Patent GB-191517494-A (GB)
Title: Improvements in or relating to Hand Grenades and like Percussive Bombs.
Inventor: HAMILTON JOHN ROBERT
IPC: F42C1/06
Filed: 1915-12-14
Abstract: 17,494. Hamilton, J.R., [Hamilton, J. D.]. Dec. 14. [Cognate Applications, 17/16 and 77/16.] Projectiles ; projectile fuses.-Relates to handgrenades or other projectiles which are caused to explode on impact by means of one or more firing-pins. According to this invention, the projectile comprises an outer casing or shell and an inner shell containing the explosive charge and detonator, the operative movement of the firing-pin or pins being effected on impact, by relative displacement of the two shells. The inner shell may be normally locked in the safe position by distance-pieces which are automatically withdrawn when the projectile is thrown or discharged, and the spacing of the shells is maintained during flight by devices which yield on impact. Fig. 1 shows a hand-grenade in which there are a number of firing pins h disposed within tubes h<1>, which radiate from a detonator casing d within the charge-container a. Springs h<2> normally maintain the pins with their points clear of the detonator and their heads in contact with the outer casing b. The springs also act as spacing- devices for the inner and outer shells, for which purpose separate additional springs may be provided. Normally, the inner and outer shells are relatively fixed by pins s passing through holes in the shell b, the pins being fixed on spring-pressed plates g which are adapted to be secured externally by safety-pins p. In use, after the withdrawal of the pins p, the plates g are held down by hand, but are thrown off by springs g<2> when the grenade leaves the thrower's hand. Consequently, the shell a moves relatively to the casing b when impact in any direction occurs, and one or other of the pins h fires the detcnator d. In a modification, the safety devices consist of headed studs, the shank of which contains an ejecting-spring. Fig. 5, which does not show the safety device, shows an arrangement of openings and covers b<3>, m whereby ready access can be had to the inner shell for filling in the explosive charge f and inserting the detonator. The heads of the firing-pins are, in a further construction, rigidly secured to the outer shell b. The pins are, in this case, made of brittle material, so that those which do not lie in the direction in which impact occurs may snap off ; or, according to the Provisional Specification 17/16, the pins may be flexible. In the construction shown in Fig. 8, the outer ends of the tubes h<1> which receive the firing-pins are cupped, and the beads of the pins are held out of these cups until impact occurs, by hard washers w. In order to facilitate the breaking of the washers on impact, the surfaces on which they rest may be undercut. To increase the sensitiveness of the device, the heads of the firing-pins may engage in recesses in the outer case b, when this is spherical ; or the case itself may be ovoid, as shown ; or the pins may have ball heads. A single safety-pin p with a loop p<1> may be used in connexion with the safety-stops g, or may pass through the outer shell and the firing-pins so as to engage under the washers w. The single safety-pin p is applicable to all the forms of apparatus described. For the purpose of withdrawing this pin automatically when the grenade is thrown, a wrist strap fitted with a hook to engage in the loop p<1> may be used. In another modification, the firing-pins may be held in the inoperative position against the action of springs, by detents consisting, for example, of members each of which is pivoted to the outer shell at a point between its ends and bears against the inner shell. Percussion caps acted upon by the firing-pins may be used. The detonator may be arranged otherwise than in the central position shown. The Provisional Specification 17/16 also describes a modification iu which firing-pins are adapted to strike caps on the charge container, the caps being connected to the firing-tube directly or by instantaneous fuses. It is further stated that electric firing-means controlled by the relative displacement of the inner and outer shells may be used.