Granted Patent
Utility
US 6,340,064 · App. 09/392,043
Bi-center bit adapted to drill casing shoe
Inventors:
Coy M. Fielder, Rogerio H. Silva
Patented Case
View Patent ↗
Granted: Jan 22, 2002
Filed: Sep 8, 1999
Inventors
Coy M. Fielder
Rogerio H. Silva
Assignee (at issue)
Diamond Products International, 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.