Hydraulic exercising device

Claim 1

An exercise device of the type wherein an exercising person works against a force occasioned by a pressure difference between ends of a hydraulic actuator, comprising: frame means; a reaction bar engageable by an exercising person for sequential movement with respect to the frame means in a first direction and in a second direction generally opposite to the first direction; fluid operated means including a first hydraulic actuator of the type having a housing defining a chamber, a piston movably located in the chamber, and a rod fixed to the piston and extendible and retractable with respect to the housing, said hydraulic actuator being operably connected between the frame means and the reaction bar to exert hydraulic force on the reaction bar; said housing and chamber having a high pressure end and a low pressure end whereby the piston tends to move toward the low pressure end to tend to move the reaction bar in the second of said directions; a source of hydraulic fluid under pressure; an adjustable flow control valve with a valve inlet connected to the source of hydraulic fluid under pressure and a valve outlet connected to the high pressure end of the hydraulic actuator housing; a first adjustable pressure reduction valve having a valve inlet connected to the valve outlet of the flow control valve, and a valve outlet connected to the low pressure end of the housing whereby the pressure difference between the high pressure end and the low pressure end of the housing provides a force on the reaction bar tending to move it in said second direction and whereby the exercising person exerts manual force on the reaction bar opposed to the force exerted upon the reaction bar by the hydraulic actuator to overcome the force to move the reaction bar in the first direction and then resist the force while permitting the movement of the reaction bar in the second direction.