Granted Patent
Utility
US 4,253,472 · App. 06/093,575
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Inventor:
James F. Rayfield
Patented Case
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Granted: Mar 3, 1981
Filed: Nov 13, 1979
Inventor
James F. Rayfield
Assignee (at issue)
Sperry Corp.
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.