GB138136A - Improvements in automatic firearms - Google Patents

Abstract

138,136. Fairfax, H. W. Gabbett-. Sept. 17, 1918. Machine guns.-Relates to automatic guns of the kind described in Specification 128,354, in which the breech mechanism is operated by air or other fluid compressed by the energy developed on discharge, and consists in storing the air or fluid in one or more receivers, whence it may be taken as required for operating the gun. The invention is shown in Fig. 1 as applied to a barrel-recoil gun having a muzzle-sleeve B of the type described in Specification 128,515. This sleeve is driven forwardly against the action of a spring B' by the discharge gases as they escape from the muzzle, and through links D<2>, E, F causes a piston G to compress air in a cylinder H and deliver it to a receiver N through a pipe fitted with a non-return valve. A second piston G' working in a cylinder H<1> is connected by a link C<1> to a rod C rigidly fixed to the barrel A so that, when this recoils on discharge, compressed air is delivered to the receiver N through the pipe D<1>. The receiver N communicates with the action cylinder J<1> through a pipe P fitted with a valve P<1> adapted to be actuated by tappets R<1>, R<2>, on a rod R moving with the barrel A. Near the end of the recoil movement the tappet R<2> rotates the valve P<1> to connect the receiver N to the cylinder J<1>, whereupon the compressed air drives the piston J<2> rearwardly against the action of the return spring L to open the breech. On the return movement of the barrel, the tappet R<1> rotates the valve P<1> to disconnect the receiver N from the cylinder J<1> and to uncover an exhaust port P<3>, whereupon the spring L returns the actionpiston J<2> to close the breech. Another cylinder charged from the receiver N may be provided to actuate the cartridge-feed mechanism. The cylinders H, H<1> are provided with holes which, when uncovered by the pistons in their forward positions, serve to admit air at atmospheric pressure to the cylinders. A modification is described in which separate receivers are charged by the recoil cylinder and the gas cylinder; these receivers may be employed for performing separate functions. Either of the fluid compressing-devices may be employed separately. In one of the Provisional Specifications it is stated that normally the cylinders and receiver are filled with fluid under pressure.