Abstract: This drilling bit includes a bit body centered on a tool central axis, a plurality of buttons protruding from a tip surface of the bit body, a discharge flow path disposed from the tip surface of the bit body over an outer peripheral surface, and a blow hole that extends inside the bit body and is open at the tip surface. The discharge flow path has a first flow path which has a groove shape located on the tip surface and extending in a tool radial direction, and at which the blow hole is open, and a second flow path located outward in the tool radial direction from the blow hole on the tip surface to communicate with the first flow path, and extending in a tool circumferential direction.

Abstract: A one-piece cutting head for a drill bit includes a main cutting edge that extends between radial extremities of the cutting head. The main cutting edge is disposed between main rake surfaces and main relief surfaces. Each main rake surface includes one or more rake facets, and each main relief surface includes one or more relief facets. Adjacent rake facets and relief facets define a primary transverse edge therebetween that extends away from the main cutting edge. The cutting head further includes a plurality of side cutters that are transverse to the main cutting edge and that propagate from the primary transverse edge to a radial extremity of the cutting head. Each side cutter includes a side cutting edge between a side cutting rake facet and a side cutting relief facet.

Abstract: A drill bit for percussion drilling includes a drill bit body including a front surface. The front surface includes a first circular area arranged transverse and coaxially to the axis of the drill body, a second area surface surrounding the first area surface, and a third area surface surrounding the second area surface. A number of buttons are arranged in the second and third area surfaces. The button body of each button has a forward end surface. The buttons are arranged in circular recesses extending substantially transverse from the second surface and third area surface into the drill bit body. The recesses have a radius corresponding to the button body radius and a depth corresponding to the length of the button body, such that the button bodies are fitted within the drill bit body with the forward end surface exposed in the second and third area surfaces.

Abstract: Provided is a casing protection bit mounted on a casing tube in combination with a cutter bit to prevent abrasion or chipping of the cutter bit. The present invention is to provide a casing protection bit 1 to be mounted on a casing tube, the casing protection bit including: a base portion 2 that protrudes in an axial direction of the casing tube, the base portion having a mountain shape; and two leg portions 3 and 4 extending continuously with the base portion 2 and facing each other at a predetermined distance. In the casing protection bit cemented carbide tips 5a to 5j are disposed on all planes of the base portion 2 except for a plane from which the leg portions 3 and 4 extend.

Abstract: A drill bit (11) for the drilling, in particular the rotary percussive drilling, of a hole, in particular a tap hole of a melting furnace, the drill bit (11) comprising a drill head (10), which has at least one hard material insert (16), and a base body (12) for connecting the drill bit to a driving element, the hard material insert (16) being inserted into a seat, which is formed in an axial end face (13) of the drill head (10), in such a manner that at least a head cutting edge (18) of the hard material insert (16) protrudes beyond the axial end face (13), wherein the seat has a flank portion and a mating flank portion located opposite the flank portion, between which the hard material insert (16) is disposed, the flank portion, which is disposed opposite a recess formed in the hard material insert (16), being provided with a material projection (35) which is at least partially made of a welding material, is bonded to the drill head (10) via the welding material and protrudes into the recess so as to establ

Abstract: Cutting elements for earth-boring tools may include a substrate and a polycrystalline, superhard material secured to an end of the substrate. A first, greatest diameter of the polycrystalline, superhard material may be greater than a second, greatest diameter of the substrate, as measured in a direction at least substantially parallel to a cutting face of the polycrystalline, superhard material. Methods of making cutting elements for earth-boring tools may involve securing a polycrystalline, superhard material to an end of a substrate. A first, greatest diameter of the polycrystalline, superhard material may be rendered greater than a second, greatest diameter of the substrate, as measured in a direction at least substantially parallel to a cutting face of the polycrystalline, superhard material.

Abstract: A method for forming a hole plug in a laminate structure is provided. A laminate structure, is formed, including at least a dielectric layer and a first conductive foil on a first side of the dielectric layer. An unpierced or blind hole is formed in the laminate structure extending toward the first conductive foil from a second side of the dielectric layer and at least partially through the dielectric layer, the hole having a hole depth to hole diameter aspect ratio of less than twenty (20) to one (1). In yet another example, the hole aspect ratio may be less than one (1) to one (1). Via fill ink may then be deposited in the hole. The via fill ink is then dried and/or cured to form a hole plug.

Abstract: A rotary drill bit may include a bit body rotatable about a central axis. The rotary drill bit may also include at least one cutting element coupled to the bit body. The at least one cutting element may have a cutting face, a cutting edge adjacent the cutting face, and a back surface opposite the cutting face. The at least one cutting element may be oriented so that a substantial portion of the cutting edge has a positive clearance angle, which may be defined by a first vector that is normal to the cutting face and a second vector that is tangential to a helical path traveled by the cutting edge during drilling.

Abstract: Cutting elements, earth-boring drill bits having such cutting elements and related methods include a cutting element having a superabrasive table positioned on a substrate, and at least one recessed surface in a cutting face of the superabrasive table.

Abstract: A cutting element that includes a substrate; and an outer layer of polycrystalline diamond material disposed upon the outermost end of the cutting element, wherein the polycrystalline diamond material: a plurality of interconnected diamond particles; and a plurality of interstitial regions disposed among the bonded diamond particles, wherein the plurality of interstitial regions contain a plurality of metal carbide phases and a plurality of metal binder phases together forming a plurality of metallic phases, wherein the plurality of metal carbide phases are formed from a plurality of metal carbide particles; wherein the plurality of interconnected diamond particles form at least about 60 to at most about 85% by weight of the polycrystalline diamond material; and wherein the plurality of metal carbide phases represent at least 35% by weight of the plurality of metallic phases is disclosed.

Abstract: A rotary drill bit for engaging an earth strata material includes an elongate drill bit body having an axial forward end and an axial rearward end, and a cutting insert attached to the axial forward end of the elongate drill bit body. The cutting insert has an elongate insert body rotatable about a central axis and includes a pair of symmetrical halves symmetrical about the central axis, each symmetrical half including a leading face, a top surface having a relief surface, a T-land surface extending between the leading face and the relief surface and a cutting edge formed at the intersection of the T-land surface and the relief surface. The cutting edge can have a negative axial rake angle. The relief surface can include a primary relief surface and a secondary relief surface.

Abstract: A two-prong rotary drill bit for engaging an earth strata material includes a drill bit body having an axis of rotation, the drill bit body having a head portion at an axial forward end and a shank portion at an axial rearward end, the head portion having two mounting arms offset from the axis of rotation of the drill bit body. The two-prong rotary drill bit also includes a cutting insert attached to each mounting arm at the axial forward end of the drill bit body. Each cutting insert includes a leading face facing in the direction of rotation, a top surface having a relief surface, a T-land surface extending between the leading face and the relief surface of the top surface and a cutting edge formed at the intersection of the T-land surface and the relief surface of the top surface.

Abstract: A cutting head for a drill bit comprises four substantially identically shaped cutting arms extending radially from a common central axial point, each cutting arm comprising a cutting edge extending, outwardly and axially backwards from the common central axial point. The cutting edges are equianguiarly spaced apart from each other about the central axis of the cutting head. Each cutting, arm further comprises a side chamfer extending between its radially outer face and its rotationally trailing side face.

Abstract: A drill bit for use in percussive drilling includes a body having a front face, at least one face button on the front face, and a plurality of gauge buttons. Each of the buttons has a working face. At least a portion of at least one gauge button working face has a curvature which deviates further from being flat by comparison to a curvature of any curved portion of at least one face button working face, so that the portion of at least one gauge button working face projects further than the portion of at least one face button working face.

Abstract: A drill bit having a bit body intermediate a shank and a working face having at least one cutting insert. A bore is formed in the working face co-axial within an axis of rotation of the drill bit. A jack element is retained within the bore by a retaining element that intrudes a diameter of the bore.

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 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: A hard cutting insert for use with a roof drill bit includes a first webbed notch and a second webbed notch structured and arranged on the hard insert for removing or evacuating drilling debris from an upper surface of the hard insert during a drilling operation. A roof drill bit including a hard cutting insert having a first webbed notch and a second webbed notch structured and arranged on the hard insert.

Abstract: A roof-bolt drill bit has a bit body that is rotatable about a central axis, a coupling pocket defined in the bit body, and at least one cutting element mounted to the bit body, the at least one cutting element having a non-cylindrical periphery. The at least one cutting element includes a cutting face, a cutting edge adjacent the cutting face, a back surface opposite the cutting face, and a side surface extending between the cutting edge and the back surface, at least a portion of the side surface of the at least one cutting element being bonded to a side surface of the coupling pocket. The roof-bolt drill bit includes a coupling projection extending from the at least one cutting element, the coupling projection being bonded to a coupling recess defined in the bit body.

Abstract: A percussion drill bit for drilling a borehole. The drill bit includes a bit body having a bit face disposed on an axial end portion thereof. First and second cutting elements are disposed on the bit face. A cutting plane is defined in tangential contact with crest portion of the first and second cutting elements. A third cutting element on the bit face is at least partially positioned between the first and second cutting elements. The third cutting element is at least partially conical, and a crest portion of the third cutting element is offset from the cutting plane.

Abstract: A hammer bit for drilling a borehole in earthen formations includes a bit body having a bit axis and a bit face, a plurality of gage cutter elements mounted to the bit face in a circumferential gage row, and a plurality of adjacent to gage cutter elements mounted to the bit face in a circumferential row that is radially adjacent the gage row. The ratio of the radial overlap distance to the radial span distance between radially overlapping gage cutter elements and adjacent to gage cutter elements is greater than 0.25. The ratio of the radial overlap distances to the diameter of the gage cutter element is greater than 0.25. An average cutting area of the gage cutter elements per gage cutter element is less than an average surface area of an entire cutting surface of each of the gage cutter elements.

Abstract: A non-rotational drill bit for a down-the-hole drill hammer is provided that includes a head and a shank extending from the head. The head includes a plurality of axisymmetric cutting members about its working face. The drill bit also includes a porting system that includes a central through hole, an air inlet port, an exhaust outlet port and a central exhaust port for exhausting air from an interior of the drill hammer and for clearing drilling debris from the face of the drill bit.

Abstract: A plurality of cutting faces is attached sequentially at a distal end of a drill string. The forward most cutting face that is distal to the top of the hole is exposed and used for drilling until worn to a point of inefficiency. The forward most or distal cutting face is then detached, exposing the next cutting face in the sequence. Detachment of the forward most cutting face is performed by remote actuation at the top of the drill string and/or outside the hole. A new cutting face is provided without the necessity of removing the drill string. The detachment process is repeated as long as drilling is continued and cutting faces remain.

Abstract: A roof-bolt drill bit may include a bit body that is rotatable about a central axis and at least one cutting element mounted to the bit body. The at least one cutting element may include a cutting face, a cutting edge adjacent the cutting face, a back surface opposite the cutting face, and at least one coupling feature positioned adjacent the at least one cutting element. The at least one cutting element may be secured to the bit body by the at least one coupling feature.

Abstract: A hammer bit for drilling a borehole in earthen formations. In an embodiment, the bit comprises a bit body having a bit axis and a bit face. The bit face includes an inner region extending from the bit axis to about 50% of the bit radius and an outer region extending from the inner region to the outermost radius. In addition, the bit comprises a plurality of gage cutter elements mounted to the bit face in a circumferential gage row in the outer region. Further, the bit comprises a plurality of adjacent to gage cutter elements mounted to the bit face in a circumferential adjacent to gage row in the outer region. The cutting profile of at least one cutter element in each row in the outer region radially overlaps with the cutting profile of at least one other cutter element in a different row in rotated profile view.

Abstract: A drill bit for drilling a borehole in earthen formations, the bit comprising: a bit body having a bit axis and a bit face including a cone region, a shoulder region, and a gage region; a first primary blade extending radially along the bit face from the cone region to the gage region; a plurality of cutter elements mounted to the first primary blade, wherein a first of the plurality of cutter elements has a planar cutting face and a second of the plurality of cutter elements has a convex cutting face; and wherein each cutting face is forward-facing.

Abstract: Drill bits and cutting elements having a functionally-engineered surface comprise a cermet material selected from the group consisting of refractory metal carbides, nitrides, borides, carbonitrides and mixtures thereof. A functionally-engineered material is disposed over a surface portion one of the cutting elements to form a wear resistant surface thereon having a hardness that is different than that of the underlying cutting element. The wear resistant surface is provided by forming a conformable material mixture by combining one or more powders selected from the group consisting of cermets, carbides, borides, nitrides, carbonitrides, refractory metals, diamond particles, cubic boron nitride particles, Co, Fe, Ni, and combinations thereof, with an applying agent. The applied material mixture is pressurized under conditions of elevated temperature to consolidate and sinter the material mixture, thereby forming the wear resistant surface having desired properties of hardness and/or fracture toughness.

Abstract: A hammer bit for drilling a borehole in earthen formations comprises a bit body having a bit axis and a bit face. The bit face includes an inner region extending from the bit axis to about 50% of the bit radius and an outer region extending from the inner region to the outermost radius. In addition, the bit comprises a plurality of gage cutter elements mounted to the bit face in a circumferential gage row in the outer region. Further, the bit comprises a plurality of adjacent to gage cutter elements mounted to the bit face in a circumferential adjacent to gage row in the outer region. The cutting profile of at least one cutter element in each row in the outer region radially overlaps with the cutting profile of at least one other cutter element in a different row in rotated profile view.

Abstract: A hard metal insert for a drill bit for percussion drilling. A wear part includes a cap including a wear surface. A mount includes a cylindrical part having a cross-sectional area and a diameter. The cap includes a front part with an extension along an axis of symmetry of the insert from a first point on the wear surface to a second point in the cap. The front part includes a volume between a first plane intersecting the axis at the first point and a second plane intersecting the axis at the second point. The volume is ?0.6 times a cross-sectional area of the front part in the second plane times a distance along the axis between the first and second points. A diameter of the front part in the second plane is ?0.5 times the mount diameter and ?0.6 times the mount diameter.

Abstract: In various embodiments, a polycrystalline diamond compact (“PDC”) comprises a substrate including an interfacial surface having a raised region. The PDC comprises a polycrystalline diamond (“PCD”) table bonded to the interfacial surface of the substrate. The PCD table defines an upper surface and exhibits a thickness over the raised region. The PCD table includes a plurality of bonded diamond grains defining a plurality of interstitial regions. A first region of the PCD table adjacent to the substrate includes metal-solvent catalyst disposed interstitially between the bonded diamond grains thereof, and a leached second region of the PCD table extends inwardly from the upper surface. The interstitial regions of the leached second region are depleted of metal-solvent catalyst. The geometry of the PCD table and raised region may be selected so that residual compressive stresses therein are retained to a sufficient level after leaching to provide a damage tolerant/thermally-stable PCD table.

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: A hard cutting insert for use with a roof drill bit includes a first webbed notch and a second webbed notch structured and arranged on the hard insert for removing or evacuating drilling debris from an upper surface of the hard insert during a drilling operation. A roof drill bit incorporating the hard cutting insert is also provided.

Abstract: A rotary drill bit with cutting elements operable to control depth of cut and rate of penetration during formation of a wellbore are provided. Respective sets of secondary cutting elements and primary cutting elements may also be disposed on exterior portions of a rotary drill bit. A number of blades may extend from exterior portions of the drill bit with a number of cutting elements disposed on exterior portions of each blade. Each cutting element may include a substrate with a cutting surface disposed thereon. A respective protector may extend from the cutting surface of one or more cutting elements to limit depth of penetration of the associated cutting element into adjacent portions of a downhole formation and/or to control rate of penetration of an associated rotary drill bit.

Abstract: A roof drill bit has an elongate roof drill bit body, which has a forward end and a rearward end. The roof drill bit body contains a slot at the forward end. The roof drill bit body contains a dust port wherein the dust port has a central longitudinal dust axis. The roof drill bit further has a hard insert received within the slot wherein the hard insert has a leading surface. The leading surface of the hard insert is rotationally forward of the central longitudinal dust axis of the dust port.

Abstract: An abrasive wear-resistant material includes a matrix material and a plurality of ?40/+80 ASTM mesh dense sintered carbide pellets. A rotary drill bit having an exterior surface and an abrasive wear-resistant material disposed on at least a portion of the exterior surface of the bit body is provided. Methods for applying an abrasive wear-resistant material to a surface of a drill bit are also disclosed.

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: Drill bit (10) for a rock drilling tool (12), which drill bit (10) has a drilling surface (10b) that contacts rock during drilling. A longitudinal cross section (10t) of the drill bit (10) through the drilling surface (10b) exhibits the following relationships of Ltot(depth)/Ltot(5.0) and H(depth)/H(5.0) at the specied depths, where H(depth)/H(5.0) is measured according to a Vickers test and Ltot(depth)/Ltot(5.0) is measured according to the Palmqvist method, described in this document substantially along the drill bit's longitudinal axial centre line (C): (table (I)). If the drill bit (10) has en length (L) of 10 mm or greater, and a longitudinal cross section (10t) of the drill bit (10) through the drilling surface (10b) exhibits the following relationships of Ltot(depth)/Ltot(3.5) and H(depth)/H(3.5) at the specified depths, where H(depth)/H(3.5) is measured according to a Vickers test and Ltot(depth)/Ltot(3.

Abstract: A bit includes a body portion having a first shape, a first length, a first end and a second end. A collar portion having a second shape, a thickness, a first surface disposed adjacent a second end of the body portion and a second surface forming a ledge for seating against a surface of a rotary cutting head of a mining machine. A shank portion, has a diameter and a second length. A first end of the shank is secured to the second surface of the collar portion. A groove formed around the shaft portion closely adjacent the second end thereof. A bit tip disposed adjacent the first end of the body portion to contact a hard surface. The bit tip tapers to a pointed end. A connecting means is disposed in the groove for connecting the bit to the working machine. A plurality of fins is disposed along an outer surface of the body portion.

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: An insert for an earth boring drill bit, such as a PDC rock bit or a roller cone rock bit, is provided. The insert includes a base integrally joined to a top section, the top section having a first flank that curves in a substantially helical manner about a longitudinal axis of the insert to join a crest.

Abstract: Thermally stable ultra-hard polycrystalline materials and compacts comprise an ultra-hard polycrystalline body that wholly or partially comprises one or more thermally stable ultra-hard polycrystalline region. A substrate can be attached to the body. The thermally stable ultra-hard polycrystalline region can be positioned along all or a portion of an outside surface of the body, or can be positioned beneath a body surface. The thermally stable ultra-hard polycrystalline region can be provided in the form of a single element or in the form of a number of elements. The thermally stable ultra-hard polycrystalline region can be formed from precursor material, such as diamond and/or cubic boron nitride, with an alkali metal catalyst material. The mixture can be sintered by high pressure/high temperature process.

Abstract: A hammer bit for drilling a borehole in earthen formations. In an embodiment, the bit comprises a bit body having a bit axis and a bit face. The bit face includes an inner region extending from the bit axis to about 50% of the bit radius and an outer region extending from the inner region to the outermost radius. In addition, the bit comprises a plurality of gage cutter elements mounted to the bit face in a circumferential gage row in the outer region. Further, the bit comprises a plurality of adjacent to gage cutter elements mounted to the bit face in a circumferential adjacent to gage row in the outer region. The cutting profile of at least one cutter element in each row in the outer region radially overlaps with the cutting profile of at least one other cutter element in a different row in rotated profile view.

Abstract: A drilling insert includes a cylindrical body and a top portion of the drilling insert. The top portion is on top of the cylindrical body providing a contact area, wherein the contact area provides a flat area for distributing contact stress when the drilling insert impacts the formation.

Abstract: A hard material head (1) for a rotary percussion drill bit (2) having an elongated shaft (15) including at least three cutting edges (4) distributed circumferentially within a circumscribing circle, a bottom surface (6) located opposite the cutting edges (4) and fastened by a material bond to an end (8) of the drill bit shaft (15) of the rotary percussion drill bit (2), concave side surfaces (5) formed circumferentially between adjacent cutting edges (4), and a peripheral pocket (9) opening toward the bottom surface (6) and formed, respectively, in at least two concave side surfaces (5) located opposite one another, and in which a corresponding axial pin (10, 10?) formed on a shaft end (8) is form-locking engageable.

Abstract: A hard composite cutting insert useful for cutting strata such as earth or rock that includes a body that is tough. The body contains a member that is harder than the body (i.e., has a harder region). The combination of the tough body with the harder member (or region) embedded therein provides a hard composite cutting insert with advantageous properties when used in conjunction with a bit body for impinging upon, and thereby disintegrating, the earth strata.

Abstract: A drill, a drill assembly, and a tool head for a cutting tool. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

Abstract: A percussion drill bit for drilling into a subterranean earth formation. The drill bit has a central longitudinal axis and is operable by applying axial percussive motion along the axis and rotary motion about the axis. The drill bit is provided with a plurality of blades protruding from the drill bit and, a plurality of flow channels stretching along the drill bit in a substantially radial direction whereby the successive flow channels are formed between two adjacent blades. Shear cutters are provided in a row on or close to the leading edge of at least one of the blades with respect to the direction of rotary motion trailingly adjacent to the flow channel that is associated with it. A fluid may be run through the flow channel to remove cutting debris accumulating in front of the row of shear cutters. In addition to these shear cutters, axial cutters are located, with respect to the direction of rotary motion, in a trailing position with respect to the row of shear cutters and its associated flow channel.

Abstract: A rock drilling bit includes at least one button having a button sidewall and button bottom, the button sidewall and the button bottom having a button sidewall geometry and a button bottom geometry, respectively. The rock drilling bit further comprises a bit body having at least one button-receiving hole having a hole sidewall and a hole bottom, the hole sidewall and the hole bottom having a hole sidewall geometry complementary to the button sidewall geometry and a hole bottom geometry, and a deformable seat compressed between the buttom bottom and the hole bottom so that the seat conforms to a hole bottom geometry and the button bottom geometry. The seat comprises tin.

Abstract: A hole coring system is provided that greatly stabilizes a tubular core drill bit for drilling into concrete or other materials enabling large diameter holes to be drilled with a handheld tool. The drill bit is guided by a mandrel which is attached to the concrete. The mandrel serves as a central guidepost that ensures that a relatively large diameter, tubular core drill bit remains precisely centered relative to the guide mandrel. This enables the operator to use a commonly available tool to rotate the drill and apply drill pressure only. The motor may rotate the drill bit via a gear box. The gear box may have a lever arm which may be used to resist any torquing action of the gear box due to the friction between the drill bit and the concrete. Additionally, in the event the motor's housing is not fixed to the gearbox and allowed to rotate, a brace may be attached to the lever arm which may be used to resist any torquing action of the motor's housing due to the friction between the drill bit and the concrete.

Abstract: A pneumatically operated, deep hole rock drilling system for non-rotating drilling includes a pneumatically operated drive, a hammer sleeve with hammer mechanisms therein/connected thereto, a hammer bit below the hammer sleeve and a tube string above the hammer sleeve. The pneumatically operated drive includes a pneumatic pressure delivery mechanism and a drive piston. Further, this drive means has air flow channel means for delivery of air to the drive piston for reciprocally driving a hammer bit. The hammer bit has a convex bottom and a sidewall. The convex bottom has a plurality of impact buttons. The convex bottom has a center, with the sidewall being a predetermined distance X from the center.