摘要 |
A tool holder of the two-jaw type is provided which has the centering accuracy and gripping power of a three-jaw geared chuck. The tool holder includes a body having ways formed by a polygonal passageway which is perpendicular to the central axis of the tool holder body. The jaw mechanism includes a differential screw which mates, on one end, with the body of the tool holder and, on the other end, with a pair of anvil pieces. The face of the differential screw and the anvil pieces move toward and away from the central axis of the tool holder along the ways formed by the polygonal passageway and provide the tool-gripping means. |