Granted Patent
Utility
US 4,676,324 · App. 06/823,681
Drill bit and cutter therefor
Inventors:
John D. Barr, John M. Fuller
Patented Case
View Patent ↗
Granted: Jun 30, 1987
Filed: Jan 29, 1986
Inventors
John D. Barr
John M. Fuller
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.