Granted Patent
Utility
US 6,679,289 · App. 09/968,257
Swing check valve
Inventor:
David E. Sisk
Patented Case
View Patent ↗
Granted: Jan 20, 2004
Filed: Oct 1, 2001
Inventor
David E. Sisk
Assignee (at issue)
Sure Seal, 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.