Patents by Inventor John L. Schrag

John L. Schrag 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).

  • Apparatus and method for determining the viscoelasticity of liquids
    Patent number: 4754640
    Abstract: A rheometer for determining the viscoelasticity of a liquid from the mechanical impedance which the liquid presents to an oscillating surface. The incremental power required to maintain a fixed amplitude of oscillation of the surface upon immersion in the liquid is determined. The differential shift in oscillation frequency due to immersion in the liquid is also determined. By relating (i) the incremental oscillation power to mechanical resistance presented by the liquid to the oscillating surface, and (ii) the differential shift in a oscillation frequency to the mechanical reactance presented by the liquid to the oscillating surface, the viscoelasticity of the liquid is determined. Applications include laboratory measurements and process control.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: July 5, 1988
    Assignee: National Metal and Refining Company, Ltd.
    Inventors: J. Vincent Fitzgerald, Frank J. Matusik, Donald W. Nelson, John L. Schrag