Clamp profiling control method

A clamp profiling control method in which a stylus is made to alternately perform a profiling feed operation and a pick-feed operation along only one direction of a profiling path, and a profiling starting point return operation, and in which clamp feed is initially performed at an initial set clamp level, said method comprising the steps of

• specifying a clamp region by storing a starting position at which the clamp feed at said initial set clamp level first occurs and an ending position at which the clamp feed at said initial set clamp level subsequently ceases during the course of said profiling feed in said one direction along said profiling path,
• successively executing repetitive clamp profiling control over said clamp region, in said one direction along the respective portion of said profiling path between said starting and ending positions, while respectively increasing the clamp level for each said clamp profiling control, wherein, after each said clamp profiling control over said clamp region for which said clamp feed at the respective clamp level occurs, a rapid traverse of said stylus is provided from said ending position to said starting position, and
• discriminating that the clamp feed is no longer performed during the course of profiling feed of said repetitive clamp profiling control within said clamp region, setting the clamp level to said initial set clamp level, and proceeding further along said profiling path.