Static forward and reverse engagement control system for a multiple ratio automatic transmission
US6007445A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1998 |
| Grant date | Dec 28, 1999 |
| Priority date | — |
| Expiry date | Feb 3, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2312/02
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control valve system for a multiple ratio automatic transmission having a reaction brake for forward drive and a reaction brake for reverse drive. A first clutch establishes a driving connection between an input gear element and a torque input shaft establishes a forward drive torque flow path when the forward drive brake is engaged. A second clutch connects a different torque input gear element of the transmission to the torque input member when the reverse reaction brake is applied. A pressurized valve circuit with three variable force solenoids, including one variable force solenoid, establishes a controlled circuit pressure, a second variable force solenoid is dedicated for reverse engagement control and a third variable force solenoid is dedicated for forward engagement control, whereby independent reverse engagement pressures and independent forward engagement pressures on the clutches and brakes, are established. A neutral idle characteristic conditions the clutches and the brakes for minimal threshold capacity, which effectively interrupts the torque delivery path through the transmission when the torque input shaft is driven at idle speeds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.