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:
Jul. 25, 2006
Filed:
Mar. 26, 2003
Yasumi Watanabe, Kanagawa, JP;
Shigeru Okita, Kanagawa, JP;
Masato Kato, Gunma, JP;
NSK Ltd., Tokyo, JP;
Abstract
A ball screw has a screw shaft including a spiral-shaped ball rolling groove formed in an outer peripheral surface thereof; a nut including a spiral-shaped ball rolling groove formed in an inner peripheral surface thereof; a plurality of balls disposed in a raceway formed by the two rolling grooves; and, a return path for moving the balls from the terminal point of the raceway to the start point of the raceway, the two end portions of the return path respectively including a rising surface rising from the ball rolling groove of the nut and a stopper portion disposed opposed to the rising surface to form the end portion of the raceway, wherein a boundary portion between the rising surface and the ball rolling groove of the nut is formed a round portion having the radius of curvature 0.05 times the diameter of the ball or more.