Patents by Inventor David W. Trunko

David W. Trunko 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: 4698289
    Abstract: A process for making a ferrite spherical particulate toner carrier core from a raw fly ash comprising recovering the magnetic particles from the non-magnetic particles of the raw fly ash; selecting a desired size for the particles of the raw fly ash and screening the fly ash to obtain the desired sized particles; and purifying the resultant raw fly ash to obtain a ferrite composition having a particle size from 20-300 microns, in which the particles are essentially spherical, having an apparent density of at least 1.8 g/cm.sup.3, a saturation magnetization of 43-70 emu/g, a remanence of 5 emu/g or less, a Hall Flow of 20 sec. or greater/50 g.
    Type: Grant
    Filed: February 27, 1986
    Date of Patent: October 6, 1987
    Assignee: Halomet Inc.
    Inventors: Robert G. Aldrich, Geoffrey H. Earl, David W. Trunko
  • Patent number: 4592988
    Abstract: A ferrite toner carrier core composition derived from flyash comprising a mixture of spherical particulates of the general formula ##EQU1## wherein iron is the principal metallic element and i,j,k denote the number of atoms of monovalent, divalent and trivalent atoms present in one mole of the compound, andM.sub.x denotes monovalent atoms from Group IA of the Periodic Table, the alkali metals, usually sodium or potassium, alone or together.M.sub.y denotes divalent atoms from Group IIA of the Periodic Table, the alkali earth metals, usually magnesium or calcium, alone or together.M.sub.z denotes trivalent atoms from Group IVB, usually titanium, Group IVA, usually silicon and Group IIIA, usually aluminum. All permutations and combinations may be present.
    Type: Grant
    Filed: August 15, 1984
    Date of Patent: June 3, 1986
    Assignee: Halomet, Inc.
    Inventors: Robert G. Aldrich, Geoffrey H. Earl, David W. Trunko