Patent GB-944164-A (GB)
Title: Percussion fuze with or without delay mechanism for unrotated projectiles, more especially mortar bombs
Inventor: KAISER PAUL
IPC: F42C14/00
Filed: 1960-02-17
Abstract: 944,164. Ammunition fuzes. GEB. JUNGHANS A.G. Feb. 17, 1960, No. 5618/60. Heading F3A. A percussion fuze for unrotated projectiles has a body 10 in which an inner housing 12 is slidably mounted but thrust rearwardly against a detonator 16 by a spring 13. Extending through an axial bore of the housing 12, is a firing pin 18 having a head 19 and surrounded by a collar 20 adjacent the tip. Slidably mounted on the pin 18 is an inertia sleeve 21 supported by springs 24, 25 and extending into a brake sleeve 23 on which are rack teeth 22 meshing with a pinion 52, Fig. 2. During transport the sleeve 21 is secured by a ball 32 held in engagement with a groove 33 by a bolt 36 supported by a spring 37. The pin 18 is prevented from moving towards the detonator by a plate 39 abutting the collar 20 and sandwiched between plates 26, 40, all three plates being mounted on a pin 41. Beneath plate 40 is a rotatable member 46 housing in parallel bores a primer 44 and a delay 45, Fig. 6, the member 46 being held at safe by a finger 51 extending from the brake 23 through the plates 26, 40. Pinion 52 has fixed connection with a wheel 53 meshing with a pinion 54 on the arbor of which is fixed an escapement wheel 55 engaging an escapement pallet 56 from which depends a weight 58<SP>1</SP>. To set the fuze for instantaneous operation, a setting member 59<SP>1</SP> is turned until its screw-driver slot is parallel to the longitudinal axis of the fuze, a projection 61<SP>1</SP>, Figs. 1, 6, then moving into engagement with a recess 62<SP>1</SP> in the member 46. By rotation of member 59<SP>1</SP> through a further 90 degrees the projection 61<SP>1</SP> is moved out of the recess 62<SP>1</SP> and the fuze for delayed action. In the first position, the member 46, when released by finger 51, can rotate until the primer 44 is aligned with pin 18 and in the second position, the delay 45 is so aligned, a stop 64 being provided to arrest the member 46. Above the detonator is a closure disc 65 with a central flash hole 60. A second disc may be used where high firing pressures occur. Rotation of the housing 12 is prevented by a screw 70 projecting through the body 10 into a longitudinal groove in the housing 12. In a modification, Fig. 14, the ball 32 is replaced by a safety lever 72 having one end pressed into a groove in the sleeve 21 by a spring 75 and bearing against the bolt 36 at the other end. The bolt 36 in this construction has an enlarged head 77, and the sleeve 21 has an arm 79 extending through a cap 30. The detonator 80 is screwed into a mount 81, which slides into a ring 82 screwed into the body 10. On firing a projectile equipped with the fuze of Fig. 1, the bolt 36 sets back due to inertia and releases the ball 32, which escapes tnrough a hole in the cap 30. The sleeve 21, thus released, then sets back, compressing springs 24, 25, into the brake sleeve 23 and a spring 29 snaps into a groove 27 of sleeve 21. The two sleeves thus coupled are moved forwardly by spring 25 when deceleration starts, the forward motion being regulated through the rack mechanism by the escapement 55, 56. Finger 51 is thus withdrawn from the member 46, which is thrust by its spring 48 to the position corresponding to the setting. When sleeves 21, 23 have moved sufficiently to withdraw finger 51 from the plate 39, a spring 43 rotates the plate until the pin 18 is freed and completes the arming of the fuze, so that a blow on the diaphragm 68 closing the nose will operate the pin 18. If impact is oblique, the housing 12 is thrown forwardly with its contents and the primer 44 hits the pin 18. In the fuze of Fig. 14, the bolt 36 sets back as before and a frustoconical part 78 rocks the lever 72, so freeing the sleeve 21. Should the fuze be dropped in transit, the bolt 36 and sleeve 21 may set back due to inertia, but are moved forwardly again by their springs, the arm 79 being a guide for the return motion which prevents the lever 72 rotating.