Patent ID: 6450270
Filing Date: 2002-09-17
Classification: E21B

Abstract:
An improved rotary cone bit, comprising:a drill bit body having a threaded end and two or more leg portions extending from an end of the bit body, and a plurality of bearing pins, one each forming a part of a respective leg portion of the bit body, each bearing pin extending inwardly; a plurality of cutter cones, one each of said cones journaled to rotate on the respective bearing pin; at least one nozzle in the bit body for directing a drilling fluid between and around the cutter cones; wherein each of the leg portions of the bit body has a longitudinal axis and a bearing pin surface area, each of the leg portions of the bit body comprising: a plateau extending along the longitudinal axis from the bearing pin surface area toward the threaded end, the surface of the plateau extending in substantially the same plane and having substantially the same surface configuration as the bearing pin surface area, and the surface of the plateau tapering to the threaded end, the surface of the plateau extends in the same plane as the plane of the bearing pin surface area from the bearing pin surface area about one-third to two-thirds of the distance between the bearing pin surface area to the threaded end; a first contoured surface contiguous to a first side of the plateau and having a longitudinal axis substantially parallel to the longitudinal axis of the plateau, said first contoured surface angled down and away from the plateau and extending from the bearing pin surface area to the threaded end; and a second contoured surface contiguous to a second side of the plateau opposite from the first side and having a longitudinal axis substantially parallel to the longitudinal axis of the plateau, said second contoured surface angled down and away from the plateau and extending from the bearing pin surface area to the threaded end.