Granted Patent
Utility
US 4,243,209 · App. 06/088,263
Multiple level refractory hearth for vertical shaft metal melting furnaces
Inventors:
Ronald L. Pariani, David F. Arp
Patented Case
View Patent ↗
Granted: Jan 6, 1981
Filed: Oct 25, 1979
Inventors
Ronald L. Pariani
David F. Arp
Assignee (at issue)
Southwire Company, LLC
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.