Patents by Inventor Dan B. Justman

Dan B. Justman 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).

  • Bearing structure for downhole motors
    Patent number: 5037212
    Abstract: A bearing assembly for a downhole motor comprising a pair of annular support rings, each having a plurality of polycrystalline diamond thrust bearing inserts mounted thereon. The rings are oriented to have the respective inserts face and bear against each other. In operation, drilling mud passes through the space between the inserts to cool the inserts. The rings are made of tungsten carbide to prevent erosion of the areas at the bases of the inserts, thereby improving the life of the thrust bearings.
    Type: Grant
    Filed: November 29, 1990
    Date of Patent: August 6, 1991
    Assignee: Smith International, Inc.
    Inventors: Dan B. Justman, George A. Cross