NO129310B

• Main Authors: MOREL R,CH, SIMMEN R,CH
• Format: Patent
• Language: English
• Published: 25.03.1974
• Subjects: AMMUNITION; AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR; BLASTING; HEATING; LIGHTING; MECHANICAL ENGINEERING; WEAPONS

1296326 Projectile fuzes MEFINA SA 4 May 1971 [14 May 1970] 13051/71. Heading F3A A fuze for a non-gyratory mortar projectile comprises a first firing pin 15 which co-operates with a first percussion fuse 34 to enable instantaneous detonation of the projectile on impact, and a second firing pin 57 which co-operates with a second percussion fuze (not shown), fixed in a clockwise-controlled transversely rotatable member 64, to enable delayed detonation on impact . The firing pin 15 is rotatable with an ogive 8 to align a squared section 18 with a corresponding slot 17. The firing pin 57 forms parts of a plunger 55 which is locked in the fuze holder 32 by balls 60. An inertia ring 45 holds the elastic fingers 40 of a ring 38 in a groove 43 in the fuze holder 32. A bolt 42, biased outwardly by a spring against a land lying between two recesses (Fig. 9, not shown) also engages the shoulder 41 of ring 38. The member 64 is held against rotation, under the action of a spring, by means of a spring-biased bolt 74. This bolt is held in the locking position by virtue of an abutting toothed sector 75 forming part of the clockwork delay mechanism. The firing pin 57 abuts against a pin 79 extending from the toothed sector and thereby locks the sector against rotation. To set the fuze for instantaneous detonation the ogive 8 is rotated such that the bolt 42 moves into one of the two said recesses to free the shoulder 41, whilst the squared section 18 of the firing pin 15 is aligned with the slot 17. Upon firing, the rings 45 and 38 set back, and the elastic fingers 40 snap into a further groove 44 in the fuze carrier 32. The fingers are locked in this groove when the ring 45 is moved forwards again by a spring 46. A spring 35 also moves the primer carrier, and the plunger 55 locked therein, forwards to a position in which the fuze 34 is adjacent the firing pin 15. The firing pin 57 simultaneously moves out of engagement with the toothed sector pin 79. The toothed sector consequently rotates under the delaying action of the clockwork mechanism to a position where the bolt 74 is disengaged and moves out of its locking position by means of a spring 70. The member 64 then rotates to align the second percussion with the striker 57 and charges 5 and 6. At the moment of impact, the firing pin 15 is driven into the fuze 34 and the flames travel along a passage 58 to detonate the second fuze and thereby the charges 5 and 6. To set the fuze for delayed detonation on impact the ogive is rotated such that the bolt 42 moves into the other of said two recesses and the squared section 18 of the firing pin 15 lies transversely across the slot 17. Upon firing, the fuze follows the same sequence of events as previously. However, upon impact, the firing pin 15 is prevented from penetrating the fuze 34 by its squared section 18. Instead the plunger 55 is thrown forwards and pushes the locking balls 60 into the surrounding recess 63, whereupon a spring 56 drives the firing pin 57 into the second percussion fuze with delay.