Granted Patent
Utility
US 4,531,579 · App. 06/461,649
Valve latch device for drilling fluid telemetry systems
Inventors:
Michael L. Larronde, Robert G. Hoos
Patented Case
View Patent ↗
Granted: Jul 30, 1985
Filed: Jan 27, 1983
Inventors
Michael L. Larronde
Robert G. Hoos
Assignee (at issue)
NL Industries, 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.