Expansion sleeve for applying precise circumferential stress

摘要

An expansive sleeve provided with at least one stress cover associated with a hollow workpiece, which stress cover is provided with basically annular thickened regions bearing respective stress surfaces. It is desired that these outer stress surfaces be essentially in the form of cylindrical casing surfaces but that there be no radial outbowing of the individual stress surface so as to form a contact locus in the form of an arc resulting from a peak. This is achieved in that the basically annular thickened regions each comprise a protruding structure equipped with a cylindrical stress surface. With this expansive sleeve, the stress surface is no longer subject to bowing and formation of a peak contact locus comprised of an arc, because the stress surface is on the protruding structure.