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:
Jan. 05, 1988
Filed:
Feb. 04, 1985
Wataru Ichikawa, Tokyo, JP;
Yuji Matsuki, Tokyo, JP;
Kabushiki Kaisha SG, Tokyo, JP;
Abstract
This detection device comprises a coil section and a rod section which is capable of linear displacement relative to the coil section. The rod section has a magnetic substance portion changing reluctance of a magnetic circuit passing through the coil section in accordance with the linear displacement and a conductive substance portion provided in part of the rod section where the reluctance is caused to increase relatively in such a manner that an eddy current path will be formed relative to flux. By this arrangement, in places where reluctance increases due to absence of the magnetic substance, reluctance is caused to further increase by the eddy current loss produced by presence of the conductive substance portion whereby the secondary side induced voltage level is further attenuated and the accuracy of detection can be improved. The rod section may be so constructed as to produce only the reluctance change due to the conductive substance portion. This detection device is applicable to detection of a piston rod position of a fluid powered cylinder.