Patent GB-601517-A (GB)
Title: Improvements in or relating to machine carbines
IPC: F41A19/34
Filed: 1944-08-30
Abstract: 601,517. Automatic guns. BIRMINGHAM SMALL ARMS CO., Ltd., PERRY, C. A.; and WACKROW, R. D. Aug. 30, 1944, No. 16528. [Class 119] The breech-block 3 of a machine carbine is moved backwards into cocked position from its safety position, Fig. 2, after the release of a locking lever 93 (see below), by longitudinal movement of a hand-grip 39 sliding on a bearing sleeve 41 fixed to the barrel 37. The grip 39 carries a flexible spring arm 47 projecting into the body 1 of the gun, and upon sliding the grip forwards as far as stops 43, 45 on the grip and bearing sleeve allow, a catch 52 at the end of the arm 47 snaps into engagement with a mating surface on the front of the breechblock, Fig. 3. Rearward movement of the grip then moves the breech-block back against the recoil spring 7 until, after the sear bent 17 has ridden over to behind the sear 53, the catch 52 engages a cam plate 55 fixed to the body 1 lifting it out of engagement with the breechblock which then slips forward a short distance until retained by the sear 53. The cam plate 55 is formed with a catch to engage the catch 52, retaining the arm 47 and sleeve 39 in the rear position until again required. The grip may be made of synthetic resin or other poor heat conductor. General construction.-The carbine comprises a tubular body 1 in which slides the breechblock 3 shouldered at 5 to receive one end of the recoil spring 7, the other end of which abuts against a locking plate 9 in a knurled cap 11 screwed on the body 1. The plate 9 is rotatably mounted in the cap and has projections to engage recesses in the cap and an arm 15 engaging a slot in the body 1 to retain the plate in position relative to the body. The breech-block is formed with a striking pin 19 and carries the sear bent 17 which works in a channel 21 at the base of the body 1 and thus prevents rotation of the block. The breech-block is channelled at 23 on its left side, Fig. 6, to provide clearance for the movement of the block past the magazine support. A lug 27 in the channel 23 engages the foremost cartridge in the magazine as the breech-block moves forward and feeds it into the breech chamber in the barrel. A longitudinal bore in the breech-block houses a flexible arm 31, Figs. 6 and 7, having a catch 33 at the fore end to engage over the lip of the cartridge, which after firing, is ejected through a slot in the right-hand side of the body 1 by a spring- loaded plunger 29, also housed in the breechblock, in co-operation with the catch 33. A barrel block 35, secured in the front of the body 1, has a frustro-conical seat on its rear face for the base of the cartridge case and is internally threaded to receive the rifled barrel 37 and also has a portion externally threaded to receive the bearing sleeve 41 for the handgrip 39. The firing mechanism described, including the breech block safety locking lever 93, released and set by the fire control lever 97, is identical with that described in Specification 601,581. The body 1 carries at its rear end a folding butt comprising two tubular arms 139 carrying a butt plate 141, Figs. 2 and 8. The butt plate is hinged to the arms 139 by two ears 133 and retained in the position shown or in folded position parallel to the arms 139 by spring-loaded catches 147 in the arms engaging one of two sets of notches 149 in the ears 143. Each arm 139 at its forward end has a lug 151 with upper and lower flat surfaces and an elongated somewhat wedgeshaped slot 153 through which passes a pin 155 housed in a depending boss 157 on the body 1 and also passing through the heads of bolts 159 mounted in the arms 139 and urged by springs 161 inwards thereof. The upper flat surfaces on the lugs 151 are thus urged into contact with the underneath of the body 1 and the pin 155 against the rear of the slots 153 where it is wedged. To fold the butt it is first pulled backwards against the springs 161, disengaging the upper surface of the lugs from the body 1 and releasing the pin 155 whereupon the arms 139 may be pivoted on the pin 155 to lie along the underneath of the carbine on either side of the hand grip 73. On releasing the arms 139 the springs 161 force the pin 155 to the now forward ends of the slots 153 and the former under, now upper, flat surfaces of the lugs 151 against the underneath of the body 1, to secure the butt in the folded position shown in dotted lines, the butt plate having previously been folded relative to the arms 139. Specification 601,582, which describes a folding magazine holder, also is referred to.