Abstract: A rolling cone rock bit includes a plurality of PDC or other cutters mounted to the leg of the drill bit and positioned to cut the corner of the bottomhole. The plurality of cutters may be the primary cutting component at gage diameter, or may be redundant to gage teeth on a rolling cutter that cut to gage diameter. Consequently, the occurrence of undergage drilling from the wear and failure of the gage row on a rolling cutter is lessened. Also included is a mud ramp that creates a large junk slot from the borehole bottom up the drill bit. The resulting pumping action of the drill bit ramp speeds up the removal of chips or drilling cuttings from the bottom of the borehole, reduces the level of hydrostatic pressure at the bottom of the borehole and minimizes the wearing effect of cone inserts regrinding damaging drill cuttings.

Abstract: A drill bit configures hydraulic streams from the bit nozzles for the particular cutting structure to be cleaned based on the cutting structure location and geometry. The projected impingement location for each hydraulic stream projected fluid path is customized for a corresponding roller cone, with each nozzle or nozzle receptacle being individually positioned according to improve cone cleaning. At least two nozzles or nozzle receptacles should differ on the drill bit.

Abstract: A novel rolling cone rock bit includes a plurality of PDC or other cutters mounted to the leg of the drill bit and positioned to cut the troublesome corner of the bottomhole. The plurality of cutters may be the primary cutting component at gage diameter, or may be redundant to gage teeth on a rolling cutter that cut to gage diameter. Consequently, the occurrence of undergage drilling from the wear and failure of the gage row on a rolling cutter is lessened. Another inventive feature is the inclusion of a mud ramp that creates a large junk slot from the borehole bottom up the drill bit. The resulting pumping action of the drill bit ramp speeds up the removal of chips or drilling cuttings from the bottom of the borehole, reduces the level of hydrostatic pressure at the bottom of the borehole and minimizes the wearing effect of cone inserts regrinding damaging drill cuttings.

Abstract: A cutter element for a drill bit has a crest that defines a crest line. The crest can be non-rectilinear. The crest line of each cutter element defines an angle with respect to the axis of the rolling cone on which the cutter element is mounted. The cutter elements define different angles with respect to the cone axis and with respect to each other.

Abstract: A novel rolling cone rock bit includes a plurality of PDC or other cutters mounted to the leg of the drill bit and positioned to cut the troublesome corner of the bottomhole. The plurality of cutters may be the primary cutting component at gage diameter, or may be redundant to gage teeth on a rolling cutter that cut to gage diameter. Consequently, the occurrence of undergage drilling from the wear and failure of the gage row on a rolling cutter is lessened. Another inventive feature is the inclusion of a mud ramp that creates a large junk slot from the borehole bottom up the drill bit. The resulting pumping action of the drill bit ramp speeds up the removal of chips or drilling cuttings from the bottom of the borehole, reduces the level of hydrostatic pressure at the bottom of the borehole and minimizes the wearing effect of cone inserts regrinding damaging drill cuttings.

Abstract: A cutter element for a drill bit has a non-rectilinear crest. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A drill bit having one or more nozzle retention bodies attached by a single orientation mounting is disclosed, as is the associated method for its manufacture. The upper end of the nozzle retention body has a fluid inlet in communication with the internal fluid plenum of the drill bit, and the lower end of the nozzle retention body includes a fluid outlet that defines an exit flow angle. The exit flow angle is angularly disposed from the longitudinal axis of the drill bit. The nozzle retention body may advantageously be chamfered or the like to provide a reduced cross-sectional area at the lower end of the nozzle retention body. The outer surface of the nozzle retention body (and attached hardened elements) may extend substantially to gage, or may fall short of that diameter.

Abstract: A cutter element for a drill bit has a non-rectilinear crest. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A roller cone drill bit includes a bit body adapted to be rotated about a longitudinal axis. At least one leg which terminates in a shirttail portion depends from the bit body. The shirttail portion defines a first end face having a first circumferential groove thereon. The first circumferential groove has a radius equal to the radius of a tip of the shirttail portion. A journal is cantilevered from the leg, and a roller cone is rotatably mounted on the journal. The roller cone has a second end face adjacent to the first end face. A second circumferential groove is formed on the second end face.

Abstract: A novel rolling cone rock bit includes a plurality of PDC or other cutters mounted to the leg of the drill bit and positioned to cut the troublesome corner of the bottomhole. The plurality of cutters may be the primary cutting component at gage diameter, or may be redundant to gage teeth on a rolling cutter that cut to gage diameter. Consequently, the occurrence of undergage drilling from the wear and failure of the gage row on a rolling cutter is lessened. Another inventive feature is the inclusion of a mud ramp that creates a large junk slot from the borehole bottom up the drill bit. The resulting pumping action of the drill bit ramp speeds up the removal of chips or drilling cuttings from the bottom of the borehole, reduces the level of hydrostatic pressure at the bottom of the borehole and minimizes the wearing effect of cone inserts regrinding damaging drill cuttings.

Abstract: A cutter element for a drill bit. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A drill bit having a canted or non-canted leg backface, a canted or non-canted seal in the interface between the cone backface and the shirttail, and a canted seal that can be semi-encapsulated so that there is no straight-line path across the seal.

Abstract: A novel nozzle and retainer assembly are used in an earth boring rock bit. A tapered interface between the nozzle and retainer protects the nozzle from impact and breakage downhole. A bushing may also be used in conjunction with an alternative nozzle and retainer assembly.

Abstract: A rotary cone rock bit has bearing inserts pressed into the side of the shirttail portion of the rock bit body for stabilizing the rock bit during drilling. Such a rock bit has a steel bit body with a threaded upper pin for connection to a drill string. Cutter cones are mounted on lower leg portions of the rock bit body. The rock bit body gradually decreases in diameter from the gage diameter adjacent the lower tips of the shirttails adjacent to the cones to a smaller diameter shoulder the pin end of the body. The lowermost bearing insert protrudes laterally from the gradually decreasing diameter part of the bit body approximately half way between the lower tip of the shirttail and the shoulder at the upper end of the shirttail. The outer ends of the bearing inserts are rounded and substantially at the gage diameter of the bit for bearing on the wall of the borehole being drilled without appreciably reaming the borehole.

Abstract: A milled tooth rotary cone rock bit, as it is operated in a borehole, subjects the heel of each cone into contact with the borehole wall when the gage row milled teeth wear. The heel row of each cone is relieved and tungsten carbide chisel inserts are equidistantly placed within the relieved heel row. The heel row inserts cooperate with the gage row milled teeth and progressively cut more of the gage of the borehole as the row of milled teeth on the gage of the cone wear. Moreover, the gage row milled teeth are partially hardfaced leaving relieved areas on the cutting side of each tooth to enhance the cutting action of the gage row of each cone.

Abstract: The inserts for a roller cone of a multiple cone rock bit are positioned or angled in the cone to attack an earthen formation such that the inserts are subjected to more compressive forces and the formation is subjected to more shear forces as the roller cutters roll over the bottom of the formation.