Granted Patent
Utility
US 4,652,276 · App. 06/837,974
High toughness silicon nitride cutting tools
Inventor:
Stephen J. Burden
Patented Case
View Patent ↗
Granted: Mar 24, 1987
Filed: Mar 10, 1986
Inventor
Stephen J. Burden
Assignee (at issue)
GTE Valeron Corporation
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.