Patents Assigned to Hepworth Minerals and Chemicals, Limited
  • Surfacing composition
    Patent number: 5041320
    Abstract: A sports surface comprises a pile fabric (11) and a layer of coated grains (13) in which the pile is partly submerged. The grains are of sand coated with a rubber.
    Type: Grant
    Filed: January 3, 1989
    Date of Patent: August 20, 1991
    Assignee: Hepworth Minerals & Chemicals Limited
    Inventors: William C. S. Meredith, Martin J. Luxton
  • Binders
    Patent number: 4952616
    Abstract: A foundry binder comprising an aqueous solution of sodium polyacrylate and calcium hydroxide is cured by the addition of a liquid ester.
    Type: Grant
    Filed: November 15, 1988
    Date of Patent: August 28, 1990
    Assignee: Hepworth Minerals & Chemicals Limited
    Inventors: Martin J. Luxton, William C. S. Meredith, Andrew Harrod
  • Preparation of foundry molds or cores
    Patent number: 4848443
    Abstract: Foundry molds and cores are prepared by using as a binder a phenolic resin in solution in aqueous sodium hydroxide and using an ester to cure the binder. The ester may be incorporated in the mixture prior to shaping, or the ester in gaseous form may be passed through the shaped mixture.
    Type: Grant
    Filed: July 27, 1987
    Date of Patent: July 18, 1989
    Assignee: Hepworth Minerals and Chemicals, Limited
    Inventors: Geoffrey W. Westwood, Raymond A. Higgins