Patent ID: 7296456

Claim:
A method for manufacturing an article having a thickened peripheral portion, comprising: squeezing a first intermediate peripheral portion of a first intermediate article, to thereby form a second intermediate article having a second intermediate peripheral portion that is thickened, and reverse squeezing an initial peripheral portion of an initial article as a preliminary processing, to thereby form the first intermediate article, wherein the reverse squeezing step is performed in a direction opposite to the direction of the squeezing step wherein the reverse squeezing step comprises compressing the initial peripheral portion of the initial article in a direction of thickness of the article, to thereby form an inclined surface in the first intermediate peripheral portion so that the first intermediate peripheral portion has opposite surfaces of different area, and wherein the reverse squeezing step is performed, such that when the first intermediate peripheral portion of the first intermediate article is clamped between a pair of restraint dies in the squeezing step, a restraint surface of one of the restraint dies extends outwardly beyond one of opposite surfaces of the first intermediate peripheral portion.