Patent 7996977 was granted and assigned to Hilti on August, 2011 by the United States Patent and Trademark Office.
A stack arrangement has a first plate-shaped workpiece (12), at least one another plate-shaped workpiece, and an eyelet (14; 34) that connects the first workpiece (12) and the at least one another workpiece (13), with material of the first workpiece (12) being drawn through a through-opening (15) in the at least one another workpiece (13), and with a rim (17) of the through-opening (15) of the at least one another workpiece (13) conically narrowing in a direction of the first workpiece (12).