Granted Patent
Utility
US 6,601,662 · App. 09/947,678
Polycrystalline diamond cutters with working surfaces having varied wear resistance while maintaining impact strength
Inventors:
Terry R. Matthias, Nigel Dennis Griffin, Peter Raymond Hughes
Patented Case
View Patent ↗
Granted: Aug 5, 2003
Filed: Sep 6, 2001
Inventors
Terry R. Matthias
Nigel Dennis Griffin
Peter Raymond Hughes
Assignee (at issue)
GRANT PRIDECO, L.P.
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.