Abstract: A cutting tool comprises a tool body having a first end and a second end, and a longitudinal axis extending between the first end and the second end. The first end comprises two or more cutting portions, with each of the cutting portions comprising a cutting edge and a flank surface. Each cutting edge extends radially outwardly from a centre region of the first end to a perimetral edge of the first end, with the cutting edge being angled relative to the longitudinal axis. Each flank surface extends circumferentially from the cutting edge. Each of at least two of the two or more flank surfaces comprises an abrasive portion extending over at least a part of the respective flank surface and each abrasive portion comprises a plurality of abrasive features.

Abstract: A bit for drilling a wellbore includes: a shank having a coupling formed at an upper end thereof; a body mounted to a lower end of the shank; and a cutting face forming a lower end of the bit. The cutting face includes: a blade protruding from the body; a cutter including: a substrate mounted in a pocket formed in the blade; and a cutting table made from a superhard material, mounted to the substrate, and having a non-planar working face with a cutting feature; and a cutter orienting system including: a keyway formed in the substrate and angularly located opposite from the cutting feature; and a key formed in or mounted to the pocket and engaged with the keyway.

Abstract: Embodiments disclosed herein relate to downhole tools capable of creating a vibration, and more particularly to methods and apparatus for creating tunable pressure pulses for imparting vibration to a downhole drill string.

Abstract: A fixed-cutter drill bit is provided that includes a metal-matrix composite body having at least one metal-matrix composite blade. Cutters are disposed on the blades. A ductile insert is partially disposed within the body and has an exposed surface. The ductile insert has a greater ductility than the metal-matrix composite thereby alleviating stresses imposed on the metal-matrix composite during manufacture of the bit or drilling.

Abstract: A drill bit including a button array having different radii extending from the center of a head section, and more particularly, to a drill bit in which buttons are arranged so as to have different radii from the center of a drill bit head section, thereby striking bedrock points having different radii and improving the efficiency of a drilling operation.

Abstract: In one aspect of the present invention, a drill string has a drill bit with a body intermediate a shank and a working face. The working face has a plurality of blades converging at a center of the working surface and diverging towards a gauge of the working face. At least one blade has a cutting element with a carbide substrate bonded to a diamond working end with a pointed geometry. The diamond working end also has a central axis which intersects an apex of the pointed geometry. The axis is oriented between a 25 and 85 degree positive rake angle.

Abstract: A drill bit for rock drilling tools includes a drill bit head having a front surface including a face surface defining a forward-most end of the drill bit head. The face surface has an outer edge, a gauge surrounding the face surface, the gauge having an inner edge, and a transition region that extends in a direction of a longitudinal axis of the drill bit between the outer edge of the face surface and the inner edge of the gauge. An entirety of the face surface from which the cutting surfaces extend is non-flat so that a center of the face surface is axially forward of the outer edge of the face surface. The gauge includes a first gauge surface defining a first angle with the longitudinal axis over a first portion of a circumference of the gauge and a second gauge surface defining a second angle with the longitudinal axis over a second portion of the circumference of the gauge.

Abstract: A drill bit for percussive rock drilling tools includes a drill bit head having a front surface including a face surface defining a forward-most end of the drill bit head and at least one hole in the drill bit head for receiving a button. The drill bit includes at least one recess located in the face surface. The recess is larger than the hole. The hole is disposed in the recess so that an open end of the hole is disposed below the face surface. The drill bit head further includes a gauge surrounding the face surface, the recess being partially disposed in the gauge.

Abstract: An indexable thread forming tap including: a body in a shaft shape; and a tip concentrically and detachably attached to a leading end portion of the body by screw-fastening and rotationally driven around an axial center along with the body for rolling of a female thread, the body being disposed with a screw hole concentrically to the axial center such that a screw shaft disposed on the tip concentrically to the axial center is screwed into the screw hole for the screw-fastening, a leading end surface of the screw shaft being pressed against a bottom surface of the screw hole into close contact with each other by the screw-fastening to integrally fix the tip to the body without the leading end of the body abutting on the tip, the body being disposed with a restraining hole concentrically to the axial center.

Abstract: Embodiments of the invention relate to polycrystalline diamond compacts (“PDCs”) including a domed polycrystalline diamond (“PCD”) table that exhibit improved wear resistance and/or thermal stability. In an embodiment, a PDC includes a substrate having an interfacial surface, and a domed PCD table bonded to the interfacial surface of the substrate. The domed PCD table includes an exterior, convex generally cylindrical peripheral surface extending away from the interfacial surface of the substrate. The domed PCD table further includes a domed portion defining an upper, convex generally spherical surface, and an optional chamfer extending between the exterior, convex generally cylindrical peripheral surface and the upper, convex generally spherical surface.

Abstract: A rock drilling tool includes a drilling head provided with a cutting body and a helix arranged between the drilling head and a shaft. The cutting body extends continuously over a nominal diameter of the rock drilling tool and has an inner region configured as a centering tip and an outer region bordering the centering tip in the radial direction. The outer region is offset towards the rear in relation to the centering tip in the active direction of the rock drilling tool. The centering tip is configured as a pyramid or a truncated pyramid and has pyramidal edges with lateral surfaces located therebetween. At least one lateral surface of the centering tip is configured as a cavity.

Abstract: A downhole cutting tool may include a tool body; a plurality of blades extending from the tool body; a first blade comprising at least one pointed cutting element thereon, the at least one pointed cutting element comprising a first polycrystalline diamond material on a first carbide substrate, the first polycrystalline diamond material extending away from the first carbide substrate to terminate in a substantially pointed geometry opposite the first carbide substrate; a second blade comprising at least one shear cutting element, the at least one shear cutting element comprising a second polycrystalline diamond material on a second carbide substrate, the second polycrystalline diamond material forming a planar cutting surface opposite the substrate; wherein, when the first blade and the second blade are superimposed on each other, a central axis of the at least one pointed cutting element is offset from a central axis of the at least one shear cutting element.

Abstract: A down-hole hammer comprising a drill bit (10) and a drive collar (11) with an interconnection therebetween for causing rotation of the drill bit upon rotation of the drive collar. The drill bit (10) comprises a drill bit head (13) and a shank (19), the drill bit head (13) defining a cutting face (15) and having a circumferential shoulder section (17) adjacent the cutting face (15). The shank (19) extends from the shoulder section (17) in the direction away from the cutting face (15). The interconnection between the drill bit (10) and the drive collar (11) comprises a spline assembly including at least one spline (43) on the shoulder section (17) for mating engagement with at least one counterpart spline (63) on the drive collar (11) to provide a drive coupling therebetween while also allowing the drill bit (10) to slide axially within the drive collar (11) to perform a percussive action.

Abstract: The present invention relates to a drill bit assembly for fluid-operated percussion drill tools comprising a percussion bit (1) having a head portion (3) formed with an axially extending stub shank (32); axially extending splines (36) on the stub shank (32) slideably engageable with complementary splines (35) formed on a drive chuck (4) whereby rotational drive from the chuck (4) may be transmitted to the stub shank (32); bit retaining means adapted for engagement with complementary retaining means on the stub shank to retain the stub shank in the drill bit assembly; and engagement means on the chuck (4) adapted for connecting the chuck (4) to a drive means (5) of the fluid-operated percussion drill tool. The bit retaining means comprises a bit retaining ring (41), and the complementary retaining means comprises a retaining shoulder (37) on the stub shank, wherein the bit retaining ring is arranged to engage the retaining shoulder to retain the stub shank in the drill bit assembly.

Abstract: A rock drill bit having a shank fitted with a clamping end and a drilling tip located from the clamping end. The drilling tip has at least three blades and a central zone centered on a drill bit axis. The blades each include on a top side thereof a lip constituted by a leading chipping face and a trailing flank. The lips substantially converge onto each other within a the central zone of the drilling tip, wherein in the central zone, a long lip of the lips runs through the drill bit axis and has a commensurate overshoot segment extending beyond the drill bit axis.

Abstract: A roof-bolt drill bit may have a forward end, a rearward end, and a rotational axis extending between the forward end and the rearward end. A cutting element for the roof-bolt drill bit may include a cutting face and a peripheral surface extending around an outer periphery of the cutting face. The cutting element may include at least one chamfer region and a peripherally extending chamfer extending from the at least one chamfer region along the outer periphery of the cutting element, a width of the at least one chamfer region being greater than a width of the peripherally extending chamfer.

Abstract: A method and apparatus for down-the-hole drilling. The drilling is carried out by a drilling device including a casing and a drilling unit. The drilling head includes a first drill for drilling a center hole, a second drill for reaming the center hole and a flushing flow arrangement including a first flusher for leading a flushing medium onto a drilling surface and a second flusher for returning of the flushing medium and drilling waste inside the casing. The first drill is removably coupled with the second drill to enable removal thereof from the hole. The casing is arranged to be drawn into a hole to be drilled by the drilling unit. The flushing medium is brought onto the drilling surface and returned therefrom by axially directed flow arrangements disposed in a cross-section view on an outer periphery of the first drill and/or in an inner periphery of the second drill.

Abstract: A hammer assembly is actuated to drive an earth bit through a formation. The hammer assembly includes a piston, and a flow control tube which extends through the piston. The flow control tube includes drive and return guide ports. The piston is repeatably moveable relative to the drive and return guide ports in response to a fluid flow through the flow control tube. In this way, the hammer assembly is actuated.

Abstract: A drilling unit for drilling a borehole and having an outer drill bit being rotationally driven by a primary rotary drive mechanism about a primary axis of rotation and having an outer bit cutting face disposed for drilling engagement with formation material. The outer drill bit defines an inner bit passage intersecting the outer bit cutting face. An inner drill bit is rotationally driven within the inner bit passage by a secondary rotary drive mechanism and has a secondary axis of rotation that can be the same or can be laterally offset from the primary axis of rotation. An inner bit cutting face is defined by the inner drill bit and is located within the inner bit passage. Rotation of the outer drill bit for borehole drilling causes orbital rotation of the inner drill bit about the primary axis of rotation simultaneously with rotation of the inner drill bit about the secondary axis of rotation for continuously cutting away formation material at the central region of the borehole being drilled.

Abstract: A hammer bit is herein described with tapered lateral sides and a modified face section. The tapered lateral sides taper inward towards a rear portion of the hammer bit. The modified face section includes a gauge portion and a larger angled or heel portion. The hammer bit provides improved penetration and directional control for drilling into the earth.

Abstract: A percussion drilling assembly includes an outer tubular, an inner tubular coupled within the outer tubular at a threaded region, a drill bit slideably disposed within the inner tubular, and a locking system located proximate the threaded region. The locking system is actuatable by translation of the drill bit relative to the locking system, whereby the locking system is configured to prevent rotation of the inner tubular relative to the outer tubular in at least a first direction.

Abstract: A polycrystalline diamond drill bit for percussion drilling uses very low torque and thrust that is formed of very specific insert and bit body dimensions to achieve maximum penetration rates and bit life when drilling very hard, high silica ground. The bits are made using a double chisel design, or a modified double chisel design, in the placement of the inserts on the face of the drill bit. The inserts are set into the body are very specific angles. The inserts have specific length to cut clearance for the bit body. The cutting angle and radius on the tip of the inserts are of very specific dimensions. The diameter of the inserts is of a specific diameter to retard the inserts from shearing off. The thrust and torque settings on the drill when using these PCD bits is less than 20 bar. When assembled in the manner as described this provides a system for use and application of PCD drill bits in hard rock drilling.

Abstract: A method of boring through a formation includes providing a drilling machine and drill string and operatively coupling an earth bit to the drilling machine through the drill string. An air flow is provided through the drill string at an air pressure less than about one-hundred pounds per square inch (100 psi) and an overstrike force is applied to the earth bit, wherein the overstrike force is less than about five foot-pounds per square inch (5 ft-lb/in2).

Abstract: A rock drill bit for percussive drilling includes a bit head attached at an end of a drill element of a drilling assembly. The bit head has a diameter larger than that of the drill element. The bit head has at a front end as seen in the intended drilling direction a plurality of buttons distributed thereon to engage material to be crushed. At least one of the buttons is allowed to rotate about its own symmetry axis.

Abstract: A button and a rock drill bit for percussive drilling including a bit head attached at an end of a drill element of a drilling assembly. The bit head has at a front end, as seen in the intended drilling direction, a plurality of buttons distributed over the bit head to engage material to be crushed. At least one of the buttons has a shank portion made of a substrate material of particles of a first material embedded in a binder phase. The first material is harder than the binder phase. The shank portion at least partially forms a bearing portion, the material of which is harder than the binder phase. At least one of the buttons is allowed to rotate about its own respective symmetry axis.

Abstract: A down-the-hole drill (DHD) hammer having a casing, a drill bit proximate a distal end of the casing, a piston mounted within the casing and a self-indexing drive transmission is provided. The piston includes a plurality of helical and axial splines. The drive transmission includes a driver sleeve, a driven sleeve and a wrap spring clutch assembly. The driver sleeve and driven sleeve are housed within the casing and circumscribes the piston. The driver sleeve includes a plurality of openings for receiving a plurality of bearings. The driver sleeve bearings are configured to operatively engage the helical splines on the piston. The wrap spring clutch assembly includes a wrap spring circumscribing the driver sleeve and driven sleeve. The driven sleeve operatively engages the drill bit to rotationally index the drill bit.

Abstract: A rotationally locked drive assembly for a VSI crusher comprises a drive shaft 52 rotatably securable in a bearing cartridge assembly 60, the drive shaft having a tapered upper end portion 62 for forming a taper joint in cooperation with the tapered central opening 72 of a flywheel 54, a top opening key receptor 81 formed on the top surface 76 of the flywheel for receiving a locking key 56, whereby tightening of fasteners 58 secures locking key 56 in key receptor 81, presses flywheel 54 onto drive shaft 52, thereby fortifying the taper joint between the flywheel 54 and drive shaft 52, and locking drive shaft 52, flywheel 54 and locking key 56 in rotational alignment.

Abstract: A method of boring through a formation includes providing a drilling machine and drill string and operatively coupling an earth bit to the drilling machine through the drill string. An air flow is provided through the drill string at an air pressure less than about one-hundred pounds per square inch (100 psi) and an overstrike force is applied to the earth bit, wherein the overstrike force is less than about five foot-pounds per square inch (5 ft-lb/in2).

Abstract: A down-hole hammer comprising a drill bit (10) and a drive collar (11) with an interconnection therebetween for causing rotation of the drill bit upon rotation of the drive collar. The drill bit (10) comprises a drill bit head (13) and a shank (19), the drill bit head (13) defining a cutting face (15) and having a circumferential shoulder section (17) adjacent the cutting face (15). The shank (19) extends from the shoulder section (17) in the direction away from the cutting face (15). The interconnection between the drill bit (10) and the drive collar (11) comprises a spline assembly including at least one spline (43) on the shoulder section (17) for mating engagement with at least one counterpart spline (63) on the drive collar (11) to provide a drive coupling therebetween while also allowing the drill bit (10) to slide axially within the drive collar (11) to perform a percussive action.

Abstract: A down-hole hammer comprising a drill bit (10) and a drive collar (11) with an interconnection therebetween for causing rotation of the drill bit upon rotation of the drive collar. The drill bit (10) comprises a drill bit head (13) and a shank (19), the drill bit head (13) defining a cutting face (15) and having a circumferential shoulder section (17) adjacent the cutting face (15). The shank (19) extends from the shoulder section (17) in the direction away from the cutting face (15). The interconnection between the drill bit (10) and the drive collar (11) comprises a spline assembly including at least one spline (43) on the shoulder section (17) for mating engagement with at least one counterpart spline (63) on the drive collar (11) to provide a drive coupling therebetween while also allowing the drill bit (10) to slide axially within the drive collar (11) to perform a percussive action.

Abstract: A drill bit for attachment to an elongate drill rod, the drill bit including means for attachment to an end of the drill rod, and a leading end which defines a pair of diametrically opposed slots which open axially for receipt of a portion of a drill tip which projects axially from the slots. The drill tip being fixedly secured within each of the slots. Further, a drill rod or a self drilling roof bolt comprising the drill bit.

Abstract: The present invention relates to a drill bit assembly for fluid-operated percussion drill tools comprising a percussion bit (1) having a head portion (3) formed with an axially extending stub shank (32); axially extending splines (36) on the stub shank (32) slideably engageable with complementary splines (35) formed on a drive chuck (4) whereby rotational drive from the chuck (4) may be transmitted to the stub shank (32); bit retaining means adapted for engagement with complementary retaining means on the stub shank to retain the stub shank in the drill bit assembly; and engagement means on the chuck (4) adapted for connecting the chuck (4) to a drive means (5) of the fluid-operated percussion drill tool. The bit retaining means comprises a bit retaining ring (41), and the complementary retaining means comprises a retaining shoulder (37) on the stub shank, wherein the bit retaining ring is arranged to engage the retaining shoulder to retain the stub shank in the drill bit assembly.

Abstract: A drill head extending along a drill axis made of hard metal for rock drills is disclosed. The drill head features at least one major cutting edge and at least one minor cutting edge, where the major cutting edge extends from a first radially inner end to a first radial outer end which lies on a first diameter and where the minor cutting edge extends from a second radially inner end to a second radially outer end which lies on a second diameter that is smaller than the first diameter. A first enveloping surface defined by the minor cutting edge projects completely axially over a second enveloping surface defined by the major cutting edge.

Abstract: A chuck assembly, an assembly for an earth-boring drill assembly, and a method of retaining a drill bit for an earth-boring drill assembly, the drill assembly including a casing. The assembly includes a drill bit having a generally cylindrical head, a chuck connectable to the casing and operable to support the bit, the chuck having an outer surface with a radially-outwardly extending chuck ridge, an axially-extending first slot being defined in the ridge, a sleeve having an inner surface with a radially-inwardly extending sleeve ridge engageable with the chuck ridge to limit axial movement of the sleeve relative to the chuck, the sleeve having a first lug supported on the inner surface, the first lug being positionable in the first slot to limit relative rotational movement between the sleeve and the chuck. The assembly may also include a retainer assembly provided between the sleeve and the bit.

Abstract: A drilling device used for drilling into ground, rock or for reaming a predrilled hole includes several hammering bits in a circular shape and equipped with hammers, whereupon they together drill a hole which has a larger diameter. A casing tube can be pulled out of the hole/pushed into the drilled hole. A tubular, rotatable drill rod tube resides in the casing tube. The hammers are located in a circular shape and are each attached to the outer surface of the drill rod tube by joint/hinge attachments lying essentially in the drilling direction. Rotation of the drill rod tube in a first direction turns the hammers and associated bits outwardly from the drill rod tube, and rotation in another direction turns the hammers with their bits inwardly towards the drill rod tube so that they can be pulled away with the drill rod tube from inside the casing tube.

Abstract: A drill bit for percussive rock drilling of the type that comprises a front head and a tubular skirt, which extends rearward from the head to a rear, ring-shaped end and includes an internal thread for the transfer of combined impact and rotary motions to the drill bit is disclosed. The rear end of the skirt is, via an unelastic joint, e.g., a friction weld, united to a front end of a sleeve having an envelope surface, from which a plurality of projections are peripherically spaced-apart from each other project, e.g., ridges, having the purpose of guiding the drill bit in the drill hole. By assembling the drill bit of two parts, the internal thread can be turned with high accuracy and smoothness, at the same time as the drill bit is given an inherent good controllability. In an additional aspect, a method for the manufacture of such a drill bit is also disclosed.

Abstract: A rock drill bit comprising a shank fitted with a clamping end and a drilling tip at the end away from the clamping end, the drilling tip comprising at least three, preferably exactly three blades which are alar in topview, said blades each comprising at their top side a lip constituted by a leading chipping face and a trailing flank, the lips substantially converging onto each other within a central zone centered on the drill bit axis, characterized in that, in the central zone, a single lip—long lip—runs through the bit axis and comprises a commensurate overshoot segment extending beyond the bit axis.

Abstract: A drill string having a drill bit with a bit body located between a shank and a working face. The working face has at least one cutting element and a jack element disposed partially within the drill bit body and partially protruding from the working face. The jack element is adapted to be rotated with respect to the bit body by a driving mechanism disposed within a bore of the drill string. A generator or motor with a rotor is incorporated into a torque transmitting mechanism that links the driving mechanism to the jack element, and configured so that at least one waveform is produced in the generator or motor when the jack element is rotated. The waveform is processed by an electronic processing device to determine the rotational position of the jack element.

Abstract: The invention relates to a rock drill (1) for rotational and percussive action, comprising a drill head (2), a conveying helix (3), a clamping shank and a longitudinal drill axis (L), wherein the drill head (2) has at least one secondary cutting element (5a, 5b) with a front and a rear side face (10a, 10b) and wherein the secondary cutting element (5a, 5b) has a center of mass (M) and a cutting edge (11), the center of mass (M) and the cutting edge (11) defining a first plane (E1), the front side face (10a) of the secondary cutting element (5a, 5b) defining a second plane (E2) and the rear side face (10b) of the secondary cutting element (5a, 5b) defining a third plane (E3).

Abstract: In a hard metal plate for insertion in to a seat formed at one end of a drill shaft of a rock drill, comprising a substantially rectangular base shape having two opposed long sides extending in the axial direction of the drill shaft which are at least partially covered by the seat, two opposed, substantially axial free short sides, a radial bottom side facing towards the seat and a cutting face facing away from the seat, both short sides are formed by an axial section having a purely axial direction component and a conical section inclined towards the axial direction, so that at the short side, the substantially rectangular plate tapers towards the bottom side.

Abstract: A drill bit comprises a plurality of cutting blades arranged circumferentially, the cutting blades having a cutting edge formed by a connecting ridge line between a cutting face and a flank; and a tip formed by coupling radially inner ends of the cutting edges to each other at a center portion of a bit tip end, wherein at least one of the cutting blades has a first flank and a second flank, wherein the first flank has a blade tip side flank close to the cutting edge and a base end side flank formed on the base end side of the blade tip side flank, and wherein a tilt angle ?1 of the blade tip side flank 3a is smaller than a tilt angle ?2 of the base end side flank 3b which is tilted toward the axial direction.

Abstract: A drill, which is used in a hammer drill for drilling holes in stone, concrete and the like, includes a one-piece drilling head (10, 20, 30) formed of a hard material and provided, at its first end (5), with at least one main bit having a tip (4) and at least one cutting structure (3) integral to the one-piece drilling head (10; 20; 30), and at a second end (6) located opposite the first end (5), with a bottom surface (7) for the mounting the drilling head (10; 20; 30) on the drill stem (8), and having a plurality of axially extending through-grooves (11; 21; 31) for removing drillings produced during a drilling process and having a cross-section which increases, at least regionwise, in a direction toward the bottom surface (7) of the drilling head (10; 20; 30).

Abstract: A cutting head for a drill bit has a body with an overall cruciform shape. One pair of opposing arms defines a main cutting edge. The other pair of opposing arms defines an auxiliary edge. The main cutting edge is defined by rake surfaces and relief surfaces. Each rake surface and relief surface is defined by a plurality of facets. The main cutting edge includes a chisel edge. A first pair of planar rake facets, one on each end of said chisel edge, and a first pair of planar relief facets, adjacent said chisel edge, defines a portion of the cutting edge. A remaining portion of the main cutting edge is defined at the apex of a plurality of curved rake facets and curved relief facets. The auxiliary edge is defined by a plurality of curved surfaces.

Abstract: A drill bit having a plurality of cutters on its lower surface, each of which can having a plurality of PDC cutter elements disposed thereon. The cutting surface on each of the cutters is mounted in in an orientation that allows drilling of oversize boreholes which enables the drill bit to be turned more easily to facilitate the boreholes being drilled on a smaller radius. The placement of the cutters on each of the blades enables the drill bit to drill both vertically and laterally.

Abstract: The invention relates to a rock drill (1) for rotational and percussive action, comprising a drill head (2), a conveying helix (3), a clamping shank and a longitudinal drill axis (L), wherein the drill head (2) has at least one secondary cutting element (5a, 5b) with a front and a rear side face (10a, 10b) and wherein the secondary cutting element (5a, 5b) has a centre of mass (M) and a cutting edge (11), the centre of mass (M) and the cutting edge (11) defining a first plane (E1), the front side face (10a) of the secondary cutting element (5a, 5b) defining a second plane (E2) and the rear side face (10b) of the secondary cutting element (5a, 5b) defining a third plane (E3).

Abstract: A cross-key rotational alignment locking device for a VSI-type mineral breaker comprises a generally annular keyway 102 in the top edge portion of the main shaft 12 of the breaker, the annular keyway defining an upwardly extending pilot key 104, a plurality of circumferentially spaced slots 126 in the upper portion of a cylindrical taper lock 108 disposed around the main shaft, the slots in communication with the annular keyway, and a cross-key 130 having a generally annular main body 132 disposed in the annular keyway 102, the pilot key 104 received in a central aperture 136 in the main body 132 of the cross-key 130, and the cross-key having a plurality of radially-extending arms 128 disposed in the plurality of slots 126, such that the taper lock 108 is locked in rotational alignment with the shaft 12. In the preferred embodiment a bronze sleeve 110 having a longitudinally extending split 120 is interposed between the taper lock 108 and the shaft 12.

Abstract: The invention relates to a drilling tool, especially for percussion drilling, which comprises a cutting element (3) that is configured as a plate (3) or head and that has at least one cutting edge (11) defined by a cutting face (6) and a free face (10). The cutting edge (11) is associated with a first free face section (10a) which is limited in a cutting plane at a right angle to the cutting edge (11) and parallel to the longitudinal axis (L) of the drilling tool (1) by a convex bulge (13) or a convex polygon outline. The vertical height of a rib (14) defined by the first free face section (10a) and an associated first cutting face section (6a) ranges from 0.1 mm to 1.0 mm.

Abstract: A mechanism for drilling or coring by a combination of sonic hammering and rotation. The drill includes a hammering section with a set of preload weights mounted atop a hammering actuator and an axial passage through the hammering section. In addition, a rotary section includes a motor coupled to a drive shaft that traverses the axial passage through the hammering section. A drill bit is coupled to the drive shaft for drilling by a combination of sonic hammering and rotation. The drill bit includes a fluted shaft leading to a distal crown cutter with teeth. The bit penetrates sampled media by repeated hammering action. In addition, the bit is rotated. As it rotates the fluted bit carries powdered cuttings helically upward along the side of the bit to the surface.

Abstract: The present invention relates to a percussion hammer for enlarging drilled holes. The hammer comprises an external outer wear sleeve (5), an inner cylinder (7) mounted co-axially within the outer wear sleeve (5), a tubular torque shaft (3) disposed axially and centrally of the hammer assembly, and extending longitudinally through the assembly. The hammer further comprises a sliding piston (6) mounted for reciprocating movement within the inner cylinder (7) and outer wear sleeve (10) and about the tubular torque shaft (3) to strike a hammer bit (1) for reciprocal movement in a chuck (4) adjacent a forward end of the hammer assembly. The hammer bit (1) has a central bore (46) through which the torque shaft (3) extends, such that the torque shaft (3) protrudes forwardly of the hammer.

Abstract: A drill bit for drilling a borehole in an earth formation. The drill bit has a central longitudinal axis and may be operated by applying at least a rotary motion about the central longitudinal axis and optionally applying longitudinal reciprocal movement to the drill bit so as to exert a percussive force on the borehole bottom. The drill bit has a surface provided with a plurality of shear cutters having a rake surface arranged to induce a scraping movement along the borehole bottom upon application of the rotary motion. The rake surface, during operation, faces the direction of rotation at a back-rake angle of less than 90°, wherein the backrake angle is defined as the angle included between the projection of a line perpendicular to the rake surface on a plane defined by the central longitudinal axis and the direction of the tangential velocity component of the shear cutter and a plane perpendicular to the longitudinal axis.