GB1375774A - - Google Patents

Abstract

1375774 Air guns VICTOR COMPTOMETER CORP 15 March 1972 [16 March 1971] 11948/72 Heading F3C A fluid operated gun comprises a barrel 20, a source of high pressure fluid, movable projectile holding means 34 interposed between the barrel 20 and source and a first sealing means, preferably in the form of a self-supporting axially extending elastomeric sealing means 40, mounted between the source and the movable projectile holding means for providing a sealed fluid passage therebetween. The projectile holding means 34 comprises a cylindrical body having a plurality of equispaced chambers and is mounted for rotation in bearings on opposite sides of a loading slot 38 in a plastics support member 16. The projectile holding means 34 is rotatable manually to bring successive chambers into line with the barrel, a spring loaded detent 46 having abutment surface means for cooperation with at least one of a plurality of abutment means on the projectile holding means for holding the latter in its chamber alignment condition. Each chamber is provided with a shoulder and ribs to hold a projectile until a predetermined pressure has built up behind the projectile during firing of the gun. The sealing means 40 has a base portion 180 which seals the forward end of an air compression chamber 22 and a sleeve portion 182 which passes through a bore in the support member 16 to a position adjacent the projectile holding means 34. The base portion 180 is connected to the sleeve portion 182 by a portion of reduced thickness such that, on pressure build-up in the compression chamber 22 the sleeve portion 182 is allowed to move axially so that its forward end engages sealingly the projectile holding means 34. Air is compressed by a spring-loaded piston and piston-rod assembly, the assembly being cocked by a cocking lever and released by a trigger (Fig. 1, not shown). The piston carries a projection (193, Fig. 7, not shown) so that the volume of the compression chamber after firing of the gun is minimal due to the projection entering the sleeve portion 182 of the sealing means. The spring loading of the detent urges the projectile holding means rearwardly into engagement with the sealing means, the sealing means being held in the gun by a retaining member 64 which cooperates with a retaining, forwardly positioned lip of the sleeve portion of the sealing means. During firing both the sleeve portion of the sealing means and the projectile holding means move forwardly under the action of the compressed air the forward face of the projectile holding means around the aligned chamber then being also sealed with respect to the barrel by means of an "O"-ring.