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公开(公告)号:US1976804A
公开(公告)日:1934-10-16
申请号:US52807431
申请日:1931-04-06
Applicant: RCA CORP
Inventor: ABRAHAM RINGEL
IPC: H01B11/18
CPC classification number: H01B11/1834
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公开(公告)号:US1871739A
公开(公告)日:1932-08-16
申请号:US26753328
申请日:1928-04-05
Applicant: RCA CORP
Inventor: ABRAHAM RINGEL
IPC: H04R11/00
CPC classification number: H04R11/00
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公开(公告)号:US1866831A
公开(公告)日:1932-07-12
申请号:US29721828
申请日:1928-08-03
Applicant: RCA CORP
Inventor: IRVING WOLFF , MAY RUSSELL P , ABRAHAM RINGEL
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