GB486907A - Improvements in or relating to firearms - Google Patents

Abstract

486,907. Smallarms. JOHNSON, jun., M. M. March 5, 1937, No. 6588. Convention date, April 2, 1936. [Class 119] The rotary unlocking and locking movements of the breech-bolt of a, semi-automatic firearm of the short barrel-recoil type are effected by a lug 21, at the rear end of the bolt 6, Fig. 7, provided on opposite sides with inclined cam faces 25, 25<1>, and which during the recoil and return movements slides within a guideway 22, Fig. 5, in the breech casing, in contact with a spring-loaded plunger 7. In the locked position shown in Fig. 5, the lug 21 engages in a recess 23 in the guideway 22, a cam face 24 of which engages with the face 25 of the lug and thereby effects the unlocking of the bolt during the initial recoil movement. The plunger 7 is formed with a cam face 26 which engages with the face 25<1> of the lug to effect locking of the bolt at the end of the return movement. Links 28 connect the plunger 7 with the return spring mounted in the butt of the gunstock. Forward movement of the barrel 5 is limited by a sleeve 9, Fig. 11, pressfitted thereon and engageable with a collar 10 secured to the forward end of the receiver 4, and rotary movement of the barrel is prevented by a lug 11 depending from the sleeve 9 and a lug projecting downwardly from the rear end of the barrel, both of which lugs engage in a slot in the underside of the receiver 4. The lower end of the lug 11 is provided with a socket 14 to receive the end of a compression spring 15 which returns the barrel to its forward position after recoil. An extractor comprises a partial flange 31, Fig. 6, integral with the breech bolt and an ejector projects into a slot 32 in the opposite side of the bolt.