| 摘要 |
A tractor transmission comprises a main change speed mechanism 11, a forward/reverse mechanism 13, a high/low change speed mechanism 14, an auxiliary change speed mechanism 15, a super-reduction change speed mechanism 16 and an overdrive mechanism 45. A single switching device 29 is shiftable, when the super-reduction mechanism 16 is in neutral, to operate either the super-reduction mechanism 16 or the overdrive mechanism 45. A separate shift lever 30 is used to select output of the change speed mechanisms 11, 14 and 15. Switching device 29 projects from and is restricted to move in a guide groove (35a, fig 13) for on-off- neutral selection of the super-reduction mechanism 16. A bridge region (35c) allows the device 29 to move perpendicular to the groove (35a) into another groove (35b) where on-off of the overdrive mechanism 45 may be selected. Sensor, eg a potentiometer (31, fig 8), detects the movement of the device 29 from groove (35a) to groove (35b). In another embodiment the device 29 also controls a speed stage of the change speed mechanism 11. |
