Patent ID: 7145115

Claim:
An apparatus for hardening cylindrical bearing locations on a crankshaft having at least one bearing surface and having undercut surfaces adjacent the bearing surface, the undercut surfaces being defined by transition radii, the apparatus having a heating unit which is connected to a power supply, the apparatus further having an inductor which includes two heating conductor arms that are arranged at a distance from one another and in the peripheral direction of the, bearing, each of the two heating conductor arms having an inner bearing-surface hardening branch and two outer radius hardening branches, the bearing-surface hardening branch being mechanically connected to the radius hardening branches by current-carrying elements which bear the radius hardening branches, the current-carrying elements taking the form of a deformable loop, the ends of the loop respectively being connected to the bearing-surface hardening branch and to the radius hardening branches, and the loop extending in the radial direction, with respect to the shaft between the two ends, the mechanical connection being sufficiently elastic for the radius hardening branches to be displaceable relative to the bearing-surface hardening branch in the axial direction of the shaft that is to be hardened.