Patent ID: 6742767
Filing Date: 2004-06-01
Classification: B66F

Abstract:
A hydraulic jack, comprisingan oil reservoir that stores a hydraulic fluid therein; an inner chamber axially disposed within the oil reservoir; a piston rod axially disposed within the inner chamber; a piston rod chamber is provided in the piston rod; a pump assembly having a pump piston that reciprocates therein and a pumping chamber that receives hydraulic fluid from the oil reservoir, wherein the pumping chamber's volume is between about Â¼ to Â¾ of the piston rod chamber's volume; and a sequence valve that is press fitted into the hydraulic channel, held in place by a plug, includes a spherical ball having a hydraulic interacting surface and regulates fluid flow in one direction from the pumping chamber to the piston rod chamber and the inner chamber.