GB1172982A - Improvements in or relating to a Change-Speed Gearing and to Associated Control Means. - Google Patents

Abstract

1,172,982. Variable-ratio gear and control. AUTO TRANSMISSIONS Ltd. 21 Nov., 1966 [12 Jan., 1966], No. 1363/66. Headings F2C and F2D. In a planetary change-speed gear, drive ratios are established by a synchronized positive clutch-sleeve 68 (Fig. 1), actuated by a snapaction toggle (Fig. 3). The under- or (as shown), over-drive epicyclic gear follows a main vehicle change-speed gear (not further described), and comprises a driving planet carrier 17, a driven annulus 24, and a reaction sun 25, the sun being alternatively clutched to the carrier 17 for one-to-one directdrive or locked to a stationary housing 14 by the synchronized engagement of the dog-clutch sleeve 68, axially slidable from a central neutral position, to clutch dog teeth 66, 64 on the carrier and housing respectively. The clutch-sleeve 68 is moved axially by a slide 94 freely mounted on a bar 91 and biased by springs 97, 98 into a central neutral position. Movement of the bar 91 compresses the respective spring 97, 98 to move slide 94 only when synchronization is achieved after torque reversal. A manual lever 102, Fig. 3, which moves bar 91, has a toggle connection at one end such that it is biased by by a spring 125 into either of two extreme positions either side of a neutral dead centre position, the biasing spring 125 being stronger than springs 97, 98. A shown, the sleeve 68 slides on a hub 69 splined on an extension of the sun 25, coned balk rings 73, 74 abutting a friction brake surface 63 and clutch surface 64 respectively, and three circumferentially spaced plates 76 are urged radially out of slots in the hub 69 by expander rings 80 to engage recesses 81 in the sleeve 68, the ends of the plates being received in recesses in the balk rings to provide a lost motion connection. Lubrication of the gear is by means of a ring 49 on the annulus which dips into the lubricant and feeds it to a scoop 51 from which it is fed to the splined connection between the carrier 17 and input shaft 13 via bores 52, 53, 55 and 56, the lubricant then flowing between the sun and input shaft, and also through a bush 58 to be centrifugally fed into the path of a catcher plate 60 which deflects it into three hollow pins 21 carrying the planets to lubricate the planet bearings. The rest of the gearing is splash lubricated. A splined connection between the output shaft 20 and propeller shaft 36 obviates the necessity of providing a separate telescopic coupling in the propeller shaft. In Fig. 4 (not shown), the gearing is entirely splash lubricated, and the hub 69 is formed integral with the sun gear. The sleeve 68 is formed with three longitudinal slots (134) into which project fingers (143) having balk shoulders (144, 145), Figs. 5-8 (not shown), and formed on synchronized detector rings ( 141 ), (142) carried by, and spring-biased into engagement with, to allow slipping, a pair of hubs (135), (136), in splined engagement with teeth 64, 66 respectively.