Granted Patent
Utility
US 4,669,556 · App. 06/693,848
Drill bit and cutter therefor
Inventors:
John D. Barr, Terry R. Matthias, Malcolm R. Taylor
Patented Case
View Patent ↗
Granted: Jun 2, 1987
Filed: Jan 25, 1985
Inventors
John D. Barr
Terry R. Matthias
Malcolm R. Taylor
Assignee (at issue)
NL 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.