GB507875A - Improvements in automatic breech closing mechanism for fire-arms - Google Patents

Abstract

507,875. Automatic guns. GAL, A. Sept. 26, 1938, No. 28031. Convention date, Sept. 27, 1937. [Class 92 (ii)] A breech mechanism for automatic or semi. automatic firearms comprises a breech-block 5 coupled, with longitudinal lost motion, to a, member 4 by the interengagement of extensions 7, 6 on the member 4 and on the breech-block, respectively. The breech casing has longitudinal guides 8 with inclined offsets 10, in which engage lozenge-shaped locking-members 9, each having a forward vertical face to receive the thrust of the breech-block. The members 9 are retained in locking position by surfaces on the member 4, this member being adapted to receive the thrust of a return spring 3 and of a cushioning spring device 17. The firing pin 14 is slidable in the breech-block within limits determined by a pin-and-slot connection, the firing pin being normally urged by a spring 15 into such position that its end projects beyond the end faces of the extensions 6 on the breechblock. When the gun is fired, a gas-operated rod 21 imparts a rearward blow to an arm 18 on the member 4, whereupon the member 4 retires and allows the members 9 to descend along the inclined grooves 10, on to the reduced forward end of the member 4, thereby unlocking the breech-block, which retires with, but spaced from the member 4, so that the firing pin is retracted. If the trigger has been released, after firing, the arm 18 is caught by the sear 19, which is controlled by a trigger-actuated wedge 20. On the return of the members 4, 5, either automatically, or by pulling the trigger, the members 4, 5 move together until the breechblock reaches closed position, after which the member 4 continues alone to slide the locking members 9-into locking position in the inclined grooves 10 and to actuate the firing pin 14 to. fire the next cartridge. The mechanism may be applied to a gun having a recoiling barrel, and may be actuated by hand.