| 摘要 |
A ball endmill comprises a cylindrical body and a cutting element secured to one end of the cylindrical body. The face of the cutting element is convexed and forms a part of the surface of an imaginary cone, the axis of which is inclined to the axis of the cylindrical body. The cutting element is constituted by one or more parts and has at least one arcuate cutting edge. The cutting edge has its starting point located near the axis of the cylindrical edge and cuts in a workpiece a spherical concave as the cylindrical body is rotated. To cut a deep hole with a spherically curved bottom, the ball endmill may be provided with an auxiliary cutting element. The auxiliary cutting element is secured to the periphery of the cylindrical body and has a straight cutting edge extending parallel to the axis of the cylindrical body. The straight cutting edge cuts a straight cylindrical hole in a workpiece as the cylindrical body is rotated. |
