Granted Patent
Utility
US 5,699,577 · App. 08/773,696
Magnetic cleaning pig
Inventor:
William J. Rankin
Patented Case
View Patent ↗
Granted: Dec 23, 1997
Filed: Dec 27, 1996
Inventor
William J. Rankin
Assignee (at issue)
TDW Delaware, 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.