Patents by Inventor Frank H. Campbell

Frank H. Campbell 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).

  • Gypsum set accelerator and method of making the same
    Patent number: 6221151
    Abstract: A composition for accelerating the setting reaction of an aqueous calcined gypsum slurry, and a method of making the same are disclosed. The composition includes a vibratory ball milled mixture of calcium sulfate dihydrate and a surfactant. The composition is prepared by subjecting the mixture to the high-frequency, low-impact grinding action of a vibratory ball mill. The resultant composition has a potency superior to that of conventional gypsum set accelerators.
    Type: Grant
    Filed: August 16, 1999
    Date of Patent: April 24, 2001
    Assignee: National Gypsum Company
    Inventors: Frank H. Campbell, Robert J. Piasecki, Larry W. Kingston, Edward A. Burkard