Granted Patent
Utility
US 5,233,164 · App. 07/800,192
Modified heater for in situ soil heating
Inventors:
Lynton W. R. Dicks, Paul C. Johnson, Arnold R. Marsden, Jr., David Weingaertner
Patented Case
View Patent ↗
Granted: Aug 3, 1993
Filed: Nov 27, 1991
Inventors
Lynton W. R. Dicks
Paul C. Johnson
Arnold R. Marsden, Jr.
David Weingaertner
Assignee (at issue)
SHELL OIL COMPANY
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.