GB823913A - Improvements in projectile fuzes - Google Patents

Abstract

823,913. Ammunition fuzes. FUSELEC S. A. March 27, 1958, No. 9892/58. Class 9(1) A direct-action percussion fuze, which can be set for instantaneous or retarded action, comprises a casing 1 which can be screwed into the nose of a projectile and has an extension on to which a detonator 4 is screwed. Within the casing is a rotatable barrel 5 having two diametral bores 7, 8 housing a delayed-action primer 10 and an instantaneous-action primer 9 respectively, the barrel being locked against rotation by a cranked pin 33 with the bores 7, 8 out of alignment with a flash passage 40 leading to the detonator. In this position should a primer explode accidentally the gases are vented harmlessly into a cavity 12 housing the setting means. The pin 33, which is axially slidable, is secured by an arm 36a extending from a relay 36 mounted on a plate 37 closing the nose of the fuze. The setting means comprises a piston 13 supported by a spring 28 and provided with diametrally opposed longitudinal grooves, one of which houses a spring stirrup 16, Fig. 4, straddling one end of a pivoted rod 20 connecting the piston to the barrel and the other groove receives a finger 17d projecting from an arm 17c manually rotatable by means of a head 17b in the casing wall. By rotating the head 17b, the arm 17c can be moved between two extreme positions in each of which it abuts a shoulder 18 of the casing, the two positions corresponding to instantaneous and delayed settings respectively. As the arm is rotated, the piston is turned and swings the connecting rod slightly to left or right, the major part of the rotation being taken up by deformation of the stirrup 16. Rod 20 is pivoted on an eccentric stud 21 projecting from a crank disc 22 on an end face of the barrel 5, a diametrically opposed stud 23 being engaged in a notch of a plate 25 fixed to the casing 1 to prevent rotation of the disc 22. Two screws 32 mounted in the barrel extend through symmetrically placed slots 31 in the disc 22 and a stud 44 mounted in the casing engages a groove 45 in the opposite end face to limit rotation of the barrel. During the initial portion of the projectile's travel, the piston 13 sets back due to inertia and stresses the spring 28, the thrust of the piston being transmitted by the rod 20 to the disc 22. When the piston has set back a distance equal to the depth of the notch 24, the disc 22 is freed and is then rotated by the stressed stirrup 16 by means of the rod 20, so that one screw 32 arrives at the lower end of a slot 31 and the other screw at the upper end of its slot. As the projectile decelerates the piston 13 is returned forwardly by the spring 28 and carries forward the rod 20 and the disc 22. When the relay 36, which may be mechanical, electrical or chemical, is operated the arm 36a releases the pin 33 and the barrel 5 rotates, due to the pressure exerted by the disc 22 on the screws, until the selected primer is aligned with the flash passage and a spring-supported striker 42. The fuze is then armed for operation on impact.