HYDRAULIC JACK Russian patent published in 2004 - IPC

FIELD: mechanical engineering; materials handling facilities. SUBSTANCE: proposed hydraulic jack contains one or several working pistons, each installed in its cylinder, reservoir for working liquid and plunger pump to deliver working liquid into cylinder along main line with check valves and shutoff needles, pressure gauge and manifold. Central rod is arranged in space of each working pistons secured in base of cylinder. Spacer spring is installed on said rod. Each piston is made up of piston ring forming cylindrical guide sliding pair with surface of central rod, with space fitted on cylindrical support concentrically secured on end face of central rod and forming other guide sliding pair. Spacer spring is located between cylindrical support and piston ring. Space of rod communicates through holes in cylindrical support and in piston ring with zone of delivery of working liquid to cylinder. EFFECT: improved reliability owing to elimination of cocking of piston. 3 cl, 4 dwg