| 摘要 |
586,629. Pneumatic guns. HOLMAN BROS., Ltd., and HOLMAN, A.'T. Sept. 26, 1939, Nos. 26676/39, 409/40 and 12788/40. [Class 92 (ii)] A pneumatic gun, particularly one of trench mortar type, has valve means for admitting compressed air to the gun barrel behind a projectile and a device actuated by the projectile on reaching its firing, position for permitting or effecting operation of the valve means for discharging the projectile. The invention is shown applied to a trench mortar of the Stokes' type in which discharge is effected by the base impact of a projectile sliding down the barrel 3. Air under pressure for discharge passes from reservoir 10 through ports 14 past the seat 12 of a valve 11 which tends to open under pressure acting on steps 48, 49. The chamber 23 below the valve is under pressure from a previous discharge through passages 50, 52 uncovered by the valve, and this pressure is relieved at the moment of discharge by acting through a cam-operated trigger-rod 34 on an atmospheric relief-valve 30. A pivoted distance-piece 46 on a lever 45 on a rod 16, which is moved transversely by the pressure of the projectile on a trip lever 41, prevents action of the rod 34 on the valve 30 except when the projectile is in discharge position resting on the rod 16. The trigger-rod is operated by a cam 37 on a rotatable hand-grip 36. A projection 53 on the lever 45 permits direct operation of the valve 30 if the projectile siezes in the barrel or for practice purposes without using a projectile. |
