Granted Patent
Utility
US 4,405,990 · App. 06/282,999
Apparatus for determining the ratio of two signal repetition rates
Inventors:
William Pickering, David J. Urbanc
Patented Case
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Granted: Sep 20, 1983
Filed: May 26, 1981
Inventors
William Pickering
David J. Urbanc
Assignee (at issue)
Caterpillar Tractor Co.
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.