GB293517A - Improvements in or relating to projectile fuzes - Google Patents

Abstract

293,517. Vickers, Ltd., and Mellstrom, C. G. May 7, 1927. Projectile fuzes.-Relates to percussion and graze fuzes for projectiles of the kind having a spring - controlled firing member normally held by a detent which is moved, to release the firing member, by reason of its rotational inertia, when the projectile impinges on a target. According to the invention, the detent or retaining member normally engages directly with the spring-controlled firing member. In the construction shown, the holder of a percussion cap B<2> is a slidable plunder B, normally held against the action of a spring B<1> by a detent D pivoted at D<1>. This detent, as shown in Fig. 3, is formed a curved arm, so weighted and arranged that during the flight of the shell it is liept by centrifugal force against a stop D<x>, in which position it engages under a shoulder B<3> of the member B. A centrifugal safety-catch E, itself locked by an inertia bolt E<2>, locks the detent D until the shell is discharged from a gun. The firing needle may be fixed to the body of the fuze, but in the construction shown it is mounted on a member C<1> pivoted at C<x> in a slot in a block C. The part C<1> is normally locked in the position shown in Fig. 5, with the firing-needle C<2> shielded and out of alignment with the percussion cap B<2>, by centrifugal bolts C<3>. The block C carries spring plungers C<4>, which prevent forward creeping of the block during the flight of the shell. The action is as follows. When the shell is discharged, the bolt E<2> sets back, releasing the catch E which moves outwards under centrifugal force, unlocking the detent D. On cessation of the forward acceleration, the bolt E<2> is moved forward again by a spring, preventing the return of the part E. The spin of the projectile also effects the release of the member C<1> from the bolts C', and. causes the part C' to swing so as to bring the needle C<2> into line with the peroussion cap. If the shell grazes an obstacle, so that the spin is reduced, the detent D turns about its pivot D<1>, by reason of its rotational inertia, and frees the plunger B, which is thereupon driven towards the needle C<2> by its spring, causing ignition. Impact of the shell with an obstacle, as distinct from merely grazing, causes the block C to move forward by momentum, forcing the firing needle against the percussion cap. ,