Patent · US Expired

Clutch stroke control metering valve for an automatic transmission

US4446759A · kind A · utility

13Cited by
11References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 2, 1981
Grant dateMay 8, 1984
Priority date
Expiry dateOct 2, 2001

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H2061/0466
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A control system for an automatic transmission having planetary gear elements that define several forward driving torque delivery paths that are established and disestablished upon engagement and release of friction clutches and brakes including a timing valve for controlling the timing of the ratio change from a high direct drive ratio to an intermediate underdrive ratio including a pair of friction clutches that are engageable to establish the high speed ratio torque delivery path and a reaction brake that is applied upon release of one of the friction clutches to establish an intermediate speed ratio torque delivery path, the timing valve being effective to delay application of the brake during the downshift interval thus effecting a smooth ratio transition.

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