Granted Patent
Utility
US 4,667,752 · App. 06/874,818
Top head drive well drilling apparatus with stabbing guide
Inventors:
Joe Rodney Berry, William R. Hamilton
Patented Case
View Patent ↗
Granted: May 26, 1987
Filed: Jun 12, 1986
Inventors
Joe Rodney Berry
William R. Hamilton
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.