Patents Assigned to Camco International Limited
  • Patent number: 6082474
    Abstract: A preform element, such as a preform cutting element for a rotary drag-type drill bit, includes a facing table of polycrystalline diamond having a front face, a peripheral surface, and a rear surface bonded to the front surface of a tungsten carbide substrate. The front surface of the substrate is formed with a plurality of recesses into which extend corresponding projections formed on the rear surface of the facing table. The recesses include at least one rebate which extends around only a part of the periphery of the substrate and into which extends a projection on the facing table which provides a part of the peripheral surface of the facing table.
    Type: Grant
    Filed: June 16, 1998
    Date of Patent: July 4, 2000
    Assignee: Camco International Limited
    Inventor: Terry R. Matthias