Title:
Telephone signaling system
United States Patent 1688453
Inventors:
Demarest, Charles S.
Loynes, Owen H.
Publication Date:
10/23/1928
Export Citation:
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Assignee:
AMERICAN TELEPHONE & TELEGRAPH
Primary Class:
455/560
Other Classes:
379/226, 379/230, 455/567
International Classes:
H04M11/00; H04M11/00
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