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:
Aug. 08, 1978
Filed:
Dec. 29, 1976
Jerry A Sigmund, Willow Grove, PA (US);
SPS Technologies, Inc., Jenkintown, PA (US);
Abstract
A preferred embodiment of the invention disclosed herein relates to a method of and tightening system for tightening a joint assembly including a fastener system to a yield point of one of the members in the assembly. According to the method, torque is applied and rotation is imparted to a fastener member, and the torque and rotational displacement of the fastener are determined at predetermined increments of rotation for use in determining the area between successive increments of rotation under the Torque-Rotation curve which could be plotted. The incremental areas are compared to determine when some member in the joint assembly has been tightened to its yield point or some similarly significant point. The tightening system includes a wrench and a control system associated with the wrench including measuring systems for developing a first signal representative of the torque applied to the fastener and a second signal representative of the rotation of the fastener. Both the first and second signals are fed to an incremental area calculating system included in the control system, which calculates and develops a signal representative of the area under the Torque-Rotation curve which could be plotted for the fastener being tightened, between successive predetermined increments of rotation. The control system further includes decision making means responsive to the incremental area signals for developing a control signal when some member in the joint assembly has been tightened to its yield point or some similarly significant point.