Slug riveting apparatus

摘要

The invention relates to slug riveting apparatus wherein a pair of opposed rivet head forming anvils move relatively toward each other to form heads at the opposite ends of a cylindrical rivet blank, more or less simultaneously, after the blank has been inserted in the workpieces. An annular elastomeric polyurethane member is associated coaxially with one of the rivet head forming anvils and has a bore for receiving and resiliently gripping a cylindrical rivet blank. The elastomeric annular member holds the blank during insertion of the blank in the workpieces as the anvils move relatively toward each other, and the rivet blank is moved out of engagement with the elastomeric annular member by the associated head forming anvil during the head forming operation by resilient radial expansion of the elastomeric annular member. The rivet forming anvils have flat bottomed head forming recesses with sloping side walls. The flat bottoms of the recesses are of substantially the same diameter as the ends of the rivet blanks or slugs to retain the latter in an accurately centered coaxial position with respect to the head forming anvils throughout the slug insertion and the head forming operations.