Granted Patent
Utility
US 4,223,464 · App. 06/022,790
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Inventor:
Donald Winrow
Patented Case
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Granted: Sep 23, 1980
Filed: Mar 22, 1979
Inventor
Donald Winrow
Assignee (at issue)
Ferranti-Packard Limited
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.