| 摘要 |
A transmission ratio selector mechanism for a transmission having two ratio selector couplers (6', 7') both of which must be engaged to provide drive through the transmission. The selector mechanism includes a selector shaft (16) which is rotatable about its longitudinal axis and also axially movable parallel to its longitudinal axis. Rotation of the selector shaft (16) is arranged to operate one (6') of the couplers via a mechanical linkage including a twin-armed member (45) and a pivoted lever (41) whilst axial movement of the shaft (16) operates the other coupler (7') via a fluid pressure-operated actuator (17) and an associated control valve mechanism (30, 40). An interlock (51, 52, 53, 54) is provided to ensure that the fluid pressure-operated coupler (7') is always engaged before the mechanically operated coupler (6'). |
