Power device for pneumatic packing tool

A power device for a pneumatic packing tool, mounted to a pneumatic packing tool, comprising:

• a gas delivery unit, having an accommodation room therein, the gas delivery unit having an air inlet and a plurality of air outlets which are in communication with the accommodation room, the accommodation room being provided with a turning block therein, the turning block having an input passage communicating with the air inlet, an expansion space being defined between the turning block and the accommodation room, the expansion space being in communication with the plurality of air outlets, an outer circumferential side of the gas delivery unit being provided with a knob, a push rod being provided and inserted in the knob and the turning block;
• a pneumatic unit, including a cylinder, the cylinder having a cylinder chamber therein, the cylinder chamber having two through holes corresponding to the input passage, an impeller being pivotally provided in the cylinder chamber, the impeller including a rotating shaft, an end of the rotating shaft extending out of the cylinder chamber and having a drive toothed portion;
• a transmission unit, connected to the drive toothed portion, the transmission unit being connected with a belt winding unit;
• thereby, through the knob, the turning block being turned to set the direction of rotation of the impeller and further to set the direction of rotation of the belt winding unit.