Granted Patent
Utility
US 6,004,522 · App. 08/887,449
Solid filtration media incorporating elevated levels of permanganate and water
Inventor:
William G. England
Patented Case
View Patent ↗
Granted: Dec 21, 1999
Filed: Jul 2, 1997
Inventor
William G. England
Assignee (at issue)
Purafil, 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.