Granted Patent
Utility
US 4,449,511 · App. 06/456,172
Recuperative furnace
Inventors:
Herbert G. Hays, Warren W. Kuipers
Patented Case
View Patent ↗
Granted: May 22, 1984
Filed: Jan 6, 1983
Inventors
Herbert G. Hays
Warren W. Kuipers
Assignee (at issue)
Amana Refrigeration, 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.