Self-penetrating fastening system

Abstract

The self-penetrating fastening device proposed consists of a rivet (3), acted on by a punch (13), and a die (15), the rivet consisting of a head (4) and a shank (6) with a central cavity (8) whose open end partly penetrates a metal sheet (1) in which it is held. At the end of the rivet shank (6) remote from the rivet head (4), the cavity (8) is essentially conical in shape, the angle of the aperture being α. In addition, the transition zone between the rivet shaft (6) and the underneath (11) of the rivet head (4) is essentially rounded (R1). A rivet joint produced using this device is sufficiently strong to meet severe requirements, and the surface of the metal sheet in the region of the rivet is not affected by the perforation process.

Dependencies are inferred from the claim text.