U.S. patent application number 10/021790 was filed with the patent office on 2003-06-19 for deflection measurement device for flexible piping.
Invention is credited to Langley, Robert M., Powers, Rodney G..
Application Number | 20030110872 10/021790 |
Document ID | / |
Family ID | 21806165 |
Filed Date | 2003-06-19 |
United States Patent
Application |
20030110872 |
Kind Code |
A1 |
Powers, Rodney G. ; et
al. |
June 19, 2003 |
Deflection measurement device for flexible piping
Abstract
A mechanical inspection sled which can be pushed through a
pipeline using a series of connecting rigid rods. Mechanical
measuring devices are mounted on the sled. These devices deflect
when the pipe's internal diameter decreases. The deflection is
visually observable by the user through a series of reflective
indicators. The measuring devices are sufficiently pliable to allow
the sled to pass beyond distorted areas and complete a full
inspection of the pipeline. The measurement devices are adjustable
to allow the sled to be used in many different pipe sizes. Because
the device is purely mechanical, it is quite rugged and able to
withstand harsh environments.
Inventors: |
Powers, Rodney G.;
(Gainesville, FL) ; Langley, Robert M.;
(Hawthorne, FL) |
Correspondence
Address: |
John Wiley Horton, Attorney
Pennington, Moore, Wilkinson, Bell & Dunbar, P.A.
2nd Floor
215 S. Monroe St.
Tallahassee
FL
32301
US
|
Family ID: |
21806165 |
Appl. No.: |
10/021790 |
Filed: |
December 19, 2001 |
Current U.S.
Class: |
73/865.8 |
Current CPC
Class: |
G01B 5/12 20130101; G01B
5/10 20130101 |
Class at
Publication: |
73/865.8 |
International
Class: |
G01M 019/00 |
Claims
Having described our invention, we claim:
1. A pipeline inspection device allowing a user to visibly inspect
for deformation of a pipeline, with said pipeline having an
internal diameter generally composed of a bottom region, a first
side region, a second side region, and a top region, and having a
horizontal diameter and a vertical diameter, comprising: a. a base
portion, having a forward end and a rear end, configured to move
along said bottom region of said internal diameter so that it lies
on said vertical diameter; b. a lateral fixed hoop, oriented
horizontally, and being mounted to said base portion by
conventional rigid means so that said lateral fixed hoop lies on
said horizontal diameter, with a portion of said lateral fixed hoop
extending outward far enough from said base portion to contact said
first side region of said internal diameter; c. a lateral test
hoop, being mounted to said base portion by conventional flexible
means, so that said lateral test hoop lies on said horizontal
diameter, with a portion of said lateral fixed hoop extending
outward far enough from said base portion to contact said second
side region of said internal diameter, and wherein said lateral
test hoop is free to elastically move inward when said inspection
device encounters a reduction in said horizontal diameter; and d.
visual indication means capable of indicating to said user when
said lateral test hoop moves inward.
2. A pipeline inspection device as recited in claim 1, further
comprising: a. a plumb, rotatably mounted to said base portion
proximate said rear end, and wherein said plumb is normally
oriented vertically; and b. a plumb reflector, affixed to said base
proximate said rear end immediately forward of said plumb and sized
so that so long as said plumb remains in said vertical orientation,
said plumb reflector is not visible to said user.
3. A pipeline inspection device as recited in claim 1, wherein said
visual indication means comprises: a. a reflector positioned so as
to be visible to said user; and b. an occluding device, moveable in
relation to said reflector, and configured so that as said lateral
test hoop moves inward, said occluding device occludes said
reflector.
4. A pipeline inspection device as recited in claim 1, wherein said
visual indication means comprises: a. a reflector positioned so as
to be visible to said user; and b. an occluding device, positioned
so as to normally occlude said reflector, but moveable in relation
to said reflector, so that as said lateral test hoop moves inward,
said occluding device moves away from said reflector thereby
exposing said reflector.
5. A pipeline inspection device as recited in claim 1, wherein said
means for mounting said lateral fixed hoop and said lateral test
hoop to said base portion allow for the use of a plurality of said
lateral fixed hoops and a plurality of said lateral test hoops,
with a particular lateral fixed hoop and lateral test hoop being
calibrated for use in a particular size of said pipeline.
6. A pipeline inspection device allowing a user to visibly inspect
for deformation of a pipeline, with said pipeline having an
internal diameter generally composed of a bottom region, a first
side region, a second side region, and a top region, and having a
horizontal diameter and a vertical diameter, comprising: a. a base
portion, having a forward end and a rear end, configured to move
along said bottom region of said internal diameter so that it lies
on said vertical diameter; b. a vertical test hoop, having a
forward end and a rear end, oriented vertically, and being mounted
to said base portion by conventional flexible means, so that said
vertical test hoop lies on said vertical diameter, with a portion
of said vertical test hoop extending outward far enough from said
base portion to contact said top region of said internal diameter,
and wherein said vertical test hoop is free to elastically move
downward when said inspection device encounters a reduction in said
vertical diameter of said pipeline; and c. visual indication means
capable of indicating to said user when said vertical test hoop
moves downward.
7. A pipeline inspection device as recited in claim 6, further
comprising: a. a plumb, rotatably mounted to said base portion
proximate said rear end, and wherein said plumb is normally
oriented vertically; and b. a plumb reflector, affixed to said base
proximate said rear end immediately forward of said plumb and sized
so that so long as said plumb remains in said vertical orientation,
said plumb reflector is not visible to said user.
8. A pipeline inspection device as recited in claim 6, wherein said
visual indication means comprises: a. a reflector positioned so as
to be visible to said user; and b. an occluding device, moveable in
relation to said reflector, and configured so that as said vertical
test hoop moves downward, said occluding device occludes said
reflector.
9. A pipeline inspection device as recited in claim 6, wherein said
visual indication means comprises: a. a reflector positioned so as
to be visible to said user; and b. an occluding device, positioned
so as to normally occlude said reflector, but moveable in relation
to said reflector, so that as said vertical test hoop moves
downward, said occluding device moves away from said reflector
thereby exposing said reflector.
10. A pipeline inspection device as recited in claim 6, wherein
said means for mounting said vertical test hoop to said base
portion allow for the adjustment of the undeflected position of
said vertical test hoop so as to allow for the inspection of a
plurality of different sizes of said pipeline.
11. A pipeline inspection device allowing a user to visibly inspect
for deformation of a pipeline, with said pipeline having an
internal diameter generally composed of a bottom region, a first
side region, a second side region, and a top region, and having a
horizontal diameter and a vertical diameter, comprising: a. a base
portion, having a forward end and a rear end, configured to move
along said bottom region of said internal diameter so that it lies
on said vertical diameter; b. a first lateral fixed hoop, oriented
horizontally, and being mounted to said base portion by
conventional rigid means so that said first lateral fixed hoop lies
on said horizontal diameter, with a portion of said first lateral
fixed hoop extending outward far enough from said base portion to
contact said first side region of said internal diameter; c. a
second lateral fixed hoop, oriented horizontally, and being mounted
to said base portion by conventional rigid means so that said
second lateral fixed hoop lies on said horizontal diameter, with a
portion of said second lateral fixed hoop extending outward far
enough from said base portion to contact said second side region of
said internal diameter; d. a flex mast, oriented vertically, having
a contact point on its upper extremity, wherein said flex mast is
mounted to said base portion so that said flex mast lies on said
vertical diameter; and e. visual indication means capable of
indicating to said user when said contact point encounters a
reduction in said vertical diameter.
12. A pipeline inspection device as recited in claim 11, wherein
said visual indication means comprises: a. a tube, perpendicularly
attached to said flex mast proximate said contact point, and
oriented with its long axis parallel to said base portion; b.
wherein said tube is closed on a first end distal to said user and
on a second end proximate said user; c. wherein said tube contains
a reflector proximate said first end and facing said user; and d.
wherein said second end opens into an orifice, so that when said
user shines a light toward said tube, said light will be reflected
back through said orifice so long as said flex mast remains
vertical, but so that said light will not be reflected if said flex
mast has deflected.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to the field of piping inspection.
More specifically, the invention comprises an adjustable sled which
detects and measures vertical and horizontal deflection in the
interior diameter of a flexible pipe as it is advanced through the
pipe. The device transmits its deflection measurements to the user
by simple visual means, eliminating the need for electronic
devices.
[0006] 2. Description of the Related Art
[0007] Piping is commonly used as a means to convey drainage water
and other liquids. Buried pipe has traditionally been made of
concrete. Concrete's widespread use is attributable to the fact
that it is readily available, durable, and quite strong. Concrete
piping may be buried deep within the soil without concern for
structural failure, Recently, however, more flexible piping has
come into widespread use. Flexible piping is often made from
thin-gage metals, or polymers such as polyvinyl chloride and
polyethylene. Such flexible piping is subject to circumferential
deflection when exposed to soil loading.
[0008] Proper installation and soil compacting is critical for
flexible piping. If the soil surrounding the flexible piping is
correctly compacted in layers, a "soil arch" develops over the top
of the piping which prevents excessive deflection. If, however, the
soil is added around the piping without properly compacting it
layer by layer, then the deflection may become excessive. While one
would intuitively expect vertical deflection, horizontal deflection
also occurs. Excessive deflection can lead to localized or
generalized failure of the pipe wall, resulting in a catastrophic
leak.
[0009] These concerns are heightened when the flexible piping is
made of a polymer, since distorting loads tend to produce buckling
and cracking in such polymers. Although the cracks may start small,
they tend to propagate through the polymer--eventually weakening it
to the point of failure. The distorting forces can also produce
failures in the joints between two sections of pipe, which must
carry the load when one pipe shifts relative to its neighbor.
[0010] It is possible to visually monitor the soil compaction
process and ensure that it is carried out correctly. However, it is
difficult or impossible to determine if the soil compaction has
resulted in excessive pipe deflection after the fact. Examination
of these deflections is often used as the criterion to determine
the acceptability of flexible piping installations. Accordingly, a
device for easily measuring such deflections would be useful.
[0011] The prior art approach to measuring the deflections has
generally been to create a mandrel having an outside diameter equal
to the minimum acceptable inside diameter of the piping. A cable is
passed through the piping and this cable is used to drag the test
mandrel back through. The shortcomings of this approach are as
follows:
[0012] 1. A new mandrel must be made for each pipe size that is to
be inspected;
[0013] 2. A cable must be passed completely through the piping
before the mandrel is introduced often a difficult process in
itself;
[0014] 3. An additional cable must be attached to the trailing end
of the mandrel to pull it free if it gets stuck;
[0015] 4. The mandrel can be lodged by debris in the piping, giving
a false impression of excessive deflection; and
[0016] 5. Once the mandrel reaches a point of excessive deflection
it can proceed no further, meaning that the remainder of the piping
system cannot be inspected.
[0017] Other more sophisticated approaches are found in the prior
art. As an example, U.S. Pat. No. 6,170,344 to Ignagni (2001)
reveals an inspection "pig" equipped with an inertial measurement
system (presumably gyroscopes and accelerometers). Another approach
employs projected laser beams and video cameras, along with
computers running software which can translate the laser
projections into distance measurements on the inner wall of the
pipeline.
[0018] The reader should appreciate that buried piping which is
used to convey drainage water--as opposed to oil or natural gas
piping--is often filled with water puddles and other contamination.
The use of electronic devices is therefore difficult, owing to the
rugged nature of the application. An electronics-intensive approach
is also inherently expensive. All these limitations are
significant.
BRIEF SUMMARY OF THE INVENTION
[0019] The present invention is a mechanical inspection sled which
can be pushed through a pipeline using a series of connecting rigid
rods. Mechanical measuring devices are mounted on the sled. These
devices deflect when the pipe's internal diameter decreases. The
deflection is visually observable by the user through a series of
reflective indicators. The measuring devices are sufficiently
pliable to allow the sled to pass beyond distorted areas and
complete a full inspection of the pipeline.
[0020] The measurement devices are adjustable to allow the sled to
be used in many different pipe sizes. Because the device is purely
mechanical, it is quite rugged and able to withstand harsh
environments. In addition, very little training is required to use
the device.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0021] FIG. 1 is an isometric view, showing the inspection
sled.
[0022] FIG. 2 is an isometric view, showing details of the rear
portion of the sled.
[0023] FIG. 3 is an isometric view with a cutaway, showing the
inspection sled in a pipe.
[0024] FIG. 4 is an isometric view with a cutaway, showing how the
inspection sled is advanced through a pipe.
[0025] FIG. 5 is an isometric view, showing the deflection of the
lateral test hoop.
[0026] FIG. 5B is an elevation view, showing the operation of the
lateral visual indicators.
[0027] FIG. 5C is an elevation view, showing the operation of the
lateral visual indicators.
[0028] FIG. 6 is an isometric view, showing the deflection of the
vertical test hoop.
[0029] FIG. 6B is an isometric view, showing the operation of the
vertical visual indicators.
[0030] FIG. 6C is an elevation view, showing the operation of the
vertical visual indicators.
[0031] FIG. 7 is a perspective view, showing the operation of the
plumb in keeping the inspection sled level.
[0032] FIG. 7B is a perspective view, illustrating the horizontal
and vertical diameters of a pipe.
[0033] FIG. 8 is an isometric view, showing how the inspection sled
can be adjusted to inspect larger pipes.
[0034] FIG. 9 is a perspective view, showing two inspection sleds
in two pipes having different diameters.
[0035] FIG. 10 is an isometric view, showing a gage used for
calibration.
[0036] FIG. 11 is an isometric view, showing the application of a
gage.
[0037] FIG. 12 is an isometric view, showing a refined version
which represents the preferred embodiment.
[0038] FIG. 13 is a detail view of the preferred embodiment.
[0039] FIG. 14 is an isometric view, showing the preferred
embodiment with its vertical deflection bar translated
downward.
[0040] FIG. 15 is a detail view of the preferred embodiment.
[0041] FIG. 16 is a detail view, illustrating portions of the
visual indicator system.
[0042] FIG. 17 is a detail view, illustrating portions of the
visual indicator system.
[0043] FIG. 17B is an isometric view, illustrating details of the
visual indicator system.
[0044] FIG. 18 is a detail view, illustrating the operation of the
visual indicator system.
[0045] FIG. 19 is an isometric view, showing another simplified
embodiment.
[0046] FIG. 20 is a detail view, showing some details of the
simplified embodiment.
[0047] FIG. 21 is an elevation view, illustrating details of the
visual indicator system.
[0048] FIG. 22 is an elevation view, illustrating details of the
visual indicator system.
[0049] FIG. 23 is an elevation view, illustrating details of the
visual indicator system.
REFERENCE NUMERALS IN THE DRAWINGS
[0050] 10 inspection sled
[0051] 12 runner
[0052] 14 front tube boss
[0053] 16 rear tube boss
[0054] 18 middle tube boss
[0055] 20 front tube clamp
[0056] 22 rear tube clamp
[0057] 24 middle tube clamp
[0058] 26 forward mast
[0059] 28 rear mast
[0060] 30 plumb mast
[0061] 32 plumb boss
[0062] 34 plumb clamp
[0063] 36 plumb bracket
[0064] 38 plumb
[0065] 40 pipe
[0066] 42 forward bracket
[0067] 44 rear bracket
[0068] 46 lateral test hoop
[0069] 48 lateral fixed hoop
[0070] 50 vertical test hoop
[0071] 52 plumb pivot
[0072] 54 plumb weight
[0073] 56 plumb reflector
[0074] 58 18"-diameter pipe
[0075] 60 extension rod
[0076] 62 rod receiver
[0077] 64 rod coupler
[0078] 66 lateral flag
[0079] 68 lateral indicator
[0080] 70 vertical flag
[0081] 72 vertical indicator
[0082] 74 24" inspection sled
[0083] 76 24" lateral fixed hoop
[0084] 78 24" lateral test hoop
[0085] 80 24" vertical test hoop
[0086] 82 24"-diameter pipe
[0087] 84 gage
[0088] 86 vertical zero
[0089] 88 horizontal zero
[0090] 90 calibration steps
[0091] 92 horizontal diameter
[0092] 94 vertical diameter
[0093] 96 bottom region
[0094] 98 first side region
[0095] 100 top region
[0096] 102 second side region
[0097] 104 vertical deflection bar
[0098] 106 forward spring bracket
[0099] 108 rear spring bracket
[0100] 110 guide rod
[0101] 112 guide rod hole
[0102] 114 compression spring
[0103] 116 stop collar
[0104] 118 point reflector
[0105] 120 flex mast
[0106] 122 contact point
[0107] 124 tube
[0108] 126 tube mount
[0109] 128 orifice
[0110] 130 reflector
[0111] 132 reflector card
[0112] 134 window card
[0113] 136 first window
[0114] 138 first reflector
[0115] 140 second reflector
[0116] 142 card mount
[0117] 144 guide slot
[0118] 146 second window
[0119] 148 third window
[0120] 150 fourth window
[0121] 152 fifth window
[0122] 154 sixth window
[0123] 156 seventh window
[0124] 158 eighth window
[0125] 160 third reflector
[0126] 162 fourth reflector
[0127] 164 fifth reflector
[0128] 166 sixth reflector
[0129] 168 seventh reflector
[0130] 170 eighth reflector
[0131] 174 ninth reflector
[0132] 176 tenth reflector
[0133] 178 eleventh reflector
[0134] 180 twelfth reflector
DETAILED DESCRIPTION OF THE INVENTION
[0135] The principal objective of the present invention is to
measure deformations in the horizontal and vertical diameters of a
pipe. The "horizontal diameter" is defined as a measurement of the
pipe's internal diameter taken through its centerline in a
direction which is parallel to the earth's surface. The "vertical
diameter" is defined as a measurement of the pipe's internal
diameter taken through its centerline in a direction which is
perpendicular to the earth's surface
[0136] FIG. 1 illustrates the major components of inspection sled
10. All the components are mounted a base element, designated in
the view as runner 12. Runner 12 is a ski-like structure, having
upturned ends. It is intended to slide along the inside lower
surface of a pipe. Although a wheeled carriage could be employed,
runner 12 is simpler and has been found to be satisfactory.
[0137] Mounted directly to runner 12 are front tube boss 14, middle
tube boss 18, rear tube boss 16, and plumb boss 32. In the
embodiment shown, runner 12 is made from sheet aluminum. The bosses
are machined from aluminum blocks, However, those skilled in the
art will appreciate that the material selection is simply one of
manufacturing expedience. As an example, runner 12 and the attached
bosses could be manufactured as an integral piece of glass
reinforced polymer--using the reaction injection molding method. As
illustrated, the bosses are simply bolted to runner 12.
[0138] Each tube boss has a cylindrical cavity running transversely
through it. Pipe 40 is laid into these cavities. Front tube clamp
20, middle tube clamp 24, rear tube clamp 22, and plumb clamp 34
are then placed over the top of pipe 40. These tube clamps also
have transverse cylindrical cavities corresponding to those found
in the tube bosses. The tube clamps are bolted to the tube bosses
using conventional fasteners, with the result that pipe 40 is
mechanically affixed to runner 12.
[0139] Forward mast 26 rises vertically from front tube clamp 20.
Forward bracket 42 is mounted to forward mast 26 by conventional
means. Forward bracket 42 is vertically adjustable, so that a user
can move it up and down forward mast 26, locking it in place in a
desired position. Rear mast 28 rises vertically from rear tube
clamp 22. Rear bracket 44 is mounted to rear mast 28 in a
vertically adjustable manner. The vertical height of forward
bracket 42 and rear bracket 44 must be adjusted in unison, as will
be explained subsequently.
[0140] Lateral fixed hoop 48 is attached to forward bracket 42 and
rear bracket 44. It is substantially rigid. It lies in a horizontal
plane, which will ideally rest on the horizontal diameter 92 of a
pipe being inspected. Opposite lateral fixed hoop 48 is lateral
test hoop 46. The forward portion of lateral test hoop 46 is fixed
to forward bracket 42. The rear portion, however, is free to move.
Lateral test hoop 46 is made of a resilient and flexible material.
Solid aluminum rod is a good choice, as it is able to bend in and
out substantially without suffering a plastic deformation. As test
sled 10 is advanced through a pipe and encounters a reduction in
the horizontal diameter 92 of the pipe, lateral test hoop 46 will
deflect, with its rearward portion moving inward.
[0141] Vertical test hoop 50 is the vertical counterpart to lateral
test hoop 46. Its forward portion is secured to forward mast 26,
but its rear portion is free to move. If test sled 10 encounters a
reduction in a pipe's vertical diameter 94, vertical test hoop 50
will deflect, with its rearward portion moving downward.
[0142] It is important that inspection sled 10 remain level during
its progress through a pipe. Otherwise, it will not be measuring
the true horizontal 92 and vertical 94 diameters of the pipe. Plumb
38 is provided as a leveling aid. Plumb mast 30 rises vertically
from plumb clamp 34. Plumb 38 is pivotally mounted to plumb mast
30. Plumb bracket 36 restricts the angular travel of plumb 38.
[0143] FIG. 2--which is a partial view--shows the rear features of
inspection sled 10 in more detail. Plumb 38 is attached to plumb
mast 30 by plumb pivot 52. Plumb 38 is free to rotate as indicated
by the arrows. Plumb weight 54 ensures that plumb 38 is oriented
vertically when inspection sled 10 is level. In that state, plumb
reflector 56 is completely obscured by plumb weight 54 (when the
device is viewed from the rear).
[0144] The reader should appreciate that inspection sled 10 will be
introduced into an open end of a pipe and advanced away from the
user. The user will customarily shine a light into the pipe to
observe the progress of the device. Provided that inspection sled
10 is level, the user will not see any reflection from plumb
reflector 56. However, if inspection sled 10 rotates, plumb 38 will
pivot and plumb reflector 56 will be exposed. This informs the user
that the device is no longer level and should therefore be
adjusted.
[0145] FIG. 2 also shows the hollow end of pipe 40, designated as
rod receiver 62. The user customarily advances the device by
sticking another length of pipe into rod receiver 62 and pushing
the device forward. Rod receiver 62 is typically equipped with a
transverse hole, into which a locking pin from the pushing rod will
lock.
[0146] FIG. 3 shows inspection sled 10 placed within 18"-diameter
pipe 58 (shown with a cutaway). FIG. 4 shows how inspection sled 10
is advanced. Extension rod 60 is placed into rod receiver 62 and
the user pushes the device forward, as indicated by the arrow. A
number of rigid extension rods 60 are used to advance the device.
Each one contains rod coupler 64, which is a necked-down cylinder
which fits within the hollow extension rod 60 before it. Extension
rods 60 contain transverse locking pins which automatically lock
successive rods together and prevent one from turning relative to
its neighbor. Owing to these features, the user can push inspection
sled 10 forward and rotate it to keep it level.
[0147] FIG. 5 illustrates the operation of lateral test hoop 46. As
explained previously, when test sled 10 encounters a reduction in
the horizontal diameter 92 of a pipe, lateral test hoop 46 deflects
inward, as shown by the arrow. Lateral flag 66 is attached to the
rearward end of lateral test hoop 46. As lateral test hoop 46
deflects inward, lateral flag 66 moves inward across the rearward
face of rear bracket 44.
[0148] FIG. 5B shows a view of the rear of test sled 10 with
lateral test hoop 46 in its undeflected state. When a force is
applied to lateral test hoop 46, lateral flag 66 moves inward in
the direction indicated. As it does so, it begins to occlude a
series of lateral indicators 68, which are affixed to the rearward
face of rear bracket 44. This view approximates the user's view of
the device, as the user looks down a pipe. FIG. 5C shows lateral
test hoop 46 in a deflected state. The reader will observe that two
of the three lateral indicators 68 have been occluded, thus
indicating to the user the state of the deflection. These lateral
indicators 68 are typically color-coded strips or dots of highly
reflective material. The use of color coding allows the user to
discern the degree of deflection of lateral test hoop 46 at great
distances. It is important to note that test sled 10 conveys all of
its information through the use of reflectors. It has no electrical
power source whatsoever.
[0149] FIG. 6 illustrates the presence of vertical flag 70 on the
rear extremity of vertical test hoop 50. As vertical test hoop 50
is deflected downward via a reduction in the vertical pipe
diameter, vertical flag 70 moves downward across the rearward face
of rear bracket 44. FIG. 6B shows a rear view of vertical test hoop
50 in its undeflected state. In this position, vertical flag 70 has
not occluded vertical indicators 72. FIG. 6C shows vertical test
hoop 50 deflected downward. The reader will observe that vertical
flag 70 has occluded two of the three vertical indicators 72.
Again, through the use of color coding in the vertical indicators
72, the degree of deflection can be observed by the user over
considerable distance.
[0150] FIG. 7 is a perspective view illustrating test sled 10
traveling through 18"-diameter pipe 58 (pipe 58 is shown with a
cutaway). In this illustration, test sled 10 has become canted in a
clockwise direction. The reader will observe that plumb 38 has
remained vertical, with the result that plumb reflector 56 is now
visible. The user is thereby informed that the device is not level
and a correction is made.
[0151] FIG. 7B illustrates the measurement objectives of the
device. 18"-diameter pipe 58 is roughly divided into top region
100, right side region 98, left side region 102, and bottom region
96. There is, of course, no clear demarcation between these regions
since the pipe is ideally cylindrical. The objective is to measure
values for horizontal diameter 92 and vertical diameter 94. In
order to measure these values, the device must be level. Returning
to FIG. 7, the reader will observe that the non-level state of the
device means that lateral fixed hoop 48 and lateral test hoop 46
are not lying in the plane of horizontal diameter 92. Likewise,
vertical test hoop 50 is not lying in the plane of vertical
diameter 94. A correction is therefore needed and the user can
supply this by twisting the push rods as he or she advances the
device.
[0152] FIG. 7 also illustrates well the device's operation. Lateral
fixed hoop 48 maintains contact with right side region 98. Lateral
test hoop 46 maintains contact with left side region 102. If a
reduction in horizontal diameter 92 is encountered, lateral test
hoop 46 will deflect. Lateral test hoop 46 is sufficiently flexible
to allow the device to pass through a substantial constriction and
continue onward.
[0153] Runner 12 maintains contact with bottom region 96. Vertical
test hoop 50 maintains contact with top region 100. If a reduction
in the vertical diameter 94 is encountered, vertical test hoop 50
will deflect. It is also sufficiently pliable to allow the device
to pass through a constricted area and continue.
[0154] Those skilled in the art will appreciate that the width of
runner 12 prevents the device from sitting on the lowest point of
the pipe's interior. The width of runner 12 must be accounted for
in determining the appropriate height of vertical test hoop 50.
This is especially true since the device contemplates that many
different pipe diameters may have to be inspected.
[0155] One inspection sled 10 may be used to inspect a wide range
of pipe diameters by incorporating adjustment features. Inspection
sled 10 is adapted to inspect an 18"-diameter pipe. FIG. 8 depicts
inspection sled 10 next to 24" inspection sled 74, which is adapted
to inspect a 24"-diameter pipe. 24" inspection sled 74 is simply
inspection sled 10 adjusted to fit a larger pipe. The reader will
observe that forward bracket 42 has been moved up its mast and
locked into a higher position. Likewise, rear bracket 44 has been
moved upward. Larger test hoops are also needed. 24" inspection
sled 74 is equipped with 24" lateral fixed hoop 76, 24" lateral
test hoop 78, and 24" vertical test hoop 80. All these hoops are
easily removed and replaced. 24" inspection sled 74 is identical to
inspection sled 10 in every respect, other than the vertical and
horizontal adjustments and the different hoops. In fact, in actual
practice, the user will typically use only inspection sled with
sets of different hoops to accommodate the different pipe
diameters.
[0156] FIG. 9 shows the two variants side by side. Inspection sled
10 fits tightly within 18"-diameter pipe 58. 24" inspection sled 74
fits tightly within 24"-diameter pipe 82. The reader will thus
observe how the use of adjustments and the different hoop sets
allow a single inspection sled to be adapted to fit many different
pipe diameters.
[0157] It is important to calibrate the inspection sled 10 for the
particular diameter of pipe that will be inspected. This goal could
be accomplished in many different ways, such as by providing
markings on the masts and hoops to indicate the correct adjusted
positions. FIG. 10 illustrates another approach using a gage. Gage
84 has horizontal zero 88, vertical zero 86, and a series of
calibration steps 90.
[0158] FIG. 11 illustrates the use of gage 84. Inspection sled 10
is placed on flat surface 86. Gage 84 is then placed against
inspection sled 10, with vertical zero 86 being placed on flat
surface 86 and horizontal zero 88 being placed against the side of
runner 12. A particular calibration step 90 (depending on the pipe
diameter involved) is use to set the correct position or lateral
fixed hoop 48, and likewise for lateral test hoop 46. The
calibration steps 90 are marked to indicate which one should be
used. A similar gage can be fabricated and employed for vertical
test hoop 50.
[0159] The device disclosed in FIGS. 1-11 is capable of measuring
deflections in a pipe's vertical 94 and horizontal 92 diameters.
Practical experience illustrates that a reduction in the pipe's
vertical diameter 94 is the more significant measurement, since
this indicates settling of the soil around the pipe. A variation
only measuring the pipe's vertical diameter 94 can therefore
provide the most needed information and also reduce complexity.
[0160] In addition, the device disclosed in FIGS. 1-11 has been
found to have certain limitations in its visual indicating system.
It is common for the user to advance the device up to 100 feet into
a pipe. At that distance, it is difficult for the user to discern
the degree of occlusion of lateral indicators 68 and vertical
indicators 72. This is true even though different colors are used
for successive indicators. At ranges approaching 100 feet, human
vision simply blurs the two colors together and makes it difficult
to observe the degree of occlusion. Thus, a more sophisticated
visual indicating system is desirable.
[0161] FIGS. 12-18 illustrate a second embodiment addressing these
concerns. Because this version remedies the problems just
discussed, it is the preferred embodiment. As seen in FIG. 12, the
structure of inspection sled 10 is the same with only a few
exceptions. Because the preferred embodiment is not designed to
measure deflections in a pipe's horizontal diameter 92, it has two
lateral fixed hoops 48. Vertical deflection bar 104 is designed to
measure reductions in a pipe's vertical diameter 94, using a
refined system. The user will observe that forward spring bracket
106 is attached to forward bracket 42. Likewise, rear spring
bracket 108 is attached to rear bracket 46.
[0162] Both forward spring bracket 106 and rear spring bracket 108
have a guide rod 110 passing through them. Guide rods 110 are free
to move up and down relative to the two spring brackets. Vertical
deflection bar 104 is attached to the upper end of each guide rod
110. Springs are employed to bias vertical deflection bar 104
toward its upper position--as shown.
[0163] FIG. 13 is a detail view. The reader will observe that the
two horizontal portions of forward spring bracket 106 are each
pierced by a guide rod hole 112. Guide rod 110 slides up and down
within guide rod holes 112. Stop collar 116 is adjustably attached
to guide rod 110. Compression spring 114 fits closely around guide
rod 110. Its lower end bears against forward spring bracket 106.
Its upper end bears against the lower surface of stop collar
116.
[0164] Identical components are located proximate rear spring
bracket 108. The result is that the two guide rods 110 are
naturally biased upward, resulting in vertical deflection bar 104
being naturally biased upward.
[0165] FIG. 14 shows the device as it would appear upon
encountering a reduction in a pipe's vertical diameter 94. Vertical
deflection bar 104 has been forced downward as indicated by the
arrow, resulting in guide rods 110 moving downward. FIG. 15 shows a
detail view of forward spring bracket 106 as vertical deflection
bar 104 is forced downward. The reader will observe that guide rod
110 has moved downward as indicated. Stop collar 116 has also moved
downward, resulting in the compression of compression spring 114.
Once the region of reduced vertical diameter 94 within the pipe is
passed, compression springs 114 will restore the device to its
undeflected state.
[0166] The use of this revised system for measuring vertical
deflection is quite effective. However, an improved means of
visually communicating the degree of deflection to the user is also
needed. FIGS. 16-18 and 21-23 illustrate the improved indicating
system. In FIG. 16, reflector card 132 has been attached to the
rear face of rear bracket 44. The reader will also observe that
card mount 142 has been attached to the rear guide rod 110. Card
mount 142 will also move up and down with guide rod 110.
Accordingly, reflector card 132 is provided with a vertical slot
allowing for clearance as card mount 142 moves downward.
[0167] In FIG. 17, the reader will note that window card 134 is
positioned to be attached to card mount 142 so that it slides up
and down with guide rod 110. Window card 134 has eight windows 136,
which allow the display of reflectors placed on reflector card 132.
Window card 134 is configured to slide up and down over the rear
surface of reflector card 132.
[0168] FIG. 17B shows reflector card 132 and window card 134 placed
side by side for comparison. Ordinarily, of course, window card 134
would be placed over the front of reflector card 132. As deflection
in the internal diameter for the pipe is encountered, window card
134 slides up and down relative to reflector card 132. Various
reflectors are thereby exposed through the eight windows in window
card 134.
[0169] The following is a listing of the reflectors found on
reflector card 132 in the preferred embodiment: (1) First reflector
138, fourth reflector 162, fifth reflector 164, and ninth reflector
174 are green; (2) Second reflector 140, third reflector 160,
seventh reflector 168, and tenth reflector 176 are yellow; and (3)
Sixth reflector 166, eighth reflector 170, eleventh reflector 178,
and twelfth reflector 180 are red. The eight windows on window card
134 are configured to interact with these reflectors in order to
convey information to the user.
[0170] FIG. 18 shows window card 134 mounted in place. In the view
shown, the device has encountered a reduction in the pipe's
vertical diameter 94, resulting in the downward movement of
vertical deflection bar 104. Guide rod 110 has moved downward as
indicated. Window card 134, being connected to guide rod 110, has
moved downward relative to reflector card 132. The windows on
window card 134 are exposing certain reflectors, thereby indicating
the degree of deflection to the user.
[0171] The arrangement of reflectors on reflector card 132 and
windows on window card 134 can be configured to convey a great deal
of information. A series of examples is provided in FIGS. 21
through 23.
[0172] FIG. 21 shows window card 134 in front of reflector card
132. The features of reflector card 132 can be seen as hidden
lines. In this view, window card 134 has traveled downward with
respect to reflector card 132. A portion of third reflector 160
(yellow) is visible through seventh window 156.
[0173] FIG. 22 shows window card 134 after it has traveled further
downward. The reader will observe that a portion of first reflector
138 (green) is visible through first window 136. Likewise, a
portion of fourth reflector 162 (green) is visible through fourth
window 150.
[0174] FIG. 23 shows window card 134 after it has traveled still
further downward, In addition to the reflectors visible in FIG. 22,
the reader will observe that a portion of fifth reflector 164
(green) is visible through fifth window 152. Thus, through the use
of the reflectors, the device can communicate very fine readings on
the degree of deflection encountered.
[0175] It is obviously important to keep window card 134 aligned
with reflector card 132. Returning now to FIG. 18, guide slot 144
is provided through window card 134. This slot engages guide
bushings mounted on reflector card 132 to prevent skew. For
purposes of visual clarity, these guide bushings have not been
shown. Those skilled in the art will appreciate that additional
windows and reflectors could be provided to convey even more
detailed information. The concept for such additional indicators
would be identical to that for the ones described.
[0176] The preferred embodiment encompasses adjustments allowing it
to be used for different pipe diameters. Returning to FIGS. 12 and
13, those skilled in the art will appreciate that the position of
the two stop collars 116 on the two guide rods 110 will determine
the vertical position of vertical deflection bar 104 in the
undeflected state. Thus, adjustment means (such as a set screw and
a corresponding series of detents in guide rods 110) can be
provided to allow the user to set the vertical position of vertical
deflection bar 104 for a variety of different pipe diameters. Of
course, different sets of lateral fixed hoops 48 must still be
employed.
[0177] Some users have expressed a desire for a very simply
"pass-fail" version of the device. This embodiment would provide a
single indication of a failing condition in a pipe's vertical
diameter 94. FIGS. 19 and 20 illustrate such a device. This is a
quick test method that could be followed by more precise methods
using other features of the device.
[0178] In FIG. 19, inspection sled 10 has two lateral fixed hoops
48. Rising from middle tube clamp 24 is flex mast 120. Flex mast
120 is typically made from a resilient material and has the general
characteristics of an automotive radio antenna. Flex mast 120 is
topped by contact point 122. Point reflector 118 is attached to
flex mast 120 just below contact point 122.
[0179] FIG. 20 shows point reflector 118 in more detail. Tube mount
126 attaches tube 124 to flex mast 120. Tube 124 is hollow (shown
with a cutaway). Its forward portion contains reflector 130. Its
rearward portion tapers to orifice 128. As a user shines a
flashlight toward the device in a pipe, light enters through
orifice 128, strikes reflector 130, and bounces back to the user as
a single bright point of light.
[0180] The height of contact point 122 is set equal to the minimum
acceptable vertical diameter 94 for the pipe being inspected.
Likewise, lateral fixed hoops corresponding to the minimum
acceptable horizontal diameter for pipe the pipe are employed. If
contact point 122 encounters a smaller vertical diameter 94, flex
mast 120 will bend backward, angling tube 124 downward. The
geometry of the device then prevents the reflection of the user's
flashlight beam. From the user's vantage point, the single bright
point of light disappears. When this happens, the user knows that a
failing condition is present. The user may then wish to reconfigure
the device using the window card and reflector card to obtain more
information.
[0181] Accordingly, the reader will appreciate that the proposed
invention provides a simple device for measuring constrictions in
the diameter of buried piping. The invention has additional
advantages in that:
[0182] 1. It can be adjusted to inspect different sizes of
pipe;
[0183] 2. It does not require a cable to be passed through the pipe
before introducing the inspection device;
[0184] 3. It is not easily obstructed by puddles or debris within
the pipe;
[0185] 4. It can pass beyond an obstructed diameter to inspect the
entire pipe; and
[0186] 5. It provides a simple visual indication system requiring
no internal electrical devices.
[0187] Although the preceding description contains significant
detail, it should not be construed as limiting the scope of the
invention but rather as providing illustrations of the various
embodiments of the invention. Thus, the scope of the invention
should be fixed by the following claims, rather than by the
examples given.
* * * * *