Granted Patent
Utility
US 4,596,496 · App. 06/643,042
Mine roof supporting truss system
Inventors:
Gary D. Tyrell, Robert W. Hill, Jerry E. Frease
Patented Case
View Patent ↗
Granted: Jun 24, 1986
Filed: Aug 22, 1984
Inventors
Gary D. Tyrell
Robert W. Hill
Jerry E. Frease
Assignee (at issue)
The Eastern Company
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.