Title:
Underfloor duct system and method of making
United States Patent 1758989


Inventors:
Walker, Hervey S.
Application Number:
US11721226A
Publication Date:
05/20/1930
Filing Date:
06/21/1926
Assignee:
Walker, Hervey S.
Primary Class:
Other Classes:
138/157
International Classes:
E04B5/48; H02G9/06
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