Patent ID: 7968830

Claim:
An inductive shrinkage appliance comprising: a tool holder having a holding section with a central holding opening configured to hold a tool shank with a press fit; an induction coil arrangement concentrically surrounding the holding section; and an attenuating adaptor configured for insertion between the holding section of the tool holder and the induction coil arrangement, wherein the attenuating adaptor is in the form of a sleeve composed of non-ferromagnetic metal; wherein the induction coil arrangement is configured to provide a magnetic flux between the induction coil arrangement and the tool holder through the attenuating adaptor to thermally widen the central holding opening of the tool holder; wherein the attenuating adaptor is configured to be positioned within the inductive shrinkage appliance so that an inner circumferential surface of the attenuating adaptor is brought into contact with an outer circumferential surface of the holding section of the tool holder, with at least a portion of the inner circumferential surface of the attenuating adaptor being in flat touching contact with the outer circumferential surface of the holding section; wherein the inner circumferential surface of the attenuating adaptor includes a conical portion configured to contact at least the outer circumferential surface of the holding section; wherein the attenuating adaptor includes a plurality of slots passing radially through the attenuating adaptor alternately in the circumferential direction, starting from axially opposite ends of the attenuating adaptor, over at least a part of the axial length of the attenuating adaptor; wherein the attenuating adaptor includes a stop tab projecting radially inward at its axial end adjacent to an insertion side for the tool shank, wherein the stop is configured to position the attenuating adaptor axially at one end surface of the holding section; and wherein the induction coil arrangement comprises a stop adapted to axially position the induction coil arrangement with respect to an end surface of the attenuating adaptor.