Granted Patent
Utility
US 4,298,077 · App. 06/047,296
Circulation valve for in-hole motors
Inventor:
Maurice M. Emery
Patented Case
View Patent ↗
Granted: Nov 3, 1981
Filed: Jun 11, 1979
Inventor
Maurice M. Emery
Assignee (at issue)
SMITH INTERNATIONAL, INC.
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.