Granted Patent
Utility
US 6,390,478 · App. 08/578,636
Sealing arrangement for a swivel
Inventor:
Martin Sigmundstad
Patented Case
View Patent ↗
Granted: May 21, 2002
Filed: Jun 27, 1996
Inventor
Martin Sigmundstad
Assignee (at issue)
Den Norske Stats Oljeselskap A.S.
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.