Patent ID: 6227314
Filing Date: 2001-05-08
Classification: E21B

Abstract:
An earth boring bit, comprising:a body having a longitudinal axis and a curvilinear exterior surface;a threaded pin on an upper end of the body for connection to a drill string;a plurality of bit legs formed symmetrically on the exterior surface of the body, each of the bit legs having an upper portion protruding from the exterior surface of the body and a lower portion extending below the body, a center point of and at the bottom of the lower portion of each of the bit legs being offset circumferentially from a center point of and at the top of the upper portion of each of the bit legs;a cutter mounted to the lower portion of each of the bit legs for rotation about a cutter axis; anda plurality of nozzle bosses formed on and protruding from the exterior surface of the body, each of the nozzle bosses housing a nozzle for discharging drilling fluid, each of the nozzle bosses being spaced between two of the bit legs, defining at least one drilling fluid return passage on the exterior surface of the body between each of the nozzle bosses and at least one of the bit legs.