Projectile propulsion and control in a gas-powered gun

Abstract

A projectile is propelled from the gun when a valve that controls the gas storage chamber of the gun is momentarily unseated, thereby admitting a short burst or charge of gas into the space immediately behind the projectile. The barrel that confines and controls the projectile during its movement out of the gun is itself driven rearwardly by spring action to accomplish unseating of the valve through an actuating stem at the rear of the barrel, and during such rearward movement of the barrel, the projectile is carried therewith so as to reduce the volume of the space behind the projectile in which the gas may expand before acting upon the projectile. After a predetermined amount of rearward movement, the projectile is released to thereby prevent interference with its propulsion from the gun, and return movement of the barrel forwardly after valve actuation is terminated short of its fully forward position, thereby minimizing the increase in the gas expansion space created by movement of the barrel and stem forwardly during firing. Stopping such forward movement in this way also positively precludes any opportunity for the barrel and actuating stem to oscillate in a rebounding manner between the spring that drives the barrel rearwardly and the spring controlling the valve, such activity otherwise causing a series of gas discharges after the projectile has already left the gun.