Granted Patent
Utility
US 4,804,464 · App. 06/727,941
System for in situ upgrading of the purity of a liquid and flushing a filtration system
Inventor:
William R. Schevey
Patented Case
View Patent ↗
Granted: Feb 14, 1989
Filed: Apr 26, 1985
Inventor
William R. Schevey
Assignee (at issue)
HMC Patents Patents Holding Co., 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.