GB578478A - Improvements in or relating to ordnance - Google Patents

Abstract

578,478. Ordnance. MOLINS, D. W., and MOLINS MACHINE CO., Ltd. June 25, 1942, No. 8765. [Class 92 (ii)] Relates to firing- mechanism for automatic guns having a sliding breech-block in which a fire-control device operates a trigger on the block through the medium of a firing lever, and consists in providing a catch device to prevent the firing lever moving under the pressure of the fire-control device until closing of the breech-block releases the catch. To diminish the pressure of the fire-control device on the sliding breech-block, a multiplying lever is included in the catch device. One form is shown applied to an automatic gun having automatic loading and ramming appliances and a sliding breech-block b opened on run-out by a cam-operated roller i and retained by the extractors for automatic closure on ramming the cartridge. The usual firing lever n, pivoted at o to the gun breech for operating the trigger w, on the breech-block, is actuated by the usual firing handle on the cradle when run-out is complete and a roller 14 on an extension Z of the firing lever n is engaged by a roller 13 on a bell-crank 12 operated by the firing handle on the cradle. According to the present invention, a second catch lever 16, pivoted at 17 and bearing against an extension 27 of a member g actuated during opening and closing of the breech, is also connected to the roller 14 by a link 19 near the pivot 17. The pressure of the firing handle or other firing device on the roller 14 is thereby conveyed to the lever 16 through a multiplying gear which diminishes the pressure of the lever 16 on the side of the breech-block. Further, the lever 16 prevents the firing lever from moving inwards to fire until the closure of the breech operates the member g and removes the extension 27 from the path of the lever 16. The firing lever has a projection u entering a recess v in the breech-block when this is closed. Fig. 4 shows in plan the means whereby the bell-crank 12 carrying the roller 13 is put under pressure at the end of run-out by a roller 11 on the bell-crank engaging a spring plunger 1 on the cradle. To permit of lanyard or like firing in place of automatic firing, a second manually-operated catch 22 may engage the plunger 1. The spring plunger 1 for effecting firing is alternative to the use of a firing handle for operating on the bell-crank 12. Fig. 7 shows a modification in which the catch-lever is in the form of an arm 37 pivoted on the axis of the roller 14 which engages a stop 38 under the pull of a spring 40 when the breech is open, thus preventing inward firing movement of the firing lever n. When the breechblock rises to closed position, a projection 41 on the block releases the arm 37 and permits firing.