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:
Apr. 22, 1997
Filed:
Jun. 06, 1995
Gregory C Givler, Issaquah, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A method of upsetting a rivet, having a headed end and a nose end, in a countersunk hole in a workpiece using an electromagnetic riveting machine having two opposed drivers, one at each end of the rivet. The rivet is upset by impelling the drivers in the electromagnetic riveter against each end of the rivet to upset the tail of the rivet into a button, and expand the shank on the rivet within the hole in the workpiece. The force exerted by the driver at the headed end of the rivet is distributed in a broader, lower time/force curve than the force distribution exerted by the driver at the nose end of the rivet, so the force on the headed end driver is lower than the force on the tail end driver to prevent dimpling of the workpiece, and the greater force on the tail end driver imparts a certain momentum to begin upsetting the tail end of the rivet, while the force exerted by the headed end driver increases sufficiently to upset the rivet shank in the vicinity of the rivet head. The tail end capacitor is charged to a lower voltage than the charging voltage to the headed end capacitor, and commencement of the headed end driver stroke is delayed until the tail end driver has already been started. The headed end electromagnetic actuator is energized with a pulse of current from its capacitor having a more gradual rate of current increase than the rate of increase from the tail end capacitor to its electromagnetic actuator.