Abstract:
An apparatus for a gate valve between chambers includes a valve housing defining a flow path. A male valve portion is rotatable on a fixed axis in the housing. The male valve portion including a first male mating surface positioned at a first angle less than perpendicular to the axis. A female valve portion is fixed in the valve housing for receiving the male portion. The female valve portion including a first female mating surface positioned at a second angle matching the first angle. An o-ring seals the male valve portion to the female valve portion when the male valve portion is rotated into the female valve portion. A polished surface contacts the o-ring when the male valve portion is rotated. When the male valve portion is rotated into the female valve portion the o-ring is compressed thereby sealing the gate valve and closing the flow path.

Description:
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER LISTING APPENDIX 
     Not applicable. 
     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office, patent file or records, but otherwise reserves all copyright rights whatsoever. 
     FIELD OF THE INVENTION 
     The present invention relates generally to vacuum process control. More particularly, the invention relates to a device that utilizes vacuum chambers in conjunction with a pendulum valve that uses a male wedge rotating on a fixed shaft into a fixed female wedge to perform the vacuum sealing function. 
     BACKGROUND OF THE INVENTION 
     Within vacuum process control industries there is a growing demand for smaller, more inexpensive and more reliable valves to isolate certain components in a system and to enable these components to operate under vacuum conditions. There are a number of different types of valves currently known for isolating components in a system. For example, without limitation, rectangular gate valves are the most common in the industry.  FIG. 1  illustrates an exemplary rectangular gate valve  100 , in accordance with the prior art. A gate  101  of rectangular gate valve  100  moves in a straight line in order to seal rectangular gate valve  100 . The movement of gate  101  in the present example is indicated by an arrow  102 . Rectangular gate valves typically require an air cylinder to actuate the valve, adding the length of the air cylinder to the overall length of the valve. For example, without limitation, referring to  FIG. 1 , an air cylinder  103  of gate valve  100  practically doubles the length of rectangular gate valve  100 . 
     Pendulum valves are also currently used in vacuum process control industries. A pendulum valve offers a smaller overall footprint than a rectangular gate valve, making pendulum valves desirable in systems where space is an issue. Rather than sliding in a straight line, the gate of a pendulum valve rotates on a shaft, driven by a set of links that rotate a drive arm and thus the gate of the valve into an opening. The air cylinder required to rotate a pendulum valve can be mounted on the valve body, thus saving space. Pendulum valves currently being used in the vacuum process controls industry typically use a gate that moves parallel to the valve body, and uses a complex series of links and wheels to lock and seal the valve in a closed position. While currently known pendulum valves rotate on shafts to seal the valve closed, there are no wedges or angled surfaces to facilitate the sealing of the valves. Thus, pendulum valves use basically the same mechanism to close and seal the valve as standard rectangular gate valves, for example, without limitation, gate valve  100 , shown by way of example in  FIG. 9 . 
     In view of the foregoing, there is a need for improved techniques for providing small, reliable and inexpensive valves for use in vacuum pressure systems that uses simple means for creating a vacuum tight seal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: 
         FIG. 1  illustrates an exemplary rectangular gate valve, in accordance with the prior art; 
         FIGS. 2 ,  3 ,  4 ,  5 , and  6  illustrate an exemplary dual wedge valve, in accordance with an embodiment of the present invention.  FIG. 2  is a side view of the valve in a closed position, where body covers of the valve have been removed to show the inside of the valve.  FIG. 3  is a top view of the valve in the closed position.  FIG. 4  is a top, transparent view of the valve in an open position.  FIG. 5  is an exploded view of the entire assembly of the valve, and  FIG. 6  is a cutaway view of the dual wedge design of the valve with the valve in the closed position; 
         FIG. 7  shows exemplary components of a dual wedge valve, in accordance with an embodiment of the present invention; and 
         FIGS. 8 ,  9  and  10  illustrate an exemplary single wedge gate valve, in accordance with an embodiment of the present invention.  FIG. 8  is a side view of the single wedge gate valve in a closed position without body sides for clarity.  FIG. 9  is a cross-sectional view of the single wedge gate valve in the closed position, and  FIG. 10  is a section view of the single wedge gate valve. 
     
    
    
     Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale. 
     SUMMARY OF THE INVENTION 
     To achieve the forgoing and other objects and in accordance with the purpose of the invention, a vacuum sealing system and device is presented. 
     In one embodiment, an apparatus for a gate valve between chambers is presented. The apparatus includes a valve housing defining a flow path between the chambers. A male valve portion is rotatable on a fixed axis in the housing. The male valve portion including at least a first male mating surface positioned at a first angle less than perpendicular to the axis. A female valve portion is fixed in the valve housing for receiving the male portion. The female valve portion including at least a first female mating surface positioned at a second angle matching the first angle. An o-ring seals the male valve portion to the female valve portion when the male valve portion is rotated into the female valve portion from a fully open position to a fully closed position. A polished surface contacts the o-ring when the male valve portion is rotated. Means for providing a sliding action between the male valve portion and the female valve portion when the male valve portion is rotated into the female valve portion. The means for providing a sliding action compressing the o-ring in the fully closed position thereby sealing the gate valve and closing the flow path. Means for rotating the male valve portion between the fully open position and the fully closed position. Another embodiment further includes means for linking the means for rotating and the male valve portion where the linking means maintains the male valve portion in the fully closed position when the means for rotating is inoperative. In other embodiments the chambers are vacuum pressure chambers and the o-ring provides a vacuum tight seal and the male valve portion is rotatable when pressures in the chambers are differentiated. In yet another embodiment the means for rotating is continuously operable for throttling between the fully open position and the fully closed position. In other embodiments the male valve portion further includes a second male mating surface positioned at a third angle less than perpendicular to the axis, the female valve portion further includes a second female mating portion positioned at a fourth angle matching the third angle, the o-ring is on the first male mating surface, the polished surface in on the first female mating surface and the sliding action means provides the sliding action between the second male mating surface and the second female mating surface. In yet other embodiments, the male valve portion further includes a second male mating surface substantially perpendicular to the axis, the female valve portion further includes a second female mating portion substantially perpendicular to the axis, the o-ring is on the first female mating surface, the polished surface in on the first male mating surface and the sliding action means provides the sliding action between the second male mating surface and the second female mating surface. 
     In another embodiment an apparatus for a gate valve between chambers is presented. The apparatus includes a valve housing defining a flow path between the chambers. A male valve portion is rotatable on a fixed axis in the housing. The male valve portion includes a first male mating surface positioned at a first angle less than perpendicular to the axis and a second male mating surface positioned at a second angle less than perpendicular to the axis. A female valve portion is fixed in the valve housing for receiving the male portion. The female valve portion including a first female mating surface positioned at a third angle matching the first angle and a second female mating surface positioned at a fourth angle matching the second angle. An o-ring is positioned on the first male matting portion for sealing the male valve portion to the female valve portion when the male valve portion is rotated into the female valve portion from a fully open position to a fully closed position. A polished surface on the first female portion contacts the o-ring when the male valve portion is rotated. A slider is between the second male valve portion and the second female valve portion where when the male valve portion is rotated into the female valve portion, the slider provides a sliding action and compresses the o-ring in the fully closed position thereby sealing the gate valve and closing the flow path. An actuator rotates the male valve portion between the fully open position and the fully closed position. Other embodiments further include a linkage between the actuator and the male valve portion where the linkage maintains the male valve portion in the fully closed position when the actuator looses power and the linkage includes a three-part linkage. In another embodiment the male and female mating portions further include generally circular shapes. In still other embodiments the o-ring is positioned in an o-ring groove and the slider includes a Kynar rod in an o-ring groove on the second male mating surface. In yet other embodiments the chambers are vacuum pressure chambers and the o-ring provides a vacuum tight seal and the male valve portion is rotatable when pressures in the chambers are differentiated. In yet another embodiment the actuator is continuously operable for throttling between the fully open position and the fully closed position. 
     In another embodiment an apparatus for a gate valve between chambers is presented. The apparatus includes means for housing the gate valve defining a flow path between the chambers, means for closing the flow path, means for receiving the means for closing, means for sealing the means for closing and the means for receiving, means for contacting the means for sealing in a low friction manner, means for providing a sliding action between the means for closing and the means for receiving and means for rotating the means for closing between a fully open position and a fully closed position. Yet another embodiment further includes means for linking the means for rotating and the means for closing. 
     Other features, advantages, and object of the present invention will become more apparent and be more readily understood from the following detailed description, which should be read in conjunction with the accompanying drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is best understood by reference to the detailed figures and description set forth herein. 
     Embodiments of the invention are discussed below with reference to the Figures. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. For example, it should be appreciated that those skilled in the art will, in light of the teachings of the present invention, recognize a multiplicity of alternate and suitable approaches, depending upon the needs of the particular application, to implement the functionality of any given detail described herein, beyond the particular implementation choices in the following embodiments described and shown. That is, there are numerous modifications and variations of the invention that are too numerous to be listed but that all fit within the scope of the invention. Also, singular words should be read as plural and vice versa and masculine as feminine and vice versa, where appropriate, and alternative embodiments do not necessarily imply that the two are mutually exclusive. 
     The present invention will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings. 
     Preferred embodiments of the present invention provide a cost-effective, reliable and efficient valve, with few moving parts, that is installed in a vacuum pressure system. In a preferred embodiment, a male wedge arm with a sealing o-ring mounted on the male wedge arm, swinging on a fixed axis into a fixed female wedge, closes the valve and creates a vacuum tight seal. The use of a wedge design eliminates the need for a number of ball bearings, bellows and other parts that are currently used in standard gate valves, such as, but not limited to, links, pins, welded gate frames, wheels, etc. Preferred embodiments may be implemented as dual wedge valves or single wedge valves. A valve according to preferred embodiments is unique in that it uses a pendulum style motion, along with a wedge style arm and valve seat to seal the valve. It is contemplated that fewer parts per assembly in preferred embodiments will result in a more cost-effective and reliable valve. Preferred embodiments generally do not require adjusting, although adjusting is provided with some embodiments. Furthermore, preferred embodiments have the ability to open under differentiated pressure because a sliding action rather than a lifting action is used to open the valve. 
       FIGS. 2 ,  3 ,  4 ,  5 , and  6  illustrate an exemplary dual wedge valve  200 , in accordance with an embodiment of the present invention.  FIG. 2  is a side view of valve  200  in a closed position, where body covers  201  of valve  200  have been removed to show the inside of valve  200 .  FIG. 3  is a top view of valve  200  in the closed position.  FIG. 4  is a top, transparent view of valve  200  in an open position.  FIG. 5  is an exploded view of the entire assembly of valve  200 , and  FIG. 6  is a cutaway view of the dual wedge design of valve  200  with valve  200  in the closed position. In the present embodiment valve  200  is sealed vacuum tight when in the closed position. Valve  200  comprises a male wedge arm  203  at a set angle that rotates on a fixed shaft  205  into a fixed female wedge  207  at a set angle. 
     Referring to  FIG. 2 , male wedge arm  203  is shown in the closed position. Both sides of male wedge arm  203  are angled at 7.5 degrees, and male wedge arm  203  swings into fixed female wedge  207  also with 7.5-degree angles on each side. Alternate embodiments may comprise wedges with various different angles. Furthermore, in some embodiments the angle of the top surface of the wedge may be different from the angle of the bottom surface of the wedge as long as the angles of the male and female wedges match to create a vacuum tight seal. 
     Referring to  FIGS. 2 and 5 , shaft  205  on which male wedge arm  203  rotates is captured within the body of valve  200  using O-rings to seal shaft  205  where it protrudes from the body of valve  200 . Male wedge arm  203  is mounted on shaft  205 , being held in position by threaded nuts  209  and washers  211 , thus enabling male wedge  203  to be adjustable in the Z position by moving threaded nuts  209 , washers  211  and male wedge arm  203  up or down shaft  205 . Once male wedge arm  203  is properly located on shaft  205  to fit within female wedge  207 , threaded nuts  209  and washers  211  restrain movement of male wedge arm  203  along shaft  205 , thus holding male wedge arm  203  in place. A key  213  is used to prevent male wedge arm  203  from rotating on shaft  205 , along with a bolt that clamps male wedge arm  203  around shaft  205 . Alternate embodiments may not enable the male wedge arm to be adjusted. In the present embodiment, the upper portion of shaft  205  is locked to an air cylinder  215  to push a drive arm  217  without fear of rotating on shaft  205 . 
     Referring to  FIGS. 2 and 6 , an o-ring  219  on male wedge arm  203  comes into contact with an ultra polished surface  221  of female wedge  207  just prior to male wedge arm  203  wedging into fixed female wedge  207 . In alternate embodiments, the o-ring may be attached to the female wedge and the male wedge arm may have an ultra polished surface. In the present embodiment, o-ring  219  briefly slides on polished surface  221  on the bottom side of female wedge  207  when valve  200  closes to perform the sealing action. Polished surface  221  of female wedge  207  has an ultra smooth surface finish in the area where o-ring  219  contacts, for example, without limitation, a 16-finish surface, a non-stick coating, etc. Polished surface  221  aids in preventing damage and wear to o-ring  219 . On the side of male wedge arm  203  opposite o-ring  219 , a Kynar rod  223  is placed in an o-ring groove and is used to provide the sliding action required when male wedge arm  203  comes into contact with the opening of fixed female wedge  207 . Those skilled in the art, in light of the present teachings, will readily recognize that a multiplicity of suitable means may be used to provide the sliding action between the male wedge and the female wedge such as, but not limited to, other types of smooth, non-wear materials, ball bearings, air bearings, etc. Furthermore, in alternate embodiments the means for providing the sliding action may be incorporated into the female wedge rather than the male wedge arm. In the present embodiment as male wedge arm  203  is driven into female wedge  207 , male wedge arm  203  pushes against polished surface  221  of female wedge  207  and Kynar rod  223  pushes against the opposite surface of female wedge  207 . This action compresses o-ring  219  against polished surface  221  to form a vacuum tight seal. 
     Referring to  FIGS. 3 and 4 , the drive system comprises drive arm  217  mounted on shaft  205 , attached to a fixed length link of a three-part linkage  225 , which in turn is attached to another link of three-part linkage  225 , which is attached at the other end to a fixed linkage mount  227  with a shoulder bolt  229 . Air cylinder  215  actuates valve  200  by driving a three-part linkage  225 , which actuates drive arm  217 , which rotates male wedge arm  203  by rotating shaft  205 . Alternate embodiments may be implemented without a three-part linkage. In these embodiments the air cylinder is connected directly to the drive arm, and the end of the drive arm not connected to the air cylinder is connected to the shaft. In the present embodiment, air cylinder  215  is a 1.5″ bore pneumatic air cylinder; however, alternate embodiments may comprise air cylinders of various sizes depending on factors such as, but not limited to, the size of the valve or the application of the valve. Other alternate embodiments may use different means for actuating the valve such as, but not limited to, hydraulic cylinders, electric motors, manual levers, etc. In the present embodiment, air cylinder  215  comprises two magnetic reed switches on each end of the air cylinder stroke to indicate the open and closed positions. Air cylinder  215  is pivotally mounted to valve  200  with a mount bracket  231  at a pivot point  233 . Shaft  205  is rotated by air cylinder  215  by pushing three-part linkage  225  and drive arm  217 , which is clamped to shaft  205 . When air cylinder  215  is in an extended position, the valve is in the open position, and as the shaft of air cylinder  209  retracts, drive arm  217  rotates, thus rotating male wedge arm  203  into female wedge  207 . Referring to  FIG. 4 , air cylinder  215  is shown fully extended, which fully extends three-part linkage  225  so that drive arm  217  is in line with the adjacent link of three-part linkage  225  and opens valve  200 , and referring to  FIG. 3 , air cylinder  215  is shown in the fully retracted position, which fully retracts three-part linkage  225  so that drive arm  217  is at a 90-degree angle to the adjacent link of three-part linkage  225  and closes valve  200 . In alternate embodiments, the drive system may be configured differently so that the links of the three-part linkage and the drive arm create various different angles in the open and closed positions. In the present embodiment, three-part linkage  225  enables valve  200  to remain sealed, or locked over, in the event of a power failure. The lock over refers to the angle of drive arm  217  and linkage  225  being at an angle at least 1 degree greater than 90 degrees. If a force is applied externally to the male wedge  203  to attempt to open the valve, the angle prevents the male wedge  203  from moving or backing out, and only when the air cylinder  215  is activated can the valve open. 
     Referring to  FIGS. 3 and 4 , a typical mounting flange  235  is also shown on body cover  201 . Mounting flange  235  enables valve  200  to be mounted to other components in the system. Those skilled in the art, in light of the present teachings, will readily recognize that a multiplicity of suitable mounting flanges are available for use on valve  200 , for example, without limitation, flanges of different shapes such as, but not limited to, squares or rectangles. 
       FIG. 7  shows exemplary components of a dual wedge valve, in accordance with an embodiment of the present invention. The components shown in  FIG. 7  include a male wedge arm  701 , a female wedge  703  within a valve body  705  and a drive shaft  707  on a drive arm  709 . Male wedge arm  701  comprises a top surface and a bottom surface; each sloped at a 7.5-degree angle to create a total angle of 15 degrees within male wedge arm  701 . Female wedge  703  also comprises a top surface and a bottom surface; each sloped at 7.5 degrees to match the angle of male wedge arm  701 . In alternate embodiments, the surfaces of the male wedge arm and the female wedge may be sloped at angles other than 7.5 degrees. The top and bottom surfaces of male wedge arm  701  each have an o-ring groove  711 . An o-ring may be inserted into one o-ring groove  711  to create a vacuum tight seal when the valve is closed, and a smooth, non-wear material, such as, but not limited to, Kynar, or other sliding means such as, but not limited to, ball bearings, may be inserted into the other o-ring groove  711  to facilitate the sliding of male wedge arm  701  along female wedge  703 . The o-ring of male wedge arm  701  slides on and creates a seal with an ultra smooth, polished surface  713  of female wedge  703 . When in an assembled valve, male wedge arm  701  is attached to drive shaft  707 . When drive shaft  707  is actuated by drive arm  709 , male wedge arm  701  rotates into or out of female wedge  703 . 
       FIGS. 8 ,  9  and  10  illustrate an exemplary single wedge gate valve  800 , in accordance with an embodiment of the present invention.  FIG. 8  is a side view of single wedge gate valve  800  in a closed position without body sides for clarity.  FIG. 9  is a cross-sectional view of single wedge gate valve  800  in the closed position, and  FIG. 10  is a section view of single wedge gate valve  800 . In the present embodiment, valve  800  comprises a rotating wedge  801  and a fixed wedge  803 . Rotating wedge  801  is a smooth faced plate that swings on a wedge arm  802  on a fixed shaft  804  toward fixed wedge  803  with a captive o-ring  805 . In the present embodiment, o-ring  805  is set into fixed wedge  803 , and rotating wedge  801  has an ultra smooth surface, for example, without limitation, a 16-finish or a non-stick coating, in the area where rotating wedge  801  comes into contact with o-ring  805 . In alternate embodiments the o-ring may be set into the rotating wedge, and the fixed wedge may have an ultra smooth finish. In the present embodiment, wedge arm  802  swings on a fixed horizontal plane. Two wheels  807  roll on an upper plate  809  creating additional pressure on rotating wedge  801  to force rotating wedge  801  against o-ring  805  in fixed wedge  803 . Those skilled in the art, in light of the present teachings, will readily recognize that a multiplicity of suitable means may be used to create additional pressure on the rotating wedge in alternate embodiments, such as, but not limited to, rollers, ball bearings, etc. In the present embodiment, rotating wedge  801  and fixed wedge  803  each have a 7.5-degree surface; however, alternate embodiments may comprise wedges with various different angles. Referring to  FIG. 10 , the surfaces of rotating wedge  801  and fixed wedge  803  are non-parallel when in an open position, and these surfaces become parallel as rotating wedge  801  comes into contact with o-ring  805 , mounted on fixed wedge  803 . 
     Similarly to the embodiment shown by way of example in  FIGS. 2 through 6 , to actuate rotating wedge  801 , an air cylinder  811  drives a drive arm  813 , which rotates shaft  804 . Wedge arm  802 , which is attached to rotating wedge  801 , is locked to shaft  804  and rotates when shaft  804  is rotated by drive arm  813 . Some embodiments may comprise a three-part linkage in the drive system, and other embodiments may not comprise a three-part linkage. Furthermore, those skilled in the art, in light of the present teachings, will readily recognize that the rotating wedge may be actuated by various different means other than an air cylinder in alternate embodiments such as, but not limited to, a hydraulic cylinder, an electric motor, a manual lever, etc. In the present embodiment, rotating wedge  801  and fixed wedge  803  generally do not require adjusting. However, adjusting may be performed by sliding wedge arm  802  up or down shaft  804  and using threaded nuts and/or a key to hold wedge arm  802  in place. Alternate embodiments may be implemented that are not adjustable. Referring to  FIGS. 8 ,  9  and  10 , single wedge embodiments have benefits over existing valves including, without limitation, a high cycle life because of the lack of bellows, the ability to water cool with no lines, ease of repair and maintenance, and suitability for throttling from completely closed to fully open. 
     Those skilled in the art, in light of the present teachings, will readily recognize that embodiments of the present invention may be used in various different applications. The foregoing description was directed to embodiments for use in vacuum process control systems; however, embodiments of the present invention may be used in other types of systems including, without limitation, fluid control systems, systems to control the flow of a gas, etc. Furthermore, some of these applications may not require a vacuum tight seal. Embodiments of the present invention for use in applications not requiring a vacuum tight seal may be implemented without sealing components such as, but not limited to, the o-ring or the ultra smooth surface on the wedge. 
     Having fully described at least one embodiment of the present invention, other equivalent or alternative methods of providing a pendulum valve incorporating wedges according to the present invention will be apparent to those skilled in the art. The invention has been described above by way of illustration, and the specific embodiments disclosed are not intended to limit the invention to the particular forms disclosed. For example, the particular implementation of the male wedge may vary depending upon the particular type of female wedge used. The male wedges described in the foregoing were directed to implementations with flat surfaces; however, similar techniques are to use wedges with curved surfaces. Curved implementations of the present invention are contemplated as within the scope of the present invention. The invention is thus to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the following claims.