Granted Patent
Utility
US 6,682,644 · App. 10/160,809
Process for producing electrolytic manganese dioxide from geothermal brines
Inventors:
John L. Featherstone, George Furmanski
Patented Case
View Patent ↗
Granted: Jan 27, 2004
Filed: May 31, 2002
Inventors
John L. Featherstone
George Furmanski
Assignee (at issue)
Midamerican Energy Holdings 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.