Frictionally welded fastening anchor

Abstract

An anchor for secure reception of a fastener such as a screw shank can be frictionally welded, by high-speed rotation of the anchor, to the structure upon which the fastener is mounted. The anchor is molded from frictionally meltable material, for example a typical engineering thermoplastic such as ABS resin. The anchor has a generally cylindrical body with an end face at one end defining a surface for frictional welding to the compatible structure. The end face has an aperture which receives the screw shank or the like. The cylindrical body has a cup-like configuration having a cavity formed therein extending from the end face to an open end at the opposite end of the cylindrical body. A cylindrical boss is formed within the cavity and extends from the aperture at an entrance end for receiving the fastener. The boss has a frangible cap covering the end of its bore opposite the entrance end. The anchor includes a coupling structure for engagement by a drive tool which rotates the anchor and generates sufficient frictional heating to weld the anchor to the structure on which the fastener is subsequently mounted and anchored. The coupling structure includes radially extending flanges on the anchor body which supports drive tabs and provides movement arms for transmitting the torque applied by the drive tool.