Patent ID: 8950300
Filing Date: 2015-02-10
Classification: B23B,Y10T

Abstract:
1. A tool holder configured to secure a tool and mounted on a rotary shaft, in which the tool holder is constructed so that the tool is secured with a cutting edge of the tool directed to a rotation center axis of the rotary shaft, a structure of the tool holder is elastically deformed by a centrifugal force produced as the tool holder is rotated by driving the rotary shaft, and the radius of rotation of the cutting edge of the tool around the rotation center axis is variable, wherein the cutting edge of the tool secured to the tool holder on the rotary shaft as viewed along the rotation center axis, in a coordinate system in which the tool holder is viewed along the rotation center axis, is configured to be located in a first position deviated from the rotation center axis by an initial offset when the rotary shaft is stationary and located in a second position when the rotational speed of the rotary shaft is maximal, the rotation center axis is located on a segment which connects the first position and the second position, and the cutting edge of the tool moves from the first position to the second position passing through the rotation center axis when the stationary state of the rotary shaft is changed into a maximum rotational speed state, and wherein the structure of the tool holder comprises two beams elastically deformable to the same degree in opposite directions by the centrifugal force, and centrifugal force components acting on the two beams cancel each other so that a rotation balance is maintained even when the rotational speed of the tool holder is changed.