Granted Patent
Utility
US 4,790,396 · App. 06/879,137
Rotary drill bits for use in coring holes in subsurface formations
Inventor:
John M. Fuller
Patented Case
View Patent ↗
Granted: Dec 13, 1988
Filed: Jun 26, 1986
Inventor
John M. Fuller
Assignee (at issue)
NL Petroleum Products Limited
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.