Abstract: A bit for directional boring according to the invention includes a bit body having a frontwardly facing sloped face effective for steering the bit in dirt. The sloped face defines a steering plane that defines an acute included angle relative to a lengthwise axis of rotation of the bit. A connection is provided at the rear of the bit body permitting the bit to be removably mounted at the lead end of a drill string, and one or more internal passages are provided in the bit body for carrying a drilling fluid to a front end of the bit body. A first cutting tooth is mounted on the bit body and extends frontwardly from the bit body at a first angle that causes the first tooth to cut along a first circular path as the bit rotates.

Abstract: An earth-boring bit for attachment to a drill string has rotatable cones with rows of cutting elements. The cutting elements are arranged in generally circumferential rows on each of the cones and interference fit into apertures in the shell surface. The rows include a heel row of cutting elements on the heel surface of each of the cones, and an adjacent row of adjacent row cutting elements next to the heel row cutting elements. Each heel row cutting element has at least one counterpart adjacent row cutting element that is spaced no farther from it than any other adjacent row cutting element, defining a proximal pair. Each of the cutting elements in each of the proximal pairs has a grip ratio, which is the barrel length divided by the diameter. Some of the proximal pairs having cutting elements with higher grip ratios than other cutting elements. None of the proximal pairs has both cutting elements with higher grip ratios.

Abstract: A rotary cone drill bit is provided with at least one cutter cone assembly having a machined cutting structure which will maintain an effective cutting profile despite abrasion, erosion and/or wear of the associated cutting elements. The machined cutting structure may be formed on a generally cone shaped blank by a series of lathe turns and/or plunge cuts. The cutting elements may be formed with an aggressive cutting profile. For one application, the crest of each cutting element has the general configuration of an ogee curve. A layer of hardfacing material may be applied over all or selected portions of the machined cutting structure.

Abstract: A roller cone drill bit in which the orientations of the teeth are varied within a single row, and/or between the heel row of one cone and the heel row of another cone, to prevent tracking.

Abstract: A bearing failure indicator for sealed and lubricated rolling cutter earth boring drill bits is disclosed. A plurality of cutting inserts, arranged in a plurality of rows, are secured in the rolling cone cutters. At least two of the rolling cone cutters are intermeshing cutters, arranged such that they have intermeshing rows of cutting inserts. A groove is formed in the intermeshing cutters with a row containing a plurality of generally flat top bearing inserts. In the normal operation of the drill bit, the rows of generally flat top bearing inserts do not contribute to the drilling action of the drill bit. However, when a bearing assembly fails in operation, the generally flat top bearing inserts engage the intermeshing rows of inserts in the adjacent intermeshing cutter causing the drilling torque to increase and thereby providing a signal indicating the bearing has failed.

Abstract: This invention relates to a roller bit applying for the oil, natural gas, mine and geological drilling, and more particularly relates to a kind of roller bit with the parallel inlayed compacts, it includes head and cone, the compact land and the teeth-groove are arranged on the cone, the difference is that there are 2 to 3 compacts having the cylindrical body being arranged on the top of the base teeth along the teeth direction. The cutting performance of the present invention is similar to that of the oblate compacts, and, by utilizing the conventional cylindrical compacts, it is not only easy to process and with low manufacturing cost, but the bit can effectively drill through the stringered earth formation with both hard and soft formation and thus better economic benefit from drilling the stringered formation can be obtained.

Abstract: A rotary cone drill bit is provided with at least one cutter cone assembly having a machined cutting structure which will maintain an effective cutting profile despite abrasion, erosion and/or wear of the associated cutting elements. The machined cutting structure may be formed on a generally cone shaped blank by a series of lathe turns and/or plunge cuts. The cutting elements may be formed with an aggressive cutting profile. For one application, the crest of each cutting element has the general configuration of an ogee curve. A layer of hardfacing material may be applied over all or selected portions of the machined cutting structure.

Abstract: A design for a gage tooth of the milled tooth variety is provided. The gage facing surface of each tooth is shaped so that only a narrow surface of each tooth contacts the borehole wall. Adjacent areas on each tooth slope away from the wall. The narrow gage facing surfaces, the sloping areas, and other areas are all covered with a suitable hard metal facing material.

Abstract: Roller cone drilling wherein the bit optimization process equalizes the downforce (axial force) for the cones (as nearly as possible, subject to other design constraints). Bit performance is significantly enhanced by equalizing downforce.

Abstract: A rotary cone drill bit is provided with at least one cutter cone assembly having a machined cutting structure which will maintain an effective cutting profile despite abrasion, erosion and/or wear of the associated cutting elements. The machined cutting structure may be formed on a generally cone shaped blank by a series of lathe turns and/or plunge cuts. The cutting elements may be formed with an aggressive cutting profile. For one application, the crest of each cutting element has the general configuration of an ogee curve. A layer of hardfacing material may be applied over all or selected portions of the machined cutting structure.

Abstract: A novel and improved roller cone drill bit and method of design are disclosed. A roller cone drill bit for drilling through subterranean formations having an upper connection for attachment to a drill string, and a plurality cutting structures rotatably mounted on arms extending downward from the connection. A number of teeth are located in generally concentric rows on each cutting structure. The actual trajectory by which the teeth engage the formation is mathematically determined. A straight-line trajectory is calculated based on the actual trajectory. The teeth are positioned in the cutting structures such each tooth having a designed engagement surface is oriented perpendicular to the calculated straight-line trajectory.

Abstract: A rotary drag-type drill bit, for drilling holes in subsurface formations, comprises a bit body having a leading face and a gauge region, a number of blades formed on the leading face of the bit and extending outwardly away from the axis of the bit so as to define between the blades fluid channels leading towards junk slots in the gauge region. Cutting elements are mounted along each blade, and nozzles in the bit body supply drilling fluid to the leading face of the bit for cleaning and cooling the cutting elements. At least some of said blades each have a leading edge which is non-linear, or convexly or concavely curved, as viewed axially of the bit, as it extends outwardly away from the axis of the bit. Blades of different shapes may be located alternately around the axis of the bit. The junk slots at the gauge region, and the kickers between which they are formed, may vary in width around the periphery of the bit, and may be inclined to the axis of the bit.

Abstract: An earth-boring bit has a rotating cutter of a hybrid design. The bit has a bit body and a bearing shaft which is cantilevered downwardly and inwardly from the bit body. The cutter is mounted for rotation on the bearing shaft and has a plurality of cutting elements arranged in circumferential rows on the cutter. These rows include inner rows and a heel row. The cutting elements in the inner row are formed of a hard metal such as tungsten carbide and are pressed interferingly into apertures in the cutter. The heel row is made up of steel teeth formed on the cutter.

Abstract: A rolling cone bit includes a cone cutter having a gage row and an adjacent nestled gage row of cutter elements that are positioned on gage so as to divide or share the borehole corner cutting duty. The wear resistance, hardness, toughness and shape of the cutter elements in the adjacent rows are optimized depending upon the type of cutting the respective rows perform, the characteristics of the formation being drilled and the drilling techniques being employed. In most applications, the nestled gage cutter elements will have cutting surfaces that are more wear resistant or harder than the cutting surfaces of the gage cutter elements which experience more bottom hole duty. The nestled gage cutter elements engage the borehole wall with a negative rake angle for increased durability. Preferably, the nestled gage cutter elements have continuously contoured and non-shearing cutting surfaces.

Abstract: Steel bodies are manufactured in a production process that employs polystyrene patterns in a lost foam casting process. The patterns are machined to permit the formation of complex shapes that cannot be reproduced in simple patterns that are extractable from reusable, two-piece pattern molds or dies. Bit patterns formed in the process have forward canted blades that are machined from mating planar surfaces to simplify the machining process. The edges of the forward canted blades form a spiral surface for mounting cutter elements. The forward canting makes the blades stronger and thus permits the blades to be thinner than non-canted blades to increase the clearance between blades, which improves the movement of the cuttings past the bit. Recesses are machined into the gauge face of the patterns to produce a recess in the casting for receiving hardfacing. The hardfacing in the recess forms a layer that cooperates with the surrounding blade material to form a smooth transition area as the bit wears during usage.

Abstract: An earth-boring bit has a bit body with at least one bearing shaft depending inwardly and downwardly therefrom. A cutter is mounted for rotation on each bearing shaft and has a cutter shell surface and a plurality of cutting elements arranged on the shell surface in generally circumferential rows. At least one row of cutting elements includes at least one reduced-projection cutting element disposed between adjacent cutting elements. The row with the reduced-projection element is an inner row, but may include heel rows as well.

Abstract: A steel tooth bit includes one or more rolling cone cutters having a generally conical surface, a heel surface, and preferably a transition surface therebetween. A row of gage cutter elements are secured to the cone cutter on the transition surface and have cutting surfaces that cut to full gage. A first inner row of off-gage steel teeth is positioned on the conical surface of the cone cutter so that the gage-facing cutting surfaces of the teeth are close to gage, but are preferably off-gage a distance D at a knee that is formed on the gage facing surface. Distance D is strategically selected such that the gage and off-gage cutter elements cooperatively cut the corner of the borehole. The lower most portion of the gage facing surface of these steel teeth are off gage a distance D' which is greater than D so as to bring the cutting tip of the teeth off gage to prevent undesired wear and rounding off of the tip of the cutter element.

Abstract: A rolling cutter drill bit has multiple rows of gage reaming inserts mounted in the gage face of the cutters. A first interlocking row of gage reaming inserts is positioned on the gage face of a cutter in close proximity to the gage row, such that the reaming inserts are closely adjacent to the mouth of the gage insert sockets. A second non-interlocking row of gage reaming inserts is positioned on the gage face of the cutter such that the reaming insert sockets are a predetermined minimum distance from the gage insert sockets and first reaming row sockets, thereby enabling a maximum number of large diameter reaming inserts to be placed in the second reaming row. Both the first and second reaming row inserts are sized and placed to maintain a desired distance between all insert sockets without affecting the size and spacing of gage row inserts.

Abstract: A drill bit includes a rolling cutter having a plurality of closed-end circumferential rows of teeth protruding from the body of the cutter. At least one of the rows of teeth lies along a path defined either by multiple helical segments or a canted planar periphery.

Abstract: A drill bit includes a rolling cutter having a plurality of circumferential rows of teeth protruding from the body of the cutter. At least one of the rows of teeth is a closed-end circumferential row located on the surface of the cutter along a closed-end circumferential path. The latter is a non-circular curve defined by a surface intersecting the body of the cutter obliquely with respect to its longitudinal axis.

Abstract: A rock bit is disclosed having a plurality of rolling cone cutters each having a gage row of inserts oriented to face the borehole bottom for crushing the same, and a second row of heel gage inserts which are oriented to face the borehole sidewall for scraping the same, heel inserts are nestled within the profile of the gage inserts in order to alleviate most of the scraping action normally encountered by gage inserts.

Abstract: An earth-boring bit is provided with three cutters, at least one of the three cutters are provided with a heel cutting structure defined by a plurality of heel inserts having crests thereon, the heel inserts being disposed in at least one substantially circumferential heel row and the crests of the heel inserts being generally aligned traversely to the rotational axis of the cutter. At least another of the cutters is provided with a substantially circumferential row of axial inserts having crests thereon disposed proximally to the base of the cutter, the crests of the axial inserts being generally aligned with the axis of rotation of the cutter.

Abstract: An earth-boring bit is provided with three cutters, two of the three cutters are provided with heel disk cutting elements defined by a pair of generally oppositely facing disk surfaces that generally continuously converge to define a circumferential heel disk crest. One of the two cutters having heel disk elements is further provided with an inner disk cutting element.

Abstract: A rotary drill bit comprises a bit body having a shank for connection to a drill string, a plurality of cutter assemblies mounted on the bit body, and a passage in the bit body for supplying drilling fluid to the surface of the bit. Certain cutter assemblies on the bit body are adapted to exhibit a volume factor which is significantly greater than the volume factor of other cutter assemblies on the bit body, with increase of rate of penetration, and at least the majority of said cutter assemblies of higher volume factor are better adapted for cutting softer formations than at least the majority of said other cutter assemblies. The bit therefore tends to act as a "heavy set" drill bit at lower rates of penetration in hard formations, and as a "light set" drill bit at higher rates of penetration in softer formations, and therefore tends to drill each formation more efficiently.

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: A rotary drill bit (10) having a plurality of roller cutters (20) with rows (32A, 32B, 32C, 32D) of cutting inserts (34,36,38,40) mounted within sockets (35,46) on the frusto-conical cutter body (30). The cutting inserts 34,36,38,40) have cutting surfaces formed with a wear-resistant material with certain cutting inserts (36,38) being formed of a wear-resistant material having a hardness higher than the hardness of the wear-resistant material on the remaining inserts (34,40) in each row. The hard cutting inserts (36,38) are positioned in each row in a predetermined pattern intermingled in a generally uniformly spaced pattern with the softer cutting inserts (34,40) and comprising generally between 20% and 50% of the total number of cutting inserts in a particular row.

Abstract: A drill bit has a plurality of roller cutters mounted on a front face of the drill bit. The roller cutters are mounted in pairs which are equidistantly spaced from an axis of rotation of the drill bit. Each roller cutter is rotatably mounted in a saddle affixed on the front face. The roller cutters are reversibly mounted in their saddles. Each roller cutter includes a plurality of circumferentially extending cutting structures spaced apart along an axis of rotation of the roller cutter. The cutting structures are arranged non-symmetrically relative to a center plane through the roller cutter so that when a roller cutter is reversed, the location of kerfs cut by the roller cutter change.

Abstract: Improvement in the drilling of vertical bore holes is achieved by an asymmetrical rotary cone bit having a substantially cylindrical body with a shank formed on the body and extending therefrom along a vertical axis for connection to a drill string. Projecting from the cylindrical body are three journal pins, which pins extend from the end of the body opposite from the shank. These three journal pins are circumferentially displaced such that the rotational axis of the first and second pins are displaced more than 120 degrees and less than 180 degrees. The axis of the third journal pin is circumferentially displaced equidistant from the axis of the other two journal pins. Journaled on the first and second journal pins are first and second roller cutter cones having substantially the same based diameter. Each of these cutter cones has cutting teeth extending from the surface thereof and includes a row of gage cutting teeth.

Abstract: A drill bit for use with a reciprocating device, wherein the bit is in the form of a rotatable corrugated frusto-conical roller, supported by a U-shaped member, attached to a mounting post. The corrugations are the cutting edges of the bit.

Abstract: A toothed tool body for a rotary drilling tool suitable not only for work normally performed with toothed roller bits or the like, but also advantageous in loamy or similar formations, has ribs extending peripherally between the teeth up to the tooth flanks and having a cross-section falling on both sides from a peak region, more particularly a roof-like cross-section. The peak region of the ribs is lower than the tips or edges of the teeth in the radial direction of the tool body.

Abstract: An oil well drilling bit is disclosed of the type utilizing hard metal inserts in the rolling cutters wherein each row of inserts on each cutter is located thereon in a sinusoidal or varying pattern rather than the strictly circumferential pattern of the prior art.

Abstract: A rock boring bit assembly which includes a body configured for engagement with associated driving mechanism. At least one roller cutter is rotatably mounted on the body. The roller cutter includes a plurality of cutting member disposed about the entire face or surface thereof in generally upstanding relationship. The cutting members are arrayed over the roller cutter surface with no channel between adjacent arrays of cutting members. The cutters have generally rectilinear edges and each of the edges is disposed in substantially oblique relationship to a plurality of other rectilinear edges of other cutting members disposed proximate thereto.

Abstract: An earth boring drill bit, particularly for large diameter shafts, has a cutter assembly with improved bearing and seal arrangement and an improved cutting insert arrangement. A cutter assembly has an axle with an enlarged central portion and reduced portions on both sides. A cutter sleeve is carried on bearings by the central portion of the axle. An annular member with a central bore is secured to each side of the cutter sleeve. A metal face seal is secured between the reduced portion and the central bore on each side. The cutter contains rows of hard metal inserts secured in holes in the exterior. To reduce tracking, the inserts within a row are separable into groups with varied pitch within each group. The groups cycle with two groups having a gradual increase in pitch and two groups having decreasing pitch.

Abstract: An earth boring drill bit for large diameter shafts has an improved cutter arrangement. The drill bit has a cutter support member with a number of cutters mounted to it for disintegrating the earth formation face. At least one inner cutter is mounted near the center for cutting the center area. A number of gage cutters are mounted at the periphery to cut the gage area of the shaft. A number of intermediate cutters are spaced between the inner and gage cutters. Each intermediate cutter overlaps one-half of its width with an adjacent intermediate cutter.

Abstract: A rotary rock bit is constructed having rolling cutter members for forming a borehole in the earth. Each rolling cutter member includes an annular row of cutting elements for cutting portions of the borehole. The cutting elements comprise cutting teeth or cutting inserts. Varied pitches are provided between the inserts/teeth. The pitches between pairs of inserts/teeth are varied so that the pitches between no two pairs of inserts/teeth in a row or group are the same. Since no two pairs of inserts/teeth have the same pitch, the probability of tracking will be remote. This increases the rate at which the bit penetrates the formation and generally decreases the probability of insert/tooth breakage therein. The present invention reduces or eliminates tracking and stumbling encountered in prior art earth boring bits.

Abstract: In boring apparatus of the type having cutters mounted for rotation about respective cutter axes in a frame which is in turn rotatable about a frame axis, each cutter having a body carrying teeth which in operation sweep a surface which is oblique to the axis of advance of the apparatus, that improvement wherein each cutter has selected tooth regions, preferably of alternating high and low tooth densities, spaced along the respective cutter axis, the tooth regions of the cutters are arranged in an ordered cycle progressing along the frame axis, and regions adjacent each other in the cycle are on different cutters and overlap each other along the frame axis.

Abstract: A drill bit has a plurality of roller cutters mounted on a front face of the drill bit. The roller cutters are mounted in pairs which are equidistantly spaced from an axis of rotation of the drill bit. Each roller cutter is rotatably mounted in a saddle affixed on the front face. The roller cutters are reversibly mounted in their saddles. Each roller cutter includes a plurality of circumferentially extending cutting structures spaced apart along an axis of rotation of the roller cutter. The cutting structures are arranged non-symmetrically relative to a center plane through the roller cutter so that when a roller cutter is reversed, the location of kerfs cut by the roller cutter change.