Granted Patent
Utility
US 5,690,816 · App. 08/556,595
Anti-drain back/pressure relieved filter cartridges
Inventor:
Edward Allen Covington
Patented Case
View Patent ↗
Granted: Nov 25, 1997
Filed: Nov 13, 1995
Inventor
Edward Allen Covington
Assignee (at issue)
DANA LIMITED
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.