Vorrichtung zum Spannen von Werkzeugen

The invention is concerned with a device for clamping and releasing work tools ( 16 ) in a tool receptacle ( 10 ). The tool receptacle ( 10 ) includes on its free end for this purpose an open socket part ( 12 ), which is adapted for frictional engaging reception of the work tool shaft ( 14 ). The work tool shaft is thereby shrunk-fit into a borehole ( 20 ) in the socket part ( 12 ). For this purpose the socket part is provided with an induction coil ( 26 ) encircling the tool receptacle ( 10 ) which coil can be acted upon by high frequency alternating current for producing heat and heating the socket part ( 12 ). For avoidance of leakage fields which could result in a undesired heating of the work tool ( 16 ), it is proposed in accordance with the invention that the induction coil ( 26 ), on its surface adjacent the free end of the socket part ( 12 ), is covered over by a pole shoe ( 34 ) having a central through hole ( 36 ) for the work tool ( 16 ) and comprised of a magnetically conductive and electrically non-conductive material.