Title:
Duplex loud-speaker
United States Patent 2638510
Inventors:
Joseph, Brami
Publication Date:
05/12/1953
Export Citation:
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Assignee:
Caesar, David Zeitouni
Primary Class:
381/341
Other Classes:
181/144, 181/159, 181/183, 381/160
International Classes:
H04R1/30; H04R1/22
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US Patent References:
2426948Coaxial dual-unit electrodynamic loud-speaker
2301459Electric megaphone
2295483Loudspeaker
2214591Signal translating apparatus
2167625Speaker unit
2077170Acoustic device
2007747Acoustic apparatus
1907723Sound reproducing device
1759614Acoustic amplifier
Foreign References:
GB442900A