Granted Patent
Utility
US 5,881,809 · App. 08/926,308
Well casing assembly with erosion protection for inner screen
Inventors:
George A. Gillespie, Stephen A. Uban
Patented Case
View Patent ↗
Granted: Mar 16, 1999
Filed: Sep 5, 1997
Inventors
George A. Gillespie
Stephen A. Uban
Assignee (at issue)
United States Filter 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.