Patent ID: 8684246

Claim:
A driving device for resetting a hitting nail bar of a pneumatic nail gun, which is mounted in a gun body comprising a main air chamber for high-pressure air, a trigger valve, and a cylinder disposed therein, wherein a piston is mounted in the cylinder to divide the cylinder into a top cylinder chamber and a bottom cylinder chamber, and wherein the trigger valve is configured for controlling the high-pressure air in the main air chamber to drive the hitting nail bar connected to the piston to hit nails, the driving device comprising: a main gas channel communicating with the main air chamber and the bottom cylinder chamber via the trigger valve, the main gas channel being in the gun body for guiding the hitting nail bar; and a sensing valve component slidably disposed in the main gas channel, the sensing valve component being controlled by the position of the hitting nail bar to be either opened or closed, wherein the sensing valve component is opened after the hitting nail bar is driven to move downwardly to hit nails but has not been moved upwardly to reset completely, the high-pressure air is introduced from the main air chamber into the bottom cylinder chamber so as to drive the hitting nail bar to move upwardly to reset, and then the sensing valve component is closed to protrude out of the main gas channel to block in a nail shooting hole and the high-pressure is prevented from entering into the bottom cylinder chamber.