Granted Patent
Utility
US 4,799,977 · App. 07/098,081
Graded multiphase oxycarburized and oxycarbonitrided material systems
Inventor:
John J. Rausch
Patented Case
View Patent ↗
Granted: Jan 24, 1989
Filed: Sep 21, 1987
Inventor
John J. Rausch
Assignee (at issue)
Fansteel 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.