Actuating device for a hydraulic lifting device

An actuating device for a hydraulic lifting device comprising:

• a body having an inlet channel adapted to communicate with an oil tank of the lift device an outlet channel adapted to be connected to a cylinder of the lifting device and a chamber defined in the body;
• a piston with a piston rod moveably received in the chamber in the body to divide the chamber into an upper chamber and a lower chamber that communicates with the inlet channel and the outlet channel in the body, the piston rod having a first end extending out from the body;
• a lever pivotally attached to the body and connected to the first end of the piston rod to actuate the piston rod to move relative to the chamber in the body;
• a first check valve received in the lower chamber to control a direction of oil flow between the inlet channel and the lower chamber;
• and
• a second check valve received in the outlet channel to control a direction of oil flow between the outlet channel and the lower chamber,
• wherein a slight gap is defined between a periphery of the piston and an inner surface of the chamber in the body and for containing oil in the gap;
• the piston has at least one feedback channel defined through the piston and communicating with the upper chamber and the lower chamber;
• and
• a sealing cover moveably mounted on a bottom of the piston to seal the at least one feedback channel and to allow the oil in the upper chamber to flow into the lower chamber while the lever is lifted,
• whereby some oil in the lower chamber is allowed to flow into the upper chamber when pressure in the outlet channel is over a desired level.