Granted Patent
Utility
US 4,838,062 · App. 07/133,340
Process for upset forging of long stands of metal bar stock
Inventor:
Otto E. Prenn
Patented Case
View Patent ↗
Granted: Jun 13, 1989
Filed: Dec 15, 1987
Inventor
Otto E. Prenn
Assignee (at issue)
Stelco 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.