Pneumatic nailer including safety trigger for disabling/enabling

Abstract

A pneumatic nailer having a safety mechanism that reduces accidental discharge of nailer is provided. The nailer includes a hollow main body housing having a main pressure chamber in pneumatic communication with a main valve housing. Pressurized gas is injected into main pressure chamber, and a metering hole between the main chamber and valve assembly allows gas pressure to equalize between the main chamber and the valve housing. A safety trigger and safety valve are in pneumatic communication with the pressurized valve housing. A ram cap positioned over the top portion of the valve assembly is struck, moving the main valve assembly downward, with unseating of a cylinder firing valve only if internal pressures have been adjusted by actuation of the safety valve by an operator. When safety valve is actuated, gas pressure drops in the valve housing, reducing pressure on the main valve side of cylinder firing valve, allowing movement of main valve and cylinder firing valve, while gas pressure flows into piston cylinder, moving downward the piston and driver blade assembly, and forcing ejection of a fastener from nailer. If safety trigger is not actuated, pressure remains constant around main valve and cylinder firing valve, remaining closed, and negating upward movement of cylinder firing valve with no movement of piston and driver blade assembly, despite striking of ram cap. Thus, the possibility of accidentally driving a fastener is virtually eliminated without operator's use of the safety trigger.