Patent GB-268843-A (GB)
Title: Improvements in or relating to variable speed gearing
IPC: F16H3/78
Filed: 1925-11-03
Abstract: 268,843. Brown, W. S. F., and Maina, J. Nov. 3, 1925. Variable-speed epicyclic gearing ; controlling variable-speed gearing.-Relates to the variablespeed gear claimed in Specification 212,679, and consists in improvements in (1) the arrangement and mounting of the gear elements, (2) the clutch and brake control gear, and (3) the selection gear. (1) The casing is formed in two parts, a main casing 1 and a front cover 2, which may be a unitary structure with the engine casing. The braked control-shaft 32, which actuates the controlling-brake by axial movement imparted by a lever 49 interconncted with the main or engine clutch control (not shown), is located in the casing sump, the controlling-brake thrustblock 38 and direct-drive clutch operating-collar 46 having respectively ball-thrust bearings 39, 46'. The reversing-member 15 and the bolted-together halves 19, 20 of the planetary cage run respectively on ball bearings 15', 22 on the driving- shaft 3, which is supported in ball bearings 4, 4'. The planet pinions 8, 17, 13, which mesh respectively with pinions 5, 6, 7 on the shaft 3 and with teeth 23, 25, 24 on the part 20, a loose ring 26, and the part 19, are carried respectively on a member 10 on the intermediate shaft 11, the cage 19, 20, and the reversing-member 15 by roller bearings 9, 18, 14, constructed as described in Specification 240,518, [Class 12 (i), Bearings, &c.]. The drum 72 of the expanding-shoe service brake 73 is mounted on the shaft 11, and is secured to one part 83 of the spherical oilretaining housing 83, 84 of a universal joint 82 coupling the shaft 11 to the final driven shaft 81. A shaft 70, gear-driven from the shaft 11, operates an oil-pump and speedometer (not shown) on opposite, sides of the casing 1. (2) The direct-drive clutch comprises a male friction cone 43 slidable on the shaft 3 by an arm 47, Figs. 1 and 9, and a spring-pressed female cone 40 slidable on teeth 41 on an extension 16 of the member 15. A final positive drive is effected by engagement of the teeth 41 with internal teeth on the cone 43. The controlling- brake, which also includes frictional and positive elements, and is released slightly after and engaged slightly before the main or engine clutch (not shown), comprises a spring-pressed cone 36, splined on the shaft 32, and a stationary cone 34, internal teeth on which finally engage teeth 33 on the shaft. (3) The selective pinion 31 is shifted along the splined braked control-shaft 32, to engage the toothed crowns 28, 29, 30 for intermediate and low speeds and reverse respectively, by a fork 50 slidable on a rod 51. The fork 50 is actuated by an arm 52, Figs. 7 and 9, on a shaft 53, the direct-drive clutch lever 47 being operated from a sleeve 55 loose on the shaft 53. The angularly and laterally movable gear-lever 67 carries an arm 58 selectively engageable with forks 56, 57 on the parts 53, 55. The forks 56, 57 are, extended to carry rollers or form cams 60, 61, Fig. 2, making constant contact with a cam or group of staggered cams 62, 63 on a "preventer" shaft 64, one revolution of which in either direction permits the complete range of successive speed changes. The shaft 64 is rotated through bevel gears 64a, preferably by a hand-lever on the vehicle steering-wheel. In a modification, the reverse is independently controlled, the three speeds governed by the " preventer " shaft then corresponding to three equiangular positions of the steering-wheel lever, so that any speed-ratio may be selected without passing through an intermediate ratio.