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. 03, 2004
Filed:
Nov. 06, 2001
Applicant:
Inventor:
Toshiharu Kajita, Kanagawa, JP;
Assignee:
NSK Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16C 2/906 ;
U.S. Cl.
CPC ...
F16C 2/906 ;
Abstract
A super finishing is carried out after grinding, so that surface roughness of a ball rolling groove of a screw shaft is made 0.12 &mgr;m or less in an average roughness (Ra). Separators having ball holding surfaces shaped in concave surface are disposed between balls respectively.