The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 1981
Filed:
Sep. 07, 1979
Eckard Schuttenberg, Stuttgart, DE;
Manfred Hauser, Schwieberdingen, DE;
Winfried Hommen, Schwieberdingen, DE;
Klaus Sopha, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
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.