Patents by Inventor Ralph C. Pratt

Ralph C. Pratt 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).

  • Insulating boards
    Patent number: 4241132
    Abstract: An insulating board has a polymeric reinforcement layer of fibrous material with a predetermined dielectric constant. A polymer is impregnated into said reinforcement layer and has a dielectric constant which is close to that of the dielectric constant of said fibrous material and the insulating board exhibits isotropic properties. A preselected desired dielectric constant or loss tangent can be built into the board by selection of fillers to preselect the dielectric constant or loss tangent without detracting from desired mechanical properties of the board.
    Type: Grant
    Filed: August 17, 1978
    Date of Patent: December 23, 1980
    Assignee: Castall Incorporated
    Inventors: Ralph C. Pratt, Robert Davis, Charles P. Howland