Granted Patent
Utility
US 5,221,473 · App. 07/979,406
Filter cartridge assembly for a reverse osmosis purification system
Inventor:
Bruce D. Burrows
Patented Case
View Patent ↗
Granted: Jun 22, 1993
Filed: Nov 19, 1992
Inventor
Bruce D. Burrows
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.