Patent ID: 6916229

Claim:
A machine-implemented method for forming a release surface of a mold, the mold having a mold cavity confined by an inner peripheral surface that defines a mold cavity axis, the release surface to be formed at the inner peripheral surface and being inclined relative to the mold cavity axis, comprising the steps of: (a) bringing a grinding surface of a rotary grinding portion of a jig grinder into contact with a part of the inner peripheral surface such that the grinding surface is inclined at a predetermined angle relative to the mold cavity axis, and rotating the grinding portion such that the grinding surface grinds said part of the inner peripheral surface; (b) separating the grinding surface from the inner peripheral surface; (c) changing relative positions of the grinding portion and the inner peripheral surface in preparation for grinding another part of the inner peripheral surface; and (d) repeating the steps (a) to (c) until the release surface is formed.