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公开(公告)号:US2280764A
公开(公告)日:1942-04-21
申请号:US27807139
申请日:1939-06-08
Applicant: ALUMINUM CO OF AMERICA
Inventor: STEPHENSON JR THOMAS I
IPC: B21B33/00
CPC classification number: B21B33/00
公开(公告)号:US2280764A
公开(公告)日:1942-04-21
申请号:US27807139
申请日:1939-06-08
Applicant: ALUMINUM CO OF AMERICA
Inventor: STEPHENSON JR THOMAS I
IPC: B21B33/00
CPC classification number: B21B33/00