Technique for providing an underground tunnel utilizing a powered boring device

• US 4,821,815 A
• Filed: 05/22/1986
• Issued: 04/18/1989
• Est. Priority Date: 05/22/1986
• Status: Expired due to Fees

• Current Assignee: UtilX Corporation (Novinium, Inc.)
• Original Assignee: Flowmole Corporation
• Inventors: Mercer, John E., Chau, Albert W., Baker, Glen, Fikse, James A.
• Primary Examiner(s): Massie, Jerome W.
• Assistant Examiner(s): Melius, Terry Lee
• Application Number:
  US06/866,240
• Time in Patent Office: 1,062 Days
• Field of Search: 175/26, 175/40, 175/45, 175/61, 175/62, 175/67, 175/73, 175/162, 175/27, 405/248, 173/4, 173/5, 173/6, 173/11, 173/12
• US Class Current: 175/26
• CPC Class Codes: E21B 44/005 Below-ground automatic control systems
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003
• CPC Class Codes: E21B 7/18 Drilling by liquid or gas jets, with or without entrained pellets E21B7/14 takes precedence
• CPC Class Codes: H02G 1/06 for laying cables, e.g. laying apparatus on vehicle
• CPC Class Codes: H02G 1/08 through tubing or conduit, e.g. rod or draw wire for pushing or pulling inserting electrical cables into tubes using wallbores E21B17/206; for optical cables G02B6/4401

Abstract

A technique for providing a continuous underground tunnel between first and second spaced-apart points and for installing new cable, pipe or conduit is disclosed herein. This technique utilizes a boring device including means for boring through soil and a thrust conduit which pushes the boring device through the soil from a first starting point to a second end point as the device bores through the soil, whereby to form a tunnel between the two points. Thereafter, the cable to be installed within the tunnel is attached to the front end of the boring device and the latter is pulled back through the tunnel to its starting point by means of the thrust cable, thereby automatically pulling the new cable in place.

Claims

1. An apparatus for providing a continuous underground tunnel between first and second spaced-apart points, comprising:

(a) a boring device including means for boring through soil; and

(b) means for driving said boring device through the soil from said first point to said second point as said device bores through the soil whereby to form a tunnel between said points, said driving means including

(i) a thrust conduit which extends in a continuous, uninterrupted manner from one end thereof to an opposite end and which is connected at said one end with said boring device, and means acting directly on the conduit behind said boring device at said first point for thrusting the conduit forward along its axis in the direction of said boring device as the latter bores through the soil whereby to push the boring device therethrough, said conduit being sufficiently rigid to push said boring device forward through the soil and yet sufficiently flexible to allow the device to move from said first point to said second point in a non-linear manner if necessary or desired, said thrusting means including rotatable means engaging said conduit, motor means for rotating said rotatable means, and means for maintaining the torque on said motor means constant regardless of the degree of compactness of the soil through which the boring device is being pushed.

2. An apparatus according to claim 1 wherein said thrust conduit is formed of a continuous hollow tube.

3. An apparatus according to claim 2 including first control means on said boring device, second control means above ground and control line means extending through said hollow thrust conduit between said first and second control means.

4. An apparatus according to claim 3 wherein said boring means includes high pressure fluid jets on said device, a source of high pressure fluid above ground, and a high pressure fluid line extending from said fluid source to said jets through said hollow thrust conduit.

5. An apparatus according to claim 1 wherein said motor means includes at least one hydraulic motor and wherein said torque maintaining means includes means for hydraulically driving said motor, means for sensing the hydraulic drive pressure at said motor, and means for adjusting the hydraulic drive pressure at said motor for maintaining a constant torque at the motor.

6. An apparatus for providing a continuous underground tunnel between first and second spaced-apart points, comprising:

(a) a boring device including means for boring through soil of the type which may vary in hardness to bore through; and

(b) means including

(i) a thrust cable connected at one end with the rearward end of said boring device,

(ii) at least one drivemotor engaging said thrust cable for pushing said cable and boring device through said last-mentioned soil from said first point to said second point as the device bores through the soil, whereby to form a tunnel between said point, and

(iii) means for maintaining the torque on said motor constant regardless of the degree of hardness of the soil to bore through by said device,

(c) said drive motor being a hydraulic motor and said torque maintaining means including

(i) means for hydraulically driving said motor,

(ii) means for sensing the hydraulic drive pressure at said motor, and

(iii) means for adjusting the hydraulic drive pressure at said motor for maintaining a constant torque at the motor.

7. An apparatus for providing a continuous underground tunnel between first and second spaced-apart points comprising:

(a) a boring device including means for boring through soil; and

(b) means for driving said boring device through soil from said first point to said second point as the device bores through the soil, whereby to form a tunnel between said points, said driving means including

(i) a hollow tubular thrust conduit which extends in a continuous, uninterrupted manner from one end thereof to an opposite end and which is connected at said one end with said boring device,

(ii) a reel assembly including a reel and motor means for initially supporting the thrust conduit in a wound condition,

(iii) a thrust assembly including a plurality of inflatable tires frictionally engaging circumferentially spaced segments of the outer surface of said thrust conduit at a location along the latter spaced from said reel and motor means for rotating said wheels in order to thrust said conduit forward along its axis in the direction of the boring device as the latter bores through the soil, whereby to push the boring device therethrough,

(iv) means for maintaining a first constant torque load on said thrust assembly motor means whereby to exert a constant driving force on said thrust conduit regardless of the degree of compactness of the soil through which the boring device is being driven and for maintaining a second, slightly lower torque load on said reel motor means whereby to apply a corresponding constant rotating force on said reel sufficient to maintain the section of said conduit between said reel and thrusting assembly taut in order to prevent the conduit from unwinding from the reel in an uncontrolled manner.

8. An apparatus according to claim 7 including an open ended, curved launching tube configured to receive said boring device and said thrust conduit and serving to initially direct the boring device into the ground from an above ground point.

9. An apparatus for providing a continuous underground tunnel between first and second spaced-apart points, comprising:

(a) a boring device including means for boring through soil; and

(b) means for driving said boring device through the soil from said first point to said second point as said device bores through the soil whereby to form a tunnel between said points, said driving means including a thrust conduit which extends in a continuous, uninterrupted manner from one end thereof to an opposite end and which is connected at said one end with said boring device, and means acting directly on the conduit for thrusting the conduit forward along its axis in the direction of said boring device as the latter bores through the soil whereby to push the boring device therethrough, said conduit being sufficiently rigid to push said boring device forward through the soil and yet sufficiently flexible to allow the device to move from said first point to said second point in a non-linear manner if necessary or desired, said driving means including a reel spaced from said thrusting means for initially supporting said thrust conduit in a wound condition, whereby as the conduit is thrust in the direction of the boring device by said thrusting means it unwinds from said reel, said driving means also including means for always maintaining the section of said conduit between said reel and thrusting means taut in order to prevent the conduit from unwinding from the reel in an uncontrolled manner, said thrusting means including rotatable means engaging said conduit and first motor means for rotating said rotatable means, said driving means including second motor means for causing said reel to rotate as said conduit is unwound from it by said thrusting means in a way which aids in unwinding the conduit, and said means for maintaining said conduit section taut includes means for always maintaining a higher amount of torque on said first motor means than on said second motor means, said torque maintaining means including means for maintaining the torque on said first motor means constant regardless of the degree of compactness of the soil through which the boring device is being pushed, said torque maintaining means includes means for maintaining the torque on said second motor means constant regardless of the amount of conduit wound around said reel, and said first and second motor means including hydraulic motors and wherein said torque maintaining means includes means for hydraulically driving said motors, means for sensing the hydraulic drive pressure at said motors, and means for adjusting the hydraulic drive pressure at said motors for maintaining a constant torque at each.

10. An apparatus according to claim 9 wherein said thrust conduit is formed of a continuous hollow tube.

11. An apparatus according to claim 10 including first control means on said boring device, second control means above ground and control line means extending through said hollow thrust conduit between said first and second control means.

12. An apparatus according to claim 11 wherein said boring means includes high pressure fluid jets on said device, a source of high pressure fluid above ground, and a high pressure fluid line extending from said fluid source to said jets through said hollow thrust conduit.