Granted Patent
Utility
US 4,668,387 · App. 06/778,939
Deep submergence rotating biological contactor apparatus
Inventors:
Richard Davie, Donald N. Gass
Patented Case
View Patent ↗
Granted: May 26, 1987
Filed: Sep 23, 1985
Inventors
Richard Davie
Donald N. Gass
Assignee (at issue)
Envirex, 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.