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:
Oct. 22, 1991
Filed:
Dec. 29, 1989
Werner Kuttruf, Scottweg, DE;
BW Hydraulik GmbH, Wuppertal, DE;
Abstract
An electrohydraulic control arrangement for controlling a hydraulic cylinder having a double-acting working piston. At least one control valve having a control slide unit that is spring-loaded at one end and can be shifted by a servomotor against the spring force is provided. A valve housing having at least one section is provided with at least one control valve for alliance with each of the pressure chambers of the hydraulic cylinder, with the control slide units of the control valves being spaced from one another and being coaxially disposed in a mirror symmetrical manner relative to one another. A common control element of the servomotor is disposed between the inner ends of the control slide units for moving the same in the same direction. Each control slide unit has a pressure chamber containing an auxiliary piston, with at least one switching valve connecting these pressure chambers with pressure medium for moving the control slide units inot an inactive position that avoids the effect of the control element. This inactive position, or 'not-stop-function', can be directly controlled from any switching position of the control slide units. In the inactive position, the servomotor can be moved into its neutral position and adjusted without thereby causing movements of the piston of the hydraulic cylinder.