Method for steering a mining machine cutter

Abstract

A control system monitors the angle of each ranging arm, with respect to the mainframe of the machine. While the machine is in a defined zone along the face, if the angle of the arm is detected to be lower than a parameter defined set-point called the undercut limit, the control system does not allow the arm to be lowered further. When entering the run of face from either gate end, if either of the ranging arms are below the set point, the horizontal movement of the shearer is stopped, and an alarm message is generated, and a warning light begins to flash, alerting the operator that he must raise the arm before horizontal movement of the shearer can be enabled.

The invention claimed is: 
     
       1. A method of steering a trailing drum of a double-ended mining machine in which the mining machine is of the kind having a body arranged to be progressed along a mineral face being cut, the body having at each end a ranging arm pivotally mounted on the body and each arm carrying a rotatable cutting drum, a plurality of sensors being mounted on the machine and being adapted to measure different parameters of the mining operation and to generate signals representative of said parameters,
 a first of said sensors being arranged to measure the positions of each of said arms with respect to the machine, 
 a second of said sensors being arranged to measure the movement and direction of the machine, 
 a third of said sensors being arranged to measure a roll of the machine along the mineral face, 
 the method comprising the steps of:
 establishing from the first and second sensors, signals indicating the direction of movement of the machine and the position of the machine relative to the mineral face, and signals indicating the position of the ranging arm relative to a mine floor, 
 establishing from the third sensor, signals indicating the roll of the machine, 
 processing the signals to determine if the machine is leaving a gate end of the mineral face in a direction towards an opposite gate end of the mineral face, 
 determining a current position of at least one ranging arm, 
 comparing the current position of the ranging arm with an undercut limit defined along the mineral face, and 
 stoppingpreventing movement of the ranging arm from the gate end when the current position of the ranging arm is below the undercut limit. 
 
 
     
     
       2. A method according to claim  1  5 wherein movement of the machine resumes when the ranging arm is no longer below the undercut limit. 
     
     
       3. A method according to claim  1  5 wherein movement of the ranging arm is stopped when the ranging arm reaches the undercut limit and when the mining machine is at a position other than a the gate end and the opposite gate end. 
     
     
       4. A method of steering a trailing drum of a double-ended mining machine in which the mining machine is of the kind having a body arranged to be progressed along a mineral face being cut, the body having at each end a ranging arm pivotally mounted on the body and each arm carrying a rotatable cutting drum, a plurality of sensors being mounted on the machine and being adapted to measure different parameters of the mining operation and to generate signals representative of said parameters,
 a first of said sensors being arranged to measure the positions of each of said arms with respect to the machine, 
 a second of said sensors being arranged to measure the movement and direction of the machine, 
 a third of said sensors being arranged to measure a roll of the machine along the mineral face,  
 the method comprising the steps of: 
 establishing from the first and second sensors, signals indicating the direction of movement of the machine and the position of the machine relative to the mineral face, and signals indicating the position of the ranging arm relative to a mine floor, 
 establishing from the third sensor, signals indicating the roll of the machine, 
 processing the signals to determine if the machine is leaving a gate end of the mineral face in a direction towards an opposite gate end of the mineral face, 
 determining a current position of at least one ranging arm, 
 comparing the current position of the ranging arm with an undercut limit defined along the mineral face, 
 stoppingpreventing movement of the ranging arm from the gate end when the current position of the ranging arm is below the undercut limit, 
 resuming movement of the machine when the ranging arm is no longer below the undercut limit, and 
 continuously determining the current position of at least one the ranging arm when the mining machine is moving along the mineral face at a position other than a the gate end and the opposite gate end, and 
 stopping movement of the ranging arm when the current position of the ranging arm is below reaches the undercut limit. 
 
 
     
     
       5. A method according to claim 1 wherein movement of the ranging arm from the gate end is prevented by stopping the machine from leaving the gate end in the direction towards the opposite gate end when the current position of the ranging arm is below the undercut limit. 
     
     
       6. A method according to claim 4 wherein the movement of the ranging arm from the gate end is prevented by stopping the machine from leaving the gate end in the direction towards the opposite gate end when the current position of the ranging arm is below the undercut limit.