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公开(公告)号:US2152008A
公开(公告)日:1939-03-28
申请号:US69954733
申请日:1933-11-24
Applicant: BAASH ROSS TOOL CO
Inventor: YARBROUGH HAROLD C
IPC: E21B43/112
CPC classification number: E21B43/112
公开(公告)号:US2152008A
公开(公告)日:1939-03-28
申请号:US69954733
申请日:1933-11-24
Applicant: BAASH ROSS TOOL CO
Inventor: YARBROUGH HAROLD C
IPC: E21B43/112
CPC classification number: E21B43/112