GB488090A - Breech-action for firearms - Google Patents

Abstract

488,090. Breech actions for automatic guns and ordnance. BROWN, H. R. S. May 5, 1937, No. 12813/36. [Classes 92 (ii) and 119] The breech-block 11 of a firearm is of prismatic form, the crosssectional shape approximating to an isosceles triangle of which the greatest angle lies between 80 and 100‹, the seat 9 and the slideway 4 for the block corresponding in form to the sides thereof which include the said angle, whereby a short transverse movement of the block seats it in the locked position, and a small movement in the opposite direction moves it clear of the seat so that it may reciprocate along the slideway to effect extraction and feeding of the cartidges. The breech-block 11 and a plate 15, which moves along grooves 8 in the slideway, are slidably connected, by dovetail joints 14, 16 with an end face and the upper face, respectively, of a triangular carrier block 13, and are connected together by links 17. A projection 5 at the forward end of the under-portion of the slideway 4 serves for the attachment of a magazine. Upon sliding the plate 15 forwardly from the rear of the slideway, the breech-block engages the end of a cartridge from the magazine and feeds it into the barrel, and when the front face of the breech-block is within a short distance of the rear end of the barrel, a pin 25, Fig. 3, carried by the breech-block is pushed rearwardly to move a spring catch 26 on the carrier block out of engagement with a notch in the breech-block, the continued forward movement of the plate 15 causing the breech-block to be moved vertically downwards by the links 17, to engage with the seat 9. Retraction of the plate 15 raises the breech-block clear of its seating and then moves it longitudinally to effect extraction of the spent cartridge. The inclined contacting surfaces of the slideway and breechblock may be plane or stepped, and the rear face of the block may be grooved for engagement with corresponding ribs on the seating 9. The rear end of the barrel 20 is formed with a triangular portion 20<1>, having a cross-section similar to that of the breech-block, and which engages in the front of a recessed portion 3 of the stock in which the seating 9 is formed, and the barrel is secured in position by means of pins inserted through holes 21<1>, 24, at the forward and rear ends of parallel arms 2 of the stock, between which the barrel lies. The stock is preferably made of pressed metal. According to a modification, the carrier block may be dispensed with, the breech-block being connected to the plate 15 by parallel links or other suitable means.