Patents by Inventor Harold A. Sreshta

Harold A. Sreshta 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: 5653299
    Abstract: A steel tooth rolling cutter earth boring drill bit comprises a bit body with a threaded upper end for attachment to the end of a drill string, and a lower end comprising three legs extending downwardly from the bit body and with a rolling cutter rotatably mounted on each leg. A layer of wear resistant material is applied to a portion of each rolling cutter and comprises were resistant particles in a substantially steel matrix. The steel matrix is integrally formed with the cutter in a rapid, solid state densification powder metallurgy (RSSDPM) process, and comprises a duplex microstructure comprising from about 10 to about 40 volume percent austenite and from about 60 to 90 volume precent martensite. The duplex microstructure may be achieved by incorporating a minor fraction of pure nickel and/or manganese powder in the powder mix used in the process, thereby providing nickel or manganese enrichment of the austenitic zones of the matrix.
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: August 5, 1997
    Assignee: Camco International Inc.
    Inventors: Harold A. Sreshta, Eric F. Drake