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:
Sep. 06, 1988
Filed:
Jun. 06, 1986
Karl Krieger, deceased, late of Wuppertal, DE;
Werner Reinelt, Bochum, DE;
Hermann Hemschedit Maschinenfabrik GmbH & Co., Wuppertal, DE;
Abstract
The invention concerns apparatus for the determination of the length of stroke of a piston in a working cylinder, especially in a hydraulic, walking, mine-roof support. For this purpose a piston shaft is rotatably mounted in one end portion of the working cylinder and extends into a hollow cylindrical piston rod of the piston. Through a pin on the piston or piston rod which engages in a helical guide groove on the piston shaft, the latter is rotated during movements of the piston. The piston shaft is connected to a code plate provided with a pattern of holes and displaceable on rotation of the shaft between light-emitting elements on one side and light-detecting diodes on the other side. The combination of irradiated and darkened light-detecting diodes represents a digitally-detectable binary numeral sequence which corresponds to a specific piston position.