Patent GB-511156-A (GB)
Title: Improvements in or relating to artillery
IPC: F41A25/00
Filed: 1938-02-11
Abstract: 511,156. Ordnance; mountings. SOC. ETUDES ET CONTROLES INDUSTRIELS. Feb. 11, 1938, No. 4376. Convention date, June 3, 1937. [Classes 92 (i) and 92 (ii)] Field artillery, adapted for high-angle fire, has a gas brake disposed adjacent to the muzzle, means to balance the gun, and means operated by the difference in velocity of the braked gun and of the breech-block to open the breech. The gun 1 has a gas brake 2 and slides in a sleeve 3 provided with arms 4 mounted on trunnions 5, the gun being elevated by pinion 11 actuated by a handwheel 12, and segments 10. The trunnions 5 are carried by a cradle 6 provided with a pivot 16, Fig. 6, mounted on ball and ball-thrustbearings in a sleeve 17 having a spherical seat 24 the sleeve being adjustable to ensure a vertical disposition of the pivot 16 by four screws 26 actuated by hand ratchets through universally-jointed rods 29. The pivot is rotated for training the gun by a hand-driven worm-gear 22, 21, and provision is made for declutching the worm 22 to enable the gun to be moved quickly approximately to the direction required. Balancing springs are mounted in tubes 7 pivoted to the cradle 6 and to the sleeve 3. The sleeve 3 has a hydro-pneumatic brake 13, Fig. 4, to the rod of which the gun is harnessed, and diagonally disposed recuperators 14 for the breech block. The breech-block 30, Fig. 3, has segmental screw threaded engagement with the barrel, for locking purposes and is mounted on a coaxial quick-pitch screw 31 fast in a slide 32, so that, when the gun is fired, the recoil of the barrel is quickly arrested by the combined action of the muzzle brake and hydro-pneumatic brake 13, whilst the slide 32 and breech-block in virtue of their momentum, effect the unlocking of the breech-block by relative movement between the slide and breechblock, the latter then retiring with the slide 32, clear .of the gun, until arrested by the recuperators 14, whose rods 34 are coupled to the slide 32 by locking levers 47, Fig. 4, which may be released by handles 50, 51 when it is desired to move the breech-block by hand. The turning movement of the breech-block, when unlocking, is limited by stops and one of the threaded segments engages in a slot in the guide 33 to prevent rotation of the breech-block during its longitudinal movement with the slide 32. The slide is caught by a catch 35 at the end of the recoil of the breech-block, the latter having an extractor to remove the cartridge case which is then ejected from the extractor during the recoil of the breech-block. When a new cartridge has been placed on the guide 33 and the catch 35 released by linkage 36 controlled by the gunner, the slide 32, screw 31 and breech-block move forwards and feed the cartridge into the breech, the breech-block moving automatically into locked position. The gun is then fired by rotating a member 45 by hand to lift a hook 43, coupled by a spring-blade to a rod 40, clear of an abutment 42 on the gun whereupon the rod 40 flies rearward under the influence of a spring 44 and impacts against one end of a lever 41 in the slide 32, the other end of the lever actuating a firing pin 39. The firing mechanism is reset by the return of the shoulder 42 of the gun, after recoil. The gun pivot is mounted on an endless track chassis, provided with short lateral anchoring members controlled by right and left handed screws, and with fore and aft screw jacks. A conical sheet metal cover 54 shields the pivot. The Specification as open to inspection under Sect. 91 stated that the gun may be mounted on a fixed or semi-fixed gun mounting and describes also the application of the invention to a 75 mm. gun as actually in service in some armies. This subject-matter does not appear in the Specification as accepted.