Patent GB-1329784-A (GB)
Title: Machine guns
IPC: F41A9/36
Filed: 1971-04-19
Abstract: 1329784 Caseless cartridges; machine guns GENERAL ELECTRIC CO 19 April 1971 [10 March 1970] 23308/71 Headings F3A and F3C A machine gun comprises a housing 10, Fig. 1, a rotor 72, Fig. 3, mounted in the housing and carrying a number of angularly-spaced barrels 78. The rotor 72 has angularly-spaced recesses 100 formed in its periphery, each recess 100 being aligned with a barrel 78. A number of angularly-spaced chambers 190, which exceed the number of barrels, are linked together in an endless chain. The chambers 190 are guided for movement around the rotor 72, each chamber periodically occupying a respective recess 100, and are guided for movement around the axis B, Fig. 10, of the angularly-spaced chambers. Each of the chambers is linked to and between its next adjacent chambers by a pivotal connection comprising bored lugs 192, 194, Fig. 3, which receive a rod 196 therein, the latter being provided with rollers 198, 200. The rollers 198, 200 are supported respectively by cam plates 210, 212 having cam tracks 220, 222 so as to guide the chambers 190 through the transition between the angular movement around the rotor and the angular movement about the axis B, Fig. 10, of the angularlyspaced chambers. Each chamber 190 has two lines of contact 201, Fig. 6, with the recess wall profile to facilitate the accurate alignment of the chamber and the respective barrel bore. The barrels and the rotor 72 rotate about an axis A, Fig. 10, the chain of chambers 190 is carried around the rotor 72 which serves as a six-tooth sprocket and is guided around the axis B. The distance between the axes A and B is equal to the link length, is equal to the transverse distance between axis A and the axis of a rod 196 engaged with the rotor 72 and is equal to the transverse distance between axis B and the axis of a rod 196 of any chamber carried around the axis B. Rounds fed into a gun by a feeder assembly 50, Fig. 4, are chambered by a rotary feed tray 230, Fig. 3, and a stationary ram cam 232. A backplate 234 is fixed to the housing and support rod 236 is attached to the backplate 234. The tray 230 has six cartride receiving recesses 235 and is rotatably mounted on a rod 136 by bearings 238, 240. An annular spur gear 242 is connected to the tray 230 and a shaft 244, Fig. 1, has a gear 246 driven by the rotor spur gear 112 and has a gear 248 which drives a gear 242, Fig. 3, of the tray 230. A gear 250, Fig. 1, of the feeder assembly 50 is driven by the gear 242. In use when a cartridge is in a feeder sprocket 58, Fig. 1, the feed tray 230, Fig. 3, the loop of chambers 190 and the rotor 72 rotate. As the feeder sprocket 58, Fig. 1, rotates, the cartidge is cammed centrifugally by side guides into a recess of the tray 230, Fig. 3. Lateral movement of the cartridge is prevented by the stationary ram cam 252. Forward ramming of the cartridge begins when it is in the tray 230, the cam 252, having a shoulder 254, rams the cartridge 256 into the chamber. The latter moves into a rotor recess 100 and is sealed between a barrel 78 and firing pin head portion 128. As the chamber passes the firing position, cam follower 164 rides off a cam ramp surface 114 and a released compression spring 186 drives a hammer arm 156 forward to impact a firing pin spindle 134 to fire the cartridge. Since the cartridge is caseless, the chamber is now empty, the gun firing all chambered cartridges before ceasing movement. A misfire ejector assembly is provided. An airblast ensures the clearing of all the chambers. Each of the six firing pins 120 is struck in sequence by a spring loaded hammer assembly which has a rod 146 mounted between blocks 148, 150. A support block 152 is attached to the rod 146 and to a rod 154 which has one end adjustably fixed to the housing by two nuts 155, Fig. 4, to prevent rotation of the rod 146. When ammunition having a primer is used the effective length of the rod 154 is adjusted by the nuts 55, this adjusting the searing of the hammer.