Granted Patent
Utility
US 4,229,124 · App. 06/012,429
Automatic roof bolting system for mines
Inventors:
G. Robert Frey, Joseph Parrotto, Francis X. Fontaine
Patented Case
View Patent ↗
Granted: Oct 21, 1980
Filed: Feb 15, 1979
Inventors
G. Robert Frey
Joseph Parrotto
Francis X. Fontaine
Assignee (at issue)
Joy Manufacturing 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.