Self-energizing hydraulic leveling device for vehicle suspension

Claim 1

A SELF-ENERGIZING HYDRAULIC LEVELING DEVICE COMPRISING, A FIXED ELEMENT, A MOVABLE ELEMENT ARRANGED IN TELESCOPING RELATION WITH SAID FIXED ELEMENT, MEANS FORMING A SPACE BETWEEN SAID ELEMENTS ADAPTED TO CAUSE RELATIVE AXIAL MOVEMENT THEREBETWEEN UPON INTRODUCTION OF HYDRAULIC FLUID THEREIN, A PRESSURIZED FLUID CHAMBER CONTAINED WITHIN SAID FIXED ELEMENT, PASSAGE MEANS PROVIDING COMMUNICATION BETWEEN SAID CHAMBER AND SAID SPACE, A FLUID RESERVOIR CONTAINED WITH SAID FIXED ELEMENT, PASSAGE MEANS PROVIDING COMMUNICATION BETWEEN SAID SPACE AND SAID RESERVOIR, VALVE MEANS DISPLACEABLE IN OPPOSITE DIRECTIONS FROM A NEUTRAL POSITION INTERRUPTING COMMUNICATION BETWEEN SAID SPACE AND AID RESERVOIR AND BETWEEN SAID CHAMBER AND SAID SPACE MOVABLE TO A FIRST POSITION ENABLING COMMUNICATING FROM SAID CHAMBER TO SAID SPACE ONLY AND TO A SECOND POSITION ENABLING COMMUNICATION FROM SAID SPACE TO SAID RESERVOIR ONLY, MEANS INCLUDING A PUMP PROVIDING COMMUNICATION BETWEEN SAID RESERVOIR AND CHAMBER, A COMMON OPERATING ELEMENT FOR SAID VALVE MEANS AND SAID PUMP, AND MEANS MOUNTED EXTERNALLY OF SAID FIXED ELEMENT FOR ACTUATING SAID COMMON ELEMENT.