You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
TECHNICAL FIELD  
         [0001]    The present invention relates to augers employed in mines and more particularly, but not exclusively, to coal augers used in conjunction with rotating cutter heads.  
         BACKGROUND OF THE INVENTION  
         [0002]    Coal augers have been used for the purposes of mining coal for many years. The coal is drilled from a coal seam by means of a rotating cuter head. The coal is then conveyed to the portal of the auger hole by helical screw conveyors (auger flights).  
           [0003]    Previously known coal augers have not provided a means by which the cutter head could be accurately located, for the purposes of directing the cutter head. A further disadvantage is the vulnerability of the cutter head and augers to fire, roof collapse and explosions due to the ignition of methane gas within the mine tunnel.  
         OBJECT OF THE INVENTION  
         [0004]    It is the objection of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.  
         SUMMARY OF THE INVENTION  
         [0005]    There is firstly disclosed herein an auger mining machine, said machine including a cutter head and an auger flight attached to the cutter head, said cutter head including:  
           [0006]    a cutter head body;  
           [0007]    a cutter drum mounted on a forward end of the body; and wherein said machine further includes:  
           [0008]    internal duct means extending from a rear portion of the flight to near the cutter drum for the delivery of a gas to adjacent the cutter drum.  
           [0009]    There is also disclosed herein a cutter head of an auger mining machine that forms a mine tunnel in a seam, the cutter head being adapted to be rotatably driven about a longitudinal axis of the head to form the tunnel, and wherein the head includes a ground probing radar antenna that rotates about said axis for the purposes of examining the seam surrounding the tunnel.  
           [0010]    There is further disclosed herein a cutter head of an auger mining machine, said head including:  
           [0011]    a hollow body;  
           [0012]    a cutter drum mounted on a forward end of the body;  
           [0013]    steering means mounted on the body and actuable to aid in steering the cutting head;  
           [0014]    motor means to cause movement of the steering means; and  
           [0015]    means to receive and respond to an electromagnetical signal to cause operation of said motor means to aid in directing said cutter head.  
           [0016]    There is still further disclosed herein an auger mining machine having a cutter head and a following auger flight, said cuter head including an electric motor, and wherein said machine further includes a source of electric power, for said motor, contained within the cutter head and/or auger flight, said source being adapted to not receive electric power from an external means during mining operation of the machine.  
           [0017]    In the above machine, preferably the source of electric power includes at least one battery, and the motor is used in steering the cutter head. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:  
         [0019]    [0019]FIG. 1 is a schematic side elevation of a prior art coal mining machine extracting coal from a coal sham;  
         [0020]    [0020]FIG. 2 is a schematic side elevation of a coal mining machine embodying the present invention, mining coal from a coal seam;  
         [0021]    [0021]FIG. 3 is a schematic sectioned side elevation of the cutter head of the machine of FIG. 2;  
         [0022]    [0022]FIG. 4 is a schematic part sectioned side elevation of an auger flight employed in the machine of FIG. 3;  
         [0023]    [0023]FIG. 5 is a schematic sectioned side elevation of the forward portion of the auger flight of FIG. 4;  
         [0024]    [0024]FIG. 6 is a schematic sectioned side elevation of the rear portion of the auger flight of FIG. 4;  
         [0025]    [0025]FIG. 7 is a schematic sectioned side elevation of the coupled end portions of adjacent auger flights;  
         [0026]    [0026]FIG. 8 is a schematic perspective view of the steering mechanism of the cutter head shown in FIG. 3; and  
         [0027]    [0027]FIG. 9 is a schematic side elevation of the electric motor and pump employed in the machine of FIG. 2. 
     
    
     DESCRIPTION OF PRIOR ART  
       [0028]    In FIG. 1 there is schematically depicted a prior art mining machine  10 . The machine  10  includes a launch vehicle  11  which drives a plurality of auger flights  12 . The forward end of the auger flights  12  is provided with a cutter drum  13 . Coal removed from the seam  14  by the drum  13  is conveyed along the mine tunnel  15  by the auger flights  12 , to be delivered to the tunnel opening  16  wherefrom the coal is conveyed to further transportation means. To inhibit explosions and fires, an inert gas is delivered via a conduit  17  to the mouth of the tunnel  15  in the direction of the arrow  18 . The inert gas is drawn into the tunnel  15  to replace the coal conveyed out through the opening  16 . Excess gas flows rearwardly in the direction of the arrow  19  to exit from within the tunnel  15 . In mines in which methane gas levels are low, the inert gas can be replaced with air. Essentially, the inert gas or air flushes the tunnel  15 . The launch vehicle  11  rotates the: auger flights  12  about the longitudinal axis  19 , so as to also cause rotation of the cutter drum  13 , also about the longitudinal axis  19 .  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    In FIGS.  2  to  7  there is schematically depicted an auger mining machine  20 . The machine  20  includes the launch vehicle  11 . The launch vehicle rotatably drives a plurality of auger flights  21 :,with the flights  21  being coupled to a cutter head  22  by a lower (battery flight) flight  60 . The vehicle  11  also provides an axial force to advance or retract the flight  21  and head  22 . The cutter bead  22  includes at its forward end, a radially inner cutter drum  21  and a radially outer cutter drum  24 . The cutter drums  23  and  24  are mounted on the hollow body  25  of the cutter head  20 .  
         [0030]    The hollow body  25  includes a portion  26  which is attached to the next adjacent auger flight  21  by means of a projection  27  which is generally square in cross section.  
         [0031]    Mounted on the portion  26  by means of bearings  28  is a steering saddle  29  which supports a ground engaging steering skid  30 . The slid  30  is ring shaped and is attached to steering cylinders  31 . Pivoted links  81  inhibit axial movement of the skid  30  which might otherwise accrue as a result of frictional engagement with the mine tunnel. By moving the skid,  30  radially relative to the saddle  29 , the rear of the body  25  can be raised and lowered alternating the direction of travel of the cutter head  22  if so required. Hydraulic fluid under pressure is delivered to the cylinders  31  to cause relative movement between the skid  30  relative to the saddle  29 . The skid  30  engages the tunnel wall  32 . Transverse horizontal steering is achieved by the same method.  
         [0032]    Electrical power required by the electronic apparatus (including computer  34  and microwave transmitter and receiver device  47 ) is provided by the batteries  64 .  
         [0033]    Microwave signals generated by the device  47  are transmitted rearwardly through the passage  45  in the projection  24 , with the microwave signals exiting from within the housing  34  by means of a microwave comms window  46 . Aligned with the window  46  is a conduit  63  which provides for the transfer of signals. Microwave signals also travel in the opposite direction through the passage  45  to be received within the body  34  for the purposes of controlling the delivery of hydraulic fluid to the cylinder  31 , More particularly, a microwave signal generating and receiving device  47  is located within the housing adjacent the window  47 . The on-board computer  34  is connected, to the device  47  and controls the delivery of hydraulic fluid under pressure to the cylinders  31 , from a pump  36 . Thus, the cutter head  22  can be directed from a location remote from the machine  20 ,  
         [0034]    The slip rings  44  provide for the transfer of signals to the valves  82  to activate the valves  82 . The pump  36  is driven by electric motor  83 , which receives power from the batteries  64 . The position of the cutter head  22  is determined by the use of a ring laser gyro  84 . Having regard to its position, the cutter head can then be directed in its movement by operation of the skid  29 .  
         [0035]    The pump  36  and motor  83  are located within a flame-proof enclosure  95  which includes a hollow box-like base  96  closed by a lid  86  by means of threaded fasteners  87 . Located within the enclosure  95  is a hydraulic fluid reservoir  87 . To eliminate voids within the hydraulic fluid within the reservoir  87 , there is provided a flexible bladder  88  filled with nitrogen. The bladder  88  changes in volume to accommodate variations in the amount of hydraulic fluid contained in the reservoir  87 . The pump  36  draws hydraulic fluid from the reservoir  87  by means of a hydraulic line  89 . Hydraulic fluid under pressure is delivered to the cylinders  31  via a high pressure hydraulic line  90 . Located within the line  90  are sintered plugs which inhibit the transmission of flame along the hydraulic lines. Electrical cabling  95  passes through cable glands in the end wall  93  again to inhibit flame propagation. A return hydraulic line  94  returns hydraulic fluid from the cylinders  31  to the reservoir  87 .  
         [0036]    In FIG. 4, one of the auger flights  21  is more fully depicted. Each auger flight  21  includes an outer sleeve  48  to which there is attached a helical member  49 .  
         [0037]    Within the sleeve  48  are two concentric tubes  50  and  51 , between which there is located an annular passage  52 . An inert gas is delivered to the passage  52  to be ducted to the cutter head  20 , The passage enclosed by the tube  51  receives the microwave signals passing between the device  47  and electronic apparatus within the launch vehicle  11 . The sleeve  48  is attached to a forward coupling member  53  which engages the rear coupling member  54  of the next adjacent auger flight  21 . The coupling member  53  is square in transverse cross-section and slideably receives a radially movable pin  55 . The pin  55  is, moved radially by use of a pivot lever  56 . The pin  55  is received within a passage  57  formed in the rear coupling member  54 . By movement of the pin  55 , the flights  27  may be coupled or uncoupled.  
         [0038]    The inner tube  51  is provided with a seal  58  which engages the tube  51  of the next adjacent flight  21 . Similarly, the coupling member  54  is provided with a seal  59  which couples the outer tubes  50 .  
         [0039]    Coal is transported rearwards from the cutter drums  23  and  24  by auger blades  60 .  
         [0040]    The auger flight  60  is similar in construction to the flight  21  except that it is modified to receive a bank of batteries  64  which receives electric charge when removed from within the tunnel. The concentric tubes  50  and  51  are diverted about the batteries  64  as is illustrated. The tube  51  is aligned with the conduit  63  so as to provide for the transfer of microwave signals therebetween. The tube  50  terminates adjacent the cutter head  22  and delivers the inert gas to a plurality of branch tubes  41  which direct the inert gas toward the cutter drums  23  and  24 . As coal is removed, the inert gas is drawn into the newly formed tunnel portion.  
         [0041]    Mounted in the body  25  so as to rotate therewith is a ground probing radar antenna  42  provided for the purpose of examining the seam surrounding the tunnel formed by the machine  20 . The antenna  42  is connected to the computer  34  so that information can be conveyed from the computer  34  via the device  47  to an operator remote from the machine  20 . For example, the antenna  42  could be used to detect features such as a coal/rock interface, air pockets or adjacent tunnels.  
         [0042]    With the use of the device  47  an operator remote from the machine  27  can control its direction by dispatching microwave signals to the device  47 .  
         [0043]    Preferably the cutter head has a gas sensor which detects, for example, levels of methane and delivers a signal indicative thereof to the computer  34 . A signal is then generated and sent by the device  47  so that methane levels can be monitored from outside the tunnel  15 .

Summary:
A mining machine ( 20 ) inclu ding a launch vehicle ( 11 ) which drives an auger flight ( 21 ). The extremity of the Auger flight ( 21 ) is a cutter head ( 22 ). An inert gas is delivered to adjacent the cutter head ( 22 ) by a tube ( 50 ). The cutter head ( 22 ) is also provided with a ground penetrating radar antenna ( 42 ) as well as a microwave transmitting/receiving device ( 47 ) which transmits and receives microwave signals for the purposes of controlling the cutter head ( 22 ) and transmitting information gathered by means of the antenna ( 42 ).