摘要 |
To permit placing an electrical-hydraulical controlled automatic transmission, selectively, in reverse or neutral position upon failure of the control or command system, a spool valve is interposed between a fluid pressure pump and the control unit, the spool valve having three positions in which it can be placed manually; one of the positions is its normal operating position in which the valve provides a straight fluid path for pressurized fluid from the pump to the control unit; the other two positions are operable under emergency conditions, a second position providing a connection directly from the valve to the hydraulic servo units associated with control of the reverse gear, and the third interrupting suppply of hydraulic fluid from the pump to the control unit so that the control unit will, effectively, be placed in neutral position.
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