Granted Patent
Utility
US 4,379,261 · App. 06/185,968
Rotating magnetic field device for detecting cracks in metal
Inventor:
Kenneth Meade Lakin
Patented Case
View Patent ↗
Granted: Apr 5, 1983
Filed: Sep 10, 1980
Inventor
Kenneth Meade Lakin
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.