Logic valving for a transmission control
US4827806A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1988 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Aug 11, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2306/00
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A transmission control has a plurality of solenoid controlled hydraulic valves that are selectively operable to control the establishment of various drive ratios in a six speed transmission. A logic valve, comprised of two spool valves and a solenoid, is disposed between the solenoid controlled hydraulic valves and some of the friction drives in the transmission which establish the various drive ratios. The logic valves are operable to establish the fourth ratio if an electrical malfunction occurs during operation in the fourth or fifth ratios, or to establish the fifth ratio if electrical malfunction occurs while operating in the sixth ratio, or to establish the third ratio if an electrical malfunction occurs while operating in the first, second or third forward speed ratios. In the alternative, the logic valves can be controlled to establish fourth ratio whenever an electrical malfunction occurs when the transmission is operating in the second through fifth ratios.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.