Drilling Tool Changer Apparatus

This application is a continuation of International Patent Application No. PCT/US2025/010575 filed Jan. 7, 2025 and entitled “Drilling Tool Changer Apparatus”, which claims priority to U.S. Non-Provisional patent application Ser. No. 18/406,550 filed Jan. 8, 2024 and entitled “Drilling Tool Changer Apparatus”, each of which is incorporated herein by reference for all purposes.

This disclosure relates to drilling systems and more particularly to a drilling tool changer apparatus for use in applications such as mining, blast-hole drilling and other down-hole drilling applications.

This background section provides a context to the invention recited in the claims. The description here may include concepts that could be pursued but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

Drilling systems generally have a vertical drill tower, or mast, constructed from structural members such as steel beams and reinforcing supports. The drill tower is often coupled to a mobile platform, usually self-propelled, for positioning the drill tower in a desired location to conduct a drilling operation. The drill tower is often equipped with a drill magazine or holder of some sort, which is adapted to support a drill string formed from a combination of drill extenders, usually called drill rods or drill pipes. The drill magazine is used to selectively add the drill pipes to the drill string for drilling a hole having a desired depth. The drill magazine is intended to allow a drilling operation to progress into the drill hole by making readily available a continuous string of drill pipes as needed for advancing a drilling tool into a drill hole.

The lowermost drill pipe in the drill string is configured to receive a drilling tool at its lower end to conduct the drilling operation. The drilling tool is usually a drill bit or a down-the-hole (“DTH”) bit and hammer chuck assembly but could be a sub with a drilling tool attached. (In this disclosure, the term “drill bit” may be used interchangeably for the general term “drilling tool”, and the term “drill pipe” may be used interchangeably for the term “drill string”, unless the context requires otherwise.) After a certain amount of usage in the drilling operation it is often desirable or necessary to remove and replace the drilling tool due to accumulated wear of an in-service drill bit, or the need to change between a drill bit and a hammering tool (or vice versa), etc. In order to minimize downtime in the drilling operation due to change-out of drilling tools, mechanisms may be provided to facilitate removing one drilling tool from the end of the drilling string and replacing it with another drilling tool from a storage or supply location.

What is needed is a replaceable magazine or carousel for drilling tools that does not require a large amount of space to accommodate swinging of an arm for the magazine, or for rotation of the magazine, which magazine can accommodate selecting drilling tools other than in a linear order, and which is readily adaptable for use in an automated or semi-automated manner to improve access for changing drilling tools, to minimize downtime during change-outs and to minimize the number of personnel required at the drilling rig.

In accordance with one embodiment, an apparatus for changing a drilling tool for a drilling rig is described, where the drilling rig comprises a drill tower supporting a drill pipe. The apparatus for changing a drilling tool comprises a drilling tool changer assembly moveable between a storage position and an exchange position; where the drilling tool changer assembly supports a rotatable carousel assembly. The rotatable carousel assembly has a plurality of bit adaptors for holding drilling tools and is selectively rotatable to bring a selected drilling tool into coaxial alignment with the drill pipe when the drilling tool changer assembly supporting the rotatable carousel assembly is moved into the exchange position. The apparatus may include means for aligning the selected drilling tool within a bit adaptor holding the selected drilling tool, and/or the apparatus may include means for aligning the drill pipe or a hammer with the selected drilling tool.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is this Summary intended to be used to limit the scope of the claimed subject matter.

shows a side view of a typical mobile drilling machine. The drilling machine has a tower, a platformsupporting the tower, and typically tracksor wheels for propelling the drilling machine over ground.also shows an operator's cabsituated on the platform. The term “cab” in this disclosure refers to either a housing for an operator or a workstation location on the platform, which may or may not be occupied by an operator; the latter would be the case in autonomous machines.shows the typical engine compartment or “power pack”, and mechanical accessories of a drilling machine. The towerwill also carry a drill stringextending through the tower, and a rotary head, being typically a hydraulic or electric motor for rotating the drill string. The drill stringis terminated at its lower end by a removable bit or drilling tool. In general, the toweris pivotably moveable so that its tilt allows operations for the change-out of drilling tools. The drill stringand its components will be discussed in more detail below. The reader should note that the improvements disclosed here could be embodied in a fixed drilling machine as well as the mobile machine illustrated, and the claims cover both embodiments.

The drilling machinefurther includes a control system, which is operatively coupled to the power pack. The associated implements operatively connected to the power packand the control systemare described in more detail below and suggested only schematically in.shows schematically the control systemoperatively associated with the example drilling machine which here includes the disclosed drilling tool changer apparatus. The control systemcomprises generally a computerthat is typically a programmable digital computer, further comprising a read-only memory, a non-transitory computer readable storage medium for storing instructions executable by a processor (such as a random-access memory), a central-processing unit or processor, and a hard drive or flash memory or the like for further storage of programs and data, as well as input and output ports.shows the example control systemoperatively connecting the computerto a visual displayfor an operator, and a control input interface, such as a joystick, or touch screen, or both. In this disclosure, the term “computer” may be used broadly to refer to both a programmable digital computer as just described, the software executed by the computer, and relevant peripheral devices connected to a computer, as well as networks of computers. One industrial example of a computersuitable for controlling the operations of actuators in a tracked vehicle is the Rig Control System (RCS) provided by Epiroc Drilling Solutions, LLC. The computerconnects by means of a bus, which may be a wired or wireless network, to the various sensors and actuators shown in(and in some embodiments, others).

The control systemincludes one or more control inputs which can be adjusted by the operator in the operator's cab. These may include one or more input controls for controlling the operation of the tower, including its tilt angle, and also the operations of the drilling tool changer assembly, described below, which is a component of the drilling tool changer apparatus.

is a perspective view of the rig platform showing the drilling tool changer assemblypositioned near the break-out area of the tower. Referring to, we see a drilling tool changer assembly, comprising an enclosurefor the carousel assembly(see). The drilling tool changer assemblyis disposed on the rig platformand mounted by a hingeso as to rotate upward from the rear (to the left in) when urged upward by changer actuators.also shows break-out tooladjacent to the base of the tower, and the operator's cabthat would typically be situated adjacent to toweron the drilling rig. The enclosurehas a lidthat can be opened by action of one or more lid actuators, which may be hydraulic or electric motors or the like. The lidis not required, but is desirable to keep dirt and foreign objects from falling into the drilling tool changer assembly.

It is advantageous that the disclosed drilling tool changer assemblyis not located over the opening in the drill deck, where it could interfere with breakout operations, and further, is not located on or connected to the tower, where it would add extra weight and complicate balancing the tower.

shows a side view of the structures of, where the lidof the carousel enclosureis opened. In, the drilling tool changer assembly, with the lidof the carousel enclosureopened, is tilted forward on the hingeby action of actuators, thus moving from a storage position as shown in, to an exchange position, as shown in.shows the tilted drilling tool changer assemblyreceiving a drilling toolfrom the drill stringheld by the now-tilted tower, where the drilling tool changer assemblyis tilted at an angle to substantially match the tilt of the tower.shows a drill stringafter a drilling toolhas been removed and placed in the drilling tool changer assembly.could also illustrate the opposite operation, where a drilling toolis attached to the drill string.show an actuator or motorfor rotating the carousel assembly. (The actuator or motormay include a gearbox.) The apparatus and procedures for the change-out or replacement of the drilling toolare described in more detail below.

is a perspective view of an embodiment of the rotatable carousel assemblyof a drilling tool changer assembly, situated in an enclosure, with bit adaptorsshown holding a plurality of drilling tools. The rotatable carousel assemblyis removable from the drilling tool changer assemblyand replaceable therein, as will be described. The rotatable carousel assemblyhas a plurality of receptacles, called here bit adaptors, for receiving drilling tools. The rotatable carousel assemblyis selectively rotatable, in either direction, via a motor, to bring a selected drilling toolinto coaxial alignment with the drill stringwhen the drilling tool changer assemblysupporting the rotatable carousel assemblyis moved into the exchange position as shown in.also shows an empty bit adaptorin a pre-determined angular positionof the rotatable carousel assembly, where a used drilling toolmay be deposited after removal from the drill string. Alternatively, this pre-determined angular positioncould be the current position of a drilling toolheld in the bit adaptor, to be attached to the drill string. In either case, the rotatable carousel assemblywill be rotated to bring the relevant bit adaptorinto the correct pre-determined angular positionfor the pick-up or drop-off of a drilling toolas determined by an operator or the control system.

The rotatable carousel assemblyhas at least one alignment pinsituated on the alignment platebelow a carousel plate, which alignment pinpasses through a slot, notch, or holein the carousel plate, so that the carousel platecan be held on the alignment platein a fixed angular position within the rotatable carousel assembly. The carousel plateof this embodiment further comprises at least one off-center alignment hole, comprising a slot, notch or hole, mating with an off-center alignment pin, for re-aligning the rotatable carousel assemblyin the same angular position on the alignment plateafter the rotatable carousel assemblyis removed from the drilling tool changer assemblyand replaced in the drilling tool changer assembly. In this way the rig operator, or an automatic process in a control system, can know which drilling toolis in which bit adaptorin the rotatable carousel assembly. The feature allows the operator or control systemto confirm or select the correct drilling toolfor the desired drilling task, because in general, drilling toolsmay be of different sizes, or types, or even have different conditions of wear, and it is highly advantageous to know without manual inspection which drilling toolis in which position in the rotatable carousel assembly, so that drilling operations are not delayed after a change-out of drilling tools.

The reader should note that the alignment pin or pins, and the off-center alignment pinare shown schematically in the figures, and represent, in general, an indexing feature. These may be any sort of finger, rod, or lug that can engage slots, notches or holes in the carousel plateto maintain the same in a given angular position in the rotatable carousel assembly, and thus the terms “alignment pin” or “off-center alignment pin” should be construed broadly according to this indexing function. In particular, in some embodiments therefore, alignment pinsor off-center alignment pindo not pierce the carousel platecompletely in order to engage it.

In some embodiments, the rotatable carousel assemblymay optionally be a first rotatable carousel assembly, and the rotatable carousel assemblyreplaced in the drilling tool changer assemblymay be a second rotatable carousel assembly, the second rotatable carouselhaving possibly replaced or exchanged drilling tools.

shows examples of drilling toolsresting in the bit adaptors. Each bit adaptoris connected to a carousel plate.shows alignment holesin the carousel platefor selectively receiving an alignment pin, and also shows at least one off-center alignment holeand off-center alignment pin, to allow indexing of the carousel plate. The carousel platemay be a single plate, or constructed of two plates bolted together by bolts or retaining pins, for ease of manufacturing.

shows the rotatable carousel assemblyas described in above, but including the alignment platethat supports the alignment pinsand off-center alignment pin or pins. (Generally, only one off-center pinwould be required for alignment, but more than one could be provided, and reference here to an “alignment pin” includes one or more.) The carousel plateand the bit adaptorsare preferably bolted together with bolts.shows the alignment platesupporting the alignment pinsand off-center alignment pin, rotatable by a bull gear. As shown in, the carousel plateis removably supported by the alignment plate, and the alignment pinsand off-center alignment pinthus pass through holes or slotsin the carousel plate. One of the holes or slots is an off-center alignment hole, so that the carousel plate(and thus the bit adaptors) can only be indexed to and replaced in one position on the alignment plate.

is a perspective view of this embodiment of the rotatable carousel assemblyviewed from the rear or bottom of the assembly depicted in.shows how the carousel plateis supported on the alignment plate, and how the alignment plateis fastened to a bull gear, which bull gearrotates the alignment plate, and thus the carousel plate, when rotation is imparted to the bull gearby an actuator, such as a motorand pinion gear (not shown in). The rotation imparted may be in either direction, under command of an operator or an automatic process in a control system, to index the rotatable carousel assemblyto the desired position, as explained below.

show a perspective view of the alignment platesupported by the bull gear. The alignment platesupports a plurality of alignment pins, and at least one off-center alignment pin. As described above with reference to, the carousel plateis supported by the alignment plate, where alignment holes(and off-center alignment hole) in the carousel platereceive, respectively, alignment pinsand the at-least one off-center alignment pin. This structure is shown in plan view in, where the circumferenceof a circle on the radius of the alignment pinsis shown, illustrating the off-center location of the at least one off-center alignment pin, as well as the respective alignment holesand off-center holein the carousel plate.

illustrates an embodiment of a sensor arrangement for detecting the angular position of the rotatable carousel assembly. A magnetor equivalent is connected to a pin or shaft, which pin or shaftis connected to the alignment plateand compelled to rotate therewith. A sensordetecting the position of the magnetis fixed to a bracketor other convenient structure that is fixed to the enclosureof the drilling tool changer assembly, so that as the alignment platerotates by action of the motor, the change in output from the sensorcorresponds to the angular position of the alignment plate, and thus the angular position of the rotatable carousel assembly, which is rotated by action of the alignment plate. Because the rotatable carousel assemblyonly fits the alignment platein one pre-determined position, the output of the sensoruniquely reports the angular position of the rotatable carousel assembly, which output is preferably communicated to the control systemby means of a connector, which can be a cable or wireless connection. A suitable magnetic sensor of this type would be the SMART Position Sensor configuration, manufactured by Honeywell International, Inc., or equivalent.

are a more detailed view of the carousel assemblyof the drilling tool changer assembly,being a plan view andbeing a perspective view of the same. In, three bit adaptorsare occupied by drilling tools, and one bit adaptoris empty. (The reader should note that the number of bit adaptorsin a carousel assembly may be more or fewer than the four shown.) In, for clarity, all the bit adaptorsare shown as empty.

show a carousel plate, which may be one integral plate, or, for convenience of construction, two or more plates fastened together, with bolts, such as the retaining pins or boltsshown. The carousel platesupports bit adaptors(described in more detail below), for receiving drilling tools. The carousel platehas holesfor receiving alignment pins, and at least one off-center holefor receiving an at least one off-center alignment pin. In this way, a particular type of drilling toollocated in a particular bit adaptor, and be replaced in the same position in the carousel assembly, if the carousel assemblyis removed and replaced in the drilling tool changer assembly.

Further referring to, the figures show lifting rings, where by a lifting apparatus, such as a crane, can attach to and lift out the carousel assemblyfor replacement of drilling toolsin the bit adaptors. The bit adaptorsare shown fastened to the carousel plateby retaining pins or bolts. As illustrated below, each bit adaptorfurther comprises a breaker plateand a bit holder. Alternatively, the breaker platemay be fastened to a bit holder platethat may be removable. The breaker plateof the bit adaptorscomprises nubsin its inner circumference to hold the drilling tooland resist the torque of the drill pipewhen the drill pipeis rotated by the break-out tool mechanism, as a drilling toolis added to or removed from the drill pipe. Therefore, no special sub or supplemental adaptor to the drilling toolis required for the breakout operations.

show more detail of bit adaptorof the drilling tool changer assembly. In, an embodiment has a breaker platewith nubs, where the nubsare sized to grasp a drilling toolof a pre-determined size and restrain its movement against the torque of the break-out operation. In, the bit holderand the bit holder plateare alternatively welded together to form an integral unit. Mounting holesare provided for mounting the bit adaptorto the carousel plate. In the embodiment of, the breaker plateis connected to a bit holder plate, where the bit holder platesupports a drilling tool inserted into the bit adaptor. The embodiment of, providing a more shallow receptacle, is adapted to support and hold smaller drilling toolsthan the embodiment of. In either embodiment, the bit adaptor functions to provide storage for the drilling toolin the carousel assembly, while also holding the drilling toolfirmly against the torque of the break-out operation.

show embodiments of the drilling tool changer assemblywhere the bit adaptorssituated in the carousel assemblyare sized to receive drilling toolsof differing sizes, both in diameter or in depth, or both dimensions.is a plan view of such an embodiment.is a side view omitting depiction of the carousel platefor clarity, and showing only the exemplary bit adaptorsof varying sizes. In, the rightmost bit adaptordepicted has a bit holder plate, but alternatively lacks a bit holder.

It is advantageous for an operator or an automatic process to detect if a bit or drilling toolis present in the rotatable carousel assembly, so that no attempt will be made to engage with the drill pipeif no bit is present. Also, it is advantageous that an operator or automatic process can detect which type of bit or drilling toolis actually present in a particular bit adaptor. To that end, embodiments can be provided with these capabilities. Radio-frequency identification (RFID) technology, for example, is known in the art.illustrates an RFID sensorsituated at some convenient location in the enclosureof the rotatable carousel assembly. The RFID sensorcan read a corresponding RFID tag (not shown) on a drilling tooland transmit this identification to an operator or automatic process in the control system, where it may be stored for further reference or use in the automatic process. For example, an automatic process could select the desired size and type of drilling toolfor particular rock strata or drilling conditions. Equivalently, electromagnetic sensors could be employed, such as near-field communications devices operating on principles generally within RFID technology, as is known in the art. In other embodiments, the RFID sensorcould be a plurality of RFID sensors, where each is associated with a particular bit adaptor.

Further,shows an ultrasonic detector, which provides the capability of detecting whether or not a drilling toolis present in a particular bit adaptorof the rotatable carousel assembly. In the case of both the RFID sensorand the ultrasonic detector, the relevant index or angular position of the rotatable carousel assembly(as known by the means described in connection withabove) can be correlated with the identification returned from the RFID sensor, or with the signal from the ultrasonic detectorto provide this information to an operator or to an automatic process in the control system, where it may be stored for future reference or use in an automatic process. Equivalents in other embodiments could be a radar sensor to detect presence of a bit, or a switch.

In some implementations, the drilling toolmay be a down-the-hole (“DTH”) drill bit and hammer chuck assembly (collectively referred to herein as a “DTH tool”), and the drill pipeat the end of the drill stringmay be replaced with a hammer that includes receiving threads to mate with the threads of the DTH tool. The DTH tool threads and the corresponding hammer threads are less tapered and therefore tend to be more susceptible to cross threading than the API or BECO threads on standard rotary drill bits and drill pipes. As such, a more precise alignment between the DTH tool and hammer may be required to make the joint and avoid cross-threading.

However, because the DTH tool includes both a hammer bit and a hammer chuck, the DTH tool is relatively longer and more top heavy than standard rotary drill bits such that when the drilling tool changer assemblyis tilted to the exchange position shown in, the DTH tool is more likely to tilt within the bit adaptorrather than staying aligned with the drill string.

depicts a side plan view of a DTH toolpositioned within the previously described bit adaptorof the present disclosure, anddepicts a side plan view of a DTH toolpositioned within an embodiment of a pivoting bit adaptorof the present disclosure. As shown in, the top heavy DTH tooltends to tilt over and fall out of alignment in the bit adaptorwhen the drilling tool changer assemblyis in the exchange position, whereas the DTH toolis held in an aligned position in the pivoting bit adaptorwhen the drilling tool changer assemblyis in the exchange position.

depicts a top-down perspective view of the pivoting bit adaptorof the present disclosure, anddepicts another top-down perspective view of the pivoting bit adaptorrotated approximately 90 degrees. The pivoting bit adaptorcomprises a bit holderwith a bit holder platecoupled to a bottom surface thereof to support a drilling tool, such as the DTH toolpositioned within the pivoting bit adaptor. A mounting ringsurrounds the bit holderand includes mounting holesfor mounting the pivoting bit adaptorto the carousel plate. The pivoting bit adaptorfurther comprises a pivoting componentthat includes a semicircular supportand a shim support. The shim supportis coupled to the semicircular supportand extends substantially perpendicular thereto. The shim supportforms a troughinto which a shim padis positioned. The shim padcan be provided in different sizes for various types and sizes of bits.

The pivoting componentis rotationally coupled to the bit holdervia a pin/flange assembly, and a return springensures the pivoting componentremains in the open position shown inandwhen the pivoting bit adaptoris empty. As best shown in, one or more keyed insertsmay be provided on an inside wall of the bit holder, and these keyed insertscan be provided in different sizes for various types and sizes of bits to inhibit rotation of the drilling tool, such as the DTH tool, when making or breaking a joint.

throughdepict a sequence of side cross-sectional views of a DTH toolbeing lowered into a pivoting bit adaptorof the present disclosure. Although the pivoting bit adaptoris shown in a horizontal position in this sequence, the pivoting bit adaptorwould perform in the same manner in a tilted position, such as the exchange position shown in.

Referring to, the pivoting bit adaptoris shown with the pivoting componentin the open position, and with the DTH toolmaking initial contact with the shim pad. Referring to, as the DTH toolcontinues to be lowered into the pivoting bit adaptor, the DTH toolpushes against the shim paduntil the force of the return springis overcome and the pivoting componentrotates about pin/flange assembly. Referring to, when the DTH toolis fully lowered into engagement with the bit holder plate, the shim pad, as well as the keyed insert(s), keep the DTH toolsnug within the pivoting bit adaptor. The shim padand keyed insert(s)are also sized to facilitate proper lowering of the pivoting componentto the position shown in. When the pivoting componentrotates to the position shown in, the semicircular supportextends horizontally/radially to surround a portion of the DTH toolpositioned within the pivoting bit adaptor, and the shim supportextends vertically/axially within the pivoting bit adaptor, with the shim padengaging the DTH tool.

Another alignment issue that may occur when the drill stringincludes a hammer or a heavier drill pipeat the end is sagging of the drill stringout of alignment with the drilling toolwhen the toweris tilted as shown in.

Referring now toand, an embodiment of a side swinging drill string supportis depicted in a stowed configuration and in an activated configuration, respectively. The side swinging drill string supportis designed to support a hammeror drill pipeat the end of the drill stringwhen making a joint between the hammeror drill pipeand a drilling toolin applications where the toweris tilted and the hammeror drill pipetends to sag out of alignment with the bit adaptor,.

The side swinging drill string supportincludes a mounting flange, a piston, a bracket, and a roller. The rolleris mounted to the bracketvia first supportand second support. A spindleextends between the supports,and through the rollerto enable the rollerto rotate with respect to the supports,. The rollerand bracketcombination are further rotationally coupled to the pistonvia a pinned connectionbetween the pistonand the second support.

In the stowed configuration shown in, the pistonis in an extended position. When the pistonextends, it applies a pushing force to the second supportthrough the pinned connection, thereby rotating the bracketand the rollerinto axial alignment with the mounting flange. In the activated configuration shown in, the pistonis in a retracted position. When the pistonretracts, it applies a pulling force to the second supportthrough the pinned connection, thereby rotating the bracketand the rollerto a position that is perpendicular to the mounting flange, as shown.

anddepict implementations of side swinging drill string supports,′ in the activated configuration. The side swinging drill string supports,′ may be identical in most respects, except for the rollers,′, which are sized to support different sized hammers/drill pipes.

anddepict the side swinging drill string supportin a representative operational environment to provide support to a sagging hammer/drill pipeat the end of a drill stringand align it with the drilling tool, such as the DTH tool. As shown in, the side swinging drill string supportis in the stowed configuration, and the centerlineof the hammeris sagging out of alignment with the centerlineof the DTH tool. As shown in, when the side swinging drill string supportis in the activated configuration, the rollerof the side swinging drill string supportengages the hammerand provides support to maintain alignment between the centerlineof the hammerand the centerlineof the DTH tool.

In various embodiments, the side swinging drill string support,′ may be configured to be operated manually, electrically, pneumatically, hydraulically, or by other methods. In some embodiments, the side swinging drill string support,′ may be operatively coupled to the control systemsuch that the rig operator, or an automatic process in the control system, determines when to move the side swinging drill string support,′ from the stowed configuration to the activated configuration and vice versa.

Referring now tothrough, in some embodiments, instead of the pivoting bit basketand/or the side swinging drill string support,′, one or more alignment clamps may be installed within the enclosurefor the carousel assemblyof the drilling tool changer assembly. The one or more alignment clamps may be used to align a drilling tool, such as a DTH tool, within a bit adaptorand/or to align a drill pipe/hammerwith the drilling tool/DTH toolto make the joint and avoid cross-threading.

anddepict side perspective views of an embodiment of an alignment clampshown in an open position and in a closed position, respectively. The alignment clampcomprises a first arm, a second arm, an actuating piston, and mounting connectors,. The first armand the second armare pivotally coupled via pin connections,to opposite ends of the actuating piston. Each of the first armand the second armfurther comprises a pad system,, respectively, coupled to the end of the arm,opposite the pin connections,.

Each of the pad systems,comprises a plurality of contact pads,, respectively, that are disposed substantially perpendicular to the plane of the arm,and positioned at different angles to one another. The contact padsof the first armmay be angularly oriented as mirror images to the contact padsof the second arm. As the alignment clampmoves to the closed position shown in, the plurality of contact pads,partially surround and engage the DTH toolto act as a wedge for alignment purposes, as further described herein.

Each of the pad systems,further comprises a plurality of flared flanges,, respectively, each coupled to an upper end of a corresponding contact pad,and extending outwardly at an angle therefrom. The flared flangesof the first armmay be oriented as mirror images to the flared flangesof the second arm. When the alignment clampis in the closed position shown in, the plurality of flared pads,form a generally funnel shape operable to guide the hammerfor alignment purposes to allow the joint to be made, as further described herein.

throughdepict the alignment clampof the present disclosure in a representative operational environment. As shown, the alignment clampmay be installed, such as via mounting connectors,, within an enclosurefor a carousel assemblycomprising a plurality of bit adaptors, one of which contains a DTH tool.throughdepict a sequence of top plan views showing the alignment clampof the present disclosure moving the DTH toolfrom a tilted position within a bit adaptorto an aligned position within the bit adaptorwhile the drilling tool changer assemblyis tilted to the exchange position shown in.

As the enclosureis tilted to the exchange position, the DTH toolfalls out of alignment with the bit adaptor.shows the alignment clampof the present disclosure in an open position, and the DTH toolin a tilted position within the bit adaptor. In this configuration, the actuating pistonof the alignment clampis extended, and the arms,of the alignment clampare pivoted open to allow rotation of the carousel assemblywithout interference.