Patents by Inventor David L. Mitchell, Jr.

David L. Mitchell, Jr. 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).

  • Atmospheres for extending life of wire mesh belts used in sintering powder metal components
    Patent number: 5613185
    Abstract: The present invention discloses novel nitrogen-hydrogen based atmospheres for sintering steel components in continuous furnaces with consistent quality and properties while prolonging the life of the wire mesh belts, reducing maintenance costs, and improving furnace productivity. Specifically, it discloses the use of a controlled amount of an oxidizing agent such as moisture, carbon dioxide, nitrous oxide, or mixtures thereof along with nitrogen-hydrogen atmospheres. The amount of an oxidizing agent added to the nitrogen-hydrogen atmospheres to pre-condition belt material prior to its use for sintering and to sinter steel components is controlled in such a way that atmospheres become oxidizing to the belt material but reducing to steel components being sintered, specifically in the high heating and cooling zones of continuous furnaces.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: March 18, 1997
    Assignee: Air Products and Chemicals, Inc.
    Inventors: James G. Marsden, Donald J. Bowe, Kerry R. Berger, Diwakar Garg, David L. Mitchell, Jr.
  • Graphite/carbon articles for elevated temperature service and method of manufacture
    Patent number: 5352523
    Abstract: Graphite carbon surfaces are protected from elevated temperature oxidation and mechanical wear by electric arc thermal spray coating exposed surfaces with a titanium nitride or multi-element (e.g., aluminum-silicon-titanium) coating.
    Type: Grant
    Filed: May 8, 1992
    Date of Patent: October 4, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Zbigniew Zurecki, Edward A. Hayduk, Jr., John G. North, Robert B. Swan, David L. Mitchell, Jr.
  • Graphite/carbon articles for elevated temperature service and method of manufacture
    Patent number: 5304417
    Abstract: Graphite carbon surfaces are protected from elevated temperature oxidation and mechanical wear by electric arc thermal spray coating exposed surfaces with a titanium nitride or multi-element (e.g., aluminum-silicon-titanium) coating.
    Type: Grant
    Filed: June 2, 1989
    Date of Patent: April 19, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Zbigniew Zurecki, Edward A. Hayduk, Jr., John G. North, Robert B. Swan, David L. Mitchell, Jr.
  • Method of forming titanium nitride coatings on carbon/graphite substrates by electric arc thermal spray process using titanium feed wire and nitrogen as the atomizing gas
    Patent number: 5254359
    Abstract: Graphite and/or carbon surfaces are coated with a titanium nitride coating by exposing the substrate to electric arc thermal spray process wherein titanium wire as the source of titanium and nitrogen is used as the propelling (atomizing) gas.
    Type: Grant
    Filed: June 14, 1991
    Date of Patent: October 19, 1993
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Zbigniew Zurecki, Edward A. Hayduk, Jr., John G. North, Robert B. Swan, David L. Mitchell, Jr.
  • Method and apparatus for individually quick freezing small surface moist articles
    Patent number: 5220802
    Abstract: Method and apparatus for quick freezing particles with surface moisture by immersion in liquid cryogen to produce a frozen crust or layer on the particles followed by agitation in content with the vaporized cryogen to complete freezing and prevent clumping of the particles.
    Type: Grant
    Filed: July 21, 1992
    Date of Patent: June 22, 1993
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Edward F. Kiczek, Earl W. Moore, David L. Mitchell, Jr., Kevin S. McAfee
  • Method and apparatus for individually quick freezing small surface moist articles
    Patent number: 5168723
    Abstract: Method and apparatus for quick freezing particles with surface moisture by immersion in liquid cryogen to produce a frozen crust or layer on the particles followed by agitation in content with the vaporized cryogen to complete freezing and prevent clumping of the particles.
    Type: Grant
    Filed: November 7, 1991
    Date of Patent: December 8, 1992
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Edward F. Kiczek, Earl W. Moore, David L. Mitchell, Jr., Kevin S. McAfee