HYDRAULIC CARGO HANDLING DEVICE

PURPOSE:To change over a manual mode and balance mode with a change-over valve for accurately locating a workpiece by providing a manual operating valve for supplying pressure oil to a contraction chamber of a hydraulic cylinder and a balance valve for adjusting workpiece weight and pressure in the contraction chamber so that both are balanced with each other. CONSTITUTION:When a manual operating valve 9 is set to a lifting position U while a mode change-over valve 11 is set to a position II, pressure oil in a pressure oil source 7 is supplied to a contraction chamber 3 of a hydraulic cylinder 1 to lift a workpiece 6. When the valve 9 is set to a lowering port position, the workpiece 6 is lowered and when set to a neutral position N, the workpiece 6 stands still to provide a manual operating mode. When the valve 11 is set to the position II while the valve 9 is set to the neutral position N to float the workpiece 6 in the air after the workpiece 6 is lifted, pressure in the chamber 3 is stored in a volume 15. Thus, pressure oil is supplied to the chamber 3 by a balance valve 10 to provide a balance mode so that the pressure in the volume 15 acts on the workpiece 6 to be manually easily located.