Hydraulic motor with piston holding means

Claim 1

A HYDRAULIC MOTOR FOR THE USE IN VEHICLES AND THE LIKE COMPRISING A STATIONARY FRAME HAVING A PLURALITY OF RADIALLY ARRANGED CYLINDERS, A PISTON RECIPROCALLY POSITIONED IN AND COOPERATING WITH EACH OF SAID CYLINDERS, A CAM-RING ROTATABLY MOUNTED TO SAID FRAME AND POSITIONED AROUND SAID PLURALITY OF CYLINDERS, EACH SAID PISTON HAVING CONTACT MEANS AT ITS OUTER END FOR ENGAGING THE INNER SURFACE OF SAID CAM-RING, A REGULATING VALVE HAVING PRESSURE CHANNELS CONNECTED BETWEEN SAID CYLINDERS AND A FIRST SOURCE OF HYDRAULIC PRESSURE FOR SELECTIVELY FORCING EACH SAID PISTON OUTWARDLY AND ENABLING EACH SAID PISTON TO MOVE INWARDLY IN A TIME SEQUENCE CORRESPONDING TO THE RELAITVE RADIAL AND ANGULAR POSITIONS BETWEEN SAID CONTACT MEANS AND SAID CAM-RING, RESPECTIVELY, A LIQUID-TIGHT HOUSING MOUNTED TO SAID FRAME AND DEFINING A CHAMBER ABOUT SAID CYLINDERS, AND MEANS FOR SELECTIVELY INCREASING FLUID PRESSURE IN SAID CHAMBER RELATIVE TO THE PRESSURE IN SAID CYLINDERS SO THAT SAID CHAMBER PRESSURE IS GREAT ENOUGH TO FORCE SAID PISTONS INWARDLY.