COMPRESSIBLE FLUID-BASED, ADJUSTABLE RESISTANCE HYDRAULIC SYSTEM FOR EXERCISE EQUIPMENT

摘要

A hydraulic system for exercise equipment and a method of providing resistance to piston motion in exercise equipment. The hydraulic system comprises: (1) a first piston in a first cylinder dividing an interior of the first cylinder into first and second chambers and having an end portion substantially sealing the first chamber of the first cylinder against fluid communication with the environment, the first cylinder further having a first fluid port, (2) a second piston in a second cylinder dividing an interior of the second cylinder into first and second chambers and having an end portion substantially sealing the first chamber of the second cylinder against fluid communication with the environment, the second cylinder further having a first fluid port, (3) an adjustable valve having a first valve fluid port coupled to the first fluid port of the first cylinder and a second valve fluid port coupled to the first fluid port of the second cylinder, (4) means for controllably adjusting a fluid resistance of the adjustable valve and (5) a compressible fluid substantially occupying the first chambers of the first and second cylinders.