Patent ID: 7577490

Claim:
A method implemented in a computer for generating a tool path for milling a region of a workpiece by a numerical control machine using a milling cutter, the tool path comprising one or more passes, each pass forming an in-process material boundary comprising a plurality of tangential continuous arcs, each pass successively advancing into the region by a predetermined pitch, the region having first, second and third sides, the first side being a current in-process material boundary and the second and the third sides being part or material boundaries, the first side meeting at its respective ends the second and the third sides, the method for determining parameters of each one of the one or more passes comprising the steps of: receiving parameters describing the region; determining the parameters of a first one of the plurality of tangential continuous arcs to be tangent to the second side and having a radius of curvature greater than one-half of a distance between the second and third sides at the points where the first side meets the second and the third sides; and determining the parameters of a second one of the plurality of tangential continuous arcs, said second one of a plurality of tangential continuous arcs being joined at one end to one end of the first one of the plurality of tangential continuous arcs and to be tangent to the third side, and having a radius of curvature less than one-half the distance between the second and the third sides at the points where the first side meets the second and the third sides, and outputting a series of instructions useful for controlling the numerical control milling machine to mill the region in accordance with the generated tool path.