Combustion powered nail driver with delayed trigger return to allow piston to return to start position

摘要

The specification describes a combustion powered nail driver as depicted above. The nail driver has a pneumatic check valve 74 that delays the return of the trigger 78 from the On to the OFF position. The pneumatic check valve has a plunger 112 working in cylinder 122. A seal 120 around the plunger 112 allows air displaced by the plunger to escape past it when the trigger is depressed. When the trigger is released, the seal allows air to flow back slowly into the cylinder. This delays the return of the trigger to the OFF position. A linkage between the trigger and the inlet valve of the combustion chamber prevents the inlet valve from opening until the trigger is in its OFF position. The delay in the return of the trigger allows time for the driver piston to return to its start position after driving the nail.