Being abutment process manner of the seal ring and abutment process manner

摘要

PROBLEM TO BE SOLVED: To provide a mitre made of synthetic resin, especially, the mitre processing method of double cut form or triple step form and a processing blade for that. SOLUTION: A mitre forming part of the main body of a ring (20) is held tight by opposed planes of a pair of jigs (21, 22), and the mitre forming part is made into straight through shape. The edge of a blade with a stepped part (26) is thrust into this mitre forming part of straight through shape. Subsequently, a second processing blade is pushed in, and after processed the mitre (2), the jigs (21, 22) are removed, and let the straight through part be the circular arc part of the original form by the self-tension of the main body of the ring (20).