Granted Patent
Utility
US 4,997,571 · App. 07/461,174
Method of treating water
Inventors:
L. Fred Roensch, Hershel Zamechek, Kelvin Y. Chang, Eric Dlugosz
Patented Case
View Patent ↗
Granted: Mar 5, 1991
Filed: Jan 5, 1990
Inventors
L. Fred Roensch
Hershel Zamechek
Kelvin Y. Chang
Eric Dlugosz
Assignee (at issue)
The Mogul 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.