Granted Patent
Utility
US 6,686,752 · App. 10/175,595
Wear indicator for refractory linings
Inventors:
William L. Heumann, Frank J. Elvin, Russell J. Lewis, Edwin D. Tenney, Joseph A. Urban, Mark Noppenberger, James F. Miller
Patented Case
View Patent ↗
Granted: Feb 3, 2004
Filed: Jun 19, 2002
Inventors
William L. Heumann
Frank J. Elvin
Russell J. Lewis
Edwin D. Tenney
Joseph A. Urban
Mark Noppenberger
James F. Miller
Assignee (at issue)
Fisher-Klosterman, 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.