GB196005A - Improvements in epicyclic gearing - Google Patents

Abstract

196,005. Davidson, A. J. Oct. 18, 1921. Variable-speed and reversing gearing suitable for motor vehicles comprises a spur epicyclic train 10, 11, 13, Figs. 1 and 2, the outer member 13 being controlled by friction rollers 8 movable through the effort of the engine by a pedal 90, Figs. 10 and 12. When the gear is disengaged while a car is running, the rollers 8 are moved automatically to their anticipated positions so as re-engage without shock. The engine shaft 1, Figs. 1 and 2, carries a spider 9 supporting the planet gears 11 and also a bevel-gear 3 continuously driving the shafts 5 upon which the rollers 8 are splined. The sun gear 10 is secured to the driven shaft 2. A spring plunger 24 normally holds a lever 18 to the right so as to press a disc face on the outer gear 13 into engagment with the rollers 8. In the outer extreme position of the rollers 8, the epicyclic train turns solid. As the rollers 8 are moved inwards, the gear 10 slows, comes to rest, and is driven reversely. 'Collars 26 upon the rollers 8 are rigidly connected to nuts 49, Figs. 3 and 5, upon a screw rod 47 which is turned in one direction or the other to gear up or down by tilting the pedal 90 down by toe or heel respectively. For this purpose worm gearing 27, 29, Fig. 2, is continuously driving through gearing 30, 31, Fig. 3, clutch members 32 loose upon the rod 47. The opposite rotations of the rod 47 are effected by engaging clutches 35 alternatively. The clutches 35 are discs thrust forward through springs 38 by levers 36. The pedal 90 acts through a lever 46 to turn a cam 45 and so displace a rod 39 as to operate one of the levers 36. When the nuts 49 have been moved by power to extreme position, a snug 51 acts to break a spring toggle 41 and stop the shifting action. Disengagement is effected by a cam 74, Fig. 1, and the synchronizing movement imparted to the rollers 8 is brought about by the differential movement of the freed disc 13 and a loose disc 62 spring-pressed against the rollers. The discs 13, 62 have wormed edges meshing with wheels 61, 70, Fig. 3, respectively. The wheel 61 is contantly connected by gearing 59 to one side member 56, of a differential train. The middle member 55, Fig. 5, of the train is secured to the screw rod 47. The other side member 57 is connected by gearing 65 to a loose clutch member 68 upon the spindle of the wheel 70. A flange 15 on the disc 13 is connected by a lever 71 to a coacting clutch 69 so that the disconnecting movement of the disc 13 connects the clutch 68, 69 so that the train 56, 55, 57 becomes operative to drive the rod 47 and shift the rollers. The pedal 90, Figs. 10 and 12, is normally held to one side by a spring 92 so as to lie over a fixed guide bracket 93. To start the drive, the pedal is turned to parallel position and depressed to the position of Fig. 10. By tilting the perlal about a pivot 99, the speed changes are effected as described.