Abstract: A three-cone rock bit employing a non-plugging center jet nozzle with a plurality of staggered inlet orifices leading to side passageways to reduce bit balling. The nozzle defines a tapered cavity through which drilling mud flows and exits in streams. Streams are directed from the nozzle through a main exit aperture of sufficient size to avoid plugging and from side passageways boring through a sidewall of the nozzle. Jetting streams promote washing of voids within the bit and of cutting surfaces. The nozzle uses staggered inlet orifices leading to side passageways, in conjunction with a tapering shape of a central passageway to facilitate maintenance of drilling mud velocity within the central passageway and thus of stream velocity to targeted regions of the drill bit.

Abstract: A three-cone rock bit employing a non-plugging center jet nozzle with a plurality of staggered inlet orifices leading to side passageways to reduce bit balling. The nozzle defines a tapered cavity through which drilling mud flows and exits in streams. Streams are directed from the nozzle through a main exit aperture of sufficient size to avoid plugging and from side passageways boring through a sidewall of the nozzle. Jetting streams promote washing of voids within the bit and of cutting surfaces. The nozzle uses staggered inlet orifices leading to side passageways, in conjunction with a tapering shape of a central passageway to facilitate maintenance of drilling mud velocity within the central passageway and thus of stream velocity to targeted regions of the drill bit. The present invention additionally provides a method of using the drill bit and non-plugging nozzle by controlling velocities of drilling mud within the nozzle.

Abstract: A non-plugging nozzle and self-cleaning drilling tool incorporating the nozzle is provided. The nozzle has a body that defines a central passageway extending axially from the top to the bottom of the body. The central passageway defines an inlet orifice at the top and an exit orifice at the bottom. A side passageway extends through the side wall of the nozzle and communicates with a cylindrical portion of the central passageway, the intersection of which defines a side inlet orifice that is substantially square. Because the intersection is substantially square, particles may not become trapped within the nozzle and plug the side passageway. When incorporated into a drilling tool, particularly a polycrystalline diamond compact (PDC) bit, the drilling tool becomes self cleaning. The side passageway of the nozzle is directed at the voids formed in the cutting face of the drilling tool creating a cross flow through the voids and preventing accumulation and balling therein.

Abstract: An improved rotary cone rock bit that provides a cross flow through the drill bit dome to reduce bailing and improve the efficiency of the drilling operation. The rotary cone rock bit has a bit body with a pin at its upper end adapted to connect to a drill string. The lower end of the bit body has three leg segments extending from its periphery in a downward direction. Drilling cones rotatably mounted to each leg segment provide the cutting action of the rock bit. The conical drilling cones extend from the leg segments toward the center axis of the rotary cone rock bit with the smaller diameter end distal the leg segments. The rotary cutter cones and the lower end of the bit body define a dome therebetween. Nozzles extend downward from the base areas between the leg segments. The nozzles are in flow communication with an opening in the bit body that transmits fluid from the drill string therethrough. The nozzles direct fluid toward the dome to create a Cross flow therethrough.