Patent GB-689508-A (GB)
Title: Improvements relating to signal discharge devices
Inventor: LOBELLE MARCEL JULES ODILON
IPC: F41C3/02
Filed: 1950-10-06
Abstract: 689,508. Signal pistols. M. L, AVIATION CO., Ltd. Sept. 11, 1951 [Oct. 6, 1950], No. 24485/50. Class 9(ii) [Also in Group XXXIII] A pistol for firing signals from a pressurized chamber, comprises a barrel extension adapted to be fastened to the wall of the chamber and is discharged through an aperture in the wall, the barrel pivoting between a firing position aligned with the extension and a loading position. When in the loading position a sealing surface associated with the barrel closes the extension. The barrel extension 11 has a cylindrical rear' wall 12 whose axis is at right-angles to the axis of the extension. The ends of this wall, Fig. 7, are spigoted into side plates 14 secured to the extension. In each plate are pivotally supported spigots 18, 20 projecting from a cylindrical body 17 in which a barrel 19 is mounted to turn with the body 17 so that it can be aligned with the barrel extension 11, i.e. firing position, or turned at right angles to the firing position to the loading position. In the loading position, the curved surface of the body 17 closes the bore of the barrel extension. The barrel 19 has a rear recess 22 to receive the rim of a signal cartridge and is closed by a hinged breech cap 25 which is itself locked by a pivoted cap 27. The breech cap forms part of an assembly including a housing 28 and a hand-grip 29 containing the firing mechanism. This assembly can be turned sideways on the breech cap hinge-pin to insert or remove a cartridge. Slidably mounted on the barrel is an extractor pin 31 operated when the cap is swung open by engagement of a double claw 32 on the breech cap with a hook-shaped member 33 fixed to the extractor pin. The breech is sealed by a rubber ring 34 circumscribing the extractor pin. In the loading position, the barrel is locked to the extension by means of a spring-pressed rod 36 slidably mounted in the spigot 18 and parallel with the barrel. The forward end of the rod enters a hole in a quadrant 37, when the barrel is in the loading position. To release the rod a finger-piece 42 is pulled rearwardly. When the rod 36 is riding the ouadrant 37, the rear end of the rod is fully inserted within a thimble piece 41 to prevent the breech lock being disengaged. The breech cap lock 27 is slotted to accommodate a pivoted pawl 44 pressed by a leaf-spring 47 against the edge of the breech cap 25. When the breech lock 27 is disengaged from the breech cap 25 and the cap 25 is lifted the pawl 44 turns until it touches an abutment 48 on the barrel, further movement being prevented by a stop-pin 49, Fig. 7. On the other side of the barrel. mounted in the spigot 20 is a second sliding lock comprising a spring- loaded rod 51 bearing against a auadrant 53 into which the rod 51 slides to lock the barrel in the firing position, a finger piece 55 being pulled rearwardly to release the rod before the barrel can be turned into the loading position. Integral with the finger-piece 55 is a stop-bar 56. This bar 56 overlies the trigger 57 which is pivoted between side plates 58 attached to the side plates 14 so that the trigger is isolated from the firing mechanism when the pistol is moved to the loading position, Fig. 6. A projection 61 on the trigger abuts the stopbar 56, when the firing position lock 51 is disengaged to prevent operation of the trigger. Behind the trigger is pivoted a trip-plate 62 carrying a roller 64 co-acting with a cam surface 65 on the trigger to rock the trip-plate. As the plate 62 rocks a spring-loaded pawl 66 engages a pivoted hammer 68 urged towards a firing pin 71 by a hairpin spring 69 which also urges the trip-plate. against the trigger. A resetting lever 72 having a pin-and-slot coupling with the trip plate withholds the hammer until moved by the trip plate on the firing stroke. The firing pin is mounted in the breech cap by means of a backing plate 74 A safety catch 75 locks the hammer 68 in the safe position. The pistol is mounted in the wall 76 of a pressure cabin by means of a sleeve 77 resiliently supported between a flange member 78 and a cover 79, Fig. 5, by rubber compression rings 81 and spacer rings 82. A sealing washer 80 is interposed between the wall and the member 78 and the sleeve 77 has four splines 83 extending from the cabin wall and terminating 'in a circumferential recess 84 thus forming a bayonet type fitting for the pistol. Four projections 85 on the muzzle extension engage with the splines, each projection having a bevelled surface. Rotation of the pistol in the sleeve is prevented by a spring-loaded catch 87 engaging in one of four grooves 86 in the sleeve. The spring 89 also presses a cover 90 against the body 17 to exclude foreign matter. To detach 'the pistol the catch 87 is withdrawn and the handgrip 29 turned through 45 degrees.