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公开(公告)号:US2497213A
公开(公告)日:1950-02-14
申请号:US59515445
申请日:1945-05-22
Applicant: NAT RES CORP
Inventor: DOWNING JAMES R O
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公开(公告)号:US2386298A
公开(公告)日:1945-10-09
申请号:US47413443
申请日:1943-01-30
Applicant: NAT RES CORP
Inventor: DOWNING JAMES R O , HUMES WILLIAM B
IPC: F04F9/00
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公开(公告)号:US2386299A
公开(公告)日:1945-10-09
申请号:US54328944
申请日:1944-07-03
Applicant: NAT RES CORP
Inventor: DOWNING JAMES R O
IPC: F04F9/00
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