Patent GB-355814-A (GB)
Title: Gas operated automatic fire arm
IPC: F41A3/32
Filed: 1930-05-29
Abstract: 355,814. Automatic firearms. CESKO-SLOVENSKA ZBROJOVKA AKCIOVA SPOLECNOST V. BRNE, 7, U. Lazaretu, and HOLEK, E., 24, Zidenice, Balbinova, both in Br³nn, Czecho- Slovakia. May 29, 1930, No. 16677. [Class 119.] The axis D, Fig. 2, of the gas cylinder 6 of a gas-operated gun and the axis B of the breech casing 3 are arranged substantially parallel with each other and at a slight angle of about 1 to the axis A of the gun barrel 1 as viewed from above. The cylinder 6 is short and open at the rear end and is formed in one with a tube 9, Fig. 6, which is fixed around the front end of the barrel. A lump 9<11> on the tube serves for the attachment of a bayonet, and a lump 9<1> for the attachment of a foresight. The rear open end of the cylinder is flared at 6<1>, and a tube 18 is arranged behind and in line with the cylinder to enclose the piston-rod 7 loosely and to protect the fore-end stock from the hot gases. The piston-rod 7, Fig. 3, is of rectangular cross section but with a cylindrical front end r. At the rear end it forms a breech-block carrier 11 with a handle 22. This carrier is guided by grooves in the breech casing 3 and has a horizontal part 12, Fig. 21, lying over the breechblock 14, which has a tooth in a slot 51, Fig. 14, in the carrier and is normally held locked against a shoulder 61 in the breech casing by the overlapping of a surface 66 of the breech-block carrier over a surface 67 of the breech-block. When the gun is fired, the gases acting on the piston 5 in the cylinder 6 drive the carrier 11 back against a recoil buffer 40, 39. At the beginning of this rearward movement of the carrier 11, the surface 66 leaves the surface 67, and an inclined face 57 on the carrier engages a corresponding face 56 on the tooth of the breech-block and wedges the breech-block away from the shoulder 61. The breech-block then follows the rearward movement of the carrier 11, thereby opening the breech, cocking the firing mechanism, and extracting and ejecting the spent cartridge. On the return stroke, a fresh cartridge is loaded into the barrel and the breech-block wedged back to the locked position by surfaces 68, 69 on the carrier and breech-block respectively. Until the breech is closed, a lug 81 on the carrier prevents the hammer, if this is prematurely released, from striking the firing-pin 21, which is mounted in the breech-block against a rebound spring 23, Fig. 13. The extractor 71, Fig. 19, is transversely slidable in guides 70 at the front end of the breech-bolt 14, and is influenced by a spring 72, which is formed with a rear end-piece fitting in a slit in the breechblock and is provided with a stud 76 fitting in a hole in the breech-block, this extractor being confined and held in position by the surrounding wall. The ejector 64 moves in a groove in the breech-block and is carried by the plate 62, on which the shoulder 61 is formed and which is fixed to the breech-casing by a screw 63. The slot 51 of carrier 11 is covered by a leaf spring 53 sprung into notches 54. The carrier is provided with a handle 22, and the breech casing is fitted with a spring-controlled cover slide, which yields to the handle 22 at the end of its rearward stroke. The carrier also acts as a cover for the ejection opening when the breech is closed. The firing- mechanism is mounted in a casing 31, Fig. 13, which completes on two sides the rear end of the breech casing 3 as shown in Fig. 23. The trigger casing 31 is attached to the stock 4, and the breech casing 3 is pivoted to the front end of the trigger casing 3<1> at 8<1> and is fastened thereto by a bolt 8. When this bolt is removed the front part of the gun can be swung, down about the pivot 8<1>, thus giving easy access to the mechanism.