Patents by Inventor Roger W. Steele

Roger W. Steele 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: 6420043
    Abstract: A flaked niobium powder is disclosed as well as electrolytic capacitors formed from the flaked niobium powders. Niobium powders having a BET surface area of at least about 0.50 m2/g are also disclosed and capacitors made therefrom, as well as niobium powders doped with an oxygen content of at least 2,000 ppm. Methods to reduce DC leakage in a niobium anode are also disclosed.
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: July 16, 2002
    Assignee: Cabot Corporation
    Inventors: James A. Fife, Jane Jia Liu, Roger W. Steele
  • Patent number: 6165623
    Abstract: A flaked niobium powder is disclosed as well as electrolytic capacitors formed from the flaked niobium powders. Niobium powders having a BET surface area of at least about 0.50 m.sup.2 /g are also disclosed and capacitors made therefrom, as well as niobium powders doped with an oxygen content of at least 2,000 ppm. Methods to reduce DC leakage in a niobium anode are also disclosed.
    Type: Grant
    Filed: November 3, 1997
    Date of Patent: December 26, 2000
    Assignee: Cabot Corporation
    Inventors: James A. Fife, Jane Jia Liu, Roger W. Steele
  • Patent number: 5986877
    Abstract: A capacitor having a central electrode body having sintered metal anode with an electrode lead, the anode having a sintered product produced from a tantalum powder having deagglomerated particles such that the product of the volume mean diameter in microns multiplied by the specific surface area measured in m.sup.2 /g is a number in the range of below about 25. Capacitors having a central electrode with the anode produced from a sintered product produced from a heat treated and oxidized tantalum powder wherein the oxidized particle size is greater than about 0.7 m.sup.2 /g. Capacitors are defined in terms of anodes produced from powders having specified ratios of Scott Bulk Density to surface area or ratio of die fill rate to surface area.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: November 16, 1999
    Assignee: Cabot Corporation
    Inventors: Viren M. Pathare, Bhamidipaty K. D. P. Rao, James Allen Fife, Hongju Chang, Roger W. Steele, Lee M. Ruch
  • Patent number: 5954856
    Abstract: A process for sizing (i.e., comminuting) a tantalum powder including agglomerates of smaller particles, which process yields a tantalum powder having an as-comminuted agglomerate size distribution with the product of the Volume Mean Diameter, MV (in microns as measured by light scattering techniques such as Microtrac analysis), times specific surface area, BET (m.sup.2 /g), being less than about 25. These powders after sizing typically have ratios of Scott Bulk Density : BET Surface Area in the range from about 20 to about 35. Also provided are powders having a substantially unimodal and narrow agglomerate size distribution in all stages of production, namely after sizing (i.e., deagglomeration by comminution), thermal agglomeration (i.e., heat treatment), and deoxidation. These resultant powders have high surface area and good flowability properties and, upon sintering, exhibit controlled shrinkage with high porosity.
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: September 21, 1999
    Assignee: Cabot Corporation
    Inventors: Viren M. Pathare, Bhamidipaty K. D. P. Rao, James Allen Fife, Hongju Chang, Roger W. Steele, Lee M. Ruch