Patent · US Active

Device for the control at least of a hydraulically operable switching element of an automatic transmission

US7635057B2 · kind B2 · utility

4Cited by

6References

3Claims

0Family size

Assignee

ZF FRIEDRICHSHAFEN AG · DE

Inventors

Georg Gierer · Kreßbronn, DE
Thilo Schmidt · Meckenbeuren, DE
Markus Herrmann · Scheidegg, DE

Key dates

Filing date	Jun 12, 2006
Grant date	Dec 22, 2009
Priority date	—
Expiry date	Apr 20, 2027

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T74/19251
WIPO fieldMechanical elements
WIPO sectorMechanical engineering

Abstract

A device for controlling a hydraulically operable switching element (2) of an automatic transmission of a vehicle with a position valve mechanism (3) having a main switch piston (6) which is spring biased into a first switch position and a second switch position with a pilot pressure (P_MV) which is adjustable through an electrically operated actuator (5). An additional switch piston (7) and the main switch piston (6) are axially actuated in a valve housing (8). Depending on the position of the pistons (6, 7), faces (6A, 7A) of the respective pistons are either spaced apart or adjacent. The additional switch piston (7) is adjustable depending on a pilot pressure (p_K) of a switching element which engages a gear for forward drive.

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