-
公开(公告)号:US1744992A
公开(公告)日:1930-01-28
申请号:US2403725
申请日:1925-04-18
Applicant: HOWARD D COLMAN
Inventor: STEWART DUNCAN J
IPC: H04L25/49
CPC classification number: H04L25/49
公开(公告)号:US1744992A
公开(公告)日:1930-01-28
申请号:US2403725
申请日:1925-04-18
Applicant: HOWARD D COLMAN
Inventor: STEWART DUNCAN J
IPC: H04L25/49
CPC classification number: H04L25/49