Control valve system for pressure fluid cylinder

Claim 1

IN A CONTROL SYSTEM FOR CONTROLLING THE OPERATION OF A PRESSURE FLUID CYLINDER HAVING A RECIPROCATING PISTON ROD, THE COMBINATION COMPRISING MEANS DEFINING A FIRST FLUID FLOW PATH COMMUNICATING WITH ONE SIDE OF SAID CYLINDER, MEANS DEFINING A RESTRICTION IN SAID FIRST FLOW PATH, MEANS DEFINING A SECOND FLUID FLOW PATH BY-PASSING SAID RESTRICTION, MEANS DEFINING A VALVE CHAMBER IN SAID SECOND FLOW PATH HAVING A SEAT AT ONE END THEREOF SURROUNDING A PORT, A VALVE ELEMENT IN SAID VALVE CHAMEBR MOVABLE BETWEEN OPEN AND CLOSED POSITONS RELATIVE TO SAID SEAT, A CAM MOVED IN UNISON WITH SAID PISTON ROD, A FOLLOWER DEVICE ENGAGEABLE WITH SAID CAM AND WITH SAID VALVE ELEMENT FOR OPERATING SAID VALVE ELEMENT IN RESPONSE TO MOVEMENT OF SAID CAM, SAID CAM BEING SO SHAPED AS TO CAUSE SAID FOLLOWER DEVICE TO MOVE SAID VALVE ELEMENT TO ITS CLOSED POSITION WHEN SAID PISTON ROD PASSES A GIVEN POINT IN MOVING IN ONE OF ITS DIRECTIONS OF RECIPROCATING MOVEMENT AND TO POSITIVELY HOLD SAID VALVE ELEMENT IN SAID CLOSED POSITION UNTIL SAID PISTON ROD PASSES SAID GIVEN POINT IN MOVING IN THE OTHER DIRECTION OF ITS RECIPROCATING MOVEMENT, MEANS DEFINING A THIRD FLUID FLOW PATH IN PARALLEL WITH SAID SECOND CHECK FLOW PATH AND ALSO BY-PASSING SAID RESTRICTION, AND A CHECK VALVE IN SAID THIRD FLOW PATH ARRANGED TO PERMIT FLOW THERETHROUGH WHEN THE PRESSURE IN SAID PORT EXCEEDS THE PRESSURE IN SAID VALVE CHAMBER.