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: A drill collar structure to facilitate measurement-while-drilling (MWD) techniques while at the same time having sufficient rigidity to facilitate the drilling operation is disclosed. In some embodiments, a metal structure involving openings such as slots, preferably oriented longitudinally along its axis, but also in other configurations, are disclosed to allow sufficient strength while at the same time allowing exit and entrance of electromagnetic energy. A composite structure is also disclosed which, for given layers, has adjacent fibers such as glass and carbon, so that when the layers are overlapped, glass areas overlap glass areas throughout the radial thickness of the composite tube to create “windows” for the entrance and exit of electromagnetic energy. In yet other embodiments, the drill collar can be made of a metallic frame structure with a multiplicity of openings which are filled with a composite material.

Abstract: A male portion for percussive rock drilling includes sections of reduced cross-sectional area. At least one thread for percussive rock drilling is provided at an end of the male portion. The end of the male portion comprises an abutment surface for the transfer of impact waves. The length of the portion is defined as the length of an imaginary cylinder from a plane of the impact surface to a point where the plane ceases to contact a crest of the thread, wherein the length divided by the external diameter of the cylinder lies within a range of 1-2.

Abstract: In a directional drilling apparatus in which a sensor/transmitter or sonde is located in one section of a drill string and an element of an adjacent section is configured to “steer” the bore drilled in a predetermined lateral direction, a device is provided for automatically ensuring correct registry or alignment of the sensor/transmitter and the steerable element, this device comprising an azimuth member on the section carrying the sensor/transmitter engageable with a reference member of the adjoining section to present, after such engagement, relative rotation of the azimuth member, which is rotatable in the section carrying it, with the sensor/transmitter, but non-rotatably connected with the sonde. The reference member or the azimuth member is resiliently displaceable axially to allow the two sections to be screwed up together.

Abstract: A system is provided for drilling and logging of a wellbore formed in an earth formation. The system comprises a drill string provided with an external recess extending in longitudinal direction of the drill string, a fluid passage for flow of drilling fluid from an upper end of the drill string to a lower end thereof, and a port providing fluid communication between the fluid passage and the recess. The system further comprises a logging tool string capable of passing through the fluid passage and from the fluid passage via the port into the recess, and a removable closure element adapted to selectively close the port.

Abstract: An apparatus and method for removing cuttings in a deviated borehole using drilling fluids. The apparatus includes a pipe string and a bottom hole assembly having a down hole motor and bit for drilling the borehole. The pipe string has one end attached to the bottom hole assembly and does not rotate during drilling. The apparatus and methods raise at least a portion of the pipe string in the deviated borehole to remove cuttings from underneath the pipe string portion.

Abstract: A drill steel for use in mine roof bolting operations. To eliminate or reduce the possibility of fracture in drill steels used in the roof bolting operations in mines the square or hexagonal surfaces of such drill steels or the elements such as couplings, collars, and recesses that are to be connected to drill steels are machined rather than forged or welded. Pieces are joined by press fitting for assembly purposes.

Abstract: A guide tube for use in a rock drill string includes a main portion, a sleeve disposed at a first end of the main portion, and a male thread portion disposed at a second end of the main portion. The sleeve forms a recess having a female thread. A flush channel extends through the guide tube. The main portion includes a section of reduced cross-section disposed adjacent the sleeve for defining a generally radially extending shoulder between the waist and the sleeve. The shoulder serves to support the guide tube on a rig as percussion is applied to the guide tube for loosening a threaded joint between the guide tube and another member.

Abstract: A stabilizer especially adapted for use with an drill string having an eccentric drilling element, such as a bi-center bit. The stabilizer has a pair of circumferentially displaced blades that lie in a common circumferential plane and extend from a rotatable sleeve supported on the stabilizer body, as well as a stationary blade. The rotating blades are aligned with the stationary blade when in a first circumferential orientation and are disposed so that the mid-point between the rotating blades is located opposite the stationary blade, thereby providing full-gauge stabilization, when the rotating blades are in a second circumferential orientation. A magnetic systems senses the circumferential orientation of the rotating blades and transmits the information to the surface via mud pulse telemetry. A piston actuated by the drilling mud locks the rotating blades into the active and inactive positions.

Abstract: The present invention relates to downhole apparatus for limiting rotation of a rotor (4) relative to a stator (8) associated with said rotor (4). Apparatus according to the invention is provided with a locking member (12) movable from a first axial position to a second axial position by the application of a static fluid pressure to a differential area of said locking member (12). The apparatus is characterised by means for selectively applying static fluid pressure to said differential area of said locking member (12).

Abstract: A tubular piling apparatus and method for penetrating the soil comprises, in a preferred embodiment, elements such as a drive shoe and/or other earth displacing structures which may be, in one presently preferred embodiment, of larger outer diameter than the surface conductor pipe. In a preferred embodiment, the invention includes a collar mountable to the pilings having an earth displacing structure formed thereon. In another aspect, a drive shoe, being of a larger size than the conductor pipe and connected to the bottom section of the conductor pipe is provided with an exterior band mounted on the outer diameter of the drive shoe. The exterior band may be located proximate the lower end of the drive shoe. The drive shoe may include teeth formed such that causes compression of earthen formation away from the inner surface of the drive shoe.

Abstract: A drill string member is formed by providing a former and a cylindrical member to be shaped in relationship with the former. Seals are provided between opposing ends of a thick wall cylinder and the cylindrical member, a pressure is applied in the annulus between the cylindrical member and the thick wall cylinder sufficient to deform the cylindrical member against the former. The drill string member thus formed has a constant wall thickness and a non-circular former provides a non-circular drill string member.

Abstract: A subsurface signal transmitting apparatus including an insulation coupler, a carrier device for mounting the telemetry instrumentation, and a by-pass system for avoiding pressure build-up either above or below the apparatus. The insulation coupler includes a housing member having a central opening defined by an interior surface extending in the longitudinal direction and a mandrel member having an exterior surface spaced from the interior surface of the housing member to provide a gap or clearance with an insulating bonding material occupying the clearance. The surfaces are oriented so that when the coupling is in tension at least a portion of the two surfaces experience interacting forces towards each other in the longitudinal direction of the coupling and in event of failure of the bonding material, the mandrel member is unable to withdraw from the housing member.

Abstract: An expandable threaded connection between segments of expandable tubulars that provides multiple sealing points along the pin and box members that can withstand high pressure is disclosed. The present invention utilizes a gap that is created between the pin nose and the back of the box member when the threaded connection is made up and a reverse trapping angle machined into the pin nose end and the back of the box. The radial expansion of the tubulars causes axial movement of the pin nose and the box member until the pin nose is in contact with the back of the box member, thereby closing the gap and forcing the pin nose into sealing engagement with the back of the box member. The reverse trapping angle forces the nose of the pin member outwardly (i.e., toward the outer diameter of the expandable tubular string) as it is forced into contact with the back of the box member during the expansion process.

Abstract: A threaded rock drill element for percussive rock drilling includes a body forming a center axis and having a hardened thread. The thread includes thread crests and thread bottoms and a hardened zone having increased hardness. The hardened zone includes first and second hardened areas extending radially from a crest and bottom (valley), respectively, of the thread, to a boundary curve of the hardened zone. The boundary curve has convex portions extending along the thread crests, and concave portions extending along the thread bottoms.

Abstract: A rock drill including a drilling rod (2), a cup-shaped drilling head (5) secured to the drilling rod (2) at one of its ends, and connection elements including at least one radially projecting, entraining web (8) associated with the drilling rod (2) and received in at least one axially extending entrain slot (9) which is formed in an entrain surface of the cup-shaped drilling head (5) for securing the drilling head (5) to the drilling rod (2) for joint rotation therewith and for a limited axial displacement relative thereto.

Abstract: A system includes a drill string for at least partial use in the ground made up of a plurality of connectable pipe sections to align the innermost passages of attached ones of the sections. An assembly is provided including a pair of adapters for installation of a first one of the adapters in a first end of the innermost passage each pipe section and installation of a second one of the adapters in a second end of each section. The first adapter defines a first electrical contact area and the second adapter defines a second electrical contact area. The adapters are configured for resiliently biasing the first and second contact areas against one another between attached ones of the pipe sections to establish an electrical connection between the pair of adapters to complete an electrically conductive, isolated path extending through the drill string.

Abstract: A method of lining and drilling a bore (10) comprises the steps: mounting a first section of bore-lining tubing (20) on the lower end portion of a drill string (18); running the drill string and tubing into a bore having an unlined section and an existing tubing lined section; locating the first tubing section (20) in the unlined section: uncoupling the first tubing section (20) from the drill string (18); and drilling the bore beyond the first tubing section.

Abstract: A sonde housing construction that is cost effective to manufacture, has a prolonged service life and has an internal cartridge that has replaceable parts and that can be entirely replaced. The cartridge which in service contains and protects a radio transmitter also serves to protect a main shell body from abrasion by drilling/cooling fluid while sealing radio wave apertures formed in the shell body. The cartridge creates an annular flow path for drilling/cooling fluid that ensures complete cooling protection of the transmitter.

Abstract: An earth borer includes a thin-walled tubular shaft (4), a shank (2) provided at one end of the tubular shaft (4), and a drilling head (5) provided at another, opposite end of the tubular shaft, projecting radially beyond the tubular shaft (4), and having at least one cutter for breaking the bore core and (6, 6a, 6b, 6c, 6d) extending, at least partially, radially inward and at least one internal groove (7, 7a, 7b) associated with the at least one cutter, and a releasable tubular connection member (8) for drivingly connecting the shank (2) with tubular shaft (4) for joint rotation with each other.

Abstract: This invention relates to a torque release coupling for use in drill strings comprising an outer string part (1) rotatably mounted outside a radially inner string part (2), and a rotation lock (3) positioned between them. The rotation lock (3) is coupled to a first of said spring parts (1, 2) with a coupling device (4, 9) adapted to allow axial shifts relative to the first string part, and comprising axial gripping organs (5) adapted for releasable engagement with cooperating gripping organs in the second string part, the rotation lock (3) comprising a spring (6) or similar adapted to apply an axial force on the rotation lock (3) directed against the cooperating gripping organs (5) from the first spring part.

Abstract: The invention relates to the assembly of a drive shaft with the cutting head hub of a submersible granulator. Said assembly comprises a connector hood which can be fixed to the drive shaft in such a way that it remains free to move. The connector hood is provided with threading for screwing the cutting head hub onto the drive shaft, said drive shaft being supported on a spherical extremity situated on the inside of the connector hood, and a cogged crown with inner-sided cogs is placed on the cutting head side of the drive shaft. The connector hood has inner-sided cogs which interlace with the cogs on the outer side of the cogged crown. The outer surface of each cog on the cogged crown is convex.

Abstract: A flightless rock auger is used for drilling postholes through rock with the use of hydraulic pressure and at slow revolution per minute. The rock auger is used in combination with a conventional flighted auger used for drilling postholes in dirt and clay. During a posthole drilling operation, the rock auger is substituted for a conventional flighted auger as needed for drilling through and removing rock or other hard material such as concrete from the posthole. The rock auger is designed for use at very low revolutions per minute and can function utilizing only the weight of the auger; however, the rock auger is designed for use with pressure drilling units as well for cutting a circular hole through the rock and forming a plug which is to be lodged in the cavity of the rock auger cylinder to be removed from the posthole.

Abstract: Method and apparatus for drilling a well bore in a hydrocarbon formation using concentric coiled tubing drill string having an inner coiled tubing string and an outer coiled tubing string defining an annulus there between. A drilling means comprising a reciprocating air hammer and a drill bit, a positive displacement motor and a reverse circulating drill bit, or a reverse circulating mud motor and a rotary dill bit, is provided at the lower end of the concentric coiled tubing drill string. Drilling medium is delivered through the annulus or inner coiled tubing string for operating the drilling means to form a borehole. Exhaust drilling medium comprising drilling medium, drilling cuttings and hydrocarbons are removed from the well bore by extraction through the other of the annulus or inner coiled tubing string.

Abstract: A steering assembly includes upper and lower tubular housings connected by a universal joint. An angle cam is disposed on the end of the lower housing and projects into the upper housing. A plurality of wedge members extend axially from the upper housing and into engagement with the angle cam. Drive trains are connected to the wedge members to move the wedge members toward and away from the angle cam so as to pivot the lower housing at the universal joint and change the angle and azimuth of the lower housing with respect to the upper housing. The lower housing is connected to a bearing pack supporting a drill bit such that upon changing the angle and azimuth of the lower housing, the direction of the drilling of the drill bit is also changed. The steering assembly being connected to composite tubing having conductors in the wall thereof for conducting data and commands between the steering assembly and a processor at the surface and for providing power to the steering assembly.

Abstract: A method of drilling and lining a bore in an earth formation comprises providing a tubular outer elongate member and an inner elongate member located within the outer member. At least one of the members is spoolable. A drill bit is mounted to one of the members and a bore is drilled by advancing the drill bit through the earth formation and advancing the members through the bore.

Abstract: A steering assembly includes upper and lower tubular housings connected by a universal joint. An angle cam is disposed on the end of the lower housing and projects into the upper housing. A plurality of wedge members extend axially from the upper housing and into engagement with the angle cam. Drive trains are connected to the wedge members to move the wedge members toward and away from the angle cam so as to pivot the lower housing at the universal joint and change the angle and azimuth of the lower housing with respect to the upper housing. The lower housing is connected to a bearing pack supporting a drill bit such that upon changing the angle and azimuth of the lower housing, the direction of the drilling of the drill bit is also changed. The steering assembly being connected to composite tubing having conductors in the wall thereof for conducting data and commands between the steering assembly and a processor at the surface and for providing power to the steering assembly.

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 is configured for coupling of the drill steel to drill bits at one end and to a motorized drill driving device at an opposite end.

Abstract: In the present invention, in a drill rod for a boring machine, a rod outside diameter is large so as to be approximately equal to a bore diameter, external threads are provided at one end and internal threads are provided at the other end, and at least one small-diameter portion is formed near an internally threaded portion. This step tube rod can reduce a bore bend.

Abstract: A method to deliver an expandable casing string to an uncased borehole coaxially upon a composite coiled tubing drilling string is presented. Once the drilling operation is completed, the casing string is expanded by supplying pressure between the coaxially positioned strings to expand the casing string to the borehole. Preferably, the outer diameter of the casing string contains an adhesive agent designed to be activated by the expansion of the casing string against the borehole wall. Alternatively, the mechanical structure of the casing string itself may be configured to prevent the casing string from collapsing once it has been expanded. Once expanded, the casing string is left behind to isolate the well formation from drilling and production fluids that may subsequently flow therethrough.

Abstract: A disconnect assembly connecting two portions of a downhole assembly having a downhole apparatus attached to a coiled tubing string. The disconnect assembly includes a first housing connected to one portion of the downhole assembly and a second housing connected to another portion of the downhole assembly. The housings are releasably connected by a release assembly. The release assembly is coupled to a drive train on a motor by a connection transferring rotational motion into translational motion. The release assembly includes locking members having a connected position engaging both housings and a released position wherein the housings can be separated. The motor is connected to the surface by conductors extending through the coiled tubing whereby the motor may be actuated from the surface to move the release assembly between the connected and disconnected positions.

Abstract: The steering assembly includes upper and lower tubular housings connected by a universal joint. An angle cam is disposed on the end of the lower housing and projects into the upper housing. A plurality of wedge members extend axially from the upper housing and into engagement with the angle cam. Drive trains are connected to the wedge members to move the wedge members toward and away from the angle cam so as to pivot the lower housing at the universal joint and change the angle and azimuth of the lower housing with respect to the upper housing. The lower housing is connected to a bearing pack supporting a drill bit such that upon changing the angle and azimuth of the lower housing, the direction of the drilling of the drill bit is also changed. The steering assembly being connected to composite tubing having conductors in the wall thereof for conducting data and commands between the steering assembly and a processor at the surface and for providing power to the steering assembly.

Abstract: The invention provides a T-post hole-forming device, comprising (a) a shaft; (b) a head for receiving a driving force at the top of said shaft; (c) a flat plate affixed to one side of said shaft, the shaft terminating in a pointed end for piercing the ground. Also provided is a method for installing a T-post into the ground. The method involves (a) piercing the ground with the T-post hole-forming device to produce a hole; (b) removing the device from the ground, and (c) inserting a T-post into the hole, thereby installing the T-post into the ground.

Abstract: A system includes a drill string made up of a plurality of connectable pipe sections. An assembly is provided for use with each pipe section including contact arrangement for forming an isolated electrical connection between attached pipe sections at each end of each pipe section. An electrically conductive arrangement is located in the innermost passage of each pipe section and is in electrical communication with the contact arrangement to extend therebetween in a way which provides an electrically conductive path that is arranged against the inner wall of the innermost passage of each pipe section in cooperation with the contact arrangement to form an overall electrically isolated conductive path through the drill string. The electrically conductive arrangement resiliently biases the electrically conductive path against the inner wall, which path may take the form of a helix.

Abstract: A drilling and/or chiseling tool (1) comprises a shaft (2) and a cylindrical insertion end (4) connected with the shaft (2) with at least one elongated recess (5 to 8), open toward the outer surface of and toward the free end of the insertion end (9) and forming a rotationally locking groove. A collar (3) is disposed between the shaft (2) and the insertion end (4) and extends at least partially around the tool (1) and projects at least radially outwardly of the shaft (2) and of the insertion end (4). The cylindrical insertion end (4)has a diameter not less than 18 mm and preferably larger than 22 mm. The at least one recess (5 to 8) has a cross-sectional area, extending perpendicularly to the axis of the tool (1), and expands toward the outer surface and is provided essentially in the form of an arc of a circle.

Abstract: A torque shock absorber apparatus (39) comprised of a mandrel (2) and cylinder (8) with torque absorbing mechanism (8-12, 27) to absorb excessive torque while permitting the transmission of rotational energy to the drill string is connected in the drill string or as the drive mechanism in a jar or accelerator (40) to prevent excessive torque loading of the drill string.

Abstract: There is provided an adjustable housing for use with a drill string for controlled directional drilling of a well hole. The housing includes an upper sub and a lower sub each having a first portion extending along a primary axis and a second portion extending along a secondary axis offset from the primary axis by a predetermined angle. The second portions are rotatably mounted together such that the secondary axes of the respective upper and lower subs are coincident. The upper sub is thus rotatable in relation to the lower sub between a bent position wherein the primary axes of the upper and lower subs are misaligned and a parallel position wherein the primary axes of the upper and lower subs are parallel to each other. A locking member is slidably mounted on splines extending radially from the second portion of the upper sub such that the locking member is slidable between an engaged position and disengaged position.

Abstract: In general, the present invention provides a contactless apparatus for power and data transfer over a gap between rotating and non-rotating members of downhole oilfield tools. The gap usually contains a fluid, such as drilling fluid, or oil for operating hydraulic devices in the downhole tool. The downhole tool in one embodiment is a drilling assembly wherein a drive shaft is rotated by a downhole motor to rotate the drill bit attached to the bottom end of the drive shaft. A substantially non-rotating sleeve around the drive shaft includes at least one electrically-operated device. An electric power and data transfer device transfers electric power and data between the rotating and non-rotating members. An electronic control circuit associated with the rotating member controls the transfer of power and data from the rotating member to the non-rotating member.

Abstract: A portable apparatus for creating holes in rock. A rock drill connected to a compressed air supply is engaged with a connector attached between the rock drill and a rock bit. The connector has a substantially tubular shaft for transporting compressed air from the air supply to the rock bit. The tubular shaft uniquely maximizes the air available for removing rock cuttings and minimizes the possibility of rock bit sticking in the rock hole. The invention is particularly suited to seismic shothole drilling requiring portable equipment operable by a single person.

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: To eliminate or reduce the possibility of fracture in drill steels used in the roof bolting operations in mines the square or hexagonal surfaces of such drill steels or the elements such as couplings or collars which are to be connected to them are machined rather than forged.

Abstract: In an assembly for cylindrical drill pipes made for the transport of different kinds of fluids, a combined flange assembly can combine the functions and can be assembled under low time consumption and at low cost. Drill rods are connected by axially directed bolts inserted in the outer wall of a first drill rod (1) and extending axially past the end of the first drill rod (1) into internally threaded blind holes (21, 22) in the next drill rod to be connected to the first drill rod. Each terminal surface of a drill rod is made with arrangements (13-17, 23-27) for at least one coupling plug (31, 33) for the transport of different kinds of fluids in the drill string.

Abstract: A sectional drive system for transmitting rotational power to an output, which system includes multiple splined drive segments which are nested and interlocked as a drive string that is rotatable in a selected straight or curved path. The top one of the drive segments cooperates with a drive mechanism to effect rotation of the nested drive segments in concert, and the bottom one of the drive segments connects to a suitable output such as a drill bit. Multiple, tapered and truncated exterior splines on each of the drive segments mesh with complementary interior splines on the adjacent drive segment to enable slight angular positioning of the drive segments on each other and facilitate dampening of drive vibration and bending of the drive string in or out of the chosen path in any desired direction as the drive string transmits rotational power in a curved path of desired magnitude from the drive mechanism to the output.

Abstract: Opposite ends, or terminals, of the sub are connected by a tubular arbor with threaded pins on each end. The arbor is bent in the middle. A mating threaded box on the upper terminal is tilted an amount equal to the bend angle of the arbor and mates with the bent end of the arbor. If the arbor is rotated in the box, the centerline of the other threaded end describes a cone. One line on the cone is the axis of rotation of the upper terminal. If the lower terminal is locked in that position, the sub is in the straight configuration. Locked in any other rotational position, the sub is bent an angle that is a function of the amount of arbor rotation. To make the arbor adjustable from the outside, an indicator ring is mounted on splines on the arbor. The ring can slide axially on the arbor. The lower terminal can be tightened on the lower end of the arbor to jam the indicator against the upper arbor, locking the assembly for use.

Abstract: To eliminate or reduce the possibility of fracture in drill steels used in the roof bolting operations in mines the square or hexagonal surfaces of such drill steels or the elements such as couplings or collars which are to be connected to them are machined rather than forged.

Abstract: An earth borer including a thin-walled tubular shaft (4) having smooth inner and outer surfaces, a shank (2) provided at one end of the tubular shaft (4), a drilling head (5) provided at another, opposite end of the tubular shaft, projecting radially beyond the tubular shaft (4), and having at least one cutter (6, 6a, 6b, 6c, 6d) extending, at least partially, radially inward and at least one internal groove (7, 7a, 7b) associated with the at least one cutter, and a releasable tubular connection member (8) for drivingly connecting the shank (2) with tubular shaft (4) for joint rotation with each other.

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 drill for forming undercuts in cylindrical bores formed in stone or concrete and including a drilling member (2;22) having a stem (3;23) provided, at its opposite longitudinal ends, respectively, with a shank (4;24) receivable in a chuck of a hand-held drilling tool and a cutting head (5;25) with abrasive cutting bodies, and a sleeve (7;27) for receiving the drilling member (2;22) and having, at its end adjacent to the shank (4;24), a radial collar (8;28), a drag bearing (11) arranged in side the sleeve for supporting the drilling member (2;22), and at least one opening (15;35, 36, 37) formed in a front, in a direction toward the cutting head (5;25), section of the sleeve and spaced axially from the drag bearing (11) by a distance (a) amounting to from about 0.05×D to about 0.6×D, where D is an outer diameter of the sleeve in the drag bearing region of the sleeve.

Abstract: A laser is fired down the drill pipe (20) and directed to the bottom of the hole by the stationary (25) and the rotating (30) mirrors.

Abstract: T Post Hole Driver is a manual, portable, reusable metal stake when driven into the ground and removed forms a hole for insertion of T Posts. The T Post Hole Driver is driven with a sledge hammer into the soil to create a properly shaped hole for the T Post. The T Post Hole Driver is removed and the T Post is inserted in the usual manner. The T Post Hole Drive allows for more accurate and uniform placement of T Posts with much less effort and time.