Granted Patent
Utility
US 4,391,339 · App. 06/211,662
Cavitating liquid jet assisted drill bit and method for deep-hole drilling
Inventors:
Virgil Johnson, Jr., T. R. Sundaram, Andrew F. Conn
Patented Case
View Patent ↗
Granted: Jul 5, 1983
Filed: Dec 1, 1980
Inventors
Virgil Johnson, Jr.
T. R. Sundaram
Andrew F. Conn
Assignee (at issue)
Hydronautics, Incorporated
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.