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:
Jan. 13, 2004
Filed:
Aug. 17, 2001
Noriaki Sekiya, Maebashi, JP;
Daisuke Maruyama, Maebashi, JP;
Toshiyuki Iehisa, Maebashi, JP;
Kazuo Miyaguchi, Maebashi, JP;
NSK Ltd., Tokyo, JP;
Abstract
A ball screw apparatus is provided with a screw shaft having a spiral ball screw groove, a nut member having a screw groove, and a plurality of balls. A smoothly continuous worked portion is formed at a portion of the screw groove by grinding a corner portion between the screw groove and a connecting way. The worked portion is formed such that the distance between the screw grooves is gradually reduced regarding an advancing direction of the ball entering from the connecting way in between the screw grooves. This worked portion extends from an end of the connecting way in a circumferential direction of the nut member and within a range of 90° from the corner portion along the circumferential direction of the nut member.