Granted Patent
Utility
US 4,774,861 · App. 07/117,272
Drill pipe spinner
Inventors:
William R. Hamilton, Harry D. Hebard
Patented Case
View Patent ↗
Granted: Oct 4, 1988
Filed: Nov 5, 1987
Inventors
William R. Hamilton
Harry D. Hebard
Assignee (at issue)
Hughes Tool Company LLC
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.