Granted Patent
Utility
US 4,776,901 · App. 07/032,186
Nitrocarburizing and nitriding process for hardening ferrous surfaces
Inventor:
William W. Heminghous
Patented Case
View Patent ↗
Granted: Oct 11, 1988
Filed: Mar 30, 1987
Inventor
William W. Heminghous
Assignee (at issue)
Teledyne Industries, 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.