Patent · US Expired

Forward clutch and lockup clutch control in an automatic transmission control system

US5725455A · kind A · utility

9Cited by
7References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 30, 1996
Grant dateMar 10, 1998
Priority date
Expiry dateJan 30, 2016

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T74/19163
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A hydraulic control system for an automatic transmission having at least a forward clutch which is unlocked in a fourth gear and locked in other forward gears and a lock-up clutch for coupling input and output elements of a torque converter together is equipped with a pressure control valve for controlling operating pressure for the forward clutch, a lock-up control valve for connecting and disconnecting the first valve from the lock-up clutch, a pressure line through which control source pressure is introduced into the forward clutch while the first valve is in communication with the lock-up clutch, and a shift valve for discharging the control source pressure from the pressure line.

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