Granted Patent
Utility
US 4,867,673 · App. 07/224,824
Condensing furnace
Inventor:
William T. Harrigill
Patented Case
View Patent ↗
Granted: Sep 19, 1989
Filed: Jul 27, 1988
Inventor
William T. Harrigill
Assignee (at issue)
The Coleman Company, 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.