Hydraulic reciprocating device

Claim 1

A HYDRAULIC RECIPROCATING DEVICE COMPRISING: A HOUSING DEFINING PRIMARY AND SECONDARY CYLINDERS, MAIN PISTON MEANS DISPOSED IN THE PRIMARY CYLINDER AND HAVING A BYPASS VALVE DISPOSED THEREIN TO PASS FLUID FROM ONE SIDE OF THE MAIN PISTON MEANS TO THE OTHER, FIRST MEANS BIASING THE MAIN PISTON MEANS TO A RETRACTED POSITION, SECOND MEANS BIASING THE BYPASS VALVE TO A CLOSED POSITION, THE FORCE OF THE SECOND BIASING MEANS ON THE BYPASS VALVE BEING IN THE SAME DIRECTION AS THE FORCE OF THE FIRST BIASING MEANS ON THE MAIN PISTON MEANS, VALVE PISTON MEANS DISPOSED IN SAID SECONDARY CYLINDER AND CONNECTED TO ACTUATE THE BYPASS VALVE AND TO CUT OFF THE FLOW OF FLUID TO THE MAIN PISTON MEANS WHEN BOTH THE MAIN AND VALVE PISTON MEANS ARE IN AN EXTENDED POSITION, A SOURCE OF HYDRAULIC PRESSURE FLUID, AND CONDUIT MEANS SUPPLYING A FIRST RESTRICTED FLOW OF FLUID FROM SAID SOURCE TO ACTUATE THE MAIN PISTON MEANS AGAINST THE FIRST BIASING MEANS, SAID CONDUIT MEANS ALSO SUPPLYING A SECOND, MORE RESTRICTED FLOW OF FLUID TO ACTUATE THE VALVE PISTON MEANS AGAINST THE SECOND BIASING MEANS, WHEREBY THE VALVE PISTON MEANS WILL MOVE RELATIVE TO THE MAIN PISTON MEANS AGAINST THE SECOND BIASING MEANS WHEN THE FLUID SUPPLY TO THE MAIN PISTON MEANS IS CUT OFF, THEREBY OPENING THE BYPASS VALVE AND CAUSING THE MAIN PISTON MEANS TO RETRACT UNDER THE INFLUENCE OF THE FIRST BIASING MEANS.