Patents by Inventor David W. Marshall

David W. Marshall 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).

  • Patent number: 4428989
    Abstract: A polymeric composition containing copper flake in sufficient quantities to render the entire thickness of the polymeric composition electrically conductive. The copper flake is treated to remove oxides and reacted with conventional epoxy resins modified with an epoxidized polyol (polyglycol). The formulation not only exhibits outstanding anti-fouling properties but also exhibits anti-sliming properties. The composition is useful as a gel coat and when utilized on ships, boats, and other water craft, a vessel results which requires no additional anti-fouling or anti-sliming treatment for several years. The composition can also be used to great advantage as a liner for pipes and conduits used to transport salt or fresh water where fouling of the pipes is a problem. In one embodiment of the invention, a composition is disclosed which will cure under water. This particular formulation can be used to great advantage in patching holes in copper clad hulls and the like while the vessel is in water.
    Type: Grant
    Filed: June 21, 1982
    Date of Patent: January 31, 1984
    Assignee: Kennecott Corporation
    Inventor: David W. Marshall
  • Patent number: 4323599
    Abstract: Copper flake is treated to remove oxides and other contaminants from its surface and incorporated into an uncured water-insoluble polymer. When applied to a marine structure such as a boat hull, the coating exhibits outstanding anti-fouling properties. The cleaned copper flake is preferably incorporated into an uncured epoxy resin modified by reaction with a polyol. In one embodiment of the invention, the coating is applied and cured underwater using a strippable carrier.
    Type: Grant
    Filed: November 28, 1979
    Date of Patent: April 6, 1982
    Assignee: Kennecott Corporation
    Inventor: David W. Marshall
  • Patent number: 4197233
    Abstract: A polymeric composition containing copper flake in sufficient quantities to render the entire thickness of the polymeric composition electrically conductive. The copper flake is treated to remove oxides and reacted with conventional epoxy resins modified with an epoxidized polyol (polyglycol). The formulation not only exhibits outstanding anti-fouling properties but also exhibits anti-sliming properties.The composition is useful as a gel coat and when utilized on ships, boats, and other water craft, a vessel results which requires no additional anti-fouling or anti-sliming treatment for several years. The composition can also be used to great advantage as a liner for pipes and conduits used to transport salt or fresh water where fouling of the pipes is a problem.In one embodiment of the invention, a composition is disclosed which will cure under water. This particular formulation can be used to great advantage in patching holes in copper clad hulls and the like while the vessel is in water.
    Type: Grant
    Filed: March 15, 1978
    Date of Patent: April 8, 1980
    Assignee: Kennecott Copper Corporation
    Inventor: David W. Marshall
  • Patent number: 4079510
    Abstract: Disclosed is an electrical conductor formed from a plurality of elongate filaments, at least a portion of which have a non-circular cross section, the filaments arranged such that the conductor has a substantially smooth exterior surface and high density of material of the filaments in a cross section through the conductor perpendicular to its axis. A preferred method for forming such an electrical conductor involves the continuous electroforming of a plurality of elongate conductive filaments. After such filaments are stripped from a cathode track upon which they are deposited, a number of them are bunched and/or twisted together to form an electrically conductive strand. Finally, that strand is compacted to reduce its cross sectional area to provide it with a smooth exterior surface.
    Type: Grant
    Filed: August 23, 1976
    Date of Patent: March 21, 1978
    Assignee: Kennecott Copper Corporation
    Inventors: Kenneth W. McGrath, David W. Marshall, William R. O'Day, Jr., Thomas C. Wilder
  • Patent number: 4071737
    Abstract: An electrically conductive resinous composition of a copper flake, the surface of which has been cleaned by removing therefrom impurities and/or oxides, a resinous binder, an amount of copper flake in said resinous composition being from 25 to 70 percent, the impurities in said copper flake being less than 7000 ppm, said resinous composition being cured with a curative comprising a polyamide or an anhydride, or mixtures thereof; these compositions are suitable for uses such as heating panels or conformable heating shapes.
    Type: Grant
    Filed: September 23, 1976
    Date of Patent: January 31, 1978
    Assignee: Kennecott Copper Corporation
    Inventors: David W. Marshall, Jagdish Chandra Agarwal
  • Patent number: 4040942
    Abstract: Disclosed is an improved cathode arrangement for use in the electroformation of metallic filaments. The cathode includes a plurality of closed-loop plating surfaces that are congruent to, and interleaved with, each other. This pattern of plating surfaces facilitates the simultaneous stripping of a number of filaments reducing the likelihood of mutual interference among the filaments being stripped.
    Type: Grant
    Filed: August 23, 1976
    Date of Patent: August 9, 1977
    Assignee: Kennecott Copper Corporation
    Inventors: David W. Marshall, Kenneth W. MCGrath, William R. O'Day, Jr., Thomas C. Wilder
  • Patent number: 3983075
    Abstract: An electrically conductive resinous composition of a copper flake, the surface of which has been cleaned by removing therefrom impurities and/or oxides, a resinous binder, an amount of copper flake in said resinous composition being from 25 to 70 percent, the impurities in said copper flake being less than 7000 ppm, said resinous composition being cured with a curative comprising a polyamide or an anhydride, or mixtures thereof; these compositions are suitable for uses such as heating panels or conformable heating shapes.
    Type: Grant
    Filed: June 21, 1974
    Date of Patent: September 28, 1976
    Assignee: Kennecott Copper Corporation
    Inventors: David W. Marshall, Jagdish Chandra Agarwal
  • Patent number: 3932143
    Abstract: A building product, such as a roofing shingle or the like, is provided with flame resistance and protected against actinic degradation, and fouling by algae and micro-organisms by flame-spraying a metal coating on at least one side of the product and thereafter applying a second flame-sprayed coating, of copper, on the first layer to cover completely at least the one side of the product.
    Type: Grant
    Filed: May 23, 1974
    Date of Patent: January 13, 1976
    Assignee: Kennecott Copper Corporation
    Inventors: David W. Marshall, William R. O'Day, Jr.