Abstract:
A hydraulic and pneumatic cylinder ( 10 ) for use on a vehicle ( 100 ) to improve the handling of the vehicle in a turn or curve. The cylinder repositions the rear wheel ( 108 ) of the vehicle in response to a change in the speed of the vehicle. When the vehicle enters a turn and decelerates, the piston of the cylinder moves to the extended position. When the vehicle exits the turn and accelerates, the piston of the cylinder moves to the compressed position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO A “MICROFICHE APPENDIX” 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to a combination hydraulic and pneumatic cylinder which has a valve in the piston to control the rate of movement of the piston. In particular, the present invention relates to a combination hydraulic and pneumatic cylinder for use in controlling the handling of a vehicle around curves. The cylinder controls the movement of at least one of the rear wheels of the vehicle during cornering. 
     (2) Description of the Related Art 
     The related art has shown various pneumatic, hydraulic and olepneumatic cylinders using a variety of different constructions to control the movement of the piston of the cylinder. In particular, the related art shows cylinders where a bore is provided through the piston rod to allow fluid to move between chambers of the cylinder through the piston rod. Illustrative are U.S. Pat. Nos. 3,110,485 to Axthammer and 4,405,119 to Masclet et al. 
     Axthammer shows a hydro-pneumatic suspension device. The device includes a hollow shell with a cavity having a transverse partition dividing the cavity into a storage space and a pressure space. The free end portion of the plunger is located in the pressure space. The plunger has an axial cavity which extends over a major portion of the plunger length. The cavity is in fluid communication with the storage space. An elongated open groove is formed in the outer surface of the plunger near its inner end portion. The groove forms a passage from the pressure space to the storage space. The storage space and pressure space are divided into three chambers. A tubular piston having an axial bar projects from the bottom of the shell into the pressure chamber. Entry of the piston into the bore during downward movement of the plunger substantially closes the cylinder space of the pump constituted by the piston and the lower end of the plunger. 
     Masclet et al shows an olepneumatic suspension having a rod sealingly mounted for sliding movement inside a cylinder filled with hydraulic liquid. A guide rod fixed with respect to the bottom of the cylinder passes through a central passage provided in the piston. The piston also has two (2) valves with permanent throttle orifices of different cross-sections. The orifice of greater cross-section provides throttling in the compression phase and the orifice of smaller cross-section provides throttling in the extrusion phase. 
     Also of interest are U.S. Pat. Nos. 2,141,541 to Levv; 2,397,640 to Bingham; 2,823,915 to Bourcier De Carbon; 3,706,362 to Faure and 4,131,139 to Tanabe which show various types of valved orifices located in pistons of a cylinder to provide dampening to the cylinder. 
     There remains the need for a combination hydraulic and pneumatic cylinder for use in controlling the cornering ability of a vehicle which controls the rate of movement of the piston in the cylinder in two (2) ways. The cylinder uses a passageway through the piston rod to control the rate of extrusion and compression of the cylinder and a control valve in the piston to allow fluid flow between the chambers of the cylinder. 
     SUMMARY OF THE INVENTION 
     The present invention is a hydraulic and pneumatic cylinder for use on a vehicle to improve the handling of the vehicle in a turn or curve. The cylinder repositions the rear wheel of the vehicle in response to a change in the speed of the vehicle. The cylinder can be used on racing vehicles to allow for better handling of the vehicle in turns at high rates of speed. The cylinder has a body and a piston member. The body of the cylinder has opposed end caps with a cylinder bore extending therebetween. The piston member includes a piston and a piston rod. A divider wall extends across the cylindrical bore to divide the cylindrical bore into two chambers. The divider wall has a center opening to allow the piston rod to extend through and a side opening to allow fluid in the body to pass between the chambers. The first end cap has a guide pin which extends into a center bore in the piston. The center bore in the piston is in fluid communication with a center bore and side bore in the piston rod. The guide pin is smaller in diameter than the center bores of the piston and piston rod such that fluid is able to pass around the guide pin to move from one side of the piston to the other side of the piston. The piston is provided with a control valve having an adjustment cylinder and a valve mounted in a valve bore. An end of the valve pin extends beyond the valve bore and contacts the divider wall as the piston is moved toward the divider wall. Contact of the valve pin with the divider wall moves the valve to the fully open position. The control valve helps to provide a controlled rate of extension and compression of the cylinder. The cylinder is preferably mounted between a frame of the vehicle and a lower control arm for the rear, passenger wheel of the vehicle. 
     The cylinder extends and compresses in response to a change in the rate of speed of the vehicle. When the vehicle enters a turn and decelerates, the piston of the cylinder moves to the extended position. As the cylinder moves to the extended position, fluid on one side of the piston pushes against the valve pin of the control valve to open the control valve. When the cylinder is almost in the fully extended position with the piston adjacent the divider wall, the end of the valve pin contacts the divider wall and moves the control valve to the fully open position. When the vehicle exits the turn and accelerates, the piston of the cylinder moves to the compressed position. The cylinder allows the rear wheel on the passenger side of the vehicle to move backwards toward the rear end of the vehicle when the vehicle decelerates. Moving the rear wheel backwards allows for greater steering ability and better handling ability in turns at high speeds. 
     The present invention relates to a combined pneumatic and hydraulic cylinder, which comprises: a body having opposed open first and second ends with a bore extending therebetween defined by an inner sidewall around a longitudinal axis of the cylinder; a first end cap mounted on the open first end of the body and having a guide pin extending along the longitudinal axis of the cylinder and projecting into the bore; a divider wall mounted in the bore between the ends of the body and having a center opening around the longitudinal axis and a side opening extending parallel to and spaced apart from the longitudinal axis wherein the side opening allows for fluid flow through the divider wall; a second end cap mounted on the open second end of the body and having a center opening around the longitudinal axis; a piston member including a rod with a piston at one end wherein the piston member is mounted such that the rod sealingly extends through the center opening in the second end cap along the longitudinal axis with the piston slidably mounted in the bore between the first end cap and the divider wall with the piston in a sealed relationship with the inner wall of the body, the rod including: (i) a center bore along the longitudinal axis; and (ii) a side bore adjacent to the piston and in fluid communication with the center bore of the rod; the piston including: (i) a center bore along the longitudinal axis wherein the center bore of the piston is in fluid communication with the center bore and the side bore of the rod and wherein the guide pin of the first end cap extends into the center bore of the piston towards the rod; and (ii) a valve means which is opened when the piston is moving toward the divider wall; and a means mounted on the body for introducing a pneumatic fluid into the bore in the body between the second end cap and the divider wall, wherein the cylinder is mounted in a substantially horizontal orientation between objects which are in motion relative to each other and provides a controlled movement of at least one of the objects along the longitudinal axis of the cylinder by means of the guide pin which is undersized relative to the center bores of the piston and rod such that fluid is able to flow through the center bores around the guide pin and wherein the valve means in the piston equalizes hydraulic fluid pressure in the cylinder as the piston approaches the divider wall. 
     Further, the present invention relates to a combined pneumatic and hydraulic cylinder, which comprises: a body having opposed open first and second ends with a bore extending therebetween defined by an inner sidewall around a longitudinal axis of the cylinder; a first end cap mounted on the open first end of the body and having a guide pin extending along the longitudinal axis of the cylinder and projecting into the bore; a divider wall mounted in the bore between the ends of the body and having a center opening around the longitudinal axis and a side opening extending parallel to and spaced apart from the longitudinal axis wherein the side opening allows for fluid flow through the divider wall; a second end cap mounted on the open second end of the body and having a center opening around the longitudinal axis; a piston member having a rod with a piston at one end wherein the piston member is mounted such that the rod sealingly extends through the center opening in the second end cap along the longitudinal axis with the piston slidably mounted in the bore between the first end cap and the divider wall with the piston in a sealed relationship with the inner wall of the body, the rod including: (i) a center bore along the longitudinal axis; and (ii) a side bore adjacent to the piston and in fluid communication with the center bore of the rod; the piston including: (i) a center bore along the longitudinal axis wherein the center bore of the piston is in fluid communication with the center bore of the rod and the side bore of the rod and wherein the guide pin of the first end cap extends into the center bore towards the rod; and (ii) a valve means including a valve bore extending through the piston having opposed open ends and extending parallel to and spaced apart from the center bore with a valve pin and an adjustment means wherein when the valve means is in the closed position, an end of the valve pin extends through one of the ends of the valve bore on a side adjacent the rod and wherein the valve means is moved to a fully open position when the end of the valve pin contacts the divider wall as the piston approaches the divider wall; and a means mounted on the body for introducing a pneumatic fluid into the bore in the body between the second end cap and the divider wall, wherein the cylinder is mounted in a substantially horizontal orientation between objects which are in motion relative to each other and provides controlled movement of at least one of the objects along the longitudinal axis of the cylinder by means of the guide pin which is undersized relative to the center bore of the piston and rod such that fluid is able to flow through the center bores around the guide pin and wherein the valve means in the piston equalizes hydraulic fluid pressure in the cylinder as the piston approaches the divider wall. 
     Still further, the present invention relates to a vehicle having a frame and wheels and mounted on spindles, the improvement which comprises: a combined pneumatic and hydraulic cylinder mounted between the frame and at least one of the wheels, which includes: a body having opposed open first and second ends with a bore extending therebetween defined by an inner sidewall around a longitudinal axis of the cylinder; a first end cap mounted on the open first end of the body and having a guide pin extending along the longitudinal axis of the cylinder and projecting into the bore; a divider wall mounted in the bore between the ends of the body and having a center opening around the longitudinal axis and a side opening extending parallel to and spaced apart from the longitudinal axis wherein the side opening allows for fluid flow through the divider wall; a second end cap mounted on the open second end of the body and having a center opening around the longitudinal axis; a piston member including a rod with a piston at one end wherein the piston member is mounted such that the rod sealingly extends through the center opening in the second end cap along the longitudinal axis with the piston slidably mounted in the bore between the first end cap and the divider wall with the piston in a sealed relationship with the inner wall of the body, the rod including: (i) a center bore along the longitudinal axis; and (ii) a side bore adjacent to the piston and in fluid communication with the center bore of the rod; the piston including: (i) a center bore along the longitudinal axis wherein the center bore of the piston is in fluid communication with the center bore and the side bore of the rod and wherein the guide pin of the first end cap extends into the center bore of the piston towards the rod; and (ii) a valve means which is opened when the piston is immediately adjacent to the divider wall; and a means mounted on the body for introducing a pneumatic fluid into the bore in the body between the second end cap and the divider wall, wherein the cylinder is mounted in a substantially horizontal orientation between objects which are in motion relative to each other and provides controlled movement of at least one of the objects along the longitudinal axis of the cylinder by means of the guide pin which is undersized relative to the center bores of the piston and rod such that fluid is able to flow through the center bores around the guide pin and wherein the valve means in the piston equalizes hydraulic fluid pressure in the cylinder as the piston approaches the divider wall; wherein the cylinder is mounted such that when a rate of movement of the vehicle decreases, the piston member moves outward such as to expand the cylinder and wherein when a rate of movement of the vehicle increases, the piston member moves inward such as to compress the cylinder. 
     Further still, the present invention relates to a method for handling a vehicle in a turn at a high rate of speed, the vehicle having a frame with wheels mounted on spindles, the method which includes: providing a combined pneumatic and hydraulic cylinder which includes: a body having opposed open first and second ends with a bore extending therebetween defined by an inner sidewall around a longitudinal axis of the cylinder; a first end cap mounted on the open first end of the body and having a guide pin extending along the longitudinal axis of the cylinder and projecting into the bore; a divider wall mounted in the bore between the ends of the body and having a center opening around the longitudinal axis and a side opening extending parallel to and spaced apart from the longitudinal axis wherein the side opening allows for fluid flow through the divider wall; a second end cap mounted on the open second end of the body and having a center opening around the longitudinal axis; a piston member including a rod with a piston at one end wherein the piston member is mounted such that the rod sealingly extends through the center opening in the second end cap along the longitudinal axis with the piston slidably mounted in the bore between the first end cap and the divider wall with the piston in a sealed relationship with the inner wall of the body, the rod including: (i) a center bore along the longitudinal axis; and (ii) a side bore adjacent to the piston and in fluid communication with the center bore of the rod; the piston including: (i) a center bore along the longitudinal axis wherein the center bore of the piston is in fluid communication with the center bore and the side bore of the rod and wherein the guide pin of the first end cap extends into the center bore of the piston towards the rod; and (ii) a valve means which is opened when the piston is moved toward the divider wall; and a means mounted on the body for introducing a pneumatic fluid into the bore in the body between the second end cap and the divider wall, wherein the cylinder is mounted in a substantially horizontal orientation between objects which are in motion relative to each other and provides a controlled movement of at least one of the objects along the longitudinal axis of the cylinder by means of the guide pin which is undersized relative to the center bores of the piston and rod such that fluid is able to flow through the center bores around the guide pin and wherein the valve means in the piston equalizes hydraulic fluid pressure in the cylinder as the piston approaches the divider wall; mounting the cylinder between the frame of the vehicle and a rear control arm for one of the rear wheels of the vehicle; decreasing the rate of speed of the vehicle as the vehicle enters the turn so that the cylinder extends allowing one of the rear wheels connected to the rear control arm connected to the cylinder to move toward a rear end of the vehicle; and increasing the rate of speed of the vehicle as the vehicle exits the turn so that the cylinder compresses moving the rear wheel toward a front end of the vehicle. 
     The substance and advantages of the present invention will become increasingly apparent by reference to the following drawings and the description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the cylinder  10  of the present invention. 
     FIG. 2 is a cross-sectional view of the cylinder  10  showing the piston member  34  in the extended position. 
     FIG. 3 is a cross-sectional view of the cylinder  10  showing the piston member  34  in the contracted position. 
     FIG. 4 is a cross-sectional view along the line  4 — 4  of FIG. 2 showing the side opening  24 B of the divider wall  24 . 
     FIG. 5 is a cross-sectional view along the line  5 — 5  of FIG. 4 showing the control valve  44  in an open position with the valve pin  48  contacting the divider wall  24 . 
     FIG. 6 is a cross-sectional view of the control valve  44  when the valve  44  is in the closed position. 
     FIG. 7 is a schematic view of the cylinder  10  mounted between the frame  102  of a vehicle  100  and the rear control arm  104  of the vehicle  100 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 to  3  show the cylinder  10  of the present invention. The cylinder  10  includes a body  12  and a piston member  34 . The body  12  has opposed open first and second ends  12 A and  12 B with a cylindrical bore  12 C extending between the ends  12 A and  12 B. The ends  12 A and  12 B of the body  12  are closed by first and second end caps  14  and  20  which are preferably threadably mounted into the center bore  12 C of the body  12  at each end. The end caps  14  and  20  can be secured on the body  12  by any well known means. In the preferred embodiment, the end caps  14  and  20  are removably mounted. However, it is understood that the end caps  14  and  20  could be permanently mounted to the body  12 . One (1) of the end caps  14  or  20  could also be constructed as a unitary piece with the body  12 . The first end cap  14  is mounted on the first end  12 A of the body  12  and has a connecting rod  16  mounted perpendicular to the end cap  14  on one side of the end cap  14  opposite the cylindrical bore  12 C of the body  12 . Although a connecting rod  16  is shown, any connection means may be mounted on the cap  14  or body  12  to allow for connection of the cylinder  10  to the vehicle  100 . The first end cap  14  has a threaded cylindrical portion  14 A which extends into the center bore  12 C of the body  12  and threadably mates into the center bore  12 C of the body  12 . A guide pin  14 B is mounted on the threaded portion  14 A and extends perpendicular to the threaded portion  14 A into the center bore  12 C of the body  12  (FIG.  2 ). The guide pin  14 B is preferably coaxial with the longitudinal axis A—A of the cylinder  10 . However, it is possible to position the guide pin  14 B off-center as long as the guide pin  14 B is parallel to the longitudinal axis A—A of the cylinder  10 . The guide pin  14 B preferably has a cylindrical shape. The second end cap  20  is threadably mounted on the open second end  12 B of the body  12 . The second end cap  20  has a center opening  20 A through which the piston rod  36  for the piston member  34  extends. The center opening  20 A is provided with concentric grooves  20 B around the inner wall of the center opening  20 A. Ring seals  22  are mounted in the grooves  20 B and extend into center opening  20 A. In the preferred embodiment, the diameter of the center opening  20 A is slightly greater than the diameter of the piston rod  36  and the inner diameter of the ring seal  22  are less than the diameter of the center opening  20 A such that the ring seals  22  contact the piston rod  36  and act to form seals between the piston rod  36  and the center opening  20 A. 
     A divider wall  24  extends across the center bore  12 C of the body  12  and divides the center bore  12 C into a first chamber  26  and a second chamber  28 . In the preferred embodiment, the divider wall  24  is threadably mounted in the center bore  12 C of the body  12 . However, the divider wall  24  can be mounted by any well known means. In addition, the divider wall  24  could also be constructed as a unitary piece with the body  12  of the cylinder  10 . The divider wall  24  is positioned in the center bore  12 C such that the first and second chambers  26  and  28  have substantially the same volume. The divider wall  24  includes a center opening  24 A and a side opening  24 B. The center opening  24 A is in the center of the divider wall  24  and is coaxial with the longitudinal axis A—A of the cylinder  10 . The inner wall  12 D of the center opening  24 A is provided with a groove  24 C within which is positioned a ring seal  30 . The center opening  24 A of the divider wall  24  preferably has a diameter slightly greater than the diameter of the piston rod  36  of the piston member  34 . The ring seal  30  preferably has an inner diameter less than the diameter of the center opening  24 A such that the ring seal  30  extends into the center opening  24 A and contacts the piston rod  36  and forms a seal between the piston rod  36  and the center opening  24 A. The side opening  24 B of the divider wall  24  is spaced apart from the center opening  24 A and extends parallel to the longitudinal axis A—A of the cylinder  10 . In the preferred embodiment, for a cylinder  10  having a body  12  with a length of about between 3.75 and 5.25 inches (9.53 and 13.34 cm) and a center bore  12 C with a diameter of 1.5 inches (3.81 cm) the side opening  24 B preferably has a diameter of 0.125 inches (0.13 cm). 
     An air inlet valve  32  extends through the sidewall  12 E of the body  12  into the second chamber  28 . The air inlet valve  32  preferably allows for inserting or injecting compressed air into the second chamber  28 . The air inlet valve  32  is preferably a one-way valve such that air or other fluids can not leak from the second chamber  28  through the air inlet valve  32 . 
     The piston member  34  is slidably mounted in the center bore  12 C of the body  12  and includes a piston rod  36  and a piston  40 . The piston rod  36  and piston  40  can be constructed as a unitary piece or two (2) separate pieces. The piston member  34  is mounted in the center bore  12 C of the body  12  such that the piston  40  is located in the first chamber  26  of the body  12  and the piston rod  36  extends from the piston  40  through the center opening  24 A of the divider wall  24 , through the second chamber  28  and through the center opening  20 A of the second end cap  20 . The piston member  34  is positioned such that the piston rod  36  extends coaxially with the longitudinal axis A—A of the cylinder  10 . The piston rod  36  has a cylindrical shape with a first end  36 A and a second end  36 B. The piston rod  36  is mounted at the first end  36 A on one end of the piston  40  perpendicular to the piston  40 . The second end  36 B of the piston rod  36  can be of any form such as to allow connection or mounting of the cylinder  10  to the vehicle  100 . The first end  36 A of the piston rod  36  is provided with a center bore  36 C and a side bore  36 D (FIG.  2 ). The center bore  36 C of the piston rod  36  preferably extends only partially into the piston rod  36  adjacent the first end  36 A of the piston rod  36  and has an open first end on the first end  36 A of the piston rod  36 . The side bore  36 D extends into the piston rod  36  to the center bore  36 C of the piston rod  36 . In the preferred embodiment, the side bore  36 D extends perpendicular to the center bore  36 C. The open first end or exit of the side bore  36 D of the piston rod  36  is preferably directly adjacent the piston  40 . The second end of the side bore  36 D intersects the center bore  36 C such that the side bore  36 D is in fluid communication with the center bore  36 C. The side bore  36 D preferably intersects the center bore  36 C at a point spaced slightly apart from the closed, second end  36 B of the center bore  36 C. The piston  40  has a cylindrical shape with opposed ends  40 A and  40 B with a sidewall  40 C extending therebetween. The outer diameter of the piston  40  is slightly less than the diameter of the center bore  12 C of the body  12  (FIG.  4 ). The sidewall  40 C of the piston  40  is provided with a groove  40 D extending circumferentially around its perimeter spaced between the ends  40 A and  40 B of the piston  40 . A ring seal  42  is mounted in the groove  40 A and has an outer diameter equal to or slightly greater than the diameter of the center bore  12 C of the body  12 . The ring seal  42  creates a fluid seal between the piston  40  and the inner wall  12 D of the body  12 . The piston  40  includes a center bore  40 E extending through the piston  40  between the ends  40 A and  40 B. The center bore  40 E extends coaxial with the guide pin  14 B and has a diameter slightly greater than the guide pin  14 B such that the guide pin  14 B can slide in the center bore  40 E. The center bore  40 E is in fluid communication with the center bore  36 C of the piston rod  36 . The center bore  36 C of the piston rod  36 , the center bore  40 E of the piston  40  and the guide pin  14 B are all coaxial. In the preferred embodiment, the length of the guide pin  14 B is greater than the length of the center bore  40 E of the piston  40  plus the length of the center bore  36 C of the piston rod  36  up to and including the intersection of the side bore  36 D with the center bore  36 C such that when the cylinder  10  is in the fully extended position, the guide pin  14 B extends into and completely through the center bore  40 E of the piston  40  and into the center bore  36 C of the piston rod  36  to the side bore  36 D to prevent fluid communication between the side bore  36 D and the center bore  36 C of the piston rod  36  (FIG.  3 ). In the preferred embodiment, the center bore  40 E of the piston  40  and the center bore  36 C and side bore  36 D of the piston rod  36  all have substantially the same diameter. 
     A control valve  44  is provided in the piston  40  spaced apart from the center bore  40 E. The control valve  44  is mounted in a valve bore  40 F and includes an adjustment cylinder  46  and a valve pin  14 B (FIGS.  5  and  6 ). The valve bore  40 F extends through the piston  40  between the ends  40 A and  40 B of the piston  40  and is parallel to the center bore  40 E of the piston  40 . The valve bore  40 F has a first portion  40 G, a second portion  40 H and a third portion  40 I. A section of the first portion  40 G of the valve bore  40 F adjacent the first end  40 A of the piston  40  is provided with threads. However in an alternative embodiment, the entire first portion  40 G is threaded. The outer wall of the adjustment cylinder  46  has threads which mate with the threads of the first section of the first portion  40 G of the side bore  36 D and allow for adjustably mounting the adjustment cylinder  46  in the side bore  36 D. The adjustment cylinder  46  has first and second ends  46 A and  46 B with a center bore  46 C extending through the adjustment cylinder  46  between the ends  46 A and  46 B. The diameter of the center bore  46 C of the adjustment cylinder  46  is preferably a 10.32 set screw. The center bore  46 C of the adjustment cylinder  46  at the first end  46 A has a shape and size such as to allow mounting of a wrench (not shown) to allow for insertion and removal and adjustment of the adjustment cylinder  46  in the valve bore  40 F. The second end  46 B of the adjustment cylinder  46  has grooves or slots  46 D which allow for the flow of fluid from the center bore  46 C of the adjustment cylinder  46  around the valve pin  14 B when the first end of the valve pin  48  is in contact with the second  46 B of the adjustment cylinder  46 . The second portion  40 H of the valve bore  40 F preferably has a smooth inner wall. In the preferred embodiment, the diameter of the second portion  40 H decreases gradually toward the third portion  40 I such that the inner wall of the second portion  40 H is angled inward adjacent the third portion  40 I. The third portion  40 I of the valve bore  40 F preferably has a diameter smaller than the second portion  40 H. In the preferred embodiment, the first portion  40 G of the valve bore  40 F has a diameter of about 0.081 inches (0.208 cm). The third portion  40 I of the valve bore  40 F preferably has a diameter of about 0.081 inches (0.208 cm). In the preferred embodiment, the first portion  40 G of the valve bore  40 F is about 0.159 inches (0.404 cm) in length. The second portion  40 H is about 0.250 inches (0.635 cm) in length and the third portion  40 I is about 0.187 inches (0.475 cm) in length. 
     The valve pin  48  is movably mounted in the valve bore  40 F. The valve pin  48  has a first end  48 A and a second end  48 B. The valve pin  48  has a first portion  48 C and a second portion  48 D spaced between the first and second ends  48 A and  48 B. The valve pin  48  has a cross-sectional shape similar to the cross-sectional shape of the second and third portions  40 H and  40 I of the valve bore  40 F. The first portion  48 C of the valve pin  48  adjacent the first end  48 A has a diameter slightly less than the diameter of the first portion  40 G of the valve bore  40 F. The second portion  48 D of the valve pin  48  has a diameter less than the diameter of the third portion  40 I of the valve bore  40 F. The valve pin  48  is positioned in the valve bore  40 F such that the first portion  48 C of the valve pin  48  is located in the second portion  40 H of the valve bore  40 F and the second portion  48 D of the valve pin  48  extends into the third portion  40 I of the valve bore  40 F. In the preferred embodiment, the length of the second portion  48 D of the valve pin  48  is greater than the length of the third portion  40 I of the valve bore  40 F such that when the valve pin  48  is in the closed position, the second end  48 B of the valve pin  48  extends beyond the valve bore  40 F and the piston  40  and the first portion  48 C of the valve pin  48  is preferably in contact with the second portion  40 H of the valve bore  40 F. 
     IN USE 
     The cylinder  10  is preferably used in a substantially horizontal position to assist in the cornering ability of a vehicle (not shown) at high rates of speed. The cylinder  10  is preferably used on high performance race cars. The cylinder  10  is preferably connected to the rear or lower control arm  104  for a rear axle  106  of the vehicle  100  (FIG.  7 ). The cylinder  10  is preferably mounted to the control arm  104  for the rear, passenger side wheel  108 . In the preferred embodiment, the cylinder  10  is mounted between a first end  104 A of the rear control arm  104  and the frame  102  of the vehicle  100 . Preferably, the second end  36 B of the piston rod  36  of the cylinder  10  is connected to the first end  104 A of the control arm  104 . The second end  104 B of the control arm  104  is connected to the axle  106  of the vehicle  100  similarly to the standard connection of the rear control arm  104  to the rear axle  106  of the vehicle  100 . In the preferred embodiment, only one (1) cylinder  10  is used per vehicle  100 . The cylinder  10  allows the rear axle  106  and wheel  108  to move relative to the front and rear ends of the vehicle  100 . In the preferred embodiment, the axle  106  and wheel  108  are able to move between about 0.0 inch and 1.0 inch (0.0 cm and 2.54 cm) toward the rear end of the vehicle  100  when the cylinder  10  is in the fully extended position. In the preferred embodiment, the cylinder  10  compresses when the driver accelerates and extends when the driver brakes. Thus, as a driver enters a turn, the driver brakes and the vehicle  100  decelerates in response, the cylinder  10  extends allowing the rear axle  106  and wheel  108  on the passenger side of the vehicle  100  to move backwards toward the rear end of the vehicle  100 . As the vehicle  100  exits the turn, the driver pushes on the accelerator and the vehicle accelerates which causes the cylinder  10  to compress and move the rear axle  106  and wheel  108  back to the standard position. In the preferred embodiment, the cylinder  10  extends at a faster rate than it collapses due to the fact that there is less force acting on the cylinder  10  when the cylinder  10  is moving to the collapsed position. In addition, preferably more force is required to compress the cylinder  10  than to extend the cylinder  10 . In the preferred embodiment, the cylinder  10  compresses at a predetermined rate. In the preferred embodiment, when the vehicle  100  is traveling at about 70 mph, the cylinder  10  compresses in about 0.25 seconds or less from the time the driver begins to accelerate. Preferably, the driver of the vehicle  100  does not feel the extension or compression of the cylinder  10 . 
     Preferably, the cylinder  10  is fully constructed and filled with fluid prior to mounting on the vehicle  100 . The type of fluid used in the cylinder  10  will effect the rate of compression and extension of the cylinder  10 . In the preferred embodiment,  10  weight synthetic shock oil is used. Compressed gas is added to the fluid in the second chamber  28  using the air inlet valve  32  to prevent the fluid from foaming during use. When constructed, the piston  40  of the piston member  34  is located in the first chamber  26  with the guide pin  14 B extending into the center bore  40 E of the piston  40 . The piston rod  36  extends through the center opening  24 A of the divider wall  24  and the center opening  20 A of the second end cap  20 . 
     In the fully extended position, the piston  40  of the piston member  34  is in contact with the divider wall  24  and the control valve  44  is in the fully open position. In the fully contracted position, the piston  40  is in contact with the first end cap  14  and the control valve  44  is in the closed position. As the piston member  34  moves from the fully extended position to the fully compressed position and the cylinder  10  is compressed, the piston  40  moves away from the divider wall  24  toward the first end cap  14 . As the piston member  34  moves, the fluid (oil and compressed air) in the first chamber  26  move from one side of the piston  40  to the other side of the piston  40 . The fluid moves through the center bore  40 E of the piston  40  around the guide pin  14 B. The difference in the diameters of the guide pin  14 B and the center bore  40 E allow the fluid to move through the center bore  40 E around the guide pin  14 B and into the center bore  36 C and side bore  36 D of the piston rod  36 . When the cylinder  10  is in the fully contracted position, the guide pin  14 B preferably extends beyond the intersection of the side bore  36 D and the center bore  36 C of the piston rod  36  and completely closes off the side bore  36 D stopping the flow of fluid into the first chamber  26  from the side bore  36 D. In addition, as the piston member  34  moves, the fluid enters the center bore  46 C of the adjustment cylinder  46  of the control valve  44 . The flow of fluid into the center bore  46 C contacts the first end  48 A of the valve pin  48  and moves the valve pin  48  into a closed position such that the first portion  48 C of the valve pin  48  is in contact with the second portion  40 H of the valve bore  40 F such that the valve pin  48  closes the valve bore  40 F preventing fluid from flowing through the valve bore  40 F. During compression of the cylinder  10 , a minimal amount of fluid may also flow from the first chamber  26  into the second chamber  28  through the side opening  24 B in the divider wall  24 . The side opening  24 B in the divider wall  24  allows for the flow of fluid from the first chamber  26  to the second chamber  28  as needed to equalize the pressure in the two (2) chambers  26  and  28 . 
     As the cylinder  10  extends and moves from the fully compressed position to the fully extended position, the fluid in the lower portion of the first chamber  26  is compressed and is forced through the valve bore  40 F for the control valve  44 . The force of the fluid in the first chamber  26  pushes against the second end  48 B of the valve pin  48  of the control valve  44  and acts to move the valve pin  48  to an open or semi-open position. In the preferred embodiment, the force of the fluid pushing against the second end  48 B of the valve pin  48  does not fully open the valve  44 . When the piston  40  approaches the divider wall  24 , the second end  48 B of the valve pin  48  contacts the divider wall  24  which moves the valve pin  48  into the completely open position and allows the piston  40  to move to the fully extended position. The adjustment cylinder  46  allows for adjusting the amount of distance the valve pin  48  is able to retract into the valve bore  40 F. In the preferred embodiment, the adjustment cylinder  46  is positioned such that the valve pin  48  is able to fully retract into the valve bore  40 F while the second end  48 B of the valve pin  48  remains in the third portion  40 I of the valve bore  40 F such as to guide the valve pin  48  when the valve pin  48  is moving to the closed position. The control valve  44  allows for faster extension of the cylinder  10 . The grooves  46 D in the second end  46 B of the adjustment cylinder  46  allow fluid to flow through the valve bore  40 F when the valve pin  48  is in the fully open position which increases the extension speed of the cylinder  10 . During expansion of the cylinder  10 , the fluid also moves into the side bore  36 D and center bore  36 C of the piston rod  36  and through the center bore  40 E of the piston  40 . Positioning the open first end of the side bore  36 D directly adjacent the piston  40  allows fluid to continue to flow through the side bore  36  and the center bores  36 D and  40 E until the cylinder  10  is in the fully extended position. 
     It is intended that the foregoing description be only illustrative of the present invention and that the present invention be limited only by the hereinafter appended claims.