GB672103A - Trigger mechanism for automatic firearms - Google Patents

Abstract

672,103. Automatic firearms. VERWALTUNGSGES. DER WERKZEUGMASCHINENFABRIK OERLIKON. June 2, 1950. [June 4, 1949] No. 13907/50. Class 92 (ii). Means are provided in the mechanical chain of intermediate members for transmitting trigger movements to a sear, which at the beginning of the release movement of the trigger, interrupt this chain immediately in front of the sear thereby elminating the inertia effect of the chain and permitting the sear to return to its locking position at once. In the construction shown, the sear 8 engages a bent 7 of the breech-block 4, and carries a spring- pressed pawl 11 which engages a cam face 16 on the breech-block as in Specification 608,349 and serves, in the position shown, to hold the sear in the locking position. The pawl can be depressed to release the sear by trigger mechanism which includes a pull rod 18, levers 14, 17, on a shaft 15, a spring-pressed pawl 20 pivotally mounted at 21 and having a degree of lost motion at 24, 25, with an arm 37 on an arm 19 of the lever 17, and a spring-pressed catch 26 mounted in the breech casing. The pawl 20 is urged by its spring to engage a surface 23 on the arm 14. Thus on pulling rod 18 both levers will move clockwise against the action of their springs 33, 34, the lever 14 serving to act on the pawl 11 to release the breech-block during this movement. After this is done the pawl 20 engages and pushes back the catch 26 and then rides over it to reach the position above the catch as shown in Fig. 3. If now the trigger is slightly released the lever 17, 19 moves anticlockwise, and the catch 26 swings the pawl 20 clear of the surface 23, thus freeing the lever 14 to move alone to its normal position shown in Fig. 2. When the last round in the magazine 3 has been fired a follower 44 rocks a lever 40 to release a spring controlled rod 36 which engages and moves the arm 37 to release the pawl 20 from the lever 14. In a modification, Figs. 10 to 12 (not shown) a pivoted trigger acting on a pivoted sear which engages the breech block, is combined with means similar to the pawl 20 and catch 26 arrangement, but in this case the catch is pivoted.