Granted Patent
Utility
US 4,863,684 · App. 07/296,666
Method and apparatus for adding shot to molten steel
Inventor:
Mark Hubbard
Patented Case
View Patent ↗
Granted: Sep 5, 1989
Filed: Jan 13, 1989
Inventor
Mark Hubbard
Assignee (at issue)
Inland Steel 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.