Patents by Inventor Donald R. Duke

Donald R. Duke 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: 5303785
    Abstract: A diamond drag bit is disclosed with a plurality of radially disposed raised rib portions formed in a cutting end of the bit body. One or more nozzles formed in the cutting end directs drilling fluid through the valleys formed by the ribs and over the ribs during operation of the bit in an earthen formation. Diamond cutters are strategically positioned in an outer face of the ribs. A multiplicity of diamond segments forming at least one flat surface thereon are strategically positioned and secured flush with the outer surface of the raised rib both rearwardly and laterally of each of the diamond cutters. The flush segments serve to protect a trailing edge of the raised ribs during drag bit operation.
    Type: Grant
    Filed: August 25, 1992
    Date of Patent: April 19, 1994
    Assignee: Smith International, Inc.
    Inventor: Donald R. Duke