Patent GB-787474-A (GB)
Title: Improved pneumatic weapon
IPC: F41B11/683
Filed: 1955-02-28
Abstract: 787,474. Pneumatically-operated small arms; ammunition. VALERO, R. S. Feb. 28, 1955 [Feb. 27, 1954], No. 5923/55. Classes 9(11 and 119 A pneumatically operated smallarm has pivotally mounted thereon, a plurality of pumps of different capacities for progressively compressing air, which pumps are manually operated by a single lever to supply compressed air to a storage chamber adapted to be placed in communication with the breech of the weapon to eject a missile. The pumps are actuated by a lever 1, Figs. 1, 3, pivoted at 2 to the weapon stock and at 3 to piston rods 8, 9, 14. Rods 8, 9 have piston heads 6, 7 working in cylinders 4, 5 to constitute high capacity pumps 4a, 5a. The rod 14 has a piston head 15 working in a cylinder 13 to constitute a low capacity pump 15a, the rod 14 passing through a hollow piston rod 10 and its associated piston head 11 of an intermediate capacity pump 11a, the cylinder of which is shown at 12. Orifices 16 permit passage of air from pumps 4a, 5a to the pump 11a and the ends of cylinders 4, 5 and 12 are provided with fluid-tight fittings and piston leathers 21 on the heads 6, 7 permit air to pass into the cylinders 4, 5 and prevent air under pressure leaking out. Leathers provided on the piston heads 11, 15 permit air to flow into the cylinder 13 in front of the head 15. The cylinder 13 is formed at its forward end with a block 22 pivoted at 24 to the stock and formed with a fluid passage communicating via a non-return valve with a fluid passage 27, Fig. 7, in the stock, the passage 27 leading to a storage chamber 23. The capacity of' the storage chamber is controlled by a piston 44 loaded by a spring 50 adjustable by a threaded plug 51. The chamber 23 communicates with the breech via a passage 52 normally shut-off from the chamber 23 bv a piston 54 which is fastened to a rod 53 extending through a slidable sleeve 55 and a fixed sleeve 58, the rod being screwed at its other end into a slidable cap 59. The sleeve 55 is urged to a position closing the passage 52 by a spring 57 and a spring 60 urges the piston 54 to its forward position. Assuming the pumps 4a, 5a are already charged with air at atmospheric pressure, movement of the lever 1 to the left moves pistons 6, 7 to the left to force the air in the pumps 4a, 5a through orifices 16 into the cylinder 12 from whence it passes the pistons 11, 15 and enters the cylinder 13. At the same time the piston 15 which is connected through rod 14 to the lever 1 moves to the left until it partly enters the piston 11 as shown in Fig. 3; at this point a sprung projection 31 on the piston rod 10 engages in a recess 32 in the rod 14 and thereafter further movement of piston 15 to the left is accompanied by that of piston 11. On the first part of its return movement the lever 1 actuates all the piston rods and pistons 11, 15 are moved to the right to compress the air in the cylinders 12, 13 until the piston 11 comes to the end of its travel. At this point, the projection 31 is released from the recess 32 and the piston 15 continues its travel forcing the air out of the cylinder 13 to the storage 'chamber 23. The above cycle is then repeated to produce the required pressure. In order to fire a safety catch 68, Fig. 7, is released and on pressing the trigger 66, a seat 62 disengages from the cap 59 thus permitting the compressed air to force the piston 54 and sleeve 55 back and to flow through the passage 52 into the breech. A cartridge 75, Fig. 8, for use in the weapon has interior flanges 76, 77 the latter serving for extraction purposes and a wad 78 is retained by the flange 76. Buckshot 79 is retained in the cartridge by a wad 80 secured by a layer 81 of wax.