Granted Patent
Utility
US 5,509,490 · App. 08/275,893
EMF sacrificial anode sub and method to deter bit balling
Inventors:
William C. Paske, Paul F. Rodney, Ronald D. Ormsby
Patented Case
View Patent ↗
Granted: Apr 23, 1996
Filed: Jul 15, 1994
Inventors
William C. Paske
Paul F. Rodney
Ronald D. Ormsby
Assignee (at issue)
Baroid Technology, 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.