Hydraulic control system for automatic transmission
US5288279A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1992 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Sep 14, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/1268
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fail-safe hydraulic control system for an automatic transmission for a vehicle is provided. This fail-safe system includes generally a frictional element which is operable to establish a reverse mode in the transmission for allowing the vehicle to move backward, a manual valve responsive to shifting operation of a selector lever to a reverse position for directing fluid pressure from a pressure power source to a reverse position pressure line, a pressure control valve for modifying hydraulic pressure supplied from the pressure power source for providing a preselected pressure level required for actuating the frictional element, an automatic transmission control unit responsive to the selector lever shifting operation to the reverse position to provide a control signal to the pressure control valve for providing the preselected pressure level to the frictional element within a given period of time, and a pressure delay circuit for establishing fluid communication between the reverse position pressure line and the frictional element to provide the preselected pressure level to the frictional element after the given period of time following the selector shifting operation to the rev…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.