Granted Patent
Utility
US 4,656,615 · App. 06/744,323
Hydrophone array polarity test circuit
Inventor:
Gordon T. Grice
Patented Case
View Patent ↗
Granted: Apr 7, 1987
Filed: Jun 13, 1985
Inventor
Gordon T. Grice
Assignee (at issue)
Digicon, 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.