Title:
Telephone repeating apparatus
United States Patent 1993486


Inventors:
Carlo, Ricchiardi Pier
Application Number:
US67354533A
Publication Date:
03/05/1935
Filing Date:
05/29/1933
Assignee:
Carlo, Ricchiardi Pier
Primary Class:
Other Classes:
379/80
International Classes:
B03C7/08; H04M1/65; H04M1/652
View Patent Images: