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. 24, 1991
Filed:
Apr. 26, 1989
Applicant:
Inventor:
Masachi Hosoya, Kanagawa, JP;
Assignee:
Nippon Seiko Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360 9908 ; 360 9807 ; 360 9904 ; 277 80 ;
Abstract
A magnetic disc device. A seal member consisting of ring magnet and ring-shaped pole pieces is built in a shaft or housing to which disc is fixed. The inner end of the seal member is fixed to the shaft side, and the outer end forms, between the housing, a gap in which electroconductive magnetic fluid is kept. The contact areas of the electroconductive magnetic fluid with the pole pieces and the housing are made remarkedly large, so that not only grounding of the static electricity generated on the disc but also sealing of dust becomes effectual.