Patents Assigned to Four E Inc.
  • Drill bit assembly
    Patent number: 4706765
    Abstract: A drill bit assembly comprised of a pilot bit and a plurality of add-on reamer sections which are sized to progressively increase the diameter of the hole in measured increments. Both the pilot bit and the reamer sections have two cutter elements which take advantage of the bi-center concept and both use knife edged cutters instead of teeth to drill the hole.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: November 17, 1987
    Assignee: Four E Inc.
    Inventors: Ernie J. Lee, William L. Thornton