IP Library › Granted Patent US 4,675,852
Granted Patent Utility
US 4,675,852 · App. 06/671,342

Apparatus for signalling within a borehole while drilling

Inventors: Michael K. Russell, Anthony Russell
Patented Case View Patent ↗
Granted: Jun 23, 1987 Filed: Nov 14, 1984
Inventors
Michael K. Russell
Anthony Russell
Assignee (at issue)
NL Industries, Inc.

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Quick Facts
Patent No.
US 4,675,852
App. No.
06/671,342
Filed
1984-11-14
Granted
1987-06-23
Kind
A