Abstract: Disclosed is an internal reamer for anchor shaft hole for mining, comprising a reaming cutter, a sleeve, a push-pull rod, a drilling machine connecting shaft and a manual hydraulic jack, wherein the push-pull rod is disposed in the sleeve coaxially, a rear end of the reaming cutter is connected to a front end of the push-pull rod, a rear end of the sleeve is connected with a guiding cylinder having an inner diameter larger than the sleeve, a rear end of the guiding cylinder is connected with a mounting cylinder coaxially, the manual hydraulic jack is installed in the mounting cylinder, a rear end of the push-pull rod is fixedly connected with a piston plate which is slidingly and sealingly matched with an inner wall of the guiding cylinder, and the front end of the drilling machine connecting shaft is fixedly connected with the rear end of the mounting cylinder.

Abstract: The invention relates to a concreting installation for concreting an excavation. The installation includes a concreting column having a top end arranged to be open in order to be at atmospheric pressure, and at least one controlled retention device situated at a distance from the open top end of the concreting column and adapted, in at least one configuration, to retain a volume of concrete inside the column. The invention also relates to a method of concreting an excavation.

Abstract: An anchoring device for a self-propelled irrigation system includes a drive assembly that drives a soil auger into the ground to anchor a drive tower of the irrigation system. The soil auger is rotatably driven about a vertical axis and movable vertically relative to the drive tower. The soil auger includes a lower tip, a multi-sided head at an upper end, and a helical screw portion between the lower tip and the upper end. The drive assembly includes a sleeve member with an inner surface that mates with the head of the soil auger and allows the soil auger to slide within the sleeve member while rotating together with the sleeve member. A bit cleaner assembly is arranged to engage the helical screw portion of the soil auger to clean soil from the auger and to cause the auger to move vertically relative to the sleeve member upon rotation.

Abstract: A pile-forming method for a compound extruded and expanded pile, comprising using a compound extrusion and expansion drilling tool of pile-forming equipment for a compound extruded and expanded pile to drill, extrude, and expand to form a bore, wherein when upwardly rotating and lifting, expansion bodies of the compound extrusion and expansion drilling tool enlarge, and at the same time, a concrete pump is started up to pour a pile material under pressure into the pore for the pile, to reach a pile top mark height, obtaining a compound extruded and expanded pile. Pile-forming equipment for a compound extruded and expanded pile is also disclosed, comprising a compound extrusion and expansion drilling tool and a control system thereof. The compound extrusion and expansion drilling tool comprises a drill stem. A plurality of expansion bodies are provided on a threaded section of a drill bit of the drill stem.

Abstract: An apparatus and method for forming a borehole in an earthen formation includes a side cutting device comprised of a laterally extendable side cutting element that can be actuated from a retracted position to an extended position in which the side cutting element is selectively employed to create a larger borehole diameter in a down hole location than the remaining portion of the borehole that is closer to the borehole opening.

Abstract: A tubular cutter that cuts with extendable and rotating blades has its depth of cut limited upon getting through the tubular to be cut. In a preferred embodiment, the tubular has a loosely mounted member exterior thereto to be engaged by the rotating cutters. When such engagement happens the effect is that the loosely mounted member serves as a cover to the cutters to prevent them from cutting other structures beyond the tubular to be cut. The loosely mounted member is grabbed by the rotating blades for tandem rotation this preventing further cutting action. The load on the mill drops noticeably so that surface personnel have a signal to stop hydraulic pressure to the drive mechanism to allow the blades to retract and the cutter to be removed.

Abstract: An apparatus and method for forming a borehole in an earthen formation includes a side cutting device comprised of a laterally extendable side cutting element that can be actuated from a retracted position to an extended position in which the side cutting element is selectively employed to create a larger borehole diameter in a down hole location than the remaining portion of the borehole that is closer to the borehole opening.

Abstract: An apparatus and method for forming a borehole in an earthen formation includes a side cutting device comprised of a laterally extendable side cutting element that can be actuated from a retracted position to an extended position in which the side cutting element is selectively employed to create a larger borehole diameter in a down hole location than the remaining portion of the borehole that is closer to the borehole opening.

Abstract: A device is suspended from cables or other flexible or articulated structures, for the mixing in situ of earth for the formation of underground walls or diaphragms includes in its lower part a disaggregator (1) for the disaggregation of the earth. Above the disaggregator is positioned a corrector (5, 13) for the direction of the excavation.

Abstract: Provided is an excavation tool which can firmly fix a locking pin so that the locking pin does not move even in the case of an impact during excavation and/or the locking pin being pushed out in the insertion/removal direction. The excavation tool (10) includes a tool body (20) having an attaching hole (32) and an attaching member (40). The attaching member (40) is provided with an attaching shaft (45) inserted into the attaching hole (32), and the outer peripheral surface of the attaching shaft (45) is provided with a groove (46) which crosses the extension direction of the attaching shaft (45). The tool body (40) is provided with a pin hole (33) extending in a direction crossing the extension direction of the attaching hole (32). A part of the pin hole (33) passes through the attaching hole (32). A locking pin (56), which can engage with the groove (46) of the attaching shaft (45) inserted into the attaching hole (32), is inserted into the pin hole (33).

Abstract: An underreamer for well drilling comprises pivotally extendible roller cutters that extend slightly beyond the diameter of the pilot drill bit but are retained in their retracted position by the casing. Upon encountering an obstruction, the underreamer is pushed out of the casing, allowing the outer edges of the cutters to contact the obstruction. Continued downward pressure of the drill stem causes the roller arms to pivot outward to a fully extended position in which the cutters enlarge the hole to a diameter larger than the casing by rotation of the drilling stem. The advance of the casing relative to the underreamer forces the cutters to retract into the casing.

Abstract: A drill bit having a body with a stationary cutter and a rotatable cutter such that in a first position the rotatable cutter does not radially extend beyond a periphery of the stationary cutter and in a second position the rotatable cutter radially extends beyond the periphery of the stationary cutter.

Abstract: An underreamer for forming a cavity from within a well bore includes a housing adapted to be disposed within the well bore. The underreamer includes an actuator partially slidably positioned in the housing. The actuator comprises a first portion and a second portion. A cross-sectional area of the second portion is larger than a cross-sectional area of the first portion. The underreamer includes at least one cutter set, wherein each cutter set has a first end and a second end. The first end of each cutter set is pivotally coupled to the housing. The second end of each cutter set is pivotally coupled to a connector. An axial force applied to the actuator is operable to slide the actuator relative to the housing causing the second portion of the actuator to contact each cutter set and extend each cutter set radially outward relative to the housing from a retracted position to a first position. The actuator may also include a stop member proximate an end of the actuator.

Abstract: A drilling tool having an expandable bladder and a method for using the same are provided. The drilling tool includes a tool body having an interior cavity, a plurality of extendable arms coupled with the tool body, and an expandable bladder at least partially disposed within the interior cavity of the tool body. The expandable is operable to deploy the extendable arms from a retracted position relative to the exterior surface of the tool body to an extended position relative to the exterior surface of the tool body.

Abstract: The present application relates to a tool having a cutting means for enlarging a portion of an underground pile shaft. The tool is provided with a collecting means which is disposed below the cutting means in order that spoil generated when performing a cutting action on ground material surrounding the pile shaft can be collected. The size of the collecting means is adjustable thereby allowing the volume of spoil which may be accommodated by the collecting means to be varied. A compacting device for compressing the spoil collected in the collecting means may also be provided for reducing the volume of the spoil.

Abstract: A reaming tool for enlarging an earth bore in a subsurface formation in which a sub is connected to a lower end of a drill string and elongated cutter blades are pivotally secured to a lower end of the body which have cutter elements preferably in the form of rotatable cutter disks along their leading edges and a fluid delivery hose leads into fluid passages in each of the cutter blades to supply fluid under pressure to a series of fluid discharge nozzles associated with the cutter elements.

Abstract: A drill bit assembly for earth boring operations in which a sub is connected to a lower end of a drill string and elongated cutter blades are pivotally secured to a lower end of the body which have cutter elements preferably in the form of rotatable cutter disks along their leading edges and a fluid delivery hose leads into fluid passages in each of the cutter blades to supply fluid under pressure to a series of fluid discharge nozzles associated with the cutter disks.

Abstract: An underreamer (5) is formed from a tubular body (10) having a longitudinal bore therethrough, and providing an integral piston actuator (20) responsive to hydraulic pressure to move cutters (40) into engagement with the well bore and springs (60) to resist premature engagement of the cutter arms (40) and to return the cutters (40) to the body upon conclusion of the underreaming job. Skewed longitudinal grooves (45) are formed in the tubular body thereby permitting the flowpath through the underreamer to provide substantially the same inner diameter throughout the tool (5).

Abstract: A single-blade underreamer for forming a cavity within a well bore includes a housing rotatably disposed within the well bore, and a stabilizer coupled to the housing. The stabilizer is operable to stabilize the housing within the well bore during formation of the cavity. The underreamer also includes a single cutter pivotally coupled to the housing, and a piston slidably disposed within the housing and adapted to engage the cutter. A downwardly disposed force applied to the piston is operable slide the piston relative to the housing to correspondingly extend the cutter outwardly relative to the housing from a retracted position to form the cavity during rotation of the housing.

Abstract: An underreamer for forming a cavity within a well bore may include a housing rotatably disposed within the well bore. The underreamer may also include an actuation rod slidably positioned in the housing. The underreamer may further include a plurality of cutter sets nested together around the actuation rod while the cutter sets are in a retracted position where each cutter set is pivotally coupled to the housing and the actuation rod. The cutter sets are also pivotally coupled together. An axial force applied to the actuation rod operates to slide the actuation rod relative to the housing and extend the cutter sets radially outward relative to the housing to form the cavity when the housing is rotated.

Abstract: Apparatus for boring a hole from an inside of a casing outwardly at an angle relative to a longitudinal axis of the casing comprises a drill shoe having a longitudinal axis and being positionable in the casing, the shoe having first and second passageways which converge into a third passageway exiting the shoe, a torsional load transmitting element and a cutting element connecting to one end of the torsional load transmitting element, the torsional load transmitting element and cutting element being positioned in the first passageway during non-use and in the third passageway during use, and a fluid conduit and a nozzle connected to one end of the fluid conduit, the fluid conduit and nozzle being positioned in the second passageway during non-use and in the third passageway during use.

Abstract: Apparatus for boring a hole from an inside of a tube outwardly perpendicular to a longitudinal axis of the tube comprises a drill shoe having a longitudinal axis and being positionable in the tube, the shoe having an inlet, an outlet perpendicular to the shoe longitudinal axis and a passageway connecting the inlet and outlet, a torsional load transmitting element having no torsional flexibility in relation to its bending flexibility, having a longitudinal axis and being disposed in the passageway, the torsional load transmitting element being movable relative to itself with no resistance about first and second perpendicular axes both of which are perpendicular to the longitudinal axis of the torsional load transmitting element, a hole saw connected to one end of the torsional load transmitting element and a motor rotatably connected to the other end of the torsional load transmitting element.

Abstract: In a retrievable drill bit assembly, a standard drill pipe or casing pipe has a sub threaded into its lower end which forms a seat coupling for upper rounded pivotal ends of a pair of drill bits which are pivotally mounted between a pair of lift plates. The drill bits have blades extending from the pivotal ends with hardened cutter elements in staggered relation along or adjacent to the leading edge and a fluid passage leading into a series of nozzles in the blades which together with the rotational force of the drill pipe and the frictional force of the blades on the material to be bored will cause the blades to assume and maintain a mutually perpendicular position. The blades or cutters can be retrieved by a retrieval apparatus for the purpose of removal and replacement with a new set of blades.

Abstract: An apparatus for shaping boreholes used in seismic operations. A drill body is attached to a drill bit and is movable in axial and rotational directions. Selective operation of the drill body causes a moveable sleeve to operate a reaming bit to extend through a drill body port and into contact with the borehole wall. A cover seals the portion of the port not covered by the reaming bit to prevent loss of a transport fluid within the drill body and to prevent drill cuttings from entering the drill body interior. The cover can be integrated within the movable sleeve or can comprise a separate component. The force exerted by the drill body against the drill bit can be proportional to the force exerted by the reaming bit against the borehole wall. The reaming bit can be operated separately or simultaneously with operation of the drill bit, and can be retracted and reset to perform another shaping operation at a different position within the borehole.

Abstract: Apparatus for boring a hole from an inside of a tube outwardly perpendicular to a longitudinal axis of the tube comprises a drill shoe having a longitudinal axis and being positionable in the tube, the shoe having an inlet, an outlet perpendicular to the shoe longitudinal axis and a passageway connecting the inlet and outlet, a torsional load transmitting element having no torsional flexibility in relation to its bending flexibility, having a longitudinal axis and being disposed in the passageway, the torsional load transmitting element being movable relative to itself with no resistance about first and second perpendicular axes both of which are perpendicular to the longitudinal axis of the torsional load transmitting element, a hole saw connected to one end of the torsional load transmitting element and a motor rotatably connected to the other end of the torsional load transmitting element.

Abstract: A torque limiting device that allows a drill string to rotate relative to the cutting structure of the bit when a predetermined torque is applied between the cutting structure of the drill bit and the drill string. The torque limiting device utilizes a retaining member which restricts rotational movement of a first component of the torque limiting device relative to a second component. When a sufficient torque load is placed on the cutting structure of the drill bit, the retaining member allows rotational movement of the first component relative to the second component and allows the drill string to continue to rotate relative to the cutting structure of the bit until the torque is sufficiently reduced. The torque limiting device may be an integral part of a drill bit, may be a separate device attached between the drill string and the drill bit or between the drill string and a downhole motor, or may be part of a near-bit sub or incorporated in a downhole motor.

Abstract: A hydraulic percussion drill includes a piston hammer disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve disposed around the piston hammer. The drill includes a percussion bit configured to have a face portion disposed at an acute angle with respect to a plane normal to the bit and the drill central axis. Cooperating spiral splines on the bit and a bit chuck provide for directional drilling using a method which includes causing the bit to receive impact blows without rotating the cylinder housing to initiate a deviated drillhole.

Abstract: A torque limiting device that allows a drill string to rotate relative to the cutting structure of the bit when a predetermined torque is applied between the cutting structure of the drill bit and the drill string. The torque limiting device utilizes a retaining member which restricts rotational movement of a first component of the torque limiting device relative to a second component. When a sufficient torque load is placed on the cutting structure of the drill bit, the retaining member allows rotational movement of the first component relative to the second component and allows the drill string to continue to rotate relative to the cutting structure of the bit until the torque is sufficiently reduced. The torque limiting device may be an integral part of a drill bit, may be a separate device attached between the drill string and the drill bit or between the drill string and a downhole motor, or may be part of a near-bit sub or incorporated in a downhole motor.

Abstract: A drilling tool for boring in earth and rock formations includes a pilot bit which defines a longitudinal tool axis and includes a cam part having a cam axis arranged eccentrically relative to the tool axis. A reamer includes a hollow reamer body mounted on the cam part for rotation relative thereto about the cam axis. Relative rotation in one direction causes the reamer to be radially extended, and relative rotation in an opposite direction causes the reamer to be radially retracted. The reamer body carries cutting elements for enlarging a hole drilled by the pilot bit when the reamer is in its extended position. The cam part carries a first removable insert on which a first stop surface is formed. The reamer carries a second removable insert on which a second stop surface is formed. The stop surfaces are engageable with one another when the reamer body is radially extended, for transmitting rotational cutting forces to the reamer.

Abstract: A downhole unit for use in subsurface boreholes, for example a bias unit for imparting a lateral bias to the drill bit to control the direction of drilling, includes a main body and a number of pads pivotally mounted on the main body for engagement with the walls of the borehole. A thrust member is disposed inwardly of each pivotal pad and is movable along a guide passage in the main body to transmit movement to the pad. Each thrust member is movable by hydraulic pressure and a fluid-tight sliding seal is provided between the thrust member and its guide passage. The outer surface of each thrust member or the inner surface of the guide passage, or both, is in the form of a portion of a toroid centred on the pivot axis of the respective pad so as to minimise lateral movement of the seal as the thrust member moves along the passage. This also allows relative displacement between the thrust member and pad to be avoided, so that the thrust member can be integral with the pad or rigidly connected to it.

Abstract: A torque limiting device that allows a drill string to rotate relative to the cutting structure of the bit when a predetermined torque is applied between the cutting structure of the drill bit and the drill string. The torque limiting device utilizes a retaining member which restricts rotational movement of a first component of the torque limiting device relative to a second component. When a sufficient torque load is placed on the cutting structure of the drill bit, the retaining member allows rotational movement of the first component relative to the second component and allows the drill string to continue to rotate relative to the cutting structure of the bit until the torque is sufficiently reduced. The torque limiting device may be an integral part of a drill bit, maybe a separate device attached between the drill string and the drill bit or between the drill string and a downhole motor, or may be part of a near-bit sub or incorporated in a downhole motor.

Abstract: The invention relates to drill means of the type to drill and ream a hole in the ground in advance of a trailing casing tube. Drill means able to drill an oversize hole, and yet allow the drill means to be withdrawn through the casing tube when in place in the hole are known such as in U.S. Pat. No. 3,848,683. Such means are effective but are relatively complex, and the object of the invention is to provide a relatively simple inexpensive drill means capable of drilling an average hole and enabling subsequent extraction through a casing tube.

Abstract: An underreamer which may be mounted on a core drill to allow single phase underreaming or creation of a bore hole of larger diameter beneath a pilot hole. A plurality of levers are powered by a plurality of corresponding jacks which are adapted to exert pressure on the levers in order to cause them to extend beyond the periphery of the expander body. Each lever contains at least one roller-cutter rotatably mounted to the lever so that when the levers are forced outward, the roller-cutters crush rock beyond the periphery of the expander body and thus underream the bore hole.

Abstract: A drilling tool for percussive and rotary drilling in advance of a trailing casing tube (20) has a reamer (15) pivotally journalled and an eccentric shaft (12) rearwardly of a centric pilot bit (11). The reamer (15) has an eccentric portion (32) carrying axially directed hard metal button inserts (36-40) grouped within an arcuate angle (V) of a circle sector centered on the drilling axis (C). The inserts comprise primary inserts (36-38) with a radial reach defining the full diameter of the drilled hole and inner secondary inserts (39, 40) closer to the shaft (12). The reamer (15) is pivotable on the shaft (12) between a projected and a retracted position. When projected, the group of button inserts (36-40) ream up the hole from the diameter drilled by the pilot bit (11) to the full diameter of the hole enabling the casing tube (20) to advance. In the retracted position, the drilling tool (10) can pass through the casing tube (20).

Abstract: A retrievable drill bit and cutter or reamer assembly includes a fluid-drive motor, an eccentric cutter part and a concentric bit in assembly and insertable in and retrievable from the interior of a drill stem without removing the drillstem from a wellbore. The eccentric cutter is disposed on a shaft connected to the output shaft of the motor and journals an accentric cylindrical bearing member mounted on the shaft. In response to rotation of the shaft in one direction, the cutter part is displaced into a position to enlarge the wellbore to permit progress of the drillstem therethrough and in response to rotation in the opposite direction, the cutter centers itself to permit retrieval of the bit assembly throught the drillstem. The fluid-driven motor engages locking splines on a sub at the lower end of the drillstem and may be inserted in and retrieved from the drillstem by drilling fluid in forward and reverse circulation, respectively.

Abstract: Recessed grooves are cut into bore hole walls of concrete or rock materials for the purpose of interconnecting two components of such materials at an interface between these components. These recessed grooves are cut by material removing tools which can be pressed radially outwardly, while a drive shaft simultaneously rotates these tools. For this purpose, an axial movement of an adjustment body is converted into a tilting movement of pivotable shafts which carry the material removable tools, whereby the adjustment body is moved linearly by a hydraulic lifting device. The material removing tools extend radially away from the lower ends of the pivotable shaft. The common adjustment movement of all of the pivotable shafts takes place independently of the rotation of the driven shaft.

Abstract: An excavation tool, in which a device is provided which receives the striking force of a hammer and the rotational force of a hammer cylinder, in a bottom surface of which at least three axle holes are provided displaced from a center of the device and at equivalent angular intervals in the circumferential direction, block axles are inserted in the axle holes in a freely rotatable manner, blocks which are roughly fan-shaped and have bits embedded in the lead end surfaces thereof are provided at lead end parts of the block axles, so that left- and right-side faces of said blocks are in mutual opposition and arc parts of all blocks together form roughly a circle shape; and when said device is rotated in the direction of excavation, said blocks rotate as a result of the resistance to excavation of the bottom part of the excavation hole, one intersection part of the side faces and the arc part of each block protrudes beyond the outer circumferential surface of the device by a predetermined excavation amount, and

Abstract: An eccentric drilling tool comprises a guide member (10) rotatably centered by the mouth of a casing tube (11) that follows the tool downhole during drilling. A pilot bit (23) on the guide member (10) is provided with axially oriented hard metal pilot button inserts (57, 57.sup.I -57.sup.III) peripherally thereon directed to define the diameter of the pilot hole to be cut during drilling. A laterally extending eccentric bit (22) behind said pilot bit (23) has axially oriented hard metal reaming button inserts (48-51) at the eccentric top portion thereof directed to ream up the pilot hole to a maximum diameter. The eccentric bit (22) is movably supported relative to said guide member (10) between a drilling position, in which the eccentric bit (22) projects laterally beyond said casing tube (11) so as to drill jointly with said pilot bit (23) a hole larger than said casing tube (11), and a retracted position, in which the drill bit can be retracted or lowered through the casing tube (11).

Abstract: A cutting tool for forming undercuts in boreholes includes a cutting member pivotally and rotatably supported in a tubular drive shaft. The combination of the drive shaft and cutting tool provide a ball joint so that the cutting tool is pivotally supported relative to the drive shaft axis. The drive shaft has an guidance bore for the cutting tool. Guidance stop faces in the guidance bore transmit rotational movement to a head forming a cutting member on the cutting tool. The head forms the undercut. The head rolls over the surface to be undercut.

Abstract: A downhole impact drill having a drill bit head with a drill bit sector for drilling an enlarge hole upon rotation of the drill. The bit is mounted within a chuck for movement between a retracted, working position in which the bit is coaxially mounted for drilling and an extended, non-working position in which the bit is loosely mounted within the chuck to permit the bit to swing laterally to reduce the diameter of the drill bit head envelope. In its extended, non-working position, the bit is supported on the chuck at a 3.degree. angle at which the drill bit sector is positioned inwardly to facilitate installation and withdrawal of the drill.

Abstract: The invention relates to improvements in rotary groove-cutting tools of the type having a rotatable center shaft and two or more generally arcuate flyweight subassemblies mounted for rotational movement with the center shaft, each such subassembly when thus rotated being also mounted for pivotally-hinged door-like movement between a retracted inoperative position and an extended operative one in contact with the wall of the bore to be grooved about eccentrically-located axes paralleling the center shaft but displaced radially therefrom, such improvements relating to the design and placement of the abrasive-surfaced cutters carried by each of the flyweight subassemblies which especially adapts them for use in grooving concrete bores. More specifically, the invention encompasses such cutters which are circumferentially elongate to an angular extent in which they are adapted to bridge most voids in the bore wall without jamming.

Abstract: A drill tool for rotary and/or percussion drilling includes a drill string and a cutting apparatus connected to a lower end of the drill string. The cutting apparatus has an intermediate portion which is rotatable with the drill string and includes an outer surface, a reamer is mounted eccentrically on the intermediate portion for rotation relative thereto about a longitudinal axis. The reamer includes an inner surface facing the outer surface. The reamer is driven by an arrangement comprised of a tongue disposed on either of the inner and outer surfaces and a pair of circumferentially spaced shoulder surfaces disposed on the other of the inner and outer surfaces. The tongue is selectively engageable with the shoulder surfaces along an area of contact having an upper longitudinal end which terminates below an uppermost end of the reamer, and a lower longitudinal end which terminates above a lowermost end of the reamer.

Abstract: An open ended cylindrical casing is provided with a pair of semicircular blades rotatably mounted to the lower open end of the casing so that the blades may be rotated from a digging position where they project downward from the lower end of the casing to a flat position, substantially forming a bottom to the lower end of the casing. To excavate a cylindrical hole the casing is dropped with the blades in the projecting position into the ground causing the blades to dig in a shovel-like manner. By rotating the blades upward substrate is lifted into the casing, and the casing is pulled deeper into the substrate. Lifting the casing out of the hole, the blades act as a bottom to the casing carrying dirt within the casing.

Abstract: A drill tool for rotary and/or percussion drilling with drill rod means (14) within casing tube means (15) comprises a centric cutting bit (11) and an eccentric reamer cutter (12), both provided with hard metal inserts. For purposes of obtaining a life of the drill tool as long as possible the first frontal insert (23) on the reamer cutter (12) is positioned in front of the first peripheral insert (18) when seen in the rotational direction (D) during drilling, and the centric cutting bit (11) provided with more inserts on the half (38) of its front surface opposed to the reamer cutter (12) during drilling than on the other half (39).

Abstract: A well bore is formed which runs down to an underground region having deposits of mineral material to be mined, by installing a casing or a drill pipe into the ground. A piping assembly is placed in the bore hole through the casing and the mineral material comminuted by means of water jet action or by vibratory action of a portion of the piping thereagainst or by both types of action operating simultaneously. The mineral material is mixed with the water in the bore hole to form a slurry which is removed from the bore hole through the piping by sonic pumping action or by virtue of the slurry rising to the surface as the bore hole fills, with oil floating to the top of the slurry material.

Abstract: The advancement angle of a borehole cut by a rotary drill bit of the type which forms a cylindrical sidewall, a drill face and a circumferentially extending gage corner, is controlled by removing a different amount of the gage corner material over a selected partial arc of the gage corner circumference during each rotation of the drill bit. The different amount of material removed causes the remaining arc of the gage corner circumference to apply a slight lateral force on the drill bit, thus forcing the drill bit in a desired direction. Gage corner removal apparatus include selectively extendable cutter devices, a hinged connector hingeably connecting the drill bit to the end of the drill string, and a pivotable single cutting wheel member. Selectively activating the gage corner removal apparatus during each of a plurality of subsequent drill bit revolutions results in a cumulative angle change effect.

Abstract: Method for sinking a cased borehole for producing cased pile foundations. The method uses an apparatus comprising a crane, a drilling appliance capable of being lowered into the borehole and a tube extraction machine with double-acting lifting cylinders for increasing the drilling pressure and for extracting the drop tube after the pile has been concreted. The drilling appliance is capable of producing a borehole with a larger diameter than that of the drop tube and can be fixed to the drop tube by means of a clamping device for withstanding the torque of the motor used for driving the drilling tool. In the method, the drop tube is axially secured and is prevented from locating with respect to the ground, a section of borehole having a greater diameter than the diameter of the drop tube is drilled, and subsequently the axial securement of the drop tube is released so that the drop tube slides downwards by a length corresponding to the length of the section of borehole drilled.

Abstract: A rotary boring head for earth and rock formations with pivotal wings which may be swung radially outwardly and which are provided with inclined return rails. Upon upward movement of the rotary boring head the earth mass presses upon the inclined return rails, so that the pivotal wings are reliably swung inwards again and cannot impinge on the bore tube.

Abstract: An earth auger is disclosed in which an auger shaft is provided with freely expansible and contractible rotary blades in such manner that said rotary blades may expand automatically when said auger shaft is rotated in the foward direction and may contract automatically when said auger shaft is rotated in the reverse direction. Also a method for driving piles and the like is disclosed which comprises the steps of positioning a pile or shoring adjacent to said auger shaft and above said blades, advancing said pile or the like into an earth bore excavated by said rotary blades, and filling said bore excavated by the rotary blades with mortar or the like.

Abstract: A method for establishing an anchor inside of a retaining wall is described; in which an auger bore is excavated through said retaining wall with an earth auger and thereafter by reversing the rotation of said earth auger an enlarged bore is formed at the extreme end portion of said auger bore; and in which an auger head and an auger shaft are separated from each other to leave an anchor plate formed integrally with said auger head as well as a rod connected to said anchor plate within the enlarged bore and the auger bore, and then mortar is filled in these bores to establish an anchor made of concrete in the earth. In one preferred embodiment of the invention, the rod and the anchor plate are connected to each other by fastening with a nut, this connecting portion being enclosed in a box, and also the peripheral surface of said rod is coated with a synthetic resin film, whereby a provision is preliminarily made such that the rod may be easily extracted from the anchor after the use of the anchor has ended.