Valve for controlling the rate of movement of a fluid powered motor unit

Claim 1

A VALVE FOR USE IN A FLUID SYSTEM FOR CONTROLLING THE ACTUATION OF A FLUID POWERED MOTOR UNIT COMPRISING, A HOUSING HAVING AN INLET PORT AND A FIRST MOTOR PORT AND AN EXHAUST PORT AND A SECOND MOTOR PORT, SAID HOUSING HAVING A PAIR OF CHAMBERS DISPOSED IN FLUID COMMUNICATION WITH SAID INLET AND EXHAUST PORTS, AND A PAIR OF PASSAGE MEANS IN FLUID COMMUNICATION WITH SAID CHAMBERS AND THE RESPECTIVE MOTOR PORTS, A POWER CHECK VALVE MECHANISM DISPOSED IN EACH OF SAID PASSAGE MEANS TO CONTROL FLUID PRESSURE BETWEEN SAID MOTOR PORTS AND SAID INLET AND EXHAUST PORTS, EACH OF SAID VALVE MECHANISMS INCLUDING A VALVE SEAT AND A RESILIENTLY LOADED, HOLLOW VALVE MEMBER ADAPTED FOR SEALING ENGAGEMENT WITH THE ASSOCIATED VALVE SEAT, AND A RESILIENTLY LOADED PISTON MEMBER DISPOSED AT ONE END FOR MOVEMENT IN EACH OF THE RESPECTIVE VALVE MEMBERS, EACH OF SAID VALVE MEMBERS INCLUDING AN OPENING AT ITS END ADJACENT ITS VALVE SEAT, ONE OF SAID PISTON MEMBERS IS EXPOSED TO PRESSURE FROM SAID INLET AND THE ASSOCIATED FIRST MOTOR PORT AND THE OTHER PISTON MEMBER IS EXPOSED TO PRESSURE FROM SAID EXHAUST PORT AND THE ASSOCIATED SECOND MOTOR PORT, SAID OPENINGS IN SAID VALVE MEMBERS PROVIDING A FLUID PATH FOR EXPOSING SAID ONE PISTON TO THE INLET PORT PRESSURE AND SAID OTHER PISTON TO THE EXHAUST PORT PRESSURE, SEALING MEANS DISPOSED IN FLUID SEALING ENGAGEMENT BETWEEN SAID PISTON MEMBERS AND THE ASSOCIATED VALVE MEMBERS, A PLUNGER MEMBER DISPOSED IN FLUID SEALING RELATIONSHIP BETWEEN SAID CHAMBERS FOR RECIPROCAL MOVEMENT FOR COACTING ENGAGEMENT WITH ONE OF THE RESPECTIVE VALVE MEMBERS, SAID PLUNGER MEMBER AT ONE END BEING EXPOSED TO PRESSURE FROM SAID INLET PORT AND AT ITS OTHER END BEING EXPOSED TO PRESSURE FROM SAID SECOND MOTOR PORT, AND RETAINER MEANS DISPOSED IN EACH OF SAID VALVE MEMBERS FOR LIMITING MOVEMENT OF THE ASSOCIATED PISTON MEMBERS RELATIVE TO THE RESPEECTIVE VALVE MEMBER, WHEREBY THE RESPECTIVE VALVE AND ASSOCIATED PISTON MEMBERS ARE CAUSED TO MOVE, AS A UNIT, IN A DIRECTION AWAY FROM THE ASSOCIATED VALVE SEATES IN RESPONSE TO A PRESSURE AT SAID INLET PORT WHICH ACTS TO UNSEAT THE VALVE MEMBER WHICH IS IN COMMUNICATION WITH INLET PORT AND ITS ASSOCIATED FIRST MOTOR PORT AND WHICH ACTS ON SAID PLUNGER MEMBER TO UNSEAT THE OTHER VALVE MEMBER WHICH IS IN COMMUNICATION WITH THE EXHAUST PORT AND ITS ASSOCIATED SECOND MOTOR PORT FOR MAINTAINING THE PRESSURE IN ONE OF SAID CHAMBERS SUBSTANTIALLY PROPORTIONAL TO THE PRESSURE IN THE OTHER OF SAID CHAMBERS.