Hydraulic force resister

Claim 1

A push-pull isokinetic exerciser affording substantially uniform resistance to motion throughout its expansion and compression strokes, said exerciser comprising: A. a hydraulic bar formed by inner and outer telescoping cylindrical tubes having handle-ends, each provided with an axially-projecting bolt, said tubes being rotatable relative to each other, said inner tube being sealed at both ends to define an oil-filled chamber, said inner tube enclosing a piston whose actuating rod is attached to the handle-end of the outer tube so that as the tubes are brought together, the piston shifts axially to vary the ratio between the left and right sections of the chamber on either side of the piston, said piston having valves therein functioning alternatively to allow oil to pass from the right to the left section when the tubes are brought together in the compression stroke and to allow oil to pass from the left to the right section when the tubes are pulled apart in the expansion stroke; and B. handle pieces attached to the handle-ends of the inner and outer tubes, each piece being constituted by a cylinder cap which concentrically covers and protects the end of the tube to which it is attached, a U-shaped yoke secured to the base of the cap and having arms projecting therefrom and a handle bridging these arms, the cap, yoke and handle of each handle-piece being integral with each other and being formed to synthetic plastic material, each cap base having a nut embedded therein to threadably receive the bolt projecting from the handle end of the associated tube to provide a connected and safe attachment therefor.