Title:
Audiphone
United States Patent 2233848

Inventors:
Polk, Robert E.
Publication Date:
03/04/1941
View Patent Images:
Download PDF 2233848 pdf       PDF help
Export Citation:
Click for automatic bibliography generation
Assignee:
BELL TELEPHONE LABOR INC
Primary Class:
381/323
Other Classes:
381/326, 381/313, 200/6BB, 330/65, 330/61R
International Classes:
H04R25/04