Patent · US Expired

Device for control of a hydraulically actuatable shifting element

US6905433B2 · kind B2 · utility

4Cited by

7References

15Claims

0Family size

Assignee

ZF FRIEDRICHSHAFEN AG · DE

Inventors

Thilo Schmidt · Meckenbeuren, DE
Georg Gierer · Kreßbronn, DE
Klaus Steinhauser · Kreßbronn, DE

Key dates

Filing date	Aug 25, 2003
Grant date	Jun 14, 2005
Priority date	—
Expiry date	Aug 25, 2023

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF16H2063/303
WIPO fieldMechanical elements
WIPO sectorMechanical engineering

Abstract

A device for control of a hydraulically actuatable shifting element of a motor vehicle transmission, having one clutch piston which defines, with a first surface, a hydraulically pressurizable piston space and, with a second surface of different size, a hydraulically pressurizable reset space and comprising a first clutch valve associated with the piston space, a second clutch valve associated with the reset space and a holding valve associated with the reset space. The valves can be moved according to a control pressure adjusted by a pressure adjuster, a change between a pressurization of the clutch piston on the piston space side and on the reset space, side being performed as a control function so that the clutch piston on its surface facing the reset space is pressurized in an unshifted state of the shifting element and is discharged in a shifted state of the shifting element.

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