Patent GB-777292-A (GB)
Title: An improved pistol for driving pegs into a compact mass
IPC: B25C1/12
Filed: 1955-05-06
Abstract: 777,292. Cartridge actuated tools and ammunition therefor. LEIMGRUBER SOC. ANON., J. May 6, 1955 [May 7, 1954; Oct. 1, 1954], No. 13225/55. Classes 9 (1) and 119. A pistol for driving pegs into a compact mass comprises a barrel 8 carried by a member 1 which is pivoted at 2 to the breech 4, the member 1 being fitted with a sleeve 34 which, by rotation, serves to lock the barrel to the breech, and, by longitudinal movement, serves to allow or prevent firing. The barrel 8 is urged forwards by a spring 6, and its rear end 13 is of castellated form, its three projecting parts being provided with internal threads 19 adapted to engage with threads on three parts of a striker carrier 21 when the barrel is rotated by the sleeve 34. Within the end 13 is a support 14 for a peg to be fired, and on the support are four radial pins 16 on which loosely fit four segments 17 adapted to receive a cartridge. With the parts, as in Fig. 3, the segments move apart to allow the peg and cartridge to be inserted, and with the parts as shown in Fig. 2, the conical outer surfaces of the segments enter a conical bore of the carrier 21 and serve to hold the cartridge firmly in position Action. With the peg and cartridge now in position the sleeve 34 is first pulled by hand to the rear, a pin 35 thereon moving in slots 36, 37 in the barrel and member 1 respectively. The sleeve is then rotated, sliding during this movement over the part 38 at the rear end of the member 1, and rotating the barrel so that its threads 19 engage with those on the carrier 21. At this stage an extension 40 of the sleeve lies beneath the end 73 of a triggeroperated lever 63 to prevent firing. Firing is effected by pressing the barrel against the mass into which a peg is to be driven ; this compresses the spring 6 and also the spring 55 of a striker 23 which is carried back with the barrel. The sleeve 34 is now moved forwards, the pin 35 entering a notch 39 in the member 1 and the extension 40 moving clear of the lever 63. A pull on the trigger 69 rocks the lever 63 to depress a spring-urged rod 46 to bring a bore therein in line with the striker thus enabling the latter to strike the cartridge. On firing, the expanding gases drive the striker carrier 21 together with the barrel to the rear, the surface 85 of the carrier striking a movable disc 57 to compress a recoil spring 59. In a modification, Fig. 13, firing is prevented if the blast screen 9 is removed. To effect this, the screen is formed with a sleeve whose rear end serves to centre a ring 92 which is urged downwardly by a spring 95. With the ring centred the barrel can be pressed rearwards for firing to be effected, but when the screen is removed the ring is pushed downwards to provide a stop for a shoulder 96 on the barrel. Peg construction. The peg 29, Fig. 12, to be fired is fitted, immediately prior to firing, with a soft metal cap 30. The flange 31 of this cap acts as a stop when the peg is loaded into the weapon, and is burred upon firing whereby the cap acts as a guide piston for the peg as they travel down the barrel.