Granted Patent
Utility
US 4,482,456 · App. 06/416,953
Reverse osmosis liquid treating apparatus
Inventor:
John R. Grayson
Patented Case
View Patent ↗
Granted: Nov 13, 1984
Filed: Sep 13, 1982
Inventor
John R. Grayson
Assignee (at issue)
RainSoft Water Conditioning Co.
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.