Patent · US Expired

Hydraulic pressure-control device with parallel compression springs

US5069111A · kind A · utility

10Cited by

6References

5Claims

0Family size

Assignee

Zahnradfabrik Friedrichshafen AG · DE

Inventors

Alfons Loffler · Friedrichshafen, DE
Walter Marte · Ulisbach, CH
Peter Wiggermann · Tettnang, DE

Key dates

Filing date	Oct 3, 1989
Grant date	Dec 3, 1991
Priority date	—
Expiry date	Oct 3, 2009

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T137/7925
WIPO fieldMechanical elements
WIPO sectorMechanical engineering

Abstract

A hydraulic pressure-control device, specially for powershift transmissions of motor vehicles, comprises a fluid pump (1) and a main valve for regulating the pressure in at least one high-pressure consumer device (6), which is attached to a pressure pipe (3) between the fluid pump (1) and the main pressure valve. The main pressure valve is designed as pressure-relief valve. In the main pressure valve is integrated the operation of a second pressure-relief valve. Two different pressure limits can be adjusted in the pressure pipe (3) by a valve piston (21) through two compression springs (17, 18) connected in parallel of which one compression spring (18) is bound.

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