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: 
FIELD OF INVENTION 
       [0001]    This invention will be found useful in the boring of tunnels through strata where unstable tunnel roofs conditions occur. It will be advantageous to use this invention in tunnels being bored by fairly large tunnel boring machines (TBM&#39;s) which have tunneling capacities exceeding 3 meters. This invention may be most advantageously employed where roof instability is a problem. 
         [0002]    Basically this invention involves the removal of any extension parts from the front part of the TBM such as extension fingers on the stabilizer of the TBM and extrusion of tunnel roof lining members against the roof surface of the tunnel as the boring process is being carried out. The tunnel lining members are secured in place at predetermined spacing intervals. These tunnel lining members will be fed into suitable receptacles formed on the TBM just behind the rotating boring head. As the machine gradually advances during the tunnel boring process, the material previously inserted into the receptacles provided for the tunnel lining members is fed out (extruded) to be placed against the roof of the tunnel. 
         [0003]    At predetermined distances, roof ribs (bow members) are secured (as soon as possible) in place behind the TBM. This assures that any debris from the tunnel roof which might fall due to roof instability is prevented from falling into the tunnel. 
         [0004]    In boring large tunnels through strata of varying density, there is a tendency for the TBM boring head to undergo severe radial displacement as the boring process proceeds. In order to prevent such unwanted movement of the TBM boring head, TBM designers have developed a TBM stabilizing system which prevents the TBM&#39;s rotating head from executing non-circular movement (wobble) in boring the tunnel. 
         [0005]    The stabilizing section of the TBM is located just behind the rotating boring head and presses against the entire circumferential surface of tunnel just previously bored so as to prevent the “wobble” of the rotating cutting head. The rotating head may weigh several tons and the spalling wheels which press against the tunnel face must not be subjected to any side thrust. This is prevented by the presence of the stabilizing section of the TBM. 
         [0006]    TBM&#39;s function in a fundamental manner by using the walls of a tunnel just previously bored to be used to supply the force which presses the rotating head against the tunnel face. A pair of shaped wall grippers mounted on the TBM push against the walls of the tunnel and are subsequently used as a stop to press the rotating head against the tunnel face. The resulting force which is developed by the wall grippers which presses the rotating head against the tunnel face is massive. It easily overcomes the stabilizing force produced in the TBM by the stabilizing system which is quite small in comparison to the force generated by the wall grippers. 
         [0007]    The diameter of tunnel is determined by the diameter of the rotating head and it fell to the TBM operator to see that any excentric rotation of the tunneling machine head is avoided and thus prevent the wobble of the head during a tunnel boring operation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The description of the machine of this invention will be best understood when taken with the following drawings in which: 
           [0009]      FIG. 1  shows an illustration of a plan view of the TBM to which this invention has been applied; 
           [0010]      FIG. 2  is a sectional elevational view of the TBM shown in  FIG. 1 ; 
           [0011]      FIG. 3  is a sectional view taken at Section 3.3 shown in  FIG. 2  showing the expanding stabilizer of this invention; 
           [0012]      FIG. 4  is a sectional elevational view taken at Section 4.4 of  FIG. 2  showing the tunnel wall gripper mechanism of this invention; 
           [0013]      FIG. 5  is a representation of the receptacles in the surface of the expanding stabilizer of this invention; 
           [0014]      FIG. 6  is a sectional view of the tunneling machine stabilizing member as per this invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0015]    Referring now to the drawings,  FIGS. 1 and 2  show the TBM  10  to which this invention has been applied. The TBM has a frame structure  12  (sometimes referred to as the main beam) on which most components involved in the tunneling operations are mounted. 
         [0016]    At the very front of the TBM  10  is mounted a rotating head  14  which carries a series of wheels  16  rotatably mounted in bearings (not shown) for contacting the tunnel face. Wheels  16  are made from a hard substance and have a sharp profile to spall the surface of the tunnel face. The materials selected for the wheels  16  tend to fracture rather than bend when subjected to lateral forces. For this reason, it is imperative that the rotating head  14  remains in the center of the tunnel at all times during a tunnel boring operation. 
         [0017]    The rotating head  14  is journalled in a suitable bearing  18  which is securely mounted on frame or main beam  12 . This assures that any transverse forces experienced by the rotating head  14  are transferred to the frame  12 . 
         [0018]    The rotating head is driven by a plurality of drive motors  20  two of which are shown in  FIG. 2 . The drive motors  20  are supplied with suitable spur gears  22  which engage bull gear  24  which is rigidly attached to rotating head  14 . 
         [0019]    Rotating wheel  14  is supplied with a series of loading buckets such as  26  which are placed at the periphery of wheel  14  so as to gather the debris or “muck” spalled from the tunnel rock face during its excursion from the bottom position of the wheel  14  to its top-most position on wheel  14 . At the top-most position of wheel  14  the bucket such as the one shown as  26  empties the debris or muck previously gathered on the upward excursion of bucket  26  into chute  28  of TBM  10 ; onto conveyor  30  which is mounted in the TBM  10  inside frame  12 . Conveyor  30  removes the debris so obtained to a second conveyor or an awaiting railway car located behind the TBM (not shown). 
         [0020]    Mounted on frame  12  just behind the rotating head  14 , is a non-rotating stabilizing member  40 . Member  40  is more clearly shown in section in  FIG. 3 . Here the member  40  is shown mounted on frame or main beam  12  by means of sliding joint  42 . The sliding joint  42  comprises a mating box like structure which has an inner box  44  and an outer box  46  which is firmly secured to stabilizing member  40 . Inner box member  44  is firmly secured to frame  12 ; in this manner the stabilizing member is confined to translatory movement in a plane fixed by the sliding joint  42 . It is noted that the conveyor  30  is shown in the interior of the frame or main beam  12 . 
         [0021]    It is noted that the exterior diameter of the stabilizing member  40  is adjustable within certain predetermined limits. Upper shell  50  is movable up and down by a pair of actuating piston-cylinders  52  and  54  which are pivotably attached to main beam  12  at pivot points  56  respectively. Actuators  52  and  54  are also pivotably attached to upper shell  50  at pivot points  58  and  60 . This permits upper shell to be moved vertically up and down by actuators  52  and  54  with respect to main beam  12 . The upper shell  50  is provided with a pair of sliding joints  62  and  64  at the junction of the upper shell  50  and the lower shell  66 . 
         [0022]    Lower shell  66  is a composite structure having lower side members  68  and  70  being pivotably supported on bottom support member  72  at pivots  74  and  76  respectively. Bottom support member is usually firmly attached to frame  12  and is incapable of any movement. The lower side members  68  and  70  are movable about pivots  74  and  76  by a pair of actuators; thus the diameter of the lower shell  66  is also adjustable within “certain” limits by means of actuators  78  and  80 . This allows the upper shell  50  and the lower shell  66  of the stabilizing device  40  to be adjusted (within limits) to accommodate variations in tunnel diameters. 
         [0023]    It is noted that in  FIG. 3 , only 3 drive motors  20  are shown for ease of illustration; there may be more motors driving wheel  24  of TBM  10 . 
         [0024]    A pair of propulsion actuators  82  and  84  are shown also in  FIGS. 1 ,  2  and  3 . The actuators  82  and  84  are pivotably attached to frame  12  at one end thereof and pivotably attached to gripper device  90  more fully described in  FIG. 4 . Gripper device  90  comprises a pair of actuator cylinders  92  and  94  in which a pair of gripper pistons  96  and  98  are respectively received. A pair of grippers  102  are separately actuated and are mounted on the ends of piston rods  96  and  98  respectively. Grippers  102  are used to contact the walls of the tunnel where it has been driven to provide a reference position for the TBM  10  as well as providing a fulcrum for pushing TBM  10  ahead to engage the tunnel face. 
         [0025]    The gripper device  90  is slidably mounted on main beam or frame  12  of TBM  10  so as to slide along on tracks  102  and  104  as boring proceeds. 
         [0026]    A pair of steering actuators  108  and  110  are shown to change the angle of beam  12  once the grippers  102  have been deployed against the tunnel walls. Here the actuators  108  and  110  are used to cause movement of the main beam  12  about gripper trunion assembly  100 . Most of the steering of the TBM is accomplished by the adjustment of actuators  108  and  110  and adjustment of actuators  96  and  98  on the gripper shoes  102 . 
         [0027]    A rear support cylinder  112  is shown in  FIG. 2  having piston  114  and sliding pad  116  attached thereto to carry the rear of TBM  10  during periods of gripper adjustment. 
         [0028]    The TBM as illustrated functions as follows: The TBM of  FIG. 1  is shown with driving arms  82  and  84  fully extended. In order to prepare the TBM for future movement rear cylinder  112  is actuated until piston  114  and slider  116  make contact with the tunnel surface. Cylinder  112  is actuated until the desired angle of TBM  10  in the tunnel is achieved. At this time grippers  102  are retracted and propulsion actuators  82  and  84  are withdrawn to pull gripper device  90  ahead on slides  104  to the position in  FIG. 2 . 
         [0029]    At this time grippers  102  are actuated to contact the tunnel walls and grippers  102  are set in their working position. Propulsion cylinders are then actuated to push the rotating head against the tunnel face to continue the boring operation. It is understood that steering devices  108  and  110  have been adjusted to be set at the desired angle of TBM  10  in the tunnel so that the steering of TBM  10  is maintained. Some steering (trim) is obtained through the adjustment of devices  52 ,  54 ,  78  and  80  of stabilizer  40 . 
         [0030]    Stabilizer  40  is supplied with adjustable upper shell  50  and adjustable lower shell  66 . The upper shell is movable by actuating actuators  52  and  54  as shown in  FIG. 3 . Because stabilizing member  40  is so long (maybe 3-4 meters) a second set of actuators may be used in  FIG. 2  having pivot points  60 . 
         [0031]    Mounted on the exterior surface of top shell  50  of stabilizer  40  is a series of longitudinally extending members  130 . 
         [0032]    Members  130  are usually steel angles and form a series of receptacles  132  on top shell  50  of stabilizer  40 . The receptacles  132  in this instance are rectangular in cross section but may be of any desired shape. 
         [0033]    In this instance the receptacles  132  are formed by “L” shaped angle members welded or secured to top shell  50  of the stabilizer  40 . The shape of the resulting receptacles  132  is dictated by the shape of members  130 . The members  130  extend the entire length of the stabilizer  40  thus the receptacles  132  are of the same length as members  130 . 
         [0034]    In operation the TBM functions as follows. The grippers  102  contact the tunnel walls with the propulsion actuators  82  and  84  retracted as shown in  FIG. 2 . Great force is exerted on the tunnel walls by the actuation of grippers  102 . The actuators  96 ,  98 ,  110  and  108  on gripper device  90  are set to orient the TBM in the desired direction. Rotating head  14  is now stabilized for a tunnel boring operation. The members  130  secured to top shell  50  contact the surface of the tunnel with considerable force. 
         [0035]    Each receptacle  132  is filled with a “roof support” member  134  which has been previously fed into the receptacles  130  by a laborer on the scene. The roof support members  134  are “extruded” from the receptacles  132  as the TBM  10  moves ahead in the tunnel boring process. 
         [0036]    It is important that the members  134  do not form a joint in the tunnel roof as the boring process proceeds but that the roof supporting members  134  form staggered joints in the roof as the TBM moves ahead. 
         [0037]    At predetermined intervals depending on the stability exhibited by the tunnel roof, roof supports in the form of tunnel arch members  140  or complete tunnel rings  142  may be installed as to support the extruded tunnel roof members  134  against the surface of the tunnel roof as shown in  FIG. 6 . These supporting rings  142  should be installed as quickly as possible after the TBM  10  moves ahead. 
         [0038]    Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that the modifications and embodiments are intended to be included within the scope of the dependent claims.

Summary:
A TBM having a cylindrically shaped member located on said TBM just behind the rotating boring head, said member being of similar diameter as said tunnel and comprising sectionalized components so as to be adjustable in diameter, said member having a plurality of steel angle members welded to the surface of the top-most component so as to extend axially along the length of said cylindrically shaped member, said steel angle members forming axially extending receptacles therein.