GB482493A - Control means for toric race transmissions - Google Patents

Abstract

482,493. Variable - speed friction gearing. GENERAL MOTORS CORPORATION. Aug 6, 1937, No. 21708. Convention date, Aug 6, 1936. [Class 80 (ii)] Relates to toric race frictional gearing with rollers 20 operating by precession in forked carriers 22 each moored at one end on a swivelling anchoring pivot 24, Fig. 2, and comprises a three-armed control lever 50, Fig. 1, in line with the roller axis. Each roller engages driving and driven races 10,12, and is integral with an arbor 26 which turns and slides in bushes 28, 28a pinned to the two limbs of the carrier 22. Precession to change-speed is initiated by sliding the carrier axially upon the arbor 26, which has the effect of tilting the roller about an axis joining its two friction, contact points. To this end, the arms 52, 56, 54 of the lever 50 are connected respectively to the carrier 22, to the arbor 26, and to a sliding central control sleeve 64. The arm 52 is pivoted to the enlarged or piston end 44 of a control pin 42 which passes through the arbor 26 and is connected at 40 with the outer carrier limb so as to push and pull the carrier while the roller and pin rotate. The piston end 44 damps vibration at 32. The second lever arm 56 engages at 58 over a control flange 34 rigid with the inner end of the arbor 26. Axial displacement of the sleeve 64 rocks the lever 50 and this effects an axial displacement of the carrier upon the arbor 26 and the roller 20 so starting the spiralling of the roller on the discs, which terminates when the arbor 26 has come again into line with the lever arm 54, " restoration " thus being automatic. The control sleeve 64 may be actuated by a manual lever 66, Fig. 3. The control lever 50 and pin 42 are prevented from rotating with the flange 34 by a stop 74, Fig. 1, on the carrier. If the direction of rotation of the driving-disc 10 is reversed, the lever 50 turns back with the reversed roller until the lever is stopped by another stop 74a, after which the control acts as before. In the arrangement so far described, there is a separate control lever 50 for each roller. There is described with reference to Figs 7 and 8 (not shown) an arrangement in which the control is applied to the outer end of a single master roller, the inner end of the central control pin of which moves a secondary control sleeve sliding on the central shaft and operating the remaining rollers as does the sleeve 64, Figs. 1 and 3. The invention may be applied to transmissions in which two sets of rollers and races operate in parallel.