Gear shift control in motor vehicles with automatic transmissions
US4422350A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1981 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Feb 18, 2001 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0258
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The time required for shifting gears from an old to a new gear and the jolt created by the shift is decreased by initiating a known overlap of disengagement of the friction elements of the old gear and engagement of the friction elements of the new gear at the time the hydraulic unit operating the friction elements of the new gear is completely filled. Since a voltage pulse occurs across the solenoid winding of the pressure regulator when the hydraulic unit is completely filled, the solenoid valve is monitored by a threshold circuit which responds to the pulse. The output of the threshold circuit sets a flipflop. The flipflop is reset in response to a gear shift initiation signal furnished by a microprocessor. The microprocessor samples the flipflop output to determine whether the hydraulic unit is completely filled and initiates the overlap portion of the gear shift when this is so.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.