GB978502A - Improvements in or relating to air or gas pressure guns - Google Patents

Abstract

978,502. Pneumatic guns. BIRMINGHAM SMALL ARMS CO. Ltd. Dec. 28, 1960 [Dec. 31, 1959], No. 44346/59. Heading F3C. Relates to a pneumatic gun of the type in which a vertically slidable pellet-feeding member 18, Fig. 1, having a pellet receiving passage 19 moves between a firing position in which the passage 19 is aligned with the bore of the barrel and the outlet orifice 17 of a compression or gas cylinder and a loading position in which the passage 19 is accessible to receive a pellet, the member 18 being moved to the loading position by a slide 8 moving parallel to the barrel axis on cocking the gun by the actuation of a cocking lever 10. In one form applied to a piston air gun with a magazine, the body 2 which is integral with the barrel includes a compression cylinder 4 in which is slidable a piston 5 urged forwardly by a compression spring 6. The piston 5 is retracted against its spring by a slide 8 connected by a link 9 to a cocking lever 10 pivoted at its rear end to the body. The pellet feeding member 18 in the loading position receives a pellet from a magazine tube 20 and is raised to this position by actuation of the cocking lever 10. For this purpose the lower end of the member 18 projects into a slot 23 in the slide 8, the forward end of the slot 23 being formed with a sloped cam surface 24 so that rearward movement of the slide raises the member 18 to the loading position. On returning the cocking lever to the position shown, the member 18 is lowered to the firing position by means of a pivoted lever 21 and a compression spring 22. A rotatable pin 28 with a cut-away surface 27 can also be manually operated to swing the lever 21 so that the member 18 is raised to a " safe " position in which the passage 19 is located between the firing and loading positions. The member 18 is a close sliding fit between the front and rear walls of its guide passage but fits relatively loosely between the side walls to provide for lateral adjustment for aligning the passage 19 with the bore of the barrel. For this purpose a blade spring 36, Fig. 4, is located in a recess in one side of the member 18 and a grub screw 37 permits lateral adjustment. A further grub screw 39 permits vertical adjustment. A tubular seal member 40 of resilient material such as polyethylene is closely but slidably fitted in the outlet orifice 17 of the cylinder and is anchored by a transverse pin 41 engaging a recess in the member 40, thus permitting it a degree of longitudinal movement. The rear end of the member 40 and the rear end of the passage 19 are countersunk so that on firing the member 40 moves forwardly and expands to prevent air leakage. In another embodiment. Fig. 5 (not shown), having no magazine feed, the seal member 42 comprising a tubular element of metal with an enlarged head, is resiliently mounted by means of a rubber washer 43 in the orifice 17 and is also used to locate the member 18 in its loading and firing positions. The cocking mechanism may be arranged to return the member 18 to the firing position when the cocking lever is returned to its normal position after cocking.