Patent GB-1354307-A (GB)
Title: Device for launching a projectile
IPC: F41B11/72
Filed: 1971-06-17
Abstract: 1354307 Pneumatic guns; projectiles S-G-L INDUSTRIES Inc 17 June 1971 28390/71 Headings F3C and F3A A pneumatic gun comprises a gas receiving chamber 31 adapted to be charged with gas from a pressure source, a firing chamber 64 fed with compressed gas from the receiving chamber 31, means for holding a projectile prior to launch thereof, means for releasing the pressurized gas in the firing chamber 64 to the holding means to fire the projectile and means operable by the drop of pressure in the firing chamber 64 on the firing of the projectile to cause gas to flow from the receiving chamber 31 to the firing chamber 64 to recharge the same. In the construction shown gas is fed to the firing chamber 64 from the receiving chamber through a hollow tubular member 38 sliding sealably in the housing 26 of the gun, a bore 40 of a piston member 42, a gas retaining chamber 48 and a channel 66 in a slide member 56. The piston member 42 slides within a bore of the slide member 56, a sealing ring 52 in the forward end of the bore acting as a valve seat for the piston member 42. The slide member 56 also at its forward end forms a valve member for controlling the application of the gas in the firing chamber 64 to the holding means. The slide member 56 is held in its forward valve sealing position by the sear 88 of a firing mechanism. Pressurized gas in the gas retaining chamber 48 causes the piston member 42 to be urged rearwardly against its spring loading opening the valve formed by the piston member 42 and sealing ring 52 to allow the firing chamber to be pressurized. The rearward movement of piston member 42 proceeds as the pressure progressively increases until such time that the rear end of the hollow tubular member 38 seats in a seal 35. The position of the seal 35 is adjustable to thereby adjust the pressure level in the firing chamber. In depression of the sear 88 the slide member 56 is urged rearwardly by the pressure in the firing chamber 64 to allow the gas to enter the projectile holding means to thereby fire the projectile. As the pressure decreases in the firing chamber 64, the spring 44 urges the piston member 42 and slide member 56 forwardly to unseat the hollow tubular member 38 and thus allow a charging operation, the sear preventing rearward movement of the slide member 56. The pressure source comprises a gas cartridge housed in a chamber 24 and thrust on to a hollow piercing pin 25 by a cam arrangement (Figs. 8 to 13, not shown). A projectile assembly (Fig. 4) comprises a casing 112 in which is housed an outer member 132 of the projectile. The projectile further includes a mass 138 located within a guiding member 136 and held stationary therein while the projectile is within the casing by a pin 134. A primer arrangement 150, 152, 154 is provided within the mass which is released from the guiding member 136 after firing of the projectile so that on the projectile striking the target the primer arrangement is urged against a firing pin 144. A firing charge in a chamber 142 then explodes to liberate a load, e.g. tear gas, dye, flash powder, wadding, in a chamber 156. A layer of flash powder 158 may be provided within the projectile. The projectile may comprise two parts containing shot, the parts falling apart in flight to liberate the shot (Fig. 5, not shown). In a further embodiment having an initially fixed mass, a one-way valve is provided in the rear end of the projectile so that a proportion of the propelling gas may enter the projectile and be used to effect dispersal of the load within the projectile (Fig. 6, not shown). A glass container moving with an initially restressed mass to be broken against a projection may also be provided within the projectile (Fig. 7, not shown).