Patent ID: 8550759

Claim:
A joining element to be anchored in an opening provided in an object with the aid of a thermoplastic material and mechanical vibration, the joining element comprising: a proximal end and a distal end, the proximal end and the distal end being distanced from each other in the direction of an axis, a contact face in the area of the proximal end, the contact face being suitable for being contacted with a vibrating tool for applying, to the joining element, mechanical vibration and a force parallel to the axis, a wall anchoring portion and adjoining at a proximal side of the wall anchoring portion a sealing portion, said two portions being situated between the proximal and the distal end, wherein the sealing portion is cylindrical or slightly conical and has a smooth circumferential surface, wherein the wall anchoring portion has a circumferential surface comprising the thermoplastic material and being equipped with a plurality of recesses and energy concentrating elements between the recesses, wherein a cross section of the sealing portion envelopes a cross section of the wall anchoring portion and wherein the sealing portion and the wall anchoring portion meet at a border line or a border groove; and a central element extending axially through at least part of the joining element; wherein the sealing portion extends distally from the proximal end of the joining element; wherein, in the area of the distal end, a plurality of radial wings are attached to the central element; and wherein the energy concentrating elements of the wall anchoring portion protrude radially.