Abstract: The present disclosure provides a cutting head adapted to removably couple to a bit body of a drill bit assembly. The cutting head includes a leading cutting tip for cutting into earth and a trailing receiving portion for receiving a second end of the bit body in an internal cavity defined by the trailing receiving portion to allow the cutting head to be removably coupled to the second end of the bit body.

Abstract: A downhole tool, or earth-boring bit, for use in disintegrating structures in a cased wellbore includes a tool body having a central axis about which the tool body rotates and an outermost gage surface on the tool body. At least one gage cutting element on the gage surface has a blunt outermost projection and a sharp cutting edge recessed from the blunt outermost projection, wherein, during rotation of the tool body, the blunt outermost surface contacts the cased wellbore and the sharp cutting edge does not. The blunt outermost projection may be on a leading element while the sharp cutting edge is on a separate, trailing element.

Abstract: Systems and methods for manufacturing a macroscopically reinforced metal-matrix composite (MMC) fixed-cutter bit are provided. The reinforced drill bit may include a bit body constructed from an infiltrated MMC material and featuring several blade portions extending radially outward and downward from a shank of the drill bit. These blade portions are designed for contacting a subterranean formation. The drill bit also includes the shank, which is coupled to an end of the bit body opposite the blade portions, to connect the bit body to an upstream component of a drill string. The drill bit further includes a number of macroscopic bit reinforcements that are at least partially enclosed within the bit body. These bit reinforcements are each disposed in and aligned substantially with a corresponding blade portion of the bit body.

Abstract: A percussive rock drill bit includes a head having an annular gauge collar and a central island. An annular cutting channel is defined between the collar and the island such that specifically positioned cutting buttons are effective to create an annular ridge in the cut rock face having a reduced rock breaking resistance.

Abstract: A milling tool has a tool shank and a cutting head fastened to the forward end of the tool shank by way of a clamping connection. The clamping connection has a protrusion with clamping faces, and a recess with centering faces that interact with the clamping faces. Each of the centering faces has a first region where the centering faces are spaced from a longitudinal axis of the tool shank by a first distance and a second region at a smaller distance. The first region merges into the second region. The clamping faces of the protrusion are introducible into the recess between the first regions of the centering faces and are movable, by rotation of the cutting head about the longitudinal axis, into a clamping position in which the clamping faces interact in a force-fit with the second regions of the centering faces.

Abstract: A rotatable tool for chip removing machining, including a basic body having front and rear ends between which there extends a first geometrical center axis, and a loose top having front and rear ends between which a second geometrical center axis extends. The front end of the basic body includes a jaw, which is delimited by two drivers and an intermediate bottom and in which a part of the loose top is received. A centering pin protrudes axially rearward from the loose top and is inserted in an axial center hole, which mouths in the bottom of the jaw and in which a threaded hole mouths for a screw co-operating with the center pin. The center hole includes a cylindrical support surface, which is concentric with the center axis of the basic body and against which the centering pin of the loose top is pressed by the screw.

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 dust collecting device disposed circumferentially around a roof tool and in association with a roof drill bit and slidable thereon for collecting and removing dust generated during a dry drilling operation. The dust collecting device comprises a cylinder member, a bushing, and a mounting assembly comprising a top washer, a rubber insert, and a bottom washer. Another aspect of the invention provides a dust collecting device comprising a cylinder member, a bushing, and a mounting assembly comprising a disk and clips. The rubber insert and the clips resist movement of the dust collecting device along the drill steel of the roof tool during the drilling operation.

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 latch body for use in a drilling head assembly including a fluid control subassembly, a check valve element, and/or a hollow spindle. A distal end portion of the latch body includes a port section that defines a chamber for receiving the check valve element and promoting movement of the check valve element between a blocking position and an open position. The hollow spindle of the fluid control subassembly is operatively coupled to the chamber of the port section and supports the check valve element in the blocking position. A proximal end portion of the latch body supports the fluid control subassembly of the drilling head assembly in an operative position. The latch body includes male protrusions extending inwardly toward and spaced from a longitudinal axis of the latch body. A plurality of channels extend radially outwardly from the longitudinal axis of the latch body, spanning between adjacent male protrusions.

Abstract: A pressurized fluid flow system for a normal circulation down-the-hole hammer comprises a cylinder coaxially disposed in between an outer casing and a piston which reciprocates due to changes in pressure of pressurized fluid contained inside a front chamber and rear chamber located at opposites sides of the piston, supply/discharge of fluid to/from these chambers being conducted through a supply chamber and a discharge chamber defined by recesses on the inner surface of the casing and separated by a dividing wall, the front/rear chambers' in/out fluid flow being controlled solely by the overlap of the piston and the cylinder. A hammer having this system comprises a drill bit with one or more flushing passages which extend from channels cooperatively formed between splines on the inner surface of the driver sub and on the outer surface of the drill bit shank up to the front face of the drill bit.

Abstract: A retaining assembly for a cylindrical member and support sleeve in the bore of a component of a DTH. The cylindrical member and support sleeve may, for example, be a foot valve assembly for insertion into a counter bore in a bit. The cylindrical member has a cylindrical member rigidity and at least a portion of the support sleeve has a rigidity greater than the cylindrical member rigidity. A gap is provided between the sleeve and the component bore of the DTH. The cylindrical member deforms in the gap, resulting in the cylindrical member being fixedly sandwiched between the support sleeve and the component bore.

Abstract: Provided is an excavation tool for efficiently taking waste rocks produced during excavation into the inner peripheral side of a casing pipe. An excavation tool (10) includes a casing shoe (11), a casing pipe (15), a rod (60), a device (40), and an excavation bit (20). The excavation bit (20) has a head portion (22) and a skirt portion (23). The head portion (22) is provided with: a face flute (27), which is open into the tip face of the head portion and extends radially outward; a connection flute (28), which is integrally connected to the outer peripheral end of the face flute (27) and extends toward the rear end side, and an intake hole (29), which is integrally connected with the discharge flute (46) of the device (40) and is open to the inner peripheral side of the skirt portion (23) from the connection flute (28).

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 percussion drilling assembly includes an outer tubular, an inner tubular coupled within the outer tubular, a drill bit slideably disposed within the inner tubular, and a locking system that 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. In some embodiments, the locking system includes a plurality of locking members, each rotatable between an engaged position, wherein the inner tubular is prevented from rotating relative to the outer tubular in the first direction, and a disengaged position, wherein the inner tubular is rotatable relative to the outer tubular in a second direction opposite the first direction. In other embodiments, the locking system includes a locking member which is extendable to prevent rotation of the inner tubular relative to the outer tubular in at least the first direction.

Abstract: A percussive drill bit provided with an improved chuck assembly for a down-the-hole drill hammer. The bit has a head at its forward end with a shank extending from the head. The shank is screw threaded along its length. A reciprocating chuck is provided as a sleeve with internal screw thread as corresponding to those of the shank. The shank is releasably secured in the chuck with the read end of the shank providing a striking face. An arrangement of external splines on the chuck, and a retaining shoulder at its rear end, provide for the required guided movement of the chuck within a drill hammer wear sleeve.

Abstract: A geothermal in-ground conduit system and a method of constructing and installing same are described. The system comprises at least one loop of flexible tubing adapted to convect a heat exchange liquid therein. The loop has a lower end section and opposed spaced-apart elongated side sections communicating with one another. The lower end section is retained in a soil penetrating head. The soil penetrating head has a leading soil penetrating and ramming face formation. A force transmitting shaft is engageable with the soil penetrating head for transmitting a pushing force against the soil penetrating head to displace same in the soil while pulling the loop and guiding the loop into the soil as the penetrating face forms passages for permanent burial of at least a major portion of the loop together with the soil penetrating head, or the soil penetrating head can be retracted.

Abstract: A percussive drill bit provided with an improved chuck assembly for a down-the-hole drill hammer. The bit has a head at its forward end with a shank extending from the head. The shank is screw threaded along its length. A reciprocating chuck is provided as a sleeve with internal screw thread as corresponding to those of the shank. The shank is releasably secured in the chuck with the read end of the shank providing a striking face. An arrangement of external splines on the chuck, and a retaining shoulder at its rear end, provide for the required guided movement of the chuck within a drill hammer wear sleeve.

Abstract: A bit assembly is for a percussive drill that includes a casing with an interior chamber and includes a bit connectable with the casing and having a longitudinal bore and an axis through the bore. The bore has a retainer portion with one or more generally. conical inner surfaces extending circumferentially about and facing generally toward the axis. A generally cylindrical valve has a longitudinal passage with an inlet fluidly connectable with the casing chamber and an outlet fluidly connectable with the bit central bore and an axis through the passage. An engagement portion with at least one generally conical outer surface extends circumferentially about and faces generally away from the valve axis. The valve engagement portion is disposable within the bit bore retainer portion such that the valve conical outer surface is disposed within and against the bit conical inner surface to retain the valve coupled with the bit.

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 hydraulic breaker hammer comprises a housing (10) with a longitudinal bore (12), a cylinder sleeve (14), and a cylinder sleeve (14) engaging rear end cover (16), a hammer piston (15) reciprocally powered in the cylinder sleeve (14) for delivering blows to a working implement inserted in a guide sleeve (20) at the front end of the bore (12), wherein the guide sleeve (20) is provided with radial openings (22a,b) for communication of lubricant from a lubricant supply passage (21) in the housing (10) to the inside of the guide sleeve (20), and the guide sleeve (20) is provided with external seal rings (23 a-d) forming annular compartments located between the lubricant supply passage (21) and the radial openings (22 a,b) for spreading lubricant on the outside surface of the guide sleeve (20), a distribution valve (31) communicating with the pressure fluid source and the cylinder sleeve (14) and comprising both a clearance seal means (44) and a seat seal (45,46) for improved tightness, and a pressure accumulator

Abstract: A device is for channeling solids and fluids within a reverse circulating, fluid operated drill that has first and second ends, an axis extending between the ends, a casing and a piston. The casing has a bore extending between the drill ends and drive and valve chambers defined within the bore, the piston being movably disposed within the bore. The channeling device includes an elongated body disposeable within the casing bore so as to extend along the casing axis and through the piston. The body has a longitudinal axis, a first end locatable proximal to the drill first end, and a second end spaced from the first end and locatable proximal to the drill second end. A material transport passages extends axially between the two body ends and provides a path for moving solid materials through the drill. A fluid passage is configured to couple the valve and drive chambers.

Abstract: A pneumatic rockdrill having a housing; a cylinder connected to a compressed air supply inlet by a set of air passages; an impact piston, at least part of which is reciprocable within the cylinder; and a controller for the supply of compressed air from the air supply inlet to the cylinder. At least one pair of contact surfaces are located at the interface between the piston and the cylinder, where those relatively moving parts contact one another. At least one water supply inlet and water paths connected to the water supply inlet(s) are configured so as in operation to convey water to a drilling tool to flush a hole being drilled, and to supply water to wet the contact surfaces.

Abstract: An apparatus (10) for use in boring is described, the apparatus including a rotatable drive shaft (12), a cam member (20) and followers (16) for converting rotational motion into reciprocal motion, and a shroud (24) having a cutting edge (26) driven by the cam member and followers. The shroud may be selectively engageable with the cam member and followers, allowing the drive shaft to be removed through the shroud. A fluid circulation arrangement (31), (13) allows air to be injected into loose drilling substrate, so assisting removal of drill cuttings from the boring apparatus. Also described is a drill string incorporating a similar arrangement, allowing the drill string to be reciprocated within a bore. The drill string may further include casing sections, which may have intumescent coatings to allow the sections to be fixed in a wellbore.

Abstract: The present invention relates to a rock drill bit for percussive drilling. The drill bit comprises a bit body; a head portion defining a longitudinal center axis. The head portion comprises a front face having an outer surface portion, and an inner surface portion disposed radially inside of the outer surface portion. The inner surface portion is partially recessed by a cavity with respect to the outer surface portion. A plurality of fluid channels extends through the head portion and communicates with the cavity for conducting a flushing medium thereto. The inner surface portion comprises a raised portion carrying a plurality of buttons. An imaginary circle intersects centers of the fluid channels and also intersects an equal number of buttons.

Abstract: In one aspect of the invention a drill bit comprises an axis of rotation a body and a working face. The body comprises a fluid passageway with a first seat and houses a jack element substantially coaxial with the axis. A stop element is disposed within the passageway and has a first near-sealing surface. The jack element has a shaft intermediate an indenting end and a valve portion. The valve portion has a second near-sealing surface disposed adjacent the first near-sealing surface and a second seat disposed adjacent the first seat. As a formation strongly resists the jack element, the distance between the sealing surfaces narrows. This causes an increase in fluid pressure within the passageway and forces the indenting end down into the formation. This movement of the jack element relieves the pressure build up such that the formation pushes the jack element back, thereby oscillating the jack element.

Abstract: A drill bit assembly comprises a bit body intermediate a shank and a working face. The shank is adapted for connection to a drill string. The drill string comprising a fluid passage at least partially disposed within the body. A hammer assembly is movably disposed within the fluid passage along it central axis, the hammer assembly comprises a proximal end stabilized by a centralized upper bearing and a distal end stabilized by centralized a lower bearing. The distal end protrudes out of the working face and the hammer assembly comprises a carrier between the upper and lower bearings. Wherein, under normal drilling operations the carrier is adapted to resist a fluid pressure within the fluid passageway such that the fluid pressure will further extend the distal end of the hammer assembly from the working face by pushing on the carrier.

Abstract: A drill bit intended for percussive rock drilling is formed to reduce the occurrence of cavitation during percussive drilling. The drill bit includes an integral skirt and at least one channel for transport of flush medium, such as water. The drill bit has a front face provided with buttons, which define a greatest first external diameter (D0). A recess with a female thread, such as a rope or trapezoid thread for percussive drilling, extends into the drill bit from a rear end face of the drill bit. The recess has an axial depth (L0). The external surface of the skirt includes a conical portion having an axial extension that is greater than one-eighth of the depth (L0) of the recess but smaller than the depth (L0) of the recess.

Abstract: A device is for channeling solids and fluids within a reverse circulating, fluid operated drill that has first and second ends, an axis extending between the ends, a casing and a piston. The casing has a bore extending between the drill ends and drive and valve chambers defined within the bore, the piston being movably disposed within the bore. The channeling device includes an elongated body disposeable within the casing bore so as to extend along the casing axis and through the piston. The body has a longitudinal axis, a first end locatable proximal to the drill first end, and a second end spaced from the first end and locatable proximal to the drill second end. A material transport passages extends axially between the two body ends and provides a path for moving solid materials through the drill. A fluid passage is configured to couple the valve and drive chambers.

Abstract: The invention is a transmission sleeve for the reverse circulation down hole hammer activated by fluid under pressure, the hammer including an outer hammer casing, a drill bit retaining means (17) and a drill bit (10) retaining means (17) and extending forwardly therefrom. The transmission sleeve (25) comprises a transmission sleeve retaining means to retain the transmission sleeve (25) to the hammer, a flange (28) to direct exhaust fluid from the hammer extending from the transmission sleeve retaining means towards the cutting face (14) of the drill bit (10) so that the exhaust fluid is directed towards the cutting face (14) and a chamber (30) that extends circumferentially around the drill bit (10) into which the exhaust fluid flows prior to discharge from the end of the flange (28).

Abstract: A down-the-hole hammer includes a casing and a piston movable in the casing between a lowermost operating position and an uppermost operating position. A recess is provided between the piston and the casing so that the piston and the casing define an intermediate chamber between a top end of the piston and a bottom end of the piston. A passageway is provided between a source of pressurized fluid and the intermediate chamber such that, at all positions of the piston between the lowermost and the uppermost operating positions, the source of pressurized fluid is in flow communication with the intermediate chamber through the passageway. An opening in the piston at least partially defines the passageway.

Abstract: A fluid distributor device is for a percussive drill assembly including a generally tubular casing (2) having a longitudinal centerline and a piston (6) disposed within the casing so as to define a reservoir chamber (27) in the casing. The distributor device comprises a generally cylindrical body (12) disposed within the casing and including a central axis, two opposing ends spaced apart along the axis, first and second interior chambers and a port fluidly connecting the two chambers. The body further has a plurality of fluid passages extending between the two ends and fluidly connecting the first chamber with the reservoir chamber and a deflectable retainer portion (16) releasably engaged with the casing so as to retain the body at a desired position with respect to the casing centerline. A valve (7) is disposed within the body and is configured to permit fluid flow through the port and to alternatively prevent fluid flow through the port.

Abstract: The invention relates to a method for drilling, being carried out by a drilling apparatus, having a drilling device (1) that comprises a casing part (2) and a drilling unit (3), in the drilling head (I) of which there are first drilling means (4) for drilling a center hole and second drilling means (5) for reaming of the center hole for the casing part (2) as well as flushing flow arrangement (6) for flushing of waste, being generated. At least during the drilling situation, the first drilling means (4) are coupled by a power transmitting and, in order to enable removal of the same from the hole, removable arrangement, such as a bayonet coupling or like, with the second drilling means (5).

Abstract: A rock drill includes a housing in which are disposed a reciprocable percussive device, slidably mounted in the housing, a rotary device, and a shank adapter aligned with the percussive device. The shank adapter includes first and second adapter portions. The first adapter portion has a front end and a rear end, the rear end arranged to be impacted by the percussive device and rotated by the rotary device. The second adapter portion has a rear end releasably connected to the front end of the first adapter portion, and a front end carrying a coupling adapted for connection with a drill rod component.

Abstract: A concrete drill for a rotary and percussively driven hand tool machine with a cutting part (1) and a striking part (2) that is axially and limited displaceable relative to the cutting part (1). Each of the cutting part (1) and the striking part (2) have a respective facial surface work area for machining a bore hole surface. The respective facial surface work area of the cutting part (1) and the striking part (2) radially overlap upon rotation of the concrete drill.

Abstract: A drill bit assembly includes a drill bit having a leading end to which a drill tip is bonded. The drill tip has a front cutting edge, a pair of side cutting edges, a rear end and a pair of parallel side walls extending between the respective edges. The leading end is arranged to support the drill tip along the rear end and against the parallel side walls. The drill bit includes a bore extending axially therethrough and opening into the leading end. The drill tip extends across the bore but permits egress of flushing liquid from the bore. The drill tip includes projections arranged to cooperate with an engagement face formed at the leading end to locate the drill tip in a bonding position relative to the leading end prior to bonding of the drill tip to the leading end. The cooperation is such as to resist shifting movement of the drill tip in a direction of elongation of the tip and out of the bonding position.

Abstract: In a liquid downhole drilling machine, the guiding bushing (31) for the drill bit is rotatably journaled in the housing (11, 12) and, via a one-way coupling (29), coupled to a turning sleeve (22) that has axial ridges (24) that bound a number of chambers (25, 26, 27) and form turning pistons for turning the turnable sleeve to and fro. A number of these chambers are coupled to be pressurized and depressurized simultaneously with said pressure chamber (47) with the piston area (46) for urging the piston hammer (30) forwards. As a result, the drill bit (13) will be indexed a defined angle between each impact so that the button inserts of the drill bit will change contact points with the rock between every impact and fragment the rock efficiently. The drill tube is not rotated.

Abstract: In a method and device for drilling, in particular impact drilling or rotary percussion drilling, a hole in soil or rock material and forming an anchorage in the hole, wherein a bore hole is formed by the introduction of a drill bit, it is provided that the drill rod assembly of the drilling device includes at least one expandable element having at least one hollow space extending substantially in the longitudinal direction of the bore for introducing a fluid under pressure to at least partially widen the outer periphery of the expandable element, and/or the drill rod assembly is connected with at least one expandable element each including at least one hollow space substantially extending in the longitudinal direction of the bore for introducing a fluid under pressure to widen the outer periphery, thus ensuring a safe anchorage by the expansion of the expandable elements both over the periphery and over the length of the device at a simplified overall construction.

Abstract: A drill bit for drilling a borehole into an earth formation is provided. The drill bit has a central longitudinal axis and a bottom surface facing the borehole bottom during drilling with the drill bit, and comprises primary fluid injection means arranged at the bottom surface and located at a selected radial distance from the central longitudinal axis, the primary fluid injection means being arranged to eject a primary stream of fluid into the borehole, the primary stream having a component in a transverse plane of the drill bit, directed from the fluid injection means to the central longitudinal axis.

Abstract: Fluid roof bits for mining typically supply high pressure water to a location immediately adjacent the cutting insert of the roof bit to flush debris and cool the cutting insert. The present invention is a drill steel assembly for a wet roof bit that reduces the fluid pressure loss supplied to the roof bit. A drill head body is connected to the drill steel by an intermediate adaptor. The adaptor has a spring loaded button thereon that mates with an opening in the drill head body so that the drill head body can be conveniently snapped onto the drill head assembly. A bushing seal made from a flexible material is clamped between said drill steel adaptor and the drill head body to limit fluid pressure losses.

Abstract: A bit head retaining system includes a bit head having an upper end and a working face, and a retention sleeve adapted to be connected to an end of a drill casing and having an internal opening in which at least a portion of the bit head above the working face is disposed, the bit head being secured to the retention sleeve so as to be axially immovable relative to the retention sleeve. A method of method of installing a bit head in a percussion drill is also disclosed.

Abstract: In a method and device for drilling, in particular impact drilling or rotary percussion drilling, a hole in soil or rock material and forming an anchorage in said hole, wherein a bore hole is formed by the introduction of a drill bit (2), it is provided that the drill rod assembly of the drilling device is comprised of at least one expandable element (3, 4) having at least one hollow space extending substantially in the longitudinal direction of the bore for introducing a fluid under pressure to at least partially widen the outer periphery of the expandable element (3, 4), and/or the drill rod assembly is connected with at least one expandable element (3, 4) each including at least one hollow space substantially extending in the longitudinal direction of the bore for introducing a fluid under pressure to widen the outer periphery, thus ensuring a safe anchorage by the expansion of the expandable elements (3, 4) both over the periphery and over the length of the device at a simplified overall construction.

Abstract: A rock drill that comprises a shank (6), the back end of which a percussion piston (10) is arranged to hit. Further, a pulling element (17, 29) is arranged around the shank, to which a pulling force can be directed in such a manner that the shank (6) can by means of said pulling force be moved toward the percussion piston (10), when stuck drilling equipment is freed. During rock drilling, a push force is arranged to act on the pulling element (17, 29), the push force being opposite with respect to the pulling force. The push force is designed in such a manner that during drilling the pulling element (17, 29) moves due to said push force toward the front section of the drill to be at a predefined distance from the position corresponding to the impact point of the shank.

Abstract: A rock drilling tool including a tip (3) formed of a hard material and provided at one end of the tool stem and a shank (4) provided at an opposite end of the stem (2) and having a plurality of entrain grooves (5) extending up to a free end surface of the shank (4), with an entire recessed surface (11) of an entrain groove (5) being larger than an entire outer surface (10) of a groove-forming rest web (6), and with a mean rest cross-sectional area (A′), which is measured within an axial section of the drilling tool having a length at least equal to a product of a natural logarithm base and a stem diameter (e×D), deviating from a mean rest cross sectional area (A) along the entire tool length maximum by 20%.

Abstract: There is provided drilling apparatus (10) comprising a hammer casing (11), a free piston motor piston guide and porting sleeve (12), a drive sub (13), a drill bit (15) splined by shank (16) to the drive sub (13). Below the splined portion (17) the drive sub is relieved at (23) to form an annular air space for motor exhaust air from the splines (16) and (17). The drive sub (13) retains a gauge sleeve (24) via an annular flange (25) between the hammer casing (11) at (26) and a shoulder (27) on the drive sub (13). Below the shoulder (27) the outer diameter of the drive sub (13) is provided with eight grooves that form conduits (30) with the lower portion (31) of the gauge sleeve (24) extending parallel to the drill axis in communication with the space (23) via ports (32). The lower portion (31) extends down the side of the drive sub (13) and terminates with it at (34) adjacent the shoulder (33) at the transition from the bit shank (16) and the bit head (35).

Abstract: A rock drilling apparatus includes a drill string terminating in a drill chuck (32) and a drill bit (16) detachably fitted into the drill chuck, the drill bit having a shank (18) received in the drill chuck, the drill chuck (32) and the drill bit shank (18) having complementary splines and grooves allowing rotation or movement of the drill chuck to be transmitted to the drill bit whilst allowing limited longitudinal movement of the drill chuck relative to the drill bit. The drill bit has a drill head (22) at its lower end which is of greater diameter than said shank, said head having a part (26) above that lower end and below the splined region.

Abstract: A drill head for rock drilling comprising cutting edges (1) made of hard material, which is detachably connected axially, over a bearing surface (3), with a drilling shaft (4) with at least one radially projecting driver blade (5a, 5b, 5c) by a bayonet-type connection slot (6a, 6b, 6c), wherein at least one connection slot (6a, 6b, 6c) is present, which forms two axially opposing undercuts (7a, 7b), within which the driver blade (5a, 5b, 5c) has limited axial movement.

Abstract: A drill member, or “drill steel,” is used in a drilling system for installing roof bolts in a mine. The drill member comprises an elongated bar having a central through bore and opposite open ends. The bar has a cross section that defines a circular outside perimeter and a polygonal inside perimeter. The polygonal inside perimeter allows for convenient coupling of the drill steel to drill bits at one end and to a motorized drill driving device at an opposite end. The drill steel can be cut to any length and the cut open end can accommodate components without the need for machining a specialized coupling element or configuration to the drill steel. Additionally, the round outside perimeter allows the drill steel to be more quietly rotated within the drilled hole.

Abstract: A down-the-hole percussive hammer for rock drilling includes a cylindrical casing and a drill bit disposed at a front end of the casing. The drill bit includes a forwardly facing cutting surface and a center longitudinal passage extending forwardly through a rearwardly facing rearwardmost end surface of the drill bit. The passage includes a rearwardly facing impact surface. A piston is mounted in the casing longitudinally behind the drill bit for reciprocation in a longitudinal direction. The piston includes a front portion sized to enter the center passage of the drill bit and strike the impact surface of the drill bit during each forward stroke of the piston. The impact surface of the drill bit is spaced forwardly from the rearwardmost end surface of the drill bit by a distance of at least ten percent of a total longitudinal length of the drill bit.

Abstract: A down-the-hole percussive hammer includes a cylindrical casing adapted to carry a drill bit, and a piston mounted in the casing for reciprocal movement to repeatedly strike the drill bit. A top sub is mounted at a rear portion of the casing, the top sub including a front face facing the piston. A feed tube is mounted to the top sub and extends forwardly along a center axis of the casing and defines an air-conducting passage. The piston includes an axial through-hole which slidably receives the feed tube. The front face and the feed tube together define a recess opening toward the piston. A removable volume-changer is insertable into the recess to vary a volume of a space in which the piston slides, and thus control a pressure at which the piston operates.