Patent GB-398933-A (GB)
Title: Improvements in automotive change-speed transmission gearing
IPC: F16H61/02
Filed: 1932-04-13
Abstract: 398,933. Variable-speed gearing. KELLER, R. E., 670, East Woodbridge Street, Detroit, Michigan, U.S.A. April 13, 1932, No. 10620. Convention date, April 13, 1931. [Class 80 (ii).] In change-speed gearing for motor vehicles, having a free-wheel clutch at each speedchanging stage, some of the clutches are controlled by governors interposed in the gearing and arranged to rotate the driven shaft at different speeds as the speed of the driving shaft increases, and means are provided for selectively altering the operating condition of the change-speed gear from one of selective manual control to one of automatic control by the governors. A gear 4, Fig. 1, on the driving-shaft 2 is constantly in mesh with a gear 10 on the countershaft 7 on which are also fixed gears 11, 12, 13. The gears 11, 12 are in constant mesh with gears 14, 15 loose on the driven shaft 5, and the gear 13 engages an idler for the reverse drive. Drums 27, 271 integral with the gears 15, 4 respectively form the outer members of clutches, the inner members of which are cores 28, 28<1>. For automatic operation of the variable speed gear, a rod 47 is moved forwardly by a single rearward movement to position A of the ordinary gear shifting lever from the neutral position N, Fig. 7, causing forks depending from it to move shift collars 26, 39 so that projections 31, 41 on the cores engage recesses 33, 42 in these collars. The collar 26 is slidably keyed on a sleeve 20 loose on the driven shaft 5, and the collar 39 is likewise keyed to a sleeve 37 which forms an extension of a shift collar 36, also slidably keyed to the driven shaft 5. Rollers 22 in wedge recesses in the gear 14 engage in ratchet manner the sleeve 20. Wedges 29, carrying rollers 71, Fig. 1a adapted to engage the inside of the drum 27, slide in recesses 70 in the core 28. The wedges are guided on the inclined lower surfaces of the recesses by tongues engaging grooves 74 in the recesses and are urged radially inwardly by springs 76. As the speed of the driven shaft increases, governor arms 81, Fig. 3, pivoted on the core 28 at 82 and urged by springs 85 towards the hub of the core, are urged outwardly by centrifugal force .over inner and outer inclined faces 79, 78 on the wedges, balls or rollers 88 on the arms 81 facilitating this action. Toothed quadrants on the arms 81 engage a toothed ring 89 loose on the core to ensure uniform operation of the governor arms. The outer inclined surfaces 78 act as a locking-device for the governor arms in such a way that the clutch 27, 28 does not engage until the governors 81 are between the surfaces 78 and the rear 77 of the core 28 and is kept in engagement during slight fluctuations of the normal speed. The clutch 27<1>, 28<1> is provided with similar wedges and governor arms. The rollers 71 rest in recesses 72 which are deeper at one side than the other. The clutches 27, 28 and 27<1>, 28<1> act as roller ratchet clutches and engagement is impossible until the rollers occupy the deeper parts of the recesses and the governor arms rest against the surfaces 78. The automatic low gear is brought in immediately by engagement of the gear 14 with the sleeve 20 which is keyed to the collar 26 in turn keyed to a collar 30, fixed on the driven shaft, by means of teeth 32. The speed of the driven shaft 5 increases and gradually approaches that of the constantly driven drum 27, the slight deceleration of which at this stage by the release of the accelerator causes a slight overrunning of the clutch member 28 and forces the governors over on to the outer surfaces 78. Thus the second gear is engaged and the clutch 20, 22 then overruns. As the speed increases further, the clutch 271, 28<1> is engaged in a similar manner, the clutch 27, 28 then overrunning. For positive manual control of the gears, a rod 48 carrying a fork is moved forwardly so that a gear 16 slidably fixed on the shaft 5 is moved by its integral collar into engagement with the gear 14 by means of projections 19 and recesses 24. The intermediate gear is brought in through gears 4, 10, 12, 15 and the shaft 5, when projections 34 on the gear 15 engage recesses in the collar 36, which is operated by a fork on the rod 46. The direct drive is obtained by the engagement of recesses 44 in gear 4 with projections 45 on the sleeve 37. The gear 16 is moved rearwardly to bring in the reverse drive. The rods 46, 47, 48 are moved in turn by the lower end of a universally mounted gear-shift lever and are looked in position by spring-pressed detents 49. The positions of the top of the gear lever for both manual and automatic control are shown in Fig. 7.