Arrangement to obtain equal travel of hydraulic cylinders

Abstract From the Canadian patent

Control apparatus for a hydraulic lift which permits a pair of lifting cylinders to be raised equal amounts and which permits lowering of the lift without expenditure of energy and without the necessity of the pressure source being in service. Two single acting lifting cylinders are powered by a common pressure source. Two valves in the lines from the pressure source to the cylinders are rigidly interconnected and are attached to a cable which engages pulleys on the lift. Deviation of the lift from a level position alters the position of the end of the cable and operates the valve, in such a manner as to permit flow of fluid to one cylinder only to return the lift to a level position. …