GB190508286A - Improvements in and relating to Aiming or Practice Rifles for Ordnance. - Google Patents

Abstract

8286. Dawson, A. T., and Buckham, G. T. April 18. Ordnance, adapting for miniature-ammunition practice; breech mechanism.-Relates to aiming- tubes of the kind described in Specification No. 3024, A.D. 1904. Fig. 1 is a longitudinal vertical section, showing the tube in place in the gun, and Fig. 5 is a sectional plan of the breech end of the tube. The aiming-tube B, provided with a vertically-sliding breech-block C, is secured in the gun by a bush B<2>, projections on which engage with the interruptions in the thread B9 of the breech opening, and by an adaptor B<5>, locked by a spring bolt B<8> to the tube, and engaging with the thread B<9>. The tube is locked against rotation in the bush B<2> by a bolt b<2> sliding in a groove in the tube and actuated by the cam bx on the lever b<1>. When the lever is in the position shown in Fig. 5, the aiming-tube is locked to the bush B<2>, but by raising the lever the tube is unlocked and may be rotated to engage the adaptor B<5> with the thread B9. Normally, the bush and adaptor are locked together by a spring catch B<4>, but when inserted in the gun they are disengaged by the lug B<10>. The firing lever d can only be actuated when the bolt b<2> is in the safety position. When used with large guns having the Vickers' breech-screws, the adaptor may be enclosed by the bush B<2>, and the tube is centred in the chamber by a cup fitting the obturator-seating and screwed on to the tube at B<12x>.