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:
Oct. 02, 1990
Filed:
Feb. 01, 1989
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05B / ;
U.S. Cl.
CPC ...
318600 ; 173 12 ; 318652 ; 388810 ;
Abstract
The turn-of-nut tightening method that is improved by determining the starting point only through measurements of the angle and time relationship to determine the linear portion of the tightening curve, which is extended to the previous free running speed point where the corresponding angle is determined as the starting angle, to which is added a fixed turning amount to control the end of the tightening. As a specific embodiment, the turning angle is chosen as the variable and measured with specific time intervals. Using fixed time intervals, time is removed as a variable. Therefore, with a simple and economical angle measuring device, such as a shaft encoder, tightening is accurately controlled.