Method and apparatus for preparing numerical control data

Abstract

An apparatus for preparing NC data is used in machining an involute curve on a workpiece by relatively moving a tool and the workpiece along mutually perpendicular first and second axes encompassed within a plane while relatively rotating the tool and the workpiece about a third axis which is perpendicular to the plane. In the apparatus, there is provided involute curve definition devie defines the involute curve based upon input parameters, machining point calculation means calculates a series of machining points on the involute curve, and tangential line calculation device calculates a tangential line which connects the involute curve at each of the machining points. The apparatus further includes angle calculation device calculates a conversion angle through which each of the machining points is to be rotated about the third axis so as to make the tangential line at each of the machining points intersect one of the first and second axes at a right angle, coordinate conversion device converts coordinate values of each of the machining points into modified coordinate values which each of the machining points would have if the same were rotated about the third axis through the conversion angle calculated by the angle calculation device, and data preparation device prepares NC data of numerous data blocks each including the conversion angle and the converted coordinate values of each of the machining points.

Dependencies are inferred from the claim text.