Underground boring systems and apparatus

Abstract

A steering head has a body and an auger extending through the body. An outer surface of the steering head may have a rear portion that does not extend beyond a maximum perimeter of the exterior of a forward portion. An outer surface of the steering head may have openings that receive respective steering flaps. The steering head may have cutting bits that pivot between extracted and retracted positions in response to the auger's rotation. The auger may have a helical blade that contacts an internal surface of the body. The steering head may have three light elements that emit light visible at the rear of the steering head.

What is claimed is: 
     
         1 . A steering head comprising:
 an auger;   a cutting bit; and   a body having an exterior surface extending from a forward end of the body to a rear end of the body, the body defining an interior volume between the forward end and the rear end, the auger being positioned in the interior volume so that the auger is rotatable within the volume about an axis that extends through the forward end and the rear end, and wherein the cutting bit is disposed at least partially forward of the forward end of the body and is attached to the auger,   wherein   a first part of the exterior surface defines a first maximum perimeter of the exterior surface about the axis between the forward end and a position rearward of the forward end, and   a second part of the exterior surface defines a second maximum perimeter about the axis between the position and the rear end of the body that does not extend beyond the first maximum perimeter radially with respect to the axis, wherein the second part defines a portion thereof extending from the rear end of the body to the position that is radially inward of the first maximum perimeter with respect to the axis.   
     
     
         2 . The steering head of  claim 1 , wherein the first part of the exterior surface is generally cylindrical, the second part of the exterior surface is generally cylindrical, and the generally cylindrical first part of the exterior surface has a general diameter perpendicular to the axis that is greater than a general diameter of the generally cylindrical second part of the exterior surface perpendicular to the axis. 
     
     
         3 . The steering head of  claim 1 , further comprising a cover mounted on the portion of the second part of the exterior surface, the cover enclosing a space between the cover and the portion in which is disposed at least one conduit extending from the rear end of the body to the position. 
     
     
         4 . The steering head of  claim 3 , wherein neither the second part of the exterior surface nor the cover extends outward of the first maximum perimeter radially with respect to the axis. 
     
     
         5 . The steering head of  claim 3 , wherein the at least one conduit is a fluid conduit and the cover defines a fluid outlet to an exterior of the cover that is in fluid communication with the at least one conduit. 
     
     
         6 . A steering head comprising:
 an auger;   a cutting bit;   a body comprising
 an interior body having an exterior body surface extending from a forward end of the interior body to a rear end of the interior body, the interior body defining an interior volume between the forward end and the rear end, the auger being positioned in the interior volume so that the auger is rotatable within the volume about an axis that extends through the forward end and the rear end, and wherein the cutting bit is disposed at least partially forward of the forward end of the interior body and is attached to the auger, and 
 an outer tube assembly mounted on and outward of the interior body with respect to the axis, comprising
 a first outer tube having a first inner side and a first outer side, wherein the first outer side is outward of the first inner side with respect to the axis, the first outer tube having a forward end and a rearward end, and the first outer side defining a first maximum perimeter about the axis between the forward end of the first outer tube and the rearward end of the first outer tube, and 
 a second outer tube mounted on the body rearward of the first outer tube and having a second inner side and a second outer side, wherein the second outer side is outward of the second inner side with respect to the axis, the second outer tube having a forward end and a rearward end, and the second outer side defining a second maximum perimeter about the axis between the forward end of the second outer tube and the rearward end of the second outer tube that does not extend beyond the first maximum perimeter radially with respect to the axis, wherein the second outer side defines a portion thereof extending from the rearward end of the second outer tube to the forward end of the second outer tube that is radially inward of the first maximum perimeter with respect to the axis. 
 
   
     
     
         7 . The steering head of  claim 6 , wherein the first outer side is generally cylindrical, the second outer side is generally cylindrical, and the generally cylindrical first outer side has a general diameter perpendicular to the axis that is greater than a general diameter of the generally cylindrical second external side perpendicular to the axis. 
     
     
         8 . The steering head of  claim 7 , wherein a center axis of the generally cylindrical first outer surface is parallel to a center axis of the generally cylindrical second outer surface. 
     
     
         9 . The steering head of  claim 8 , wherein the center axis of the generally cylindrical first outer surface is offset from the center axis of the generally cylindrical second outer surface. 
     
     
         10 . The steering head of  claim 6 , further comprising a cover mounted on the portion of the second outer side of the second outer tube, the cover enclosing a space between the cover and the second outer side in which is disposed at least one conduit extending from the rearward end of the second outer tube to the forward end of the second outer tube. 
     
     
         11 . The steering head of  claim 10 , wherein neither the second outer side nor the cover extends outward of the first maximum perimeter radially with respect to the axis. 
     
     
         12 . The steering head of  claim 10 , wherein the at least one conduit is a fluid conduit and the cover defines a fluid outlet to an exterior of the cover that is in fluid communication with the at least one conduit. 
     
     
         13 . The steering head of  claim 6 , further comprising one or more steering flaps disposed on the outer tube assembly and having a distal end, a first flap face facing radially inwardly toward the body surface and an opposing second flap face facing radially outwardly away from the axis, the one or more steering flaps being moveable between an extended position and a retracted position. 
     
     
         14 . A steering head comprising:
 an auger;   a cutting bit;   a body having an exterior surface extending from a forward end of the body to a rear end of the body, the body defining an interior volume between the forward end and the rear end, the auger being positioned in the interior volume so that the auger is rotatable within the volume about an axis that extends through the forward end and the rear end, and wherein the cutting bit is disposed at least partially forward of the forward end of the body and is attached to the auger, wherein the body defines one or more openings extending inward from the exterior surface toward the axis;   one or more steering flaps respectively disposed in the one or more openings, each steering flap having a distal end, a first flap face facing radially inwardly toward the axis and an opposing second flap face facing radially outwardly away from the axis, each of the one or more steering flaps being moveable between an extended position in which the distal end extends away from the axis and a retracted position in which the steering flap, including its distal end, is received in its said opening; and   one or more hinges, each hinge connected to the exterior surface and the second flap face of a respective steering flap of the one or more steering flaps to thereby permit pivotal movement of the steering flap between the extended position and the retracted position, wherein the hinge is received in an opening in the exterior surface and an opening in the second flap face of the respective steering flap so that the hinge does not extend outward of the exterior surface, and does not extend outward of the second flap face of the respective steering flap, with respect to the axis.   
     
     
         15 . The steering head of  claim 14 , wherein the body comprises
 an interior body having an exterior body surface extending from a forward end of the interior body to a rear end of the interior body, the interior body defining the interior volume, and   an outer tube assembly mounted on and outward of the interior body with respect to the axis, the outer tube assembly defining the exterior surface.   
     
     
         16 . The steering head of  claim 15 , wherein the outer tube assembly comprises a first outer tube having a first inner side and a first outer side, the first outer side being outward of the first inner side with respect to the axis and the first outer tube having a forward end and a rearward end, and wherein first outer tube defines the one or more openings. 
     
     
         17 . The steering head of  claim 14 , wherein each opening of the one or more openings has a depth so that the steering flap received in the opening, in its said retracted position, does not extend outward of the exterior surface with respect to the axis. 
     
     
         18 . The steering head of  claim 17 , wherein each of the one or more steering flaps is biased towards the retracted position. 
     
     
         19 . The steering head of  claim 18 , further comprising one or more hydraulic cylinders, wherein each hydraulic cylinder of the one or more hydraulic cylinders is disposed operatively between the body and a respective steering flap of the one or more steering flaps, the one or more hydraulic cylinders biasing the one or more steering flaps toward the retracted position. 
     
     
         20 . The steering head of  claim 14 , wherein only one hinge is used to attach each steering flap of the one or more steering flaps to the body.