Gear arrangement and method for selecting gears of an automatic transmission
US6079288A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1999 |
| Grant date | Jun 27, 2000 |
| Priority date | — |
| Expiry date | Apr 1, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/19251
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A novel transmission is provided that has a first, second, third and fourth gear, wherein said second gear includes two alternate and selectable speed ratios. The primary speed ratio of the second gear is used during upshifts and downshifts of adjacent gears. The alternate speed ratio of the second gear is utilized exclusively during downshifts from non-adjacent gears and may also be utilized during a downshift from the third gear depending on certain conditions and parameters. The primary speed ratio is larger than the alternate speed ratio of the second gear to provide better acceleration characteristics of the transmission during upshifting. The smaller alternate speed ratio of the second gear can provide smoother downshifts because of the less abrupt speed ratio change from the higher gears. Also, a method for controlling the gear selection of an automatic transmission having a plurality of gears is provided, wherein one position includes two speed ratios.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.