Control apparatus of an automatic transmission with a lock-up clutch
US4618038A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 1, 1984 |
| Grant date | Oct 21, 1986 |
| Priority date | — |
| Expiry date | Mar 1, 2004 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/143
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control apparatus in an automatic transmission includes first and second shift valves which are independently actuable to define four distinct states corresponding to four speed ranges of the transmission. In the first state, neither valve participates in achieving the first range. In the second state, only the first valve participates in achieving the second range. In the third state, only the second valve participates in achieving the third range. In the fourth state, both valves participate in locking a lock-up clutch by being fluidly interconnected by an interconnecting passage so as to define a signal pressure passage which conducts a signal pressure to a lock-up relay valve to implement a locking of the lock-up clutch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.