Holder for rotary cutting tools

摘要

A tool holder for holding a rotary cutting tool, attachable to a spindle of a machine tool, has a holder body fixed to the machine spindle. A rotatable shaft having a tool-mounting portion is coupled to the holder body such that the shaft is axially and radially displaceable relative to the holder body. A positioning member is fixedly disposed on the machine tool body radially outwardly of the machine spindle. A casing is disposed radially outwardly of the rotatable shaft such that the casing and the rotatable shaft are rotatable relative to each other, the casing being engageable with the positioning member to accurately position the rotatable shaft when the holder body is fixed to the machine spindle. A guide bushing is fixedly supported at one axial end portion of the casing remote from the holder body. The guide bushing has a bore which is engageable with an outer circumferential surface of a guide portion of the cutting tool held by the tool-mounting portion of the rotatable shaft, thereby rotatably guiding the cutting tool.