UDD dragline bucket machine and control system

Abstract

A UDD mining machine provided with a control system directs the movement of the bucket within a prescribed carry envelope to limit unequal wearing of the hoist lines. In one construction, the control system directs the bucket within a range of motion where the loads on the hoist lines are kept within a prescribed variance of each other during the carry phase or most of the carry phase of a digging cycle. Movement of the bucket will be controlled by the mining machine with the inventive control system so that, in the carry phase, the loads applied to the front hoist line are within, for example, 5%, 10% or 15% of the loads applied to the rear hoist lines. This general equaling of the loads in the hoist lines results in longer wear life for the front hoist lines, and generally equal wearing of the front and rear hoist lines to enable simultaneous replacement.

1 . A UDD mining machine comprising:
 a bucket including a cavity for receiving earthen material, a front portion having a front digging edge, and an opposite rear portion;   a boom;   hoist lines for connecting the bucket to the boom to move the bucket vertically relative to the boom, one said hoist line being a front hoist line connecting the front portion of the bucket to the boom to independently raise and lower the front portion of the bucket, and another said hoist line being a rear hoist line connecting the rear portion of the bucket to the boom to independently raise and lower the rear portion of the bucket;   a drag line for pulling the bucket in a digging operation; and   a control system for directing the movement of the bucket in a digging operation which includes a digging phase where earthen material is gathered into the cavity of the bucket, a dump phase where the gathered earthen material is discharged from the bucket, and a carry phase where the bucket is moved from a first location at an end of the digging phase to a second location where the earthen material is discharged from the bucket, the control system directing the bucket to move predominantly within a range of motion in the carry phase so that a load on the front hoist line is generally maintained within a predetermined variance relative to a load on the rear hoist line.   
   
   
       2 . A UDD mining machine in accordance with  claim 1  wherein the control system directs the bucket to move in the carry phase so that the load on the front hoist line is maintained to be within about five percent of the load on the rear hoist line. 
   
   
       3 . A UDD mining machine in accordance with  claim 1  wherein the control system directs the bucket to move in the carry phase so that the load on the front hoist line is maintained to be within about ten percent of the load on the rear hoist line. 
   
   
       4 . A UDD mining machine in accordance with  claim 1  wherein the control system directs the bucket to move in the carry phase so that the load on the front hoist line is maintained to be within about fifteen percent of the load on the rear hoist line. 
   
   
       5 . A UDD mining machine in accordance with  claim 1  wherein the control system directs the bucket to move in the carry phase predominantly below an upper datum that generally has an increasing slope in a direction opposite the pulling of the bucket by the drag line. 
   
   
       6 . A UDD mining machine in accordance with  claim 1  wherein the control system directs the bucket to move in the carry phase predominantly below an upper datum that generally has a bell-shaped configuration. 
   
   
       7 . A UDD mining machine in accordance with  claim 1  wherein the range of motion widens generally at an increasing rate in a direction opposite the pulling by the drag line. 
   
   
       8 . A UDD mining machine in accordance with  claim 1  wherein the control system includes motors, operator controls and a computer. 
   
   
       9 . A UDD mining machine in accordance with  claim 8  wherein the control system includes an indicator to guide the operator to move the bucket within the range of motion in the carry phase. 
   
   
       10 . A UDD mining machine in accordance with  claim 8  wherein the bucket is moved under computer control within the range of motion in the carry phase. 
   
   
       11 . A UDD mining machine comprising:
 a bucket including a cavity for receiving earthen material therein, a front portion having a front digging edge, and an opposite rear portion;   a boom;   hoist lines for connecting the bucket to the boom to move the bucket vertically relative to the boom, one said hoist line being a front hoist line connecting the front portion of the bucket to the boom to independently raise and lower the front portion of the bucket, and another said hoist line being a rear hoist line connecting the rear portion of the bucket to the boom to independently raise and lower the rear portion of the bucket;   a drag line for pulling the bucket in a digging operation; and   a control system for directing the movement of the bucket in a digging operation which includes a digging phase where earthen material is gathered into the cavity of the bucket, a dump phase where the gathered earthen material is discharged from the bucket, and a carry phase where the bucket is moved from a first location at an end of the digging phase to a second location where the earthen material is discharged from the bucket, the control system directing the bucket to move in the carry phase predominantly below an upper datum that generally has an increasing slope in a direction opposite to the pulling by the drag line.   
   
   
       12 . A UDD mining machine in accordance with  claim 11  wherein the control system includes motors, operator controls and a computer. 
   
   
       13 . A UDD mining machine in accordance with  claim 12  wherein the control system includes an indicator to guide the operator to move the bucket within the range of motion in the carry phase. 
   
   
       14 . A UDD mining machine in accordance with  claim 12  wherein the bucket is moved under computer control within the range of motion in the carry phase. 
   
   
       15 . A UDD mining machine comprising:
 a bucket including a cavity for receiving earthen material therein, a front portion having a front digging edge, and an opposite rear portion;   a boom;   hoist lines for connecting the bucket to the boom to move the bucket vertically relative to the boom, one said hoist line being a front hoist line connecting the front portion of the bucket to the boom to independently raise and lower the front portion of the bucket, and another said hoist line being a rear hoist line connecting the rear portion of the bucket to the boom to independently raise and lower the rear portion of the bucket;   a drag line for pulling the bucket in a digging operation; and   a control system for directing the movement of the bucket in a digging operation which includes a digging phase where earthen material is gathered into the cavity of the bucket, a dump phase where the gathered earthen material is discharged from the bucket, and a carry phase where the bucket is moved from a first location at an end of the digging phase to a second location where the earthen material is discharged from the bucket, the control system directing the bucket to move in the carry phase in a range of motion that depends on the expected relative loads on the hoist lines.   
   
   
       16 . A UDD mining machine in accordance with  claim 15  wherein the control system includes motors, operator controls and a computer. 
   
   
       17 . A UDD mining machine in accordance with  claim 16  wherein the control system includes an indicator to guide the operator to move the bucket within the range of motion in the carry phase. 
   
   
       18 . A UDD mining machine in accordance with  claim 16  wherein the bucket is moved under computer control within the range of motion in the carry phase. 
   
   
       19 . A UDD mining machine in accordance with  claim 17  wherein the control system directs the bucket to move in the carry phase so that in the range of motion the loads on the front hoist line are on average at about a predetermined amount higher than the loads on the rear hoist lines to control the replacement time for the front hoist line. 
   
   
       20 . A control system for a UDD mining machine having a bucket, a boom, hoist lines for connecting the bucket to the boom and a drag line for pulling the bucket in a digging operation, the control system comprising means for independently adjusting a front one of the hoist lines to vertically move a front portion of the bucket, means for independently adjusting a rear one of the hoist lines to vertically move a rear portion of the bucket, and means for adjusting the drag line to pull the bucket along the ground, the control system directing the movement of the bucket in a digging operation which includes a digging phase where earthen material is gathered into the bucket, a dump phase where the gathered earthen material is discharged from the bucket, and a carry phase where the bucket is moved from a first location at an end of the digging phase to a second location where the earthen material is discharged from the bucket, and the control system directing the bucket to move in the carry phase predominantly within a range of motion so that a load on the front hoist line is generally maintained within a predetermined variance relative to a load in the rear hoist line. 
   
   
       21 . A control system for a UDD mining machine in accordance with  claim 20  which moves the bucket in the carry phase predominantly below an upper datum that generally has an increasing slope in a direction opposite the pulling by the drag line. 
   
   
       22 . A control system for a UDD mining machine in accordance with  claim 20  wherein the range of motion in which the control system directs the bucket to move in the carry phase generally widens in a direction opposite the pulling by the drag line. 
   
   
       23 . A control system for a UDD mining machine in accordance with  claim 20  wherein the range of motion widens generally at an increasing rate in a direction opposite the pulling by the drag line. 
   
   
       24 . A control system in accordance with  claim 20  further including motors, operator controls and a computer. 
   
   
       25 . A control system in accordance with  claim 24  further including an indicator to guide the operator to move the bucket within the range of motion in the carry phase. 
   
   
       26 . A control system in accordance with  claim 24  which moves the bucket under computer control within the range of motion in the carry phase. 
   
   
       27 . A control system for a UDD mining machine having a bucket, a boom, hoist lines for connecting the bucket to the boom, and a drag line for pulling the bucket in a digging operation, the control system comprising means for independently adjusting a front one of the hoist lines to vertically move a front portion of the bucket, means for independently adjusting a rear one of the hoist lines to vertically move a rear portion of the bucket, and means for adjusting the drag line to pull the bucket along the ground, the control system directing the movement of the bucket in a digging operation which includes a digging phase where earthen material is gathered into the bucket, a dump phase where the gathered earthen material is discharged from the bucket, and a carry phase where the bucket is moved from a first location at an end of the digging phase to a second location where the earthen material is discharged from the bucket, and the control system directing the bucket to move in the carry phase predominantly below an upper datum that generally has an increasing slope in a direction opposite the pulling by the drag line. 
   
   
       28 . A control system for a UDD mining machine having a bucket a boom, hoist lines for connecting the bucket to the boom, and a drag line for pulling the bucket in a digging operation, the control system comprising means for independently adjusting a front one of the hoist lines to vertically move a front portion of the bucket, means for independently adjusting a rear one of the hoist lines to vertically move a rear portion of the bucket, and means for adjusting the drag line to pull the bucket along the ground, the control system directing the movement of the bucket in a digging operation which includes a digging phase where earthen material is gathered into the bucket, a dump phase where the gathered earthen material is discharged from the bucket, and a carry phase where the bucket is moved from a first location at an end of the digging phase to a second location where the earthen material is discharged from the bucket, and the control system directing the bucket to move in the carry phase in a range of motion that depends on the expected relative loads on the hoist lines. 
   
   
       29 . A control system for a UDD mining machine in accordance with  claim 28  wherein the control system directs the bucket to move in the range of motion so that the loads on the front hoist line are on average at about a predetermined amount higher than the loads on the rear hoist lines to control the replacement time for the front hoist line. 
   
   
       30 . A method of operating a UDD mining machine having a bucket for receiving earthen material and a boom, the method comprising:
 pulling a drag line connected to the bucket to move the bucket along the ground to gather earthen material;   moving the boom and independently adjusting each of a front hoist line connected to a front portion of the bucket and a rear hoist line connected to a rear portion of the bucket to move the bucket from a first location at an end of the pulling of the bucket by the drag line to a second location where the gathered earthen material is discharged from the bucket so that the bucket moves within a range of motion such that a load on the front hoist line is generally maintained within a predetermined variance relative to a load on the rear hoist line.   
   
   
       31 . A method of operating a in accordance with  claim 30  where the bucket is moved from the first location to the second location predominantly below an upper datum that generally has an increasing slope in a direction opposite the pulling by the drag line. 
   
   
       32 . A method of operating a UDD mining machine in accordance with  claim 30  wherein the range of motion generally widens in a direction opposite the pulling by the drag line. 
   
   
       33 . A method of operating a UDD mining machine in accordance with  claim 30  wherein the range of motion widens generally at an increasing rate in a direction opposite the pulling by the drag line. 
   
   
       34 . A method of operating a UDD mining machine having a bucket for receiving earthen material and a boom, the method comprising:
 pulling a drag line connected to the bucket to move the bucket along the ground to gather earthen material;   moving the boom and independently adjusting each of a front hoist line connected to a front portion of the bucket and a rear hoist line connected to a rear portion of the bucket to move the bucket from a first location at an end of the pulling by the drag line to a second location where the earthen material is discharged from the bucket so that the bucket moves below an upper datum that generally has an increasing slope in a direction opposite the pulling of the drag line.   
   
   
       35 . A method of operating a UDD mining machine in accordance with  claim 34  wherein the range of motion widens generally at an increasing rate in a direction opposite the pulling by the drag line.