Fluid cylinder

Claim 1

IN A FLUID CYLINDER HAVING A PISTON AXIALLY MOVABLE THEREIN IN RESPONSE TO FLUID PRESSURE, A PISTON ROD, AT LEAST ONE CUSHION ELEMENT CONNECTED TO SAID PISTON ROD FOR MOVEMENT THEREWITH AND A BORE DEFINED WITHIN AT LEAST ONE END PORTION OF SAID CYLINDER FOR SLIDINGLY AND SEALINGLY ENGAGING ONE OF SAID CUSHION ELEMENTS TO PROVIDE SEALING OF EXHAUST FLOW THROUGH SAID BORE PRIOR TO THE TERMINATION OF THE STROKE OF SAID PISTON, THE IMPROVEMENT WHICH COMPRISES SAID CUSHION ELEMENT BEING CONSTRUCTED AS AN ELONGATED GENERALLY CYLINDRICAL MEMBER, SAID ROD PROJECTING CONCENTRICALLY FROM SAID PISTON THROUGH SAID CUSHION ELEMENT, SAID CUSHION ELEMENT AND ROD DEFINING A RADIAL CLEARANCE AT LEAST EQUAL TO ANY ECCENTRICITY BETWEEN THE AXIS OF SAID ROD AND THE AXIS OF SAID BORE, A RETAINER SECURED TO SAID ROD SPACED AXIALLY FROM SAID PISTON, A PORTION OF SAID CUSHION ELEMENT BEING INTERPOSED BETWEEN SAID RETAINER AND THE FACE OF SAID PISTON, SAID CUSHION ELEMENT BEING FREE TO SLIDE RADIALLY WITH RESPECT TO THE FACE OF SAID PISTON AND SAID RETAINER, SEALING MEANS HELD IN ENGAGEMENT BETWEEN SAID RETAINER AND SAID CUSHION ELEMENT IN THE AREA WHEREIN RADIAL SLIDING MOVEMENT BETWEEN SAID ELEMENT AND RETAINER IS PERMITTED, AND MEANS FOR MOVING SAID CUSHION ELEMENT RADIALLY WITH RESPECT TO SAID BORE UPON MOVEMENT OF SAID ELEMENT INTO SAID BORE TO CENTER SAID ELEMENT THEREIN, SAID RETAINER BEING POSITIONED ON SAID ROD RELATIVE TO SAID CUSHION ELEMENT TO EXERT AN AXIAL COMPRESSION LOADING AGAINST SAID CUSHION ELEMENT TO HOLD SAID ELEMENT IN SAID CENTERED POSITION WHEN SPACED AXIALLY OF SAID BORE.