Fluid cylinder and valve control means therefor

Claim 1

IN COMBINATION WITH A FLUID CYLINDER HAVING A DOUBLE ACTING RECIPROCATORY PISTON THEREIN AND A HEAD ATTACHED TO AND CLOSING EACH END OF THE CYLINDER AND EACH HEAD HAVING A THREADED PORT THEREIN LEADING TO THE INTERIOR OF THE CYLINDER, OF A CONTROL UNIT MOUNTED ON SAID CYLINDER HEADS FOR OPERATION OF THE PISTON, SAID CONTROL UNIT COMPRISING AT ONE END A THREADED COUPLING MEANS HAVING A DUCT THERETHROUGH COMMUNICATING WITH THE THREADED PORT IN ONE HEAD OF THE CYLINDER AND HAVING AT ITS OTHER END A VALVE BASE BLOCK SEATING ON THE OTHER CYLINDER HEAD AND HAVING A DUCT THEREIN LEADING TO A BLIND THREAD SOCKET COMMUNICATING WITH THE THREADED PORT IN THE OTHER HEAD OF THE CYLINDER, A 4-WAY VALVE MOUNTED ON THE BASE BLOCK AND HAVING A SINGLE INLET PORT, A SINGLE EXHAUST PORT AND A THIRD AND A FOURTH PORT COMMUNICATING RESPECTIVELY WITH THE AFOREMENTIONED PORTS IN THE BASE BLOCK AND IN THE COUPLING MEANS, AN EXTERNALLY DOUBLE-THREADED TUBULAR ADAPTER ENGAGING PARTIALLY IN THE PORT IN THE CYLINDER HEAD AND PARTIALLY IN THE BLIND THREADED SOCKET IN THE BASE BLOCK, WHICH SOCKET COMMUNICATES WITH THE DUCT LEADING TO THE THIRD PORT IN THE BASE BLOCK, THE SAID PROVIDING COMMUNICATING BETWEEN THE THREADED COUPLING MEANS AND THE FOURTH PORT IN THE BASE BLOCK, THE SAID ADAPTER AND COUPLING MEANS SERVING TO MOUNT THE CONTROL UNIT ONTO SAID CYLINDER HEADS, THE 4-WAY VALVE HAVING A MOVABLE VALVE ELEMENT FOR SELECTIVELY ESTABLISHING FLUID COMMUNICATION BETWEEN THE INLET PORT AND EITHER THE FLUID OR FOUTH PORTS, RESPECTIVELY, WHILE ESTABLISHING FLUID COMMUNICATING BETWEEN THE EXHAUST PORT AND EITHER THE FOURTH AND THIRD PORTS, RESPECTIVELY.