Patent · US Expired

Method and apparatus for controlling manual downshifting in an automatic transmission

US5305657A · kind A · utility

8Cited by
11References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 11, 1992
Grant dateApr 26, 1994
Priority date
Expiry dateMay 11, 2012

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T74/1926
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

An apparatus is provided for use in a vehicle having an engine driven transmission which includes a plurality of gear ratios. The apparatus includes a sensor adapted to sense a parameter indicative of vehicle speed and responsively produce a vehicle speed signal. A downshift switch is provided to controllably produce a downshift signal. An engine speed sensor senses engine speed and responsively produces an engine speed signal. A controller is adapted to receive the vehicle speed, engine speed, and downshift signals, process the vehicle speed signal to produce a transmission control signal, produce a down shift enable value as a function of the engine speed signal, and modify the transmission control signal to correspond to a lower gear ratio in all but the lowest gear ratio when the downshift signal is received and a value responsive to the vehicle speed signal is less than the down shift enable value signal. An actuator is adapted to receive the transmission control signal and responsively control the transmission gear ratio.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.