GB190403024A - Improvements in and relating to Breech Loading Ordnance - Google Patents

Abstract

3024. Dawson, A. T., and Buckham, G. T. Feb. 6. Adapting for miniature-ammunition practice; ordnance breech mechanism.- The aiming-tube B provided with a separate breech mechanism is formed with an interrupted screw b, protected when removed from the gun A by a bush B' with a similar thread. The tube B and bush B<1> are inserted in the breech together, when a partial rotation of the tube by the lever B' causes the thread b partly to engage with the thread of the screw-box, between the interruptions of which the bush B<1> engages, and lock the aiming-tube in the gun. When in this position, the lever B' is turned down on the pivot-pin b<3> so that the toe-piece b<4> enters a recess in the bush B' preventing any angular displacement of the aiming-tube, the lever itself being locked by a spring catch b<5>, b<6>. When withdrawn from the gun, the bush is locked to the aiming- tube by a spring plunger b<10>. The bell-mouthed forward end of the aiming-tube is supported by a soft metal bush B<3>. The breech mechanism consists of an interrupted screw breech-block C supported by a carrier C<1> hinged at c to lugs depending from the aiming-tube B. The unlocking motion of the breech-screw is effected by a crank d' actuated by a lever D and provided with a coned roller d' working in a cam-groove c<x> in a projection c' on the breech-block. The handle of the lever D is provided with a spring catch d<3> by which it is held in its locking position. The unlocking of the breech-screw when the lever B' is raised is prevented by a catch c' normally pressed back by the lug b<12>. The slip-lock is of the type described in Specification No. 22,078, A.D. 1903, and is shown in horizontal section by Figs. 4 and 5. The firing-cam e<6> is rotated on a vertical axis, formed by the trunnions e<9> by means of a lanyard attached to the eye e<6>x. The main spring e is supported at its rear end by a movable spring case e' provided on its underside with a stud e<8> working in an eccentric groove e<7> in the firing cam e<6>, by means of which the spring receives an initial compression during the rotation of the cam. The nose e of the cam engages the slip-block e<5> pivoted to the striker E and further compresses the spring e by retracting the striker, until the limit of contact between the nose e<x> and the block.e<5> is reached when the striker is released. A safety-catch e<12> is provided, by which the striker may be locked, and a stop c' prevents any motion of the firing-cam should the breech-screw C be partly unscrewed. The extractor F is of the type described in Specification No. 15,672, A.D. 1901.