Process and apparatus for realizing safe start-up shifting and energy saving idling of motor vehicles provided with automatic transmissions
US4891758A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1988 |
| Grant date | Jan 2, 1990 |
| Priority date | — |
| Expiry date | Jan 21, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2312/02
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control system for an automatic transmission, which prevents start-up shifting unless safe conditions exist. Sensors detect engine speed, vehicle speed, shift selection, and throttle position. For start-up shifting to be enabled, engine speed must be at idle, vehicle speed near zero, a start-gear selected, and the throttle initially at rest. Thereafter, displacement of the throttle from its rest position enables a shift command to be forwarded to the transmission to effectuate the shift selection. In a further embodiment, start-up shifting with the vehicle in motion is enabled, provided the direction of motion is consistent with the start-up gear selection. When the throttle is released, with the vehicle in motion, the transmission shift control is disabled, shifting the transmission into "neutral", when vehicle speed drops below a predetermined level, allowing the vehicle to free wheel, without being dragged forward by the idling engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.