GB461230A - Improvements in or relating to sear control mechanisms for automatic guns - Google Patents

Abstract

461,230. Automatic guns. WERKZEUGMASCHINEN-FABRIK OERLIKON. July 20, 1936, No. 20090. Convention date, July 22, 1935. [Class 92 (ii)] The sear-control mechanism of an automatic firearm consists of a sear hook 3 adapted to engage with the breech-block 1 by selfreleasing cam faces, a locking device 34c for positively holding the sear in its locking position, and a releasing device operated by a Bowden cable 23 for actuating the locking device, the arrangement being such that upon releasing the Bowden cable the releasing device is positively returned by the breechblock 1 to the position in which it moves the locking device into the locking position. In the construction shown, the sear engages with a pivoted catch 2 on the breech-block 1 in such manner that it is thrown out of engagement therewith by the recoil spring when not positively held. The cable 23 is attached to the upper forked arms 34d of a block 34 which carries the locking member. This block is pivotally and slidably mounted upon a slide-block 33, and is urged rearwardly by a spring 35 and in an anti-clockwise direction by a spring 10. A hook 34a thereon normally, engages with a spring-controlled detent 30 pivotally mounted in the breech-block. When the cable is pulled, the hook is first lifted clear of the detent and the block is then urged rearwardly by the spring 35, thus moving the locking member clear of the sear. When the cable is released, the hook is urged downwardly by the spring 10 into the path of the detent 30 which, upon the forward movement of the breech-block 1, catches the hook and moves the block 34 and thus the locking member into the locking position. To prevent accidental .discharge, the block 34 is prevented from rotating by a pivoted catch 7 controlled by a spring 13 and actuated by a second Bowden cable 25. The two cables pass through a slide 15 which is mounted in vertical grooves in the side walls of an enlargement V<1> of the breech casing, in which casing the locking and releasing devices are mounted. The enlargement has a laterally removable cover 18<1 >which is normally held in position by a spring-pressed pin in the slide 15. In a modified construction, the looking member is positively moved by the breech-block into its locking position during the recoil movement of the latter.