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:
Dec. 12, 1989
Filed:
Jul. 02, 1987
Katsuhiko Asano, Hitachi, JP;
Hiroshi Hashimoto, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The iron core of an electromagnet includes a stack of steel sheets stacked perpendicular to a horizontal axis, presents a sectional shape symmetrical with respect to the horizontal axis and is provided therein with a groove of a specified shape. The iron core is produced by stacking and integrating a desired number of steel sheets into a one-piece iron core and finally forming the specific shaped groove therein. Accordingly, no gaps are generated in the iron core and the density thereof becomes high even in the case of a sector iron core. Furthermore, the groove formation is conducted as a final step after the integration of the stacked steel sheets. Thus the heat during the welding operation for such an integration has no adverse effect on the groove in the iron core and the problem of lack of magnetic force is solved thereby.