Patent ID: 7640833

Claim:
A method of manufacturing a molding body having at least one groove thereon, the method being performed by the following steps of: A: rotating a workpiece having a curved face with a predetermined curvature; B: forming a first groove; and C: changing a relative position between the tip and the workpiece, in the step of A, the workpiece being rotated about a rotation axis which agrees with a center of the curvature of the curved face thereof; in the step B, the first groove being formed in such a manner that, while an angle of the rake face of the tip relative to a plane including the rotation axis is fixed in a direction orthogonal to the plane, the workpiece and the tip are converged and the tip is engaged with the curved face of the rotating workpiece so as to form on the curved face the first groove defined by the outer edge shape of the tip, and engagement orientation and depth of the rake face relative to the curved face of the workpiece; and in the step C, the relative position between the tip and the workpiece being changed by translating the position of the tip in the direction orthogonal to the rotation axis and parallel to the plane.