Trolley for rock bolt

Abstract

A rock bolt trolley (100) for connecting a self-drilling rock bolt (10) to a rock bolt support apparatus includes a drive shaft (102) having a central bore (114) and defining a proximal end and a distal end, the drive shaft defining an engagement member (112) for engagement with a corresponding engagement member (82) positioned on the proximal end of the rock bolt. A sleeve (150) is mounted over the distal end of the drive shaft and is arranged to slide along and over the drive shaft and defines a female engagement member (162) at the distal end for engagement with a nut (14) threadably connected to the proximal end of the rock bolt. The interior of the sleeve and the exterior of the drive shaft are configured to rotate together about its central axis. A spring (200) biases the distal end of the sleeve away from the distal end of the drive shaft. The trolley operates in two modes, in one mode, the nut and the rod rotate together, and in a second mode, the nut rotates on the rod.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Australian Provisional Patent Application No. 2022901533 filed on June 3, 2022, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates to a trolley for installing rock bolts and to an associated system and method for installing rock bolts, in particular self-drilling rock bolts. Background Art

[0004] Rock bolts are used in soft and hard underground mines to provide ground support for mining excavations and in particular to support the mine walls and roof.

[0005] A commonly used method of installing rock bolts involves the use of a self-drilling rock bolt that uses a sacrificial drill bit attached to a hollow rock bolt. This allows the rock bolt to be used in harsh ground conditions, where the self-drilling rock bolt is used as a drill steel and remains in the borehole after drilling. The applicant has previously filed an Australian innovation patent AU2021105904 for a self-drilling rock bolt, the entire contents of which are incorporated by reference. The self-drilling rock bolt consists of a self-drilling hollow rod and a mechanical anchor in the form of an expansion shell that is activated after drilling. Any attempt to pull the rod out of the hole activates the mechanical anchor. This can be done by pre-tensioning the rock bolt using a nut and a bearing plate positioned above the rock face.

[0006] To install a self-drilling rock bolt as described in AU2021105904, a two-stage, or drilling apparatus with multiple arms is required, first drilling the bolt and then pre-tensioning it. The present invention aims to speed up the installation of such bolts.

[0007] Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is not to be taken as an admission that any or all of these form part of the prior art base or were common general knowledge in the field relevant to the present disclosure by virtue of their existence before the priority date of each of the appended claims. Summary of the invention

[0008] Thus, according to a first aspect of the invention, there is provided a rock bolting trolley for connecting a self-drilling rock bolt to a rock bolting apparatus, such as a jack-up rig, a rock drill or the like, and the rock bolting trolley is arranged to transfer torque and optionally impact energy applied to the trolley by the rock bolting apparatus to the rock bolt during installation of the rock bolt, the rock bolt comprising an externally threaded rod having a proximal end and a distal end defining a drill bit, the trolley defining at its proximal end a coupling member for engagement with the rock bolting apparatus, the trolley further comprising:

[0009] a drive shaft having a central bore and defining a proximal end and a distal end, the drive shaft defining an engagement member at the distal end for engaging a corresponding engagement member positioned on or defined on the proximal end of the rock bolt;

[0010] a sleeve mounted over the distal end of the drive shaft and arranged to slide along and over the drive shaft and defining a female engagement member at its distal end for engagement with a nut or the like threaded onto the proximal end of the rock bolt, the interior of the sleeve and the exterior of the drive shaft being configured such that the drive shaft and sleeve rotate together about their central axis, and

[0011] a biasing member for biasing the distal end of the sleeve away from the distal end of the drive shaft;

[0012] The arrangement is such that in a first mode, with the biasing member compressed, the engagement member of the drive shaft engages with the corresponding engagement member positioned on or defined at the proximal end of the rock bolt, and the concave engagement member of the sleeve engages with a nut or the like threaded onto the proximal end of the rock bolt, so that the trolley rotates the rod and the nut together so that the nut does not translate along the rod, and in a second mode, with the biasing member expanded, the engagement member of the drive shaft disengages from the corresponding engagement member, and the concave engagement member of the sleeve engages with the nut or the like, and the trolley rotates only the nut which translates along the externally threaded rod of the rock bolt.

[0013] Thus, in a first mode, the rock bolt may be drilled into a rock face with the drill bit, thereby creating a borehole and the nut, and the associated bearing plate remains at the proximal end of the rock bolt as the rod is rotated simultaneously at the same angular velocity as the nut. Drilling is terminated once the bearing plate is in contact with the rock face and the rock bolting device is retracted (which allows the biasing member to expand) and the engagement member of the drive shaft is disengaged from the corresponding engagement member located on or defined at the proximal end of the rock. When the rock bolting device applies rotation, only the nut is engaged and translates along the rod, and the rod does not rotate, and this retracts the distal end of the rod, thereby causing the housing to expand through the drill bit, which in turn applies tension to the rock bolt. The trolley may then be disconnected and post-grouting may be performed.

[0014] In a preferred embodiment, the exterior of the main body portion of the drive shaft is polygonal, preferably hexagonal, and the sleeve defines a correspondingly shaped polygonal aperture in which the main body portion is located and slidable.

[0015] It is preferred that holes extend through the trolley to allow the passage of fluids such as water for flushing fines, liquid grout or the like.

[0016] Typically, the biasing member comprises a spring, typically a compression spring.

[0017] In one embodiment, the corresponding engagement member positioned on or defined on the proximal end of the rock bolt comprises an adapter mounted on the proximal end of the rock bolt, the adapter generally defining a hexagonal drive.

[0018] In another embodiment, the corresponding engagement member positioned or defined on the proximal end of the rock bolt comprises a hexagonal driver machined onto the shaft of the rock bolt.

[0019] A second aspect of the invention provides a rock bolt for use with a rock bolt trolley, the rock bolt comprising:

[0020] an elongated rod having a central bore and being externally threaded, the rod having a first or distal end and a second or proximal end, wherein the proximal end of the rod defines an engagement member for engaging with a corresponding engagement member of the rock bolt trolley, the engagement member being used to rotate the rod of the rock bolt about its central axis during installation;

[0021] a drill bit mounted on the distal end, the drill bit being used to drill a hole in a formation such as rock or the like, wherein the sides of the drill bit taper outwardly toward a cutting end of the drill at an angle of about 1° to 10°;

[0022] an expansion housing mounted about an exterior of the rod adjacent the drill bit, the housing defining at least one longitudinal slot to allow expansion and contraction of the housing;

[0023] a stop for maintaining the expansion housing in close proximity to the drill bit and limiting movement of the expansion housing toward the proximal end of the rock bolt;

[0024] wherein the exterior of the housing is contoured to define a series of ridges or the like, and wherein the widest portion of the housing is wider than the drill bit, and wherein the interior of the housing is wider than the exterior of the elongated rod to allow the rod to rotate relative to the housing, and wherein the housing freely rotates relative to the drill bit and tapers inwardly toward the proximal end;

[0025] an engagement member for rotating the elongated rod, the engagement member being fixed to or defined at the proximal end of the rock bolt and being fixed to the rod such that rotation of the engagement member rotates the elongated rod;

[0026] The arrangement is such that when the rock bolt is installed in a formation, the drill bit forms a hole in the formation and when advanced during drilling, the housing tends to drag along the wall of the hole and remain largely away from the rotating rod and the drill bit, and when drilling is stopped, the rock bolt moves out of the hole causing the drill bit to engage and expand the housing.

[0027] In one embodiment, the corresponding engagement member positioned on or defined on the proximal end of the rock bolt comprises an adapter mounted on the proximal end of the rock bolt, the adapter generally defining a hexagonal drive.

[0028] In another embodiment, the corresponding engagement member positioned or defined on the proximal end of the rock bolt comprises a male or female hexagonal driver machined onto the proximal end of the rod of the rock bolt.

[0029] The present invention also contemplates a method of installing a self-drilling rock bolt according to the second aspect in a rock face using a rock bolt trolley according to the first aspect, the method comprising the following steps:

[0030] installing the rock bolt on the rock bolt trolley;

[0031] inserting the nut or the like threaded onto the proximal end of the rock bolt into the female engagement member of the sleeve;

[0032] pushing the distal end of the defined drill bit of the rock bolt against the rock face until, with the biasing member compressed, the engagement member of the drive shaft engages with the corresponding engagement member located on or defined on the proximal end of the rock bolt;

[0033] rotating both the nut and the rod of the rock bolt using the drill bit, applying rotation and optionally impact to the rock bolt trolley to drill the rock bolt into the rock face;

[0034] terminating drilling after a support plate positioned on the proximal end of the rock bolt contacts the rock face;

[0035] retracting the rock bolting apparatus to disengage the engagement member of the drive shaft from the corresponding engagement member positioned on or defined on the proximal end of the rock bolt; and

[0036] With the nut or the like threaded onto the proximal end of the rock bolt still engaged with the female engagement member of the sleeve due to the biasing member, the trolley is rotated in the same direction as during drilling to rotate the nut along the shaft of the rock bolt, which draws the distal end of the rock bolt back towards the rock face / bearing plate and expands the expansion housing of the rock bolt and applies tension to the rock bolt.

[0037] Typically, a central hole in the drive shaft is used to convey fluid during drilling to flush fine material out of the hole and for cooling.

[0038] The present invention also contemplates a method of installing a self-drilling rock bolt in a rock face using a rock bolt trolley during an extension drilling process, the method comprising the following steps:

[0039] a) installing a starter rock bolt to the rock bolt trolley, the starter rock bolt comprising:

[0040] an elongated rod having a central bore and external threads, the rod having a first or distal end and a second or proximal end;

[0041] a drill bit mounted on the distal end, the drill bit being used to drill a hole in a formation such as rock or the like, wherein the sides of the drill bit taper outwardly toward a cutting end of the drill at an angle of about 1° to 10°, preferably about 5°;

[0042] an expansion housing mounted about an exterior of the rod adjacent the drill bit, the housing defining at least one longitudinal slot to allow expansion and contraction of the housing;

[0043] a stop for maintaining the expansion housing in close proximity to the drill bit and limiting movement of the expansion housing toward the proximal end of the rock bolt;

[0044] wherein the exterior of the housing is contoured to define a series of ridges or the like, and wherein the widest portion of the housing is wider than the drill bit, and wherein the interior of the housing is wider than the exterior of the elongated rod to allow the rod to rotate relative to the housing, and wherein the housing freely rotates relative to the drill bit and tapers inwardly toward the proximal end; and

[0045] an engagement member for rotating the elongated rod, the engagement member being positioned on or defined at or near a proximal end of the rock bolt, the engagement member corresponding to the engagement member defined on the distal end of the drive shaft; wherein the mounting step comprises engaging a corresponding engagement member of a starter rod with the engagement member defined on the distal end of the drive shaft;

[0046] b) pushing the drill bit of the starter rock bolt against the rock face and imparting rotation to the rock bolt trolley to drill the rock bolt into the rock face using the drill bit;

[0047] c) terminating the drilling after the sleeve of the trolley approaches the rock surface;

[0048] d) retracting the rock bolting apparatus to disengage the engagement member of the drive shaft from the corresponding engagement member located on or defined on the proximal end of the starter rock bolt;

[0049] e) mounting the extension rod or trimmer rod having a coupler mounted on the distal end of the extension rod to the trolley;

[0050] f) optionally, where an extension rod is used, engaging an engagement member positioned on or defined at or near the proximal end of the extension rod for rotating the extension rod with the engagement member defined on the distal end of the drive shaft, aligning the extension rod with the starter rod or a previous extension rod connected thereto using the coupler, and drilling the rock bolt further into the rock face using a combination of rotation and feed pressure, and terminating drilling after the sleeve of the carriage approaches the rock face;

[0051] g) optionally, repeating step f) one or more times with one or more additional stretching rods;

[0052] h) mounting a dresser bar to the rock bolt trolley, the dresser bar comprising an engagement member positioned on or defined at or near the proximal end of the rock bolt for rotating the elongated rod of the dresser bar, the engagement member corresponding to the engagement member defined on the distal end of the drive shaft; wherein the mounting step comprises engaging the corresponding engagement member of the starter bar with the engagement member defined on the distal end of the drive shaft, the dresser bar further comprising a nut or the like threaded onto the proximal end of the rock bolt, the nut being inserted into the concave engagement member of the sleeve and further defining a coupler on the distal end thereof;

[0053] i) aligning the dresser rod with the starter rod or previously extended rod, connecting the rods using the coupler and drilling the rock bolt further into the rock face using a combination of rotation and feed pressure, and terminating drilling after the sleeve of the trolley or the bearing plate associated with the nut approaches the rock face;

[0054] j) disengaging the drive shaft from the dresser bar; and

[0055] h) with the nut or the like threaded onto the proximal end of the dresser bar still engaged with the female engagement member of the sleeve, rotating the trolley in the same direction as during drilling to rotate the nut along the stem of the dresser bar which draws the distal end of the starter bar back towards the rock face / bearing plate and expands the expansion housing of the starter bar and applies tension to the rock bolt.

[0056] Throughout this specification, the word "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of stated elements, integers or steps or groups of elements, integers or steps but not the exclusion of any other elements, integers or steps or groups of elements, integers or steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Specific embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:

[0058] Figure 1 A self-drilling rock bolt is shown;

[0059] Figure 2 A rock bolting rig is shown;

[0060] Figure 3 Shown through Figure 2 The section of the trolley on AA is shown;

[0061] Figure 4 shows an enlarged end view of the trolley as seen from direction B;

[0062] Figure 5 Shown through Figure 2 The cross section of the dolly on CC shown;

[0063] Figure 6 Shown through Figure 2 The cross section of the trolley on DD is shown;

[0064] Figure 7 shows an enlarged end view of the trolley as seen from direction E;

[0065] Figures 8a to 8g Shows the use of Figures 2 to 7 Trolley installation shown Figure 1 The various stages of self-drilling rock bolts;

[0066] Figures 9a to 9g Shown through Figures 8a to 8g Cross-sections of the various stages are shown.

[0067] Fig.10 Shows Figure 1 A variation of the self-drilling rock bolt shown;

[0068] Fig.11 Shown for use with Fig.10 A rock bolting trolley for use with an embodiment of the present invention;

[0069] Fig.11A Shows Fig.11 The cross section on AA is shown;

[0070] Fig.12 Shown for use with Fig.11 Starter rods used with rock bolting rigs;

[0071] Fig.13 Shows Fig.12The cross section on GG is shown;

[0072] Fig.14 Shown for use with Fig.11 Extension rods for use with rock bolting rigs;

[0073] Fig.15 Shows Fig.14 The cross section on HH is shown;

[0074] Fig.16 Shown for use with Fig.11 Dresser bars for use with rock bolting rigs;

[0075] Fig.17 Shows Fig.16 The cross section on JJ is shown;

[0076] Figures 18a to 18j Shows the use of Fig.11 Trolley extension installation shown Fig.12 and 16 The various stages of self-drilling rock bolts;

[0077] Figures 19a to 19j Shown through Figures 18a to 18j Cross-sections of the various stages are shown.

[0078] Fig. 20 Shows Figures 2 to 7 Another variation of the trolley shown;

[0079] Fig. 20A yes Fig. 20 The cross section on AA;

[0080] Fig.21 Shown for use with Fig.11 Starter rods used with rock bolting rigs;

[0081] Fig. 22 Shows Fig.21 The cross section on BB is shown;

[0082] Fig.23 Shown for use with Fig.11 Extension rods for use with rock bolting rigs;

[0083] Fig.24 Shows Fig.23 The cross section on CC is shown;

[0084] Fig.25 Shown for use with Fig.11 Dresser bars for use with rock bolting rigs;

[0085] Fig.26 Shows Fig.25 The cross section on DD is shown;

[0086] Figures 27a to 27j Shows the use of Fig.11 Trolley installation shown Fig.21 and 25 The various stages of a self-drilling rock bolt as shown; and

[0087] Figures 28a to 28j Shown through Figures 18a to 18j Cross-sections of the various stages are shown. DETAILED DESCRIPTION

[0088] With reference to the accompanying drawings, Figure 1 A self-drilling rock bolt 10 is shown. The rock bolt 10 comprises an elongated hollow rod / bar 12 having a central bore (not shown) and external R32 threads which are industry standard, but the size and threads on the rod may vary. The rod / bar is typically made of steel. An R32 hexagonal nut 14 and a support plate 15 are threaded onto the proximal end 16 of the rod. In the depicted embodiment, an R32 button head drill bit 18 having internal R32 threads is mounted on the distal end of the rock bolt, but other types of drill bits and configurations may be employed. An expansion housing 22, described in detail below, is positioned on the rod 12 between the drill bit 18 and the stop 20.

[0089] The R32 button head drill bit 18 has a drilling end 30 for drilling through earth formations (typically rock) and has an outer side surface 32 that tapers outwardly from the threaded end to the drill bit end at an angle of 5° relative to the longitudinal axis of the rock bolt.

[0090] The housing 22 has a generally annular cross section. The exterior of the housing is serrated, defining a series of ridges in the form of wedges 40. The outer diameter of the housing is excessively large compared to the outer diameter of the drill bit 30 and the borehole formed by the drill bit 30 in use.

[0091] The diameter of the inner surface of the housing is larger than the outer diameter of the R32 rod so that the housing floats on the rod and the rod can rotate / swivel relative to the housing 22. The inner surface of the housing has a 5° taper relative to the longitudinal axis of the rock bolt and flares outwardly towards the distal end of the rock bolt.

[0092] The shell defines passages in the form of elongated slots that extend the entire length of the shell, thereby allowing the shell to expand and compress. Five additional passages in the form of partial slots 56 are also provided, which help reduce the force required to compress the shell and allow for the removal of fines, as discussed below. The passages also allow the flow of curable material, such as resin or grout, after the holes have been drilled.

[0093] like Figure 1As shown, a driver adapter 80 is mounted on the proximal end of the rod adjacent the hexagonal nut 14. The driver adapter defines a male engagement member in the form of a hexagonal shape or hexagonal nut 82 for engaging with a corresponding female engagement member in the form of a hexagonal socket. As an alternative to the driver adapter, the hexagonal shape may be formed directly on the rod by machining or the like. This will be referred to as Fig.10 This is described in detail below.

[0094] Figures 2 to 7 Shown for installation Figure 1 The trolley 100 of the rock bolt is shown. The trolley includes an elongated drive shaft 102. One end 104 of the drive shaft 102 is externally threaded and fixed to a handle adapter 106. Figure 2 As best seen in FIG. 1 , the other end 108 is enlarged relative to the main body portion 110 of the drive shaft and defines a hollow hexagonal drive socket 112 for receiving the hexagonal drive nut 82 of the rock bolt or the driver adapter 80 connected to the rock bolt. A bore 114 extends from one end of the drive shaft to the other end. The exterior of the main body portion 110 of the drive shaft 102 has a hexagonal cross-section, as shown in FIG. Figure 2 and 5 Best seen in.

[0095] The shank adapter 106 has one end 120 defining an internally threaded hole 122 that is threaded onto the corresponding externally threaded end 104 of the drive shaft 102 and an annular groove 123 for receiving the end of the spring 200. The opposite end 124 further defines an internally threaded hole 126 that is configured to mate with a drive shaft of a rock bolting device (such as a bolt punch, etc.), which is typically T38 or T45 threaded. Hole 130 connects the two ends of the drive shaft.

[0096] A tubular sleeve or sliding outer body 150 is mounted over the other end of the drive shaft 102. The first or proximal end of the sleeve 152 defines a shallow annular channel or circular groove 154 for receiving a biasing member in the form of a compression spring 200, and then narrows to define an inner bore 156 which is hexagonal and slightly larger than the outer diameter of the main body portion 110 of the drive shaft so that it can slide along the outside of the drive shaft. The bore widens at a step 157 to define a wider cylindrical bore 158 which extends the remaining length of the sleeve to a distal end 160 which defines a hexagonal socket 162.

[0097] A compression spring 200 is mounted around the exterior of the drive shaft 102 and has its ends positioned in the grooves 154 and 123 , respectively, and biases the sleeve 150 away from the stem adapter 106 .

[0098] Now refer to Figures 8a to 9g The installation of the rock bolt 10 using the trolley 100 is described. Figure 8a and 9a The bolt 10 is mounted to the trolley 100, either manually or using a mechanized bolting turntable. The male hexagonal nut 14, which is threaded onto the rod and is freely rotatable, is inserted into the female hexagonal socket 162 located at the front of the tubular sleeve 150 of the trolley.

[0099] The anchor 10 is then pushed against the rock face using a rig / drilling motor (not shown) and the drive shaft 102 is forced forward until the hexagonal socket 112 engages the nut 82 of the driver adapter 80, as shown in FIG. Figure 9b The compression spring 200 is compressed between the sleeve 150 and the handle adapter 106, which preloads the sliding outer body 150 onto the hexagonal nut 14. The exposed spring 200 provides visual feedback to the operator indicating whether the driver adapter is properly engaged with the drive shaft. In a variation not shown, the spring can be covered by a dust cover that can be transparent.

[0100] The bolt is drilled into the rock mass using a combination of impact and rotation or just torque and just rotation. Fig.9c The portion of the rock bolt 10 that has been drilled into the rock mass is shown. During drilling, the interlocking geometry between the sliding outer body, the drive shaft and the hexagonal nut 14 restricts the free or slightly fixed hexagonal nut 14 from translating along the rod. This is because the sleeve 150 and the drive shaft 102 rotate at the same angular rotation and thus rotate the hexagonal nut 14 through the socket 162, and rotate the threaded rod 12 through the driver adapter 80 and the hexagonal nut 82 together at the same angular rotation. Therefore, the nut 14 does not translate along the rod 102 when it rotates with the rod 12. As shown in FIG. Figure 9d As shown, once the support plate 15 encounters the rock face 300, drilling stops.

[0101] refer to Fig.9e , the drilling motor is then retracted, which disengages the drive shaft 102 from the hex nut 82 and the driver adapter 80. During retraction, the preload from the compression spring 200 maintains the sleeve 150, and specifically the socket 162, in engagement with the hex nut 14. When the drive shaft reaches its fully retracted position, the operator stops retracting the rack drill / drill motor, as shown in FIG. Fig.9e When the drive shaft is fully retracted, the sleeve 150 remains engaged with the hexagonal nut 14.

[0102] With the drive shaft 102 retracted and the sleeve 150 still engaged with the hex nut 14, rotation is applied to the drilling motor in the same direction as the hole is being drilled. This causes the socket 162 of the sleeve 150 to rotate the hex nut 14, which in turn winds along the threaded rod 12 and pulls the anchor out of the drill hole. The action of pulling the anchor out of the drill hole pulls the drill bit 18 toward the proximal end of the anchor 10, which in turn activates and expands the expansion shell 22 against the wall of the hole and applies tension to the anchor.

[0103] refer to Figure 9f , the drilling motor rotates until it stops, indicating that the bolt 10 has been tightened. The geometry of the sliding outer body and the drive shaft allows sufficient clearance to prevent interference between the drive shaft and the bolt end when the bolt is pulled out of the borehole.

[0104] The trolley 100 is then fully retracted and post-grouting can commence. Typically, a grouting system independent of the trolley is used to inject grout through the bore of the rock bolt. The grout may be of any suitable material, but is typically cementitious or polymeric to suit the ground conditions and / or requirements of the system.

[0105] Fig.10 Shows Figure 1 A variation of the rock bolt 10A is shown in which a hexagon 81 is machined into the proximal end of the rod / bar 12A. If the hexagon 81 is the same size as the hexagon 82 provided on the driver adapter 80, it can engage with the hexagonal drive socket 112 of the trolley 100. The rock bolt 10A is otherwise identical to the rock bolt 10. Typically, the hexagon will be slightly smaller than the hexagon 82 provided on the driver adapter 80, and then Fig.11 and 11A The illustrated trolley 100A is provided with a correspondingly smaller hexagonal drive socket 112A. The trolley 100A is otherwise identical to the trolley 100 and identical components are provided with the same reference numerals.

[0106] The rock bolt 10A is otherwise identical to the rock bolt 10. The method and process of installing the rock bolt 10A is similar to that of Figures 8a to 9g The installation process of the rock bolt 10 shown is the same.

[0107] The same trolley 100A and rock bolt 10 or 10A may be used in a variation of the installation process in which a longer rock bolt is required, known as reach drilling. Figures 18a to 19j The machining process of the 10A type rock bolt is shown, which illustrates the use of the trolley 100A for extension drilling, in which a hole longer than the rock bolt is drilled and an extension is added to form a longer rock bolt in the hole. Essentially the same process is used to install the rock bolt 10 with the extension.

[0108] Figures 12 to 17 A rod assembly for extending a borehole is shown. The starter rod 10A is Fig.10 The rock bolt 10A shown is identical except that the starter rod does not have the hexagonal nut 14 and support plate 15 mounted on the proximal end of the rod.

[0109] The extension rod 10B is a length of rod / bar 12A having a hexagon 81 machined onto one end and a coupler 310 attached to the distal end, the same rod as used for the rock bolt 10A.

[0110] Dresser bar 10C is based on the same length rod / bar 12A with a hexagon 81 machined on one end, a coupler 310 at its distal end, and has a hexagonal nut 14 and support plate 15 mounted on the proximal end of the bar 10B.

[0111] First reference Fig.18a and 19a In a first step, the starter rod 10A is mounted to the dolly 100A, either manually or using a mechanized bolting turntable. The male hexagonal nut 81 is machined onto the end of the rod and inserted into the female hexagonal socket 112A located at the front of the drive shaft portion of the dolly. It should be noted that the biasing member / spring 200 is largely uncompressed and the sleeve 150 does not engage the starter rod 10A.

[0112] In the second step, if Fig.18b and 19b As shown, the rock bolt 10A is then pushed against the rock face 300 where impact and rotation (or just rotation and feed pressure) are applied to the rock bolt 10 by engagement of the hexagonal nut 81 with the drive shaft 102 of the trolley 100A to begin drilling the rock bolt into the rock face 300. Drilling is continued until the sleeve 150 almost touches the rock face 300.

[0113] In the third step, refer to Fig.18c and 19c , then the drilling is stopped and the rig / drilling motor (not shown) is retracted from the rock face. As the drilling motor is retracted, the trolley 100A disengages from the bolt 10A. The bolt remains in the borehole due to the self-engaging design of the expansion housing 22, which engages when the bolt is pulled back.

[0114] In the fourth step, the dresser bar 10C or the extension bar 10B (not shown in FIG. 18 or 19 ) is installed in the carriage 100A. In order to avoid over-complexity of the drawings, the step of installing the extension bar 10B is not shown. Fig.18d and 19dA dresser bar 10C described below with reference to the accompanying drawings is shown being installed.

[0115] In the case where a longer hole or rock bolt is required, one or more extension rods 10B may be used. In the case of using an extension rod, a male hexagonal nut 81 machined onto the proximal end of the extension rod 10B is inserted into a female hexagonal socket 112A located at the front of the drive shaft portion of the trolley. A coupler 310 is mounted on the distal end of the extension rod. The extension rod is then realigned with the rock bolt 10A and the coupler is screwed onto the rock bolt 10A using a combination of rotation and feed pressure. The rock bolt is then drilled into the rock face until the sleeve approaches the rock face when drilling stops. The second and third steps are repeated until the desired depth of drilling is reached (allowing for the length of the dresser rod).

[0116] In the fourth step, if Fig.18d and 19d As shown, the dresser bar 10C is installed into the dolly 100A either manually or using a mechanized bolting carousel.

[0117] The male hexagonal nut 14, which is threaded onto the rod and can rotate freely, is inserted into the female hexagonal socket 162 located at the front of the tubular sleeve 150 of the dolly.

[0118] refer to Fig.18e and 19e , in step 5, the dresser bar 10C is then realigned with the starter bar / rock bolt 10A or previously extended bar and pushed up against the bar using the drilling motor feed.

[0119] The drill / drilling motor (not shown) is then used to push the trimmer bar 10C against the rock face and force the drive shaft 102 forward until the hexagonal socket 112A engages the hexagonal nut 81, as shown in FIG. Fig.12 e. The compression spring 200 is compressed between the sleeve 150 and the stem adapter 106 which preloads the sliding outer body 150 onto the hex nut 14. The exposed spring 200 provides visual feedback to the operator indicating whether the driver adapter is properly engaged with the drive shaft.

[0120] Next in step 6, refer to Fig.18f and 19f Once the socket 112 is engaged with the hexagonal nut 81 , the drill motor feed and pressure are used to thread the proximal end of the starter rod 10A (or extension rod) into the coupler 310 .

[0121] refer to Figure 18g and 19g, drilling continues, and the bolt is drilled into the rock mass 300 using a combination of impact and rotation or just torque and rotation. During drilling, the interlocking geometry between the sliding outer body, the drive shaft and the hexagonal nut 14 restricts the hexagonal nut 14 from translating along the rod. This is because the sleeve 150 and the drive shaft 102 rotate at the same angular rotation and in turn rotate the hexagonal nut 14 through the socket 162, and rotate the threaded rod 12 together with the hexagonal nut 81 at the same angular rotation. Therefore, when the nut 14 rotates with the rod 12, the nut does not translate along the rod 12. Figure 19g As shown, drilling stops once the support plate 15 encounters the rock face 300. During drilling, fluid is passed along a central channel in the bore of the trolley and rock bolt to flush out fine material and for cooling purposes.

[0122] refer to Figure 18h and 19h , in step 8, the drilling motor is then retracted, which causes the drive shaft 102 to disengage from the hexagonal nut 81. During retraction, the preload from the compression spring 200 maintains the sleeve 150 and specifically the socket 162 in engagement with the hexagonal nut 14. When the drive shaft reaches its fully retracted position, the operator stops retracting the rack drill / drill motor, as shown in FIG. Figure 19h When the drive shaft is fully retracted, the sleeve 150 remains engaged with the hexagonal nut 14.

[0123] refer to Fig.18i and 19i , with the drive shaft 102 retracted and the sleeve 150 still engaged with the hexagonal nut 14, rotation is applied to the drilling motor in the same direction as the borehole. This causes the socket 162 of the sleeve 150 to rotate the hexagonal nut 14, which in turn winds along the threaded rod 12A and pulls the anchor out of the borehole. The action of pulling the anchor out of the borehole pulls the drill bit 18 toward the proximal end of the anchor 10, which in turn activates and expands the expansion shell 22 against the wall of the hole and applies tension to the anchor. The drilling motor rotation continues until it stops, indicating that the anchor has been tensioned. The geometry of the sleeve 150 and the drive shaft 102 allows sufficient clearance to prevent interference between the drive shaft and the tail end of the rock bolt as it is pulled out of the borehole.

[0124] Finally, if Fig.18j and 19j As shown, the trolley 100A is then fully retracted and the rock bolt can now be grouted. This can be done by any suitable means, including manually attaching the grouting tool or using a remotely propelled grouting arm mounted to the giant arm.

[0125] Although Figure 1The driver adapter 80 shown is a male hex driver, but it will be appreciated that the driver adapter could also be in the form of a female socket, in which case the hex socket 112 would be a corresponding male hex driver. The spring 200 could also be replaced by an alternative biasing member, such as a stack of disc springs.

[0126] Fig. 20 A variation is shown in which dolly 100B is identical to dolly 100 except that the hexagonal socket on the distal end of drive shaft 102 is replaced by a male hexagonal driver 350 . Figures 21 to 26 A starter bar 400A and an extension bar 400B and a trimmer bar 400A are shown for use with the dolly 100A.

[0127] Starter Rod 400A with Figure 1 The rock bolt 10 shown is identical except that the starter rod does not have the hexagonal nut 14 and support plate 15 mounted on the proximal end of the rod 12, and the adapter 80 is replaced by a coupler 402 comprising a female hexagonal driver adapter 420. Fig. 22 As best seen in FIG. 4 , the hexagonal drive adapter / coupler 402 is a standard coupler, but has a female hexagonal socket 420 defined on one end of the coupler.

[0128] Extension rod 400B is a length of rod 12 having a hexagonal driver adapter / coupler 402 only at its proximal end.

[0129] The trimmer rod 400C is a length of rod 12 having a hexagonal driver adapter 410 on its proximal end defining a first hole 412 threaded onto the end of the rod 12 and defining a stop 414 and a hexagonal socket 416 on a side of the stop opposite the hole 412. The trimmer rod 400C also has a hexagonal nut 14 and a support plate 15 mounted on the proximal end of the rod adjacent the hexagonal driver adapter 410.

[0130] Not shown is a standard non-extension / intact rock bolt which is identical to the dresser bar 400C but includes a stopper 20, expansion housing 22 and drill bit 18 at its distal end, ie the same end as the distal end of the starter bar 400A.

[0131] Figures 27a to 28j The installation of rods 400A and 400C during the extended drilling process is shown. The process is largely similar to Figures 18a to 19j The installation process shown is the same.

[0132] In the first step, refer to Fig.27a and 28a, the starter bar 400A is installed to the dolly 100B, either manually or using a mechanized bolting turntable. The male hexagonal driver 350, positioned at the front of the drive shaft portion of the dolly, is inserted into the female hexagonal socket 420 of the coupler 402. It should be noted that the biasing member / spring 200 is largely uncompressed and the sleeve 150 does not engage the starter bar 400A.

[0133] In the second step, if Figure 27b and 28b As shown, the bolt 400A is then pushed against the rock face 300 where impact and rotation (or just rotation and feed pressure) are applied to the rock bolt 10 through engagement of the hexagonal socket 420 with the drive shaft 102 of the trolley 100B to begin drilling the rock bolt into the rock face 300. Drilling is continued until the sleeve 150 almost touches the rock face 300.

[0134] In the third step, refer to Fig.27c and 28c , drilling is then stopped and the rig / drilling motor (not shown) is retracted from the rock face 300. As the drilling motor is retracted, the trolley 100B disengages from the bolt 400A. The bolt remains in the borehole due to the self-engaging design of the expansion shell 22, which engages when the bolt is pulled back.

[0135] In the fourth step, if Fig.27d and 28d As shown, the dresser bar 400C is installed into the carriage 100B manually or using a mechanized bolting carousel. (The option of installing the extension bar 400B is not shown, but it is similar to the above reference Figures 18a to 19j The earlier extension drilling process described is substantially the same.) The male hexagonal nut 14, which is threaded onto the rod and is freely rotatable, is inserted into the female hexagonal socket 162 located at the front of the tubular sleeve 150 of the cart 100B.

[0136] refer to Fig.27e and 28e , in step 5, the dresser bar 400C is then realigned with the starter bar / rock bolt 400A or previously extended bar and pushed upwards against the bar 400A using the drilling motor feed.

[0137] The drill / drilling motor (not shown) is then used to push the trimmer bar 400C against the rock face and force the drive shaft 102 forward until the hexagonal driver 350 engages the female hexagonal socket 416 of the hexagonal driver adapter 410, as shown in FIG. Fig.28eThe compression spring 200 is compressed between the sleeve 150 and the shank adapter 106 which preloads the sliding outer body 150 onto the hexagonal nut 14 .

[0138] Next in step 6, refer to Figure 27f and 28f Once the hex driver 350 is engaged with the hex socket 416 , the drill motor feed and pressure are used to thread the proximal end of the trimmer rod 400C (or extension rod) into the coupler 402 .

[0139] refer to Figure 27g and 28g , drilling continues, and the bolt is drilled into the rock mass 300 using a combination of impact and rotation or just torque and rotation. During drilling, the interlocking geometry between the sliding outer body, the drive shaft, and the hexagonal nut 14 restricts the hexagonal nut 14 from translating along the rod. This is because the sleeve 150 and the drive shaft 102 rotate at the same angular rotation and in turn rotate the hexagonal nut 14 through the socket 162, and together with the threaded rod 12 through the hexagonal adapter 410, rotate at the same angular rotation. Therefore, when the nut 14 rotates with the rod 12, the nut does not translate along the rod 12. Figure 27g As shown, drilling stops once the support plate 15 encounters the rock face 300. During drilling, fluid is passed along a central passage in the bore of the trolley 100B and rock bolt 12 to flush out fine material and for cooling purposes.

[0140] refer to Figure 27h and 28h , in step 8, the drill motor is then retracted, which disengages the drive shaft 102 / hexagonal driver 350 from the hexagonal socket 416 and the driver adapter 410. During retraction, the preload from the compression spring 200 maintains the sleeve 150, and specifically the socket 162, in engagement with the hexagonal nut 14. When the drive shaft reaches its fully retracted position, the operator stops retracting the rack drill / drill motor, as shown in FIG. Figure 28h When the drive shaft is fully retracted, the sleeve 150 remains engaged with the hexagonal nut 14.

[0141] refer to Fig.27i and 28i, with the drive shaft 102 retracted and the sleeve 150 still engaged with the hexagonal nut 14, rotation is applied to the drilling motor in the same direction as the borehole. This causes the socket 162 of the sleeve 150 to rotate the hexagonal nut 14, which in turn winds along the threaded rod 12 and pulls the anchor out of the borehole. The action of pulling the anchor out of the borehole pulls the drill bit 18 toward the proximal end of the anchor 10, which in turn activates and expands the expansion shell 22 against the wall of the hole and applies tension to the anchor. The drilling motor rotation continues until it stops, indicating that the anchor has been tensioned. The geometry of the sleeve 150 and the drive shaft 102 allows sufficient clearance to prevent interference between the drive shaft and the tail end of the rock bolt as it is pulled out of the borehole.

[0142] Finally, if Fig.18j and 19j As shown, the trolley 100B is then fully retracted and the rock bolt can now be grouted. This can be done by any suitable means, including manually attaching the grouting tool or using a remotely propelled grouting arm mounted to the giant arm.

[0143] It will be appreciated that the trolley may be used for other types of self-drilling rock bolts than the one shown in Australian innovation patent AU2021105904.

[0144] Those skilled in the art will appreciate that various changes and / or modifications may be made to the above-described embodiments without departing from the broad general scope of the present disclosure. Therefore, the embodiments of the present invention should be considered in all aspects as illustrative and not restrictive.

Claims

1. A rock bolt trolley for connecting a self-drilling rock bolt to a rock bolting equipment, such as a jack-up rig, a rock drill or the like, and arranged to transmit torque applied to the trolley by the rock bolting equipment to the rock bolt during installation of the rock bolt, the rock bolt comprising an externally threaded rod having a proximal end and a distal end defining a drill bit, the trolley defining at its proximal end a coupling member for engaging with the rock bolting equipment, the trolley further comprising: a drive shaft having a central bore and defining a proximal end and a distal end, the drive shaft defining an engagement member at the distal end for engaging a corresponding engagement member positioned on or defined on the proximal end of the rock bolt; a sleeve mounted over the distal end of the drive shaft and arranged to slide along and over the drive shaft and defining a female engagement member at a distal end for engaging with a nut or the like threaded onto the proximal end of the rock bolt, the interior of the sleeve and the exterior of the drive shaft being configured such that the drive shaft and sleeve rotate together about their central axis, and a biasing member for biasing the distal end of the sleeve away from the distal end of the drive shaft; The arrangement is such that in a first mode, with the biasing member compressed, the engagement member of the drive shaft engages with the corresponding engagement member positioned on or defined at the proximal end of the rock bolt, and the concave engagement member of the sleeve engages with the nut or the like threaded onto the proximal end of the rock bolt, so that the trolley rotates the rod and the nut together so that the nut does not translate along the rod, and in a second mode, with the biasing member expanded, the engagement member of the drive shaft disengages from the corresponding engagement member, and the concave engagement member of the sleeve engages with the nut or the like, and the trolley rotates only the nut which translates along the externally threaded rod of the rock bolt.

2. A rock bolting trolley according to any one of the preceding claims, wherein the exterior of the main body portion of the drive shaft is polygonal, preferably hexagonal, and the sleeve defines a correspondingly shaped polygonal aperture, in which the main body portion is positioned and can slide therein.

3. A rock bolting trolley according to any one of the preceding claims, wherein holes extend through the trolley to allow the passage of fluids such as water for flushing fines, liquid grouting or the like.

4. A rock bolting rig according to any one of the preceding claims, wherein the biasing member comprises a spring, typically a compression spring.

5. A rock bolting rig according to any one of the preceding claims, wherein the engagement member defined at the distal end of the drive shaft is a hexagonal socket.

6. A rock bolt trolley according to any one of the preceding claims, wherein the corresponding engagement member positioned or defined on the proximal end of the rock bolt comprises an adapter mounted on the proximal end of the rock bolt, the adapter defining a hexagonal drive.

7. A rock bolt trolley according to any one of claims 1 to 5, wherein the corresponding engagement member positioned or defined on the proximal end of the rock bolt comprises a hexagonal driver machined onto the shaft of the rock bolt.

8. A rock bolt trolley according to any one of claims 1 to 4, wherein the engagement member located at the distal end of the drive shaft is a hexagonal drive, and the corresponding engagement member located on or defined on the proximal end of the rock bolt includes a hexagonal socket formed in an adapter mounted on the end of the rod of the rock bolt.

9. A rock bolt comprising: an elongated rod having a central bore and external threads, the rod having a first or distal end and a second or proximal end; a drill bit mounted on the distal end, the drill bit being used to drill a hole in a formation such as rock or the like, wherein the sides of the drill bit taper outwardly toward a cutting end of the drill at an angle of about 1° to 10°, preferably about 5°; an expansion housing mounted about an exterior of the rod adjacent the drill bit, the housing defining at least one longitudinal slot to allow expansion and contraction of the housing; a stop for maintaining the expansion housing in close proximity to the drill bit and limiting movement of the expansion housing toward the proximal end of the rock bolt; wherein the exterior of the housing is contoured to define a series of ridges or the like, and wherein the widest portion of the housing is wider than the drill bit, and wherein the interior of the housing is wider than the exterior of the elongated rod to allow the rod to rotate relative to the housing, and wherein the housing freely rotates relative to the drill bit and tapers inwardly toward the proximal end; an engagement member for rotating the elongated rod, the engagement member being fixed to or defined at the proximal end of the rock bolt and being fixed to the rod such that rotation of the engagement member rotates the elongated rod; The arrangement is such that when the rock bolt is installed in a formation, the drill bit forms a hole in the formation and when advanced during drilling, the housing tends to drag along the wall of the hole and remain largely away from the rotating rod and the drill bit, and when drilling is stopped, the rock bolt moves out of the hole causing the drill bit to engage and expand the housing.

10. The rock bolt of claim 9, wherein the corresponding engagement member positioned or defined on the proximal end of the rock bolt comprises an adapter mounted on the proximal end of the rock bolt, the adapter generally defining a hexagonal driver.

11. The rock bolt of claim 9, wherein the corresponding engagement member positioned on or defined on the proximal end of the rock bolt comprises a male hexagonal driver machined onto or into the proximal end of the rod of the rock bolt.

12. The rock bolt of claim 9, wherein the corresponding engagement member positioned or defined on the proximal end of the rock bolt comprises an adapter mounted on the proximal end of the rock bolt, the adapter generally defining a hexagonal socket.

13. A method of installing a self-drilling rock bolt according to any one of claims 9 to 12 in a rock face using a rock bolt trolley according to any one of claims 1 to 8, the method comprising the following steps: installing the rock bolt on the rock bolt trolley; inserting the nut or the like threaded onto the proximal end of the rock bolt into the female engagement member of the sleeve; pushing the distal end of the defined drill bit of the rock bolt against the rock face until, with the biasing member compressed, the engagement member of the drive shaft engages with the corresponding engagement member located on or defined on the proximal end of the rock bolt; rotating both the nut and the rod of the rock bolt using the drill bit to impart rotation to the rock bolt trolley to drill the rock bolt into the rock face; terminating drilling after a support plate positioned on the proximal end of the rock bolt contacts the rock face; retracting the rock bolting apparatus to disengage the engagement member of the drive shaft from the corresponding engagement member positioned on or defined on the proximal end of the rock bolt; as well as With the nut or the like threaded onto the proximal end of the rock bolt still engaged with the female engagement member of the sleeve, the trolley is rotated in the same direction as during drilling to rotate the nut along the shaft of the rock bolt, which draws the distal end of the rock bolt back towards the rock face / bearing plate and expands the expansion housing of the rock bolt and applies tension to the rock bolt.

14. The method according to claim 13, comprising the steps of: The rock bolt trolley is retracted and the rock bolt is post-grouted after tensioning.

15. A method of installing a self-drilling rock bolt in a rock face during an extension drilling process using a rock bolt trolley according to any one of claims 1 to 8, the method comprising the following steps: a) installing a starter rock bolt to the rock bolt trolley, the starter rock bolt comprising: an elongated rod having a central bore and external threads, the rod having a first or distal end and a second or proximal end; a drill bit mounted on the distal end, the drill bit being used to drill a hole in a formation such as rock or the like, wherein the sides of the drill bit taper outwardly toward a cutting end of the drill at an angle of about 1° to 10°, preferably about 5°; an expansion housing mounted about an exterior of the rod adjacent the drill bit, the housing defining at least one longitudinal slot to allow expansion and contraction of the housing; a stop for maintaining the expansion housing in close proximity to the drill bit and limiting movement of the expansion housing toward the proximal end of the rock bolt; wherein the exterior of the housing is contoured to define a series of ridges or the like, and wherein the widest portion of the housing is wider than the drill bit, and wherein the interior of the housing is wider than the exterior of the elongated rod to allow the rod to rotate relative to the housing, and wherein the housing freely rotates relative to the drill bit and tapers inwardly toward the proximal end; as well as an engagement member for rotating the elongated rod, the engagement member being positioned on or defined at or near a proximal end of the rock bolt, the engagement member corresponding to the engagement member defined on the distal end of the drive shaft; wherein said mounting step comprises engaging a corresponding engagement member of a starter rod with said engagement member defined on said distal end of said drive shaft; b) pushing the drill bit of the starter rock bolt against the rock face and imparting rotation to the rock bolt trolley to drill the rock bolt into the rock face using the drill bit; c) terminating the drilling after the sleeve of the trolley approaches the rock surface; d) retracting the rock bolting apparatus to disengage the engagement member of the drive shaft from the corresponding engagement member located on or defined on the proximal end of the starter rock bolt; e) mounting the extension rod or trimmer rod having a coupler mounted on the distal end of the extension rod to the trolley; f) optionally, where an extension rod is used, engaging an engagement member positioned on or defined at or near the proximal end of the extension rod for rotating the extension rod with the engagement member defined on the distal end of the drive shaft, aligning the extension rod with the starter rod or a previous extension rod connected thereto using the coupler, and drilling the rock bolt further into the rock face using a combination of rotation and feed pressure, and terminating drilling after the sleeve of the carriage approaches the rock face; g) optionally, repeating step f) one or more times with one or more additional stretching rods; h) mounting a dresser bar to the rock bolt trolley, the dresser bar comprising an engagement member positioned on or defined at or near the proximal end of the rock bolt for rotating the elongated rod of the dresser bar, the engagement member corresponding to the engagement member defined on the distal end of the drive shaft; wherein the mounting step comprises engaging the corresponding engagement member of the starter bar with the engagement member defined on the distal end of the drive shaft, the dresser bar further comprising a nut or the like threaded onto the proximal end of the rock bolt, the nut being inserted into the concave engagement member of the sleeve and further defining a coupler on the distal end thereof; i) aligning the dresser rod with the starter rod or previously extended rod, connecting the rods using the coupler and drilling the rock bolt further into the rock face using a combination of rotation and feed pressure, and terminating drilling after the sleeve of the trolley or the bearing plate associated with the nut approaches the rock face; j) disengaging the drive shaft from the dresser bar; as well as h) with the nut or the like threaded onto the proximal end of the dresser bar still engaged with the female engagement member of the sleeve, rotating the trolley in the same direction as during drilling to rotate the nut along the stem of the dresser bar which draws the distal end of the starter bar back towards the rock face / bearing plate and expands the expansion housing of the starter bar and applies tension to the rock bolt.

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