Vehicle leveling system

Claim 1

IN A COMBINATION SHOCK ABSORBER AND FLUID SUSPENSION UNIT THE COMBINATION OF, A SHOCK ABSORBER HAVING AN OUTER CYLINDRICAL SURFACE WITH A LARGE DIAMETER AT ONE END THEREOF AND A SMALL DIAMETER AT THE OPPOSITE END THEREOF, A PUMPING CYLINDER ARRANGED COAXIALLY OF SAID OUTER SURFACE IN SPACED RELATIONSHIP THEREWITH TO FORM A SMALL VOLUME FLUID RESERVOIR AND A LARGE VOLUME FLUID RESERVOIR COMMUNICATED THROUGH A SPACE BETWEEN SAID SMALL DIAMETER SURFACE AND SAID PUMPING CYLINDER, A PISTON ROD EXTENDING EXTERIORLY OF SAID PUMPING CYLINDER HAVING A FIRST SUPPORT MOUNT ON ONE END THEREOF ADAPTED TO BE CONNECTED TO A SPRUNG MASS, A SECOND SUPPORT MOUNT ON THE END OF THE SMALL DIAMETER OUTER SURFACE ADAPTED TO BE CONNECTED TO AN UNSPRUNG MASS, A PISTON ON SAID PISTON ROD RECIPROCABLY MOUNTED IN SAID CYLINDER TO FORM SPACED APART VARIABLE VOLUME COMPARTMENTS, MEANS FLUIDLY COMMUNICATING THE INTERIOR OF SAID PUMPING CYLINDER WITH SAID FLUID RESERVOIRS, A FLUID OUTLET FROM ONE OF SAID COMPARTMENTS THROUGH WHICH FLUID IS DISCHARGED BY SAID PISTON UPON NORMAL HIGH FREQUENCY MOVEMENTS BETWEEN THE SPRUNG AND UNSPRUNG MASSES, A MOVABLE TUBULAR JACK PISTON MEMBER SURROUNDING SAID SMALL DIAMETER OUTER CYLINDRICAL SURFACE INCLUDING A PORTION THEREON SPACED FROM SAID SURFACE TO FORM A PRESSURIZABLE VARIABLE VOLUME CAVITY BETWEEN SAID PISTON MEMBER AND CYLINDRICAL SURFACE, MEANS FOR SEALING THE OPPOSITE ENDS OF SAID PISTON MEMBER FOR PREVENTING LEAKAGE EXTERIORLY OF SAID PRESSURIZABLE CAVITY, SPRING MEANS SUPPORTED BETWEEN SAID TUBULAR JACK PISTON MEMBER AND SAID FIRST SUPPORT MOUNT FOR DIRECTING A PREDETERMINED PORTION OF THE WEIGHT OF THE SPRUNG MASS AGAINST SAID MOVABLE JACK PISTON MEMBER FOR PRESSURIZING SAID CAVITY, AND FLUID CONTROL MEANS RESPONSIVE TO THE PRESSURE IN SAID CAVITY FOR CONTROLLING FLOW OF FLUID BETWEEN SAID RESERVOIR AND SAID PRESSURIZABLE CAVITY FOR MOVING SAID TUBULAR MEMBER INTO A PREDETERMINED RELATIONSHIP WITH THE SHOCK ABSORBER TO MAINTAIN A PREDETERMINED HEIGHT RELATIONSHIP BETWEEN THE SPRUNG AND UNSPRUNG MASSES.