Patent ID: 7037053

Claim:
A tool holder comprising: a holder body having an elastically deformable tool attaching portion adapted to receive a tool; a ring member rotatable about a center axis of the holder body but not movable along the center axis; a cylindrical member adapted to be located adjacent to the ring member; and a force generation mechanism provided in the ring member and adapted to generate a force in a direction substantially parallel to the center axis to actuate the cylindrical member so that the tool attachment portion is elastically deformed in a radial direction perpendicular to the center axis such that tip run-out of the tool approaches zero; wherein the force generation mechanism comprises: an eccentric cam disposed within the ring member, the eccentric cam extending radially though the ring member and being rotatable about a radially extending axis; and a pin disposed within the ring member wherein one end of the pin is in contact with the eccentric cam and the other end of the pin is in contact with the cylindrical member; wherein the eccentric cam is rotatable so as to adjust a force that the pin applies to the cylindrical member to thereby elastically deform a base end portion of the tool attaching portion in such a manner that tip run-out of the tool approaches zero.