Patent GB-191320009-A (GB)
Title: Improvements in Automatic Guns.
IPC: F41A9/42
Filed: 1913-09-04
Granted: 1914-10-05
Abstract: 20,009. Armstrong, Whitworth, & Co., Sir W. G., Hadcock, A. G., and Forster, G. Sept. 4. Machine guns; cartridge hoppers and magazines.-Relates to recoiling-barrel guns of the kind having a longitudinally-sliding breecb-block which is locked to the gun by a locking - block. According to the invention, the locking - block is moved transversely during the recoil by a crank-arm, the shaft of which is formed with two other arms, one of which strikes a fixed part of the gun casing during recoil and thereby effects the unlocking rotation of the shaft, while the second arm releases the automatic sear as the unlocking block reaches the locking position, The locking-block is retained in the disengaged position by a spring catch, which is released by the return of the breech-block to the closed position. A loading-tray is pivoted to the rear of the gun breech, and is actuated by an arm guided by a cam-groove in the gun casing, so that during the recoil it is rocked out of the path of the extracted cartridge case, and is returned to the receiving position at the end of the run-out. If the cartridge case has not been ejected properly, an arm on the tray completes the ejection as the tray returns. Fig. 1 is a side elevation of the breech action showing the breech closed, and ready for firing. Fig. 4 is a transverse section on the line 4-4, Fig. 1. Fig. 5<a>. shows the rear end of the gun-casing with the breechblock in its rearmost position, the barrel having again advanced, and Fig. 6 is a rear elevation of the locking-block. The locking-block j is U-shaped and has external ribs j<2> and internal ribs j<4>. The ribs j<2> engage with vertical ribs in the side walls of the breech opening, while the ribs j<4> engage with the ribs k<2> on the breech-block k. A shaft m, pivoted transversely to the gun-barrel a, has a crank m<Î> which engages in a recess in the front ofthe block j, an arm m<1> which, during the recoil, strikes a fixed abutment b<2> and rocks the shaft m, thereby lowering the locking-block, and a toe m<2> which bears upon a spring plunger n mounted in a housing in the gun-barrel. Another arm m<3> on the shaft m engages with the arm v<3> of the automatic sear v which is pivoted to the right-hand side of the gun and is rocked in a clockwise direction by a spring. The loading-tray t is pivoted by a pin t<1> to the rear end of the gun a and has a lateral arm t<2> projectiog into a cam-groove b<3> in the casing b. When the gun recoils after firing, the locking-block is lowered by the rotation of the shaft m and is held down against the pressure of the spring n by a pivoted spring catch o, the lower end of which enters a notch j<Î> in the block. At the same time the loading-tray is rocked aside by the cam groove b<3>, and the breech-closing spring l is compressed. At the end of its rearward travel, the breech-block, which is guided by its lateral ribs k<1> in grooves b<1> in the casing b, is caught back by a spring-pressed latch p pivoted in the casing. The barrel is run-out by the usual return spring and the empty cartridge case is extracted by the extractor q. TowarJs the end of the return movement of the barrel, the loading-tray is lowered again into position to receive a cartridge from the magazine z and its lip t<3> completes the ejection ofthe extracted case. A projection a<2> on the barrel rocks a feed-arm r pivoted to the gun casing and pushes a cartridge out of the magazine on to the loading - tray. Finally, a projection a<3> on the barrel releases the latch p and permits the return of the breech-block. The breech-block passes over the loading-tray driving the new cartridge into the breech and as it reaches the closed position disengages the catch o by means of a projection k<3> and frees the locking-block. The spring plunger n then rocks the shaft m and raises the locking-block to the locked position, and causes the arm m<3> to release the automatic sear. The hand sear w is pivoted on the other side of the gun-breech and is actuated by a firing-lever x pivoted in the gun casing. The firing-pin u has a T-shaped head u<2>, the arms of which are caught by the two sears during the run-out of the breech-block. Arms v<2>, w<2> on the sears are adapted to enter notches j<ÎÎ> in the locking-block, so that firing is impossible until the block is in the locking position. This firing-gear does not form part of the invention. The magazine, which also is not a part of the invention, is a detachable rotary one, and is actuated by inclined ribs a', a<5> on the gun barrel. A handlever a<6>, pivoted to the gun-casing, has an arm a, which engages an arm m<5> on the shaft m, and enables the locking block to be lowered by band. The Provisional Specification also describes a rotary magazine which encircles the breech end of the gun, and an interrupted-screw breech-action for machine guns.