TW200502492A - Clinch-type blind nut - Google Patents

Abstract

A threaded blind insert includes a shank with an axial bore therethrough having a head at one end and a threaded region of the bore at the opposite end. The wall of the shank between its outer surface and the bore includes a weakened deforrnable portion created by a reduced outside diameter of the shank in that area. A reinforcement collar integral with the shank is located at approximately the middle of the deformable portion of the shank thus providing a more rigid area at the collar which creates bulges in the deformable portion on either side of the collar when the insert is compressed. A flange located adjacent the underside of the head of the insert has an outer diameter greater than the shank but less than the head. When fitted into a mounting hole of a workpiece, the flange centers the insert and provides an annular gap between the shank and the mounting hole. As the insert is compressed by an installation tool, the bulges provide a reactive force against the backside of the workpiece which clamps the workpiece between the bulges and the head of the insert. Reaction forces of the bulges are sufficient to embed the head into the panel completely so that the installation provides a flush attachment. Alternately, the reinforcement collar may be replaced by a band of greater hardness on the deformable wall which can be created by heat treatment.