Granted Patent
Utility
US 4,339,153 · App. 06/159,581
Apparatus for extending and retracting the cutter bars of a boring type mining machine
Inventors:
Maurice K. LeBegue, Earl C. Michael
Patented Case
View Patent ↗
Granted: Jul 13, 1982
Filed: Jun 16, 1980
Inventors
Maurice K. LeBegue
Earl C. Michael
Assignee (at issue)
National Mine Service 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.