Granted Patent
Utility
US 4,739,746 · App. 06/922,398
Heat exchanger for furnace
Inventor:
Ronald S. Tomlinson
Patented Case
View Patent ↗
Granted: Apr 26, 1988
Filed: Oct 23, 1986
Inventor
Ronald S. Tomlinson
Assignee (at issue)
Heil-Quaker Home Systems, 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.