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. 17, 1979
Filed:
Nov. 17, 1977
Carl-Gustaf Carlin, Tyreso, SE;
Stefan M Skyllermark, Nacka, SE;
Atlas Copco Aktiebolag, Nacka, SE;
Abstract
A method and apparatus for tightening a screw joint to a predetermined axial load F.sub.p providing the spring constant k=(F/.phi.) of the joint is known, wherein the torque/rotation relationship M (.phi.) is determined during the linear, elastic deformation part of the tightening process by calculating the joint stiffness (dM/d.phi.) at an arbitrarily chosen torque level M.sub.2. A theoretical, tensionless angular position .phi..sub.0 of the joint is calculated by extrapolating the determined torque/rotation relationship M (.phi.), and the tightening process is interrupted as an angular interval .DELTA..phi. from said theoretical, tensionless position .phi..sub.0 has been passed, which interval according to the spring constant k of the joint corresponds to the predetermined axial load F.sub.p.