Patents by Inventor Robert T. Duncan

Robert T. Duncan 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).

  • Method and apparatus for regulating the size and frequency of bubbles employed for mixing liquids
    Patent number: 4136970
    Abstract: A few large, fast rising gas bubbles are generated near the bottom of a sample container and the upward movement of the bubbles causes a mixing action of the sample. The bubbles result from the periodic injection of discrete quantums of gas into the bottom of the container. The volume of a discrete gas quantum determines the size of a resulting bubble. Both the volume and frequency of generation of the quantums of gas are controlled by a timing circuit which operates a solenoid valve that permits each discrete quantum of gas to pass into the sample container.
    Type: Grant
    Filed: December 15, 1977
    Date of Patent: January 30, 1979
    Assignee: Coulter Electronics, Inc.
    Inventors: Pedro P. Cabrera, Robert T. Duncan