Patent GB-136166-A (GB)
Title: Improvements in or relating to Machine Guns.
Inventor: ELBERT FOWLER
IPC: F41A9/38
Filed: 1919-12-03
Abstract: 136,166. Fowler, E., and Watson, J. A. Dec. 4, 1918, [Convention date]. Void [Published under Sect. 91 of the Act]. Machine guns.-Relates to short-recoil guns, and consists (1) in a breech-block mounted to reciprocate on side plates secured to the barrel, and adapted to be locked by a member which swings on cranks pivoted to the side plates and which serves also to accelerate the breech-block during its opening movement; (2) in a recoil buffer mounted on the rear end of the side plates; (3) in a member adapted to serve the dual function of cocking the firing-pin and of extracting a cartridge from the belt to feed it into the chamber; (4) in a trigger mechanism and a safety device therefor; (5) in cartridge-belt feed mechanism carried by the breech cover of the gun; and (6) in a cooling-jacket integral with the breech casing, the gun barrel being obliquely disposed to the axis of the jacket, and the breech casing being closed at the rear by a hollow hand-block secured by a latch which also serves to look the breech cover in position. In the form shown in Figs. 5 and 6 with the breech-block in its forward position, the barrel 1 is slidably mounted in the cooling-jacket 2 and carries side recoil plates 4 slidably supporting the breech-block 17. Pivoted to the recoil plates 4 are cranks 8 carrying the locking-member 7, the cranks being connected to an arm enclosed in a casing 10<a> and adapted to be rotated in this casing through approximately 60 degrees during the reciprocation of the breech-block by cams so arranged that, when the breech-block reaches its forward position, the locking-member 7 is swung upwards into a recess in the block with the faces 20, 21 in looking engagement; while, on the initial recoil of barrel and breech-block, the member 7 is swung downwards out of locking engagement and, bearing against a vertical face 18 on the block, serves to accelerate the rearward movement of the block relatively to the barrel. The recoil plates 4 carry at their rear ends a buffer 73 to check the recoil of the breech-block. A hand operating-slide 91 is provided in the bottom wall of the breech casing. The helical return spring 24 is housed in a boring 23 in the breechblock; it is seated at its rear end against a transverse pin 83, Fig. 14, and at its forward end against a head 42 adapted to bear against the extractor 40, which is pivoted at 41 to a link 40<b> bearing in a socket 41<c> in the block, and has projections 39, 40<1> engaging respectively a slot 38 in the firing-pin 32 and a socket 40<a> in the bolt. The movements of the extractor are guided, during the recoil and the return movements, by the engagement of a pin 82 on the extractor with cam-plates 83 mounted on the breech casing, so that the extractor withdraws a cartridge from the feed-belt, swings it down to insert its head into the flangeway 22 in the breech-bolt, and finally returns into position to withdraw another cartridge from the belt. During the downward swing of the extractor claw 40f, the ejector 80 mounted on the pin 82 ejects the empty shell, and the projection 39 pushes the firing-pin rearwardly and cocks it with its lug 31 in the recess 30 of the sear 29, which is pivoted to the breech-block and is actuated by the firing-spring 34. The sear has a lug 28 adapted to engage a tripping-nose 27 on the sliding trigger-tube 26 when the breech-block is in its forward position. A trigger safety-device comprises a ring 79<k>, Fig. 14, normally blocking the rearward movement of the trigger 79<f>, but adapted to be rotated by pressing inwards a button 79<o>, to cause slots 79<m> in the ring to register with the head 79<h> and the part 799 of the trigger, and thereby to permit this to be retracted. The cartridge-belt feed mechanism comprises a feed-cam 50 slidably mounted in the cover 57 and connected to the breech-block so as to be reciprocated therewith by a member 48; this cam has a curved cam-groove 60, Fig. 7, engaged by a lug 66 on a feed-slide 62 supported by the cover 57, so that as the breech-bolt reciprocates, the slide 62 is caused to reciprocate transversely. Pivotally mounted on brackets depending from the slide 62 is the feed-pawl 74, the spring-pressed claw of which is adapted to ride over a cartridge as the slide moves from the right to left, and grip it with the serrated edge 74<1> ready to move it, on the return movement of the slide, into position to be engaged by the claw of the extractor 40. A spring-pressed dog 68 projects through the part 77 of the cartridge feed-box, and prevents the cartridge belt from moving in the wrong direction. The barrel and breech mechanism are preferably inclined to the axis of the casing, as shown in Fig. 18, so that the water in the cooling-jacket may cover the barrel at all elevations. The water-jacket is preferably integral with the breech casing, which is closed at its rear end by a hollow handle-block 121 having interrupted threads 122 engaging with corresponding grooves in the breech casing, to which it is locked bv a slidable latch 124 which serves also to lock the cover 128 to the casing. A filling valve is provided in the upper side of the rear of the water jacket. A special form of trunnion mounting is described.