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公开(公告)号:US2923537A
公开(公告)日:1960-02-02
申请号:US72695558
申请日:1958-04-07
Applicant: WILCOX MFG COMPANY
Inventor: WILCOX JOHN L
IPC: E21C27/22
CPC classification number: E21C27/22
公开(公告)号:US2923537A
公开(公告)日:1960-02-02
申请号:US72695558
申请日:1958-04-07
Applicant: WILCOX MFG COMPANY
Inventor: WILCOX JOHN L
IPC: E21C27/22
CPC classification number: E21C27/22