| 摘要 |
An apparatus and method is provided wherein a circular sheet blank is formed into a cup-shaped article which is substantially free of defects. The apparatus and method utilize a pair of cooperating die assemblies having a pair of rings provided with a pair of cooperating blank-engaging surfaces each defined by a plurality of alternating concentric grooves and projections. The grooves and projections of one of the surfaces partially intermeshes with associated projections and grooves respectively of the other of the surfaces to define concentric undulations in the peripheral portion of the blank. One of the die assemblies has a male member provided as a part thereof and the other assembly has a cooperating die cavity whereby upon relatively moving the assemblies together the blank is drawn by the male member into the die cavity enabling the undulations to serve as integral columnar members which allow controlled flow of the peripheral portion to define a tubular wall of the cup-shaped article which is free of defects.
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