Patent Description:
The present disclosure relates to drill rigs, such as a drilling and bolting tool for forming a hole and/or inserting a bolt into a hole in a rock surface.

Drilling and bolting rigs may include an extendable frame and a drive unit movable along the frame for inserting a drill bit or bolt into a rock surface. Components of a drilling and bolting rig are typically actuated by fluid power (e.g., hydraulic power), requiring complicated fluid power systems as well as fluid conduits or hoses to be connected to the drilling and bolting rig. <CIT> describes a boom for supporting a drilling and bolting tool.

In one independent aspect, a boom for supporting a drilling and bolting tool includes a first portion including a first end, a second end, and a longitudinal axis extending between the first end and the second end; a second portion including an elongated shaft having a proximal end and a distal end, the proximal end supported by a shaft support for translational movement relative to the first portion in a direction parallel to the longitudinal axis, the distal end configured to support the drilling and bolting tool; an actuator for moving the second portion relative to the first portion in a direction parallel to the longitudinal axis; the first portion includes a cylindrical portion and a portion positioned radially outward of the cylindrical portion, the boom further including a guide track positioned within the radially outward position; and a guide member for engaging the track, the guide member positioned on one of the first portion and the second portion, the guide member extending in a radial direction and inhibiting rotation of the shaft support about the longitudinal axis, the guide member positioned within the radially outward portion.

In some aspects, the guide member includes a spherical bearing for engaging the guide track.

In some aspects, the actuator includes a hydraulic cylinder, an end of the hydraulic cylinder coupled to the guide member, wherein actuation of the hydraulic cylinder is operable to cause translational movement of the second portion relative to the first portion in the direction parallel to the longitudinal axis.

In some aspects, the radially outward has a rectangular profile , wherein the elongated shaft is positioned within the cylindrical portion.

In some aspects, a spherical bearing is positioned within the radially outward portion.

In some aspects, the boom further includes: a rotary flow distributor positioned within the first portion and in fluid communication with a fluid source; and a plurality of conduits extending between the rotary flow distributor and the distal end of the second portion, the plurality of conduits extending through the shaft support and the elongated shaft.

In some aspects, the plurality of conduits are configured to provide communication between a first end of the first portion and the drilling and bolting tool.

In some aspects, the guide member is secured to the shaft support by an interference fit.

In some aspects, the shaft support includes a slot having a wedge surface, wherein the guide member includes a wedge surface engaging the wedge surface of the slot in the interference fit, and the guide member is secured by at least one fastener passing through a portion of the shaft support.

In some aspects, the guide member is further retained within the slot of the shaft support by a retaining block positioned adjacent an end of the guide member.

In another independent aspect, a boom for supporting a drilling and bolting tool includes a first portion including a first end, a second end, and a longitudinal axis extending between the first end and the second end; a second portion including a proximal end and a distal end, the proximal end supported for translational movement relative to the first portion in a direction parallel to the longitudinal axis, the distal end configured to support the drilling and bolting tool; a support portion supporting the second portion for movement relative to the first portion; a plurality of passages extending at least between the distal end and the proximal end; and a torsion member extending between the proximal end and the distal end and transmitting torque between the proximal end and the distal end, the torsion member reducing a torque exerted on the passages.

In some aspects, the torsion member includes a tube extending between the proximal end and the distal end, wherein the plurality of passages are positioned within the tube.

In some aspects, the boom further includes: a rotary flow distributor positioned adjacent one of the proximal end and the distal end of the second portion, the rotary flow distributor including a rotatable portion and a non-rotatable portion, wherein the torsion member is secured to the non-rotatable portion.

In some aspects, the plurality of passages extend between the distal end and the first end of the first portion.

In some aspects, the boom further includes: a rotary flow distributor positioned within the first portion and in fluid communication with a fluid source, a portion of the rotary flow distributor being rotatable with the second portion, wherein the plurality of passages extend between the rotary flow distributor and the distal end of the second portion, the plurality of conduits extending through the second portion and the support portion.

In some aspects, the boom further includes: a rotary flow distributor positioned within the second portion and in fluid communication with a fluid source, a portion of the rotary flow distributor being rotatable with the second portion, wherein the plurality of passages extend between the rotary flow distributor and the first end of the first portion, the plurality of conduits extending through the second portion and the support portion.

In some aspects, the boom further includes: a pair of guide tracks extending along an inside of the first portion and engaging an outside of the support portion to inhibit rotation of the support portion relative to the first portion.

In some aspects, the pair of guide tracks are positioned on opposite sides of the support portion.

In some aspects, the boom further includes: a flow distributor secured to the distal end of the second portion, the flow distributor configured to support the drilling and bolting tool.

In some aspects, the boom further includes: an extension cylinder positioned within the first portion and receivable within the second portion, the extension cylinder including a hydraulic actuator operable to extend the distal end of the second portion away from the first portion and the hydraulic actuator.

In yet another independent aspect, a boom for supporting a drilling and bolting tool includes: a first portion including a first end, a second end, and a longitudinal axis extending between the first end and the second end; a second portion including a proximal end and a distal end, the proximal end supported for translational movement relative to the first portion in a direction parallel to the longitudinal axis, the distal end configured to support the drilling and bolting tool; and a flexible cable positioned within the second portion and coupled between the first portion and the second portion.

In some aspects, the boom further includes a cable guide supporting the flexible cable and controlling the bending of the cable as the second portion moves relative to the first portion.

In some aspects, a first end of the cable guide chain is fixed relative to the first portion and a second end of the cable guide chain is fixed relative to the second portion.

In some aspects, the cable guide chain is slidably retained within a cable guide bracket.

In some aspects, the boom further includes a support portion supporting the second portion for movement relative to the first portion.

In some aspects, at least a portion of the flexible cable is a spirally coiled cable.

Other aspects will become apparent by consideration of the detailed description and accompanying drawings.

Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. Use of "including" and "comprising" and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of "consisting of" and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof.

In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, aspects may be implemented in software (for example, stored on non-transitory computer-readable medium) executable by one or more processing units, such as a microprocessor, an application specific integrated circuits ("ASICs"), or another electronic device. As such, it should be noted that a plurality of hardware-based and software-based devices, as well as a plurality of different structural components may be utilized to implement the disclosure. For example, "controllers" described in the specification may include one or more electronic processors or processing units, one or more computer-readable medium modules, one or more input/output interfaces, and various connections (for example, a system bus) connecting the components.

<FIG> illustrate a mobile mining machine <NUM>, such as a drill jumbo or bolting machine. In the illustrated embodiment, the machine <NUM> includes a frame or chassis <NUM> supported by traction drive members <NUM> (e.g., wheels), and a support member or boom 30A coupled to the chassis <NUM>. The boom 30A supports a drilling and bolting rig, or drill tool <NUM>, for forming holes in a mine surface (e.g., a roof, a floor, or a rib or side wall - not shown) and/or installing a drill element (e.g., a bit or a bolt - not shown). In the illustrated embodiment, the drill tool <NUM> performs both drilling and bolting operations. Among other things, an installed bolt may anchor or support a safety mesh (not shown) to protect personnel against rock that may fall or become dislodged from the mine surface. In other embodiments, the drill tool <NUM> may be mounted on another type of mining machine, such as a continuous mining machine (not shown). In some embodiments, the machine may include multiple booms, each of the booms supporting a drilling and bolting rig.

Referring to <FIG>, the drill tool <NUM> includes a base frame <NUM>, a feed frame <NUM> supported for telescoping movement relative to the base frame <NUM>, and a drive unit <NUM> for driving a bit or a bolt. In the illustrated embodiment, the drive unit is a drifter that includes both rotation and percussion in driving the bit. In other embodiments, the drive unit <NUM> may include a rotation unit. The drive unit <NUM> is movable along the feed frame <NUM> and the base frame <NUM> to drive the bit or bolt into a rock surface. In some embodiments, the drill tool <NUM> may be similar to the drilling and bolting tool described in <CIT>, the entire contents of which are hereby incorporated by reference.

<FIG> and <FIG> illustrate a boom 30B according to one embodiment. The boom 30B includes an elongated housing 42B and a shaft 46B (<FIG>) supported for movement relative to the housing 42B. The housing 42B includes a first end 50B (e.g., which is coupled to a chassis of the machine <NUM>) and a second end 58B opposite the first end 50B. A housing axis <NUM> extends between the first end 50B and the second end 58B. In some embodiments, the second end 58B includes a bearing to support the shaft 46B for translational movement relative to the housing 42B. The first end 50B can be supported on a bracket or carrier <NUM> to permit pivoting about multiple axes (e.g., a first axis <NUM> and a second axis <NUM> - <FIG>), and the housing 42B can be driven by actuators <NUM> (e.g., fluid cylinders) to pivot about the axes <NUM>, <NUM>.

<FIG> illustrates a boom <NUM> according to an exemplary embodiment. The boom <NUM> includes a housing <NUM> and a shaft <NUM> supported for movement relative to the housing <NUM>. The housing <NUM> includes a first end <NUM> and a second end <NUM> opposite the first end <NUM>. A housing axis <NUM> extends between the first end <NUM> and the second end <NUM>. The first end <NUM> can be supported in a similar manner as boom 30B described above with respect to <FIG> and <FIG>.

In the illustrated embodiment, the housing <NUM> has a hollow cylindrical shape, and the shaft <NUM> is movable to extend and retract relative to the housing <NUM> in a telescoping manner. A proximal end <NUM> of the shaft <NUM> is supported within the housing <NUM>, while a distal end <NUM> is positioned beyond the second end <NUM> of the housing <NUM>. The distal end <NUM> may support a drill tool <NUM> (<FIG>), and the distal end <NUM> may be coupled to and support a combined actuator and flow distributor <NUM> (<FIG>) that in turn is coupled to and supports the drill tool <NUM>. The drill tool <NUM> is coupled to the combined actuator and flow distributor <NUM> (e.g., by a pin joint <NUM> - <FIG>), and an actuator <NUM> may pivot the drill tool <NUM> about an end of the combined actuator and flow distributor <NUM>.

As shown in <FIG> and <FIG>, the boom <NUM> includes an intermediate rotary actuator or shaft support <NUM> and a rotary flow distributor <NUM> (<FIG>). In the illustrated embodiment, the shaft support <NUM> is positioned within the housing <NUM>. The shaft support <NUM> includes a body and a bearing <NUM> engaging an inner surface of the housing <NUM>. In the illustrated embodiment, the boom <NUM> also includes a second bearing <NUM>, which may be a non-contact bearing that prevents metal-on-metal contact in the event the boom deflects beyond a predetermined amount. In other embodiments, the second bearing may be omitted. The shaft support <NUM> includes an outer portion <NUM> and an inner portion <NUM> (<FIG>). The outer portion <NUM> engages the housing <NUM>, while the inner portion <NUM> engages the shaft <NUM>. The shaft <NUM> supports therein trombone tubes <NUM>, which provide passages that communicate between the ends of the boom <NUM> (for example, between the flow distributor <NUM> and the carrier <NUM>). For example, these passages may carry fluids (e.g., hydraulic fluid), or wired connections. In some embodiments (e.g., <FIG>), a torque tube <NUM> may be positioned between the trombone tubes <NUM> and the shaft <NUM>, to resist torsional stress from the shaft <NUM> to inhibit the torque from breaking or overly stressing the trombone tubes <NUM>.

As shown in <FIG> and <FIG>, the shaft support <NUM> includes a guide member (e.g., a guide pin <NUM>) that extends radially away from the shaft support <NUM>. As shown in the section view of <FIG>, the overall profile of the housing <NUM> is key-shaped to facilitate proper orientation of the shaft support <NUM> relative to the housing <NUM>, and limit the rotational movement of the shaft support <NUM> relative to the housing <NUM>. Stated another way, the housing <NUM> includes a portion <NUM> having a circular profile, and a portion <NUM> that is positioned radially outward of the portion <NUM>. The radially outward portion <NUM> may have a rectangular profile. In the illustrated embodiment, the shaft support <NUM> includes a portion having a circular profile positioned within the portion <NUM> of the housing <NUM> having a circular profile and locates the shaft <NUM> within the housing <NUM>. The guide pin <NUM>, on the other hand, is connected to a spherical bearing <NUM> positioned within the portion <NUM> of the housing <NUM> having a rectangular profile. A hydraulic cylinder <NUM> (is positioned adjacent the portion <NUM> and includes a rod end <NUM> coupled to the guide member <NUM> (e.g., by a yoke <NUM>). Actuation of the hydraulic cylinder <NUM> moves the guide pin <NUM> along at least a portion of the housing <NUM> in a direction parallel to the axis <NUM>. Since the guide pin <NUM> is connected to the shaft support <NUM>, actuation of the hydraulic cylinder <NUM> moves the shaft support <NUM> axially within the housing <NUM>. Further, the guide pin's <NUM> engagement with the spherical bearing <NUM> positioned within the rectangular portion <NUM> of the housing <NUM> prevents rotation of the support shaft <NUM> within the housing <NUM>.

As shown in <FIG>, in some embodiments, the trombone tubes <NUM> do not rotate relative to the housing <NUM>, and the tubes <NUM> are positioned within a torque member (e.g., torque tube <NUM>). The torque tube <NUM> is connected to the outer portion of the shaft support <NUM> and to an inner portion of the shaft <NUM>. In some embodiments, the torque tube <NUM> may be formed as multiple portions. In the illustrated embodiment, the flow distributor <NUM> (<FIG>) is positioned proximate a distal end <NUM> of the shaft <NUM> and includes an inner portion 106A and an outer portion 106B that rotate relative to one another. During operation, the outer portion 106A of the flow distributor <NUM>, an outer portion <NUM> (<FIG>) of the shaft <NUM>, and the inner portion <NUM> (<FIG>) of the shaft support <NUM> rotate. An inner portion <NUM> (<FIG>) of the shaft <NUM> (including the torque tube <NUM> and the trombone tubes <NUM>), the outer portion <NUM> of the shaft support <NUM>, and the inner portion 106A of the flow distributor <NUM> do not rotate. The torque tube <NUM> inhibits and/or limits the stresses exerted on the trombone tubes <NUM>, minimizes flexing of the trombone tubes, avoids damage to the tubes. Also, the torque tube <NUM> may improve accuracy of a sensed boom position in cases in which the movement of the shaft <NUM> relative to the flow distributor housing is used to monitor the boom position angle (i.e., a sensed position of the flow distributor shaft may more closely reflect the actual angle of the boom). Such flexing may be present in other booms in which, for example, interaction between a shaft support and trombone tubes results in the trombone tubes rotating with an inner portion of the shaft support, causing a male portion 130A or female portion 130B of the trombone tubes <NUM> to flex significantly.

In the illustrated embodiment of <FIG>, the shaft support <NUM> is positioned adjacent the proximal end <NUM> of the shaft <NUM> and the flow distributor <NUM> is positioned adjacent the distal end <NUM> of the shaft <NUM>. It is understood that this embodiment is one example, and other embodiments may incorporate a different configuration. Also, it is understood that, in other embodiments, the shaft support or the flow distributor may be configured in a reverse manner with respect to connection to the non-rotating first end <NUM> of the boom <NUM>.

In other embodiments, as shown for example in <FIG>, the inner portion <NUM> of the shaft support <NUM> may be coupled to the hydraulic cylinder <NUM>, which causes the axial movement of the shaft <NUM> and shaft support <NUM>. The outer portion <NUM> may be coupled to the shaft <NUM>. As a result, the outer portion of the flow distributor <NUM>, the shaft <NUM>, and the outer portion <NUM> of the shaft support <NUM> are rotatable in the illustrated embodiment. The inner portion of the rotary flow distributor <NUM>, the inner portion <NUM> of the shaft support <NUM> (including the torque tube <NUM> and female portions 130B of the trombone tubes <NUM>), and the guide pin <NUM> are not rotatable. One advantage is that the torque tube <NUM> can be coupled directly to the inner portion <NUM> of the shaft support <NUM> and avoids providing a portion of the torque tube <NUM> passing through the shaft support <NUM>.

Cables or wires may carry control power and communications signals between the fixed (i.e., the first end <NUM>) and the extending portions (i.e., the distal end <NUM>) of the boom <NUM>. In some cases, the cables or wires remain the same length while the boom <NUM> axially extends and retracts, but there may be limited space within the boom <NUM> to house extra length of cable or wire when the boom <NUM> is in a retracted state.

As shown in <FIG>, the boom <NUM> may include a cable guide chain <NUM>. <FIG> illustrates the shaft <NUM> in a retracted position relative to the first end <NUM>, while <FIG> illustrates the shaft <NUM> in an extended position. The cable guide chain <NUM> may include a plurality of links coupled to the cable, and the links of the cable guide chain <NUM> can bend/flex in a controlled manner within the boom <NUM>. One end of the cable guide chain <NUM> is connected to a tube <NUM> (i.e., one of the trombone tubes <NUM>) that carries the cables or wires from a connection point <NUM> to the inside of the shaft <NUM>. Another end of the cable guide chain <NUM> is connected at a connection point <NUM> to a portion of the boom <NUM> that extends, for example, an inside wall of the shaft <NUM>. This allows the cables or wires to be guided by the cable guide chain <NUM> in a controlled manner and extend and retract within the shaft <NUM> free from damage. The cable guide chain <NUM> manages the cables or wires to minimize the risk of tangling, twisting, shearing, or other damage.

The cable guide chain <NUM> may be supported within a guide bracket <NUM> (<FIG>). In the illustrated embodiment, the guide bracket <NUM> extends alongside the trombone tubes <NUM>. The guide bracket <NUM> retains the cable guide chain <NUM> to control the position of the cable guide chain <NUM> as the shaft <NUM> extends and retracts and minimizes the risk that the cable guide chain <NUM> will twist or catch on another structure. <FIG> illustrates a portion of a cable <NUM> extending from the connection point <NUM>. The cable <NUM> is guided from the shaft <NUM> into a slip ring <NUM> within the flow distributor <NUM> to be connected to equipment at the distal end <NUM> of the shaft <NUM>.

<FIG> illustrate a device and method for coupling the guide member <NUM> to the shaft support <NUM>. In some cases, the guide member <NUM> transmits large forces between the housing <NUM> and the shaft support <NUM>. The guide member <NUM> may be coupled to the shaft support <NUM> with an interference fit to prevent excessive movement and wear between the interface of the guide member <NUM> and shaft support <NUM>, while also facilitating removal/replacement of the guide member <NUM> as needed without requiring complicated disassembly (e.g., removing the shaft support <NUM>).

In the illustrated embodiment, the guide member <NUM> is coupled to the shaft support <NUM> by a wedge-shaped protrusion <NUM> secured within a wedge-shaped pocket <NUM>. In the illustrated embodiment, the wedge-shaped protrusion is positioned on the guide member <NUM> and the wedge-shaped pocket <NUM> is positioned on the shaft support <NUM>; it is understood that, in other embodiments, the coupling may be accomplished in a different manner.

The wedge-shaped protrusion <NUM> is positioned within the wedge-shaped pocket <NUM> and retained therein by drive bolts <NUM> that engage the shaft support <NUM> from the first end <NUM>. The drive bolts <NUM> draw the guide member <NUM> into the wedge-shaped pocket <NUM> to provide an interference fit. The guide member <NUM> is further fixed into the wedge-shaped pocket <NUM> via a retaining block <NUM> that, when tightened against the shaft support <NUM> with retaining block bolts <NUM>, interferes with the wedge-shaped protrusion <NUM> to hold the guide member <NUM> against the shaft support <NUM>. To remove the guide member <NUM>, the retaining block bolts <NUM>, the retaining block <NUM>, and drive bolts <NUM> are removed, and the guide member <NUM> can be tapped out of the wedge-shaped pocket <NUM> to disengage the interference fit between the protrusion <NUM> and the wedge-shaped pocket <NUM>. Thus, the guide member <NUM> can be easily removed from the wedge-shaped pocket <NUM>, without requiring a time-consuming and expensive process for accessing and servicing the guide pin.

Referring now to <FIG>, the shaft support <NUM> may be provided with a hydraulic cylinder along the central axis of the boom <NUM> that operates to extend the shaft <NUM> from an extension cylinder <NUM>. In <FIG>, the housing <NUM> is shown in broken lines to better illustrate these features. The extension cylinder <NUM> passes though the shaft support <NUM>. The flow distributor <NUM> is positioned at the first end <NUM>, and the flow distributor <NUM> is connected to the extension cylinder <NUM>. The shaft support <NUM> is slidably connected to the extension cylinder <NUM> and is connected to the shaft <NUM>. As a result, the extension cylinder <NUM> operates to extend or retract the shaft support <NUM> and shaft <NUM> (<FIG>) and extend the shaft support <NUM> and shaft <NUM> (<FIG>) relative to the housing <NUM>. The flow distributor <NUM> and the shaft support <NUM> are rotationally fixed with respect to the housing <NUM>, but the extension cylinder <NUM> and the shaft <NUM> are rotatable along the housing axis <NUM>. <FIG> illustrates cylinder guide grooves <NUM>, which are the rotational connection between the extension cylinder <NUM> and the shaft <NUM>. The cylinder guide grooves <NUM> are provided on opposite exterior walls of the extension cylinder <NUM> (i.e., the cylinder guide grooves <NUM> are diametrically opposed) to interface with a protrusion (not shown) on an interior wall of the shaft <NUM> such that the shaft <NUM> is axially slidable relative to the extension cylinder <NUM>, but is not rotatable relative to the extension cylinder <NUM>. It is understood that, in other embodiments, the cylinder guide grooves and the corresponding protrusions may be configured in another manner.

As seen in <FIG>, trombone tubes <NUM> are provided within the shaft <NUM> and extension cylinder <NUM>. In the illustrated embodiment, male portions 130D (<FIG>) of the trombone tubes are positioned in the extension cylinder <NUM>, and one end of each male portion 130D is received in an associated female portion 130C positioned within the shaft <NUM>. A person of skill in the art would understand that this could be reversed, i.e., male trombone tubes 130D could be positioned within the shaft <NUM> for insertion into female trombone tubes 130C in the extension cylinder <NUM>. These trombone tubes 130C and 130D provide passages from the first end <NUM> to the distal end <NUM> to carry fluids, electrical connections, or the like along the length of the boom <NUM>. The cylinder guide grooves <NUM> secure the extension cylinder <NUM> against rotation relative to the shaft <NUM>, so that when these components are rotated with the male and female trombone tubes 130C and 130D therein, the trombone tubes 130C and 130D are not subject to twisting or torsional forces.

Referring now to <FIG>, guide members are provided on opposite interior walls of the housing <NUM>. In the illustrated embodiment, the guide members include guide tracks 146A, 146B that are diametrically opposed and positioned on the shaft support <NUM>, and guide protrusions positioned on an interior surface of the housing <NUM> engage the tracks 146A, 146B. These guide members secure the shaft support <NUM> against rotation relative to the housing <NUM>, but allow the shaft support <NUM> to be slidable relative to the housing <NUM>. It is understood that, in other embodiments, the guide tracks and the corresponding protrusions may be configured in another manner.

As best illustrated in <FIG>, <FIG>, trombone tubes <NUM> provide a channel in order to transfer an electronic control signal and control power via a cable <NUM> (e.g., a spirally coiled cable) from the first end <NUM> to the distal end <NUM>. A cable inner tube <NUM> houses a straight portion of the cable <NUM> of a fixed length, and a cable outer tube <NUM> houses a spirally wound portion of the cable <NUM> that can stretch by nature of the spiral winding (e.g., by reducing diameter and extending pitch). The cable <NUM> is connected to a slip ring <NUM> (<FIG>) within the flow distributor <NUM> to provide an electrical connection for both the rotating and non-rotating parts of the boom <NUM>. <FIG> and <FIG> illustrate the cable <NUM> in a retracted position (e.g., while the distal end of the shaft <NUM> is retracted with respect to the second end <NUM> of the housing <NUM>). <FIG> and <FIG> illustrate the cable <NUM> in an extended position (e.g., while the distal end of the shaft <NUM> is extended away from the second end <NUM> of the housing <NUM>). <FIG> and <FIG> differ from <FIG> in that <FIG> are illustrated with the shaft <NUM> removed to more easily show the cable <NUM> in the trombone tube <NUM>.

<FIG> illustrate another embodiment of a boom <NUM> in retracted (<FIG>) and extended (<FIG>) positions. An orientation of the cylinder is reversed, and the boom <NUM> includes guide rods or guide tubes <NUM>. For example, male and female trombone tubes 130E and 130F are inserted inside an extension cylinder outer portion <NUM>, pass through an extension cylinder piston <NUM>, and then pass into the extension cylinder inner portion <NUM>. In this configuration, the extension cylinder outer portion <NUM> can be fixed to a rotary actuator (e.g., actuator <NUM> - see <FIG>) and the trombone tubes <NUM> provide fluid conduits from a control valve (not shown) that controls the rotation of the rotary actuator <NUM>. In this embodiment, the outer portion of the shaft support <NUM> and the outer portion of the flow distributor <NUM> are rotatably fixed relative to the housing <NUM>. Other interior components, such as the extension cylinder inner portion <NUM>, extension cylinder piston <NUM>, shaft <NUM>, the inner portion of the shaft support <NUM>, and the inner portion of the flow distributor <NUM> may be rotatable relative to the housing <NUM>.

<FIG> illustrate the boom <NUM> of <FIG> in extended (<FIG>) and retracted (<FIG>) positions with the extension cylinder outer portion <NUM> and the housing <NUM> shown in broken lines to better illustrate the extension cylinder <NUM> and the shaft <NUM>. Trombone tubes or guide tubes 130F (male) and <NUM> (female) are shown inset to better illustrate these features within the extension cylinder <NUM> and the shaft <NUM>.

Claim 1:
A boom (<NUM>) for supporting a drilling and bolting tool (<NUM>), the boom comprising:
a first portion (<NUM>) including a first end (<NUM>), a second end (<NUM>), and a longitudinal axis extending between the first end and the second end;
a second portion including an elongated shaft (<NUM>) having a proximal end (<NUM>) and a distal end (<NUM>), the proximal end supported by a shaft support (<NUM>) for translational movement relative to the first portion (<NUM>) in a direction parallel to the longitudinal axis, the distal end configured to support the drilling and bolting tool (<NUM>);
an actuator for moving the second portion relative to the first portion in a direction parallel to the longitudinal axis; characterized in that
the first portion (<NUM>) includes a cylindrical portion (<NUM>) and a portion (<NUM>) positioned radially outward of the cylindrical portion (<NUM>), the boom further including,
a guide track positioned within the radially outward portion (<NUM>); and
a guide member (<NUM>) for engaging the track, the guide member positioned on one of the first portion and the second portion, the guide member extending in a radial direction and inhibiting rotation of the shaft support (<NUM>) about the longitudinal axis, the guide member positioned within the radially outward portion (<NUM>).