Granted Patent
Utility
US 5,779,885 · App. 08/367,843
Rotating biological filter system
Inventors:
Roy S. Hickok, Roger W. McGrath
Patented Case
View Patent ↗
Granted: Jul 14, 1998
Filed: Dec 30, 1994
Inventors
Roy S. Hickok
Roger W. McGrath
Assignee (at issue)
Aquaria, 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.