Clamping device for underground drilling machinery

Abstract

The present disclosure relates to a clamp device for a directional drilling machine. The clamp device may include a translatable and pivotable clamp. The clamp device may also include an upper drill rod guide / support and a lower drill rod guide / support. The clamp device may also include a lubricant dispenser.

Description

[0001] This application is a divisional application of the patent application with the application number 201810755410.5, the invention name of "Clamping Device for Underground Drilling Machinery", and the application date of July 10, 2018. Technical Field

[0002] The present disclosure generally relates to underground drilling machinery. More specifically, the present disclosure relates to a system for forming and disconnecting threaded joints between drill pipes of a drilling machine. Background Art

[0003] Utility pipelines for water, electricity, gas, telephone, cable television, optical fiber, etc. typically run underground for reasons of safety and aesthetics. Sometimes, underground facilities are buried in a trench and then the trench is backfilled. However, trenching can be time-consuming and may cause substantial damage to existing structures or roads. Alternatively, underground drilling processes and systems have been developed for installing facilities underground. A common underground drilling process first involves drilling a pilot hole from a starting point to an ending point. Once the pilot hole is drilled, the pilot hole can be enlarged using a reaming process. During reaming, a product (e.g., a pipe) can be pulled into the reamed hole behind the reamer. For some drilling techniques, the starting point and the ending point can be underground (e.g., in a pit). Other drilling techniques can set the starting point and the ending point on the ground plane. For this type of drilling process, the drilled hole typically defines a curved path that enters the ground at an angle from the starting point and gradually curves upward to reach the ending point. Known techniques can be used to steer the drilling machine during drilling so that the drilled hole follows the desired path. By coupling a relatively large number of drill pipes together to form a drill string, a relatively long hole can be drilled.

[0004] One type of directional drilling machine includes an elongated track (e.g., a rack), and the elongated track can be aligned with an inclined orientation relative to the ground. A rotary drive (e.g., a gearbox) (e.g., via a carriage) is mounted on the track so as to be movable along a drive axis extending parallel to the length of the track. In some examples, a rack and a pinion drive are used to advance the rotary drive along the track. The rotary drive can include a drive member, and the rotary drive causes the drive member to rotate about the drive axis. The drive member is adapted to be connected to a drill pipe (e.g., a drill string). The drill pipe can have threaded ends, and the threaded ends include female threads or male threads.

[0005] To drill a hole using a directional drilling machine of the above type, the track is oriented at an inclined angle relative to the ground and the rotary drive is moved to the upper end of the track. Next, the drill pipe is unloaded from the drill pipe storage structure (e.g., magazine) of the directional drilling machine and the upper end of the drill pipe is typically coupled to the drive member of the rotary drive by a threaded connection. After the upper end of the drill pipe has been coupled to the rotary drive, if the drill pipe is the first drill pipe to be introduced into the ground, the lower end of the drill pipe is coupled to the drill bit, or if the drill string has been initiated, the lower end of the drill pipe is coupled to the uppermost drill pipe of the existing drill string. Thereafter, the rotary drive is driven in the downward direction along the inclined track while the drive member rotates simultaneously about the drive axis. As the rotary drive is driven downward along the track, the rotary drive transfers axial thrust and torque to the drill string. The axial thrust and torque are transmitted through the drill string to the drill bit, causing the cutting elements (e.g., drill cutters) of the drill bit to rotationally drill through the ground. As drill pipes are gradually added to the drill string, the length of the hole gradually increases. Drill pipes are most commonly secured together by threaded connections at the joints between the drill pipes.

[0006] After the hole has been drilled, the drill string must be pulled back to remove the drill string from the hole. During the pullback, the drill pipes of the drill string are individually withdrawn from the ground, separated from the drill string and returned to the drill pipe storage structure. Typically, reaming is accomplished as part of the pullback process. To separately withdraw a drill pipe from the remainder of the drill string, the threaded connection between the withdrawn drill pipe and the subsequent drill pipe of the drill string needs to be broken before the withdrawn drill pipe can be returned to the pipe storage structure. Due to the torque loads associated with drilling and reaming, the threaded connections between the drill pipes of the drill string can become very tight and difficult to disconnect.

[0007] The drilling machine has incorporated components and features for improving the efficiency related to drill pipe manipulation and the efficiency related to disconnecting and forming joints. For example, linear and / or pivotable pipe handling devices can be provided on the drilling machine for moving the drill pipe between the pipe storage structure and the drive axis of the rotary drive. U.S. Patent Nos. 5,556,253; 5,607,280; 6,332,502; and 6,543,551 disclose examples of pipe handling devices. Also, one or more clamps can be provided on the drilling machine to facilitate forming and disconnecting threaded joint connections. U.S. Patent No. 9,598,905; U.S. Patent Application Publication No. US 2009 / 0095526; and PCT Publication No. WO 2017 / 020008 disclose exemplary clamp devices for a drilling machine. In addition, systems have been developed for applying a lubricant such as grease to the threaded joints of the drill pipe to facilitate disconnecting the joints after drilling. U.S. Patent No. 6,550,547 discloses a system on a drilling machine for applying grease to the threaded ends of the drill pipe.

[0008] Directional drilling machines can use different types of drill pipes. One type of drill pipe includes a single pipe. In use, the single pipes are strung together and used to rotate a borehole drill bit at the lower end of the drill string. The borehole drill bit can include a steering surface that is manipulated to turn the drill string. Another type of drill pipe includes an inner pipe located within an outer pipe. This type of system is disclosed in U.S. Patent No. 9,598,905, the entire content of which is hereby incorporated by reference in its entirety. When dual-pipe drill pipes are strung together, the resulting drill string includes an inner drill string section and an outer drill string section that can rotate independently. Generally, the inner drill string section can be used to rotate the drill bit, while the outer drill string section can be used to control the position or orientation of the steering characteristics of the drill string.

[0009] Regardless of the type of drill pipe used, efficiency is an important aspect of the operation of any drilling machine. In this regard, the ability to effectively form and break joints between drill pipes is an important efficiency consideration. Reducing wear is another important consideration in drilling machine design. Summary of the Invention

[0010] The operational design of the rod handling system and the clamp system greatly affects the efficiency with which a drilling machine can be operated. A rod handling system that linearly moves a rod in a motion between a rod storage position and the drive axis of a rotary drive can be operated in a very efficient manner. Also, because the drilling machine operator is provided with a more open view of the rod joint location when forming or breaking a joint, a clamp system having top-opening clamps can be operated very effectively. Because the top-opening clamps are closed on their sides themselves, preventing the rod from being laterally loaded into the clamp system, the ability to combine a linear rod handling system with a top-opening clamp system can be problematic. Certain aspects of the present disclosure relate to top-opening clamp systems that are capable of being compatible with a linear rod handling device and can be combined with the linear rod handling device to be operated effectively. In certain examples, when a threaded joint between a drill pipe and a rotary drive of a drilling machine is formed or broken, the top-opening clamp system can be used to prevent the drill pipe from rotating, eliminating the need to load a rod clamping / gripping device, such as a clamp, into the rod handling device to perform this function.

[0011] Wear and durability can also greatly affect the efficiency of operating a drilling machine. Wear and lack of durability can lead to damage or wear of components that need to be repaired. Repair requirements result in costs associated with the repair itself as well as costs associated with machine downtime. Regarding the clamp system, poor alignment between the drill pipe and the clamp can cause wear of the clamp and the drill pipe. Specifically, if the rod is not centered relative to the clamp before clamping, during the clamping process, the conical shape of the clamp will typically actively force the rod to center, which causes the rod to slide from an eccentric position across the conical surface of the clamp to the center position. This sliding action under clamping pressure can cause wear of the clamp and / or the drill pipe over time. Certain aspects of the present disclosure relate to a clamp system having a self-centering feature for centering a drill pipe within the clamps of the clamp system. In some examples, the self-centering feature does not include any moving parts and is relatively simple and durable in design. In some examples, the self-centering feature includes a rod support or a rod guide, and the clamps of the clamp system are positioned between the rod support or the rod guide. In some examples, the rod support or the rod guide includes a ring. In some examples, the self-centering feature is compatible with a drill pipe having an end portion and an intermediate section, the end portion having an enlarged outer diameter and the intermediate section having a reduced outer diameter.

[0012] One aspect of the present disclosure relates to a drilling machine having a clamping device for forming and disconnecting joints between drill pipes, the clamping device having features that enhance an operator's ability to visually monitor the position of the joint within the clamping device. In some examples, the clamping device may include a top-opening clamp for enhancing an operator's ability to visually monitor the joint position of the joint between two drill pipes to be clamped / secured by the clamp. In some examples, the clamping device is compatible with a linear rod manipulation device that linearly moves a drill pipe along a drill pipe transfer path between a rod storage structure and a drive axis of the drilling machine. In some examples, the clamping device includes at least one clamp that can be translated along the drive axis between a first axial position and a second axial position. In some examples, at the first axial position, the translatable clamp is offset from the drill pipe transfer path, and at the second position, the translatable clamp intersects the rod transfer path. In one example, at the second axial position, the translatable clamp axially overlaps a rod loading / unloading area of the rod storage structure. The rod loading / unloading area of the rod storage structure may be an opening or spacing below the rod storage structure through which the rod moves to unload the rod from the rod storage structure and load the rod into the rod storage structure. In some examples, when in the second axial position, the translatable clamp can be used to grip onto a drill pipe to allow a rotary drive (e.g., gearbox) of the drilling machine to form or not form a threaded joint with the drill pipe. In some examples, a clamp-free (e.g., clamp-less) rod manipulation device can be used to move the rod between the rod storage structure and the drive axis. In some examples, the rod manipulation device may include a drill pipe receiving position, and the drill pipe can be magnetically fixed at the drill pipe receiving position. In some examples, because the translatable clamp of the clamping device can be used to prevent rotation of the drill pipe when the drill pipe is coupled to and decoupled from the rotary drive, the rod manipulation device may not need to include any durable clamping devices, such as one or more clamps. In some examples, the rod manipulation device can include one or more linear shuttles. In some examples, a linear shuttle can include an arm that linearly slides between an extended position and a retracted position. In some examples, the shuttle is configured to align the drill pipe with the drive axis of the rotary drive when extended and position the drill pipe below the rod storage structure when retracted. In some examples, the linear shuttle can include a blocking surface that blocks the bottom side of the opening of the rod storage structure. In some examples, the ability to translate at least one clamp of the translation clamp device allows the translatable clamp to move between a first position and a second position, at the first position, the translatable clamp does not impede the rod from being moved by the rod manipulation device from the rod storage structure to the drive axis, and at the second position, the translatable clamp does impede the rod from being linearly moved by the rod manipulation device from the rod storage structure to the drive axis. In some examples, the translatable clamp is not configured to be able to laterally receive the drill pipe linearly from the rod manipulation device.

[0013] Another aspect of the present disclosure relates to a clamp device for forming and disconnecting drill pipe joints, the clamp device including rod guiding / supporting means for reducing wear of the clamps and / or the drill pipe. In some examples, the guiding / supporting means may include a lower hole guide / support positioned below the clamp device and an upper hole guide / support positioned above the clamp device. In some examples, the guide / support means may include a guide / support ring having a tapered introduction surface. In some examples, the guide / support ring may be centered on the clamping axis of the clamp. In some examples, the clamping axis of the clamp may be coaxially aligned with the drive axis of the drilling machine. In some examples, the clamp device may be used with a drill pipe having an enlarged end, the enlarged end having an enlarged diameter. In some examples, the enlarged ends of two drill pipes meeting at a joint may define a length, and the guide / support means may be axially spaced apart by a distance less than or equal to this length. In this way, it is ensured that when the joint is aligned between the clamps, the enlarged end is located within the guide / support means. In some examples, the guide / support means may be configured to automatically center the drill pipe relative to the clamping axis of the clamp of the clamp device. In some examples, the guide / support means does not have any movable parts and provides passive centering of the drill pipe relative to the clamp before clamping. In some examples, the guide / support means may be configured to self-center the rod within the clamp device.

[0014] Another aspect of the present disclosure relates to a drilling machine having a lubrication system for applying a lubricant, such as grease, to the threaded joints of a drill string. In some examples, the drilling machine may include a rotary drive having a rod coupler that is adapted to be rotatably driven about a drive axis. The rod coupler is adapted to be threadedly connected to the drill pipe of the uppermost hole of the drill string. In some examples, the rod coupler may include a recessed connection interface that includes an internal thread. In some examples, the drilling machine may include a lubricant dispenser for dispensing lubricant into the recessed interface and onto the internal thread. By applying lubricant to the recessed interface, this lubricant is transferred to the threads of the drill pipe when the drill pipe is coupled to the rod coupler of the rotary drive. In some examples, the lubricant dispenser may be positioned and / or oriented to facilitate dispensing lubricant into the recessed coupling interface of the rod coupler. In some examples, the dispenser may have a dispensing axis oriented at an inclined angle relative to the drive axis about which the rotary coupler is translated and rotated. In some examples, the dispenser may be carried by a translatable clamp that can be translated along the drive axis.

[0015] Another aspect of the present disclosure relates to an underground drilling machine that includes a rotary drive having a rotatably driven rod coupler adapted to be connected to an end of a drill string. The rod coupler is capable of rotating about a drive axis. The rotary drive is mounted to move back and forth along the drive axis. The underground drilling machine also includes a rod storage structure positioned alongside the drive axis and rod handling means for transferring drill string back and forth between the drive axis and the rod storage structure along a rod transfer path. The underground drilling machine also includes a first rod clamp and a second rod clamp positioned along the drive axis. In some examples, the first rod clamp has an open top. The second rod clamp is positioned between the first rod clamp and the rotary drive. The second rod clamp is movable relative to the first rod clamp along the drive axis between a first axial position and a second axial position. When in the first axial position, the second rod clamp is offset from the rod transfer path such that the second rod clamp does not prevent the drill string from moving between the rod storage structure and the drive axis through the rod handling means. When in the second axial position, the second rod clamp intersects the rod transfer path and is thus positioned to impede the movement of the drill string between the rod storage structure and the drive axis through the rod handling means. The second rod clamp is pivotally movable about the drive axis between a first pivotal position and a second pivotal position. In some examples, when the second rod clamp is in the first pivotal position, the open side of the second rod clamp faces upward.

[0016] Another aspect of the present disclosure relates to an underground drilling machine that includes a rotary drive having a rotatably driven rod coupler adapted to be connected to an end of a drill string. The rod coupler is capable of rotating about a drive axis. The rotary drive is mounted to move back and forth along the drive axis. The rod coupler includes a recessed connection interface that includes an internal thread. The underground drilling machine also includes a drill string storage structure positioned alongside the drive axis and rod handling means for transferring drill string back and forth between the drive axis and the drill string storage structure. The underground drilling machine also includes at least one rod clamp positioned along the drive axis and a joint lubricant dispenser positioned for dispensing joint lubricant into the recessed connection interface. The lubricant dispenser is movable along the drive axis.

[0017] Another aspect of the present invention relates to an underground drilling machine, which includes a rotary drive having a rotatably driven rod coupler adapted to be connected to the end of a drill rod. The rod coupler is capable of rotating about a drive axis and is mounted to move back and forth along the drive axis. The underground drilling machine further includes a drill rod storage structure positioned side by side with the drive axis and a rod handling device for transferring the drill rod back and forth between the drive axis and the drill rod storage structure. The underground drilling machine further includes a first rod clamp and a second rod clamp positioned along the drive axis. The second rod clamp is positioned between the first rod clamp and the rotary drive. The second rod clamp can pivotally move about the drive axis between a first pivot position and a second pivot position. The underground drilling machine further includes a first rod guide / support corresponding to the first clamp and a second rod guide / support corresponding to the second clamp. The rod guide / support can be configured to self-align the drill rod within the rod clamp.

[0018] Various advantages of the present disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the various aspects of the present disclosure. It should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and do not limit the broad inventive concept upon which the embodiments are based. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings illustrate specific embodiments of the present invention and thus do not limit the scope of the present invention. The drawings are not to scale and are intended to be used in conjunction with the description of the following detailed description. Embodiments of the present invention will be described below in conjunction with the drawings, wherein like numerals represent like elements.

[0020] Figure 1 is a schematic view of a drilling system including a horizontal directional drilling machine according to the principles of the present invention.

[0021] Figure 2 is a longitudinal cross-sectional view of an exemplary drill rod.

[0022] Figure 2A is Figure 2 an enlarged view of one end of the drill rod.

[0023] Figure 2B is Figure 2 an enlarged view of the other end of the drill rod.

[0024] Figure 3 is an enlarged view of the joint between two drill rods.

[0025] Figure 4 is a perspective view of an exemplary drilling machine according to the principles of the present disclosure.

[0026] Figure 5 is Figure 4Side view of the drilling machine.

[0027] Figure 6A is Figure 4 Top view of the drilling machine, wherein the translatable clamp of the drilling machine is shown in a first axial position, at which the translatable clamp does not interfere with the linear movement of the drill pipe between the rod storage structure of the drilling machine and the drive axis of the drilling machine.

[0028] Figure 6B is Figure 4 Top view of the drilling machine, wherein the translatable clamp of the drilling machine is shown in a second axial position, at which the translatable clamp impedes the linear movement of the drill pipe between the rod storage structure of the drilling machine and the drive axis of the drilling machine.

[0029] Figure 6C is Figure 6B An enlarged view of a part, showing the translatable clamp in the second axial position.

[0030] Figure 7A A cross-sectional view taken along section line 7-7 of FIG. 6, showing the rod manipulation shuttle in the retracted position, wherein the rod receiving position of the shuttle is positioned below the rod storage structure of the drilling machine.

[0031] Figure 7B A cross-sectional view taken along section line 7-7 of FIG. 6, showing the rod manipulation shuttle in the extended position, wherein the rod receiving position of the shuttle is positioned to align the drill pipe to be received therein with the drive axis of the drilling machine.

[0032] Figure 8 Perspective view of a clamp device according to the principles of the present invention, which can be incorporated as part of Figure 4 the drilling machine, the clamp device including a translatable and pivotable clamp shown in the first axial position and the first pivot position.

[0033] Figure 9A shows Figure 8 the upper hole side of the clamp device.

[0034] Figure 9B shows Figure 8 the upper hole side of the clamp device, wherein the translatable and pivotable clamp is pivoted to the second pivot position.

[0035] Figure 10 shows Figure 8 the lower hole side of the clamp device.

[0036] Figure 11 is Figure 8 the first side view of the clamp device.

[0037] Figure 12 is Figure 8 a second side view of the clamp device of

[0038] Figure 13 is Figure 8 a top view of the clamp device of

[0039] Figure 14 is Figure 8 a cross-sectional view of the clamp device of Figure 13 taken along section line 14-14 of

[0040] Figure 15 is Figure 8 a cross-sectional view of the clamp device of Figure 13 taken along section line 15-15 of

[0041] Figure 16 is Figure 8 a cross-sectional view of the clamp device of Figure 13 taken along section line 16-16 of

[0042] Figure 17 is a perspective view of an exemplary rotary drive that can be incorporated as part of Figure 4 a drilling machine of

[0043] Figures 18 - 25 is Figure 4 a schematic view of a drilling machine of depicting the sequence for adding drill pipes to a drill string as the drill string extends during a drilling operation.

[0044] Figures 26 - 37 is Figure 4 a schematic view of a drilling machine of showing an exemplary sequence for removing drill pipes from a drill string during a pullback operation after drilling. DETAILED DESCRIPTION

[0045] Figure 1 illustrates an exemplary drilling system 20 in accordance with the principles of the present disclosure. The drilling system 20 includes a drilling machine 22 positioned at a starting point 24. The drilling machine 22 drills a drill string 26 along a borehole path extending from the starting point 24 to an end point 28. It should be understood that horizontal directional drilling techniques may be used to manipulate the drill string 26 during drilling such that the drill string 26 generally follows the desired borehole path. As Figure 1As shown, when the hole path extends from the starting point 24, the depicted hole path first extends along a downward trajectory and gradually transitions along a curved path from the downward trajectory to an upward trajectory. In this way, the hole path extends generally horizontally beneath the ground and can pass beneath obstacles on the ground. It will be appreciated that the end of the drill string 26 can include a drill bit 30, which can include a transmitter (e.g., a probe) for positioning the drill string 26 from the surface of the ground, and also preferably includes a cutting design (e.g., drill cutters), the cutting design being adapted to drill a hole when the drill string 26 is rotated by the boring machine 22. This type of directional drilling, where the drilling path is predominantly horizontal, is commonly referred to as horizontal directional drilling (HDD).

[0046] It will be appreciated that the drill string 26 is formed of a plurality of drill pipes that are joined end-to-end in an end-to-end configuration. It will be appreciated that the drill pipes can each have a single pipe configuration or a multi-pipe configuration (e.g., a dual-pipe arrangement). Figure 2 An exemplary drill pipe 32 having a dual-pipe configuration is shown. The drill pipe 32 includes an outer pipe 34 and an inner pipe 36. The outer pipe 34 and the inner pipe 36 are capable of rotating independently of each other. The drill pipe 32 includes a first end 38 positioned opposite a second end 40. At the first end 38, the outer pipe 34 includes a threaded male connection interface 42 having an external thread, and the inner pipe 36 includes a non-threaded female connection interface 44. The first end 38 of the drill pipe 32 can be referred to as the pin end of the drill pipe 32. The non-threaded female connection interface 44 can include a socket having an internal cross-sectional shape that is preferably not circular. In some examples, the internal cross-sectional shape is hexagonal, square, splined, or other shape known to be capable of transmitting torque. At the second end 40 of the drill pipe 32, the outer pipe 34 includes a threaded female connection interface 46 having an internal thread, and the inner pipe 36 includes a non-threaded male connection interface 48. The second end 40 of the drill pipe 32 can be referred to as the internal thread end of the drill pipe 32. In some examples, the non-threaded male connection interface 48 can include a driver, such as a square driver, a hexagonal driver, a spline driver, or other shape of driver that is adapted to transmit torque when mating with a complementary-shaped female connection interface. Figure 2A is an enlarged view of the first end 38 of the drill pipe 32, and Figure 2B is an enlarged view of the second end 40 of the drill pipe 32.

[0047] Figure 3 is an enlarged view of a coupling joint 50 formed when two drill pipes 32a, 32b are joined end-to-end. As Figure 3As shown, a first end 38 of one of the drill pipes 32a is shown mating with a second end 40 of another drill pipe 32b such that the drill pipes 32a, 32b are joined end-to-end. In this mating configuration, a threaded male connection interface 42 of the drill pipe 32a has been threadedly engaged into a threaded female connection interface 46 of the drill pipe 32b. Moreover, a non-threaded female connection interface 44 of the drill pipe 32a has received a non-threaded male connection interface 48 of the drill pipe 32b. It should be understood that when the threaded connection interfaces 42, 46 are threadedly joined together, the non-threaded connection interfaces 44, 48 are simultaneously assembled together in a sliding fit manner.

[0048] Referring again to Figure 2 , the drill pipe 32 includes enlarged ends 38a, 40a adjacent to the first end 38 and the second end 40. Compared with an intermediate portion 39 of the drill pipe 32 having a reduced outer diameter, the enlarged ends 38a, 40a have an enlarged outer diameter at the internal-thread (box) end and the pin end of the pipe. It can be understood that the enlarged ends 38a, 40a can be manufactured using a upsetting process and can be referred to as "upsets". When two drill pipes 32a, 32b are joined together as Figure 3 shown, the joined enlarged ends 38a, 40a cooperate to define a length L of a diameter-enlarged section, and the length L of the diameter-enlarged section corresponds to the length of the enlarged-diameter section formed by the combined axial lengths of the joined enlarged ends 38a, 40a.

[0049] The enlarged ends 38a, 40a have respective axial lengths, each axial length extending from a shoulder to a respective terminal portion of the outer pipe 34. The shoulder is a step in the outer surface of the outer pipe 34 at which the enlarged ends 38a, 40a transition from the enlarged outer diameter corresponding to the enlarged ends 38a, 40a to the reduced outer diameter corresponding to the intermediate portion 39. The enlarged end 40a has an axial length longer than that of the enlarged end 38a. As Figure 3As shown, a joint 50 is formed when the two enlarged ends 38a, 40a are threadedly connected together. So formed, the seam is located between the joined enlarged ends 38a, 40a and represents the outer demarcation line between the joined enlarged ends 38a, 40a. When the joint is formed, the length of the enlarged end 38a extends from its corresponding shoulder to the seam, and the length of the enlarged end 40a extends from the seam to its corresponding shoulder. Since the enlarged end 40a has a longer axial length than the enlarged end 38a, the enlarged end 40a represents a greater percentage of the length L of the enlarged diameter section relative to the enlarged end 38a. Accordingly, the joint is asymmetric about the seam, with the enlarged end 40a section of the joint 50 being longer than the enlarged end 38a section of the joint 50. It will be appreciated that the enlarged diameter section represents the portion of the drill string that is heavier, more durable, and stiffer compared to the intermediate portion. In some examples, shortening the length of the enlarged diameter section by making the enlarged end 38a shorter than the enlarged end 40a can explicitly affect the flexibility of the drill string. However, in other examples, the joint can be symmetric, and various aspects of the present disclosure are not limited to drill pipes with enlarged ends having different axial lengths.

[0050] Although a drill pipe having a dual pipe configuration is shown for illustrative purposes, it should be understood that various aspects of the present disclosure also apply to drill pipes having a single pipe configuration or other drill pipes.

[0051] Figure 4 An exemplary drilling machine 60 in accordance with the principles of the present disclosure is shown. The drilling machine 60 can include a chassis supported on a propulsion structure 64. As shown, the propulsion structure 64 is shown as including continuous metal tracks, but other propulsion structures such as wheels or continuous rubber tracks can also be used. An operating console 66 is shown supported on the chassis. The operating console 66 can optionally include an enclosed cabin. A shroud or body 68 is also supported on the chassis. In some examples, the shroud 68 can enclose a prime mover such as a diesel engine, spark ignition engine, fuel cell, etc., which is used to power the drilling machine 60 for propulsion and drilling operations. The body 68 can also house a hydraulic pump, transmission, generator, or other mechanisms for transferring energy from the prime mover to different driven components of the drilling machine. The drilling machine 60 also includes a drilling rack 70 pivotally connected to the chassis. During transportation, the drilling rack 70 can generally be arranged horizontally. During drilling operations, the drilling rack 70 can be pivoted relative to the chassis of the drilling machine 60 into an inclined or angled configuration. When in the angled configuration, the base end 72 of the drilling rack 70 is supported on the ground, and the upper end 74 of the drilling rack 70 is positioned above the ground. The base end 72 can include an anchor 75, such as a screw drill, for firmly anchoring the base end 72 of the drilling rack 70 to the ground during drilling operations.

[0052] The drilling machine 60 further includes a drill pipe storage structure 76 mounted on the drilling machine frame 70. In a preferred example, the drill pipe storage structure 76 is a removable cassette from the drilling machine frame 70, but a non-removable storage structure may also be used. In some examples, the drill pipe storage structure 76 may include a plurality of vertical columns 77, each vertical column 77 for holding a separate vertical column of drill pipes. In some examples, the drill pipe storage structure 76 may have an open bottom that allows pipes to be loaded into and dispensed from the pipe storage structure through the bottom of the pipe storage structure. It should be understood that the pipe storage structure may generally be referred to as a pipe box, pipe rack, pipe cassette, or similar terms. Example pipe storage structures are disclosed in U.S. Patent Nos. 6,332,502; 5,556,263; 5,607,280, and 6,543,551, the entire contents of which are hereby incorporated by reference. In other examples, a drill pipe storage structure according to the principles of the present disclosure may have columns oriented in a direction different from the vertical direction, or may not have columns at all, and may or may not have an open bottom.

[0053] Referring to Figure 4 -7, the drilling machine 60 further includes a rotary drive 80 that includes a rotatably driven pipe coupler 82 adapted to be connected to the end of the drill pipe 32. The pipe coupler 82 may be referred to as a valve stem, chuck, stub, spindle, or similar terms. The pipe coupler 82 may also include additional components, such as auxiliary protectors. It should be understood that the rotary drive 80 may include a drive mechanism (see FIGS. 6 and 18) for rotating the pipe coupler 82 about the drive axis 84. The drive mechanism may include one or more motors, such as one or more hydraulic motors, pneumatic motors, or electric motors. Torque may be transmitted from the drive motor to the pipe coupler 82 through a mechanical device for transmitting torque, such as a sprocket, chain, gear, screw drive, or other device.

[0054] As Figure 17As shown, the rotary drive 80 includes a gearbox 86 that is adapted to apply torque to drive the rotation of a drill string having a dual pipe. The gearbox 86 includes a motor 88 and a motor 92. The motor 88 is for driving an outer rotary drive 90 for rotating the outer pipe 34 of the dual pipe drill string, and the motor 92 is for driving an inner rotary drive (not shown) for rotating the inner pipe 36 of the dual pipe drill string. It should be understood that the motor 88 can be directly or through a suitable gear arrangement coupled to the outer rotary drive 90. The motor 92 can be directly or through a suitable gear arrangement coupled to the inner rotary drive. Further details regarding the gearbox can be found in U.S. Patent Application No. 15 / 967,975, filed on May 1, 2018, which is hereby incorporated by reference in its entirety. U.S. Patent No. 9,598,905 discloses another gearbox for use with a dual pipe drill pipe and is hereby incorporated by reference. It should be understood that a rotary drive for use with a single pipe drill string can include only one drive motor, which can be directly coupled to the rod coupler of the rotary drive or can be coupled to the rotary coupler through an intermediate mechanism for transmitting torque.

[0055] In the depicted example, the outer rotary drive 90 of the rotary drive 80 is provided with a recessed connection interface having an internal thread 81. The recessed connection interface provided by the outer rotary drive 90 is adapted to be coupled to the threaded male connection interface 42 of the drill pipe 32. The inner rotary drive of the rotary drive 80 has a non-threaded male connection interface adapted to mate with the non-threaded recessed connection interface 44 of the drill pipe 32. In other examples, the outer rotary drive can have a male interface and the inner rotary drive can have a recessed interface.

[0056] Reference Figure 6B, a rotary drive 80 is mounted on a carriage 100 which travels along an elongate track 102 extending between a base end 72 and an upper end 74 of a drill rig 70. The track mounting structure of the carriage 100 is configured to allow the rotary drive 80 to move or reciprocate back and forth along the length of the drill rig 70 as the drill pipe is drilled into the ground or pulled back from the ground. The track may include one or more guiding structures for guiding the linear movement of the carriage 100, such as tracks, racks, rods, linear motion bearings or similar structures. It should be understood that as the carriage 100 moves along the track 102, the rotary drive 80 moves along a drive axis 84. Preferably, the rotary drive 80 moves linearly along the drive axis 84. In some examples, a translation drive is provided for moving the carriage 100 and the rotary drive 80 mounted thereon back and forth along the length of the track 102. The translation drive provides a drilling thrust for driving the drill string into the ground and also provides a pull-back force for removing the drill string from the ground. By way of example, the translation drive may include an actuator or an actuator system, which may include a hydraulic cylinder or a pneumatic cylinder; a hydraulic motor or a pneumatic motor; a rotary gear; an electric motor; a linear gear, such as a rack, a belt, a chain, a sprocket, a pulley and a screw drive; and so on. In some examples, the carriage 100 is driven by a rack and pinion system, which includes any elongate rack 103 extending along the length of the track 102 and a pinion engaging the opposite side of the rack 103. The pinion may be driven by a motor 106 (e.g., a hydraulic motor, an electric motor, a pneumatic motor or other motor) mounted on the carriage 100.

[0057] The drilling machine 60 also includes a rod handling device 110 (see Figure 6B , 7A and 7B) for transferring drill pipes back and forth between the drive axis 84 and the rod storage structure 76. In Figure 7A and 7B the illustrated example, the rod handling device 110 is mounted below the rod storage structure 76, and the rods are loaded into the rod storage structure 76 through the bottom of the rod storage structure 76 and are also unloaded from the rod storage structure 76 through the bottom of the rod storage structure 76. A lifting device 112 (schematically shown in Figure 18 ) may be provided for raising and lowering the drill pipes within the rod storage structure 76. The rod handling device 110 may include one or more carrying arms for carrying the drill pipes along a rod transfer path between the drive axis 84 and the rod storage structure 76. In one example, the carrying arm may include a shuttle arm 114 for linearly moving the drill pipes along a linear rod transfer path between the drive axis 84 and the rod storage structure 76. One or more shuttle arms may include two parallel shuttle arms 114 which are spaced apart along the drive axis 84 and may be in a retracted orientation (see Figure 7A) and extended orientation (see Figure 7B ). The shuttle arm 114 can linearly move between Figure 18 (schematic diagram). The shuttle arm 114 can linearly move through a drive mechanism 115 (see Figure 7B ) and can be supported by a linear motion bearing for linear motion. The drive mechanism 115 is, for example, a rack and pinion drive, a linear actuator such as a hydraulic and pneumatic cylinder, a belt drive, a chain drive, a screw drive, or a similar mechanism. The shuttle arm 114 can include a rod receiver 116 defined by the shuttle arm 114 at a position closest to the drive axis 84 of the shuttle arm. When the shuttle arm 114 is fully extended, as shown in

[0058] As shown, when the drill pipe is carried by the shuttle arm, one or more magnets 119 (see Figure 18 ) associated with each shuttle arm 114 can be used to hold the drill pipe within the rod receiver 116. As shown, the rod receiver 116 is depicted as a shelf, and the receiver 116 has an open side facing the drive axis. In a preferred example, the rod handling device 110 does not include any clamps, such as tongs or other devices for mechanically clamping the rod within the rod receiver 116 when the shuttle arm 114 is extended. When the receiver 116 is located below the column of the rod storage structure 76, an auxiliary member 121 is provided for holding the rod at the receiver 116. The weight of a column of pipes can be sufficient to overcome the magnetic force holding the rod in the receiver 116. When the receiver is located below the rod storage structure, the auxiliary member 121 is lifted into place to prevent a column of pipes from being inadvertently discharged. When the shuttle arm 114 is extended, the auxiliary member 121 does not provide a rod holding function.

[0059] In some examples, the shuttle arm 114 includes a stop surface 118 that stops the underside of the rod storage structure 76 to prevent the rods from falling out when the rods are loaded into or unloaded from the rod storage structure 76. The stop surface 118 works in combination with the lifting device 112. It can be understood that the rods are unloaded from the rod storage structure 76 starting from the column closest to the drive axis 84 and working progressively away from the drive axis column by column. Conversely, when loading the rods back into the rod storage structure 76, the columns are loaded in the opposite direction, starting with the unloaded column that is farthest from the drive axis and working back towards the drive axis column by column. The column from which the rods are unloaded or into which the rods are loaded can be referred to as the selected column. To unload drill rods from the rod storage structure, the shuttle retracts to a position directly below the selected column of the rod storage structure where the receiver 116 is located. At this time, the lifting device 112 holds the drill rods in the raised position. Then the lifting device 112 is lowered to the lowered position so that the bottommost rod of the column of pipes in the selected column is received at the receiver 116 and the rods of the other columns are supported on the stop surface 118. Then, the shuttle arm 114 extends and the stop surface 118 moves below the selected column to prevent the remaining rods in the selected column from falling out. Once the rod in the receiver 116 has passed through the rod storage structure, the elevator can be raised to lift the remaining rods in the rod storage structure to reduce the friction on the shuttle arm. This process is repeated to remove more rods from the rod storage device. To load rods into the rod storage structure, the lifting device 112 is lowered and the shuttle arm 114 retracts to place the receiver 116 that holds the rods to be loaded into the rod storage structure directly below the selected column. The lifting device 112 then raises to lift the rods into the selected column. This process is repeated to load more rods into the rod storage structure. Other details regarding the exemplary rod handling device are disclosed in U.S. Patent Nos. 6,332,502; 5,556,253; 6,543,551; and 5,607,280, which are incorporated herein by reference in their entirety. Although a linearly moving rod handling device is of course preferred, other types of rod handling devices (e.g., pivotally moving, arcuately moving, combinations of different motions, etc.) can also be used.

[0060] Refer to Figure 6A , 6B , 6C and Figures 8 - 16, the drilling machine 60 further includes a clamp device 130 for assisting in forming and / or disconnecting joints between drill pipes 32. The clamp device 130 is mounted on the drilling machine frame 70, adjacent to the base end portion 72 of the drilling machine frame 70. The clamp device 130 is shown to include a first rod clamp 132 and a second rod clamp 134. In one example, the first rod clamp 132 is a non-translatable and non-pivotable clamp, while the second rod clamp 134 is both translatable and pivotable. The first rod clamp 132 is positioned closer to the base end portion 72 of the frame 70 than the second rod clamp 134. Thus, due to the tilting of the frame during typical use of the drilling machine, the first rod clamp 132 is positioned lower and closer to the starting point than the second rod clamp 134. The first rod clamp 132 can be referred to as a low-hole clamp or a lower-hole clamp, and the second rod clamp 134 can be referred to as a high-hole clamp or an upper-hole clamp. The clamp device 130 further includes a first rod guide / support 160 and a second rod guide / support 162, which respectively correspond to the first rod clamp 132 and the second rod clamp 134. The rod guides / supports 160, 162 are used to self-align the drill pipes within the clamps 132, 134 such that the central axis of the drill pipes is aligned with the central clamping axis of the clamps 132, 134. The clamps 132, 134 are positioned between the rod guides / supports 160, 162. Due to the tilting of the frame during typical use of the drilling machine, the first guide / support 160 is positioned lower and closer to the starting point than the second guide / support 162. Therefore, the first rod guide / support 160 can be referred to as a low-hole guide / support or a lower-hole guide / support, and the second rod guide / support 162 can be referred to as a high-hole guide / support or an upper-hole guide / support. The first guide / support 160 is positioned between the first clamp 132 and the base end portion 72 of the frame and / or the starting point of the hole. The second guide / support 162 is positioned between the second clamp 134 and the rotary drive 80, and when the second clamp 134 is translated along the drive axis 84, the second guide / support 162 is carried with the second clamp 134. The second guide / support 162 does not pivot with the second clamp 134. The clamp device 130 further includes a joint thread lubricant dispenser 166, which is carried with the second rod clamp 134 when the second rod clamp 134 is translated along the drive axis 84. In one example, the lubricant dispenser 166 is mounted on the upper-hole side of the second guide / support 162 by a bracket 168. The lubricant dispenser 166 is configured to dispense lubricant into the rod coupler 82 of the rotary drive 80. Preferably, lubricant is dispensed into the rod coupler through the dispenser 166 each time before the rod coupler is threadedly connected to the next drill pipe.

[0061] Refer to Figure 6A and 6B, the first clamp 132 and the second clamp 134 are positioned along the drive axis 84. The second rod clamp 134 is located between the first rod clamp 132 and the rotary drive 80. The second rod clamp is capable of moving (e.g., translating) relative to the first rod clamp 132 along the drive axis 84 between a first axial position (see Figure 6A ) and a second axial position (see Figure 6B ). When the second rod clamp 134 is in the first axial position, the second rod clamp 134 is close to the first rod clamp 132 and is offset from the rod storage structure 76 and the rod transfer path such that the second rod clamp 134 does not intersect the rod transfer path and does not form an obstacle to prevent the drill pipe from moving between the rod storage structure 76 and the drive axis 84 through the rod handling device 110. Thus, when the second rod clamp 134 is in the first axial position, the second rod clamp 134 does not impede or obstruct the ability to linearly move the rod from the drive axis 84 to the rod storage structure 76 or from the rod storage position 76 to the drive axis 84. When the second rod clamp 134 is in the second axial position, the second rod clamp 134 intersects the rod transfer path and coincides or axially overlaps with the rod loading / unloading area of the rod storage structure. Thus, when the second rod clamp 134 is in the second axial position, the second rod clamp impedes the ability to linearly move the rod between the bottom of the rod storage structure 76 and the drive axis 84. In other words, when the second rod clamp 134 is in the second axial position, the second rod clamp 134 impedes or obstructs the ability to linearly move the rod from the drive axis 84 to the rod storage structure 76 and from the rod storage position 76 to the drive axis 84.

[0062] In one example, the first rod clamp 132 is not mounted to pivot about the drive axis 84 relative to the frame 70 and is not configured to slide or translate along the drive axis 84 relative to the frame 70. Thus, the first rod clamp 132 can be referred to as a fixed clamp. In contrast, the second rod clamp is configured to pivot about the drive axis 84 relative to the frame 70 and the first rod clamp 132 and is also configured to slide along the drive axis 84 relative to the frame and the first rod clamp 132.

[0063] Referring to Figure 8 , the clamp device 130 includes a bottom plate 170, and the bottom plate 170 is mounted to the frame 70 adjacent to the base end portion 72 of the frame 70. A linear motion bearing 172 (e.g., a track, a rod, a track, a guide, etc.) is mounted on the bottom plate 170 to guide the movement of the second rod clamp 134 between the first axial position and the second axial position. The second rod clamp 134 includes an outer frame 174 mounted on the linear motion bearing 172 and configured to slide back and forth along the linear motion bearing 172. The second rod guide / support 162 is mounted on the upper hole side of the outer frame 174. Such as a hydraulic cylinder 173 (see Figure 14) The actuator is used to move the second rod clamp 134 along the linear motion bearing 172 between a first axial position and a second axial position. The hydraulic cylinder 173 includes one end attached to the base plate 170 and the opposite end attached to the outer frame 174 of the second rod clamp 134.

[0064] The second rod clamp 134 further includes an inner frame 176, and the inner frame 176 is pivotally mounted within the outer frame 174 to allow the second rod clamp 134 to pivot about the drive axis 84 between a first pivot position and a second pivot position. A rotational motion bearing centered on the drive axis 84 may be provided between the inner frame 176 and the outer frame 174 to allow the inner frame 176 to pivot relative to the outer frame 174. The clamp jaws 178, 180 (see Figure 16 ) are mounted within and carried by the inner frame 176. The clamp jaws 178, 180 include opposing portions 178a, 180a, and the opposing portions 178a, 180a include opposing dies 178b, 180b. The jaws 178, 180 are sized to clamp and hold an enlarged diameter portion of the drill pipe 32. The dies 178b, 180b may include clamping sides, and each clamping side may have a tapered, generally concave groove shape 182 for receiving the enlarged diameter portion of the drill pipe 32. The clamping sides may include teeth. The jaw 178 is depicted as a fixed jaw fixed relative to the inner frame 176, and the jaw 180 is depicted as a movable jaw linearly movable relative to the inner frame 176. In other examples, both jaws may be movable or more than two jaws may be provided. By an actuator such as a hydraulic cylinder 184 mounted to and carried by the inner frame 176, the jaw 180 may be linearly moved relative to the jaw 178. The cylinder 184 may have a cylindrical portion coupled to the inner frame 176 and a piston rod coupled to the jaw 180. By retracting the cylinder 184, the second rod clamp 134 may be moved to an open position at which the rod may be axially inserted therein. In the open position, the second rod clamp 134 defines a lateral dimension interval 191 between the opposing portions 178a, 180a, and the lateral dimension interval 191 is greater than the enlarged end diameter of the drill pipe. When the cylinder 184 extends, the jaw 180 moves relative to the jaw 178, causing the interval 191 between the opposing portions 178a, 180a of the jaws 178, 180 to decrease. In this way, the second rod clamp 134 moves toward a closed position at which the opposing portions 178a, 180a engage and hold the drill pipe, and the drill pipe is compressed between the opposing portions 178a, 180a. This clamping action prevents the drill pipe from rotating relative to the second rod clamp 134 when forming and disconnecting the threaded joint. At least when the second rod clamp 134 is in the closed position, the opposing portions 178a, 180a define a centered clamp axis 193, and the centered clamp axis 193 is preferably coaxially aligned with the drive axis 84.

[0065] An actuator, such as hydraulic cylinder 186, is used to pivot the second rod clamp 134 relative to the frame 70 and the outer frame 174. The cylinder 186 may include a cylinder portion 188 coupled to the outer frame 174 and a piston rod 190 coupled to the inner frame 176. The cylinder 186 is configured to pivot the second clamp 134 about the drive axis 84 between a first position (see Figure 9A ) and a second position (see Figure 9B ). The second rod clamp 134 pivots relative to the first rod clamp 132 from the first position to the second position to break the connection between two drill pipes. Thus, the first position may be referred to as the original pivot position, and the second position may be referred to as the connection break pivot position. The jaws 178, 180 and the inner frame 176 define an open side 300 of the second rod clamp 134. When the second rod clamp 134 is in the original pivot position, the open side 300 faces upward. Thus, the second rod clamp 134 is a top-opening clamp.

[0066] The first rod clamp 132 includes an outer frame 274 fixed relative to the base plate 170. The first rod clamp 132 also includes an inner frame 276 fixed within the outer frame 274. The clamp jaws 278, 280 (see Figure 15 ) are mounted in the inner frame 276. The clamp jaws 278, 280 include opposing portions 278a, 280a, and the opposing portions 278a, 280a include opposing dies 278b, 280b. The jaws 278, 280 may be sized to grip and clamp an enlarged diameter portion of the drill pipe 32 and may have the same structure and operate in substantially the same manner as described for the jaws 178, 180 to provide gripping. The jaw 278 is depicted as a fixed jaw fixed relative to the inner frame 276, and the jaw 280 is depicted as a movable jaw linearly movable relative to the inner frame 276. In other examples, both jaws may be movable or more than two jaws may be provided. By an actuator such as a hydraulic cylinder 284 mounted to the inner frame 276, the jaw 280 may be linearly moved relative to the jaw 278. Actuation of the cylinder 284 may open the first rod clamp 132 such that the enlarged diameter portion of the drill pipe may be inserted therein, and may close the rod clamp 132 on the drill pipe to grip the rod and prevent the rod from rotating relative to the clamp 132 when forming or breaking a threaded connection. In the open position, the clamp 134 defines a lateral dimension interval 291 between the opposing portions 278a, 280a, and the lateral dimension interval 291 is greater than the enlarged end diameter of the drill pipe. At least when the first rod clamp 132 is in the closed position, the opposing portions 278a, 280a define a centering clamp axis 293, and the center clamp axis 293 is preferably coaxially aligned with the drive axis 84.

[0067] To disconnect the joint between two drill pipes 32a, 32b, the joint is positioned to have a seam between the first pipe clamp 132 and the second pipe clamp 134, while the second pipe clamp 134 is in a first axial position along the drive axis 84 and is also at a first pivot position (i.e., the in-situ pivot position) about the drive axis. By visual inspection through the top open side of the clamp, the correct positioning in the joint can be easily determined visually. By properly positioning the joint between the first pipe clamp 132 and the second pipe clamp 134, the first pipe clamp 132 and the second pipe clamp 134 are clamped onto their corresponding drill pipes, and the second pipe clamp 134 is pivoted from the first pivot position to the second pivot position to disconnect the joint. Once the joint is disconnected, the second pipe clamp 134 can be opened, and the rotary drive 80 can reverse-rotate the pipe coupler 82 to completely loosen the joint. Once the joint is loosened, the rotary drive 80 moves upward along the track 102 to pull the drill pipe into alignment with the pipe loading / unloading area 117 of the pipe storage structure 76. As the rotary drive 80 moves upward along the track 102, the second pipe clamp 134 is simultaneously moved upward along the track from the first axial position to the second axial position by the hydraulic cylinder 173. Thus, the second pipe clamp 134 follows the movement of the rotary drive 80. When the drill pipe is aligned with the pipe loading / unloading area 117 of the pipe storage structure, the pipe handling device 110 extends such that the pipe is received in the pipe receiver 116. Then the second pipe clamp 134 is clamped, and the rotary drive 80 reverse-rotates the pipe coupler 82 to loosen the pipe coupler 82 from the upper end of the pipe. Then the second pipe clamp 134 is opened and lowered to the first axial position such that the second pipe clamp does not obstruct the linear movement of the pipe from the drive axis 84 to the loading / unloading area 117 along the pipe transfer path. Then the pipe handling device 110 is retracted to move the pipe from the drive axis 84 through the pipe loading / unloading area 117 to a position below the column of the pipe storage structure 76. Then the lifting device 112 is used to push the pipe upward into the pipe storage structure, and the rotary drive 80 moves downward along the track to connect with the next drill pipe pulled back from the hole. Once the next drill pipe is pulled back, the above process can be repeated.

[0068] To form a connection between two drill pipes, instead of using the second rod clamp 134, only the first rod clamp 132 and the rotary drive 80 are used. To form the connection, the first rod clamp 132 grips the upper hole end of the uppermost rod in the drill string and the second rod clamp 134 is opened. Then the rod is linearly transferred from the loading / unloading area 117 of the rod storage structure 76 to a position coaxially aligned with the rotary drive 80. Then, the rotary drive 80 is slowly advanced downward along the track 102 while the rod coupler 82 is rotated to apply the make-up torque to the threaded connection between the upper end of the drill pipe and the rod coupler 82 and also to apply the make-up torque to the connection between the lower end of the drill pipe and the upper end of the drill pipe gripped by the first rod clamp 132. Once the connection is made up, the first rod clamp 132 is opened and the rod handling device 110 is retracted so that the made-up section of the drill pipe is ready to be pushed into the ground by the rotary drive 80.

[0069] The first rod guide / support 160 and the second rod guide / support 162 of the clamp device 130 are passive, non-active components that function to self-align the enlarged ends 38a, 40a of two drill pipes 32a, 32b that need to be joined together at a threaded connection. The first rod guide / support 160 is positioned to engage the drill pipe and self-align the drill pipe before clamping, and the drill pipe enters the rod clamp device from the lower hole direction. The second rod guide / support 162 is positioned to engage the drill pipe and self-align the drill pipe before clamping, and the drill pipe enters the rod clamp device from the upper hole direction. The rod guides / supports 160, 162 can be configured to align the enlarged ends 38a, 40a relative to the center clamp axes 193, 293, and the center clamp axes 193, 293 are preferably coaxial with the drive axis 84 of the rotary drive 80. In one example, the rod guides / supports 160 / 162 are configured to align the enlarged ends 38a, 40a within 0.25 inches or 0.125 inches of the center clamp axes 193, 293. In certain examples, the first rod guide / support 160 is fixed to the lowermost hole wall of the rod clamp device 130, and the second rod guide / support is fixed to the uppermost hole wall of the rod clamp device 130. In certain examples, the first rod guide / support 160 is attached to the lower hole wall of the outer frame 174 of the first rod clamp 130, and the second rod guide / support 160 is attached to the upper hole wall of the outer frame 174 of the second rod clamp 134. In certain examples, the first rod guide / support 160 and the second rod guide / support 162 correspondingly define an inner lateral dimension (e.g., inner diameter), and the inner lateral dimension is smaller than the lateral dimension intervals 191, 291 of the clamps 130, 132 when the clamps 130, 132 are in the open position. In certain examples, the rod guide / support defines an inner lateral dimension (e.g., inner diameter) that is 0.25 inches or less larger than the rated outer diameter that the drilling machine defined by the enlarged end of the drill pipe is sized to accommodate, or is larger than the rated outer diameter by a dimension in the range of 0.1 inch to 0.25 inches. In certain examples, the first rod guide / support is located below the rod clamp device 130 and the second rod guide / support is located above the rod clamp device 130. In certain examples, the first rod guide / support is located below the rod clamp device 130 and has a tapered inlet portion that faces the lower hole direction, and the second rod guide / support is located above the rod clamp device 130 and has a tapered inlet portion that faces the upper hole direction. In certain examples, the tapered inlet line corresponds to an inner opening having a lateral dimension (e.g., diameter), and the size of the inner opening decreases when the inner opening extends toward the rod clamp device 130. In certain examples, the first rod guide / support 160 and the second rod guide / support 162 are rings.In some examples, the first rod guide / support 160 and the second rod guide / support 162 define an inner guide opening that is circular in shape and centered on the central clamp axes 193, 293, and the drive axis 84. In some examples, the first guide / support 160 and the second guide / support 162 are spaced apart by an interval less than or equal to the length L of the enlarged diameter section of the rod joint between the two rods, and the rod joint is sized to be compatible with the drilling machine. In some examples, the rod guide / support may be referred to as a rod alignment or rod centering member or component. In some examples, the rod alignment member or rod centering member may include an aligned centering opening having a circular cross-sectional shape. In other examples, the rod guide / support may be referred to as a rod centering ring or a rod alignment ring.

[0070] It should be understood that the rod guides / supports 160, 162 provide mechanical contact with the enlarged end of the drill pipe to pre-align the central axis of the drill pipe with the central axes of the clamps 132, 134 as needed before the drill pipe is clamped by the clamps 132, 134. When the enlarged end of the drill pipe is inserted into one of the rod guides / supports 160, 162, if the enlarged end is not aligned with the drive axis 84 and the clamp axes 193, 293, the enlarged end contacts the corresponding rod guide / support 160, 162 and is moved to a central position substantially aligned with the axes 84, 193, 293 by this contact. This occurs before the drill pipe is clamped by any one of the clamps 132, 134. Thus, since the rod is pre-aligned, during the clamping process, the opposing jaws of the clamps 132, 134 do not need to move the rod to the central position by contacting the angled groove portions of the jaws. This reduces wear. Preferably, the spacing between the guides / supports 160, 162 is less than or equal to the length L of the enlarged diameter section of the rod joint between two rods, and the rod joint is sized to be compatible with the drilling machine. This ensures that when the seam of the joint is positioned between the clamps 132, 134 of the clamp device 130, the enlarged end of at least one of the two rods is within one of the guides / supports 160, 162 and is supported in central alignment as needed. If the spacing is larger, the smaller diameter intermediate portion of one or both rods may be located within the corresponding guides / supports 160, 162, such that the rod can drop by gravity and thus not be aligned with the clamp axes 193, 293. In one example, the spacing from the midpoint of the clamps 132, 134 to the upper rod guide 162 is less than or equal to the length of the enlarged diameter portion 140a (i.e., the length of the longer enlarged diameter portion of the drill pipe), and the spacing from the midpoint of the clamps 132, 134 to the lower rod guide 160 is also less than or equal to the length of the enlarged diameter portion 140a. In one example, the spacing from the midpoint of the clamps 132, 134 to the upper rod guide 162 is equal to the spacing from the midpoint of the clamps 132, 134 to the lower rod guide 160. In other examples, the spacing from the midpoint of the clamps 132, 134 to the upper rod guide 162 may be different from (e.g., greater than or less than) the spacing from the midpoint of the clamps 132, 134 to the lower rod guide 160.

[0071] It should be understood that aspects of the rod guiding system disclosed herein are applicable to drill pipes having enlarged ends 38a, 40a of different lengths. When the joint 50 is correctly positioned within the clamping device 130, the outer seam of the joint lies between the clamps 132, 134. Since the enlarged end 38a of the joint 50 is shorter, the corresponding shoulder of the enlarged end 38a is positioned upwardly of the hole relative to the lower rod guide 160. However, at the same time, the enlarged end 40a is positioned within the rod guide 162 to provide pre-alignment of the central longitudinal axis of the joint 50 and the axes 193, 293 of the clamps 132, 134 prior to clamping of one or both of the clamps 132, 134. This is particularly useful during a pull-back operation in the absence of the upper rod guide 162. When the seam of the joint 50 lies between the clamps 132, 134, the positioning of the upper hole of the lower guide 160 of the shoulder of the enlarged end section 38a will allow the joint 50 to drop by gravity prior to clamping of the clamps 132, 134 without being aligned relative to the clamps 132, 134. In this case, the upper rod guide 162 provides a centering function for the central axis of the joint, which extends longitudinally relative to the central axes of the clamps 132, 134 through the enlarged joint length L. The inclusion of both the upper guide 160 and the lower guide 162 allows the system to be easily used regardless of whether the drilling machine uses a drill string in which each drill pipe has the enlarged end 38a oriented upwardly of the hole and the enlarged end 40a oriented downwardly of the hole (as shown), or alternatively, the enlarged end 38a is oriented downwardly of the hole and the enlarged end 40a is oriented upwardly of the hole. Moreover, the use of the guides 160, 162 allows clamps 132, 134 having relatively wide jaws to be used to enhance the clamping of the drill pipe while providing pre-alignment of the enlarged ends of the drill pipe within the clamps 132, 134. Additionally, providing the rod guide 162 carried by the upper clamp 134 allows the guide 162 to maintain or provide centering of the end of the drill pipe when the clamp 134 is opened and moved to a second (e.g., upper) axial position. For example, during a pull-back operation following disconnection of the joint between two drill pipes, the clamp 134 is opened, the rotary drive 80 is used to fully disengage the joint, and the uncoupled drill pipe is moved upwardly along the track 102 to align with the rod storage structure 76. When the clamp 132 is in the second axial position, in the presence of the upper guide 162, the clamp 132 can also be axially moved to ensure centering of the rod relative to the clamp 132. In this way, when the clamp 132 is closed again, centering of the rod relative to the clamp 132 is ensured, thereby preventing rotation of the rod when clamping on the rod to disconnect the connection between the rod and the rod coupler 82 of the rotary drive 80 via rotation of the rod coupler 82.

[0072] The lubricant dispenser 166 of the drilling machine 60 is configured to dispense lubricant into the rod coupler 82 of the rotary drive 80. In one example, the dispenser 166 is oriented at least partially upwardly toward the bore direction and is optionally mounted at the uppermost bore wall of the rod clamping device 130. In one example, the rod coupler 82 has a recessed threaded interface that connects with the internal thread 81, and the dispenser 166 is oriented to dispense lubricant (e.g., grease) into the interior of the recessed threaded interface onto the internal thread 81. In one example, the dispenser 166 is positioned to dispense joint lubricant along a dispensing axis 167 (see Figure 11 ), and the dispensing axis 167 is oriented at an inclined angle relative to the drive axis 84. In one example, the inclined angle A of the dispensing axis 167 is in the range of 20 degrees to 70 degrees relative to the drive axis. In another example, the inclined angle of the dispensing axis is in the range of 30 degrees to 60 degrees relative to the drive axis. In another example, the joint lubricant dispenser is carried by the translatable clamp 134 when the translatable clamp 134 moves between a first axial position and a second axial position. In some examples, the dispenser 166 is a nozzle, nozzle tip, injector, or similar structure. In some examples, the dispenser 166 receives lubricant (e.g., grease) from a reservoir and includes a pressure source (e.g., a pump) for transporting the lubricant from the reservoir to the dispenser 166 through a tube, hose, conduit, or other means. In some examples, an actuator such as a switch, button, etc. can be manually engaged by an operator to cause the dispenser to dispense a certain amount of lubricant.

[0073] In some examples, the drilling machine 60 includes only a single lubricant dispenser 166. In some examples, the lubricant is not directly dispensed onto the threads of the rod, but only onto the threads of the rod coupler of the rotary drive 80 and is transferred to the threads of the rod by contact with the rod coupler. In some examples, the lubricant is applied to the rod coupler during drilling and pullback operations. In some examples, the lubricant is applied to the rod coupler at a location near the clamp device close to the base of the track as the rotary drive moves along the track. In some examples, during the drilling operation, as the rotary drive 80 moves from the lower hole position on the track to the upper hole position on the track, the lubricant is applied to the rod coupler when the rotary drive 80 stops at the lubrication station. The upper hole position on the track is the position where the rod coupler can be connected to another rod to be added to the drill string. In some examples, during the pullback operation, as the rotary drive 80 moves from the upper hole position on the track to the lower hole position on the track, the lubricant is applied to the rod coupler when the rotary drive 80 stops at the lubrication station. The lower hole position on the track is the position where the rod coupler can be connected to the uppermost rod in the drill string, which will be removed from the ground and disconnected from the drill string. In one example, the system includes a movable lubricant dispenser. In one example, the system includes a lubricant dispenser capable of moving along the drive axis 84. In one example, the system includes a lubricant dispenser movable with the clamp.

[0074] Figures 18 - 25 Schematically depicts Figure 4 a series of operating steps of the machine, showing adding a drill rod to the drill string during a drilling operation to extend the drill string. In Figure 18 , the drill rod 32a has just been drilled into the ground and the rod coupler 82 of the rotary drive 80 is connected to the upper end of the drill rod 32a. In this state, the rotary drive 80 is located at the bottom of the track 102, adjacent to the rod clamp device 130, both rod clamps 132, 134 are open, and the upper clamp 134 is in a first axial position, directly adjacent to the lower clamp 132. In Figure 19 , the lower clamp 132 is shown closing on the upper end of the drill rod 32b to prevent the drill rod 32a from rotating as the joint between the upper end of the drill rod 32a and the rod coupler 82 is disconnected. In Figure 20 , the rotary drive 80 reversely rotates the rod coupler 82 and moves slightly upward along the drive axis 84 along the track 102 to disconnect and loosen the joint with the upper end of the drill rod 32a. After the joint is loosened, the rotary drive is advanced upward along the track 102 along the drive axis 84 and stops at the lubrication station where the recessed threaded interface of the rod coupler 82 intersects the dispensing axis of the lubricant dispenser 166. As Figure 21As shown, the actuation lubricant dispenser is actuated to dispense a quantity of grease into the rod coupler 82. Next, the rotary drive 80 is moved completely upward along the track 102 along the axis until the top position of the track, at which the rod coupler 82 does not interfere with the rod handling device 110 moving the new rod 32b from the rod storage structure 76 to the drive axis 84 for coaxial alignment with the rod coupler 82 (see Figure 22 ). Thereafter, the shuttle arm 114 extends to convey the drill pipe 32a from the rod storage position 76 to the drive axis 84 along the linear rod conveyance path (see Figure 23 ). Next, the rotary drive 80 is slowly moved downward along the track 102 while rotating the rod coupler 82 to engage the threaded joint between the rod coupler 82 and the upper end of the drill pipe 32b and apply a tightening torque to the threaded joint, and also apply a tightening torque to the threaded joint between the lower end of the drill pipe 32a and the upper end of the drill pipe 32a (see Figure 24 ). Then the shuttle arm 114 is retracted (see Figure 25 ) and the lower clamp 132 is opened (see Figure 25 ). Then the rotary drive 80 can be advanced downward along the track 102 while rotating the rod coupler 82 to drive the drill pipe 32b into the ground. Once the drill pipe 32b is in the ground, the drilling machine is again in the Figure 18 configuration, and this sequence can be repeated for subsequent drill pipes until the drill string reaches the termination point.

[0075] Figures 26 - 37 Schematically depicts a series of operating steps of the Figure 4 machine, showing the drill pipe being withdrawn from the drill string during the pull-back operation to contract the drill string. In Figure 26 , the drill pipe 32b has been pulled out of the ground. In this state, the rotary drive 80 is near the top of the frame 70, the upper clamp 134 is in the lower axial position and pivoted to the original position, both clamps 132, 134 are open, the rod coupler 82 is coupled to the upper end of the drill pipe 32b, the lower end of the drill pipe 32b is coupled to the upper end of the drill pipe 32a, the shuttle arm 114 is retracted, and the rods in the rod storage structure are lifted. In Figure 27 , the joint between the drill pipes 32a, 32b is aligned between the rod clamps 132, 134, the upper clamp 134 has closed on the enlarged lower end of the drill pipe 32a, and the lower clamp 132 has closed on the enlarged upper part of the drill pipe 32b. The configuration of the top openings of the clamps 132, 134 facilitates proper axial alignment of the joint between the clamps 132, 134. In Figure 28 , the upper clamp 134 is rotated in the reverse direction to the joint-disconnect pivot position, thereby disconnecting the joint between the rods 32b, 32a. In Figure 29In this process, the upper clamp 134 is opened and moved back to its original pivot position, and the rotary drive 80 rotates the rod coupler 82 in the reverse direction and slowly moves upward along the track 102 to completely disengage the connection between the drill pipes 32b and 32a. Once the connection is disengaged, the rotary drive 80 moves upward along the track 102 to a position where the drill pipe 32b is aligned with the loading / unloading area 117 of the rod storage structure 76, and the upper clamp 134 follows the movement of the rotary drive 80 and simultaneously moves to the second / upper axial position (see Figure 30 ). At the second / upper axial position, the lower end portion of the drill pipe 32b is axially received in the upper clamp 134. Next, the shuttle arm 114 extends to receive the drill pipe, and the upper clamp 134 clamps on the lower end portion of the drill pipe 32a (see Figure 31 ). The rod coupler 82 rotates in the reverse direction and slowly moves upward along the track 102 (see Figure 32 ) to disconnect and disengage the connection between the rod coupler and the upper end portion of the drill pipe 32b. The rotary drive 80 moves upward along the track 102 until the rod coupler 82 passes through the upper end portion of the drill pipe 32b (see Figure 33 ). Then the upper clamp 134 is opened and moved to the lower axial position, at which the upper clamp 134 does not obstruct the movement of the drill pipe back to the rod storage structure 76 (see Figure 34 ). The rods in the rod storage structure 76 are lowered by the elevator 112, the shuttle arm 114 retracts to move the rod 32b under the rod storage structure, and the elevator raises to push the rod 32b into the column of the rod storage structure 76 (see Figure 35 ). Then, the rotary drive 80 moves downward along the track 102 to the lubrication station, where the dispensing axis of the lubricant dispenser 166 intersects the rod coupler 82. Then grease is dispensed into the rod coupler 82 (see Figure 36 ). After lubrication, the rotary drive 80 further moves downward along the track, and the rod coupler 82 rotates to tighten the upper end portion of the drill pipe 32a with the connection torque, and the upper end portion is clamped in the lower clamp 132 (see Figure 37 ). The lower clamp 132 is released and the rotary drive 80 moves upward along the track 102 while the rod coupler 82 rotates to pull back the rod 32a and return to the state of Figure 26 . Then the process steps are repeated for each subsequent drill pipe until the drill string is completely withdrawn from the ground.

[0076] As used herein, actuators can include pneumatic and hydraulic cylinders, screw drives, electric motors, hydraulic motors, and pneumatic motors, and similar devices. As used herein, terms such as upper, lower, upper bore, and lower bore are relative terms that have been used to assist in describing the relative positioning of certain portions of components. For components above the ground, the upper portion of such a component is positioned further away from the starting point 24 of the drilling machine compared to a relatively lower portion. Similarly, for components located above the ground, the upper bore portion of the component is positioned at a location further away from the starting point of the drilling machine compared to the lower bore portion of the component.

[0077] Example

[0078] Illustrative examples of the underground drilling machines disclosed herein are provided below. Embodiments of the underground drilling machines can include any one or more of the examples described below, as well as any combination.

[0079] Example 1 is an underground drilling machine that includes a rotary drive having a rotatably driven rod coupler adapted to be connected to an end of a drill rod. The rod coupler is capable of rotating about a drive axis. The rotary drive is mounted to move back and forth along the drive axis. The underground drilling machine further includes a drill rod storage structure positioned alongside the drive axis and rod handling means for conveying the drill rod back and forth between the drive axis and the rod storage structure along a rod conveyance path. The underground drilling machine further includes a first rod clamp and a second rod clamp positioned along the drive axis. The second rod clamp is positioned between the first rod clamp and the rotary drive. The second rod clamp can move along the drive axis relative to the first rod clamp between a first axial position and a second axial position. When in the first axial position, the second rod clamp is offset from the rod conveyance path such that the second rod clamp does not prevent the drill rod from moving through the rod handling means between the rod storage structure and the drive axis. When in the second axial position, the second rod clamp intersects the rod conveyance path and is thus positioned to impede the movement of the drill rod through the rod handling means between the rod storage structure and the drive axis. The second rod clamp can pivotally move about the drive axis between a first pivotal position and a second pivotal position.

[0080] In Example 2, the subject matter of Example 1 is further configured such that in order to disconnect the connection between two drill pipes, the connection is located between a first pipe clamp and a second pipe clamp, and the second pipe clamp is in a first axial position along the drive axis and is also in a first pivot position around the drive axis. By positioning the connection between the first pipe clamp and the second pipe clamp, clamping the first pipe clamp and the second pipe clamp on their corresponding drill pipes, and pivoting the second pipe clamp from the first pivot position to the second pivot position to disconnect the connection. The two drill pipes include an upper hole drill pipe and a lower hole drill pipe. The upper hole drill pipe includes an upper hole end coupled to a pipe coupler that is rotationally driven and a lower hole end coupled to the lower hole end of the lower hole drill pipe at the connection. The first pipe clamp clamps on the upper hole end of the lower hole drill pipe, and the second clamp clamps on the lower hole end of the upper hole drill pipe.

[0081] In Example 3, the subject matter of Example 2 is further configured such that once the connection is disconnected, the second pipe clamp releases the clamping on the upper hole drill pipe and the rotary drive is used to completely loosen the connection between the upper hole drill pipe and the lower hole drill pipe, while the first clamp clamps on the upper hole end of the lower hole drill pipe.

[0082] In Example 4, the subject matter of Example 3 is further configured such that once the connection is completely loosened, the rotary drive axially moves in the upper hole direction along the drive axis to pull the upper hole drill pipe to a pipe loading position aligned with the drill pipe storage structure. The second clamp moves to a second axial position to support the lower hole end of the upper hole drill pipe.

[0083] In Example 5, the subject matter of Example 4 is further configured such that when the upper hole drill pipe moves in the upper hole direction to align with the drill pipe storage structure, the second clamp simultaneously moves from the first axial position to the second axial position as the upper hole of the rotary drive moves.

[0084] In Example 6, the subject matter of Example 5 is further configured such that when the second clamp is in the second axial position, the second clamp clamps on the lower hole end of the upper hole drill pipe and the rotary drive rotates in the reverse direction to release the pipe coupler from the upper hole end of the upper hole drill pipe.

[0085] In Example 7, the subject matter of Example 6 is further configured such that once the upper hole drill pipe has axially moved to align with the drill pipe storage structure, the pipe handling device is extended to engage and support the upper hole drill pipe. After the upper hole end of the upper hole drill pipe is released from the pipe coupler of the rotary drive, the second clamp releases the clamping. When the lower hole end of the upper hole drill pipe has been released from the second clamp and the rotary drive has released the upper hole end of the upper hole drill pipe, the pipe handling device supports the upper hole drill pipe. When the upper hole drill pipe has been released from the second clamp and the rotary drive has released the upper hole end of the upper hole drill pipe, the pipe handling device moves the upper hole drill pipe to the pipe storage structure. Before the pipe handling device moves the upper hole drill pipe to the pipe storage structure, the second clamp moves to the first axial position.

[0086] In Example 8, the subject matter of Example 1 further includes an upper hole rod centering member corresponding to the second clamp and a lower hole rod centering member corresponding to the first clamp. The first clamp and the second clamp are located between the upper hole centering member and the lower hole centering member. The upper hole centering member and the lower hole centering member are configured to center the drill rod relative to the first clamp and the second clamp when the first clamp and the second clamp are opened.

[0087] In Example 9, the subject matter of Example 8 is further configured such that when the second clamp moves between a first axial position and a second axial position, the upper hole rod centering member is carried by the second clamp.

[0088] In Example 10, the subject matter of Example 8 is further configured such that the upper hole rod centering member has an upper hole surface with a tapered introduction portion. The lower hole rod centering member includes a lower hole surface with a tapered introduction portion.

[0089] In Example 11, the subject matter of Example 8 is further configured such that the upper hole rod centering member and the lower hole rod centering member define a rod centering opening having a diameter that is less than the lateral dimension interval defined between the opposing jaws of the first clamp and the second clamp when the first clamp and the second clamp are opened.

[0090] In Example 12, the subject matter of Example 11 is further configured such that the upper hole rod centering member and the lower hole rod centering member include a rod centering ring that is centered on the drive axis. The first clamp and the second clamp have a clamp gripping axis that is coaxial with the drive axis.

[0091] In Example 13, the subject matter of Example 8 is further configured such that the drill rod includes an enlarged end portion having an enlarged outer diameter compared to the middle portion of the drill rod, wherein when two drill rod ends are joined end-to-end at a joint, the joined enlarged end portions at the joint define a length, and wherein when the second clamp is in the first axial position, the spacing between the first centering member and the second centering member is less than or equal to the length.

[0092] In Example 14, the subject matter of Example 1 is further configured such that when the second clamp is in the second axial position, the second clamp will impede the movement of the drill rod from the rod storage structure to the drive axis through the rod handling device.

[0093] In Example 15, the subject matter of Example 1 is further configured such that the rod handling device does not include any clamping members that clamp the drill rod therebetween.

[0094] In Example 16, the subject matter of Example 1 is further configured such that the rod handling device includes at least one shuttle member that moves linearly between a retracted position and an extended position.

[0095] In Example 17, the subject matter of Example 16 is further constructed such that the shuttle member includes a shelf for supporting a drill pipe and at least one magnet for holding the drill pipe on the shelf.

[0096] In Example 18, the subject matter of Example 1 is further constructed such that the first clamp is positioned downwardly of the hole relative to the second clamp, and wherein the first clamp cannot move axially along the drive axis.

[0097] In Example 19, the subject matter of Example 1 further includes a joint lubricant dispenser carried by the second clamp.

[0098] In Example 20, the subject matter of Example 19 is further constructed such that the joint lubricant dispenser is positioned to dispense joint lubricant along a dispensing axis that is oriented at an inclined angle relative to the drive axis.

[0099] In Example 21, the subject matter of Example 20 is further constructed such that the inclined angle of the dispensing axis relative to the drive axis is in the range of 20 degrees to 70 degrees.

[0100] In Example 22, the subject matter of Example 20 is further constructed such that the inclined angle of the dispensing axis relative to the drive axis is in the range of 30 degrees to 60 degrees.

[0101] In Example 23, the subject matter of Example 19 is further constructed such that the rod coupler includes a recessed connection interface having an internal thread. The joint lubricant dispenser dispenses joint lubricant into the recessed connection interface.

[0102] In Example 24, the subject matter of Example 19 is further constructed such that the joint lubricant dispenser dispenses grease into the recessed connection interface.

[0103] In Example 25, the subject matter of Example 1 is further constructed such that the first clamp includes an open top side.

[0104] In Example 26, the subject matter of Example 1 is further constructed such that the open side of the second rod clamp faces upward when the second rod clamp is in the first pivot position.

[0105] Example 27 is an underground boring machine that includes a rotary drive that includes a rod coupler that is rotationally driven and that is adapted to be connected to an end of a drill rod. The rod coupler is capable of rotating about a drive axis, and the rotary drive is mounted to move back and forth along the drive axis. The rod coupler includes a recessed connection interface that includes an internal thread. The underground boring machine includes a drill rod storage structure positioned side-by-side with the drive axis. The underground boring machine includes rod handling means for transferring drill rods back and forth between the drive axis and the drill rod storage structure. The underground boring machine includes at least one rod clamp positioned along the drive axis. The underground boring machine includes a joint lubricant dispenser positioned to dispense joint lubricant into the recessed connection interface. The joint lubricant dispenser is capable of moving axially along the drive axis.

[0106] In Example 28, the subject matter of Example 27 is further constructed such that the joint lubricant dispenser is positioned to dispense joint lubricant along a dispensing axis that is oriented at an inclined angle relative to the drive axis.

[0107] In Example 29, the subject matter of Example 28 is further constructed such that the inclined angle of the dispensing axis relative to the drive axis is in the range of 20 degrees to 70 degrees.

[0108] In Example 30, the subject matter of Example 28 is further constructed such that the inclined angle of the dispensing axis relative to the drive axis is in the range of 30 degrees to 60 degrees.

[0109] In Example 31, the subject matter of Example 27 further includes a translatable clamp capable of moving along the drive axis between a first axial position and a second axial position. When the translatable clamp moves between the first axial position and the second axial position, the joint lubricant dispenser is carried by the translatable clamp.

[0110] In Example 32, the subject matter of Example 27 is further constructed such that the joint lubricant dispenser is part of a joint lubricant dispensing system for dispensing joint lubricant only into the recessed connection interface and not directly onto the threads of the drill rod.

[0111] Example 33 is an underground drilling machine that includes a rotary drive. The rotary drive includes a rod coupler that is rotationally driven and is adapted to be connected to the end of a drill rod. The rod coupler is capable of rotating about a drive axis, and the rotary drive is mounted to move back and forth along the drive axis. The underground drilling machine includes a drill rod storage structure positioned side by side with the drive axis. The underground drilling machine includes rod handling means for transferring drill rods back and forth between the drive axis and the drill rod storage structure. The underground drilling machine includes a first rod clamp positioned along the drive axis. The underground drilling machine includes a second rod clamp positioned along the drive axis. The second rod clamp is positioned between the first rod clamp and the rotary drive. The second rod clamp is pivotally movable about the drive axis between a first pivot position and a second pivot position. The underground drilling machine includes a first rod guide / support corresponding to the first clamp and a second rod guide / support corresponding to the second clamp. The first rod guide / support and the second rod guide / support are configured to center the drill rod relative to the first clamp and the second clamp when the first clamp and the second clamp are open. The first clamp and the second clamp are positioned between the first rod guide / support and the second rod guide / support.

[0112] In example 34, the subject matter of example 33 is further constructed such that the first rod guide / support includes a first tapered introduction portion facing away from the rotary drive. The second rod guide / support includes a tapered introduction portion facing the rotary drive.

[0113] In example 35, the subject matter of example 33 is further constructed such that the first rod guide / support and the second rod guide / support include guide / support rings.

[0114] In example 36, the subject matter of example 35 is further constructed such that the guide / support rings are centered on the drive axis. The first clamp and the second clamp have a clamp gripping axis coaxial with the drive axis.

[0115] In example 37, the subject matter of example 33 is further constructed such that the drill rod includes an enlarged end portion having an enlarged outer diameter compared to the middle portion of the drill rod. When two drill rods are end-to-end coupled at a joint, the coupled enlarged end portions at the joint define a certain length. The spacing between the first rod guide / support and the second rod guide / support is less than or equal to this length.

[0116] Example 38 is a downhole drilling machine that includes a rotary drive that includes a rotatably driven rod coupler adapted to connect to the end of a drill string. The rod coupler is capable of rotating about a drive axis, and the rotary drive is mounted to move back and forth along the drive axis. The downhole drilling machine includes a drill string storage structure positioned side-by-side with the drive axis. The downhole drilling machine includes rod handling means for transferring the drill string back and forth between the drive axis and the drill string storage structure. The downhole drilling machine includes at least one rod clamp positioned along the drive axis. The downhole drilling machine includes a joint lubricant distribution system for distributing joint lubricant only to recessed connection interfaces and not directly to the threads of the drill string.

[0117] The above-described embodiments are provided by way of example only and should not be construed as limiting the appended claims thereto. Those skilled in the art will readily recognize that various modifications and changes can be made without departing from the true spirit and scope of the following claims, not in accordance with the exemplary embodiments and the applications illustrated and described herein.

Claims

1. An underground drilling machine, comprising: a rotary drive including a rod coupler that is rotationally driven, the rod coupler being adapted to connect to the end of a drill rod, the rod coupler being capable of rotating about a drive axis, and the rotary drive being mounted to move back and forth along the drive axis; a drill rod storage structure positioned side by side with the drive axis; a rod handling device for transferring a drill rod back and forth between the drive axis and the drill rod storage structure along a rod transfer path; a first rod clamp positioned along the drive axis and having a clamping axis coaxial with the drive axis; a second rod clamp positioned along the drive axis and having a clamping axis coaxial with the drive axis, the second rod clamp being positioned between the first rod clamp and the rotary drive, the second rod clamp being movable relative to the first rod clamp along the drive axis between a first axial position and a second axial position, the first axial position being positioned such that the second rod clamp does not intersect the rod transfer path when the second rod clamp is in the first axial position, the second axial position being positioned such that the second rod clamp intersects the rod transfer path when the second rod clamp is in the second axial position, and the second rod clamp being pivotally movable about the drive axis between a first pivot position and a second pivot position; and an upper hole rod centering member and a lower hole rod centering member, the upper hole rod centering member being attached to an upper hole wall of an outer frame of the second rod clamp for moving with the second rod clamp between the first axial position and the second axial position, the lower hole rod centering member being attached to a lower hole wall of an outer frame of the first rod clamp, wherein the first rod clamp and the second rod clamp are positioned between the upper hole rod centering member and the lower hole rod centering member, and the upper hole rod centering member and the lower hole rod centering member are configured to align a drill rod with the first rod clamp and the second rod clamp while the first rod clamp and the second rod clamp are open.

2. The underground drilling machine according to claim 1, wherein in order to disconnect a joint between two drill rods, the joint is located between the first rod clamp and the second rod clamp while the second rod clamp is in the first axial position along the drive axis and is also in the first pivot position about the drive axis, wherein when the joint is located between the first rod clamp and the second rod clamp, the first rod clamp and the second rod clamp are clamped on their corresponding drill rods, and the second rod clamp pivots from the first pivot position to the second pivot position to disconnect the joint, wherein the two drill rods together define an upper hole drill rod and a lower hole drill rod, wherein the upper hole drill rod includes an upper hole end connected to the rotationally driven rod coupler and a lower hole end connected to the upper hole end of the lower hole drill rod at the joint, and wherein the first rod clamp is clamped on the upper hole end of the lower hole drill rod, and the second rod clamp is clamped on the lower hole end of the upper hole drill rod.

3. The underground drilling machine according to claim 2, wherein Once the joint is disconnected, the second rod clamp releases the clamping on the upper hole drill rod, and the rotary drive is used to completely loosen the joint between the upper hole drill rod and the lower hole drill rod, while the first rod clamp remains clamped on the upper hole end of the lower hole drill rod.

4. The underground drilling machine according to claim 3, wherein, once the joint is completely loosened, the rotary drive axially moves in the upper hole direction along the drive axis to pull the upper hole drill rod to a rod loading position aligned with the drill rod storage structure, and wherein the second rod clamp moves to a second axial position to support the lower hole end of the upper hole drill rod.

5. The underground drilling machine according to claim 4, wherein, as the upper hole drill rod moves in the upper hole direction to align with the drill rod storage structure, simultaneously with the upward movement of the rotary drive, the second rod clamp moves from the first axial position to the second axial position, wherein, when the second rod clamp is in the second axial position, the second rod clamp clamps on the lower hole end of the upper hole drill rod, and the rotary drive rotates in the reverse direction to release the rod coupler from the upper hole end of the upper hole drill rod.

6. The underground drilling machine according to claim 5, wherein, once the upper hole drill rod has axially moved to align with the drill rod storage structure, the rod manipulation device extends to engage and support the upper hole drill rod, wherein after the upper hole end of the upper hole drill rod has been released from the rod coupler of the rotary drive, the second rod clamp releases the clamping, wherein when the lower hole end of the upper hole drill rod has been released from the second rod clamp and the rotary drive has released the upper hole end of the upper hole drill rod, the rod manipulation device supports the upper hole drill rod, wherein after the upper hole drill rod has been released from the second rod clamp and the rotary drive has released the upper hole end of the upper hole drill rod, the rod manipulation device moves the upper hole drill rod to the drill rod storage structure, and wherein before the rod manipulation device moves the upper hole drill rod to the drill rod storage structure, the second rod clamp moves to the first axial position.

7. The underground drilling machine according to claim 1, wherein, the upper hole rod centering member has an upper hole surface, and the lower hole rod centering member includes a lower hole surface, and the upper hole surface and the lower hole surface have tapered introduction portions.

8. The underground drilling machine according to claim 1, wherein, the upper hole rod centering member and the lower hole rod centering member define a rod centering opening, and the diameter of the rod centering opening is smaller than the lateral dimension interval defined between the opposing jaws of the first rod clamp and the second rod clamp when the first rod clamp and the second rod clamp are opened, and wherein the upper hole rod centering member and the lower hole rod centering member include a rod centering ring centered on the drive axis and the clamping axes of the first rod clamp and the second rod clamp.

9. The underground drilling machine according to claim 1, wherein, the first rod clamp is positioned downward with respect to the second rod clamp, and the first rod clamp cannot axially move along the drive axis.

10. The underground drilling machine according to claim 1, further comprising, A joint lubricant dispenser carried by the second rod clamp, wherein the joint lubricant dispenser is positioned to dispense joint lubricant along a dispensing axis that is oriented at an inclined angle relative to the drive axis.

11. The underground drilling machine according to claim 1, wherein, the first rod clamp includes an open top side.

12. The underground drilling machine according to claim 1, wherein, when the second rod clamp is in the first pivot position, the open side of the second rod clamp faces upward.

13. The underground drilling machine according to claim 10, wherein, the inclined angle of the dispensing axis is in the range of 20 degrees to 70 degrees relative to the drive axis.

14. The underground drilling machine according to claim 10, wherein the rod coupler includes a recessed connection interface that includes an internal thread, and the joint lubricant dispenser is attached to the upper hole wall of the outer frame of the second rod clamp and is positioned to dispense joint lubricant into the recessed connection interface along the upper hole direction; and wherein the joint lubricant dispenser is part of a joint lubricant dispensing system for dispensing joint lubricant only into the recessed connection interface and not directly onto the threads of the drill pipe.

15. An underground drilling machine, comprising: a rotary drive including a rod coupler that is rotationally driven and is adapted to be connected to the end of a drill pipe, the rod coupler being capable of rotating about a drive axis, the rotary drive being mounted to move back and forth along the drive axis; a drill pipe storage structure positioned side by side with the drive axis; rod handling means for transferring drill pipes back and forth between the drive axis and the drill pipe storage structure; a first rod clamp positioned along the drive axis and having a clamping axis coaxial with the drive axis; a second rod clamp positioned along the drive axis and having a clamping axis coaxial with the drive axis, the second rod clamp being located between the first rod clamp and the rotary drive, the second rod clamp being pivotally movable about the drive axis between a first pivot position and a second pivot position; a first rod guide / support and a second rod guide / support, the first rod guide / support being attached to the lower hole wall of the outer frame of the first rod clamp, the second rod guide / support being attached to the upper hole wall of the outer frame of the second rod clamp, the first rod guide / support and the second rod guide / support being configured to align the drill pipe with the first rod clamp and the second rod clamp while the first rod clamp and the second rod clamp are open, the first rod clamp and the second rod clamp being positioned between the first rod guide / support and the second rod guide / support; wherein the first rod guide / support includes a first tapered introduction portion facing away from the rotary drive, and wherein the second rod guide / support includes a tapered introduction portion facing the rotary drive; and Wherein, the first rod guide / support and the second rod guide / support include guide / support rings, and wherein the guide / support rings are centered on the drive axis and on the clamping axes of the first rod clamp and the second rod clamp.

16. The underground drilling machine according to claim 15, wherein, the drill pipe includes an enlarged end portion having an outer diameter enlarged compared to the middle portion of the drill pipe, wherein when two drill pipe ends are joined end-to-end at a joint, the enlarged end portions joined at the joint define a length, and wherein the spacing between the first rod guide / support and the second rod guide / support is less than or equal to the length.

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