Patent Publication Number: US-2012032494-A1

Title: Underground boring machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application 61/370,342, filed Aug. 3, 2010, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to mining equipment, and in particular to an underground boring machine. 
     Conventional underground excavation machines provide a rotating cutter head for creating an entry or tunnel in a wall of material. The cutter head includes a cutting mechanism for breaking material from the wall. These excavation machines have difficulty changing the direction of the tunnel, as this often requires changing the orientation of the entire boring machine. This can be a complicated task, since it requires maneuvering the boring machine within the confines of the excavated tunnel. In addition, the cutting mechanism of conventional boring machines can create high stresses, decreasing the working life of the machine and requiring frequent maintenance. 
     SUMMARY OF THE INVENTION 
     In one embodiment, the invention provides an underground boring machine for creating a tunnel in a wall, the machine comprising a vehicle frame, a boom, and a boring cutter head. The boom includes a first end coupled to the vehicle frame and a second end. The boring cutter head includes a rotary joint, a first arm, and a second arm angularly spaced apart from the first arm. The rotary joint defines an axis of rotation and supports the boring cutter head for rotation with respect to the second end of the boom. The first arm includes a first end coupled to the rotary joint, a second end, and at least one disc cutter coupled to the first arm and oriented to engage the wall. The first arm extends from the first end toward the second end in a plane that is perpendicular to the axis of rotation. The second arm includes a first end coupled to the rotary joint, a second end, and at least one disc cutter coupled to the second arm and oriented to engage the wall. The second arm extends from the first end toward the second end in a plane that is perpendicular to the axis of rotation. 
     In another embodiment, the invention provides an underground boring machine for creating a tunnel in a wall. The underground boring machine is supported on a floor defining a floor plane, and the underground boring machine includes a vehicle frame, a boom, and a boring cutter head. The vehicle frame supports the underground boring machine on the floor and defines a frame axis that is parallel to the floor plane. The boom includes a first end slidably coupled to the vehicle frame, a second end, a first portion proximate the first end, a second portion pivotably coupled to the first portion, and a third portion proximate the second end and pivotably coupled to the second portion. The boring cutter head includes a rotary joint, a first arm, and a second arm angularly spaced apart from the first arm. The rotary joint defines a rotary axis and is rotatably coupled to the second end of the boom. The first arm includes a first end coupled to the rotary joint, a second end, and at least one disc cutter coupled to the first arm and oriented to engage the wall. The second arm includes a first end coupled to the rotary joint, a second end, and at least one disc cutter coupled to the second arm and oriented to engage the wall. The second boom portion pivots with respect to the first boom portion about a first axis that is substantially perpendicular to the frame axis. The third boom portion pivots with respect to the second boom portion about a second axis that is substantially perpendicular to the first axis, and the boring cutter head rotates with respect to the second end of the boom about the rotary axis. 
     In yet another embodiment, the invention provides a cutter head for boring through a wall, the cutter head comprising a rotary union, a first arm, and a second arm. The rotary union defines a rotary axis and supports the cutter head for rotation about the rotary axis. The first arm includes a first end, a second end, and at least one disc cutter. The first end is coupled to the rotary union. The first arm extends from the first end toward the second end in a direction that is substantially perpendicular to the rotary axis. The at least one disc cutter is coupled to the first arm and oriented to engage the wall. The second arm is angularly spaced apart from the first arm. The second arm includes a first end, a second end, and at least one disc cutter. The first end is coupled to the rotary union. The second arm extends from the first end toward the second end in a manner that is substantially perpendicular to the rotary axis. The at least one disc cutter is coupled to the second arm and oriented to engage the wall. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a boring machine according to one embodiment of the invention. 
         FIG. 2  is a side view of the boring machine of  FIG. 1 . 
         FIG. 3  is a top view of the boring machine of  FIG. 1 . 
         FIG. 4  is an enlarged section view taken from the side of the boring machine of  FIG. 3 . 
         FIG. 5  is a top view of the boring machine of  FIG. 1 , with a boring cutter head articulated to the left. 
         FIG. 6  is a front view of the boring machine of  FIG. 1 . 
         FIG. 7  is a perspective section view of the boring cutter head. 
         FIG. 8  is a side view of the boring cutter head. 
         FIG. 9  is a perspective view of a profiling cutter head. 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  illustrate an underground boring machine  10  for engaging a wall (not shown) to create a tunnel or entry into the wall. The boring machine  10  includes a vehicle frame  18 , a boom  22 , a boring cutter head  26 , a pair of profiling cutter heads  30 , a stabilization system  34 , and a material handling system  38 . The frame  18  defines a frame axis  46  ( FIG. 3 ) and includes a pair of tracks  50  for supporting the vehicle frame  18  on a floor or support surface. In other embodiments, the frame  18  may include a hydraulic walking or hydraulic pushover mechanism, and may include fewer or more profiling cutter heads  30 . The frame  18  may also include additional pump stations and power packs (not shown) for providing primary drive energy to the boring cutter head  26  and the profiling cutter heads  30 . 
     As shown in  FIGS. 3 and 4 , the boom  22  includes a first end  58  ( FIG. 4 ), a second end  62 , a first portion  66  ( FIG. 4 ) proximate the first end  58 , a second portion  70  pivotably coupled to the first portion  66 , a third portion  74  proximate the second end  62  and pivotably coupled to the second portion  70 , advance cylinders  78  ( FIGS. 2 and 4 ), a vertical actuator  82  ( FIG. 2 ), and a horizontal actuator  86 . As used in this application, the term “horizontal” and variants thereof refer to a direction in a plane that is parallel to the floor. As used in this application, the term “vertical” and variants thereof refer to a direction in a plane that is perpendicular to the floor. The first end  58  of the boom  22  is coupled to the vehicle frame  18  by, for example, a rail (not shown), permitting the boom  22  to slidably extend and retract in a direction parallel to the frame axis  46 . Advance cylinders  78  drive the first end  58  of the boom  22  to move the boom  22  with respect to the vehicle frame  18 . 
     The second portion  70  of the boom  22  is pivotably coupled to the first portion  66  of the boom  22  by a first pivot joint  90  ( FIG. 4 ) defining a first axis  94 . The second portion  70  pivots with respect to the first portion  66  about the first axis  94 . In the illustrated embodiment, the vertical actuators  82  drive the second portion  70  to rotate about the first axis  94 . The first axis  94  is substantially perpendicular to the frame axis  46  and is substantially parallel to the floor. Thus, rotation of the second portion  70  about the first axis  94  changes the pitch or vertical height of the second end  62  of the boom  22 . 
     The third portion  74  of the boom  22  is pivotably coupled to the second portion  70  of the boom  22  by a second pivot joint  98  defining a second axis  102 . The third portion  74  pivots with respect to the second portion  70  about the second axis  102  ( FIG. 4 ). As shown in  FIG. 5 , the horizontal actuators  86  drive the third portion  74  to rotate about the second axis  102 . The second axis  102  is substantially perpendicular to the first axis  94  and substantially perpendicular to the frame axis  46 . Thus, rotation of the third portion  74  about the second axis  102  changes the horizontal orientation of the second end  62  of the boom  22 . In the illustrated embodiment, the vertical actuators  82  and horizontal actuators  86  are hydraulic cylinders. 
     In other embodiments, a rotary actuator, including a gearcase, may be coupled to the pivot joints  90 ,  98  to articulate the second portion  70  and the third portion  74 . Also, the first pivot joint  90  may be positioned vertically in order to control the horizontal orientation of the second end  62  of the boom  22 , and the second pivot joint  98  may be positioned horizontally to control the vertical position of the second end  62  of the boom  22 . 
     Referring to  FIG. 3 , the boring cutter head  26  includes a rotary base joint  110  ( FIG. 4 ), a motor (not shown), a body  118 , a first arm  126 , and a second arm  130  ( FIG. 6 ). The rotary base joint  110  defines a rotary axis  134 , and includes a support member  142  and a rotary coupler  146 . The support member  142  is coupled to the second end  62  of the boom  22  and is rotatably coupled to the rotary coupler  146 . The rotary coupler  146  is attached to the body  118  of the boring cutter head  26 . The rotary coupler  146  can rotate continuously with respect to the support member  142 , permitting continuous rotation of the boring cutter head  26  with respect to the second end  62  of the boom  22 . The motor is positioned within the support member  142  and drives the rotary coupler  146  for rotation about the rotary axis  134 . As illustrated in  FIG. 6 , the boring cutter head  26  rotates counterclockwise. The rotary base joint  110  supports hydraulic, electrical, and vacuum conduit to connect to the motor and other components within the boring cutter head  26 , while the boring cutter head  26  rotates. Rotary base joints are commonly known in the art, and no further description of them is provided here. 
     As shown in  FIGS. 6 and 7 , the body  118  is positioned behind the first arm  126  and the second arm  130  and defines an interior cavity  158  ( FIG. 7 ). In the illustrated embodiment, the body  118  generally is shaped as a flat disc having a diameter that is substantially equal to the combined length of the first arm  126  and the second arm  130 , and includes four intake ducts  162 . The body  118  rotates with the support member  142  about the rotary axis  134 . The ducts  162  are positioned to follow the first arm  126  and the second arm  130  as the arms  126 ,  130  rotate, and the ducts  162  collect the material that is liberated from the wall and guides the material into the interior cavity  158 . In other embodiments, the body  118  may include fewer or more ducts  162  and may have a different size or shape. For instance, the body  118  may be a simple a frame for supporting the first arm  126  and the second arm  130   
     Referring again to  FIGS. 3 and 6 , the first arm  126  includes a first end  170 , a second end  174 , and multiple disc cutters  178  coupled to the first arm  126 . The first arm  126  is coupled to the body  118  and is substantially perpendicular to the rotary axis  134 . The second arm  130  also includes a first end  186 , a second end  190 , and multiple disc cutters  178  coupled to the second arm  130 . The second arm  130  is coupled to the body  118  and is substantially perpendicular to the rotary axis  134 . The first arm  126  and the second arm  130  rotate with the body  118  about the rotary axis  134 . 
     In the illustrated embodiment, the first arm  126  and the second arm  130  extend radially from the rotary axis  134 . The first arm  126  and second arm  130  are spaced apart by an angle of 180°, and the first arm  126  and second arm  130  are formed as a unitary member. In other embodiments, the first arm  126  and, optionally, the second arm  130  may extend in an arcuate manner from the rotary axis  134 , such that the first arm  126  and the second arm  130  have a spiral shape when viewed along the rotary axis  134 . The first arm  126  and second arm  130  may also be formed to have a straight portion and an arcuate portion. In other embodiments, the first arm  126  and the second arm  130  may be spaced apart by a different angle, and the first arm  126  and second arm  130  may be formed as two separate pieces. In other embodiments, the boring cutter head  26  may include fewer or more arms. 
     As shown in  FIG. 8 , the first arm  126  and the second arm  130  define a mounting surface  202  proximate the front of the boring cutter head  26 . In the illustrated embodiment, the mounting surface  202  has a convex shape defined by the first arm  126  and the second arm  130 . The mounting surface  202  extends farther forward of the vehicle frame  18  proximate the first end  170  of the first arm  126  and proximate the first end  186  of the second arm  130 . The mounting surface  202  tapers toward the vehicle frame  18  near the second end  174  of the first arm  126  and the second end  190  of the second arm  130 . This convex shape relieves stress on the disc cutters  178  as they bore into the wall of material. In other embodiments, the mounting surface  202  may be more or less tapered to form a more deep or shallow convex shape, or the mounting surface  202  may have a flat shape. 
     The disc cutters  178  are mounted in the first arm  126  and the second arm  130  for engaging the wall. Each disc cutter  178  is independently rotatable in order to provide for a uniform contact and a symmetrical extraction pattern. The disc cutters  178  minimize uncut benches or steps and provide a clean face profile. Referring again to  FIG. 3 , the disc cutters  178  are oriented at an attack angle  210  with respect to a plane  206  that is tangent to the mounting surface  202 , and the disc cutters  178  engage the wall as the first arm  126  and the second arm  130  rotate about the rotary axis  134 . In the illustrated embodiment, the first arm  126  and the second arm  130  each includes four disc cutters  178 , and the attack angle is approximately 10° with respect to the plane  206 . In other embodiments, each arm may include fewer or more disc cutters  178 . 
     The boring cutter head  26  includes an inertial mass that is integrated into the body  118  for absorbing the dynamic load of the disc cutters  178 . The mass is positioned to provide relative stiffness and damping properties to the boring cutter head  26  in order to maintain the overall shock and vibration levels within acceptable machine design limits. The mass isolates the dynamic load from the rest of the boring machine  10 . 
     As the boring cutter head  26  rotates (counterclockwise as shown in  FIG. 6 ), the leading edge of each disc cutter  178  is angled forward. This is best illustrated in  FIG. 8 . Each disc cutter  178  rotates about an axis (not shown) that is perpendicular to the mounting surface  202 , and the disc cutter  178  chips and breaks apart material in the wall. Each disc cutter  178  is coupled to an inertial mass, such as lead, held within each arm  126 ,  130 . In the illustrated embodiment, four disc cutters  178  are coupled to each arm  126 ,  130 , and the attack angle  210  is approximately 10°. In other embodiments, fewer or more disc cutters  178  may be mounted on each arm  126  and  130 , and the disc cutters  178  may be oriented at a different attack angle  210 . 
     In another embodiment (not shown), each disc cutter  178  may include a load cell equipped with a strain gauge that measures the cutting force on the disc cutter  178 ,  194 . The load cell includes multiple measuring points to quantify linear forces in three dimensions as well as torque about the axis of rotation of the disc cutter  178 . This data is sent to a control system (not shown) that receives feedback from the load cell in order to control cutting speeds. 
     As shown in  FIGS. 3 and 9 , the profiling cutter heads  30  are positioned behind the boring cutter head  26  and proximate the floor. Each profiling cutter head  30  includes an integrated inertial mass, which provides relative stiffness and damping properties to the profiling cutter head  30 . The inertial mass maintains the overall shock and vibration levels within acceptable machine design limits. In the illustrated embodiment, each profiling cutter head  30  includes five disc cutters  178 , and each profiling cutter head  30  is rotatable by hydraulic cylinders  218  to change the orientation of the disc cutters  178  with respect to the wall and adjust the angle of attack  210 . In other embodiments, the profiling cutter head  30  may include fewer or more disc cutters  178 , and the profiling cutter head  30  may be rotatable by a rotary actuator, such as a gear drive. Referring to  FIG. 6 , as the boring cutter head  26  penetrates through the material wall, the profiling cutter heads  30  clear away material near the floor in order to provide a rectangular section in the lower part of an excavation profile  222 , creating a pathway for the tracks  50  and forming a flat floor and flat walls. Stated another way, the profiling cutter heads  30  square off the sides of the tunnel as the boring machine  10  advances. Each profiling cutter head  30  is independently rotatably in order to provide for a uniform contact and a symmetrical extraction pattern even if the boring cutter head  26  is turned. The profiling cutter heads  30  minimize uncut steps and provides a clean face profile. 
     As shown in  FIGS. 1-3 , the stabilization system  34  includes four stabilizer cylinders  230  and six grippers  234 . Each of the stabilizer cylinders  230  is positioned at a corner of the vehicle frame  18 . In other embodiments, the stabilization system  34  may include fewer or more stabilizer cylinders  230  and grippers  234 . Each stabilizer cylinder  230  includes a headboard  238  for engaging the floor or support surface. The cylinders  230  are extendable to permit the boring machine  10  to be supported off the tracks  50  during the boring operation. Similarly, the grippers  234  are extendable from the top of the vehicle frame  18  to support the roof or tunnel portion that is above the boring machine  10 . 
     As shown in  FIG. 2 , the material handling system  38  includes a suction source  242 , a vacuum duct  246  in fluid communication with the interior cavity  158  of the body  118 , a collector  250 , and a conveyor  254  mounted on the rear of the vehicle frame  18 . The suction source  242  is positioned on the vehicle frame  18  and provides vacuum pressure within the intake ducts  162 , the interior cavity  158  and the vacuum duct  246 . The vacuum duct  246  extends from the interior cavity  158  of the body  118  through the rotary base joint  110  and into the collector  250 . The vacuum duct  246  may be constructed of a flexible material to accommodate the movement of the boring cutter head  26 . The collector  250  is positioned on the vehicle frame  18  and separates the liberated material from any water in the collector  250 . After separation, the material is transferred to the conveyor  254 , which in turn transports the material to a conveyor system (not shown) for transportation away from the boring machine  10 . 
     In another embodiment (not shown), after the material is separated from the water, it may be transported away from the boring machine  10  by a conduit under suction pressure. In another embodiment (not shown), the boring cutter head  26  includes an entrainment system for trapping material liberated by the disc cutters  178  against the wall. The entrainment system may include multiple water spray blocks for dampening the dirt and dust from the wall and preventing the dirt from traveling past the boring cutter head  26  and profiling cutter heads  30  toward the rear of the machine  10 . 
     During operation, the stabilizer cylinders  230  are extended to lift the boring machine  10  off of the tracks  50  and make sure the vehicle frame  18  is level. In addition, the grippers  234  are extended to engage the roof and provide support above the boring machine  10 . While the vehicle frame  18  is in the supported position, the boom  22  is pivoted to orient the boring cutter head  26  in the proper direction for excavating an entry or tunnel. The boom  22  slides with respect to the vehicle frame  18  in order to extend the boring cutter head  26  along the rotary axis  134  and bore deeper into the wall. Alternatively, the boring machine  10  may be operated while the vehicle frame  18  is supported on the tracks (i.e., without extending the stabilizer cylinders and grippers), such that the weight of the boring machine  10  stabilizes the boring cutter head  26 . The profiling cutter heads  30  are also positioned to engage the portion of the wall between the boring cutter head  26  and the floor. 
     The boring cutter head  26  is driven by the motor to rotate about the rotary axis  134 . As the boring cutter head  26  rotates, the disc cutters  178  engage the wall at the attack angle  210 , causing material to chip and break away from the wall.  FIG. 8  shows the orientation of the disc cutters  178  on each arm  126  and  130 . In the illustrated embodiment, the disc cutters  178  proximate the rotary axis  134  engage the wall first, and the disc cutters  178  that are progressively farther away from the rotary base joint  110  engage the wall as the boring cutter head  26  is moved into the wall. As the boring machine  10  advances through the wall, the profiling cutter heads  30  engage a portion of the wall below the boring cutter head  26  and above the floor, forming the excavation profile  222  illustrated in  FIG. 6 . The profiling cutter heads  30  extend the cutting profile of the boring cutter head  26 , permitting the vehicle frame  18  to advance through the wall. The profiling cutter heads  30  may be extended or retracted to change the width of the lower portion. 
     As material is liberated from the wall, suction pulls the material through the intake ducts  162  and into the interior cavity  158 . The material then passes into the vacuum duct  246  and is transported to the collector  250 . After the collector  250  separates the material from any water, the material is deposited on the conveyor  254  at the rear of the machine  10 . The conveyor  254  transports the material to the conveyor system, which transports the material away from the boring machine  10 . 
     The machine  10  is provided with an onboard control and automation system that operates the machine as described above, including controlling orientation of the boom  22 , by remote control, onboard operators, or both. The pivot joints  90 ,  98  may include sensors for monitoring the magnitude of the reaction forces while cutting, such that the automation system controls the position of the advance cylinders  78  based on feedback from the cutting force sensors. Such sensors may include, for example, angular transducers, load cells and/or strain gauges. This increases the life of the disc cutters  178 . 
     Thus, the invention provides, among other things, an underground boring machine. Various features and advantages of the invention are set forth in the following claims.