Lock-up clutch control device for a multi-speed automatic transmission
US4697474A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 31, 1986 |
| Grant date | Oct 6, 1987 |
| Priority date | — |
| Expiry date | Mar 31, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/908
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A lock-up clutch control device for an automatic transmission having a torque converter with a lock-up clutch and a speed changing gear mechanism including a sub-transmission unit and a main transmission unit. The device has a lock-up operation device for producing a control signal when the sub-transmission unit is in the higher speed mode or when the main transmission unit selects 2nd or a higher speed gear. The control signal is delivered to a lock-up relay valve which operates effectively while it receives the control signal. Therefore, the torque converter can be locked up at 2nd or higher speeds of the automatic transmission which, because of various combinations of the states of the sub-transmission and main transmission units, outputs multiple speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.