GB443751A - Improvements in or relating to gun breech mechanisms - Google Patents

Abstract

443,751. Ordnance breech mechanism. SKODA WORKS, PLZEN, 37n, Jungmannova, and HASEK, J., 18, Vladislavova, both in Prague. March 8, 1935, No. 7269. Convention date, March 8, 1934. [Class 92 (ii)] A hollow breechscrew 26 integral with a cam-plate 19 is arranged in line with a breechblock 11 carried by a rocking spindle 15 having a crankpin 18 in engagement with the cam grooves of the plate 19, so that, starting from the closed position shown, a rotation of the cam plate and breech-screw by a handle 20 first releases the axial pressure on the breech-block and then swings the breech-block about the axis of the spindle thereby opening the breech. The weight of the swinging parts is counterbalanced by a spring. The breech-block may be mounted directly on the spindle 15 and formed with a rim engaged by a hook 25 on the breech-screw, as shown in Fig. 4 ; the breech-screw 26 then exerts closing pressure directly on the breech-block and withdraws it for opening by the hook 25, which does not interfere with the outward swing. Or, as shown in Fig. 1, the breech-block is mounted in a breech-nut 10 in a spring cage 12 and held against rotation by a strap 12a, these parts being carried by the spindle 15. The nut 10 and the breech-screw temporarily interconnect by a dog clutch 24. The axial closing pressure and its release is applied to the breech-block 11 by the nut 10 when this is rotated by the breech-screw ; and the nut and breech-block are swung in and out together when the dog clutch is out of engagement and the cam groove in operation.