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公开(公告)号:US2233073A
公开(公告)日:1941-02-25
申请号:US29441339
申请日:1939-09-12
Applicant: FREDERIC B SCHRAMM
Inventor: BRANN GEORGE E
IPC: G06G1/10
CPC classification number: G06G1/10
公开(公告)号:US2233073A
公开(公告)日:1941-02-25
申请号:US29441339
申请日:1939-09-12
Applicant: FREDERIC B SCHRAMM
Inventor: BRANN GEORGE E
IPC: G06G1/10
CPC classification number: G06G1/10