Granted Patent
Utility
US 4,894,619 · App. 07/076,288
Impulse induced eddy current type detector using plural measuring sequences in detecting metal objects
Inventors:
Erkki Leinonen, Kari T. J. Aittoniemi
Patented Case
View Patent ↗
Granted: Jan 16, 1990
Filed: Jul 22, 1987
Inventors
Erkki Leinonen
Kari T. J. Aittoniemi
Assignee (at issue)
Outokumpu Oyj
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.