Patents by Inventor Norman O. Clark

Norman O. Clark 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).

  • Finely divided calcium carbonate compositions
    Patent number: 4732748
    Abstract: Finely divided, wet-ground, dispersant-free calcium carbonate filler or pigment compositions are disclosed in which the particles of calcium carbonate are distributed in particular amounts in a particular fashion--broadly stated: in fine particle size distribution. Such compositions are useful in aqueous slurry or dry form as opacifying fillers for paper.
    Type: Grant
    Filed: December 10, 1986
    Date of Patent: March 22, 1988
    Assignee: Cyprus Mines Corporation
    Inventors: Robert D. Stewart, Norman O. Clark, Yew C. Chang
  • Pressure filters
    Patent number: 4447327
    Abstract: A tube pressure filter is provided with a filter element comprising a filter cloth sleeve which is tailored from a woven material so that the warp and/or weft filaments extend helically around the inner tubular body on which the filter element is supported whereby the filter cloth sleeve can be stretched transversely of the length thereof.
    Type: Grant
    Filed: October 22, 1979
    Date of Patent: May 8, 1984
    Assignee: English Clays Lovering Pochin & Co. Ltd.
    Inventor: Norman O. Clark
  • Pressure filters
    Patent number: 4300277
    Abstract: A tube pressure filter is provided with a filter element comprising a filter cloth sleeve which is tailored from a woven material so that the warp and/or weft filaments extend helically around the inner tubular body on which the filter element is supported whereby the filter cloth sleeve can be stretched transversely of the length thereof.
    Type: Grant
    Filed: October 22, 1979
    Date of Patent: November 17, 1981
    Assignee: English Clays Lovering Pochin & Company, Ltd.
    Inventor: Norman O. Clark
  • Mineral fillers
    Patent number: 4174279
    Abstract: In a method of dewatering by pressure filtration an aqueous suspension of a clay containing a small proportion of particles having an equivalent spherical diameter smaller than 1 micron, the improvement which comprises treating the aqueous suspension of the clay, prior to dewatering by pressure filtration at a pressure in excess of 150 pounds per square inch, with a water-soluble polyelectrolyte flocculant having a high density of positive charges.
    Type: Grant
    Filed: March 29, 1978
    Date of Patent: November 13, 1979
    Assignee: English Clays Lovering Pochin & Co. Ltd.
    Inventors: Norman O. Clark, Thomas R. Jones
  • Magnetic separation
    Patent number: 4129498
    Abstract: A magnetic field is established in a predetermined zone. A quantity of fluid, from which native magnetizable particles are to be separated, is passed through the predetermined zone; and, at the same time, a magnetizable material is passed through the predetermined zone in the same direction as the fluid, so that native magnetizable particles are attracted to the magnetizable material.
    Type: Grant
    Filed: November 24, 1975
    Date of Patent: December 12, 1978
    Assignee: English Clays Lovering Pochin & Co. Limited
    Inventors: Norman O. Clark, James H. P. Watson