Patents Assigned to Drilling & Service U.K. Limited
  • Rotary drill bits and method of use
    Patent number: 4397363
    Abstract: A rotary drill bit for use in subsurface formations includes fluid channels for the passage of drilling mud to remove cuttings. According to the invention to clear blockages there are only one or two unbranched channels for the passage of mud past the cutting elements and these are arranged in a spiral.
    Type: Grant
    Filed: January 2, 1981
    Date of Patent: August 9, 1983
    Assignee: Drilling & Service U.K. Limited
    Inventor: John M. Fuller
  • Rotary drill bits
    Patent number: 4382477
    Abstract: In a rotary drilling bit having preform cutting elements, a partial or total structural discontinuity is disposed between the elements and the underlying structure or within the underlying structure to reduce the bending strain upon the preform cutting elements. In this way there is a reduction in the fracture or damage of preform cutting elements.
    Type: Grant
    Filed: January 9, 1981
    Date of Patent: May 10, 1983
    Assignee: Drilling & Service U.K. Limited
    Inventor: John D. Barr