Granted Patent
Utility
US 4,786,409 · App. 07/040,468
Duplex filter assembly
Inventor:
Daniel W. Miller
Patented Case
View Patent ↗
Granted: Nov 22, 1988
Filed: Apr 20, 1987
Inventor
Daniel W. Miller
Assignee (at issue)
Parker-Hannifin Corporation
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.