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公开(公告)号:US3417774A
公开(公告)日:1968-12-24
申请号:US55708166
申请日:1966-06-13
Applicant: DRESSER IND
Inventor: DOUGLAS BOBBY L , FOTIADES STEPHEN M
IPC: E21B43/12
CPC classification number: E21B43/123 , Y10T137/2934
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公开(公告)号:CA848246A
公开(公告)日:1970-08-04
申请号:CA848246D
Applicant: DRESSER IND
Inventor: DOUGLAS BOBBY L , FOTIADES STEPHEN M
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