Granted Patent
Utility
US 3,983,198 · App. 05/549,415
Method of increasing the oxidation resistance of silicon nitride
Inventor:
John A. Mangels
Patented Case
View Patent ↗
Granted: Sep 28, 1976
Filed: Feb 12, 1975
Inventor
John A. Mangels
Assignee (at issue)
Ford Motor 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.