
8. A process as described in claim 4, in which the minor amount of said cationic thermosetting polymeric material is added to the textile-coloring composition as an aqueous solution which has been adjusted to a pH of 89 before being added thereto.
9. A textile web decorated by the process described in claim 1.
10. A textile web decorated by the process described in claim 2.
11. A textile web decorated bythe process described in claim 3.
12. A textile web decorated by the process described in claim 4.
References Cited UNITED STATES PATENTS 2,926,154 2/1960 Keim 260-29.2 2,995,512 8/1961 Weidner et al. 117--163 X 3,062,686 11/1962 Graulich et al. 117139.5 X 3,211,580 10/1965 Langmann et al. ll7l43 X 3,224,986 12/1965 Butler et al. 117139.5 X
WILLIAM D. MARTIN, Primary Examiner.
H. W. MYLIUS, M. LUSIGNAN, Assistant Examiners.
1. A PROCESS FOR DECORATING TEXTILES CONSISTING ESSENTIALLY OF (1) APPLYING TO A TEXTILE WEB AN ANIONIC, PIGMENT-CONTAINING, TEXTILE-COLORING COMPOSITION AT A PH OF ABOUT 8-9 CONTAINING A POLYMERIC MATERIAL CONTAINING CARBOXYL GROUPS TO WHICH HAS BEEN ADDED A MINOR AMOUNT OF A CATIONIC, WATER-SOLUBLE THERMOSETTING POLYMERIC MATERIAL MADE BY REACTNG A POLYALKYLENE POLYAMINE HAVING TWO PRIMARY AMINE GROUPS AND AT LEAST ONE SECONDARY AMINE GROUP WITH A DICARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF DIGLYCOLLIC AND C3 TO C8 SATURATED ALIPHATIC DICARBOXYLIC ACIDS TO FORM A WATER-SOLUBLE LONG CHAIN POLYAMIDE CONTAINING SECONDARY AMINE GROUPS, THE MOLE RATIO OF POLYALKYLENE POLYAMINE TO DICARBOXYLIC ACID BEING FROM ABOUT 0.8 TO 1 ABOUT 1.4 TO 1, AND THEN REACTING THE JPOLYAMIDE IN AQUEOUS SOLUTION WITH EPICHLOROHYDRIN IN A MOLE RATIO OF FROM ABOUT 0.5 TO 1 MOLE OF EPICHLOROHYDRIN TO ABOUT 1.8 TO 1 MOLE OF SECONDARY AMINE GROUPS OF SAID POLYAMIDE TO FORM AN AQUEOUS SOLUTION OF A WATER-SOLUBLE CATIONIC THERMOSETTING RESIN WHICH RESIN IS REACTIVE WITH SAID POLYMERIC MATERIAL CONTAINING CARBOXYL GROUPS, (2) APPLYING TO THE SO-TREATED TEXTILE WEB AN AQUEOUS SOLUTION OF AN ACID SUITABLE FOR ACIDIFYING THE APPLIED LIQUORS TO A PH OF ABOUT 6, AND (3) SUBSEQUENTLY DRYING THE TREATED TEXTILE WEB.
| 1963-07-17 | en | 1967-05-30 |
US-28947981-A | Portable tube holder
ABSTRACT
A portable holder for transporting rolled-up blueprints or other materials. The holder is comprised of at least two elongated hollow tubes fixed together at their ends by front and rear headers. A carrying handle is fixed to one of the tubes to allow a person to easily lift and transport the holder in one hand. The front header is provided with openings aligned with the hollow interior of each tube to allow materials to be inserted into or removed therefrom. The front header may be provided with hinged doors which are secured in the closed position to insure the integrity of the materials within the tubes.
Each of the headers may also be provided with projecting fingers and aligned holes on opposite side edges to enable a number of portable holders to be stacked together and held in place by the coaction of mating fingers and holes of adjacent portable holders.
BACKGROUND OF THE INVENTION
The present invention relates generally to blueprint holders and more particularly to a portable tube holder for easily transporting and/or storing a number of rolled-up blueprints or other materials.
The most widely used methods of storing blueprints or other similar materials consists of either placing flattened blueprints in a suspension drawer in a vertical file having a number of such drawers, or the mere rolling up of the blueprints, fixing them in the rolled position, and stacking them in cubbyholes or any convenient vacant area. Means have been suggested for storing rolled-up blueprints in tubes which may be joined together with other sides. However, none of these suggested means can be used to easily store and transport a number of separated blueprints.
In addition, none of the known means for either storing and/or transporting blueprints seems to take into account the rough handling blueprints may be subjected to during transit or at a job site.
Examples of the known means for storing rolled-up blueprints are shown in U.S. Pat. Nos. 2,871,080; 2,872,265; 3,011,852; 3,071,283; and 3,567,298.
There therefore exists a need for a blueprint holder which may be used to store blueprints and which is strong and adaptable enough that it may be used to transport rolled-up blueprints in complete security, and to prevent the blueprints from being damaged during transit, or when stored and/or used at a construction or other job site.
SUMMARY OF THE INVENTION
The present invention provides an improved portable tube holder for storing or securely transporting rolled-up blueprints to and from a construction site or other installation. The portable tube holder comprises a plurality of relatively light-weight, but strong, elongated hollow tubes joined together at their ends by headers. One of the headers is provided with openings to allow rolled-up blueprints to be inserted in or taken out of the tubes. The other of the headers is solid to close the tubes and to provide a closed hollow compartment within each of the tubes.
In one embodiment of the invention, each of the openings in the header is provided with a moveable door, which door may be provided with sealing and securing means to safely hold materials in each tube during transport and/or storage. Separate blueprints may be placed in each tube, locked in the tube, and identified on the respective door, as by labelling.
In another embodiment of the portable tube holder of the present invention each of the headers is provided with a number of projecting fingers or tips on one side edge thereof, and an equal number of aligned openings formed in the opposite side edge. Therefore, when a portable tube holder of the present invention is placed on the floor or any other flat surface, another portable holder may be stacked on top of it, with the aligned fingers in one holder held in the respective openings of the other. In this manner, any number of portable holders may be stacked one on top of the other, and firmly held together by the coaction of the aligned fingers and openings in each holder.
If required, as when the tubes are very long, or are made from a material which might allow the tubes to sag, the portable tube holder of the present invention may be provided with one or more additional headers or stiffening members to provide it with the necessary rigidity and strength. These stiffening members may be made smaller than the end headers, or may be made the same size. They may also include projecting fingers and aligned openings on the same edges as those of the end headers to provide additional mating and holding surfaces when a number of holders are stacked together.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features of the invention will be better understood from the following detailed description of the preferred embodiments illustrated in the accompanying drawing in which:
FIG. 1 is a perspective view of a portable tube holder of the present invention;
FIG. 2 is a front elevational view of the portable holder of FIG. 1 showing, in broken line, partial corresponding portable holders stacked above and below it; and
FIG. 3 is a partial sectional view taken along line 3--3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing wherein like numerals indicate like parts throughout the several figures, numeral 10 indicates a portable tube holder of the present invention. The portable holder is comprised of a plurality of spaced apart, elongated hollow tubes 12. Three tubes are shown in the drawing for illustration purposes only, it being understood that for purposes of this invention, the portable holder may be comprised of any number of tubes, with the preferred number ranging from two to eight, depending upon where and how the holder is to be used.
Each of the tubes 12 is substantially circular in cross section, and as shown more clearly in FIGS. 2 and 3, has a wall 14 enclosing a hollow interior 16.
The tubes 12 are preferably made from a lightweight, strong material, such as a high-strength plastic to provide long life and to absorb shocks if dropped or handled roughly.
A handle 18 is fixed to one of the outside tubes, as by riveting, if the handle is to be permanently attached, or by some easily removable arrangement, if the handle is to be removed when the holder is used for storage. The handle is placed in such a position that a person may grasp the handle in one hand and easily lift and transport the holder and any materials contained therein.
The holder 10 is provided with headers 20 and 22 fixed to either end of each tube, and maintaining the tubes at a fixed distance from each other. Each of the headers is identical or nearly identical in size with the first or front header 20 having a plurality of openings 24 passing therethrough aligned with and providing access to the hollow interior 16 of each of the tubes. The second or rear header 22 is one piece or solid, to provide a closure or wall across the rear end of each tube.
The headers are preferably made from the same rigid material as the tubes 12, and are permanently fixed to the tubes, in any convenient manner, to form sealed, weatherproof connections which prevent the passage of air and/or moisture between the ends of each tube and the headers. As shown more clearly in FIG. 3, each tube 12 has a front end 23 fitted into and sealed in a recess 25 formed in the back face of the front header 20. The rear end of each tube is sealed to the front face of the rear header 22 in the same manner.
Depending on the length of the tubes, the holder may be provided with any number of further headers or stiffening members 26 to provide support for the tubes and to give the necessary overall rigidity to the holders. These stiffening members may be the same size or may be smaller than the front and rear headers 20, 22. In addition, to add further strength, webs 28 may be fixed between each corner of the headers 20, 22 and 26, and at least the outside tubes 12.
To enable the portable holder of the present invention to more easily and securely transport rolled-up blueprints, the front header 20 is provided with doors 30 aligned with and covering each opening 24. Each of the doors is provided with securing means, such as a latch 32, opened and closed by a key operated lock 34 and cooperating with a slot 42 formed within the opening 24.
The doors are detachably mounted on the front face of the front header 20 in any convenient manner, as by a hinge 36 removably fixed between the header 20 and each door. A sealing means, such as a circular O-ring seal 38, larger than the openings 24, is held in a groove 40 on the inside of each door. In this manner, when the doors are in the closed position, with the latches 32 locked in the complementary slots 42, the circular seals will be forced against the front face of the header 20 to provide a weatherproof seal around each opening.
Both the front header 20 and the rear header 22 are provided with a number of projecting fingers 44 on one side edge thereof. These fingers may be formed integrally with the side edge. An equal number of aligned holes 46 are formed in the opposite side edge of each header.
As shown more clearly in FIGS. 2 and 3, when the portable holder 10 of FIG. 1 is stacked upon a similar holder 10A, and a further holder 10B is stacked upon the holder 10, all of the holders will be accurately aligned and firmly held together. This is caused by the projecting fingers 44 of both the front and rear headers of holder 10 entering into and being firmly held in or interlocked with the aligned holes 46A of the lower holder 10A. At the same time, the projecting fingers 44B of the upper holder 10B will be firmly seated in the holes 46 of the holder 10 to form a three tiered stack of holders firmly interlocked together.
Any number of holders may be stacked together in one manner described above to form a convenient filing cabinet with lockable enclosures for securely storing rolled-up blueprints. Also, if the stacked holders are to be permanently left in the stacked position, some or all of the doors 30 may be quickly removed to allow ready access to the hollow interiors of some or all of the tubes 12.
The front of each door 30 may be provided with a depression 48 or the like to allow a removable label to be affixed to the door to identify the contents of each tube.
When used to transport rolled-up blueprints or other materials, the rolled-up blueprints are selectively placed in the separate tubes 12 and the doors 30 locked in position. An identifying label may then be applied to each door. The portable holder, which is sufficiently strong to resist heavy abuse may then be thrown in the trunk of a car or the back of an open pickup to be taken to a construction or other job site. Should the portable holder with the blueprints contained therein be subjected to rough handling, inclement weather or accidental immersion in water, the strong weatherproof construction of the portable holder will protect the contents of each tube. In addition, the locked door on the front of each tube will prevent the accidental loss of materials of each tube, as well as unauthorized removal of such materials.
At the job site, the rolled-up blueprints may be easily removed by authorized personnel by merely unlocking the respective doors.
By using one or several portable holders of the present invention to both transport and store materials, the need for separate shipping containers and extra files or filing space together with the attendant cost may be eliminated in many circumstances. There are many other advantages of the portable holder of the present invention, too numerous to be mentioned.
While the invention has been described in considerable detail, it is not to be limited to such details as have been set forth except as may be necessitated by the appended claims.
What is claimed is:
1. A portable tube holder comprising at least two elongated tubes, each of said tubes having two open ends, a surrounding wall, and a hollow interior;a single front header permanently sealed to one end of each tube to fixedly hold said one end of each tube thereto in a spaced apart relationship, said front header being provided with a plurality of openings extending therethrough, said openings being equal in number to said tubes, and each of said openings being aligned with said hollow interior of one of said tubes to allow materials to be placed in and removed from said hollow interior of each tube; a single, solid rear header permanently sealed to the other end of each tube to fixedly hold said other end of each tube thereto in a spaced apart relationship, and to form an end wall for each tube; a carrying handle attached to one of said tubes to allow said portable holder to be lifted and transported; and a plurality of moveable doors removeably mounted on said front header, with each door being in aligned relationship with one of said openings, and locking securing means held in each of said doors and cooperating with said aligned tube whereby each of said doors may be selectively locked in position covering said aligned opening.
2. The portable holder of claim 1 wherein each of said doors is provided with sealing means whereby when each of said door is in the locked position, said hollow interior of each tube will be weatherproofed to protect the contents thereof.
3. The portable holder of claim 1 or 2 wherein each of said front and rear headers includes a front face, a rear face, and a number of side edges, said tubes being fixed to the rear face of said front header and the front face of said rear header, a plurality of fingers projecting from one side edge of each header, and an equal number of aligned holes formed in the opposite side edge of each header, said portable holder being adapted to be stacked on and securely held on the top of other portable holders by the coaction of the projecting fingers of one portable holder entering into and being held by the holes of the other portable holder.
4. The portable holder of claim 1 wherein each of said front and rear headers includes a front face, a rear face, and a number of side edges, said tubes being fixed to the rear face of said front header and the front face of said rear header, at least one stiffening member secured to said tubes between said front and rear headers, a plurality of fingers projecting from one side edge of each of said headers, and an equal number of aligned holes formed in the side edge opposite said one side edge, said portable holder being adapted to be stacked on and securely held on the top of other portable holders by the coaction of the projecting fingers of one portable holder entering into and being held by the holes of the other portable holder.
5. The portable holder of claim 4 wherein there are three tubes and each of said tubes is provided with a movable door; said three tubes being permanently sealed to said front and rear headers to prevent air or moisture from entering into the hollow interior of each tube, and each of said three doors is provided with circular sealing means whereby when each of said three doors is in the locked position, said circular sealing means will be seated around the respective opening to prevent air or moisture from entering into the hollow interior of each of said tubes.
| 1981-08-03 | en | 1984-02-07 |
US-50223795-A | Therapy tomograph with homogeneity device
ABSTRACT
In an NMR tomograph with superconducting main field coil (10) and large transverse access opening a compensation of inhomogeneities of the static magnetic field without hindering the axial and transverse access to the investigational volume (V) can be effected by the following elements:
ferromagnetic homogeneity elements (20) which are arranged on the surface of the room temperature bore on both sides of the transverse access opening;
at least one or more (a number p≧1) superconducting correction coils (C 1 and C p ) which can be separately supplied with current and which are coaxial to the main field coil (10), whereby each correction coil (C 1 through C p ) comprises at least two partial coils (C 1i , C 1a through C pi , C pa ), whereby all partial coils of all correction coils (C 1 through C p ) are cylindrical coils coaxial to a common axis (z) having a diameter less than the inner diameter (d a2 ) of the outer field coil (1a, 1b), whereby in each correction coil one partial coil (C 1i through C pi ) has, in each case, as small a separation from the middle plane (E) as possible generally equal to the separation of the radially inner field current pair (2a, 2b) from the middle plane and whereby each correction pair has, in each case, at least one second partial coil (C 1a through C pa ) with an oppositely directed current which has a larger axial separation from the middle plane (E) than the radially inner field coil pair (2a, 2b).
This application is a continuation-in-part of application Ser. No. 437,598 filed May 9, 1995 now U.S. Pat. No. 5,485,088.
BACKGROUND OF THE INVENTION
The invention concerns a nuclear magnetic resonance (NMR) tomograph with a superconducting main field coil for the production of a static, homogeneous magnetic field in an investigational volume of the magnetic resonance imaging system whose center coincides with the center of a coordinate origin of a cartesian x-, y-, z-coordinate system, having a pair of mutually similar outer field coils which are arranged on a common axis (z) at an axial separation (g1) with respect to each other as well as a pair of inner likewise mutually similar field coils coaxial to the outer field coils, whereby both coils pairs are arranged symmetrically with respect to a central middle plane (E) which runs perpendicular to the common axis (z), whereby the axial separation (g1) of the outer field coils assumes a value between 1/4 and 3/4, preferentially 1/2 of the inner diameter (da2) of the outer field coils, whereby the axial separation (g2) of the inner field coils is slightly, e.g. up to 15%, different than the axial separation (g1) of the outer field coils, whereby, during operation of the main field coil, the current flow direction in the inner field coils is oppositely directed to that in the outer field coils, with an axial room temperature bore extending in the direction of the homogeneous magnetic field and a transverse access opening extending transversely to the direction of the homogeneous magnetic field and having a device for the compensation of inhomogeneities in the static magnetic field.
An NMR tomograph of this kind is known the art, for example, from DE 39 07 927 A1.
The main field coil of the tomograph which is known in the art consists of a double Helmholtz-coil configuration with opposite current directions. An NMR tomography magnetic system of this type, having relatively small axial and radial dimensions as well as relatively low overall weight, facilitates a free access to the investigational volume from a plurality of different directions, whereby the configuration is also relatively insensitive to eddy currents which can occur during switching of the field gradients necessary for tomography. Transverse access openings to the investigational volume are particularly important since claustrophobia problems are strongly reduced or do not occur for the patient being examined in the tomograph. In addition, a plurality of therapeutic measures, for example surgery, in particular microsurgery or irradiation, which can be directly monitored and checked with a tomography apparatus, require as free an axial and transverse access to the patient as possible.
On the other hand, the NMR slice images which are created with a therapeutic tomograph of this type should have as high a resolution and as high a signal-to-noise ratio as possible. For this reason it is necessary for the static magnetic field produced by the main field coil in the investigational volume to have as high a homogeneity as possible.
A useful mathematical tool for the description of inhomogeneities in a region about the symmetry center of a magnetic field is given by the expansion of the field in spherical harmonics. In NMR tomographs only the axial, e.g. the z-components dominate. In general one has: ##EQU1## In ideal rotationally symmetric configurations all terms in the sum vanish which are associated with non-rotationally symmetric field components, e.g. all terms with m not equal to 0. In the usual notation these types of terms are designated "tesseral" whereas terms having m=0 are called "zonal".
Furthermore with a mirror-symmetric configuration all terms except those with amplitudes An0 having odd values of n vanish. In addition with coil configurations associated with the above cited DE 39 07 927 A1, all terms with n<8 vanish. The following expression then results for the homogeneous magnetic field in the z-direction: ##EQU2## In particular along the z-axis one has for the double Helmholtz-configuration with oppositely directed currents
B.sub.z =A.sub.00 +A.sub.80 z.sup.8 +A.sub.10,0 z.sup.10 + (3)
A00 is the desired homogeneous field. The remaining terms represent field distortions which are unavoidable with this coil configuration even in the event of a perfect construction which at z- or r-values of 20 cm from the symmetry center have relative, e.g. relative to A00, magnitudes of approximately 10 ppm. For smaller z- or r-values these distortions are generally much smaller due to the zn -dependence (n≧8) so that, within a spherical volume about the symmetry center with a diameter of approximately 40 cm, only field distortions below 10 ppm occur and high quality NMR imaging methods are thereby possible.
Due to mechanical tolerances during the manufacture of the coil bodies as well as to the in principle helical instead of ideally rotationally symmetrical shape of the windings of the main field coil, one obtains deviations from this ideal behavior which can result in non-vanishing distortion amplitudes Anm, Bnm with n<8 and m≧0. In practice one must experimentally determine these distortion amplitudes through measurements and compensate for them with the assistance of superconducting or resistive auxiliary coils or with strategically and advantageously placed pieces of iron, for example in the bore of the magnet coil.
A compensation of this kind is known in the art as "shiming". For example, superconducting shim-coils are described in DE 35 11 303 A1. The utilization of ferromagnetic shim plates is known in the art from DE 17 64 564 A1.
With a therapeutic tomograph having sidewardly and axially open coil systems facilitating both an axial as well as a transverse access to the investigational volume, there is the additional difficulty compared to conventional tomographs that there is neither a bore for securing iron pieces nor another support body for attaching superconducting or resistive correction coils in the entire region of the sideward access opening. Substantial limitations therefore obtain for the placing of shim elements. Certain types of field distortions can therefore no longer be easily compensated for. The preferred locations in conventional systems for these types of shim elements, in the middle region near to the homogeneity volume, are located, in the described therapy systems, in the vicinity of the transverse access and therefore must remain free.
Furthermore it is necessary, with all superconducting correction coils, to prevent inductive coupling to the superconducting main field coil. Otherwise, for example, a time dependent drift of the homogeneous magnetic field produced by the main field coil would lead to a discharge of the correction coils.
It is therefore the purpose of the present invention to introduce an NMR tomograph of the above mentioned kind with which homogeneity of the magnetic field is facilitated without hindering the axial or transverse access to the investigational volume.
SUMMARY OF THE INVENTION
This purpose is achieved in accordance with the invention in that the device for compensation of static magnetic field inhomogeneities includes the following elements:
ferromagnetic homogeneity elements, preferentially plates, which are brought onto certain positions at the surface of the room temperature bore on both sides of the transverse access opening in such a fashion that at least one component of the tesseral field distortion of the type Anm with n=1 through 3, preferentially n=1 through 6, and m=1 through n are compensated,
at least one or more (a number p≧1) superconducting correction coils (C1 through Cp) which can be separately fed with current and which are arranged coaxially with respect to the main field coil, whereby each correction coil (C1 through Cp) comprises at least two partial coils (C1i, C1a through Cpi, Cpa) which have current flowing through them in opposite directions during operation, whereby all partial coils of all correction coils are cylindrical coils coaxial to the common axis (z) having a diameter which is less than the inner diameter (da2) of the outer field coils, whereby, in each correction coil (C1 through Cp) a partial coil (C1i through Cpi) has, in each case, as small a separation with respect to the middle plane (E) as possible, which is generally equal to the separation of the radially inner field coil pair from the middle plane so that these partial coils extend in an axial region g2 /2≧|z|≧g2 /2+b and whereby each correction coil (C1 through Cp) has, in each case, at least one second partial coil (C1a through Cpa) having opposite current flow direction, which has a larger axial separation from the middle plane (E) than the radially inner field coil pair.
The underlying realization of the invention is that, by introducing iron on the inner cylinder outside of the middle region where the sideward access openings are located, a simultaneous compensation of all tesseral and zonal distortion terms is not possible. However, a complete compensation of all tesseral terms alone to at least 6th order (n=1 through 6; m=1 through n) is possible. Thereby additional zonal distortion terms, in particular A20, A40, A60, are produced which, however, can be kept relatively small. The solution-principle of the present invention is that all tesseral terms up to 6th order are compensated by means of ferromagnetic homogeneity elements on the inner cylinder of the room temperature bore outside of the middle region (access opening), whereas all remaining zonal distortion terms can be corrected through special superconducting correction coils which are accommodated along with the superconducting main field coil in a helium cryostat.
In an embodiment the winding numbers of all partial coils of a correction coil are chosen in such a fashion that the mutual inductance between the main field coil and the correction coil vanishes. In this manner a coupling between the main field coil and correction coils can be completely avoided. Therefore no discharge of the correction coils in the event of a possible drift of the main field coil takes place and the danger of destroying superconducting correction coils in the event of quench of a superconducting coil system is avoided.
In a further preferred embodiment all partial coils of the correction coils which are closest to the middle plane (E) have a larger inner diameter than the outer diameter di1 of the inner field coil pair. This leads to particularly high amplitudes for the produced correction field.
In another preferred embodiment one provides that, with at least one correction coil, the partial coil closer to the middle plane has a larger inner diameter and the partial coil more distant from the middle plane a smaller inner diameter.
With these measures particularly high correction field amplitudes can also be obtained.
Even higher produced correction field amplitudes are obtained in an improvement of this embodiment with which the inner diameter of the additional correction coil partial coil distant from the middle plane is approximately equal to the inner diameter d12 of the inner field coil.
In another preferred embodiment one provides that, in at least one correction coil, both partial coils have approximately the same inner diameter.
In an embodiment of the NMR tomograph in accordance with the invention which is compact and particularly simple to produce one provides that the correction coil partial coils closer to the middle plane are accommodated in a common coil support winding chamber together with the corresponding inner field coil and the correction coil partial coils distant from the middle plane are accommodated in an additional common coil support winding chamber.
In an embodiment of the NMR tomograph in accordance with the invention, the ferromagnetic homogeneity elements can be at least partially replaced by an additional system of superconducting correction coils in the form of saddle coils which are arranged generally at the radius of the inner field coil. In this fashion the conventional tedious experimental determination of the locations of the homogeneity elements is replaced by a simpler experimentation with the additional saddle coil correction currents.
Finally, in an alternate embodiment, the ferromagnetic homogeneity elements are permanent magnets. In this fashion the direction of the magnetization relative to the field direction can be fully chosen so that additional improved possibilities for compensation of field distortions are given.
With the NMR tomography system in accordance with the invention, additional room temperature shim systems can be provided to eliminate field distortions of the types A10, A11 and B11 as well as A20 can be provided. In this fashion an additional degree of freedom compared to a system having solely superconducting persistent current mode operated shim coils can be achieved.
In particular, field distortions of the type A11 and B11 can be compensated for by a weak DC portion in an x-, y-gradient coil system according to FIGS. 8, 9a and 9b of DE 42 30 145 A1 and the accompanying description the complete contents of which is herein incorporated by reference. Instead, additional shim coils can also be provided for which have a spatial construction corresponding to that of the gradient coils described in DE 42 30 145 A1.
A correction of field distortions of the type A10 can be eliminated through a shielded z-gradient coil system in accordance with DE 42 30 145 A1 which realizes the features of claim 14 and 15 of the above mentioned laid open publication.
Finally, field interference from distortion terms of the type A20 can be compensated by four air coils wound coaxially with respect to the z-axis which are positioned either at the inner wall of the room temperature bore or on the inner side of a transverse access opening.
Further advantages of the invention can be derived from the description and the accompanying drawing. The above mentioned features in accordance with the invention as well as those to be described below can be utilized individually or collectively in arbitrary combination. The embodiments shown and described are not to be considered as an exhaustive enumeration, rather have exemplary character only.
The invention is represented in the drawing and is described and explained with the assistance of concrete embodiments.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a main field magnet system having transverse access according to prior art in a simplified schematic cut representation in a radial plane containing the central longitudinal axis z of the magnet system;
FIG. 2 shows a perspective overall view of the NMR tomography system in accordance with the invention with associated cryostats for a superconducting main field magnet coil;
FIG. 3 shows a cut through the sideward access opening of the system represented in FIG. 2 with a view onto the patient bore of one of the two main coil halves and the shim plates introduced therein; and
FIG. 4 shows a schematic cross sectional representation of the NMR tomography system in accordance with the invention in a radial plane containing the central longitudinal axis z of the magnet system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The main field coil system 10 represented in FIG. 1 includes an outer pair of windings or field coils 1a and 1b as well as an inner pair of windings or field coils 2a and 2b which run coaxially along a common central axis z and are generally symmetrically positioned relative to a central transverse middle plane E extending at right angles to the central axis. The outer windings 1a and 1b as well as the inner windings 2a and 2b are wound on a coil body labelled in its entirety with 3 comprising two support rings 3a and 3b which support the outer and inner windings 1a and 2a and 1b and 2b respectively each arranged on one side of the transverse middle plane E. These coil body 3 support rings 3a and 3b each have outwardly facing perpendicular mutually adjacent U-shape defining section arms 4a or 4b by means of which, in accordance to the representation of FIG. 1, the clearance width B in the axial direction as well as the radially measured depth (da1 -da2)/2 of the rectangular cross-sectional area of the winding chambers 5a or 5b spanned by the windings of the outer field coil 1a or 1b in as dense a packing as possible is defined, whereby da1 designates the outer diameter and da2 the inner diameter of the outer winding 1a or 1b.
Furthermore, the support rings 3a and 3b each have an inner profile defined by perpendicular mutually adjacent U-shape defining section arms 6a or 6b which, according the representation of FIG. 1, likewise open outwardly and by means of which the clearance width b in the axial direction as well as the radially measured depth (di1 -di2)/2 of the likewise rectangular cross sectional shape of the winding chambers 7a or 7b which is spanned by the windings in the inner field coils 2a or 2b in as dense a packing as possible is defined, whereby di1 designates the outer diameter and di2 the inner diameter of the inner winding 2a or 2b. The support rings 3a or 3b of both partial coil pairs are, for practical reasons, formed from separate partial rings 3a1 and 3a2 or 3b1 and 3b2 for acceptance of one winding 1a and 2a or 1b and 2b each. After winding the windings the partial rings are each assembled into one support ring 3a or 3b and securely connected to each other. The support rings 3a and 3b formed in this fashion are, for their part, securely connected to each other by means of longitudinal struts 8, whereby the axial separation of the support rings 3a and 3b can be adjusted in a manner not shown.
In the preferred embodiment shown in FIG. 2, the coil body 3 includes three such longitudinal struts which are arranged symmetrically with respect to the longitudinal middle plane marked by the plane of the drawing and containing the central z axis of the magnet system 10 and thereby, as viewed along the perpendicular axis, can be grouped axially symmetrically about the axis at equal angular separations. The axial forces which the windings 1a, 1b and 2a, 2b exercise upon each other in the current flowing state of the magnet system are taken-up by the struts 8. The axial separation g1, at which the outer windings 1a and 1b are arranged with respect to each other, can be varied in the magnet system 10 between 1/4 and 3/4 of the inner coil diameter da2 of the outer field coils 1a or 1b, whereby a preferred value of this separation g1 is approximately half this inner coil diameter da2.
The axial separation g1 at which both windings 1a and 1b of the outer coil pair can be separated from each other can assume a value between 1/4 and 3/4 of the inner diameter da2 of the outer coil pair 1a, 1b and, in a particular configuration of this coil pair, is approximately, e.g. within a deviation of ±10%, half as large as the inner coil diameter da2. In this fashion the center of gravity of the winding cross sections 1a and 1b (axially (g1 +B)/2, radially (da1 +da2)/2) are axially further separated than in a Helmholtz-configuration of the winding pair.
The inner coil pair 2a, 2b is smaller, with respect to its characteristic dimensioning--outer diameter di1 and inner diameter di2 --than the outer coil pair 1a, 1b, whereby the magnitude of its winding density is equal to that of the outer coil pair. If necessary the winding densities can differ.
The axial separation g2 of the inner winding 2a and 2b is, to a deviation of at most 15%, equal to the axial separation g1 of the outer windings 1a and 1b and, in the special embodiment represented, is slightly smaller than the axial separation g1 of the outer winding 1a and 1b, so that the axial clearance between the two windings 2a and 2b is similar to that between the two outer windings 1a and 1b.
The current flowing through the inner pair of winding 2a, 2b during operation of the magnet system 10 is, with regard to its direction, opposite to that flowing through the outer pair 1a, 1b so that the magnetic fields produced by the two winding pairs 1a, 1b and 2a, 2b are directed oppositely to each other, whereby the winding numbers of the outer winding 1a and 1b, assuming the same current strength in the windings 1a and 1b as well as in 2a and 2b, compared to the winding numbers of the inner windings 2a and 2b have a ratio of approximately 4/1, whereby this ratio can vary within a margin of ±20%.
Through a suitable choice of strength of the currents which flow through both winding pairs 1a, 1b and 2a, 2b, it is possible to produce a static magnetic field which is sufficiently homogeneous within the circular bordered investigational volume V indicated with dashed lines in FIG. 1 whose diameter is approximately 40 cm (field deviation 20 ppm).
In a preferred configuration of the magnet system 10 with superconducting magnet coils, the axial separation g1 of the outer winding pairs 1a, 1b assumes a value of 887 mm and the axial width B of the winding chamber, 220 mm. The axial extension L' between the outer walls of the winding chambers 5a and 5b of the magnet system 10 assumes a value of 1327 mm. The inner diameter da2 of the outer winding chambers 5a and 5b assumes a value of 1818 mm and the outer diameter da1 of the outer windings 1a and 1b, 1997 mm. The winding density in the outer winding chambers 5a and 5b assumes a value of 18.40 windings/cm2.
The axial separation of the winding chambers 7a and 7b of the inner winding pair 2a, 2b assumes a value of 881.5 mm, whereby the axial width b of these winding chambers 7a and 7b assumes a value of 39.2 mm in each case. The inner diameter di2 of the windings 2a and 2b has a value of 1400 mm, whereas the outer diameter di1 of the inner windings 2a and 2b has a value of 1507 mm. The winding density of the inner windings 2a and 2b is opposite to that of the outer windings 1a and 1b and has a value of -46.73 windings/cm2. With the mentioned separation g2 of the winding chambers 7a and 7b of the inner coil pair 2a and 2b, it is possible to construct a superconducting cryogenic magnet system with a usable intermediate volume z of 660 mm and a room temperature bore having a diameter of 1250 mm for the acceptance of gradient coils in accordance with the invention.
With a current strength of 157 A, a homogeneous magnetic field in the center of the magnet system 10 of 0.5 Tesla results.
The perspective overall view of an embodiment of the NMR measuring system in accordance with the invention of FIG. 2 shows, among other things, the overall height H of the apparatus which is determined by the outer diameter of the cryostat, the height h of the horizontal patient bore, the width g of the sideward access opening to the central investigational volume, and the length L of the entire apparatus.
Further details of the cryostat system superconducting main field magnet coil which is likewise shown in FIG. 2 are not discussed here. All superconducting coils are accommodated in the helium tank of the cryostat.
FIG. 3 shows a cut through the sideward access opening of the NMR tomograph which is perpendicular to the central z axis. Connecting pipes 11 between the two sides of the helium tank of the cryostat system containing the superconducting magnet coil as well connecting pipes 12 between the liquid nitrogen tanks surrounding the helium tanks are visible through the cut-open longitudinal struts 8. The conventional radiation shields are not shown. Ferromagnetic homogeneity elements 20 in the form of shim plates are distributed around the room temperature bore.
FIG. 4 shows a schematic cross section through the NMR tomography system in accordance with the invention in a plane which contains the z axis. Outer field coils 1a and 1b as well as the inner field coils 2a and 2b on both sides of the middle plane E can be recognized. Four superconducting correction coils C1 through Cp, which can be separately fed with current, are arranged symmetrically about the z axis radially within the outer field coils 1a and 1b. Each correction coil C1 through Cp comprises at least two partial coils C1i, C1a through Cpi, Cpa which are driven with oppositely directed currents during operation. Each correction coil C1 through Cp contains a partial coil C1i through Cpi which has as small a separation as possible with respect to the middle plane E and which extends generally in an axial region g2 /2≧|z|≧g2 /2+b. At least one second partial coil C1a through Cpa of each correction coil C1 through Cp has, in contrast, a larger axial separation from the middle plane E than the radially inner field coil pair 2a or 2b.
A coil support is indicated in the right upper quadrant of the configuration schematically shown as a cross section in FIG. 4, which comprises a winding chamber 21 in which the partial coils C1i and C2i which are closer to the middle plane E are commonly accommodated together with the inner field coil 2b. The partial coils C1a and C2a which are located further from the middle plane E are mutually accommodated in an additional coil support winding chamber 22. Similar common winding chambers are also provided for the other four quadrants of the represented cross section but are not shown in the drawing of FIG. 4 for reasons of clarity.
A chamber 23 having liquid helium is represented in the lower left quadrant of the schematic cross sectional drawing in which the corresponding superconducting coil portions of the lower left quadrant are accommodated. The helium chamber is likewise not shown in the remaining quadrants of FIG. 4 for reasons of clarity.
The electrical switching of the partial coils can, in an embodiment not shown in the drawing, also be such that two coil parts of a particular correction coil are arranged on either side of the middle plane E.
Indicated in FIG. 4 on the inner side of the indicated room temperature bore at various locations along the z-axis are, finally, ferromagnetic homogeneity elements 20 which must not necessarily be distributed in a symmetric fashion relative to the plane E or the z-axis. The concrete locations for placing of the corresponding homogeneity elements 20 is individually experimentally determined for each NMR system in such a manner that the tesseral field distortions are largely eliminated.
Plates on the order of 50×40×0.3 mm3 placed on the surface of the room temperature bores in both cryostat halves are preferred. As already mentioned the axial extension for the distribution of the ferromagnetic correction elements 20 usually lies in the range between |z|=g/2 and 1.4 g, whereby g is the width of the transverse access opening to the investigational volume V.
The mounting radius r for the correction elements 20 (=radius of the room temperature bore) typically assumes a value of approximately 1.8 g≧r≧2 g.
The ferromagnetic correction elements 20 are arranged in such a fashion that only the tesseral distortion terms (m not equal to 0) as well as the odd zonal distortion terms (n odd, m=0) vanish. Due to the large separation of the iron pieces from the middle plane E, this iron distribution produces, in principle, additional zonal distortion terms A20, A40, A60 which add to those produced by the main field coil of the same kind. The zonal distortion terms A40 and A60 can likewise be kept negligeably small. There are mathematical methods with which the amount of iron utilized can be minimized. The sign of the A20 term is A20 <0.
A compensation of the remaining zonal distortion terms is effected in accordance with the invention with the assistance of the above described specially arranged superconducting cylindrically symmetric correction coils C1 through Cp which are arranged together with the partial coils 1a, 1b, 2a, and 2b of the main field coil in the helium chamber 23. In principle the correction coils C1 through Cp can also be fed from a power supply. It is preferred when the correction coils, however, exhibit a superconducting switch and are driven in the "persistent mode" e.g. short-circuited.
Two of the p correction coils C1 through Cp are located in both halves of the cryostat.
We claim:
1. A superconducting magnetic resonance imaging apparatus having a homogeneous magnetic field directed along a z-coordinate axis and having a center at an origin of the z-coordinate axis, the apparatus comprising:a pair of mutually similar outer coils coaxial with the z-axis at a first axial separation g1 from each other and symmetric with respect to a middle plane perpendicular to the z-axis, the first axial separation being between 1/4 and 3/4 of an outer coil inner diameter, the outer coils having a first current flowing in a first current direction; a pair of mutually similar inner coils, having an inner coil width b, coaxial with the outer coils at a second axial separation g2 from each other and symmetric with respect to the middle plane, the second axial separation being within 15% of the first axial separation, the inner coils having a second current flowing in a second current direction opposite the first current direction; a cryostat containing the outer and inner field coils and having an axial room temperature bore extending along the z-axis and having a transverse access opening transverse to the z-axis; ferromagnetic homogeneity means, located at selected positions on a surface of the room temperature bore on both sides of the transverse access opening, the positions being selected to compensate at least one component of a tesseral field distortion of a type Anm with n=1 through 6 and m=1 through n; and at least one or more superconducting correction coils, each correction coil having separate current terminals and being coaxial with the outer and inner field coils, each correction coil comprising a first partial coil having a first partial current flowing in a first partial current direction and a second partial coil having a second partial current flowing in a second partial current direction opposite the first partial current direction, wherein the first and second partial coils are coaxial with the z-axis and have a first partial diameter and a second partial diameter which are less than the outer coil inner diameter, wherein the first partial coils are located at an axial distance z1 from the center, with g2 /2≧|z1 |≧g2 /2+b and the second partial coils are located at an axial distance z2 from the center, with g2 /2+b<|z2 |.
2. The apparatus of claim 1, wherein winding numbers of the correction coils are chosen to cancel mutual inductances between the inner and outer coils and the correction coils.
3. The apparatus of claim 1, wherein the first partial diameter is larger than an inner coil outer diameter.
4. The apparatus of claim 1, further comprising a third partial coil having a third partial diameter and a 4th partial coil having a fourth partial diameter, the third partial coil being closer to the middle plane than the fourth partial coil and the third partial diameter being larger than the fourth partial diameter.
5. The apparatus of claim 4, wherein the fourth partial diameter is generally equal to an inner diameter of the inner field coils.
6. The apparatus of claim 1, further comprising a first coil support for supporting the first partial coils and the inner coils and a second coil support for supporting the second partial coils and the outer coils.
7. The apparatus of claim 1, further comprising superconducting saddle coils arranged at a first separation from the z-axis generally equal to a second separation of the inner coils from the z-axis.
8. The apparatus of claim 1, wherein the ferromagnetic homogeneity mean are permanent magnets.
9. The appartus of claim 1, wherein the first and second partial diameters are generally equal.
| 1995-07-13 | en | 1996-08-13 |
US-78453485-A | Apparatus for medical treatments
ABSTRACT
In an apparatus for medical treatments, examinations or tests comprising ahamber connectible to a vacuum source and having at its one end side a passage aperture with a flexible sealing member, the chamber is formed of a foldable bellow provided with a support structure adapted to be dismantled. In axial direction of the bellow, the support structure contains a plurality of substantially parallel-mounted peripheral members backing up peripherally the bellow and being mobile relative to each other, as well as mobile longitudinal stiffening elements secured to the peripheral members.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an apparatus for medical treatments, examinations or tests comprising a chamber connectible to a vacuum source and having at its one end side a passage aperture with a flexible sealing member.
2. Description of the Invention
There has been known vacuum containers (German Patent No. 28 39 283) used for medical treatments and adapted to receive the lower body of the patient or testee, the container or chamber being closed airtightly and a vacuum pressure being produced in it upon the admission of the patient. Due to the reduced air and oxygen partial pressure, it is possible to gather information about the psychomotoric behaviour and blood circulation of the human body. Due to their size and weight, such apparatuses are locally bound in practice, their use outside a blood circulation test lab being prohibitive.
It is the object of an invention to provide an apparatus of the above mentioned type which is of a portable design, requiring little space and being of a low weight.
SUMMARY OF THE INVENTION
The problem is solved according to one embodiment of the invention in that the chamber is formed of a foldable bellow provided with a support structure adapted to be dismantled.
Such a foldable apparatus need not be mounted stationarily, but it may be used as a mobile unit outside labs for specific tests, for instance in orbital space to make medical tests when performing work under zero-gravity and under vacuum pressure conditions, e.g. tests concerning the failure of the sense of balance. Due to the apparatus of the invention, the chamber may be of a light-weight design having a sufficient stability under mechanical loads and not requiring much space when set up.
In the axial direction of the bellow, the support structure preferably contains a plurality of substantially parallel-mounted peripheral members backing up peripherally the bellow and being mobile relative to each other. Further it comprises mobile longitudinal stiffening elements which, on the one hand, are adapted to stretch the bellow skin to form the cavity of the vacuum chamber, and by which the bellow skin is supported against external pressure.
Due to the mobility of the longitudinal stiffening elements, the bellow may be folded without the need of disassembling the support structure elements.
According to one embodiment, each rod of the longitudinal stiffening elements is hinge-connected to a tensioning element of a peripheral member while at least one end is detachably locked at the adjacent tensioning element. By this means, a rigid connection between the peripheral members is ensured in axial direction of the bellow.
Preferably, the rods consist of two axially offset, interconnected rod arms which, in the central region of the offset plane are pivoted at each second tensioning element and whose respective ends may be locked with two adjacent tensioning elements. At the same time, the rod arms are interconnected via a rod connecting element which, by means of a hinge joint, is supported by the respective tensioning element. Further, via swivel joints, the rod arms may be so connected to the ends of the rod connecting elements that they may be swivelled radially to the inside relative to the bellow. As a result thereof, the space requirement of the bellow in telescoped condition is reduced once more in that the rod arms may rest against the bellow.
According to one advantageous embodiment, the swivel joints include a barrier to prevent the rod arms from swivelling to the outside in radial direction. Thus, the extracted bellow may not collapse under the action of vacuum pressure.
An angle of 90° between the longitudinal axis of the bellow and the peripheral elements is maintained because the rod arms being distributed peripherally cannot yield to the outside.
Adjacent to the pivot point on the tensioning elements, there are fixed two stops limiting the rotary angle of the rod arms. At least two longitudinal stiffening elements symmetrically fitted circumferentially comprise a different orientation of the displacement of the rod arms to thus obtain a high torsional resistance of the bellow and an increase of stability of the total device without a resultant higher weight or larger space requirement.
Another advantageous embodiment of the invention provides that the cross section of the passage aperture may be altered by a lamellar slide to permit to adapt the passage aperture to the body shape of the testee, while, with the application of a vacuum pressure, the flexible seal at the passage aperture may find its support at the lamellar slide.
BRIEF DESCRIPTION OF THE DRAWINGS
One preferred embodiment of the invention will be explained hereunder in more detail with reference to the enclosed drawings.
FIG. 1 is a side view of a bellow-type vacuum chamber in extracted condition,
FIG. 2 is a front view of said chamber comprising a lamellar slide secured to an annular flange, and a sealing member,
FIG. 3 is a plan view of the lamellar slide,
FIG. 4 is a side view of the folded bellow,
FIG. 5 is a cross section of a peripheral element,
FIG. 6 is a perspective view of the sealing member and
FIG. 7 is a rod connection element having at its ends a hinge-joint and swivel joints.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The vacuum chamber of the apparatus illustrated in FIG. 1 is formed by drawing out a foldable bellow 1, which, when unfolded, is of a substantially frustoconical shape, whose one end side 2 is closed while a circumjacent annular flange 3 is provided at its other end side. A flexible rest surface e.g. a tarpaulin is fixed in the lower part of the vacuum chamber to serve as a support for a body, while a belt 5 engaging during an examination the crotch of the examinee offers the required backing so that he may not slip down too deeply into the vacuum chamber.
Bellow 1 consists of a support structure composed of rigid peripheral members 6 and of movable longitudinal reinforcing elements 7 as well as of a bellow skin of transparent plastic sheet of a high stability.
The bellow 1 with its support structure may rest on a non-illustrated underframe serving as a vertical support.
As for the peripheral elements 6, they each consist of an annular support tube 9 to back up the sheet material 8 from the radial inside, and of a bracing ring 10 peripherally enclosing the support tube 9 and being made of a straight-cylindrical ring portion 11 from whose two end sides a respective annular flange portion 12,13 projects radially to the inside and axially to the outside. With its annular groove formed by the ring portion 11 and the ring flange elements 12,13, the bracing ring 10 encompasses the support tube 9, the plastic sheet 8 of the bellow 1 being radially clamped between the bracing ring 10 and the support tube 9. At the radially circumjacent clamping point, the sheet material 8 is provided with a reinforcement which may be formed by an additional second sheet that may be applied by welding.
On the entire length of the bellow 1, there are mounted five parallel peripheral members 6 in total, which, in pulled-out condition of bellow 1, are mutually spaced axially at an equal distance. The diameter of said peripheral members 6 decreases towards the closed end plate 2 so as to save weight, on the one hand, and to permit an adaptation to the body shape, on the other hand.
The mentioned mobile longitudinal elements 7 are attached at the bracing rings 10 of the peripheral elements 6 and in their one end position, the bellow 1 may be stretched, while it may be folded up in their other end position. Each of the longitudinal stiffening elements 7 consists of a rod 14 pivoted at a bracing ring 10 and consisting of two axially mutually offset rod arms 15,16 being interconnected and joined to each other via a rod connecting element 17 extending substantially at an angle of 45°.
Said rod connecting element 17 is supported in a hinge joint 35 at the bracing ring 10 in an axis of symmetry extending vertically through the plane of displacement. In common with the rod arms 15 or 16, the ends of the rod connecting element 17 form a swivel joint 36,37 enabling the rod arms 15,16 to swivel radially inwardly relative to the bellow 1. One joint half of the swivel joints 36,37, for inst. rod arms 15,16 in FIG. 7, includes a barrier 38 only allowing an inward swivel of the rod arms 15,16, the barrier 38 inhibiting that, with vacuum action, the stretched out rod arms 15,16 allow a torsional movement of the bracing ring plane relative to the longitudinal axis of the bellow 1 or a collapse of said bellow 1. By the barriers 38 mounted at the hinge-side ends of the peripherally distributed rod arms 15,16, an angle of 90° is strictly maintained between the bracing rings 10 and the longitudinal bellow axis.
The axis of rotation of the swivel joints 36,37 is formed by bolts 39 extending in the plane of the respective rod connecting elements 17 and traversing a corresponding fork-shaped joint half 41 at the ends of the rod connecting element 17 and the end forming the second joint half 40 of the respective rod arm 15,16 and being inserted in the fork-shaped joint half 41. With respect to the bolt rotation axis, said joint halves 40 of the rod arms 15,16 have an external plate-shaped barrier 38 overengaging the corresponding joint 36,37 and inhibiting in connection with the rod connecting element a swivel movement of the rod arms 15,16 about the axis of rotation of bolt 39 towards the outside in that the barrier 38 abuts against the rod connecting element 17.
The length of the rod arms 15,16 is conformed to the desired distance between two peripheral elements 6. The ends of the rod arms 15,16 are caught in a lock 19 with the respective bracing ring 10. The rods 14 are supported externally at each second bracing ring 10 so that a longitudinal reinforcement 7 keeping apart five peripheral members 6 can be formed with two rods 14 accordingly. Three corresponding longitudinal stiffening elements 7 formed of two rods 14 each are peripherally distributed in a preferred vertical-symmetric arrangement. The bracing rings 10 forming the support of rods 14 comprise two stops 18 each situated above and beneath the pivot point of the rods 14 and limiting the swivel range to 90° of the corresponding rod 14 so that, in one stop position, the rod arms 15,16 extend horizontally in axial direction of the bellow while, in the other stop position, they extend in parallel to the peripheral members 6.
The displacement of the rod arms 15,16 in associated with the rod connecting elements 17 adjoining the stops 18 is responsible for an improved torsional stability of the bellow because, by the stops 18, a torsion-based rotation of the rods 14 beyond the extracted position is inhibited. One longitudinal stiffening element 7 extends substantially centrally of the bellow at its highest point, while two longitudinal stiffening elements 7 mounted vertically-symmetrically relative to each other extend at opposite peripheral sites in the lower portion of the bellow 1. The orientation of the respective rod connecting elements 17 at both sides of the bellow being the same in axial direction, torsional forces in both senses of rotation are caught accordingly.
Rod arms 15,16 may be also distributed peripherally in a manner different from that shown in FIGS. 1 and 2. Above all, rods 14 of a longitudinal stiffening element 7 may be mounted differently in peripheral direction. In other words, each rod 14 will act independently upon the adjacent rod 14.
The end side 2 of bellow 1 is provided with connecting pieces 20,21 which may be connected for inst. with a suction source in order to generate a vacuum in the bellow 1.
The annular flange 3 at the one end side of the bellow 1 receives a sealing member 26 embracing the annular flange 3 to form a U-shape at both end sides and at the outer edge. The sealing member 26 is integrated with a conical portion 29 being tapered outwardly and ending in a nearly cylindrical ring 30 which is closed by a bead-type collar 31. Further, within the region of the conical section 29 and ring 30, there is provided an elongated vacuum-tight zip fastener 32 due to which the passage aperture of the sealing member 26 may be enlarged thus permitting a trouble-fee entrance into the sleeve or its application also with different body sizes. The sealing sleeve 26 forms an airtight end of the chamber. At the same time, its external part acts as a sealing between the annular flange 3 and the adjacent peripheral element 6. Further, between the bracing ring 10 of the respective peripheral member 6 and the annular flange 3, there is fitted an additional non-illustrated Moltopren seal.
The upper body portion of a testee projecting out of the sealing sleeve 26 is resting on a non-illustrated movable table.
To save weight, the annular flange 3 may be of an aluminum-honeycomb design. As evident from FIG. 2, it receives a lamellar slide 22 comprising several lamellar plates 23, for inst. three, adapted to be vertically displaceable so that the passage aperture of the annular flange 3 may be correspondingly accomodated to the upper body size of a testee. If vacuum pressure is applied, the flexible sealing sleeve 26 may join the lamellar plates 23 over the trunc of the testee. Thus, in case of vacuum pressure, the flexible sealing sleeve 26 is not withdrawn into the bellow interior and the testee is protected from probable pain. The aluminum lamellar plates 23 are guided in vertical profiled aluminum rails 24 fixed at the annular flange 3.
The operation of the apparatus will be now explained with reference to a blood circulation test: First off, by swivelling rods 14 into the horizontal abutment position, the bellow is pulled out to take a stretched position. The sealing sleeve 26 situated in the annular flange 3 at one end of the bellow will be opened by the zip 32 to allow access to the testee who may slide through the sealing sleeve to the rest surface 4 in the bellow 1 to take the right position in which the ring 30 of the sealing sleeve 26 encloses the body nearly about the waist. Subsequently, the lamellar plates 23 of the slide 22 are let down to the trunk of the person.
Thereafter, the vacuumtight zip fastener 32 is closed. Now, vacuum pressure may be produced in the bellow 1. This may be controlled by a suitable measuring instrument. As a rule, the vacuum pressure applied is about 0.133 bar. The upper body portion of the testee being outside the vacuum chamber, the proposed measurements may be performed substantially outside the vacuum chamber. Due to the transparent bellow material,, the effects of the vacuum pressure may be observed (dilatation).
The bellow is particularly suited to be used in orbital space where a space-saving, lightweight design of a vacuum chamber is needed.
What is claimed is:
1. In an apparatus for medical treatments, examinations or tests having a chamber configured to be connected to a vacuum source and including at one end thereof a passage aperture having a flexible sealing member, an improved chamber support structure adapted to be dismantled comprising:a foldable bellow; at least three substantially parallel peripheral members disposed to support the bellow, said peripheral members being capable of relative movement with respect to each other, a longitudinal stiffening element secured to a first one of the peripheral members by a hinge, said hinge enabling rotation of said longitudinal stiffening element from a first position substantially parallel to said first peripheral member to a second position substantially perpendicular to said first peripheral member, means for engaging said peripheral members to said stiffening element when said stiffening element is in said second position, whereby said stiffening element in said second position restrains relative movement among said peripheral members.
2. Apparatus according to claim 1, wherein said longitudinal stiffening element exerts an axial tension along the bellow in said second position while allowing a telescoping of the bellow in said first position.
3. Apparatus according to claim 1, wherein the longitudinal stiffening element comprises a rod which, in the second position, may be rigidly interconnected to at least two of the peripheral members.
4. Apparatus according to claim 1, wherein at least one of said peripheral members comprises:a frame element disposed in the interior of the bellow, and a bracing element disposed on the exterior of the bellow, said bracing element being positioned to clamp a portion of the bellow material between the bracing element and the frame element.
5. Apparatus according to claim 4, wherein said stiffening element comprises a rod secured by said hinge to said bracing element, said rod having at least one end which may be detachably locked to an adjacent peripheral member.
6. Apparatus according to claim 5, wherein the rod comprises two axially offset, interconnected rod arms which are supported rotatably at said bracing element and whose respective ends are lockable with two adjacent peripheral members.
7. Apparatus according to claim 6, further comprising at least two longitudinal stiffening element arranged symmetrically about the periphery of the bellow, each of said stiffening elements having a different orientation with respect to the displacement of the rod arms.
8. Apparatus according to claim 6, wherein the rod arms are interconnected via a rod connecting element which is supported on the bracing element by means of a hinge joint.
9. Apparatus according to claim 8, wherein each of the rod arms is connected via a swivel joint to the ends of the rod connecting element so that the rod arms may be swivelled radially toward the bellow.
10. Apparatus according to claim 9, wherein the swivel joints further comprise a barrier for preventing the rod arms from swivelling radially away from the bellow.
11. Apparatus according to claim 9, further comprising two stops disposed adjacent to the hinge joint on the bracing element, said two stops acting to limit the swivel angle of the rod arms.
12. Apparatus according to claim 1, wherein the shape of the peripheral members is annular.
13. Apparatus according to claim 1, wherein the bellow is made of a transparent plastic sheet.
14. Apparatus according to claim 1, further comprising a lamellar slide positioned in said passage aperture, wherein the cross section of the passage aperture may be changed by displacement of the lamellar slide.
15. Apparatus according to claim 1, wherein the bellow is tapered from the end including the passage aperture to the end not including the passage aperture.
16. Apparatus according to claim 1, further comprising: a flexible rest surface disposed within the bellow and one or more retaining belts attached to the bellow at the end side having the passage aperture.
| 1985-10-04 | en | 1987-09-08 |
US-27800894-A | Handle operated draw latch with safety catch
ABSTRACT
A handle operated, toggle type draw latch assembly is mountable on one of two members and is operable to selectively engage and disengage a latch-engageable formation connected to the other of the two members. The latch assembly includes a complexly configured operating handle that is pivotally connected near one end to a mounting base for movement relative to the base between closed and open positions, that provides a hand grip near its opposite end, and that, at locations between its opposite ends pivotally mounts a drawbar for movement between extended and retracted positions, and defines not only a pair of stops but also a catch-engageable formation. One stop engages the base when the handle is closed. The other stop engages the drawbar when the drawbar is retracted. When the handle is open, the drawbar can be pivoted into and out of extended positions for selectively embracing the latch-engageable formation. If the handle is pivoted to its closed position while the drawbar is extended to embrace the latch-engageable formation, the drawbar exerts force on the latch-engageable formation that tends to draw the two members relatively toward each other. A base-carried safety catch pivots between latched and unlatched positions for receiving and releasably retaining the catch-engageable formation of the handle when the handle is closed. Other features include a selection of drawbar embodiments and a choice of pivotal connections for use in coupling a selected drawbar to the latch handle.
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of each of two co-pending applications, namely utility application Ser. No. 08/065,283 filed May 21, 1993 by Lee S. Weinerman and Arthur J. Kuminski entitled HANDLE OPERATED DRAW LATCH WITH SAFETY CATCH, now abandoned, and design application Ser. No. 29/008,629 filed May 21, 1993 by Lee S. Weinerman and Arthur J. Kuminski entitled HANDLE OPERATED DRAW LATCH ASSEMBLY WITH LOCKABLE SAFETY CATCH, now abandoned, the disclosures of which are incorporated herein by reference.
Reference also is made to a related design application, the disclosure of which is incorporated herein by reference, entitled HANDLE OPERATED DRAW LATCH ASSEMBLY WITH LOCKABLE SAFETY CATCH, Ser. No. (Atty's Docket No. 5-036) filed (concurrently herewith) by Lee S. Weinerman and Arthur J. Kuminski.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a handle operated, toggle type draw latch for joining two members and for exerting force that tends to draw the two members relatively toward each other. More particularly, the present invention relates to a handle operated toggle latch that has a lockable safety catch for securely retaining the handle in a closed position until the safety catch is operated to release the handle for movement to an open position, and that utilizes a relatively complexly configured handle that cooperates in a variety of ways with other components of the latch to provide a number of desired features such as stops to limit the ranges of movement that can be executed by relatively movable components. Other features include a selection of drawbar embodiments and a choice of pivotal connections for use in coupling a selected drawbar to the latch handle.
2. Prior Art
Toggle latches of a variety of types have been proposed for use in releasably joining two relatively movable members. Usually, what is referred to as a "toggle latch" has at least a pair of pivotally interconnected, link-like components that are "toggled" through an "over center" position to effect latching and unlatching movements.
Toggle latches that are operable to releasably join and to draw two relatively movable members toward each other are sometimes referred to as "draw latches." Usually, a toggle-type draw latch includes a latch assembly that can be mounted on-a first of two relatively movable members, and has what is referred to as a "drawbar" that can be moved, when the latch is "open," into and out of connection with a latch-engageable formation that is connected to the second of the relatively movable members. When components of the latch are moved latchingly toward a "closed" position, the drawbar serves not only to engage the latch-engageable formation to join the first and second relatively movable members but also to exert force on the latch-engageable formation that tends to move the members relatively toward each other.
While some toggle-type draw latches rely solely on tension force that is applied through over-center connected components to retain latch components in their "closed" positions, proposals have been made to use spring acting safety catches of various forms to releasably retain latch components closed. Some proposed safety catches are mere leaf springs, portions of which are deflectable for movement into and out of latching engagement with relatively movable components--an arrangement that may not be well suited for use in a high-load application where vibration is present. Another safety catch proposal calls for the use of a spring-biased slide carried on one movable component for being received in an aperture defined by another movable component--an arrangement that involves no secure connection of the safety catch to a stationary base member, and that is not lockable to secure the safety catch.
Previously proposed handle operated, toggle type draw latches have not exhibited a desired degree of versatility. Toggle latches intended for different uses have tended to utilize toggle latch components that are quite differently configured. Basic operating components of such latches have not been designed with sufficient versatility in mind to permit their use, for example, with a variety of drawbar configurations, and with a selection of drawbar-to-handle connection components that not only provide different pivotal connection characteristics but also permit a selected degree of resilience (or no resilience at all) to be incorporated into their drawbar-to-handle connections.
While proposals also have been made to provide various forms of toggle latches with component-carried apertures that are alignable to receive the shanks of padlocks when the latches are closed, the alignable apertures typically have not been associated with base-mounted safety catches.
SUMMARY OF THE INVENTION
The present invention addresses the foregoing and other needs and drawbacks of the prior art by providing a novel and improved, handle operated, toggle type draw latch for joining two members and for exerting force thereon that tends to draw the two members relatively toward each other, with the latch including a base-carried spring-biased safety catch° that is padlockable not only to secure the safety catch but also to physically block opening movements of latch components by effectively locking the operating handle to the base of the latch.
In one preferred form of practice, the present invention provides a toggle type draw latch assembly that is mountable on one of two members and is operable to selectively engage and disengage a latch-engageable formation connected to the other of the two members, with the latch assembly including a complexly configured operating handle 1) that is pivotally connected near one end to a mounting base for movement relative to the base between closed and open positions, 2) that provides a handgrip near its opposite end, 3) that, at one location spaced between its opposite ends pivotally mounts a drawbar for movement between extended and retracted positions, and that, at other locations spaced along its length 4) defines one stop that engages the base when the handle is closed, 5) defines another stop that engages the drawbar when the drawbar is retracted, and 6) defines a catch-engageable formation that is latchingly engaged by a spring-biased safety catch when the handle is closed. Moreover, when the handle is latched closed by the safety catch, the safety catch can be secured by a padlock that concomitantly locks the handle to the base.
A feature of the preferred practice of the present invention resides in the provision of an drawbar that can have its effective length adjusted, and in the provision of a handle-defined stop formation for engaging the drawbar when it is retracted. The stop formation takes a generally triangular-shaped form that provides an inclined surface that extends along a selected portion of the length of the handle to assure that, regardless of where within its range of adjustment that the effective length of the drawbar is set, the drawbar will, nonetheless, properly engage the inclined surface of the stop formation when the drawbar is retracted. In accordance with most preferred practice, the drawbar-engageable stop formation is located adjacent a handgrip that is defined by a distal end region of the handle, with the inclined surface of the stop formation being oriented to hold the retracted drawbar increasingly farther away from a centerline of the handle grip as the adjusted effective length of the retracted drawbar brings the drawbar into increasingly closer proximity to the handle grip when the drawbar is retracted--a safety feature to ensure that the retracted drawbar is kept a suitable distance away from where one's hand engages the handgrip.
Still another feature of the preferred practice of the present invention resides in forming the handle from a pair of handle components that are fastened securely together in regions where the handle components cooperate to define the drawbar-engageable stop and the hand-grip, and that extend in spaced relationship to form a yoke-shaped structure that is provided with one set of aligned holes to receive a first pivot pin that connects the handle to the base structure, and another set of aligned holes to receive a second pivot pin that connects the handle to the drawbar. An optional torsion coil spring may be provided to extend about the second pivot pin in the space that is provided between the second set of aligned holes, with the spring having a center portion that engages a projecting pin that is driven into a hole that extends diametrically through the second pivot pin, and that has end regions that engage the handle to bias the second pivot pin to pivot the drawbar toward its retracted position.
Also addressed by the present invention is the need, mentioned above, to provide a handle operated, toggle type draw latch that utilizes basic operating components that are of sufficiently versatile design to permit their being used with a variety of drawbar configurations and drawbar-to-handle connection components that give rise to a family of latch products featuring a variety of operating characteristics that can be produced using simple sets of interchangeable parts. Rigid and semi-rigid drawbar components of a variety of configurations are provided.
Each of the drawbars preferably incorporates a threaded adjustment that permits the "effective length" of the drawbar (relative to a so-called "second pivot pin" that connects the drawbar to the operating handle of the latch) to be adjusted as desired. "Second pivot pins" that can pivot relative to the operating handle either 1) about a single axis (thereby offering only one "degree of freedom" of relative movement) or 2) about a point (thereby offering plural "degrees of freedom" of relative movement) also can be chosen for use with a drawbar of selected configuration to give the resulting latch operating characteristics that are chosen to be correct for use in a particular application.
Optional compression coil springs may be installed to extend about threaded portions of the drawbars to give the drawbars something of an "automatically adjustable effective length" that "self-adjusts" in response to variations in tension force encountered by the drawbar during use. The compression coil springs also provide something of a "cushioning action" that permits a limited degree of relative movement to take place between the two members that are joined and drawn toward each other by the latch assembly.
In preferred practice, the safety catch includes a mounting bracket 1) that is welded to the base structure of the latch assembly, 2) that has spaced upstanding projections for defining aligned holes which mount a pivot pin, 3) that is pivotally connected by the pivot pin to a thumb releasable catch member for relative pivotal movement between latched and unlatched positions, and 4) that has a Z-shaped leaf spring interposed between the mounting bracket and the thumb-operable catch member for biasing the catch member toward its latched position. The catch member preferably is configured and positioned to be engaged by a catch-engageable formation of the handle and cammed away from its latched position as the handle is moved toward its fully closed position. When the handle reaches its closed position, the spring-biased catch member snaps into latched engagement with the catch-engageable formation of the handle to releasably retain the handle closed.
The catch member preferably defines an aperture through which the shackle of a padlock can be inserted as the padlock is being installed to embrace portions of the handle and of the mounting bracket to concomitantly secure the catch member latched while locking the handle to the base. Optionally, the handle and the base also may be provided with aperture-defining formations that extend in juxtaposed relationship with their apertures aligned when the handle is latched closed to receive a padlock shackle that also extends through the catch-defined aperture to strengthen the manner in which the padlock concomitantly secures the safety catch and locks the handle to the base.
To summarize, in preferred practice, the present invention provides a toggle type draw latch that incorporates a number of desirable features while employing a simple set of well-designed, highly interactive components that are relatively inexpensive to manufacture and that are easy to assemble and adjust to provide latch assemblies that function as may be required for use in particular applications.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, and a fuller understanding of the present invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a first embodiment of a handle operated, toggle type draw latch that embodies one form of preferred practice of the present invention, with the view showing a handle of the latch assembly in its closed position, showing a drawbar of the latch assembly in its retracted position, showing one of two drawbar-mounted compression coil springs in a normal state of minimal compression, and showing a safety catch in its normal, non-operated position;
FIG. 2 is a rear side elevational view thereof, with the components thereof positioned in agreement with what is depicted in FIG. 1;
FIG. 3 is a top plan view thereof, with the components thereof positioned in agreement with what is depicted in FIGS. 1 and 2;
FIG. 4 is an exploded perspective view showing components of the latch assembly, with optional formations that can be provided on one of the base members and on one of the handle members for receiving a padlock shackle when the handle is latched closed being depicted in phantom;
FIG. 5 is a front side elevational view of the latch assembly shown mounted on a surface that is defined by a member that extends beneath the latch assembly, with the handle shown in its closed position, with the drawbar shown in its retracted position, with one of the drawbar-mounted compression coil springs shown minimally compressed, and with the safety catch shown pivoted to an operated position;
FIG. 6 is a front side elevational view of the mounted latch assembly but with the handle shown pivoted to one of many possible open positions, with the drawbar shown in solid lines as having been pivoted to one of many possible extended positions (and shown in phantom in a retracted position), with one of the drawbar-mounted compression coil springs shown minimally compressed, and with the safety catch shown in its normal, non-operated position;
FIG. 7 is a front side elevational view of the mounted latch assembly and of a latch-engageable post formation that is connected to a member that is to be joined to the member on which the latch assembly is mounted, with the members on which the latch assembly and the latch-engageable post formation are mounted being spaced relatively far apart, with the handle shown pivoted to another of many possible open positions, with the drawbar shown in solid lines as as having been pivoted to an extended position wherein the drawbar embraces the latch-engageable post formation (and shown in phantom in a retracted position), with one of the drawbar-mounted compression coil springs shown minimally compressed, and with the safety catch shown in its normal, non-operated position;
FIG. 8 is a front side elevational view of the mounted latch assembly and mounted latch-engageable post formation, with the members on which the latch assembly and the latch-engageable post formation are mounted having been drawn together as the handle was pivoted from the open position that is depicted in FIG. 7 to the nearly closed position that is depicted in FIG. 8, with the drawbar shown embracing the latch-engageable post formation, with one of the drawbar-mounted compression coil springs shown compressed by the drawbar's having been extended relative to the handle during the drawing together of the two members on which the latch assembly and post formation are mounted, and with the safety catch in the process of being cammed toward its operated position by a cam-engageable formation that is carried by the handle;
FIG. 9 is a front side elevational view of the mounted latch assembly and mounted latch-engageable post formation, with the members on which the latch assembly and the latch-engageable post formation having been drawn together as the two members on which the latch assembly and the post formation were joined by operating the latch assembly, with the handle shown in its closed position, with the drawbar shown embracing the latch-engageable post formation, with one of the drawbar-mounted compression coil springs shown compressed, and with the safety catch shown in its normal, non-operated position wherein (when the handle is closed as is depicted) the safety catch functions to releasably retain the handle in its closed position;
FIG. 10 is a top plan view similar to FIG. 3 but with the view showing both the latch assembly and the latch-engageable post formation, with the drawbar shown embracing the latch-engageable post formation, with both of the drawbar-mounted compression coil springs shown compressed, and with the handle locked closed and the safety catch locked in its normal position by means of a padlock that is installed on the latch assembly;
FIG. 11 is a sectional view as seen from planes that are indicated by the broken line 11--11 in FIG. 10;
FIG. 12 is a right end elevational view of the mounted latch assembly with the components thereof positioned as is depicted in FIGS. 10 and 11;
FIGS. 13, 14 and 15 are sectional views as seen from planes that are indicated by lines 13--13, 14--14 and 15--15 in FIG. 10, respectively;
FIG. 16 is a top plan view similar to FIG. 10 but showing a second embodiment of handle operated, toggle-type draw latch with safety catch that embodies selected features of the first latch assembly embodiment that is depicted in FIGS. 1-15;
FIG. 17 is a sectional view thereof, as seen from planes that are indicated by the broken line 17--17 in FIG. 16;
FIG. 18 is a top plan view similar to FIGS. 3 and 10 but showing a third embodiment of handle operated, toggle-type draw latch with safety catch with its drawbar shown in solid lines in an extended position embracing a latch-engageable post formation (and shown in phantom in a retracted position) with both of the drawbar-mounted compression coil springs shown compressed, and with the handle of the latch assembly being retained in its closed position by a safety catch that is shown in its normal, non-operated position;
FIG. 19 is a front side elevational view thereof;
FIG. 20 is a top view similar to FIG. 18, but with the drawbar shown in solid lines pivoted to one side to engage a latch-engageable post formation that is depicted in solid lines as being in one non-aligned position (and with the drawbar shown in phantom pivoted to an opposite side to engage a latch-engageable post formation that is depicted in phantom in another non-aligned position);
FIG. 21 is a top plan view similar to FIGS. 3, 10 and 18 but showing a fourth embodiment of handle operated, toggle-type draw latch with safety catch with its drawbar shown in solid lines in an extended position embracing a latch-engageable post formation (and shown in phantom in a retracted position), with both of the drawbar-mounted compression coil springs shown compressed, and with the handle of the latch assembly being retained in its closed position by a safety catch that is shown in its normal, non-operated position;
FIG. 22 is a front side elevational view thereof;
FIG. 23 is a top view similar to FIG. 21, but with the drawbar shown in solid lines pivoted to one side to engage a,latch-engageable post formation that is depicted in solid lines as being in one non-aligned position (and with the drawbar shown in phantom pivoted to an opposite side to engage a latch-engageable post formation that is depicted in phantom in another non-aligned position);
FIG. 24 is a top plan view similar to FIGS. 3, 10, 18 and 21 but showing a fifth embodiment of handle operated, toggle-type draw latch with safety catch with its drawbar shown in solid lines in an extended position embracing a latch-engageable post formation (and shown in phantom in a retracted position), with both of the drawbar-mounted compression coil springs shown compressed, and with the handle of the latch assembly being retained in its closed position by a safety catch that is shown in its normal, non-operated position;
FIG. 25 is a front side elevational view thereof;
FIG. 26 is a top view similar to FIG. 24, but with the drawbar shown in solid lines pivoted to one side to engage a latch-engageable post formation that is depicted in solid lines as being in one non-aligned position (and with the drawbar shown in phantom pivoted to an opposite side to engage a latch-engageable post formation that is depicted in phantom in another non-aligned position); and,
FIG. 27 is an exploded perspective view that selectively depicts components of the handle and drawbar sub-assemblies utilized by the third, fourth and fifth embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-15, a first embodiment of handle operated draw latch assembly with safety catch incorporating features of the preferred practice of the present invention is indicated generally by the numeral 100. Because many of the features of the latch assembly 100 are arranged in a substantially symmetrical manner about an imaginary "center plane," reference is made to FIGS. 3 and 12-15 wherein what will be referred to as the "center plane" of the latch assembly 100 is indicated generally by the numeral 125.
Referring briefly to FIGS. 16 and 17, a second embodiment of handle operated draw latch assembly with safety catch (that incorporates only a selected number of features of the latch assembly 100) is designated generally by the numeral 1100. Because the only difference between the latch assemblies 100 and 1100 is that the latch assembly 1100 (as depicted in FIGS. 16 and 17) incorporates a lesser number of the features that will be described in conjunction with the latch 100 (as depicted in FIGS. 1-15), the extent to which there is correspondence between components that are used in the latches 100 and 1100 will be made clear by the use in FIGS. 16 and 17 of reference numerals that are identical to those that are used in FIGS. 1-15 except that the "corresponding numerals" used in FIGS. 16 and 17 have been increased in magnitude by adding "one thousand" thereto. Thus, for example, when the latch 100 is described as having a handle 200 and a drawbar 250, it will be understood that the numerals 1200 and 1250 as used in FIGS. 16 and 17 designate a "corresponding" handle 1200 and a "corresponding" drawbar 1250 of the latch embodiment 1100.
Likewise, with respect to a third latch embodiment 2100 that is depicted in FIGS. 18-20, a fourth latch embodiment 3100 that is depicted in FIGS. 21-23, and a fifth latch embodiment 4100 that is depicted in FIGS. 24-26, "corresponding numerals" are used to designate "corresponding components." Corresponding components of the third and first embodiments are designated by numerals that differ by a magnitude of two thousand. Corresponding components of the fourth and first embodiments are designated by numerals that differ by a magnitude of three thousand. Corresponding components of the fifth and first embodiments are designated by numerals that differ by a magnitude of four thousand.
In view of the foregoing explanation, it will be understood that the use made herein of "corresponding numerals" eliminates the need to repeat feature descriptions that are applicable to a plurality of depicted embodiments. The description of the first latch embodiment 100 that follows is applicable to the second, third, fourth and fifth latch embodiments 1100, 2100, 3100 and 4100 insofar as features that are designated "corresponding numerals" are concerned. To the extent that some features of the first and second embodiments 100 and 1100 do not carry over to the third, fourth and fifth embodiments 2100, 3100 and 4100, it will be found that alternative features that are shared by the third, fourth and fifth embodiments (but not by the first and second embodiments) are introduced in conjunction with a discussion of the third embodiment 2100.
In the detailed description that follows, orientation terms such as "front," "rear," "left" and "right," and orientation expressions such as "leftwardly extending, "rightwardly extending, "vertically extending" and "horizontally extending" are not intended to be viewed as suggesting that the latch assemblies 100, 1100 can only be used if oriented in a particular manner. Rather, orientation terms and expressions are used merely as an expedient in rendering the description clear and easy to follow, as those who are skilled in the art will readily understand. Indeed, a significant feature of the latch assemblies 100, 1100, 2100, 3100, 4100 resides in the fact that they can be used in a wide variety of orientations, especially inasmuch as each of the latch assemblies 100, 1100, 2100, 3100, 4100 incorporates a "safety catch" that not only will serve to releasably retain an associated operating handle in its closed position, but also can be "padlocked" to further assure that, regardless of latch orientation, the operating handle will be securely retained in its closed position.
With the exception of FIG. 2 (which is deliberately "reversed" relative to the other drawing views to depict typical rear side features of a latch that embodies features of the preferred practice of the present invention), it will be understood that when a latch component is said to be "left" or "leftwardly extending" in character, such component is likely to be found toward the left side (except in FIG. 2 where "left" components appear toward the right side). Likewise, "right" and "rightwardly extending" components are likely to be found toward the right side (except in FIG. 2 where "right" components appear toward the left side).
In top plan views (such as FIGS. 3 and 10), components or features located below a horizontally extending center plane line (such as is indicated in FIGS. 3 and 10 by the numeral 125) will be said to be "front" or "forwardly extending" in character, while components or features located above the center plane line will be said to be "rear" or "rearwardly extending" in character.
In overview, and referring variously to FIGS. 1-15, the latch assembly 100 includes among its more major components a base assembly (or "base") that is indicated generally by the numeral 150, an elongate handle assembly (or "handle") that is indicated generally by the numeral 200, a U-shaped drawbar assembly (or "drawbar") that is indicated generally by the numeral 250, and a safety catch assembly (or "safety catch") that is indicated generally by the numeral 300. A first pivot pin 170 extends along an axis 175 to pivotally interconnect the base 150 and the handle 200. A second pivot pin 270 extends along an axis 225 to pivotally interconnect the handle 200 and the drawbar 250. A third pivot pin 370 extends along an axis 275 to pivotally interconnect a latching component 325 of the safety catch 300 to a mounting bracket 340 of the safety catch 300 that is welded to the base 150.
Referring to FIGS. 7-11, the handle operated draw latch assembly 100 typically is used in concert with a suitably configured latch-engageable post formation such as is indicated generally by the numeral 50. An enlarged head formation 52 is provided atop the post 50. In preferred practice, the latch assembly 100 is mounted atop a surface 20 of one of two relatively movable members 30, 40 that are to be "joined" by drawing the members 30, 40 relatively toward each other from a separated position, such as is depicted in FIG. 7, to a more closely juxtaposed position, such as is depicted in FIGS. 8-11. The "drawing together" function of the latch assembly 100 has caused the term "draw latch" to be relatively commonly associated with latches that perform such a function.
Moreover, because the latch assembly 100 has handle and drawbar components 200, 250 that are pivotally connected for relative movement about the pivot axis 225, with the handle 200 being pivotally connected to the base 150 for relative movement about the pivot axis 175, and with the drawbar 250 in essence establishing a "partially pivotal connection" with the latch-engageable post formation 50 (compare how the drawbar 250 is angled upwardly in FIG. 7 with how the drawbar is more nearly horizontally inclined in FIGS. 8 and 9), the pivotally interconnected "links" 200, 250 are viewed by some as constituting "toggle links" that are alignable "on center" and that pass "over center" to utilize such forces as are incurred by the components 200, 250 to selectively assist in effecting "latching" and "unlatching" movements--which arrangement has given rise to this general type of latch being referred to as a "toggle type latch," or more simply as a "toggle latch."
Referring to FIGS. 1, 4 and 12-15, the base 150 includes "front" and "rear" members 152, 162 that have flat bottom portions 154, 164 that extend contiguously, side by side in a common plane atop the mounting surface 20. The front and rear base members 152,162 have upwardly turned flange portions 156, 166 that extend in juxtaposed, side-by-side engagement. Referring to FIGS. 4 and 13, aligned holes 158, 168 are formed through the upturned flanges 156, 166 to receive a first pivot pin 170 in a slip fit. The holes 158, 168 extend coaxially about the pivot axis 175 whereby, when the pivot pin 170 is positioned in the aligned holes 158, 168, the pivot pin 170 extends coaxially about the pivot axis 175.
Referring to FIGS. 1-4 and 14-15, the front and rear base members 152, 162 have "left" end surfaces 172, 182, and have "right" end surfaces 174, 184 (wherein the designations of "left" and "right" are correct as regards what is depicted in FIGS. 1 and 3-11, but must be "reversed" when looking at the rear side elevational view that comprises FIG. 2). Referring principally to FIG. 4, the front base member 152 has a front edge surface 176, and a centerline surface 178 (that is partially defined by the rear face of the upstanding flange portion 156) that extends along the center plane 125. Similarly, the rear base member 162 has a rear edge surface 188, and a centerline surface 186 (that is partially defined by the front face of the upstanding flange portion 166) that extends along the center plane 125.
To mount the base members 152,162 atop the surface 20 of the underlying-member 30, suitable holes (not shown) can be drilled through the bottom portions 154, 164 to receive suitable fasteners such as bolts (not shown). Alternatively, the base members 152, 162 can be welded in place as by utilizing conventional welding techniques. While no connection is shown between the base members 152, 162 themselves (other than the presence of the pivot pin 170 which extends through the aligned holes 158,168 as is depicted in FIG. 13), the abuttingly engaging surfaces 178, 188 of the upwardly turned flange portions 156, 166 can be welded or otherwise suitably connected, as can other portions of the abutting centerline surfaces 178, 188.
Referring to FIGS. 1, 3 and 4, the handle 200 is an elongate structure that is formed as an assembly of elongate front and rear members 202, 212 that are, for the most part, substantially identical except that the front member 202 is a mirror image of the rear member 212, and vice versa. Actually, the front handle member 202 does differ slightly from being a true mirror image of the rear handle member 212 in that the front handle member 202 defines a formation that is not present on the rear handle member 212, namely a forwardly-extending catch-engagement formation 223 that is located about mid-way along the length of the front handle member 202.
While the handle 200 of the first latch embodiment 100 (and the identical "200" style handle 1200 of the second latch embodiment 1100) has front and rear members 202, 212 that are designed to be rigidly interconnected solely by welding, the handle 2200 of the third latch embodiment 2100 (and the identical "2200" style handles 3200 and 4200 of the fourth and fifth latch embodiments 3100 and 4100, respectively) has aligned holes 2801, 2803 formed through the members 2202, 2212 (see FIG. 27) to receive rivets 2802, 2804, respectively. The rivets 2802, 2804 serve to rigidly interconnect the handle members 2202, 2212.
Referring principally to FIG. 4, the front and rear handle members 202,212 have rounded left end regions 204, 214 and rounded right end regions 230, 232, respectively. When the handle portions 228, 238 of the front and rear handle members 202, 212 are brought together so that their similarly configured features extend substantially congruently to form the handle 200, a handgrip 249 is defined by the right end region of the assembled handle 200. Defining opposite front and rear sides of the handgrip 249 are a front face of the front handle member 202 and a rear face of the rear handle member 212. Bordering the front and rear faces 202, 212 in the region of the handgrip 249 are a) contiguously extending wave-form bottom surfaces 233,243 of the front and rear handle members 202, 212, b) contiguously extending curved end surfaces 230, 232 of the front and rear handle members 202, 212, and c) contiguously extending flat top surfaces 235, 245 of the front and rear handle members 202, 212. Referring to FIGS. 2, 5-9 and 11, the bottom surfaces 233, 243 and the top surfaces 235, 245 extend generally along opposite sides of an imaginary centerline 375 of the handgrip 249. The centerline 375 parallels the top surfaces 235, 245 and centrally intersects the curved end surfaces 230,232.
Also formed by the rigidly interconnected portions 228, 238 of the front and rear handle members 202, 204, and extending along the top surface of the handle 200 is a generally triangular shaped stop formation that is indicated generally by the numeral 242. Defining opposite front and rear sides of the stop formation are the front face of the front handle member 202 and the rear face of the rear handle member 212. Bordering the front and rear faces of the handle members 202, 212 in the region of the triangular shaped stop formation 242 are contiguously extending flat bottom surfaces 231, 241 of the front and rear handle members, b) contiguously extending flat top surface portions 205, 215 that join with contiguously extending inclined flat top surface portions 227, 237, and c) flat rightly-facing surfaces 229, 239 that are connected by smoothly rounded "corners" to the inclined surface portions 227,237 and to the flat top surfaces 235,245 of the handgrip 249.
Other features of the front and rear handle members 202, 212 will be described beginning generally from the vicinities of the rounded left end regions 204, 214 and extending rightwardly along the length of the handle members 202, 212.
Referring to FIGS. 3 and 10, the rounded left end regions 204, 214 are spaced equally from the center plane 125 sufficiently to extend in a yoke-like manner along forwardly and rearwardly facing surfaces 157,167 of the abuttingly engaged upstanding flange portions 156, 166 of the front and rear base members 152, 162, respectively.
Referring to FIG. 4, extending rightwardly from the left end region 204 of the front handle member 202 is a forwardly angled portion 206 that forms a transition between the end region 204 and a flat portion 208 of the front handle member 202 that parallels the center plane 125 but at a greater distance therefrom than does the left end region 204. In like manner, extending rightwardly from the left end region 214 of the rear handle member 212 is a rearwardly angled portion 216 that forms a transition between the end region 214 and a flat portion 218 that parallels the center plane 125. Forming transitions between the handle portions 208, 218 and the handle portions 228, 238 are angled portions 226, 236 of the handle members 202, 212, respectively.
Extending rightwardly from the rounded left end regions 204, 214 and defining lengthy top surface reaches of the handle members 202, 212 are the flat top surfaces 205, 215 that join eventually with the upwardly inclined surfaces 227,237 of the stop formation 242.
Extending rightwardly from the rounded left end regions 204, 214 of the handle members 202, 212 are flat bottom surfaces 203, 213. The flat bottom surfaces 203, 213 underlie the angled transition portions 206, 216 and join smoothly with rounded bottom surface formations 207, 217 that underlie the widely spaced formations 208, 218. At their lowest point, the rounded bottom formations 207, 217 cooperate to define a stop 247 (i.e., the side-by-side formations bottom surfaces 207, 217 act, in unison, to cooperatively define the stop 247) that engages the base members 152, 162 when the handle 200 is in its "closed" position, as is depicted in FIGS. 1-3 and 9-11, and as is shown in the sectional view of FIG. 14.
The rounded bottom surface formations 207, 217 that define the stop formation 247 join with upwardly curved, rightwardly extending bottom surface portions 209, 219 that also underlie the widely spaced formations 208, 218. The curved surfaces 209,219 join with flat surface portions 211,221 that underlie the regions 226, 236.
Referring to FIG. 4, the flat surface 211 of the front handle member 202 extends rightwardly to a point where the bottom surface of the handle is cut away adjacent the provision of the forwardly extending, generally flat, catch-engaging formation 223. From the right side of the catch-engaging formation 223, the flat bottom surface 231 that underlies the stop formation 242 extends rightwardly to join with the wave-form bottom surface 233 that forms a part of the handle grip 249. Likewise, the rear handle member 212 has a bottom surface 241 that is partially defined by the flat bottom surface portion 233 that underlies the stop formation 242 and joins with the wave-form bottom surface 243.
Also depicted in FIG. 4, but in phantom, are a depending formation 502 that optionally can be provided as an integral depending portion of the front handle member 202, and an upwardly extending formation 504 that optionally can be provided as an integral upwardly extending portion of the rear base member 162. If the formations 502, 504 are provided in the manner that is depicted in phantom in FIG. 4, the apertures 512, 514 that they respectively define will align (when the handle 200 is latched closed by the safety catch 300, as will be described in greater detail shortly) to receive the shackle 552 of a padlock 550 that can be installed on the latch assembly 100 to lock the safety catch 300 in its latched position, and to lock the handle 200 to the base 150, as is depicted in FIGS. 10 and 11. While it will be understood that optional formations that correspond to the formations 502, 504 can be included when the latch embodiments 1100, 2100, 3100, 4100 are manufactured, such corresponding formations are not depicted in the drawings.
Aligned holes 210, 220 (see FIGS. 4 and 13) are formed through the rounded left end regions 204, 214 of the front and rear handle members 202, 212, respectively. The aligned holes 210, 220 extend coaxially about the first pivot axis 175, receive the first pivot pin 170 in a slip fit, and orient the first pivot pin 170 to extend coaxially along the first pivot axis 175. Spring retainer clips 180 engage grooves 181 that are formed in opposite end regions of the first pivot pin 170 and extend along a front face of the front handle member 202 and along a rear face of the rear handle member 212 to secure the first pivot pin 170 in place.
While the front and rear handle members 202, 212 that form the "200" style handle (that is utilized by the first and second latch embodiments 100, 1100) are configured quite like the front and rear handle members 2202, 2212 that form the "2200" style handle (that is utilized by the third, fourth and fifth latch embodiments 2100, 3100, 4100), there are differences between the "200" style of handle and the "2200" style of handle. Referring to FIG. 4 (wherein the front and rear handle members 202, 212 of the handle 200 are depicted) and to FIG. 27 (wherein the front and rear handle members 2202, 2212 of the handle 2200 are depicted), it will be seen that, while the handle members 202, 212 have aligned holes 185, 195 that are sized to closely receive their associated second pivot pin 270 to form a substantially "play free" connection therebetween (i.e., a so-called "slip fit"), the handle members 2202, 2212 have aligned holes 2185, 2195 that are "over-sized" to quite loosely receive uniform diameter end regions 2901, 2911 of their associated second pivot pin 2270.
While the holes 2185, 2195 are "over-sized" so as to loosely receive the uniform diameter end regions 2901, 2911, the holes 2185, 2195 are not so large in diameter as to permit an enlarged spherical formation 2900 of the pin 2270 to pass therethrough--whereby the spherical formation 2900 is caused to be confined between the handle members 2202, 2212. Referring to FIG. 27, the holes 2185, 2195 are chamfered to define substantially frusto-conical shaped bearing surfaces 2985, 2995 that are configured to matingly engage opposite side portions of the spherical formation 2900 to provide, in essence, a "ball joint" type of connection between the handle 2200 and the second pivot pin 2270. This "spherical" or "ball joint" type of connection that couples the pivot pin 2270 to the handle 2200 provides plural degrees of freedom of relative movement--whereby limited movement of the second pivot pin 2270 is permitted to take place relative to the handle 2200 in substantially any chosen direction about an imaginary center point that is located along the axis 2225 at a position that is centered within the spherical formation 2900 (see FIGS. 18-20 wherein such a center point is indicated by the numeral 2925).
The "plural degrees of freedom of relative movement" that are afforded by the "spherical" or "ball joint" connection that is formed between the handle 2200 and the second pivot pin 2270 is unlike the "single degree of freedom of relative movement" that is afforded by the much simpler "axial rotation" type of connection that is formed between the handle 200 and the second pivot pin 270 of the latch embodiment 100. The constant diameter holes 185, 195 receive the constant diameter pin 270 in a slip fit, and limit movement of the second pivot pin 270 relative to the handle 200 to simple rotation about the common axis 225 of the holes 185,195 and of the second pivot pin 270.
An advantage afforded by the "spherical" or "ball joint" type of connection that is formed between the second pivot pin 2270 and- the handle 2200 of the third latch embodiment 2100 (which type of connection also is employed in the third and fourth latch embodiments 3100, 4100), is to permit a drawbar 2250 (that is connected to opposite end regions 2901, 2911 of the second pivot pin 2270) to tilt forwardly and rearwardly with respect to the center plane 2125 of the latch 2100 to engage a post formation 2050 that is not aligned with the center plane 2125. To illustrate this feature, reference is made to FIG. 20 wherein rearward tilting of the drawbar 2250 to engage a post formation 2050 that is positioned rearwardly with respect to the center plane 2125 is depicted in solid lines, and wherein forward tilting of the drawbar 2250 to engage a post formation 2050 that is positioned forwardly with respect to the center plane 2125 is depicted in phantom (see also FIGS. 23 and 26 wherein similar solid-line and phantom depictions of drawbars 3250, 4250 and of nonaligned post formations 3050, 4050 are presented to illustrate how this feature applies to the third and fourth latch embodiments 3100, 4100, respectively).
Another difference between the "200" and "2200" handle styles has to do with the manner in which their associated second pivot pins 270, 2270 are constrained from moving axially (i.e., constrained from moving "transversely" in forward and rearward directions relative to the handles 200, 2200). With the "2200" style of handle, the bearing surfaces 2985, 2995 of the front and rear handle members 2202, 2212 engage the spherical formation 2900 to provide a "ball joint" type of connection between the second pivot pin 2270 and the handle 2200 that keeps the second pivot pin 2270 "centered" with respect to the handle 2200 whereby axial (i.e., "transverse") movement of the second pivot pin 2270 relative to the handle 2200 is prevented.
Because the "200" style of handle has no "enlarged spherical formation" located mid-way along the length of its associated second pivot pin 270 that can be confined by its handle members 202,212 to keep the second pivot pin 270 "centered" with respect to the handle 200, a different approach is taken. Referring to FIGS. 4 and 11, a coil-formed pin 191 is driven part way into a hole 193 that is formed diametrically through the second pivot pin 270 at a location that extends within the center plane 125 (i.e., at a location that is mid-way along the length of the second pivot pin 270). A torsion coil spring 197 has a central portion 198 that connects with a projecting end region 199 of the coil-formed pin 191. The torsion coil spring 197 also has front and rear coils 194, 196 that are located on opposite sides of the pin 191 and that are interposed between the pin 191 and the front and rear handle members 202,212, respectively. The front and rear coils 194, 196 thus serve in one capacity as "spacers" that keep the coil-formed pin 191 "centered" between the front and rear handle members 202,212--and thereby also serve to keep the second pivot pin 270 "centered" relative to the handle 200.
Another function provided by the torsion coil spring 197 is to bias the second pivot pin 270 clockwise relative to the handle 200 (i.e., "clockwise when the latch 100 is viewed in front side elevation, as in FIGS. 5-9) to bias the drawbar 250 toward its retracted position (the drawbar 250 is depicted in its retracted position in FIGS. 1-3 and 5). Opposed, hook-shaped end regions 201 of the torsion coil spring 197 engage flat bottom surface portions 211,221 of the handle members 202,212 (at locations where the flat bottom surface portions 211,221 join the curved surface portions 209, 219) and cooperate with the spring's central portion 198 (which engages the projecting end region 199 of the coil-formed pin 191) to permit the front and rear coils 194,196 to effect "clockwise" biasing of the drawbar 250 toward its retracted position. When the drawbar 250 is in its retracted position, a crossbar 260 of the drawbar 250 engages the inclined surfaces 227, 237 of the stop formation 242, as is depicted in solid lines in FIGS. 1-3 and 5-7, and in phantom in FIGS. 6 and 7.
The "2200" style handle does not utilize a single torsion coil spring and a single coil-formed pin that are situated between its handle members 2202, 2212 to bias its second pivot pin 2270 "clockwise" (i.e., to bias its drawbar 2250 toward its retracted position, as has been described above in conjunction with the biasing of the drawbar 250 of the latch 100). Rather, a pair of torsion coil springs 2927, 2937 and a pair of coil-formed pins 2921, 2931 (see FIG. 27) are connected to the constant diameter end regions 2901, 2911 of the second pivot pin 2270--with the spring 2927 and the pin 2921 being situated forwardly along the pivot axis 2225 with respect to the front handle member 2202, and with the spring 2937 and the pin 2931 being situated rearwardly along the pivot axis 2225 with respect to the rear handle member 2202.
The coil-formed pins 2921, 2931 are driven part way into holes 2905, 2915 that are formed diametrically through the constant diameter end regions 2901, 2915, respectively, of the second pivot pin 2270. The springs 2927, 2937 have hook-shaped end region 2928, 2938 that connect with the pins 2921, 2931, and have hook-shaped end regions 2929, 2939 that engage the bottom surface portions of the handle members 2202, 2212. By this arrangement, the torsion coil springs 2927, 2937 serve the function of biasing the drawbar 2250 about the axis 2225 away from extended positions (see the solid-line extended-position depiction of the drawbar 2250 in FIGS. 18 and 19) toward the drawbar's retracted position (see the phantom-line depiction of the drawbar 2250 in FIGS. 18 and 19).
Referring principally to FIG. 4, the drawbar 250 is a U-shaped structure that has front and rear leg portions 252,262 that are interconnected by a transversely extending cross-leg 260. Rounded bends 254, 264 are provided where the front and rear leg portions 252, 262 join with the cross-leg 260. Threaded end regions 256, 266 are defined by the front and rear leg portions 252, 262, respectively. The threaded end regions 256, 266 extend through holes 272, 282 that are formed through the second pivot pin 270 (see FIG. 14). Tightly fitting nuts 274, 284 and locknuts 276, 286 are threaded onto the threaded end regions 256, 266 at locations on opposite sides of the holes 272,282 that extend through the second pivot pin 270.
While the second and third latch embodiments 1100, 2100 utilize drawbars 1250, 2250 that are identical to the drawbar 250, the fourth and fifth latch embodiments 3100, 4100 utilize differently configured drawbars 3250, 4250. Referring to FIGS. 21-23 and 27, the drawbar 3250 is a generally V-shaped structure that has front and rear leg portions 3252, 3262 that are bent midway along their lengths to provide leg portions 3253, 3263 that angle toward each other and interconnect to form a V-shaped juncture 3255.
Referring to FIGS. 24-26 and 27, the drawbar 4250 is a U-shaped structure that differs from the U-shaped drawbar 250 in that the drawbar 4250 is not entirely rigid. The drawbar 4250 has three rigid components, and two flexible components. The rigid components include front and rear leg portions 4252, 4262 (located adjacent to and formed integrally with the threaded end regions 4256, 4266), and a tubular U-shaped member 4281 that defines a cross-leg 4260, front and rear leg portions 4251, 4261, and rounded corner regions 4254, 4264 of the drawbar 4250.
The two flexible components of the drawbar 4250 are defined by two exposed lengths 4277, 4287 of a steel cable 4285 (i.e., a cable that is formed by weaving steel strands to form what often is referred to as "wire rope"). The exposed lengths of cable 4277, 4287 are spaced portions of a single length of cable 4285 that extends through the rigid tubular member 4281. The type of steel cable selected for this use is relatively stiff but exhibits sufficiently flexibility to permit the rigid U-shaped tubular member 4281 to be moved out of a plane in which the rigid front and rear leg portions 4254, 4264 extend--whereby the drawbar 4250 is given a characteristic bit of flexibility.
To manufacture the drawbar 4250, the cable 4285 is threaded through the tubular member 4281 at a time before the tubular member 4281 is deformed by bending to take on its U-shaped configuration. The bending of the tubular member 4281 is effected in a manner that causes the tubular member 4281 to grip the cable 4285 so that, when the bending of the tubular member 4281 is complete, the cable 4285 is rigidly connected to the tubular member 4281. Opposite end regions of the cable 4285 are rigidly connected to the front and rear leg portions 4252, 4262 by conventional crimp-type cable connectors 4253, 4263.
While the drawbars 3250, 4250 are depicted in the drawings as being used only with "2200" style handles, the drawbars 250, 1250, 2250, 3250, 4250 can be interchangeably mounted on any of the latch embodiments 100, 1100, 2100, 3100, 4100--as the needs of a particular application may dictate. Drawbar interchangeability is one of the ways in which latches that embody the preferred practice of the present invention exhibit a high degree of versatility.
Carried on the threaded end regions 256, 266 of the drawbar 250 of the first latch embodiment 100 are several components--identical quantities of which are utilized by the drawbars 2250, 3250, 4250 of the third, fourth and fifth latch embodiments 2100, 3100, 4100, but with lesser quantities of some of these components being required by the drawbar 1250 of the second latch embodiment 1100. For example, the latch 100 has three washers 278 and three washers 288 positioned on the threaded end regions 256, 266, while the latch 1100 has only two of the washers 1278 and two of the washers 1288 positioned on its threaded end regions 1256, 1266. While two compression coil springs 290,292 are interposed (together with two of the washers 278, 288) between the locknuts 276,286 on the threaded end regions 256, 266 of the latch 100, no compression coil springs at all are installed on the threaded end regions 1256, 1266 of the latch 1100.
The purpose for providing the threaded end regions 256, 266 and the nuts 274, 284 and 276, 286 is to permit the "effective length" of the crossbar 250 (i.e., the distance between the crossleg 260 of the drawbar 250 and the pivot axis 225 of the second pivot pin 270) to be adjusted as may be needed to permit the latch assembly 100 to properly engage and apply force to the latch-engageable formation 50. Because the tight fitting nuts 274,284 and the locknuts 276, 286 can be adjusted along the threaded end regions 256, 266, the line of engagement along which the crossleg 260 of the drawbar 250 engage the inclined surfaces 227,237 of the stop formation 242 will vary when the drawbar 250 is retracted as is depicted in FIGS. 1-3 and 5. However, the length and location of the inclined surfaces 227, 237 is sufficient to assure that the crossbar 260 will not extend beyond the upstanding end surfaces 229, 239 of the stop formation 242 but rather will always engage the inclined surfaces 227,237--and will therefor always be prevented from engaging the handgrip formation 249 that is provided near the right end regions 230 of the handle 200. The same applies to the drawbars 1250, 2250, 3250, 4250 of the latch embodiments 1100, 2100, 3100, 4100--namely that their drawbars 1250, 2250, 3250, 4250 will engage their inclined stop formations 1242, 2242, 3242, 4442 when the drawbars 1250, 2250, 3250, 4250 are in their retracted positions.
The compression coil springs 290, 292 give the latch assembly 100 an ability to self-adjust and to apply a suitable drawing force to the latch-engageable formation 50. The same is true with respect to corresponding coil springs 2290, 2292; 3290, 3292; and 4290, 4292 of the latch embodiments 2100, 3100, 4100. This is in contrast with the latch assembly 1100 which utilizes no corresponding springs and therefore does not self-adjust but rather operates in a way that relies on the proper adjustment of the nuts 1274, 1276 and 1284, 1286 to position the drawbar 1250 relative to the second pivot pin 1270.
While the drawbars 2250, 3250, 4250 are depicted in the drawings as carrying compression coil springs (in the manner that has been described in conjunction with the first latch embodiment 100), it will be understood that the drawbars 2250, 3250, 4250 can be utilized (in the manner that has been described in conjunction with the second latch embodiment 1100) without having compression coil springs installed thereon.
Referring to FIGS. 1-12 and 15, the safety catch 300 includes the mounting bracket 340, the pivotally movable catch member 325, the pivot pin 370 that mounts the catch member 325 on the bracket 340 for pivotal movement about the third pivot axis 275, and a generally Z-shaped leaf spring 380.
Referring to FIG. 4, the mounting bracket 340 has a generally H-shaped bottom structure 342 that is welded to the front base member 152. The location of the bracket 340 atop the bottom portion 154 of the front base member 152 is selected to position front and rear upwardly turned arm portions 345, 347 of the bracket 340 so that aligned holes 344, 346 that are formed through the arm portions 345, 347 to mount the pivot pin 370 position the pivot pin 370 and its pivot axis 275 directly beneath the position that is occupied by the catch-engagement formation 223 when the handle 200 is in its closed position (for example as is depicted in FIGS. 1-3, 5 and 9-12).
Referring to FIG. 4, the pivotally mounted catch member 325 has a top wall 329 that has a smoothly curved, downwardly extending left end region 331, and a smoothly rounded right end region 333. The catch member 325 has a pair of generally triangular shaped front and rear arm portions 335,337 that depend from smoothly rounded junctures with the top wall 329 to extend in juxtaposed relationship with the upwardly turned arm portions 345, 347 of the mounting bracket 340. Aligned holes 334, 336 are formed through the arm portions 335, 337, through which the pivot pin 370 is received in a slip fit to pivotally mount the catch member 325 on the mounting bracket 340.
Referring to FIG. 4, the top surface of the top wall 329 of the pivotally mounted catch member 325 is provided with a series of upwardly-facing thumb-grip indentations 339 that help to retain one's thumb in place atop the catch member 325 for operating the catch member 325 by depressing the right end region 333 of the catch member 325 to pivot the catch member 325 about the third pivot axis 370 to the unlatched position that is depicted in FIG. 5.
The latching notch 327 of the catch member 325 is defined in part by aligned notches 315, 317 that are formed in the depending front and rear arm portions 335, 337, and by a downwardly-facing surface 319 of the downwardly turned left end region 331 of the top wall 329. When the latching notch 327 of the catch member 325 receives the catch-engagement formation 223 of the handle 200 (as is best seen in FIGS. 1, 9 and 11), the handle 200 is said to be "latched closed" inasmuch as the handle 200 is prevented thereby from pivoting out of its closed position until the catch member 325 is pivoted to its unlatched position (as is depicted in FIG. 5).
Referring to FIG. 8, a feature of the catch member 325 is that the rounded left end region 331 of the top wall 329 is configured to be engaged by the catch-engagement formation 223 during movement of the handle 200 toward its closed position. As the handle 200 is pivoted progressively toward its closed position, the handle-carried catch-engagement formation 223 progressively cams the base-carried catch member 325 to pivot the catch member 325 in opposition to the biasing action of the leaf spring 380. As the catch member 325 is progressively caused to pivot away from its latched position toward its unlatched position, the latch-engagement formation 223 slides progressively along the rounded left end region 331 of the top wall 329 of the catch member 325. The sliding of the latch-engagement formation 223 along the rounded left end region 331 continues until the formation 223 drops beneath the end surface 319 of rounded left end 331 and into the latching notch 327, whereupon the handle 220 attains its closed position as the biasing action of the leaf spring 380 snaps the pivotally mounted catch member 325 back to its latched position--whereby the latch-engagement formation 223 is received within the latching notch 327 of the safety catch 300 (i.e., the handle 200 is "latched closed").
The Z-shaped leaf spring 380 has a relatively flat upper reach 382 that underlies the top wall 329 of the pivotally mounted catch member 325 and biases the pivotally mounted catch member 325 toward a latched position that is depicted in FIGS. 1-3, 6, 7, 9-12 and 15. The leaf spring 380 has a relatively flat lower reach 384 that rests atop portions of the mounting bracket 340; an upwardly inclined left portion 386 that extends between the left end of the lower reach 384 and a smoothly rounded bend 388; a flat central reach 390 that extends rightwardly from the bend 388; and an upwardly inclined right portion 392 that extends between the right end of the center reach 390 and a bend 394 that joins with the right end of the upper reach 382.
Referring to FIG. 11, the curved bend 388 extends about portions of the pivot pin 370 to prevent unwanted rightward movement of the leaf spring 380. Unwanted leftward movement of the leaf spring 380 is prevented by the left end region of the upper reach 382 extending adjacent the downwardly turned end region 331 of the top wall 329. Thus, the generally Z-shaped leaf spring 380 tends to be held in place once it has been interposed as described between the mounting bracket 340 and the pivotally mounted catch member 325.
A feature of the pivotally mounted catch member 325 is that its downwardly turned front and rear arms 335, 337 have relatively large aligned apertures 395, 397 (although the aperture 395 is easily discerned in FIG. 4 and other views, the aperture 397 is best seen in FIG. 2) formed therethrough at a location just beneath the top wall 329 for receiving the shackle 552 of a padlock 550 that can be installed on the latch assembly 100, as is depicted in FIGS. 10 and 11. Because the safety catch assembly 300 is securely connected to the front base member 152, the effect of installing the padlock shackle 552 through the aligned apertures 395, 397 in a manner that also embraces portions of the handle 200 (as shown in FIGS. 10 and 11) is a) to secure the safety catch 300 (i.e., to prevent the catch member 325 from pivoting away from its latched position toward its unlatched position), and b) to concomitantly lock the handle 200 to the base 150. If desired, the formations 502, 504 that are depicted in phantom in FIG. 4 can be provided as integral parts of the front handle member 202 and the rear base member 162 for positioning their apertures 512, 514 in alignment with the apertures 395, 397 to also receive the padlock shackle 552 and to enhance the strength of the secure connection that is provided between the handle 202 and the base 150 when the padlock 550 is installed on the latch assembly 100 in the manner that is depicted in FIGS. 10 and 11.
The remaining portion of this description is principally devoted to an explanation of a typical manner in which the latches 100, 1100, 2100, 3100, 4100 are put to use. While the operational description that follows refers principally to the latch embodiment 100, it will be understood that the description is equally applicable to latch embodiments 1100, 2100, 3100, 4100.
In operation, the various components of the latch assembly 100 normally assume the positions depicted in FIG. 1 when the latch assembly 100 is not being used to engage the latch-engagement formation 50. In the positions depicted in FIG. 1, the handle 200 is latched closed by the safety catch 300, and the drawbar 250 is held in its retracted position (with its crossleg 260 engaging the stop formation 242 of the handle 200) by the action of the torsion coil spring 197.
To move the drawbar 250 into embracing engagement with the latch-engagement formation 50, the safety catch 300 is operated (as is depicted in FIG. 5 to release the engagement of the latching notch 327 with the catch-engagement formation 223), and the handle 200 is pivoted about the first pivot axis 175 from its closed position to the open position shown in FIG. 6, and onward to the open position shown in FIG. 7. As the handle 200 is moved into the open position shown in FIG. 7, the drawbar 250 is pivoted relative to the handle 200 about the second pivot axis 225 to move the drawbar away from its retracted position toward extended positions that are shown in solid lines in FIGS. 6 and 7 to bring the drawbar 250 into embracing engagement with the post-like latch-engagement formation 50, as is depicted in FIG. 7.
With the drawbar 250 embracing the post-like latch-engagement formation 50, the handle 200 is pivoted about the first pivot axis 175 toward its closed position. As the handle 200 approaches its closed position, the catch-engagement formation 223 cams the pivotally mounted catch member 325 in opposition to the action of the leaf spring 380 away from its latched position toward its unlatched position, as is shown in FIG. 8. As the handle 200 reaches its closed position, the biasing action of the leaf spring 380 snaps the pivotally mounted catch member 325 into its latched position to bring its latching notch 327 into retaining engagement with the catch-engagement formation 223 of the handle.
To ensure that the drawbar 250 properly applies force to the latch-engagement formation 50 during closure movement of the handle 200, the lock nuts 274, 284 and 276, 286 may be adjusted along the threaded end regions 256, 266 of the drawbar 250, as needed. In the latch embodiment 100, the adjustment of the lock nuts 274, 284 and 276, 286 affects not only the "effective length" of the drawbar 250 but also the extent to which the drawbar-carried springs 290, 292 will be compressed as the handle 200 is pivoted to its closed position. Referring to FIGS. 16 and 17, if no compression coil springs are installed on the drawbar 1250, the adjustment of the lock nuts 1274, 1284 and 1276, 1286 affects only the "effective length" of the drawbar 1250.
While the invention has been described with a certain degree of particularity, it will be understood that the present disclosure of the preferred embodiment has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of elements can be resorted to without departing from the true spirit and scope of the invention as hereinafter claimed. It is intended that the patent shall cover, by suitable expression in the claims, such features of patentable novelty as exist in the invention.
What is claimed is:
1. In a toggle type draw latch assembly that has a base, an elongate operating handle pivotally connected to the base near one end region thereof for moving between an open position and a closed position wherein a portion of the handle is situated relatively near to the base, having a hand grip formed near the opposite end region thereof, having a drawbar pivotally connected to the handle at a location that is nearer to the one end region of the handle than to the hand grip, with the drawbar being pivotally movable relative to the handle between an extended position and a retracted position wherein a portion of the drawbar is situated relatively near to the hand grip, the improvement comprising:a) means for adjusting the effective length of the drawbar within a given range of adjustment, with such adjustment affecting the nearness of the drawbar to the hand grip when the drawbar is in its retracted position; b) first stop formation means connected to the handle for defining drawbar engaging surface means at a location near the hand grip for being engaged by the drawbar when the drawbar is in its retracted position; c) with the drawbar engaging surface means including a surface that extends for a sufficient distance along the length of the handle at said location near the hand grip for being engaged by the drawbar when the drawbar is in its retracted position regardless of where within said given range of adjustment the means for adjusting the effective length of the drawbar is set; and, d) with the drawbar engaging surface being configured to ensure that the retracted position of the drawbar is held at a sufficiently far distance away from the location of the hand grip to ensure that, regardless of where within said given range of adjustment the means for adjusting the effective length of the drawbar is set, the retracted drawbar will not so closely approach the hand grip as to endanger portions of a hand that is gripping the hand grip being contacted by the retracted drawbar.
2. The toggle type draw latch assembly of claim 1 wherein the hand grip extends about an imaginary centerline that generally parallels the length of the elongate handle so as to extend through said one and opposite end regions of the handle, and the drawbar engaging surface is configured to extend progressively farther from said centerline the closer that it approaches the hand grip.
3. The toggle type draw latch assembly of claim 2 wherein the drawbar engaging surface is planar in character in that it extends substantially within a common plane that is inclined relative to said centerline so as to more closely approach the centerline as it extends away from the hand grip.
4. The toggle type draw latch assembly of claim 1 wherein the handle also defines second stop formation means connected to the handle for defining base engaging surface means at a location that is near the location where the drawbar is pivotally connected to the handle for engaging the base when the handle is pivoted to said closed position to define the closed position of the handle.
5. The toggle type draw latch assembly of claim 4 wherein the base engaging surface means presents a convexly curved surface that engages the base when the handle is in its closed position.
6. The toggle type draw latch assembly of claim 1 additionally including drawbar biasing means for biasing the drawbar to pivot relative to the handle toward its retracted position.
7. The toggle type draw latch assembly of claim 6 wherein 1) the handle has at least one hole formed therethrough, 2) an elongate pivot pin has a central portion that extends through said at least one hole, 3) the elongate pivot pin is pivotally connected to the handle for movement relative to the handle about an imaginary pivot axis that extends centrally along the length of the elongate pivot pin, 4) the drawbar is connected to opposite end regions of the elongate pivot pin for pivotal movement therewith relative to the handle, and 5) said biasing means includes torsion coil springs interposed between the handle and the elongate pivot pin for biasing the drawbar toward its retracted position.
8. The toggle type draw latch assembly of claim 7 additionally including connection means for establishing a pivotal connection between the handle and the elongate pivot pin at a location near where the elongate pivot pin extends through said at least one hole, and for defining a pivotal connection of the type that limits relative movement of the drawbar and the handle to pivotal movement about said imaginary pivot axis.
9. The toggle type draw latch assembly of claim 8, wherein:a) the handle is comprised of two substantially congruently extending handle members that are spaced apart at one location along their length, and that are rigidly connected together in at least one other location along their length where the handle members extend into engagement with each other; b) the at least one hole formed through the handle includes aligned holes formed through the two handle members at said location where the handle members are spaced apart; c) the elongate pivot pin extends through the aligned holes; and, d) the aligned holes are configured to receive the elongate pivot pin in a slip fit that strictly confines relative pivotal movement between the elongate pivot pin and the handle to pivotal movement about said imaginary pivot axis.
10. The toggle type draw latch assembly of claim 9 wherein the biasing means includes a torsion coil spring having coils that are reeved relatively loosely about a portion of the elongate pivot pin that extends between the aligned holes at said location where the handle members are spaced apart.
11. The toggle type draw latch assembly of claim 10 wherein:a) a radially extending hole is formed in said portion of the elongate pivot pin that extends between the aligned holes, with the radially extending hole being located substantially mid-way between the two handle members; b) an elongate pin member has one portion that is pressed into the radially extending hole, and another portion that projects radially outwardly from the radially extending hole; and, c) the biasing means includes a torsion coil spring that has:1) a first end region that is connected to a first of the two handle members; 2) a second end region that is connected to a second of the two handle members;3) a central region that is connected to said another portion of said elongate pin member near where said elongate pin member emerges from said radially extending hole; 4) a first set of coils that is formed integrally with said first end region and with said central region, and that are reeved loosely about the elongate pivot pin along a portion of the elongate pivot pin that extends between said first one of the two handle members and the location where the elongate pin member emerges from said radially extending hole; and, 5) a second set of coils that is formed integrally with said second end region and with said central region, and that are reeved loosely about the elongate pivot pin along a portion of the elongate pivot pin that extends between said second one of the two handle members and the location where the elongate pin member emerges from said radially extending hole.
12. The toggle type draw latch assembly of claim 7, wherein:a) the handle is comprised of first and second substantially congruently extending handle members that are that spaced apart at one location along their length, and that are rigidly connected together in at least one other location along their length where the first and second handle members extend into engagement with each other; b) the at least one hole formed through the handle includes first and second aligned holes that are formed through the first and second handle members, respectively, at said location where the first and second handle members are spaced apart; c) the elongate pivot pin has first and second end regions that are generally cylindrical in shape, that are of substantially uniform diameter along their lengths, and that extend through the first and second aligned holes, respectively; d) the elongate pivot pin also has an enlarged central region of generally spherical shape that extends between and connects the first and second end regions; e) the first and second holes are sized to quite loosely receive the first and second end regions, but to not permit the enlarged central region to pass therethrough; and, f) bearing means for engaging and mounting the generally spherically shaped central region for movement relative to the first and second handle means about an imaginary point that is located along said imaginary axis centrally within the spherically shaped central region, with the bearing means including a first generally frusto-conically shaped bearing surface defined by the first hole for engaging one side of the spherically shaped central region adjacent where said one side of the central region joins with the first end region, and including second generally frusto-conically shaped bearing surface defined by the second hole for engaging an opposite side of the spherically shaped central region adjacent where said opposite side of the central region joins with the second end region.
13. The toggle type draw latch assembly of claim 12 wherein the biasing means includes a first torsion coil spring having a first set of coils that are reeved relatively loosely about the first end region of the elongate pivot pin, and a second torsion coil spring having a second set of coils that are reeved relatively loosely about the second end region of the elongate pivot pin.
14. The toggle type draw latch assembly of claim 13 wherein:a) a first radially extending hole is formed in the first end region of the elongate pivot pin at a location spaced from the first handle member; b) a second radially extending hole is formed in the second end region of the elongate pivot pin at a location spaced from the second handle member; c) a first elongate pin member has one portion that is pressed into the first radially extending hole, and another portion that projects radially outwardly from the first radially extending hole; d) a second elongate pin member has one portion that is pressed into the second radially extending hole, and another portion that projects radially outwardly from the second radially extending hole; e) the first torsion coil spring has:1) a first chosen end region that is connected to the first handle member; 2) a second chosen end region that is connected to the first elongate pin member portion that projects radially outwardly from the first radially extending hole; and, 3) said first set of coils is formed integrally with said first chosen end region and with the second chosen end region, and is reeved loosely about the first end region of the elongate pivot pin; and, f) the second torsion coil spring has:1) a first designated end region that is connected to the second handle member; 2) a second designated end region that is connected to the second elongate pin member portion that projects radially outwardly from the second radially extending hole; and, 3) said second set of coils is formed integrally with said first designated end region and with the second designated end region, and is reeved loosely about the second end region of the elongate pivot pin.
15. The toggle type draw latch assembly of claim 1 wherein pivot pin means is provided for pivotally connecting the drawbar and the handle so that the drawbar can move relative to the handle, the pivot pin means includes an elongate pivot pin that extends through a hole formed through the handle, and connection means is provided for establishing a ball-swivel connection between the pivot pin means and the handle at a location near said hole.
16. The toggle type draw latch assembly of claim 1 wherein:a) the handle is formed from two elongate handle members that extend side-by-side, that have portions located near said one end region that are spaced apart, and that have portions located near said opposite end region that engage for a continuous distance along a length of the handle that defines at least the hand grip; b) first pivot pin means extends through aligned first holes formed through the spaced apart portions of the handle members and through at least one hole that is defined by the base for pivotally connecting the handle to the base; c) a second pivot pin means extends through aligned second holes formed through the spaced apart portions of the handle members for pivotally connecting the drawbar to the handle; and, d) drawbar biasing means is provided for biasing the drawbar to pivot relative to the handle toward its retracted position including a torsion coil spring that extends about a portion of the second pivot pin means that is located between the spaced apart portions of the handle members.
17. The toggle type draw latch assembly of claim 16 wherein the torsion coil spring has one portion that is connected to the Second pivot pin means, and another portion that is connected to at least one of the handle members for biasing the pivot pin relative to the handle to bias the drawbar relative to the handle toward its retracted position.
18. The toggle type draw latch assembly of claim 17 additionally including projection means connected to the second pivot pin means and extending substantially radially therefrom at a location between the spaced apart portions of the handle members for establishing a connection between said one portion of the torsion coil spring and the second pivot pin means.
19. The toggle type draw latch assembly of claim 1 additionally including:a) safety catch means movably connected to the base for extending adjacent the handle when the handle is in its closed position, with the safety catch means being connected to the base at a location that positions the safety catch means beside a selected portion of the handle that is located between said one and opposite end regions when the handle is in its closed position; and, b) catch engagement formation means connected to the handle and being movable therewith as the handle pivots relative to the base between said open and closed positions, with the safety catch engagement formation means including a catch engagement formation that is configured for engaging and being releasably retained by the safety catch means when the handle is in its closed position.
20. The toggle type draw latch assembly of claim 19 wherein the safety catch means includes a catch member that is pivotally connected to the base for movement between latched and unlatched positions, includes biasing means for biasing the catch member toward its latched position, is operable to engage and releasably retain the catch engagement formation when the handle is in its closed position and the catch member is in its latched position, and is configured such that, as the handle moves toward its closed position, the catch member is engaged by the catch engagement formation and is caused by such engagement to be cammed away from its latched position in opposition to the biasing action of the biasing means to permit the catch engagement formation to move into engaged, releasably retained relationship with the catch member when the handle reaches its closed position.
21. The toggle type draw latch assembly of claim 20 wherein the safety catch means defines first shackle engagement formation means for receiving the shackle of a padlock when the catch member is in its latched position, with the received shackle physically blocking movement of the catch member from its latched position to its unlatched position.
22. The toggle type draw latch assembly of claim 21 wherein the handle includes second shackle engagement formation means for receiving said shackle of said padlock that is received by the first shackle engagement formation means for enabling the padlock to establish a locked connection between the handle and the base that prevents pivotal movement of the handle from its closed position when the padlock lockingly engages its shackle.
23. In a toggle type draw latch assembly that has a base, an elongate operating handle pivotally connected to the base near one end region thereof for moving between an open position and a closed position wherein a portion of the handle is situated relatively near to the base, having a hand grip formed near the opposite end region thereof, having a drawbar pivotally connected to the handle at a location that is nearer to the one end region of the handle than to the hand grip, with the drawbar being pivotally movable relative to the handle between an extended position and a retracted position for engaging a latch-engageable formation to establish a connection between the latch assembly and the latch-engageable formation, the improvement comprising:a) safety catch means movably connected to the base for extending adjacent the handle when the handle is in its closed position, with the safety catch means being connected to the base at a location that positions the safety catch means beside a selected portion of the handle that is located between said one and opposite end regions when the handle is in its closed position; b) catch engagement formation means connected to the handle and being movable therewith as the handle pivots relative to the base between said open and closed positions, with the safety catch engagement formation means including a catch engagement formation that is configured for engaging and being releasably retained by the safety catch means when the handle is in its closed position; c) wherein the safety catch means 1) includes a catch member that is pivotally connected to the base for movement between latched and unlatched positions, 2) includes biasing means for biasing the catch member toward its latched position, 3) is operable to engage and releasably retain the catch engagement formation when the handle is in its closed position and the catch member is in its latched position, and 4) is configured such that, as the handle moves toward its closed position, the catch member is engaged by the catch engagement formation and is caused by such engagement to be cammed away from its latched position in opposition to the biasing action of the biasing means to permit the catch engagement formation to move into engaged, releasably retained relationship with the catch member when the handle reaches its closed position; and, d) with the safety catch means also defining first shackle engagement formation means for receiving the shackle of a padlock when the catch member is in its latched position, with the received shackle physically blocking movement of the catch member from its latched position to its unlatched position.
24. The toggle type draw latch assembly of claim 23 wherein the handle includes second shackle engagement formation means for receiving said shackle of said padlock that is received by the first shackle engagement formation means for enabling the padlock to establish a locked connection between the handle and the base that prevents pivotal movement of the handle from its closed position when the padlock lockingly engages its shackle.
25. The toggle type draw latch assembly of claim 23 additionally including drawbar biasing means for biasing the drawbar to pivot relative to the handle toward its retracted position.
26. The toggle type draw latch assembly of claim 25 wherein:a) the handle is formed from two elongate handle members that extend side-by-side, that have portions located near said one end region that are spaced apart, and that have portions located near said opposite end region that engage for a continuous distance along a length of the handle that defines at least the hand grip; b) first pivot pin means extends through aligned first holes formed through the spaced apart portions of the handle members and through at least one hole that is defined by the base for pivotally connecting the handle to the base; c) a second pivot pin means extends through aligned second holes formed through the spaced apart portions of the handle members for pivotally connecting the drawbar to the handle; and, d) the drawbar biasing means for biasing the drawbar to pivot relative to the handle toward its retracted position includes at least one torsion coil spring that extends about at least one portion of the second pivot pin means.
27. The toggle type draw latch assembly of claim 26 wherein the torsion coil spring has one portion that is connected to the second pivot pin means, and another portion that is connected to at least one of the handle members for biasing the second pivot pin means relative to the handle to bias the drawbar relative to the handle toward its retracted position.
28. The toggle type draw latch assembly of claim 27 additionally including projection means connected to the second pivot pin means and extending substantially radially therefrom at a location between the spaced apart portions of the handle members for establishing a connection between said one portion of the torsion coil spring and the second pivot pin means.
29. The toggle type draw latch assembly of claim 23 additionally including:a) means for adjusting the effective length of the drawbar within a given range of adjustment, with such adjustment affecting the nearness of the drawbar to the hand grip when the handle is in its retracted position; b) first stop formation means connected to the handle for defining drawbar engaging surface means at a location near the hand grip for being engaged by the drawbar when the drawbar is in its retracted position; c) with the drawbar engaging surface means including a surface that extends for a sufficient distance along the length of the handle at said location near the hand grip for being engaged by the drawbar when the drawbar is in its retracted position regardless of where within said given range of adjustment the means for adjusting the effective length of the drawbar is set; and, d) with the drawbar engaging surface being configured to ensure that the retracted position of the drawbar is held at a sufficiently far distance away from the location of the hand grip to ensure that, regardless of where within said given range of adjustment the means for adjusting the effective length of the drawbar is set, the retracted drawbar will not so closely approach the hand grip as to endanger portions of a hand that is gripping the hand grip being contacted by the retracted drawbar.
30. The toggle type draw latch assembly of claim 29 wherein the hand grip extends about an imaginary centerline that generally parallels the length of the elongate handle so as to extend through said one and opposite end regions of the handle, and the drawbar engaging surface is configured to extend progressively farther from said centerline the closer that it approaches the hand grip.
31. The toggle type draw latch assembly of claim 30 wherein the drawbar engaging surface is planar in character in that it extends substantially within a common plane that is inclined relative to said centerline so as to more closely approach the centerline as it extends away from the hand grip.
32. The toggle type draw latch assembly of claim 29 wherein the handle also defines second stop formation means connected to the handle for defining base engaging surface means at a location that is near the location where the drawbar is pivotally connected to the handle for engaging the base when the handle is pivoted to said closed position to define the closed position of the handle.
33. The toggle type draw latch assembly of claim 32 wherein the base engaging surface means presents a convexly curved surface that engages the base when the handle is in its closed position.
34. The toggle type draw latch assembly of claim 23 wherein 1) the handle has at least one hole formed therethrough, 2) an elongate pivot pin has a central portion that extends through said at least one hole, 3) the elongate pivot pin means for mounting the drawbar is pivotally connected to the handle for movement relative to the handle about an imaginary pivot axis that extends centrally along the length-of the elongate pivot pin.
35. The toggle type draw latch assembly of claim 23 wherein pivot pin means is provided for pivotally connecting the drawbar and the handle so that the drawbar can move relative to the handle, the pivot pin means includes an elongate pivot pin that extends through a hole formed through the handle, and connection means is provided for establishing a ball-swivel connection between the pivot pin means and the handle at a location near said hole.
36. A handle operated toggle-type draw latch assembly for mounting on one of two members for engaging a latch-engageable formation connected to the other of the two members for exerting force on the two members that tends to draw the two members relatively toward each other and for releasably retaining the two members in joined relationship, comprising:a) base means including base structure for being connected to a mounting surface of said one of two members that are to be joined and releasably retained in joined relationship, for defining handle mounting means that extends away from the mounting surface, for defining safety catch mounting means that extends away from the mounting surface at a location spaced along the mounting surface from the location of the handle mounting means, with a first imaginary pivot axis being defined by the handle mounting means, and with a third imaginary pivot axis being defined by the safety catch mounting means; b) first pivot pin means connected to the handle mounting means at the first location and being configured to extend along the first pivot axis; c) handle means including an elongate handle having opposed first and second end regions, for defining pivot pin receiving means located near the first end region and extending about the first pivot axis to receive portions of the first pivot pin means to pivotally connect the handle means to the base means, for defining first and second stop formations located along the length of the handle between the first and second end regions, for defining a catch-engageable formation located along the length of the handle between the first and second stop formations, for being connected to the handle mounting means for pivotal movement relative to the base means about the first pivot axis in a "closing" direction of movement toward a closed position wherein the handle relatively closely overlies the mounting surface and wherein the first stop formation engages the base means to prevent further relative movement of the handle in said "closing" direction of movement, and in an "opening" direction of movement that extends oppositely about the first pivot axis toward an open position wherein the handle extends generally away from the mounting surface, and for defining a second pivot axis that extends transversely to the length of the handle in a direction that substantially parallels the first pivot axis but is spaced along the length of the handle from the first pivot axis; d) second pivot pin means connected to the handle and being configured to extend generally along the second pivot axis; e) drawbar means including an elongate drawbar for being connected to the second pivot pin means for pivotal movement relative to the handle for selectively being brought into engagement with the latch-engageable formation when the handle is pivoted to its open position, and for transmitting force to and establishing a joining connection with the latch-engageable formation when the handle is moved to its closed position while the drawbar means is engaging the latch-engageable formation, and for being pivoted to a retracted position wherein the drawbar engages the second stop formation of the handle; f) third pivot pin means connected to the safety catch mounting means at the second location along the base means and being configured to extend along the third pivot axis; and, g) safety catch means including a safety catch member for being pivotally connected by the third pivot pin means to the base means for pivotal movement relative to the base means about the third pivot axis between latched and unlatched positions, for defining a safety catch formation engagement means for receiving and releasably retaining the safety catch formation of the handle when the handle is pivoted to its closed position and when the safety catch is pivoted to its latched position, and including biasing means interposed between the base means and the safety catch member for biasing the safety catch member away from its unlatched position toward its latched position.
37. The latch assembly of claim 36 wherein the safety catch formation is configured to engage and cam the catch member out of its latched position toward its unlatched position as the handle is moved toward its closed position.
38. The latch assembly of claim 36 wherein the connection of the drawbar to the second pivot pin means is adjustable to control the length of the drawbar relative to the second pivot axis so as to influence where along the length of the handle that the drawbar engages the second stop formation when the drawbar is retracted, and the second stop formation defines an elongate surface that will be engaged by the drawbar regardless of where within its range of adjustment that the connection of the drawbar to the second pivot pin is set.
39. The latch assembly of claim 38 wherein:a) handgrip formation means is defined by the handle near the second end region for extending along an imaginary centerline of the handle that intercepts both of the first and second end regions for being configured to be gripped by one's hand in order to pivot the handle about the first pivot axis; and, b) the elongate surface of the second stop formation is inclined relative to said center axis for holding the retracted drawbar at an increasing distance from the handgrip as the effective length of the drawbar brings the portion of the drawbar that engages the second stop surface closer to the handgrip.
40. The latch assembly of claim 36 wherein the drawbar is rigid U-shaped member.
41. The latch assembly of claim 36 wherein the drawbar is a rigid V-shaped member.
42. The latch assembly of claim 36 wherein the drawbar is a U-shaped structure including rigid formation means for being connected to the second pivot pin means, and having non-rigid formation means connected to the rigid formation means for permitting at least one portion of the U-shaped structure to move relative to said rigid formation means.
43. The latch assembly of claim 42 wherein the non-rigid formation means is defined at least in part by at least one reach of flexible cable.
44. The latch assembly of claim 42 wherein said at least one portion of the U-shaped structure is defined by an elongate tubular member through which a length of flexible cable extends, and said at least one reach of flexible cable includes a first reach of flexible cable that extends from one end of the elongate tubular member and connects to the second pivot pin means, and a second reach of flexible cable that extends from the other end of the elongate tubular member and connects to the second pivot pin means.
45. The latch assembly of claim 44 wherein the length of tubular cable that extends through the tubular member is rigidly connected to the tubular member, and the first and second reaches of flexible cable are formed integrally with said length of flexible cable.
46. In a toggle type draw latch assembly that has a base, an elongate operating handle pivotally connected to the base near one end region thereof for moving between an open position and a closed position wherein a portion of the handle is situated relatively near to the base, having a hand grip formed near the opposite end region thereof, having a drawbar pivotally connected to the handle at a location that is nearer to the one end region of the handle than to the hand grip, with the drawbar being pivotally movable relative to the handle between an extended position and a retracted position wherein a portion of the drawbar is situated relatively near to the hand grip, the improvement comprising means establishing a ball-swivel connection between the drawbar and the handle to permit the drawbar to move a limited amount in substantially any direction relative to the handle about a point that is located along the length of the elongate operating handle.
47. The latch assembly of claim 46 wherein the drawbar is rigid U-shaped member.
48. The latch assembly of claim 46 wherein the drawbar is a rigid V-shaped member.
49. The latch assembly of claim 46 wherein the drawbar is a U-shaped structure including rigid formation means for being connected to the second pivot pin means, and having non-rigid formation means connected to the rigid formation means for permitting at least one portion of the U-shaped structure to move relative to said rigid formation means.
50. The latch assembly of claim 49 wherein the non-rigid formation means is defined at least in part by at least one reach of flexible cable.
51. The latch assembly of claim 49 wherein said at least one portion of the shaped structure is defined by an elongate tubular member through which a length of flexible cable extends, and said at least one reach of flexible cable includes a first reach of flexible cable that extends from one end of the elongate tubular member and connects to the second pivot pin means, and a second reach of flexible cable that extends from the other end of the elongate tubular member and connects to the second pivot pin means.
52. The latch assembly of claim 51 wherein the length of tubular cable that extends through the tubular member is rigidly connected to the tubular member, and the first and second reaches of flexible cable are formed integrally with said length of flexible cable.
| 1994-07-20 | en | 1995-08-29 |
US-58797384-A | Substituted phenoxybenzoic acids and derivatives thereof as herbicides
ABSTRACT
2-Nitro-5-(substituted-phenoxy) benzoic acids and esters, salts, amides, and acyl halides thereof comprise a class of compounds that are highly effective herbicides.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 490,357 filed May 2, 1983, now abandoned, which is a continuation of application Ser. No. 181,491 filed Sept. 4, 1980, now abandoned, which is a continuation of copending application Ser. No. 837,957 filed Sept. 29, 1977, now abandoned, which is a continuation of Ser. No. 702,367, filed July 2, 1976, now U.S. Pat. No. 4,606,758, which is a continuation-in-part of copending application Ser. No. 617,569, filed Sept. 29, 1975, now U.S. Pat. No. 3,979,437 which is a continuation of copending application Ser. No. 398,610, filed Sept. 19, 1973, now U.S. Pat. No. 3,941,830, which is a continuation of application Ser. No. 114,712, filed Feb. 11, 1971, now U.S. Pat. No. 3,784,635, which is a continuation-in-part of application Ser. No. 819,412, filed Apr. 25, 1969, now U.S. Pat. No. 3,652,645, said Ser. No. 702,367, (now U.S. Pat. No. 4,606,758) is a continuation-in-part of Ser. No. 545,232, Jan. 29, 1975, U.S. Pat. No. 4,002,662, which is a continuation-in-part of Ser. No. 398,610, Sept. 19, 1973, U.S. Pat. No. 3,941,830.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is concerned with certain phenoxy-benzoic acid compounds and their use as herbicides.
2. Description of the Prior Art
It has been proposed to use as herbicides 2-methoxy-benzoic acids (U.S. Pat. No. 3,013,054) and 4-phenoxybenzoic acids (France No. 1,502,538). It is the discovery of this invention, however, that benzoic acids having a phenoxy substituent in the 5-position are very effective herbicides.
SUMMARY OF THE INVENTION
This invention provides herbicidal compounds having the formula: ##STR1## wherein X is a member selected from the group consisting of hydrogen, halogen (e.g., iodine, fluorine, chlorine and bromine), nitro trifluoromethyl, cyano, COOH, ##STR2## (e.g. alkyl of 1 to 4 carbon atoms), hydroxy, alkoxy of 1 to 4 carbon atoms, alkyl of 1 to 4 carbon atoms, ##STR3## SH, SR1, SOR1, SO2 R1, SO2 NH2 and combination thereof, R1 and R2 are selected from the group consisting of alkyl of 1 to 4 carbon atoms, R is selected from the group consisting of hydroxy, alkoxy of 1 to 5 carbon atoms, aryloxy, chloro, amido, alkylamido of 1 to 4 carbon atoms, dialkylamido of 2 to 6 carbon atoms, SH, SR1, and OM in which M is an alkali metal (e.g., lithium sodium and potassium), alkylammonium of 1 to 4 carbon atoms or alkanolammonium of 1 to 4 carbon atoms, n is an integer of 1 to 5, and in which compound at least one X is other than hydrogen; their use as herbicides; and a herbicidal composition comprising at least one of said compounds and a carrier therefor.
DESCRIPTION OF SPECIFIC EMBODIMENTS
The compounds of this invention are readily prepared by the Ullmann ether synthesis reaction between the alkali metal, (e.g., Na, K) salt of a suitable substituted phenol and a 5-halo (e.g., F, Cl, Br)-2-nitrobenzoic acid or an ester, amide, or salt thereof. The 5-halo-2-nitro-benzoic acid or ester is readily prepared by nitrating a m-halotoluene, followed by oxidation of the methyl group by well-known procedures. Also, the m-halobenzoic acid or ester may be directly nitrated by well-known procedures.
Non-limiting examples of the compounds of this invention are:
propyl 2-nitro-5-(2',4',6'-tribromophenoxy)benzoate;
phenyl 2-nitro-5-(2',4',5'-trifluorophenoxy)benzoate;
2-nitro-5-(2',4',6'-triiodophenoxy)benzoic acid;
2-nitro-5-(2',4',6'-trichlorophenoxy)benzoyl chloride;
2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide;
N-ethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide;
N-isopropyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide;
N,N-dimethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide;
ethylammonium 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate;
ethanolammonium 2-nitro-5l-(2',4',6'-trichlorophenoxy)benzoate;
methyl 2-nitro-5-(2',3',4',5',6'-pentachlorophenoxy)benzoate;
n-pentyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate;
2-nitro-5-(2',4'-dichlorophenoxy)benzoic acid;
methyl 2-nitro-5-(2'-chlorophenoxy)benzoate;
methyl 2-nitro-5-(4'-chloro-3'-methylphenoxy)benzoate;
methyl 2-nitro-5-(3'-methylphenoxy)benzoate;
ethyl 2-nitro-5-(2',6'-dichlorophenoxy)benzoate;
isopropyl 2-nitro-5-(2',4'-dichloro-6'-methylphenoxy)benzoate;
ethyl 2-nitro-5-(2'-chloro-4'-fluorophenoxy)benzoate;
2-nitro-5-(2'-chloro-4'-fluorophenoxy)benzoic acid;
methyl 2-nitro-5-(2',4'-dinitrophenoxy)benzoate;
2-nitro-5-(2',4'-dinitrophenoxy)benzoic acid;
2-nitro-5-(2'-chloro-4'-nitrophenoxy)benzoic acid;
isopropyl 2-nitro-5-[3'-(α,α,α-trifluoromethyl)phenoxy]benzoate;
isopropyl 2-nitro-5-[3',5'-dicarbomethoxyphenoxy]benzoate;
methyl 2-nitro-5-(2'-methoxyphenoxy)benzoate;
methyl 2-nitro-5-(4'-chloro-2'-nitrophenoxy)benzoate;
2-nitro-5-(2',4'-dichloro-6'-fluorophenoxy)benzoic acid;
methyl 2-nitro-5-(2',4'-dichloro-6'-fluorophenoxy)benzoate;
methyl 2-nitro-5-(2',4'-dicarbomethoxyphenoxy)benzoate;
methyl 2-nitro-5-[2'-cyano-4'-(α,α,α-trifluoromethyl)phenoxy]benzoate;
methyl 2-nitro-5-(3'-carbomethoxy-4'-hydroxyphenoxy)benzoate;
methyl 2-nitro-5-[4'-chloro-2'-(α,α,α-trifluoromethyl)phenoxy]benzoate;
methyl 2-nitro-5-(3'-carbomethoxy-4'-nitrophenoxy)benzoate;
methyl 2-nitro-5-(4'-chloro-2',6'-dibromophenoxy)benzoate;
methyl 2-nitro-5-(2',4'-dicyanophenoxy)benzoate;
methyl 2-nitro-5-[2'-dimethylamino-4'-(α,α,α-trifluoromethyl)phenoxy]benzoate;
ethyl 2-nitro-5-[2'-amino-4'-(α,α,α-trifluoromethyl)phenoxy]benzoate;
methyl 2-nitro-5-[2'-methyl-4'-methylthiophenoxy]benzoate;
N,N-dimethyl 2-nitro-5[2',6'-dimethyl-4'-methylthiophenoxy]benzamide;
methyl 2-nitro-5-[2'-methyl-b 4'-methylsulfonylphenoxy]benzoate;
ethyl 2-nitro-5-[2'-chloro-4'-methylsulfinylphenoxy]benzoate;
methyl 2-nitro-5-[4'-(N-trifluoromethylsulfonamido)phenoxy]benzoate;
methyl 2-nitro-5-(4'-cyanophenoxy)benzoate;
ethyl 2-nitro-5-(4'-carboethoxyphenoxy)benzoate;
methyl 2-nitro-5-(4'-hydroxyphenoxy)benzoate;
2-nitro-5-[2'-t-butylphenoxy]benzoic acid;
2-nitro-5-[2'-carboxyphenoxy]benzoic acid;
methyl 2-nitro-5-(4'-aminophenoxy)benzoate;
methyl 2-nitro-5-(4'-diethylaminophenoxy)benzoate;
methyl 2-nitro-5-(2'-methylaminophenoxy)benzoate;
methyl 2-nitro-5-(4'-mercaptophenoxy)benzoate;
ethyl 2-nitro-5-(4'-methylthiophenoxy)benzoate;
methyl 2-nitro-5-(2'-sulfonamidophenoxy)benzoate;
ethyl 2-nitro-5-(4'-methylsulfinylphenoxy)benzoate;
methyl 2-nitro-5-(4'-methylsulfonylphenoy)benzoate; and
2-nitro-5-(2',4'-dichlorophenoxy)thiobenzoic acid.
The following example illustrates the preparation of a typical compound of this invention and demonstrates a method for product recovery.
EXAMPLE 1
Methyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate
A stirred solution of methyl 5-chloro-2-nitro-benzoate (17.0 g., 0.079 mole) and the potassium salt of 2,4,6-trichlorophenol (18.6 g, 0.079 mole) in dimethyl sulfoxide (100 ml.) was heated at 90° C. for 17 hours. The cooled:reaction mixture was diluted with water (500 ml.) and then extracted with ether (3×100 ml.). The combined ether fractions were washed with 10% sodium hydroxide solution (2×30 ml.) and then with a saturated aqueous sodium chloride solution. The ether solution was dried (Na2 SO4) and the solvent evaporated to give a dark oil. Two crystallizations (petroleum ether) gave 1.91 g. of a pale yellow solid, m.p. 101°-103° C.
Example 1
IR(nujol): c=o 1723, c-o 1240, and 1260 cm-1
NMR (CDCl3): methyl 3.91 ppm (3H), quartet 6.96 ppm (1H, J=2.5 and 8 c.p.s.), doublet 7.05 ppm (1H, J=2.5 c.p.s.), broad singlet 7.05 ppm (2H), and doublet 801 ppm. (1H, J=8 c.p.s.)
EXAMPLES 2 THROUGH 24
Using procedures similar to that described in Example 1, twenty-three other compounds within the scope of this invention were prepared. These compounds are
(2) 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoid acid, m.p. 184°-189° C.
(3) sodium 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate m.p.>300° C.
(4)methyl 2-nitro-5-(2',4',5'-trichlorophenoxy)benzoate m.p. 100°-103° C.
(5) methyl 2-nitro-5-(2',4'-dichlorophenoxy)benzoate, m.p. 84°-86° C.
(6) ethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate, m.p. 60°-64° C.
(7) methyl 2-nitro-5-(2',4'-dibromophenoxy)benzoate, m.p. 98°-100° C.
(8) methyl 2-nitro-5-(4'-chloro-2'-methylphenoxy)benzoate, m.p. 70°-72° C.
(9) methyl 2-nitro-5-(2',4'-dimethylphenoxy)benzoate, oil.
(10) 2-nitro-5-(2',4'-dichlorophenoxy)benzamide, m.p. 130°-133° C.
(11) isopropyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate, m.p. 71°-74° C.
(12) ethyl 2-nitro-5-(2',4'-dichlorophenoxy)benzoate, m.p. 83°-85° C.
(13) isopropyl 2-nitro-5-(2',4'-dichlorophenoxy)benzoate, m.p. 59°-62° C.
(14) methyl 2-nitro-5-(2',4',6'-trichlorophenoxy)thiobenzoate, m.p. 96°-100° C.
(15) methyl 2-nitro-5-(2',4'-dichloro-6'-methylphenoxy)benzoate, m.p. 85°-89° C.
(16) methyl 2-nitro-5-(2'-chloro-4'-fluorophenoxy)benzoate, m.p. 67°-70° C.
(17) isopropyl 2-nitro-5-(2'-chloro-4'-fluorophenoxy)benzoate, m.p. 48°-51° C.
(18) N-methyl 2-nitro-5-(2',4'-dichlorophenoxy)benzamide, m.p. 137° C.
(19) ethyl 2-nitro-5-(4'-nitrophenoxy)benzoate, m.p. 75°-82° C.
(20) methyl 2-nitro-5-(3'-methyl-4'-nitrophenoxy)benzoate, m.p. 75°-82° C.
(21) isopropyl 2-nitro-5-[2'-nitro-4'-(α,α,α-trifluoromethyl) phenoxy]benzoate, oil.
(22) ethyl 2-nitro-5-[2'-nitro-4'-(α,α,α-trifluoromethylphenoxy]benzoate, oil.
(23) methyl 2-nitro-5-[2'-chloro-4'-nitrophenoxy]benzoate, m.p. 97°-102° C.
(24) 2-nitro-5-(2'-chloro-4'-nitrophenoxy)benzoic acid, m.p. 185° C.
EXAMPLE 25
2-Nitro-5-[2'-nitro-4'-(α,α,α-trifluoromethyl) phenoxy]benzoic acid
A stirred solution of 4-chloro-3-nitrobenzotrifluoride (22.55 , 0.1 mole) and the potassium salt of 3-methyl-4-nitrophenol (19.12 g, 0.1 mole) in dimethyl acetamide (75 ml) was heated at 150° for 4 hours. The cooled reaction solution was diluted with water (300 ml) to precipitate a brown solid which was filtered and dried to give 28.9 g (85%) of 4-nitro-3-tolyl-2'-nitro-α,α,α-trifluoro-4'-tolyl ether, which had an m.p. of 82°-85° C. To a stirred solution of the above diphenyl ether product (25.0 g, 0.073 mole) and sodium dichromate (35.8 g, 0.12 mole) in glacial acetic acid (200 ml) was added concentrated sulfuric acid (60 ml, 1.15 moles) over about 30 minutes. The temperature was maintained below 70° C. during the addition and then raised to 110° C. for 15 hours. The reaction solution was cooled to 60° C. and extracted with hot chloroform. The extract was evaporated to dryness to give an oily solid, which was leached free of starting material with an ether-ligroin mixture. The resulting off-white solid acid weighed 13.6 g (51%), m.p. 185°-187°.
EXAMPLE 26
2-Nitro-5-[2'-nitro-4'-(α,α,α-trifluoromethyl) phenoxy]benzoic acid methyl ester
A stirred solution of the acid from Example 6 (3.5 g, 0.0094 mole) in a 25 wt. %/vol. solution of borontrifluoride in methanol (50 ml) was refluxed for 10 hours. The cooled solution was poured onto water (250 ml) and the resulting oil separated and dried to give 3.4 g (93.5%) of the desired product.
EXAMPLE 27
Methyl 2-nitro-5-(2',4'-dichlorophenoxy) thiobenzoate
Into a solution of 2-nitro-5-(2',4'-dichlorophenoxy) benzoyl chloride (4.16 g., 0.012 mole), prepared from the corresponding acid, in 40 ml. benzene was bubbled methanethiol gas for 0.5 hour at room temperature. The gas bubbling was stopped and the reaction mixture was refluxed for 15 minutes and then cooled. The mixture was diluted with diethyl ether, washed twice with 10% aqueous NaOH, once with NaCl solution, dried, and evaporated to dryness to give 4.3 g. of an oil. Infrared analysis showed a large amount of initial benzoyl chloride was unreacted. The oil was dissolved in 100 ml. benzene and 1.5 g. triethylamine was added. The reaction mixture was heated to 65°-70° C. and methanethiol was bubbled in. There was an immediate precipitate. After 1.5 hours, the reaction mixture was cooled, filtered, and evaporated to dryness to give 4.6 g. of the desired product.
EXAMPLE 28
Ethyl 2-nitro-5-(2',4'-dichlorophenoxy) thiobenzoate
A mixture of 2-nitro-5-(2',4'-dichlorophenoxy) benzoyl chloride (4.16 g., 0.012 mole) and ethanethiol (2.24 g., 0.036 mole) in 40 ml. benzene was heated at reflux for 2 hours and 50 minutes and then cooled. The mixture was diluted with diethyl ether, washed twice with 10% aqueous NaOH, once with NaCl solution, dried, and evaporated to dryness to give 4.2 g. of an oil. Infrared analysis showed a large amount of initial benzoyl chloride and some desired product. The oil was dissolved in 100 ml. benzene and 3.0 g. ethanethiol and about 1.5 g. triethylamine were added. A precipitate formed immediately. The reaction mixture was refluxed for 1.5 hours, cooled, filtered and evaporated to dryness to give 4.65 g. of the desired product.
COMPARATIVE EXAMPLE
A series of compounds were prepared which are position isomers of the compounds of Example 1 through 4. Each compound is designated by the number of the corresponding isomeric compound of Examples 1 through 4, followed by "a" or "b". These compounds are:
(1a) methyl 5-nitro-2-(2',4',6'-trichlorophenoxy) benzoate, m.p. 128°-133° C.
(2a) 5-nitro-2-(2',4',6'-trichlorophenoxy)benzoic acid, m.p. 175°-177° C.
(2b) 4-nitro-2-(2',4',5'-trichlorophenoxy)benzoic acid, m.p. 190°-193° C.
(3a) sodium 5-nitro-2-(2', 4', 6'-trichlorophenoxy)benzoate, m.p. >300° C.
(4a) methyl 5-nitro-2-(2', 4', 5'-trichlorophenoxy) benzoate, m.p. 104°-106° C.
(4b) methyl 4-nitro-2-(2', 4', 5'-trichlorophenoxy)benzoate, m.p. 127°-131° C.
As is apparent from the date in the Table set forth hereinafter, the compounds embodied herein in which the nitro group is in the 2-position and the substituted phenoxy group is in the 5-position exhibit markedly higher effectiveness as herebicides than do the comparable compounds in which the nitro group and the substituted phenoxy group are in different positions.
The compounds of this invention can be applied in various ways to achieve herbicidal action. They can be applied, per se, as solids or in vaporized form, but are preferably applied as the toxic components in pesticidal compositions of the compound and a carrier. The compositions can be applied as dusts, as liquid sprays, or as gas-propelled sprays and can contain, in addition to a carrier, additives such as emulsifying agents, binding agents, gases compressed to the liquid state, odorants, stabilizers, and the like. A wide variety of liquid and solid carriers can be used. Non-limiting examples of solid carriers include talc, bentonite, diatomaceous earth, pyrophyllite, fullers earth, gypsum, flours derived from cotton seeds and nut shells, and various natural and synthetic clays having a pH not exceeding about 9.5. Non-limiting examples of liquid carries, include water; organic solvents, such as alcohols, ketones, amides and esters; mineral oils, such as kerosene, light oils, and medium oils and vegetable oils, such as cottonseed oil.
In practice, herbicidal application is measured in terms of pounds of herbicide applied per acre. The compounds of this invention are effective herbicides when applied in herbicidal amounts, i.e., at rates between about 0.2 pounds and about 10 pounds per acre.
HERBICIDAL EFFECTIVENESS
Method of Propagating Test Species
______________________________________
Crabgrass Digitaria sanguinalis
Yellow Foxtail grass
Setaria glauca
Johnson grass Sorgum Halepense
Barnyard grass Echinochloe crus-galli
Amaranth pigweed
Amaranthus retroflexus
Turnip Brassica sp.
Cotton Gossypium hirsutum var.
DPL smooth leaf
Corn Zea Mays var. Golden Bantam
Bean Phaseolus vulgaris var.
Black Valentine
______________________________________
All crop and weed species are planted individually in 3" plastic pots containing potting soil. Four seeds of each of corn, cotton, and snapbeans are seeded to a depth equal to the diameter of the seed. All other species are surface seeded and sprinkled with screened soil in an amount sufficient to cover the seeds. Immediately after planting, all pots are watered by sub-irrigation in greenhouse trays. Pots for the pre-emergence phase are seeded one day before treatment.
Planting dates for the post-emergence phase are varied so that al the seedlings will reach the desired state of development simultaneously. The proper state of seedling development for treatment in the post-emergence phase is as follows:
GRASSES: 2 inches in height
PIGWEED & TURNIPS: 1 or 2 true leaves visible above cotyledons.
COTTON: first true leaf 1 inch in length; expanded cotyledons.
CORN: 3 inches-4 inches in height
BEANS: primary leaves expanded, growing point at primary leaf node.
Method of Treatment
Spray applications are made in a hood containing movable belt and fixed spray nozzle. For passage through the spray hood, one pot of each species (pre-emergence phase) is placed on the forward half of a wooden flat and one pot of established plants (post-emergence phase) is placed on the rear half of the flat. Treatments are moved to the greenhouse after spraying. Watering during the observatin period is applied only by sub-irrigation.
Compounds are screened initially at a rate of application equivalent to four or eight pounds per acre. Two weeks after treatment the pre- and post-emergence percent effectiveness is visually rated. Subsequent testing is carried out at 2,1 and 0.5 pounds per acre.
Herbicidal testing of the compounds of Examples 1 through 28 and of the comparative compounds provided the results set forth in the Table. The plants are tabulated using the following abbreviations:
______________________________________
Crabgrass CG Pigweed PW
Yellow Foxtail grass
YF Turnip TP
Johnson grass JG Cotton CT
Barnyard grass BG Corn CN
Bean BN
______________________________________
TABLE
__________________________________________________________________________
PRE/POST-EMERGENCE HERBICIDAL ACTIVITIY* OF CERTAIN SUBSTITUTED
PHENOXYBENZOIC ACIDS AND DERIVATIVES THEREOF
COMPOUND
COMPOUND
OF CONCENTRATION,
EXAMPLE LBS./ACRE CG YF JG BG PW TP CT CN BN
__________________________________________________________________________
1 4 100/100
100/100
60/50
60/70
100/100
80/100
0/100
0/40
30/100
2 100/100
80/100
30/70
20/80
100/100
0/100
90/100
30/20
70/100
1 100/90
80/100
20/60
0/60
100/100
30/90
0/100
0/20
80/100
0.5 40/50
60/80
30/60
0/40
100/70
0/80
40/20
0/20
30/70
1a 4 20/20
0/20
0/20
0/20
20/0 0/30
100/0
50/0
20/80
(Comparative)
2 4 70/70
--/--
70/90
60/70
--/--
100/100
0/100
0/70
80/70
2a 4 20/30
0/20
20/30
0/20
--/20
30/90
50/20
0/0 50/70
(Comparative)
2b 4 0/30
40/0 50/30
20/20
20/20
0/50
40/20
30/30
80/0
(Comparative)
3 4 50/80
--/--
30/60
40/60
--/--
95/100
50/100
0/40
50/100
3a 4 0/20
0/20
0/20
0/20
50/50
0/60
100/0
30/0
50/40
(Comparative)
4 4 90/60
--/--
80/90
50/50
--/--
40/70
80/70
0/50
80/80
4a 8 30/30
0/20
20/30
0/20
30/30
40/0 0/30
0/0 60/0
(Comparative)
4b 4 20/20
0/20
0/20
0/20
0/20
0/60
30/50
0/30
0/60
(Comparative)
5 4 100/95
--/--
90/90
90/90
--/--
80/100
50/80
0/40
50/100
6 4 100/80
--/--
80/50
50/70
100/100
40/90
30/100
0/100
100/100
7 8 80/60
--/--
50/40
60/50
100/100
20/100
30/90
0/50
100/100
8 8 50/60
--/--
20/30
0/20
100/100
0/40
0/30 100/100
9 8 30/30
--/--
0/40
20/20
90/90
20/50
0/70
0/40
100/90
10 4 80/70
--/--
40/40
40/30
100/100
20/70
100/40
0/20
100/100
11 4 60/70
--/--
30/60
20/50
90/100
0/50
30/70
0/30
80/60
12 8 90/90
--/--
90/90
60/90
100/100
0/100
0/100
0/70
0/100
4 100/90
--/--
90/100
60/60
100/100
0/100
30/90
0/70
30/100
2 100/100
100/--
40/60
80/70
--/100
30/100
80/70
0/70
100/100
1 100/100
--/--
40/90
50/80
--/--
30/100
20/80
0/20
50/80
13 8 70/90
--/--
30/90
20/80
90/100
0/30
30/70
0/20
100/100
14 4 70/80
--/--
20/90
0/40
100/100
70/100
90/90
20/20
0/80
15 8 100/100
100/--
50/70
50/--
--/100
70/90
0/90
0/30
50/100
4 90/90
0/--
40/60
0/60
--/--
60/90
100/60
0/40
0/100
2 90/70
--/--
30/40
20/70
--/--
70/60
0/60
0/50
0/100
16 8 100/90
100/100
80/100
100/90
100/100
100/100
40/100
80/40
80/100
4 100/100
100/100
100/100
80/80
100/100
70/100
40/90
20/80
80/100
2 100/100
100/100
90/100
80/90
100/100
80/100
30/90
0/80
0/90
0.8 90/60
100/80
70/50
40/50
100/100
40/100
80/60
30/20
50/100
17 8 100/40
90/40
70/40
50/30
100/100
0/60
0/80
0/30
0/90
4 100/90
100/100
80/90
50/70
100/100
0/40
0/50
0/30
0/90
2 100/90
100/90
30/90
30/90
100/100
20/30
0/50
0/30
0/90
1 60/50
100/80
90/60
20/30
100/100
0/40
90/30
30/0
80/80
18 8 90/80
--/--
60/80
70/40
--/--
90/100
30/80
0/80
0/100
19 10 40/30
--/--
90/--
--/--
--/--
0/90
--/60
--/--
--/60
20 10 50/20
--/--
90/--
--/--
--/--
20/20
--/30
--/--
--/40
21 3 100/--
100/--
100/--
30/--
--/--
50/--
30/--
0/--
0/--
22 1 90/--
100/--
100/--
30/--
--/--
30/--
50/--
60/--
0/--
23 10 80/--
100/--
100/--
30/--
--/--
80/--
-- /--
--/--
--/--
24 10 100/--
--/--
30/--
--/--
--/--
100/--
--/--
--/--
--/--
25 8 80/60
90/100
50/40
30/60
100/100
100/100
30/50
0/30
30/90
26 8 100/80
100/90
40/20
90/60
100/100
90/90
0/50
0/20
70/90
4 100/90
100/100
70/90
80/50
100/100
100/100
0/50
0/20
0/90
2 90/70
100/100
60/60
40/70
100/100
90/90
0/50
0/30
0/90
27 8 20/30
80/--
--/--
--/--
--/--
100/100
--/100
--/--
--/100
28 8 0/30
--/--
--/--
--/--
--/--
100/100
--/100
--/--
--/100
__________________________________________________________________________
*Herbicidal activity is measured in percent effectiveness
Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims.
What is claimed is:
1. An herbicidal composition comprising as an effective herbicide, a herbicidally effective quantity of 2-nitro-5-(substituted-phenoxy) benzoic acid, salts thereof selected from the group consisting of lithium salts, sodium salts, potassium salts, alkylammonium salts of 1 to 4 carbon atoms and alkanolammonium salts of 1 to 4 carbon atoms, alkyl esters thereof of 1 to 5 carbon atoms and the phenyl ester thereof, wherein said phenoxy is substituted only by a combination of two members selected from the group consisting of halogen, trifluoromethyl, COOH, ##STR4## alkyl of 1 to 4 carbon atoms), hydroxy, alkoxy of 1 to 4 carbon atoms, ##STR5## SH, SR1, SOR1, SO2 R1, SO2 NH2 wherein R1 and R2 are selected from the group consisting of alkyl of 1 to 4 carbon atoms, and an agronomically acceptable carrier selected from the group consisting of solid carriers, water and organic solvents.
2. A composition according to claim 1 wherein said carrier is a solid carrier selected from the group consisting of talc, bentonite, diatomaceous earth, pyropyllite, fullers earth, gypsum, cotton seed flour, nut shell flour, natural clays and synthetic clays, said clays having a pH not exceeding about 9.5.
3. A composition according to claim 1 wherein said carrier is water.
4. A composition according to claim 1 wherein said carrier is an organic solvent.
5. A composition according to claim 1 wherein one member of said combination is halogen.
6. A composition according to claim 5 wherein one member of said combination is trifluoromethyl.
7. A composition according to claim 1 wherein one member of said combination is trifluoromethyl.
8. A method for controlling plant growth which comprises applying a composition consisting essentially of: an herbicidal amount of a compound having the formula: ##STR6## wherein (X)n is a combination of the members selected from the group consisting of halogen, trifluoromethyl, COOH, ##STR7## (alkyl having 1 to 4 carbon atoms), hydroxy, alkoxy having 1 to 4 carbon atoms, ##STR8## SH, SR1, SOR1, SO2 R1, SO2 NH2 ; R1 and R2 are selected from the group consisting of alkyl having 1 to 4 carbon atoms, R is selected from the group consisting of hydroxy, alkoxy having 1 to 5 carbon atoms, and OM wherein M is an alkali metal of lithium, sodium or potassium, alkylammonium having 1 to 4 carbon atoms or alkanolammonium having 1 to 4 carbon atoms and n is the integer 2; and an agronomically acceptable carrier selected from the group consisting of solid carriers, water and organic carriers.
9. A method according to claim 8 wherein an X is trifluoromethyl.
10. A method according to claim 8 which comprises applying said composition to the surface of a growth medium, prior to the emergence of the plants from the growth medium.
11. A method according to claim 8 which comprises applying said composition to plant seedlings after their emergence.
12. A method according to claim 8 which comprises spraying plants with an herbicidally effective amount of said composition.
13. A method according to claim 8 wherein an X is halogen.
14. A method according to claim 13 wherein an X is trifluoromethyl.
15. A method according to claim 8 which comprises applying to plants said compound at a rate of about 0.2 to about 10 pounds per acre.
| 1984-03-09 | en | 1987-07-21 |
US-83373777-A | Hand-powered tool
ABSTRACT
A hand-powered tool in which a spindle for driving a tool attachment is driven by a bevel gear. The spindle is supported in bearings on both sides of the bevel gear and extends through an opening in a stationary transverse shaft on which the bevel gear is journaled. Two pinions fixed to the spindle on opposite sides of the transverse shaft are moved into and out of meshing engagement with the bevel gear by shifting the spindle longitudinally in order to reverse the direction of rotation of the spindle.
BACKGROUND OF THE INVENTION
This invention relates to rotary hand tools, and it relates more particularly to lever-operated hand-powered tools for driving or removing screws, nuts or bolts and the like.
Numerous hand-powered tools have been devised heretofore, such as the spiral ratchet tools currently available. In this type of tool, it is necessary to apply the driving force for rotating the spindle in a direction lengthwise of its axis. Such an arrangement requires more space to operate than is available in many situations where the tool might be used, and is sometimes awkward to handle, especially where the tool is used for removing screws when the driving force along the length of the spindle tends to press the screw into place instead of removing it. Such tools also require two hands to operate, and the forces exerted are not efficiently applied.
A pistol-grip type of hand-powered tool, on the other hand, is more adaptable to the human hand because only the squeeze of the fingers is utilized to rotate the spindle, while the desired amount of pressure for forcing the screw or other fastener into place is applied with the palm of the hand on the grip of the tool independently of the force required to rotate the spindle. U.S. Pat. No. 3,035,451 to O'Connell et al discloses a pistol-grip type of hand-powered rotary tool in which the direction of rotation of the spindle is reversed by shifting the pinion on the spindle laterally into engagement with one or the other of a pair of beveled gears located on opposite sides of the pinion. A similar type of bevel-gear drive is disclosed in U.S. Pat. No. 3,132,549 to Lee, but in this case the two bevel gears are alternatively shifted into engagement with the pinion on the spindle for reversing its direction of rotation. The difficulty with both these bevelgear mechanisms is that in order to reverse the spindle, it is necessary either to shift the pinion gear and spindle laterally into engagement with one of a pair of bevel gears, or to shift the bevel gears into engagement with the pinion gear. In both cases, the spindle can be mounted only at one end of the housing for the tool. Furthermore, in the case where the spindle must be moved laterally, the mounting therefor is complicated and is characteristically unreliable.
It is an object of the present invention to provide a simple hand-grip tool with a bevel-gear drive and spindle-reversing mechanism, in which both the spindle and bevel-drive gear are sturdily mounted in the housing of the tool for smooth reliable operation.
SUMMARY OF THE INVENTION
The invention resides basically in the concept of extending the spindle for a gear-driven rotary hand tool through an opening provided in a non-rotatable shaft on which the drive gear is journaled. In this way, the spindle can be mounted in bearings at both ends of the housing for the tool in order to provide as much support as possible. At the same time the shaft for the drive gear can also be solidly supported at both ends in opposite side walls of the housing. A pair of pinion gears are provided on the spindle for rotation therewith and for alternate meshing engagement of one or the other with the drive gear at opposite points on the periphery thereof, depending on the direction in which it is desired to rotate the spindle. Suitable means are provided for rotating the drive gear in one direction only, such means comprising, for example, a pawl and ratchet arrangement which is actuated by a finger-lever.
The tool is also provided with means for shifting the pinion gears into and out of mesh with the drive gear and for locking them in position for the desired direction of rotation of the spindle. Where the spindle is movable lengthwise, such means may consist for example of a yoke or shoe that straddles one of the pinion gears and is connected to a thumb-lever on the outside of the housing so that the spindle can be moved lengthwise in one direction or the other until one or the other pinion gear engages the drive gear.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION
Other objects and advantages of the invention will be more apparent from the description of one embodiment shown in the accompanying drawings, wherein
FIG. 1 is a side elevational view of a rotary handpowered tool in accordance with the invention, with the housing therefor partially broken away in order to expose the drive gears;
FIG. 2 is a cross-sectional view thereof taken on the line 2--2 of FIG. 1;
FIG. 3 is another cross-sectional view taken on the line 3--3 of FIG. 1, with the finger-lever in its closed or retracted position; and
FIG. 4 is a detail view of the driving ratchet for the bevel gear.
The tool of the present invention is provided with a two-piece housing 10 having a depending handle or grip 12 formed integrally therewith. A spindle 14 is rotatably supported within housing 10 in a pair of bearings 16 located at opposite ends of the housing. One end of spindle 14 extends out of the housing and is provided with a chuck (not shown) by which a screw driver, socket wrench or other tool attachment is fixed to it. A beleved drive gear 18 is journaled on a fixed transverse shaft 20 supported at both ends in opposite side walls of housing 10. As best seen in FIGS. 2 and 3, shaft 20 and spindle 14 intersect, shaft 20 being provided with an opening 22 through which spindle 14 extends. Fixed to spindle 14 for rotation therewith, is a pair of beveled pinion gears 24, 26 disposed on opposite sides of shaft 20. Spindle 14 is not only rotatable, but is also movable longitudinally in bearings 16 so that either pinion gear 24 or 26 can be shifted into meshing engagement with bevel gear 18, while the other is being simultaneously disengaged therefrom. Since pinion gears 24 and 26 engage bevel gear 18 at diametrically opposite points on its periphery, rotation of bevel gear 18 in one direction (e.g. counterclockwise as viewed in FIG. 1) will rotate spindle 14 in one direction when pinion 24 meshes with gear 18, and in the opposite direction when pinion 26 meshes with gear 18.
Bevel gear 18 is driven by a finger-lever 28, which is pivotally mounted on shaft 20, and is provided with a springloaded pawl 30 (FIGS. 3 and 4), which engages a ratchet wheel 32 integral with gear 18. Finger-lever 28 is bifurcated at its inner end to form a pair of arms 34, 36 which are freely pivoted on shaft 20 adjacent opposite ends thereof so that they span both the bevel gear 18 and spindle 14. Pawl 30 is urged by a spring 38 into constant engagement with the teeth of wheel 32, so that when finger-lever 28 is drawn toward handle 12 from the full-line to the phantom-line positions shown in FIG. 1, bevel gear 18 is driven in a counterclockwise direction (or clockwise as shown in FIG. 4); but when it is moved back to its initial, full-line position, pawl 30 simply slides across the teeth of wheel 32 without rotating gear 18. A torsion spring 40 is provided for returning finger-lever 28 to its open or full-line position, the central mounting coils of spring 40 encircling the transverse shaft 20, while one end of the spring engages a fixed pin in the side wall of housing 10 and the other end constantly presses against the arm 34 of finger-lever 28.
It will be apparent from the foregoing that by holding the tool in one hand with the handle 12 against the palm of the hand and the fingers engaging the finger-lever 28, the spindle can be rapidly rotated, using either long or short strokes of the finger-lever. Due to the length of finger-lever 28 and the size of bevel gear 18 as compared to that of the pinion gears 24 and 26, a substantial torque can be applied by spindle 14 for tightening or loosening screws and the like.
In order to reverse its direction of rotation, spindle 14 is moved forward longitudinally from the position shown in FIGS. 1 and 2, thereby disengaging pinion 24 from bevel gear 18 and simultaneously moving pinion 26 into driving engagement therewith at a point diametrically opposite the point of engagement of pinion 24. This is accomplished in this instance by means of a thumb-lever 42 on the outside of housing 10. Thumb-lever 42 has a shaft 44, which extends through an elongated slot 46 in housing 10 and has a U-shaped shoe 48 at its inner end. The two legs of shoe 48 span the pinion 26 and are each provided with an opening through which spindle 14 extends. The legs of shoe 48 fit close to, and in bearing engagement with, the opposite ends of the sleeve portion of pinion 26, so that when thumb-lever 42 is moved along slot 46, which is parallel with spindle 14, the spindle assembly (including pinions 24 and 26) is moved lontigudinally in order to operatively engage one or the other of pinions with bevel gear 18.
Spindle 14 is locked in each of its operating positions by the thumb-lever 42, which is connected to shaft 44 by a pin 50, permitting limited pivotal movement of thumb-lever 42 with respect to the housing 10. An inwardly projecting locking pin 52 is rigidly fixed in one end of thumb-lever 42 for engagement within one of two recesses 54, 54 in the side of housing 10. A leaf-spring 56 is fixed to an outwardly inclinded inner wall 58 at the other end of thumb-lever 42 from pin 52 for urging thumb-lever 42 clockwise (as viewed in FIG. 2) about pivot pin 50. Locking pin 52 is therefore urged by spring 56 into engagement within one or the other of recesses 54. By pressing thumb-lever 42 inwardly against the pressure of spring 56, the opposite end of lever 42 is moved outward withdrawing locking pin 52 from one of the recesses so that lever 42 and spindle 14 can be shifted to the other operating position of the spindle, at which point the locking pin 52 is re-engaged with the other recess 54 by spring 56.
It will be noted that during the power stroke of the finger-lever 28 of the tool shown in the drawing, the spindle 14 is rotated, in a clockwise direction as viewed from the rear when the pinion gear 24 meshes with the drive gear 18 in order to tighten a screw or bolt having a right-hand thread. In this position the pinion gear 26 is located out of engagement with drive gear 18, and the rear leg of the shoe 48 rests against the end of the rear bearing 16. The end of this bearing thus forms an abutment surface on the housing for receiving the force exerted longitudinally of the spindle as the tool is pressed against the fastener that is being tightened. Accordingly, the longitudinal thrust on the spindle is taken directly by the housing, rather than indirectly through the thumb-lever 42, thereby providing a much sturdier and more reliable construction.
On the other hand, when the direction of rotation of spindle 14 is reversed for loosening such a fastener by moving the spindle forward until pinion gear 26 meshes with drive gear 18, for force exerted longitudinally of spindle 14 as the tool is pressed against the fastener is considerably less than that required when the tool is being used for tightening. Consequently, in the position for reverse rotation, the locking pin 52 on thumb-lever 42 is adequate for purposes of holding spindle 14 in place without fear of shifting the pinion gear 26 out of meshing engagement with the drive gear 18.
From the foregoing it will be apparent that the hand-powered tool of the present invention is provided with a mechanically simple driving mechanism, which is capable of producing a substantial torque. Smooth, reliable operation is assured by supporting the shaft for the drive gear, as well as the spindle, on both sides of the drive gear and at the same time making the spindle reversible simply by shifting it longitudinally.
What is claimed is:
1. A hand-powered rotary tool having a housing,a spindle rotatably mounted within said housing at opposite ends thereof, one end of said spindle extending through said housing for rotating a tool attachment at said one end, a non-rotating shaft mounted at both ends in opposite sides of said housing transversely of said spindle and having an opening through which said spindle extends, a drive gear rotatably mounted on said shaft, means for rotating said drive gear in one direction only, a pair of pinion gears secured to said spindle for rotation therewith, said pinion gears being disposed on opposite sides of said shaft and movable in unison along the longitudinal axis of said spindle into alternative operating positions in which one of said pinion gears meshes with said drive gear such that when said pinion gears are moved in one direction along said axis, one of said pinion gears is shifted into meshing engagement with said drive gear at one point along its periphery for rotating said spindle in one direction while the other of said gears is disengaged from said drive gear, and when said pinion gears are moved in the other direction axially of said spindle, said one pinion gear is disengaged from said drive gear while said other pinion gear is shifted into meshing engagement with said drive gear at a point diametrically opposite said one point in order to rotate said spindle in the opposite direction, and means for shifting said pinion gears along said axis into and out of mesh with said drive gear and for locking them in each of said operating positions.
2. A hand-powered tool as defined in claim 1, wherein said drive and pinion gears are beveled and which further includes a handle rigidly mounted on said housing, said means for rotating said drive gear comprising a finger-lever pivoted on said transverse shaft for movement to and from said handle and a ratchet device interposed between said finger-lever and said drive gear.
3. A hand-powered tool as defined in claim 2, wherein said spindle is mounted for limited longitudinal movement as well as for rotation and said pinion gears are rigidly mounted on said spindle in spaced relation to each other for movement in unison therewith into and out of mesh with said drive gear.
4. A hand-powered tool as defined in claim 3, wherein said drive gear, said means for rotating the same and said one pinion gear are arranged such that said spindle is rotated in a direction for tightening a threaded fastener, said one pinion gear being disposed such that it meshes with said drive gear when said spindle is shifted rearwardly of said housing, said housing having provision for positively limiting such rearward longitudinal movement of said spindle when said one pinion gear is in meshing engagement with said drive gear, whereby the force exerted longitudinally of said spindle when said tool is pressed against said fastener while tightening it is transmitted directly to said housing.
5. A hand-powered tool as defined in claim 3, wherein said means for shifting and locking said spindle comprises a thumb-lever disposed outside said housing and having a shoe connected to said spindle for moving it longitudinally.
6. A hand-powered tool as defined in claim 5, wherein said thumb-lever is movably connected to said shoe and has a locking member disposed for locking engagement within one of two spaced recesses in said housing corresponding to each operating position of said spindle, and means for urging said thumb-lever in a direction for engaging said locking member in one of said recesses.
7. A hand-powered tool as defined in claim 5, wherein said shoe is a U-shaped member having its legs disposed on opposite sides of one of said pinion gears for bearing engagement with the ends thereof.
| 1977-09-16 | en | 1979-05-15 |
US-67408191-A | Safety valve for discharge chutes on cement mixer
ABSTRACT
A safety valve which prevents the discharge chute from rapidly falling due to a sudden loss of hydraulic fluid pressure. The valve is located between the chute lift cylinder port and hydraulic system hose. The valve is actuated when the flow leaving the chute lift cylinder exceeds a predetermined flow. The valve immediately stops the hydraulic fluid from leaving the chute lift cylinder maintaining the position of the discharge chute.
BACKGROUND OF THE INVENTION
This invention relates generally to a safety valve for use in a hydraulic line system which prevents flow of a working hydraulic fluid above a specific flow rate and more particularly to a safety valve which screws directly into the chute lift cylinder port and the chute lift hydraulic hose of a ready-mix concrete truck. The delivery chute on the rear of ready-mix concrete trucks is conventionally hydraulically raised and lowered. In normal operating use, the chute is often full of concrete and held in position by a hydraulic cylinder.
The hydraulic hose connected to the hydraulic cylinder is subject to wear, damage and deterioration by the nature of its application. Frequent inspections for cuts, abrasions, wear, acid wash damage, etc. are necessary to prevent hose failure during operation. Failure may occur if the hose is not regularly inspected or from damage to the hose occurring on the job. Workers tugging and pulling on a heavy, full concrete chute can cause pressure spikes in the chute life hydraulic hose. Previously damaged hose may potentially break from the pressure spikes. A broken hose results in a sudden pressure loss and the fluid flow is no longer controlled. The sudden loss of pressure causes hydraulic fluid to rapidly flow from the hydraulic cylinder, resulting in the chute crashing downward and potentially seriously injuring workers.
What is needed is a way to prevent the chute from crashing downward due to a sudden loss of hydraulic fluid pressure.
SUMMARY OF THE INVENTION
The invention is a safety valve which prevents the chute from rapidly falling due to a sudden loss of hydraulic fluid pressure. The safety valve screws directly onto the chute lift cylinder port. The chute lift hydraulic cylinder hose fitting then screws directly into the safety valve. Normal hydraulic fluid flow coming out of the chute lift cylinder is less than three gallons per minute. The gallons per minute flow increases dramatically should the hydraulic hose break. The safety valve is actuated any time the flow leaving the chute lift cylinder exceeds a predetermined value, e.g., approximately four gallons per minute. The safety valve immediately blocks further hydraulic fluid from leaving the chute lift cylinder and, thus, the chute cannot fall.
The principle object of this invention is to provide a safety valve to prevent the rapid falling of a hydraulically held concrete chute due to sudden loss of hydraulic pressure because of a hydraulic line failure.
Another object is to provide a safety valve that directly mounts to the chute lift cylinder on one end and the hydraulic hose on the opposite end.
These and other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial side view of a ready mix concrete truck with an extended concrete chute incorporating the present invention.
FIG. 2 is an enlarged view showing the invention in location between cylinder and hydraulic lines.
FIG. 3 is a cross sectional view taken along line 3--3 in FIG. 2 of the safety valve in the open position.
FIG. 4 is a cross sectional view taken along line 3--3 in FIG. 2 of the safety valve in the closed position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a work-type vehicle, namely a ready-mix concrete truck, is indicated generally by 10. It includes a rotatable mixer drum 12. Cement or concrete is emptied through discharge spout 13 into a discharge chute 15. This discharge chute 15 is used to cause the concrete to flow into a bucket, wheel barrel, or to a space defined by erected concrete forms. Discharge chute 15 is positioned by means of the chute lift hydraulic cylinder 20. Workers also pull and tug on the chute for lateral positioning thereof.
The present invention relates to a safety valve device 25 located between discharge chute cylinder 20 and hydraulic hose 28, as shown in FIG. 2. The safety valve 25 screws into the cylinder port (not shown) and the hydraulic hose 28 screws onto the opposite end. Controlled flow of the hydraulic fluid is from the hydraulic hose 28 into the cylinder 20.
As shown in FIGS. 3 and 4, the safety valve has a generally cylindrical body with two members: second body member 32 and first body member 30. Second body member 32 is attached to the hydraulic system port by threads, preferably J.I.C.-6, 37° flare, 9/16-18 thread. These threads are shown at 36 on the system port end of the plug member. First body member 30 has a longitudinal bore 70 and a counterbore 40 which receives second body member 32 therein. Counterbore 40 also contains a moveable spool 50, compression spring 45 and a poppet 60 which will be described in further detail below. Threads, preferably 1/4 NPTF type thread, are shown at 38 on the cylinder port end of the first body member 30 for attaching the safety valve to the hydraulic cylinder port.
The valve seat, poppet 60, in located in counter bore 40 and has a radial flange 61 and base containing opening 62. The flange 61 abuts second body member 32. The poppet 60 has a main cylindrical body 63 containing bore 64. The main body 63 tapers to section 65 containing two opposed ports 66 and 68. The two ports provide for fluid communication between bore 64 and the spool interior 55. Poppet 60 then tapers into conical end 69.
Spool 50 is located within first body member counterbore 40. The spool spring 45 is also located within counterbore 40. Spring 45 surrounds poppet 60 and extends into spool interior 55. FIG. 3 shows spring 45 during controlled flow. FIG. 4 shows spring 45 during restricted flow. Spring 45 provides the biasing means to urge spool 50 towards the poppet, blocking the fluid passageway as aperture 52 engages conical end 69 of poppet 60. Aperture 52 of spool 50 is of a diameter greatly smaller than the diameter of longitudinal bore 70. This aperture may, for example, be 0.125 inch. Spool interior 55 enlarges the fluid passageway allowing fluid communication with poppet ports 66 and 68.
The arrows in FIG. 3 show the flow of fluid from the cylinder through the valve. Hydraulic fluid flows from the cylinder port fluid inlet port into longitudinal bore 70, passes through spool aperture 52 into spool interior 55 around conical end 69 of poppet 60, and enters ports 66 and 68 as indicated. Fluid flows through bore 64 and then through the base opening 62 into longitudinal bore 75. The fluid then enters hydraulic hose 28.
Fluid will readily pass in either direction when the flow rate within the valve is less than a predetermined rate, e.g., approximately four gallons per minute. Flow rate less than the predetermined rate is the controlled flow rate of the hydraulic system. Spring 45 has sufficient stiffness such that fluid pressure on spool surface 53 as fluid enters spool aperture 52 is insufficient to cause spool 50 to move against the force of spring 45. When the flow rate from cylinder port exceeds approximately four gallons per minute, fluid pressure on spool surface 53 will increase as the fluid rushes to enter spool aperture 52. The increased fluid pressure on spool surface 53 causes spool 50 to move against the force of spring 45 toward poppet 60. Spool aperture 52 engages the conical end 65 of poppet 60 restricting fluid flow as shown in FIG. 4.
In the event the hydraulic hose breaks, the fluid pressure decreases rapidly on the system port end. Hydraulic fluid leaves the cylinder port at an increased flow rate to compensate for the sudden pressure decrease. Accordingly, fluid pressure increases against spool surface 53 as the hydraulic fluid enters the spool aperture 52 at an increased flow rate. When flow rate exceeds the predetermined flow rate, spool 50 moves against the force of spring 45 toward poppet 60. The flow is restricted as conical end 69 of poppet 60 engages aperture 52. Hydraulic fluid can no longer flow through the safety valve. Consequently, the hydraulic fluid remains in the hydraulic cylinder maintaining the concrete discharge chute's position.
It is understood that the above disclosure of the presently preferred embodiment is to be taken as illustrative of the invention. Furthermore, it is to be understood that those skilled in the art be capable of making modifications without departing from the true spirit and the scope of the invention.
What is claimed is:
1. In combination with a redi-mix concrete truck of the type including a discharge chute positionable by a hydraulic cylinder coupled and in circuit with an hydraulic pump by a hose, a safety device for preventing said chute from dropping upon a failure of said hose comprising a flow responsive valve means coupled between said hydraulic cylinder and said hose, said flow responsive valve means having:(a) a first body member attachable to said hydraulic cylinder and including a longitudinal bore for defining a fluid inlet port and a counterbore defining a cylindrical chamber; (b) a second body member attachable to said hose and sealingly fitted into said counterbore of said first body member; (c) a generally tubular spool disposed in said cylindrical chamber for longitudinal movement, said spool being generally closed at one end except for a fluid passageway of a predetermined small diameter relative to that of said fluid inlet port; (d) a valve seat member disposed in said cylindrical chamber of said first body member and aligned with said fluid passage; and (e) spring means for normally maintaining said one end of said spool out of contact with said valve seat member but permitting movement of said spool against said valve seat member upon a predetermined loss of pressure in said hose; and said valve means being normally opened to permit flow of hydraulic fluid therethrough in the event the flow rate exceeds a predetermined value.
2. The combination as in claim 1 wherein the flow responsive valve closes to block hydraulic fluid from flowing therethrough when the flow rate exceeds the predetermined value of approximately four gallons per minute.
3. The combination as in claim 1 wherein the fluid passage of said spool is 0.125 inch.
4. The combination as in claim 1 wherein flow responsive valve means is coupled to said hydraulic cylinder by 1/4 NPTF type threads and the flow responsive valve means is coupled to hose by J.I.C.-6, 37° flare, 9/16-18 type threads.
| 1991-03-25 | en | 1992-04-28 |
US-3653731D-A | Roller bearing
ABSTRACT
A roller bearing having a cantilevered outer race design to relieve Hertzian stress. The outer annulus of the outer race may also be slotted to control resilience.
United States Patent [151 3,653,731
Rau [451 Apr. 4, 1972 [541 ROLLER BEARING FOREIGN PATENTS OR APPLICATIONS 72] Inventor; John C 213 0 Daisy Lane 408,283 1/1910 France ..308/184 Southfield, Mich. 48075 Primary Examiner-Edgar W. Geoghegan [22] Filed: Aug. 14, 1970 Assistant Examiner-F rank Susko pp No: 63,742 Y Attorney-Barnard, McGlynn & Relsmg [57] ABSTRACT [52] U.S. Cl ..308/184, 308/214 A roller bearing having a cantilevered outer race design to 19/04, F16: 33/64 lieve Hertzian stress. The outer annulus of the outer race may [5 8] Field of Search ..308/184, 212, 1, 214 also be slotted to 1 i1i 56] References Cited 16 Claims, 4 Drawing figures UNITED STATES PATENTS 3,404,925 10/1968 Bailey ..308/184 PATEHTEDAPR 4 I972 INVENTOR. M56 C Gm AT TORN am/zwgm This invention relates to bearings and more particularly to the construction of an outer race for an anti-friction roller bearing for the purpose of effecting load transfer and improved bearing life.
A major cause of roller bearing failure is the inadequate transfer of Hertzian stress loads to the outer race. This inadequate transfer often results in a substantiallynonuniform stress distribution over the roller, leading to gouging of the races and eventually to the failure of the bearing. This situation is aggravated by slight dimensional nonuniforrnities in the rollers or races.
In accordance with the invention, Hertzian stress transfer and improved bearing operation is accomplished by way of a bearing having an outer race structure with a radially resiliently supported portion in contact with the rollers. This permits adjustment between the inner and outer races to accommodate contact and stress load irregularities.
In a preferred embodiment of the invention the bearing comprises an inner race, a plurality of rollers, a cage or separator and an outer race which is so constructed as to provide an outer annulus securable to a load and an inner annulus integral with the outer annulus and resiliently pivotally supported thereby for engagement with the rollers. The inner annulus is effectively cantilevered relative to the outer annulus by means of an integral joint to permit essentially radial flexure of the outer annulus as required to effect a transfer of roller loads to the outer race.
In a specific embodiment illustrated herein the flexure between the inner and outer annuli of the outer race is limited by means of a portion of one annulus which extends radially into spaced relation with the other annulus. This may permit the construction of the bearing from lighter stock and also prevent the fiexure of the outer race beyond the elastic limit under abnormally high load conditions.
According to a further feature of the invention, the outer annulus of the outer race may be varied in a selected structural characteristic to vary the degree of resilience of the roller supporting surface relative to the outer annulus. For example, the outer annulus may be slotted axially at spaced intervals about the circumference. Alternatively, the inner annulus may be tapered, i.e., axially nonuniform in thickness.
The invention is applicable to both straight and tapered rollers as well as both true radial and radial-thrust bearings as will be apparent from the foregoing description of several illustrative embodiments, this description being taken with the accompanying drawings of which:
FIG. 1 is a cross-sectional view of a first bearing assembly of the radial-thrust type;
FIG. 2 is a perspective view of the outer race of the assembly of FIG. 1;
FIG. 3 is a cross-sectional view of a second radial-thrust type bearing assembly; and,
FIG. 4 is a cross-sectional view of a pure radial bearing using straight rollers.
Referring now to FIG. 1, a first bearing assembly is shown mounted, as an example, on a front wheel spindle 12. Bearing assembly 10 comprises a solid inner race 14 having an inclined bearing surface for receiving a plurality of tapered rollers 16. The rollers 16 are maintained in spaced relationship with one another by means of a conventional cage or separator 18. Bearing assembly 10 further comprises an outer race 20 having an outer annulus 21 which is axially flat so as to be securable to a load, and an inner annulus 22 which is inclined to engage the rollers 16. The outer annulus 21 is integrally joined with the inner annulus 22 by means of a pivot joint 23 having a relieved area 24 to minimize stress concentrations and fatigue. The inner and outer annular portions 22 and 21 intersect one another at an acute angle of approximately 22 5%". Int lntegrally formed with the inner annular portion 22 is a radially extending lip portion 25 which is radially spaced from the inner surface of the outer annular portion 21 by means of a gap 47 to limit the deflection of the inner annular portion 22 about the pivot joint 23. The gap 47 between the radially extending lip portion 25 of the outer race and the outer annulus 21 may be on the order of 0.010 inch or less. All of the elements of the assembly 10 are preferably fabricated from steel; the outer race 20 preferably having a hardness of 60 or more on a Rockwell C" scale.
FIG. 2 shows the outer race 20 of the assembly 10 in greater detail. It can be seen in FIG. 2 that slots 26 are cut into the outer annulus 21' so as to extend in the axial direction at circumferentially spaced intervals. The number and spacing of slots 26 is selected from zero to 16 or more so as to enhance the resilient or flexural characteristic of the race 20 as desired. The width of each slot is preferably between 0.010 and 0.125 inches.
Referring now to FIG. 3, a second bearing assembly 27 is shown to comprise an inner race 14, a plurality of tapered rollers 16, a cage or separator 18 and an outer race 28. Obviously, structurally like elements as between FIGS. 1 and 3 are identified by the same reference. Outer race 32 is made up of the integral assembly of an outer annulus 29 having a nonuniform or axially tapered thickness and an inner annulus 32, the plane of which intersects the plane of the outer annulus 29 at an acute angle. The flexural joint area is internally relieved at 31 to minimize stress concentrationsas before. Again the outer race 28 is constructed of steel so as to be satisfactorily resilient, yet strong, to permit transfer of loads from the rollers 16 to the outer race 28 by means of the pivotal fiexure and essentially radial displacement of the inner annulus 32 relative to the outer annulus 29. The degree of taper of annulus 29 is variable to vary the beam characteristics of annulus 32.
Referring now to FIG. 4, a third bearing assembly 34 is shown to comprise an inner race 36 having a flat bearing surface for receiving a plurality of straight or cylindrical rollers 38. The rollers 38 are maintained in spaced relationship by means of a cage or separator 40. Bearing assembly 34 further includes an outer race 41 having parallel outer and inner annular portions 42 and 43, respectively. The outer and inner annular portions are maintained in spaced relationship by means of an integral flexural joint 44 having a small radius of curvature and generally radially extending joining portion 45.
. At the free end of the outer annular portion 41 an inturned radially extending lip portion 46 extends toward but is spaced from the lefthand end of the inner annulus 43 as shown in FIG. 4. The spacing between the radially extending lip portion 46 and the inner annulus 43 again defines a gap 48 of between five and ten thousandths of an inch to limit the essentially radial deflection of the inner annulus 43 relative to the secured outer annulus 41.
It is to be understood that the foregoing descriptions are illustrative in character and are not to be construed in a limiting sense.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A roller bearing assembly comprising an inner race, a plurality of rollers disposed over the inner race, an outer race having an inner annular portion defining a flat inner surface to receive said rollers and an outer annular portion securable to a load, the inner annular portion being in engagement with the rollers, the inner and outer annular portions being resiliently and pivotally interconnected along a first side to produce a cantilevered suspension of said inner annular portion and to permit pivotal flexure of the inner annular portion relative to the outer annular portion, and stop means extending partially and substantially radially between the inner and outer portions along a second side to define the limit of said pivotal fiexure.
2. The roller bearing assembly defined in claim 1 wherein the rollers are straight.
3. The roller bearing assembly as defined in claim 1 wherein the rollers are tapered.
4. The roller bearing assembly defined in claim 1 including a separator for maintaining a predetermined relationship between the rollers.
5. The roller bearing assembly defined in claim 1 wherein the inner and outer annular portions of the outer race are integral.
6. The bearing assembly defined in claim 1 wherein the inner and outer annular portions are parallel.
7. The bearing assembly defined in claim 1 wherein the planes of the inner and outer annular portions intersect at a predetermined acute angle.
8. The bearing assembly defined in claim 1 wherein the inner and outer annular portions are integrated with one another by means of a resilient joint which is of lesser thickness than the outer annular portion.
9. The bearing assembly defined in claim 1 wherein the outer annular portion is axially slotted at spaced intervals about the circumference thereof.
10. The bearing assembly defined in claim 1 wherein the thickness of the inner annular portion is axially nonuniform.
1 1. The bearing assembly of claim 1 wherein the stop means for limiting comprises a radially extending lip portion integral with said inner annular portion.
12. An outer race for use in a tapered roller bearing assembly comprising an outer annular portion and an inner annular portion, the inner annular portion having a flat inner surface to receive tapered rollers in contact therewith, the outer and inner annular portions being integrally formed to define a stress-relieved flexural joint along one common side thereof to permit essentially pivotal displacement of the inner annular portion relative to the outer annular portion in the fashion of a cantilevered beam.
13. The race defined in claim 12 wherein the inner and outer annular portions intersect at an acute angle.
14. The race defined in claim 12 wherein the outer annular portion is axially slotted at spaced intervals about the circumference thereof.
15. The bearing race defined in claim 12 wherein the inner and outer annular portions are parallel.
16. The race defined in claim 12 including stop means for limiting the essentially radial displacement between the inner and outer annular portions.
1. A roller bearing assembly comprising an inner race, a plurality of rollers disposed over the inner race, an outer race having an inner annular portion defining a flat inner surface To receive said rollers and an outer annular portion securable to a load, the inner annular portion being in engagement with the rollers, the inner and outer annular portions being resiliently and pivotally interconnected along a first side to produce a cantilevered suspension of said inner annular portion and to permit pivotal flexure of the inner annular portion relative to the outer annular portion, and stop means extending partially and substantially radially between the inner and outer portions along a second side to define the limit of said pivotal flexure.
2. The roller bearing assembly defined in claim 1 wherein the rollers are straight.
3. The roller bearing assembly as defined in claim 1 wherein the rollers are tapered.
4. The roller bearing assembly defined in claim 1 including a separator for maintaining a predetermined relationship between the rollers.
5. The roller bearing assembly defined in claim 1 wherein the inner and outer annular portions of the outer race are integral.
6. The bearing assembly defined in claim 1 wherein the inner and outer annular portions are parallel.
7. The bearing assembly defined in claim 1 wherein the planes of the inner and outer annular portions intersect at a predetermined acute angle.
8. The bearing assembly defined in claim 1 wherein the inner and outer annular portions are integrated with one another by means of a resilient joint which is of lesser thickness than the outer annular portion.
9. The bearing assembly defined in claim 1 wherein the outer annular portion is axially slotted at spaced intervals about the circumference thereof.
10. The bearing assembly defined in claim 1 wherein the thickness of the inner annular portion is axially nonuniform.
11. The bearing assembly of claim 1 wherein the stop means for limiting comprises a radially extending lip portion integral with said inner annular portion.
12. An outer race for use in a tapered roller bearing assembly comprising an outer annular portion and an inner annular portion, the inner annular portion having a flat inner surface to receive tapered rollers in contact therewith, the outer and inner annular portions being integrally formed to define a stress-relieved flexural joint along one common side thereof to permit essentially pivotal displacement of the inner annular portion relative to the outer annular portion in the fashion of a cantilevered beam.
13. The race defined in claim 12 wherein the inner and outer annular portions intersect at an acute angle.
14. The race defined in claim 12 wherein the outer annular portion is axially slotted at spaced intervals about the circumference thereof.
15. The bearing race defined in claim 12 wherein the inner and outer annular portions are parallel.
16. The race defined in claim 12 including stop means for limiting the essentially radial displacement between the inner and outer annular portions.
| 1970-08-14 | en | 1972-04-04 |
US-85578177-A | Method and apparatus for fastening object to clay tile roof
ABSTRACT
A method and apparatus for fastening an object, such as a board to which another object may be fastened, to a clay tile roof utilizes rod threaded at both ends with a wing expansion nut on one end that is passed through a hole drilled in the tile and supporting wood at a wing point where the tile rests on the wood. A rubber washer backed by a metal washer and nut seals the hole in the clay tile and secures the rod in an upright position. A washer and second nut at the other end of the rod then secures the object to the roof with the object spanning the ridge points of two or more tiles. A third nut locks the second nut on the rod, and allows the rod to be turned like a bolt to drive the excess rod into the roof. To facilitate installation, the rod is preferrably threaded from end to end.
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for fastening an object, or objects, to a clay tile roof.
For many years it has been customary to fasten radio and television antennas to a roof, usually by fastening the end of a pole to a plate, and steading the pole with guys. The problem has been with fastening the plate and guys to a clay tile roof. Now it has become necessary to also fasten solar heating devices, such as hollow plastic panels through which water circulates for heating with solar energy. The problem of fastening to a corrugated clay tile roof is much greater for solar heating devices because they are by their very nature large and are required to be fastened to the roof at more than one point.
The problem with fastening an object to a clay tile roof is that the clay tile will easily crack or break if placed under any great stress. Clay tile will withstand relatively high and static compressive stress, but hardly any other kind of stress. An object of this invention is to provide an improved method and apparatus for fastening to a corrugated clay tile roof.
SUMMARY OF THE INVENTION
In accordance with the present invention, a hole is drilled through a corrugated clay tile and its supporting wood at a valley point where the tile is resting on the wood. A wing expansion nut threaded on the end of a rod is then inserted through the hole. Once the expansion nut passes through the hole in the clay tile and wood, it expands so that the tile may be placed under compressive stress by a first nut threaded on the rod. A rubber washer covered by a metal washer is placed between the first nut and the clay tile to seal the hole in the clay tile, thus securing the rod to the roof. In an upright position an object spanning two or more tile ridge points may then be placed with a hole through it over the rod. The object is then secured with a washer and a second nut threaded on the upper end of the rod. The second nut is tightened only until the object is held firm against the tile with substantially no tension on the rod so as not to stress the tile. A third nut is then threaded on the rod over the second nut and tightened to put the rod between the second and third nut under tension, thus locking the second and third nuts in place on the rod. During installation, the second and third nuts may be thus locked on the upper extreme end of the rod in order to turn the nuts with the rod and thus drive any excess rod through the expansion nut and the first nut into the roof. Alternatively, a capped nut may be threaded on the end of the rod and used to drive the excess rod into the roof until the capped nut secures the object firmly on the tile. In that manner two locked nuts or a single capped nut may be used as means threaded on the upper end of the rod to drive the rod in and secure the object firmly on the tile.
The novel features of the invention are set forth with particularity in the appended claims. The invention will best be understood from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view illustrating the present invention, and
FIG. 2 illustrates a variant of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1, a portion of a corrugated clay tile roof is shown with a tile 10 resting on a plywood sheet or board 12, referred to hereinafter as simply supporting wood. A suitable roofing paper (not shown) is spread over the supporting wood as a moisture barrier before the clay roof is laid down.
To secure an object to the roof, such as board 14 to which another object may be secured, such as a solar heating panel, a hole is first drilled through the tile and supporting wood at a point where the tile rests on the supporting wood as shown.
A rod threaded at both ends, and preferably threaded from end to end, is prepared with expansion nut 18, rubber washer 20, metal washer 22 and nut 24 on one end. Then, the rod and wing expansion nut are inserted through the hole in the tile 10 and supporting wood 12 until the expansion nut expands.
The nut 18 is of a conventional type having two wings which fold up against a spring to allow it to pass through the hole. The spring then causes the wings to unfold. Once the rod is pulled up with light tension, the wings embed themselves in the supporting wood 12. The nut 24 may then be turned to compress the rubber washer 20 between the metal washer 22 and the tile to seal the hole in the tile. For a good seal, the rubber washer 20, not only has an outside diameter greater than the hole in the tile, but also has an inside diameter substantially less then the diameter of the rod to seal around the threads. Once the nut 24 is tightened to place the rubber washer 20 under compression, and the lower end of the rod under slight tension, the rod is secure in an upright position with the tile under only slight compressive stress.
The board 14, or other object that spans the ridges of two or more tiles, and which has a mounting hole 25 for securing it to the roof, is then placed on the roof with its hole over the rod. A metal washer 26 and a nut 28 are then placed over the rod and tightened to secure the board 14 on the roof tile, but without placing large tension on the rod 16. The amount of tension, if any, that may be placed on the rod will depend upon the rigidity of the board or other object being fastened, and to the number of tiles that the board or object spans. However, it is not necessary to place the rod under any but the most minimal tension to secure the object firmly to the roof. Moreover, to avoid placing any stress on the tile upon tightening the nut 28, a metal or plastic tube could be placed over the rod to fit between the washer 22 and the underside of the board 14. A metal washer would then be placed between the upper end of the tube and the board. However, the task would then be to cut a piece of tube of the proper length so that the board 14 will rest with its weight on the ridges of the tile roof in order to distribute its weight over a plurality of tiles. It has been found that such a tube can be dispensed within most cases, provided care is taken not to tighten the nut 28 so much as to overstress the tile on either side of the rod.
Any wind that may tend to lift the object from the roof will place some tension on the rod, but that tension will exert a force on only the wood 12, and not stress the tile on the roof. The weight of the object, and any wind force on the object in the same direction as the weight will be evenly distributed over the tiles on which the wood 14 rests.
To lock the second nut 28 in place, a third nut 30 is placed over the second nut and tightened against the second nut. In order that any excess length of all-thread rod be inside the roof, and not project up more than a few turns of thread, as shown, the object may be placed on the roof with its hole over the rod 16 to determine the excess length of rod. The excess may then be screwed into the expansion nut 18 and the first nut 24 by first locking the second nut on the upper end of the rod with the third nut, and then turning the second nut and third nut with the rod like a bolt to thread the excess rod into the roof after the first nut 24 and washer 22 are first tightened firmly against the tile. Alternatively, a capped nut 32 may be threaded over the upper end of the rod, as shown in FIG. 2, in order to turn the rod like a bolt until the nut 32 and washer 22 are firmly against the object being fastened to the roof, which is the board 14 in this illustration.
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art. It is therefore intended that the claims be interpreted to cover such modifications and variations.
What is claimed is:
1. A method for fastening an object having a fastening hole to a corrugated clay tile roof utilizing a rod, threaded over at least a substantial portion at both ends, with a wing expansion nut at one end comprising the steps of: drilling a hole through said tile at a valley point where said tile rests on supporting wood; inserting said expansion nut through said hole sufficiently for its wings to expand, thus preventing the expansion nut threaded on the end of the bar from being pulled out of said hole; placing a washer of resilient material on said rod over the drilled hole in said tile, placing a first rigid washer on said rod over said resilient washer, and threading a first nut on said rod over said washer to press said resilient washer against the hole in said tile thereby to seal the hole in said tile around said rod; placing said object on said roof with the object spanning the ridges of two or more tiles for support so that said rod protrudes through said fastening hole in said object; placing a second washer of nonresilient material on said rod over said object; and threading a second nut on said rod over said second washer of resilient material to fasten said object on said roof.
2. The method of claim 1 wherein said second nut is threaded on said rod only slightly below its upper end, including the steps of threading a third nut on said rod over said second nut, and tightening said third nut against said second nut to lock the two together, and tightening said second nut against said last washer to tighten said object on said roof against said supporting tile by turning said second and third nuts as one to turn said rods in the threads of said expansion nut and said first nut, thereby to tighten said object on said roof while threading excess length of said rod down below supporting wood for said tile.
3. The method of claim 1 wherein said second nut is a capped nut, whereby tightening said second nut on the upper end of said rod permits said rod to be driven into said roof by turning it from the second nut like a bolt.
4. A method for fastening an object having a fastening hole to a corrugated clay tile roof utilizing a rod, threaded over at least a substantial portion at both ends, with a wing expansion nut threaded on one end with a resilient washer, rigid washer and a first nut, spaced behind it, and in that order, comprising the steps of: drilling a hole through said tile at a valley point; inserting said expansion nut through said hole sufficiently for it to expand, thus preventing the expansion nut threaded on the end of the bar from being pulled out of said hole; pressing said washer of resilient material over the drilled hole in said tile, by tightening said first nut on said rod over said rigid washer, thereby to press said resilient washer against the tile around said hole, thereby to seal the hole in said tile around said rod; placing said object on said roof with the object spanning ridge points of two or more tiles for support so that said rod protrudes through said fastening hole in said object; placing a second washer of nonresilient material on said rod over said object; and threading a second nut on said rod over said second washer of resilient material to fasten said object on said roof.
5. The method of claim 4 including the steps of threading a third nut on said rod over said second nut, and tightening said third nut against said second nut to lock the two together, and tightening said second nut against said last washer to tighten said object on said roof against said supporting tile by turning said second and third nuts as one to turn said rod in the threads of said expansion nut and said first nut, thereby to tighten said object on said roof while threading excess length of said rod down below supporting wood for said tile.
| 1977-11-25 | en | 1980-01-01 |
US-80912791-A | Apparatus for testing a PLA by measuring a current consumed by the PLO when activated with known codes
ABSTRACT
A test circuit for testing a programmable array of a microprocessor including an instruction register for receiving an instruction signal from a data bus in response to a control signal and for outputting the received instruction signal to output lines, and a programmable logic array having a plurality of NAND circuits each forming a conductive path between first and second terminals when a predetermined instruction signal is received thereby from the register. Each of the NAND circuits includes a first terminal, a second terminal and a plurality of MOSFETs each having a first, a second and a gate electrode with the gate electrode coupled to an output line of the instruction register, and with the first and second electrodes being connected in series between the respective first and second terminals. A first precharge circuit is coupled to the first terminal of the NAND circuits, to a test terminal for providing a test signal and to a precharge terminal for providing a precharge signal, with this first precharge circuit supplying a first potential level to the first terminal of the NAND circuits in response to either the precharge signal or the test signal. A second precharge circuit is coupled to the second terminal of the NAND circuits, to the precharge terminal and to a power supply terminal for supplying a second potential level, with the second precharge circuit supplying the second potential level to the second terminal of the NAND circuits in response to the precharge signal. The current flowing through the power supply terminal, and thus through a conductive NAND circuit or circuits when the first and second potential levels are present, can then be measured to test the array.
This is a division of application Ser. No. 07/415,275 filed Sept. 22, 1989, now U.S. Pat. No. 5,101,483 which was originally filed as PCT/JP89/00065 of Jan. 25, 1989.
TECHNICAL FIELD
The present invention relates to a microcomputer including a programmable logic array therein (hereinafter referred to as MC) and a method of testing the same.
BACKGROUND OF THE INVENTION
As illustrated in FIG. 1, a conventional MC includes a data bus, an instruction register IR, a programmable logic array PLA, a data register D, a stack pointer SP, accumlators A and B, temporary registers TRB and TRC, a programmable counter PC, a ROM, and a RAM.
The program counter specifies instructions stored in the ROM, the instructions being sequentially transmitted to the instruction register IR via the data bus.
The PLA includes control output lines connected to internal registers and memories, etc., decodes instruction data transmitted from the IR, and delivers control signals such as an EM (enable memory) signal, a WACC (write accumulator) signal, an EROM (enable read only memory) signal, and a WM (write memory) signal. Those control signals are to switch on and off the internal registers and the memories, and transfer the data stored in the RAM, accumulator, and ROM, etc., onto the data bus or write the data on the data bus in the RAM and accumulator, etc.
The ROM stores instruction codes constituting instructions shown in FIG. 2a and FIG. 2b for exmaple. An instruction "ADD A, #N", which is represented by an instruction code "1010, 1010" or "A, A", means that the contents stored in the accumulator A are added with #N, that is, the contents of the second byte, and then, a result of the addition is stored into the accumulator. An instruction "ADD A, M", which is represented by an instruction code "0110, 0101" or "6, 5", means that the contents stored in the accumulator A are added with the contents stored in the RAM, and then a result of the addition is stored into the accumulator.
The PLA 200 includes, as illustrated in FIG. 3a for example, a plurality of NAND decoders 1, precharge circuits 2, 3, and a sense amplifier 18. The NAND decoder 1 comprises enhancement FETs indicated by circles (0) as illustrated in FIG. 3b and depletion FETs indicated by crosses (x) as illustrated in FIG. 3c. The precharge FET 2 has its one terminal connected to one terminal of the NAND decoder 1 and its other terminal connected to ground. The precharge FET 3 has its one terminal connected to the other terminal of the NAND decoder 1 and its other terminal connected to a power supply VDD. Those precharge FETs 2, 3 further have their gates connected to precharge signal lines PRC, respectively.
In the following, operation of the PLA circuit shown in FIGS. 3a-3c will be described with reference to timing charts shown in FIGS. 6(a), (b). In a time interval T1 of a timing cycle in an interval M1 of a machine cycle, the control signal EROM opens the output gate of the ROM to fetch out the instruction code stored in the ROM onto the bus and the control signal WIR opens the input gate of the instruction register 30 to store the instruction code on the bus in the instruction register 100. When the instruction code fetched out from the instruction register IR 100 is "A, A", the NAND decoders 1 on decode lines L'1, L'3 become conductive in a machine cycle interval M2 to permit the sense amplifier 18 to input a signal "H" into the AND gate 6. Therefore, in a timing cycle interval T3 the control output signal EACC is generated on a control output signal line 4 via the AND gates 6, and in a timing cycle interval T4 the control output signal WACC is generated. Additionally, when the instruction code is "6, 5", the NAND decoders 1 located on decode lines L'2, L'4 become conductive in a machine cycle interval M2 to permit the sense amplifier 18 to input a signal "H" into the AND gate 6. Therefore, in the timing cycle interval T3 the control output signal ACC is generated on the control output signal line 4, and in a timing cycle interval T4 the control output signal WACC is generated. Here, the control signals such as EROM, WIR, PCUP, and the like illustrated in FIG. 1 are issued from a timing control circuit T/C.
Such a conventional PLA circuit however, has a problem that all instruction codes for an instruction must be decoded to generate the control signals necessary for the execution of the instruction. One instruction code generally requires four decode lines on the average, for example the instruction "A, A" requires the decode lines L'1, L'3, the instruction "6, 5" requires the decode lines L'2, L'4, L'5, . . . . That is, about 100 instructions require about 400 decode lines in all. If the width of a single decode line of the PLA circuit which is formed on a semiconductor chip is assumed to be 10 μm upon integrating the PLA, the PLA has its entire width ranging from 4 to 7 mm and hence occupies a wide areas of the semiconductor chip, therefore requiring that the chip be large.
Such a PLA incorporated, in the MC must be tested to determine whether or not it is operates in a proper manner. Such a test is carried out two or three times during the last stage of the manufacture of semiconductors or during a process of packaging the semiconductors. A typical MC includes about 100 to 200 output lines 4 for the control signals issued from the PLA. However, those control signal output lines 4 are connected to input/output gates of various of registers included in the MC but are not connected to external output terminals. This does not allow a direct check on that any control signal is issued from the PLA. Accordingly, to test the existence of any short-circuit in the wiring in the PLA and that of any abnormal FET in the same, a MC program stored in the ROM is first executed in succession for every instruction. Then, contents in each register which is the object of an instruction, and contents in all registers other than that which is the object of each instruction are read out each time for their checks. It is thereby checked that decoding and execution control of the instructions are carried out correctly, and tested indirectly that the PLA is normal. When for example an instruction "MOV A, B" is given from the outside to the MC and executed, a check of the contents stored in an accumulator (ACC) and a temporary register B (TRB) is performed to confirm that the contents stored in the TRB have been moved into the ACC, and to check that there is no change in the contents stored in other registers and the like after fetching out those contents to the outside followed by execution of the instruction "MOV A, B". However, the aforementioned operation to test the PLA requires, a data check concerning internal circuits amounting to 1000 to 100000 steps using the tester, which substantially makes it impossible to achieve the complete test. In addition, since the tester must usually be employed for varieties of test excepting the aforementioned object, use of such an expensive tester over a long period of time makes uneconomical the associated device. Furthermore, a program for such a test is very complicated, requiring much labor for preparation thereof.
In view of the drawback of the prior art, it is an object of the present invention to reduce the absolute number of decode lines while retaining their same functions as in the prior art. It is another object of the invention to provide a test of short duration of whether or not all of the wiring in the programmable logic array circuit is operationally normal.
SUMMARY OF THE INVENTION
A microcomputer includes in general varieties of instructions amounting in total of about one hundred, some of which have a very similar format. For example, the foregoing instructions "ADD A, #N" and "ADD A, M" are the same instruction of addition, and are different only in that the former allows data to be fetched from "#N" or the second byte thereof or the buffer from a memory designated at "M". Such similar instructions have almost common formats of control line signals and timing of the same.
A microcomputer in accordance with the first embodiment of the invention comprises, in view of a feature of those similar instructions being common in operation timing, a memory for storing a first instruction including a first byte and a second instruction including a first byte and a second byte having the same code as that of the first byte of the first instruction, an instruction register and means for loading the second byte of the second instruction to the instruction register after decoding the first byte of the second instruction.
In accordance with the second embodiment of the invention, there is provided a test circuit for testing a microcomputer which has a programmable logic array, said programmable logic array comprising:
(a) a NAND type decoder having (i) inputs for receiving an instruction code and a timing signal, (ii) a control signal output line, and (iii) a plurality of MOSFETs serially connected;
(b) a first precharge MOSFET connected between one end of the output line of the decoder and the ground; and
(c) a second precharge MOSFET connected between the other end of the output line of the decoder and a power supply; the improvement wherein the test circuit further has means for making the first precharging MOSFET conductive during testing the programmable logic array.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit block diagram illustrating a typical microcomputer (MC);
FIGS. 2a and 2b are views illustrating formats of conventional instruction code;
FIG. 3a is a circuit block diagram illustrating a conventional programmable logic array;
FIG. 3b is a detail showing the enhancement FET which comprises a cross-point marked with an (o) in the NAND decoder of FIG. 3a;
FIG. 3c is a detail showing the depletion FET which comprises a cross-point marked with an (x) in the NAND decoder of FIG. 3a;
FIG. 4 is a circuit block diagram illustrating a programmable logic array (PLA) of an embodiment according to the present invention;
FIGS. 5a and 5b are views illustrating formats of instruction codes in the embodiment of FIG. 4;
FIGS. 6a and 6b are timing charts illustrating the operation of the embodiment of FIG. 4;
FIG. 7 is a logic circuit diagram illustrating a sense amplifier for use in the present invention;
FIG. 8 is a logic circuit diagram illustrating a delay circuit for use in the present invention;
FIG. 9 is a circuit diagram illustrating a PLA test circuit of the embodiment according to the present invention;
FIG. 10 is a logic circuit diagram illustrating an OR gate for use in the present invention;
FIG. 11 is a timing chart illustrating a test on the PLA of the embodiment according to the present invention; and
FIG. 12 is a circuit diagram illustrating a PLA test circuit of another embodiment according to the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
In the following, a first embodiment of the invention will be described with reference to FIGS. 4 through 8.
FIG. 5a and 5b illustrate addition instructions "ADD A, #N" and "ADD A, M", the latter being analogous to the former, addition instruction "ADD, A, M" previously described in relation to the prior art. The former addition instruction "ADD A, #N" is not different from the conventional instruction code illustrated in FIG. 2a and 2b. Against this, a first byte code 11 of a certain addition instruction "ADD A, M" is not different from the conventional one, but a second byte code 12 of the same possesses the same code as the first byte code 13 of the analogous addition instruction "ADD A, #N".
As illustrated in FIG. 4, which exhibits a circuit for a PLA of the embodiment according to the first invention, a decode line L1 is a NAND decoder for a code "6, 5", that is, the addition instruction "Add A, M", which is operated in a machine cycle interval M1. Namely, when the first byte instruction code "6, 5" of the instruction "ADD A, M" is entered into an instruction register 100, the decode line L1 is activated (i.e., to a "L" level) to permit a "H" level signal (load signal) to be entered into a delay circuit 17 via a sense amplifier 18. Here, the sense amplifier 18 and the delay circuit 17 are arranged as illustrated in FIGS. 7 and 8. The delay circuit 17 issues a control signal WIR to open the instruction register IR in the next timing cycle interval M2, T1 under the control of gates 14, 15, 16, for thereby loading the instruction register IR with a second byte code "A, A" from a bus. Simultaneously, a control line signal WTRB is prohibited from being generated. When the decode line L1 decodes the first byte of the instruction as described above, the delay circuit 17, and the gates 14, 15, 16 load the instruction register IR with the second byte of that instruction. A decode line L4 corresponds to the decode line L5 shown in the circuit diagram of the conventional PLA of FIG. 3a. It therefore issues a control signal EM in a timing cycle interval M1, T4. Decode lines L2, L3, which correspond to L'1, L'3 involved in the conventional PLA circuit of FIG. 3a, and respectively, issue a control signal EACC in a timing cycle interval M2, T3 and a control signal WACC in a timing cycle interval M2, T4.
Thus the PLA of the embodiment according to the first invention illustrated in FIG. 4 can exhibit the operation timing of control signals illustrated in FIG. 6, does the coventional PLA shown in FIG. 3a. It should here be understood from a comparison of the decode lines in the PLA of FIGS. 3a and 4 that the conventional decode lines L'2 and L'4 are not required and L1 is nonexistent in the conventional case.
Decode lines for control signals WTRC and FADD can also be reduced, although not illustrated in the PLA circuit diagram of FIG. 4.
The MC includes substantially about 16 groups of analogous instructions such as ADD, ADC, SUB, SBB, OR, AND, EOR, INC, DEC, CMP, CPL, RRC, RLC, SRC, SLC, and the like. In a typical MC operational with about 8 bits, 5 decode lines on the average can be reduced among analogous instructions and about 80 decode lines as a whole can be reduced.
Although in the above description the first and second byte instruction codes were shown as being commmon as an illustrative example, a combination of the second and third bytes may also be possible or with a replacement thereof for the machine cycles a combination of second and third machine cycles may be possible, as a matter of course.
In succession, an embodiment of a test circuit for a microcomputer according to the second embodiment will be described with reference to FIGS. 9, 10, and 11. Here, the like symbols shall be applied to the like constituent elements as those of the conventional one and the first invention, and the description thereof will here be omitted. Namely, a PLA circuit which includes in itself a NAND decoder 1, precharge FETs 2, 3, and a sense amplifier, etc., is constructed as in the first embodiment. In the circuit diagram of a PLA test circuit of an embodiment according to the second invention illustrated in FIG. 9, an OR gate 21 has its input connected to a test terminal 22 and a PRC (precharge) signal line and has its output connected to a gate of a precharge FET 2. The precharge FET2, which is of an enhancement type as described previously, grounds the NAND decoder 1 at all times when the test terminal 22 is "H" at its input together with the conventional PRC input being "H", or when a test is executed. On the contrary, an external power supply 25 is connected via an external ammeter 24 to a VDD terminal 23 disposed on a semiconductor chip. The VDD terminal 23 is connected to one end of a precharge FET 3 whose other end is connected to the output of the NAND decoder 1. In the present embodiment, the ammeter 24 is a current measuring unit in a general-purpose tester, and the DC power supply 25 is a +5V one included in the same tester.
FIG. 11 is a timing chart illustrating a test operation for the PLA in the MC in the embodiment according to the second invention. In what follows, operation of the just mentioned test operation will be described with reference to FIG. 11 and to the circuit diagram of FIG. 9.
In a test interval for the PLA, the test terminal 22 is kept at a "H" level. Hereby, the precharge FET 2 becomes conductive to permit the NAND decoder 1 to be grounded at its one end at all times. In succession, in the timing T1, an instruction is entered. For example, when an instruction "MOV A, B" is entered, the NAND decoder 1 for an instruction code corresponding to that instruction becomes conductive. In the timing T1, the precharge signal (PRC) is at a "H" level, and the PRC becomes a "L" level. Hereby, the precharge FET 3 becomes conductive because of its being of a P channel type, and in the timing T1 a current IDD from the power supply 25 flows through a current route: precharge FET 3, NAND decoder 1, and precharge FET 2 because all those elements become conductive thereupon, allowing a current corresponding to the single NAND decoder or that corresponding to the single control signal to be read by the ammeter 24.
Such a conduction current through the single NAND decoder is approximately 50 μA when the MC is constructed with CMOS semiconductors. Consequently, if a current of that degree is detected, then it can be estimated that one control signal has been activated. In addition, although in the above situation a current flowed in the timing T1 corresponding to one control signal, the reason is that since the timing lies during the time when an instruction is entered, only that instruction is selected. Then, when the PRC becomes a "L" level in the timing T2, the PRC becomes a "H" level and the precharge FET 3 is switched off. Hereby, no power supply current IDD flows.
It is now assumed that two control outputs are activated to a "H" level in a timing T3 for execution of the instruction "MOV A, B". Hereupon, two NAND decoders 1 have been conductive unless there is any short-circuit through wirings or any disconnection therealong. In this situation, the PRC changes to a "H" level in the timing T3, a conduction current flows through the precharge FET 3 because the NAND decoder 1 and the precharge FET 3 have already been conductive. Since thereupon the two NAND decoders have been conductive, there flows approximately 100 μA of the power supply current IDD corresponding to the two control singals.
In succession, it is assumed on the design that the four control signal outputs have been at an active "A" level in the timing T4. Since in this situation, the four NAND decoders are conductive as in the timing T3, there flows the power supply current corresponding to the four control signal outputs. It is thus possible to measure the number of the control signal outputs by measuring the power supply current in each timing. Accordingly, a complete test can be achieved for all NAND decoders. If there is any trouble such as disconnection or short-circuit of wirings or bad transitors, or the like in the PLA in the manufacture of semiconductors of the MC, then the measured number of NAND decoders made conductive is not equal to that of NAND decoders made conductive according to the design in each timing, allowing a bad PLA to be immediately detected by a tester program.
The PLA of a MC generally includes about 100-500 NAND decoders requiring the steps for its test to be about 400 through 2000 even when the test is assumed to be done in respective timings of T1 and T2. This corresponds to a very short time.
A PLA circuit of another embodiment according to the second invention illustrated in FIG. 12 is the same in its principle of operation as that of the first embodiment illustrated in FIG. 9. Namely, a precharge FET 2 is made conductive to establish a DC path through a NAND decoder 1. In this situation, if there is any signal to be decoded corresponding to an input from an instruction register 100, a T timing input, and a M timing input, then a DC current flows from a power supply VDD via a precharge FET 3. The current is compared with the number of decoded signals for determination of the quality of the measurement.
Although in the present specification the PLA of the MC was described, the present invention is applicable also for a PLA of a microprocessor.
INDUSTRIAL APPLICABILITY
According to the MC of the first invention, as described above, the number of decode lines can be reduced by employing analogous instruction codes as being common. That is, since the second byte of a certain instruction set among analogous instruction sets can intactly utilize a control signal output of the first byte of the certain instruction set being an analogous instruction of that instruction. Accordingly, if there is a decode line only for the first byte of the certain instruction set, then the intact use of that decode line in the analogus instruction enables the analogus instruction to be executed. Thus, the first invention, which employs a certain decode line for other decode lines, can reduce the occupation area of those decode lines on the chip compared with the prior MCs, which include for a different instruction code a corresponding decode line. To be concrete, 400 through 600 decode lines can be reduced by about 80 ones, and the area occupied by the PLA on the whole semiconductor chip area can be reduced by 10 to 20%. The first invention can thus reduce the chip area greatly, keeping the same function of the device as in the conventional PLA circuit, and assuring very high industrial applicability.
Additionally, according to the PLA test circuit of the second invention, the number of the conducted NAND decoders is measured on the basis of the power supply current IDD in the part of the PLA of the MC. Accordingly, the power supply current IDD may be measured only for all timings of the instruction sets possessed by the MC. This simplifies a data check, which in the conventional case amounts to 10000 through 100000 steps, to about 2000 steps. Furthermore, according to the second invention, a direct test of the circuit part of the PLA can be achieved without requiring a check on data stored in registers, etc., which can be checked externally of the MC. Thus, greater shortening of the time required for a test and sharp reduction of the step number for preparation of a test program can be realized, assuring very high industrial applicability.
I claim:
1. A test circuit for testing a microprocessor having a data bus comprising:an instruction register connected to the data bus and having a control input and a plurality of output lines, said instruction register receiving an instruction signal from the data bus in response to a control signal received by the control input and outputting the received instruction signal to said output lines; a programmable logic array having a plurality of NAND circuits each forming a conductive path between first and second terminals when a predetermined instruction signal is received thereby, each of said NAND circuits including a said first terminal, a said second terminal and a plurality of MOSFETs each having a first electrode, a second electrode and a gate electrode coupled to an ouput line of said instruction register, and with the MOSFETs being connected in series by the first and second electrodes between the respective said first and second terminals; a test terminal for providing a test signal; a precharge terminal for providing a precharge signal; a first precharge circuit coupled to said first terminals of said NAND circuits, to said test terminal and to said precharge terminal, said first precharge circuit supplying a first potential level to said first terminal of said NAND circuits in response to either the precharge signal or the test signal; a power supply terminal for supply a second potential level; and a second precharge circuit coupled to said second terminals of said NAND circuit, to said precharge terminal and to said power supply terminal, said second precharge circuit supplying the second potential level to said second terminal of said NAND circuits in response to the precharge signal, whereby the NAND circuits are independently tested by knowing the instruction signal that activate the NAND circuits and by measuring a current drain of the activated NAND circuits.
2. A test circuit according to claim 1, wherein the first potential level is a ground level and the second potential level is a power supply voltage level.
3. A test circuit according to claim 2, further comprising means for measuring a current drain at said power supply terminal.
4. A test circuit according to claim 1, wherein said first precharge circuit includes a plurality of MOSFETs each having a first electrode coupled to said first terminal of a respective said NAND circuit, a second electrode coupled to a node applied to the first potential level, and a gate electrode coupled to said precharge terminal and to said test terminal.
5. A test circuit according to claim 4, further comprising a gate circuit having a first input terminal coupled to said precharge trminal, a second input terminal coupled to said test terminal and an output terminal coupled to said gate electrode of said MOSFET of each of said first precharge circuits.
6. A test circuit according to claim 5, wherein said gate circuit is an OR gate circuit.
7. A test circuit according to calim 1, wherein said second precharge circuit includes a plurality of MOSFETs each having a first electrode coupled to said second terminal of a respective said NAND circuit, a second electrode coupled to said power supply terminal and a gate electrode coupled to said precharge terminal.
8. A test circuit according to claim 7, further comprising an ammeter connected between said power supply terminal and a power supply.
9. A test circuit according to claim 10, further comprising:a plurality of sense amplifiers each having an input coupled to the second terminal of a respective said NAND circuit and an ouput, each of said sense amplifiers outputting a sensed signal to the output thereof; and a control signal generating circuit connected between the output of one of said sense amplifiers and said control input of sid instruction register, said control signal generating circuit receiving the sensed signal output from said one of said sense amplifiers and an instruction register writing signal, and generating the control signal for said instruction register from the received signals.
10. A test circuit for testing a microprocessor having a data bus, the microprocessor operated in a plurality of machine cycles, the test circuit comprising:an instruction register coupled to the data bus and having a plurality of output lines, said instruction register receiving an instruction signal from said data bus and outputting the received instruction signal to said output lines; a plurality of first lines supplying timing signals which represent the machine cycle; a programmable logic array having a plurality of first NAND circuits and second NAND circuits, each of the NAND circuits including a first terminal, a second terminal and a plurality of MOSFETs each having a first electrode, a second electrode and a gate electrode, with the MOSFETs being interconnected in series by the first and second electrodes between the respective first and second terminals, said gate electrodes of said MOSFETs of said first NAND circuits being coupled to said output lines of said instruction register, said gate electrodes of said MOSFETs of said second NAND circuits being coupled to said first lines, said second terminal of each of said first NAND circuits being coupled to a said first terminal of a said second NAND circuit to form an electric path between said first terminal of the respective said first NAND circuit and said second terminal of the respective associated said second NAND circuit when the respective said first NAND circuit receives a predetermined instruction signal and the respective associated said second NAND circuit receives a predetermined timing signal; a test terminal for providing a test signal; a precharge terminal for providing a precharge signal; a first precharge circuit coupled to said first terminal of said first NAND circuits, to said test terminal and to said precharge terminal, said first precharge circuit supplying a first potential level to said first terminals of said first NAND circuits in response to either the precharge signal or the test signal; a power supply terminal for supplying a second potential level; and a second precharge circuit coupled to said second terminals of said second NAND circuits, to said precharge terminal and to said power supply terminal, said second precharge circuit supplying a second potential level to said second terminal of said second NAND circuits in response to the precharge signal, whereby the NAND circuits are independently tested by knowing the instruction signals that activate the NAND circuits and by measuring a current drain of the activated NAND circuits.
11. A test circuit according to claim 10, wherein the first potential level is a ground level and the second potential level is a power supply voltage level.
12. A test circuit according to claim 11, further comprising means for measuring a current drain at said power supply terminal.
13. A test circuit according to claim 10, wherein: said first precharge circuit includes a plurality of MOSFETs with each MOSFET having a first electrode coupled to said first terminal of a respective said first NAND circuit, a second electrode coupled to a node applied to the first potential level, and a gate electrode coupled to said test terminal and to said precharge terminal; and said second precharge circuit includes a plurality of MOSFETs with each said MOFET having a first electrode coupled to said second terminal of at least one said second NAND circuit, a second electrode coupled to said power supply terminal, and a gate elecrode coupled to said precharge terminal.
14. A test circuit according to claim 13, further comprising an ammeter connected between said power supply terminal and a power supply for said second potential.
15. A test circuit according to claim 10, wherein: said first NAND circuits include a plurality of groups of said first NAND circuits; said second terminals of said first NAND circuits of the same said group are coupled to said first terminal of a common one of said NAND circuits; and said second terminals of a plurality of said second NAND circuits are coupled together.
| 1991-12-18 | en | 1993-07-27 |
US-51809574-A | Radioimmunoassay method for human chorionic gonadotropin in the presence of luteinizing hormone
ABSTRACT
A highly specific antiserum with respect to human chorionic gonadotropin (HCG) is prepared by absorbing anti-HCG-β-subunit serum with HCG-α-subunit. Such antiserum is suitable for use in radioimmunoassay of HCG in the presence of luteinizing hormone.
This is a division of application Ser. No. 319,782 filed on Dec. 29, 1972, now abandoned.
BACKGROUND OF THE INVENTION
Immunological hormone assay techniques rely upon the ability of a given hormone to act as an antigen in a given immunological reaction.
Based on this principle, radioimmunoassay techniques have recently been developed in which an unknown amount of unlabeled (cold) hormone to be determined is incubated -- in the presence of a known amount of the same labeled hormone -- with a suitable amount of a specific antiserum. Thus, an unknown amount of hormone can be easily estimated from the radioactivity count of the antigen-antibody complex through comparison with a standard curve previously constructed using known amounts of the specific anti-serum, cold hormone and labeled hormone, both cold and labeled hormones having proportionally concurred (that is, in proportion to their respective amounts) in the formation of the said antigen-antibody complex. Obviously, the radioactivity count of said antigen-antibody complex is inversely proportional to the amount of cold hormone added to the reaction mixture, the antiserum and labeled hormone amounts being left unchanged.
Unfortunately, the radioimmunoassay techniques have not been applicable as yet to the determination of human chorionic gonadotropin (HCG) in the presence of comparable amounts of luteinizing hormone (LH), because of the extreme difficulty of obtaining a specific antiserum for either hormone.
On the other hand, the need of reliable means for performing such determination is particularly recognized in this field. In fact, it is known that such reliable means would permit, among other things, pregnancy to be quickly ascertained (within a few days from conception) and choriocarcinoma as well as any HCG-producing tumors to be detected and controlled.
Therefore, the enormous clinical utility of such specific antiserum in diagnosing and controlling said tumors, as well as in ascertaining pregnancy at an early stage, is clearly apparent.
Very recently Ross et al., "Structure-activity relationships of protein and polypeptide hormones," Part 1 -- Reports-Proceedings of the Second International Symposium Liege, Sept. 28-Oct. 1, 1971; pages 153-7; M. Margoulies and F. C. Greenwood Editors; published by Excerpta Medica (1971) have tested antisera raised against α and β subunits of HCG (hereinafter referred to as HCG-α and HCG-β, respectively) in radioimmunological reactions and found that the antiserum raised against HCG-β has a higher specificity.
From a graphic display in which, among other curves, two inhibition curves of the radioimmunological reaction between anti-HCG-β serum and labeled HCG-β appear, which have been constructed using HCG and human pituitary LH, respectively, it can be noted that the said two inhibition curves differ in slope.
Urinary LH was not tested by Ross. Since it is known that urinary LH and pituitary LH have generally different immunological behavior, probably due to their dissimilar chemical structures and antigenic sites, no suggestion can be drawn from Ross on whether and to what extent inhibition will be produced by urinary LH on the anti-HCG-β serum plus labeled HCG-β system.
Furthermore, from the quantitative point of view, the two curves reported by Ross are almost coincident at least as far as the portions corresponding to low levels of cold hormone are concerned (that is, up to about 250-300 m I.U./ml).
In this respect, it should be noted that the above mentioned low hormone levels are just the levels at which a discrimination of HCG hormone from LH is required, since the physiological LH levels is urine may at most amount to 150 m I.U./ml. Consequently, the technique developed by Ross et al. cannot be used for a standard assay method of determining HCG in the presence of comparable amounts of LH.
As used herein, "m I.U." means the thousandth part of the International Unit adopted by the World Health Organization on the basis of the relevant reference preparation which is the "Second International Standard for HCG" when HCG is concerned or the "Second International Reference Preparation -- HMG" when LH is concerned. Both of the said reference preparations are available from the Biological Standard Department of W.H.O., England.
As used herein "comparable amounts of LH" means amounts of this hormone (as expressed in terms of m I.U./ml) up to about 10 times those of HCG.
SUMMARY OF THE INVENTION
In accordance with the present invention, it has been found that urinary LH and HCG are immunologically discriminated in the anti-HCG-β serum plus labeled HCG-β system at about the same extent as pituitary LH and HCG are discriminated in the same system.
It has also been found that when an anti-HCG-β serum is used, which has been previously absorbed with HCG-α, the resulting inhibition curves with respect to HCG and LH are such that LH amounts at least 10 times higher than HCG amounts are required in order to achieve an equivalent degree of inhibition in the radioimmunological reaction.
The invention therefore provides a method for radioimmunologically discriminating HCG from urinary LH in which an anti-HCG-β serum plus labeled HCG-β system is used.
The invention also provides a novel highly specific antiserum for radioimmunoassay which is obtained by absorbing anti-HCG-β serum with HCG-α subunit.
The invention further provides a method for the radioimmunoassay of HCG in presence of comparable amounts of LH in which an HCG-α-absorbed anti-HCG-β serum plus labeled HCG-β system is used to discriminate HCG from LH. Such method is particularly suitable for use in ascertaining pregnancy at an early stage.
DETAILED DESCRIPTION OF THE INVENTION
The anti-HCG-β serum from which the highly specific antiserum of this invention is obtained can be prepared, as usual, by injecting human HCG-β in such heterologous anumals as rabbit, sheep, goat, guinea-pigand so on.
For the sake of convenience a common laboratory animal is preferred, particularly the rabbit.
An immunization schedule has been used which is similar to that suggested by Ross. It is understood, however, that the invention is not restricted to this particular immunization schedule, since the later may be changed according to the kind of animal, the special adjuvants used and so on.
In general, the absorption of anti-HCG-β serum is performed using suchHCG-α amounts that the highest specificity is ultimately achieved in the antiserum. Such amounts can somewhat vary according to the particular antiserum used. According to the present invention, they usually range from 0.05 to 2 mg. HCG-α per ml. anti-HCG-β serum; a preferred range is from 0.1 to 0.4 mg HCG-α per ml. anti-HCG-β serum.
As used herein, the term "absorption" has its generally accepted meaning inimmunology, that is, it refers to a procedure of reacting an antiserum witha given antigen in order to remove from the antiserum the antibody specifically reacting with that antigen. Time and temperature conditions of such immunological reaction are not critical. The reaction leads to an insoluble antigen-antibody complex which is centrifuged and discarded to give an "absorbed" (purified) antiserum supernatant.
The following Example 1 illustrates a typical preparation of the anti-HCG-β serum whereas Example 2 illustrates the absorption of the above antiserum to give the highly specific antiserum of this invention.
EXAMPLE 1
Preparation of anti-HCG-β serum
Using intradermic injections administered at multiple body sites, each of agroup of rabbits was given an ultra-sound homogenized mixture consisting of50 γ (micrograms) HCG-β dissolved in 1 ml. physiological salt solution plus 1 ml. Freund's complete adjuvant (Difco) plugs 5 mg. dried tubercle mycobacteria (H37RA Difco).
In a separate body site, each rabbit was subcutaneously given 0.5 ml. pertussis vaccine.
One month later, a mixture was injected intradermally which consisted of 50 γ HCG-β dissolved in 1 ml. physiological salt solution plus 1 ml. Freund's complete adjuvant.
The animals were first bled by puncture of the marginal ear vein one week after the last mentioned injection. The blood, collected in an Erlenmeyer flask, was allowed to clot by maintaining the flask inclined at room temperature for about 4 hours, and then left standing overnight at 4° C. The coagulated blood was centrifuged the next morning to separate serum to which sodium azide (1 to 10,000 weight/volume) was added. In this context, parts by weight and parts by volume bear the same relation as do milligrams and milliliters.
The animals were bled weekly thereafter. When the antiserum titer tended todecrease, the animals were subcutaneously given a booster injection consisting of 50 γ HCG-β dissolved in 1 ml. physiological salt solution.
EXAMPLE 2
Absorption of anti-HCG-β serum with HCG-α
0.2 mg. HCG-α was added to 1 ml. anti-HCG-β serum. The mixture was kept for 2 hours at 37° C in a thermostat and then for 24 hoursat 4° C. A precipitate formed which was centrifuged and discarded.
The absorbed antiserum supernatant was found to be highly specific with respect to HCG in the presence of comparable amounts of LH.
The following Example 3 shows that the anti-HCG-β serum plus labeled HCG-β system is able to discriminate between HCG and urinary LH at about the same extent as HCG and pituitary LH are discriminated in the same system.
EXAMPLE 3
An anti-HCG-β serum which had been prepared in accordance with Example1 was suitably diluted with a 0.01M phosphate buffer at pH 7.5 containing normal rabbit serum (1:1000), tetrasodium ethylenediaminetetraacetate (0.014M) and bovine serum albumin (0.25%).
Using the same buffer which, however, did not contain the rabbit serum, three series of solutions having gradually varied concentrations were prepared containing a commercial HCG preparation (Roussel, 3200 I.U./mg.),a urinary LH preparation (100 I.U./mg.) and a pituitary LH preparation (1300 I.U./mg.), respectively.
A HCG-β preparation, which had been labeled with 125 I in accordance with the Chloramine-T method described in Greenwood et al., Biochem. J. 89, 114 (1963), was suitably diluted with the same buffer usedto prepare the above mentioned HCG and urinary or pituitary LH solutions.
A fixed amount of diluted anti-HCG-β serum was incubated for 24 hours at 37° C with an aliquot part of each of the HCG or LH solutions. To each of the incubation mixtures, an amount corresponding to 10,000 counts per minute of labeled HCG-β was added. Incubation was continued at 37° C for 24 hours, and anti-rabbit-gammaglobulin serum was added in a sufficient amount to precipitate the formed antigen-antibody complex. After further incubation at 37° C for 24 hours, the precipitate was separated from the supernatant by centrifugation, the latter being discarded. Finally, the precipitate radioactivity was counted.
An inhibition curve was constructed for each of the three hormones; in saidcurves the precipitate radioactivity was plotted against the hormone concentration. From the comparison between the three curves so obtained, it could be observed that 27 m I.U./ml. HCG, 109 m I.U./ml. urinary LH and110 m I.U./ml. pituitary LH, respectively, were needed to achieve 50% inhibition of the reaction between anti-HCG-β serum and labeled HCG-β.
The following Examples 4 and 5 show that urinary or pituitary LH amounts more than 10 times higher than HCG amounts are necessary in order to achieve an equivalent degree of inhibition of the radioimmunological reaction when an HCG-α-absorbed anti-HCG-β serum plus labeled HCG-β system is used to discriminate HCG from LH.
EXAMPLE 4
An anti-HCG-β serum which had been absorbed with HCG-α in accordance with Example 2 was diluted 1 to 2000 with a 0.01 M phosphate buffer at pH 7.5 containing normal rabbit serum (1:1000), tetrasodium ethylenediaminetetraacetate (0.014M) and bovine serum albumin (0.25%).
Using the same buffer which, however, did not contain the rabbit serum, twoseries of solutions having gradually varied concentrations were prepared containing a commercial HCG preparation (Roussel, 3200 I.U./mg.) and a urinary LH preparation (100 I.U./mg.), respectively.
A HCG-β preparation, which had been labeled with 125 I in accordance with the Chloramine-T method described in Greenwood et al., Biochem. J. 89, 114 (1963), was suitably diluted with the same buffer usedto prepare the above mentioned HCG and LH solutions.
A fixed amount of diluted anti-HCG-β serum was incubated for 24 hours at 37° C with an aliquot part of each of the HCG or LH solutions. To each of the incubation mixtures, an amount corresponding to 10,000 counts per minute of labeled HCG-β was added. Incubation was continued at 37° C for 24 hours, and anti-rabbit-gammaglobulin serum was added in a sufficient amount to precipitate the formed antigen-antibody complex. After further incubation at 37° C for 24 hours the precipitate was separated from the supernatant by centrifugation, the latter being discarded. Finally, the precipitate radioactivity was counted.
An inhibition curve was constructed for each of the two hormones; in said curves the precipitate radioactivity was plotted against the hormone concentration. From the comparison between the two curves so obtained, it could be observed that 45 m I.U./ml. HCG and 523 m I.U./ml. LH, respectively, were needed to achieve 50% inhibition of the reaction between anti-HCG-β serum and labeled HCG-β.
EXAMPLE 5
The procedure described in Example 4 was repeated to effect similar radioimmunoassays, except that the urinary LH preparation was replaced with a pituitary LH preparation (1300 I.U./mg).
The comparison between the two curves constructed as described above showedthat 44.8 m I.U./ml. HCG and 559 m I.U./ml. LH, respectively, were needed to achieve 50% inhibition of the reaction between anti-HCG-β serum and labeled HCG-β.
As illustrated by the Examples hereinafter, the assay method based on the use of the highly specific anti-serum of this invention can be applied to the radioimmunoassay of HCG in the presence of LH not only in a buffered, e.g., phosphate buffered, solution of the hormones but even directly in a sample of human urine.
As stated above, the physiological LH levels in urine may at most amount to150 m I.U./ml. Therefore, the novel highly specific antiserum of this invention is able to detect HCG amounts as low as about 15 m I.U./ml. in the presence of physiological amounts of LH.
EXAMPLE 6
The procedure described in Example 4 was repeated to effect similar radioimmunoassays, except that the HCG or LH solutions in the incubation mixtures were replaced with urine samples collected from normally menstruating women during the luteal phase.
In no case, a significant (that is, higher than about 20%) degree of inhibition of the radioimmunological reaction between anti-HCG-β serum and labeled HCG-β was observed.
EXAMPLE 7
The procedure described in Example 4 was repeated to effect similar radioimmunoassays, except that the HCG or LH solutions in the incubation mixtures were replaced with urine samples collected from early pregnant women (6 to 12 days after ovulation and coitus). The tested samples gave degrees of inhibition ranging from 20 to 70%.
EXAMPLE 8
To a urine sample collected during the luteal phase of menstrual cycle (physiological LH level of 10 to 15 m I.U./ml.), gradually varied amounts of commercial HCG were added.
From radioimmunoassays performed in accordance with the procedure describedin Example 4, a significant degree of inhibition was observed for HCG amounts higher than 20-25 m I.U./ml.
To a similar urine sample, gradually varied amounts of LH were added. A significant degree of inhibition could not be observed until LH amounts ofat least 200 m I.U./ml. were added.
Various changes and modifications can be made in the process and products of this invention without departing from the spirit and the scope thereof.The various embodiments set forth herein were intended to further illustrate the invention but were not intended to limit it.
What we claim is:
1. A method for radioimmunologically discriminating human chorionic gonadotropin from urinary luteinizing hormone in a specimen which comprises mixing the specimen with anti-human chorionic gonadotropin - β serum and radioactively labeled human chorionic gonadotropin - β, and thereafter determining the degree of inhibition of the immunological reaction between the anti-human chorionic gonadotropin-β and the labeled human chorionic gonadotropin-β.
2. The method of claim 1 wherein the inhibition is determined by effecting a radioimmunological assay of the mixture and comparing the results with a known standard.
3. A radioimmunological method for quantitatively determining human chorionic gonadotropin in a specimen containing human chorionic gonadotropin in the presence of up to about 10 times the amount in m I.U./ml of luteinizing hormone, which comprises mixing the specimen to be tested with human chorionic gonadotropin-α-absorbed anti-human chorionic gonadotropin-β serum and radioactively labeled human chorionic gonadotropin-β, and thereafter determining the degree of inhibition of the immunological reaction between the human chorionic gonadotropin-α-absorbed anti-human chorionic gonadotropin β serum and the labeled human chorionic gonadotropin β, the observed inhibition being substantially due to human chorionic gonadotropin.
4. The method of claim 3 wherein the inhibition is determined by effecting a radioimmunological assay of the specimen and comparing the results with a known standard.
5. The method of claim 3 wherein each milliliter of anti-human chorionic gonadotropin-β serum was absorbed with about 0.05-2 milligrams of human chorionic gonadotropin-α.
6. The method of claim 3 wherein each milliliter of anti-human chorionic gonadotropin-β serum was absorbed with 0.1 to 0.4 milligrams of human chorionic gonadotropin-α.
7. A method for radioimmunologically ascertaining pregnancy which comprises effecting the method of claim 6 using a sample of urine as the specimen, pregnancy being positively ascertained when the inhibition is greater than about twenty percent.
8. A method for radioimmunologically ascertaining pregnancy which comprises effecting the method of claim 3 using a sample of urine as the specimen, pregnancy being positively ascertained when the inhibition is greater than about 20 percent.
| 1974-10-25 | en | 1976-11-16 |
US-21486894-A | Magnetic roller
ABSTRACT
A magnetic roll for use in roller pairs of a drafting system on a textile machine. Each magnetic roll includes a central pole member having a rare earth magnet positioned on either side thereof. An end pole member is provided adjacent each magnet, and a cot is provided next to each end pole member for gripping and propelling fibers between the roller pairs of the drafting system.
BACKGROUND OF THE INVENTION
This invention relates generally to a magnetic roller for use in the drafting system of a textile machine, such as a spinning machine, roving machine, drawframe, card machine, or the like.
In drafting fibers on a textile processing machine, such as a spinning machine, a band of fibers is passed between at least two pairs of rollers, the second, downstream, pair of rollers being driven at a faster rate than the first, upstream, pair of rollers such that the band of fibers becomes elongated, or "drafted" between the two pairs of rollers. A typical drafting system may include two pairs of such cooperating rollers or additional pairs of rollers to form successive drafting zones therebetween.
In order to draft the fibers, pressure must be applied between the rollers in each roller pair in a manner sufficient to cause the nip zone at the interface between the roller pair to both grip and propel the fibrous material. Weights, springs, levers, hydraulic, pneumatic or other pressure systems for forcing the rollers towards one another have been used in the past. However, a drawback of such systems is that they require substantial supporting structures to counteract the external weighting applied to the rollers. The supports must be strong enough to prevent undesirable deflection in the rollers being weighted. Also, bearings must be included which can both support the rollers for rotation and withstand the forces delivered by the external weighting.
As an alternative to the external weighting, magnetic weighting can be used. In magnetic weighting, at least one roll of each roller pair is magnetized such that it is attracted to the other roll of the pair, which is constructed of either a ferrous material or a magnetic material. In this system, the magnetic force between the rollers pulls the rollers together and applies sufficient pressure therebetween to grip and propel the fibers being processed. No additional weights, springs, levers, hydraulic or pneumatic systems are required for weighting the rollers. By eliminating the need for such weighting systems, the corresponding roller support structures can be simplified since roller deflection is essentially eliminated. Also, the bearing systems for the rollers will not have to withstand the externally-delivered forces caused by other types of weighting.
In some magnetic roller designs, the magnets are carried internally within the rollers and are contained within cylinders or sleeves. The shells are typically constructed of a non-magnetic material. With such magnetic roller designs, the magnets and corresponding pole members for the magnets are typically rotatably supported on gudgeons or journals.
Further, prior magnetic rollers were limited by the amount of magnetic force which could be delivered, due to the composition of the magnets used. Because of the type of magnets used and the diameter of the magnets required to achieve the necessary attractive force, a shorter, and therefore a more desirable, draft zone was not achievable between adjacent roller pairs. Additionally, prior magnetic rollers were prone to de-magnetization over time and could actually be de-magnetized if the rollers were not inserted and oriented properly with respect to adjacent rollers.
Prior magnetic roller designs include U.S. Pat. No. 3,134,057, issued to Tsunoo, et al, which discloses a magnetic roller having magnetic pieces fitted on pole rings. U.S. Pat. No. 3,150,419, issued to Aurich, discloses magnetic rollers having conventional magnets carried within a roll and housed by a metal sleeve. The magnets are separated by pole pieces, and gudgeons are used for supporting the rollers for rotation. German Patent document No. 1,185,961, discloses a magnetic roller having magnet rings adjacent to one another and iron pole pieces located adjacent to and outboard of the magnet rings. U.S. Pat. No. 3,457,618, issued to O'Neal, discloses a magnetic crush roll for use with a carding machine, the roll including magnetic modules carried on a shaft. U.S. Pat. Nos. 3,364,545 and 3,605,229, also disclose magnetic crush rolls.
U.S. Pat. No. 4,829,277, issued to Stahura, et al, and U.S. Pat. No. 5,055,812, issued to Abele, et al, both disclose magnetic resonance imaging devices used in the medical field. Each of the patents disclose the use of rare earth magnets of neodymium, iron, and boron alloy compositions.
While prior magnetic roller designs are available, they present limitations which may prevent desirable roller pressure interfaces being achieved between rolls of drafting roller pairs and also draft zones of minimum lengths.
SUMMARY OF THE INVENTION
It is the principal object of the present invention to provide a magnetic roller for use in a textile drafting system which allows for an increased gripping force between pairs of drafting rollers.
It is a further object of the present invention to provide a magnetic roller which allows for a draft zone of minimum length.
It is another object of the present invention to provide a magnetic roller which does not tend to de-magnetize over time.
It is still another object of the present invention to provide a magnetic roller which can be oriented in either of two directions.
It is still another object of the present invention to provide a system for forcing drafting roller pairs together without using springs or other systems for externally delivering pressure or weighting.
It is yet another object of the present invention to provide a drafting roller pair system which minimizes bottom roller deflection and bearing structural requirements.
Further, another object of the present invention is to provide a magnetic roller of minimum diameter.
These and other objects and aspects of the present invention will become further evident upon reference to the following drawings and accompanying specification.
Generally, one embodiment of the present invention includes a magnetic roller for use in conjunction with a driven roller of a drafting roller pair of a textile drafting system. The magnetic roll comprises at least one rare earth magnet and at least one resilient member associated with the rare earth magnet for engaging the driven roller of the textile drafting system. Such a roll would also include support means associated with the rare earth magnet and the resilient member for substantially coaxially supporting the magnet and the resilient member together for rotation in the textile drafting system.
A preferred embodiment of the present invention includes a magnetic roller for use in a textile drafting system of a spinning machine, roving machine, drawframe, card machine, or the like, comprising at least one substantially cylindrical central pole member having a first side and a second side opposite the first side. The central pole member defines a central pole member aperture therein. A first substantially cylindrical rare earth magnet is provided adjacent to the first side of the central pole member, and a second substantially cylindrical rare earth magnet is positioned adjacent to the second side of the central pole member. Each of the first and second rare earth magnets define an aperture therein.
Also provided is a first end pole member adjacent to the first rare earth magnet and opposite the first side of the central pole member. A second end pole member is provided adjacent to the second rare earth magnet and opposite the second side of the central pole member, each of the first and second end pole members defining an aperture therein.
An elongated shaft is also provided which passes through each aperture of the central pole member, the first and second rare earth magnets and the first and second end pole members, for maintaining the central pole member, the first and second rare earth magnets, and the first and second end pole members in substantially coaxial alignment with respect to one another.
More specifically, the magnetic roll of the present invention includes the pole members being individually greater in width, or mass, than either of the first and second rare earth magnets. Also, the rare earth magnets are preferably of a neodymium-iron-boron composition.
BRIEF DESCRIPTION OF THE DRAWING
The foregoing, as well as other objects of the present invention, will be further apparent from the following detailed description of the preferred embodiment of the invention, when taken together with the accompanying drawings, in which:
FIG. 1 is a perspective view of a magnetic roller assembly constructed in accordance with the present invention; and
FIG. 2 is a side elevational view, with parts cut away, of a magnetic roller constructed in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, wherein like reference characters represent like elements or features throughout the various views, the magnetic roller of the present invention is designated generally in the Figures by a reference character 10.
Referring to FIG. 1 of the drawings, the magnetic roll system of the present invention is illustrated in a drafting system 1 for a spinning machine. The drafting system as shown in FIG. 1 includes four drafting roller pairs, generally 12, one pair 14 being shown in phantom, and includes slivers or rovings 16 entering through condensers or trumpets 18 and into a first roller pair 20 which includes a magnetic roller 10 constructed in accordance with the present invention. Magnetic roller 10 is attracted to a ferrous bottom roller 22, preferably constructed of steel, which may extend the length of the spinning machine or through several sections of the spinning machine. Each roller pair 12 includes an upper roller, generally 26, which is preferably a magnetic roller 10, and a lower roller 22.
Generally the lower roller 22 is driven while the upper roller 26 rotates through frictional interaction with the lower roller 22 brought about through the magnetic attraction of the upper roller 26 to the lower roller 22. Preferably, attached to the ends 24 of alternating upper rollers 26 and bottom rollers 28, are apron belts 30 which are propelled about carriers 32 by the rotation of the upper and lower rollers 26, 22. Use of belts 30 allows for a further reduction of the drafting zone length as the belts 30 allow fibers to be delivered and released closely adjacent to the nip zone of the succeeding downstream roller pair 12.
The upper roller 26 is carried for rotation through engagement of the ends of a support means or member such as a shaft 34, preferably constructed of non-magnetic steel, such as stainless steel, or other non-magnetic material, which passes through the entire length of each magnetic roller 10 and which extends outwardly from each end thereof. A holder which engages the ends of the shaft 34 is not shown, but could be of conventional design.
As illustrated in FIGS. 1 and 2, each magnetic roller 10 includes a substantially cylindrical central pole member 36, having an aperture 37 extending therethrough, centrally located along the length of the shaft 34. Positioned adjacent to and on either side of the central pole member 36 is a rare earth magnet 38, 40 constructed in accordance with the present invention. Each magnet 38, 40 is preferably of neodymium-iron-board composition, although a variety of other rare earth magnet compositions could also be used, and it is to be understood that the composition of the rare earth magnet is not to be limited to such a neodymium-iron-boron composition.
Each magnet 38, 40 defines a centrally located aperture 42 extending therethrough for receipt of the shaft 34. Positioned adjacent to each magnet, opposite the central pole member 36, are first and second end pole members 44, 46. The end pole members 44, 46 are also of cylindrical shape and have a hole 48 passing through the center thereof. The end pole members are preferably of slightly larger diameter than the magnets 38, 40, although they could be of greater, less or equal diameter, if desired. The central pole piece 36 and the end pole pieces 44, 46 are preferably constructed of steel, although other suitable ferrous or magnetic-attractive materials could also be used.
Positioned adjacent to each end pole piece 44, 46 is a cylindrical spacer 50, preferably constructed of a non-ferrous material such as aluminum, onto the surface of which a resilient member such as a rubber cot 52 is provided for rolling engagement with engagement portions 54 of the lower steel roll 22. The fibers being drafted are gripped and propelled by cots 52 the nip zone between the rubber cots 52 and the lower roll 22. Spacers 50 are preferably press-fit to shaft 34 to retain spacers 50, pole members 36, 44, 46 and magnets 38, 40 on shaft 34.
Roving or sliver passing through the drafting system 1, exits the final pair of rollers, and is spun into a yarn 57 in a conventional manner on a rotating bobbin 58 acting in conjunction with a thread guide 60 and a conventional ring 62 and traveller 64 system.
In one particular embodiment, the central pole member 36 is of greater width than the magnets 38, 40, which are each approximately the same width and diameter with respect to one another. Also in such embodiment, the end pole members 44, 46 are approximately the same width as the magnets 38, 40. Further, while the end pole pieces 44, 46 and central pole members 36 are approximately the same diameter, the central pole member 36 is preferably of a larger diameter than magnets 38, 40. While such a combination of dimensions has been found desirable, a variety of other widths and diameters of rare earth magnets and pole members could also be used to achieve satisfactory results.
The magnetic rollers 10 of the present invention exert a much greater magnetic force as compared to the magnets used in prior designs. This allows for greater strength in gripping of the fibers being drafted and also allows for reduction in the diameter of the magnetic rolls 10 as compared to prior magnetic roller designs. By reducing the diameter of the magnetic rolls, the drafting roller pairs 12 can be placed closer to one another, to thereby shorten the drafting zones therebetween, which, accordingly, allows for greater drafting control. In one embodiment, it has been found that magnetic rollers having magnets and pole members of approximately 28 mm in diameter can be used, which is generally a smaller diameter than prior art magnetic rollers, while still delivering a significantly increased attractive force than was possible with the prior art magnetic rollers. However, magnets for top rolls having apron belts 30 provided thereon can be of greater diameter than those rolls not having apron belts 30, while still providing favorable drafting. Also, magnets of larger diameters may find particular use in drafting systems such as those found on roving machines, draw frames, carding machines and the like.
In the embodiment illustrated, the north poles of each magnet 38, 40 are adjacent to the central pole piece 36, and the south poles of each of the magnets 38, 40 are adjacent to the end pole pieces 44, 46, respectively, although other orientations of the magnets 38, 40 with respect to the other pole pieces could also be used.
The shaft 34 passing through the magnetic roll 10 is preferably a constant diameter throughout its length. This is contrasted with prior magnetic roller designs, which were prone to de-magnetization, and which therefore had to be oriented in a specific relationship to prevent de-magnetization caused by adjacent magnetic rollers. To prevent improper orientation, some magnetic roller designs have used gudgeons of different diameters which would prevent the magnetic roller from being inserted in an improper orientation. Because the rare earth magnets used in the magnetic rolls of the present invention are not subject to de-magnetization, orientation of the rolls with respect to adjacent rolls is not critical, and therefore, the shaft 34 does not require ends of differing diameters. However, while shaft 34 has been shown for coaxially aligning pole to members 36, 44, 46, and magnets 38, 40 together, the apertures of the pole members 36, 44, 46, and magnets 38, 40 could be eliminated and half-shafts or gudgeons attached to spacers 50 used to support roller 10 instead.
It is also to be understood that a variety of shapes of pole members 36, 44, 46 and magnets 38, 40 could be used instead of the cylindrical shapes illustrated. Although roll 10 is shown having only two magnets and three pole members, a larger or smaller number of magnets and pole members could also be used to construct roller 10. Further, the diameters, widths, and masses of the magnets and pole members could be varied with respect to that disclosed to also achieve satisfactory results.
For example, the central pole member and end pole members of each roll can be of greater or less width than the width of the magnets, depending on the space available on the roll and for the roll itself in the specific drafting application. Specifically, there may be embodiments where it is desirable to have pole members of lesser width and/or mass than the magnets. Also, because the spindle gauge of spinning machines can vary from one type of machine to another, the width relationship between the pole members and the magnets can vary depending on the particular gauge of spinning machine on which the rolls are used. It has been found that the pressure exerted between the rollers of the roller pairs, wherein at least one of the rollers is a magnetic roller constructed in accordance with the present invention, may be increased when the mass of the central pole member is greater than the mass of either of the magnets. Similarly, the pressure exerted can be increased by increasing the mass of the end pole members such that the mass of each of the end pole members is greater than the mass of the magnets. The increase in attractive force caused by increasing the mass of the pole members in relation to the magnets will be limited to a point, in that sufficient magnet mass must be present on the roller to provide at least a minimum threshold of attractive force and that the roller is of finite length, thereby placing inherent size limitations on the relationships between the pole members and the magnets.
Another variation of the present magnetic roller design could include eliminating the central pole member altogether, using only the end pole members. Alternately, all pole members could be eliminated, with a single or series of magnets extending the length of the roll 10, or a portion thereof. Such a design could include resilient cots thereon for engaging the lower driven roller of a roller pair and the yarn in a nip zone formed therebetween.
While preferred embodiments of the invention have been described using specific terms, such description is for present illustrative purposes only, and it is to be understood that changes and variations to such embodiments, including but not limited to the substitution of equivalent features or parts, and the reversal of various features thereof, may be practiced by one of ordinary skill in the art, without departing from the spirit or scope of the following claims.
What is claimed is:
1. A magnetic roll for use in conjunction with a driven roll of a drafting roller pair in a textile drafting system, comprising:at least one circumferentially extending rare earth magnet having a first end and a second end opposite said first end; at least one resilient member associated with said at least one rare earth magnet for engaging the driven roll of the textile drafting system; and support means associated with said at least one rare earth magnet and said at least one resilient member for substantially coaxially supporting said at least one magnet and said at least one resilient member together for rotation in the textile drafting system.
2. The magnetic roll as defined in claim 1, further wherein said at least one rare earth magnet includes first and second rare earth magnets.
3. The magnetic roll as defined in claim 2, further comprising at least one central pole member having a first side and second side opposite said first side, said central pole member being positioned between said first and second rare earth magnets.
4. The magnetic roll as defined in claim 1, further comprising a first end pole member positioned proximate to said first end of said at least one rare earth magnet, and a second end pole member positioned proximate to said second end of said at least one rare earth magnet.
5. A magnetic roll as defined in claim 3, wherein said central pole member is constructed of a magnetic-attractive material.
6. A magnetic roll as defined in claim 1, wherein said at least one resilient member includes first and second cot members, one of each being provided on each end of the magnetic roll.
7. A magnetic roll as defined in claim 1, wherein said at least one rare earth magnet is constructed of a composition including neodymium, iron, and boron.
8. A magnetic roll as defined in claim 4, wherein the combined mass of said first and second end pole members is greater than the mass of said at least one rare earth magnet.
9. A magnetic roll for use in a textile drafting system, comprising:at least one pole member having a first side and a second side opposite said first side; first and second rare earth magnets; said first magnet being positioned adjacent said first side of said central pole member, and said second magnet being positioned adjacent said second side of said central pole member; a first end pole member positioned adjacent to said first rare earth magnet, opposite said first side of said central pole member, and a second end pole mender positioned adjacent to said second rare earth magnet, opposite said second side of said central pole member; at least one shaft member associated with said first and second end pole members for maintaining said central pole member, said first and second rare earth magnets, and said first and second end pole members in substantially coaxial alignment with respect to one another.
10. A magnetic roll as defined in claim 9, wherein:said central pole member defines a central pole member aperture therein; each of said first and second rare earth magnets define a magnet aperture therein; each of said first and second end pole members define an end pole aperture therein; and said support means includes an elongated shaft, said elongated shaft passing through said central pole member aperture and each of said magnet apertures of said first and second rare earth magnets and each of said end pole apertures of said first and second end pole members, for maintaining said central pole member, said first and second rare earth magnets, and said first and second end pole members in substantially coaxial alignment with respect to one another.
11. A magnetic roll as defined in claim 9, wherein said at least one shaft member is an elongated shaft constructed of non-magnetic material.
12. A magnetic roll as defined in claim 9, wherein said central pole member and said first and second end pole members are constructed of a ferrous material.
13. A magnetic roll as defined in claim 9, further comprising first and second spacer members, said first spacer member being positioned adjacent to said first end pole member, and said second spacer member being positioned adjacent to said second end pole member.
14. A magnetic roll as defined in claim 13, wherein said first and second spacer members are constructed of a non-ferrous material.
15. A magnetic roll as defined in claim 13, further comprising said first and second spacer members each having a resilient cot provided thereon.
16. A magnetic roll as defined in claim 9, wherein said central pole member is of greater width than each of said first and second magnets.
17. A magnetic roll as defined in claim 9, wherein said first and second rare earth magnets are constructed of a composition including neodymium, iron, and boron.
18. A magnetic roll as defined in claim 9, wherein said central pole member and said first and second rare earth magnets are substantially cylindrical and said central pole member is of a larger diameter than each of said first and said second magnets.
19. A magnetic roll as defined in claim 9, wherein said first and second rare earth magnets and said first and second end pole members are substantially cylindrical and wherein the diameter of each of said first and said second end pole members is larger than the diameter of each of said first and second magnets.
20. A magnetic roll as defined in claim 9, wherein each of said first and second end pole members is of greater width than each of said first and second rare earth magnets.
21. A magnetic roll as defined in claim 9, wherein each of said first and second end pole members is of less width than each of said first and second rare earth magnets.
22. A magnetic roll as defined in claim 9, wherein the combined mass of said first and second end pole members is greater than the combined mass of said first and second rare earth magnets.
23. A magnetic roll as defined in claim 9, wherein the mass of said central end pole member is greater than the mass of either of said first and second rare earth magnets.
24. A magnetic roll for use in a textile drafting system, comprising:at least one central pole member having a first side and a second side opposite said first side; first and second rare earth magnets; said first rare earth magnet being positioned adjacent said first side of said central pole member, and said second rare earth magnet being positioned adjacent said second side of said central pole member; a first end pole member positioned adjacent to said first rare earth magnet, opposite said first side of said central pole member, and a second end pole member positioned adjacent to said second rare earth magnet, opposite said second side of said central pole member; and at least one shaft member associated with said central pole member aperture, said first and second magnets, and said first and second end pole members for maintaining said central pole member, said first and second magnets, and said first and second end pole members in substantially coaxial alignment with respect to one another.
25. A magnetic roll as defined in claim 24, further comprising first and second spacers, said first spacer being positioned adjacent to said first end pole member, and said second spacer being positioned adjacent to said second end pole member; each of said first and second spacers defining an aperture therethrough for receipt of said elongated shaft.
26. A magnetic roll as defined in claim 25, further comprising first and second aprons associated with each of said first and second spacers, respectively; andfirst and second belts; said first belt passing over said first spacer and said first apron for movement with respect thereto, and said second belt passing over said second spacer and said second apron for movement with respect thereto.
27. A magnetic roll as defined in claim 24, wherein said first and second rare earth magnets are constructed of a composition including neodymium, iron, and boron.
28. A magnetic roll assembly for use in conjunction with a roll of a drafting roller pair in a textile drafting system, the magnetic roll assembly comprising:first and second rare earth magnets, each of said first and second rare earth magnets having an end; and at least one pole member positioned between the end of said first rare earth magnet and the end of said second rare earth magnet.
29. A magnetic roll assembly as defined in claim 28, further comprising at least one resilient member provided on the roll.
30. A magnetic roll assembly as defined in claim 28, further comprising support means associated with said first and second rare earth magnets and said pole member for substantially coaxially supporting said first and second rare earth magnets and said pole member together for rotation in the textile drafting system.
| 1994-03-17 | en | 1995-09-12 |
US-52876774-A | Method for pelleting carbon black
ABSTRACT
Apparatus and method for treating particulate material by selectively separating the particles on the basis of size. There is disclosed a process for pelleting a particulate material such as carbon black wherein wet pelleting material is classified and only desired size pellets are passed to a dryer or drying zone.
This is a continuation-in-part application of copending application Ser. No. 298,659 filed Oct. 18, 1972, now abandoned.
It is desirable to treat particulate material by selectively separating the particles on the basis of size. Further, it is often desirable to dry a selected portion of the separated particles, recycle the other selected portions of the wet separated particles, and retreat the particles prior to selective separation thereof.
This invention therefore resides in apparatus and method for treating particulate material by selectively separating the particles on the basis of size.
Other aspects, objects, and advantages of the present invention will become apparent from a study of the disclosure, the appended claims, and the drawing.
The drawing is a diagrammatic view of the apparatus of this invention.
FIG. 1 shows the apparatus of this invention,
FIG. 2 shows an enlarged view of the separating apparatus, and
FIG. 3 shows another embodiment of the separating apparatus.
FIG. 1 shows the apparatus of this invention associated with, for example, carbon black processing apparatus. It should be understood, however, that the method and apparatus of this invention can be used with other particulate material and should not be limited to carbon black and the carbon black process.
Referring to FIG. 2, a rotatable separating apparatus 2 has first and second opposed ends 4,6 and at least first and second spaced-apart screen drums connected to and positioned within an outer member 12. The first screen drum 8 is positioned within the second screen drum 10 and the second screen drum 10 is positioned within the outer member 12 forming a first annulus 14 between the first and second screen drums 8,10 and a second annulus 16 between the second screen drum 10 and the outer member 12 with the first screen drum 8 open at only the first end 4, the first annulus 14 open at only the second end 6 and the second annulus 16 open at only the first end 4.
Each of the screen drums is of a different mesh size with the respective mesh numbers increasing in magnitude in a direction from the innermost screen drum 8 toward the outer member 12. For example, the first screen drum 8 is constructed of 10 mesh screen and the second screen drum 10 is constructed of 60 mesh screen.
The particular mesh sizes selected are dependent upon the size of the particles and the separations desired as will be later more fully described. One particular useful mesh size combination for carbon black particle separation is a first screen drum 8 being of 10 mesh and the second screen drum 10 being about 60 mesh. This allows charging only the desired pellet size, smaller than 10 mesh and larger than 60 mesh to the dryer 18 (FIG. 1). As is known in the art, as the mesh number increases in magnitude the openings through the screen decrease in size. For example, the width of the opening of 10 mesh is 0.066 in. and that of the 60 mesh is 0.0098 in.
The separator apparatus 2 of this invention can be connected to a particle dryer 18 via a collar 20, for example. The second end 6 of the apparatus 2 is connected to the heated rotary dryer 18 thereby positioning the first annulus 14 in communication with the dryer 18. In this construction, wet particles of a preselected size range which pass through the first screen drum 8 and are maintained on the second screen drum 10 pass from the first annulus 14 into the dryer for subsequent drying.
In the preferred embodiment, the dryer 18 is mounted on powered rotating supports 19 for rotating the separating apparatus 2 in response to rotation of the dryer 18, as seen in FIG. 1.
Referring to FIGS. 1 and 2, a purge gas line 24 is in communication at one end to the dryer 18 and at the other end to the section of a purge fan 26.
Oversize and undersize particulate material discharging from the first end 4 of the apparatus 2 can be injected into line 24 for recycling by the purge fan 26 for further processing. These oversize (and undersize) recycled wet pellets are broken up in fan 26, so that the oversize pellets will not continue to build up in size during each cycle, or ultimately only large, oversize pellets would exit from the wet pelleter 32 via conduit 23. In this manner, the oversize and undersize wet pellets are not passed through the dryer, loading the dryer, which is one of the most costly unit operations in carbon black manufacture.
For example, the particulate material injected into line 24 can be recycled via line 28 into a purge gas filter system 30. Separated carbon black is returned to the wet pelleter or mixer 32, preferably by way of conduit 31 and loose or flocculent carbon black storage or surge bin 33. These recycled pellets and flocculent black from bin 33 are passed to the wet pelleter by way of conduit 29. The mixer 32 is connected to line 23 which passes the wet pelleted material into the first screen drum 8. The wet pellets, prior to being discharged from mixer 32 by way of conduit 23 into separator 2 or that of 3, are treated with quenched reactor smoke containing carbon black and/or with flocculent black from bin 33, passed into the mixer 32 by way of conduits 27 and 25, respectively. When the wet pellets, such as wet carbon black pellets, are sticky, it is necessary to treat or coat the sticky pellets with a drying material, such as dry flocculent or loose carbon black, and/or with quenched reactor smoke containing carbon black, prior to charging the pellets to screening, in order to effect proper screening and not to plug the screens with sticky pellets.
FIG. 3 shows a separating apparatus having screen drums 8,10 of a different configuration. In this embodiment, the first screen drum 8 and the outer member 12 are each of a frusto-conical configuration with the larger end of each being positioned at the first end 4 of the apparatus and with the second screen drum 10 being of a substantially cylindrical configuration. In this construction, the lowermost floors of the first screen drum 8 and the outer member 12 are downwardly, angularly disposed relative to the horizontal in a direction toward the first end of 4. This construction enhances the movement of the particulate material across its supported member for discharge from the apparatus 2. The apparatus 2, shown in FIG. 2, can also be constructed with the first end 4 maintained at a higher elevation than the second end 6 for enhancing the movement of the particulate material. The embodiment shown in FIG. 3 can be constructed and maintained at an attitude such that the discharge end of the first screen drum 8 and the first and second annulus 14,16 are at a lower elevation than their opposed ends.
It should be understood, however, that rotation of the apparatus 2 and buildup of the particles on their respective supporting structure will cause said particles to be discharged from the apparatus even where each screen drum 8,10 and the outer member 12 are of cylindrical configuration and maintained at a horizontal attitude. However, maintaining the supporting floors at an angle θ with the horizontal in the range of about 5° to about 15° will enhance discharge of the particles. At greater angles than about 20° or more, the particles may not have an opportunity to pass through the screen openings before being discharged from the apparatus. This is particularly true where the apparatus is being charged at high rates.
In the operation of the method of this invention, a stream of particulate material comprised of a multiplicity of different sized particles is directed into the first, innermost screen drum 8 by pipe 34. The drum is rotated for passing the material along the first screen drum 8, passing a first portion of particles (e.g., smaller than 10 mesh) through the first screen drum 8 and causing larger or oversize (e.g., greater than 10 mesh) particles maintained on the first screen drum 8 to be discharged from the first end 4 of the first screen drum 8. The separator, preferably, is a unit attached to the rotating dryer, and members 8, 10, and 12 are rigidly affixed to each other, respectively, so that the separator rotates as a unit.
As the unit is rotating, the second screen drum also is rotating for passing the first portion of particles along the second screen drum 10, passing a second portion of particles through the second screen drum, and causing particles remaining on the second screen drum, the desired particle size range, to be discharged from the second end 6 of said second screen drum 10, preferably into the dryer 18.
Also the outer member 12 is rotated for passing the second portion of particles along the outer member and discharging said second portion from the first end 4 of the apparatus 2. In this construction, the particles being discharged from the second end 6 are within a preselected preferred size range intermediate the particles being discharged from the first end 4 of the apparatus, e.g., smaller than 10 mesh and larger than 60 mesh.
The undesirable size particles discharging from the first end 4 can thereafter be recycled to a purge gas filter, as at 30, incorporated with other formed particles, contacted with a drying agent in the wet pelleter or mixer 32 for drying of the outer surfaces of the particles which inhibit sticking of the particles one to the other and to the apparatus, and thereafter passing into the separating apparatus 2.
In the purge gas filter system and/or other process apparatus to which the recycle particles are passed, e.g., wet pelleter or mixer 32, their size is altered relative to the particle size rejected by the separating apparatus 2.
The method and apparatus of this invention therefore not only selectively separate particle sizes for drying which reduces the expenditures of labor and equipment needed for drying and thereby avoiding waste, but additionally provide an end product having a preselected size range.
While this invention has been described in conjunction with a presently preferred embodiment, it obviously is not limited thereto.
What is claimed is:
1. A method for treating carbon black to obtain pellets within a desired size, said method comprising:1. Pelleting a mass of particles; 2. Classifying the pelleted mass to remove therefrom pellets which are larger than a desired size range and pellets which are smaller than a desired size range, said classifying by:a. Directing a stream of pellets comprised of a multiplicity of different sized pellets into a first, innermost screen drum; b. Rotating the first screen drum for passing the pellets along the first screen drum; c. Passing a portion of the pellets through the first screen drum, and causing larger pellets maintained along the first screen drum to be discharged from the first end of the first screen drum; d. Rotating a second screen drum positioned about first screen drum for receiving the first portion of pellets passing through the first screen drum, passing the first portion of pellets along the second screen drum, passing a second portion of pellets through the second screen drum, and causing pellets maintained along the second screen drum to be discharged from the second end of said second screen drum; e. Rotating an outer member positioned about said second screen drum for receiving the second portion of pellets, passing the second portion of pellets along the outer member, and discharging said second portion of pellets from the first end of said outer member, said pellets being discharged from the second end of the second screen drum being of a preselected size range intermediate the pellets being discharged from the first end; and f. Passing the pellets discharged from the second end of the second screen drum into a dryer wherein said pellets discharged from the second end of the second screen drum are dried;
3. Passing the remaining pellets, said pellets being of the desired size range, to a drying zone;4. Recycling said pellets which are larger than the desired size and pellets smaller than the desired size range to the pelleting operation with the aid of a gas taken from a drying zone in a manner to cause disintegration of the pellets; and 5. Repelleting the recycled material.
| 1974-12-02 | en | 1976-11-02 |
US-57269575-A | Fuser roll sleeve
ABSTRACT
For use in a xerographic reproducing apparatus, a fuser roll structure comprising a core member having a sleeve carried thereby and a heat source disposed internally or externally of the core member. The fuser roll structure is characterized by the fabrication process wherein the sleeve is elevated in temperature above the operational temperature of the fuser roll structure and/or the core is chilled below ambient or room temperature. The sleeve is then installed on the core, and the assembly allowed to return to normal room temperature thereby creating a secure shrink fit of the sleeve onto the core. Structurally, the fuser roll comprises a sleeve the inside diameter of which is slightly larger than the outside diameter of the core when the sleeve temperature is elevated above said operational temperature and/or the core is chilled below said room or ambient temperature. At the operating temperature or below the aforementioned shrink fit exists. The process is also suitable for the fabrication of other types of roll structures for employment in a xerographic reproducing apparatus, for example, transport rolls which move the copy paper through the apparatus.
BACKGROUND OF THE INVENTION
This invention relates in general to the fixing of developed latent electrostatic images on a substrate, and more particularly, to apparatus for obtaining the desired permanent bonding of toner material, employed for development purposes in a xerographic copying machine, to the substrate.
In an automatic xerographic process of a type familiar to those skilled in the art and exemplified by U.S. Pat. No. 3,062,108, issued in the name of Clyde R. Mayo, the utilization of a heated fixing mechanism for achieving the permanent bonding of the developed latent electrostatic image onto the copy medium has proven highly satisfactory. One such fixing mechanism is commonly referred to as a fuser roll assembly. The fuser roll assembly additionally functions to feed the copy medium, such as paper, through the transfer station of the typical xerographic process. In providing the foregoing function, the fuser roll assembly cooperates with a backup roll. An example of such fuser roll assembly is disclosed in U.S. Pat. No. 3,291,466 issued to Aser et al.
In a typical construction of a fuser roll assembly, a hollow, generally cylindrical roll is mounted for rotation about its longitudinal axis, and is provided, along this axis, with an electric heating element. Such a roll is usually constructed of copper or aluminum and is normally provided with a coating of a suitable thermoplastic material, for example, polytetrofluoroethylene (hereinafter referred to as PTFE). PTFE is a fluorocarbon resin currently sold under the trademark "Teflon" by the E. I. duPont de Nemours and Company, Inc.
In operation, fuser roll assemblies are subjected to relatively high temperatures and pressures and this, together with manufacturing difficulties in obtaining perfect adhesion of the PTFE to the surface of the assembly roll, is the cause of deterioration of the PTFE coating which makes the roll unsatisfactory for continued use, thus necessitating its replacement. Where the roll is formed of copper, the roll is returned from the field, the PTFE being thereafter machined off (PTFE being almost chemically inert cannot be stripped easily without machining back to the base material). This machining operation causes loss of diameter beyond diameter tolerances, so the roll is deliberately machined slightly below true diameter and then built up oversize again, as by spraying with aluminum. The roll is then machined again to true diameter, and coated with PTFE as an original roll. This is a costly and tedious process.
When the roll is formed of aluminum, which is less expensive than copper, it is found economical to discard the aluminum rolls entirely when they can no longer be satisfactorily employed in copying machines. New roll assemblies are then substituted for the discarded assemblies. The difference in initial material costs plus the elimination of shipping costs from the field to the fuser assembly renovation site approximates the cost of repairing fuser roll assemblies including copper rolls. It is apparent that neither of these repair methods for fuser roll assemblies is satisfactory.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide fuser roll assemblies that may be readily repaired at minimal cost.
It is a further object of the invention to provide a fuser roll assembly that may be repaired at centralized field locations in lieu of returning the assembly to the place of manufacture.
It is a further object to provide a fuser roll assembly that is less expensive to manufacture and to repair, and one that will require less maintenance.
These and other objects of the invention are obtained by forming the fuser roll assembly in a unique manner.
The assembly or fuser roll structure in accordance with the invention includes a cylindrical roll, which functions as the assembly core member having an electrical heating element preferably disposed internally thereof and along its longitudinal axis. A substantially cylindrical sleeve or shell member is slidably mounted about the core while its temperature is elevated and/or the core is chilled. The sleeve-core assembly is thereafter allowed to cool to room temperature at which time the inside diameter of the sleeve tends to be slightly less than the outside diameter of the core member. It will be appreciated that a secure fit between the two members is thus created.
With the foregoing procedure, minimum equipment and process steps are required as compared to known processes. Consequently, the repair of such fuser roll structures or assemblies can economically be accomplished at centralized field locations in lieu of returning them to a single location such as the place of manufacture.
By employing the fuser roll assembly of the present invention, when the shell is worn or otherwise rendered unsuitable for further use, it may be removed by such means as slitting the sleeve on opposite sides along its entire length thereby allowing the sleeve halves, thus formed, to be removed and thereafter discarded. A new shell or sleeve at the required temperature may then be positioned concentrically about the core at the required temperature and spaced apart from the core, the sleeve-core assembly being allowed to return to operating temperature or below, thus creating the aforementioned secure fit between the sleeve and core.
Other objects of the invention and further features thereof shall become apparent to those skilled in the art in view of the following detailed disclosure and description of a preferred embodiment of the invention, particularly when read in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a fuser roll structure or assembly prior to the sleeve member being shrunk-fit onto a core member; and
FIG. 2 is a perspective view of the fuser roll assembly or structure as contemplated by the present invention with the sleeve shrunk-fit onto the core.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Since the xerographic reproducing process is well-known, a detailed description thereof is omitted. For those considering a description of the xerographic process necessary before a complete understanding of the present invention, reference may be had to U.S. Pat. Nos. 3,718,116 and 3,745,972 which patents are incorporated herein by reference.
FIGS. 1 and 2 of the drawings illustrate a fuser roll assembly or structure 10 which is adapted to be utilized in a xerographic reproducing apparatus for fusing toner images to copy paper. The assembly 10 comprises a hollow core or roll 12 of cylindrical shape preferably fabricated from copper material and adapted to be mounted for rotation about its longitudinal axis by means of stainless steel hub portions 14 (only one of which is shown). The core may have an outside diameter on the order of 27/8 inches.
In one embodiment contemplated by the present invention, a resistance heating element 16 is disposed internally of the core and is co-extensive with the longitudinal axis thereof. The resistance heating element may be energized when desired by actuation of suitable means (not shown) as for example a switch connects element 16 to a source of electrical power (also not shown).
A hollow cylindrical shell or sleeve 18, preferably formed of aluminum material is shrunk-fit onto the core 12 by elevating the temperature of the sleeve to a temperature of about 700° F. and inserting the core 12 into the sleeve and allowing the sleeve to cool to room temperature thereby effecting the shrink fit of the sleeve onto the core 12. The outside diameter of the sleeve may have a nominal dimension of three inches. While the sleeve 18 preferably comprises a bare sleeve of aluminum material a coating of PTFE may be applied to the surface thereof.
At room temperature, the inside diameter of the sleeve is slightly less than the outside diameter of the core 12. However, when elevated to a temperature of 700° F. as by placing in a suitable oven for a sufficient period of time the sleeve 18 expands such that the inside diameter thereof is slightly greater (See FIG. 1) than the outside diameter of the core 12. Upon cooling (FIG. 2) the sleeve 18 becomes shrunk-fit onto the core 12.
While the heating element 16 is described as a resistance heating element disposed internally of the core 12 the means for elevating the temperature of the fuser roll structure during operation may comprise an external source such as radiant heating element of the type disclosed in U.S. Pat. No. 3,498,596, incorporated herein by reference. The surface temperature of the sleeve may also be elevated by other suitable energy sources, for example, microwave or induction. An alternative for raising the sleeve temperature would be to provide the sleeve with an electrically resistive coating through which an electrical current could be passed during the fusing operation. When the sleeve is externally heated as disclosed, the core 12 may be fabricated from materials other than copper and may be fabricated from certain insulating materials suitable for providing a rigid cylindrical configuration.
Those skilled in the art will recognize that the foregoing illustrative embodiment of the invention represents but a single embodiment and various modifications can be made to the apparatus without departing from the spirit of the inventive concept. Accordingly, the scope of protection set by Letters Patent is to be defined solely by the appended claims.
What is claimed is:
1. Fuser apparatus for use in reproducing apparatus, including:an elongated rigid core member having a generally circular cross section adapted to be mounted for rotation about its longitudinal axis; a sleeve member having an inside diameter slightly greater than the outside diameter of said core when the temperature of said sleeve is elevated above the operational temperature of said fuser apparatus and/or the core is chilled below ambient temperature and wherein the outer surface of said rigid core securely engages the inner surface of said sleeve when the sleeve-core assembly is at or below operating temperature; and means for elevating the temperature of said sleeve member whereby toner images supported on substrates are softened when they are contacted by said sleeve.
2. Apparatus according to claim 1 wherein the outer surface of said sleeve is coated with a fluorocarbon resin.
3. Apparatus according to claim 2 wherein said means for elevating the temperature of said sleeve comprises a heater disposed internally of said core member.
| 1975-04-28 | en | 1977-05-24 |
US-9651279-A | Tool breakdown detecting system
ABSTRACT
A tool breakdown detecting system having at least one predicted standard pattern of change in the cutting resistance of a tool corresponding to a possible breakdown is prestored in a memory and compared with an actual change pattern of the cutting resistance of the tool monitored during working. When a coincidence is found between the prestored change pattern and the actual change pattern of the tool this indicates a breakdown of tool an alarm signal is generated. The alarm signal can activate a visual or audible alarm as well as regulate the further movement of the tool.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a tool breakdown detecting system for automatically detecting a breakdown of a tool attached to a numerical-controlled machine tool or the like during working to prevent various troubles which would otherwise result from the breakdown of the tool.
2. Description of the Prior Art
In an automatically controlled machine tool such as a numerical-controlled machine, if working is continued after the tool has broken down by some cause during working, a workpiece being machined becomes defective and, in addition, there is the possibility of incurring a serious trouble such as a breakdown of the machine tool itself. To avoid this, it is desired to detect the breakdown of the tool, but no satisfactory means has been developed for detecting the breakdown of the tool with sufficient accuracy.
SUMMARY OF THE INVENTION
An object of this invention is to provide a tool breakdown detecting system for automatically detecting a breakdown of the tool during working.
Another object of this invention is to provide a tool breakdown detecting system which detects automatically and rapidly a breakdown of the tool during working through utilization of a change pattern of the cutting resistance of the tool and prevents troubles which would otherwise result from the breakdown of the tool.
Briefly stated, in the tool breakdown detecting system of this invention, a change pattern of the cutting resistance of a tool which would be produced by its breakdown is stored as a standard change pattern in a memory, and the actual change pattern of the cutting resistance during working is compared with the standard change pattern to detect occurrence of a breakdown of the tool by detecting coincidence of them.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are, respectively, a diagram of a tool and a work piece and a graphical representation of the cutting resistance with time;
FIGS. 3 and 4 are, respectively, a diagram of a tool and another work piece and a graphical representation of the cutting resistance with time;
FIG. 5 is a graphical representation which shows an example of obtaining a change pattern from the cutting resistance of tool during working; and
FIG. 6 is a block diagram illustrating an embodiment of the apparatus system in accordance with this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a case where a work piece W1 having a stepped portion, driven in the direction of the arrow, is cut by a tool CT1 along the one-dot chain line, and FIG. 2 shows a change in the cutting resistance with time in this case. FIG. 3 illustrates a case where a columnar work piece W2 driven in the direction of the arrow is cut by a tool CT2 along the one-dot chain line, with the tool being broken down at a point P, and FIG. 4 shows a change in the cutting resistance with time in this case.
In the case of FIG. 1 in which nothing is wrong with the CT1 in the course of cutting work even if the work piece W1 has the stepped portion, the change in the cutting resistance with time merely presents such a characteristic as shown in FIG. 2 in which the cutting resistance abruptly increases at the stepped portion but thereafter remains constant. In the case where the tool CT2 is broken down during cutting work as shown in FIG. 3, the change in the cutting resistance presents, for example, such a characteristic as shown in FIG. 4 in which the cutting resistance decreases temporarily at the time of the breakdown of the tool but thereafter sharply increases. The reason for this is that in the case of a breakdown of the tool, the cutting resistance is decreased temporarily due to cracking of the tool tip or the like and is then abruptly increased due to the edge of the tool having no cutting ability.
The present invention makes use of such a particular cutting resistance change pattern produced in the case of a breakdown of the tool and is intended to detect the breakdown of the tool by successively comparing the particular or standard cutting resistance change pattern, which is supposed to appear in the case of a breakdown of the tool and which is stored in a memory, with the actual cutting resistance change pattern during working. Next, a description will be given of a method for comparing the stored standard cutting resistance change pattern with the actual cutting resistance change pattern during working.
For example, as shown in FIG. 5, during working the cutting resistance is detected at all times and the detected cutting resistance value is read in response to each one of sampling pulses sp having such a period as shown in FIG. 5 and a difference between each sampled value and an immediately preceding one is obtained. Next, the relationship of the thus obtained difference in magnitude to a preset value σ is coded by using the following relationship equations, and three values, 0, +1 and -1, are provided, respectively.
-σ≦(current sampled value)-(preceding sampled value)≦σ→0 (1)
(current sampled value)-(preceding sample value)>σ→1 (2)
(current sampled value)-(preceding sample value)<-σ→-1 (3)
The value of σ is determined in consideration of variations in the cutting resistance during normal cutting work.
Assuming that the value of σ, for example, such as shown in FIG. 5, is set as a result of the above consideration, a cutting resistance change pattern represented by the abovementioned three values becomes that shown at the lower part of FIG. 5; in the illustrated case, the progression (-1, 1, 1, 1) indicates a breakdown of the tool.
A plurality of standard cutting resistance change patterns, which are supposed to occur in the case of a breakdown of the tool, are converted into progressions of the abovementioned ternary composition, for example (-1, 1, 1, 1), (-1, 0, 1, 1), (-1, 1, 1, 0), etc., which are stored in a memory. By successively comparing these stored progressions with a progression obtained in actual working, their coincidence is detected. When such a coincidence is detected, it is decided that the tool is broken down.
In the above illustrated system and method, the cutting resistance change patterns are compared using progressions of four figures, but the number of figures may be selected as desired and the standard cutting resistance change patterns which are supposed to appear in the case of a breakdown of the tool are not limited specifically to the aforementioned ones.
FIG. 6 illustrates in block form an embodiment of the tool breakdown detecting system of the present invention based on the principles described above as being applied to a numericalcontrolled machine. In FIG. 6, reference character NC indicates a numerical controller; TP designates a command tape; TR identifies a tape reader; DEC denotes a decoder; OSC represents a feed pulse oscillator; INT shows an interpolator; PWC refers to a power controller; TPG indicates a timing pulse generator; RET designates a tool retreat program memory; SAX and SAZ identify servo circuits; SMX and SMZ denote servomotors; T represents a tool; W shows a work piece; SP refers to a spindle; SPMC indicates a spindle motor controller; SPM designates a spindle motor; R identifies a resistor; RE denotes a rotary encoder; SCT represents a smoothing circuit; ADC shows an A-D converter; ART1 and ART2 indicate arithmetic circuits; REG1, REG2, DREG, REGσ and PREG1 to PREGN designate registers; FF identifies a flip-flop; DRV denotes a driver, LMP represents a lamp; and GT and G1 to G7 show gates.
The command tape TP, which has recorded thereon command values for the amount of feed and feedrate of the tool T, etc. and auxiliary function commands, such as command values for the number of revolutions of the spindle SP and so forth, is read by the tape reader TR of the numerical controller NC, and the command information read from the command tape TR is decoded by the decoder DEC. If the content thus decoded is directed to an auxiliary function command, it is provided to the power controller PWC; for example, if the auxiliary command is one for the number of revolutions of the spindle SP, the power controller PWC applies a number-of revolutions command to the spindle motor controller SPMC, controlling the spindle motor SPM, such as a DC motor or the like, to rotate at the commanded speed. In other words, the spindle motor controller SPMC controls the firing phase of a thyristor for current supply to the spindle motor SPM so that a speed detection signal FBP of the rotary encoder RE mounted on the spindle may coincide with the spindle speed command signal, as is well known in the art.
When the content of the tape decoded by the decoder DEC is a tool feedrate command, it is applied to the feed pulse oscillator OSC to determine its output pulse frequency. When the decoded content of the tape is the command value for the amount of feed of the tool, it is provided to the interpolator INT, which responds to the command information to distribute output pulses fed thereto from the feed pulse oscillator OSC via the gate GT. The distributed pulses are supplied to the servo circuits SAX and SAZ, which drive the servomotors SMX and SMZ to control the relative movement of a movable machine part, for example, the tool T to the work piece W, achieving desired working of the piece work W. Such an operation is already known in the art; therefore, no detailed description will herein be
The cutting resistance of the tool T on the work piece W during working can be detected by various methods. In the present embodiment, the cutting resistance is detected by the voltage across the resistor R connected in series with the spindle motor SPM, utilizing the fact that the voltage is proportional to the cutting resistance. The smoothing circuit SCT is provided to remove noise components contained in the detected voltage across the resistor R and is formed by a low-pass filter, which applies an analog output signal to the A-D converter ADC. The A-D converter ADC converts the analog detection signal from the smoothing circuit SCT into digital form in synchronization with a sampling signal GSO which is outputted from the timing pulse generator TPG upon each input thereto of a one-rotation signal RP from the rotary encoder RE. In other words, the cutting resistance value during working is read in a digital form by the smoothing circuit SCT and the A-D converter ADC for each rotation of the spindle SP.
The digital output signal from the A-D converter ADC is stored in the register REG1 via the gate circuit G1, the arithmetic circuit ART1 and the gate circuit G2 using gate signals GS1 to GS7 provided to the gate circuits G1 to G7 from the timing pulse generator TPG. In the register REG2 there is stored a digital value of the cutting resistance obtained by the preceding sampling, and based on the sample values stored in the both registers REG1 and REG2, the arithmetic circuit ART1 performs the following calculation:
Content of register REG1 (current sample value)-Content of register REG2 (preceding sample value)
and stores the calculated result in the register REG2. Then, the arithmetic circuit ART1 makes a comparison between the content of the register REG2 and the preset value σ stored in the register REGσ and, in accordance with the result of comparison, provides one of the three values, 0, 1 and -1, as shown in the aforementioned equations (1), (2) and (3). The thus obtained value is set at a first stage of the register DREG via the gate circuit G7. Thereafter, the arithmetic circuit ART1 performs the same operation as described above for each rotation of the spindle SP; namely, any one of the values 0, 1 and -1 is applied to the register DREG with the preceding value being sequentially shifted, resulting in the actual cutting resistance change pattern of the tool being stored in the register DREG in the aforementioned ternary composition.
In the registers PREG1 to PREGN, there are stored various kinds of standard cutting resistance change patterns which would appear in actual cutting resistance in the case of a breakdown of the tool, each pattern having a ternary composition of four figures. Upon each shift of the content of the register DREG by writing therein new information at the digit of its first stage, the arithmetic circuit ART2 makes a comparison between each of the contents of the registers PREG1 to PREGN, successively outputted by output timing signals GSR1 to GSRN from the timing pulse generator TPG, with the content of the register DREG. When the content of the register DREG and the content of any of the registers PREG1 to PREGN coincide with each other, the arithmetic circuit ART2 sets the flip-flop FF to generate a tool breakdown signal, that is, an alarm signal AL.
This alarm signal AL can be utilized in various ways. In the present embodiment, the alarm signal AL is applied via the driver DRV to the alarm lamp LMP to light it and, at the same time, the signal AL is provided to the gate circuit GT of the numerical controller NC for closing the gate circuit GT, interrupting the feed pulse supply to the interpolator INT, and thus stopping the feed of the tool T. Further, for quickly retracting the tool T, the tool retreat program memory RET is activated by the alarm signal AL to provide a tool retract command value to the interpolator INT, thereby returning the tool T to its predetermined position, for example, a tool change point.
In the foregoing embodiment, the detection of cutting resistance is achieved by detecting the voltage across the resistor R connected in series with the spindle motor SPM. However, the present invention is not limited specifically to the above method and other known detecting methods can be employed. It is possible to detect the cutting resistance, for example, by installing a strain gauge on the tool T to detect a voltage corresponding to a strain of the tool T.
As has been described in the foregoing, in the present invention utilizing the fact that a peculiar cutting resistance change pattern is provided when a tool breaks down, a comparison is always made between a predicted standard cutting resistance change pattern in the case of a breakdown of the tool and the actual cutting resistance change pattern detected at all times during working, and coincidence of the two patterns is regarded as indicative of the breakdown of the tool; namely, the breakdown of the tool can automatically be detected during working, enabling prevention of various troubles which would otherwise result from the breakdown of tool. Accordingly, the tool breakdown detecting system of this invention is of great utility when applied to a machine tool such as a numerical-controlled machine.
It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts of this invention.
What is claimed is:
1. A tool breakdown detecting system comprising:memory means for storing at least one predetermined change pattern of the cutting resistance of a tool corresponding to a tool breakdown condition during working; means for detecting the actual cutting resistance of the tool during working and forming a change pattern of the actual cutting resistance of the tool; and comparing means for comparing the predetermined change pattern stored in the memory means with the actual change pattern of the cutting resistance of the tool during working, wherein coincidence of the two change patterns thus compared indicates a tool breakdown condition.
2. A tool breakdown detecting system according to claim 1, wherein the detecting and forming means detects and samples the cutting resistance and, for each sampling, a difference is obtained between the currently sampled value and the previously sampled one, and wherein the difference is coded and used to form the change pattern of the cutting resistance.
3. A tool breakdown detecting system according to claim 1, further comprising means for retreating the tool and wherein the comparing means is operatively connected to the tool retreating means and wherein the predetermined change pattern stored in the memory and the change pattern of the cutting resistance during working are compared and, in the case of coincidence, the tool is retreated.
4. A system for automatically detecting a breakdown of a tool during working comprising:means for detecting cutting resistance of the tool during working; means operatively connected to the detecting means for sampling the cutting resistance detected by the detecting means; means operatively connected to the sampling means for storing sampled values obtained by the sampling means; arithmetic means operatively connected to the storing means for calculating a difference between the sampled values stored in the storing means, the arithmetic means further comparing the difference calculated between the sampled values to a preset value and coding the difference between the sampled values on the basis of the compared preset value; first memory means operatively connected to the arithmetic means for storing a progression of figures coded by the arithmetic means representing the actual change pattern of the tool; second memory means for storing a progression of figures coded to represent at least one predetermined standard change pattern associated with a breakdown condition in the tool; and comparing means operatively connected to the first and second memory means for comparing the actual change pattern with the at least one predetermined standard change pattern, the comparing means having means for comparing the progressions of coded figures stored in the first and second memory means with each other and means for generating a tool breakdown signal when the compared progressions of figures coincide with each other.
5. A tool breakdown detecting system according to claim 4 wherein the arithmetic means calculates, compares and codes a difference between successively sampled values of the cutting resistance of the tool.
6. A tool breakdown detecting system according to claim 4 further comprising a motor for driving a work piece held in a spindle which is to be machined by the tool, means for supplying power to the spindle motor and wherein the detecting means comprises resistor means connected in series with the spindle motor and spindle power supplying means for generating a voltage signal proportional to the cutting resistance of the tool.
7. A tool breakdown detecting system according to claim 6 further comprising means operatively connected to the spindle motor and to the sampling means for generating a sampling signal wherein the sampling means samples the actual cutting resistance voltage signal in synchronization with the sampling signal.
8. A tool breakdown detecting system according to claim 7 wherein the sampling signal generating means includes a rotary encoder for providing a signal corresponding to a predetermined rotation by the motor of the spindle.
9. A tool breakdown detecting system according to claim 8 wherein the sampling signal is generated for each rotation of the spindle.
10. A tool breakdown detecting system according to claim 7 or 8 wherein the sampling means comprises an A-D convertor which provides a digital output signal from the sampled voltage signal in synchronization with the sampling signal.
11. A tool breakdown detecting system according to claim 10 further comprising means operatively connected between the resistor means and the A-D convertor for removing noise components contained in the detected voltage signal and applying an analog signal to the A-D convertor corresponding to the cutting resistance of the tool.
12. A tool breakdown detecting system according to claim 11 wherein the removing means comprises a pass band filter.
13. A tool breakdown detecting system according to claim 4 wherein the arithmetic means codes the difference between the sampled values in a ternary composition and the second memory means stores a progression of figures representing the at least one predetermined change pattern in a coded ternary composition.
14. A tool breakdown detecting system according to claim 4 or 13 wherein the progression of figures compared by the comparing means is four.
15. A system for automatically detecting a breakdown of a tool during working comprising:memory means for storing at least one predetermined change pattern of cutting resistance of the tool, with the change pattern corresponding to a tool breakdown condition during working; means for detecting actual cutting resistance of the tool during working; means for forming a change pattern of the actual cutting resistance of the tool detected by the detecting means; and comparing means for comparing the at least one predetermined change pattern stored in the memory means with the acutal cutting resistance change pattern formed by the forming means, wherein coincidence of the two change patterns compared by the comparing means indicates a tool breakdown condition.
16. A tool breakdown detecting system according to claim 15, wherein the forming means comprises sampling means for time sampling values of the actual cutting resistance of the tool detected by the detecting means and coding means for coding a difference between values of the actual cutting resistance time sampled by the sampling means, thereby forming the actual cutting resistance change pattern of the tool.
17. A tool breakdown detecting system according to claim 16, wherein the coding means codes a difference between successively sampled values of the actual cutting resistance of the tool.
18. A tool breakdown detecting system according to claim 15 further comprising means operatively connected to the comparing means for generating a tool breakdown signal when the two compared change patterns compared by the comparing means coincide with each other.
19. A tool breakdown detecting system according to claim 18 or 11 further comprising gate means operatively connected to the tool breakdown signal generating means for controlling supply of a feed pulse which causes the tool to be fed, wherein the gate means is activated by a tool breakdown signal to interrupt the feed pulse supply for stopping the feed of the tool.
20. A tool breakdown detecting system according to claim 18 or 4 further comprising means operatively connected to the tool breakdown signal generating means for retreating the tool to a predetermined position, wherein the tool retreating means is activated by a tool breakdown signal to retreat the tool.
21. A tool breakdown detecting system according to claim 18 or 4 further comprising means operatively connected to the tool breakdown signal generating means for providing a visual or audible signal when a tool breakdown signal is generated.
| 1979-11-21 | en | 1982-04-20 |
US-9023379-A | Millimeter wave transmission line using thallium bromo-iodide fiber
ABSTRACT
Millimeter wave transmission lines are disclosed for propagating electromagnetic waves of a wavelength ranging from about 10 mm to about 0.4 mm. The transmission lines comprise a fiber of co-crystallized thallium bromo-iodide consisting of from about 40 mole percent to about 46 mole percent thallium bromide and from about 60 mole percent to about 54 mole percent thallium iodide. The fiber may be cladded with a dielectric material having a dielectric constant less than that of the fiber. A number of alternate fiber and cladding cross-sectional configurations are disclosed including circular, square, rectangular, and elliptical.
TECHNICAL FIELD
This invention relates to electromagnetic wave transmission, and more particularly it relates to dielectric fiber transmission lines for millimeter waves.
BACKGROUND ART
The use of dielectric rods as waveguides for propagating electromagnetic waves in the microwave and millimeter wave region of the spectrum is well known: see "An Investigation of Dielectric Rod as Wave Guide", by C. H. Chandler, Journal of Applied Physics, Vol. 20 (December 1949), pages 1188-1192.
In the past waveguides of the foregoing type usually were constructed with materials having relatively low dielectric constants (e.g., polystyrene, quartz, and Teflon). In order for propagating millimeter waves to be confined within rods of low dielectric constant material, rod diameters are required which are excessively large for a number of applications. On the other hand, when such rods are only a fraction of a wavelength in diameter, the greater part of the propagating wave energy lies outside of the rod, creating evanescent fields which make it extremely difficult to support the rods in a practical manner. Moreover, when dielectric rods which propagate large evanescent fields are bent or have other surface imperfections, considerable power may be lost by radiation.
Alternatively, previous rod waveguide materials with high dielectric constants (e.g. gallium arsenide, silicon, and sapphire) were quite rigid, and waveguides which could be fabricated from these materials were limited to a few centimeters in length. Thus, flexible, long, readily supportable dielectric rod waveguides for millimeter waves were beyond the state of the art.
A further area of prior art of relevance to the present invention but which heretofore was never associated with millimeter wave propagation is that relating to optical waveguides using fibers of thallium bromo-iodide, alternatively known as KRS-5. Crystals of thallium bromo-iodide have long been used for the refraction and dispersion of light, particularly at infrared wavelengths, as discussed in a paper by William S. Rodney and Irving H. Malitson, "Refraction and Dispersion of Thallium Bromide Iodide", Journal of the Optical Society of America, Vol. 46, No. 11 (November 1956), pages 956-961. More recently, extrusion techniques have been devised for producing co-crystalized fibers of thallium bromo-iodide in continuous lengths of up to 200 meters. These extrusion techniques are described in detail in patent application Ser. No. 37,581, filed May 9, 1979 by Douglas A. Pinnow et al and entitled "Infrared Transmitting Fiber Optical Waveguides Extruded from Halides", which application is a continuation of application Serial No. 800,149, filed May 24, 1977, now abandoned and in a paper by D. A. Pinnow et al "Polycrystalline Fiber Optical Waveguides for Infrared Transmission", IEEE Journal of Quantum Electronics, QE-13, No. 9 (September 1977), page 91D.
Thallium bromo-iodide fibers made by the aforementioned extrusion techniques have been found to be optically transparent over a range of light wavelengths from approximately 0.6 μm in the visible region to approximately 35 μm in the infrared region, and hence are particularly suited for use as a fiber optical waveguide for the transmission of light at infrared wavelengths. However, prior to the present invention there was nothing to suggest that such fibers also could be used for propagating electromagnetic waves at millimeter wavelengths. In fact there is a dearth of published literature on appropriate parameter values (e.g. dielectric constant and loss tangent) which would give any clue to the usefulness of co-crystalized thallium bromo-idoide for millimeter wave propagation.
More specifically, in the book by A. R. Von Hippel, Dielectric Materials and Applications, Technology Press of MIT and John Wiley, New York (1954), page 302, values are given for the dielectric constant and loss tangent of thallium bromo-iodide for a number of radio frequencies ranging from 100 Hz to 10 MHz; however, no values are given corresponding to wavelengths shorter than 30,000 mm. The only other previous radio frequency measurements known for thallium bromo-iodide are the dielectric constant measurements of R. C. Powell of the National Bureau of Standards Boulder Laboratories at wavelengths of 300 mm and 1500 mm, and which are given on page 958 of the aforementioned Rodney and Malitson paper.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a highly flexible dielectric fiber transmission line for propagating electromagnetic waves at millimeter wavelengths which retains the evanescent energy of the propagating waves close to the fiber, thereby facilitating arrangement and support of the transmission line in a practical and effective manner.
It is a further object of the invention to provide a low-loss, flexible millimeter wave fiber transmission line of small cross-sectional dimensions and long length.
It is still another object of the invention to provide a millimeter wave fiber transmission line which is less sensitive to bends and surface imperfections in the transmission line medium than millimeter wave dielectric rod transmission lines of the prior art.
A transmission line according to the invention comprises a fiber of co-crystalized thallium bromo-iodide consisting of from about 40 mole percent to about 46 mole percent thallium bromide and from about 60 mole percent to about 54 mole percent thallium iodide. The fiber is used to propagate electromagnetic waves of a wavelength ranging from about 10 mm to about 0.4 mm.
Additional objects, advantages, and characteristic features of the invention will become readily apparent from the following detailed description of preferred embodiments of the invention when considered in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawing:
FIG. 1 is a side view, partly in section and partly in block form, illustrating a millimeter wave transmission line according to one embodiment of the invention coupled to a millimeter wave source and a detector;
FIGS. 2 and 3 are cross-sectional and longitudinal sectional views, respectively, illustrating an exemplary electromagnetic field pattern for millimeter waves propagating along the transmission line of FIG. 1; and
FIGS. 4-10 are cross-sectional views showing various clad millimeter wave transmission lines according to respective further embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 with greater particularity, a millimeter wave transmission line according to the invention utilizes a fiber 10 of co-crystalized thallium bromo-iodide, alternatively known as KRS-5. The composition of the fiber 10 preferably ranges from about 40 mole percent to about 46 mole percent thallium bromide and from about 60 mole percent to about 54 mole percent thallium iodide. A specific exemplary composition which has been employed consists of 45.7 percent thallium bromide and 54.3 mole percent thallium iodide. In the embodiment shown in FIG. 1, the fiber 10 has a circular cross-section, although as discussed in more detail below, a number of other cross-sectional configurations are also suitable and may be used instead. Exemplary diameters for the fiber 10 range from about 0.1 mm to about 3 mm. Exemplary fiber lengths range from a few centimeters to hundreds of meters.
The fiber 10 may be fabricated by heating billets of thallium bromo-iodide in a screw press to a temperature of from about 200° C. to about 350° C. (which is below the 414° C. melting point of thallium bromo-iodide). The press is provided with an orifice having a diameter corresponding to the desired diameter of the fibers being fabricated. The press piston is advanced until sufficient pressure is provided to cause the fiber to be extruded through the orifice. Typical extrusion rates are about several centimeters per minute. For further details concerning fabrication of the fiber 10, reference may be to the aforementioned patent application Ser. No. 37,581, now abandoned.
Measurements of the dielectric constant (ε) and the loss tangent (tan δ) of a fiber 10 of the aforementioned specific exemplary composition of thallium bromo-iodide at the millimeter wavelengths of 8.6 mm and 3.2 mm have indicated a high dielectric constant (ε=32) together with an unexpected low loss tangent (tan δ=2×10-3), which is less than one-tenth of the loss of a hollow rectangular metallic waveguide at the frequencies in question. This surprising combination of parameters makes thallium bromo-iodide fiber 10 especially suitable for propagating electromagnetic waves in the millimeter region of the spectrum, i.e. at wavelengths ranging from about 10 mm to about 0.4 mm. The latter wavelength is the estimated upper wavelength limit of the reststrahlen region which is characterized by absorption resonances in the molecular structure.
Referring again to FIG. 1, millimeter waves to be launched onto the fiber 10 may be generated by a suitable millimeter wave source 12 such as an IMPATT diode, klystron, or traveling-wave tube. In the arrangement shown in FIG. 1, millimeter waves from the source 12 initially propagate along a hollow rectangular metallic waveguide 14 and are then launched onto the fiber 10 by means of a transition coupler 16. However, it should be understood that, alternatively, millimeter waves may be launched onto the fiber 10 directly from the source 12. Moreover, the particular transition coupler 16 illustrated in FIG. 1 is only exemplary, and a number of other coupling arrangements may be employed instead.
In the specific exemplary arrangement shown in FIG. 1, the end of the waveguide 14 away from the source 12 defines a flared transition portion 18 having a cross-section which gradually changes from rectangular to circular. The end of the fiber 10 onto which the millimeter waves are lauched is disposed within a plug 20 defining a pair of conically tapered ends, the end away from the fiber 10 being inserted within the waveguide flared portion 18. The plug 20 is preferably of a dielectric material having a dielectric constant less than that of the fiber 10, an exemplary material being Teflon.
At the other end of the fiber 10 a like transition coupler 16' removes the propagating millimeter waves from the fiber 10 and launches them onto a hollow rectangular waveguide 22 for travel to a suitable detector 24 such as a Schottky diode. As specific example solely for illustrative purposes, when the arrangement of FIG. 1 is used to propagate millimeter waves at a wavelength of 3.2 mm, the waveguides 14 and 22 may have cross-sectional dimensions of 2.5 mm by 1.25 mm, with the fiber 10 having a diameter of 0.5 mm.
An exemplary electromagnetic field pattern (HE11 mode) for millimeter waves propagating along the fiber 10 is illustrated in FIGS. 2 and 3. As may be seen, in contrast to low dielectric constant rod transmission lines of the prior art wherein evanescent fields propagate outside of the rod to a distance of several centimeters, with a transmission line according to the present invention evanescent fields extend radially outwardly from the fiber 10 by only a few millimeters. Thus, millimeter wave transmission lines according to the invention may be arranged and supported far more practically and effectively than heretofore has been possible. In addition, a millimeter wave transmission line according to the invention is considerably less sensitive to bends and surface imperfections in the transmission line medium than millimeter wave dielectric rod transmission lines of the prior art. Moreover, transmission lines according to the invention have low loss, are flexible, and may be fabricated in very long lengths.
The radial extent to which electromagnetic energy propagates outside of a transmission line according to the invention may be reduced still further or even eliminated entirely by disposing a cladding of low-loss dielectric material having a dielectric constant less than that of the fiber 10 about the lateral surface of the fiber 10. This enables millimeter wave transmission lines according to the invention to be routed and supported in a manner similar to optical fibers or coaxial cables. Exemplary cladding materials which may be employed are Telfon and polystyrene, although it should be understood that other cladding materials are also suitable and may be used instead. The cladding may be either coextruded with the fiber 10 or coated on the fiber surface after the fiber 10 has been extruded.
A number of alternate milimeter wave transmission line configurations employing clad thallium bromo-iodide fibers according to respective further embodiments of the invention are illustrated in FIGS. 4-10.
In the embodiment of FIG. 4 fiber 10a of circular cross-section is shown disposed within cladding 26a which has a circular cross-sectional perimeter.
In the embodiments of FIGS. 5 and 6, the respective fibers 10b and 10c both have a square cross-section. However, cladding 26b of FIG. 5 has a square cross-sectional perimeter, while the cross-sectional perimeter of cladding 26c of FIG. 6 is circular.
In the embodiments FIGS. 7 and 8, respective fibers 10d and 10e are both shown as having an elliptical cross-section. Elliptically cross-sectioned fibers such as 10d and 10e typically may be dimensioned with a major axis-to-minor axis ratio of about two-to-one. In the embodiment of FIG. 7 cladding 26d has an elliptical cross-sectional perimeter, while cladding 26e of the embodiment of FIG. 8 has a circular cross-sectional perimeter.
In the embodiments of FIGS. 9 and 10, respective fibers 10f and 10g both have a rectangular cross-section, typically dimensioned with a side length ratio of two-to-one. Cladding 26f in the embodiment of FIG. 9 has a rectangular cross-sectional perimeter, while the cross-sectional perimeter of cladding 26g of FIG. 10 is circular. Non-circular cross-sectioned fibers 10b-10g are especially useful for preserving millimeter wave polarization around bends, twists, or loops in the fiber.
Although the present invention has been shown and described with reference to particular embodiments, nevertheless, various changes and modifications which are obvious to a person skilled in the art to which the invention pertains are deemed to lie within the spirit, scope, and contemplation of the invention.
What is claimed is:
1. A transmission line comprising:a fiber of co-crystalized thallium bromo-iodide consisting of from about 40 mole percent to about 46 mole percent thallium bromide and from about 60 mole percent to about 54 mole percent thallium iodide, and means for launching electromagnetic waves of a wavelength ranging from about 10 millimeters to about 0.4 millimeter onto said fiber.
2. A transmission line according to claim 1 wherein said fiber has a transverse extent ranging from about 0.1 millimeter to about 3 millimeters.
3. A transmission line according to claim 1 wherein a cladding of a dielectric material having a dielectric constant less than that of said fiber is disposed about the lateral surface of said fiber.
4. A transmission line according to claim 3 wherein said fiber has a circular cross-section, and said cladding has a circular cross-sectional perimeter.
5. A transmission line according to claim 3 wherein said fiber has a square cross-section, and said cladding has a square cross-sectional perimeter.
6. A transmission line according to claim 3 wherein said fiber has a square cross-section, and said cladding has a circular cross-sectional perimeter.
7. A transmission line according to claim 3 wherein said fiber has an elliptical cross-section, and said cladding has an elliptical cross-sectional perimeter.
8. A transmission line according to claim 3 wherein said fiber has an elliptical cross-section, and said cladding has a circular cross-sectional perimeter.
9. A transmission line according to claim 3 wherein said fiber has a rectangular cross-section, and said cladding has a rectangular cross-sectional perimeter.
10. A transmission line according to claim 3 wherein said fiber has a rectangular cross-section, and said cladding has a circular cross-sectional perimeter.
11. A transmission line according to any of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 wherein said electromagnetic waves are of a wavelength ranging from about 8.6 millimeters to about 3.2 millimeters.
12. A method for transmitting millimeter wave energy comprising launching electromagnetic waves of a wavelength ranging from about 10 millimeters to about 0.4 millimeter onto a fiber of co-crystallized thallium bromo-iodide consisting of from about 40 mole percent to about 46 mole percent thallium bromide and from about 60 mole percent to about 54 mole percent thallium iodide, and removing said electromagnetic waves from said fiber.
13. A method according to claim 12 wherein said electromagnetic waves are of a wavelength ranging from about 8.6 millimeters to about 3.2 millimeters.
14. A new use for a KRS-5 waveguide which is comprised of co-crystalized thallium bromo-iodide having from about 40 mole percent to about 46 mole percent thallium bromide and from about 60 mole percent to about 54 mole percent thallium iodide, wherein said new use comprises:utilizing said KRS-5 waveguide to transmit electromagnetic energy in the 0.4 to 10 millimeter wavelength range.
| 1979-11-01 | en | 1981-10-06 |
US-61459290-A | Apparatus for determining change of fuel flow
ABSTRACT
This invention discloses a device by which fuel flow within a pressurized fuel system can accurately be measured to determine if the flow of fuel falls within an acceptable range. If the device detects that the fuel flow is not within normal operating ranges of the fuel system, then the device will provide a warning indication that a malfunction or fuel leakage is present in the fuel system or shut off power to the fuel pump providing the flow of fuel. The detection device can either be a device which detects the actual flow of the through the fuel line, or a device which detects the pressure within the fuel line. By this invention, a pending malfunction, such as fuel filter blockage or leaking fuel line, can be ascertained before the malfunction becomes a serious problem.
BACKGROUND OF THE INVENTION
This invention is drawn to an apparatus for sensing changes in flow of a fluid, and more specifically, an apparatus for sensing changes in flow of fuel through a pressurized automotive fuel system.
Current automotive or vehicular fuel systems provide pressurized fuel from the fuel tank to the vehicle's engine. Generally, these fuel systems include a fuel pressure regulator to control the pressure of the fuel through the fuel system. To enable the pressure regulator to maintain good fuel regulation, and to keep the fuel operating temperature at a minimum, a substantial amount of excess fuel is supplied to the engine from the fuel tank than is actually used by the engine. The fuel which is not used by the engine is subsequently returned back to the fuel tank.
Since the automotive fuel system includes a fuel line from the fuel tank to the engine, and a fuel line from the engine back to the fuel tank, as well as a variety of fuel system components along the way, there are a number of places where fuel system integrity could be breached and cause fuel leakage, especially since the fuel system is pressurized. Further, catastrophic loss of fuel system integrity as a result of collisions or the like provides additional concerns. For many obvious reasons, leakage of fuel from the fuel system could cause a number of serious problems. Current automotive fuel systems incorporate clips, latches, or check valves at the connections between the fuel lines and the different components to prevent fuel leakage by increasing the durability of the fuel system. Although these devices provide additional integrity against the leakage of fuel from the fuel system, they add a certain amount of excessive cost to the fuel system, and further, cannot provide an indication of leakage within the fuel system if it happens to occur. Moreover, these devices do not provide safety mechanisms in the event of catastrophic fuel system leakage, such as may occur from an automobile accident or the like. In addition, current automotive fuel systems do not provide adequate means for determining certain malfunctions of the fuel system components.
What is needed then is an automotive fuel system incorporating means for providing an indication of loss of fuel system integrity from either fuel leakage within the fuel system or other fuel system component malfunction, and to stop the fuel pump in the event of catastrophic loss of fuel system integrity. It is therefore an object of this invention to provide such a means.
SUMMARY OF THE INVENTION
According to a preferred embodiment of this invention, a device is incorporated at a strategic point or strategic points along the fuel line of a pressurized fuel system which is sensitive to the flow of fuel through the line. Ideally, a single device will be placed at a position proximate the fuel tank on a return fuel line from the engine to the fuel tank. This position enables the device to detect fuel leakage along most of the entire length of the fuel system. If the device detects a decrease or increase in the flow of fuel through the return fuel line, it can activate a warning signal provided at a desirable location, or can switch off the fuel pump providing the fuel pressure completely in the event of a major malfunction. Since many automotive fuel systems today incorporate a computerized fuel system for delivering an accurate amount of fuel to the engine, the fuel flow sensing device can be calibrated to relatively small changes in fuel flow, and thus be triggered by minor changes in fuel flow which may anticipate major problems about to occur.
The fuel flow detection device can either, according to preferred embodiment of this invention, be a device which measures the actual fuel flow through the device, or a device which measures a change in pressure drop within the device. The accuracy of the system enables the fuel flow measuring device to detect leakage within the system, blocked fuel filters, malfunctioning regulators, or air trapped in the fuel system, as well as other breaches in fuel system integrity.
Additional objects, advantages, and features of the present invention will become apparent in the following description and appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an automotive fuel system incorporating a fuel flow detection device according to a preferred embodiment of this invention;
FIG. 2A is a fuel flow detection device according to a preferred embodiment of this invention incorporating a pressure transducer;
FIG. 2B is a fuel flow detection device according to a preferred embodiment of this invention incorporating a pressure detecting diaphragm; and
FIG. 3 is a fuel flow detection device according to a preferred embodiment of this invention incorporating a flow detector.
DETAILED DESCRIPTION OF THE INVENTION
The following description is merely exemplary in nature and is in no way intended to limit the invention or its application or uses.
FIG. 1 shows generally an automotive fuel system 10 incorporating a fuel flow detection device 30 according to a preferred embodiment of this invention. Fuel system 10 includes a fuel tank 12 generally located near the rear of the automobile as shown in phantom. Fuel tank 12 can take a variety of different shapes, sizes and locations to accommodate the designs of different automobiles. Located within fuel tank 12 is a fuel pump 14 for providing pressurized fuel to the engine (not shown) of the automobile. Fuel pump 14 is connected to an adapter 16 positioned on an outer surface of fuel tank 12. A first fuel inlet tube 18 is connected at one of its ends to adapter 16. Fuel inlet tube 18 is connected at its other end to an inlet end of a fuel filter 20 as is well known in the art. Attached to an outlet end of fuel filter 20 opposite first fuel inlet tube 18 is a second fuel inlet tube 22. Second fuel inlet tube 22 is connected at its other end opposite fuel filter 20 to a fuel rail 24. Fuel rail 24 is generally elongated in shape, and provides fuel to the cylinders of the automobile by means (not shown) well known in the art. Attached to an end of fuel rail 24 opposite second fuel inlet tube 22 is a fuel pressure regulator 26. Fuel leaving fuel rail 24 is introduced into fuel pressure regulator 26. A first fuel outlet tube 28 is connected at one end to fuel pressure regulator 26 and at its other end to fuel flow detection device 30. At an end of fuel detection device 30 opposite first fuel exit tube 28 is a second fuel exit tube 32. Second fuel exit tube 32 is connected to adapter 16 at its other end. Therefore, the fuel system components as shown in FIG. 1 provide a loop for fuel to leave fuel tank 12, and then return to it. The parameters of each of the fuel tubes 18, 22, 28 and 32, the fuel filter 20, the fuel rail 24, the fuel pressure regulator 26, the adapter 16, the fuel pump 14 and the fuel tank 12 are determined by the different operating characteristics of the specific automobile in which they are incorporated as is well known in the art. Further, other fuel system components not specifically disclosed here can be incorporated into fuel system 10.
In operation, a signal supplying power applied to fuel pump 14 by means not shown, such as a signal from the ignition system of the automobile, instructs the fuel pump 14 to pump fuel from fuel tank 12 into first fuel inlet tube 18 through adapter 16. The pressure, amount and rate of the fuel pumped from fuel tank 12 by fuel pump 14 is also determined upon the different operating characteristics of the specific automobile in which they are used. Fuel leaving fuel tank 12 is directed along first inlet tube 18 by means of adapter 16. As fuel travels down first inlet tube 18 towards the engine it encounters fuel filter 20. Fuel filter 20 removes impurities and the like trapped in the fuel by means well known to those skilled in the art. Fuel leaving fuel filter 20 is then directed along second inlet tube 22. Second inlet tube 22 directs the fuel into fuel rail 24. Fuel rail 24 supplies fuel to fuel injectors which in turn supply the necessary or predetermined amount of fuel to the engine by means also well know to those in the art. The pressure and amount of fuel available from fuel rail 24 is determined by fuel pressure regulator 26. Fuel pressure regulator 26 enables the fuel pressure to be maintained in the input portion of the fuel system 10 and to be applied to the engine at a desirable amount. To provide accurate regulation of the fuel to enable efficient engine performance, the pressure regulator 26 requires substantially more fuel than what is actually used by the engine. Further, excess fuel pumped through the fuel system 10 provides a method of keeping the operating temperature of the fuel at a minimum. The excess fuel supplied to the fuel rail 24 leaves fuel regulator 26 through first outlet tube 28. The excess fuel travels through first outlet tube 28 until it reaches fuel flow detection device 30 according to a preferred embodiment of this invention. Fuel flow detection device 30 detects the amount of fuel traveling through first outlet tube 28 to second outlet tube 32 as will be described hereunder. Second outlet tube 32 returns the excess fuel back to fuel tank 12 through adapter 16 to be pumped back through the fuel system 10.
Fuel flow detection device 30 provides a means for determining fuel leakage or fuel component malfunction within the fuel system 10. Any significant change in fuel flow will be interpreted by detection device 30 as a loss of fuel system integrity, such that appropriate service can be rendered to the fuel system 10. Detection device 30 includes computer means 31 to shut pump 14 off entirely in the event of a catastrophic fuel system failure from events such as an accident or collision. Therefore, many different fuel system malfunctions can be assessed and remedied quickly and efficiently before a costly or dangerous situation arises. In addition, detection device 30 eliminates the need for costly devices for preventing fuel leakage.
Ideally, fuel flow detection device 30 is positioned as close as possible to fuel tank 12 on the return side of fuel system 10. In other words, first fuel outlet tube 28 is made as long as possible, and second fuel outlet tube 32 is made as short as possible. By this configuration, fuel flow detection device 30 can detect the flow of fuel which has traveled through almost the entire length of fuel system 10, thus enabling it to detect loss of fuel system integrity at nearly every location of fuel system 10. In addition, fuel flow detection device 30 can be used at alternate desirable locations such as in liner 18 or 22, or at a multiplicity of locations to isolate certain fuel system components, such as the fuel pump 14. Therefore if fuel flow detection device 30 detects a decrease or increase in fuel flow the malfunctioning components can be quickly identified. For a fuel flow detector isolating the fuel pump, its most desirable location would be along first fuel inlet line 18, as close to adapter 16 as possible.
Many automotive fuel systems today incorporate a computerized fuel system for applying an accurate amount of fuel to the engine of the automobile and continuously monitoring this amount, thus enhancing efficiency of operation of the vehicle. Therefore, these computerized fuel systems enable an acceptable amount of fuel to be applied to the engine within a narrow range. Since the computerized fuel system will monitor the amount of fuel being used by the engine, the computer can compare this amount to the flow of fuel through detection device 30. It follows then that fuel flow detection device 30 can be calibrated to respond to a small change in fuel flow which is not caused by the computer control. By this, detection device 30 can respond to relatively small leaks within the fuel system, early detection of blockage of fuel filter 20, or small malfunctions with fuel pump 14, etc. Therefore, the fuel system can be serviced before a serious malfunction occurs.
Electrical leads from fuel flow detection device 30 can be connected to a warning system, such as an indicator light on the dashboard of the automobile, to indicate malfunctions of the fuel system. Further, fuel flow detection device 30 can be electrically connected to fuel pump 14 or an electrical component (not shown) which controls fuel pump 14, such that fuel flow detection device 30 can shut down fuel pump 14 in the event of a major malfunction.
FIG. 2A shows a certain type of fuel flow detection device 130 which can be incorporated in fuel system 10 of FIG. 1 as device 30. Detection device 130 detects the flow of fuel by measuring a change in pressure drop within the detection device 130. Fuel flow detection device 130 includes a main chamber 132 having an entrance chamber 138 at one end and an exit chamber 140 at the other end. Attached to entrance chamber 138 is an entrance connection 136 for connecting chamber 138 to a fuel tube of the fuel system. Exit chamber 140 includes exit connection 142 for connecting chamber 142 to a fuel tube at the opposite end of chamber 132. The flow of fuel through chamber 132 is indicated by the arrow labeled F. If fuel detection device 130 is used as detection device 30 of FIG. 1, entrance connection 136 will be connected to fuel tube 28 and exit connection 142 will be connected to fuel tube 32.
Positioned within chamber 132 of fuel detection device 130, proximate the end closest to exit chamber 140, is a pressure increasing means 134. Pressure increasing means 134 is generally a structure of rigid material traversing part of the width of chamber 132 perpendicular to the flow of the fuel through chamber 132, as shown. Located substantially opposite pressure increasing means 134 is pressure transducer 144. Pressure transducer 144 has a pressure sensitive end 145 located within chamber 132. The opposite end of transducer 144 extends out of chamber 132 at an upper location. Connected to the end of pressure transducer 144 opposite pressure sensitive end 145 by means of electrical leads is an electrical signaling device 146 for interpreting electrical signals from pressure transducer 144. Electrical device 146 includes electrical leads 148, 150, and 152. Generally, electrical lead 148 will provide power to pressure transducer 144. Electrical lead 150 will provide a signal line to indicate an unacceptable pressure drop within chamber 132. And electrical lead 152 will be connected to fuel pump 14 to switch it off in certain situations of substantial pressure drop.
In operation, fuel will enter inlet chamber 138 through entrance connection 136. The fuel will continue to flow through inlet chamber 138 and then into chamber 132. When the fuel encounters pressure increasing means 134 it is deflected transverse to the normal flow of fuel causing a pressure increase within chamber 132 which is read by the pressure sensitive end 145 of pressure transducer 144. In normal operation, electrical signalling device 146 will interpret this pressure as an acceptable pressure. The fuel continues to flow out of chamber 132 through exit chamber 140 and out through exit connection 142. A change of flow through chamber 132 will be read as a change in the pressure within the chamber caused by pressure increasing means 134. If the pressure changes, whether it be an increase in pressure or a decrease in pressure, pressure transducer 144 will emit an electrical signal indicative of this change to electrical signalling device 146. Electrical device 146 will interpret this signal as being within an acceptable range. If the signal from pressure transducer 144 indicates an unacceptable pressure, electrical device 146 can either emit an electrical signal along line 150 to a warning system, or along line 152 to shut down fuel pump 14 or both.
FIG. 2B shows a similar fuel flow detection device 230 to that of detection device 130 of FIG. 2A. Fuel flow detection device 230 also includes a main chamber 232 having an inlet chamber 238 and an outlet chamber 240. Entrance connection 236 for connecting a fuel tube to inlet chamber 238 is positioned at one end of fuel flow detection device 230, and exit connection 242 for connecting outlet chamber 240 to a fuel tube is positioned at an opposite end of fuel flow detector 230. Positioned within main chamber 232 is a pressure increasing means 234 as described above. The pressure increasing means 234 causes a pressure increase in main chamber 232 as disclosed above for pressure increasing means 134. This time, however, the change in pressure is detected by a diaphragm 254 located at one end of a chamber 258 at an opposite side of main chamber 232. Chamber 258 is positioned in a wall of main chamber 232 such that it extends partially within chamber 232 and partially out of chamber 232. Diaphragm 254 comprises a wall of chamber 258. Within chamber 258 is an electrical signalling device 246 similar to that of electrical signalling device 146 of FIG. 2A. Electrical leads 248, 250, and 252 serve the same function in fuel flow detection device 230 as they do in fuel flow detection device 130, as described above. Diaphragm 254 will respond to the pressure within chamber 232 caused by pressure increasing means 234. If a change in pressure occurs within chamber 232, diaphragm 254 will indicate this along lines 255 and 256 attached to electrical signalling device 246. Electrical indicator signalling device 246 will determine if this change in pressure is outside of an acceptable range, and if so will provide a warning signal or shut off fuel pump 14, as described above. It may be desirable to have device 246 transmit the signal indicative of the fuel flow to a device remote from fuel flow detection device 230, such as a computer, to determine what action will be taken concerning the flow of fuel.
FIG. 3 shows a fuel flow detection device 330 incorporating a means for detecting the actual flow of fuel through the detection device 330 Fuel flow detection device 330 includes a main chamber 332 having an inlet chamber 338 and an exit chamber 340. An entrance connection 336 for connecting inlet chamber 338 to a fuel tube and an exit connection 342 for connecting chamber 340 to an exit fuel tube is also included, as described above. Included within main chamber 332 is a flow detection means 260 incorporating a spring biasing means 262 for measuring the flow of fuel through chamber 332. As fuel flows through chamber 332, fuel flow detection means 260 applies a force proportional to the rate of flow against spring biasing means 262. Spring biasing means 262 emits an electrical signal along lines 263 and 264 relative to the amount of compression in the spring means 262. Electrical lines 263 and 264 are connected to an electrical indicator device 346, as described above. Electrical leads 348, 350, and 352 have the same functions as electrical leads 150, 148 and 152, or 248, 250 and 252, above. Therefore, changes in the flow of fuel through fuel detector 330 can be accurately determined.
Certain automotive fuel system operations would provide a situation in which the fuel flow through the fuel system is not at normal operating flow. Specifically, at engine start-up there may be certain fluctuations in the fuel flow, which would not necessarily indicate a malfunction or fuel leakage. It would, therefore, be desirable to include certain delays or acceptances in the fuel flow detectors described above, such that the detectors would not indicate a malfunction is present when it actually was not. In computerized fuel systems, it would be relatively easy to program many characteristics of the fuel system which may be encountered without necessarily meaning a malfunction of the system.
This invention describes an efficient and practical means for warning of fuel system malfunctions or pending malfunctions. Providing such a device to detect malfunctions, as well as fuel line leakage, negates the need for providing redundant or extraordinary measures for insuring fuel system integrity. Therefore, this invention eliminates many costly additives to the fuel system.
The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
What is claimed is:
1. A fuel system comprising:a fuel tank for holding a certain quantity of fuel; at least one fuel line connected to said fuel tank; and means for determining a total flow of fuel through said at least one fuel line relative to a predetermined value, at a single point, so as to indicate a malfunction of the total fuel flow in said fuel system.
2. The fuel system of claim 1, wherein the means for determining flow is a device for determining the actual total flow of fuel.
3. The fuel system of claim 1 wherein said at least one fuel line is an inlet line connected to the fuel tank and an engine and an outlet line also connected to the fuel tank and the engine, and said means for determining flow is positioned on said outlet line proximate said fuel tank, wherein fuel flows from said fuel tank through said inlet line and from the engine through said outlet line to said fuel tank.
4. The fuel system of claim 1 wherein the means for determining flow include means for providing a warning signal.
5. The fuel system of claim 1 wherein the means for determining flow includes means for terminating flow of fuel.
6. The fuel system of claim 5 wherein the means for terminating flow of fuel is a means for electrically shutting off a fuel pump providing fuel to the fuel system.
7. The fuel system of claim 1 further comprising a fuel pressure regulator said regulator located between said inlet line and said outlet line and a fuel pump, said fuel pump positioned within the fuel tank.
8. The fuel system of claim 1 further comprising a fuel filter positioned on said at least one fuel line.
9. A fuel system for a vehicle comprising:a fuel tank for holding a certain quantity of fuel; a supply fuel line directing fuel from said fuel tank to a vehicle engine; a return fuel line directing fuel from the engine back to the fuel tank; a fuel pump positioned within the fuel tank for pumping fuel into the supply fuel line; a pressure regulator for regulating the fuel pressure in the fuel system; and means for measuring the flow of fuel through the return fuel line proximate the fuel tank, at a single point, so as to sense the fuel flow rate relative to a predetermined value and provide information relating to an abnormal fuel flow condition anywhere in said supply and return lines.
10. The fuel system according to claim 9 wherein the means for measuring measures the actual flow of fuel.
11. The fuel system according to claim 9 wherein the means for measuring the flow of fuel includes means for electrically shutting off the fuel pump.
12. The fuel system according to claim 9 wherein the measuring the flow of fuel includes means for providing a warning signal.
13. A method for supplying fuel from a fuel tank to a fuel rail comprising the steps of:pumping the fuel along a first fuel line between the fuel tank and the fuel rail; measuring the flow of fuel through the first fuel line at a single point therealong; and comparing the measured flow of fuel to the flow that would be expected during normal operation of fuel flow so as to detect a leak anywhere in said first fuel line.
14. The method of claim 13 further comprising the step of regulating the pressure along the fuel line.
15. The method of claim 13 further comprising returning fuel along a second fuel line from the engine to the tank and measuring the flow of fuel along the second fuel line proximate the fuel tank.
16. The method of claim 13 wherein the step of measuring includes measuring the actual flow of fuel.
17. The method of claim 13 wherein the step of measuring includes measuring the fuel pressure.
18. The method of claim 13 further comprising the step of providing a warning signal if the measured flow is outside a predetermined range.
19. The method of claim 13 further comprising the step of stopping the pumping of fuel if the measured flow is outside a predetermined range.
20. A vehicle fuel system comprising:a fuel tank for holding a quantity of fuel; at least one fuel line connected to said fuel tank and a fuel rail of said vehicle, for supplying said fuel to said fuel rail; and a single fuel flow pressure detecting device disposed proximate said fuel rail to detect a fuel flow malfunction occurring anywhere in said fuel line.
21. A vehicle fuel system comprising:a fuel tank for holding a quantity of fuel; a fuel supply line coupled to said fuel tank and to an engine of said vehicle; a fuel return line coupled between and to said engine and said fuel tank; and single fuel flow sensing means disposed proximate said fuel tank in said fuel return line for sensing an actual fuel flow in said fuel supply and return lines and detecting a change in said actual fuel flow, from a predetermined amount, anywhere in said fuel supply and return lines, to thereby provide an indication of a malfunction in said fuel supply and return lines.
| 1990-11-15 | en | 1993-01-19 |
US-92844986-A | Transfer system
ABSTRACT
An improved transfer station baffle arrangement provided with first and second baffles, the first baffle provided with a curved sheet supporting surface imparting a bow to sheets passing thereby, the second baffle normally biasing the sheets against the first baffle, and biasable out of position with respect thereto. A flexible lip may be provided on the second baffle to absorb spring force energy in sheets passing through the baffle arrangement as the direction of sheet travel is changed.
BACKGROUND OF THE INVENTION
The present invention relates to xerographic reproduction machines, and more particularly to improving the transfer of an image from a photoreceptor to a transfer member such as a sheet of paper.
In electrophotographic reproduction, a photoreceptor comprising a layer of photosensitive insulating material affixed to a conductive substrate is used to support electrostatic latent images. The surface of the photosensitive material is electrostatically charged, and exposed to a light pattern of an image to be reproduced to selectively discharge the surface in accordance with the image. The undischarged areas of the surface form an electrostatic charge pattern (an electrostatic latent image) conforming to the original pattern. The latent image is then developed by contacting it with a finely divided electrostatically attractable powder referred to as "toner". Toner is held on the image areas by the electrostatic charge on the surface. Thus, a toner image is produced in conformity with a light image of the copy being reproduced. The toner image is then transferred to a suitable substrate (e.g. paper), and the image is affixed thereto to form a permanent record of the original document. The process is well known, and is useful for light lens copying from an original, and printing applications from electronically generated or stored originals.
During the toner transfer, a substrate or transfer member such as a sheet of paper (hereinafter sheet or copy sheet) is caused to move in synchronized contact with the photosensitive surface during the transfer operation, and an electrical potential opposite from the polarity of the toner is applied to the side of the sheet remote from the photosensitive surface to electrostatically attract the toner image from the photoreceptor surface to the sheet. The copy sheet may be fed to the transfer station from a supply, a manual bypass path, or a duplex path to an area where it will contact the photoreceptor. To provide for an even transfer of toner material to the sheet, without undesirable dispersions or deletions caused by failure of toner to reach the copy sheets at the position corresponding to the original image, it is necessary that the copy sheet intimately contact the photoreceptor smoothly, without folds or wrinkles which, by causing surface variations in the copy sheet, cause transfer inconsistencies, and accordingly poor image quality.
To transfer the toner from the photoreceptor to the copy sheet, intimate contact between the two is required. However, during movement from the copy sheet supply through sheet feeding nip rolls and through a transfer station paper guide, or baffle arrangement to the contact position with the photoreceptor, the flimsy sheet tends to ripple, and there is a tendency for the side edges of the sheet, parallel to the direction of sheet travel, to contact the photoreceptor before the center portion of the sheet. As the photoreceptor is electrostatically charged, the sheet side edges tack to the photoreceptor somewhat tightly, and the sheet does not naturally smooth itself to form the required smooth intimate contact with the photoreceptor necessary for good image quality. In heavier, less flimsy paper weight sheets, the described problem is less noticeable as the heavier paper has a greater beam strength, which maintains the respective desired orientation of the edges and central portions of the sheets to allow appropriate contact. The problem of sheet non-smoothness is a particular problem with sheets returning from a duplex path having been subject to heating and extensive handling.
As the sheet leaves the transfer station baffle, there is a tendency of the trail edge of the sheet to flip away from the baffle due to a combination of factors including spring forces on the paper induced by the change in direction of the sheet as it moves away from the transfer baffle to contact with the photoreceptor, and the energy stored in the curled sheet releasing as it departs from the baffle. As a result of these forces on the paper, the trail edge of the sheet is caused to move suddenly towards the photoreceptor upon leaving the control of the transfer baffle. In this case, transfer of toner from the photoreceptor to the sheet is believed to occur before the trail edge of the sheet has made intimate contact with the photoreceptor, a phenomenon known as "gap transfer", causing a type of toner deletion known as "trail edge deletion".
U.S. Pat. No. 3,984,183 to Maksymiak suggests that increasing beam strength in a sheet improves post transfer stripping characteristics. Complementary curved photoreceptor and guide members accomplish this end by creating a curve extending in the sheet parallel to the direction of travel. The arrangement of curved guide members serves to provide a curve in the sheet matching a curve on the photoreceptor, whereby beam strength of sheets is increased. Increasing beam strength of sheets by applying a bow in a direction parallel to the path of paper travel is known in the printing arts as shown, for example, by U.S. Pat. Nos. 3,516,657 to Knudsen; 4,204,672 to Grivet; and 4,350,332 to Knight. These patents do not, however, teach applying a curvature to the sheet to induce a portion of the sheet to contact the photoreceptor prior to another portion.
U.S. Pat. No. 3,820,889 to Nitanda teaches a paper guide arrangement for avoiding certain deletion problems, including a pair of parallel spaced guide plates for directing transfer material to the photoreceptor. Either or both of the parallel guide plates are provided with a crowned edge in the plane of the guide plates.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to improve the delivery of transfer materials such as copy sheets to the photoreceptor in a copying device.
It is another object of the invention to deliver sheets to the photoreceptor in a manner which advantageously prevents the early tacking of sheet edges to the photoreceptor.
It is yet another object of the invention to provide an arrangement which does not disadvantageously affect sheets not requiring photoreceptor contact control.
It is yet another object of the invention to provide an arrangement which prevents flipping trail edge deletions.
In accordance with the invention, an electrophotographic device having a transfer station for transferring developed toner images from a photoreceptor surface to transfer material such as a copy sheet, is provided with a baffle arrangement for directing sheets from a copy sheet supply to the area in which contact between the photoreceptor and the copy sheets is desired. The baffle arrangement is provided with upper and lower baffle members comprising elongated members supported transverse and parallel to the direction of sheet travel therepast. The lower baffle member is provided with a curved support surface portion extending into the path of paper travel to impart a curve to sheets passing thereby whereby a central portion of the sheets contacts the photoreceptor prior to the edge portions. Thus, the invention advantageously avoids the problems of early side edge tacking to the photoreceptor.
In accordance with another aspect of the invention, the upper baffle member is supported for free pivotal movement out of the plane of paper travel, and normally biased towards or against the lower baffle member to aid in imparting a curve corresponding to the curve on the lower baffle member to sheets passing thereby. When heavier weight sheets pass through the baffle arrangement, however, the upper pivoting baffle member is biased out of the path of paper travel reducing baffle drag on such sheets. The invention thereby avoids problems of baffle drag, which causes copy smearing on sheets which do not have the problem of early side edge tacking.
In accordance with yet another aspect of the invention, the upper baffle member is provided with a flexible lip extending transversely across the path of paper travel to contact sheets passing thereby. The flexible lip serves to release the trail edge of the sheet slowly thereby absorbing energy and reducing the spring forces in the sheet associated with flipping trail edge deletions.
These and other objects and advantages of the invention will become apparent as the following description is reviewed in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic view of an xerographic reproduction machine of the type contemplated to embody the present invention;
FIG. 2 is a cross sectional view of a portion of a transfer station in accordance with one embodiment of the invention;
FIG. 3 is a view along the section 3--3 of FIG. 2, showing the lower baffle member of the transfer baffle arrangement; and
FIG. 4 is a view along the section 4--4 of FIG. 2 of the lower baffle member.
DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein the showings are for the purpose of illustrating a preferred embodiment of the invention and not for the purpose of limiting same, FIG. 1 schematically depicts the various components of an illustrative electrophotographic device contemplated to incorporate the present invention therein. Inasmuch as the art of electrophotography is well known, the various processing stations employed in the FIG. 1 device will be shown hereinafter schematically and the operation described briefly with reference thereto.
As shown in FIG. 1, the electrophotographic device employs a belt 10 having a photoconductive surface 12 deposited on a conductive substrate. Belt 10 moves in the direction of arrow 14 to advance successive portions of photoconductive surface 12 sequentially through the various processing stations disposed about the path of movement thereof. Belt 10 is entrained around drive roller 16, and tension rollers 18 and 20. Drive roller 18 is mounted rotatably in engagement with belt 10 and driven by suitable means such as a conventional motor (not shown).
With continued reference to FIG. 1, initially a portion of belt 10 passes through charging station A. At charging station A, a corona generating device 22 charges photoconductive surface 12 of the belt 10 to a relatively high, substantially uniform potential. The corona generating device comprises charging electrode 24 and conductive shield 26. A high voltage power supply 28 controlled by controller 30 is connected to the charging electrode 24 to provide a high charging voltage and control the charge placed on the surface 12. Controller 30 is preferably a known programmable controller or combination of controllers, which conventionally controls all of the other machine steps and functions described herein and including the operation of document feeders, the paper path drives, and other machine operations. Controller 30 also conventionally provides for storage and comparisons of counted values including copy sheets and documents, and numbers of desired copies, and control of operations selected by an operator.
Next, the charged portion of photoconductive surface 12 is advanced through exposture station B. At exposed station B, an original document 32 is positioned face down upon transparent platen 34. Optics assembly 36 contains optical components which incrementally scan and illuminate original document 32 and project a reflected image on surface 12 of belt 10. Shown schematically, these optical components comprise an illumination scan assembly 40, comprising illumination lamp and reflector 42, and full rate scan mirror 44 mounted on scan carriage 46. The carriage is supported for reciprocating movement in accordance with copying requirements along rails (not shown) extending parallel and below the length of the platen 34. Light reflected from the image is reflected by full rate scan mirror 44 to corner mirror assembly 48 on half rate scan carriage 50, which follows full rate carriage 44 at half the speed of the full rate carriage. The reflected light image from corner mirror assembly 48 is directed through lens 52, to a second corner mirror arrangement 54, and projected therefrom onto the charged portion of photoconductive surface 12 by mirror 56 to selectively dissipate the charge on the photoconductive surface. This records an electrostatic latent image on photoconductive surface 12 which corresponds to the information areas contained within original document 32. It will, of course, be appreciated that a similar function is accomplished by an electronic printer employing a laser to selectively dissipate charge from a photoconductive surface.
Thereafter, belt 10 advances the electrostatic latent image recorded on photoconductive surface 12 to development station C. At development station C, a magnetic brush development system 60, including a magnetic brush developer roller 62 within housing 64 advances a developer mix of toner particles and carrier granules into contact with the electrostatic latent image. The latent image attracts the toner particles from the carrier granules forming a toner powder image on photoconductive surface 12 of belt 10. Additional toner is stored for use upon demand in toner particle dispenser 65.
Belt 10 then advances the toner powder image on surface 12 to transfer station D. A substrate, which may include paper sheets, transparencies, computer fan fold stacks, rolls of paper stock, etc., and hereinafter referred to as a sheet P is advanced toward transfer station D by a pair of feed roll pairs 68 and 70 in a timed sequence by a suitable conventional feeding arrangement so that the toner powder image developed on the photoconductor surface synchronously contacts the advancing sheet P at transfer station D.
Transfer station D includes a corona generating device 72 which sprays ions onto the back side of sheet P passing through the station. The toner powder image from the photoconductive surface 12 is thereby attracted to the sheet, and a normal force is provided which causes photoconductive surface 12 to take over transport of the advancing sheet P. After transfer, the sheet continues to move advancing to fusing station E.
Fusing station E includes a fuser assembly, indicated generally by the reference number 74, where a sheet is stripped from the photoreceptor surface and passed through a heated nip roll pair whereby the toner powder image is permanently affixed to the sheet. After fusing, the advancing sheet is directed to an output for removal from the printing machine by the operator. Alternatively the sheets may be directed to a finishing module where further paper handling functions, such as stapling, stacking, collating, etc., are available.
Invariably, after the sheet support material is separated from the photoconductive surface 12 of belt 10, some residual particles remain adhering thereto. These residual particles are removed from photoconductive surface 12 at cleaning station F.
In accordance with the invention, and referring more particularly to FIG. 2, transfer material such as paper sheets are fed from a supply such as sheet tray, a duplex path or a manual sheet bypass path toward the photoreceptor and transfer station D through nip roll pair 70. On passing nip roll pair 70, sheets are directed through a baffle arrangement 100 comprising upper and lower baffle members 102 and 104 respectively, which, in combination, direct sheets into contact with photoconductive surface 12. Lower baffle 104 may be an elongated member extending transversely across and generally parallel to the path of sheet travel providing a sheet support surface, generally parallel to the path of sheet travel therepast. As shown in FIGS. 2 and 3, lower baffle 104 may be provided with a flanged lip 106 having a crowned edge 108. Crowned edge 108 may be provided with an arcuate or chevroned edge in the flanged lip 106 similar to that provided in U.S. Pat. No. 3,820,889. The edge of flanged lip 106 extends convexly towards the photoreceptor in the plane of the flanged lip and having an apex or outermost extending point A of the arc or chevron along the center of the path of paper travel. The arcuate or chevroned edge may range a distance L about 0.25 to 0.5 mm from the horizontal at the apex point.
In accordance with the invention, and as best seen in FIGS. 2 and 4, flanged lip 106 is also provided with a bowed surface 109 forming a bowed paper supporting surface transverse to the direction of paper travel, and extending convexly outwardly from flanged lip 106 towards the photoreceptor surface, which will contact sheets passing thereby. In a preferred embodiment bowed surface 109 is generally an arcuate surface having an outermost extending point along the center of the path of paper travel, although it is well within the scope of the invention to provide two planar surfaces intersecting at an apex to form a slight angle. The bowed surface may range a distance M of approximately 0.25 to 0.5 mm from a plane defined by the flanged lip 106. In a preferred embodiment, the flanged lip 106 is a single sheet metal member which is stamped or blanked to form crown 108, and subsequently bowed to form the bowed surface 109. The formed member is then fixed to the lower baffle member to form an integral member.
Sheets passing lip 106 are directed toward the photoreceptor surface, and provided with a bend corresponding to bowed surface 109 through a central portion of the sheet along a line parallel to the direction of sheet travel. The bow or curve thereby imparted to the sheets has the tendency to place the central portions of the sheet along a line parallel to the path of travel of the sheet, into contact with the photoreceptor prior to the side edges parallel to the path of travel. The sheet side edges come into contact with the photoreceptor at a later time, and the intimate contact required between the sheet and the photoreceptor is achieved with the central portion of the sheet tacked to the photoreceptor first, and the edges tending to naturally follow the central portion into proper contact positions. It will no doubt be appreciated that other non-planar shapes of paper or substrate supporting surfaces may be provided within the scope of the invention, which force the central portion of the sheet passing thereby into contact with the photoreceptor prior to the side edges.
Referring again to FIG. 2, upper baffle member 102 is arranged generally parallel to the lower baffle, transverse to the path of sheet travel. Upper baffle member 102 is supported at an end close to the nip roll pair 70 for free pivoting motion about an axis 112, also arranged transverse to the path of sheet travel and parallel to lower baffle 104. Upper baffle 102 is naturally biased by its own weight to a position towards or against lower baffle 104. The weight of upper baffle 102 serves to aid in imparting a bow corresponding to the curvature of curved surface 109 to sheets passing thereby by biasing sheets against flanged portion 106 and the curved sheet supporting surface 109 as the sheets pass between the two baffle members 102 and 104.
In accordance with another aspect of the invention, pivoting upper baffle member 102 is pivotally moved out of its biasing relationship with lower baffle member 104 on the passage of heavier sheets of paper therebetween as shown in phantom in FIG. 2. Sheets of paper having paper weight of about 32 lbs. bond or greater have a naturally greater beam strength associated with the heavier weight, and a baffle arrangement has a tendency to create a drag on such sheets causing smearing in the contact with the photoreceptor. The pivotal movement of the upper baffle out of biasing engagement with the lower baffle has the effect of reducing this drag. Accordingly, the weight and size of baffle member 104 are selected to provide a biasing force on the baffle member to allow pivoting movement upon the passage of heavy weight sheets thereby. Other biasing arrangements such as spring bias or counter weight bias are well within the scope of the invention.
In accordance with yet another aspect of the invention, as best seen in FIGS. 2 and 4, upper baffle member 102 is provided with a flexible lip or edge member 150 extending along the edge of the baffle member closest to the photoreceptor transverse to the path of paper travel, and having a free end extending in the direction of copy sheet travel through the baffle arrangement. Flexible edge member 150 may be of a thin plastic material such as polycarbonate, about 0.1 mm thick, and extending about 5 mm from the edge of the upper baffle member 102 closest to the photoreceptor. The flexible edge member 150 is supported to be flexible in the direction of the photoreceptor with the force of paper upon it. Sheets traveling through the baffle arrangement 100 and over flange 106 change direction of travel by an angle of between 45° and 85° as sheets contact surface 12 of the photoreceptor. Associated with this significant change of direction is a spring force which causes the trailing edge of the sheet to flip suddenly away from engagement with baffle member 102, and into contact with the photoreceptor upon leaving the rigid arrangement 100 causing degradation of the latent toner image on the photoreceptor surface 12. Accordingly, the flexible member 150 has the effect of reducing and slowing the flipping movement by allowing the spring force of the sheets to exert some of the stored energy against the flexible member 150. In this manner, the distance associated with the flip of the trail edges from the baffle to the photoreceptor surface is somewhat reduced, and image degradation caused by this factor is lessened.
While the invention has been described with reference to the structure disclosed, it is not confined to the details set forth or the embodiment described. The invention may find advantageous use with other printing processes requiring smooth intimate contact between a substrate and an image bearing surface, and is intended to cover such modifications or changes as may come within the scope of the following claims.
We claim:
1. Electrophotographic apparatus, wherein a developed image is transferred from an imaging surface to a substrate placed in intimate contact therewith at a transfer station, and including a baffle arrangement extending from a substrate supply towards the transfer station directing the substrate from the substrate supply towards the imaging surface, said baffle arrangement comprisinga first baffle member, said first baffle member provided with a non-planar substrate supporting surface extending at a central portion towards the imaging surface for imparting a bow to the substrate passing therealong, along a line parallel to the direction of movement of the substrate, whereby a central portion of said substrate contacts with the imaging surface prior to edge portions of the substrate; a second baffle member, arranged generally closely spaced from said first baffle member, supported for free pivotal movement away from said first baffle member, and biased generally towards said first baffle member, whereby the substrate is biased by said second baffle member against said non-planar substrate supporting surface, and substrates having heavier weight bias the second baffle member away from said first baffle member to avoid imparting a bow to said heavier weight substrates.
2. The apparatus of claim 1 wherein said non-planar substrate supporting surface is a generally curved surface.
3. The apparatus of claim 1, wherein the bow imparted to the substrate by the non-planar substrate supporting surface extends in the range of 0.25 to 0.5 mm from horizontal.
4. The apparatus of claim 2, wherein the bow imparted to the substrate by the curved surface extends in the range of 0.25 to 0.5 mm from horizontal.
5. The apparatus of claim 1 wherein said second baffle member is adapted to be biased away from said first baffle member by substrates having a heavier weight, whereby drag on said substrates is minimized.
6. The apparatus of claim 1 wherein said second baffle member is biased towards said first baffle member by the weight of said second baffle member.
7. Electrophotographic apparatus, wherein a developed image is transferred from a photoreceptor surface to a copy sheet which is placed in intimate contact with the photoreceptor surface at a transfer station, and including a baffle arrangement extending from a copy sheet supply towards the transfer station carrying copy sheets from said copy sheet supply to said photoreceptor surface, said baffle arrangement comprising:a first lower baffle member fixedly supported with respect to said photoreceptor surface, and extending transversely across and parallel to the path of copy sheet movement from said copy sheet supply towards said transfer station, and provided with a lip portion arranged closely adjacent to said photoreceptor surface, and transverse and parallel to the path of copy sheet movement to said photoreceptor surface, said lip portion further comprising a bowed sheet supporting surface extending towards said photoreceptor surface, most closely adjacent thereto at a midpoint, whereby a central portion of said copy sheets passing thereby is urged into contact with said photoreceptor surface prior to edge portions of said copy sheets; and a second upper baffle member arranged generally closely spaced to said first lower baffle member, between said photoreceptor surface and said first lower baffle member, supported for free pivotal movement in a direction away from said first baffle member; and biased generally towards said first baffle member, whereby copy sheets moving therepast are biased by said second upper baffle member against said bowed surface, and copy sheets having heavier weight bias the second baffle member away from said first baffle member to avoid imparting a bow to said heavier weight copy sheets.
8. The apparatus of claim 7 wherein said bowed paper supporting surface provides a curve extending in the range of about 0.25 to 0.5 mm from the horizontal.
9. The apparatus of claim 7 wherein said second upper baffle member is adapted to be biased away from said first lower baffle member by copy sheets having a heavier weight, whereby drag on said copy sheets is minimized.
10. The apparatus of claim 9 wherein said second baffle member is biased towards said first baffle member by the weight of said second baffle member.
11. Electrophotographic apparatus, wherein a developed toner image is transferred from a imaging surface to a copy sheet placed in intimate contact with the imaging surface at a transfer station, and including a copy sheet guide means extending from a copy sheet supply means towards the transfer station, carrying copy sheets from said copy sheet supply means to said imaging surface, said copy sheet guide means comprising:a first baffle member fixedly supported with respect to said imaging surface, and extending transversely across and parallel to the path of copy sheet movement from said copy sheet supply means towards said transfer station, and provided with flanged portion arranged on a said baffle member closely adjacent to said imaging surface, transverse and parallel to the path of copy sheet movement to said imaging surface, said flanged portion including an arcuate paper supporting surface, having a central portion extending towards said imaging surface, whereby said central portion of said copy sheets passing thereby is urged into contact with said imaging surface prior to edge portions of said copy sheets; and a second baffle member, arranged generally closely spaced from said first baffle member, between said imaging surface and said first baffle member, supported for pivotal movement in a direction away from said first baffle member, and biased generally towards said first baffle member, whereby copy sheets moving therepast are biased by said second baffle member against said arcuate surface.
12. Electrophotographic apparatus, wherein a developed toner image is transferred from a photosensitive surface to a copy sheet placed in intimate contact with the photosensitive surface at a transfer station, and including a copy sheet guide means extending from a copy sheet supply means towards the transfer station, carrying copy sheets from said copy sheet supply means to said photosensitive surface, said copy sheet guide means comprising:a first baffle member fixedly supported with respect to said photosensitive surface, and extending transversely across and parallel to the path of copy sheet movement from said copy sheet supply means towards said transfer station, and provided with flanged portion arranged on a said member closely adjacent to said photosensitive surface, transverse and parallel to the path of copy sheet movement to said photosensitive surface, said flanged portion including an arcuate paper supporting surface, having a central portion extending towards said photosensitive surface, whereby said central portion of said copy sheets passing thereby is urged into contact with said photosensitive surface prior to edge portions of said copy sheets; a second baffle member, arranged generally closely spaced to said first baffle member, between said photosensitive surface and said first baffle member, supported for pivotal movement in a direction away from said first baffle member, and biased generally towards said first baffle member, whereby copy sheets moving therepast are biased by said second upper baffle member against said curved surface; and a flexible edge member along an edge of said second baffle member, closely adjacent to the photosensitive, and extending in the direction of copy sheet movement through the sheet guide means, said flexible edge member flexing towards said photosensitive surface on contact with a trail edge of the copy sheets passing thereby.
| 1986-11-10 | en | 1988-04-19 |