Breech head for gun with locking bolts to hold breech in position - has mechanism which prevents firing of gun unless both locking bolts are in place

摘要

The gun breech (2) is housed in the breech head (1) and has a stepped central bore to receive the firing pin (4) which is pressed rearwards by a spring. The breech is locked in the breech head by two sliding bolts (8,9) in guides (7), engaging the undersurfaces (10) of the lugs of the breech. A lever (11) is mounted on a pivot (12) in a longitudinal slot on each side of the breech. Each lever has a projection (15) which limits the axial movement of the firing pin, when radially projecting lugs (16) on the firing pin abut against the projections. When the breech is locked in the head, the levers are rotated against the force of attached leaf springs (14) and allow the firing pin to be moved against the force of a compression spring (5). If only one bolt is engaged, the lever on the opposite side remains in the position to prevent the axial movement of the firing pin. ADVANTAGE - Firing prevention on incomplete locking.