Granted Patent
Utility
US 4,909,980 · App. 07/225,675
Electromagnetic apparatus for positioning objects located behind a conductive wall
Inventor:
Matija Cenanovic
Patented Case
View Patent ↗
Granted: Mar 20, 1990
Filed: Jul 26, 1988
Inventor
Matija Cenanovic
Assignee (at issue)
Ontario Hydro
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.