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. 08, 2011
Filed:
Jun. 16, 2006
Akimasa Yoshida, Tokyo, JP;
Masakazu Uesugi, Tokyo, JP;
Kentaro Nishimura, Tokyo, JP;
Satoshi Fujita, Kyoto, JP;
Satoru Nagai, Tokyo, JP;
Hiroyuki Arai, Tokyo, JP;
Akimasa Yoshida, Tokyo, JP;
Masakazu Uesugi, Tokyo, JP;
Kentaro Nishimura, Tokyo, JP;
Satoshi Fujita, Kyoto, JP;
Satoru Nagai, Tokyo, JP;
Hiroyuki Arai, Tokyo, JP;
THK Co., Ltd., Tokyo, JP;
Abstract
The present invention provides a screw device which takes a heavy load in one direction along the axis of the screw shaft and only a light load in the opposite direction, the screw device capable of providing ease of control of preloading. The screw device of the present invention has a screw shaftwith an outer surface having a ball rolling groovefor rolling ballsand a roller rolling groovefor rolling rollersboth spirally formed thereon; a ball nutwith an inner surface having a ball rolling groovespirally formed thereon facing the ball rolling grooveof the screw shaft; a roller nutwith an inner surface having a roller rolling groovespirally formed thereon facing the roller rolling grooveof the screw shaft; a plurality of ballsarranged between the screw shaftand the ball nut; and a plurality of rollersarranged between the screw shaftand the roller nut. The ball nutand the roller nutare connected along an axis of the screw shaft