Granted Patent
Utility
US 6,401,820 · App. 09/446,930
Downhole tool
Inventors:
Ian Kirk, William Barron, Alistair Clark
Patented Case
View Patent ↗
Granted: Jun 11, 2002
Filed: Dec 29, 1999
Inventors
Ian Kirk
William Barron
Alistair Clark
Assignee (at issue)
Downhole Products plc
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.