Granted Patent
Utility
US 4,441,997 · App. 06/469,888
Liquid filtration system
Inventor:
Larry D. Fields
Patented Case
View Patent ↗
Granted: Apr 10, 1984
Filed: Feb 25, 1983
Inventor
Larry D. Fields
Assignee (at issue)
Yardney Electric 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.