Granted Patent
Utility
US 4,741,471 · App. 07/040,381
Method for manufacturing a rotary rock bit
Inventor:
Eric C. Sullivan
Patented Case
View Patent ↗
Granted: May 3, 1988
Filed: Apr 20, 1987
Inventor
Eric C. Sullivan
Assignee (at issue)
Hughes Tool Company - USA
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.