Patent · US Expired

Electrohydraulic directional control valve system

US4266572A · kind A · utility

19Cited by

3References

5Claims

0Family size

Assignee

Robert Bosch GmbH · DE

Inventors

Eckard Schuttenberg · Stuttgart, DE
Manfred Hauser · Schwieberdingen, DE
Winfried Hommen · Ebersberg, DE
Klaus Sopha

Key dates

Filing date	Sep 7, 1979
Grant date	May 12, 1981
Priority date	—
Expiry date	Sep 7, 1999

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T137/86614
WIPO fieldMechanical elements
WIPO sectorMechanical engineering

Abstract

The electrohydraulic directional control valve system includes a preliminary directional control valve and a main control valve, the latter having a control spool which is normally brought into its neutral or blocking position by means of two springs arranged in pressure chambers at respective ends of the control spool. The preliminary control valve has a sliding spool which at one end is urged by a spring into an additional safety position in which the pressure chambers of the main control valve are interconnected and pressure relieved, and the intake of the pressure fluid is blocked. A single proportionally operating solenoid counteracts the spring at the other end of the control spool of the preliminary control valve.

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