Patents by Inventor Bruce L. Campbell

Bruce L. Campbell 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).

  • Rock bits and inserts therefor
    Patent number: 4811801
    Abstract: The present invention is a rock bit insert including a polycrystalline diamond surface on an insert body having a head portion made from a material with elasticity and thermal expansion properties advantageously tailored for use in three types of rock bits, as well as the three types of rock bits made with such inserts. The three types of bits are a roller cone rock bit adapted to be used with mud as the drilling fluid, a roller cone rock bit adapted to be used with air as the drilling fluid, and a percussion rock bit.
    Type: Grant
    Filed: March 16, 1988
    Date of Patent: March 14, 1989
    Assignee: Smith International, Inc.
    Inventors: William J. Salesky, Bruce L. Campbell