Hydraulic control system for automatic transmission
US6846259B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 9, 2003 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Jun 11, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/1264
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control system for an automatic transmission includes a 3-4 shift valve that outputs a source pressure through a first path for shift speeds lower than a fourth shift speed established by directly connecting an input shaft with an output shaft of the automatic transmission, i.e., third shift speed. The hydraulic control system further includes a clutch apply control valve that outputs a source pressure through a second path at a shift speed higher than the fourth shift speed, i.e., fifth speed. The 3-4 shift valve and the clutch apply control valve serve to interrupt supply of the source pressure through the first path and the second path, respectively, in the fourth speed or the lock-up stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.