PILOT-CONTROLLED CHECK VALVE Russian patent published in 1994 - IPC

FIELD: lifting mechanisms converted toto hydraulic operation. SUBSTANCE: housing with outlet and inlet holes and check valve form space communicating with inlet hole and space communicating through channel with outlet hole. Unloading valve is arranged in check valve. Check valve has hole connecting undervalve space with above-valve space when unloading valve is open. Installed in housing are control piston with rod and partition. Summary area of cross section of holes in check valve is less than cross section area of channel and it is chosen to meet this requirement. EFFECT: enhanced reliability. 1 dwg