Granted Patent
Utility
US 4,838,477 · App. 07/193,758
Method of welding flanged pipe sections and apparatus therefor
Inventors:
Max Jerry Roach, Jack Curtus Taylor
Patented Case
View Patent ↗
Granted: Jun 13, 1989
Filed: May 13, 1988
Inventors
Max Jerry Roach
Jack Curtus Taylor
Assignee (at issue)
DuPont Canada 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.