摘要 |
A rotary power transmission having a series of up to five gear trains and two clutches alternately engagable to provide drive paths through the gear trains in series sequence has control means including a fluid pressure source and three solenoid-operated valves to direct source fluid to two spool valves which provide discrete fluid pressure signals for engagement of gear trains two at a time in progressively over-lapping pairs, the gear trains being for eventual drive according to clutch engagement. |