Patent ID: 7182558
Filing Date: 2007-02-27
Classification: B23B,Y10T

Abstract:
1. A tool holder system for holding a rotary tool having an axis of rotation and a fixing shank, the tool holder system comprising: a tool holder having a clamping shank and an annularly closed bush part at a tool-side end of the clamping shank, wherein the bush part comprises a mounting opening coaxial to the axis of rotation for mounting the fixing shank of the rotary tool, a radially outer circumferential region, and a radially inner circumferential region; and induction heating means for heating the radially outer circumferential region of the bush part, by means of eddy currents magnetically induced in the bush part, so as to radially expand the mounting opening to a width enabling the fixing shank to be pushed in or pulled out of the mounting opening, wherein by cooling the bush part, the mounting opening is radially shrinkable to a width holding the fixing shank in an interference fit, and wherein the bush part further comprises a plurality of annularly closed heat-insulating apertures provided in the radially inner circumferential region of the bush part and extending along the axis of rotation for reducing the thermal conductivity of the radially inner circumferential region compared with the radially outer circumferential region, thus reducing the radial heat-conducting cross-section of the bush part, and a plurality of slots extending radially outwardly from the mounting opening each in between a pair of adjacent apertures.