Granted Patent
Utility
US 4,480,224 · App. 06/332,549
System for indicating the direction and net distance travelled by a medium containing a periodic asymmetrical flux pattern
Inventor:
Ralph Kricker
Patented Case
View Patent ↗
Granted: Oct 30, 1984
Filed: Dec 21, 1981
Inventor
Ralph Kricker
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.