Hydraulic control appartus for automatic transmission
US5441459A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1993 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | Dec 28, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/0276
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control device for an automatic transmission including a first frictional engaging element for achieving a low-speed side position, a second frictional engaging element for achieving a position higher in speed than the low-speed side position, a third frictional engaging element for achieving a position even higher in speed than the high-speed side position, a regulator valve for regulating pressure from an oil pump to a predetermined pressure and reducing the predetermined pressure in response to supply of a pilot pressure, and a control valve for controlling the pressure from the regulator valve to a desired hydraulic pressure, for controlling hydraulic pressures to the plural frictional engaging elements. A change-over valve is provided for making the control valve in communication with one of the first frictional engaging element and the third frictional engaging element and supplying and discharging the pilot pressure to the regulator valve, so that the change-over valve is operated by hydraulic pressure supplied to the second frictional engaging element and takes a first position where the control valve communicates with the first frictional engaging element and b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.