GB1234350A - - Google Patents

Abstract

1,234,350. Odometer drives. FORD MOTOR CO. Ltd. 30 Dec., 1969, No. 63209/69. Heading B7H. [Also in Division F2] A motor vehicle including an auxiliary gearbox 5 which is operable to disconnect the drive to the rear wheels and to connect the output from a change-speed transmission 1 to a power take-off shaft 15, e.g. for driving a vehiclemounted cement mixer, and an odometer 19 drivable from the transmission 1, is provided with an isolator device 23 (Fig. 2) in the drive line to the odometer whereby, when the drive is connected to the power take-off shaft, the odometer is disconnected from the transmission 1. The isolator device includes an input ring gear 31, an output shaft 35 and a planetary gearset comprising sun-gear 39 on shaft 35 and planet carrier 37 rotatable on shaft 35 and carrying planet gears 36 meshing with ring and sun-gears 31, 39. The sun-gear carries a clutch plate 4 fixed to shaft 35 and having a tab 45 interengageable with a tab 43 on the planet carrier, and is axially slidable on shaft 35 under the influence of a solenoid 49 which is actuable by a switch 51 adjacent control lever 17 of the auxiliary bear-box 5. In the position shown in Fig. 2, in which the drive is connected to the rear wheels, the odometer 19 is driven via shaft 35 of the isolator device since the clutch plate 41 and ring gear 31 are locked together by interengagement of the tabs 45, 43. When the auxiliary gear box is operated to connect the drive from transmission 1 to the power take-off shaft 15, solenoid 49 is energized and causes the clutch plate 41 and sun-gear 39 to move axially to the left (as in Fig. 2) whereby the tabs disengage and the sun-gear is held against rotation. As a result the shaft 35 does not receive any drive from the ring gear 31. Where the rear axle is a two-speed axle, change of ratio in the axle is compensated for in the drive line to the odometer by a device 53. This device (Fig. 4, not shown) is similar to the isolator device but differs in that: (a) the planet carrier is splined to the output shaft, and (b) the sun gear and clutch plate are rotatable on said shaft. Hence, while the output shaft will be driven in both axial positions of the sun-gear and clutch plate, the ratio of the drive input to output will differ at these positions since, in one instance, the sun gear is rotatable with the planet carrier due to interengagement of the tabs and, in the other instance the sun gear is locked against rotation due to energization of the solenoid, the latter being energized in dependence upon the rear axle ratio selected.