Granted Patent
Utility
US 4,299,059 · App. 06/128,520
Thermally insulated, fire resistant attic door
Inventor:
William Smith
Patented Case
View Patent ↗
Granted: Nov 10, 1981
Filed: Mar 10, 1980
Inventor
William Smith
Assignee (at issue)
Cardinal Industries, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.