Granted Patent
Utility
US 4,591,226 · App. 06/462,662
Annular electrical connectors for drill string
Inventors:
Hoke S. Hargett, Charles E. Barton, William D. Boles
Patented Case
View Patent ↗
Granted: May 27, 1986
Filed: Jan 31, 1983
Inventors
Hoke S. Hargett
Charles E. Barton
William D. Boles
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.