Granted Patent
Utility
US 4,948,437 · App. 07/155,040
Process for the heat-after treatment of a pig iron port
Inventor:
Horst Metzler
Patented Case
View Patent ↗
Granted: Aug 14, 1990
Filed: Feb 11, 1988
Inventor
Horst Metzler
Assignee (at issue)
Schwabische Huttenwerke GmbH
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.