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:
Feb. 26, 1991
Filed:
Nov. 15, 1988
Applicant:
Inventor:
Noriaki Hishida, Kyoto, JP;
Assignee:
Nippon Densan Corporation, Kyoto, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360 9908 ; 360 9807 ; 310 90 ;
Abstract
A spindle motor used for example to drive magnetic discs comprises a central shaft and a cylindrical member rotatable relative to the central shaft through a pair of bearings. A small annular clearance is formed between the central shaft and the cylindrical member to communicate with an interior space adjoining one of the bearings. A helical groove is provided at the annular clearance and serves to force any fluid, such as grease vapor, into the interior space.