GB191311016A - Improvements in Firearms. - Google Patents

Abstract

11,016. White, J. C. May 22, 1912, [Convention date]. Breech actions, sliding breech-block; smoke, disposing of; clcaning. - Relates to automatic guns of the type in which there is no positive lock for the breechbolt, which however is braked to delay its opening by an independent pivoted member which must be swung out of the path of the breechbolt before the bolt can recoil freely. The invention consists mainly in forming this brake as a rotary inertia member having a large part of its mass remote from its axis and engaged by the bolt at a point between its axis and its centre of percussion. Another feature of the invention is a delayaction extractor. As shown in Figs. 1 and 5, the braking-member H comprises a segment h<2> fixed between two disks h, h<1> by which it is mounted in the gun casing. The face h<3> of the segment h<2> is normally pressed against the back of the bolt D by a spring h<8>, and after the discharge is swung round by the back pressure of the bolt, this movement being delayed by inertia, and by the friction of the bearing disks. In a modification, the rotary member is mounted on trunnions, to reduce the friction. In another modification, there are two rotary members, one on each side of the bolt near the front. The retarding-member may also serve as the hammer as shown in Fig. 9. To facilitate hand operation, a slide d<2>, Fig. 4, is mounted on the breech-block and acts on the rotary member at a greater distance from the centre. The extractor G, Fig. 7, is mounted so as to be capable of longitudinal movement. In the construction shown in Fig. 9, the front r<27> of the breechbolt is made integral with the extractor. To increase the extracting impulse, the rotary member H may be provided with an arm R<1>, Fig. 10, which strikes a lug r<24> on the bolt, or on the extractor as shown in Fig. 11, as the member H swings round. The firing-pin F, Fig. 7, may be hand cocked by a lever g<5>. The trigger mechanism shown in Figs. 1, 7, and 8 comprises a laterally-sliding sear k<4> which embraces the firing-pin and is actuated by the bevelled end of the lever k<5>. In the construction shown in Fig. 1, a spring buffer K is provided for the breech-bolt. From the end of the chamber k<1> in which the buffer fits, an airpassage k<3> leads to the breech chamber for the purpose of expelling the residual powder gases after each discharge. To ensure safety, a notch h<10>, Fig. 3, may be formed in the rotary member, and a stud h<11> provided on the searactuating member k<5> so that the trigger cannot be pulled unless the rotary member is in position engaging the breech-bolt.