Title:
Telephone
United States Patent 1380981


Inventors:
Irving, Langmuir
Application Number:
US16373017A
Publication Date:
06/07/1921
Filing Date:
04/21/1917
Assignee:
GEN ELECTRIC
Primary Class:
International Classes:
B06B1/08; H04R1/24; H04R19/00
View Patent Images: