Breech-locking mechanism for over and under guns

741,947. Breech locking mechanism for over and under guns. CHURCHILL (GUNMAKERS), Ltd., E. J. Jan. 6, 1954 [Jan. 15, 1953], No. 1278/53. Class 119. In an over and under gun, the breech locking bolts D, Fig. 2, are adapted to enter bites A 1 formed in the upper barrel only and axe inclined downwardly so that they are radial to the transverse axis B about which the barrels rotate on opening and closing the breech. The bolts D are mounted on a spindle E carrying an operating lever F and cams H formed with tongues H 1 which engage slots D 1 in the bolts D. Pivoted in the action strap is a link plate J formed with side extensions J, and sloping depending faces J 2 , each face J 2 providing a bearing for a spring K normally biasing the link plate J so that each extension J 1 bears against one of three eccentric flat faces H, on each cam H, and 'in this position maintains the lock bolts D in operative position. To break the gun the lever F is depressed to the position shown in Fig. 4 causing withdrawal of the bolts D from the bites A,. The clockwise movement of the cams H causes an anti-clockwise rotation of the link plate J which compresses the springs K, which in this position tend to rotate the cams H still further in a clockwise direction due to the extensions J 1 being forced to press on the upper eccentric fla faces H 2 of the cams H. Thus the bolts D are kept within the action body and pressure on the lever F can be released. On closing the breech the cams H are rotated slightly in an anti-clockwise direction by a cam S which derives its motion from the breech-closing action through a rod R as described in Specification 741,954. This motion of the cams H causes the extensions J 1 of the link plate to move over the eccentric faces H, and press on the lower of these faces whereupon the link plate J pivots clockwise under the action of the springs K and rotates the cams H, to move the bolts D in the bites A 1 , thus automatically locking the breech when it is closed. The link plate J, Fig. 8, also forms a safety device to prevent firing of the gun when closed but not properly sealed. In this condition the link plate J intercepts the tumblers N, O as they move to hit the strikers L, M. Specification 672,199 also is referred to.