GB833902A - Centrifugally armed fuze for rotating projectile - Google Patents

Abstract

833,902. Ammunition fuzes. BREVETS AERO-MECANIQUES S.A. April 1, 1958 [April 25, 1957], No. 10463/58. Class 9(1) A direct action percussion fuze for spinstabilized projectiles comprises a casing 2 in which a slidably mounted striker 1 for firing a primer 3 is immobilized by a split sleeve 4 surrounding the striker and abutting a shoulder 1a thereof, the sleeve being held against expansion during the initial part of the trajectory, to delay arming, by a strip 5 wound around the sleeve in such a way that as the strip unwinds, due to centrifugal force produced by the spin of the projectile, the sleeve 4 tends to rotate around the striker in the sense opposed to the centrifugal force. The strip 5 may be resilient or non-resilient metal, e.g. tin, and have say twelve turns, the inner end being anchored to the sleeve 4 and the outer end secured to the casing 2 either permanently or by centrifugal force developed when the projectile is launched. An outer split ring 6 may retain the strip 5 in position, the ring 6 opening under centrifugal force as soon as the projectile starts to spin. The sleeve 4 split at 4a is provided with radial notches 4b, 4c to increase its flexibility and to prevent the sleeve opening until the strip is fully unwound the inner end of the strip may be pressed into the notch 4b on each side of the split 4a. When the ring 6 has moved into contact with the outer surface of the annular housing 7, the strip 5 is released and also moves outwardly causing the sleeve 4 to rotate on the striker 1 in the reverse direction to the spin of the projectile. When the strip is fully unwound, the bent portions leave the notches 4b and the sleeve 4 expands under centrifugal force and frees the striker for operation on impact.