Granted Patent
Utility
US 5,647,428 · App. 08/496,142
Recovery of tube cleaners
Inventor:
James F. Echols
Patented Case
View Patent ↗
Granted: Jul 15, 1997
Filed: Jun 28, 1995
Inventor
James F. Echols
Assignee (at issue)
Betzdearborn, 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.