Granted Patent
Utility
US 4,419,567 · App. 06/239,630
Heating element for electric water heater
Inventors:
Robert A. Murphy, George L. Fehrmann
Patented Case
View Patent ↗
Granted: Dec 6, 1983
Filed: Mar 2, 1981
Inventors
Robert A. Murphy
George L. Fehrmann
Assignee (at issue)
Apcom, 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.