Selective signaling system
United States Patent 1900499

Inventors:
Hershey, Harry E.
Publication Date:
03/07/1933
View Patent Images:
Download PDF 1900499 pdf       PDF help
Export Citation:
Click for automatic bibliography generation
Assignee:
ASSOCIATED ELECTRIC LAB INC
Primary Class:
340/7.620
Other Classes:
341/176
International Classes:
H04Q7/20