Abstract: An actuating device for a hydraulic lifting device has a body, a piston and a lever. The body has an inlet channel communicating with an oil tank and an outlet channel connected to a cylinder. The piston is moveably received in the body to divide a chamber into an upper chamber and a lower chamber that communicates with the inlet channel and the outlet channel in the body. Two check valves are respectively received in the inlet channel and the outlet channel in the body. A slight gap is defined between the periphery of the piston and the inner surface of the chamber in the body. Accordingly, some oil in the lower chamber is allowed to flow into the upper chamber when the pressure in the outlet channel is over a desired level, and the structure of the actuating device is simple.

Abstract: An actuating device for a hydraulic lifting device has a body, a piston and a lever. The body has an inlet channel communicating with an oil tank and an outlet channel connected to a cylinder. The piston is moveably received in the body to divide a chamber into an upper chamber and a lower chamber that communicates with the inlet channel and the outlet channel in the body. Two check valves are respectively received in the inlet channel and the outlet channel in the body. A slight gap is defined between the periphery of the piston and the inner surface of the chamber in the body. Accordingly, some oil in the lower chamber is allowed to flow into the upper chamber when the pressure in the outlet channel is over a desired level, and the structure of the actuating device is simple.