Auger boring machine with two-stage guidance control system

Abstract

An auger boring machine includes a two-stage guidance control system for controlling a pilot tube during formation of an underground pilot hole which is subsequently followed by an auger to form a larger hole for installation of underground pipe. The system includes a first stage guidance control mechanism for guiding the pilot tube during a first stage of driving the pilot tube and a second stage guidance control mechanism for guiding the pilot tube during a second subsequent stage of driving the pilot tube. The first stage mechanism typically includes a theodolite which allows for pilot tube control during the first several hundred feet of pilot hole formation. The second stage mechanism typically includes a sonar sensor such as a radio frequency receiver for sensing signals transmitted from within the pilot tube and allows for pilot tube control when the first stage mechanism is no longer functional.

Description

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates generally to an auger boring machine and a method of use in the trenchless installation of underground pipe. More particularly, the invention relates to such a machine which utilizes a pilot tube for forming a pilot hole for guiding the auger of the machine. Specifically, the invention relates to a two-stage guidance control system for guiding the pilot tube through the earth to form a pilot hole which is several hundred feet long.

2. Background Information

The use of an auger boring machine for installing underground pipe between two locations without digging a trench there between is broadly known. In addition, it is known to use a pilot tube formed of a plurality of pilot tube segments to create a pilot hole for guiding an auger which bores a larger hole so that the auger remains within a reasonably precise line and grade. For example, see U.S. Pat. No. 6,206,109 granted to Monier et al. Commonly, a theodolite is used to control the line and grade of the pilot tube in forming the pilot hole. However, the theodolite system has limitations in that when the pilot hole extends past a certain distance, usually in the range of about 400 feet, the illuminated target adjacent the pilot tube is too far away to be properly sensed from the area of the pilot drive assembly. Thus, in forming pilot holes which are extremely long, there is a need for a guidance control system to ensure that the remaining portion of the pilot hole remains on line and grade. The present invention solves this and other problems in the art.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an apparatus comprising: an auger boring machine pilot tube; a first stage guidance control mechanism for guiding the pilot tube during a first stage of driving the pilot tube; and a second stage guidance control mechanism for guiding the pilot tube during a second subsequent stage of driving the pilot tube.

The present invention further provides a method comprising the steps of: (a) sensing a position of an auger boring machine pilot tube with a first sensing device during a first stage of driving the pilot tube to form a pilot hole in the ground; (b) guiding the pilot tube during the first stage of driving the pilot tube in response to step (a); (c) sensing a position of the pilot tube with a second sensing device during a second subsequent stage of driving the pilot tube; and (d) guiding the pilot tube during the second stage of driving the pilot tube in response to step (c).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a side elevational view of the auger boring machine of the present invention shown in a pit formed in the earth.

FIG. 2 is a top plan view of the auger boring machine.

FIG. 3 is a perspective view of the drive and control assembly.

FIG. 4 is a fragmentary sectional view showing a pilot tube segment with the LED target disposed therein and connected to the sonde segment and a trailing pilot tube segment. FIG. 4 also illustrates the flow of lubricant through these segments of the pilot tube.

FIG. 5 is a sectional view taken on line 5-5 of FIG. 4 showing the LED target within the pilot tube.

FIG. 6 is a side elevational view of the sonde segment of the pilot tube.

FIG. 7 is a sectional view taken on line 7-7 of FIG. 6 and also includes the connection of the sonde segment to the steering head and the pilot tube segment which houses the LED target.

FIG. 8 is a sectional view taken on line 8-8 of FIG. 7.

FIG. 9 is a sectional view taken on line 9-9 of FIG. 8.

FIG. 10 is a top plan view of the pilot tube drive assembly prior to formation of the pilot hole.

FIG. 11 is a top plan view of the drive assembly showing an extension of the hydraulic actuators to provide an initial stage of pilot hole formation and also showing the steering capability of the pilot tube.

FIG. 12 is similar to FIG. 11 and shows the subsequent pilot tube segment connected to the previously driven pilot tube segment and the drive mechanism.

FIG. 13 is similar to FIG. 12 and shows the extension of the hydraulic actuators of the drive mechanism to drive the pilot tube with the newly installed pilot tube segment thereof to lengthen the pilot hole.

FIG. 14 is a diagrammatic view showing the second stage of the guidance control system in which the sonde transmits a signal to a receiver above ground.

Similar numbers refer to similar parts throughout the drawings.

DETAILED DESCRIPTION OF THE INVENTION

The auger boring machine of the present invention is indicated generally at 10 in FIGS. 1 and 2. Referring to FIG. 1, machine 10 is typically disposed in a pit 6 formed in the earth's soil or ground 8 and configured to bore a hole through ground 8 for the purpose of laying underground pipe in the bored hole. Machine 10 typically bores a hole from within a pit such as pit 6 to another pit which is spaced several hundred feet away. Machine 10 includes a frame 12 which extends from a front end 14 to a rear end 16 of machine 10. Front and rear end 14 and 16 define there between an axial direction of machine 10. Machine 10 further has first and second opposed sides 18 and 20 (FIG. 2) defining there between a lateral direction of machine 10.

An engine compartment 22 is mounted on frame 12 and houses therein a fuel powered engine 24, an electric generator 26 powered by engine 24 and a hydraulic pump 28 also powered by engine 24. An auger drive compartment 30 is disposed in front of compartment 22 and houses therein an auger drive having a rotational output shaft 32 for rotationally driving an auger 34 (FIG. 25). Frame 12 further includes a pair of spaced axially extending rails 36 secured to a plurality of cross bars 38 which are mounted on ground 8 in the bottom of pit 6. A pair of adjustable stabilizing poles 40 are telescopically received in and adjustably mounted respectively on rails 36 and configured to press against the wall of ground 8 which bounds pit 6.

In accordance with a feature of the invention, a two-stage pilot tube guidance control and drive assembly 42 is mounted on frame 12, and more particularly is removably mounted on rails 36 via mounting legs 44 (FIG. 3) which are removably insertable into openings 46 formed in each of rails 36. Mounting legs 44 and the mounting mechanism of which they are a part are described in further detail in the copending application entitled Pilot Tube System And Attachment Mechanism for Auger Boring Machine which is incorporated herein by reference and filed concurrently herewith. Assembly 42 when mounted on frame 12 is positioned so that a central axially extending axis X of a pilot tube 48 is coaxial with an axially extending axis Y which passes centrally through output shaft 32 and about which shaft 32 is rotated when driving an auger and cutting head (not shown). Assembly 42 includes a generally circular rear plate 50 which abuts compartment 30 when assembly 42 is mounted on frame 12.

Assembly 42 includes front and rear mounting assemblies 52 and 54 which are seated on rails 36 of frame 12 when assembly 42 is mounted on frame 12. A pair of axially extending parallel spaced rails 56 and 58 are rigidly mounted on assemblies 52 and 54. Adjustable stabilizing poles 60 are telescopically mounted respectively within first and second rails 56 and 58 and are adjustable to provide force against ground 8 in the same manner as poles 40.

A rigid front cross member 62 extends between and is connected to each of rails 56 and 58 adjacent the front thereof with a front pilot tube support 64 mounted thereon centrally between rails 56 and 58. Support 64 includes a plurality of bearings which engage the pilot tube 48 to allow axial movement of tube 48 as well as rotational movement of tube 48 about axis X to allow for the steering thereof. Rear plate 50 and associated structure attached thereto serve as a rear cross member for rigidly connecting rails 56 and 58 to one another at the rear of assembly 42. An intermediate cross member 66 extends laterally between rails 56 and 58 and is supported respectively on rails 56 and 58 by first and second roller assemblies 68 and 70. Each roller assembly includes a pair of upper rollers 72 and lower rollers 74 which respectively rollingly engage upper and lower surfaces 76 and 78 of respective rails 56 and 58.

An electric guidance control motor 80 having a rotational drive is mounted on cross member 66 for selectively rotating pilot tube 48 in either direction about axis X. A lubricant feed swivel 82 having a lubricant inlet 84 is mounted on motor 80 by a pair of spaced mounting rods 86 extending forward from motor 80. Swivel 82 is connected to pilot tube 48 and thus serves as an engaging member for drivingly engaging tube 48 during operation of assembly 42. Inlet 84 of swivel 82 is in fluid communication with a lubricant feedline which is in fluid communication with a source of lubricant, which is typically water. Swivel 82 receives water through inlet 84 to pump the water through pilot tube 48 and through a steering head 88 connected to the front of pilot tube 48, the water flowing out a forward exit opening 90 and a plurality of lateral exit openings 92. A crane stand 94 is mounted on the frame of assembly 42 for supporting a crane (not shown) used for lifting pilot tube segments into position for connecting the various segments to form pilot tube 48 during the process of driving tube 48 to form the pilot hole. A cord carrier 96 is mounted atop rail 56 and includes a plurality of links 98 which are pivotally connected to one another so that electrical cords for powering motor 80 and other electrical components will not become tangled during the longitudinal driving of pilot tube 48.

In accordance with the invention, during the first stage of driving pilot tube 48, a steering mechanism keeps tube 48 on line and grade using a theodolite which utilizes a camera 100 in electrical communication with a display monitor 102 which displays the view of the camera through pilot tube 48 of an illuminated LED target 104 (FIGS. 4-5) disposed within pilot tube 48 adjacent steering head 88. In order for camera 100 to view light rays transmitted from LED target 104, pilot tube 48 is hollow, as are the other structures intermediate camera 100 and target 104, such as motor 80 and swivel 82, in order to provide a line of sight Z (FIGS. 4, 11, 13) between camera 100 and target 104. A guidance control unit 106 is mounted on rail 58 and includes manually operable controls 108 typically in the form of joysticks in electrical communication with motor 80 in order to send a signal to motor 80 to control rotation of pilot tube 48.

Assembly 42 includes a continuous stroke drive mechanism 110 comprising a pair of hydraulic actuators in the form of piston-cylinder combinations 112 powered by pump 28. Combinations 112 must provide a substantial amount of forward and reverse thrust. For example, the forward thrust produced by combinations 112 on one preferred embodiment has a maximum thrust of 280,000 pounds while the reverse thrust has a maximum thrust of 140,000 pounds. Combinations 112 are capable of a continuous stroke throughout the extension thereof and likewise during the retraction thereof. The continuous stroke drive mechanism of the present invention is described in further detail in the copending application entitled Method And Apparatus For Providing A Continuous Stroke Auger Boring Machine which is incorporated herein by reference and filed concurrently herewith.

In accordance with the invention, pilot tube 48 includes a target-containing pilot tube segment 122 and a sonde segment 125 removably connected to the leading end of segment 122 and the trailing end of steering head 88. The various pilot tube segments of pilot tube 48 are connected end to end to sequentially increase the length of pilot tube 48 during the driving process. Typically, all or nearly all of the pilot tube segments are of the same length and are interchangeable with one another. However, some of the pilot tube segments may be of a different length. Segments 122 and 125 are shorter than the standard pilot tube segments 124 connected sequentially behind segment 122. Pilot tube segment 122 has a length of roughly two feet while segment 125 is roughly three feet long and pilot tube segments 124 typically come in lengths of five feet although this may vary.

As noted previously, pilot tube 48 is configured with lubricant through passages to allow a lubricant such as water to flow therethrough to steering head 88. The lubrication system of assembly 42 is described in further detail in the copending application entitled Lubricated Pilot Tubes For Use With Auger Boring Machine Pilot Steering System which is incorporated herein by reference and filed concurrently herewith. However, some of the lubricant passages of pilot tube 48 are discussed herein. More particularly, FIG. 5 shows a sectional view of a trailing portion of sonde segment 125, segment 122 and a leading portion of a pilot tube segment 124, which in part shows the lubricant passages therethrough. Segment 122 has a first trailing coupling member 130 which threadably engages a second leading coupling member 132 of the leading segment 124 to connect segments 122 and 124 together. Six lubricant passages 140 are formed in first coupling member 130 and are circumferentially equally spaced from one another. A central through passage 162 is formed in pilot tube segment 124. Six lubricant passages 164 are also formed in segment 124 radially outwardly of passage 162 and are circumferentially evenly spaced from one another in order to align with passages 140 when first and second coupling members 130 and 132 are joined to one another.

FIG. 5 shows additional passages in pilot tube 48 allowing for a flow of lubricant therethrough to steering head 88. More particularly, six lubricant passages 172 are formed through segment 122 in a manner similar to passages 140 and passages 164 in order to allow communication with passages 140 of coupling member 130. Passages 172 are disposed radially outwardly of a central interior chamber 173 which is formed in segment 122 and which houses target 104. Passages 172 merge into a central chamber 174 formed in the rear portion of sonde segment 125 via respective passages 176 which extend radially outwardly from chamber 174. FIG. 4 further shows that lead tube segment 122 defines a central passage providing for line of sight Z therethrough to provide a clear view of illuminations 180 (FIG. 5) of target 104.

Referring to FIGS. 6-9, sonde segment 125 and steering head 88 are further described. Segment 125 has a substantially solid cylindrical main body 134 which makes up most of its length. Body 134 has a leading end 136 and a trailing end 138 with a mounting neck 140 extending rearwardly from trailing end 138. Neck 140 is stepped inwardly from body 134 and is also substantially cylindrical. Neck 140 defines a pair of axially spaced annular grooves in which are disposed a respective pair of annular seals 142. Neck 140 further defines an annular groove 143 between seals 142 in communication with each of passages 176. A neck-receiving cavity 144 is formed in body 134 and extends rearwardly from leading end 136 for receiving therein a neck 146 of steering head 88 which is similar to neck 140 of segment 125. Body 134 defines a central transmitter cavity 148 which is in communication with cavity 144 and in which a radio frequency (RF) transmitter 150 is disposed. Six axially elongated transmission slots 152 are formed in body 134 and extend radially outwardly from cavity 148 to the outer surface of body 134. Slots 152 are circumferentially equally spaced from one another.

Central chamber 174 converges into a central passage 154 which extends from chamber 174 into the rear portion of body 134. Six radial passages 156 (only four shown) communicate with and extend radially outwardly from central passage 154 respectively to six axially extending passages 158 which extend forward therefrom to adjacent leading end 136 of body 134. Passages 158 are circumferentially evenly spaced from one another and each passage 158 is positioned centrally between an adjacent pair of slots 152. Another set of six radial passages 160 are formed in the cylindrical wall which bounds cavity 144 and extend respectively radially inwardly from passages 158 to cavity 144. Similarly, a set of six radial passages 166 are formed in the cylindrical portion of pilot tube segment 122 which defines a front portion of interior chamber 173 and extend respectively radially inwardly from the leading ends of passages 172 to interior chamber 174. Passages 166 thus communicate with annular groove 143 of mounting neck 140. Pilot tube segments 122 and 125 are connected, to one another by a plurality of bolts 168 extending through holes formed in segment 122 and threadably engaging threaded holes 170 formed in neck 140.

Referring to FIGS. 7 and 9, steering head 88 is further described. Steering head 88 includes a head portion 188 from which neck 146 extends rearwardly. Portion 180 includes a flat, oval-shaped forward facing steering face 182 (FIG. 3) which angles from a tip 184 on one side of portion 180 rearwardly across to the other side of portion 180. Like neck 140 of segment 125, neck 146 defines a pair of axially space annular grooves in which a pair of annular seals 186 are respectively disposed. Another annular groove 188 is formed in the cylindrical outer surface of neck 146 between seals 186 and communicates with passages 160 when steering head 88 is connected to segment 125. Six radial passages 190 are formed in neck 146 and extend radially inwardly from groove 188 and respectively adjacent passages 160 to a central interior chamber 192 formed in neck 146 and a rear portion of head portion 180. A central passage 194 extends forward from chamber 192 and then branches into a plurality of exit passages 196 formed in head portion 180. One of exit passages 196 extends forward to exit opening 90 (FIG. 3) and the remaining passages 196 extend to respective exit openings 192 on the outer surface of head portion 80. A plurality of bolts 198 extend through holes formed in the front portion of segment 125 and into respective threaded holes in neck 146 of steering head 88 to connect steering head 88 and segment 125 to one another.

Thus, segments 122 and 125 and steering head 88 are configured with various lubricant passages to allow the flow of lubricant particularly in the form of water to flow from lubricant feed swivel 82 all the way to the outer surface of steering head 88 while allowing target 104 and transmitter 150 to be disposed within pilot tube 84 separate from the flow of the water. The arrows in FIGS. 5 and 7 indicate the flow of lubricant through the various passages from swivel 82 through pilot tube 48 and steering head 88.

The operation of boring machine 10 is now described with reference to FIGS. 10-14. FIGS. 10-13 are shown without main frame 12 of machine 10 for simplicity. FIG. 10 shows assembly 42 prior to the driving of pilot tube 48 to form a pilot hole with an operator 204 preparing to begin operation of assembly 42. The pistons of piston cylinder combinations 112 are shown in a fully retracted position FIG. 10. Assembly 42 is operated to actuate combinations 112 in order to extend pistons 116 thereof to drive pilot tube 48 into ground 8 as indicated in arrow E in FIG. 11 to form the initial stages of a pilot hole 206. During the extension of pistons 116 and pilot tube 48, camera 100 senses or receives input in the form of light rays from LED target 104 and relays the images of illuminations 180 on the monitor 102. Operator 204 views display monitor 102 in order to determine the position or orientation of pilot tube 48 and thus whether steering head 88 needs to be adjusted to maintain the line and grade of pilot tube 48. Operator 204 uses controls 108 in order to make any necessary adjustments, specifically rotating pilot tube 48 as indicated in arrow F in FIG. 11 via motor 80. Simultaneously with driving and steering pilot tube 48, water may be pumped through the lubricant through passages in pilot tube 48 via swivel 82 to steering head 88 and through the exit openings thereof in order to facilitate the formation of pilot hole 206. At this early stage of pilot hole formation, only one of the standard size pilot tubes 124A is being used, as shown in FIGS. 10 and 11.

Once the initial driving of tube 48 is performed, pistons 112 are retracted as shown in FIG. 12 at arrow G and a pilot tube segment 124B is connected to tube segment 124A and a rotatable portion of swivel 82 as indicated at arrow H in preparation for additional driving of tube 48. Drive mechanism 110 is then operated to extend piston 116, roller assemblies 68 and 70 and pilot tube 48 including segments 124A and B to lengthen pilot hole 206 as indicated at arrow J in FIG. 13 while operator 204 provides any rotational adjustment to steering head 88 as indicated at arrow K. The pattern of adding tube segments and continuing to drive pilot tube 48 goes on until the pilot hole is completed or more particularly so that the pilot tube 48 extends out of ground 8 so that sections of pilot tube 48 may be removed as the auger boring operation is underway and thus moves pilot tube 48 gradually forward.

However, pilot tube 48 may only be controlled by the theodolite control assembly to maintain a proper line and grade thereof for a certain distance, which is typically about 400 feet from camera 100, as represented by D1 in FIG. 14 although camera 100 is not shown in FIG. 14. When the distance is too far for camera 100 to sense the illuminations 180 (FIG. 5) of target 104, the second stage of guidance control of pilot tube 48 comes into play. At this point, transmitter 150 emits an RF signal as indicated at the dotted line in FIG. 14 which is received by an RF receiver 208 carried by a second operator 218 above ground. Thus, as pilot tube 48 is driven forward as indicated at arrow L in FIG. 14, second operator 210 walks along as indicated at arrow M with receiver 208 in order to receive the transmitter signal and thus determine the position of pilot tube 48 at its leading end in order to determine how it should be steered. Operator 210 then communicates the findings to operator 204 by any suitable means of communication or a remote control may be used in order to control motor 80 in rotating pilot tube 48 to keep pilot tube 48 on a proper line and grade during the remainder of driving the pilot tube to complete pilot hole 206.

Once pilot hole 206 is completed, assembly 42 is removed from frame 12 of auger boring machine 10 and an auger is then connected to a rotational output shaft powered by engine 24 along with the pipe or casing in which the auger is disposed and cutting head connected to the front of the auger. A swivel is also connected to the trailing end of pilot tube 48 and the front of the cutting head to allow for the rotation of the auger and cutting head independent of rotating pilot tube 48. The swivel is described in greater detail in the copending application Method of Installing Large Diameter Casing and Swivel For Use Therewith which is incorporated herein by referenced and filed concurrently herewith.

In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.

Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.

Claims

1. An apparatus comprising:

an auger boring machine pilot tube;

a first stage guidance control mechanism for guiding the pilot tube during a first stage of driving the pilot tube; and

a second stage guidance control mechanism for guiding the pilot tube during a second subsequent stage of driving the pilot tube.

2. The apparatus of claim 1 further comprising a radio frequency transmitterwithin the pilot tube; and an illuminated target within the pilot tube.

3. The apparatus of claim 2 further comprising a radio frequency receiver separate from the pilot tube and operationally connected to the transmitter for receiving radio frequency signals therefrom.

4. The apparatus of claim 3 wherein the pilot tube has leading and trailing ends; and further comprising a line of sight passage formed in the pilot tube from the target to the trailing end; and a camera adjacent the trailing end of the pilot tube and aligned for viewing the target through the line of sight passage.

5. The apparatus of claim 4 further comprising a motor having a rotational drive operatively connected to the pilot tube for rotating the pilot tube.

6. The apparatus of claim 2 wherein the pilot tube has an outer surface; and further comprising a plurality of transmission openings formed in the pilot tube extending from the transmitter to the outer surface of the pilot tube.

7. The apparatus of claim 2 further comprising at least one lubrication through passage formed in the pilot tube extending alongside the transmitter and the target.

8. The apparatus of claim 2 wherein the pilot tube has leading and trailing ends; and the transmitter is disposed between the leading end and the target.

9. The apparatus of claim 8 further comprising a steering head on the leading end of the pilot tube; and wherein the transmitter is disposed between the steering head and the target.

10. The apparatus of claim 9 wherein the pilot tube comprises a first pilot tube segment which carries the transmitter and is removably connected to the steering head; and a second pilot tube segment which carries the target and is removably connected to the first pilot tube segment.

11. The apparatus of claim 1 wherein the first stage mechanism comprises a theodolite; and the second stage mechanism comprises a sonar sensor.

12. A method comprising the steps of:

(a) sensing a position of an auger boring machine pilot tube with a first sensing device during a first stage of driving the pilot tube to form a pilot hole in the ground;

(b) guiding the pilot tube during the first stage of driving the pilot tube in response to step (a);

(c) sensing a position of the pilot tube with a second sensing device during a second subsequent stage of driving the pilot tube; and

(d) guiding the pilot tube during the second stage of driving the pilot tube in response to step (c).

13. The method of claim 12 wherein step (a) comprises the step of sensing the position of the pilot tube with a theodolite.

14. The method of claim 13 wherein step (c) comprises the step of sensing the position of the pilot tube with a sonar sensor.

15. The method of claim 13 wherein step (c) comprises the step of sensing a radio frequency transmission from within the pilot tube.

16. The method of claim 15 wherein step (c) comprises the step of sensing the radio frequency transmission with an above ground radio frequency receiver.

17. The method of claim 12 wherein step (a) comprises the steps of transmitting light rays through the pilot tube from adjacent a leading end thereof to adjacent a trailing end thereof; and calculating the position of the pilot tube based on the light rays.

18. The method of claim 17 wherein step (c) comprises the step of sensing a radio frequency signal transmitted from the pilot tube adjacent its leading end.

19. The method of claim 12 wherein step (c) comprises the step of sensing a radio frequency signal transmitted from the pilot tube adjacent its leading end.

20. The method of claim 12 wherein each of steps (b) and (d) comprises the step of rotating the pilot tube and a steering head mounted thereon.