Patent GB-557964-A (GB)
Title: Improvements in or relating to fuze setting apparatus for shells
IPC: F42C17/00
Filed: 1939-03-23
Abstract: 557,964. Setting projectile fuzes. HARVEY, V. P., and MOLINS MACHINE CO., Ltd. March 23, 1939, No. 9159. [Class 9 (i)] Fuze-setting apparatus of the kind in which rotary members or holders are adapted to engage with the fuze-rings of the projectile comprises a differential gear and driving means operative to drive one sun gear of the differential, the other sun gear being arranged to drive only. one holder, the other holder being driven in the opposite direction by rotation of the planet carrier of the differential operating through a train of gears. The casing 1 has a detachable part 3 carrying a roller 4 serving to support the projectile 7. In operative position, the fuze rings 21, 23 of the shell lie within setting rings or holders 20, 22 having pawls adapted to engage notches in the fuze rings. The nose of the shell displaces a slidable member 8 against the action of a spring 10 and later against the action of a dashpot 15 and spring 16, both connected to a locking lever 11 adapted to be moved by a collar 14 on the member 8. The ring 20 is secued to a sleeve 9 mounted on the member 8 and the ring 22 is secured to a member 24 rotatably mounted on the sleeve 9. The operating lever 60 (not shown) is secured to a toothed quadrant 30 which drives the shaft of a split gear wheel 32 meshing with a sleeve member 34 rotatably mounted on the sleeve 9 and forming at one end a bevel gear 35 constituting one sung gear of a differential. The other sun gear 36 is fixed to the sleeve 9 and setting ring 20. A planet gear 37 meshing with the gears 35 and 36 is carried by a rotatable gear 39 meshing with a gear 40 mounted on a counter-shaft 41. Another gear 42 on the countershaft meshes with gear teeth 43 formed on the member 24 carrying the ring 22. On operating the lever 60, the ring 20 will be rotated through the gears 35, 37 and 36 until its pawls engage within the notch in the fuze ring 21. The increased resistance to motion (whether the ring 21 be fixed or movable) will then cause the gear 37 to move orbitally and drive the ring 22 through the gears 39, 40, 42 and 43. The apparatus is so adjusted that the rings 20 and 22 rotate in opposite directions and through a total angle of just over 720 degrees relatively to each other, thus ensuring that both rings engage their respective notches. At the end of this movement the apparatus is locked by means of a stop 69 on the gear wheel 32 riding over a spring pressed stop 62 and into engagement with a fixed stop.68. On removing the shell, the stop 62 is withdrawn by the lever 11 and the operating lever 60 may be moved back to its starting position. The final relative angular positions between the pawls of the rings 20, 22 are adjusted by means of a hand wheel 50 on a spindle 490 carrying a bevel gear 49 which drives through a gear 48, a shaft 53 having a worm 47 meshing with a gear ring 46 forming part of a rotary casing including the countershaft 41. This casing is mounted on ball bearings 27 and 45 to rotate about the axis of the sun gears 35, 36. The hand wheel also operates through a worm 52 a followthe-pointer needle in the receiver 57 of the predictor. Each of the rings 20, 22 has pawls designed to engage only the notches of a fixed or a movable ring and if a change from setting powder fuzes to setting clockwork type fuzes is to be made, the pointer 3 of the casing is removed and the rings 20, 22 are changed. In a modified form, each setting ring may have two sets of axially disposed pawls, one for engaging a fixed and the other a movable ring. An additional bevel gear 480 (not shown) mounted with the gear 48 on a sliding sleeve allows the shaft 53 to be rotated in opposite directions by the hand-wheel according to which type of fuze is being set. In order to prevent backlash between the gear 49 and the gear 48 (or 480, not shown), slight axial adjustment of the shaft 53 is provided by means of a member 493 which is in screw threaded engagement with a bush 491 and which has an internal flange 494 engaging a shoulder 495 on the spindle 490.