Granted Patent
Utility
US 6,684,948 · App. 10/053,207
Apparatus and method for heating subterranean formations using fuel cells
Inventor:
Marshall T. Savage
Patented Case
View Patent ↗
Granted: Feb 3, 2004
Filed: Jan 15, 2002
Inventor
Marshall T. Savage
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.