Patent GB-156518-A (GB)
Title: Improvements in automatic hand firearms
IPC: F41A11/04
Filed: 1921-01-05
Abstract: 156,518. Rosebush, W. E. Nov. 19, 1917, [Convention date]. Breech actions, sliding breech-block; adapting for miniature ammunition; stocks.-Relates to automatic pistols of the kind in which the barrel is carried by a barrel-receiver pivoted to the main frame, and consists mainly in a construction to facilitate assembling and disassembling of the main frame, barrel, barrel-receiver, breechblock and handle side-plates. The Specification also describes an extractor, firing and safety mechanism, and a catch for holding the breech open when the magazine is empty. The barrel 49 has a reduced rear part 48 fitting into a sleeve 46 on the barrel-receiver and secured by a bayonet-joint. The barrel-receiver 45, Fig. 3, fits on pivots 43, Fig. 9, at the front of the main frame 40 and is locked by a pivoted back-strap 100, Fig. 10, having shoulders 103 engaging shoulders 104 on the barrel-receiver. A projection 60, Fig. 4, at the rear of the barrel enters a notch 61 in a lug 62 on the main frame when the barrel-receiver is in position, and locks the barrel against rotation. The back-strap contains the hammer spring 106, Fig. 4, which acts to hold the strap in the locking position and also acts on a magazine catch 121. When the hammer is cocked, a projection 127 thereon engages the back-strap and locks it. The breechblock 70, Fig. 7, which slides on the barrelreceiver 45 and on a lug 76 on the main frame has forwardly projecting arms 71, 72 joined by a cross-bar 73 carrying a forwardly projecting tube 81 containing part of the recoil spring. The rear abutment of the spring is a nut 83 on a guiderod 84 the rear end of which projects through apertures in lugs 86, 62 in the barrel-receiver and main frame respectively thus forming an additional lock for the barrel-receiver. The nut is prevented from rotating by the side bars 71, 72 of the breech-block, so that by rotating the rod 84 by its head 85 the pressure of the spring can be adjusted. The firing-mechanism comprises a firing-pin 114 mounted in the breech-block, a hammer 112, a sear 170, Fig. 20, loosely mounted in a pivot hole 177 in the frame so as to be capable of sliding and rotating, and a trigger 184, Fig. 21. The trigger has, above its pivot, a projection 181 engaging a shoulder 180 at the front of the sear, so that when the trigger is pulled the sear is moved forwards to release the hammer. A safety piece 200, Fig. 19, resting on the sear has two upward arms 201 engaging notches 203 in the undersides of the breechblock so that the sear is depressed out of engagement with the trigger except when the breech is closed. The extractor 151, Fig. 6, is mounted in a boring in the breech-block and has a lateral projection 154 entering a recess. The extractor is acted on by a spring plunger 157. When the magazine is empty, the finger piece 225 of the follower actuates a detent lever 228, Fig. 4, which retains the breech-block in the open position. The side plates 250 of the handle have inward offset portions fitting in recesses 252 in the sides of the frame, the bottoms of the recesses being undercut. At the top, the offset portions fit underneath the side plates of the barrel-receiver. Magazines.-The Specification as open to inspection under Sect. 91 (3) (a) comprises also a box magazine adapted to take different sized cartridges. The magazine is adapted to take short cartridges by means of a filling piece 210, Fig. 4 and Fig. 26 (Cancelled), extending the whole length of the magazine. For smallcalibre cartridges, the magazine has inwardly curved sides, as shown in Fig. 26 (Cancelled), and for larger calibre cartridges the sides are straight. The bottom of the magazine is closed by a slide 124, Fig. 4, locked in position by a plunger 214 which forms the guide for the lower end of the feeding-spring. This subject-matter does not appear in the Specification as accepted.