GB653280A - Variable-speed friction gearing - Google Patents

Abstract

653,280. Variable-speed gearing. SOC. ALGOL. Jan. 13, 1948, Nos. 992 and 993. Convention dates, Jan. 15, 1947, and Dec. 4, 1947. [Class 80(ii)] In a variable-speed friction gearing having input friction rings 55 and output friction discs 58, one or more intermediate friction elements 81 are provided, each having a series of slidable driving rings 57. a series of slidable driven discs 56 and means for varying simultaneously and to the same extent the contact points on both rings and discs of co-acting discs and rings. As shown in Fig. 2, five intermediate elements 81 are employed, the odd-numbered elements 81 being rotatably mounted on turnable eccentrics 85<SP>1</SP>, Fig. 3, and the even-numbered elements 81 being rotatably mounted on full-profile portions 84<SP>1</SP> of a fixed supporting shaft 87 cut away at 85<SP>11</SP> to clear the eccentrics 85<SP>1</SP>. A shaft 89 on which the eccentrics 85<SP>1</SP> are fast is turned from a handwheel (not shown) by a worm and quadrant 93, 92 to effect the required contact point variation and thus change the gear ratio. The gearing is connected to off-set input and output shafts 99, 100 by toothed pinion pairs. The Specification as open to inspection under Sect. 91 comprises also friction gearings of the kind in which one or more internal or external cone surfaces 4, Fig. 1 (Cancelled) are moved eccentrically to co-acting complementary surfaces as by pivoting the axes of the surfaces 4 about a shaft 8 to which they are drivingly connected by gears 6, 7. Series arrangements of two such gearings may be employed having an intermediate member which is movable eccentrically to vary the gear ratio in both gearings and which may be in the form of an annulus encircling the other gearing members. A gearing is described in which a single annular disc is coned on its inner and outer peripheries to co-act with complementarily coned driving and driven members, and is movable eccentrically to vary the gear ratio. Fig. 6 (Cancelled) shows a gearing arrangement in which contact pressure between multiple bi-conical friction members 14, 16 is supplied by a spring 21. Alternatively, to avoid sliding spline connections, coned friction members may consist of resilient halves 28, Fig. 7 (Cancelled) rotatively connected by pins 30 and having elastic elements 31 between them. The elements 31 may be replaced by springs nested about the pins 30. Known centrifugal means may be employed to give speed-responsive contact pressure between friction elements. Alternatively, camming balls, screw threads or analogous means may be used to provide torque-responsive contact pressure, initial pressure being supplied by a spring or by electrical or pneumatic means. Fig. 10 (Cancelled), shows balls 50 acting between camming pockets 51. in a sliding sleeve 52 carrying coned discs, and similar pockets 49 on a collar 48 which may be directly connected to a supporting shaft 33 or, as shown, slidably splined thereto and re-acting thereon through a Belleville washer 54. The axial movement of the collar 48 may be arranged to operate an electrical device to cut off the power supply to the gearing. In Fig. 18 (Cancelled), friction gearing is combined with epicyclic gearing, a planet carrier 112 being variably driven from an input shaft 101 through a gear pair 103, 105 and co-acting discs and rings 108, 110, and carrying stepped planets 115 meshing respectively an output sun 116 and an annulus 118 driven from the input shaft 101 by a gear pair 104, 119. The discs 108 and gear 105 are mounted on an arm 123 pivoted about the shaft 101 by a worm drive 121, 122 to effect changes in the gear ratio. This subject-matter does not appear in the Specification as accepted.