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Hydraulic exercise equipment

Exercise equipment takes many forms: free weights; rowing, skiing, and bicycling simulators; weight and elastic tension based machines. Each provides a work load and some means to judge the amount of work performed. A variety of stationary exercise equipment has accordingly been developed which permits single station or multi-station usage. Typically these assemblies include a user selectable weight or mass. The movement of the mass is controlled in relation to one or more movable members and interconnecting linkages. Some assemblies control movement in relation to controlled friction mechanisms, springs and spring-like mechanisms. Others control motion in relation to assemblies containing weights, chains, ropes and magnets. Exercise devices of various types have been proposed to utilize handlebars, pedals and the like, all of which are moved against some load, such as generated by static or moving weights, springs, friction, and pneumatic or hydraulic arrangements. Exercise equipment, such as, for example, exercise rowing machines, commonly employ hydraulic cylinder units with double-acting pistons to resist movement of pivoted arms to be manipulated for exercise. The use of hydraulic systems for providing the resistive force utilized in exercising equipment is preferred since these systems have relatively few moving parts and are reliable. In general, a hydraulic system includes a cylinder and a piston that is reciprocally mounted in the cylinder. One of either the piston or the cylinder is mounted to a stationary member and the other one of the piston and cylinder is attached to a movable member. Rowing assemblies also exist which include hydraulic assemblies capable of applying predetermined static amounts of resistance to separate handle motion. Applicants are also aware of various hydraulic exercise apparatus which include controlled flow paths to a liquid (i.e. water). The media are directed through in a variable path to provide controlled resistance to user motion.

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