Abstract: A pressurized fluid flow system for a reverse circulation down-the-hole hammer includes a cylinder and a cylindrical control tube that are respectively coaxially disposed in between the outer casing and the piston of the hammer and in between the piston and the sample tube. Two chambers help to respectively supply and discharge pressurized fluid into and out of the front and rear chambers that exert work on the piston: an internal chamber, defined by a central recess in the inner surfaces of the piston and permanently connected to the source of pressurized fluid, and a discharge chamber, defined by one or more recesses in the inner surface of the outer casing and permanently communicated with the bottom of the hole. A hammer provided with this system has one or more end discharge ports connected to respective longitudinal discharge channels formed on the outer surface of the outer casing.

Abstract: An apparatus for drilling hole, comprising: a cluster drill of down-the-hole (DTH) percussion hammers having two or more DTH percussion hammers; and a special distributor having rotatable swivels for sourcing compressed air or pressurized fluid from independent supply sources and distributing to the DTH percussion hammers; wherein the DTH percussion hammers are arranged such that one or more circumferential layers of drill bits are formed covering the drilling area; and wherein within each circumferential layer, at least one DTH percussion hammer is supplied with the compressed air or pressurized fluid from an independent supply source that is different from the independent supply source supplying the other DTH percussion hammers.

Abstract: A method of using jarring tool in a wellbore, where the jarring tool is electrically activated to apply an impact force transmitted to at least another tool in the well. The method may further comprise operating a hydraulic mechanism in response to electrical activation of the jarring tool to cause a first member of the jarring tool to be moved to collide with a second member of the jarring tool to apply the impact force. Also, the method may involve electrically activating the jarring tool by communicating at least one command over at least one electrical conductor to the jarring tool.

Abstract: A downhole tool comprises a first connector sub coupled to an outer housing. A mandrel is disposed in the outer housing and is coupled to a mandrel. The second connector sub is slidably engaged with the outer housing so that torque loads are transferred from the first connector sub to the second connector sub through the outer housing independently of the mandrel.

Abstract: The present invention relates to a down-the-hole hammer comprising an external cylindrical outer wear sleeve (5), a sliding piston (8) mounted for reciprocating movement within the outer wear sleeve to strike a percussion bit (1) of a drill bit assembly located at the forward end of the outer wear sleeve.

Abstract: The present invention provides an attachment (1) for a fluid-operated percussion drill tool (2), the drill tool having a backhead assembly (4) for attachment to a drill rod (10). The attachment comprises a shaft (3) attachable to the backhead assembly, wherein the shaft comprises a central bore (16) in fluid communication with a pressure bore of the drill rod. The attachment further comprises a sleeve (5) co-axially slidably mounted on the shaft, the sleeve comprising an outer shoulder (7) at a rear end thereof, and at least one rearwardly-directed exhaust passage. Pressurised air is supplied from the central bore of the shaft to urge the sleeve rearwards into a closed position in which air is prevented from exhausting through the exhaust passage. When a restriction is encountered at the shoulder, the sleeve moves forward to an open position in which air is permitted to exhaust through the exhaust passage adjacent the restriction.

Abstract: A boom arrangement (7) for a rock drill rig (5) including a feed beam unit (8) for displaceable reception of at least one rock drilling machine (10, 10?), a support unit (13) for connection to and support of a rotator unit (12), a boom unit (11) between the rotator unit (12) and the feed beam unit (8) for displacement of the feed beam unit in planes essentially at right angle to a main plane (P) for the support unit (13), wherein the rotator unit (12) is arranged for rotating the feed beam unit (8) around an axis (A), which is essentially-perpendicular to said main plane (P), wherein the support unit (13) is connectable to a vehicle unit being part of the rock drill rig (5), and being arranged for displacing the rock drill rig. The support unit (13) has joint connecting elements (14) being sidewardly connectable for connection to a sidewardly directed carrier device (15, 17) which is attachable to the vehicle unit, and a lower abutment side (16) for lying supporting against an outer substrate.

Abstract: A device has a first, lower sub housing, a second, upper sub housing, and an extensible joint connecting the lower sub housing to the upper sub housing. A pressure equalization chamber is attached to the upper sub housing and demarcates an inner zone including an internal mechanism of the extensible joint, and an outer zone open to well bore fluids and pressure. A fluid barrier moves within the pressure equalization chamber in response to changes in well bore pressure to alter a volume of the inner zone to equalize a pressure of the inner zone.

Abstract: A method and apparatus for delivering repetitive jarring impacts to a stuck object downhole. The jarring tool is deployed on coiled tubing or other tubular well conduit, and fluid pressure is used to cycle the jar without reciprocating the well conduit at the wellhead. A hydraulic reset assembly is included. The hydraulic chamber is in fluid communication with the flow path through the tool. Thus, when the internal fluid pressure inside the tool exceeds the external pressure in the well, the fluid pressure drives the piston in the hydraulic chamber to urge the tool toward the contracted position. In this way, the reset assembly can overcome the tendency of fluid pressure to extend the tool. The reset assembly can be configured to equalize the extension pressure, to prevent undesired cocking of the tool, or to overcome the extension pressure to contract the tool for recocking the jar mechanism.

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 comprising a bit head configured to be attached at an end of a drill element of a drilling assembly and having a diameter larger than that of a said drill element. The bit head has at a front end as seen in the intended drilling direction a generally frusto-conical shape defined by a substantially circumferential ring provided with a plurality of gauge buttons distributed along the extension of the ring for engaging material to be crushed. A central flush channel extends through the bit head and has at least one flushing hole opening at said front end to conduct flushing medium to said front end. At least one peripheral flushing hole of said at least one flushing hole opening at said front end opens in said substantially circumferential ring. At least two peripheral flushing holes open in said substantially circumferential ring.

Abstract: An underground drilling method where drilling fluid pulsing down hole tool is combined with a multiple in series pistons down hole tool to provide vigorous vibrations in the drill string and deliver vibrating energy to the drill bit to increase penetration rates and reduce friction between the drill string and the hole. One example method and apparatus shown can operate a simple percussive down hole mud hammer.

Abstract: A downhole tool string, comprising a tool string bore and a drill bit located at the bottom of the tool string. The drill bit comprises a body intermediate a shank and a working surface. The working surface may comprise a substantially coaxial rotationally isolated jack element with a portion of the jack element extending out of an opening formed in the working surface to engage a subterranean formation. The tool string may comprise a driving mechanism adapted to rotate the jack. The clutch assembly disposed within the tool string bore may comprise a first end in communication with the jack element and second end in communication with the driving mechanism.

Abstract: A DHD hammer that can exhaust working air volumes partially through a proximal end of the DHD hammer's actuator assembly includes a drive chamber, a return chamber, and a backhead that includes exhaust ports. Working air volumes from the drive chamber are exhausted through the backhead while working air volumes from the drive chamber are exhausted primarily through a drill bit.

Abstract: A hammer assembly comprises a jack element substantially coaxial with an axis of rotation of a drill bit. The jack element includes a distal end extending beyond a working face of the drill bit. A porting mechanism within the bore comprises a first and second disc substantially contacting along a flat interface that is substantially normal to the axis of rotation. The first disc is attached to a turbine which is adapted to rotate the first disc with respect to the second disc. The first disc comprises a first set of ports adapted to align and misalign with a second and third set of ports in the second disc. As the first disc rotates, the sets of ports are adapted to route a drilling fluid into a piston chamber where a porting mechanism causes the jack element to repeatedly extend further beyond the working surface of the drill bit and then retract at a constant frequency.

Abstract: A drilling apparatus including a hydraulically powered hammer having a piston to impact a drill bit; a shuttle valve to control reciprocation of the piston; and an accumulator for hydraulic fluid; at least one drill rod having a first connection valve for connection of the drill rod to the connection valve of the hammer; and a second connection valve for connection of the drill rod to the first connection valve of a like drill rod or to a rotation device. The piston and shuttle valve are positioned substantially in-line to the axis of movement of the hammer. The accumulator is positioned proximate to the shuttle valve; and the first connection valve, and second connection valve having at least one poppet valve positioned proximate to a corresponding valve seat.

Abstract: Disclosed is an apparatus for vibrating a downhole drill string operable to have a drilling fluid pumped therethrough. The apparatus comprises a tubular body securable to the drill string and having a central bore therethrough, a valve in the tubular body for venting the drilling fluid out of the drill string and a valve actuator for cyclically opening and closing the valve. The method comprises pumping a drilling fluid down the drill string and cyclically venting the drilling fluid through the valve so as to cyclically reduce the pressure of the drilling fluid in the drill string. The valve can comprise a tubular body port and a corresponding rotor port selectably alignable with the tubular body port as the rotor rotates within the central bore. The valve actuator can comprise at least one vane on the rotor for rotating the rotor as the drilling fluid flows therepast.

Abstract: A bidirectional jarring tool that allows repetitive firing in one direction without firing the tool in the opposite direction. One of the tubular members provides up and down anvil surfaces, and the other member provides up and down hammer surfaces. Inner and outer tubular members define a hydraulic chamber with a restricted section that divides the chamber into an upper section and a lower section. Upper and lower pistons, each with a valved flow channel, reciprocate through the restricted section to produce up and down jarring impacts. When the restricted section is disposed between the upper and lower pistons, the tool is in a neutral position and can be jarred repetitively in either direction.

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 downhole tool including a fluid-actuated piston and a motor-driven valve. The fluid-actuated piston is operatively associated with a reciprocating mass. The motor-driven valve is configured to supply actuating fluid sequentially to drive the piston downwards and upwards. A method of reciprocating a mass in a downhole tool. The method including cycling a motor-driven valve between a first configuration and a second configuration. In the first configuration actuating fluid pressure drives a piston associated with the mass downwards. In the second configuration actuating fluid pressure drives the piston upwards.

Abstract: A variable frequency down hole drill, includes a drill bit, a reciprocating piston operable to deliver an impact load to the drill bit, and means for changing the frequency with which the piston delivers impact loading to the drill bit, also resulting in a change in overall power of the drill. The means for changing frequency and overall power may operate during continuous operation of the drill. The means for changing the frequency and overall power may include a valve for selectively changing the effective volume of a drive or return chamber, an actuator for changing the timing of placing the drive or return chamber in communication with exhaust, or a system for changing the frequency in response to sensing an predetermined operating parameter of the drill, such as pressure or piston position.

Abstract: A down-hole hammer includes a two-piece drill bit retained in a casing having an interior surface with a plurality of longitudinal grooves formed therein. The bit shank and the casing are rotationally connected by a number of pins received in the grooves. A symmetrical free piston divides the casing into an upper working chamber and a lower working chamber. The piston slides on an air control assembly including a ported tube extending axially from said air supply to an axial bore in the shank of the bit to guide exhaust air through discharge ports at the cutting face of the bit, the bit reciprocating on the end of the tube. The upper and lower check valves in the air control assembly and openable by supply pressure against a spring bias in response to working fluid supply pressure.

Abstract: A fluid actuated downhole tool for inducing movement of a downhole apparatus is described. The tool comprises a body for coupling to downhole apparatus, the body being adapted to accommodate now of fluid therethrough and including a flow-modifying arrangement for modifying the flow of fluid through the body. The flow-modifying arrangement is configurable in an inactive configuration and in an active configuration. The fluid activated tool is selectively operated from the surface by varying an operating condition which causes the flow through the tool to either bypass or flow through the flow-modifying arrangement to induce movement of the downhole apparatus.

Abstract: A bidirectional drilling jar, capable of repeated unidirectional firing, including a sliding assembly that is disposed in a sliding relation to the interior of a barrel assembly. A portion of the inner diameter of the barrel assembly forms a restricted barrel segment. The restriction intermediate an upper chamber and a lower chamber. A metering system comprising an upper flange a meter valve, and a lower flange. The meter valve slideably disposed on the sliding assembly between the upper and lower flanges. The metering system travels between the upper chamber and the lower chamber providing limited, controlled flow of the fluid contained therein when passing through the restriction in order to pressurize the system and produce a jarring stroke. Alternatively, the metering system comprises an upper flange, a meter ring, a meter valve, and a lower flange. The meter valve and meter ring are slideably disposed on the sliding assembly intermediate the upper and lower flanges.

Abstract: A percussive assisted rotary drill includes a top sub for connection with a drill pipe. The drill pipe imparts torque to the drill and also supplies motive fluid to the drill. The drill includes a shank adapter to facilitate affixing a rotary drill bit to the drill. The motive fluid is divided between a bit flow which flows through the bit to clear debris at the bottom of the drill, and an actuator flow. An actuator, which may be in the form of a reciprocating piston, moves within the drill under the influence of the actuator flow to impart cyclical blows to the shank adapter. The blows are transferred to the drill bit through the shank adapter to provide a relatively high frequency low amplitude percussive force on the rotating drill bit to assist in the drilling operation. At least a portion of the actuator flow portion of the motive fluid is exhausted through the top end of the drill.

Abstract: A drilling apparatus including a hydraulically powered hammer having a piston to impact a drill bit; a shuttle valve to control reciprocation of the piston; and an accumulator for hydraulic fluid; at least one drill rod having a first connection valve for connection of the drill rod to the connection valve of the hammer; and a second connection valve for connection of the drill rod to the first connection valve of a like drill rod or to a rotation device. The piston and shuttle valve are positioned substantially in-line to the axis of movement of the hammer. The accumulator is positioned proximate to the shuttle valve; and the first connection valve, and second connection valve having at least one poppet valve positioned proximate to a corresponding valve seat.

Abstract: There is provided a method for drilling a hole into the ground and installing a geothermal transfer loop. A drilling apparatus is positioned at a desired location. The drilling apparatus includes a rotating and vibrating apparatus, such as a sonic drill, for rotating and vibrating a hollow drill string into the ground. The hollow drill string having an inner space. A hole is drilled to a desired depth by rotating and vibrating the hollow drill string into the ground while discharging fluid into the inner space of the hollow drill string. The fluid forming a fluid column in the inner space of the drill string. The fluid column impedes entry of ground materials into the inner space of the drill string and is vibrated to create a water hammer for adding an additional drilling force. A geothermal transfer loop is lowered into the inner space of the hollow drill string and the drill string is removed from the ground. The method may also include discharging grouting material into the hole.

Abstract: The invention concern an arrangement for a down-the-hole hammer drill (1), particularly for use in soil consolidation through a process known as “jet grouting”, and comprising a principally cylindrical machine housing (2), an impact mechanism (3) driven by pressurised fluid that, mounted in the machine housing, is arranged to give impacts onto a drill bit (5) fixed mounted in a chuck (4) in the machine housing in a manner that allows reciprocating motion, whereby the machine housing has a central supply line (6) for the driving fluid to the impact mechanism in which channels in the drill bit constitute outlets for used driving fluid.

Abstract: There is provided a downhole hammer including a drill bit (2) retained by short (4) and long (5) drive pins in the bore of a driver chuck (1). The chuck (1) and bit (2) shank have machined longitudinal grooves (3), every second bit shank groove being blind and connected to the adjacent open groove by a short-pin length relief. The shorter pins (4) are inserted into the visible holes formed by the alignment of the open drill bit grooves and driver chuck grooves (3). The chuck (1) is then indexed which shunts the short pins (4) sideways until the longer pins (5) are insertable. The driver chuck (1) and drill bit (2) are engaged rotationally. The bit (2) slides by the desired distance due to the shorter pins (4) being entrapped in the blind grooves. The arrangement does not require a bit shank extension to accommodate a conventional bit retainer ring.

Abstract: A down-the-hole drill hammer having a housing, a backhead and a tubular sliding check valve assembly that includes a distal end, a threaded male proximal end, a supply inlet and an exhaust port. The exhaust port communicates between an interior of the backhead and an exterior of the backhead. The tubular sliding check valve assembly includes a distributor, a sliding valve, and a biasing member. The distributor has a central opening extending through the distributor, an aperture extending through the distributor, and an exhaust gallery. The sliding valve is slidable along the central opening. The biasing member biases the sliding valve to a closed position.

Abstract: A fluid-actuated percussive impact tool includes a drill bit disposed partially within a casing for respective longitudinal movement between extended and retracted positions. A bearing having a bore is fixedly disposed within the casing. A piston is located in the chamber and a second end thereof is configured to selectively enter the bore of the bearing through the first end to impact the first end of the drill bit. At least one groove is formed in an exterior surface of the piston proximate the second end thereof. The tool has a sealed position when the drill bit is in the extended position wherein a water seal is formed between an interior surface of the bearing and a portion of the exterior surface of the piston between the first end of the piston and the first end of the at least one groove.

Abstract: A pressure reversing valve for a down-the-hole percussive drilling (“DHD”) apparatus has a first valve pressure surface, a second valve pressure surface and a third valve pressure surface. The first valve pressure surface engages an internal surface of a housing of the DHD hammer. The second valve pressure surface is in communication with a high pressure port of the DHD hammer. The third valve pressure surface is in communication with a passageway that extends through a distributor within the DHD hammer. The valve also includes a valve passageway that extends through the valve and which is in communication with a first volume of the DHD hammer. The first volume is formed by surfaces of the distributor and the third valve pressure surface.

Abstract: A percussion drilling assembly for drilling through earthen formations and forming a borehole. In some embodiments, the drilling assembly includes a retainer sleeve having an upper end with an outer diameter and a tubular casing engaging the retainer sleeve. The tubular casing includes a first, second, and third tubular portion. The first tubular portion engages the upper end of the retainer sleeve at a first end having an outer diameter substantially equal to the outer diameter of the retainer sleeve. The second tubular portion is connected to the first tubular portion at a first end and has a second end with an outer diameter that differs from the outer diameter of the retainer sleeve. The third tubular portion is coupled to the second tubular portion. The first and third tubular portions each have a length configured to enable gripping of the tubular casing using tongs.

Abstract: The present invention relates to a method for controlling a rock drilling process, in which an impulse-generating device comprising an impact element transmits a shock wave to a tool connected to the impulse-generating device, whereby a portion of the energy of the shock wave is transmitted to the rock by means of the tool and a portion of the energy of the shock wave is reflected and brought back to the impulse-generating device as reflected energy. The method comprises steps of generating at least one parameter value representing the reflected energy, and regulating the interaction of said impact element with said tool at least partially based on said value or values to control the rise time and/or length of said shock wave. The invention also relates to a regulation device, an impulse-generating device and a drilling rig.

Abstract: The present invention relates to a control device for an impulse-generating device for inducing a shock wave in a tool, in which said impulse-generating device comprises an impact element for transmitting said shock wave to said tool, a counter pressure chamber acting against the impact element and a device for reducing a pressure in the counter-pressure chamber. The control device comprises control means for regulating the reduction of the pressure in said computer-pressure chamber. The invention also relates to an impulse-generating device.

Abstract: A percussive assisted rotary drill includes a top sub for connection with a drill pipe. The drill pipe imparts torque to the drill and also supplies motive fluid to the drill. The drill includes a shank adapter to facilitate affixing a rotary drill bit to the drill. The motive fluid is divided between a bit flow which flows through the bit to clear debris at the bottom of the drill, and an actuator flow. An actuator, which may be in the form of a reciprocating piston, moves within the drill under the influence of the actuator flow to impart cyclical blows to the shank adapter. The blows are transferred to the drill bit through the shank adapter to provide a relatively high frequency low amplitude percussive force on the rotating drill bit to assist in the drilling operation. At least a portion of the actuator flow portion of the motive fluid is exhausted through the top end of the drill.

Abstract: An expandable reamer apparatus and methods for reaming a borehole are disclosed, including at least one laterally movable blade carried by a tubular body selectively positioned at an inward position and an expanded position. The at least one laterally movable blade, held inwardly by at least one blade-biasing element, may be forced outwardly by drilling fluid selectively allowed to communicate therewith or by at least one intermediate piston element. For example, an actuation sleeve may allow communication of drilling fluid with the at least one laterally movable blade in response to an actuation device being deployed within the drilling fluid. Alternatively, a chamber in communication with an intermediate piston element in structural communication with the at least one laterally movable blade may be pressurized by way of a movable sleeve, a downhole turbine, or a pump.

Abstract: A percussive assisted rotary drill includes a top sub for connection with a drill pipe. The drill pipe imparts torque to the drill and also supplies motive fluid to the drill. The drill includes a shank adapter to facilitate affixing a rotary drill bit to the drill. The motive fluid is divided between a bit flow which flows through the bit to clear debris at the bottom of the drill, and an actuator flow. An actuator, which may be in the form of a reciprocating piston, moves within the drill under the influence of the actuator flow to impart cyclical blows to the shank adapter. At least a portion of the actuator flow portion of the motive fluid is exhausted through the top end of the drill.

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 that reciprocates due to changes in pressure of the pressurized fluid contained inside of a front chamber and a rear chamber located at opposites sides of the piston, wherein the flow into and out of these chambers is controlled solely by the overlap or relative position of the piston and the cylinder as a supply chamber and a discharge chamber defined by recesses on the inner surface of the outer casing and separated by a dividing wall control the flow of pressurized fluid in and out of the front and rear chambers the.

Abstract: A portion of a drill assembly operated by a supply of compressed fluid comprises a backhead, a cylinder portion, a hollow elongate wear sleeve and a piston. The backhead has a proximal end connectable to the supply, an axial bore and an open distal end having an integrated cylinder portion defined therein. The backhead has passages extending between the axial bore and the outer surface of the backhead. The cylinder portion is aligned with and in selective fluid communication with the backhead. The hollow elongate wear sleeve surrounds the cylinder portion and is connected to the backhead. The piston is housed by the wear sleeve and has a proximal end shaped to fit within the cylinder portion. The piston is slideably movable along the wear sleeve and the cylinder portion in response to compressed fluid conveyed through the backhead. When the drill assembly is in a drop open position, the proximal end of the piston is radially spaced apart from a nearest surrounding surface.

Abstract: A method and drilling apparatus for drilling. The drilling is carried out by a drilling apparatus including a drilling device including a casing part and at least during drilling a drilling unit. At the drilling head of the drilling apparatus are at least first drilling elements, a second drilling element, a flushing flow arrangement and a pressure medium operated hammering device. The first drilling elements are coupled with the second drilling element power-transmittedly in order to carry out cooperation thereof at least during drilling with the second drilling elements for a rotational motion, a feeding motion and the hammering motion, and are coupled removably to enable removal thereof from the hole. For producing the hammering motion a hammering device is used that is operated essentially by a water-based pressure medium. At least a part of the water-based pressure medium operating the hammering device is used as the flushing medium.

Abstract: A percussion drilling assembly for boring into the earth is disclosed. The percussion drilling assembly includes a top sub, a casing coupled to the top sub, and a feed tube assembly disposed within the top sub and the casing. The feed tube assembly includes a non-rigid coupling having a throughbore and a tubular body disposed therein. The tubular body is translatable in the radial position and/or rotatable relative to a longitudinal centerline extending through the non-rigid coupling.

Abstract: A fluid distributor cylinder is for a percussive drill assembly that includes a casing having an inner circumferential surface defining a central bore, a central axis extending through the bore, a bit movably coupled with the casing and a piston movably disposed within the casing bore. The distributor cylinder includes a generally tubular body disposeable within the casing bore and having first and second ends, a central axis extending generally between the first and second ends, an outer circumferential surface. At least a section of the outer surface is configured to engage with the inner surface of the casing so to form an interference fit between the body and the casing. The cylinder includes an exterior thread and/or a radially-extending shoulder configured to releasably engage with the casing inner surface so as to substantially prevent axial displacement of the distributor body with respect to the casing.

Abstract: The 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). The stub shank is provided with axially extending splines (36), which are slideably engageable with complementary splines (35) formed on a drive chuck (4). Rotational drive from the chuck (4) may be transmitted to the stub shank (32) by means of the splines. Bit retaining means (6, 7, 41, 42) at the chuck are adapted for engagement with complementary retaining means (37, 51) at a spline portion of the stub shank to retain the stub shank in the drill bit assembly. Engagement means on the chuck (4) are adapted for connecting the chuck (4) to a drive means (5) of the fluid-operated percussion drill tool.

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 pressurized fluid flow system for a reverse circulation down-the-hole hammer having a cylinder coaxially disposed in between an outer casing and the piston. This piston reciprocates due to changes in pressure of the pressurized fluid contained inside of a front chamber and a rear chamber at opposite sides of the piston, where the flow into and out of these chambers is controlled solely by the overlap or relative position of the piston and the cylinder as a supply chamber and a discharge chamber, which are defined by recesses on the inner surface of the outer casing and separated by a dividing wall, respectively, supply to and discharge from the front and rear chambers, the pressurized fluid. An internal chamber may also be provided in between the piston and a sampling tube coaxial with the outer casing for a more efficient filling of the chambers.

Abstract: A drilling assembly in an elongated hole including a housing defining an interior with a plurality of motor stages in the interior. Each motor stage has at least one blade with supporting platform surfaces. A casing within the interior surrounds the plurality of motor stages and defines an annular flowpath with the housing. The casing also defines at least one offtake passage adjacent each motor stage. A shielding fluid passes through the annular flowpath and, in turn, the at least one offtake of each motor stage to coat and protect the at least one blade and supporting platform surfaces. A driving fluid passes through the casing for propelling the at least one blade of each motor stage. Preferably, the shielding fluid is at a relatively higher pressure than the driving fluid with a substantially constant ratio maintained between the between the shielding fluid and the driving fluid.

Abstract: A double-acting compounder is disclosed having a first end and a second end, and comprising an outer housing, an upper mandrel, and a lower mandrel. The outer housing defines the first end. The upper mandrel is at least partially disposed telescopically within the outer housing to define an uphole fluid chamber between the upper mandrel and the outer housing, the upper mandrel defining the second end. The lower mandrel is at least partially disposed telescopically within the outer housing to define a downhole fluid chamber between the lower mandrel and the outer housing. The uphole fluid chamber and the downhole fluid chamber each contain fluid, have a variable stroke-dependent volume, and are sealed at an uphole end and a downhole end. The upper mandrel has a first shoulder engagable with and facing a second shoulder of the lower mandrel to move the lower mandrel during at least a portion of a stroke.

Abstract: A valve device (V, 4?) for controlling the movement in a machine housing (2) of a reciprocating percussion piston (3) of a percussion device (1) for a rock drilling machine with a first chamber (5) that can be pressurized for forward driving of the percussion piston (3) and a second chamber (8) that can be pressurized for back-driving of the percussion piston (3), wherein the valve device includes a to and fro movable valve element (20), the movement of which being controlled as a response to the position of a valve portion (V) of the percussion piston in a valve housing portion by periodically pressurizing a signal chamber (21) actuating the movement of the valve element over signal conduit means (22, 23, 24).

Abstract: A slotting device (100) to be used with a rock drilling apparatus (1) to drill closely together a plurality of parallel intersecting holes so as to form a slot in a brittle material, such as rock, masonry or concrete. The slotting device (100) includes a guide portion (110) connected to a body portion (120) with at least one strut (130). The guide portion (110) is disposed in a previously drilled hole, and the body portion (120) and a rotary percussion tool (7) mutually define a variable volume chamber (140) that contains flushing fluid that damps transmission of impact stress waves from a percussion device (4) of the drilling apparatus (1) to the slotting device (100).