Abstract: A down hole apparatus for generating a pulsing action includes a tubular housing a rotating first mandrel with a first cam profile and a reciprocating second mandrel with a second cam profile, which engages the first cam profile. Upon rotational movement of the first mandrel, the first cam profile exerts an axial force upon the second cam profile to initiate a pulsing action by forcing the second mandrel away from the first mandrel. Springs bias the second mandrel back toward the first mandrel, thereby completing the pulsing action and maintaining the second cam profile engaged with the first cam profile.

Abstract: The present invention relates to method and apparatus for drilling a large diameter hole in the ground. The present invention comprises a hammer drill (40) installed at the bottom of a rod (104) assembled in multi-stages at support means on the ground comprising a pilot hammer drill (44, 48, 49) and a reamer hammer drill (41, 46, 47) coupled to each other through a key structure (42, 43) formed in the vertical direction so as to allow simultaneous rotation and up-and-down movement relative to each other, wherein in a drilling operation, a repetition is made such that the hammer drill (40) is made to rotate and the pilot hammer drill (44, 48, 49) is lowered to drill a pilot hole of small diameter (w) to a predetermined depth (d) and is lifted up to original position, and then the reamer hammer drill (41, 46, 47) is lowered to enlarge the hole to a large diameter (W) down to the predetermined depth (d).

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

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

Abstract: 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 down-the-hole drill hammer assembly includes a casing, a drill stem, a drilling lug segment and a pilot drill bit is provided. The drill stem is housed within the casing and includes an abutment surface. The drilling lug segment is slidably engaged with a distal end of the drill stem and movable between an initial configuration and an extended configuration. The drilling lug segment includes a proximal end engageable with the abutment surface of the drilling lug segment. The drill stem is movable between first and second positions within the pilot drill bit. In moving to the second position, the drill stem slidingly engages the drilling lug segment and moves the drilling lug segment to the extended configuration.

Abstract: A method of drilling a subterranean wellbore can include extending coiled tubing into the wellbore, and actuating an impact tool interconnected to the coiled tubing, thereby delivering impacts to a drill bit. A coiled tubing drilling system for drilling a subterranean wellbore can include coiled tubing, a drill bit, and an impact tool which delivers impacts to the drill bit.

Abstract: A rock drilling machine and an axial bearing module. The rock drilling machine is equipped with an axial bearing having at least one axial piston for axially positioning a drill shank and for damping stress pulses returning from the rock. The axial bearing includes a module that is detachable in one piece from one installation direction. The axial bearing module includes the required pressure medium channels, seals, bearing surfaces, and a module frame having at least bearing housing in connection therewith.

Abstract: Excavation apparatus are provided that can include a fixed portion configured to couple with a first conduit, a rotatable extendible portion movably coupled to the fixed portion, and a coiled conduit associated with extendible portion and in fluid communication with the first conduit. Excavation methods are provided that can include extending an excavating tool from an excavation apparatus to within an excavation site while rotating the excavating tool in relation to a fixed portion of the excavation apparatus, and maintaining fluid communication between the fixed portion and the excavating tool.

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 percussive driving apparatus for an environmental sampling or test device. The driving apparatus comprises a percussion stem (10), a weighted percussion plunger (20) having a longitudinal bore through which the percussion stem (10) is received, the percussion plunger (20) being slidable along a length of the percussion stem (10), a lift element (80) to permit lifting of the percussion plunger (20) along at least a portion of said length of the percussion stem (10), and a percussion pad (30) affixed to the percussion stem (10) at or near a first end thereof. The percussion pad (30) is configured to receive percussive driving force from the percussion plunger (20). The percussion tube (10) is also adapted at the first end to connect to a probe (40) (for example a shielded or unshielded piezometer, or a split spoon sampler, a seepage meter, long term data logging monitoring device, or seismic device) for environmental sampling and/or testing.

Abstract: A percussion drilling assembly for boring into the earth. In an embodiment, the assembly comprises a tubular case having a central axis and a lower end. In addition, the assembly comprises a driver sub having an upper end threadingly engaged with the lower end of the case. Further, the assembly comprises a annular locking member disposed about the driver sub. The annular locking member engages the case and the driver sub and restricts the rotation of the driver sub relative to the case about the central axis.

Abstract: A method of steering a drill bit while drilling a wellbore can include periodically delivering an impact to the drill bit as the drill bit is rotated by a drill string. The impact may be delivered to the drill bit when an axis of the drill bit is oriented in a desired azimuthal direction relative to an axis of the drill string. Another method of steering a drill bit while drilling a wellbore may include interconnecting a bend in a drill string between an impact tool and the drill bit, and periodically delivering an impact from the impact tool to the drill bit as the drill bit is rotated by the drill string. A directional drilling system can include a drill string having a bend interconnected therein, an impact tool, and a drill bit, the bend being interconnected in the drill string between the drill bit and the impact tool.

Abstract: An arrangement and a method for controlling at least one drill parameter when drilling in rock with a rock drill, comprising an impulse-generating device arranged to induce shock waves in a tool acting against the rock with a percussive force generated via a shock wave-generating pressure. The arrangement also comprises a rotation-generating device arranged to supply a torque to the impact device with a rotation generated via a rotation pressure, and a pressurisable damping chamber arranged to at least partially regulate the rock drill's contact with the rock via the prevailing pressure in the damping chamber, in which connection the shock wave-generating pressure is regulated depending on the rotation pressure.

Abstract: The invention relates to an earth boring device including a housing which has at least one portion with an inner thread, and a threaded element which has a corresponding outer thread, wherein the threaded element is slotted and has a receptacle for a securing element which increases the outer diameter of the threaded element and the contact pressure of the threaded connection between threaded element and housing, when inserted in the receptacle.

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 directional drilling system, a drilling hammer and a fluid flow telemetry modulator use a plurality of magnets arranged to convert rotational motion into reciprocating linear motion. Various types of motor can provide rotational motion to a part of the magnets and various linkages and other devices can cause steering or operation of a modulator valve. A torsional drilling hammer uses a plurality of magnets arranged to convert reciprocating linear motion into reciprocating rotational motion. A motor and linkage drives the linearly moving part of the magnets, and the rotating part provides torsional impact be striking the linearly moving part of the magnets.

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 down-the-hole drill hammer is provided that includes a housing, a piston mounted within the housing, a drill bit mounted below the housing, and a drive coupling operatively engaged with the housing and drill bit. The drive coupling can be configured with a plurality of lugs circumferentially disposed about the drill bit and coupled with the casing for providing rotation thereof. Alternatively, the drive coupling can be configured with segmented lugs configured to circumscribe the drill bit, or as a cylindrical chuck formed out of arch-shaped chuck segments which radially assemble onto the shank of the drill bit.

Abstract: A percussion adapter that is driven to generate a percussive axial motion on a wellbore structure. One percussion adapter includes a drive connection to mechanically convert rotational drive to axially directed percussive motion. Another percussion adapter employs a valve that creates back pressure causing axially directed percussive motion. A wellbore tubular connection is also disclosed that transitions torque to resist back off when left hand or right hand torque is applied.

Abstract: The invention relates to a horizontal directional drilling system, comprising a dual string (1), said dual string (1) comprising an inner string (2), and an outer string (3), said inner string (2) is rotatable independently of said outer string (3), a first rotary drive system (4) to drive said inner string (2), a second rotary drive system (5) to drive said outer string (3), a frame (11) to movably support said rotary drive systems (4, 5), a front casing (7) fitted to a distal end of said outer string (3), a drive shaft (8) coaxially positioned into said front casing (7) and connected with said inner string (2) and a hammer (9) connected to said front casing (7) and operable in response to rotation of said drive shaft (8), said hammer (9) comprising a drill head (90) and a drill bit (91) wherein said drill head (90) generating percussive energy using pressurized fluid, e.g. pressurized air, supplied through an annular passage between said outer string (3) and said inner string (2).

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: The present invention relates to a pulse generating device for inducing a shock wave in a tool, wherein the said pulse generating device comprises an impact means (201; 301) for transferring energy to a drill string (202) connected to the said tool, and wherein the energy transfer gives rise to the said shock wave, in which the said energy is mainly constituted by elastic energy stored in the impact means (201; 301) and/or an energy store. The device comprises control means for controlling the interaction of the impact means (201; 301) with the drill string (202), wherein the said control means for controlling the interaction of the impact means (201; 301) with the drill string (202) comprises a motor (207; 307), and wherein the said motor (207; 307) is designed to, through rotation, alternately open ducts for pressurization and depressurization of at least one drive surface (205) acting upon the said impact means.

Abstract: Slough removal assemblies and methods for removing slough from boreholes are described. A slough removal assembly containing a slough barrel is lowered into a borehole having excess slough, driven into the slough to cause the slough to enter the slough barrel, and the slough removal assembly is then removed along with the excess slough. The slough removal assembly may contain a shoe coupled to the slough barrel and configured to be driven into the slough, a retainer positioned between the shoe and the slough barrel to retain slough inside of the slough barrel, and a driving mechanism (such as a drop hammer) to drive the slough assembly into the slough. The slough removal assembly may be coupled either to a wireline system or to a drill string for insertion into and removal from the borehole.

Abstract: A vibrating tool comprising a hammer and valve that oscillate axially inside a housing to produce vibrations solely in response to fluid flow through the tool at an operating flow rate. The valve is supported by a spring that resists compression until a minimum operating flow rate is achieved, and hammer is also spring-loaded. When the valve strokes down and engages the hammer, flow through the hammer is restricted. Increased fluid pressure pushes the hammer down away from the valve, resulting in a sudden decrease in pressure, allowing both the hammer and valve to rebound and create vibrational impacts. The cycle repeats continuously as long as an adequate flow rate is maintained.

Abstract: A retainer device for a drill bit, an earth-boring drill assembly and methods of retaining a drill bit and operating drill assembly. The earth-boring drill assembly includes a casing having a central axis, the bit having a generally cylindrical head. The retainer device includes an annular sleeve connectable to the casing and a retainer assembly provided between the sleeve and the bit. The retainer assembly includes an axial slot defined by one of the sleeve and the bit, the slot having an axially-extending side wall defining an opening and an axial end wall, and a lug supported on the other of the sleeve and the bit, the lug being positionable in the slot through the opening in the side wall, the lug being engageable with the end wall to restrict axial movement of the bit from the sleeve and away from the casing.

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

Abstract: Apparatus and methods for using the drilling apparatus to increase the linear direction of the drilling action are described. The drilling apparatus contains a drill rod that is fitted with a reinforcing sleeve that is located on the drill rod as close as possible to the drill bit. The outer diameter of the sleeve is configured to be substantially the same as the bit diameter and, if necessary, just slightly smaller than the bit diameter. The sleeve reinforces the drill rod next to the drill bit and reduces and substantially eliminates the gap between the drill rod and the borehole in the vicinity of the drill bit. The sleeve, therefore, reduces the wobble of the drill bit in the borehole and reduces the drill bit from wavering from a straight linear drilling direction. The reinforcing sleeve can contain helical channels for moving material displaced by the drilling process away from the drill bit.

Abstract: A method and downhole tool are presented herein for driving completion equipment in a borehole. The method comprises the steps of positioning the completion equipment in the borehole; and moving the completion equipment along the borehole by operation of a downhole driving tool connected to the completion equipment. Operation of the driving tool comprises accumulating energy in the driving tool and releasing the energy to force a moveable member against an impact surface in the driving tool to provide a driving force which is applied to the completion equipment to move the completion equipment in the borehole, wherein the step of accumulating energy in the driving tool comprises providing energy to the driving tool by means of an energy source located at the surface selected from the group consisting of an electrical energy source provided by a wireline cable, a hydraulic energy source provided by a pipe, and combinations thereof.

Abstract: A percussion drilling assembly for boring into the earth. In an embodiment, the assembly comprises a tubular case having a central axis, an upper end, and a lower end. In addition, the assembly comprises a piston slidingly disposed within the tubular case. Further, the assembly comprises a driver sub coaxially coupled to the lower end of the tubular case. The driver sub includes an upper end disposed within the case and a lower end extending axially from the lower end of the case. Still further, the assembly comprises a hammer bit coaxially disposed within the driver sub. The hammer bit including an upper end disposed within the driver sub and a lower end extending from the lower end of the driver sub. The upper end of the driver sub extends axially from the upper end of the hammer bit and is adapted to receive the piston.

Abstract: A percussion drilling assembly for drilling through earthen formations and forming a borehole. In an embodiment, the percussion drilling assembly comprises a fluid conduit including a tubular body having a first end, a second end, a through passage extending between the first end and the second end, and an inlet port in fluid communication with the through passage. In addition, the percussion drilling assembly comprises an adjustable choke at least partially disposed in the through passage and including a first bypass port. The adjustable choke is adapted to decrease the volumetric flow rate of a compressed fluid through the first bypass port.

Abstract: A percussion drilling assembly for boring into the earth. In an embodiment, the assembly comprises a tubular case having a central axis and a lower end. In addition, the assembly comprises a driver sub having an upper end threadingly engaged with the lower end of the case. Further, the assembly comprises a annular locking member disposed about the driver sub. The annular locking member engages the case and the driver sub and restricts the rotation of the driver sub relative to the case about the central axis.

Abstract: An improved ground support member insertion device comprising means for attaching the device to a jackleg drill, a clutch assembly disposed adjacent to the attaching means and adapted for holding a ground support member while it is being inserted into a first drill hole; and, anchoring means disposed opposite the clutch assembly and adapted for temporarily anchoring the device for stabilization in a rock formation during insertion of the ground support member. An impact tool for engaging the proximate end of the ground support member providing rotation and impact to the ground support member to mix the resin and to secure the ground support member in a rock formation. The impact tool can also be used to manually or mechanically tension the ground support member once installed.

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: A percussion drilling assembly for drilling through earthen formations and forming a borehole. In an embodiment, the percussion drilling assembly comprises a fluid conduit including a tubular body having a first end, a second end, a through passage extending between the first end and the second end, and an inlet port in fluid communication with the through passage. In addition, the percussion drilling assembly comprises an adjustable choke at least partially disposed in the through passage and including a first bypass port. The adjustable choke is adapted to decrease the volumetric flow rate of a compressed fluid through the first bypass port.

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

Abstract: A 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 thread joint for transmitting percussive forces includes a male thread on a male member and a female thread on a female member. The male member includes a first portion including an outer surface having a maximum first outer cross section, a second portion having a second maximum outer dimension, and a third portion having the male thread formed thereon. The second portion is disposed axially between the first and third portions. The male thread includes a thread start and a thread end. The third portion terminates in an axially facing first end surface. The female member has a recess in which the female thread is formed, the female thread having a mouth defined by a ring-shaped second end surface. The recess includes a cylindrical inner surface disposed between the second end surface and the female thread. The inner surface faces the cylindrical center portion of the male member.

Abstract: In representative embodiments, a backhead for a drill assembly comprises an elongate member having a proximal end connectible to a source of pressurized fluid, a side wall defining an axial bore and an open distal end. A portion of the bore extending proximally from the distal end has an inner surface defining a cylinder portion shaped to receive an axially movable piston. The axial bore also comprises a check valve receiving area shaped to receive a check valve and to separate, during normal operation when a check valve is received in the check valve receiving area, an inlet area extending proximally to the proximal end from the cylinder portion extending distally to the distal end. Various improvements in retaining the distributor and increasing flow efficiency are described.

Abstract: An improved ground support member insertion device comprising means for attaching the device to a jackleg drill, a clutch assembly disposed adjacent to the attaching means and adapted for holding a ground support member while it is being inserted into a first drill hole; and, anchoring means disposed opposite the clutch assembly and adapted for temporarily anchoring the device for stabilization in a rock formation during insertion of the ground support member. An impact tool for engaging the proximate end of the ground support member providing rotation and impact to the ground support member to mix the resin and to secure the ground support member in a rock formation. The impact tool can also be used to manually or mechanically tension the ground support member once installed.

Abstract: A drive collar is disclosed for use in a percussion drilling apparatus of the type for boring into the earth. Embodiments of the drive collar include a generally tubular, one-piece body further having an inner surface, an outer surface, a first end and a second end. Embodiments further include a threaded section on the outer surface, a retention mechanism on the inner surface, a plurality of splines on the inner surface; and a shoulder on the outer surface.

Abstract: A bit retainer system includes a bit having a head and a shank, a driver sub disposed around the shank of the bit and adapted to engage a hammer case, a bit retainer including a segmented retainer ring configured with a circumferential groove on an outside diameter of the segmented ring, the bit retainer disposed around the shank of the bit and abutting an upper end of the driver sub. The bit retainer system further includes a secondary retainer disposed around the bit retainer, wherein the secondary retainer includes a plurality of webs disposed at selected locations along the secondary retainer configured to engage the circumferential groove of the segmented retainer ring.

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 jar for use in a downhole environment comprises an hydraulic timing device which allows pressure to be controllably increased to a desired level and, on firing, a near-instantaneous release of that pressure, and which allows for selective bi-directional firing of the jar.

Abstract: A jar mechanism comprises a housing having a fluid chamber therein, a piston encircled by an annular metering sleeve and movably mounted in the fluid chamber for movement between a first position and a second position, and a jar member moveably mounted in the housing such that a pull or push force exerted on the jar member moves the piston from the first position to the second position within the fluid chamber against the resistance of the fluid, and the action of the pull or push force exerted on the jar member actuates a release device. The jar member is releasably coupled to the piston by the release device such that, when the piston is in the first position in the fluid chamber, the jar member is coupled to the piston by the release device for movement therewith. Actuation of the release device enables the jar member to be uncoupled from the piston.

Abstract: The invention relates to a method and device for the drilling, in particular the percussive drilling or rotary percussive drilling of holes (9) in the ground or in rock, a bore hole (9) being formed by a drill bit (1) that is mounted on a drill pipe (3), by a percussive and/or rotary movement. Several drill points (2), which can be coupled to the drill pipe (3) and driven independently of one another, are provided on the drill bit (1). According to the invention, the drill points (2) can be uncoupled from their rigid coupling to the drill pipe (3) upon completion of the drilling process and can be displaced towards the centre of the bore hole (9), thus permitting the entire drill bit (1) together with the drill points (2) and the drill pipe (3) to be simply and reliably removed upon completion of the bore hole (9).

Abstract: A wireline jar tool delivers instrument packages into wellbores and retrieves tools when they get stuck. The jar has several stored spring chambers connected to accelerate an upper spring chamber away from a stuck lower carrier chamber that supports instrument packages. Wireline tension actuates the jarring action and then lowers a sinker bar for reset as many times as required to incrementally jar the un-stick fish uphole. The wire line connects to a conductor that extends inside the tool through a main operating shaft, release coupling, hammer and anvil, lost motion coupling, into the lower chamber where the end connects to the instruments for communication to the surface. A small wireline tension provides unexpected large impact forces.

Abstract: A back bit (20) is disclosed which is to used in conjunction with drilling equipment (10) which may include a derrick (11), a drilling pipe (12), a back head (14), a starting rod (13), and a cutting bit (15) mounted to the lower end of the starting rod. The back bit has a tubular body (21) with a plurality of upwardly extending cutting teeth (22).

Abstract: A hydraulic rotary percussive hammer drill includes a body containing a reciprocating percussion piston sliding under the effect of a main hydraulic supply circuit, this main circuit also being intended to cause the sliding of a roughly annular abutment piston housed in a cavity of the body, and having, on the one hand, a front face in contact with a shank and intended to place this shank a predetermined distance away from the percussion piston and, on the other hand, a rear face facing a rear wall of the cavity, characterized in that an external hydraulic supply circuit is able, when the main circuit is shut down, to introduce fluid under pressure between the rear face of the abutment piston and the rear wall of the cavity so as to maintain a space between these items.