GB584268A - Improvements relating to ammunition belt feed mechanisms for automatic guns - Google Patents

Abstract

584,268. Cartridge feed mechanism. NASH, A. G. FRAZER-. May 2, 1944, No. 8268. [Class 92 (ii)] An ammunition belt feed mechanism for automatic guns, comprising a feed sprocket driven by a moving part of the gun and a cam track for forcing the ammunition axially through the belt links, has axially guided slides or pushers interposed between the cam track and the ammunition. As shown in Fig. 3, the feed mechanism is contained in a housing 1 which has an inlet mouth for the belted ammunition, a discharge outlet for the disintegrated links and a feed mouth 9 for conducting the rounds to the breech of the gun. When the gun is in operation, a cam 15, connected to the outer breech bar, reciprocates between a fixed roller 17 on the housing and a roller 20 on a pivoted lever 21. The resulting oscillating movements of the lever are transmitted by a link 23 to a casing 25 mounted to rock on a short shaft 26, the casing, being biassed by a spring 25a which thereby maintains roller 20 in constant contact with cam 15. Pawls, one on the casing 25 and one on the housing 21 serve to cause the oscillating casing to impart a step-by-step rotation to the shaft 26, thereby to stress a spring 32, one end of which is anchored to the shaft and the other to a housing 36. Casing 25 has a tommy-bar socket whereby the spring may be initially stressed and spring-controlled plungers which engage the pawls under manual pressure when the tension on the spring is to be released. The torque produced on housing 36 by spring 32 is transmitted to a shaft 11 to produce the required rotation of three sprocket discs 5, 6, 7, which forward the belt of ammunition towards the feed mouth 9. The housing 36, see Fig. 19, carries rods 53 which form guides for slides 50, the latter being fitted with rollers 54 which engage with a cylindrical cam 55 riveted to the end cap 57 of housing 1, see Fig. 3. Thus, as housing 36 rotates, the slides are moved by the cam and serve to push the ammunition rounds 44 back through their links, which links are prevented from moving by their contact with the face of sprocket 6. A further cam 60, Fig. 3, serves to move the slides in the reverse direction. After being moved endwise the rounds engage with and rotate a four-toothed star-wheel which, in conjunction with a pointed horn which engages under tailpieces 47, Fig. 15, of the links of the belt, serves to strip the links at a point adjacent the discharge outlet. Each link has double clips 46a on one side for resiliently holding the rounds, a single clip fitting the rounds loosely on the other side, and a tailpiece 47 having its end bent to engage a cannelure in one of the rounds 44. The rounds, now freed from their links, approach the feed mouth 9 above which is arranged a spring- controlled lever, Fig. 5 (not shown), which is first deflected as each round engages it and which is so shaped that as it returns, under the action of its spring, it accelerates the round downwards. A further spring-controlled lever 78, Fig. 6, is also pivoted above the feed mouth 9 and is normally urged to the right by the rounds. When, however, the last round has passed into the feed mouth, the spring 83 urges lever 78 to the left and a blade 80, carried by another arm of the lever and normally engaging a recess in the feed mouth, is moved downwards and its lower bevelled edge causes it to move inwards to grip the last two rounds. The mechanism may be fitted with an automatic stop mechanism as disclosed in Specification 584,267.