Cut-back pressure control device for multi-speed automatic transmission
US4727774A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 31, 1986 |
| Grant date | Mar 1, 1988 |
| 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 cut-back pressure control device for a multi-speed automatic transmission includes a cut-back valve that has a spool which is controlled by both hydraulic pressure which changes in response to shifting of a sub-transmission unit between high-speed and low-speed modes and a hydraulic pressure which is established by the operation of the main transmission unit at 2nd or higher speeds. The spool is moved to a position where it interrupts the cut-back pressure when the main transmission unit selects the 1st speed while the sub-transmission unit is in the low-speed mode, whereas, when the sub-transmission unit is in the high-speed mode or when the main transmission unit selects the 2nd or a higher speed, the spool is held at a position at which it permits the supply of the cut-back pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.