Patent ID: 6401886
Filing Date: 2002-06-11
Classification: A63B,F16F

Abstract:
A hydraulic cylinder structure utilizing oil for reverse force function comprising: a piston rod with one threaded end and one ring base on the other end, and a step portion inbetween; and further comprising a first and second elastic cushion, a cover body, a cushioning circle, a first spring, a cushioning ring and a piston; said first elastic cushion being disposed between the said ring base and the said cover body; said second elastic cushion being mounted inside one end portion of the cover body for being pushed tightly by the cushioning circle and the first spring; oil returning grooves being carved on the surface inside of the second elastic cushion for allowing oil to flow into the said hydraulic cylinder structure when the said piston rod is extended, the improvement being:a spring fastening member with one end welded on the said cover body; and a flange base and a threaded portion extending from the other end; a tension spring having two ends, with one end having an opening diameter and the other end having an opening diameter smaller than the diameter of the one end, said tension spring with its big opening diameter placed onto the said spring portion and said small opening diameter housed near the step portion of the piston rod; for providing the reverse force function.