Patent GB-512282-A (GB)
Title: An automatic fire-arm
IPC: F41A17/14
Filed: 1938-06-28
Abstract: 512,282. Automatic guns. SKODA WORKS, PLZEN ISCHUH, J., and BENAK, K. June 28, 1938, No. 19196. Convention date, June 28, 1937. [Class 92 (ii)] An automatic gun comprises two barrels or two groups of barrels, each of which is formed integrally with the breech-block of the other barrel or groups of barrels. The arrangement is such that when one barrel or group of barrels is discharged the breech-block thereof moves rearwardly and carries the other barrel or barrels to the firing position against the action of a return spring. The barrels are held by retaining means in the firing position until their respective breech-blocks have moved rearwardly through a predetermined distance. In the construction shown, the breech-block 28, Figs. 1 and 6, of the barrel 1 is carried by an extension of the barrel 2, and the breech-block 27 of the barrel 2 by an extension of the barrel 1. The barrels are shown in the position they occupy before firing and are held in their respective positions by spring-controlled catches 12, 8. The catch 12 is controlled by a trigger-lever 14 which also controls a further catch 5 adapted to function when the trigger is depressed. Upon depressing the trigger-lever, the barrel 1 moves forward under the action of a spring 3 and the cartridge in the barrel 2 is fired by the firing pin carried by the breech-block 27. The barrel 1 then recoils under the influence of the back pressure on the breech-block and is held in its retracted position by the catch 5. During this recoiling movement a spring-pressed stop 24, carried by the extension of the barrel 1, engages with the catch 8 and the latter is moved to free the barrel 2, which then moves forwardly under the influence of the spring 4 and fires the cartridge in the barrel 1. A spring-pressed stop 25 is fitted to the extension of the barrel 2 for co-acting with the catch 5 during the recoil of the barrel 2. The barrels are equipped with hydraulic regulators, each comprising a fixed hollow piston rod 18 secured to the breech-casing 11, a fixed piston 17, and a cylinder 15 which is secured to a barrel. The cylinder is completely filled with fluid, and in operation this fluid flows from one side of the piston to the other through openings 19 in the piston rod, the speed of flow being regulated by an adjustable slide 21. As shown in Fig. 6, each barrel is shaped to provide a guide for the other barrel. The barrels are also guided by a central guide 26 which houses an hydraulic transmission arrangement associated with a mechanical cocking device. The device is operated by a handle 46, Fig. 7, which, through a chain drive and a screw-and-nut device 22, 43, imparts a longitudinal movement to a rod 42. The latter rocks a toothed segment 40 meshing with a rack which is secured to a piston 39 working in a cylinder of large diameter. Fluid in this cylinder is forced into or withdrawn from a smaller cylinder containing a spring-urged piston 47, the piston rod of which is fitted with a tiltable cam 50 adapted to engage with stops 52-55 on the barrels. In operation, the handle is first wound in one direction to cock one barrel by, for instance, the engagement of the cam 50 with the stop 52, and then in the reverse direction. During this latter movement the cam is tilted by its engagement with the stop 53 and, when the handle is turned in the original direction, engages with the stop 54 to cock the other barrel. In a modification, compressed air is used to drive a piston mechanically connected with the segment 40. In order to prevent firing when a cartridge is jammed in the loading chamber of a barrel, a safety device, Fig. 10, is provided. This device incorporates a pin 60 which projects into the cartridge chamber of the barrel and which has a lower forked end which slides upon a rockable guide 61. When jamming occurs the pin is depressed and the guide is rocked about its axis and a two-armed lever 62, co-acting with the guide, is tilted about its fulcrum 63 and projected into the path of a lever 65 carried by the breech-block 28. Further forward movement of the breech-block is thus prevented.