HYDRAULIC HOIST SYSTEM Russian patent published in 1994 - IPC

FIELD: supply and discharge of hydraulic fluid. SUBSTANCE: truck of hoist is linked with piston mounted in cylinder forming working chamber. Pump inlet is brought in communication with the hydraulic fluid source and its outlet is brought in communication, via the shut-off valve, with the inlet of main shut-off valve provided with control cylinder. Valve outlet is brought in communication with the working chamber of the hoist cylinder and with inlet of overflow valve. Inlet of adjustable metering valve is connected to the pressure hydraulic line of shut-off valve and its outlet is connected to the return hydraulic line brought in communication with the hydraulic tank. The first line of the guide three-line valve is brought in communication with the control cylinder, the second line is brought in communication with outlet of piston valve and third line is brought in communication with the return hydraulic line. Outlet of overflow valve is brought in communication with inlet of main shut-off valve. EFFECT: enhanced efficiency. 1 dwg