GB662416A - Improvements in automatic firearms - Google Patents

Abstract

662,416. Automatic firearms. BREVETS AERO-MECANIQUES SOC. ANON. Dec. 9, 1949. [Dec. 20, 1948; Nov. 3, 1949; Nov. 22, 1949] Nos. 31707/49, 31708/49 and 31709/49. Class 92 (ii). Relates to automatic firearms of the kind in which the barrel 1 and breech casing 2 recoil, upon firing, with respect to a fixed casing S, and in which the longitudinally slidable breechblock 3 carries a member 5 which is held in locking engagement with a part 6 of the breech casing, when a shot is fired, by one or more slidable bars 7, which are moved by a gas piston 11 and rod 9, for instance, upon firing. According to the invention at least one retractable abutment member 14 is interposed betewen the bars 7 and breech casing to prevent the bars from moving to a position where they release the members 5, until the firearm has moved rearwards with respect to the fixed support 5 through such a distance as would only take place upon the firing of a shot. In the construction shown the member 14 has a front forked end so that it can abut against both the bars 7. The rear end of the member has a surface 14b adapted to engage a surface on a cam 15 on the fixed support S. The member, which is acted upon by a spring 16, can lie wholly within a housing 2a in the breech casing 2 and can pivot about an edge 2b. In operation the cam 15 normally causes the member 14 to swing to the upper retracted position when, upon the firing of a shot, the firearm recoils with respect to the support S. The bars 7 can then recoil until their recesses 7a permit the member 5 to rise to the breech-block unlocking position. In the case of miss-fire or hangfire,- however, the absence of recoil enables the member 14 to remain in its operative position, thus limiting the rebound of the bars 7 which therefore hold the breech-block locked. A lever 21, 21b acting on the rear end of the member 14 moves the member to the retracted position when the parts are re-cocked by a pneumatic piston 18 working in a cylinder 17. In a modification the parts are so arranged that the bars 7, which carry the firing pin, cannot complete their forward movement unless the member 14 is in its active position. In another modification the abutment members are pivoted to the bars 7.