Granted Patent
Utility
US 5,478,053 · App. 08/419,449
Refractory gas purging device
Inventors:
Tomas Richter, John E. Shoff, John Skok
Patented Case
View Patent ↗
Granted: Dec 26, 1995
Filed: Apr 10, 1995
Inventors
Tomas Richter
John E. Shoff
John Skok
Assignee (at issue)
NORTH AMERICAN REFRACTORIES 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.