Electronic transmission control and method therefor
US4208925A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1977 |
| Grant date | Jun 24, 1980 |
| Priority date | — |
| Expiry date | Aug 11, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/1926
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control for the automatic shifting of a multi-ratio power transmission. A memory is provided and programmed with the optimum vehicle speed shift points for upshift and downshift from each gear of the automatic range. The actual speed of the vehicle is periodically sampled, and each time it is, such speed is compared with the shift points for the gear which the transmission is in to see if a shift from such gear should be made. If it is determined from the speed sample that an upshift should be made, then the upshift speed points of higher gears are examined with reference to such speed sample to find the gear to which the transmission should be upshifted, i.e., the gear just above the highest gear having an upshift speed point which is less than the sampled speed. Having found such gear, the transmission is shifted thereto. Correspondingly, if it is determined from the speed sample that a downshift should be made (or can be made, in the event of a forced downshift condition), the downshift speed points of lower gears are examined with reference to such speed to find the gear to which a downshift should be made, i.e., the gear just below the lowest gear having a downshift speed po…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.