Patent ID: 7144210

Claim:
A rotary tool holder for detachably retaining a rotary tool in a tapered bore of a spindle, the rotary tool holder comprising: a shank having a tapered outer surface corresponding to the tapered bore, the shank having a front contact portion and a rear contact portion; a flange adjacent the front contact portion; a first circular cantilever adjacent one of the front and rear contact portions, the first circular cantilever having a fixed end and a free end; wherein rotation of the rotary tool holder when disposed in the spindle results in the free end of the first circular cantilever expanding radially under the influence of centrifugal force such that the free end maintains contact with the tapered bore which also radially expands under the influence of centrifugal force during rotation; a cavity formed in a rear face of the shank, the cavity having an exterior surface forming at least part of the first circular cantilever; a pull stud having a first end captured in the cavity and a second end external of the cavity, the second end adapted to have tension applied thereto after the rotary tool holder is positioned in the spindle; and wherein the tension on the second end causes the first end to apply an outward radial force on the cavity which urges the exterior surface in a radially outward direction toward the tapered bore when the shank is positioned therein.