Improvements in breech mechanisms for guns of small and medium calibres

摘要

222,447. Schneider et Cie. Sept. 28, 1923, [Convention date]. Ordnance breech mechanism. - Relates to breech-locking devices for automatic or semiautomatic guns of the long-recoil type in which the locking block is released when the barrel separates from the breech-block at the end of recoil, the re-engagement of the locking block being effected after the breech-block has returned to the barrel. According to the invention a cvlindrical breech-block C is locked in closed position by two or more toothed jaws D which are hinged to the breech-block or gun tube and engage corresponding teeth on the gun tube or breech-block. The jaws are opened during run-out by cams formed on a breech-block carrier E which is held fast while the barrel returns, the return of the carrier by a spring H' cocked during recoil serving to close the jaws. In the form shown, the jaws D are hinged to the breechblock which has a limited sliding movement on the carrier E which slides in guides B2 during recoil and compresses the spring H1. When the gun runs out the carrier is retained by a catch 1, the jaws are released by inclines e1 on the carrier spigot E', and a spring-bolt c2 retains the jaws in the position shown. On releasing the bolt I by hand or automatically, the carrier is returned by the spring H1. the jaws are freed by the engagement of the bolt c2 with an incline A3 on the gun, and the jaws are locked against the gun by the carrier spigot.