Granted Patent
Utility
US 5,263,422 · App. 07/986,279
Protected gate lock for hopper cars
Inventor:
Richard Barefoot
Patented Case
View Patent ↗
Granted: Nov 23, 1993
Filed: Dec 7, 1992
Inventor
Richard Barefoot
Assignee (at issue)
Ellcon National, 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.