Granted Patent
Utility
US 4,723,807 · App. 06/855,923
Wheel and track system
Inventors:
David M. Pruett, Robert D. Brown
Patented Case
View Patent ↗
Granted: Feb 9, 1988
Filed: Apr 25, 1986
Inventors
David M. Pruett
Robert D. Brown
Assignee (at issue)
Portec, 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.