Granted Patent
Utility
US 4,280,913 · App. 06/114,764
Water purification process
Inventors:
Charles S. Applegate, Paul R. Erickson
Patented Case
View Patent ↗
Granted: Jul 28, 1981
Filed: Jan 23, 1980
Inventors
Charles S. Applegate
Paul R. Erickson
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.