GB662513A - Automatic firearm - Google Patents

Abstract

662,513. Automatic firearms. SCHWEIZERISCHE INDUSTRIE-GES. Sept. 5, 1949. [Sept. 3, 1948] No. 23000/49. Class 92 (ii). The breech-block of an automatic firearm comprises three relatively slidable parts 2, 4, 5, one part (2) of which is locked in the firing position by elements 14 which are forced outwards into locking engagement with notches 21 in the breech casing 1 as the result of the forward momentum of the part 4 which carries firing pin 3 after the breech-block has reached its forward position. The outward movement is affected by cooperating inclined surfaces 19 on the elements 14 and a conical surface 18 on the part 4. The latter has a tubular rearward extension which has a pin and slot connection 11, 12, in the parts 2 of the breech-block and which is acted upon by a return spring 6. An enlargement 8 at the rear end of the extension strikes against the rear part 5 of the breechblock towards the end of its forward movement and the part 5 is then drawn forwards to compress a spring 9 arranged between it and a shoulder 10 on the part 4. The spring 9 serves, through the part 5, to give a rearward impulse to the firing pin after firing, and after a short rearward movement of the firing pin the locking elements are forced inwards to permit recoil of the breech-block.