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:
Feb. 25, 1986
Filed:
Feb. 27, 1984
Heinz D Hannes, Duren-Echtz, DE;
Josef Lothmann, Langerwehe, DE;
Ludwig Walther, Duren-Niederau, DE;
Zimmermann & Jansen GmbH, Duren, DE;
Abstract
An apparatus for the exact position feedback of a double-acting power piston in a hydraulic power cylinder subjected to extreme environmental conditions, especially high temperatures, comprising a double-acting detecting (measuring), or follower cylinder, having a volume corresponding to that of said power cylinder and including a detecting piston the position of which is sensed by an electrical detector, wherein a pair of working spaces of power and detecting cylinders are in fluid communication with each other via a connecting pipe, while the respective other working spaces are adapted to be connected to a (pressursized) fluid pump or a reservoir through a control valve. Pressure limiting switches are each positioned in said connecting pipe as well as in the fluid line extending between the power cylinder and the control valve, and both the power piston and detecting piston each include a valve-controlled acknowledgement passage by which fluid communication can be established between the two working spaces of the power and detecting cylinders.