Directional drilling system and apparatus

• US 6,082,470 A
• Filed: 06/04/1999
• Issued: 07/04/2000
• Est. Priority Date: 06/10/1997
• Status: Expired due to Term

• Current Assignee: Charles T. Webb
• Original Assignee: Charles T. Webb
• Inventors: Webb, Charles T., Chandler, Roy L.
• Primary Examiner(s): NEUDER, WILLIAM P
• Application Number:
  US09/326,795
• Time in Patent Office: 396 Days
• Field of Search: 175/45, 175/61, 175/62, 175/73, 175/74, 175/75, 175/76, 175/38, 175/19, 340/853.4
• US Class Current: 175/45
• CPC Class Codes: E21B 47/0232 at least one of the energy sources or one of the detectors being located on or above the ground surface
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003
• CPC Class Codes: E21B 7/062 the tool shaft rotating inside a non-rotating guide travelling with the shaft E21B7/067 and E21B7/068 take precedence

Abstract

The apparatus, in one embodiment has guide housing with a shaft extending through the guide housing with a drill bit coupled to its forward end. The shaft may be moved to a forward drilling position or to a rearward shifting position relative to the guide housing. A cam is located inside of the guide housing. A cam follower is coupled to the shaft. In the shifting mode, the cam follower is disengaged from the cam. A clutch is provided for coupling the cam to the shaft when the shaft is in the shifting position such that the cam follower may be rotated with the shaft relative to the cam to allow the cam follower to engage the cam when the shaft is moved to the forward drilling position. In the forward drilling position of the shaft, the clutch release the cam from the shaft and the cam follower engages the cam to allow straight drilling to occur or to cause the axis of said guide housing to shift relative to the axis of the shaft to cause the direction of drilling by the shaft and drill bit to change.

Claims

1. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be moved to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

cam means coupled to said guide housing around said shaft,

a cam follower means surrounding said shaft and being rotatable relative to said shaft,

said cam follower means being movable longitudinally with said shaft relative to said cam means,

a clutch for coupling said cam means to said shaft to prevent rotation of said cam means relative to said shaft when said shaft is in said shifting position such that said cam means may be rotated with said shaft to allow said cam means to rotate said cam follower means to a selected angular position,

when said shaft moves toward said forward drilling position, said clutch allows said cam means to be uncoupled from said shaft such that in said forward drilling position of said shaft, said cam follower means engages said cam means and causes said axis of said guide housing to shift relative to said axis of said shaft to cause the direction of drilling by said shaft and said cutting means to change,

a first stop coupled to said cam follower means,

a second stop coupled to said guide housing forward of said first stop such that said shaft may move said cam follower means and hence said first stop to an engaging position sufficient to engage said second stop when said shaft is moved forward,

in said engaging position said cam follower means is moved forward sufficient to be uncoupled from said shaft but not far enough to significantly move said axis of said guide housing out of alignment with the axis of said shaft.

2. The apparatus of claim 1, wherein:

said shaft comprises first and second shaft members with one of said shaft members having a central opening at one end and the other of said shaft members having an end located in said central opening such that said first and second shaft members may move toward and away from each other,

and means for preventing said first and second shaft members from rotating relative to each other.

3. The apparatus of claim 1, wherein:

said cam means comprises a central axis with surrounding wall structure,

an aperture formed through said wall structure transverse to said central axis of said cam means,

brake means comprising a piston located in said aperture at a position to be moved outward against said guide housing by said cam follower means to prevent rotation of said cam means when said cam follower means engages said cam means for causing said axis of said guide housing to shift relative to said axis of said shaft.

4. The apparatus of claim 1, wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

5. The apparatus of claim 1, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said second stop.

6. The apparatus of claim 2, wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

7. The apparatus of claim 2, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said second stop.

8. The apparatus of claim 6, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said second stop.

9. The apparatus of claim 1, comprising:

means for preventing said guide housing from rotating in the hole being drilled.

10. The apparatus of claim 1, wherein:

said second stop is located such that when said first stop engages said second stop said cam follower means is coupled to said shaft,

said clutch is sufficient to rotate said cam follower means when said first stop engages said second stop to rotate said guide housing in the hole being drilled when said shaft is rotated.

11. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be moved to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

a cam follower means surrounding said shaft and being rotatable about said shaft,

a cam ring comprising cam means supported in said guide housing around said shaft for rotation relative to said guide housing and relative to said shaft,

said cam follower means being movable longitudinally with said shaft relative to said cam ring,

a clutch for coupling said cam follower means to said shaft to prevent rotation of said cam follower means relative to said shaft when said shaft is in said shifting position such that said cam follower means may be rotated with said shaft relative to said cam ring,

when said shaft moves toward said forward drilling position, said clutch allows said cam follower means to be uncoupled from said shaft such that in said forward drilling position of said shaft, said cam follower means engages said cam means of said cam ring and causes said axis of said guide housing to shift relative to said axis of said shaft to cause the direction of drilling by said shaft and said cutting means to change,

a first stop coupled to said cam ring,

a second stop coupled to said cam ring forward of said first stop and angularly spaced from said first stop relative to said axis of said cam ring such that in said shifting position, said shaft may move said cam follower means to a first engaging position to engage said first stop when said shaft and cam follower means are moved forward for rotating said cam ring and hence said cam means to a desired angular position relative to said guide housing,

in said shifting position, said shaft may rotate said cam follower means to a second engaging position to engage said second stop when said shaft and cam follower means are moved forward,

in said second engaging position said cam follower means is moved forward sufficient to be uncoupled from said shaft but not enough to significantly move said axis of said guide housing out of alignment with the axis of said shaft.

12. The apparatus of claim 11, comprising:

a second clutch coupled to said guide housing and to said cam ring for locking said cam ring to said guide housing during drilling operations and for releasing said cam ring from said guide housing for allowing said shaft and cam follower means to rotate said cam ring to a desired angular position.

13. The apparatus of claim 11, wherein:

said shaft comprises first and second shaft members with one of said shaft members having a central opening at one end and the other of said shaft members having an end located in said central opening such that said first and second shaft members may move toward and away from each other,

and means for preventing said first and second shaft members from rotating relative to each other.

14. The apparatus of claim 11, wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

15. The apparatus of claim 11, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said first and second stops.

16. The apparatus of claim 13, wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

17. The apparatus of claim 13, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said first and second stops.

18. The apparatus of claim 16, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said first and second stops.

19. The apparatus of claim 11, comprising:

means for preventing said guide housing from rotating in the hole being drilled.

20. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be moved to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

a cam follower means surrounding said shaft and being rotatable about said shaft,

a cam ring comprising cam means fixed to in said guide housing around said shaft,

said cam follower means being movable longitudinally with said shaft relative to said cam ring,

a clutch for coupling said cam follower means to said shaft to prevent rotation of said cam follower means relative to said shaft when said shaft is in said shifting position such that said cam follower means may be rotated with said shaft,

when said shaft moves toward said forward drilling position, said clutch allows said cam follower means to be uncoupled from said shaft such that in said forward drilling position of said shaft, said cam follower means engages said cam means of said cam ring and causes said axis of said guide housing to shift relative to said axis of said shaft to cause the direction of drilling by said shaft and said cutting means to change,

a cam follower stop coupled to said cam follower,

a ring stop coupled to said cam ring at a given longitudinal position such that when engaged by said cam follower stop said clutch is still engaged with said shaft,

said clutch is sufficient to rotate said cam follower means when said cam follower stop is engaged with said ring stop to rotate said guide housing in the hole being drilled when said shaft is rotated.

21. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be movable to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

cam means coupled to said guide housing around said shaft and being rotatable relative to said guide housing,

a cam follower means surrounding said shaft and being rotatable relative to said shaft,

said cam follower means being movable longitudinally with said shaft relative to said cam means,

a clutch for coupling said cam means to said shaft to prevent rotation of said cam means relative to said shaft when said shaft is in said shifting position such that said cam follower means may be rotated with said shaft relative to said guide housing to allow said cam follower means to rotate said cam follower means to a selected angular position relative to said guide housing,

when said shaft moves toward said forward drilling position, said clutch allows said cam follower means to be uncoupled from said shaft such that in said forward drilling position of said shaft, said cam follower means engages said cam means and causes said axis of said guide housing to shift relative to said axis of said shaft to cause the direction of drilling by said shaft and said cutting means to change,

a ring rotatably supported in said guide housing forward of said cam means,

a first stop coupled to said cam follower means,

a second stop coupled to said ring forward of said cam follower means such that said shaft may move said cam follower means and hence said first stop to an engaging position sufficient to engage said second stop when said shaft is moved forward,

in said engaging position, said cam follower means is moved forward sufficient to be uncoupled from said shaft but not far enough to significantly move said axis of said guide housing out of alignment with the axis of said shaft, and

a third stop coupled to said ring forward of said cam follower longitudinally positioned to stop longitudinal displacement between cam follower and shaft such that said clutch is still engaged allowing shaft to rotate said ring,

a second clutch for removably coupling said ring to said guide housing during drilling operations and for releasing said ring from said guide housing for allowing said shaft and said cam follower means to rotate said ring and hence said second stop to a desired angular position.

22. The apparatus of claim 21, wherein:

said shaft comprises first and second shaft members with one of said shaft members having a central opening at one end and the other of said shaft members having an end located in said central opening such that said first and second shaft members may move toward and away from each other, and

means for preventing said first and second shaft members from rotating relative to each other.

23. The apparatus of claim 21, wherein:

said cam means comprises a central axis with surrounding wall structure,

an aperture formed through said wall structure transverse to said central axis of said cam means,

brake means comprising a piston located in said aperture at a position located to be moved outward against said guide housing by said cam follower means to prevent rotation of said cam means when said cam follower means engages said cam means for causing said axis of said guide housing to shift relative to said axis of said shaft.

24. The apparatus of claim 21, wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

25. The apparatus of claim 21, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said second and third stops.

26. The apparatus of claim 22,wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

27. The apparatus of claim 22, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said second and third stops.

28. The apparatus of claim 26, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said second and third stops.

29. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be movable to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

cam means coupled to said guide housing around said shaft,

said cam means comprising an annular member having a given axis with said annular member comprising wall structure defining a conical shaped surface having an axis offset from said given axis,

a cam follower means coupled to a cam follower housing which surrounds said shaft,

said cam follower being disengaged from said cam means when said shaft is in said shifting position,

said cam follower housing and said cam follower means being rotatable together relative to said guide housing when said shaft is in said shifting position,

said cam follower being movable longitudinally with said shaft relative to said cam follower housing and relative to said cam means,

a clutch for coupling said cam follower housing to said shaft to prevent rotation of said cam follower means relative to said shaft when said shaft is in said shifting position such that said cam follower housing and hence said cam follower means may be rotated with said shaft relative to said cam means to allow said cam follower means to engage said cam means at a selected angular position around said shaft when said shaft is moved to said forward drilling position,

when said shaft moves toward said forward drilling position, said clutch allows said cam follower means housing to be uncoupled from said shaft such that in said forward drilling position of said shaft, said cam follower means engages said cam means and causes said axis of said guide housing to shift relative to said axis of said shaft to cause the direction of drilling by said shaft and said cutting means to change.

30. The apparatus of claim 29, wherein:

said shaft comprises first and second shaft members with one of said shaft members having a central opening at one end and the other of said shaft members having an end located in said central opening such that said first and second shaft members may move toward and away from each other,

and means for preventing said first and second shaft members from rotating relative to each other.

31. The apparatus of claim 29, wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

32. The apparatus of claim 29, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam means.

33. The apparatus of claim 30, wherein:

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

34. The apparatus of claim 30, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam means.

35. The apparatus of claim 33, comprising:

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam means.

36. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be movable to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

means for shifting the axis of said guide housing relative to the axis of said shaft while said apparatus is drilling forward,

said shaft comprises first and second shaft members with one of said shaft members having a central opening at one end and the other of said shaft members having an end located in said central opening such that said first and second shaft members may move toward and away from each other, and

means for preventing said first and second shaft members from rotating relative to each other.

37. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis, a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

drill cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be movable to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

said shaft is defined as a drill shaft having said forward end and a rear end opposite said forward end,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

at least one side cutting means coupled to a cutter shaft supported by said front shaft support housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into said guide slot as said apparatus is moved in the hole being drilled.

38. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a drill shaft extending through said guide housing,

said drill shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said drill shaft being movable longitudinally relative to said guide housing such that said shaft may be movable to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

a front shaft support housing coupled to said guide housing with said drill shaft extending through said front shaft support housing,

first and second spaced apart side cutting means coupled together by a first shaft supported by said front shaft support housing,

said first shaft having a first axis extending transverse to said axis of said drill shaft and located on a first side of said axis of said drill shaft,

third and fourth spaced apart side cutting means coupled together by a second shaft for rotation together by said second shaft,

said second shaft having a second axis generally parallel to said first axis and located on a second side of said axis of said drill shaft opposite to said first side of said axis of said drill shaft,

said first and third cutting means being located on one side of a plane which extends through said axis of said drill shaft transverse to said first and second axes,

said second and fourth cutting means being located on a side of said plane opposite said one side of said plane,

means coupled to said drill shaft for rotating said first and second shafts in opposite directions to rotate the portions of said first and third cutting means facing away from said drill shaft toward the rear end of said drill shaft and to rotate the portions of said second and fourth cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations and to cut four guide slots in the hole being drilled, and

at least one guide means coupled to said apparatus rearward of said front shaft support housing which extends into at least one of said four guide slots respectively as said apparatus is moved in the hole being drilled.

39. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,

said shaft being movable longitudinally relative to said guide housing such that said shaft may be moved to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,

cam means coupled to said guide housing around said shaft,

a cam follower coupled to a cam follower housing which surrounds said shaft,

said cam follower being disengaged from said cam means when said shaft is in said shifting position,

said cam follower housing and said cam follower being rotatable together relative to said guide housing when said shaft is in said shifting position,

said cam follower means being movable longitudinally with said shaft relative to said follower housing and relative to said cam means,

a clutch for coupling said cam follower housing to said shaft when said shaft is in said shifting position such that said cam follower housing and hence said cam follower may be rotated with said shaft relative to said cam means to allow said cam follower to engage said cam means to a selected angular position around said shaft when said shaft is moved to said forward drilling position,

when said shaft moves toward said forward drilling position, said clutch allows said cam follower housing to be uncoupled from said shaft such that in said forward drilling position of said shaft, said cam follower engages said cam means and causes said axis of said guide housing to shift relative to said axis of said shaft to cause the direction of drilling by said shaft and said cutting means to change,

a first indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said cam follower means, and

a second indicating means for sensing and transmitting to the surface a signal indicative of the rotational position of said guide housing.

40. An apparatus for drilling a hole in the earth, comprising:

a housing having a given axis,

a drill shaft extending through said housing,

said drill shaft having a central axis, a forward end and a rear end opposite to said forward and,

drill cutting means coupled to said forward end of said drill shaft for drilling purposes, upon rotation of said drill shaft,

at least one side cutting means coupled to a cutter shaft supported by said housing,

said cutter shaft having an axis extending transverse to said axis of said drill shaft and located on one side of said axis of said drill shaft,

means coupled to said drill shaft for rotating said cutter shaft in a direction to rotate the portion of said side cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations.

41. The apparatus of claim 40, wherein:

said side cutting mean is located to cut a guide slot in the hole being drilled, and

means coupled to said apparatus rearward of said front shaft support housing which extends into the guide slot as said apparatus is moved in the hole being drilled.

42. An apparatus for drilling a hole in the earth, comprising:

a housing having a given axis,

a drill shaft extending through said housing,

said drill shaft having a central axis, a forward end and a rear end opposite said forward end,

cutting means coupled to said forward end of said drill shaft for drilling purposes, upon rotation of said drill shaft,

first and second spaced apart side cutting means coupled together by a first shaft supported by said housing,

said first shaft having a first axis extending transverse to said axis of said drill shaft and located on a first side of said axis of said drill shaft,

third and fourth spaced apart side cutting means coupled together by a second shaft for rotation together by a second shaft supported by said housing,

said second shaft having a second axis generally parallel to said first axis and located on a second side of said axis of said drill shaft opposite to said first side of said axis of said drill shaft,

said first and third cutting means being located on one side of a plane which extends through said axis of said drill shaft transverse to said first and second axes,

said second and fourth cutting means being located on a side of said plane opposite said one side of said plane,

means coupled to said drill shaft for rotating said first and second shafts in opposite directions to rotate the portions of said first and third cutting means facing away from said drill shaft toward the rear end of said drill shaft and to rotate the portions of said second and fourth cutting means facing away from said drill shaft toward the rear end of said drill shaft to help move said apparatus forward during drilling operations.

43. The apparatus of claim 42, wherein:

said side cutting means are located to cut four guide slots in the hole being drilled, and

at least one guide means coupled to said apparatus which extends into at least one of said guide slots as said apparatus is moved in the hole being drilled.

44. An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,

a shaft extending through said guide housing,

said shaft having a central axis and a forward end,

a drill rig stem connected to rear end of said shaft,

cutting means coupled to said forward end of said shaft for drilling purposes upon rotation and thrust of said shaft by means of said drill rig stem,

said shaft being movable longitudinally relative to said guide housing by means of said drill rig stem such that said shaft may be movable to a forward position relative to said guide housing and to a rearward position relative to said guide housing,

said guide housing being movable forward and rearward by means of said drill rig stem,

means located in said guide housing to vary the alignment of said axis of said guide housing relative to axis of said shaft during longitudinal displacement of said shaft relative to said guide housing for locating said axis of said guide housing in at least first and second positions relative to said axis of said shaft,

said shaft being adapted to rotate said cutting means during and after longitudinal displacement,

in said first position, said axis of said housing generally coincides with said axis of said shaft to allow said apparatus to drill straight,

in said second position, said axis of said guide housing is shifted relative to said axis of said shaft to cause the direction of said apparatus to turn while drilling operations are carried out.