Granted Patent
Utility
US 5,836,167 · App. 08/646,372
Method and apparatus for freezing large pipe
Inventors:
Stuart D. Clouston, Paul S. Goodwin
Patented Case
View Patent ↗
Granted: Nov 17, 1998
Filed: May 8, 1996
Inventors
Stuart D. Clouston
Paul S. Goodwin
Assignee (at issue)
Nowsco Well Service Ltd.
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.