Patents by Inventor J. Barry French

J. Barry French has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4329582
    Abstract: A tandem quadrupole mass spectrometer system having first, second and third quadrupole sections close coupled in series with one another. AC-only is applied to the center section and conventional AC and DC voltages are applied to the two end sections. The AC applied to all three sections is synchronized in frequency. The AC phase shift between each section is of magnitude between 0 and 0.1 cycles in absolute value, preferably between 0 and 0.03 cycles in absolute value, and in the preferred embodiment the AC phase shift between each section is essentially zero. The sections are spaced apart longitudinally by a very short distance not exceeding r.sub.o, the radius of the inscribed circle within the quadrupole rods.
    Type: Grant
    Filed: July 28, 1980
    Date of Patent: May 11, 1982
    Inventors: J. Barry French, Peter H. Dawson