Hydraulic pneumatic shock absorber

Claim 1

A DIRECT ACTING TELESCOPING CYLINDER-AND-PISTON SHOCK ABSORBER, COMPRISING A CYLINDER ENCLOSING A WORKING CHAMBER CONTAINING A DAMPING LIQUID; A WORKING PISTON DISPOSED FOR RECIPROCATION IN SAID DAMPING LIQUID WITHIN SAID CHAMBER AND HAVING A PISTON ROD FIXEDLY SECURED THERETO AND EXTENDING THROUGH A PACKED OPENING IN ONE END OF SAID CYLINDER, VALVED OPENINGS IN THE PISTON FOR THE CONTROLLED PASSAGE OF DAMPING LIQUID FROM ONE SIDE OF THE PISTON TO THE OTHER UPON RECIPROCATION OF THE PISTON IN THE CYLINDER; MEANS FOR ATTACHING THE REMOTE ENDS OF THE CYLINDER AND PISTON ROD RESPECTIVELY TO THE MEMBERS THE RELATIVE MOVEMENT OF WHICH IS TO BE DAMPED; A QUANTITY OF GAS UNDER PRESSURE DISPOSED WITHIN THE CYLINDER AT THE END THEREOF REMOTE FROM THE PACKED END OF THE CYLINDER THROUGH WHICH THE PISTON ROD EXTENDS; A FLOATING PISTON DISPOSED WITHIN SAID CYLINDER AND HAVING A PERIPHERAL SEALING MEANS CONTACTING THE INNER WALLS OF THE CYLINDER, SAID PISTON SERVING TO SEPARATE THE DAMPING LIQUID FROM THE GAS UNDER PRESSURE, AND ADAPTED TO BE FORCED OUTWARDLY AGAINST THE PRESSURE OF THE GAS BY THE LIQUID DISPLACED BY THE ENTRANCE INTO THE CHAMBER OF SUCCESSIVE PORTIONS OF THE WORKING PISTON ROD UPON THE COMPRESSION STROKE OF THE SHOCK ABSORBER, THE SEALING MEANS FOR THE FLOATING PISTON COMPRISING AN O-RING OF ELASTOMERIC MATERIAL AND OF CIRCULAR SECTION SEATED WITHIN A PERIPHERAL GROOVE IN THE FLOATING PISTON AND SNUGLY CONTACTING THE BOTTOM OF THE GROOVE AND THE WALLS OF THE CYLINDER, THE WIDTH OF THE GROOVE BEING OF A PREDETERMINED DIMENSION GREATER THAN THE WIDTH OF THE O-RING SECTION, WHEREBY UPON MOVEMENT OF THE WORKING PISTON AND THE CONSEQUENT MOVEMENT OF THE FLOATING PISTON IN EITHER DIRECTION, THE O-RING WILL BE SUBJECT TO ROLLING MOVEMENT BEFORE IT BEGINS TO SLIDE ALONG THE SURFACE OF THE CYLINDER WALLS, THE LENGTH OF SAID ROLLING MOVEMENT BEARING THE SAME RATIO TO THE LENGTH OF MOVEMENT OF THE WORKING PISTON AND THAT OF SAID TWO MEMBERS, AS THE RATIO OF THE CROSS-SECTIONAL AREA OF THE PISTON ROD TO THAT OF THE WORKING PISTON.