| 摘要 |
<p>Disclosed is an embodiment of an electro-mechanical shifter (80) for use with hydraulic transmission (62) of the type having first and second valve means (C, D) that in the same and opposite open and closed conditions provide at least one range of gear ratios for driving an output member (64) such as a motor vehicle drive shaft (64). Shifter (80) is provided with a control arm (9) positionable along a frame (10) to a plurality of gear positions at which sensors (30) provide a triggering signal to respective gates (46, 48) in a manner that gates (46, 48) provide an output signal to respective actuating circuit means (49, 50) which provide respective actuating signals to respective actuator means (A, B) for actuating valves (C, D) according to the particular position of control arm (9). Control arm (9) further preferably carries a first pin (11) operative to rotate a cam (12) to actuate a universal gear to provide a second range of gear ratios and further preferably carries a second pin (24) operated by an actuator (32) which extends into an arcuate cam opening (22) in frame (10) having spaced-apart stops along its upper and lower edges operative to enable arm (9) to move between gear positions within each range of gear ratios as long as the clutch is engaged and prevent arm (9) from being moved from the highest gear ratio of the first range of gear ratios beyond the lowest gear ratio of the second range of gear ratios and from the lowest gear ratio of the second range of gear ratios to a gear ratio lower than the highest gear ratio to the first range of gear ratios upon disengagement of the clutch which in turn, may preferably be overridden by the operator pressing a button (40) in arm (9) causing pin (24) to move to an intermediate position within cam opening (22).</p> |
