Abstract: A reamer used in downhole oil well operations, particularly in reaming while drilling applications includes a plurality of helical blades. Each blade extends along a center axis of the reamer body and includes a sequence of a sloping leading edge, a central blade length, and a sloping trailing edge. Each edge slopes away from the central blade length and toward the center axis. A first series of a first type of cutter are positioned along the central blade length; separate pluralities of a second type of cutter are respectively positioned along the leading edge and the sloping trailing edge. A third type of cutter is positioned in a first transition zone located between the leading edge and the central blade length, an additional instance of the third type of cutter is positioned in a second transition zone located between the trailing edge and the central blade length.

Abstract: A downhole tool includes at least a pilot section, a first expansion section, and a second expansion section. The pilot section has a plurality of cutting elements to cut a pilot hole. Each of the expansion sections has a plurality of cutting elements to successively expand the pilot hole to achieve a final wellbore radius. The pilot section, first expansion section, and second expansion section each have one or more stabilizer pads on respective gages to stabilize the downhole tool during wellbore creation.

Abstract: A wellbore reamer assembly positionable on a drill string in a wellbore includes a reamer body having an internal cavity and multiple radial openings, multiple cutting structures each positioned in one of the radial openings in the reamer body, and a fluid-activated expandable support element positioned in the internal cavity of the reamer body adjacent the cutting structures. The cutting structures are extendable radially away from a central longitudinal axis of the reamer body through respective radial openings and retractable toward the central longitudinal axis of the reamer body.

Abstract: A cutting tool holding mechanism includes a base, a handle and a locking assembly. The base includes an abutting portion, a receiving bore, at least one limiting bore and at least one limiting hole. The limiting hole is disposed at the base and communicated with the limiting bore. The handle abutted against the base includes a sleeved portion and a plurality of positioning surfaces. The locking assembly includes a packing ring, a locking screw, a locking member and a guiding bolt. The locking member received inside the limiting bore includes a screwed hole and a guiding groove. The guiding groove disposed at one side of the locking member and is aligned with the limiting hole when the locking member is disposed inside the limiting bore. The guiding bolt is disposed in the limiting hole and is abutted against the guiding groove to inhibit the locking member from rotating.

Abstract: A rotary dill bit with a drill bit head and a connecting portion, wherein the rotary bit is positioned and oriented for shearing a surface of a subterranean formation. The drill bit head is comprised of one or more cutting discs, wherein each cutting disc is rotatably mounted to at least one shaft between a pair of support structures with each cutting disc having a cutting disc edge extending outwardly beyond the support structures. The cutting discs have cutting inserts in an overlapping pattern, wherein each cutting insert comprises a projection extending from the cutting disc edge and angled from the cutting disc edge at a side rake and a front rake angle.

Abstract: An invented reamer provides an annular body supporting two or more blades wherein each blade includes a spiral section disposed between two tapered sections placed on an exterior of the body. The spiral section fixes a plurality of a one type of cutting insert, e.g., tungsten carbide inserts, and the two tapered sections may each fix cutting inserts of an alternate type, e.g., polydiamond inserts. Certain embodiments provide of the tapered sections have a first flat surface area that extends towards and away from a central longitudinal axis of the annular body and/or a second surface area that positions cutting surfaces of attached cutting inserts linearly along a line that intersects the central longitudinal axis.

Abstract: The present invention provides a method and apparatus for increasing the drift diameter and improving the well path of the well bore, accomplished in one embodiment by cutting away material primarily forming surfaces nearer the center of the drift, thereby reducing applied power, applied torque and resulting drag compared to conventional reamers that cut into all surfaces of the well bore.

Abstract: An improved subsurface drilling tool comprises a shank having a cutting end opposite a pin end configured to attach to a drill string. A plurality of ear portions is associated with the proximate end of the shank and configured to form a socket. A ball-shaped cutting tool is configured to fit inside the socket and is rotatably attach to the ear portions via an axle. A locking pin may be installed within one or more of the ear portions and perpendicular to the axle. A plurality of blade inserts is connected to the ball-shaped cutting tool. The blade inserts may be removable and/or configurable to be oriented in varied directions. A series of milling courses may extend longitudinally along an outside length of the shank. A fluid course may extend longitudinally within the shank to deliver drilling fluid to the cutting end.

Abstract: A cutting element has a sleeve with a first inner diameter and a second inner diameter, where the second inner diameter is larger than the first inner diameter and located at a lower axial position than the first inner diameter. A rotatable cutting element having an axis of rotation extending therethrough is at least partially disposed within the sleeve. The rotatable cutting element has a cutting face and a body extending axially downward from the cutting face, at least one hole extending from an outer surface of the body toward the axis of rotation, and a locking device disposed in each hole. The locking device protrudes from the hole to contact the second inner diameter of the sleeve, thereby retaining the rotatable cutting element within the sleeve.

Abstract: An apparatus for drilling a hole in the ground has a hammer drill installed at a bottom of a rod assembled in multi-stages at support structure on the ground. The hammer drill has a pilot hammer drill and a reamer hammer drill coupled to each other through a key structure formed in the vertical direction so as to allow simultaneous rotations and up-and-down movements relative to each other.

Abstract: A drill bit is disclosed, wherein the drill bit has a bit body with a longitudinal axis extending there through and a bit face. A plurality of blades extends from the bit body, wherein the plurality of blades has a blade profile including a nose.

Abstract: Methods, systems, and tool assemblies for distributing weight between a bit and a reamer device are disclosed. For example, at least one of the drill bit and the reamer may be configured to selectively distribute a weight-on-bit between the drill bit and the reamer, such as within a predetermined range. Additionally, methods of drilling wellbores may include selectively distributing a weight-on-bit applied to a bottom hole assembly between a drill bit and a reamer of the bottom hole assembly. Also, a reamer may be configured to exhibit a first maximum rate-of-penetration into a relatively hard formation, and a drill bit may be configured to exhibit a second maximum rate-of-penetration into a relatively soft formation that is less than the first maximum rate-of-penetration.

Abstract: A hole opener having a hybrid reaming section for reaming subterranean wellbores may include a tubular reamer body having a longitudinal axis and upper and lower ends, a rolling cutter mount coupled to the body, a rolling cutter rotatably coupled to the mount, and a fixed blade coupled to the body adjacent the mount. A method of forming a hybrid reamer tool for downhole use may include providing a tubular stem having couplers on the upper and lower ends, coupling a reamer body having an outer periphery to the stem between the stem upper and lower ends, coupling a rolling cutter mount to the outer periphery of the reamer body, the mount having a rolling cutter rotatably coupled thereto, and coupling a fixed blade to the outer periphery of the reamer body adjacent the rolling cutter mount.

Abstract: The milling head which serves for the machining of the head of a pile consisting of a pile core, a pile shaft and a metal reinforcement lying therebetween comprises a coupling device that can be connected to a drive shaft and a plurality of picks that are used to remove concrete. According to the invention a central milling cutter provided with a plurality of central picks and an annular milling cutter provided with a plurality of annular picks are fixedly coupled with each other and arranged coaxially with the longitudinal axis of the drive shaft. The central picks are arranged within a central circular ring and the annular picks, separated by a middle circular ring, are arranged in an outer circular ring whereby the circular rings lie at least approximately perpendicular to and concentric with the longitudinal axis of the drive shaft.

Abstract: A drill bit for drilling a borehole in earthen formations comprises a bit body having a central bit axis, a first end adapted to be connected to a drillstring, and a second end opposite the first end. In addition, the bit comprises a pilot bit extending from the second end of the bit body. Further, the bit comprises a reamer section extending radially from the bit body and axially positioned between the first end of the bit body and the pilot bit. The reamer section comprises a rolling cone cutter rotatably mounted to a journal shaft extending from the bit body. Moreover, the rolling cone cutter has a cone axis of rotation, a backface proximal the bit body, and a nose opposite the backface and distal the bit body.

Abstract: A milling tool which includes a nose cutting portion, a cutting section having a plurality of hardened cutters and a shaft portion. A wear pad is disposed on the cutting section and shaft portion. Upon the shaft portion, the wear pad extends radially outwardly to an engagement diameter that exceeds the maximum cutting diameter of the cutters.

Abstract: A reamer bit for use in earth boring operations comprising a body, cutter mounts having rolling cutters on the bit body, and stabilizers pads on the body placed between adjacent cutter mounts. The reamer may further include a pilot bit on a drill pipe extending downward from the reamer body. The reamer bit outer periphery with its stabilizers and bit body has a radial profile approximating a circle thereby reducing dynamic perturbations during drilling operations.

Abstract: A reamer for subterranean wellbores may include a composite framework, which may include one or more high strength stems, each having one or more reamer bodies coupled thereto. The body may include a plurality of plates coupled together and may include additional components formed integrally therewith or coupled thereto. A method of forming a reaming tool may include forming a high strength stem and a reamer body and coupling the body to the stem. A method of using the reaming tool may include coupling one or more bodies in a drill string and reaming a wellbore.

Abstract: The present disclosure relates to a microtunnelling apparatus including a cutting apparatus adapted to be rotated by a drill shaft defining a central axis of rotation that extends along a length of the drill shaft. The cutting apparatus includes a front cutting rotor having a hub defining a shaft receiver that extends at least partially through the hub in a direction extending from a back side toward a front cutting side of the front cutting rotor. The shaft receiver is configured to receive the drill shaft. The drill shaft and the shaft receiver cooperate to define a torque transmitting mechanical interface for allowing torque to be transferred between the drill shaft and the front cutting rotor such that the drill shaft can be used to rotate the front cutting rotor about the central axis of rotation. The front cutting rotor also includes a plurality of cutting bars that project at least partially radially outwardly from the hub.

Abstract: A hole opener having a hybrid reaming section for reaming subterranean wellbores may include a tubular reamer body having a longitudinal axis and upper and lower ends, a rolling cutter mount coupled to the body, a rolling cutter rotatably coupled to the mount, and a fixed blade coupled to the body adjacent the mount. A method of forming a hybrid reamer tool for downhole use may include providing a tubular stem having couplers on the upper and lower ends, coupling a reamer body having an outer periphery to the stem between the stem upper and lower ends, coupling a rolling cutter mount to the outer periphery of the reamer body, the mount having a rolling cutter rotatably coupled thereto, and coupling a fixed blade to the outer periphery of the reamer body adjacent the rolling cutter mount.

Abstract: A drilling assembly for simultaneous hole enlargement operations comprises a drill bit, an adjustable diameter reamer, and a hole opener. The reamer is coupled with, and positioned uphole from the drill bit. The reamer is adjustable between a first diameter and a second diameter that is larger than the first diameter. The hole opener is coupled with, and positioned uphole from the reamer.

Abstract: A drill bit system for a drilling assembly is disclosed. The drill bit system may include a chassis, a head, and a first plurality of gauge pads. The head may include a first plurality of cutters coupled with an end of the head, and the head may be movably coupled with chassis. The first plurality of gauge pads may include a second plurality of cutters, and the first plurality of gauge pads may be fixedly coupled with the chassis.

Abstract: A drilling tool (10) includes a pilot bit (14) and a plurality of mills (16) encircling the pilot bit. The pilot bit and the plurality of mills are each driven by a separate, hydraulically powered turbine or positive displacement motor. (20) The drilling tool does not include a transmission for transmitting power from the turbine or motor to any of the plurality of mills or the pilot bit.

Abstract: This invention includes drilling assemblies, drilling reamer arm assemblies, and methods of drilling. In one implementation, a drilling assembly includes a cutting head apparatus configured to cut into earthen material as the cutting head apparatus is rotated. A drive shaft extends aft of and is configured to rotate the cutting head apparatus. A plurality of reamer arm assemblies projects radially outward of the drive shaft and are mounted for rotation therewith aft of the cutting head apparatus. Individual of the reamer arm assemblies include a radial inner portion extending radially outward of the drive shaft. A radial outer portion connects with and extends radially outward of the radial inner portion. The radial outer portion includes a cutter. At least one breakaway retainer fastens the radial inner and outer portions together and restrains the radial outer portion from moving relative to the radial inner portion towards the cutting head apparatus and the drive shaft. Other aspects are contemplated.

Abstract: A reamer bit for use in earth boring operations comprising a body, cutter mounts having rolling cutters on the bit body, and stabilizers pads on the body placed between adjacent cutter mounts. The reamer may further include a pilot bit on a drill pipe extending downward from the reamer body. The reamer bit outer periphery with its stabilizers and bit body has a radial profile approximating a circle thereby reducing dynamic perturbations during drilling operations.

Abstract: A microtunnelling apparatus and system that includes an external drive system having rotational and linear thrust drive means, a drill head section having drill rotor and drill rod and connecting to intermediate drill rods allowing extension of the boring hole created by the drill head section driven by the drive system. The drill head includes a modular construction having a plurality of circular disc like elements, a bearing module, a steering module, a spacer module, and a mounting module, for axial alignment and abutment and mounting within a cylindrical steering shell. Directional steering of the drill head includes a plurality of substantially radially extending channels in steering module, each with an hydraulically movable protuberance movable by control means to redirect the outer steering casing and thereby redirect the drill head section mounted on the distal end of the drill rods.

Abstract: A rolling cone rock bit includes a plurality of PDC or other cutters mounted to the leg of the drill bit and positioned to cut the corner of the bottomhole. The plurality of cutters may be the primary cutting component at gage diameter, or may be redundant to gage teeth on a rolling cutter that cut to gage diameter. Consequently, the occurrence of undergage drilling from the wear and failure of the gage row on a rolling cutter is lessened. Also included is a mud ramp that creates a large junk slot from the borehole bottom up the drill bit. The resulting pumping action of the drill bit ramp speeds up the removal of chips or drilling cuttings from the bottom of the borehole, reduces the level of hydrostatic pressure at the bottom of the borehole and minimizes the wearing effect of cone inserts regrinding damaging drill cuttings.

Abstract: A roller cone drill bit includes a bit body adapted to be coupled to a drill string, a bearing journal depending from the bit body, and a single roller cone rotatably attached to the bearing journal. The single roller cone has a plurality of cutting elements, where at least one of the plurality of cutting elements is formed of an inner region that is at least partially surrounded by an outer region, where the inner region is more abrasive resistant than the outer region. Such an arrangement in a single roller cone bit allows the at least one cutting element to be “self-sharpening.

Abstract: A drill bit includes a body defining an axis and first and second cylindrical portions, a coupling adapted for connection with a rotary driver, and a depth stop adjustably secured to a first portion by a plurality of adjusting fasteners in a manner to limit penetration of the bit into a target surface. A method of drilling a hole into the surface includes locating a drilling machine fitted with a drill bit over a target location, compensating for wear on the bit by setting a depth stop to limit travel of the bit at the predetermined depth, drilling at the target location until the depth stop contacts a surface, where the primary cutting surface forms a portion of the hole defined by a first diameter and the secondary cutting surface forms a portion of the hole defined by a second diameter in a single step, and removing the drill bit from the hole.

Abstract: A ground drilling machine comprises a controller for automatically controlling the injection of working liquid according to the output signal output as a function of the rotating condition of the pilot head 20. When the pilot head 20 is driven forward or backward, working liquid can be injected by switching the working liquid transfer valve 111 so long as the pilot head 20 is revolving in order to improve the digging efficiency, the soil delivering efficiency and the cooling efficiency of the machine. The injection of working liquid can be suspended when the direction of propelling the pilot head 20 is shifted while stopping the revolution of the pilot head 20 because no working liquid is required for delivering the dug soil and cooling the leading body. Thus, working liquid can be injected always at an optimal rate depending on the rotating condition of the pilot head 20 to suppress any waste of working liquid and reduce the construction cost.

Abstract: A novel drill bit includes a cutting reamer portion that cuts to gage diameter, and a pilot portion that cuts to a radius about 50%-80% of the reamer portion. The pilot portion extends downward from the reamer portion to create a distinct cutting area including pilot. The torque and weight on bit is evenly distributed between said pilot portion and said reamer portion of said drill bit by iterative adjustment of criteria such as backrake, siderake, cutter height, cutter size, and blade spacing.

Abstract: A drilling tool having a pilot bit on an end of a main shaft is surrounded by outer shafts having mills on their ends. The bit and mills employ cutters with PDC. The pilot bit rotates in a direction opposite the direction of rotation of the mills. A transmission for rotating a main shaft, on which the pilot bit is mounted, and several secondary shafts, on which the mills are respectively mounted, is carried within a housing using diamond thrust and radial bearings. Power is applied to the main shaft and transmitted to the secondary shafts through diamond hardened gears. Drilling fluid is used to cool and lubricate the bearings and gears.

Abstract: A drill bit including a roller cone and fixed cutters positioned external to the roller cone and radially from the bit axis of rotation. The roller cone is located so that a drill diameter of the cone is substantially concentric with an axis of rotation of the bit. The fixed cutters can be made of tungsten carbide, polycrystalline diamond, boron nitride, or any other superhard material. The fixed cutters are positioned to either maintain the hole diameter drilled by the roller cone or to drill a larger diameter hole than the hole drilled by the roller cone. The single roller cone may be located in the center of a multi-cone bit arrangement or in the center of a PDC bit to assist in drilling the center of a wellbore. The single roller cone may be used to form a bi-center bit in combination with a reaming section. The single roller cone may also be located on an independent sub that is removably attached to the bit body.

Abstract: A tubing shoe (30) comprising: a body (32) for mounting on the end of a tubing string; and reaming members (36) extending longitudinally and helically around the body, the reaming members providing substantially complete circumferential coverage of the body whereby, in use, when the tubing shoe is advanced axially into a bore, the reaming members (36) provide reaming around the shoe circumference. A rotatable torque reducing sleeve or centraliser (38) may also be mounted on the body, rearwardly of the reaming members.

Abstract: A hole opener for use in the Horizontal Directional Drilling (HDD) Industry is provided having an interchangeable sleeve reamer. The hole opener is in the form of a three-piece tool comprising a top shaft member, an interchangeable sleeve member and a bottom sub member, the interchangeable sleeve member being configured to be securely and removably mounted onto the top shaft member such that is does not rotate freely about the axis of the shaft member. In one embodiment, the bottom sub member also is interchangeable with other bottom sub members.

Abstract: A reaming apparatus for enlarging a borehole, including a tubular body having one or more longitudinally and generally radially extending blades circumferentially spaced thereabout. Each of the blades carries highly exposed cutting elements, on the order of fifty percent exposure, on its profile substantially all the way to the gage. At least one of the blades is a primary blade for cutting the full or drill diameter of the borehole, while one or more others of the blades may be secondary blades which extend a lesser radial distance from the body than the primary blade. A secondary blade initially shares a large portion of the cutting load with the primary blade while the borehole size is in transition between a smaller, pass through diameter and drill diameter. It functions to enhance the rapidity of the transition while balancing side reaction forces, and reduces vibration and borehole eccentricity.

Abstract: A hole opener used in conjunction with drilling in at least one of boulder and rubble stone formations includes first and second sets of cutters. Each of the cutters of the first and second sets of cutters has cutter teeth thereon and further include a shaft. The hole opener also includes a tubular carrier body, a first device for fixing the first set of cutters to the tubular carrier body so that the first set of cutters is positioned in a common first lateral plane with respect to a longitudinal axis of the tubular carrier body, and second device for fixing the second set of cutters to the tubular carrier body so that the second set of cutters is located in a second lateral plane with respect to the longitudinal axis of the tubular carrier body and at an axial distance from the first set of cutters along the longitudinal axis.

Abstract: A drill bit for use in drilling a well bore comprises a main drill body adapted to be rotated about a substantially vertically disposed axis of rotation and having therein a duct extending longitudinally along such axis, for supplying a drill fluid under pressure to the well bore. At least one generally circular, rotatable cutting discs are mounted on the outside of the main drill body at equally spaced locations, with the cutting discs each having cutting elements disposed in a ring-shaped array. Each of the cutting discs has an axis of rotation disposed at an acute angle to the vertical centerline about which the main drill body rotates. The axis of rotation of each cutting disc is slightly offset laterally in a rearward direction from the centerline of the main drill body, thus to cause the entire bit to be placed in a non-equilibrium position with the rotation of the main body enabling the cutting disc to be positioned to be particularly effective and aggressive in cutting the well bore.

Abstract: A combined drill and underreamer tool capable of selectively drilling and underreaming a well hole on command, which includes a fluid distribution system wherein drilling mud under pressure is accumulated in a central chamber and from that central chamber a portion is distributed to the drill bit while another portion is distributed to the underreamer tool when that tool is operative, and, further, employing drilling mud under pressure to activate and deactivate the underreamer tool by selectively blocking and unblocking a fluid a passage thereto.

Abstract: A drill bit for use in drilling a well bore in accordance with this invention comprises a main drill body adapted to be rotated about a substantially vertically disposed axis of rotation and having therein a duct extending longitudinally along such axis, for supplying a drill fluid under pressure to the well bore. Three generally circular, rotatable cutting discs are mounted on the outside of the main drill body at equally spaced locations, with the cutting discs each having cutting elements disposed in a ring-shaped array. Each of the cutting discs has an axis of rotation disposed at an acute angle to the vertical centerline about which the main drill body rotates. Importantly, the axis of rotation of each cutting disc is slightly offset from the centerline of the main drill body, thus to cause the cutting discs to be positioned to be particularly effective and aggressive in cutting the well bore.

Abstract: A tubing bit opener is disclosed having upper and lower cutters with the lower cutters being carried by mounting blocks having bevelled edges which are received in matching undercut grooves in the tubing bit opener. The upper cutters are attached to arms which are slidable within inclined pockets of the tubing bit opener for inward and outward movement relative to the tubing bit opener. Both the mounting blocks carrying the lower cutters and the arms carrying the upper cutters are easily removable for maintenance and repair. The lower mounting blocks are held securely in place by the drill body. Because the surfaces of the lower mounting blocks extend laterally along a considerable extent of the adjacent lowr cutters, the cutters are supported for stable rotation without vibration. The tubing bit opener is typically used to sink six inch diameter or larger caissons in any rock formation on land or under water.

Abstract: A drill bit assembly comprised of a pilot bit and a plurality of add-on reamer sections which are sized to progressively increase the diameter of the hole in measured increments. Both the pilot bit and the reamer sections have two cutter elements which take advantage of the bi-center concept and both use knife edged cutters instead of teeth to drill the hole.

Abstract: In a borer head for drilling boreholes in rock structures and including a drive shaft connected to a drive of a drilling machine, a central shaft coupled to the drive shaft, and a tool holder with cutters driven by a planetary gearing connected to the central shaft, supporting elements, engageable with a cylindrical wall of the borehole being drilled, are provided. The supporting elements are operatively connected to the central shaft and also to the tool holder so that the tool holder is driven into a slow rotation about the central shaft.

Abstract: An earth boring machine with a rotating cutter head having a multiple of individual cutters positioned at different distances from the center of rotation and angularly spaced from one another on the cutter head while the cutter head itself is shaped to direct the cuttings into a collecting area, which may be under the center of the rotary head or which may be concentric about the center area, has elevator means, which may be mechanical, hydraulic or pneumatic, to remove the cuttings from the collection area, and has one or more crushing rollers thereon arranged to crush cuttings which are too large for effective removal by the elevator means into small chips or fragments together with barrier means for restraining such oversize pieces in the path of the crushing roll or rollers so as to prevent their entry into the collection area until they have been adequately crushed. The barrier means so provided are arranged to permit the smaller fragments and chips to move into the collection area with little impedance.

Abstract: A raise bit for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole is provided with a cutter arrangement that provides a continuous angle bottom configuration in the range of 134.degree. to 60.degree..

Abstract: A large diameter drill bit is disclosed that is capable of drilling various size bores. In the preferred embodiment, the drill functions as a raise bit for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations surrounding the pilot hole. In the primary stage, the raise bit includes a primary body supporting a plurality of yokes positioned at various radial locations thereon. A frusto-conical cutter is rotatively mounted on each yoke for contacting and disintegrating the above-mentioned earth formations, with the outermost cutters forming the gage row. For the second stage, in which larger diameter holes are to be drilled, a plurality of ear assemblies are provided for attachment to the primary body at circumferential locations between the outermost primary cutters. Each ear assembly comprises a unitary support frame having a yoke and cutter mounted thereon. A vertically oriented roller stabilizer is also mounted on each support frame.

Abstract: The present invention consists of an under reamer tool for enlarging, scraping or smoothing a well bore. The tool is attached to a conventional drill string above a conventional bit and involves cutting elements that have retractable cutters arranged for extension from the tool to engage the well bore wall, each cutter, when the drill string is turned, being urged outwardly by centrifugal force until it engages the well bore wall, continued turning thereafter, pulling that cutter into its extended cutting attitude, reaming the wall to the desired diameter, cutter retraction involving ceasing turning the drill string and the pulling of the drill string and connected tool from the well bore.

Abstract: A hole reamer according to the invention includes a main body or support with roller cutters rigidly connected to a drill stem, and an additional support with roller cutters arranged co-axially with the main body or support. A additional support device can move along the axis of the main body and is provided with a means to effect this longitudinal movement. The main body and additional support device are adapted to drill holes of one diameter with consequent reaming thereof.

Abstract: A reaming apparatus for enlarging a borehole, including a tubular body having one or more longitudinally and generally radially extending blades circumferentially spaced thereabout. Each of the blades carries highly exposed cutting elements, on the order of fifty percent exposure, on its profile substantially all the way to the gage. At least one of the blades is a primary blade for cutting the full or drill diameter of the borehole, while one or more others of the blades may be secondary blades which extend a lesser radial distance from the body than the primary blade. A secondary blade initially shares a large portion of the cutting load with the primary blade while the borehole size is in transition between a smaller, pass through diameter and drill diameter. It functions to enhance the rapidity of the transition while balancing side reaction forces, and reduces vibration and borehole eccentricity.

Abstract: A cutting element for a drill bit includes an outer support element and an inner rotatable cutting element, a portion of which is disposed in the outer support element, where the inner rotatable cutting element has a body with a non-planar cutting face.