Back-up device for an electronic control system of an automatic transmission
US4628772A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1985 |
| Grant date | Dec 16, 1986 |
| Priority date | — |
| Expiry date | Sep 13, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/907
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A back-up device for an electronic control system of an automatic transmission in an automotive vehicle, of the type including at least first and second frictionally engaging elements hydraulically actuable, respectively, for establishing a first speed ratio for lower speed running of the vehicle and a second speed ratio for higher speed running of same, selector valves adapted to selectively assume first and second positions, respectively, for connecting the first and second frictionally engaging elements to an operating fluid source, electromagnetic valves for driving the selector valves to select the first position or the second position, and an electronic control unit for selectively energizing and deenergizing the electromagnetic valves in accordance with a predetermined gear shifting manner responsive to electrical signals indicative of the vehicle speed and the engine output. The back-up device comprises a vehicle speed sensing device for generating an output signal having a value thereof increasing as the vehicle speed increases, and a control mechanism for causing the selector valves to assume the second position, irrespective of the operation of the electromagnetic valves…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.