AU2013204003B2

AU2013204003B2 - A machine and method for installing rock bolts

Info

Publication number: AU2013204003B2
Application number: AU2013204003A
Authority: AU
Inventors: Alain Comorge; Anssi Kouhnia; Maunu Manttari; Mietek Rataj
Original assignee: Sandvik Intellectual Property AB
Current assignee: Sandvik Intellectual Property AB
Priority date: 2012-11-19
Filing date: 2013-04-11
Publication date: 2014-11-13
Anticipated expiration: 2033-04-11
Also published as: WO2014076274A2; ZA201503206B; US20150275667A1; EP2920418A2; CA2887473A1; WO2014076274A3; CA2887473C; EP2920418B1; AU2013204003A1

Abstract

A machine 10 for installing cable bolts, including a drill 11 for drilling a bore 12 into a rock wall 13, a grout delivery system 15 for delivering grout 16 into the bore 12, a cable dispensing arrangement 24 for dispensing cable 23 into the bore 12, an attachment device 30 for attaching a bore anchor 21 to the leading end 22 of the cable 23 prior to the cable bolt being fed into the bore 12, and a severing device 35 for severing the cable 23 to form a trailing end 40. A method of installing a cable rock bolt into a bore is also provided. <filename> . I '~ '~ 'N.. .~ A iz± . k ~1 I Ix~c1~ N it 'zv~Z'1> / I N~ ' I' ( 'N'. ~ ft. jF Th <N 1 -~* -J .\ ~ N ~< 'NA **'N~ ~"' %~j4 <N ~ N'.~~ N N >xN> I7 '~H ~ N,'." -N K) "N" ~ - / '1 ill NJ \1P.N ~Jj ' .' \:k 'N> V 'V " '-. ~ 'N, 'Ax """"' N 'N\N '1 N' ____ N'. N~. N fr~"' ___________ 'QvxmN'.N nA' x§i9~~tz§r >: 'K I ""4 ' <N"' (V

Description

1 A MACHINE AND METHOD FOR INSTALLING ROCK BOLTS Technical Field [0001] The present invention relates to a machine and a method for inserting cable rock bolts into rock substrates in order to stabilise the substrate against fracture and failure. Background of Invention [0002] The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application. [0003] Rock bolts for use in underground mining include solid bar rock bolts and cable rock bolts. Solid bar rock bolts employ a rigid bar or rod and because the bar is rigid, the maximum length of the rock bolt is determined by the position and orientation in which it is to be installed and the dimensions of the space in the area installation. For example, if the rock bolt is to be installed in the roof of a mine tunnel perpendicular to the floor of the tunnel, then the length of the bolt can be no longer than the height of the tunnel. [0004] In contrast, because cable rock bolts employ a flexible cable rather than a solid bar, cable rock bolts have the benefit that the length of the bolt can be greater than the dimensions of the space in the area of installation because the cable can be fed into a bore from a direction not aligned with the bore. Advantageously, the length of a cable rock bolt can be significantly greater than the height of the mine tunnel and in many circumstances, many times greater than the height of the tunnel. [0005] Where cable bolts are installed, it is normal to install them as secondary bolts following the installation of shorter primary bolts. The shorter primary bolts are normally solid bar bolts in the order of 1.8 to 3m long and these primary bolts provide immediate strata support. As will become apparent from the discussion below, current installation procedures for cable bolts do not provide immediate support and <filename> 2 therefore the use of primary bolts is essential for mine safety until the cable bolts are installed and become effective. [0006] One method of installing cable rock bolts involves first drilling a bore in the rock substrate to the required depth. This can be in the order of 10m deep. Then cement grout is pumped into the bore and once the bore is sufficiently filled with grout, the cable bolt is fed from a reel into the bore, pushing through the grout. Once sufficient cable has been fed into the bore, the trailing end of the cable is severed, usually leaving about 0.3m extending from the opening of the bore. [0007] The grout of the installation described above is then left to cure until it has sufficient strength to hold the cable within the bore against tension which is later applied to the cable via the trailing end of the cable which protrudes from the bore. Tension is applied to the cable to place the rock substrate in compression to resist substrate fracture or failure. The tension load applied to the cable is usually in the order of 10 tonne. [0008] Until the grout has cured to a minimum acceptable level, the cable cannot be tensioned because there is no support to hold the cable against pulling out of the bore under the tension load applied. A period of about three days is required before the grout will have cured sufficiently for tension to be applied to the cable. Full curing of the grout to maximum support takes in the region of three to four weeks. If the primary bolts do not provide adequate support, until the grout cures to the minimum required amount, the substrate wall in which the cable has been installed cannot be considered fully supported. The primary bolts typically provide significant support but in some cases the support is considered sufficient only in the period before the tunnel is subjected to additional loading due to the commencement of mining. In some operations cable bolts are installed immediately after the primary bolts are installed so as to achieve full support as soon as possible. However, the development of the tunnel cannot proceed until the cable bolt grout cures to allow the cable bolts provide the full or substantially full support required. [0009] Moreover, because cable bolts are usually installed into high roof surfaces, special equipment usually is employed to access the trailing end of the cable to apply tension to the cable. Usually a so-called "cherry picker" is employed to lift relevant <filename> 3 equipment and personnel. Because of the need to work at height, specially trained personnel are required. [0010] Even when the cable of a rock bolt installed in the above manner has been tensioned, the tensioning might not necessarily be very effective as explained below. [0011] Cable tensioning is intended to apply load to the rock plate that engages the substrate or rock surface about the periphery of the bore. As indicated above, that load is intended to clamp the rock against fracture. In effect, once the cable has been tensioned, it acts as a spring and the tension is maintained in the cable after the load has been applied by a gripping arrangement applied to the trailing end of the cable, which usually comprises a barrel and wedge arrangement that bears against the rock plate. [0012] After the tension has been applied to the cable, the tensioner is released from the cable, but a small amount of tension is lost in the cable as the wedges move into the barrel to grip the cable and to hold the tension. The amount of tension that is lost is at least partly dependent on the length of the cable that is able to contract upon movement of the wedges within the barrel. Where the length is long, the relative movement of the wedges is small and the lost tension will be small also. However, where the length is small then the relative movement of the wedges will be relatively significant and the loss of tension can be significant also. Accordingly, when the cable is tensioned after the grout has cured, the available length of cable that can contract is that length that extends out of the grout and that length is usually small, sometimes in the order of only 30mm to 100mm. The loss of tension can be significant (this is known as "bleed load") and in the order of 50-80% of the tension load applied by the tensioner. [0013] A drawback that occurs when the tension in the cable is insufficient is that the wedges do not always engage the cable with sufficient force to bite into the cable and grip the cable sufficiently or effectively. This can be fatal to the proper operation of the rock bolt particularly if, before the bolt becomes loaded by the rock strata, the gripping teeth of the wedges are affected by rust. If that occurs, then the gripping arrangement might not support the rock plate and the bolt will become ineffective against the prevention of strata failure. <filename> 4 [0014] Applicant has recognised the above deficiencies of the prior art and has developed the invention with the aim to overcome or at least alleviate one or more of the deficiencies. Summary of Invention [0015] According to the present invention there is provided, a machine for installing cable bolts, including: a drill for drilling a bore into a rock wall; a grout delivery system for delivering grout into the bore; a cable dispensing arrangement for dispensing cable into the bore; an attachment device for attaching a bore anchor to the leading end of the cable, prior to the cable bolt being fed into the bore; a severing device for severing the cable to form a trailing end. [0016] The present invention can also provide an alternative machine for installing cable bolts, including: a drill for drilling a bore into a rock wall; a grout delivery system for delivering grout into the bore; a cable dispensing arrangement for dispensing cable into the bore; facility to allow attachment of a bore anchor to the leading end of the cable, prior to the cable bolt being fed into the bore; a severing device for severing the cable to form a trailing end. [0017] The facility to allow attachment of a bore anchor to the leading end of the cable can include the attachment device described above, but also includes other forms of attachment, such as manual attachment. The present invention also provides a method of installing a cable rock bolt, the method including; drilling a bore into a rock wall; delivering grout into the bore; attaching a bore anchor to the leading end of a cable, and then feeding the cable into the bore; severing the cable to form a trailing end once the cable has been fed to the desired depth into the bore; <filename> 5 applying a rock plate and a cable anchor to the trailing end of the cable: applying tension to the trailing end of the cable to cause the bore anchor to anchor the leading end of the cable within the bore and to cause the rock plate to engage the rock face under pressure. [0018] The present invention advantageously allows the complete installation of a cable rock bolt at one time rather than in the two stage process of the prior art because of the use of a bore anchor. The bore anchor allows the cable to be tensioned immediately it is installed rather than having to wait for the grout to cure. A rock bolt installed in accordance with the invention can thus provide immediate strata support and thus limit or eliminate the need for the installation of solid bar rock bolts discussed above that provide support in the period before the cable bolts become operative. [0019] The invention is thus expected to provide significant savings by eliminating or significantly reducing the time taken to properly support an area of strata, which will have obvious safety benefits as well. Further, savings are expected to arise as a result of a reduction of the need for specialist personnel for the installation procedure as well as for the elimination of the need for extra equipment for the second stage of the prior art installation. [0020] A further advantage arises in the reduced loss of tension in the cable of the cable bolt upon tensioning as a result of the cable being anchored at the leading end only when tension is applied so that the tension can be applied through substantially the full length of the cable rather than just the length of the cable that extends from the grout as in the prior art. When tension is applied to the cable in the invention, the cable is immersed in grout, but the grout is yet to cure, so the cable can shift (elastically lengthen) within the grout as tension is applied. The grout then cures about the tensioned cable .As explained above, the reduction in the loss of tension in the cable bolt of the invention compared to the prior art can be significant, so that where the loss of tension in the prior art can be in the order of 50 to 80%, in the invention, the loss is expected to be in the order of about 5 to 10%. [0021] The drill used in machines according to the invention can be of any suitable form and may be rotary, or rotary percussive for drilling into rock strata. The drill can <filename> 6 use rigid drill rods which are coupled together as the length of the drilled bore extends, or flexible and continuous drill rods can be used. The drill can be configured for either style of drill rod. The selection of drill rod can be dependent on the type of rock strata being drilled, in particular the hardness of the rock strata. [0022] The grout delivery system used in machines according to the invention can also take any suitable form. In some forms, machines of the invention can include a cement grout mixer and/or a reservoir of grout and a grout pump that can deliver grout into the bore via one or more hoses. Thus, the machines can include a reservoir for storing grout that is mixed on the machine or separately from the machine, or the machines can include facility for connecting to a grout supply which is separate from the machine. The machine is operable to control delivery from the supply into the bore as required. [0023] The grout delivery system used in machines according to the invention can include a hose support that can position the open end of the hose within the bore and that can retract the hose as grout is delivered into the bore. The bore is preferably filled with grout from the inner end of the bore first and continues to be filled as the hose is gradually withdrawn from the bore. [0024] A cable reel can be mounted on machines according to the invention or the machines can be arranged to interact with a reel that is not mounted on the machine. In either case, the machines will include suitable arrangements to dispense cable into the bore and where the grout is delivered into the bore first, the cable dispensing system will push the cable into through the grout. [0025] In some forms of the invention, the cable dispensing system can include a pinch roller arrangement to draw cable from a cable reel and to push the cable into the bore. The pinch roller can cooperate with a cable reel which is mounted on the machine or with a reel that is not mounted on the machine. Other forms of dispensing systems could be employed alternatively. [0026] The attachment device which is employed in some machines of the invention and that is used to attach a bore anchor to the leading end of the cable, prior to the cable bolt being fed into the bore, can be of any suitable form. In some forms, the attachment device can include a rotatable cartridge that can hold one or <filename> 7 more anchors and that can rotate into a position of alignment with the leading end of the cable, so that when a cable is to be inserted into a bore, the cartridge can rotate to a position at which an anchor held by the cartridge is aligned with the leading end, so that the leading end can be advanced into the anchor. The cable can travel through the cartridge as the cable is pushed into the bore and when the leading end of the cable has reached the final position within the bore, the cable can be severed or cut to form a trailing end to which accessories such as a rock plate and a cable tensioning device can be applied. Once the cable has been severed, the cable can exit the cartridge, such as by the cartridge being moved beyond the severed end of the cable. Of course, the cable does not need to travel through the cartridge in all forms of the invention, and other forms of cartridge can be arranged so that once the anchor has been applied to the cable end, the cartridge is displaced or shifted away from the cable. [0027] The cable can be severed or cut in any suitable manner and for example, a suitable guillotine can be used for that purpose. This can be manually or automatically activated. [0028] In all forms of the invention, the leading end of the cable can attach to the anchor in any suitable manner to maintain attachment as the cable is pushed into the bore. The anchor could for example, grip the leading end of the cable, or it can include an abutment that the leading end of the cable bears against so that as the cable is pushed into the bore, the anchor moves with the leading end. Other arrangements could be employed. [0029] In all forms of the invention, the anchor applied to the leading end of the cable can have any suitable form and one form appropriate for use is disclosed in applicant's co-pending Australian patent application no. 2012902554, the full disclosure of which is incorporated herein by cross-reference. That form of anchor has a gripping arrangement for gripping the leading end of a cable and an expansion arrangement for expanding within a bore and anchoring the leading end of the cable within the bore. The anchor of Australian patent application no. 2012902554 can include a closed end so that the leading end of the cable can push against the closed end to push the anchor into the bore as the cable is pushed into the bore. Thus the anchor does not slide down the cable as the cable is pushed into the bore. <filename> 8 [0030] Machines according to the invention can also include a device for applying the rock plate to the trailing end of the cable and for applying the cable gripping device that grips the cable to maintain tension in the cable (often a barrel and wedge arrangement) after tension has been applied. The machines of the invention can further include a device for applying tension to the cable once the cable has been inserted into the bore and has been severed from the cable reel. Advantageously, this arrangement allows the rock plate, the cable gripping device and the tension to be applied to the cable in one operation. [0031] Machines and the method of the invention are not limited to the insertion of a single cable into the drilled bore. In some arrangements, more than a single cable can be inserted and for example, it is within the scope of the invention to insert a second cable into the bore. In this form of the invention, the second cable can be inserted without an anchor applied to the leading end and the second cable does not need to be of the same length as the first or primary cable. The second cable can be longer than the first cable but the expectation is that the second cable will be shorter than the first cable and in some arrangements, will not extend out of the open end of the bore. [0032] The cable used in machines and the method of the invention can be of any suitable form although the expected form is a wire cable formed of about seven strands of wire comprised of a central wire and six further wires wound about the central wire. Most forms of the invention are expected to form the cable with periodic deformations, bulges or other formations suitable to increase the bond strength between the cement grout and the cable when the grout cures. The periodic deformations can be formed by radially expanding the wire windings at specific positions along the length of the cable or the cable can have projections attached to it (known in the art as "buttons") or the wires of the cable can be bent or buckled at regular intervals, for example at every 0.5m. Alternatively, the individual wires of the cable can be deformed prior to forming the cable such as including indentations or ribs. [0033] As an alternative to the use of an attachment device for attaching a bore anchor to the leading end of the cable as part of the machine operation, in other machines according to the invention in which facility to allow attachment of a bore <filename> 9 anchor to the leading end of the cable prior to the cable bolt being fed into the bore is provided, the anchor can be attached to the leading end of the cable by hand. The facility can be a space provided for manual application of the bore anchor to the leading end of the cable. However, while this option falls within the scope of the present invention, the preference is to automatically attach the anchor to the cable by an attachment device, as that is expected to be faster than manual attachment by hand, at least because manual attachment will either require the leading end of the cable to be lowered to ground level for manual attachment, or for personnel to be elevated to the area of the open end of the bore. Brief Description of Drawings [0034] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which: [0035] Figures 1 a to 1f illustrate a machine in accordance with one form of the invention. [0036] Figure 2 illustrates an attachment device for use in the machine of Figures la to 1f. [0037] Figure 3 illustrates a cable gripping and tensioning device for use in the machine of Figures 1a to 1f. Detailed Description [0038] Figures 1a to 1f illustrate a machine 10 in accordance with one form of the invention which is capable of installing a cable bolt into a bore drilled into rock strata. Figures 1a to 1f also illustrate the method employed for cable bolt installation. [0039] The machine 10 includes a drill 11 for drilling a bore 12 into rock strata 13. In the figures, the bore 12 is shown broken through a centre-line thereof so that only the inner and outer ends of the bore 12 are illustrated, as the bore typically will be very long, and in the order of approximately 1Om. The drill 11 will typically be formed from separate drill rods, which are coupled together, and which would have a nominal length of approximately 1.5m. Thus, as the depth of the bore 12 increases, drill rods will be added to form a drill string until the required depth of the bore 12 is reached. <filename> 10 [0040] The drill 11 is driven by a drive 14 which can be a hydraulic drive. [0041] Once the bore 12 has been drilled, the drill 11, made up of a plurality of separate drill rods, can be removed from the bore 12. The drill 11 can be removed in any suitable manner, and typically, it is withdrawn from the bore 12 progressively as each drill rod is decoupled from the drill string. [0042] The machine 10 further includes a grout delivery system for delivering grout into the bore 12 and this step in the cable bolt installation method is illustrated in Figures 1b and 1c. In Figure 1b, the drill 11 has been removed from the bore 12 and a cement hose 15 is shown inserted into the bore 12 and is shown dispensing grout 16 into the inner end of the bore 12. In order to properly fill the bore 12, the hose 15 is advanced into the bore 12 fully to the bore end 17 and the hose 15 is slowly retracted from the bore 12 as grout fills the bore. The hose 15 can be retracted on a hose reel 18 and grout can be pumped to the reel 18 through a delivery hose 19. The hose 19 extends to a reservoir 20 that contains a supply of grout. The grout is thus pumped from the reservoir 20 through the delivery hose 19 and into the hose 15 for delivery into the bore 12. [0043] Figure 1c shows the bore 12 substantially filled with grout 16. Also, Figure 1c shows a bore anchor 21 attached to the leading end 22 of a cable 23 which is being pulled from a cable reel 24. [0044] The bore anchor 21 can be any suitable anchor, such as described in applicant's co-pending Australian provisional patent application no. 2012902554. That form of anchor 21 has a closed leading end 25, against which the distal end of the cable 23 can abut, so that as the cable 23 is advanced into the bore 12, the anchor 21 will move with the cable 23. This is illustrated in Figure 1d, in which the cable 23 has pushed into and through the grout 16, and the anchor 21 has moved with the cable 23 so as to also push through the grout 16. The manner with which the anchor 21 is attached to the leading end 22 of the cable 23 will now be described with reference to Figure 2. [0045] Attachment of the bore anchor 21 to the leading end 22 of the cable 23 occurs by an attachment device 30 illustrated in Figure 2, which forms part of the machine 10. The attachment device 30 includes a rotatable magazine or cartridge 31 <filename> 11 that in the embodiment illustrated in Figure 2, includes a plurality of openings 32 into which can be loaded a plurality of anchors 21 (the anchors 21 are not shown loaded into the openings 32 for clarity purposes). [0046] It will be appreciated that the cartridge 31 can be of any suitable size and can include any number of openings 32. For example, a single opening could be provided, or as shown in Figure 2, eleven openings can be provided. A greater or lower number of openings can be provided as required. [0047] The device 30 includes a hollow conduit or boom 33 through which the cable 23 travels. The cable 23 is driven through the conduit 33 upwardly in the orientation of the device 30 shown in Figure 2, so that it can advance through the conduit 33 and into one of the openings 32 to engage an anchor 21 disposed in the relevant opening 32. As shown in Figure 2, the cable 23 has advanced through the conduit 33 and through an opening 32 and into an anchor 21. As the cable 23 advances into an anchor 21, it advances to engage the closed end 25 of the anchor 21 and once that engagement occurs, further advancement of the cable 23 lifts the anchor 21 out of its respective opening 32. The anchor 21 then continues to advance with further advancement of the cable 23 in the manner shown in Figures 1c and 1d. [0048] The device 30 further includes a severing device 34 which includes a guillotine located within the device 34 so as not to be visible in Figure 2. The guillotine can be of any suitable known form and is hydraulically actuated by a hydraulic cylinder 35. The guillotine operates to sever the cable 23 once the cable 23 has advanced fully within the bore 12 of Figures 1a to 1f. Upon severing of the cable 23, a trailing cable end is formed and this will be discussed in more detail in relation to Figure 3. [0049] Once the cable 23 has been severed, the attachment device 30 can be lowered to expose the trailing end of the cable 23 and to completely remove the cable 23 from the device 30. The rotatable cartridge 31 can thereafter be rotated to bring a further opening 32 into alignment with the leading end of a new section of cable 23 so that the process of attaching an anchor 21 to the new leading end can again be facilitated. Once each of the anchors 21 has been removed from the openings 32 of the attachment device 30, a new set of anchors can be inserted into the openings 32. <filename> 12 Alternatively, as each anchor 21 is removed from an opening 32, a new anchor can be inserted into the respective opening 32 upon rotation of the cartridge 31. This can be a manual or automatic process. [0050] Once the cable 23 has been severed as described above, the machine 10 can apply accessories to the trailing end of the cable end 23, such as a rock plate and a cable gripping device. Such an arrangement is shown in Figure 3. In that figure, the trailing end 40 of the cable 23 is illustrated, which constitutes a cable portion of approximately 0.3m projecting out of the bore 12. Figure 3 illustrates a rock plate 41 and a cable gripping device 42 that comprises an outer barrel 43 and inner wedges 44. A plurality of wedges 44 are accommodated within the barrel 43 with an inclined or frustoconical interface 45 between the internal face of the barrel 43 and the external face of the wedges 44 promoting an increased grip on the outer surface of the trailing end 40 as the wedges 44 move into the barrel 43. [0051] A tensioning head 46 bears against the cable gripping device 42. The tensioning head 46 accommodates a spring 48, which bears against the base surface 49 of the head 46 and the facing surface 50 of the wedges 44. [0052] Each of the rock plate 41, the cable gripping device 42 and the tensioning head 46 can be applied to the cable 23 by the machine 10. Once these components have been applied to the cable end 40, the machine 10 can also apply tension to the end 40 via the tensioning grippers 51. Loading is applied by a hydraulic cylinder in the directions indicated by the arrows T1 and T2 in Figure 3 to the tensioning head 46 and the tensioning grippers 51, which grip the outer surface of the trailing cable end 40, so that the cable end 40 is tensioned in the direction T. [0053] Under tension, the cable 23 will tend to pull through the cable gripping device 42. So that the wedges 44 do not move with the cable 23, the spring 48 exerts pressure against the surface 50 of the wedges 44 maintaining them within the barrel 43. Once sufficient tension has been applied to the cable 23, the grippers 51 can be released from gripping the trailing cable end 40 and the cable gripping device 42 will grip the cable 23 and maintain the tension in the cable 23. A slight loss of tension will occur as the cable 23 pulls the wedges 44 into the barrel 43, but as described earlier herein, that loss of tension, while significant in the prior art, is much less significant in <filename> 13 the present invention. This is because the full length of the cable 23 is tensioned, so that for example, tension is applied through 10m of cable as opposed to potentially about 30mm to 100mm of cable as occurs in the prior art. [0054] It will be appreciated that as tension is applied to the cable 23, the bore anchor 21 attached to the leading end of the cable 23 will expand and grip against the facing surface of the inner end of the bore 12. This is illustrated in Figures le and 1f. Thus, the leading end of the cable 23 is anchored at the inner end of the bore 12 by the bore anchor 21, while the trailing cable end 40 is anchored by the cable gripping device 42. The cable 23 is thus held under tension within the bore 12. That tension is applied despite that the grout 16 has not been left to cure. Advantageously, by applying tension to the cable 23 and maintaining that tension in the manner discussed above, the cable bolt can provide immediate structural support to the rock strata 13. [0055] Moreover, the steps described above are completed in a single installation operation without the need for further installation steps. This contrasts with prior art arrangements in which tensioning of the cable bolt is undertaken two or three days after the bolt has been installed due to the requirement for the grout to cure before tensioning takes place. Moreover, it can be seen that via the machine of the invention, all of the steps required for the installation of the cable bolt can be carried out without the need for specialized installation personnel as required in the prior art. For example, as discussed above, in the prior art installation methodology, a cable bolt would be installed into a grout filled bore and two or three days later, tension would be applied to the bolt. It is this latter activity which can be avoided by the present invention and thus the present invention can provide cost savings in terms of the time taken to properly install the cable bolt and the reduction in personnel required for the installation steps. Moreover, the safety of installation personnel is improved, given that personnel are no longer required to be elevated well above the mine floor to tension cable bolts, and personnel are not put into areas of a mine which are not completely secured by installed rock bolts. [0056] With reference to Figure 1 e, that figure illustrates the application of the rock plate 41 to the rock bolt, and other accessories including the cable gripping device 42 to the trailing end 40 of the cable 23. Figure 1f illustrates the application of tensioning grippers 51 (not seen in Figure 1f) to the cable end 40 and the application of tension <filename> 14 to the cable 23. Once the application of tension has been made as shown in Figure 1f, the tensioning grippers 51 can be released from the cable end 40 and the machine 10 can move to the next site for cable bolt installation. At that next site, the steps illustrated in Figures la to 1f can be repeated. [0057] It is envisaged that a single operator will operate the machine 10 through each of the steps illustrated in Figures la to 1f. Alternatively, the machine 10 could be remotely operated. [0058] While it has not been mentioned before, it will be clear that the machine 10 moves on wheels 52, four of which are provided, and includes a body 53 which houses the grout reservoir 20, and which supports the cable reel 24. The body 53 further supports an arm 54 which is hydraulically operated and which is operable to manipulate the various functions of the machine 10 relating to drilling the bore 12, filling the bore 12 with grout 16, and advancing the cable 23 with the anchor 21 applied to the leading end thereof into the bore 12. The arm 54 is effectively operable to lift and lower, as well as shift various operational equipment of the machine 10. As shown in the figures, the hose reel 18 is mounted on the arm 54, although that position of mounting could easily be made on the body 53. [0059] The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the present disclosure. [0060] Throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps. <filename>

Claims

1. A machine for installing cable bolts, including a drill for drilling a bore into a rock wall, a grout delivery system for delivering grout into the bore, a cable dispensing arrangement for dispensing cable into the bore, an attachment device for attaching a bore anchor to the leading end of the cable prior to the cable bolt being fed into the bore, and a severing device for severing the cable to form a trailing end.

2. A machine according to claim 1, the attachment device including a rotatable cartridge that can hold one or more anchors and that can rotate into a position of alignment with the leading end of a cable being fed into the drilled bore, so that the leading end can be advanced into the anchor.

3. A machine according to claim 2, the cartridge including one or more openings for holding one or more anchors and the leading end of the cable being advanced into an opening to engage an anchor.

4. A machine according to any one of claims 1 to 3, the severing device being a guillotine located behind the attachment device in the direction of feed of the leading end of the cable into the bore.

5. A machine for installing cable bolts, including, a drill for drilling a bore into a rock wall, a grout delivery system for delivering grout into the bore, a cable dispensing arrangement for dispensing cable into the bore, facility to allow attachment of a bore anchor to the leading end of the cable, prior to the cable bolt being fed into the bore and a severing device for severing the cable to form a trailing end.

6. A machine according to claim 5, the facility to allow attachment of a bore anchor to the leading end of the cable comprising a space provided for manual application of the bore anchor to the leading end of the cable.

7. A machine according to any one of claims 1 to 6, the anchor being arranged to grip the leading end of the cable when the leading end is advanced into the anchor. <filename> 16

8. A machine according to any one of claims 1 to 6, the anchor including an abutment that the leading end of the cable bears against so that as the cable is fed into the bore, the anchor moves with the leading end.

9. A machine according to any one of claims 1 to 8, further including a device for applying a rock plate to the trailing end of the cable.

10. A machine according to any one of claims 1 to 9, further including a device for applying the cable gripping device to the cable.

11. A machine according to any one of claims 1 to 10, further including a device for applying tension to the cable once the cable has been fully fed into the bore and has been severed to form a trailing end.

12. A machine according to any one of claims 1 to 11, the cable dispensing device being a cable reel located on the machine and the cable being pulled from the reel for feeding into the bore.

13. A machine according to any one of claims 1 to 11, the cable dispensing device being a device for pulling cable from a cable reel which is apart from the machine.

14. A method of installing a cable rock bolt, the method including, drilling a bore into a rock wall, delivering grout into the bore, attaching a bore anchor to the leading end of a cable, and then feeding the cable into the bore, severing the cable to form a trailing end once the cable has been fed to the desired depth into the bore, applying a rock plate and a cable anchor to the trailing end of the cable, applying tension to the trailing end of the cable to cause the bore anchor to anchor the leading end of the cable within the bore and to cause the rock plate to engage the rock face under pressure. <filename>