Patents by Inventor Leonard E. Dolhert

Leonard E. Dolhert 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: 7267292
    Abstract: Grinding media, including shaped media such as spheres or rods ranging in size from about 0.5 micron to 100 mm in diameter, are formed from a multi-carbide material consisting essentially of two or more carbide-forming elements and carbon, with or without carbide-forming elements in their free elemental state. The media have extremely high mass density, extreme hardness, and extreme mechanical toughness.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: September 11, 2007
    Assignee: Primet Precision Materials, Inc.
    Inventors: Robert Dobbs, Leonard E. Dolhert
  • Patent number: 5256609
    Abstract: Green ceramic formulations comprising an atactic polypropylene-containing binder are suitable for tape casting and can be effectively removed during thermal processing in reducing atmospheres. The binder may be removed in substantially dry reducing atmosphere. The tapes may be used for forming ceramic substrates and metallized ceramics such as those used in electronic packaging.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: October 26, 1993
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Leonard E. Dolhert
  • Patent number: 5217946
    Abstract: Superconductors having a composition Bi.sub.2-a-b-c Sn.sub.a Pb.sub.b Sb.sub.c Sr.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+4 can be made by firing the appropriate mixtures of designated oxides or carbonates. In the composition a=about 0.001-0.4, b about 0-0.4, c about 0-0.4, and n 2 or 3. The addition of Sn improves the superconductive properties of comparable compositions that lack Sn. For example, Bi.sub.1.6 Sn.sub.0.4 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x (x=ca 10), calcined at 830.degree. C. for 15 hours shows superconductivity by magnetic susceptibility tests at about 77.degree. K. whereas Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 prepared under the same conditions but lacking Sn, shows nothing at this temperature.
    Type: Grant
    Filed: May 1, 1989
    Date of Patent: June 8, 1993
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Leonard E. Dolhert
  • Patent number: 5203936
    Abstract: Green ceramic formulations comprising a polyisobutylene binder are suitable for tape casting and can be effectively removed during thermal processing in reducing atmospheres. The binder may be removed in substantially dry reducing atmosphere. The tapes may be used for forming ceramic substrates and metallized ceramics such as those used in electronic packaging.
    Type: Grant
    Filed: December 16, 1991
    Date of Patent: April 20, 1993
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Leonard E. Dolhert, James D. Idol, Jr.
  • Patent number: 5200249
    Abstract: Metallization formulations containing a mixture of AlN and metal are used to form hermetic vias in AlN dielectric bases for electronic packaging. The metal may be W, Mo, or mixtures thereof. The metallization may be cofired with the AlN dielectric base. The metallization is especially useful for making electrically conductive hermetic through-vias in AlN bases.
    Type: Grant
    Filed: August 22, 1991
    Date of Patent: April 6, 1993
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Leonard E. Dolhert, Jack H. Enloe, Ellice Y. Luh, John W. Lau
  • Patent number: 5164345
    Abstract: The processes of the invention involve the formation of an initial reactant mixture by combining sources of SiO.sub.2, B.sub.2 O.sub.3, aluminum, and carbon. The mixture may then optionally be shaped or compacted. The reactant mixture is then heated to start a reaction which is described by the formula:4 C+3 SiO.sub.2 +2 B.sub.2 O.sub.3 +8 Al.fwdarw.4 Al.sub.2 O.sub.3 +B.sub.4 C+3 SiC.Depending on the actual reactant mixture compositions and reaction conditions, other reactions may also occur.
    Type: Grant
    Filed: March 21, 1991
    Date of Patent: November 17, 1992
    Assignee: W.R. Grace & Co.-Conn.
    Inventors: Roy W. Rice, Leonard E. Dolhert, Jack H. Enloe
  • Patent number: 5021400
    Abstract: Improved process for making Tl-Ca-Ba-CuO superconductors. A solution of the monocarboxylates (e.g., acetates) of Ca, Ba, and Cu is dried, calcined, mixed with Tl.sub.2 O.sub.3, and the mixture is heated to make a superconductor. The method minimizes introduction of contaminants. Novel compositions result.
    Type: Grant
    Filed: October 17, 1989
    Date of Patent: June 4, 1991
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Jacob Block, Leonard E. Dolhert
  • Patent number: 5002926
    Abstract: Improved process for making Tl-Ca-Ba-Cu oxide superconductors. A solution of the nitrated of Ca, Ba, and Cu is reacted with a quaternary ammonium carbonate in a slurry (heel) of Tl.sub.2 O.sub.3. Carbonates of Ca, Ba, and Cu precipitate homogeneously on the Tl.sub.2 O.sub.3 particles. Solids are recovered, dried, and heated to make a superconductor. The method minimizes introdution of contaminants. Novel compositions result.
    Type: Grant
    Filed: June 3, 1988
    Date of Patent: March 26, 1991
    Assignee: W. R. Grace & Co.- Conn.
    Inventors: Nicholas D. Spencer, Leonard E. Dolhert
  • Patent number: 4720362
    Abstract: An article of manufacture is provided comprising a polycrystalline cubic aluminum oxynitride having a density of at least 98% of theoretical density, and being transparent to electromagnetic radiation in the wavelength range from 0.3 to 5 micrometers with an in-line transmission of at least 20% in this range.A method of preparing the optically transparent aluminum oxynitride is also provided comprising the steps of forming a green body of substantially homogeneous aluminum oxynitride powder and pressureless sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron and yttrium in elemental or compound form.
    Type: Grant
    Filed: March 20, 1985
    Date of Patent: January 19, 1988
    Assignee: Raytheon Company
    Inventors: Richard L. Gentilman, Edward A. Maguire, Leonard E. Dolhert
  • Patent number: 4520116
    Abstract: An article of manufacture is provided comprising a polycrystalline cubic aluminum oxynitride having a density of at least 98% of theoretical density, and being transparent to electromagnetic radiation in the wavelength range from 0.3 to 5 micrometers with an in-line transmission of at least 20% in this range.A method of preparing the optically transparent aluminum oxynitride is also provided comprising the steps of forming a green body of substantially homogeneous aluminum oxynitride powder and pressureless sintering said green body in a nitrogen atmosphere and in the presence of predetermined additives which enhance the sintering process. Preferred additives are boron and yttrium in elemental or compound form.
    Type: Grant
    Filed: January 13, 1984
    Date of Patent: May 28, 1985
    Assignee: Raytheon Company
    Inventors: Richard L. Gentilman, Edward A. Maguire, Leonard E. Dolhert