DOUBLE TELESCOPIC HYDRAULIC CYLINDER Russian patent published in 1999 - IPC

FIELD: cargo-hoisting machines, travelling cranes, lifting units for repair of oil and gas wells. SUBSTANCE: hydraulic cylinder has housing with two pairs of output working members located inside it; working members are made in form of plungers with bearing eyes. It is provided with thrust split rings locked by bearing guide rings. Inner plungers have open inner cavity. All plungers are provided with grooved beads where bearing guide rings are laid. Housing is made in form of pipe with bores and grooves where seals of outer plungers and thrust split rings are laid; they are used for connecting the outer plungers with housing. Bearing eyes are provided with beads for engagement of inner plungers with outer ones and with housing when plungers are retracted into housing. EFFECT: increased loading capacity of hydraulic cylinder; reduced expenses for manufacture. 1 dwg