Title:
Telephone signaling system
United States Patent 1688453


Inventors:
Demarest, Charles S.
Loynes, Owen H.
Application Number:
US11025126A
Publication Date:
10/23/1928
Filing Date:
05/19/1926
Assignee:
AMERICAN TELEPHONE & TELEGRAPH
Primary Class:
Other Classes:
379/226, 379/230, 455/567
International Classes:
H04M11/00
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