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:
Aug. 06, 1991
Filed:
Oct. 30, 1990
Tatsuya Oue, Ako City, JP;
Yuji Shimada, Ako City, JP;
Abstract
An electromagnet having a magnetic shield, in which dummy holes generally equal in shape to a hole conventionally provided for a service port are formed in a pair of end plates of a magnetic shield. The holes formed in each of the end plates are in equal radial-direction positions and are arranged in the circumferential direction at equal angular intervals, and the positions of the holes formed on the two end plates are symmetric on the center point of the electromagnet and/or the plane containing the center point and perpendicular to the center axis. Portions of the end plates in the vicinity of the holes are increased in thickness to compensate for the loss of the magnetic material due to the formation of the holes.