Title:
Combination breathing valve and speaking diaphragm unit
United States Patent 3348537


Inventors:
Miller, John C.
Cotabish, Harry N.
Buban, Elmer E.
Application Number:
US43607065A
Publication Date:
10/24/1967
Filing Date:
03/01/1965
Assignee:
MINE SAFETY APPLIANCES CO
Primary Class:
Other Classes:
128/205.24
International Classes:
A62B18/08; A62B18/10
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US Patent References:
Foreign References:
AU837532A
FR776709A1935-02-01