Telephone system
United States Patent 2227488

Inventors:
Collis, Raymond E.
Dehn, Joseph W.
Hersey, Ralph E.
Newsom, James B.
Publication Date:
01/07/1941
View Patent Images:
Download PDF 2227488 pdf       PDF help
Export Citation:
Click for automatic bibliography generation
Assignee:
BELL TELEPHONE LABOR INC
Primary Class:
379/224
International Classes:
H04Q3/00