GB518870A - Improved method and means of operating machine guns with miniature cartridges for instructional purposes - Google Patents

Abstract

518,870. Machine guns. PARKER-HALE, Ltd., and HALE, S. C. Aug. 10, 1938 No. 23543. [Classes 9 (i) and 92 (ii)] A gas-operated machine gun is,adapted for practice fire with miniature ammunition by providing the barrel 6 with a sub-calibre tube 12 and feeding the gun with carrier cartridges 55, Fig. 4, for the sub-calibre ammunition 54, the gun being operated by gas pressure from an external source applied to the gas piston. In the arrangement shown, gas pressure from a bottle 29, Fig. 3, is applied to the gas piston 10 past a valve 20 which is automatically opened on the return movement of the gas piston by a member 46 thereon. The normal gas port 15 is closed by the practice tube 12 and a special chamber 16 is attached as shown to the gun barrel 6 and gas cylinder 9. The chamber contains the spring-pressed ball valve 20 for admitting pressure .air to the gas cylinder through a pipe line 28 which leads from the bottle 29 through a reduction valve 39. The gas piston 10 is mounted with play, upon its rod 11 and moves under the initial pressure impulse against the action of a spring 51 into engagement with the flange 49 to seal the channel 53 through which the air escapes on the return movement of the' piston. The valve 20 is opened automatically by the stem 46 each time the piston completes its forward movement under the action of the return spring of the gun, provided that the gun trigger is kept pressed. The reducing valve 39 is controlled by a diaphragm 41 subjected to the action of an adjustable spring 42. Fig. 4 shows the cartridge carrier member 55 for miniature ammunition 54 used in conjunction with the practice tube 12. The carrier is adapted for rim fire ammunition by the provision of a sliding plug 61 which is actuated by the normal striker 47 of the gun. The plug is retained by a spring pin 65 engaging an elongated slot 59 in the carrier. The cartridge carriers 55 are fed to the gun from a magazine in the usual manner.