Granted Patent
Utility
US 4,865,137 · App. 07/186,716
Drilling apparatus and cutter
Inventors:
Thomas F. Bailey, John E. Campbell
Patented Case
View Patent ↗
Granted: Sep 12, 1989
Filed: Apr 22, 1988
Inventors
Thomas F. Bailey
John E. Campbell
Assignee (at issue)
Drilex Systems, 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.