Patents by Inventor David W. Cairns

David W. Cairns 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 for determining the dynamic complex hardness of resilient roll coverings
    Patent number: 3979948
    Abstract: Apparatus for determining the dynamic complex hardness of resilient roll coverings including a portable housing for positioning directly on the resilient roll covering to be tested. The portable housing includes an adjustable probe coupled to force and displacement transducers. The adjustable probe is placed in contact with the resilient roll covering and vibrated. The transducers produce output signals in accordance with the force encountered by and displacement of the probe during displacement of the surface of the resilient roll covering. The output signals from the transducers are coupled to dynamic hardness and loss angle circuitry for providing direct measurements of the magnitude and phase angle of the dynamic complex hardness.
    Type: Grant
    Filed: September 8, 1975
    Date of Patent: September 14, 1976
    Assignee: Gravure Research Institute, Inc.
    Inventors: Harvey F. George, Charles G. Marrara, Robert H. Oppenheimer, David W. Cairns