Granted Patent
Utility
US 4,372,895 · App. 06/144,480
Disc for aeration of sewage
Inventor:
Edward P. Saffran
Patented Case
View Patent ↗
Granted: Feb 8, 1983
Filed: Apr 28, 1980
Inventor
Edward P. Saffran
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.