Explosive powder driven setting gun with silencing device

Abstract

In an explosive powder driven setting gun, the barrel is laterally enclosed by a sleeve and at least a portion of their juxtaposed surfaces are spaced apart forming an axially extending ring-shaped slot intermediate the ends of the barrel. At the end of the ring-shaped slot closer to the rearward end of the bore in the barrel, connecting passages communicate between the bore and the ring-shaped slot. Axially extending gas passages in the form of slots extend radially inwardly from the ring-shaped slot to the bore in the barrel. At the forward end of the barrel, outlet openings extend from the bore to the muzzle end of the barrel. Preferably, the outlet openings are grooves formed in the surface of the bore and they extend between the gas outlet passages and the muzzle end of the barrel so that the cross sectional area of the bore at the muzzle is increased. Gases generated within the bore when the setting gun is fired flow through the connecting passages into the ring-shaped slot where they change direction and pass through the gas outlet passages back into the bore and finally out of the barrel through the outlet openings at its muzzle end to afford a silencing effect.