Granted Patent
Utility
US 4,891,587 · App. 07/267,618
Magnetic field sensor using variations in ultrasound to determine magnetic field
Inventor:
Patrick T Squire
Patented Case
View Patent ↗
Granted: Jan 2, 1990
Filed: Nov 3, 1988
Inventor
Patrick T Squire
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT CORPORATION
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.