Patent GB-429768-A (GB)
Title: Improvements in and connected with change speed gears
IPC: F16H61/02
Filed: 1933-12-06
Abstract: 429,768. Variable - speed gearing. CLAYTON, A. C., 64, Church Road, Willesden, London. Dec. 6, 1933, Nos. 34355 /33 and 20627/34. [Class 80 (ii)] [See also Group XXXIV] Reaction elements, such as annuli 10, 11, or a planet-carrier 6, of an epicyclic variable-speed gear, are arrested against rotation in either or only one direction, by roller or ball detents 44, 65, carried in cages 46, 64, which are turned preselectively to move the rollers into or out of operative relation with respect to stationary wedging surfaces 45, 67. A clutch-dog 18 also takes part in the control of the speed gear, and a vehicle clutch-pedal renders operative the preselected speed. The fourspeed and reverse gear is similar to that described in Specification 412,757, comprising an input sun-wheel 3 on a driving shaft 2, and an output member 20 which can be clutched by the dog 18 to either or both an output sun-wheel 8 and a planet-carrier 6. Planetwheels 4, 9 are secured to spindles 5, the wheels 9 meshing, through idlers 12, with the annulus 11. The cage 64, Fig. 5, for controlling the oppositely-acting detent-rollers 65, 66 of the annulus 11 has three positions corresponding to neutral, clockwise and anticlockwise arrest of the annulus for neutral, second speed and reverse. Blade or coil springs 68 hold the rollers off the annulus in neutral. The annulus 10 is arrested only in one direction, for first and third speeds, and has single roller detents in a cage 46 which has a single locking and a neutral position only. Depression of the vehicle clutch-pedal rocks a shaft 21, which acts through an arm 30, Fig. 4, to rock a shaft 36, having fingers 74, Fig. 5, which turn both cages 46, 64 in a clockwise direction against tension-springs 69. The extent of the anticlockwise return movement, on release of the clutch - pedal, is determined by engagement of a threetoothed ratchet 78 secured to the cage 64, and a two-toothed ratchet on the cage 46, respectively with pawls 70, 53, preselectively positioned by turning a cam-shaft 35 which stresses a pair of spring-arms 75 on each pawl. At the same time, depression of the clutch-pedal acts through an arm 29 to rock the loosely-mounted clutch-dog fork 22 in an anticlockwise direction, the extent of the return movement of the fork, under spring- tension 27 on release of the clutch-pedal, being determined by engagement of a threetoothed ratchet, turning with the fork, with a pawl 31 positioned by a cam 40 on the preselector shaft 35, such cam stressing spring- loaded arms 37, pivoted on the pawl 31. The rocking pawls 31, 53, 70 are freely carried on a shaft 36, parallel to the preselector shaft 35, which latter is turned through screwgearing 34 by a hand-controlled shaft 32. To facilitate change, the driving shaft 2 is connected to the planet-carrier 6 by a friction clutch 80, which is disengaged automatically when the main clutch is engaged. In a modification, Figs. 9-14, not shown, the ratchettoothed members such as 78, Fig; 5, are not attached to the cages, but are formed as toothed segments gearing therewith. Three such ratchet-elements are directly mounted, with lost-motion, on a shaft rocked by the main-clutch control, and operate on doubleroller cages controlling both the annuli and the planet carrier.