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:
Nov. 09, 2004
Filed:
Oct. 30, 2002
Kazuo Miyaguchi, Maebashi, JP;
Tsutomu Ohkubo, Maebashi, JP;
Takeshi Nakazawa, Maebashi, JP;
Shirouji Yabe, Maebashi, JP;
Soichiro Kato, Maebashi, JP;
Nobumitsu Takahashi, Maebashi, JP;
Ryouichi Sato, Maebashi, JP;
Hiroki Yamaguchi, Maebashi, JP;
Yoshinori Mizumura, Maebashi, JP;
NSK Ltd., Tokyo, JP;
Abstract
In a ball screw device comprising a screw shaft and a nut which make relative movement to each other through a multiplicity of balls, as well as in a linear motion device comprising an outer member and an inner member which make the relative movements to each other through the multiplicity of balls, a spacer having two concave surfaces facing respectively to balls, is disposed between the balls adjacent to each other. A section of each of the concave surfaces of the spacer is formed of two circular arcs of which central positions deviate from each other to form a Gothic arch. The spacer has such a configuration that the balls adjacent to each other come into contact with outer edges thereof or portions vicinal to the outer edges. The spacer also has such a configuration that the balls adjacent to each other come into contact with at least three or more outer edge portions thereof or portions vicinal to the outer edges. The spacer may have a through-hole formed in a thinnest portion thereof.