Leveling valve mechanism

Claim 1

IN A VEHICLE SUSPENSION SYSTEM A DEVICE FOR CONTROLLING THE AMOUNT OF AIR IN AN AIR SPRING COMPRISING IN COMBINATION THE COMBINATION OF: A VALVE BODY; AN AIR INLET VALVE IN SAID VALVE BODY; AN AIR EXHAUST VALVE IN SAID VALVE BODY; A NON-RETURN INLET CHECK VALVE CONNECTED TO SAID INLET VALVE; AN EXHAUST CHECK VALVE CONNECTED TO SAID EXHAUST VALVE; A ROTATABLE SHAFT IN SAID VALVE BODY; A LEVER FIXED TO SAID SHAFT FOR ACTUATING EITHER SAID INLET OR EXHAUST VALVE DEPENDING ON THE DIRECTION OF ROTATION OF SAID SHAFT; MEANS DEFINING A CHAMBER IN SAID VALVE BODY AND ASSOCIATED WITH SAID AIR INLET VALVE AND SAID AIR EXHAUST VALVE; MEANS IN SAID VALVE BODY DEFINING A CAVITY; A VANE FIXED TO SAID SHAFT IN SPACED RELATION TO SAID LEVER, SAID VANE BEING DISPOSED WITHIN SAID CAVITY AND A VISCOUS LIQUID IN SAID CAVITY, SAID VANE BEING SO ARRANGED SO AS TO ALLOW FLOW OF SAID VISCOUS LIQUID FROM ONE SIDE OF SAID VANE TO THE OTHER WITHIN SAID CAVITY SO THAT SAID VISCOUS LIQUID IMPOSES A DRAG ON SAID VANE AND THEREBY ON SAID SHAFT WHEREBY SAID LEVER CAN BE MOVED TO ACTUATE EITHER OF SAID VALVES BY A SUSTAINED MOMENT APPLIED TO SAID SHAFT; AND A RELAY VALVE ASSEMBLY ASSOCIATED WITH SAID VALVE BODY FOR PASSING AIR BETWEEN SAID CHAMBER AND AN AIR SPRING, SAID RELAY VALVE ASSEMBLY COMPRISING A RESTRICTOR VALVE FOR REGULATING THE RATE OF AIR FLOW TO OR FROM THE AIR SPRING, MEANS DEFINING A RELATIVELY SMALL CLEARANCE IN SAID RESTRICTOR VALVE FOR ALLOWING A RELATIVELY SMALL AMOUNT OF AIR TO PASS BETWEEN SAID CHAMBER AND THE AIR SPRING WHEN SAID RESTRICTOR VALVE IS IN A CLOSED POSITION, AND MEANS DEFINING A RELATIVELY LARGE OPENING IN SAID RESETRICTOR VALVE FOR ALLOWING A RELATIVELY LARGE AMOUNT OF AIR TO PASS BETWEEN SAID CHAMBER AND THE AIR SPRING WHEN SAID RESTRICTOR VALVE IS IN AN OPEN POSITION.