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:
Dec. 10, 1996
Filed:
Feb. 08, 1994
Toshiaki Yamaguchi, Gunma, JP;
Kazuo Miyaguchi, Gunma, JP;
NSK Ltd., Tokyo, JP;
Abstract
A preliminary thrusting mechanism for a screw device serves to achieve not only constant position type preliminary thrusting but also constant pressure type preliminary thrusting. The preliminary thrusting mechanism includes as essential components a screw shaft having a spirally extending screw groove formed axially along the outer surface thereof, a first nut threadably engaged with the screw shaft, a second nut operatively connected to the first nut in series and threadably engaged with the screw shaft, a rotation stopping unit for preventing the second nut from being rotated relative to the first nut, a thrusting unit including a thrusting member adapted to impart to the first nut and the second nut a certain intensity of thrusting power effective in the opposite direction for allowing them to be displaced away from each other in the axial direction, and a stopping unit for preventing the thrusting member from being displaced further when the thrusting member is displaced by a predetermined distance. In practice, the thrusting unit includes a liquid pressure source, a liquid pressure supplying path and a pressure chamber, and the stopping unit includes flanges each serving to prevent further displacement of the thrusting member.