Roller cone drill bit with cuttings evacuator

A roller cone drill bit, comprising:

• a bit body defining an inner plenum configured to contain a drilling fluid;
• a plurality of roller cutter cones disposed in a cavity of the roller cone drill bit;
• a leg extending from the bit body and defining an evacuation hole having an inlet and an outlet, the inlet configured to receive cuttings from the cavity, the cuttings exiting the evacuation hole through the outlet;
• and
• a drilling fluid hole having a first end intersecting the inner plenum and a second end intersecting the evacuation hole.

A roller cone rock bit, comprising:

• a bit body defining an inner plenum configured to contain a drilling fluid;
• a plurality of roller cutter cones disposed in a cavity of the roller cone rock bit;
• a plurality of legs, each leg extending from the bit body and defining an evacuation hole having an inlet and an outlet, the inlet configured to receive cuttings from the cavity, the cuttings exiting the evacuation hole through the outlet;
• a plurality of drilling fluid holes, each drilling fluid hole having a first end intersecting the inner plenum and a second end intersecting a respective evacuation hole;
• a plurality of cuttings restrictors each disposed at and partially blocking a respective inlet, each cuttings restrictor having a generally cylindrical inner tapered surface increasing in diameter as the surface extends into the respective evacuation hole;
• and
• a plurality of excluders each disposed at a respective outlet and having a prong at least partially blocking an opening of the excluder, the prong configured to open to allow cuttings to exit the respective evacuation hole.

A drill bit, comprising:

• a bit body defining an inner plenum configured to contain a drilling fluid;
• a plurality of roller cutter cones disposed in a cavity of the drill bit;
• and
• a plurality of legs, at least one of the legs defining an evacuation hole configured to receive cuttings from a cavity of the drill bit, the cuttings moving through the evacuation hole and exiting the drill bit through an outlet, the evacuation hole having a tapered interior surface proximate an inlet and being configured to allow only cuttings sized to pass through the evacuation hole to enter the evacuation hole.