Piston return mechanism

Claim 1

IN A FLUID ENERGY TRANSLATING DEVICE INCLUDING A HOUSING AND VALVING MEANS, A CYLINDER BARREL HAVING A PLURALITY OF CYLINDER BORES COMMUNICATING WITH SAID VALVING MEANS, PISTONS ARRANGED FOR RECIPROCATION IN SAID CYLINDER BORES, A CAM PLATE OPERATIONALLY ENGAGING SAID PISTONS, THE COMBINATION THEREWITH OF A PISTON RETURN MECHANISM COMPRISING, SPRING MEANS BIASING EACH PISTON TOWARD SAID CAM PLATE, PISTON SHOES UNIVERSALLY MOUNTED ON SAID PISTONS AND HAVING SURFACES BEARING AGAINST SAID CAM PLATE, AND PLATE MEANS OPERATIVELY INTERCONNECTING SAID PISTON SHOES, SAID PLATE MEANS AND SAID PISTON SHOES HAVING CO-ACTING MEANS TO PREVENT TITLING OF SAID PISTON SHOES WITH RESPECT TO EACH OTHER AND TO MAINTAIN SAID SURFACES OF SAID PISTON SHOES CO-PLANAR WHILE PERMITTING RELATIVE MOVEMENT OF SAID PISTON SHOES WITH RESPECT TO SAID PLATE MEANS IN THE PLANE OF SAID PLATE MEANS, SAID PLATE MEANS BEING PERIPHERIALLY SUPPORTED AND CONFIGURED AND ARRANGED TO MOVE AWAY FROM SAID CAM PLATE WITH SAID PISTON SHOES, WHEREBY WHEN THE FORCES RESISTING THE PISTONS'' RETURN EXCEED THE BIASING FORCES OF THE SPRING MEANS AND THE PISTON SHOES LIFT FROM SAID CAM PLATE THE BEARING SURFACES OF SAID PISTON SHOES ARE MAINTAINED COPLANAR BY SAID PLATE MEANS.