Granted Patent
Utility
US 4,375,242 · App. 06/177,292
Sealed and lubricated rock bit with air protected seal ring
Inventor:
Edward M. Galle
Patented Case
View Patent ↗
Granted: Mar 1, 1983
Filed: Aug 11, 1980
Inventor
Edward M. Galle
Assignee (at issue)
Hughes Tool Company LLC
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.