United States Patent 3154139
Inventors:
Hager Jr., Nathaniel E.
Publication Date:
10/27/1964
Assignee:
ARMSTRONG CORK CO
Other Classes:
165/135, 165/904, 165/133, 62/383, 126/908, 126/710, 62/DIG.001
International Classes:
E04B1/80; F24F5/00; F28D15/02