Patent GB-191503217-A (GB)
Title: Projectile more particularly intended to be Discharged or Dropped from Aircraft.
Inventor: BERGERY-DEROCLE FRANCK
IPC: F42C1/09
Filed: 1915-02-27
Granted: 1915-08-12
Abstract: 3217. Derocle, F. Bergery-. Feb. 4, 1914, [Convention date]. Projectiles ; projectile fuses.-Relates to projectiles intended to be dropped from aircraft and comprising a shrapnel shell partly enclosed in an outer casing from which it is expelled on impact, the explosion of the shell taking place in the air after its expulsion. According to the invention, the whole shrapnel shell B, Fig. 1, moves forwards on impact to fire the percussion cap a<7>, which ignites the charge a<10> serving to expel the shrapnel shell, the shrapnel shell being provided with a firing-pin b<5> and being normally held to the outer casing A by pins b<3>. These pins are fixed to the shell B and fit into a groove a<4>, Figs. 1 and 2, formed within a flange a<3> at the open end of the outer casing A, which is slit at four places a<5>, Figs. 2 and 6, forming two wide and stiff tongues a<13> and two smaller and weaker tongues a<14>. When the shrapnel shell is inserted into the outer casing, the smaller tongues yield and then snap over the pins b<3>, and when impact takes place, the tongues again yield and allow the shrapnel shell to move forwards. For safety during transport the tongues are locked by a ring F, Fig. 5, which is attached to the flange a<3> by a bayonet-like connexion formed by lugs f<2> on the ring and slots a<12> in the flange ; the partial rotation of the ring to secure it in place is transmitted to the shell by lugs f<1> on the ring fitting in recesses d<1> in the rear part of the shell and the rotation of the shell shifts the pins b<3> from the weak tongues a<14> to the stiff tongues a<13>, thus giving additional safety. The ring F is removed before the projectile is inserted in the discharging-tube G, and while the projectile is in the tube, the tongues are locked at safe by the wall of the tube. The shrapnel shell contains a central explosive charge b<8> surrounded by bullets b<1> in radial chambers covered by a thin sleeve b<2>. The charge b<8> is exploded when a spring hammer C is released and strikes an anvil b<9>. the flash being led to the charge by a perforated tube b<6>. Rebound of the hammer is prevented by a rod c<2>, which is attached to the hammer and leaves a sleeve c<3> when the hammer is thrown forwards by its spring c<4>. The hammer is normally held cocked by catchpieces e<5> in slots c<7> in a ring e<6> by a sleeve c<8>, The ring is attached to a rod c' passing through the shrapnel shell and connected at c<11> to one end of a wire (not shown), which is coiled in the space x and is attached at its other end to the casing A. When the shrapnel shell is expelled from the surrounding casing, the wire unwinds and then pulls on the rod c<9> and draws the ring c<6> down against a spring c<12> ; the catches c<5> are thus released and can no longer retain the hammer C which thereupon explodes the shrapnel a certain height above ground. The projectile is shaped as shown, and the rear part of the shrapnel shell comprises a light hollow casing D with windows d opposite the ring c<6> and a winged tail E, and is secured to the body of the shell by a central tube c and a screw cap c, the tube c serving also to enclose and to guide the hammer C, and the screw cap e to hold the sleeve c<3> in place.