Abstract:
A drilling rig includes a base and a rotation unit for drilling a hole in a mine surface. The rotation unit is moveably coupled to the base. The drilling rig further includes a cable feed device for feeding a cable bolt into the hole created by the rotation unit. The cable feed device is moveably coupled to the base and includes a pair of wheels and a transmission. The cable bolt is received between the pair of wheels. The transmission is coupled between the rotation unit and at least one of the wheels to transmit power from the rotation unit to at least one of the wheels.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 12/762,682, filed on Apr. 19, 2010, which claims priority to Australian Patent Application No. AU2009201533, filed on Apr. 20, 2009, the entire contents of both applications are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The disclosure relates to an apparatus for reinforcing rock with a cable bolt, also called a tendon. More particularly, the disclosure relates to an apparatus for inserting the tendon into the rock. 
         [0003]    The reinforcement of rock originally involved the use of passive support systems that utilized timber and steel structural supports. Active support systems were subsequently developed including the provision of relatively rigid roof bolts that have been widely used and still find application. Early roof bolts were provided with mechanically operated wedge devices to facilitate anchorage of the roof bolts in the relevant rock. Later, concrete grout and chemical anchoring materials were developed for anchorage of roof bolts. Most recently, flexible wire tendons or cable bolts have found widespread application and are commonly used with such anchoring materials. The cable bolts usually have spaced apart cage sections along their length where the plurality of wires that make up the cable bolt are spread apart to assist in permitting the anchoring material to grasp the cable bolt. 
         [0004]    To install such a wire tendon, the bore for receipt of the tendon is first drilled into the rock to be supported. Given the length of the tendon, it is common to use a number of drill rod extensions to obtain the required bore depth. The selected anchoring material is then inserted in the bore and the wire tendon manually or mechanically driven into the bore prior to being tensioned to thereby support the rock once it has been anchored in position by the anchoring material. 
         [0005]    The anchoring material is typically contained in a cartridge that facilitates its insertion into the drilled bore. The material exists in the cartridges as separate adhesive and catalyst components that are mixed together by the tendon, when inserted in the bore, to cause the anchoring material to set and so anchor the tendon in position. 
         [0006]    A cable bolt can be up to 10 meters long and weigh up to 32 kilograms. Currently an operator has to feed the cable bolt by hand. It has been highlighted by mine managers that this is a significant health and safety concern due to the difficulty and regularity of the process, and can lead to a possible injury. Also, there is a possibility for the cable bolt to fall on the operator as it is being fed into the drilled hole. 
         [0007]    Below is a typical cable bolting procedure. 
         [0008]    1. Drill: 
         [0009]    Insert a first drill steel component (with cutter at top) into square chuck in rotation unit of a drill rig, drill up (with washer plate used for aligning), and clamp when at full travel, retract drill unit and load extension drill segment, spin and feed (ensuring that the threads engage). Continue process until all needed segments are used and then remove drill segments with same procedure in reverse. 
         [0010]    2. Load Chemicals: 
         [0011]    Slide a one-way catch device over a first chemical sausage. Push chemical up hole with a flexible plastic rod (pusher) to the top of the hole. Load a second chemical with catch device up to meet the first at the top of the hole. And then continue until the drilled hole is filled. 
         [0012]    3. Load Cable bolt: 
         [0013]    Manually push cable bolt up hole by hand and then load the free end into the drill rig rotation unit. 
         [0014]    4. Mix Chemical: 
         [0015]    Feed the cable bolt up and then spin, stopping the feed when the cable bolt reaches the top of the hole, but continue to spin for  10  seconds or so to mix chemicals. 
         [0016]    5. Tension Cable bolt: 
         [0017]    Retract the stab-jack. Insert a tension collar and grout pipes through washer plate. Lift tensioner and attach to end of cable bolt. 
         [0018]    Activate tensioner. 
         [0019]    6. Grout at a later time. 
       SUMMARY 
       [0020]    In one embodiment, the invention provides a drilling rig includes a base and a rotation unit for drilling a hole in a mine surface. The rotation unit is moveably coupled to the base. The drilling rig further includes a cable feed device for feeding a cable bolt into the hole created by the rotation unit. The cable feed device is moveably coupled to the base and includes a pair of wheels and a transmission. The cable bolt is received between the pair of wheels. The transmission is coupled between the rotation unit and at least one of the wheels to transmit power from the rotation unit to at least one of the wheels. 
         [0021]    In another embodiment the invention provides a drilling rig including a base and rotation unit for drilling a hole in a mine surface. The rotation unit is moveably coupled to the base. The drilling rig further includes a cable feed device that has a housing removably and slidably coupled to the base for feeding a cable bolt into the hole created by the rotation unit. The housing is removably coupled to the rig rotation unit and is movable with the rig rotation unit to position the cable bolt adjacent the hole. A transmission unit is coupled between the rotation unit and the cable feed device and the rotation unit. The transmission unit is configured to feed the cable bolt through the housing to the hole. 
         [0022]    Disclosed is a cable bolt lifting and feeding device to be used with a drill rig including a base, and a drill rig rotation unit translatable along the drill rig base. The lifting and feeding device includes a housing, a pair of spaced apart wheels, adapted to engage a cable bolt, and mounted within the housing, and wheel rotating means connected to the wheels for rotating the wheels, and adapted to be connected to the drill rig rotation unit. 
         [0023]    Also disclosed is a device for grasping a cable bolt, the device being adapted to be attached to a drill rig rotation unit, and movable with the drill rig rotation unit to position the cable bolt adjacent a pre-drilled hole in a roof or rib. The device includes means for grasping a cable bolt having an enlarged section, and means for permitting the enlarged section to pass through the device, and for automatically holding the cable bolt in the device after feeding the cable bolt into the device. 
         [0024]    More particularly, the means for grasping a cable bolt comprises a pair of spaced apart wheels, adapted to engage the cable bolt, and mounted within the housing, and wheel rotating means connected to the wheels for rotating the wheels, and adapted to be connected to the drill rig rotation unit. 
         [0025]    This disclosure provides a device to help reduce the health risks involved with manually inserting a cable bolt, and to provide an efficient and sustainable aid to the cable bolting process. 
         [0026]    An object of this disclosure is to provide such a device that is lightweight and that can be used with an existing drill rig. 
         [0027]    Another object of this disclosure is to provide such a device that can take advantage of the power already supplied to the drill rig, by taking advantage of the available drill rotation unit. Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]      FIG. 1  is an isometric view of a drill rig including a cable bolt lifting and feeding device. 
           [0029]      FIG. 2  is a side view of the device shown in  FIG. 1 . 
           [0030]      FIG. 3  is a side view of the cable bolt lifting and feeding device shown in  FIG. 1 . 
           [0031]      FIG. 4  is a top view of the device shown in  FIG. 3 . 
           [0032]      FIG. 5  is a partial cross-sectional view of the device shown in  FIG. 4  taken along the line  5 - 5  in  FIG. 4 . In  FIG. 5 , a pair of pivotally connected wheel arms is shown in a closed position. 
           [0033]      FIG. 6  is a partial cross-sectional view of the device shown in  FIG. 4  taken along the line  5 - 5  in  FIG. 4 . In  FIG. 6 , the pair of pivotally connected wheel arms is shown in an open position. 
           [0034]      FIG. 7  is a partial cross-sectional view of the device shown in  FIG. 4  taken along the line  7 - 7  in  FIG. 4 . Fig. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Use of “including” and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of” and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Further, it is to be understood that such terms as “forward”, “rearward”, “left”, “right”, “upward” and “downward”, etc., are words of convenience and are not to be construed as limiting terms. 
         [0036]    As illustrated in the drawings, a lifting and feeding device  10  is disclosed that assists a cable bolt-bolting operator (not shown) in raising and feeding a cable bolt  14  from ground level into a pre-drilled hole (not shown) in the roof or rib. The disclosed device improves step 3 above—Load Cable bolt. Although usable with a cable bolt without cage sections, the device  10  can accommodate the cable bolt  14  with cage sections  16 . 
         [0037]    As shown in  FIGS. 1 and 2 , the lifting and feeding device  10  is used with a drill rig  20  including a base  24 , and a drill rig rotation unit  28  translatable along the drill rig base  24 . 
         [0038]    More particularly, the drill rig base  24  includes two spaced apart parallel feed rods  26  that extend from one end of the drill rig  20  to the other. The drill rig rotation unit  28  is translatable along the drill rig  20  by sliding along the parallel feed rods  26 . Means (not shown) is also provided for moving the rotation unit  28  along the feed rods  26 . In other less preferred embodiments (not shown), the device  10  can sit on the drill rotation unit  28  without being attached to the feed rods  26 . 
         [0039]    As illustrated in  FIGS. 1 and 2 , the lifting and feeding device  10  grasps the cable bolt  14 , and is movable with the drill rig rotation unit  28  to position the cable bolt  14  adjacent a pre-drilled hole (not shown). 
         [0040]    As illustrated in  FIGS. 3 through 7 , the lifting and feeding device  10  includes a housing  40 , and grasping means  44  for grasping the cable bolt  14 . The grasping means  44  (see  FIGS. 5 and 6 ) is in the form of a pair of spaced apart wheels  45  and  46  mounted within the housing  40 . The wheel  45  and  46  are adapted to engage or grasp the cable bolt  14 . The grasping means  44  also permits, as further explained below, for the cable bolt cage section  16  to pass through the device  10 . The grasping means  44  also automatically holds the cable bolt  14  in the device  10 , as further explained below, after feeding the cable bolt  14  into the device  10 . 
         [0041]    More particularly, the wheels  45  and  46  are each connected to the housing by a respective pivoting arm  70  and  72 , respectively. Wheel rotating or drive means  48  is connected to the right-most wheel  46 , as shown in the drawings, for rotating the drive wheel  46 . The wheel rotating means  48  is connected to the drill rig rotation unit  28  via a belt drive  52  as shown in  FIG. 7 , including a bevel gear set  56  (see  FIG. 5 ), a poly-V belt  60 , and pulleys  64  and  65 , all connected to a drive housing  88  that pivots relative to the housing  40 . The belt drive  52  rotates the wheel  46 , as shown in  FIGS. 5 and 6 , in a clockwise direction, and prohibits rotation of the drive wheel  46  in the reverse direction. A torque limiting friction clutch  66  is used on the large pulley  65 . The two wheels draw closer as they lower, as shown in  FIG. 5 , until they reach a stop  67 . 
         [0042]    In other embodiments, transmitting power from the rotation unit  28  to the wheels  45  and  46  can be achieved in a number of ways. This device  10  uses the bevel gear set and the poly-V belt and the pulley design. This combination was selected due to weight, size and speed reduction requirements. Plastic was used wherever possible to reduce the weight of the device. 
         [0043]    The wheels are mounted to the two separate pivoting arms  70  and  72 . This enables the larger diameter (approx  45 mm) cage sections to be pushed through the feed tube formed by the spaced apart wheels  45  and  46  ( 50 mm inside diameter) when inserting the cable bolt  14 . 
         [0044]    The lifting and feeding device  10  is adapted to be connected to the housing  40  and slidably along the drill base  24  for translatable movement along the drill base  24  with the drill rig rotation unit  28 . More particularly, as shown in  FIGS. 1 and 2 , the device  10  sits atop of the rotating unit  28 , and the device  10  moves with the rotation unit  28 . The device  10  includes two locating brackets  33  that are secured around the pair of spaced apart parallel feed rods  26  in the form of steel bars that form part of the base  24 . As a result of the locating brackets  33  having notches  34  that grasp the outside of the feed rods  26 , as shown in  FIG. 1 , the device can readily slide along the feed rods  26  and move with the rotational unit  28  up and down the drill rig  20 . 
         [0045]    As illustrated in  FIGS. 3 ,  5  and  6 , a square drive  73  fits into a mating opening (not shown) in the top of the rotating unit  28 . The square drive  73  rotates; turning the bevel gear set  56 . The bevel gear set  56 , in turn, drives the first plastic pulley  64 , as shown in  FIG. 7 , which, in turn, drives the V belt  60 , which, in turn, drives the large pulley  65 , and the torque-limiting clutch  66 . The torque-limiting clutch  66  in turn is drivingly connected to the drive wheel  46 . 
         [0046]    As shown in  FIGS. 5 and 6 , and mentioned earlier, the wheels  45  and  46  are mounted on the pivoting arms  70  and  72 . The arms  70  and  72  are connected to one another by a link pin  75 . When a cable  14  is fed between the wheels  45  and  46 , if the cable  14  is larger than the spacing between the wheels  45  and  46 , then the arms  70  and  72  will pivot away from the cable  14 , increasing the spacing between the wheels  45  and  46 . This allows a cage section  16  to readily pass between the wheels  45  and  46  when spaced apart, as shown in  FIG. 6 . When the cable is released it will tend to fall due to gravity and with any such retractive motion the arms will pivot down resulting in the grasping of the cable  14 . This grasping force increases as the retractive force increases (ie. as it lifts more weight or if someone pulls on the cable) preventing any slippage. The drive wheel will not rotate because the drive system is engaged with the drill. Therefore the only movement of the cable in either the upward or downward directions is in a controlled manner via the drill controls. 
         [0047]    In order to permit the pivoting of the rightmost arm  72 , the belt drive  52  pivots with the arm  72 , for the belt drive  52  is pivotally mounted to the housing  40  at the first pulley  64  by a pin  80 , so that the belt drive can pivot about the bevel gear set  56 . 
         [0048]    In summary, the device is a lightweight unit that mounts into the drill rig rotation unit. It uses the mechanical power provided in the rotation unit to drive the set of wheels that engage with the cable bolt, causing the cable bolt to be pushed through the device and into the pre-drilled hole. 
         [0049]    Procedure (at Stage 3 of the cable bolting procedure in the background): 
         [0050]    1. Loading device onto drill rig: 
         [0051]    The device  10  is located by a drive shaft in the rotation unit  28 , and the two brackets  33  that slide on the feed rods  26 , thus becoming an extension of the rotation unit and able to move up and down the drill rig  20 . To place the device in position, the brackets must be engaged first by rotating the device  10  (approximately 30 degrees) and hooking the brackets  33  around the back of the feed rods  26 . After straightening the device  10  up, the brackets are engaged and the device can be lowered into the rotation unit chuck. 
         [0052]    2. Position device: 
         [0053]    Next the device (with the rotation unit) needs to be positioned at an appropriate height on the feed to align the pre-drilled hole with the outlet hole of the device. This is done by operating the drill rig and raising the rotation unit. 
         [0054]    3. Preload cable bolt: 
         [0055]    Most cable bolts have a number of cage sections at the top end of the cable bolt for improved performance. The cable bolt must be fed through the device and up into the hole until the last cage section passes out the end of the device. The cable bolt can then be released where the automatic detent system holds the cable bolt in position. 
         [0056]    4. Feed cable bolt into hole: 
         [0057]    Once loaded, the cable bolt can be fed by operating the rotate function of the drill rig. 
         [0058]    This will spin the wheels and drive the cable bolt into the pre-drilled hole. 
         [0059]    5. Retract device and remove: 
         [0060]    Using clamping jaws  84  incorporated in the drill rig top plate, the cable bolt  14  is clamped and held while the device (with rotation unit) is retracted. This leaves a cable bolt end hanging from the hole. Once retracted, the feed device can be removed by a reverse of step 1, (possibly a brief reverse spin of the rotation unit is required first to disengage the drive shaft). 
         [0061]    6. Load cable bolt end into rotation unit: 
         [0062]    By operating the drill rig and raising the rotation unit the suspended cable bolt end is engaged into the chuck. 
         [0063]    In addition to the pivoting arms allowing a size variation in the cable bolt  14  to be pushed through, the sprag motion is utilized to auto detent the cable bolt from dropping. The sprag motion (where the two wheel arcs draw closer as they lower until they reach the stop  67 ) increases the force applied to the cable bolt exponentially until it jams. To limit this jamming force from becoming self-destructive, an elastomeric bushing  86  (or any other type of spring) is used at the end of the pivot arm  70 . This force will be applied to the cable bolt when the device is both driven and stopped. To retract the cable bolt the rotation unit must be operated in reverse, which causes the pivot arms to rise and reduce the load on the cable bolt. 
         [0064]    The second arm is connected to the first via a pin that ensures that the two wheels rise and fall approximately together. This prevents any offsetting of the wheels and ensures that the loading is in approximately the same direction on the wheels as they rise and fall. This angle is approximately perpendicular to the cable bolt. 
         [0065]    The torque limiting friction clutch  66  is used on the large pulley  65  to ensure that high torque loads are not transferred to any of the transmission elements. This high torque is produced if the wheels clamp too hard on the cable bolt  14  when the elastomeric bushing  86  reaches maximum deflection. 
         [0066]    It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text. All of these different combinations constitute various alternative aspects of the invention. 
         [0067]    Various features and advantages of the invention will be apparent in the following claims.