GB911474A - Projectile fuzes - Google Patents

Abstract

911,474. Ammunition fuzes. INDUSTRIALHOLDING-ESTABLISHMENT. June 12, 1959 [June 14, 1958], No. 20271/59. Class 9 (1). A projectile fuze operating on impact has a body 1 on which a cap 2 enclosing the percussion means is held by a split ring 3 housed within slots 4, 5 in the cap and body respectively so that the cap may be rotated relatively to the body. A screw 6 bearing on the ring 3 is tightened to lock the cap in any desired position, the periphery of the cap being quartered by markings indicating safety, instantaneous action, short delay and long delay respectively, when brought into register with a datum line 10 on the body 1. When set at safety the firing-pin 11, which is engaged by a spring-supported striker 12, is held by a bolt 14 secured in the locking position by a stud 17 projecting from a piston 18. The piston is thrust forward by a spring 19 and held by a ball 21, which bears against the inner surface of the cap 2, within which surface are three recesses 24, Fig. 3, corresponding to the other settings of the fuze. The appropriate recess 24 is brought into alignment with the ball 21, when the fuze is set. At the same time a barrel 33 rotates about a pivot 35, which slides in a radial slot 36, and thus brings the appropriate primer 34 into register with the pin 11. The barrel may, alternatively, be rotated by providing a groove in the barrel co-operating with a pin extending from the casing. When an unrotated projectile fitted with the fuze is launched, the piston 18 sets back due to inertia, forcing the ball 21 into the recess 24, withdrawing the stud 17 and becoming wedged on a member 42. The bolt 14 is then held only by a rod 52, which bears against an obturating plate 40 having a toothed segment 47 co-operating with clockwork 48 to prevent arming in the initial stage of the trajectory. As soon as acceleration ceases, the piston 18 and member 42 move forward together, withdrawing a pin 43 and so unlocking a rocking lever 44 forming part of the clockwork. The spring motor 46 then drives the clockwork, which rotates a barrel 26 until a detonator 30 housed therein is aligned with a flash passage 39 and the selected primer 34. When the quadrant 47 has rotated sufficiently for plate 40 to free the rod 52, the bolt 14 frees the pin 11 and the fuze is armed. The barrel 33 is slidable in its housing 23, so that if the projectile is arrested by impact with soft ground, the barrel moves towards the firing pin to initiate the primer. Such action may also be produced by deceleration. The toothed quadrant may be replaced by a rack driven by a spring in an unrotated projectile or by centrifugal force in rotated projectiles.