GB1439309A - Semi-automatic firearm - Google Patents

Abstract

1439309 Firearm F S THOMAS 28 Aug 1974 [4 Sept 1973] 37561/74 Heading F3C A firearm comprises a frame 17, Figs. 2, 3 and 4, having a hand grip 67, a barrel 15 which is supported by the frame 17 and has a firing- chamber 31, a slide-member 21 which surrounds the barrel 15, a spring 25 which is located between the slide-member 21 and the barrel 15 and urges the slide-member 21 towards the muzzle of the barrel 15, a firing-pin 41 axially movable within the slide-member 21, a spring 49 which is positioned between the firing-pin 41 and the slide-member 21 and urges the firing-pin towards the muzzle, the spring 49 being stronger than the spring 25, a trigger 57 pivotally mounted on the frame 17, a triggerbar 73 which is movable by the trigger 57 to engage the firing-pin 41 and move it in the direction away from the muzzle and then release it, and a lever 95, Figs. 5 and 6, which is pivotally mounted on the frame 17 and can restrain the slide-member 21 against movement relative to the frame when the hand grip 67 is grasped by a shooter. In use the pulling of the trigger 57 urges the shooter's hand against the lever 95 and forces legs 103 thereof into recesses 113 and prevents the slide-member 21 from moving rearwardly. A sear 83, Figs. 3 and 4, on leg 79 of the triggerbar 73 engages a sear 51 on the firing-pin 41 causing the rearward motion of a trigger-bar 73 to move the firing-pin 41 rearwardly, and the spring 49 is compressed. At a predetermined position of the trigger 57, the leg 79 of the trigger-bar 73 disengages the sear 83 from the sear 51, the spring 49 overcomes the force of a firing-pin return-spring 45 so as to thrust the firing-pin 41 forwardly, and a cartridge 33 is fired. Gas pressure generated urges a leg 101, Figs. 5 and 6, of the lever 95, to cause the legs 103 to abut the recesses 113 and retain the slide-member 21. The recoil force exerted rearwardly against the slide 21 is greater than the force exerted by the lever 95, thus the legs 103 leave the recesses 13 and the slide 21 is released to move rearwardly. The latter is retarded by lips 111 thereof being in frictional contact with the legs 103 of the lever 95. A magazine safety bar 125, Fig. 2, is attached by a pin 127 to the hand grip 67 and extends into a magazine receiver 69. An end 129 of the bar 125 is alignable with leg 81 of the trigger-bar 73 and, when aligned, prevents the bar moving rearwardly and the weapon from being fired. A portion 131 of the bar 125 is engaged by a magazine 71 which is in the receiver 69. The bar 125 is moved sideways so that its end 129 is out of alignment with the leg 81. The triggerbar 73 is then free to move rearwardly when the trigger 57 is actuated. A slide lock is provided to secure the slide 21 in its fully open position after the last round in the magazine 71 is inserted in the chamber 31. An extractor 157, Fig. 3, having a claw 155, removes the spent cartridges from the firing- chamber 31.