INSPECTION SYSTEM AND METHOD FOR USE IN UNDERGROUND BORING OPERATIONS
FIELD
[0001] The present disclosure relates generally to the field of
underground utility construction and, more particularly, to an inspection system
and method for use in underground boring operations to assist in preventing
utility line crossbores.
BACKGROUND
[0002] This section provides background information related to the
present disclosure which is not necessarily prior art.
[0003] Underground utility lines are sometimes installed using any of a
variety of trenchless installation technologies, including horizontal boring
technologies. Horizontal boring technologies provide efficient and cost effective
ways to install gas, water, electric and communications lines, particularly when it
is difficult or cost prohibitive to plow or trench the ground, such as when there
are ground obstructions (e.g., a road, sidewalk, driveway, or landscaping) along
the path of the utility line that prevent those techniques. Some horizontal boring
technologies include underground pneumatic boring, auger boring, wet boring,
horizontal directional drilling (HDD), impact moling, pipe jacking and
microtunneling.
[0004] The process of underground pneumatic boring involves
launching a pneumatic boring or piercing tool that creates a horizontal bore hole
along a straight path to create a tunnel through the ground. A utility line (e.g., for
gas, water, electric or communications) can then be pulled back through the
tunnel for installation underground.
[0005] A conventional system and method for underground pneumatic
boring can be understood with reference to FIGs. 1A, 1B and 1C. In an area 10
where a new underground utility line is to be installed, the existing utility lines
and a surface obstacle 12 (e.g., a road) to be traversed by the new utility line is
surveyed. Then a path along which to create an underground bore or tunnel 14
for the new utility line is chosen. Thereafter, two pits are excavated on the
opposite sides of the obstacle; a pit 16 at the path's origin (the entrance pit) and
a pit 18 at its target destination (the exit pit). The pits 16, 18 are large enough to
fit a boring tool 20 and to permit an operator to work. The pits are also deep
enough so that as the boring tool 20 creates the tunnel 14 , the surface of the
ground above it remains undisturbed.
[0006] The boring tool 20, shown best in FIG. 1C, is a well-known
device and comprises a pneumatically-operated boring tool that cuts through
soil, rock, etc. The boring tool 20 is connected to a supply of compressed air by
an air supply hose 22. A guide tool 24 and a sighting device 26 (both shown in
FIG. 1B) are used to align the boring tool along the desired path and toward the
intended destination. The boring tool 20 is then activated and it proceeds to cut
the tunnel 14 , advancing through the wall of the entrance pit with the air supply
hose 22 following behind it. Once the boring tool 20 has progressed beyond the
guide tool 24, the location of the boring tool 20 is tracked through the ground
with a radio frequency receiver that detects a radio signal generated by a radio
transmitter that is built into the boring tool.
[0007] When the boring tool 20 reaches the target destination, it has
completed the tunnel 14 through which the new utility line can be run, between
the entrance and exit pits 16, 18 and beneath the surface obstacle 12. The
boring tool 20 is then removed from the air supply hose 22. The utility line is
then attached to the air supply hose 22 (such as by taping the utility line to the
hose 22), and the hose 22 and utility line are pulled back through the tunnel
together, thereby installing the utility line underground.
[0008] Underground pneumatic boring, however, has drawbacks which
can result in difficulties in completing a bore for an underground utility line. For
example, the boring tool is not steerable, and once it has exited the guide tool
the operator no longer has control over the boring tool's trajectory.
Consequently, the boring tool can be deflected from the desired path by rocks
and different soil densities, for example. Even minor deflections can cause
significant deviations from the desired path over long distances. Consequently,
the boring tool could unintentionally cross the path of other already existing
underground utilities. Therefore, and notwithstanding the fact that existing
underground utility lines are located and marked from above ground before the
pneumatic boring underground is carried out, it is possible that the boring tool
can tunnel through an existing utility line, such as a sanitary sewer line, without
the operator knowing. Then, when the new utility line is installed it would run
right through the existing sewer line. In such an instance, a crossbore - that is,
an intersection of two or more underground utilities - is created.
[0009] A significant concern for the underground utility construction
industry, regardless of the horizontal boring process employed, is unknowingly
tunneling through a sewer line and thereafter running a utility line, such as a
natural gas pipeline or power line, through the sewer line. The crossbored utility
line may remain in place for months or years before a blockage develops in the
sewer line. Then, in the process of clearing the sewer line, the utility line can be
severed, ruptured, or otherwise damaged by a power drain auger or other tool or
machine that is used to clear the sewer line. Any resulting damage to the
crossbored utility line can lead to a catastrophic failure, such as an explosion, if
the crossbored utility line is a gas line; or injury to the operator of the sewer
cleaning machine if the crossbored utility line is a power line; or disruption of
services if the crossbored utility line is a communications line, for example.
SUMMARY
[0010] This section provides a general summary of the disclosure, and
is not a comprehensive disclosure of its full scope or all of its features.
[001 1] The disclosure is generally directed to an inspection system
and method for use in the underground utility construction industry, and
particularly in underground boring operations. The inspection system generally
includes a sensor, a sensor carrier, and an output device. The sensor is
employed to obtain inspection data regarding the condition of the tunnel created
by a boring tool connected to a retrieval mechanism. The sensor carrier is
adapted to incorporate the sensor and connect to the retrieval mechanism to
transport the sensor through the tunnel. The output device receives an output
signal from the sensor corresponding to the inspection data and presents it to an
operator for interpretation and/or otherwise documents and/or records the
inspection data.
[0012] In an exemplary aspect, the disclosure is directed to a visual
inspection system and method for its use in underground boring operations to
assist in preventing utility line crossbores. The visual inspection system includes
a small camera that is configured for travel through the tunnel created in an
underground pneumatic boring operation before a new utility line is run. As the
camera traverses through the tunnel, an operator can view real-time images
(e.g., still pictures and/or video) of the tunnel on a display device and make a
visual inspection of the tunnel to determine whether another already existing
utility line, such as a sanitary sewer line, has been intersected during the boring
operation. By doing so, the potential for crossbores is significantly reduced. In
addition, of course, the inspection images can be recorded to document the
underground boring operation, that no crossbores were created, that no
underground utilities were damaged, and/or that there were no other obstacles in
the path of the tunnel.
[0013] The visual inspection system is disclosed to comprise a
camera, a display, and a camera rigging. The camera rigging includes a frame,
a camera connector clamp, a camera guide, and a connector fitting that adapts
the camera rigging for connection to an end of an air hose, a utility line, and/or a
drill bit.
[0014] A method according to the disclosure for visually inspecting an
underground bore for potential crossbores comprises creating an underground
tunnel for a utility line using a boring tool, removing the boring tool from an air
supply hose, attaching a camera to the air supply hose by way of a camera
rigging, pulling the air supply hose and the camera through the tunnel, visually
inspecting the tunnel, disconnecting the air supply hose from the camera rigging,
attaching a utility line to the camera rigging and pulling the camera rigging and
the utility line through the tunnel. Another method according to the disclosure for
visually inspecting an underground bore for potential crossbores comprises
creating an underground tunnel for a utility line using a drill bit, attaching a
camera to the drill bit by way of a camera rigging, pulling the drill bit and the
camera through the tunnel, visually inspecting the tunnel, disconnecting the drill
bit from the camera rigging, attaching a utility line to the camera rigging, and
pulling the camera rigging and the utility line through the tunnel.
[0015] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples in this
summary are intended for purposes of illustration only and are not intended to
limit the scope of the present disclosure. For example, a variety of different
sensor technologies could be employed in the inspection system, in addition to a
camera that obtains inspection data in the form of visible images. Other sensors
that alternatively could be employed, for example, are passive sensors like touch
sensors, infrared sensors and vapor sensors, or active sensors like sonar, radar
and laser. Consequently, the underground tunnels can be inspected for other
conditions in addition to crossbores.
DRAWINGS
[0016] The drawings described herein are for illustrative purposes only
of selected embodiments and not all possible implementations, and are not
intended to limit the scope of the present disclosure.
[0017] FIGs. 1A, 1B and 1C illustrate a conventional system and
method for underground pneumatic boring.
[0018] FIG. 2 is a perspective view of an inspection system according
to the present disclosure, the inspection system including a camera rigging.
[0019] FIG. 3 shows a perspective view of the camera rigging of FIG.
2, including a connector fitting, and adapters for coupling the connector fitting to
an air supply hose, a drill bit, and/or a utility line.
[0020] FIG. 4 is a partially exploded perspective view of a portion of
the camera rigging of FIG. 2.
[0021] FIG. 5 illustrates a front perspective view in partial cross-section
of a portion of the camera rigging of FIG. 2, including the connector fitting, and
the adapter for coupling the connector fitting to an air supply hose.
[0022] FIGs. 6A and 6B show front and rear perspective views,
respectfully, of the camera rigging of FIG. 2, including a camera guide and a
camera.
[0023] FIGs. 7A and 7B are rear perspective views of a portion of the
camera rigging of FIG. 2, including a camera connector clamp, shown in a
closed position and an open position, respectively.
[0024] FIG. 7C shows a cross-sectional view of the camera connector
clamp taken along a line 7C-7C shown in FIG. 7A.
[0025] FIGs. 8A, 8B, and 8C are schematic diagrams illustrating a
method for using a visual inspection system according to the present disclosure
in conjunction with underground pneumatic boring.
[0026] FIGs. 9A, 9B, and 9C are schematic diagrams illustrating a
method for using a visual inspection system according to the present disclosure
in conjunction with horizontal directional drilling.
[0027] FIG. 10 shows a perspective view of a portion of an alternative
embodiment of a visual inspection system according to the present disclosure,
the inspection system including a camera rigging.
[0028] FIG. 11 is an exploded perspective view of the camera rigging
of FIG. 10.
[0029] FIG. 12 illustrates a front perspective view in partial crosssection
of a portion of the camera rigging of FIG. 10, including a connector fitting,
and an adapter for coupling the connector fitting to an air supply hose.
[0030] FIGs. 13A and 13B show front and rear perspective views,
respectfully, of the camera rigging of FIG. 10, including a camera guide and a
camera.
[0031] FIG. 14 is an exploded perspective view showing a portion of
the camera rigging of FIG. 10, including a camera connector clamp.
[0032] FIG. 15 is a perspective view of another alternative embodiment
of a visual inspection system according to the present disclosure, the inspection
system including a camera rigging having guide wipers.
[0033] FIG. 16 is a cross-sectional view of the camera rigging of FIG.
15 taken along a line 16-1 6 shown in FIG. 15.
[0034] Corresponding reference numerals indicate corresponding parts
throughout the several views of the drawings.
DETAILED DESCRIPTION
[0035] Example embodiments are provided so that this disclosure will
be thorough, and will fully convey the scope to those who are skilled in the art.
Numerous specific details are set forth such as examples of specific
components, devices, and methods, to provide a thorough understanding of
embodiments of the present disclosure. It will be apparent to those skilled in the
art that specific details need not be employed, that example embodiments may
be embodied in many different forms and that neither should be construed to
limit the scope of the disclosure. In some example embodiments, well-known
processes, well-known device structures, and well-known technologies are not
described in detail. Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0036] An inspection system and method according to the present
disclosure is broadly applicable for use in the underground utility construction
industry, and particularly in underground boring operations used for installing
underground utility lines.
[0037] The inspection system generally includes a sensor, a sensor
carrier, and an output device. The sensor is employed to obtain inspection data
regarding the condition of the tunnel created by the underground boring
operation. Any of a variety of different sensor technologies could be employed in
the inspection system, such as a camera that captures visible images of the
tunnel, as well as passive sensors like touch sensors that can physically sense
features of the tunnel, infrared sensors that can capture infrared images of the
tunnel, or vapor sensors that can sense the presence of Volatile Organic
Compounds (VOCs) or other gases in the tunnel, or active sensors like sonar,
radar and lasers that can measure features of the tunnel.
[0038] The sensor carrier is adapted to incorporate the sensor and
connect to means for transporting the sensor through the tunnel.
[0039] The output device receives an output signal from the sensor
corresponding to the inspection data and presents it to an operator for
interpretation and/or otherwise documents and/or creates a record of the
inspection. In addition, the output device can include a user interface that
enables an operator to add a user input to a record of the inspection, such as
notes, commentary, or the like. The user input can take any of a variety of
forms, including typewritten text, audio, time stamping or bookmarking, to name
a few. Additionally, the output device can be configured to broadcast or post a
record of the inspection so it is accessible to specified recipients, including to a
database of the operator, to local municipalities, to regulatory agencies, to utility
companies, to other contractors, and to property owners.
[0040] In one exemplary aspect of the disclosure a visual inspection
system and method for its use in underground pneumatic boring to assist in
preventing utility line crossbores is provided. Referring now to FIG. 2, a visual
inspection system according to the present disclosure is generally indicated at
100. The visual inspection system 100 includes an inspection camera 102 that
is configured for travel through a tunnel created in an underground pneumatic
boring operation before a new utility line is run. As the camera 102 traverses
through the tunnel, an operator can view a real-time image of the tunnel on a
display device 104 and make a visual inspection of the tunnel to determine
whether another already existing utility line, such as a sanitary sewer line, has
been intersected during the boring operation. By doing so, the potential for
crossbores is significantly reduced. A camera cable 106, also referred to as a
push cable or a pushrod, connects the camera 102 to the display 104 via an
interface cable 107. The interface cable has a first end 107a that connects to
the display 104 and a second end 107b opposite form the first end 107a that
connects to the camera cable 106 using, for example, a cable connector (not
shown). The interface cable 107 can be mounted on a reel (not shown) to store
the length of the interface cable 107 and adjust the amount of slack in the
interface cable 107 as the camera 102 traverses through the tunnel.
[0041] A suitable inspection camera for use with a visual inspection
system of the present disclosure is available from Ridge Tool Company of Elyria,
OH, such as one of the SeeSnake® drain and sewer inspection camera and
cable reels. The output from the camera can include still pictures and/or video.
In addition, a suitable display device for viewing and/or recording the output from
the camera is likewise available from Ridge Tool Company, such as the
SeeSnake® monitors and recorders. Also, the lens of the camera can be varied
to alter the viewing angle and/or field of view of the camera. For example, a "fish
eye" lens may be incorporated so that the walls of a bore peripheral to the
camera are captured within the camera's field of view. In addition, the inspection
images can be recorded and/or otherwise saved to document the underground
boring operation, that no crossbores were created, that no underground utilities
were damaged, and/or that there were no other obstacles in the path of the
tunnel.
[0042] The visual inspection system 100 further includes a tether 108
and a camera rigging 110 comprising a camera connector clamp 112, a camera
guide 114 , a frame 116 comprising a flexible member (e.g., wire, rope), and a
connector fitting 118. The connector fitting 118 is configured to connect to a
thread adapter 120 or an eye bolt 122, which can be included in the system 100.
With brief reference to FIGs. 8B, 8C, 9B, and 9C, the connector fitting 118
adapts the system 100 for connection to, for example, a mating fitting 124 that
correspondingly connects to an end of the air supply hose 22 (shown in FIG.
8B). In addition, the air supply hose 22 can be disconnected from the mating
fitting 124, and a utility line 128 can be connected to the mating fitting 124
(shown in FIG. 8C). The connector fitting 118 adapts the system 100 for
connection to, for example, a swivel coupling 130 that correspondingly connects
to an end of a drill bit 132 for use in horizontal directional drilling (shown in FIG.
9B). Additionally, the drill bit 132 can be disconnected from the swivel coupling
130, and the utility line 128 can be connected to the swivel coupling 130 (shown
in FIG. 9C).
[0043] With reference to FIGs. 3, 4 , 5, 6A, 6B, 7A, 7B, and 7C, the
features and construction of an exemplary embodiment of the camera rigging
110 can be understood. The camera rigging 110 comprises the frame 116,
which has the camera connector clamp 112 attached at one end and the
connector fitting 118 attached at the other end. The camera guide 114 is
attached to the frame 116 and the camera 102 and located intermediate the
opposite ends of the frame 116.
[0044] The frame 116 connects together components of the camera
rigging 110, including the camera connector clamp 112, the camera guide 114,
and the connector fitting 118, while separating the camera connector clamp 112
and the connector fitting 118 a fixed distance apart when, for example, the
camera rigging 110 is pulled through a tunnel. The flexibility of the frame 116
enables the frame 116 to flex in response to curves or bends in a tunnel instead
of breaking or permanently deforming. The frame 116 comprises a single
flexible member that includes a first segment 134, a second segment 136, and a
third segment 138. The first segment 134 extends from the connector fitting 118,
through the camera guide 114 and the camera connector clamp 112, and to the
second segment 136. The second segment 136 forms a loop that extends
between and connects the first segment 134 and the third segment 138. The
third segment 138 extends from the second segment 136, through the camera
connector clamp 112 and the camera guide 114 , and to the connector fitting 118.
[0045] The tether 108 can be releasably attached to the camera
rigging 110 using a clip 139 (e.g., a carabiner, a spring snap, a snap hook) that
clips onto the loop formed by the second segment 136 of the frame 116.
Releasably attaching the tether 108 to the camera rigging 110 allows an operator
to remove the tether 108 to make the camera rigging 110 easier to handle and
allows the operator to replace the tether 108 with a different tether. The tether
108 comprises, for example, a flexible rope or cord that extends at least as long
as a tunnel created during a boring operation, and is preferably longer. The
tether 108 is used to pull the camera 102 and camera rigging 110, together with
a new utility line, back through a tunnel after an inspection process has been
completed.
[0046] As shown in FIG. 5, opposite ends 140 of the single flexible
member forming the frame 116 extend into corresponding apertures 14 1 in the
connector fitting 118 and are secured to the connector fitting 118 such as by set
screws 142 that engage corresponding female threads 144 formed in the
connector fitting 118. As shown in FIGs. 7A, 7B, and 7C, the segments 134, 138
of the frame 116 are secured to the camera connector clamp 112 such as by set
screws 146 that engage corresponding female threads 148 formed in the camera
connector clamp 112. It should be appreciated that although the frame in this
embodiment includes a single flexible member, the frame can include multiple
flexible members and/or one or more rigid members (e.g., rods).
[0047] FIG. 5 shows an enlarged view of the connector fitting 118.
The connector fitting 118 is a generally cylindrically shaped component having a
diameter that is at least equal to, and preferably just slightly greater than, the
diameter of the air supply hose 22. On a first end 150, the connector fitting 118
includes a connection portion 152 that is threaded for engagement with a
threaded portion 154 on the thread adapter 120 or a threaded portion 156 on the
eye bolt 122 (shown in FIG. 3), enabling the camera rigging 110 to be easily
attached to and detached from the air supply hose 22, the utility line 128, and the
drill bit 132. Alternatively, the connection portion 152 can incorporate a quickconnect
device that engages a corresponding quick-connect device on the air
supply hose 22, the utility line 128, and/or the drill bit 132. An outer surface 158
of the connector fitting 118 at the first end 150 is rounded over or tapered to a
slightly reduced diameter. This feature is included in order to minimize the
potential for "snow plowing," i.e., scraping the walls of a bore and creating a
buildup of soil, as the visual inspection system is pulled through the tunnel during
an inspection step.
[0048] On a second end 160 of the connector fitting 118 opposite to
the connection portion 152 is included a tapered cone portion 16 1 . The cone
portion 16 1 is centered in the frame 116 and is located directly in front of the
camera 102. The outer surface of the cone portion 16 1 is reflective, and the
angle of the taper of the cone portion 16 1 enables a peripheral vision inspection
of the walls of a bore relative to the axis of the camera 102. As such, an
operator can easily inspect the walls of a bore that may otherwise be outside the
field of view of a camera lens 162 (shown in FIGs. 6A and 6B) because the
images appear within the view of the camera lens 162 as a reflection on the
cone portion 16 1 of the connector fitting 118. The cone portion 16 1 also
minimizes the potential for snow plowing when the camera rigging 110 is pulled
back through a tunnel while carrying a new utility line. Additionally included in
the connector fitting 118 is a passageway 164 that extends through the
component from the connection portion 152 to the cone portion 16 1. When the
camera rigging 110 is connected to the air supply hose 22, the passageway 164
enables bursts of compressed air to be shot through the connector fitting 118 in
order to remove any buildup of soil or debris that may lodge on the camera 102
during the inspection process, or to clear a localized collapse of a tunnel, should
that occur.
[0049] FIGs. 6A and 6B show enlarged views of the camera guide 114 .
The camera guide 114 is received within the frame 116, with the segments 134,
138 of the frame 116 passing through corresponding apertures 166 through the
camera guide 114 . The camera guide 114 , in turn, receives the camera 102 and
serves to orient and align the camera 102 within the frame 116. In addition, the
camera guide 114 prevents the camera 102 from dragging along a tunnel
surface which, in turn, helps prevent dirt and/or debris from building up on the
camera lens 162. Preferably, the camera 102 is centered within the camera
guide 114 for optimal positioning for viewing the walls of a bore while conducting
an inspection.
[0050] The camera guide 114 can be fixed in its position intermediate
the connector fitting 118 and the camera connector clamp 112. Alternatively, the
position of the camera guide 114 can be adjusted such as by sliding it back and
forth along the segments 134, 138 of the frame 116. In FIGs. 6A and 6B, the
camera guide 114 is shown to be generally cylindrical with a maximum outer
diameter at its midpoint 168, and tapering inwardly from the midpoint 168 to a
smaller diameter at its opposite ends 170, 172. The maximum outer diameter of
the camera guide 114 is approximately the same as the maximum outer
diameter of the connector fitting 118. The tapered shape of exterior surfaces
174, 176 of the camera guide 114 enables it to move within a tunnel in either
direction while limiting the potential for snow-plowing. The shape of the camera
guide 114 helps maintain the integrity of a bore, especially around the camera
102, during the inspection process.
[0051] The camera guide 114 has a unitary body with a longitudinal slit
178 extending radially through a portion of the camera guide 114, and an
aperture 180 extending longitudinally through the center of the camera guide 114
and receiving the camera 102. The camera 102 is secured to the camera guide
114 using a fastener such as a screw 182 that engages corresponding female
threads disposed in an aperture 184 extending through the camera guide 114
perpendicular to the slit 178. Since the slit 178 does not extend radially through
the entire camera guide 114 to divide the camera guide 114 into two halves, only
one screw is required to clamp the camera guide 114 onto the camera 102. The
inner diameter of the camera guide 114 can be slightly greater than the outer
diameter of the camera 102 so that the camera guide 114 can be easily slid over
the camera 102. A gap exists between opposite edges 186 of the slit 178.
Consequently, tightening the screw 182 into the aperture 184 narrows the width
of the slit 178 and causes the camera guide 114 to clamp onto the camera 102.
Securing the camera 102 in this manner prevents damage to the camera 102.
[0052] Turning to FIGs. 7A, 7B, and 7C, enlarged views of the camera
connector clamp 112 are shown. When closed, the camera connector clamp
112 has a generally cylindrical shape with a tapering conical portion 188 located
at each of its opposite ends 190, 192. The camera connector clamp 112 has a
maximum outer diameter that is approximately the same as the maximum outer
diameter of the connector fitting 118. The tapering conical portions 188 of the
camera connector clamp 112 enable it to move within a tunnel in either direction
while limiting the potential for snow-plowing. The camera connector clamp 112
includes a plurality of apertures 194 extending through the camera connector
clamp 112 that each receives corresponding ones of the segments 134, 138 of
the frame 116. As previously discussed, the segments 134, 138 of the frame
116 are secured to the camera connector clamp 112 such as by the set screws
146, which engage the female threads 148 in the camera connector clamp 112.
[0053] As shown in FIGs. 7B and 7C, the camera connector clamp 112
includes an inner bulb 196 and an outer shell 198. The inner bulb 196 and the
outer shell 198 can be formed (e.g., machined or injection molded) from plastic
or metal (e.g., stainless steel). The inner bulb 196 clamps onto the camera
cable 106 and the outer shell 198 clamps onto the inner bulb 196 to secure the
camera cable 106 to the camera connector clamp 112. The inner bulb 196
includes a pair of hemispherical body members 200, 202 that are joined together
using fasteners such as screws 204. The body members 200, 202 have Ushaped
grooves 206 extending longitudinally through the center thereof to
accommodate the camera cable 106, and apertures 208 disposed on opposite
sides of the grooves 206, some of which are threaded for engagement with the
screws 204. The body members 200, 202 also have U-shaped grooves 2 10
extending longitudinally through an outer radius thereof to accommodate the
segments 134, 138 of the frame 116.
[0054] The outer shell 198 includes a pair of half-cylinder body
members 2 12, 214 that pivot relative to each other about a hinge 2 16 and are
joined together using fasteners such as screws 2 18. The body members 2 12,
2 14 have U-shaped grooves 220 extending longitudinally through the center
thereof to accommodate the camera cable 106, as well as apertures 222
disposed on opposite sides of the grooves 220, some of which are threaded for
engagement with the screws 2 18. The body members 2 12, 2 14 also have
hemispherical pockets 224 bisecting the grooves 220 to accommodate the
hemispherical body members 200, 202. The body members 2 12, 2 14 of the
outer shell 198 include brackets 226 defining apertures 227 that receive a pin
228 to form the hinge 2 16. One end of the pin 228 can be knurled and the
remainder of the pin 228 can be relatively smooth. The smooth portion of the pin
228 can be inserted into the apertures 227 first, yielding a slip fit between the
smooth portion of the pin 228 and the inner surface of the apertures 227. Then,
after the smooth portion of the pin 228 is inserted into the apertures 227, the
knurled end engages the inner surfaces of the apertures 227 to yield a press fit
that retains the pin 228 in the apertures 227.
[0055] The outer shell 198 is secured to the inner bulb 196 using the
screws 2 18, which engage corresponding female threads disposed in the
apertures 222 formed in the outer shell 198. When the outer shell 198 is closed
as shown in FIGs. 7A and 7B, the pockets 224 form a single pocket having an
inner diameter that is greater than the outer diameter of the inner bulb 196. A
gap 230 exists between opposite edges 232 of the body members 2 12, 2 14 .
Consequently, tightening the screws 2 18 into the apertures 222 narrows the
width of the gap 230 and clamps the outer shell 198 onto the inner bulb 196,
which in turn causes the inner bulb 196 to clamp onto the camera cable 106.
Additionally, the engagement between the segments 134, 138 of the frame 116
and the corresponding apertures 194 in the camera connector clamp 112
prevent the camera 102 from rotating around the camera cable 106.
[0056] FIGs. 8A, 8B, and 8C illustrate an exemplary method for using
a visual inspection system according to the present disclosure. As shown in
FIG. 8A, the boring tool 20 first creates the tunnel 14 for the new utility line 128
using the well-known underground pneumatic boring technique. After the tunnel
14 has been created, the boring tool 20 extends from the tunnel 14 into the exit
pit 18, and the air supply hose 22 remains in the tunnel. As shown in FIG. 8B,
the boring tool 20 is removed from the air supply hose 22, and then the camera
rigging 110, with the camera 102 secured thereto, is attached to the air supply
hose 22 by way of the thread adapter 120. The air supply hose 22 is then pulled
back through the tunnel 14 , bringing the camera rigging 110 and the camera 102
with it as it is reeled in. The air supply hose 22 is reeled-in at a pace that
enables an operator of the system 100 to inspect the bore by viewing the output
from the camera 102 on the display device 104. In doing so, the operator can
determine whether the boring tool 20 has bored through existing underground
utility lines, such as a sanitary sewer line, and created the potential for a
crossbore. After the air supply hose 22 has been retrieved, and the camera 102
has passed through the entire length of the tunnel 14 , the air supply hose 22 is
disconnected from the thread adapter 120. If the operator determines that there
is no crossbore potential, the mating fitting 124 engaged with the new utility line
128 is attached to the thread adapter 120, as shown in FIG. 8C. Finally, the
tether 108 is used to pull the camera rigging 110 and the attached utility line 128
back through the tunnel 14 to effect installation of the new utility line 128.
[0057] FIGs. 9A, 9B, and 9C illustrate another exemplary method for
using a visual inspection system according to the present disclosure. As shown
in FIG. 9A, the boring tool 20 first creates the tunnel 14 for the new utility line
128 using a well-known horizontal directional drilling technique. For example, a
drill (not shown) can rotate the drill bit 132 using drill pipes 234, and additional
ones of the drill pipes 234 can be added as the drill bit 132 proceeds to cut the
tunnel 14 . After the tunnel 14 has been created, the drill bit 132 extends from
the tunnel 14 into the exit pit 18, and the drill pipes 234 remain in the tunnel. As
shown in FIG. 9B, the camera rigging 110, with the camera 102 secured thereto,
is then attached to the drill bit 132 by way of the eye bolt 122 and the swivel
coupling 130. The drill pipes 234 are then pulled back through the tunnel 14 ,
bringing the drill bit 132, the camera rigging 110, and the camera 102 with them
as they are pulled in. The drill pipes 234 are pulled back at a pace that enables
an operator of the system 100 to inspect the bore by viewing the output from the
camera 102 on the display device 104. In doing so, the operator can determine
whether the drill bit 132 has bored through existing underground utility lines,
creating the potential for a crossbore. After the drill pipes 234 have been
retrieved, and the camera 102 has passed through the entire length of the tunnel
14 , the drill bit 132 is disconnected from the swivel coupling 130. If the operator
determines that there is no crossbore potential, the new utility line 128 is
attached to the swivel coupling 130, as shown in FIG. 9C. Finally, the tether 108
is used to pull the camera rigging 110 and the attached utility line 128 back
through the tunnel 14 to effect installation of the new utility line 128.
[0058] Referring now to FIG. 10, an alternative embodiment of a visual
inspection system according to the present disclosure is generally indicated at
300. The visual inspection system 300 includes the camera 102, the display
device 104, the camera cable 106, the tether 108, and a camera rigging 302
including a camera connector clamp 304, a camera guide 306, a frame 308, and
a connector fitting 3 10. The connector fitting 3 10 is configured to connect to the
thread adapter 120 (as shown) or the eye bolt 122 (shown in FIG. 2), which can
be included in the system 300. The connector fitting 3 10 adapts the system 300
for connection to, for example, the air supply hose 22, the utility line 128, and/or
the drill bit 132 (shown in FIGs. 8A, 8B, 8C, 9A, 9B, and 9C).
[0059] The camera connector clamp 304 is attached to one end of the
frame 308 and the connector fitting 3 10 is attached to the other end thereof. The
camera guide 306 is attached to the frame 308 and located intermediate the
opposite ends of the frame 308. The frame 308 separates the camera connector
clamp 304 and the connector fitting 3 10 a fixed distance apart. The frame 308
comprises a plurality of straight, rigid rod members 3 12. As shown in FIG. 12,
the rod members 3 12 are secured to the connector fitting 3 10 such as by male
threads 3 14 formed at the ends of the rod members 3 12 that engage
corresponding female threads 3 16 formed in the connector fitting 3 10. As shown
in FIGs. 11 and 14, the opposite ends of the rod members 3 12 include L-shaped
portions 3 18 that retain the rod members 3 12 within the camera connector clamp
304, the ends of the rod members 3 12 being sandwiched between a pair of body
members 320, 322 included in the camera connector clamp 304.
[0060] FIG. 12 shows an enlarged view of the connector fitting 3 10.
The connector fitting 3 10 is a generally cylindrically shaped component having a
diameter that is at least equal to, and preferably just slightly greater than, the
diameter of the air supply hose 22. On a first end 324, the connector fitting 3 10
includes a connection portion 326 that is threaded for engagement with the
threaded portion 154 on the thread adapter 120 or the threaded portion 156 on
the eye bolt 122 (shown in FIG. 3), enabling the camera rigging 302 to be easily
attached to and detached from the air supply hose 22, the utility line 128, and the
drill bit 132. Alternatively, the connection portion 326 can incorporate a quickconnect
device that engages a corresponding quick-connect device on the air
supply hose 22, the utility line 128, and/or the drill bit 132. An outer surface 328
of the connector fitting 3 10 at the first end 324 is rounded over or tapered to a
slightly reduced diameter to minimize the potential for snow plowing.
[0061] On a second end 330 of the connector fitting 3 10 opposite to
the connection portion 326 is included a tapered cone portion 332. The cone
portion 332 is centered in the frame 308 and is located directly in front of the
camera 102. The outer surface of the cone portion 332 is reflective, and the
angle of the taper of the cone portion 332 enables a peripheral vision inspection
of the walls of a bore relative to the axis of the camera 102. As such, an
operator can easily inspect the walls of a bore that may otherwise be outside the
field of view of the camera lens 162 (shown in FIGs. 13A and 13B) because the
images appear within the view of the camera lens 162 as a reflection on the
cone portion 332 of the connector fitting 3 10. The cone portion 332 also
minimizes the potential for snow plowing when the camera rigging 302 is pulled
back through a tunnel while carrying a new utility line. Additionally included in
the connector fitting 3 10 is a passageway 334 that extends through the
component from the connection portion 326 to the cone portion 332. When the
camera rigging 302 is connected to the air supply hose 22, the passageway 334
enables bursts of compressed air to be shot through the connector fitting 3 10 in
order to remove any buildup of soil or debris that may lodge on the camera 102
during the inspection process, or to clear a localized collapse of a tunnel, should
that occur.
[0062] FIGs. 13A and 13B show enlarged views of the camera guide
306. The camera guide 306 is received within the frame 308, with the rod
members 3 12 passing through corresponding apertures 336 through the camera
guide 306. The camera guide 306, in turn, receives the camera 102 and serves
to orient and align the camera 102 within the frame 308. In addition, the camera
guide 306 prevents the camera 102 from dragging along a tunnel surface which,
in turn, helps prevent dirt and/or debris from building up on the camera lens 162.
Preferably, the camera 102 is centered within the camera guide 306 for optimal
positioning for viewing the walls of a bore while conducting the inspection. The
camera guide 306 can be fixed in its position intermediate the connector fitting
3 10 and the camera connector clamp 304. Alternatively, the position of the
camera guide 306 can be adjusted such as by sliding it back and forth along the
rod members 3 12. In FIGs. 13A and 13B the camera guide 306 is shown to be
generally cylindrical at a maximum outer diameter in its midpoint 338, and
tapering inwardly from the midpoint 338 to a smaller diameter at its opposite
ends 340, 342. The maximum outer diameter of the camera guide 306 is
approximately the same as the maximum outer diameter of the connector fitting
3 10. The tapered shape of exterior surfaces 344, 346 of the camera guide 306
enables it to move within a tunnel in either direction while limiting the potential for
snow-plowing. The shape of the camera guide 306 helps maintain the integrity
of a bore, especially around the camera 102, during the inspection process.
[0063] The camera guide 306 has a unitary body with an aperture 348
extending longitudinally through the camera guide 306 and receiving the camera
102. The camera 102 is secured to the camera guide 306 using a fastener such
as a set screw 350 that engages corresponding female threads disposed in an
aperture 352 formed in the camera guide 306.
[0064] Turning to FIG. 14, an enlarged view of the camera connector
clamp 304 is shown. As discussed above, the camera connector clamp 304
includes the body members 320, 322, which sandwich the L-shaped portions
3 18 of the rod members 3 12 to retain them within the camera connector clamp
304. When assembled, the camera connector clamp 304 has a generally
cylindrical shape with a tapering conical portion 354 located at each of its
opposite ends. The camera connector clamp 304 has a maximum outer
diameter that is approximately the same as the maximum outer diameter of the
connector fitting 3 10. The conical portions 354 of the camera connector clamp
304 enable it to move within a tunnel in either direction while limiting the potential
for snow-plowing. A pair of grooves 356 extend through each of the body
members 320, 322 at a first end 358 of the clamp 304 to accommodate of the
rod members 3 12.
[0065] The body members 320, 322 are joined together using
fasteners such as screws 360. The body members 320, 322 have U-shaped
grooves 362 extending longitudinally through the center thereof to accommodate
the camera cable 106. In addition, the body members 320, 322 include
apertures 364 disposed on opposite sides of the grooves 362, some of the
apertures 364 being threaded for engagement with the screws 360. The body
members 320, 322 also have hemispherical pockets 366 bisecting the grooves
362. The tether 108 is secured to the clamp 304 in an interior space thereof
formed by the hemispherical pockets 366. For example, a knot 368 can be tied
in the tether 108 to retain the tether 108 within the interior space. The tether 108
passes through an aperture 370 that extends between the interior space and a
second end 372 of the clamp 304 that is opposite from the first end 358.
[0066] Referring now to FIGs. 15 and 16, another alternative
embodiment of a video inspection system according to the present disclosure is
generally indicated at 400. The video inspection system 400 includes the
camera 102, the camera cable 106, and a camera rigging 402 including a
camera guide 404, a frame 406, a connector fitting 408, and a pair of guide
wipers 4 10. The connector fitting 408 is configured to connect to the thread
adapter 120 (as shown) or the eye bolt 122 (shown in FIG. 3), both of which can
be included in the system 400. The connector fitting 408 adapts the system 400
for connection to, for example, the air supply hose 22, the utility line 128, and/or
the drill bit 132 (shown in FIGs. 8A, 8B, 8C, 9A, 9B, and 9C).
[0067] The frame 406 comprises one or more elongated members
4 12. The frame 406 maintains the camera guide 404 and the connector fitting
408 a fixed distance apart when, for example, the camera rigging 402 is pulled
through a bore 4 14 (shown in FIG. 16). The connector fitting 408 is secured to
the frame 406 by, for example, a press fit between the elongated members 4 12
of the frame 406 and apertures 4 16 formed in the connector fitting 408 that
receive the elongated members 4 12. The elongated members 4 12 of the frame
406 extend longitudinally through apertures 4 18 formed in the camera guide 404.
The camera guide 404 positions the camera 102 relative to the frame 406.
[0068] The guide wipers 4 10 protect the camera lens 162 from dirt or
debris as the camera rigging 402 is pulled through the bore 4 14 . The guide
wipers 4 10 accomplish this by engaging the walls of the bore 4 14 to form a seal
therebetween. The guide wipers 4 10 can be formed from flexible material (e.g.,
rubber, plastic). The engagement between the guide wipers 4 10 and the walls of
the bore 4 14 causes the guide wipers 4 10 to flex as indicated at 420 and 422
when the camera rigging 402 is pulled in the direction of arrows 424 and 426,
respectively. One of the guide wipers 4 10 is secured to the camera guide 404
and the other one of the guide wipers 4 10 is secured to the connector fitting 408.
The guide wipers 4 10 can be secured to the camera guide 404 and the
connector fitting 408 using, for example, split retaining rings 428. The camera
guide 404 and the connector fitting 408 can each include a groove 430 that
receives an inner edge of a corresponding one of the retaining rings 428 and a
clamped portion of a flange 432 on a corresponding one of the guide wipers 4 10.
[0069] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not intended to be
exhaustive or to limit the disclosure. Individual elements or features of a
particular embodiment are generally not limited to that particular embodiment,
but, where applicable, are interchangeable and can be used in a selected
embodiment, even if not specifically shown or described. The same may also be
varied in many ways. Such variations are not to be regarded as a departure from
the disclosure, and all such modifications are intended to be included within the
scope of the disclosure.
CLAIMS
What is claimed is:
1. An inspection system for inspecting an underground bore created
by a boring tool connected to a retrieval mechanism, comprising:
a sensor for obtaining inspection data regarding the condition of a tunnel;
a sensor carrier adapted to incorporate the sensor and connect to the
retrieval mechanism to transport the sensor through the tunnel; and
an output device for receiving an output signal from the sensor
corresponding to the inspection data.
2. The inspection system of claim 1 wherein the boring tool includes
one of a pneumatic boring tool and a drill bit, and the retrieval mechanism
includes one of a pneumatic hose and a drill pipe.
3. The inspection system of claim 2 wherein the sensor includes a
camera, the sensor carrier includes a camera rigging, and the output device
includes a display.
4 . The inspection system of claim 3 wherein the camera rigging
includes a frame, a camera connector clamp, a camera guide, and a connector
fitting that adapts the camera rigging for connection to at least one of the
pneumatic hose, a utility line, and the drill bit.
5. A visual inspection system for use in underground boring
comprising:
a camera;
a display; and
a camera rigging comprising:
a frame comprising at least one elongated member;
a camera connector clamp;
a camera guide; and
a connector fitting that adapts the camera rigging for connection to
at least one of a pneumatic hose, a utility line, and a drill bit.
6. The camera rigging of claim 5 wherein the camera connector
clamp and the connector fitting are secured to the frame.
7. The camera rigging of claim 6 wherein the camera guide positions
the camera relative to the frame.
8. The visual inspection system of claim 7 further comprising a cable
that connects the camera to the display, wherein the cable extends through and
is secured to the camera connector clamp.
9. The visual inspection system of claim 7 further comprising a tether
that connects to the camera rigging for pulling the camera through a tunnel.
10. The visual inspection system of claim 9 further comprising a snap
clip that releasably attaches the tether to the camera rigging.
11. The visual inspection system of claim 10 wherein the tether
extends into an interior space of the camera connector clamp and is secured
therein.
12. A camera rigging for a visual inspection system for use in
underground pneumatic boring, the camera rigging comprising:
a frame comprising at least one elongated member;
a camera connector clamp;
a camera guide; and
a connector fitting that adapts the camera rigging for connection to at
least one of a pneumatic hose, a utility line, and a drill bit.
13. The camera rigging of claim 12 wherein the camera connector
clamp and the connector fitting are secured to the frame.
14 . The camera rigging of claim 13 wherein the camera guide is
configured to position a camera relative to the frame.
15. The camera rigging of claim 14 wherein the camera connector
clamp is configured to secure a cable that connects the camera to a display.
16. The camera rigging of claim 15 wherein the at least one elongated
member includes flexible rope.
17. The camera rigging of claim 16 further comprising fasteners
threaded into apertures in the camera connector clamp and the connector fitting
to secure the camera connector clamp and the connector fitting to the frame.
18. The camera rigging of claim 15 wherein the camera connector
clamp includes a pair of body members joined together by fasteners.
19. The camera rigging of claim 18 wherein the body members define
a pair of grooves that are configured to receive the cable.
20. The camera rigging of claim 18 wherein the camera connector
clamp includes a hinge and the body members pivot about the hinge.
2 1. The camera rigging of claim 18 wherein the camera connector
clamp includes a bulb that is configured to clamp onto the cable, the body
members cooperating to form a pocket that receives and retains the bulb.
22. The camera rigging of claim 18 wherein the at least one elongated
member includes a plurality of rigid rods.
23. The camera rigging of claim 22 wherein the rigid rods have Lshaped
ends and the body members define grooves that receive and retain the
L-shaped ends to secure the camera connector clamp to the frame.
24. The camera rigging of claim 23 wherein the rigid rods have
threaded ends opposite the L-shaped ends that engage female threads formed
in the connector fitting to secure the connector fitting to the frame.
25. The camera rigging of claim 12 wherein the camera guide has a slit
extending through a portion thereof and an aperture extending perpendicular to
the slit for receiving a fastener to secure the camera within the camera guide.
26. The camera rigging of claim 12 wherein the camera is secured
within the camera guide using a fastener that extends through the camera guide
and engages the camera.
27. The camera rigging of claim 12 further comprising a pair of guide
wipers that are configured to engage the tunnel to form a seal therebetween,
wherein the camera guide is located between the camera connector clamp and
the connector fitting, and each of the guide wipers are secured to one of the
camera guide and the connector fitting.
28. A method for visually inspecting an underground bore for potential
crossbores, comprising:
creating an underground tunnel for a utility line using a boring tool;
removing the boring tool from an air supply hose;
attaching a camera to the air supply hose by way of a camera rigging;
pulling the air supply hose and the camera through the tunnel;
visually inspecting the tunnel;
disconnecting the air supply hose from the camera rigging;
attaching a utility line to the camera rigging; and
pulling the camera rigging and the utility line through the tunnel.
29. A method for visually inspecting an underground bore for potential
crossbores, comprising:
creating an underground tunnel for a utility line using a drill bit;
attaching a camera to the drill bit by way of a camera rigging;
pulling the drill bit and the camera through the tunnel;
visually inspecting the tunnel;
disconnecting the drill bit from the camera rigging;
attaching a utility line to the camera rigging; and
pulling the camera rigging and the utility line through the