Patent GB-426136-A (GB)
Title: Continuously variable gears
IPC: F16H29/00
Filed: 1933-09-28
Abstract: 426,136. Variable - speed gearing. HEPPNER, F., 93, Genferstrasse, Reimickendorf, Berlin, and KANTOROWICZ, 0., 43, Oxford Terrace, Hyde Park, London. Sept. 28, 1933, Nos. 26761, 26762, 26763, and 26764. Convention dates, Dec. 19, 1932, July 17, 1933, Aug. 7, 1933, and Aug. 29, 1933. [Class 80 (ii)] Continuously - variable - speed gearing comprises friction-discs 8, Fig. 3, secured to toothed pinions 7, which mesh, directly or through planetary gearing, with a toothed wheel 4 on the driven (or driving) shaft 3, the friction-discs being brought, by movement in their own plane, into successive and temporary locking engagement with surfaces on the driving (or driven) member 10, whereby they are braked to impart drive through their pinions to the wheel 4. The torque to be transmitted supplies the friction pressure. In some forms, Figs. 3 to 13, speed-variation is obtained by relative eccentric displacement of the driving and driven shafts, whilst modifications, Figs. 14-22, use variable-throw cranks. In Figs. 3 and 4, the friction-discs 8 and their double pinions 7 are supported on a loose ring 13, and are guided by straight or arcuate slots 5, or by radius-links, on a plate 11 freely mounted on the driving-shaft 2. The friction-discs are braked over an arc alpha by spokes 9 of a driving-plate 10, so as to impart solid drive to the wheel 4 over this arc. The wheel 4 and its shaft 3 are eccentrically adjustable to vary the radius of action of driving-arc alpha. A spring 12 between the plates 10, 11 ensures contact between the friction-surfaces 8, 9, which latter have a wedging, single or multi-conical, or rounded engagement. In the form shown, in Figs. 12 and 13, the variable eccentricity between the shafts 2, 3 is not used to effect the successive brakings of the discs 8, but instead, the frictionspokes are replaced by levers 19 freely pivoted on the driving-disc 10 and carrying short, arcuate friction-surfaces 9 at their free ends, which are collectively maintained circular and at a fixed eccentricity to the discs 8, by sliding engagement of lateral extensions 20 thereof in an annular groove in the face of a disc 22 eccentrically mounted on the drivenshaft 3, or by means of a cam. The frictiondiscs 8 are mounted on radius-links 15, pivoted to the disc, and their pinions 7 are maintained in engagement with the driven-wheels 4 by an external ring 13. The eccentricity of the driven-shaft 3 is varied by swinging an arm 16 about a pin 17. A diagrammatic representation of a construction described with reference to Fig. 16 is shown in Fig. 15. A toothed wheel 33 is the driving-element and the friction-surfaces 9 are on a star-wheel 36. Each friction-disc 8 is mounted on a revoluble plate 24, secured to the driven shaft concentric with the driving-wheel 33, and its pinion 7 meshes with the wheel 33 through planetary gearing comprising a freely-mounted internally and externally toothed ring 26, 27, and a toothed pinion, freely carried on a bellcrank lever 28, pivoted on the disc-spindle and variably oscillated by a variable-throw crank 34, driven, through reversing-gearing, not shown, in the opposite direction to that of the driving-wheel 33. The star-wheel 36 is revolubly-mounted on an eccentric 35 rigidly secured to the rotating crank 34. The friction discs, as before, are successively braked, and the driving phase of the oscillating lever 28 drives the plate 24, and the star-wheel 36, at a greatly reduced, zero, or reversed speed, depending on the setting of the variable-throw crank 34. In a modification, Fig. 14, (not shown) the star-wheel is the driver and the crank-pin 34 is stationary. In Fig. 16 the spur-wheel 33 is driven from the driving-shaft 2, through a bevel reversing-gear 42, and drives each friction-disc through a bevel epicyclic gear 25. The variable-throw crank, which oscillates the planet-carriers 25, comprises a bush 41, slidable along an inclined crank 34 of the driving-shaft 2. The star-wheel 36 is eccentrically mounted on the driving shaft, and is drivingly connected to the aligned driven shaft 3 by a loose pin-coupling 47. The casing revolves freely about both shafts. The discs 8 may be arranged in more than one plane. The variable thrust on the crank-bush 41 may be balanced by counterweights moved along the crank-pin 34 by the bush 41. A simple known friction-gear is shown in Fig. 1 and comprises solid friction-blocks 6, guided in radial slots 5 in a driving-plate 1 and pressed outwardly into driving contact with a driven drum 4 only over a limited arc alpha. The driven drum is arranged at varying eccentricities, to vary the effective radius of the arc alpha and so its speed.