Patent GB-760905-A (GB)
Title: Improvements in and relating to a fuse for a projectile and applications thereof
Inventor: RAYMOND JASSE JOSEPH
IPC: F42C9/02
Filed: 1954-12-17
Abstract: 760,905. Projectile fuzes. SOC. NOUVELLE DES ETABLISSEMENTS BRANDT. Dec. 17, 1954 [Dec. 24, 1953], No. 36556/54. Class 9 (1). An impact-operated fuze has a part 2 of the body 1 screw-threaded for engagement in the head 3 of a hollow charge rocket 4. Screwed into the body 1 is a guide 7 for a tubular member 8 in which fits an impact nose 9 screwed on to a firing pin 11. Surrounding the member 8 and supporting the nose 9 is an elastic ring 14 which may be of rubber. A spring 15 bears against a flange 17 within the member 8 and against a shoulder 16 of the guide 7 abutting a flange 18 on the firing pin. Within a housing 19, which may be brass, is a detonator 26 containing a charge 27 and a primer 28, a ring 29 being provided to space the striker 12 from the primer. The housing 19 rests on a washer 21, e.g..of aluminium, inserted in a ring 23 screwed into the body 1. Balls 30, e.g. of steel, holding the firing pin at rest are locked by a tube 33 mounted on the guide 7 and urged forwardly by a spring 34 so that a flange 35 bears against a flange 36 of a sleeve 37. Grooves 39 in the sleeve have semi-circular notches into which extend locking pins 40 mounted in the body 1. On firing the projectile, due to its initial acceleration, the sleeve 37 sets back by inertia, an oscillatory motion being given to the sleeve by the pins 40, until blades 42 integral with a cup 43 engage in a notch 41 at the base of the sleeve 37. As the sleeve 37 is displaced, it draws back the tube 33 to free the balls 30. During acceleration of the projectile, the balls are urged against the conical seating 32, but when the acceleration falls below a given safety value, the balls are thrown outwards by centrifugal force if the projectile rotates or by inertia if the projectile is non-rotating. The striker is then armed. On impact, the nose 9 compresses the ring 14 and the firing pin moves rearwardly. Due to inertia, whether impact occurs on the nose 9 or not, the detonator housing moves forwardly, so that the firing pin strikes the primer 28. In the case of a rocket provided with the fuze, if the rocket is dropped without ignition of the propellant, arming cannot take place and on impact the washer 21 ruptures to prevent relative movement of the firing pin and the primer 28. Similarly a blow on the rear end of the projectile causes only a limited movement of the sleeve 37 after which the sleeve returns to the rest position. In Fig. 5 the fuze F is housed in a sleeve 45 sealing the cavity of the charge 43. The charge lines 44 has a tubular part 46 extending through the charge and housing a secondary detonator 47 ignitible by the detonator 26. In a modification, the ring 14 is omitted and the firing pin is fixed, the fuze being adapted for operation by inertia. In Fig. 7 the fuze is mounted in a rocket containing a charge 49, the ring 23 being replaced by a tubular member 23a which supports the auxiliary detonator 50. The fuze and its extension 23a are housed in a sealing tube 51. For anti-tank rockets in which the launching acceleration is low, the travel of the arming device is increased and the sleeve 37 is immobilized by a safety pin. The pin, which extends through the sleeve, is the end of a spring seated in a groove encircling the fuze.