Patent GB-744578-A (GB)
Title: A change speed transmission gearing assembly
IPC: B60K17/08
Filed: 1953-12-30
Abstract: 744,578. Chance-speed gear; claw clutches. TIMKEN DETROIT AXLE CO. Dec. 30, 1953 [Jan. 9, 1953], No. 36216/53. Class 80(2) A two-speed direct-reduced, no-neutral, planet gear in the drive to the pinion shaft 18 of a vehicle axle from an input shaft 22 carrying a ring-gear 42, is controlled by a facially-toothed clutch-detent collar 102 slidable on splines on a reaction sun 84 to clutch selectively a clutch member 88 on an output-mounted planetcarrier 56 for direct-drive, or a non-rotary detent ring 90 for reduced drive, the tooth characteristics being as follows. All the clutch teeth have inclined faces 108, Fig. 4 (as in Maybach's Specification 298,186 [Class 80(ii) ]) and the axial distance between the highest points of the tooth faces on opposite sides of the slidable collar 102 is greater than, that between the highest points of the teeth of the clutch and detent members 88, 90 in their normal position (Fig. 4), so that the teeth on both sides of the collar 102 ratchet over the clutchdetent teeth during shift, and either the clutch or detent member, shown as the latter 90, is mounted for limited axial movement, in opposition to a diaphragm spring 96 or coil springs, Fig. 9, not shown, from said normal position, defined by a snap-ring 100, to a rearward position which it occupies when engaged by the shiftable collar 102. The detent member 90 is freely splined or pin-mounted on the fixed casing. The clutch-collar 102 is actuated through a rod 160 by a selectively energized diaphragm 130 operating through an energystoring spring 162 which, in the initial stage of a shift, becomes compressed as movement of the shift-rod 160 is prevented by drive-torque on the clutch-teeth and by lock-pawls 180, which latter are released'at a later stage of the diaphragm movement. The diaphragm 130 is secured to a sleeve 136 connected to the shift-rod 160 through the double-acting spring 162, and also carrying spring fingers 182 which slide over and control the lock-pawls 180 as follows. To initiate downshift from the directdrive position shown, the operator moves a selector-valve 202 to its opposite setting, either electrically by full depression of the usual accelerator pedal 194, or through a cable by a separate control button. This communicates an engine-manifold conduit 208 with the left side of the diaphragm 130 to move the sleeve 136 immediately to its leftward limit determined by a stop 185. By engaging shoulders 170, Fig. 2, the pawls 180 hold back the shift-rod 160 until the spring fingers 182, moving with the diaphragm-sleeve 136, ride over the pawl faces 186 on to their opposite faces 188, thereby tilting the pawls 180 about their fixed pivots 178 to release rod-shoulders 170. Providing the drive-torque has been released by the operator temporarily releasing the accelerator-pedal, the spring 162 is now free to assert itself on the rod 160 to move the clutch sleeve 102 out of mesh with the planet carrier teeth 88, and confront its teeth 106 with those of the non- rotary detent member 90. The teeth then ratchet and reject mesh until synchronism is produced by the operator depressing the accelerator pedal, whereupon mesh is completed and the pawls 180 lock over shoulders 172 on the rod 160. Upshift is similar except that synchronism is produced by accelerator-release. The sun 84 is journalled on needles 86 only at the end remote from its gear end, which latter floats freely. U.S.A. Specification 2,044,660 also is referred to.