Patent GB-235592-A (GB)
Title: Improvements in automatic machine guns
IPC: F41A3/10
Filed: 1924-12-08
Abstract: 235,592. Browning, J. M. Dec. 15, 1928, [Convention date]. Machine guns. - Relates to cartridge-feed mechanism for automatic guns of the longrecoil type adapted to fire shells of large calibre and mainly intended for use on aircraft. The invention is more particularly concerned with the automatic gun described in Specification 226,197, in which a transversely - sliding wedge breech-block is actuated by the longitudinal reciprocations of a member such as the lockframe. According to the present invention a cartridge, fed transversely above the barrel, is pushed between the lock-frame and the barrel by a cartridgecarrier that is released only when the cartridge is in proper transverse position. Further, the cartridge is supported in line with the barrel and pushed into the chamber by the lockframe which is released by the movement of the cartridgecarrier. The invention also includes means for automatically moving a cartridge feedstrip step-by-step transversely above the loading opening, a cartridge-carrier for moving the cartridges downwardly from the feed-strip, and an inclined guide-lever which supports the cartridges and gradually aligns them with the breech chamber as they are carried forward by the returning lock-frame. Special cartridge extracting and ejecting mechanism is also provided. Fig. 6 shows the barrel 7, barrel-extension 8, breech-block 10, and lock-frame 12 in the firing position. On recoil, these parts move rearwards together against the action of a barrel recuperator spring 9 and a lock-frame return spring 17. The breech-block is lowered in guides on the barrelextension by fixed cams which operate upon an actuating bell-crank lever 11 hinged at 11<a> to the lock-frame, and carrying a stud 11<d> for engagement with a groove 10<c> in the block. The barrel and breech-block return alone to forward position, the lock-frame being retained by a dog 56 engaging a notch 58 whilst a cartridge is being lowered between the recoil plates of the barrelextension. When the lock-frame moves forwards to load a cartridge, the lever 11 engages the fixed cams to raise the breech-block, the last part of the closing movement being effected by momentum and by the reaction of a spring, and the pin 11<d> finally passing out of the slot 10<c>. The cartridges are fed to the gun on strips 12d, Fig. 15, which slide in transverse guides in the feed-box 4, Fig. 13, the strips being those described in Specification 248,003. Fig. 10 shows in plan the bell-crank lever 24 for automatically feeding the strips through the agency of a pawl 23 engaging notches on the strips. The feedpawl lever 24 is reciprocated by a swinging feedlever 33, pivoted at 34, controlled by a twoarmed wire spring 39, and operated by a stud 40 on the barrel-extension to feed the strip forward during the return of the barrel. The catches 16 holding the cartridges in the strips are cammed back by a projection 60 on the feedbox as the strip is fed, an incline 48, Fig. 13, forcing the cartridges out of the strip.. The downward movement of a cartridge operates a catch 51 to release the cartridge-carrier 44 which is under the action of a strong spring 57 compressed by the upward movement of the dog 56 during the recoil of the lock-frame. The cartridge is now supported on an inclined guidelever 62, Fig. 9, which drops on to a stop 71 on a pivoted member 66. The movement of the cartridge-carrier releases the dog 56 that retains the lock-frame and the cartridge is then gripped by sliding extractor claws on the lock-frame and carried forward into the breech, the lever 62 being further lowered by the removal of the stop 71 towards the end of the loading-movement. The lever 62 is returned by a pin on the breechblock. The empty cartridge case is ejected by a lever 92 on the barrel-extension actuated by a stud 96 on the lock-frame. The openings in the feed-box are closed by hinged spring-controlled doors. The firing mechanism is that described in Specification 235,591.