Combined thermal fit and rotational locking machine tool assembly

Abstract

An illustrative embodiment of a machine tool assembly has a tool holder, a keyed recess, and a cutting tool. The assembly prevents relative rotation and substantially reduces eccentricity between a cutting tool and a tool holder. The tool holder has a receiving bore axially formed at the tool end of the tool holder. The keyed recess is at the base of the receiving bore. The keyed recess has multiple corners formed around an inner surface of the recess. The cutting tool has a cylindrical shank and multiple edges formed on the machine tool end of the shank. The cylindrical receiving bore has diameter that is less than the diameter of the tool shank so that a thermal transitional fit is provided. Coupling of the cutting tool and holder includes heating the holder until the diameter of the bore expands sufficiently to receive the tool shank. When inserted within the bore of the holder and into the keyed recess, the multiple edges of the cutting tool abut with the multiple corners of the recess.

Dependencies are inferred from the claim text.