Underground boring apparatus with controlled steering capabilities

An underground boring apparatus comprising a boring head, elongated means connected at its front end to end extending rearwardly from said boring head for supporting the latter, means for moving said boring head and supporting means in a generally forward direction through the earth, an elongated tubular housing having an opened front end and containing a rearward end section of said elongated means therein, means disposed within said housing and supporting said elongated means at a predetermined point along its contained back end section for pivotal movement about at least one axis relative to said housing whereby to cause said boring head to pivot about said axis, and means for pivoting said supporting means about said axis and for maintaining the latter in any one of its pivoted positions during movement through the earth whereby to guide the boring head through both linear and non-linear paths in the earth, said pivoting means including a plurality of piston/cylinder arrangements, means for moving said pistons individually between extended and retracted positions parallel to the axis of said housing, means responsive to the positions of said pistons for causing supporting means to pivot to a particular position about the axis, and means for moving all of the pistons to equivalent extended positions and for maintaining the position in these latter positions so as to maintain said supporting means and boring head in axial alignment with said tubular housing whereby to cause said boring head to follow a linear path through the earth.

An underground boring apparatus comprising:

• a boring head;
• elongated means connected at its front end to and extending rearwardly from said boring head for supporting the latter;
• means for moving said boring head and supporting means in a generally forward direction through the earth;
• means supporting said elongated means at a predetermined point along its length for pivotal movement about at least one axis whereby to cause said boring head to pivot about said axis;
• and means for pivoting said supporting means about said axis or axes and for maintaining the latter in any one of its pivoted positions during movement through the earth whereby to guide the boring head through both linear and non-linear paths in the earth, said pivoting means including a plurality of piston/cylinder arrangements, means for moving said pistons individually between extended and retracted positions, means responsive to the positions of said pistons for causing said supporting means to pivot to particular positions about said axis of axes depending upon the positions of said pistons, and means for moving all of said pistons to equivalent extended positions and for maintaining the pistons in these equivalent positions so as to maintain said supporting means and boring head in a fixed position such that they follow a linear path through the earth.

An underground boring apparatus comprising:

• a boring head;
• an elongated shaft arrangement connected at its front end to and extending rearwardly from said boring head for supporting the latter;
• an elongated tubular housing having an opened front end and containing a back end segment of said shaft arrangement therein such that a front end segment of said shaft arrangement and said boring head are disposed in front of said housing, said housing having an outermost surface which tapers outwardly from opposite ends thereof to a central point along its length such that the cross sectional size of said housing at said point is approximately the same size as the maximum cross sectional configuration of said boring head;
• a circumferential collar located within said tubular housing adjacent the front end of the latter and fixedly disposed around a circumferential segment of said shaft arrangement within said housing, said collar having an outer surface which defines the circumferential segment of a sphere, said outer surface cooperating with said tubular housing for supporting said shaft arrangement for pivotal movement about any axis coextensive with a diameter of said spherical segment whereby to cause said boring head to be movable to any point on a circle normal to and radially outwardly of said tubular housing;
• means for pivoting said shaft arrangement about any one of said axes and for maintaining said shaft arrangement in any one of its pivoted positions, said pivoting means including four pistons/cylinders arrangements disposed within and extending parallel with said tubular housing and equally circumferentially spaced about the axis of the latter rearwardly of said shaft arrangement, means for moving said pistons individually between extended and retracted positions in directions parallel to the axis of said housing, means including cooperating inclined surfaces responsive to the positions of said pistons for causing said shaft arrangement to pivot to particular positions about particular axes depending upon the positions of said pistons relative to one another, and means for moving all of said pistons to equivalent extended positions and for maintaining the pistons in these positions so as to maintain said shaft arrangement and boring head in axial alignment with said tubular housing;
• and means for moving said boring head, shaft arrangement and tubular housing in a generally forward direction through the earth whereby the position of said shaft arrangement and boring head relative to said tubular housing determines the specific path taken by these components as they move through the earth.