Granted Patent
Utility
US 6,717,093 · App. 10/034,154
Methods and systems for fabricating spiral welded cylinders
Inventors:
Stephen A. Coughlin, Warner G. Fencl, Robert Shaner, Michael R. Williams
Patented Case
View Patent ↗
Granted: Apr 6, 2004
Filed: Dec 27, 2001
Inventors
Stephen A. Coughlin
Warner G. Fencl
Robert Shaner
Michael R. Williams
Assignee (at issue)
American Railcar Industries, 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.