Ventilator wall and window blocks
United States Patent 2216420
Inventors:
Carl, Rose
Publication Date:
10/01/1940
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Export Citation:
Assignee:
George, Allison N.
Primary Class:
Other Classes:
49/52, D25/53, D25/52, 256/19, D25/156
International Classes:
E06B7/04; E06B7/02