Granted Patent
Utility
US 6,828,372 · App. 09/800,171
Railroad tie and method for making same
Inventors:
Henry W. Sullivan, Gregory P. Krouse, William J. Krygsman
Patented Case
View Patent ↗
Granted: Dec 7, 2004
Filed: Mar 5, 2001
Inventors
Henry W. Sullivan
Gregory P. Krouse
William J. Krygsman
Assignees (at issue)
TieTek, Inc.
North American Technologies Group, 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.