GB191001610A - Improvements in Automatic Fire Arms. - Google Patents

Abstract

1610. Ross, Sir C. H. A. F. L. Jan. 21. Breech actions, sliding barrel and breechblock.-Relates to the automatic fire-arm described in Specification 25,395/07, in which the barrel slides backwards and forwards about its normal firing position under the influence of two springs under opposed compression. The invention consists mainly in the breechlocking mechanism in the trigger and firing- appliances, and in the ejector. The breechblock 26, Fig. 3, is mounted by screw-threads in a sliding sleeve 21, which engages over the rear of the barrel, and is locked by a part turn, interrupted rings in the sleeve engaging corresponding rings on the barrel. The rotation of the sleeve is produced by the engagement of lugs 30, Fig. 30, on the locking - sleeve, with cam-surfaces on the fixed casing, and on a spring latch 36, Figs. 12 and 14. The action of the gun is as follows. On the discharge, the barrel 1 recoils for a short distance against a strong spring 9, Fig. 2, and the sleeve 21 is unlocked by the engagement of the lugs 30 with cam surfaces 32, Fig. 12, on the fixed casing. The barrel is then impelled forwards beyond its firing position against a lighter spring 3, Fig. 2. The sleeve 21 and breech-block are also pressed forwards for a shorter distance without rotating by a spring-urged pivoted yoke 57, Figs. 3 and 5. During this non-rotary movement, the pivoted spring latch 36, Figs. 12 and 14, is pressed outwards by one of the lugs 30, which engages the inclined under surface of the latch, but, when the forward movement is completed, the latch snaps back with its cam surface 35 in engagement with the lug. The returning barrel, after picking up a cartridge from the magazine, now enters the locking - sleeve and carries it rearwards; the lug 30 rides up the inclined surface 35 on the latch, and thus rotates and locks the sleeve. The hammer 60, Fig. 3, and sear 65 are both carried by the swinging yoke 57, and are controlled by a single spring 72. As the yoke swings rearwards, the hammer is cocked by the engagement of its lower end with a surface 100 on the pivot pin 58 of the yoke. To enable the hammer to be cocked by hand, this pin is provided with exterior means for rotating it in an anti-clockwise direction. The sear-operating link 79 is so arranged that it can only engage the sear when the breechblock is in the firing position shown in Fig. 3. When the breech-block is forward of the firing position, as shown in Fig. 5, the end of the link is below the sear. As an additional safety device, the locking-sleeve is provided with a rearward projection 105, Fig. 30, which, when the sleeve is not locked, is in the path of a projection 64 on the hammer, and thus prevents it from striking the firing-pin. The ejector consists of a double pin 46, Fig. 3, mounted in the breech-block and urged forward by the rebounding spring 45 of the firing-pin. When the magazine is empty, the barrel is held in its forward position by a catch 92, Fig. 3, operated by the cartridge lifter. The gun can then be used as a single loader.