Nail driver actuated by gas explosion - has valves operated in sequence to supply correct mixture of air and gas

摘要

The nail driver has a main piston (29) which pushes a rod through the guide to drive the nails held in the magazine. When handgrip is depressed it pushes down a U-shaped member which opens the gas inlet valve and allows the gas to flow into a chamber inside the hollow piston rod (36). Further movement of the handgrip depresses a plunger which allows a spring to pull a lever downwards. The motion of this lever releases a series of interconnected levers and valves with the result that the gas flows into the combustion chamber followed by the correct amount of air. The mixture is then ignited and drives the piston (29) downwards against a spring.