Precision cutting of screw threads - involves eccentric multiple tool holder performing rotational motion around rotating workpiece

摘要

A method of cutting screw threads with a very high degree of precision uses a circular tool holder which carries four equally spaced cutting tools. The tool holder has a central hole to receive the workpiece. The workpiece is mounted eccentrically with respect to the tool holder and both workpiece and tool holder rotate in the same direction but with the workpiece rotating at a much lower speed than the tool holder. The axis of the tool holder is inclined to the axis of the workpiece to suit the lead angle of the thread.