Granted Patent
Utility
US 4,386,667 · App. 06/145,549
Plunger lubricant compensator for an earth boring drill bit
Inventor:
Stuart C. Millsapps, Jr.
Patented Case
View Patent ↗
Granted: Jun 7, 1983
Filed: May 1, 1980
Inventor
Stuart C. Millsapps, Jr.
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.