Granted Patent
Utility
US 4,919,204 · App. 07/298,688
Apparatus and methods for cleaning a well
Inventors:
Walter Baker, Malcolm N. Council
Patented Case
View Patent ↗
Granted: Apr 24, 1990
Filed: Jan 19, 1989
Inventors
Walter Baker
Malcolm N. Council
Assignee (at issue)
Otis Engineering 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.