Apparatus and method for manufacturing a cable bolt

Abstract

An apparatus for manufacturing a cable bolt includes a rotatably driven pay-out reel ( 20 ) for paying out a cable ( 1 ) coiled in use about the pay-out reel ( 20 ). An upstream accumulator ( 40 ) is located downstream of the pay-out reel ( 20 ) for accumulating cable ( 1 ) advanced from the pay-out reel ( 20 ). A bulb forming device ( 80 ) is located downstream of the upstream accumulator ( 40 ), for forming a bulb ( 2 ) in cable ( 1 ) advanced from the upstream accumulator ( 40 ). A cable drive ( 60 ) is located downstream of the upstream accumulator ( 40 ), for advancing cable ( 1 ) through the bulb forming device ( 80 ). The pay-out reel ( 20 ) is configured to rotate at least substantially continuously whilst the cable drive ( 60 ) is configured to advance the cable ( 1 ) after formation of each bulb ( 2 ) to a position for formation of a subsequent bulb ( 2 ) in the cable. The cable drive ( 60 ) stops a central portion ( 1 b ) of the cable downstream of the upstream accumulator ( 40 ) for formation of the subsequent bulb ( 2 ), the upstream accumulator accumulating or decumulating an upstream portion ( 1 a ) of the cable ( 1 ) as required throughout operation of the apparatus to allow at least substantially continuous rotation of the pay-out reel ( 20 ) whilst the central portion ( 1 b ) of the cable ( 1 ) is stationary.

1 . An apparatus for manufacturing a cable bolt, said apparatus comprising:
 a rotatably driven pay-out reel for paying out a cable coiled in use about said pay-out reel;   an upstream accumulator, located downstream of said pay-out reel, for accumulating cable advanced from said pay-out reel;   a bulb forming device, located downstream of said upstream accumulator, for forming a bulb in cable advanced from said upstream accumulator;   a cable drive, located downstream of said upstream accumulator, for advancing cable through said bulb forming device;   wherein said pay-out reel is configured to rotate at least substantially continuously whilst said cable drive is configured to advance the cable after formation of each bulb to a position for formation of a subsequent bulb in the cable, said cable drive stopping a central portion of the cable downstream of said upstream accumulator for formation of the subsequent bulb, said upstream accumulator accumulating or decumulating an upstream portion of the cable as required throughout operation of said apparatus to allow at least substantially continual rotation of said pay-out reel whilst the central portion of the cable is stationary.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 a downstream accumulator, located downstream of said bulb forming device and said cable drive, for accumulating cable advanced from said bulb forming device; and   a rotatably driven take-up reel for taking up cable advanced from said downstream accumulator;   wherein said take-up reel is configured to rotate at least substantially continuously, said downstream accumulator accumulating or decumulating a downstream portion of the cable as required throughout operation of said apparatus to allow at least substantially continuous rotation of said take-up reel whilst the central portion of the cable is stationary.   
     
     
         3 . The apparatus of  claim 1 , wherein said cable drive is located upstream of said bulb forming device. 
     
     
         4 . The apparatus of  claim 1 , wherein said upstream accumulator is configured to engage an upstream portion of the cable and deflect the path of the upstream portion of the cable in a direction tending to maintain a constant tension in the upstream portion of the cable. 
     
     
         5 . The apparatus of  claim 4 , wherein said upstream accumulator comprises a pulley mounted on a displaceable shaft. 
     
     
         6 . The apparatus of  claim 2 , wherein said downstream accumulator is configured to engage a downstream portion of the cable and deflect the path of the upstream portion of the cable in a direction tending to maintain a constant tension in the upstream portion of the cable. 
     
     
         7 . The apparatus of  claim 6 , wherein said downstream accumulator comprises a pulley mounted on a displaceable shaft. 
     
     
         8 . The apparatus of  claim 1 , wherein said bulb forming device comprises:
 a first clamp adapted to releasably clamp the central portion of the cable with the central portion of the cable extending along a longitudinal axis;   a second clamp longitudinally spaced from said first clamp and adapted to releasably clamp the central portion of the cable with the central portion of the cable extending along said longitudinal axis; and   a clamp displacement drive for longitudinally displacing said first clamp, relative to said second clamp, along said longitudinal axis.   
     
     
         9 . The apparatus of  claim 2  further comprising a cutting device, located downstream of said bulb forming device for cutting cable advanced from said bulb forming device,
 wherein said downstream accumulator and said take-up reel accumulator are displaceable from an operative position downstream of said bulb forming device. 
 
     
     
         10 . An apparatus for manufacturing a cable bolt, said apparatus comprising:
 a cable supply;   a bulb forming device, located downstream of said cable supply, for forming a bulb in cable advanced from said cable supply;   a cable drive, located downstream of said cable supply, for advancing cable through said bulb forming device;   a downstream accumulator, located downstream of said bulb forming device and said cable drive, for accumulating cable advanced from said bulb forming device; and   a rotatably driven take-up reel for taking up cable advanced from said downstream accumulator;   wherein said said take-up reel is configured to rotate at least substantially continuously whilst said cable drive is configured to advance the cable after formation of each bulb to a position for formation of a subsequent bulb in the cable, said cable drive stopping a central portion of the cable between said cable supply and said downstream accumulator for formation of the successive bulb, said downstream accumulator accumulating or decumulating a downstream portion of the cable as required throughout operation of said apparatus to allow at least substantially continuous rotation of said take-up reel whilst the central portion of the cable is stationary.   
     
     
         11 . The apparatus of  claim 1 , wherein said cable drive is located upstream of said bulb forming device. 
     
     
         12 . The apparatus of  claim 2 , wherein said downstream accumulator is configured to engage a downstream portion of the cable and deflect the path of the upstream portion of the cable in a direction tending to maintain a constant tension in the upstream portion of the cable. 
     
     
         13 . The apparatus of  claim 6 , wherein said downstream accumulator comprises a pulley mounted on a displaceable shaft. 
     
     
         14 . The apparatus of  claim 1 , wherein said bulb forming device comprises:
 a first clamp adapted to releasably clamp the central portion of the cable with the central portion of the cable extending along a longitudinal axis;   a second clamp longitudinally spaced from said first clamp and adapted to releasably clamp the central portion of the cable with the central portion of the cable extending along said longitudinal axis; and   a clamp displacement drive for longitudinally displacing said first clamp, relative to said second clamp, along said longitudinal axis;   further comprising a cutting device, located downstream of said bulb forming device, for cutting cable advanced from said bulb forming machine.   
     
     
         15 . A method for manufacturing a cable bolt, said method comprising:
 rotatably driving a pay-out reel having a cable coiled thereon to pay-out said cable from said pay-out reel;   operating a cable drive, located downstream of said pay-out reel, to advance said cable through said cable drive and a bulb forming device;   operating said cable drive to intermittently stop a central portion of said cable whilst continuing to rotatably drive said pay-out reel;   whilst said central portion of said cable is stopped, forming a bulb in said central portion of said cable with said bulb forming device; and   accumulating an upstream portion of said cable, located upstream of said cable drive and said bulb forming device, whilst said central portion of said cable is stopped.   
     
     
         16 . The method of  claim 10 , further comprising the steps of:
 rotatably driving a take-up reel, located downstream of said bulb forming device, to take up cable advanced from said bulb forming device; and   accumulating a downstream portion of said cable, located downstream of said cable drive and said bulb forming device, whilst said portion of said cable is being advanced.   
     
     
         17 . A method for manufacturing a cable bolt, said method comprising:
 supplying cable from a cable supply;   operating a cable drive, located downstream of said cable supply, to advance said cable through said cable drive and a bulb forming device;   rotatably driving a take-up reel, located downstream of said bulb forming device, to take up cable advanced from said bulb forming device;   operating said cable drive to intermittently stop a central portion of said cable whilst continuing to rotatably drive said take-up reel;   whilst said central portion of said cable is stopped, forming a bulb in said central portion of said cable with said bulb forming device; and   accumulating a downstream portion of said cable, located downstream of said cable drive and said bulb forming device, whilst said portion of said cable is being advanced.   
     
     
         18 . A method for manufacturing a cable bolt, said method comprising:
 a) driving a cable along a longitudinally extending path through a bulb forming device having an upstream clamp and a downstream clamp longitudinally spaced from said upstream clamp;   b) at a position upstream of said bulb forming device, measuring displacement of said cable along said path whilst said cable is being driven;   c) stopping at least a portion of said cable extending through said bulb forming device upon a first predetermined measured displacement of said cable equal to said displacement measured at step b);   d) clamping said portion of said cable with said upstream clamp and said downstream clamp;   e) displacing said upstream clamp towards said downstream clamp, thereby longitudinally compressing said portion of said cable to form a bulb in said portion of said cable;   f) unclamping said portion of said cable;   g) further driving said cable along said path;   h) at said position upstream of said bulb forming device, measuring further displacement of said cable along said path whilst said cable is being further driven;   i) stopping at least a further portion of said cable extending through said bulb forming device upon a further predetermined measured displacement of said cable equal to said further displacement measured at step h);   j) clamping said further portion of said cable with said upstream clamp and said downstream clamp;   k) displacing said upstream clamp towards said downstream clamp, thereby longitudinally compressing said further portion of said cable to form a further bulb in said further portion of said cable;   l) unclamping said further portion of said cable; and   m) repeating steps g) to l).   
     
     
         19 . The method of  claim 18 , wherein steps b) and f) are performed with a measuring device, output of said measuring device during step d) being disregarded when measuring displacement of said cable. 
     
     
         20 . The method of  claim 19 , wherein said measuring device is a rotary shaft encoder. 
     
     
         21 . The method of  claim 20 , wherein said shaft encoder is mounted on a wheel engaging said cable, said shaft encoder measuring rotation of said wheel. 
     
     
         22 . The method of  claim 20 , wherein said shaft encoder is coupled to a drive shaft of said cable drive, said shaft encoder measuring rotation of said drive shaft. 
     
     
         23 . The method of  claim 18  wherein, immediately prior to unclamping said portion of said cable in step f), and immediately prior to unclamping said further portion of said cable in step l), a force applied to said upstream clamp to displace said upstream clamp toward said downstream clamp is removed, thereby allowing said upstream clamp to be displaced away from said downstream clamp during elastic recovery of said portion of said cable and during classic recovery of said further portion of said cable.