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:
Nov. 08, 1988
Filed:
Feb. 04, 1986
Karl Krieger, Wuppertal, DE;
Werner Reinelt, Bochum, DE;
Hermann Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Abstract
A pressure-control valve is connected to a working cylinder of an hydraulic, walking, mine roof support on one side of the piston in the cylinder. In its function as a pressure-limiting valve, it regulates the pressure in the working cylinder in dependence upon a predetermined pressure in a control conduit which is connected to the pressure chamber of a prop of the mine roof support. Through it a spring-loaded control piston of the pressure-control valve is hydraulically loaded so as to act on a spring-loaded valve closure member in the pressure-control valve. The control piston holds the valve-closure member in the closure position if the pressure in the control conduit exceeds the predetermined pressure. If the pressure in the control conduit drops off, the valve-closure member then regulates the pressure in the working cylinder to a comparatively low value.