Patent · US Expired

Automatic transmission line pressure control system

US5159856A · kind A · utility

10Cited by
9References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 24, 1991
Grant dateNov 3, 1992
Priority date
Expiry dateSep 24, 2011

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H2061/0255
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

An automatic transmission line pressure control system controls line pressure in an automatic transmission equipped with a torque convertor for hydraulically coupling and uncoupling friction coupling elements of the automatic transmission. The automatic transmission line pressure control system regulates line pressure for selectively coupling and uncoupling the friction coupling elements so as to shift the automatic transmission into desired speed gears. The line pressure is forcibly dropped to a level lower than a level present before an occurrence of a manual shift-down operation when a shift-down sensor detects the occurrence of a manual shift-down. The line pressure is then raised as a speed sensor detects an increase in rotational speed transmitted the automatic transmission, thereby shifting the automatic transmission into desired speed gears.

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