Granted Patent
Utility
US 4,971,239 · App. 07/287,727
Method and apparatus for making welded tapered tubes
Inventors:
Truett Tyler, William A. Muller, Gregory Hart, Michael GRABOWSKI
Patented Case
View Patent ↗
Granted: Nov 20, 1990
Filed: Dec 21, 1988
Inventors
Truett Tyler
William A. Muller
Gregory Hart
Michael GRABOWSKI
Assignee (at issue)
Ameron, 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.