Hydropneumatic suspension unit

Claim 1

IN A HYDROPNEUMATIC SUSPENSION DEVICE OF THE SELFPUMPING TYPE FOR MOTOR VEHICLES COMPRISING: A CYLINDER PROVIDING A CYLINDER CHAMBER AND A PUMP CHAMBER LOCATED REMOTE FROM SAID CYLINDER CHAMBER; A PISTON RECIPROCABLY DISPOSED WITHIN SAID CYLINDER AND IN WORKING RELATIONSHIP TO SAID CYLINDER AND PUMP CHAMBERS; A HOUSING AXIALLY EXTENDING FORMING AN OUTER CHAMBER AROUND SAID CYLIINDER; AN ANNULAR PARTITION MEMBER DISPOSED IN SAID LAST MENTIONED CHAMBER TRANSVERSELY BETWEEN SAID HOUSING AND SAID CYLINDER FOR ESTABLISHING A SEALINGLY DISCONNECTED FIRST AND SECOND PORTION WITHIN SAID HOUSING, SAID FIRST PORTION PROVIDING A HIGH PRESSURE CHAMBER AND SAID SECOND PORTION PROVIDING A FLUID RESERVOIR; A FLEXIBLE PARTITION COAXIALLY DISPOSED RELATIVE TO SAID CYLINDER DIVIDING SAID FIRST PORTION INTO TWO COMPARTMENTS, ONE OF WHICH IS FILLED WITH GAS UNDER RELATIVELY HIGH PRESSURE AND THE OTHER WITH A HYDRAULIC MEDIUM; MEANS FOR ESTABLISHING AND CONTROLLING FLUID INTERCOURSE BETWEEN THE COMPARTMENT CONTAINING THE HYDRAULIC MEDIUM AND THE CYLINDER CHAMBER; MEANS FOR ESTABLISHING AND CONTROLLING FLUID INTERCOURSE BETWEEN THE FLUID RESERVOIR OF SAID SECOND PORTION AND SAID PUMP CHAMBER; AND A PRESSURE RELIEF VALVE OPERABLY SECURED TO SAID ANNULAR PARTITION MEMBER FOR ESTABLISHING FLUID COMMUNICATION FROM SAID HIGH PRESSURE CHAMBER DIRECTLY TO SAID FLUID RESERVOIR WHEN THE FLUID PRESSURE IN SAID HIGH PRESSURE CHAMBER EXCEEDS A PREDETERMINED VALUE.